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Sample records for induces mitochondria-mediated apoptosis

  1. The mitochondria-mediate apoptosis of Lepidopteran cells induced by azadirachtin.

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    Jingfei Huang

    Full Text Available Mitochondria have been shown to play an important role in apoptosis using mammalian cell lines. However, this seems not to be the case in Drosophila, an insect model organism; thus more in-depth studies of insect cell apoptosis are necessary. In the present study, mitochondrial involvement during azadirachtin- and camptothecin-induced apoptosis in Spodoptera frugiperda Sf9 cells (isolated from Spodoptera frugiperda pupal ovarian tissue was investigated. The results showed that both azadirachtin and camptothecin could induce apoptosis in Sf9 cells. Reactive oxygen species (ROS generation, activation of mitochondrial permeability transition pores (MPTPs and loss of mitochondrial membrane potential (MMP were observed very early during apoptosis and were followed subsequently by the release of cytochrome-c from the mitochondria. Furthermore, the results also revealed that the opening of MPTPs and the loss of MMP induced by azadirachtin could be significantly inhibited by the permeability transition pore (PTP inhibitor cyclosporin A (CsA, which was used to identify the key role of mitochondria in the apoptosis of Sf9 cells. However, in camptothecin-treated Sf9 cells, CsA could not suppress the opening of MPTPs and the loss of MMP when apoptosis was induced. The data from caspase-3 and caspase-9 activity assays and detection of apoptosis by morphological observation and flow cytometry also uncovered the different effect of CsA on the two botanical apoptosis inducers. Although different mechanisms of apoptosis induction exist, our study revealed that mitochondria play a crucial role in insect cell line apoptosis.

  2. The mitochondria-mediate apoptosis of Lepidopteran cells induced by azadirachtin.

    Science.gov (United States)

    Huang, Jingfei; Lv, Chaojun; Hu, Meiying; Zhong, Guohua

    2013-01-01

    Mitochondria have been shown to play an important role in apoptosis using mammalian cell lines. However, this seems not to be the case in Drosophila, an insect model organism; thus more in-depth studies of insect cell apoptosis are necessary. In the present study, mitochondrial involvement during azadirachtin- and camptothecin-induced apoptosis in Spodoptera frugiperda Sf9 cells (isolated from Spodoptera frugiperda pupal ovarian tissue) was investigated. The results showed that both azadirachtin and camptothecin could induce apoptosis in Sf9 cells. Reactive oxygen species (ROS) generation, activation of mitochondrial permeability transition pores (MPTPs) and loss of mitochondrial membrane potential (MMP) were observed very early during apoptosis and were followed subsequently by the release of cytochrome-c from the mitochondria. Furthermore, the results also revealed that the opening of MPTPs and the loss of MMP induced by azadirachtin could be significantly inhibited by the permeability transition pore (PTP) inhibitor cyclosporin A (CsA), which was used to identify the key role of mitochondria in the apoptosis of Sf9 cells. However, in camptothecin-treated Sf9 cells, CsA could not suppress the opening of MPTPs and the loss of MMP when apoptosis was induced. The data from caspase-3 and caspase-9 activity assays and detection of apoptosis by morphological observation and flow cytometry also uncovered the different effect of CsA on the two botanical apoptosis inducers. Although different mechanisms of apoptosis induction exist, our study revealed that mitochondria play a crucial role in insect cell line apoptosis.

  3. Porcine parvovirus infection induces apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated pathway

    International Nuclear Information System (INIS)

    Zhang, Hongling; Huang, Yong; Du, Qian; Luo, Xiaomao; Zhang, Liang; Zhao, Xiaomin; Tong, Dewen

    2015-01-01

    Highlights: • PPV reduces PK-15 cells viability by inducing apoptosis. • PPV infection induces apoptosis through mitochondria-mediated pathway. • PPV infection activates p53 to regulate the mitochondria apoptotic signaling. - Abstract: Porcine parvovirus (PPV) infection has been reported to induce the cytopathic effects (CPE) in some special host cells and contribute the occurrence of porcine parvovirus disease, but the molecular mechanisms underlying PPV-induced CPE are not clear. In this study, we investigated the morphological and molecular changes of porcine kidney cell line (PK-15 cells) infected with PPV. The results showed that PPV infection inhibited the viability of PK-15 cells in a time and concentration dependent manner. PPV infection induced typical apoptotic features including chromatin condensation, apoptotic body formation, nuclear fragmentation, and Annexin V-binding activity. Further studies showed that Bax was increased and translocated to mitochondria, whereas Bcl-2 was decreased in PPV-infected cells, which caused mitochondrial outer-membrane permeabilization, resulting in the release of mitochondrial cytochrome c, followed by caspase-9 and caspase-3 activation. However, the expression of Fas and Fas ligand (FasL) did not appear significant changes in the process of PPV-induced apoptosis. Moreover, PPV infection activated p53 signaling, which was involved in the activation of apoptotic signaling induced by PPV infection via regulation of Bax and Bcl-2. Taken together, our results demonstrated that PPV infection induced apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated apoptosis pathway. This study may contribute to shed light on the molecular pathogenesis of PPV infection

  4. Porcine parvovirus infection induces apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated pathway

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    Zhang, Hongling; Huang, Yong; Du, Qian; Luo, Xiaomao; Zhang, Liang; Zhao, Xiaomin; Tong, Dewen, E-mail: dwtong@nwsuaf.edu.cn

    2015-01-09

    Highlights: • PPV reduces PK-15 cells viability by inducing apoptosis. • PPV infection induces apoptosis through mitochondria-mediated pathway. • PPV infection activates p53 to regulate the mitochondria apoptotic signaling. - Abstract: Porcine parvovirus (PPV) infection has been reported to induce the cytopathic effects (CPE) in some special host cells and contribute the occurrence of porcine parvovirus disease, but the molecular mechanisms underlying PPV-induced CPE are not clear. In this study, we investigated the morphological and molecular changes of porcine kidney cell line (PK-15 cells) infected with PPV. The results showed that PPV infection inhibited the viability of PK-15 cells in a time and concentration dependent manner. PPV infection induced typical apoptotic features including chromatin condensation, apoptotic body formation, nuclear fragmentation, and Annexin V-binding activity. Further studies showed that Bax was increased and translocated to mitochondria, whereas Bcl-2 was decreased in PPV-infected cells, which caused mitochondrial outer-membrane permeabilization, resulting in the release of mitochondrial cytochrome c, followed by caspase-9 and caspase-3 activation. However, the expression of Fas and Fas ligand (FasL) did not appear significant changes in the process of PPV-induced apoptosis. Moreover, PPV infection activated p53 signaling, which was involved in the activation of apoptotic signaling induced by PPV infection via regulation of Bax and Bcl-2. Taken together, our results demonstrated that PPV infection induced apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated apoptosis pathway. This study may contribute to shed light on the molecular pathogenesis of PPV infection.

  5. A mitochondria-dependent pathway mediates the apoptosis of GSE-induced yeast.

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    Sishuo Cao

    Full Text Available Grapefruit seed extract (GSE, which has powerful anti-fungal activity, can induce apoptosis in S. cerevisiae. The yeast cells underwent apoptosis as determined by testing for apoptotic markers of DNA cleavage and typical chromatin condensation by Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick End Labeling (TUNEL and 4,6'-diaminidino-2-phenylindole (DAPI staining and electron microscopy. The changes of ΔΨmt (mitochondrial transmembrane potential and ROS (reactive oxygen species indicated that the mitochondria took part in the apoptotic process. Changes in this process detected by metabonomics and proteomics revealed that the yeast cells tenaciously resisted adversity. Proteins related to redox, cellular structure, membrane, energy and DNA repair were significantly increased. In this study, the relative changes in the levels of proteins and metabolites showed the tenacious resistance of yeast cells. However, GSE induced apoptosis in the yeast cells by destruction of the mitochondrial 60 S ribosomal protein, L14-A, and prevented the conversion of pantothenic acid to coenzyme A (CoA. The relationship between the proteins and metabolites was analyzed by orthogonal projections to latent structures (OPLS. We found that the changes of the metabolites and the protein changes had relevant consistency.

  6. A mitochondria-dependent pathway mediates the apoptosis of GSE-induced yeast.

    Science.gov (United States)

    Cao, Sishuo; Xu, Wentao; Zhang, Nan; Wang, Yan; Luo, YunBo; He, Xiaoyun; Huang, Kunlun

    2012-01-01

    Grapefruit seed extract (GSE), which has powerful anti-fungal activity, can induce apoptosis in S. cerevisiae. The yeast cells underwent apoptosis as determined by testing for apoptotic markers of DNA cleavage and typical chromatin condensation by Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick End Labeling (TUNEL) and 4,6'-diaminidino-2-phenylindole (DAPI) staining and electron microscopy. The changes of ΔΨmt (mitochondrial transmembrane potential) and ROS (reactive oxygen species) indicated that the mitochondria took part in the apoptotic process. Changes in this process detected by metabonomics and proteomics revealed that the yeast cells tenaciously resisted adversity. Proteins related to redox, cellular structure, membrane, energy and DNA repair were significantly increased. In this study, the relative changes in the levels of proteins and metabolites showed the tenacious resistance of yeast cells. However, GSE induced apoptosis in the yeast cells by destruction of the mitochondrial 60 S ribosomal protein, L14-A, and prevented the conversion of pantothenic acid to coenzyme A (CoA). The relationship between the proteins and metabolites was analyzed by orthogonal projections to latent structures (OPLS). We found that the changes of the metabolites and the protein changes had relevant consistency.

  7. Inhibition of Drp1 protects against senecionine-induced mitochondria-mediated apoptosis in primary hepatocytes and in mice

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    Xiao Yang

    2017-08-01

    Full Text Available Pyrrolizidine alkaloids (PAs are a group of compounds found in various plants and some of them are widely consumed in the world as herbal medicines and food supplements. PAs are potent hepatotoxins that cause irreversible liver injury in animals and humans. However, the mechanisms by which PAs induce liver injury are not clear. In the present study, we determined the hepatotoxicity and molecular mechanisms of senecionine, one of the most common toxic PAs, in primary cultured mouse and human hepatocytes as well as in mice. We found that senecionine administration increased serum alanine aminotransferase levels in mice. H&E and TUNEL staining of liver tissues revealed increased hemorrhage and hepatocyte apoptosis in liver zone 2 areas. Mechanistically, senecionine induced loss of mitochondrial membrane potential, release of mitochondrial cytochrome c as well as mitochondrial JNK translocation and activation prior to the increased DNA fragmentation and caspase-3 activation in primary cultured mouse and human hepatocytes. SP600125, a specific JNK inhibitor, and ZVAD-fmk, a general caspase inhibitor, alleviated senecionine-induced apoptosis in primary hepatocytes. Interestingly, senecionine also caused marked mitochondria fragmentation in hepatocytes. Pharmacological inhibition of dynamin-related protein1 (Drp1, a protein that is critical to regulate mitochondrial fission, blocked senecionine-induced mitochondrial fragmentation and mitochondrial release of cytochrome c and apoptosis. More importantly, hepatocyte-specific Drp1 knockout mice were resistant to senecionine-induced liver injury due to decreased mitochondrial damage and apoptosis. In conclusion, our results uncovered a novel mechanism of Drp1-mediated mitochondrial fragmentation in senecionine-induced liver injury. Targeting Drp1-mediated mitochondrial fragmentation and apoptosis may be a potential avenue to prevent and treat hepatotoxicity induced by PAs. Keywords: Senecionine, Drp1

  8. Inhibition of mitochondria- and endoplasmic reticulum stress-mediated autophagy augments temozolomide-induced apoptosis in glioma cells.

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    Chien-Ju Lin

    Full Text Available Autophagy is a crucial process for cells to maintain homeostasis and survival through degradation of cellular proteins and organelles, including mitochondria and endoplasmic reticula (ER. We previously demonstrated that temozolomide (TMZ, an alkylating agent for brain tumor chemotherapy, induced reactive oxygen species (ROS/extracellular signal-regulated kinase (ERK-mediated autophagy to protect glioma cells from apoptosis. In this study, we investigated the role of mitochondrial damage and ER stress in TMZ-induced cytotoxicity. Mitochondrial depolarization and mitochondrial permeability transition pore (MPTP opening were observed as a prelude to TMZ-induced autophagy, and these were followed by the loss of mitochondrial mass. Electron transport chain (ETC inhibitors, such as rotenone (a complex I inhibitor, sodium azide (a complex IV inhibitor, and oligomycin (a complex V inhibitor, or the MPTP inhibitor, cyclosporine A, decreased mitochondrial damage-mediated autophagy, and therefore increased TMZ-induced apoptosis. TMZ treatment triggered ER stress with increased expression of GADD153 and GRP78 proteins, and deceased pro-caspase 12 protein. ER stress consequently induced autophagy through c-Jun N-terminal kinases (JNK and Ca(2+ signaling pathways. Combination of TMZ with 4-phenylbutyrate (4-PBA, an ER stress inhibitor, augmented TMZ-induced cytotoxicity by inhibiting autophagy. Taken together, our data indicate that TMZ induced autophagy through mitochondrial damage- and ER stress-dependent mechanisms to protect glioma cells. This study provides evidence that agents targeting mitochondria or ER may be potential anticancer strategies.

  9. Nickel (II)-induced cytotoxicity and apoptosis in human proximal tubule cells through a ROS- and mitochondria-mediated pathway

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    Wang, Yi-Fen; Shyu, Huey-Wen [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Chang, Yi-Chuang [Department of Nursing, Fooyin University, Kaohsiung, Taiwan (China); Tseng, Wei-Chang [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Huang, Yeou-Lih [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Lin, Kuan-Hua; Chou, Miao-Chen; Liu, Heng-Ling [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Chen, Chang-Yu, E-mail: mt037@mail.fy.edu.tw [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China)

    2012-03-01

    Nickel compounds are known to be toxic and carcinogenic in kidney and lung. In this present study, we investigated the roles of reactive oxygen species (ROS) and mitochondria in nickel (II) acetate-induced cytotoxicity and apoptosis in the HK-2 human renal cell line. The results showed that the cytotoxic effects of nickel (II) involved significant cell death and DNA damage. Nickel (II) increased the generation of ROS and induced a noticeable reduction of mitochondrial membrane potential (MMP). Analysis of the sub-G1 phase showed a significant increase in apoptosis in HK-2 cells after nickel (II) treatment. Pretreatment with N-acetylcysteine (NAC) not only inhibited nickel (II)-induced cell death and DNA damage, but also significantly prevented nickel (II)-induced loss of MMP and apoptosis. Cell apoptosis triggered by nickel (II) was characterized by the reduced protein expression of Bcl-2 and Bcl-xL and the induced the protein expression of Bad, Bcl-Xs, Bax, cytochrome c and caspases 9, 3 and 6. The regulation of the expression of Bcl-2-family proteins, the release of cytochrome c and the activation of caspases 9, 3 and 6 were inhibited in the presence of NAC. These results suggest that nickel (II) induces cytotoxicity and apoptosis in HK-2 cells via ROS generation and that the mitochondria-mediated apoptotic signaling pathway may be involved in the positive regulation of nickel (II)-induced renal cytotoxicity.

  10. Nickel (II)-induced cytotoxicity and apoptosis in human proximal tubule cells through a ROS- and mitochondria-mediated pathway

    International Nuclear Information System (INIS)

    Wang, Yi-Fen; Shyu, Huey-Wen; Chang, Yi-Chuang; Tseng, Wei-Chang; Huang, Yeou-Lih; Lin, Kuan-Hua; Chou, Miao-Chen; Liu, Heng-Ling; Chen, Chang-Yu

    2012-01-01

    Nickel compounds are known to be toxic and carcinogenic in kidney and lung. In this present study, we investigated the roles of reactive oxygen species (ROS) and mitochondria in nickel (II) acetate-induced cytotoxicity and apoptosis in the HK-2 human renal cell line. The results showed that the cytotoxic effects of nickel (II) involved significant cell death and DNA damage. Nickel (II) increased the generation of ROS and induced a noticeable reduction of mitochondrial membrane potential (MMP). Analysis of the sub-G1 phase showed a significant increase in apoptosis in HK-2 cells after nickel (II) treatment. Pretreatment with N-acetylcysteine (NAC) not only inhibited nickel (II)-induced cell death and DNA damage, but also significantly prevented nickel (II)-induced loss of MMP and apoptosis. Cell apoptosis triggered by nickel (II) was characterized by the reduced protein expression of Bcl-2 and Bcl-xL and the induced the protein expression of Bad, Bcl-Xs, Bax, cytochrome c and caspases 9, 3 and 6. The regulation of the expression of Bcl-2-family proteins, the release of cytochrome c and the activation of caspases 9, 3 and 6 were inhibited in the presence of NAC. These results suggest that nickel (II) induces cytotoxicity and apoptosis in HK-2 cells via ROS generation and that the mitochondria-mediated apoptotic signaling pathway may be involved in the positive regulation of nickel (II)-induced renal cytotoxicity.

  11. Lupeol induces S-phase arrest and mitochondria-mediated ...

    Indian Academy of Sciences (India)

    48

    Lupeol induces S-phase arrest and mitochondria-mediated apoptosis in cervical cancer cells. Nupoor Prasad1, Akash Sabarwal2, Umesh C. S. Yadav1, Rana P. Singh2,*. 1School of Life Sciences, Central University of Gujarat, Gandhinagar, Gujarat, India. 2Cancer Biology Laboratory, School of Life Sciences, Jawaharlal ...

  12. Bcl-2 prevents loss of mitochondria in CCCP-induced apoptosis

    International Nuclear Information System (INIS)

    Graaf, Aniek O. de; Heuvel, Lambert P. van den; Dijkman, Henry B.P.M.; Abreu, Ronney A. de; Birkenkamp, Kim U.; Witte, Theo de; Reijden, Bert A. van der; Smeitink, Jan A.M.; Jansen, Joop H.

    2004-01-01

    Bcl-2 family proteins regulate apoptosis at the level of mitochondria. To examine the mechanism of Bcl-2 function, we investigated the effects of the protonophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on two hematopoietic cell lines and Bcl-2 overexpressing transfectants. CCCP directly interferes with mitochondrial function and induces apoptosis. We show that Bcl-2 inhibits apoptosis and that the antiapoptotic effect of Bcl-2 takes place upstream of caspase activation and nuclear changes associated with apoptosis, since these were markedly inhibited in cells overexpressing Bcl-2. Bcl-2 does not prevent the decrease in mitochondrial membrane potential nor the alterations in cellular ATP content induced by CCCP in FL5.12 and Jurkat cells. A higher number of mitochondria was observed in untreated Bcl-2 transfected cells compared to parental cells, as shown by electron microscopy. Exposure to CCCP induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, with apparent swelling and loss of cristae in parental cells. Bcl-2 clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria. These data suggest that CCCP induces apoptosis by structural disruption of mitochondria and that Bcl-2 prevents apoptosis and mitochondrial degeneration by preserving mitochondrial integrity

  13. Bcl-2 prevents loss of mitochondria in CCCP-induced apoptosis.

    Science.gov (United States)

    de Graaf, Aniek O; van den Heuvel, Lambert P; Dijkman, Henry B P M; de Abreu, Ronney A; Birkenkamp, Kim U; de Witte, Theo; van der Reijden, Bert A; Smeitink, Jan A M; Jansen, Joop H

    2004-10-01

    Bcl-2 family proteins regulate apoptosis at the level of mitochondria. To examine the mechanism of Bcl-2 function, we investigated the effects of the protonophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on two hematopoietic cell lines and Bcl-2 overexpressing transfectants. CCCP directly interferes with mitochondrial function and induces apoptosis. We show that Bcl-2 inhibits apoptosis and that the antiapoptotic effect of Bcl-2 takes place upstream of caspase activation and nuclear changes associated with apoptosis, since these were markedly inhibited in cells overexpressing Bcl-2. Bcl-2 does not prevent the decrease in mitochondrial membrane potential nor the alterations in cellular ATP content induced by CCCP in FL5.12 and Jurkat cells. A higher number of mitochondria was observed in untreated Bcl-2 transfected cells compared to parental cells, as shown by electron microscopy. Exposure to CCCP induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, with apparent swelling and loss of cristae in parental cells. Bcl-2 clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria. These data suggest that CCCP induces apoptosis by structural disruption of mitochondria and that Bcl-2 prevents apoptosis and mitochondrial degeneration by preserving mitochondrial integrity.

  14. Heptachlor induced mitochondria-mediated cell death via impairing electron transport chain complex III

    International Nuclear Information System (INIS)

    Hong, Seokheon; Kim, Joo Yeon; Hwang, Joohyun; Shin, Ki Soon; Kang, Shin Jung

    2013-01-01

    Highlights: •Heptachlor inhibited mitochondrial electron transport chain complex III activity. •Heptachlor promoted generation of reactive oxygen species. •Heptachlor induced Bax activation. •Heptachlor induced mitochondria-mediated and caspase-dependent apoptosis. -- Abstract: Environmental toxins like pesticides have been implicated in the pathogenesis of Parkinson’s disease (PD). Epidemiological studies suggested that exposures to organochlorine pesticides have an association with an increased PD risk. In the present study, we examined the mechanism of toxicity induced by an organochlorine pesticide heptachlor. In a human dopaminergic neuroblastoma SH-SY5Y cells, heptachlor induced both morphological and functional damages in mitochondria. Interestingly, the compound inhibited mitochondrial electron transport chain complex III activity. Rapid generation of reactive oxygen species and the activation of Bax were then detected. Subsequently, mitochondria-mediated, caspase-dependent apoptosis followed. Our results raise a possibility that an organochlorine pesticide heptachlor can act as a neurotoxicant associated with PD

  15. Heptachlor induced mitochondria-mediated cell death via impairing electron transport chain complex III

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    Hong, Seokheon; Kim, Joo Yeon; Hwang, Joohyun [Department of Molecular Biology, Sejong University, Seoul 143-747 (Korea, Republic of); Shin, Ki Soon [Department of Biology, Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Kang, Shin Jung, E-mail: sjkang@sejong.ac.kr [Department of Molecular Biology, Sejong University, Seoul 143-747 (Korea, Republic of)

    2013-08-09

    Highlights: •Heptachlor inhibited mitochondrial electron transport chain complex III activity. •Heptachlor promoted generation of reactive oxygen species. •Heptachlor induced Bax activation. •Heptachlor induced mitochondria-mediated and caspase-dependent apoptosis. -- Abstract: Environmental toxins like pesticides have been implicated in the pathogenesis of Parkinson’s disease (PD). Epidemiological studies suggested that exposures to organochlorine pesticides have an association with an increased PD risk. In the present study, we examined the mechanism of toxicity induced by an organochlorine pesticide heptachlor. In a human dopaminergic neuroblastoma SH-SY5Y cells, heptachlor induced both morphological and functional damages in mitochondria. Interestingly, the compound inhibited mitochondrial electron transport chain complex III activity. Rapid generation of reactive oxygen species and the activation of Bax were then detected. Subsequently, mitochondria-mediated, caspase-dependent apoptosis followed. Our results raise a possibility that an organochlorine pesticide heptachlor can act as a neurotoxicant associated with PD.

  16. Aspirin Induces Apoptosis through Release of Cytochrome c from Mitochondria

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    Katja C. Zimmermann

    2000-01-01

    Full Text Available Nonsteroidal anti-inflammatory drugs (NSAID reduce the risk for cancer, due to their anti proliferative and apoptosis-inducing effects. A critical pathway for apoptosis involves the release of cytochrome c from mitochondria, which then interacts with Apaf-1 to activate caspase proteases that orchestrate cell death. In this study we found that treatment of a human cancer cell line with aspirin induced caspase activation and the apoptotic cell morphology, which was blocked by the caspase inhibitor zVAD-fmk. Further analysis of the mechanism underlying this apoptotic event showed that aspirin induces translocation of Bax to the mitochondria and triggers release of cytochrome c into the cytosol. The release of cytochrome c from mitochondria was inhibited by overexpression of the antiapoptotic protein Bcl-2 and cells that lack Apaf-1 were resistant to aspirin-induced apoptosis. These data provide evidence that the release of cytochrome c is an important part of the apoptotic mechanism of aspirin.

  17. Non-thermal plasma induces mitochondria-mediated apoptotic signaling pathway via ROS generation in HeLa cells.

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    Li, Wei; Yu, K N; Ma, Jie; Shen, Jie; Cheng, Cheng; Zhou, Fangjian; Cai, Zhiming; Han, Wei

    2017-11-01

    Non-thermal plasma (NTP) has been proposed as a novel therapeutic method for anticancer treatment. Although increasing evidence suggests that NTP selectively induces apoptosis in some types of tumor cells, the molecular mechanisms underlying this phenomenon remain unclear. In this study, we further investigated possible molecular mechanisms for NTP-induced apoptosis of HeLa cells. The results showed that NTP exposure significantly inhibited the growth and viability of HeLa cells. Morphological observation and flow cytometry analysis demonstrated that NTP exposure induced HeLa cell apoptosis. NTP exposure also activated caspase-9 and caspase-3, which subsequently cleaved poly (ADP- ribose) polymerase. Furthermore, NTP exposure suppressed Bcl-2 expression, enhanced Bax expression and translocation to mitochondria, activated mitochondria-mediated apoptotic pathway, followed by the release of cytochrome c. Further studies showed that NTP treatment led to ROS generation, whereas blockade of ROS generation by N-acetyl-l-cysteine (NAC, ROS scavengers) significantly prevented NTP-induced mitochondrial alteration and subsequent apoptosis of HeLa cells via suppressing Bax translocation, cytochrome c and caspase-3 activation. Taken together, our results indicated that NTP exposure induced mitochondria-mediated intrinsic apoptosis of HeLa cells was activated by ROS generation. These findings provide insights to the therapeutic potential and clinical research of NTP as a novel tool in cervical cancer treatment. Copyright © 2017. Published by Elsevier Inc.

  18. Nanoparticle Delivery of Artesunate Enhances the Anti-tumor Efficiency by Activating Mitochondria-Mediated Cell Apoptosis

    Science.gov (United States)

    Liu, Rui; Yu, Xiwei; Su, Chang; Shi, Yijie; Zhao, Liang

    2017-06-01

    Artemisinin and its derivatives were considered to exert a broad spectrum of anti-cancer activities, and they induced significant anti-cancer effects in tumor cells. Artemisinin and its derivatives could be absorbed quickly, and they were widely distributed, selectively killing tumor cells. Since low concentrations of artesunate primarily depended on oncosis to induce cell death in tumor cells, its anti-tumor effects were undesirable and limited. To obtain better anti-tumor effects, in this study, we took advantage of a new nanotechnology to design novel artesunate-loaded bovine serum albumin nanoparticles to achieve the mitochondrial accumulation of artesunate and induce mitochondrial-mediated apoptosis. The results showed that when compared with free artesunate's reliance on oncotic death, artesunate-loaded bovine serum albumin nanoparticles showed higher cytotoxicity and their significant apoptotic effects were induced through the distribution of artesunate in the mitochondria. This finding indicated that artesunate-loaded bovine serum albumin nanoparticles damaged the mitochondrial integrity and activated mitochondrial-mediated cell apoptosis by upregulating apoptosis-related proteins and facilitating the rapid release of cytochrome C.

  19. A Mitochondria-Dependent Pathway Mediates the Apoptosis of GSE-Induced Yeast

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    Cao, Sishuo; Xu, Wentao; Zhang, Nan; Wang, Yan; Luo, YunBo; He, Xiaoyun; Huang, Kunlun

    2012-01-01

    Grapefruit seed extract (GSE), which has powerful anti-fungal activity, can induce apoptosis in S. cerevisiae. The yeast cells underwent apoptosis as determined by testing for apoptotic markers of DNA cleavage and typical chromatin condensation by Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick End Labeling (TUNEL) and 4,6'-diaminidino-2-phenylindole (DAPI) staining and electron microscopy. The changes of ΔΨmt (mitochondrial transmembrane potential) and ROS (reactive oxygen species) ...

  20. Dihydroartemisinin induces apoptosis preferentially via a Bim-mediated intrinsic pathway in hepatocarcinoma cells.

    Science.gov (United States)

    Qin, Guiqi; Zhao, ChuBiao; Zhang, Lili; Liu, Hongyu; Quan, Yingyao; Chai, Liuying; Wu, Shengnan; Wang, Xiaoping; Chen, Tongsheng

    2015-08-01

    This report is designed to dissect the detail molecular mechanism by which dihydroartemisinin (DHA), a derivative of artemisinin, induces apoptosis in human hepatocellular carcinoma (HCC) cells. DHA induced a loss of the mitochondrial transmemberane potential (ΔΨm), release of cytochrome c, activation of caspases, and externalization of phosphatidylserine indicative of apoptosis induction. Compared with the modest inhibitory effects of silencing Bax, silencing Bak largely prevented DHA-induced ΔΨm collapse and apoptosis though DHA induced a commensurable activation of Bax and Bak, demonstrating a key role of the Bak-mediated intrinsic apoptosis pathway. DHA did not induce Bid cleavage and translocation from cytoplasm to mitochondria and had little effects on the expressions of Puma and Noxa, but did increase Bim and Bak expressions and decrease Mcl-1 expression. Furthermore, the cytotoxicity of DHA was remarkably reduced by silencing Bim, and modestly but significantly reduced by silencing Puma or Noxa. Silencing Bim or Noxa preferentially reduced DHA-induced Bak activation, while silencing Puma preferentially reduced DHA-induced Bax activation, demonstrating that Bim and to a lesser extent Noxa act as upstream mediators to trigger the Bak-mediated intrinsic apoptosis pathway. In addition, silencing Mcl-1 enhanced DHA-induced Bak activation and apoptosis. Taken together, our data demonstrate a crucial role of Bim in preferentially regulating the Bak/Mcl-1 rheostat to mediate DHA-induced apoptosis in HCC cells.

  1. Rhein Elicits In Vitro Cytotoxicity in Primary Human Liver HL-7702 Cells by Inducing Apoptosis through Mitochondria-Mediated Pathway

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    Guy-Armel Bounda

    2015-01-01

    Full Text Available Objective. To study rhein-induced apoptosis signaling pathway and to investigate its molecular mechanisms in primary human hepatic cells. Results. Cell viability of HL-7702 cells treated with rhein showed significant decrease in dose-dependent manner. Following rhein treatment (25 μM, 50 μM, and 100 μM for 12 h, the detection of apoptotic cells was significantly analyzed by flow cytometry and nuclear morphological changes by Hoechst 33258, respectively. Fatty degeneration studies showed upregulation level of the relevant hepatic markers (P < 0.01. Caspase activities expressed significant upregulation of caspase-3, caspase-9, and caspase-8. Moreover, apoptotic cells by rhein were significantly inhibited by Z-LEHD-FMK and Z-DEVD-FMK, caspase-9 inhibitor, and caspase-3 inhibitor, respectively. Overproduction of reactive oxygen species, lipid peroxidation, and loss of mitochondrial membrane potential were detected by fluorometry. Additionally, NAC, a ROS scavenger, significantly attenuated rhein-induced oxidative damage in HL-7702 cells. Furthermore, real-time qPCR results showed significant upregulation of p53, PUMA, Apaf-1, and Casp-9 and Casp-3 mRNA, with no significant changes of Fas and Cytochrome-c. Immunoblotting revealed significant Cytochrome-c release from mitochondria into cytosol and no change in Fas expression. Conclusion. Taken together, these observations suggested that rhein could induce apoptosis in HL-7702 cells via mitochondria-mediated signal pathway with involvement of oxidative stress mechanism.

  2. Dynamin-Related Protein 1 Translocates from the Cytosol to Mitochondria during UV-Induced Apoptosis

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    Zhang, Zhenzhen; Wu, Shengnan; Feng, Jie

    2011-01-01

    Mitochondria are dynamic structures that frequently divide and fuse with one another to form interconnecting network. This network disintegrates into punctiform organelles during apoptosis. However, the mechanisms involved in these processes are still not well characterized. In this study, we investigate the role of dynamin-related protein 1 (Drp1), a large GTPase that mediates outer mitochondrial membrane fission, in mitochondrial dynamics in response to UV irradiation in human lung adenocarcinoma cells (ASTC-α-1) and HeLa cells. Using time-lapse fluorescent imaging, we find that Drp1 primarily distributes in cytosol under physiological conditions. After UV treatment, Drp1 translocates from cytosol to mitochondria, indicating the enhancement of Drp1 mitochondrial accumulation. Our results suggest that Drp1 is involved in the regulation of transition from an interconnecting network to a punctiform mitochondrial phenotype during UV-induced apoptosis.

  3. The Predominant Pathway of Apoptosis in THP-1 Macrophage-Derived Foam Cells Induced by 5-Aminolevulinic Acid-Mediated Sonodynamic Therapy is the Mitochondria-Caspase Pathway Despite the Participation of Endoplasmic Reticulum Stress

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    Huan Wang

    2014-05-01

    Full Text Available Background: In advanced atherosclerosis, chronic endoplasmic reticulum (ER stress induces foam cells apoptosis and generates inflammatory reactions. Methods: THP-1 macrophage-derived foam cells (FC were incubated with 1 mM 5-aminolevulinic acid (ALA. After ALA mediated sonodynamic therapy (ALA-SDT, apoptosis of FC was assayed by Annexin V-PI staining. Intracellular reactive oxygen species (ROS and mitochondrial membrane potential were detected by staining with CellROX® Green Reagent and jc-1. Pretreatment of FC with N-acetylcysteine (NAC, Z-VAD-FMK or 4-phenylbutyrate (4-PBA, mitochondria apoptotic pathway associated proteins and C/EBP-homologous (CHOP expressions were assayed by wertern blotting. Results: Burst of apoptosis of FC was observed at 5-hour after ALA-SDT with 6-hour incubation of ALA and 0.4 W/cm2 ultrasound. After ALA-SDT, intracellular ROS level increased and mitochondrial membrane potential collapsed. Translocations of cytochrome c from mitochondria into cytosol and Bax from cytosol into mitochondria, cleaved caspase 9, cleaved caspase 3, upregulation of CHOP, as well as downregulation of Bcl-2 after ALA-SDT were detected, which could be suppressed by NAC. Activation of mitochondria-caspase pathway could not be inhibited by 4-PBA. Cleaved caspase 9 and caspase 3 as well as apoptosis induced by ALA-SDT could be inhibited by Z-VAD-FMK. Conclusion: The mitochondria-caspase pathway is predominant in the apoptosis of FC induced by ALA-SDT though ER stress participates in.

  4. Vitamin K2 Induces Mitochondria-Related Apoptosis in Human Bladder Cancer Cells via ROS and JNK/p38 MAPK Signal Pathways.

    Science.gov (United States)

    Duan, Fengsen; Yu, Yuejin; Guan, Rijian; Xu, Zhiliang; Liang, Huageng; Hong, Ling

    2016-01-01

    The effects of vitamin K2 on apoptosis in a variety of cancer cells have been well established in previous studies. However, the apoptotic effect of vitamin K2 on bladder cancer cells has not been evaluated. The aim of this study is to examine the apoptotic activity of Vitamin K2 in bladder cancer cells and investigate the underlying mechanism. In this study, Vitamin K2 induced apoptosis in bladder cancer cells through mitochondria pathway including loss of mitochondria membrane potential, cytochrome C release and caspase-3 cascade. Furthermore, the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 MAPK was detected in Vitamin K2-treated cells and both SP600125 (an inhibitor of JNK) and SB203580 (an inhibitor of p38 MAPK) completely abolished the Vitamin K2-induced apoptosis and loss of mitochondria membrane potential. Moreover, the generation of reactive oxygen species (ROS) was detected in bladder cancer cells, upon treatment of vitamin K2 and the anti-oxidant N-acetyl cysteine (NAC) almost blocked the Vitamin K2-triggered apoptosis, loss of mitochondria membrane potential and activation of JNK and p38 MAPK. Taken together, these findings revealed that Vitamin K2 induces apoptosis in bladder cancer cells via ROS-mediated JNK/p38 MAPK and Mitochondrial pathways.

  5. Protective role of morin, a flavonoid, against high glucose induced oxidative stress mediated apoptosis in primary rat hepatocytes.

    Directory of Open Access Journals (Sweden)

    Radhika Kapoor

    Full Text Available Apoptosis is an early event of liver damage in diabetes and oxidative stress has been linked to accelerate the apoptosis in hepatocytes. Therefore, the compounds that can scavenge ROS may confer regulatory effects on high-glucose induced apoptosis. In the present study, primary rat hepatocytes were exposed to high concentration (40 mM of glucose. At this concentration decreased cell viability and enhanced ROS generation was observed. Depleted antioxidant status of hepatocytes under high glucose stress was also observed as evident from transcriptional level and activities of antioxidant enzymes. Further, mitochondrial depolarisation was accompanied by the loss of mitochondrial integrity and altered expression of Bax and Bcl-2. Increased translocation of apoptotic proteins like AIF (Apoptosis inducing factor & Endo-G (endonuclease-G from its resident place mitochondria to nucleus was also observed. Cyt-c residing in the inter-membrane space of mitochondria also translocated to cytoplasm. These apoptotic proteins initiated caspase activation, DNA fragmentation, chromatin condensation, increased apoptotic DNA content in glucose treated hepatocytes, suggesting mitochondria mediated apoptotic mode of cell death. Morin, a dietary flavonoid from Psidium guajava was effective in increasing the cell viability and decreasing the ROS level. It maintained mitochondrial integrity, inhibited release of apoptotic proteins from mitochondria, prevented DNA fragmentation, chromatin condensation and hypodiploid DNA upon exposure to high glucose. This study confirms the capacity of dietary flavonoid Morin in regulating apoptosis induced by high glucose via mitochondrial mediated pathway through intervention of oxidative stress.

  6. Ceramide-Induced Apoptosis in Renal Tubular Cells: A Role of Mitochondria and Sphingosine-1-Phoshate

    Science.gov (United States)

    Ueda, Norishi

    2015-01-01

    Ceramide is synthesized upon stimuli, and induces apoptosis in renal tubular cells (RTCs). Sphingosine-1 phosphate (S1P) functions as a survival factor. Thus, the balance of ceramide/S1P determines ceramide-induced apoptosis. Mitochondria play a key role for ceramide-induced apoptosis by altered mitochondrial outer membrane permeability (MOMP). Ceramide enhances oligomerization of pro-apoptotic Bcl-2 family proteins, ceramide channel, and reduces anti-apoptotic Bcl-2 proteins in the MOM. This process alters MOMP, resulting in generation of reactive oxygen species (ROS), cytochrome C release into the cytosol, caspase activation, and apoptosis. Ceramide regulates apoptosis through mitogen-activated protein kinases (MAPKs)-dependent and -independent pathways. Conversely, MAPKs alter ceramide generation by regulating the enzymes involving ceramide metabolism, affecting ceramide-induced apoptosis. Crosstalk between Bcl-2 family proteins, ROS, and many signaling pathways regulates ceramide-induced apoptosis. Growth factors rescue ceramide-induced apoptosis by regulating the enzymes involving ceramide metabolism, S1P, and signaling pathways including MAPKs. This article reviews evidence supporting a role of ceramide for apoptosis and discusses a role of mitochondria, including MOMP, Bcl-2 family proteins, ROS, and signaling pathways, and crosstalk between these factors in the regulation of ceramide-induced apoptosis of RTCs. A balancing role between ceramide and S1P and the strategy for preventing ceramide-induced apoptosis by growth factors are also discussed. PMID:25751724

  7. Norcantharidin (NCTD) induces mitochondria mediated apoptosis in ...

    African Journals Online (AJOL)

    Administrator

    2011-06-15

    Jun 15, 2011 ... cancer deaths for both sexes being attributable to hepatoma. However ..... Resveratrol induces apoptosis and cell cycle arrest of human T24 bladder cancer cells in ... involvement of the CD95 receptor/ligand. J. Cancer. Res.

  8. An antimicrobial peptidomimetic induces Mucorales cell death through mitochondria-mediated apoptosis.

    Directory of Open Access Journals (Sweden)

    E Magda Barbu

    Full Text Available The incidence of mucormycosis has dramatically increased in immunocompromised patients. Moreover, the array of cellular targets whose inhibition results in fungal cell death is rather limited. Mitochondria have been mechanistically identified as central regulators of detoxification and virulence in fungi. Our group has previously designed and developed a proteolytically-resistant peptidomimetic motif D(KLAKLAK2 with pleiotropic action ranging from targeted (i.e., ligand-directed activity against cancer and obesity to non-targeted activity against antibiotic resistant gram-negative rods. Here we evaluated whether this non-targeted peptidomimetic motif is active against Mucorales. We show that D(KLAKLAK2 has marked fungicidal action, inhibits germination, and reduces hyphal viability. We have also observed cellular changes characteristic of apoptosis in D(KLAKLAK2-treated Mucorales cells. Moreover, the fungicidal activity was directly correlated with vacuolar injury, mitochondrial swelling and mitochondrial membrane depolarization, intracellular reactive oxygen species accumulation (ROS, and increased caspase-like enzymatic activity. Finally, these apoptotic features were prevented by the addition of the ROS scavenger N-acetyl-cysteine indicating mechanistic pathway specificity. Together, these findings indicate that D(KLAKLAK2 makes Mucorales exquisitely susceptible via mitochondrial injury-induced apoptosis. This prototype may serve as a candidate drug for the development of translational applications against mucormycosis and perhaps other fungal infections.

  9. An antimicrobial peptidomimetic induces Mucorales cell death through mitochondria-mediated apoptosis.

    Science.gov (United States)

    Barbu, E Magda; Shirazi, Fazal; McGrath, Danielle M; Albert, Nathaniel; Sidman, Richard L; Pasqualini, Renata; Arap, Wadih; Kontoyiannis, Dimitrios P

    2013-01-01

    The incidence of mucormycosis has dramatically increased in immunocompromised patients. Moreover, the array of cellular targets whose inhibition results in fungal cell death is rather limited. Mitochondria have been mechanistically identified as central regulators of detoxification and virulence in fungi. Our group has previously designed and developed a proteolytically-resistant peptidomimetic motif D(KLAKLAK)2 with pleiotropic action ranging from targeted (i.e., ligand-directed) activity against cancer and obesity to non-targeted activity against antibiotic resistant gram-negative rods. Here we evaluated whether this non-targeted peptidomimetic motif is active against Mucorales. We show that D(KLAKLAK)2 has marked fungicidal action, inhibits germination, and reduces hyphal viability. We have also observed cellular changes characteristic of apoptosis in D(KLAKLAK)2-treated Mucorales cells. Moreover, the fungicidal activity was directly correlated with vacuolar injury, mitochondrial swelling and mitochondrial membrane depolarization, intracellular reactive oxygen species accumulation (ROS), and increased caspase-like enzymatic activity. Finally, these apoptotic features were prevented by the addition of the ROS scavenger N-acetyl-cysteine indicating mechanistic pathway specificity. Together, these findings indicate that D(KLAKLAK)2 makes Mucorales exquisitely susceptible via mitochondrial injury-induced apoptosis. This prototype may serve as a candidate drug for the development of translational applications against mucormycosis and perhaps other fungal infections.

  10. Intense picosecond pulsed electric fields induce apoptosis through a mitochondrial-mediated pathway in HeLa cells

    Science.gov (United States)

    HUA, YUAN-YUAN; WANG, XIAO-SHU; ZHANG, YU; YAO, CHEN-GUO; ZHANG, XI-MING; XIONG, ZHENG-AI

    2012-01-01

    The application of pulsed electric fields (PEF) is emerging as a new technique for tumor therapy. Picosecond pulsed electric fields (psPEF) can be transferred to target deep tissue non-invasively and precisely, but the research of the biological effects of psPEF on cells is limited. Electric theory predicts that intense psPEF will target mitochondria and lead to changes in transmembrane potential, therefore, it is hypothesized that it can induce mitochondrial-mediated apoptosis. HeLa cells were exposed to psPEF in this study to investigate this hypothesis. MTT assay demonstrated that intense psPEF significantly inhibited the proliferation of HeLa cells in a dose-dependent manner. Typical characteristics of apoptosis in HeLa cells were observed, using transmission electron microscopy. Loss of mitochondrial transmembrane potential was explored using laser scanning confocal microscopy with Rhodamine-123 (Rh123) staining. Furthermore, the mitochondrial apoptotic events were also confirmed by western blot analysis for the release of cytochrome C and apoptosis-inducing factor from mitochondria into the cytosol. In addition, activation of caspase-3, caspase-9, upregulation of Bax, p53 and downregulation of Bcl-2 were observed in HeLa cells also indicating apoptosis. Taken together, these results demonstrate that intense psPEF induce cell apoptosis through a mitochondrial-mediated pathway. PMID:22307872

  11. Extracts of Artocarpus communis Induce Mitochondria-Associated Apoptosis via Pro-oxidative Activity in Human Glioblastoma Cells

    Directory of Open Access Journals (Sweden)

    Chiang-Wen Lee

    2018-05-01

    Full Text Available Glioblastoma multiforme (GBM is an extremely aggressive and devastating malignant tumor in the central nervous system. Its incidence is increasing and the prognosis is poor. Artocarpin is a natural prenylated flavonoid with various anti-inflammatory and anti-tumor properties. Studies have shown that artocarpin is associated with cell death of primary glioblastoma cells. However, the in vivo effects and the cellular and molecular mechanisms modulating the anticancer activities of artocarpin remain unknown. In this study, we demonstrated that treating the glioblastoma cell lines U87 and U118 cells with artocarpin induced apoptosis. Artocarpin-induced apoptosis is associated with caspase activation and poly (ADP-ribose polymerase (PARP cleavage and is mediated by the mitochondrial pathway. This is associated with mitochondrial depolarization, mitochondrial-derived reactive oxidative species (ROS production, cytochrome c release, Bad and Bax upregulations, and Bcl-2 downregulation. Artocarpin induced NADPH oxidase/ROS generation plays an important role in the mitochondrial pathway activation. Furthermore, we found artocarpin-induced ROS production in mitochondria is associated with Akt- and ERK1/2 activation. After treatment with artocarpin, ROS causes PI3K/Akt/ERK1/2-induced cell death of these tumor cells. These observations were further verified by the results from the implantation of both U87 and U118 cells into in vivo mouse. In conclusion, our findings suggest that artocarpin induces mitochondria-associated apoptosis of glioma cells, suggesting that artocarpine can be a potential chemotherapeutic agent for future GBM treatment.

  12. Nano Copper Induces Apoptosis in PK-15 Cells via a Mitochondria-Mediated Pathway.

    Science.gov (United States)

    Zhang, Hui; Chang, Zhenyu; Mehmood, Khalid; Abbas, Rao Zahid; Nabi, Fazul; Rehman, Mujeeb Ur; Wu, Xiaoxing; Tian, Xinxin; Yuan, Xiaodan; Li, Zhaoyang; Zhou, Donghai

    2018-01-01

    Nano-sized copper particles are widely used in various chemical, physical, and biological fields. However, earlier studies have shown that nano copper particles (40-100 μg/mL) can induce cell toxicity and apoptosis. Therefore, this study was conducted to investigate the role of nano copper in mitochondrion-mediated apoptosis in PK-15 cells. The cells were treated with different doses of nano copper (20, 40, 60, and 80 μg/mL) to determine the effects of apoptosis using acridine orange/ethidium bromide (AO/EB) fluorescence staining and a flow cytometry assay. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in the PK-15 cells were examined using commercially available kits. Moreover, the mRNA levels of the Bax, Bid, Caspase-3, and CYCS genes were assessed by real-time PCR. The results revealed that nano copper exposure induced apoptosis and changed the mitochondrial membrane potential. In addition, nano copper significantly altered the levels of the Bax, Bid, Caspase-3, and CYCS genes at a concentration of 40 μg/mL. To summarize, nano copper significantly (P nano copper can play an important role in inducing the apoptotic pathway in PK-15 cells, which may be the mechanism by which nano copper induces nephrotoxicity.

  13. Propofol attenuates H2O2-induced oxidative stress and apoptosis via the mitochondria- and ER-medicated pathways in neonatal rat cardiomyocytes.

    Science.gov (United States)

    Liu, Xue-Ru; Cao, Lu; Li, Tao; Chen, Lin-Lin; Yu, Yi-Yan; Huang, Wen-Jun; Liu, Li; Tan, Xiao-Qiu

    2017-05-01

    Previous studies have shown that propofol, an intravenous anesthetic commonly used in clinical practice, protects the myocardium from injury. Mitochondria- and endoplasmic reticulum (ER)-mediated oxidative stress and apoptosis are two important signaling pathways involved in myocardial injury and protection. The present study aimed to test the hypothesis that propofol could exert a cardio-protective effect via the above two pathways. Cultured neonatal rat cardiomyocytes were treated with culture medium (control group), H 2 O 2 at 500 μM (H 2 O 2 group), propofol at 50 μM (propofol group), and H 2 O 2 plus propofol (H 2 O 2  + propofol group), respectively. The oxidative stress, mitochondrial membrane potential (ΔΨm) and apoptosis of the cardiomyocytes were evaluated by a series of assays including ELISA, flow cytometry, immunofluorescence microscopy and Western blotting. Propofol significantly suppressed the H 2 O 2 -induced elevations in the activities of caspases 3, 8, 9 and 12, the ratio of Bax/Bcl-2, and cell apoptosis. Propofol also inhibited the H 2 O 2 -induced reactive oxygen species (ROS) generation, lactic dehydrogenase (LDH) release and mitochondrial transmembrane potential (ΔΨm) depolarization, and restored the H 2 O 2 -induced reductions of glutathione (GSH) and superoxide dismutase (SOD). In addition, propofol decreased the expressions of glucose-regulated protein 78 kDa (Grp78) and inositol-requiring enzyme 1α (IRE1α), two important signaling molecules in the ER-mediated apoptosis pathway. Propofol protects cardiomyocytes from H 2 O 2 -induced injury by inhibiting the mitochondria- and ER-mediated apoptosis signaling pathways.

  14. The cytotoxic effect of oxybuprocaine on human corneal epithelial cells by inducing cell cycle arrest and mitochondria-dependent apoptosis.

    Science.gov (United States)

    Fan, W-Y; Wang, D-P; Wen, Q; Fan, T-J

    2017-08-01

    Oxybuprocaine (OBPC) is a widely used topical anesthetic in eye clinic, and prolonged and repeated usage of OBPC might be cytotoxic to the cornea, especially to the outmost corneal epithelium. In this study, we characterized the cytotoxic effect of OBPC on human corneal epithelial (HCEP) cells and investigated its possible cellular and molecular mechanisms using an in vitro model of non-transfected HCEP cells. Our results showed that OBPC at concentrations ranging from 0.025% to 0.4% had a dose- and time-dependent cytotoxicity to HCEP cells. Moreover, OBPC arrested the cells at S phase and induced apoptosis of these cells by inducing plasma membrane permeability, phosphatidylserine externalization, DNA fragmentation, and apoptotic body formation. Furthermore, OBPC could trigger the activation of caspase-2, -3, and -9, downregulate the expression of Bcl-xL, upregulate the expression of Bax along with the cytoplasmic amount of mitochondria-released apoptosis-inducing factor, and disrupt mitochondrial transmembrane potential. Our results suggest that OBPC has a dose- and time-dependent cytotoxicity to HCEP cells by inducing cell cycle arrest and cell apoptosis via a death receptor-mediated mitochondria-dependent proapoptotic pathway, and this novel finding provides new insights into the acute cytotoxicity and its toxic mechanisms of OBPC on HCEP cells.

  15. Functional characterization of mitochondria in neutrophils: a role restricted to apoptosis

    NARCIS (Netherlands)

    Maianski, N. A.; Geissler, J.; Srinivasula, S. M.; Alnemri, E. S.; Roos, D.; Kuijpers, T. W.

    2004-01-01

    Mitochondria are known to combine life-supporting functions with participation in apoptosis by controlling caspase activity. Here, we report that in human blood neutrophils the mitochondria are different, because they preserve mainly death-mediating abilities. Neutrophil mitochondria hardly

  16. Feedback regulation of mitochondria by caspase-9 in the B cell receptor-mediated apoptosis.

    Science.gov (United States)

    Eeva, J; Nuutinen, U; Ropponen, A; Mättö, M; Eray, M; Pellinen, R; Wahlfors, J; Pelkonen, J

    2009-12-01

    During the germinal centre reaction (GC), B cells with non-functional or self-reactive antigen receptors are negatively selected by apoptosis to generate B cell repertoire with appropriate antigen specificities. We studied the molecular mechanism of Fas/CD95- and B cell receptor (BCR)-induced apoptosis to shed light on the signalling events involved in the negative selection of GC B cells. As an experimental model, we used human follicular lymphoma (FL) cell line HF1A3, which originates from a GC B cell, and transfected HF1A3 cell lines overexpressing Bcl-x(L), c-FLIP(long) or dominant negative (DN) caspase-9. Fas-induced apoptosis was dependent on the caspase-8 activation, since the overexpression of c-FLIP(long), a natural inhibitor of caspase-8 activation, blocked apoptosis induced by Fas. In contrast, caspase-9 activation was not involved in Fas-induced apoptosis. BCR-induced apoptosis showed the typical characteristics of mitochondria-dependent (intrinsic) apoptosis. Firstly, the activation of caspase-9 was involved in BCR-induced DNA fragmentation, while caspase-8 showed only marginal role. Secondly, overexpression of Bcl-x(L) could block all apoptotic changes induced by BCR. As a novel finding, we demonstrate that caspase-9 can enhance the cytochrome-c release and collapse of mitochondrial membrane potential (DeltaPsi(m)) during BCR-induced apoptosis. The requirement of different signalling pathways in apoptosis induced by BCR and Fas may be relevant, since Fas- and BCR-induced apoptosis can thus be regulated independently, and targeted to different subsets of GC B cells.

  17. Taurine inhibits 2,5-hexanedione-induced oxidative stress and mitochondria-dependent apoptosis in PC12 cells.

    Science.gov (United States)

    Li, Shuangyue; Guan, Huai; Qian, Zhiqiang; Sun, Yijie; Gao, Chenxue; Li, Guixin; Yang, Yi; Piao, Fengyuan; Hu, Shuhai

    2017-04-07

    2,5-hexanedione (HD) is the ultimate neurotoxic metabolite of hexane, causing the progression of nerve diseases in human. It was reported that HD induced apoptosis and oxidative stress. Taurine has been shown to be a potent antioxidant. In the present study, we investigated the protection of taurine against HD-induced apoptosis in PC12 cells and the underlying mechanism. Our results showed the decreased viability and increased apoptosis in HD-exposed PC12 cells. HD also induced the disturbance of Bax and Bcl-2 expression, the loss of MMP, the release of mitochondrial cytochrome c and caspase-3 activation in PC12 cells. Moreover, HD resulted in an increase in reactive oxygen species (ROS) level and a decline in the activities of superoxidedismutase and catalase in PC12 cells. However, taurine pretreatment ameliorated the increased apoptosis and the alterations in key regulators of mitochondria-dependent pathway in PC12 exposed to HD. The increased ROS level and the decreased activities of the antioxidant enzymes in HD group were attenuated by taurine. These results indicate that pretreatment of taurine may, at least partly, prevent HD-induced apoptosis via inhibiting mitochondria-dependent pathway. It is also suggested that the potential of taurine against HD-induced apoptosis may benefit from its anti-oxidative property.

  18. The Nitric Oxide Prodrug JS-K Induces Ca(2+)-Mediated Apoptosis in Human Hepatocellular Carcinoma HepG2 Cells.

    Science.gov (United States)

    Liu, Ling; Wang, Dongmei; Wang, Jiangang; Wang, Shuying

    2016-04-01

    Hepatocellular carcinoma is one of the most common and deadly forms of human malignancies. JS-K, O(2)-(2, 4-dinitrophenyl) 1-[(4-ethoxycarbonyl) piperazin-1-yl] diazen-1-ium-1, 2-diolate, has the ability to induce apoptosis of tumor cell lines. In the present study, JS-K inhibited the proliferation of HepG2 cells in a time- and concentration-dependent manner and significantly induced apoptosis. JS-K enhanced the ratio of Bax-to-Bcl-2, released of cytochrome c (Cyt c) from mitochondria and the activated caspase-9/3. JS-K caused an increasing cytosolic Ca(2+) and the loss of mitochondrial membrane potential. Carboxy-PTIO (a NO scavenger) and BAPTA-AM (an intracellular Ca(2+) chelator) significantly blocked an increasing cytosolic Ca(2+) in JS-K-induced HepG2 cells apoptosis, especially Carboxy-PTIO. Meanwhile, Carboxy-PTIO and BAPTA-AM treatment both attenuate JS-K-induced apoptosis through upregulation of Bcl-2, downregulation of Bax, reduction of Cyt c release from mitochondria to cytoplasm and inactivation of caspase-9/3. In summary, JS-K induced HepG2 cells apoptosis via Ca(2+)/caspase-3-mediated mitochondrial pathway. © 2015 Wiley Periodicals, Inc.

  19. Hsp105 family proteins suppress staurosporine-induced apoptosis by inhibiting the translocation of Bax to mitochondria in HeLa cells

    International Nuclear Information System (INIS)

    Yamagishi, Nobuyuki; Ishihara, Keiichi; Saito, Youhei; Hatayama, Takumi

    2006-01-01

    Hsp105 (Hsp105α and Hsp105β), major heat shock proteins in mammalian cells, belong to a subgroup of the HSP70 family, HSP105/110. Previously, we have shown that Hsp105α has completely different effects on stress-induced apoptosis depending on cell type. However, the molecular mechanisms by which Hsp105α regulates stress-induced apoptosis are not fully understood. Here, we established HeLa cells that overexpress either Hsp105α or Hsp105β by removing doxycycline and examined how Hsp105 modifies staurosporine (STS)-induced apoptosis in HeLa cells. Apoptotic features such as the externalization of phosphatidylserine on the plasma membrane and nuclear morphological changes were induced by the treatment with STS, and the STS-induced apoptosis was suppressed by overexpression of Hsp105α or Hsp105β. In addition, we found that overexpression of Hsp105α or Hsp105β suppressed the activation of caspase-3 and caspase-9 by preventing the release of cytochrome c from mitochondria. Furthermore, the translocation of Bax to mitochondria, which results in the release of cytochrome c from the mitochondria, was also suppressed by the overexpression of Hsp105α or Hsp105β. Thus, it is suggested that Hsp105 suppresses the stress-induced apoptosis at its initial step, the translocation of Bax to mitochondria in HeLa cells

  20. Research Advances on Pathways of Nickel-Induced Apoptosis

    Science.gov (United States)

    Guo, Hongrui; Chen, Lian; Cui, Hengmin; Peng, Xi; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Wang, Xun; Wu, Bangyuan

    2015-01-01

    High concentrations of nickel (Ni) are harmful to humans and animals. Ni targets a number of organs and produces multiple toxic effects. Apoptosis is important in Ni-induced toxicity of the kidneys, liver, nerves, and immune system. Apoptotic pathways mediated by reactive oxygen species (ROS), mitochondria, endoplasmic reticulum (ER), Fas, and c-Myc participate in Ni-induced cell apoptosis. However, the exact mechanism of apoptosis caused by Ni is still unclear. Understanding the mechanism of Ni-induced apoptosis may help in designing measures to prevent Ni toxicity. PMID:26703593

  1. Sinularin Induces Apoptosis through Mitochondria Dysfunction and Inactivation of the pI3K/Akt/mTOR Pathway in Gastric Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Yu-Jen Wu

    2016-07-01

    Full Text Available Sinularin is an active compound isolated from the cultured soft coral Sinularia flexibilis. In this study, we investigated the effects of sinularin on two human gastric cancer cell lines, AGS and NCI-N87. Our results demonstrated that sinularin suppressed the proliferation of gastric cancer cells in a dose-dependent manner and induced apoptosis. In addition, the loss of mitochondrial membrane potential, the release of cytochrome C, the activation of Bax, Bad and caspase-3/9, and the suppression of p-Bad, Bcl-xL and Bcl-2 were observed in the cells treated with sinularin. This finding suggests that sinularin-induced apoptosis is associated with mitochondria-mediated apoptosis and occurs through caspase-dependent pathways. Furthermore, sinularin inhibited the phosphoinositol 3-kinase/Akt/mechanistic target of the rapamycin signaling pathway. Taken together, our results show that sinularin-induced apoptosis is mediated by activation of the caspase cascade and mitochondrial dysfunction. Our findings suggest that sinularin merits further evaluation as a chemotherapeutic agent for human gastric cancer.

  2. Deregulation of Mitochondria-Shaping Proteins Opa-1 and Drp-1 in Manganese-Induced Apoptosis

    Science.gov (United States)

    Alaimo, Agustina; Gorojod, Roxana M.; Beauquis, Juan; Muñoz, Manuel J.; Saravia, Flavia; Kotler, Mónica L.

    2014-01-01

    Mitochondria are dynamic organelles that undergo fusion and fission processes. These events are regulated by mitochondria-shaping proteins. Changes in the expression and/or localization of these proteins lead to a mitochondrial dynamics impairment and may promote apoptosis. Increasing evidence correlates the mitochondrial dynamics disruption with the occurrence of neurodegenerative diseases. Therefore, we focused on this topic in Manganese (Mn)-induced Parkinsonism, a disorder associated with Mn accumulation preferentially in the basal ganglia where mitochondria from astrocytes represent an early target. Using MitoTracker Red staining we observed increased mitochondrial network fission in Mn-exposed rat astrocytoma C6 cells. Moreover, Mn induced a marked decrease in fusion protein Opa-1 levels as well as a dramatic increase in the expression of fission protein Drp-1. Additionally, Mn provoked a significant release of high MW Opa-1 isoforms from the mitochondria to the cytosol as well as an increased Drp-1 translocation to the mitochondria. Both Mdivi-1, a pharmacological Drp-1 inhibitor, and rat Drp-1 siRNA reduced the number of apoptotic nuclei, preserved the mitochondrial network integrity and prevented cell death. CsA, an MPTP opening inhibitor, prevented mitochondrial Δψm disruption, Opa-1 processing and Drp-1 translocation to the mitochondria therefore protecting Mn-exposed cells from mitochondrial disruption and apoptosis. The histological analysis and Hoechst 33258 staining of brain sections of Mn-injected rats in the striatum showed a decrease in cellular mass paralleled with an increase in the occurrence of apoptotic nuclei. Opa-1 and Drp-1 expression levels were also changed by Mn-treatment. Our results demonstrate for the first time that abnormal mitochondrial dynamics is implicated in both in vitro and in vivo Mn toxicity. In addition we show that the imbalance in fusion/fission equilibrium might be involved in Mn-induced apoptosis. This knowledge may

  3. Deregulation of mitochondria-shaping proteins Opa-1 and Drp-1 in manganese-induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Agustina Alaimo

    Full Text Available Mitochondria are dynamic organelles that undergo fusion and fission processes. These events are regulated by mitochondria-shaping proteins. Changes in the expression and/or localization of these proteins lead to a mitochondrial dynamics impairment and may promote apoptosis. Increasing evidence correlates the mitochondrial dynamics disruption with the occurrence of neurodegenerative diseases. Therefore, we focused on this topic in Manganese (Mn-induced Parkinsonism, a disorder associated with Mn accumulation preferentially in the basal ganglia where mitochondria from astrocytes represent an early target. Using MitoTracker Red staining we observed increased mitochondrial network fission in Mn-exposed rat astrocytoma C6 cells. Moreover, Mn induced a marked decrease in fusion protein Opa-1 levels as well as a dramatic increase in the expression of fission protein Drp-1. Additionally, Mn provoked a significant release of high MW Opa-1 isoforms from the mitochondria to the cytosol as well as an increased Drp-1 translocation to the mitochondria. Both Mdivi-1, a pharmacological Drp-1 inhibitor, and rat Drp-1 siRNA reduced the number of apoptotic nuclei, preserved the mitochondrial network integrity and prevented cell death. CsA, an MPTP opening inhibitor, prevented mitochondrial Δψm disruption, Opa-1 processing and Drp-1 translocation to the mitochondria therefore protecting Mn-exposed cells from mitochondrial disruption and apoptosis. The histological analysis and Hoechst 33258 staining of brain sections of Mn-injected rats in the striatum showed a decrease in cellular mass paralleled with an increase in the occurrence of apoptotic nuclei. Opa-1 and Drp-1 expression levels were also changed by Mn-treatment. Our results demonstrate for the first time that abnormal mitochondrial dynamics is implicated in both in vitro and in vivo Mn toxicity. In addition we show that the imbalance in fusion/fission equilibrium might be involved in Mn-induced apoptosis

  4. Deregulation of mitochondria-shaping proteins Opa-1 and Drp-1 in manganese-induced apoptosis.

    Science.gov (United States)

    Alaimo, Agustina; Gorojod, Roxana M; Beauquis, Juan; Muñoz, Manuel J; Saravia, Flavia; Kotler, Mónica L

    2014-01-01

    Mitochondria are dynamic organelles that undergo fusion and fission processes. These events are regulated by mitochondria-shaping proteins. Changes in the expression and/or localization of these proteins lead to a mitochondrial dynamics impairment and may promote apoptosis. Increasing evidence correlates the mitochondrial dynamics disruption with the occurrence of neurodegenerative diseases. Therefore, we focused on this topic in Manganese (Mn)-induced Parkinsonism, a disorder associated with Mn accumulation preferentially in the basal ganglia where mitochondria from astrocytes represent an early target. Using MitoTracker Red staining we observed increased mitochondrial network fission in Mn-exposed rat astrocytoma C6 cells. Moreover, Mn induced a marked decrease in fusion protein Opa-1 levels as well as a dramatic increase in the expression of fission protein Drp-1. Additionally, Mn provoked a significant release of high MW Opa-1 isoforms from the mitochondria to the cytosol as well as an increased Drp-1 translocation to the mitochondria. Both Mdivi-1, a pharmacological Drp-1 inhibitor, and rat Drp-1 siRNA reduced the number of apoptotic nuclei, preserved the mitochondrial network integrity and prevented cell death. CsA, an MPTP opening inhibitor, prevented mitochondrial Δψm disruption, Opa-1 processing and Drp-1 translocation to the mitochondria therefore protecting Mn-exposed cells from mitochondrial disruption and apoptosis. The histological analysis and Hoechst 33258 staining of brain sections of Mn-injected rats in the striatum showed a decrease in cellular mass paralleled with an increase in the occurrence of apoptotic nuclei. Opa-1 and Drp-1 expression levels were also changed by Mn-treatment. Our results demonstrate for the first time that abnormal mitochondrial dynamics is implicated in both in vitro and in vivo Mn toxicity. In addition we show that the imbalance in fusion/fission equilibrium might be involved in Mn-induced apoptosis. This knowledge may

  5. 3-Bromopyruvate and sodium citrate induce apoptosis in human gastric cancer cell line MGC-803 by inhibiting glycolysis and promoting mitochondria-regulated apoptosis pathway.

    Science.gov (United States)

    Guo, Xingyu; Zhang, Xiaodong; Wang, Tingan; Xian, Shulin; Lu, Yunfei

    2016-06-17

    Cancer cells are mainly dependent on glycolysis to generate adenosine triphosphate (ATP) and intermediates required for cell growth and proliferation. Thus, inhibition of glycolysis might be of therapeutic value in antitumor treatment. Our previously studies had found that both 3-bromopyruvate (BP) and sodium citrate (SCT) can inhibit tumor growth and proliferation in vitro and in vivo. However, the mechanism involved in the BP and SCT mediated antitumor activity is not entirely clear. In this work, it is demonstrated that BP inhibits the enzyme hexokinase (HK) activity and SCT suppresses the phosphofructokinase (PFK) activity respectively, both the two agents decrease viability, ATP generation and lactate content in the human gastric cancer cell line MGC-803. These effects are directly correlated with blockage of glycolysis. Furthermore, BP and SCT can induce the characteristic manifestations of mitochondria-regulated apoptosis, such as down-regulation of anti-apoptosis proteins Bcl-2 and Survivin, up-regulation of pro-apoptosis protein Bax, activation of caspase-3, as well as leakage of cytochrome c (Cyt-c). In summary, our results provided evidences that BP and SCT inhibit the MGC-803 cells growth and proliferation might be correlated with inhibiting glycolysis and promoting mitochondria-regulated apoptosis. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Death receptor and mitochondria-mediated hepatocyte apoptosis underlies liver dysfunction in rats exposed to organic pollutants from drinking water.

    Science.gov (United States)

    Yang, Guanghong; Zhou, Zhiwei; Cen, Yanli; Gui, Xiaolin; Zeng, Qibing; Ao, Yunxia; Li, Qian; Wang, Shiran; Li, Jun; Zhang, Aihua

    2015-01-01

    Persistent organic pollutants in drinking water impose a substantial risk to the health of human beings, but the evidence for liver toxic effect and the underlying mechanism is scarce. This study aimed to examine the liver toxicity and elucidate the molecular mechanism of organic pollutants in drinking water in normal human liver cell line L02 cells and rats. The data showed that organic extraction from drinking water remarkably impaired rat liver function, evident from the increase in the serum level of alanine aminotransferase, aspartate aminotransferase, and cholinesterase, and decrease in the serum level of total protein and albumin. Organic extraction dose-dependently induced apoptotic cell death in rat liver and L02 cells. Administration of rats with organic extraction promoted death receptor signaling pathway through the increase in gene and protein expression level of Fas and FasL. Treatment of rats with organic extraction also induced mitochondria-mediated apoptosis via increasing the expression level of proapoptotic protein, Bax, but decreasing the expression level of antiapoptotic protein, Bcl-2, resulting in an upregulation of cytochrome c and activation of caspase cascade at both transcriptional and post-transcriptional levels. Moreover, organic extraction enhanced rat liver glutathione S-transferases activity and reactive oxygen species generation, and upregulated aryl hydrocarbon receptor and glutathione S-transferase A1 at both transcriptional and translational levels. Collectively, the results indicate that organic extraction from drinking water impairs liver function, with the involvement of death receptor and mitochondria-mediated apoptosis in rats. The results provide evidence and molecular mechanisms for organic pollutants in drinking water-induced liver dysfunction, which may help prevent and treat organic extraction-induced liver injury.

  7. Death receptor and mitochondria-mediated hepatocyte apoptosis underlies liver dysfunction in rats exposed to organic pollutants from drinking water

    Science.gov (United States)

    Yang, Guanghong; Zhou, Zhiwei; Cen, Yanli; Gui, Xiaolin; Zeng, Qibing; Ao, Yunxia; Li, Qian; Wang, Shiran; Li, Jun; Zhang, Aihua

    2015-01-01

    Persistent organic pollutants in drinking water impose a substantial risk to the health of human beings, but the evidence for liver toxic effect and the underlying mechanism is scarce. This study aimed to examine the liver toxicity and elucidate the molecular mechanism of organic pollutants in drinking water in normal human liver cell line L02 cells and rats. The data showed that organic extraction from drinking water remarkably impaired rat liver function, evident from the increase in the serum level of alanine aminotransferase, aspartate aminotransferase, and cholinesterase, and decrease in the serum level of total protein and albumin. Organic extraction dose-dependently induced apoptotic cell death in rat liver and L02 cells. Administration of rats with organic extraction promoted death receptor signaling pathway through the increase in gene and protein expression level of Fas and FasL. Treatment of rats with organic extraction also induced mitochondria-mediated apoptosis via increasing the expression level of proapoptotic protein, Bax, but decreasing the expression level of antiapoptotic protein, Bcl-2, resulting in an upregulation of cytochrome c and activation of caspase cascade at both transcriptional and post-transcriptional levels. Moreover, organic extraction enhanced rat liver glutathione S-transferases activity and reactive oxygen species generation, and upregulated aryl hydrocarbon receptor and glutathione S-transferase A1 at both transcriptional and translational levels. Collectively, the results indicate that organic extraction from drinking water impairs liver function, with the involvement of death receptor and mitochondria-mediated apoptosis in rats. The results provide evidence and molecular mechanisms for organic pollutants in drinking water-induced liver dysfunction, which may help prevent and treat organic extraction-induced liver injury. PMID:26316710

  8. Apoptotic role of TGF-β mediated by Smad4 mitochondria translocation and cytochrome c oxidase subunit II interaction.

    Science.gov (United States)

    Pang, Lijuan; Qiu, Tao; Cao, Xu; Wan, Mei

    2011-07-01

    Smad4, originally isolated from the human chromosome 18q21, is a key factor in transducing the signals of the TGF-β superfamily of growth hormones and plays a pivotal role in mediating antimitogenic and proapoptotic effects of TGF-β, but the mechanisms by which Smad4 induces apoptosis are elusive. Here we report that Smad4 directly translocates to the mitochondria of apoptotic cells. Smad4 gene silencing by siRNA inhibits TGF-β-induced apoptosis in Hep3B cells and UV-induced apoptosis in PANC-1 cells. Cell fractionation assays demonstrated that a fraction of Smad4 translocates to mitochondria after long time TGF-β treatment or UV exposure, during which the cells were under apoptosis. Smad4 mitochondria translocation during apoptosis was also confirmed by fluorescence observation of Smad4 colocalization with MitoTracker Red. We searched for mitochondria proteins that have physical interactions with Smad4 using yeast two-hybrid screening approach. DNA sequence analysis identified 34 positive clones, five of which encoded subunits in mitochondria complex IV, i.e., one clone encoded cytochrome c oxidase COXII, three clones encoded COXIII and one clone encoded COXVb. Strong interaction between Smad4 with COXII, an important apoptosis regulator, was verified in yeast by β-gal activity assays and in mammalian cells by immunoprecipitation assays. Further, mitochondrial portion of cells was isolated and the interaction between COXII and Smad4 in mitochondria upon TGF-β treatment or UV exposure was confirmed. Importantly, targeting Smad4 to mitochondria using import leader fusions enhanced TGF-β-induced apoptosis. Collectively, the results suggest that Smad4 promote apoptosis of the cells through its mitochondrial translocation and association with mitochondria protein COXII. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. A Lentinus edodes polysaccharide induces mitochondrial-mediated apoptosis in human cervical carcinoma HeLa cells.

    Science.gov (United States)

    Ya, Guowei

    2017-10-01

    In this study, a homogeneous polysaccharide (LEP1) with an average molecular weight of 53kDa was successfully purified from the fruiting bodies of Lentinus edodes and its anticancer efficacy on human cervical carcinoma HeLa cells in vitro and associated possible molecular mechanism were also evaluated. MTT assay showed that LEP1 exhibited a dose-dependent inhibitory effect on the proliferation of HeLa cells and caused apoptotic death. Our present findings provided the first evidence that LEP1 induced the apoptosis of HeLa cells via a mitochondria dependent pathway, as indicated by an increase in Bax/Bcl-2 ratio, a loss of mitochondrial membrane potential (Δym), the release of cytochrome c from the mitochondria to the cytosol, activation of caspase-9 and caspase-3, and cleavage of poly (ADP-ribose) polymerase (PARP) in HeLa cells. These combined results unequivocally indicated that the involvement of mitochondria-mediated signaling pathway in LEP1-induced apoptosis and strongly provided experimental evidence for the use of LEP1 as a potential therapeutic agent in the prevention and treatment of human cervical carcinoma. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Autophagy regulates chlorpyrifos-induced apoptosis in SH-SY5Y cells

    International Nuclear Information System (INIS)

    Park, Jae Hyeon; Lee, Jeong Eun; Shin, In Chul; Koh, Hyun Chul

    2013-01-01

    Recent studies have shown that up-regulation of autophagy may be a tractable therapeutic intervention for clearing disease-causing proteins, including α-synuclein, ubiquitin, and other misfolded or aggregated proteins in pesticide-induced neurodegeneration. In a previous study, we reported that chlorpyrifos (CPF)-induced mitochondria-dependent apoptosis is mediated through reactive oxygen species in SH-SY5Y cells. In this study, we explored a novel pharmacotherapeutic approach to prevent CPF neurotoxicity involving the regulation of autophagy. We investigated the modulation of CPF-induced apoptosis according to autophagy regulation. We found that CPF induced apoptosis in SH-SY5Y cells, as demonstrated by the activation of caspase-3 and nuclear condensation. In addition, we observed that cells treated with CPF underwent autophagic cell death by monitoring the expression of LC3-II and p62. Pretreatment with the autophagy inducer rapamycin significantly enhanced the cell viability of CPF-exposed cells, and the enhancement of cell viability was partially due to alleviation of CPF-induced apoptosis via a decrease in levels of cleaved caspase-3. Specifically, rapamycin pretreatment decreased Bax and increased Bcl-2 expression in mitochondria. In addition, rapamycin significantly decreased cytochrome c release in from mitochondria into the cytosol. However, pretreatment of cells with the autophagy inhibitor, 3-methyladenine (3MA), remarkably increased CPF toxicity in these cells; this with correlated with increased expression of Bax and decreased expression of Bcl-2 in mitochondria. Our results suggest that CPF-induced cytotoxicity is modified by autophagy regulation and that rapamycin protects against CPF-induced apoptosis by enhancing autophagy. Pharmacologic induction of autophagy by rapamycin may be a useful treatment strategy in neurodegenerative disorders. - Highlights: ► Chlorpyrifos (CPF) is cytotoxic to SH-SY5Y cells ► CPF-induced cytotoxicity is mediated by

  11. Autophagy regulates chlorpyrifos-induced apoptosis in SH-SY5Y cells

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Hyeon [Department of Pharmacology, College of Medicine, Hanyang University (Korea, Republic of); Hanyang Biomedical Research Institute, Seoul (Korea, Republic of); Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul (Korea, Republic of); Lee, Jeong Eun [Department of Pharmacology, College of Medicine, Hanyang University (Korea, Republic of); Hanyang Biomedical Research Institute, Seoul (Korea, Republic of); Shin, In Chul [Department of Pharmacology, College of Medicine, Hanyang University (Korea, Republic of); Koh, Hyun Chul, E-mail: hckoh@hanyang.ac.kr [Department of Pharmacology, College of Medicine, Hanyang University (Korea, Republic of); Hanyang Biomedical Research Institute, Seoul (Korea, Republic of); Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul (Korea, Republic of)

    2013-04-01

    Recent studies have shown that up-regulation of autophagy may be a tractable therapeutic intervention for clearing disease-causing proteins, including α-synuclein, ubiquitin, and other misfolded or aggregated proteins in pesticide-induced neurodegeneration. In a previous study, we reported that chlorpyrifos (CPF)-induced mitochondria-dependent apoptosis is mediated through reactive oxygen species in SH-SY5Y cells. In this study, we explored a novel pharmacotherapeutic approach to prevent CPF neurotoxicity involving the regulation of autophagy. We investigated the modulation of CPF-induced apoptosis according to autophagy regulation. We found that CPF induced apoptosis in SH-SY5Y cells, as demonstrated by the activation of caspase-3 and nuclear condensation. In addition, we observed that cells treated with CPF underwent autophagic cell death by monitoring the expression of LC3-II and p62. Pretreatment with the autophagy inducer rapamycin significantly enhanced the cell viability of CPF-exposed cells, and the enhancement of cell viability was partially due to alleviation of CPF-induced apoptosis via a decrease in levels of cleaved caspase-3. Specifically, rapamycin pretreatment decreased Bax and increased Bcl-2 expression in mitochondria. In addition, rapamycin significantly decreased cytochrome c release in from mitochondria into the cytosol. However, pretreatment of cells with the autophagy inhibitor, 3-methyladenine (3MA), remarkably increased CPF toxicity in these cells; this with correlated with increased expression of Bax and decreased expression of Bcl-2 in mitochondria. Our results suggest that CPF-induced cytotoxicity is modified by autophagy regulation and that rapamycin protects against CPF-induced apoptosis by enhancing autophagy. Pharmacologic induction of autophagy by rapamycin may be a useful treatment strategy in neurodegenerative disorders. - Highlights: ► Chlorpyrifos (CPF) is cytotoxic to SH-SY5Y cells ► CPF-induced cytotoxicity is mediated by

  12. NDV-induced apoptosis in absence of Bax; evidence of involvement of apoptotic proteins upstream of mitochondria

    Directory of Open Access Journals (Sweden)

    Molouki Aidin

    2012-08-01

    Full Text Available Abstract Background Recently it was shown that following infection of HeLa cells with Newcastle disease virus (NDV, the matrix (M protein binds to Bax and subsequently the intrinsic pathway of apoptosis is activated. Moreover, there was very little alteration on mRNA and protein levels of Bax and Bcl-2 after infection with NDV. Finding In order to further investigate the role of members of the Bcl-2 family, Bax-knockout and wild-type HCT116 cells were infected with NDV strain AF2240. Although both cells underwent apoptosis through the activation of the intrinsic pathway and the release of cytochrome c from mitochondria, the percentage of dead Bax-knockout cells was significantly lower than wt cells (more than 10% at 48 h post-infection. In a parallel experiment, the effect of NDV on HT29 cells, that are originally Bcl-2-free, was studied. Apoptosis in HT29 cells was associated with Bax redistribution from cytoplasm to mitochondria, similar to that of HeLa and wt HCT116 cells. Conclusion Although the presence of Bax during NDV-induced apoptosis contributes to a faster cell death, it was concluded that other apoptotic protein(s upstream of mitochondria are also involved since cancer cells die whether in the presence or absence of Bax. Therefore, the classic Bax/Bcl-2 ratio may not be a major determinant in NDV-induced apoptosis.

  13. Ripk3 induces mitochondrial apoptosis via inhibition of FUNDC1 mitophagy in cardiac IR injury

    Directory of Open Access Journals (Sweden)

    Hao Zhou

    2017-10-01

    Full Text Available Ripk3-required necroptosis and mitochondria-mediated apoptosis are the predominant types of cell death that largely account for the development of cardiac ischemia reperfusion injury (IRI. Here, we explored the effect of Ripk3 on mitochondrial apoptosis. Compared with wild-type mice, the infarcted area in Ripk3-deficient (Ripk3-/- mice had a relatively low abundance of apoptotic cells. Moreover, the loss of Ripk3 protected the mitochondria against IRI and inhibited caspase9 apoptotic pathways. These protective effects of Ripk3 deficiency were relied on mitophagy activation. However, inhibition of mitophagy under Ripk3 deficiency enhanced cardiomyocyte and endothelia apoptosis, augmented infarcted area and induced microvascular dysfunction. Furthermore, ischemia activated mitophagy by modifying FUNDC1 dephosphorylation, which substantively engulfed mitochondria debris and cytochrome-c, thus blocking apoptosis signal. However, reperfusion injury elevated the expression of Ripk3 which disrupted FUNDC1 activation and abated mitophagy, increasing the likelihood of apoptosis. In summary, this study confirms the promotive effect of Ripk3 on mitochondria-mediated apoptosis via inhibition of FUNDC1-dependent mitophagy in cardiac IRI. These findings provide new insight into the roles of Ripk3-related necroptosis, mitochondria-mediated apoptosis and FUNDC1-required mitophagy in cardiac IRI.

  14. Hepatitis C virus infection induces apoptosis through a Bax-triggered, mitochondrion-mediated, caspase 3-dependent pathway.

    Science.gov (United States)

    Deng, Lin; Adachi, Tetsuya; Kitayama, Kikumi; Bungyoku, Yasuaki; Kitazawa, Sohei; Ishido, Satoshi; Shoji, Ikuo; Hotta, Hak

    2008-11-01

    We previously reported that cells harboring the hepatitis C virus (HCV) RNA replicon as well as those expressing HCV NS3/4A exhibited increased sensitivity to suboptimal doses of apoptotic stimuli to undergo mitochondrion-mediated apoptosis (Y. Nomura-Takigawa, et al., J. Gen. Virol. 87:1935-1945, 2006). Little is known, however, about whether or not HCV infection induces apoptosis of the virus-infected cells. In this study, by using the chimeric J6/JFH1 strain of HCV genotype 2a, we demonstrated that HCV infection induced cell death in Huh7.5 cells. The cell death was associated with activation of caspase 3, nuclear translocation of activated caspase 3, and cleavage of DNA repair enzyme poly(ADP-ribose) polymerase, which is known to be an important substrate for activated caspase 3. These results suggest that HCV-induced cell death is, in fact, apoptosis. Moreover, HCV infection activated Bax, a proapoptotic member of the Bcl-2 family, as revealed by its conformational change and its increased accumulation on mitochondrial membranes. Concomitantly, HCV infection induced disruption of mitochondrial transmembrane potential, followed by mitochondrial swelling and release of cytochrome c from mitochondria. HCV infection also caused oxidative stress via increased production of mitochondrial superoxide. On the other hand, HCV infection did not mediate increased expression of glucose-regulated protein 78 (GRP78) or GRP94, which are known as endoplasmic reticulum (ER) stress-induced proteins; this result suggests that ER stress is not primarily involved in HCV-induced apoptosis in our experimental system. Taken together, our present results suggest that HCV infection induces apoptosis of the host cell through a Bax-triggered, mitochondrion-mediated, caspase 3-dependent pathway(s).

  15. Involvement of phorbol-12-myristate-13-acetate-induced protein 1 in goniothalamin-induced TP53-dependent and -independent apoptosis in hepatocellular carcinoma-derived cells

    International Nuclear Information System (INIS)

    Kuo, Kung-Kai; Chen, Yi-Ling; Chen, Lih-Ren; Li, Chien-Feng; Lan, Yu-Hsuan; Chang, Fang-Rong; Wu, Yang-Chang; Shiue, Yow-Ling

    2011-01-01

    The objective was to investigate the upstream apoptotic mechanisms that were triggered by a styrylpyrone derivative, goniothalamin (GTN), in tumor protein p53 (TP53)-positive and -negative hepatocellular carcinoma (HCC)-derived cells. Effects of GTN were evaluated by the flow cytometry, alkaline comet assay, immunocytochemistry, small-hairpin RNA interference, mitochondria/cytosol fractionation, quantitative reverse transcription-polymerase chain reaction, immunoblotting analysis and caspase 3 activity assays in two HCC-derived cell lines. Results indicated that GTN triggered phorbol-12-myristate-13-acetate-induced protein 1 (PMAIP1, also known as NOXA)-mediated apoptosis via TP53-dependent and -independent pathways. In TP53-positive SK-Hep1 cells, GTN furthermore induced TP53 transcription-dependent and -independent apoptosis. After GTN treatment, accumulation of reactive oxygen species, formation of DNA double-strand breaks, transactivation of TP53 and/or PMAIP1 gene, translocation of TP53 and/or PMAIP1 proteins to mitochondria, release of cytochrome c from mitochondria, cleavage of caspases and induction of apoptosis in both cell lines were sustained. GTN might represent a novel class of anticancer drug that induces apoptosis in HCC-derived cells through PMAIP1 transactivation regardless of the status of TP53 gene. - Highlights: → Goniothalamin (GTN) induced apoptosis in hepatocellular carcinomas-derived cells. → The apoptosis induced by GTN is PMAIP1-dependent, regardless of TP53 status. → The apoptosis induced by GTN might be TP53 transcription-dependent or -independent. → GTN-induced apoptosis is mitochondria- and caspases-mediated.

  16. 3-Bromopyruvate and sodium citrate induce apoptosis in human gastric cancer cell line MGC-803 by inhibiting glycolysis and promoting mitochondria-regulated apoptosis pathway

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xingyu; Zhang, Xiaodong; Wang, Tingan, E-mail: moonsonlife@yahoo.com; Xian, Shulin; Lu, Yunfei, E-mail: doctorlife@126.com

    2016-06-17

    Cancer cells are mainly dependent on glycolysis to generate adenosine triphosphate (ATP) and intermediates required for cell growth and proliferation. Thus, inhibition of glycolysis might be of therapeutic value in antitumor treatment. Our previously studies had found that both 3-bromopyruvate (BP) and sodium citrate (SCT) can inhibit tumor growth and proliferation in vitro and in vivo. However, the mechanism involved in the BP and SCT mediated antitumor activity is not entirely clear. In this work, it is demonstrated that BP inhibits the enzyme hexokinase (HK) activity and SCT suppresses the phosphofructokinase (PFK) activity respectively, both the two agents decrease viability, ATP generation and lactate content in the human gastric cancer cell line MGC-803. These effects are directly correlated with blockage of glycolysis. Furthermore, BP and SCT can induce the characteristic manifestations of mitochondria-regulated apoptosis, such as down-regulation of anti-apoptosis proteins Bcl-2 and Survivin, up-regulation of pro-apoptosis protein Bax, activation of caspase-3, as well as leakage of cytochrome c (Cyt-c). In summary, our results provided evidences that BP and SCT inhibit the MGC-803 cells growth and proliferation might be correlated with inhibiting glycolysis and promoting mitochondria-regulated apoptosis. -- Highlights: •Blockage of glycolysis might be a novel way to anticancer. •Both 3-bromopyruvate and sodium citrate could inhibit glycolysis and regulate mitochondrial pathway in cancer cells. •Both 3-bromopyruvate and sodium citrate would be the novel agents on treatment of gastric cancer.

  17. 3-Bromopyruvate and sodium citrate induce apoptosis in human gastric cancer cell line MGC-803 by inhibiting glycolysis and promoting mitochondria-regulated apoptosis pathway

    International Nuclear Information System (INIS)

    Guo, Xingyu; Zhang, Xiaodong; Wang, Tingan; Xian, Shulin; Lu, Yunfei

    2016-01-01

    Cancer cells are mainly dependent on glycolysis to generate adenosine triphosphate (ATP) and intermediates required for cell growth and proliferation. Thus, inhibition of glycolysis might be of therapeutic value in antitumor treatment. Our previously studies had found that both 3-bromopyruvate (BP) and sodium citrate (SCT) can inhibit tumor growth and proliferation in vitro and in vivo. However, the mechanism involved in the BP and SCT mediated antitumor activity is not entirely clear. In this work, it is demonstrated that BP inhibits the enzyme hexokinase (HK) activity and SCT suppresses the phosphofructokinase (PFK) activity respectively, both the two agents decrease viability, ATP generation and lactate content in the human gastric cancer cell line MGC-803. These effects are directly correlated with blockage of glycolysis. Furthermore, BP and SCT can induce the characteristic manifestations of mitochondria-regulated apoptosis, such as down-regulation of anti-apoptosis proteins Bcl-2 and Survivin, up-regulation of pro-apoptosis protein Bax, activation of caspase-3, as well as leakage of cytochrome c (Cyt-c). In summary, our results provided evidences that BP and SCT inhibit the MGC-803 cells growth and proliferation might be correlated with inhibiting glycolysis and promoting mitochondria-regulated apoptosis. -- Highlights: •Blockage of glycolysis might be a novel way to anticancer. •Both 3-bromopyruvate and sodium citrate could inhibit glycolysis and regulate mitochondrial pathway in cancer cells. •Both 3-bromopyruvate and sodium citrate would be the novel agents on treatment of gastric cancer.

  18. Silencing of Pokemon enhances caspase-dependent apoptosis via fas- and mitochondria-mediated pathways in hepatocellular carcinoma cells.

    Science.gov (United States)

    Zhang, Yu-Qin; Xiao, Chuan-Xing; Lin, Bi-Yun; Shi, Ying; Liu, Yun-Peng; Liu, Jing-Jing; Guleng, Bayasi; Ren, Jian-Lin

    2013-01-01

    The role of Pokemon (POK erythroid myeloid ontogenic actor), a recently identified POK transcription factor with proto-oncogenic activity, in hepatocellular carcinogenesis has only been assessed by a few studies. Our previous study revealed that Pokemon is overexpressed in hepatocellular carcinomas (HCC) and promotes HCC cell proliferation and migration via an AKT- and ERK- dependent manner. In the present study, we used the TUNEL assay and FACS analysis to demonstrate that oxaliplatin induced apoptosis was significantly increased in cells with silenced Pokemon. Western blots showed that p53 expression and phosphorylation were significantly increased in Pokemon defective cells, thereby initiating the mitochondria-mediated and death receptor-mediated apoptotic pathways. In the mitochondria-mediated pathway, expression of pro-apoptotic Bcl-2 family members (including Bad, Bid, Bim and Puma) as well as AIF was increased and decreasing the mitochondrial membrane potential resulted in cytochrome C released from mitochondrial in HepG2 si-Pokemon cells. In addition, upon oxaliplatin treatment of Pokemon-silenced cells, the FAS receptor, FADD and their downstream targets caspase-10 and caspase-8 were activated, causing increased release of caspase-8 active fragments p18 and p10. Increased activated caspase-8-mediated cleavage and activation of downstream effector caspases such as caspase-9 and caspase-3 was observed in HepG2 si-Pokemon cells as compared to control. Therefore, Pokemon might serve as an important mediator of crosstalk between intrinsic and extrinsic apoptotic pathways in HCC cells. Moreover, our findings suggest that Pokemon could be an attractive therapeutic target gene for human cancer therapy.

  19. Silencing of Pokemon enhances caspase-dependent apoptosis via fas- and mitochondria-mediated pathways in hepatocellular carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Yu-Qin Zhang

    Full Text Available The role of Pokemon (POK erythroid myeloid ontogenic actor, a recently identified POK transcription factor with proto-oncogenic activity, in hepatocellular carcinogenesis has only been assessed by a few studies. Our previous study revealed that Pokemon is overexpressed in hepatocellular carcinomas (HCC and promotes HCC cell proliferation and migration via an AKT- and ERK- dependent manner. In the present study, we used the TUNEL assay and FACS analysis to demonstrate that oxaliplatin induced apoptosis was significantly increased in cells with silenced Pokemon. Western blots showed that p53 expression and phosphorylation were significantly increased in Pokemon defective cells, thereby initiating the mitochondria-mediated and death receptor-mediated apoptotic pathways. In the mitochondria-mediated pathway, expression of pro-apoptotic Bcl-2 family members (including Bad, Bid, Bim and Puma as well as AIF was increased and decreasing the mitochondrial membrane potential resulted in cytochrome C released from mitochondrial in HepG2 si-Pokemon cells. In addition, upon oxaliplatin treatment of Pokemon-silenced cells, the FAS receptor, FADD and their downstream targets caspase-10 and caspase-8 were activated, causing increased release of caspase-8 active fragments p18 and p10. Increased activated caspase-8-mediated cleavage and activation of downstream effector caspases such as caspase-9 and caspase-3 was observed in HepG2 si-Pokemon cells as compared to control. Therefore, Pokemon might serve as an important mediator of crosstalk between intrinsic and extrinsic apoptotic pathways in HCC cells. Moreover, our findings suggest that Pokemon could be an attractive therapeutic target gene for human cancer therapy.

  20. Downregulation of β1,4-galactosyltransferase 1 inhibits CDK11p58-mediated apoptosis induced by cycloheximide

    International Nuclear Information System (INIS)

    Li Zejuan; Wang Hanzhou; Zong Hongliang; Sun Qing; Kong Xiangfei; Jiang Jianhai; Gu Jianxin

    2005-01-01

    Cyclin-dependent kinase 11 (CDK11; also named PITSLRE) is part of the large family of p34 cdc2 -related kinases whose functions appear to be linked with cell cycle progression, tumorigenesis, and apoptotic signaling. The mechanism that CDK11 p58 induces apoptosis is not clear. Some evidences suggested β1,4-galactosyltransferase 1 (β1,4-GT 1) might participate in apoptosis induced by CDK11 p58 . In this study, we demonstrated that ectopically expressed β1,4-GT 1 increased CDK11 p58 -mediated apoptosis induced by cycloheximide (CHX). In contrast, RNAi-mediated knockdown of β1,4-GT 1 effectively inhibited apoptosis induced by CHX in CDK11 p58 -overexpressing cells. For example, the cell morphological and nuclear changes were reduced; the loss of cell viability was prevented and the number of cells in sub-G1 phase was decreased. Knock down of β1,4-GT 1 also inhibited the release of cytochrome c from mitochondria and caspase-3 processing. Therefore, the cleavage of CDK11 p58 by caspase-3 was reduced. We proposed that β1,4-GT 1 might contribute to the pro-apoptotic effect of CDK11 p58 . This may represent a new mechanism of β1,4-GT 1 in CHX-induced apoptosis of CDK11 p58 -overexpressing cells

  1. Plant cyclopeptide RA-V kills human breast cancer cells by inducing mitochondria-mediated apoptosis through blocking PDK1–AKT interaction

    International Nuclear Information System (INIS)

    Fang, Xian-Ying; Chen, Wei; Fan, Jun-Ting; Song, Ran; Wang, Lu; Gu, Yan-Hong; Zeng, Guang-Zhi; Shen, Yan; Wu, Xue-Feng; Tan, Ning-Hua; Xu, Qiang; Sun, Yang

    2013-01-01

    In the present paper, we examined the effects of a natural cyclopeptide RA-V on human breast cancer cells and the underlying mechanisms. RA-V significantly inhibited the growth of human breast cancer MCF-7, MDA-MB-231 cells and murine breast cancer 4T1 cells. In addition, RA-V triggered mitochondrial apoptotic pathway which was indicated by the loss of mitochondrial membrane potential, the release of cytochrome c, and the activation of caspase cascade. Further study showed that RA-V dramatically inhibited phosphorylation of AKT and 3-phosphoinositide dependent protein kinase 1 (PDK1) in MCF-7 cells. Moreover, RA-V disrupted the interaction between PDK1 and AKT in MCF-7 cells. Furthermore, RA-V-induced apoptosis could be enhanced by phosphatidylinositol 3-kinase inhibitor or attenuated by over-expression of AKT in all the three kinds of breast cancer cells. Taken together, this study shows that RA-V, which can induce mitochondria-mediated apoptosis, exerts strong anti-tumor activity against human breast cancer. The underlying anti-cancer mechanism of RA-V is related to the blockage of the interaction between PDK1 and AKT. - Highlights: ► Plant cyclopeptide RA-V kills human breast cancer cells. ► RA-V triggered mitochondrial apoptotic pathway in human breast cancer cells. ► RA-V inhibited phosphorylation of AKT and PDK1 in breast cancer MCF-7 cells. ► Its mechanism is related to the blockage of the interaction between PDK1 and AKT

  2. Plant cyclopeptide RA-V kills human breast cancer cells by inducing mitochondria-mediated apoptosis through blocking PDK1–AKT interaction

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Xian-Ying; Chen, Wei [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Han Kou Road, Nanjing (China); Fan, Jun-Ting [State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming (China); Song, Ran; Wang, Lu [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Han Kou Road, Nanjing (China); Gu, Yan-Hong [Department of Clinical Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing (China); Zeng, Guang-Zhi [State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming (China); Shen, Yan; Wu, Xue-Feng [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Han Kou Road, Nanjing (China); Tan, Ning-Hua, E-mail: nhtan@mail.kib.ac.cn [State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming (China); Xu, Qiang, E-mail: molpharm@163.com [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Han Kou Road, Nanjing (China); Sun, Yang, E-mail: yangsun@nju.edu.cn [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Han Kou Road, Nanjing (China)

    2013-02-15

    In the present paper, we examined the effects of a natural cyclopeptide RA-V on human breast cancer cells and the underlying mechanisms. RA-V significantly inhibited the growth of human breast cancer MCF-7, MDA-MB-231 cells and murine breast cancer 4T1 cells. In addition, RA-V triggered mitochondrial apoptotic pathway which was indicated by the loss of mitochondrial membrane potential, the release of cytochrome c, and the activation of caspase cascade. Further study showed that RA-V dramatically inhibited phosphorylation of AKT and 3-phosphoinositide dependent protein kinase 1 (PDK1) in MCF-7 cells. Moreover, RA-V disrupted the interaction between PDK1 and AKT in MCF-7 cells. Furthermore, RA-V-induced apoptosis could be enhanced by phosphatidylinositol 3-kinase inhibitor or attenuated by over-expression of AKT in all the three kinds of breast cancer cells. Taken together, this study shows that RA-V, which can induce mitochondria-mediated apoptosis, exerts strong anti-tumor activity against human breast cancer. The underlying anti-cancer mechanism of RA-V is related to the blockage of the interaction between PDK1 and AKT. - Highlights: ► Plant cyclopeptide RA-V kills human breast cancer cells. ► RA-V triggered mitochondrial apoptotic pathway in human breast cancer cells. ► RA-V inhibited phosphorylation of AKT and PDK1 in breast cancer MCF-7 cells. ► Its mechanism is related to the blockage of the interaction between PDK1 and AKT.

  3. Mitochondria in neutrophil apoptosis

    NARCIS (Netherlands)

    van Raam, B. J.; Verhoeven, A. J.; Kuijpers, T. W.

    2006-01-01

    Central in the regulation of the short life span of neutrophils are their mitochondria. These organelles hardly contribute to the energy status of neutrophils but play a vital role in the apoptotic process. Not only do the mitochondria contain cytotoxic proteins that are released during apoptosis

  4. Hyperthermia-enhanced TRAIL- and mapatumumab-induced apoptotic death is mediated through mitochondria in human colon cancer cells.

    Science.gov (United States)

    Song, Xinxin; Kim, Han-Cheon; Kim, Seog-Young; Basse, Per; Park, Bae-Hang; Lee, Byeong-Chel; Lee, Yong J

    2012-05-01

    Colorectal cancer is the third leading cause of cancer-related mortality in the world; death usually results from uncontrolled metastatic disease. Previously, we developed a novel strategy of TNF-related apoptosis-inducing ligand (Apo2L/TRAIL) in combination with hyperthermia to treat hepatic colorectal metastases. However, previous studies suggest a potential hepatocyte cytotoxicity with TRAIL. Unlike TRAIL, anti-human TRAIL receptor antibody induces apoptosis without hepatocyte toxicity. In this study, we evaluated the anti-tumor efficacy of humanized anti-death receptor 4 (DR4) antibody mapatumumab (Mapa) by comparing it with TRAIL in combination with hyperthermia. TRAIL, which binds to both DR4 and death receptor 5 (DR5), was approximately tenfold more effective than Mapa in inducing apoptosis. However, hyperthermia enhances apoptosis induced by either agent. We observed that the synergistic effect was mediated through elevation of reactive oxygen species, c-Jun N-terminal kinase activation, Bax oligomerization, and translocalization to the mitochondria, loss of mitochondrial membrane potential, release of cytochrome c to cytosol, activation of caspases, and increase in poly(ADP-ribose) polymerase cleavage. We believe that the successful outcome of this study will support the application of Mapa in combination with hyperthermia to colorectal hepatic metastases. Copyright © 2011 Wiley Periodicals, Inc.

  5. Lack of TXNIP protects against mitochondria-mediated apoptosis but not against fatty acid-induced ER stress-mediated beta-cell death.

    Science.gov (United States)

    Chen, Junqin; Fontes, Ghislaine; Saxena, Geetu; Poitout, Vincent; Shalev, Anath

    2010-02-01

    We have previously shown that lack of thioredoxin-interacting protein (TXNIP) protects against diabetes and glucotoxicity-induced beta-cell apoptosis. Because the role of TXNIP in lipotoxicity is unknown, the goal of the present study was to determine whether TXNIP expression is regulated by fatty acids and whether TXNIP deficiency also protects beta-cells against lipoapoptosis. RESARCH DESIGN AND METHODS: To determine the effects of fatty acids on beta-cell TXNIP expression, INS-1 cells and isolated islets were incubated with/without palmitate and rats underwent cyclic infusions of glucose and/or Intralipid prior to islet isolation and analysis by quantitative real-time RT-PCR and immunoblotting. Using primary wild-type and TXNIP-deficient islets, we then assessed the effects of palmitate on apoptosis (transferase-mediated dUTP nick-end labeling [TUNEL]), mitochondrial death pathway (cytochrome c release), and endoplasmic reticulum (ER) stress (binding protein [BiP], C/EBP homologous protein [CHOP]). Effects of TXNIP deficiency were also tested in the context of staurosporine (mitochondrial damage) or thapsigargin (ER stress). Glucose elicited a dramatic increase in islet TXNIP expression both in vitro and in vivo, whereas fatty acids had no such effect and, when combined with glucose, even abolished the glucose effect. We also found that TXNIP deficiency does not effectively protect against palmitate or thapsigargin-induced beta-cell apoptosis, but specifically prevents staurosporine- or glucose-induced toxicity. Our results demonstrate that unlike glucose, fatty acids do not induce beta-cell expression of proapoptotic TXNIP. They further reveal that TXNIP deficiency specifically inhibits the mitochondrial death pathway underlying beta-cell glucotoxicity, whereas it has very few protective effects against ER stress-mediated lipoapoptosis.

  6. Bovine lactoferricin causes apoptosis in Jurkat T-leukemia cells by sequential permeabilization of the cell membrane and targeting of mitochondria

    International Nuclear Information System (INIS)

    Mader, Jamie S.; Richardson, Angela; Salsman, Jayme; Top, Deniz; Antueno, Roberto de; Duncan, Roy; Hoskin, David W.

    2007-01-01

    Bovine lactoferricin (LfcinB) is a cationic antimicrobial peptide that kills Jurkat T-leukemia cells by the mitochondrial pathway of apoptosis. However, the process by which LfcinB triggers mitochondria-dependent apoptosis is not well understood. Here, we show that LfcinB-induced apoptosis in Jurkat T-leukemia cells was preceded by LfcinB binding to, and progressive permeabilization of the cell membrane. Colloidal gold electron microscopy revealed that LfcinB entered the cytoplasm of Jurkat T-leukemia cells prior to the onset of mitochondrial depolarization. LfcinB was not internalized by endocytosis because endocytosis inhibitors did not prevent LfcinB-induced cytotoxicity. Furthermore, intracellular delivery of LfcinB via fusogenic liposomes caused the death of Jurkat T-leukemia cells, as well as normal human fibroblasts. Collectively, these findings suggest that LfcinB caused damage to the cell membrane that allowed LfcinB to enter the cytoplasm of Jurkat T-leukemia cells and mediate cytotoxicity. In addition, confocal microscopy showed that intracellular LfcinB co-localized with mitochondria in Jurkat T-leukemia cells, while flow cytometry and colloidal gold electron microscopy showed that LfcinB rapidly associated with purified mitochondria. Furthermore, purified mitochondria treated with LfcinB rapidly lost transmembrane potential and released cytochrome c. We conclude that LfcinB-induced apoptosis in Jurkat T-leukemia cells resulted from cell membrane damage and the subsequent disruption of mitochondrial membranes by internalized LfcinB

  7. Apoptosis-inducing factor (Aif1) mediates anacardic acid-induced apoptosis in Saccharomyces cerevisiae.

    Science.gov (United States)

    Muzaffar, Suhail; Chattoo, Bharat B

    2017-03-01

    Anacardic acid is a medicinal phytochemical that inhibits proliferation of fungal as well as several types of cancer cells. It induces apoptotic cell death in various cell types, but very little is known about the mechanism involved in the process. Here, we used budding yeast Saccharomyces cerevisiae as a model to study the involvement of some key elements of apoptosis in the anacardic acid-induced cell death. Plasma membrane constriction, chromatin condensation, DNA degradation, and externalization of phosphatidylserine (PS) indicated that anacardic acid induces apoptotic cell death in S. cerevisiae. However, the exogenous addition of broad-spectrum caspase inhibitor Z-VAD-FMK or deletion of the yeast caspase Yca1 showed that the anacardic acid-induced cell death is caspase independent. Apoptosis-inducing factor (AIF1) deletion mutant was resistant to the anacardic acid-induced cell death, suggesting a key role of Aif1. Overexpression of Aif1 made cells highly susceptible to anacardic acid, further confirming that Aif1 mediates anacardic acid-induced apoptosis. Interestingly, instead of the increase in the intracellular reactive oxygen species (ROS) normally observed during apoptosis, anacardic acid caused a decrease in the intracellular ROS levels. Quantitative real-time PCR analysis showed downregulation of the BIR1 survivin mRNA expression during the anacardic acid-induced apoptosis.

  8. Piroxicam and C-phycocyanin mediated apoptosis in 1,2-dimethylhydrazine dihydrochloride induced colon carcinogenesis: exploring the mitochondrial pathway.

    Science.gov (United States)

    Saini, Manpreet Kaur; Sanyal, Sankar Nath; Vaiphei, Kim

    2012-04-01

    Apoptosis is a synchronized procedure of cell death that is regulated by caspases and proapoptotic proteins. During apoptosis, translocation of cytochrome c, an electron carrier, from mitochondria into the cytosol is regulated by Bcl-2 family members. Cytochrome c in association with an apoptotic protease activating factor (Apaf), a proapoptotic protein essential for cell differentiation and procaspase-9 form the apoptosome complex, which consecutively activates effector caspase, caspase-3, and coordinate the implementation of apoptosis. In the current study, an attempt has been made to gain insight into piroxicam, a traditional nonsteroidal antiinflammatory drug and c-phycocyanin, a biliprotein from Spirulina platensis (cyanobacterium) mediated apoptosis in DMH-induced colon cancer. Male Sprague-Dawley rats were segregated into 5 groups: control, DMH, DMH + piroxicam, DMH + c-phycocyanin, and DMH + piroxicam + c-phycocyanin. Results illustrated that piroxicam and c-phycocyanin treatments stimulate cytochrome c release by downregulating the Bcl-2 (an antiapoptotic protein) expression significantly, while promoting the level of Bax (a proapoptotic protein), thereby activating caspases (caspases-9 and -3) and Apaf-1. The outcomes of the present study clearly signify that piroxicam and c-phycocyanin may mediate mitochondrial-dependent apoptosis in DMH-induced colon cancer. Moreover, apoptosis induction was more apparent in the combination regimen of piroxicam and c-phycocyanin than the individual drugs alone.

  9. Fucoidan extract induces apoptosis in MCF-7 cells via a mechanism involving the ROS-dependent JNK activation and mitochondria-mediated pathways.

    Directory of Open Access Journals (Sweden)

    Zhongyuan Zhang

    Full Text Available BACKGROUND: Fucoidan extract (FE, an enzymatically digested compound with a low molecular weight, is extracted from brown seaweed. As a natural compound with various actions, FE is attractive, especially in Asian countries, for improving the therapeutic efficacy and safety of cancer treatment. The present study was carried out to investigate the anti-tumor properties of FE in human carcinoma cells and further examine the underlying mechanisms of its activities. METHODOLOGY/PRINCIPAL FINDING: FE inhibits the growth of MCF-7, MDA-MB-231, HeLa, and HT1080 cells. FE-mediated apoptosis in MCF-7 cancer cells is accompanied by DNA fragmentation, nuclear condensation, and phosphatidylserine exposure. FE induces mitochondrial membrane permeabilization (MMP through loss of mitochondrial membrane potential (ΔΨm and regulation of the expression of Bcl-2 family members. Release of apoptosis-inducing factor (AIF and cytochrome c precedes MMP. AIF release causes DNA fragmentation, the final stage of apoptosis, via a caspase-independent mitochondrial pathway. Additionally, FE was found to induce phosphorylation of c-Jun N-terminal kinase (JNK, p38, and extracellular signal-regulated kinase (ERK 1/2, and apoptosis was found to be attenuated by inhibition of JNK. Furthermore, FE-mediated apoptosis was found to involve the generation of reactive oxygen species (ROS, which are responsible for the decrease of ΔΨm and phosphorylation of JNK, p38, and ERK1/2 kinases. CONCLUSIONS/SIGNIFICANCE: These data suggest that FE activates a caspase-independent apoptotic pathway in MCF-7 cancer cells through activation of ROS-mediated MAP kinases and regulation of the Bcl-2 family protein-mediated mitochondrial pathway. They also provide evidence that FE deserves further investigation as a natural anticancer and cancer preventive agent.

  10. Chk2 mediates RITA-induced apoptosis.

    Science.gov (United States)

    de Lange, J; Verlaan-de Vries, M; Teunisse, A F A S; Jochemsen, A G

    2012-06-01

    Reactivation of the p53 tumor-suppressor protein by small molecules like Nutlin-3 and RITA (reactivation of p53 and induction of tumor cell apoptosis) is a promising strategy for cancer therapy. The molecular mechanisms involved in the responses to RITA remain enigmatic. Several groups reported the induction of a p53-dependent DNA damage response. Furthermore, the existence of a p53-dependent S-phase checkpoint has been suggested, involving the checkpoint kinase Chk1. We have recently shown synergistic induction of apoptosis by RITA in combination with Nutlin-3, and we observed concomitant Chk2 phosphorylation. Therefore, we investigated whether Chk2 contributes to the cellular responses to RITA. Strikingly, the induction of apoptosis seemed entirely Chk2 dependent. Transcriptional activity of p53 in response to RITA required the presence of Chk2. A partial rescue of apoptosis observed in Noxa knockdown cells emphasized the relevance of p53 transcriptional activity for RITA-induced apoptosis. In addition, we observed an early p53- and Chk2-dependent block of DNA replication upon RITA treatment. Replicating cells seemed more prone to entering RITA-induced apoptosis. Furthermore, the RITA-induced DNA damage response, which was not a secondary effect of apoptosis induction, was strongly attenuated in cells lacking p53 or Chk2. In conclusion, we identified Chk2 as an essential mediator of the cellular responses to RITA.

  11. Acrolein-induced cell death in PC12 cells: role of mitochondria-mediated oxidative stress.

    Science.gov (United States)

    Luo, Jian; Robinson, J Paul; Shi, Riyi

    2005-12-01

    Oxidative stress has been implicated in acrolein cytotoxicity in various cell types, including mammalian spinal cord tissue. In this study we report that acrolein also decreases PC12 cell viability in a reactive oxygen species (ROS)-dependent manner. Specifically, acrolein-induced cell death, mainly necrosis, is accompanied by the accumulation of cellular ROS. Elevating ROS scavengers can alleviate acrolein-induced cell death. Furthermore, we show that exposure to acrolein leads to mitochondrial dysfunction, denoted by the loss of mitochondrial transmembrane potential, reduction of cellular oxygen consumption, and decrease of ATP level. This raises the possibility that the cellular accumulation of ROS could result from the increased production of ROS in the mitochondria of PC12 cells as a result of exposure to acrolein. The acrolein-induced significant decrease of ATP production in mitochondria may also explain why necrosis, not apoptosis, is the dominant type of cell death. In conclusion, our data suggest that one possible mechanism of acrolein-induced cell death could be through mitochondria as its initial target. The subsequent increase of ROS then inflicts cell death and further worsens mitochondria function. Such mechanism may play an important role in CNS trauma and neurodegenerative diseases.

  12. Lack of HXK2 Induces Localization of Active Ras in Mitochondria and Triggers Apoptosis in the Yeast Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Loredana Amigoni

    2013-01-01

    Full Text Available We recently showed that activated Ras proteins are localized to the plasma membrane and in the nucleus in wild-type cells growing exponentially on glucose, while in the hxk2Δ strain they accumulated mainly in mitochondria. An aberrant accumulation of activated Ras in these organelles was previously reported and correlated to mitochondrial dysfunction, accumulation of ROS, and cell death. Here we show that addition of acetic acid to wild-type cells results in a rapid recruitment of Ras-GTP from the nucleus and the plasma membrane to the mitochondria, providing a further proof that Ras proteins might be involved in programmed cell death. Moreover, we show that Hxk2 protects against apoptosis in S. cerevisiae. In particular, cells lacking HXK2 and showing a constitutive accumulation of activated Ras at the mitochondria are more sensitive to acetic-acid-induced programmed cell death compared to the wild type strain. Indeed, deletion of HXK2 causes an increase of apoptotic cells with several morphological and biochemical changes that are typical of apoptosis, including DNA fragmentation, externalization of phosphatidylserine, and ROS production. Finally, our results suggest that apoptosis induced by lack of Hxk2 may not require the activation of Yca1, the metacaspase homologue identified in yeast.

  13. Lack of HXK2 induces localization of active Ras in mitochondria and triggers apoptosis in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Amigoni, Loredana; Martegani, Enzo; Colombo, Sonia

    2013-01-01

    We recently showed that activated Ras proteins are localized to the plasma membrane and in the nucleus in wild-type cells growing exponentially on glucose, while in the hxk2Δ strain they accumulated mainly in mitochondria. An aberrant accumulation of activated Ras in these organelles was previously reported and correlated to mitochondrial dysfunction, accumulation of ROS, and cell death. Here we show that addition of acetic acid to wild-type cells results in a rapid recruitment of Ras-GTP from the nucleus and the plasma membrane to the mitochondria, providing a further proof that Ras proteins might be involved in programmed cell death. Moreover, we show that Hxk2 protects against apoptosis in S. cerevisiae. In particular, cells lacking HXK2 and showing a constitutive accumulation of activated Ras at the mitochondria are more sensitive to acetic-acid-induced programmed cell death compared to the wild type strain. Indeed, deletion of HXK2 causes an increase of apoptotic cells with several morphological and biochemical changes that are typical of apoptosis, including DNA fragmentation, externalization of phosphatidylserine, and ROS production. Finally, our results suggest that apoptosis induced by lack of Hxk2 may not require the activation of Yca1, the metacaspase homologue identified in yeast.

  14. Ginsenoside Rb1 Attenuates Oxygen-Glucose Deprivation-Induced Apoptosis in SH-SY5Y Cells via Protection of Mitochondria and Inhibition of AIF and Cytochrome c Release

    Directory of Open Access Journals (Sweden)

    Pengfei Ge

    2013-10-01

    Full Text Available To investigate the role of mitochondria in the protective effects of ginsenoside Rb1 on cellular apoptosis caused by oxygen-glucose deprivation, in this study, MTT assay, TUNEL staining, flow cytometry, immunocytochemistry and western blotting were used to examine the cellular viability, apoptosis, ROS level, mitochondrial membrane potential, and the distribution of apoptosis inducing factor, cytochrome c, Bax and Bcl-2 in nucleus, mitochondria and cytoplasm. We found that pretreatment with GRb1 improved the cellular viability damaged by OGD. Moreover, GRb1 inhibited apoptosis in SH-SY5Y cells induced by OGD. Further studies showed that the elevation of cellular reactive oxygen species levels and the reduction of mitochondrial membrane potential caused by OGD were both counteracted by GRb1. Additionally, GRb1 not only suppressed the translocation of apoptosis inducing factor into nucleus and cytochrome c into cytoplasm, but also inhibited the increase of Bax within mitochondria and alleviated the decrease of mitochondrial Bcl-2. Our study indicates that the protection of GRb1 on OGD-induced apoptosis in SH-SY5Y cells is associated with its protection on mitochondrial function and inhibition of release of AIF and cytochrome c.

  15. Neuroprotective Effect of Ginkgolide B on Bupivacaine-Induced Apoptosis in SH-SY5Y Cells

    Science.gov (United States)

    Li, Le; Zhang, Qing-guo; Lai, Lu-ying; Wen, Xian-jie; Zheng, Ting; Cheung, Chi-wai; Zhou, Shu-qin; Xu, Shi-yuan

    2013-01-01

    Local anesthetics are used routinely and effectively. However, many are also known to activate neurotoxic pathways. We tested the neuroprotective efficacy of ginkgolide B (GB), an active component of Ginkgo biloba, against ROS-mediated neurotoxicity caused by the local anesthetic bupivacaine. SH-SY5Y cells were treated with different concentrations of bupivacaine alone or following preincubation with GB. Pretreatment with GB increased SH-SY5Y cell viability and attenuated intracellular ROS accumulation, apoptosis, mitochondrial dysfunction, and ER stress. GB suppressed bupivacaine-induced mitochondrial depolarization and mitochondria complex I and III inhibition and increased cleaved caspase-3 and Htra2 expression, which was strongly indicative of activation of mitochondria-dependent apoptosis with concomitantly enhanced expressions of Grp78, caspase-12 mRNA, protein, and ER stress. GB also improved ultrastructural changes indicative of mitochondrial and ER damage induced by bupivacaine. These results implicate bupivacaine-induced ROS-dependent mitochondria, ER dysfunction, and apoptosis, which can be attenuated by GB through its antioxidant property. PMID:24228138

  16. Calcium plays a key role in paraoxon-induced apoptosis in EL4 cells by regulating both endoplasmic reticulum- and mitochondria-associated pathways.

    Science.gov (United States)

    Li, Lan; Du, Yi; Ju, Furong; Ma, Shunxiang; Zhang, Shengxiang

    2016-01-01

    Paraoxon (POX) is one of the most toxic organophosphorus pesticides, but its toxic mechanisms associated with apoptosis remain unclear. The aim of this study was to investigate calcium-associated mechanisms in POX-induced apoptosis in EL4 cells. EL4 cells were exposed to POX for 0-16 h. EGTA was used to chelate Ca(2+ ) in extracellular medium, and heparin and procaine were used to inhibit Ca(2+ )efflux from the endoplasmic reticulum (ER). Z-ATAD-FMK was used to inhibit caspase-12 activity. The apoptotic rate assay, western blotting and immunocytochemistry (ICC) were used to reveal the mechanisms of POX-induced apoptosis. POX significantly increased the expression and activation of caspase-12 and caspase-3, enhanced expression of calpain 1 and calpain 2, and induced the release of cyt c, but did not change the expression of Grp 78. Inhibiting caspase-12 activity alleviated POX-induced upregulation of calpain 1 and caspase-3, promoted POX-induced upregulation of calpain 2, and reduced POX-induced cyt c release, suggesting that there was a cross-talk between the ER-associated pathway and mitochondria-associated apoptotic signals. Attenuating intracellular calcium concentration with EGTA, heparin or procaine decreased POX-induced upregulation of calpain 1, calpain 2, caspase-12 and caspase-3, and reduced POX-induced cyt c release. After pretreatment with EGTA or procaine, POX significantly promoted expression of Grp 78. Calcium played a key role in POX-induced apoptosis in EL4 cells by regulating both ER- and mitochondria-associated pathways. The cross-talk of ER- and mitochondria-associated pathways was accomplished through calcium signal.

  17. Chk2 regulates transcription-independent p53-mediated apoptosis in response to DNA damage

    International Nuclear Information System (INIS)

    Chen Chen; Shimizu, Shigeomi; Tsujimoto, Yoshihide; Motoyama, Noboru

    2005-01-01

    The tumor suppressor protein p53 plays a central role in the induction of apoptosis in response to genotoxic stress. The protein kinase Chk2 is an important regulator of p53 function in mammalian cells exposed to ionizing radiation (IR). Cells derived from Chk2-deficient mice are resistant to the induction of apoptosis by IR, and this resistance has been thought to be a result of the defective transcriptional activation of p53 target genes. It was recently shown, however, that p53 itself and histone H1.2 translocate to mitochondria and thereby induces apoptosis in a transcription-independent manner in response to IR. We have now examined whether Chk2 also regulates the transcription-independent induction of apoptosis by p53 and histone H1.2. The reduced ability of IR to induce p53 stabilization in Chk2-deficient thymocytes was associated with a marked impairment of p53 and histone H1 translocation to mitochondria. These results suggest that Chk2 regulates the transcription-independent mechanism of p53-mediated apoptosis by inducing stabilization of p53 in response to IR

  18. Naringin prevents ovariectomy-induced osteoporosis and promotes osteoclasts apoptosis through the mitochondria-mediated apoptosis pathway

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fengbo [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China); Graduate School of Tianjin Medical University, No. 22, Qixiangtai Street, Heping District, Tianjin 300070 (China); Sun, Xiaolei; Ma, Jianxiong [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China); Ma, Xinlong, E-mail: gengxiao502@163.com [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China); Zhao, Bin; Zhang, Yang; Tian, Peng [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China); Li, Yanjun [Graduate School of Tianjin Medical University, No. 22, Qixiangtai Street, Heping District, Tianjin 300070 (China); Han, Zhe [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin TJ 300050 (China)

    2014-09-26

    Highlights: • Naringin possesses many pharmacological activities, promotes the proliferation of osteoblast. • Undecalcified histological obtain dynamic parameters of callus formation and remodeling. • Naringin regulate osteoclast apoptosis by mitochondrial pathway. - Abstract: Naringin, the primary active compound of the traditional Chinese medicine Rhizoma drynariae, possesses many pharmacological activities. The present study is an effort to explore the anti-osteoporosis potential of naringin in vivo and in vitro. In vivo, we used ovariectomized rats to clarify the mechanisms by which naringin anti-osteoporosis. In vitro, we used osteoclasts to investigate naringin promotes osteoclasts apoptosis. Naringin was effective at enhancing BMD, trabecular thickness, bone mineralization, and mechanical strength in a dose-dependent manner. The result of RT-PCR analysis revealed that naringin down-regulated the mRNA expression levels of BCL-2 and up-regulated BAX, caspase-3 and cytochrome C. In addition, naringin significantly reduced the bone resorption area in vitro. These findings suggest that naringin promotes the apoptosis of osteoclasts by regulating the activity of the mitochondrial apoptosis pathway and prevents OVX-induced osteoporosis in rats.

  19. Naringin prevents ovariectomy-induced osteoporosis and promotes osteoclasts apoptosis through the mitochondria-mediated apoptosis pathway

    International Nuclear Information System (INIS)

    Li, Fengbo; Sun, Xiaolei; Ma, Jianxiong; Ma, Xinlong; Zhao, Bin; Zhang, Yang; Tian, Peng; Li, Yanjun; Han, Zhe

    2014-01-01

    Highlights: • Naringin possesses many pharmacological activities, promotes the proliferation of osteoblast. • Undecalcified histological obtain dynamic parameters of callus formation and remodeling. • Naringin regulate osteoclast apoptosis by mitochondrial pathway. - Abstract: Naringin, the primary active compound of the traditional Chinese medicine Rhizoma drynariae, possesses many pharmacological activities. The present study is an effort to explore the anti-osteoporosis potential of naringin in vivo and in vitro. In vivo, we used ovariectomized rats to clarify the mechanisms by which naringin anti-osteoporosis. In vitro, we used osteoclasts to investigate naringin promotes osteoclasts apoptosis. Naringin was effective at enhancing BMD, trabecular thickness, bone mineralization, and mechanical strength in a dose-dependent manner. The result of RT-PCR analysis revealed that naringin down-regulated the mRNA expression levels of BCL-2 and up-regulated BAX, caspase-3 and cytochrome C. In addition, naringin significantly reduced the bone resorption area in vitro. These findings suggest that naringin promotes the apoptosis of osteoclasts by regulating the activity of the mitochondrial apoptosis pathway and prevents OVX-induced osteoporosis in rats

  20. Dioscin induces caspase-independent apoptosis through activation of apoptosis-inducing factor in breast cancer cells.

    Science.gov (United States)

    Kim, Eun-Ae; Jang, Ji-Hoon; Lee, Yun-Han; Sung, Eon-Gi; Song, In-Hwan; Kim, Joo-Young; Kim, Suji; Sohn, Ho-Yong; Lee, Tae-Jin

    2014-07-01

    Dioscin, a saponin extracted from the roots of Polygonatum zanlanscianense, shows several bioactivities such as antitumor, antifungal, and antiviral properties. Although, dioscin is already known to induce cell death in variety cancer cells, the molecular basis for dioscin-induced cell death was not definitely known in cancer cells. In this study, we found that dioscin treatment induced cell death in dose-dependent manner in breast cancer cells such as MDA-MB-231, MDA-MB-453, and T47D cells. Dioscin decreased expressions of Bcl-2 and cIAP-1 proteins, which were down-regulated at the transcriptional level. Conversely, Mcl-1 protein level was down-regulated by facilitating ubiquitin/proteasome-mediated Mcl-1 degradation in dioscin-treated cells. Pretreatment with z-VAD fails to attenuate dioscin-induced cell death as well as caspase-mediated events such as cleavages of procaspase-3 and PARP. In addition, dioscin treatment increased the population of annexin V positive cells and induced DNA fragmentation in a dose-dependent manner in MDA-MB-231 cells. Furthermore, apoptosis inducing factor (AIF) was released from the mitochondria and translocated to the nucleus. Suppression in AIF expression by siRNA reduced dioscin-induced apoptosis in MDA-MB-231 cells. Taken together, our results demonstrate that dioscin-induced cell death was mediated via AIF-facilitating caspase-independent pathway as well as down-regulating anti-apoptotic proteins such as Bcl-2, cIAP-1, and Mcl-1 in breast cancer cells.

  1. Noscapine induces mitochondria-mediated apoptosis in human colon cancer cells in vivo and in vitro

    International Nuclear Information System (INIS)

    Yang, Zi-Rong; Liu, Meng; Peng, Xiu-Lan; Lei, Xiao-Fei; Zhang, Ji-Xiang; Dong, Wei-Guo

    2012-01-01

    Highlights: ► Noscapine inhibited cell viability of colon cancer in a time- and dose- dependent manner. ► G 2 /M phase arrest and chromatin condensation and nuclear fragmentation were induced. ► Noscapine promoted apoptosis via mitochondrial pathways. ► Tumorigenicity was inhibited by noscapine. -- Abstract: Noscapine, a phthalide isoquinoline alkaloid derived from opium, has been widely used as a cough suppressant for decades. Noscapine has recently been shown to potentiate the anti-cancer effects of several therapies by inducing apoptosis in various malignant cells without any detectable toxicity in cells or tissues. However, the mechanism by which noscapine induces apoptosis in colon cancer cells remains unclear. The signaling pathways by which noscapine induces apoptosis were investigated in colon cancer cell lines treated with various noscapine concentrations for 72 h, and a dose-dependent inhibition of cell viability was observed. Noscapine effectively inhibited the proliferation of LoVo cells in vitro (IC 50 = 75 μM). This cytotoxicity was reflected by cell cycle arrest at G 2 /M and subsequent apoptosis, as indicated by increased chromatin condensation and fragmentation, the upregulation of Bax and cytochrome c (Cyt-c), the downregulation of survivin and Bcl-2, and the activation of caspase-3 and caspase-9. Moreover, in a xenograft tumor model in mice, noscapine injection clearly inhibited tumor growth via the induction of apoptosis, which was demonstrated using a TUNEL assay. These results suggest that noscapine induces apoptosis in colon cancer cells via mitochondrial pathways. Noscapine may be a safe and effective chemotherapeutic agent for the treatment of human colon cancer.

  2. Metallic nickel nano- and fine particles induce JB6 cell apoptosis through a caspase-8/AIF mediated cytochrome c-independent pathway

    Directory of Open Access Journals (Sweden)

    Castranova Vincent

    2009-04-01

    induced by metallic nickel particles in JB6 cells is through a caspase-8/AIF mediated cytochrome c-independent pathway. Lamin A and beta-actin are involved in the process of apoptosis. Activation of Akt and Bcl-2 may play an important role in preventing cytochrome c release from mitochondria to the cytoplasm and may also be important in the carcinogenicity of metallic nickel particles. In addition, the results may be useful as an important reference when comparing the toxicities of different nickel compounds.

  3. Noscapine induces mitochondria-mediated apoptosis in human colon cancer cells in vivo and in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zi-Rong; Liu, Meng; Peng, Xiu-Lan; Lei, Xiao-Fei; Zhang, Ji-Xiang [Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province (China); Dong, Wei-Guo, E-mail: dongwg1966@yahoo.com.cn [Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province (China)

    2012-05-11

    Highlights: Black-Right-Pointing-Pointer Noscapine inhibited cell viability of colon cancer in a time- and dose- dependent manner. Black-Right-Pointing-Pointer G{sub 2}/M phase arrest and chromatin condensation and nuclear fragmentation were induced. Black-Right-Pointing-Pointer Noscapine promoted apoptosis via mitochondrial pathways. Black-Right-Pointing-Pointer Tumorigenicity was inhibited by noscapine. -- Abstract: Noscapine, a phthalide isoquinoline alkaloid derived from opium, has been widely used as a cough suppressant for decades. Noscapine has recently been shown to potentiate the anti-cancer effects of several therapies by inducing apoptosis in various malignant cells without any detectable toxicity in cells or tissues. However, the mechanism by which noscapine induces apoptosis in colon cancer cells remains unclear. The signaling pathways by which noscapine induces apoptosis were investigated in colon cancer cell lines treated with various noscapine concentrations for 72 h, and a dose-dependent inhibition of cell viability was observed. Noscapine effectively inhibited the proliferation of LoVo cells in vitro (IC{sub 50} = 75 {mu}M). This cytotoxicity was reflected by cell cycle arrest at G{sub 2}/M and subsequent apoptosis, as indicated by increased chromatin condensation and fragmentation, the upregulation of Bax and cytochrome c (Cyt-c), the downregulation of survivin and Bcl-2, and the activation of caspase-3 and caspase-9. Moreover, in a xenograft tumor model in mice, noscapine injection clearly inhibited tumor growth via the induction of apoptosis, which was demonstrated using a TUNEL assay. These results suggest that noscapine induces apoptosis in colon cancer cells via mitochondrial pathways. Noscapine may be a safe and effective chemotherapeutic agent for the treatment of human colon cancer.

  4. PEGylated anticancer-carbon nanotubes complex targeting mitochondria of lung cancer cells

    Science.gov (United States)

    Kim, Sang-Woo; Lee, Yeon Kyung; Lee, Jong Yeon; Hong, Jeong Hee; Khang, Dongwoo

    2017-11-01

    Although activating apoptosis in cancer cells by targeting the mitochondria is an effective strategy for cancer therapy, insufficient targeting of the mitochondria in cancer cells restricts the availability in clinical treatment. Here, we report on a polyethylene glycol-coated carbon nanotube (CNT)-ABT737 nanodrug that improves the mitochondrial targeting of lung cancer cells. The polyethylene glycol-coated CNT-ABT737 nanodrug internalized into the early endosomes via macropinocytosis and clathrin-mediated endocytosis in advance of early endosomal escape and delivered into the mitochondria. Cytosol release of the nanodrug led to apoptosis of lung cancer cells by abruption of the mitochondrial membrane potential, inducing Bcl-2-mediated apoptosis and generating intracellular reactive oxygen species. As such, this study provides an effective strategy for increasing the anti-lung cancer efficacy by increasing mitochondria accumulation rate of cytosol released anticancer nanodrugs.

  5. Avian reovirus S1133-induced apoptosis is associated with Bip/GRP79-mediated Bim translocation to the endoplasmic reticulum.

    Science.gov (United States)

    Lin, Ping-Yuan; Liu, Hung-Jen; Chang, Ching-Dong; Chen, Yo-Chia; Chang, Chi-I; Shih, Wen-Ling

    2015-04-01

    In this study the mechanism of avian reovirus (ARV) S1133-induced pathogenesis was investigated, with a focus on the contribution of ER stress to apoptosis. Our results showed that upregulation of the ER stress response protein, as well as caspase-3 activation, occurred in ARV S1133-infected cultured cells and in SPF White Leghorn chicks organs. Upon infection, Bim was translocated specifically to the ER, but not mitochondria, in the middle to late infectious stages. In addition, ARV S1133 induced JNK phosphorylation and promoted JNK-Bim complex formation, which correlated with the Bim translocation and apoptosis induction that was observed at the same time point. Knockdown of BiP/GRP78 by siRNA and inhibition of BiP/GRP78 using EGCG both abolished the formation of the JNK-Bim complex, caspase-3 activation, and subsequent apoptosis induction by ARV S1133 efficiently. These results suggest that BiP/GRP78 played critical roles and works upstream of JNK-Bim in response to the ARV S1133-mediated apoptosis process.

  6. Adenosine monophosphate activated protein kinase (AMPK), a mediator of estradiol-induced apoptosis in long-term estrogen deprived breast cancer cells.

    Science.gov (United States)

    Chen, Haiyan; Wang, Ji-Ping; Santen, Richard J; Yue, Wei

    2015-06-01

    Estrogens stimulate growth of hormone-dependent breast cancer but paradoxically induce tumor regress under certain circumstances. We have shown that long-term estrogen deprivation (LTED) enhances the sensitivity of hormone dependent breast cancer cells to estradiol (E2) so that physiological concentrations of estradiol induce apoptosis in these cells. E2-induced apoptosis involve both intrinsic and extrinsic pathways but precise mechanisms remain unclear. We found that exposure of LTED MCF-7 cells to E2 activated AMP activated protein kinase (AMPK). In contrast, E2 inhibited AMPK activation in wild type MCF-7 cells where E2 prevents apoptosis. As a result of AMPK activation, the transcriptional activity of FoxO3, a downstream factor of AMPK, was up-regulated in E2 treatment of LTED. Increased activity of FoxO3 was demonstrated by up-regulation of three FoxO3 target genes, Bim, Fas ligand (FasL), and Gadd45α. Among them, Bim and FasL mediate intrinsic and extrinsic apoptosis respectively and Gadd45α causes cell cycle arrest at the G2/M phase. To further confirm the role of AMPK in apoptosis, we used AMPK activator AICAR in wild type MCF-7 cells and examined apoptosis, proliferation and expression of Bim, FasL, and Gadd45α. The effects of AICAR on these parameters recapitulated those observed in E2-treated LTED cells. Activation of AMPK by AICAR also increased expression of Bax in MCF-7 cells and its localization to mitochondria, which is a required process for apoptosis. These results reveal that AMPK is an important factor mediating E2-induced apoptosis in LTED cells, which is implicative of therapeutic potential for relapsing breast cancer after hormone therapy.

  7. Induction of G2/M arrest and apoptosis through mitochondria pathway by a dimer sesquiterpene lactone from Smallanthus sonchifolius in HeLa cells.

    Science.gov (United States)

    Kitai, Yurika; Zhang, Xia; Hayashida, Yushi; Kakehi, Yoshiyuki; Tamura, Hirotoshi

    2017-07-01

    Dimer sesquiterpene lactones (SLs), uvedafolin and enhydrofolin, against four monomer SLs isolated from yacon, Smallanthus sonchifolius, leaf were the most cytotoxic substances on HeLa cells (IC 50 values 2.96-3.17 μM at 24 hours). However, the cytotoxic mechanism of dimer SL has not been elucidated yet. Therefore, in this study, we clarified the in vitro cytotoxic mechanism of uvedafolin on the HeLa cells, and evaluated the cytotoxicity against NIH/3T3 cells which were used as normal cells. In consequence, the dimer SLs had low toxicity for the NIH/3T3 cells (IC 50 4.81-4.98 μM at 24 hours) and then the uvedafolin mediated cell cycle arrest at the G 2 /M phase and induced apoptosis on the HeLa cells evidenced by appearance of a subG1 peak. Uvedafolin induced apoptosis was attributed to caspase-9 and caspase-3/7 activities. An effectively induced apoptosis pathway was demonstrated from mitochondria membrane potential change and cytochrome c release to cytosol. These results reveal that uvedafolin induced apoptosis via the mitochondria pathway. The present results indicate the potential of uvedafolin as a leading compound of new anticancer agents. Copyright © 2016. Published by Elsevier B.V.

  8. Mycobacterium avium MAV2052 protein induces apoptosis in murine macrophage cells through Toll-like receptor 4.

    Science.gov (United States)

    Lee, Kang-In; Choi, Han-Gyu; Son, Yeo-Jin; Whang, Jake; Kim, Kwangwook; Jeon, Heat Sal; Park, Hye-Soo; Back, Yong Woo; Choi, Seunga; Kim, Seong-Woo; Choi, Chul Hee; Kim, Hwa-Jung

    2016-04-01

    Mycobacterium avium and its sonic extracts induce apoptosis in macrophages. However, little is known about the M. avium components regulating macrophage apoptosis. In this study, using multidimensional fractionation, we identified MAV2052 protein, which induced macrophage apoptosis in M. avium culture filtrates. The recombinant MAV2052 induced macrophage apoptosis in a caspase-dependent manner. The loss of mitochondrial transmembrane potential (ΔΨm), mitochondrial translocation of Bax, and release of cytochrome c from mitochondria were observed in macrophages treated with MAV2052. Further, reactive oxygen species (ROS) production was required for the apoptosis induced by MAV2052. In addition, ROS and mitogen-activated protein kinases were involved in MAV2052-mediated TNF-α and IL-6 production. ROS-mediated activation of apoptosis signal-regulating kinase 1 (ASK1)-JNK pathway was a major signaling pathway for MAV2052-induced apoptosis. Moreover, MAV2052 bound to Toll-like receptor (TLR) 4 molecule and MAV2052-induced ROS production, ΔΨm loss, and apoptosis were all significantly reduced in TLR4(-/-) macrophages. Altogether, our results suggest that MAV2052 induces apoptotic cell death through TLR4 dependent ROS production and JNK pathway in murine macrophages.

  9. Reactive oxygen species regulated mitochondria-mediated apoptosis in PC12 cells exposed to chlorpyrifos

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    Lee, Jeong Eun [Department of Pharmacology, College of Medicine, Hanyang University, Seoul (Korea, Republic of); Hanyang Biomedical Research Institute, Seoul (Korea, Republic of); Park, Jae Hyeon [Hanyang Biomedical Research Institute, Seoul (Korea, Republic of); Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul (Korea, Republic of); Shin, In Chul [Department of Pharmacology, College of Medicine, Hanyang University, Seoul (Korea, Republic of); Koh, Hyun Chul, E-mail: hckoh@hanyang.ac.kr [Department of Pharmacology, College of Medicine, Hanyang University, Seoul (Korea, Republic of); Hanyang Biomedical Research Institute, Seoul (Korea, Republic of); Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul (Korea, Republic of)

    2012-09-01

    Reactive oxidative species (ROS) generated by environmental toxicants including pesticides could be one of the factors underlying the neuronal cell damage in neurodegenerative diseases. In this study we found that chlorpyrifos (CPF) induced apoptosis in dopaminergic neuronal components of PC12 cells as demonstrated by the activation of caspases and nuclear condensation. Furthermore, CPF also reduced the tyrosine hydroxylase-positive immunoreactivity in substantia nigra of the rat. In addition, CPF induced inhibition of mitochondrial complex I activity. Importantly, N-acetyl cysteine (NAC) treatment effectively blocked apoptosis via the caspase-9 and caspase-3 pathways while NAC attenuated the inhibition of mitochondrial complex I activity as well as the oxidative metabolism of dopamine (DA). These results demonstrated that CPF-induced apoptosis was involved in mitochondrial dysfunction through the production of ROS. In the response of cellular antioxidant systems to CPF, we found that CPF treatment increased HO-1 expression while the expression of CuZnSOD and MnSOD was reduced. In addition, we found that CPF treatment activated MAPK pathways, including ERK 1/2, the JNK, and the p38 MAP kinase in a time-dependent manner. NAC treatment abolished MAPK phosphorylation caused by CPF, indicating that ROS are upstream signals of MAPK. Interestingly, MAPK inhibitors abolished cytotoxicity and reduced ROS generation by CPF treatment. Our results demonstrate that CPF induced neuronal cell death in part through MAPK activation via ROS generation, suggesting its potential to generate oxidative stress via mitochondrial damage and its involvement in oxidative stress-related neurodegenerative disease. -- Highlights: ► Chlorpyrifos induces apoptosis. ► Chlorpyrifos inhibits mitochondrial complex I activity. ► ROS is involved in chlorpyrifos-induced apoptosis. ► Chlorpyrifos affects cellular antioxidant systems. ► Chlorpyrifos-induced apoptosis mediates activation of MAPK.

  10. Reactive oxygen species regulated mitochondria-mediated apoptosis in PC12 cells exposed to chlorpyrifos

    International Nuclear Information System (INIS)

    Lee, Jeong Eun; Park, Jae Hyeon; Shin, In Chul; Koh, Hyun Chul

    2012-01-01

    Reactive oxidative species (ROS) generated by environmental toxicants including pesticides could be one of the factors underlying the neuronal cell damage in neurodegenerative diseases. In this study we found that chlorpyrifos (CPF) induced apoptosis in dopaminergic neuronal components of PC12 cells as demonstrated by the activation of caspases and nuclear condensation. Furthermore, CPF also reduced the tyrosine hydroxylase-positive immunoreactivity in substantia nigra of the rat. In addition, CPF induced inhibition of mitochondrial complex I activity. Importantly, N-acetyl cysteine (NAC) treatment effectively blocked apoptosis via the caspase-9 and caspase-3 pathways while NAC attenuated the inhibition of mitochondrial complex I activity as well as the oxidative metabolism of dopamine (DA). These results demonstrated that CPF-induced apoptosis was involved in mitochondrial dysfunction through the production of ROS. In the response of cellular antioxidant systems to CPF, we found that CPF treatment increased HO-1 expression while the expression of CuZnSOD and MnSOD was reduced. In addition, we found that CPF treatment activated MAPK pathways, including ERK 1/2, the JNK, and the p38 MAP kinase in a time-dependent manner. NAC treatment abolished MAPK phosphorylation caused by CPF, indicating that ROS are upstream signals of MAPK. Interestingly, MAPK inhibitors abolished cytotoxicity and reduced ROS generation by CPF treatment. Our results demonstrate that CPF induced neuronal cell death in part through MAPK activation via ROS generation, suggesting its potential to generate oxidative stress via mitochondrial damage and its involvement in oxidative stress-related neurodegenerative disease. -- Highlights: ► Chlorpyrifos induces apoptosis. ► Chlorpyrifos inhibits mitochondrial complex I activity. ► ROS is involved in chlorpyrifos-induced apoptosis. ► Chlorpyrifos affects cellular antioxidant systems. ► Chlorpyrifos-induced apoptosis mediates activation of MAPK.

  11. Differential protection by wildtype vs. organelle-specific Bcl-2 suggests a combined requirement of both the ER and mitochondria in ceramide-mediated caspase-independent programmed cell death

    International Nuclear Information System (INIS)

    Deerberg, Andrea; Sosna, Justyna; Thon, Lutz; Belka, Claus; Adam, Dieter

    2009-01-01

    Programmed cell death (PCD) is essential for development and homeostasis of multicellular organisms and can occur by caspase-dependent apoptosis or alternatively, by caspase-independent PCD (ciPCD). Bcl-2, a central regulator of apoptosis, localizes to both mitochondria and the endoplasmic reticulum (ER). Whereas a function of mitochondrial and ER-specific Bcl-2 in apoptosis has been established in multiple studies, corresponding data for ciPCD do not exist. We utilized Bcl-2 constructs specifically localizing to mitochondria (Bcl-2 ActA), the ER (Bcl-2 cb5), both (Bcl-2 WT) or the cytosol/nucleus (Bcl-2 ΔTM) and determined their protective effect on ceramide-mediated ciPCD in transiently and stably transfected Jurkat cells. Expression of the constructs was verified by immunoblots. Ceramide-mediated ciPCD was induced by treatment with human recombinant tumor necrosis factor and determined by flow cytometric measurement of propidium iodide uptake as well as by optical analysis of cell morphology. Only wildtype Bcl-2 had the ability to efficiently protect from ceramide-mediated ciPCD, whereas expression of Bcl-2 solely at mitochondria, the ER, or the cytosol/nucleus did not prevent ceramide-mediated ciPCD. Our data suggest a combined requirement for both mitochondria and the ER in the induction and the signaling pathways of ciPCD mediated by ceramide

  12. Differential protection by wildtype vs. organelle-specific Bcl-2 suggests a combined requirement of both the ER and mitochondria in ceramide-mediated caspase-independent programmed cell death

    Directory of Open Access Journals (Sweden)

    Belka Claus

    2009-10-01

    Full Text Available Abstract Background Programmed cell death (PCD is essential for development and homeostasis of multicellular organisms and can occur by caspase-dependent apoptosis or alternatively, by caspase-independent PCD (ciPCD. Bcl-2, a central regulator of apoptosis, localizes to both mitochondria and the endoplasmic reticulum (ER. Whereas a function of mitochondrial and ER-specific Bcl-2 in apoptosis has been established in multiple studies, corresponding data for ciPCD do not exist. Methods We utilized Bcl-2 constructs specifically localizing to mitochondria (Bcl-2 ActA, the ER (Bcl-2 cb5, both (Bcl-2 WT or the cytosol/nucleus (Bcl-2 ΔTM and determined their protective effect on ceramide-mediated ciPCD in transiently and stably transfected Jurkat cells. Expression of the constructs was verified by immunoblots. Ceramide-mediated ciPCD was induced by treatment with human recombinant tumor necrosis factor and determined by flow cytometric measurement of propidium iodide uptake as well as by optical analysis of cell morphology. Results Only wildtype Bcl-2 had the ability to efficiently protect from ceramide-mediated ciPCD, whereas expression of Bcl-2 solely at mitochondria, the ER, or the cytosol/nucleus did not prevent ceramide-mediated ciPCD. Conclusion Our data suggest a combined requirement for both mitochondria and the ER in the induction and the signaling pathways of ciPCD mediated by ceramide.

  13. Sulforaphane induces apoptosis in T24 human urinary bladder cancer cells through a reactive oxygen species-mediated mitochondrial pathway: the involvement of endoplasmic reticulum stress and the Nrf2 signaling pathway.

    Science.gov (United States)

    Jo, Guk Heui; Kim, Gi-Young; Kim, Wun-Jae; Park, Kun Young; Choi, Yung Hyun

    2014-10-01

    Sulforaphane, a naturally occurring isothiocyanate found in cruciferous vegetables, has received a great deal of attention because of its ability to inhibit cell proliferation and induce apoptosis in cancer cells. In this study, we investigated the anticancer activity of sulforaphane in the T24 human bladder cancer line, and explored its molecular mechanism of action. Our results showed that treatment with sulforaphane inhibited cell viability and induced apoptosis in T24 cells in a concentration-dependent manner. Sulforaphane-induced apoptosis was associated with mitochondria dysfunction, cytochrome c release and Bcl-2/Bax dysregulation. Furthermore, the increased activity of caspase-9 and -3, but not caspase-8, was accompanied by the cleavage of poly ADP-ribose polymerase, indicating the involvement of the mitochondria-mediated intrinsic apoptotic pathway. Concomitant with these changes, sulforaphane triggered reactive oxygen species (ROS) generation, which, along with the blockage of sulforaphane-induced loss of mitochondrial membrane potential and apoptosis, was strongly attenuated by the ROS scavenger N-acetyl-L-cysteine. Furthermore, sulforaphane was observed to activate endoplasmic reticulum (ER) stress and the nuclear factor-E2-related factor-2 (Nrf2) signaling pathway, as demonstrated by the upregulation of ER stress‑related proteins, including glucose-regulated protein 78 and C/EBP-homologous protein, and the accumulation of phosphorylated Nrf2 proteins in the nucleus and induction of heme oxygenase-1 expression, respectively. Taken together, these results demonstrate that sulforaphane has antitumor effects against bladder cancer cells through an ROS-mediated intrinsic apoptotic pathway, and suggest that ER stress and Nrf2 may represent strategic targets for sulforaphane-induced apoptosis.

  14. Fisetin Induces Apoptosis of HSC3 Human Oral Cancer Cells Through Endoplasmic Reticulum Stress and Dysfunction of Mitochondria-mediated Signaling Pathways.

    Science.gov (United States)

    Shih, Yung-Luen; Hung, Fang-Ming; Lee, Ching-Hsiao; Yeh, Ming-Yang; Lee, Mei-Hui; Lu, Hsu-Feng; Chen, Yung-Liang; Liu, Jia-You; Chung, Jing-Gung

    2017-01-01

    Oral cancer has been reported to be one of the major cancer-related diseases in human populations and the treatment of oral cancer is still unsatisfied. Fisetin, is a flavonoid from plants and has several biological activities such as antioxidant, anti-inflammatory and anticancer function, but its cytotoxicity in human oral cancer cells is unknown. In the present study, we investigated fisetin-induced cytotoxic effects on HSC3 human oral cancer cells in vitro. Materials and Methods/Results: We used flow cytometric assay to show fisetin induced apoptotic cell death through increased reactive oxygen species and Ca 2+ , but reduced the mitochondrial membrane potential and increased caspase-8, -9 and -3 activities in HSC3 cells. Furthermore, we also used 4' 6-diamidino-2-phenylindole staining to show that fisetin induced chromatin condensation (apoptotic cell death), and Comet assay to show that fisetin induced DNA damage in HSC3 cells. Western blotting was used to examine the levels of apoptotic-associated protein and results indicated that fisetin increased expression of pro-apoptotic proteins such as B-cell lymphoma 2 (BCL2) antagonist/killer (BAK) and BCL2-associated X (BAX) but reduced that of anti-apoptotic protein such as BCL2 and BCL-x, and increased the cleaved forms of caspase-3, -8 and -9, and cytochrome c, apoptosis-inducing factor (AIF) and endonuclease G (ENDO G) in HSC3 cells. Confocal microscopy showed that fisetin increased the release of cytochrome c, AIF and ENDO G from mitochondria into the cytoplasm. Based on these observations, we suggest that fisetin induces apoptotic cell death through endoplasmic reticulum stress- and mitochondria-dependent pathways. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  15. Tributyltin interacts with mitochondria and induces cytochrome c release.

    Science.gov (United States)

    Nishikimi, A; Kira, Y; Kasahara, E; Sato, E F; Kanno, T; Utsumi, K; Inoue, M

    2001-01-01

    Although triorganotins are potent inducers of apoptosis in various cell types, the critical targets of these compounds and the mechanisms by which they lead to cell death remain to be elucidated. There are two major pathways by which apoptotic cell death occurs: one is triggered by a cytokine mediator and the other is by a mitochondrion-dependent mechanism. To elucidate the mechanism of triorganotin-induced apoptosis, we studied the effect of tributyltin on mitochondrial function. We found that moderately low doses of tributyltin decrease mitochondrial membrane potential and induce cytochrome c release by a mechanism inhibited by cyclosporine A and bongkrekic acid. Tributyltin-induced cytochrome c release is also prevented by dithiols such as dithiothreitol and 2,3-dimercaptopropanol but not by monothiols such as GSH, N-acetyl-L-cysteine, L-cysteine and 2-mercaptoethanol. Further studies with phenylarsine oxide agarose revealed that tributyltin interacts with the adenine nucleotide translocator, a functional constituent of the mitochondrial permeability transition pore, which is selectively inhibited by dithiothreitol. These results suggest that, at low doses, tributyltin interacts selectively with critical thiol residues in the adenine nucleotide translocator and opens the permeability transition pore, thereby decreasing membrane potential and releasing cytochrome c from mitochondria, a series of events consistent with established mechanistic models of apoptosis. PMID:11368793

  16. Voltage dependent anion channel-1 regulates death receptor mediated apoptosis by enabling cleavage of caspase-8

    International Nuclear Information System (INIS)

    Chacko, Alex D; Liberante, Fabio; Paul, Ian; Longley, Daniel B; Fennell, Dean A

    2010-01-01

    Activation of the extrinsic apoptosis pathway by tumour necrosis factor related apoptosis inducing ligand (TRAIL) is a novel therapeutic strategy for treating cancer that is currently under clinical evaluation. Identification of molecular biomarkers of resistance is likely to play an important role in predicting clinical anti tumour activity. The involvement of the mitochondrial type 1 voltage dependent anion channel (VDAC1) in regulating apoptosis has been highly debated. To date, a functional role in regulating the extrinsic apoptosis pathway has not been formally excluded. We carried out stable and transient RNAi knockdowns of VDAC1 in non-small cell lung cancer cells, and stimulated the extrinsic apoptotic pathway principally by incubating cells with the death ligand TRAIL. We used in-vitro apoptotic and cell viability assays, as well as western blot for markers of apoptosis, to demonstrate that TRAIL-induced toxicity is VDAC1 dependant. Confocal microscopy and mitochondrial fractionation were used to determine the importance of mitochondria for caspase-8 activation. Here we show that either stable or transient knockdown of VDAC1 is sufficient to antagonize TRAIL mediated apoptosis in non-small cell lung cancer (NSCLC) cells. Specifically, VDAC1 is required for processing of procaspase-8 to its fully active p18 form at the mitochondria. Loss of VDAC1 does not alter mitochondrial sensitivity to exogenous caspase-8-cleaved BID induced mitochondrial depolarization, even though VDAC1 expression is essential for TRAIL dependent activation of the intrinsic apoptosis pathway. Furthermore, expression of exogenous VDAC1 restores the apoptotic response to TRAIL in cells in which endogenous VDAC1 has been selectively silenced. Expression of VDAC1 is required for full processing and activation of caspase-8 and supports a role for mitochondria in regulating apoptosis signaling via the death receptor pathway

  17. Apoptosis of murine melanoma B16-BL6 cells induced by quercetin targeting mitochondria, inhibiting expression of PKC-alpha and translocating PKC-delta.

    Science.gov (United States)

    Zhang, Xian-Ming; Chen, Jia; Xia, Yu-Gui; Xu, Qiang

    2005-03-01

    In our previous study, quercetin was found to induce apoptosis of murine melanoma B16-BL6 cells. The cellular and molecular mechanism of quercetin-induced apoptosis was investigated in the present study. Nuclear morphology was determined by fluorescence microscopy. DNA fragmentation was analyzed by electrophoresis and quantified by the diphenylamine method. The transmembrane potential of mitochondria was measured by flow cytometry. Bcl-2, Bcl-X(L), PKC-alpha, PKC-beta, and PKC-delta were detected by Western blotting. Caspase activity was determined spectrophotometrically. Quercetin induced the condensation of nuclei of B16-BL6 cells in a dose-dependent pattern as visualized by Hoechst 33258 and propidium iodide dying. Phorbol 12-myristate 13-acetate (PMA), a PKC activator, significantly enhanced apoptosis induced by quercetin, while doxorubicin, a PKC inhibitor, markedly decreased it. Both PMA and doxorubicin showed a consistent effect on the fragmentation of nuclear DNA caused by various dosages of quercetin. Quercetin dose-dependently led to loss of the mitochondrial membrane potential, which was also significantly reinforced or antagonized by PMA and doxorubicin, respectively. Moreover, PMA showed reinforcement, while doxorubicin showed significant antagonization, of the quercetin-mediated decrease in the expression of Bcl-2. Quercetin promoted caspase-3 activity in a dose-dependent manner, which was also regulated by PMA and doxorubicin with a pattern similar to that seen in their effect on apoptosis, mitochondrial membrane potential and Bcl-2 expression, but none of these were directly affected by PMA and doxorubicin. Free fatty acid and chlorpromazine, a PKC activator and inhibitor, respectively, did not interfere with these effects of quercetin. B16-BL6 cells expressed PKC-alpha, PKC-beta, and PKC-delta. Quercetin dose-dependently inhibited the expression of PKC-alpha but not that of PKC-beta and PKC-delta. Doxorubicin almost completely blocked the effect of

  18. Fisetin-induced apoptosis of human oral cancer SCC-4 cells through reactive oxygen species production, endoplasmic reticulum stress, caspase-, and mitochondria-dependent signaling pathways.

    Science.gov (United States)

    Su, Chen-Hsuan; Kuo, Chao-Lin; Lu, Kung-Wen; Yu, Fu-Shun; Ma, Yi-Shih; Yang, Jiun-Long; Chu, Yung-Lin; Chueh, Fu-Shin; Liu, Kuo-Ching; Chung, Jing-Gung

    2017-06-01

    Oral cancer is one of the cancer-related diseases in human populations and its incidence rates are rising worldwide. Fisetin, a flavonoid from natural products, has been shown to exhibit anticancer activities in many human cancer cell lines but the molecular mechanism of fisetin-induced apoptosis in human oral cancer cells is still unclear; thus, in this study, we investigated fisetin-induced cell death and associated signal pathways on human oral cancer SCC-4 cells in vitro. We examined cell morphological changes, total viable cells, and cell cycle distribution by phase contrast microscopy and flow cytometry assays. Reactive oxygen species (ROS), Ca 2+ , mitochondria membrane potential (ΔΨ m ), and caspase-8, -9, and -3 activities were also measured by flow cytometer. Results indicate that fisetin induced cell death through the cell morphological changes, caused G2/M phase arrest, induction of apoptosis, promoted ROS and Ca 2+ production, and decreased the level of ΔΨ m and increased caspase-3, -8, and -9 activities in SCC-4 cells. DAPI staining and DNA gel electrophoresis were also used to confirm fisetin-induced cell apoptosis in SCC-4 cells. Western blotting also found out that Fisetin increased the proapoptotic proteins such as Bax and Bid and decreased the antiapoptotic proteins such as Bcl-2. Furthermore, results also showed that Fisetin increased the cytochrome c, AIF, and Endo G release from mitochondria in SCC-4 cells. We also used ATF-6α, ATF-6β, GADD153, and GRP78 which indicated that fisetin induced cell death through ER stress. Based on those observations, we suggest that fisetin induced cell apoptosis through ER stress, mitochondria-, and caspase-dependent pathways. © 2017 Wiley Periodicals, Inc.

  19. Cadmium induces apoptosis in pancreatic β-cells through a mitochondria-dependent pathway: the role of oxidative stress-mediated c-Jun N-terminal kinase activation.

    Directory of Open Access Journals (Sweden)

    Kai-Chih Chang

    Full Text Available Cadmium (Cd, one of well-known highly toxic environmental and industrial pollutants, causes a number of adverse health effects and diseases in humans. The growing epidemiological studies have suggested a possible link between Cd exposure and diabetes mellitus (DM. However, the toxicological effects and underlying mechanisms of Cd-induced pancreatic β-cell injury are still unknown. In this study, we found that Cd significantly decreased cell viability, and increased sub-G1 hypodiploid cells and annexin V-Cy3 binding in pancreatic β-cell-derived RIN-m5F cells. Cd also increased intracellular reactive oxygen species (ROS generation and malondialdehyde (MDA production and induced mitochondrial dysfunction (the loss of mitochondrial membrane potential (MMP and the increase of cytosolic cytochrome c release, the decreased Bcl-2 expression, increased p53 expression, poly (ADP-ribose polymerase (PARP cleavage, and caspase cascades, which accompanied with intracellular Cd accumulation. Pretreatment with the antioxidant N-acetylcysteine (NAC effectively reversed these Cd-induced events. Furthermore, exposure to Cd induced the phosphorylations of c-jun N-terminal kinases (JNK, extracellular signal-regulated kinases (ERK1/2, and p38-mitogen-activated protein kinase (MAPK, which was prevented by NAC. Additionally, the specific JNK inhibitor SP600125 or JNK-specific small interference RNA (si-RNA transfection suppressed Cd-induced β-cell apoptosis and related signals, but not ERK1/2 and p38-MAPK inhibitors (PD98059 and SB203580 did not. However, the JNK inhibitor or JNK-specific si-RNA did not suppress ROS generation in Cd-treated cells. These results indicate that Cd induces pancreatic β-cell death via an oxidative stress downstream-mediated JNK activation-triggered mitochondria-regulated apoptotic pathway.

  20. Andrographolide induces apoptotic and non-apoptotic death and enhances tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis in gastric cancer cells.

    Science.gov (United States)

    Lim, Sung-Chul; Jeon, Ho Jong; Kee, Keun Hong; Lee, Mi Ja; Hong, Ran; Han, Song Iy

    2017-05-01

    Andrographolide, a natural compound isolated from Andrographis paniculata , has been reported to possess antitumor activity. In the present study, the effect of andrographolide in human gastric cancer (GC) cells was investigated. Andrographolide induced cell death with apoptotic and non-apoptotic features. At a low concentration, andrographolide potentiated apoptosis and reduction of clonogenicity triggered by recombinant human tumor necrosis factor-related apoptosis-inducing ligand (rhTRAIL). Exposure of GC cells to andrographolide altered the expression level of several growth-inhibiting and apoptosis-regulating proteins, including death receptors. It was demonstrated that activity of the TRAIL-R2 (DR5) pathway was critical in the development of andrographolide-mediated rhTRAIL sensitization, since its inhibition significantly reduced the extent of apoptosis induced by the combination of rhTRAIL and andrographolide. In addition, andrographolide increased reactive oxygen species (ROS) generation in a dose-dependent manner. N-acetyl cysteine prevented andrographolide-mediated DR5 induction and the apoptotic effect induced by the combination of rhTRAIL and andrographolide. Collectively, the present study demonstrated that andrographolide enhances TRAIL-induced apoptosis through induction of DR5 expression. This effect appears to involve ROS generation in GCs.

  1. Glutamate-induced apoptosis in neuronal cells is mediated via caspase-dependent and independent mechanisms involving calpain and caspase-3 proteases as well as apoptosis inducing factor (AIF and this process is inhibited by equine estrogens

    Directory of Open Access Journals (Sweden)

    Bhavnani Bhagu R

    2006-06-01

    Full Text Available Abstract Background Glutamate, a major excitatory amino acid neurotransmitter, causes apoptotic neuronal cell death at high concentrations. Our previous studies have shown that depending on the neuronal cell type, glutamate-induced apoptotic cell death was associated with regulation of genes such as Bcl-2, Bax, and/or caspase-3 and mitochondrial cytochrome c. To further delineate the intracellular mechanisms, we have investigated the role of calpain, an important calcium-dependent protease thought to be involved in apoptosis along with mitochondrial apoptosis inducing factor (AIF and caspase-3 in primary cortical cells and a mouse hippocampal cell line HT22. Results Glutamate-induced apoptotic cell death in neuronal cells was associated with characteristic DNA fragmentation, morphological changes, activation of calpain and caspase-3 as well as the upregulation and/or translocation of AIF from mitochondria into cytosol and nuclei. Our results reveal that primary cortical cells and HT22 cells display different patterns of regulation of these genes/proteins. In primary cortical cells, glutamate induces activation of calpain, caspase-3 and translocation of AIF from mitochondria to cytosol and nuclei. In contrast, in HT22 cells, only the activation of calpain and upregulation and translocation of AIF occurred. In both cell types, these processes were inhibited/reversed by 17β-estradiol and Δ8,17β-estradiol with the latter being more potent. Conclusion Depending upon the neuronal cell type, at least two mechanisms are involved in glutamate-induced apoptosis: a caspase-3-dependent pathway and a caspase-independent pathway involving calpain and AIF. Since HT22 cells lack caspase-3, glutamate-induced apoptosis is mediated via the caspase-independent pathway in this cell line. Kinetics of this apoptotic pathway further indicate that calpain rather than caspase-3, plays a critical role in the glutamate-induced apoptosis. Our studies further indicate

  2. Troglitazone induced apoptosis via PPARγ activated POX-induced ROS formation in HT29 cells.

    Science.gov (United States)

    Wang, Jing; Lv, XiaoWen; Shi, JiePing; Hu, XiaoSong; DU, YuGuo

    2011-08-01

    In order to investigate the potential mechanisms in troglitazone-induced apoptosis in HT29 cells, the effects of PPARγ and POX-induced ROS were explored. [3- (4, 5)-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay, Annexin V and PI staining using FACS, plasmid transfection, ROS formation detected by DCFH staining, RNA interference, RT-PCR & RT-QPCR, and Western blotting analyses were employed to investigate the apoptotic effect of troglitazone and the potential role of PPARγ pathway and POX-induced ROS formation in HT29 cells. Troglitazone was found to inhibit the growth of HT29 cells by induction of apoptosis. During this process, mitochondria related pathways including ROS formation, POX expression and cytochrome c release increased, which were inhibited by pretreatment with GW9662, a specific antagonist of PPARγ. These results illustrated that POX upregulation and ROS formation in apoptosis induced by troglitazone was modulated in PPARγ-dependent pattern. Furthermore, the inhibition of ROS and apoptosis after POX siRNA used in troglitazone-treated HT29 cells indicated that POX be essential in the ROS formation and PPARγ-dependent apoptosis induced by troglitazone. The findings from this study showed that troglitazone-induced apoptosis was mediated by POX-induced ROS formation, at least partly, via PPARγ activation. Copyright © 2011 The Editorial Board of Biomedical and Environmental Sciences. Published by Elsevier B.V. All rights reserved.

  3. Neem oil limonoids induces p53-independent apoptosis and autophagy.

    Science.gov (United States)

    Srivastava, Pragya; Yadav, Neelu; Lella, Ravi; Schneider, Andrea; Jones, Anthony; Marlowe, Timothy; Lovett, Gabrielle; O'Loughlin, Kieran; Minderman, Hans; Gogada, Raghu; Chandra, Dhyan

    2012-11-01

    Azadirachta indica, commonly known as neem, has a wide range of medicinal properties. Neem extracts and its purified products have been examined for induction of apoptosis in multiple cancer cell types; however, its underlying mechanisms remain undefined. We show that neem oil (i.e., neem), which contains majority of neem limonoids including azadirachtin, induced apoptotic and autophagic cell death. Gene silencing demonstrated that caspase cascade was initiated by the activation of caspase-9, whereas caspase-8 was also activated late during neem-induced apoptosis. Pretreatment of cancer cells with pan caspase inhibitor, z-VAD inhibited activities of both initiator caspases (e.g., caspase-8 and -9) and executioner caspase-3. Neem induced the release of cytochrome c and apoptosis-inducing factor (AIF) from mitochondria, suggesting the involvement of both caspase-dependent and AIF-mediated apoptosis. p21 deficiency caused an increase in caspase activities at lower doses of neem, whereas p53 deficiency did not modulate neem-induced caspase activation. Additionally, neem treatment resulted in the accumulation of LC3-II in cancer cells, suggesting the involvement of autophagy in neem-induced cancer cell death. Low doses of autophagy inhibitors (i.e., 3-methyladenine and LY294002) did not prevent accumulation of neem-induced LC3-II in cancer cells. Silencing of ATG5 or Beclin-1 further enhanced neem-induced cell death. Phosphoinositide 3-kinase (PI3K) or autophagy inhibitors increased neem-induced caspase-3 activation and inhibition of caspases enhanced neem-induced autophagy. Together, for the first time, we demonstrate that neem induces caspase-dependent and AIF-mediated apoptosis, and autophagy in cancer cells.

  4. Neem oil limonoids induces p53-independent apoptosis and autophagy

    Science.gov (United States)

    Chandra, Dhyan

    2012-01-01

    Azadirachta indica, commonly known as neem, has a wide range of medicinal properties. Neem extracts and its purified products have been examined for induction of apoptosis in multiple cancer cell types; however, its underlying mechanisms remain undefined. We show that neem oil (i.e., neem), which contains majority of neem limonoids including azadirachtin, induced apoptotic and autophagic cell death. Gene silencing demonstrated that caspase cascade was initiated by the activation of caspase-9, whereas caspase-8 was also activated late during neem-induced apoptosis. Pretreatment of cancer cells with pan caspase inhibitor, z-VAD inhibited activities of both initiator caspases (e.g., caspase-8 and -9) and executioner caspase-3. Neem induced the release of cytochrome c and apoptosis-inducing factor (AIF) from mitochondria, suggesting the involvement of both caspase-dependent and AIF-mediated apoptosis. p21 deficiency caused an increase in caspase activities at lower doses of neem, whereas p53 deficiency did not modulate neem-induced caspase activation. Additionally, neem treatment resulted in the accumulation of LC3-II in cancer cells, suggesting the involvement of autophagy in neem-induced cancer cell death. Low doses of autophagy inhibitors (i.e., 3-methyladenine and LY294002) did not prevent accumulation of neem-induced LC3-II in cancer cells. Silencing of ATG5 or Beclin-1 further enhanced neem-induced cell death. Phosphoinositide 3-kinase (PI3K) or autophagy inhibitors increased neem-induced caspase-3 activation and inhibition of caspases enhanced neem-induced autophagy. Together, for the first time, we demonstrate that neem induces caspase-dependent and AIF-mediated apoptosis, and autophagy in cancer cells. PMID:22915764

  5. Mangosenone F, A Furanoxanthone from Garciana mangostana, Induces Reactive Oxygen Species-Mediated Apoptosis in Lung Cancer Cells and Decreases Xenograft Tumor Growth.

    Science.gov (United States)

    Seo, Kyung Hye; Ryu, Hyung Won; Park, Mi Jin; Park, Ki Hun; Kim, Jin Hyo; Lee, Mi-Ja; Kang, Hyeon Jung; Kim, Sun Lim; Lee, Jin Hwan; Seo, Woo Duck

    2015-11-01

    Mangosenone F (MSF), a natural xanthone, was isolated form Carcinia mangotana, and a few studies have reported its glycosidase inhibitor effect. In this study we investigated the anti lung cancer effect of MSF both in vitro and in vivo. MSF inhibited cancer cell cytotoxicity and induced and induced apoptosis via reactive oxygen species (ROS) generation in NCI-H460. MSF treatment also showed in pronounced release of apoptogenic cytochrome c from the mitochondria to the cytosol, downregulation of Bcl-2 and Bcl-xL, and upregulation of Bax, suggesting that caspase-mediated pathways were involved in MSF-induced apoptosis. ROS activation of the mitogen-activated protein kinase signaling pathway was shown to play a predominant role in the apoptosis mechanism of MSF. Compared with cisplatin treatment, MSF treatment showed significantly increased inhibition of the growth of NCI-H460 cells xenografted in nude mice. Together, these results indicate the potential of MSF as a candidate natural anticancer drug by promoting ROS production. Copyright © 2015 John Wiley & Sons, Ltd.

  6. Arsenic induces apoptosis in mouse liver is mitochondria dependent and is abrogated by N-acetylcysteine

    International Nuclear Information System (INIS)

    Santra, Amal; Chowdhury, Abhijit; Ghatak, Subhadip; Biswas, Ayan; Dhali, Gopal Krishna

    2007-01-01

    Arsenicosis, caused by arsenic contamination of drinking water supplies, is a major public health problem in India and Bangladesh. Chronic liver disease, often with portal hypertension occurs in chronic arsenicosis, contributes to the morbidity and mortality. The early cellular events that initiate liver cell injury due to arsenicosis have not been studied. Our aim was to identify the possible mechanisms related to arsenic-induced liver injury in mice. Liver injury was induced in mice by arsenic treatment. The liver was used for mitochondrial oxidative stress, mitochondrial permeability transition (MPT). Evidence of apoptosis was sought by TUNEL test, caspase assay and histology. Pretreatment with N-acetyl-L-cysteine (NAC) was done to modulate hepatic GSH level. Arsenic treatment in mice caused liver injury associated with increased oxidative stress in liver mitochondria and alteration of MPT. Altered MPT facilitated cytochrome c release in the cytosol, activation of caspase 9 and caspase 3 activities and apoptotic cell death. Pretreatment of NAC to arsenic-treated mice abrogated all these alteration suggesting a glutathione (GSH)-dependent mechanism. Oxidative stress in mitochondria and inappropriate MPT are important in the pathogenesis of arsenic induced apoptotic liver cell injury. The phenomenon is GSH dependent and supplementation of NAC might have beneficial effects

  7. Ursolic acid mediates photosensitization by initiating mitochondrial-dependent apoptosis

    Science.gov (United States)

    Lee, Yuan-Hao; Wang, Exing; Kumar, Neeru; Glickman, Randolph D.

    2013-02-01

    The signaling pathways PI3K/Akt and MAPK play key roles in transcription, translation and carcinogenesis, and may be activated by light exposure. These pathways may be modulated or inhibited by naturally-occurring compounds, such as the triterpenoid, ursolic acid (UA). Previously, the transcription factors p53 and NF-kB, which transactivate mitochondrial apoptosis-related genes, were shown to be differentially modulated by UA. Our current work indicates that UA causes these effects via the mTOR and insulin-mediated pathways. UA-modulated apoptosis, following exposure to UV radiation, is observed to correspond to differential levels of oxidative stress in retinal pigment epithelial (RPE) and skin melanoma (SM) cells. Flow cytometry analysis, DHE (dihydroethidium) staining and membrane permeability assay showed that UA pretreatment potentiated cell cycle arrest and radiation-induced apoptosis selectively on SM cells while DNA photo-oxidative damage (i.e. strand breakage) was reduced, presumably by some antioxidant activity of UA in RPE cells. The UA-mediated NF-κB activation in SM cells was reduced by rapamycin pretreatment, which indicates that these agents exert inter-antagonistic effects in the PI3K/Akt/mTOR pathway. In contrast, the antagonistic effect of UA on the PI3K/Akt pathway was reversed by insulin leading to greater NF-κB and p53 activation in RPE cells. MitoTracker, a mitochondrial functional assay, indicated that mitochondria in RPE cells experienced reduced oxidative stress while those in SM cells exhibited increased oxidative stress upon UA pretreatment. When rapamycin administration was followed by UA, mitochondrial oxidative stress was increased in RPE cells but decreased in SM cells. These results indicate that UA modulates p53 and NF-κB, initiating a mitogenic response to radiation that triggers mitochondria-dependent apoptosis.

  8. SET mediates TCE-induced liver cell apoptosis through dephosphorylation and upregulation of nucleolin.

    Science.gov (United States)

    Ren, Xiaohu; Huang, Xinfeng; Yang, Xifei; Liu, Yungang; Liu, Wei; Huang, Haiyan; Wu, Desheng; Zou, Fei; Liu, Jianjun

    2017-06-20

    Trichloroethylene (TCE) is an occupational and environmental chemical that can cause severe hepatotoxicity. While our previous studies showed that the phosphatase inhibitor SET is a key mediator of TCE-induced liver cell apoptosis, the molecular mechanisms remain elusive. Using quantitative phosphoproteomic analysis, we report here that nucleolin is a SET-regulated phosphoprotein in human liver HL-7702 cells. Functional analysis suggested that SET promoted dephosphorylation of nucleolin, decreased its binding to its transcriptional activator, c-myc, and upregulated nucleolin expression in TCE-treated cells. Importantly, TCE-induced hepatocyte apoptosis was significantly attenuated when nucleolin was downregulated with specific siRNAs. These findings indicate that TCE may induce hepatocyte apoptosis via SET-mediated dephosphorylation and overexpression of nucleolin.

  9. Molybdenum induces pancreatic β-cell dysfunction and apoptosis via interdependent of JNK and AMPK activation-regulated mitochondria-dependent and ER stress-triggered pathways

    International Nuclear Information System (INIS)

    Yang, Tsung-Yuan; Yen, Cheng-Chieh; Lee, Kuan-I; Su, Chin-Chuan; Yang, Ching-Yao; Wu, Chin-Ching; Hsieh, Shang-Shu; Ueng, Kwo-Chang; Huang, Chun-Fa

    2016-01-01

    Molybdenum (Mo), a well-known toxic environmental and industrial pollutant, causes adverse health effects and diseases in humans and has received attention as a potential risk factor for DM. However, the roles of Mo in the mechanisms of the toxicological effects in pancreatic β-cells are mostly unclear. In this study, the results revealed dysfunction of insulin secretion and apoptosis in the pancreatic β-cell-derived RIN-m5F cells and the isolated mouse islets in response to Mo. These effects were accompanied by a mitochondria-dependent apoptotic signals including a decreased in the MMP, an increase in cytochrome c release, and the activation of caspase cascades and PARP. In addition, ER stress was triggered as indicated by several key molecules of the UPR. Furthermore, exposure to Mo induced the activation of ERK1/2, JNK, AMPKα, and GSK3-α/β. Pretreatment with specific pharmacological inhibitors (in RIN-m5F cells and isolated mouse islets) of JNK (SP600125) and AMPK (Compound C) or transfection with si-RNAs (in RIN-m5F cells) specific to JNK and AMPKα effectively prevented the Mo-induced apoptosis and related signals, but inhibitors of ERK1/2 and GSK3-α/β (PD98059 and LiCl, respectively) did not reverse the Mo-induced effects. Additionally, both the inhibitors and specific si-RNAs could suppress the Mo-induced phosphorylation of JNK and AMPKα each other. Taken together, these results suggest that Mo exerts its cytotoxicity on pancreatic β-cells by inducing dysfunction and apoptosis via interdependent JNK and AMPK activation downstream-regulated mitochondrial-dependent and ER stress-triggered apoptosis pathways. - Highlights: • Molybdenum (Mo) induces pancreatic β-cell dysfunction and apoptosis. • Mo causes β-cell death via mitochondria-dependent caspase cascades signals. • ER stress-triggered apoptotic pathway also regulates Mo-induced β-cell death. • Interdependent of JNK and AMPK activation involves in Mo-induced β-cell apoptosis.

  10. Molybdenum induces pancreatic β-cell dysfunction and apoptosis via interdependent of JNK and AMPK activation-regulated mitochondria-dependent and ER stress-triggered pathways

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tsung-Yuan [Institute of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Yen, Cheng-Chieh [Department of Occupational Safety and Health, College of Health Care and Management, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Lee, Kuan-I [Department of Emergency, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung 427, Taiwan (China); Su, Chin-Chuan [Department of Otorhinolaryngology, Head and Neck Surgery, Changhua Christian Hospital, Changhua County 500, Taiwan (China); Graduate Institute of Basic Medical Science, School of Medicine, College of Medicine, China Medical University, Taichung 404, Taiwan (China); Yang, Ching-Yao [Department of Surgery, National Taiwan University Hospital, Taipei 100, Taiwan (China); Department of Surgery, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Wu, Chin-Ching [Department of Public Health, China Medical University, Taichung 404, Taiwan (China); Hsieh, Shang-Shu, E-mail: gile1123@yahoo.com.tw [Department of Emergency, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung 427, Taiwan (China); Ueng, Kwo-Chang, E-mail: kcueng@gmail.com [Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); School of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Huang, Chun-Fa, E-mail: cfhuang@mail.cmu.edu.tw [School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung 404, Taiwan (China)

    2016-03-01

    Molybdenum (Mo), a well-known toxic environmental and industrial pollutant, causes adverse health effects and diseases in humans and has received attention as a potential risk factor for DM. However, the roles of Mo in the mechanisms of the toxicological effects in pancreatic β-cells are mostly unclear. In this study, the results revealed dysfunction of insulin secretion and apoptosis in the pancreatic β-cell-derived RIN-m5F cells and the isolated mouse islets in response to Mo. These effects were accompanied by a mitochondria-dependent apoptotic signals including a decreased in the MMP, an increase in cytochrome c release, and the activation of caspase cascades and PARP. In addition, ER stress was triggered as indicated by several key molecules of the UPR. Furthermore, exposure to Mo induced the activation of ERK1/2, JNK, AMPKα, and GSK3-α/β. Pretreatment with specific pharmacological inhibitors (in RIN-m5F cells and isolated mouse islets) of JNK (SP600125) and AMPK (Compound C) or transfection with si-RNAs (in RIN-m5F cells) specific to JNK and AMPKα effectively prevented the Mo-induced apoptosis and related signals, but inhibitors of ERK1/2 and GSK3-α/β (PD98059 and LiCl, respectively) did not reverse the Mo-induced effects. Additionally, both the inhibitors and specific si-RNAs could suppress the Mo-induced phosphorylation of JNK and AMPKα each other. Taken together, these results suggest that Mo exerts its cytotoxicity on pancreatic β-cells by inducing dysfunction and apoptosis via interdependent JNK and AMPK activation downstream-regulated mitochondrial-dependent and ER stress-triggered apoptosis pathways. - Highlights: • Molybdenum (Mo) induces pancreatic β-cell dysfunction and apoptosis. • Mo causes β-cell death via mitochondria-dependent caspase cascades signals. • ER stress-triggered apoptotic pathway also regulates Mo-induced β-cell death. • Interdependent of JNK and AMPK activation involves in Mo-induced β-cell apoptosis.

  11. NFAT2 mediates high glucose-induced glomerular podocyte apoptosis through increased Bax expression

    International Nuclear Information System (INIS)

    Li, Ruizhao; Zhang, Li; Shi, Wei; Zhang, Bin; Liang, Xinling; Liu, Shuangxin; Wang, Wenjian

    2013-01-01

    Background: Hyperglycemia promotes podocyte apoptosis and plays a key role in the pathogenesis of diabetic nephropathy. However, the mechanisms that mediate hyperglycemia-induced podocyte apoptosis is still far from being fully understood. Recent studies reported that high glucose activate nuclear factor of activated T cells (NFAT) in vascular smooth muscle or pancreatic β-cells. Here, we sought to determine if hyperglycemia activates NFAT2 in cultured podocyte and whether this leads to podocyte apoptosis. Meanwhile, we also further explore the mechanisms of NFAT2 activation and NFAT2 mediates high glucose-induced podocyte apoptosis. Methods: Immortalized mouse podocytes were cultured in media containing normal glucose (NG), or high glucose (HG) or HG plus cyclosporine A (a pharmacological inhibitor of calcinerin) or 11R-VIVIT (a special inhibitor of NFAT2). The activation of NFAT2 in podocytes was detected by western blotting and immunofluorescence assay. The role of NFAT2 in hyperglycemia-induced podocyte apoptosis was further evaluated by observing the inhibition of NFAT2 activation by 11R-VIVIT using flow cytometer. Intracellular Ca 2+ was monitored in HG-treated podcocytes using Fluo-3/AM. The mRNA and protein expression of apoptosis gene Bax were measured by real time-qPCR and western blotting. Results: HG stimulation activated NFAT2 in a time- and dose-dependent manner in cultured podocytes. Pretreatment with cyclosporine A (500 nM) or 11R-VIVIT (100 nM) completely blocked NFAT2 nuclear accumulation. Meanwhile, the apoptosis effects induced by HG were also abrogated by concomitant treatment with 11R-VIVIT in cultured podocytes. We further found that HG also increased [Ca 2+ ]i, leading to activation of calcineurin, and subsequent increased nuclear accumulation of NFAT2 and Bax expression in cultured podocytes. Conclusion: Our results identify a new finding that HG-induced podocyte apoptosis is mediated by calcineurin/NFAT2/Bax signaling pathway, which may

  12. NFAT2 mediates high glucose-induced glomerular podocyte apoptosis through increased Bax expression

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ruizhao, E-mail: liruizhao1979@126.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Zhang, Li, E-mail: Zhanglichangde@163.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Southern Medical University, Guangzhou, Guangdong (China); Shi, Wei, E-mail: shiwei.gd@139.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Zhang, Bin, E-mail: zhangbinyes@yahoo.com.cn [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Liang, Xinling, E-mail: xinlingliang@yahoo.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Liu, Shuangxin, E-mail: mplsxi@yahoo.com.cn [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Wang, Wenjian, E-mail: wwjph@yahoo.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China)

    2013-04-15

    Background: Hyperglycemia promotes podocyte apoptosis and plays a key role in the pathogenesis of diabetic nephropathy. However, the mechanisms that mediate hyperglycemia-induced podocyte apoptosis is still far from being fully understood. Recent studies reported that high glucose activate nuclear factor of activated T cells (NFAT) in vascular smooth muscle or pancreatic β-cells. Here, we sought to determine if hyperglycemia activates NFAT2 in cultured podocyte and whether this leads to podocyte apoptosis. Meanwhile, we also further explore the mechanisms of NFAT2 activation and NFAT2 mediates high glucose-induced podocyte apoptosis. Methods: Immortalized mouse podocytes were cultured in media containing normal glucose (NG), or high glucose (HG) or HG plus cyclosporine A (a pharmacological inhibitor of calcinerin) or 11R-VIVIT (a special inhibitor of NFAT2). The activation of NFAT2 in podocytes was detected by western blotting and immunofluorescence assay. The role of NFAT2 in hyperglycemia-induced podocyte apoptosis was further evaluated by observing the inhibition of NFAT2 activation by 11R-VIVIT using flow cytometer. Intracellular Ca{sup 2+} was monitored in HG-treated podcocytes using Fluo-3/AM. The mRNA and protein expression of apoptosis gene Bax were measured by real time-qPCR and western blotting. Results: HG stimulation activated NFAT2 in a time- and dose-dependent manner in cultured podocytes. Pretreatment with cyclosporine A (500 nM) or 11R-VIVIT (100 nM) completely blocked NFAT2 nuclear accumulation. Meanwhile, the apoptosis effects induced by HG were also abrogated by concomitant treatment with 11R-VIVIT in cultured podocytes. We further found that HG also increased [Ca{sup 2+}]i, leading to activation of calcineurin, and subsequent increased nuclear accumulation of NFAT2 and Bax expression in cultured podocytes. Conclusion: Our results identify a new finding that HG-induced podocyte apoptosis is mediated by calcineurin/NFAT2/Bax signaling pathway

  13. The ganglioside GM3 is associated with cisplatin-induced apoptosis in human colon cancer cells.

    Directory of Open Access Journals (Sweden)

    Tae-Wook Chung

    Full Text Available Cisplatin (cis-diamminedichloroplatinum, CDDP is a well-known chemotherapeutic agent for the treatment of several cancers. However, the precise mechanism underlying apoptosis of cancer cells induced by CDDP remains unclear. In this study, we show mechanistically that CDDP induces GM3-mediated apoptosis of HCT116 cells by inhibiting cell proliferation, and increasing DNA fragmentation and mitochondria-dependent apoptosis signals. CDDP induced apoptosis within cells through the generation of reactive oxygen species (ROS, regulated the ROS-mediated expression of Bax, Bcl-2, and p53, and induced the degradation of the poly (ADP-ribosyl polymerase (PARP. We also checked expression levels of different gangliosides in HCT116 cells in the presence or absence of CDDP. Interestingly, among the gangliosides, CDDP augmented the expression of only GM3 synthase and its product GM3. Reduction of the GM3 synthase level through ectopic expression of GM3 small interfering RNA (siRNA rescued HCT116 cells from CDDP-induced apoptosis. This was evidenced by inhibition of apoptotic signals by reducing ROS production through the regulation of 12-lipoxigenase activity. Furthermore, the apoptotic sensitivity to CDDP was remarkably increased in GM3 synthase-transfected HCT116 cells compared to that in controls. In addition, GM3 synthase-transfected cells treated with CDDP exhibited an increased accumulation of intracellular ROS. These results suggest the CDDP-induced oxidative apoptosis of HCT116 cells is mediated by GM3.

  14. Nitric oxide-induced eosinophil apoptosis is dependent on mitochondrial permeability transition (mPT, JNK and oxidative stress: apoptosis is preceded but not mediated by early mPT-dependent JNK activation

    Directory of Open Access Journals (Sweden)

    Ilmarinen-Salo Pinja

    2012-08-01

    Full Text Available Abstract Background Eosinophils are critically involved in the pathogenesis of asthma. Nitric oxide (NO is produced in high amounts in asthmatic lungs and has an important role as a regulator of lung inflammation. NO was previously shown to induce eosinophil apoptosis mediated via c-jun N-terminal kinase (JNK and caspases. Our aim was to clarify the cascade of events leading to NO-induced apoptosis in granulocyte macrophage-colony stimulating factor (GM-CSF-treated human eosinophils concentrating on the role of mitochondria, reactive oxygen species (ROS and JNK. Methods Apoptosis was determined by flow cytometric analysis of relative DNA content, by Annexin-V labelling and/or morphological analysis. Immunoblotting was used to study phospho-JNK (pJNK expression. Mitochondrial membrane potential was assessed by JC-1-staining and mitochondrial permeability transition (mPT by loading cells with calcein acetoxymethyl ester (AM and CoCl2 after which flow cytometric analysis was conducted. Statistical significance was calculated by repeated measures analysis of variance (ANOVA or paired t-test. Results NO-donor S-nitroso-N-acetyl-D,L-penicillamine (SNAP induced late apoptosis in GM-CSF-treated eosinophils. SNAP-induced apoptosis was suppressed by inhibitor of mPT bongkrekic acid (BA, inhibitor of JNK SP600125 and superoxide dismutase-mimetic AEOL 10150. Treatment with SNAP led to late loss of mitochondrial membrane potential. Additionally, we found that SNAP induces early partial mPT (1 h that was followed by a strong increase in pJNK levels (2 h. Both events were prevented by BA. However, these events were not related to apoptosis because SNAP-induced apoptosis was prevented as efficiently when BA was added 16 h after SNAP. In addition to the early and strong rise, pJNK levels were less prominently increased at 20–30 h. Conclusions Here we demonstrated that NO-induced eosinophil apoptosis is mediated via ROS, JNK and late mPT. Additionally

  15. CD36 Mediated Fatty Acid-Induced Podocyte Apoptosis via Oxidative Stress.

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    Wei Hua

    Full Text Available Hyperlipidemia-induced apoptosis mediated by fatty acid translocase CD36 is associated with increased uptake of ox-LDL or fatty acid in macrophages, hepatocytes and proximal tubular epithelial cells, leading to atherosclerosis, liver damage and fibrosis in obese patients, and diabetic nephropathy (DN, respectively. However, the specific role of CD36 in podocyte apoptosis in DN with hyperlipidemia remains poorly investigated.The expression of CD36 was measured in paraffin-embedded kidney tissue samples (Ctr = 18, DN = 20 by immunohistochemistry and immunofluorescence staining. We cultured conditionally immortalized mouse podocytes (MPC5 and treated cells with palmitic acid, and measured CD36 expression by real-time PCR, Western blot analysis and immunofluorescence; lipid uptake by Oil red O staining and BODIPY staining; apoptosis by flow cytometry assay, TUNEL assay and Western blot analysis; and ROS production by DCFH-DA fluorescence staining. All statistical analyses were performed using SPSS 21.0 statistical software.CD36 expression was increased in kidney tissue from DN patients with hyperlipidemia. Palmitic acid upregulated CD36 expression and promoted its translocation from cytoplasm to plasma membrane in podocytes. Furthermore, palmitic acid increased lipid uptake, ROS production and apoptosis in podocytes, Sulfo-N-succinimidyloleate (SSO, the specific inhibitor of the fatty acid binding site on CD36, decreased palmitic acid-induced fatty acid accumulation, ROS production, and apoptosis in podocytes. Antioxidant 4-hydroxy-2,2,6,6- tetramethylpiperidine -1-oxyl (tempol inhibited the overproduction of ROS and apoptosis in podocytes induced by palmitic acid.CD36 mediated fatty acid-induced podocyte apoptosis via oxidative stress might participate in the process of DN.

  16. Apoptosis signal-regulating kinase 1 mediates denbinobin-induced apoptosis in human lung adenocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Pan Shiow-Lin

    2009-05-01

    Full Text Available Abstract In the present study, we explore the role of apoptosis signal-regulating kinase 1 (ASK1 in denbinobin-induced apoptosis in human lung adenocarcinoma (A549 cells. Denbinobin-induced cell apoptosis was attenuated by an ASK1 dominant-negative mutant (ASK1DN, two antioxidants (N-acetyl-L-cysteine (NAC and glutathione (GSH, a c-Jun N-terminal kinase (JNK inhibitor (SP600125, and an activator protein-1 (AP-1 inhibitor (curcumin. Treatment of A549 cells with denbinobin caused increases in ASK1 activity and reactive oxygen species (ROS production, and these effects were inhibited by NAC and GSH. Stimulation of A549 cells with denbinobin caused JNK activation; this effect was markedly inhibited by NAC, GSH, and ASK1DN. Denbinobin induced c-Jun phosphorylation, the formation of an AP-1-specific DNA-protein complex, and Bim expression. Bim knockdown using a bim short interfering RNA strategy also reduced denbinobin-induced A549 cell apoptosis. The denbinobin-mediated increases in c-Jun phosphorylation and Bim expression were inhibited by NAC, GSH, SP600125, ASK1DN, JNK1DN, and JNK2DN. These results suggest that denbinobin might activate ASK1 through ROS production to cause JNK/AP-1 activation, which in turn induces Bim expression, and ultimately results in A549 cell apoptosis.

  17. Myostatin induces mitochondrial metabolic alteration and typical apoptosis in cancer cells

    Science.gov (United States)

    Liu, Y; Cheng, H; Zhou, Y; Zhu, Y; Bian, R; Chen, Y; Li, C; Ma, Q; Zheng, Q; Zhang, Y; Jin, H; Wang, X; Chen, Q; Zhu, D

    2013-01-01

    Myostatin, a member of the transforming growth factor-β superfamily, regulates the glucose metabolism of muscle cells, while dysregulated myostatin activity is associated with a number of metabolic disorders, including muscle cachexia, obesity and type II diabetes. We observed that myostatin induced significant mitochondrial metabolic alterations and prolonged exposure of myostatin induced mitochondria-dependent apoptosis in cancer cells addicted to glycolysis. To address the underlying mechanism, we found that the protein levels of Hexokinase II (HKII) and voltage-dependent anion channel 1 (VDAC1), two key regulators of glucose metabolisms as well as metabolic stress-induced apoptosis, were negatively correlated. In particular, VDAC1 was dramatically upregulated in cells that are sensitive to myostatin treatment whereas HKII was downregulated and dissociated from mitochondria. Myostatin promoted the translocation of Bax from cytosol to mitochondria, and knockdown of VDAC1 inhibited myostatin-induced Bax translocation and apoptosis. These apoptotic changes can be partially rescued by repletion of ATP, or by ectopic expression of HKII, suggesting that perturbation of mitochondrial metabolism is causally linked with subsequent apoptosis. Our findings reveal novel function of myostatin in regulating mitochondrial metabolism and apoptosis in cancer cells. PMID:23412387

  18. Seleno-short-chain chitosan induces apoptosis in human non-small-cell lung cancer A549 cells through ROS-mediated mitochondrial pathway.

    Science.gov (United States)

    Zhao, Yana; Zhang, Shaojing; Wang, Pengfei; Fu, Shengnan; Wu, Di; Liu, Anjun

    2017-12-01

    Seleno-short-chain chitosan (SSCC) is a synthesized chitosan derivative. In this study, antitumor activity and underlying mechanism of SSCC on human non-small-cell lung cancer A549 cells were investigated in vitro. The MTT assay showed that SSCC could inhibit cell viability in a dose- and time-dependent manner, and 200 μg/ml SSCC exhibited significantly toxic effects on A549 cells. The cell cycle assay showed that SSCC triggered S phase cell cycle arrest in a dose- and time-dependent manner, which was related to a downregulation of S phase associated cyclin A. The DAPI staining and Annexin V-FITC/PI double staining identified that the SSCC could induce A549 cells apoptosis. Further studies found that SSCC led to the generation of reactive oxygen species (ROS) and the disruption of mitochondrial membrane potential (MMP) by DCFH-DA and Rhodamin 123 staining, respectively. Meanwhile, free radical scavengers N-acetyl-L-cysteine (NAC) pretreatment confirmed that SSCC-induced A549 cells apoptosis was associated with ROS generation. Furthermore, real-time PCR and western blot assay showed that SSCC up-regulated Bax and down-regulated Bcl-2, subsequently incited the release of cytochrome c from mitochondria to cytoplasm, activated the increase of cleaved-caspase 3 and finally induced A549 cells apoptosis in vitro. In general, the present study demonstrated that SSCC induced A549 cells apoptosis via ROS-mediated mitochondrial apoptosis pathway.

  19. A ginseng saponin metabolite-induced apoptosis in HepG2 cells involves a mitochondria-mediated pathway and its downstream caspase-8 activation and Bid cleavage

    International Nuclear Information System (INIS)

    Oh, Seon-Hee; Lee, Byung-Hoon

    2004-01-01

    20-O-(β-D-Glucopyranosyl)-20(S)-protopanaxadiol (IH901), an intestinal bacterial metabolite of ginseng saponin formed from ginsenosides Rb1, Rb2, and Rc, is suggested to be a potential chemopreventive agent. Here, we show that IH901 induces apoptosis in human hepatoblastoma HepG2 cells. IH901 led to an early activation of procaspase-3 (12 h posttreatment), and the activation of caspase-8 became evident only later (18 h posttreatment). Caspase activation was a necessary requirement for apoptosis because caspase inhibitors significantly inhibited cell death by IH901. Treatment of HepG2 cells with IH901 also induced the cleavage of cytosolic factors such as Bid and Bax and translocation of truncated Bid (tBid) to mitochondria. A time-dependent release of cytochrome c from mitochondria was observed, which was accompanied by activation of caspase-9. A broad-spectrum caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD-fmk), and a specific inhibitor for caspase-8, N-benzyloxycarbonyl-Ile-Glu-Thr-Asp-fluoromethylketone (zIETD-fmk), abrogated Bid processing and translocation, and caspase-3 activation. Cytochrome c release was inhibited by zVAD-fmk, however, the inhibition by zIETD-fmk was not complete. The activation of caspase-8 was inhibited not only by zIETD-fmk but also by zVAD-fmk. The results, together with the kinetic change of caspase activation, indicate that activation of caspase-8 occurred downstream of caspase-3 and -9. Our data suggest that the activation of caspase-8 after early caspase-3 activation might act as an amplification loop necessary for successful apoptosis. Primary hepatocytes isolated from normal Sprague-Dawley rats were not affected by IH901 (0-60 μM). The very low toxicity in normal hepatocytes and high activity in hepatoblastoma HepG2 cells suggest that IH901 is a promising experimental cancer chemopreventive agent

  20. HIV antiretroviral drug combination induces endothelial mitochondrial dysfunction and reactive oxygen species production, but not apoptosis

    International Nuclear Information System (INIS)

    Jiang Bo; Hebert, Valeria Y.; Li, Yuchi; Mathis, J. Michael; Alexander, J. Steven; Dugas, Tammy R.

    2007-01-01

    Numerous reports now indicate that HIV patients administered long-term antiretroviral therapy (ART) are at a greater risk for developing cardiovascular diseases. Endothelial dysfunction is an initiating event in atherogenesis and may contribute to HIV-associated atherosclerosis. We previously reported that ART induces direct endothelial dysfunction in rodents. In vitro treatment of human umbilical vein endothelial cells (HUVEC) with ART indicated endothelial mitochondrial dysfunction and a significant increase in the production of reactive oxygen species (ROS). In this study, we determined whether ART-induced endothelial dysfunction is mediated via mitochondria-derived ROS and whether this mitochondrial injury culminates in endothelial cell apoptosis. Two major components of ART combination therapy, a nucleoside reverse transcriptase inhibitor and a protease inhibitor, were tested, using AZT and indinavir as representatives for each. Microscopy utilizing fluorescent indicators of ROS and mitochondria demonstrated the mitochondrial localization of ART-induced ROS. MnTBAP, a cell-permeable metalloporphyrin antioxidant, abolished ART-induced ROS production. As a final step in confirming the mitochondrial origin of the ART-induced ROS, HUVEC were transduced with a cytosolic- compared to a mitochondria-targeted catalase. Transduction with the mitochondria-targeted catalase was more effective than cytoplasmic catalase in inhibiting the ROS and 8-isoprostane (8-iso-PGF 2α ) produced after treatment with either AZT or indinavir. However, both mitochondrial and cytoplasmic catalase attenuated ROS and 8-iso-PGF 2α production induced by the combination treatment, suggesting that in this case, the formation of cytoplasmic ROS may also occur, and thus, that the mechanism of toxicity in the combination treatment group may be different compared to treatment with AZT or indinavir alone. Finally, to determine whether ART-induced mitochondrial dysfunction and ROS production

  1. Role of the mitochondria in immune-mediated apoptotic death of the human pancreatic β cell line βLox5.

    Directory of Open Access Journals (Sweden)

    Yaíma L Lightfoot

    Full Text Available Mitochondria are indispensable in the life and death of many types of eukaryotic cells. In pancreatic beta cells, mitochondria play an essential role in the secretion of insulin, a hormone that regulates blood glucose levels. Unregulated blood glucose is a hallmark symptom of diabetes. The onset of Type 1 diabetes is preceded by autoimmune-mediated destruction of beta cells. However, the exact role of mitochondria has not been assessed in beta cell death. In this study, we examine the role of mitochondria in both Fas- and proinflammatory cytokine-mediated destruction of the human beta cell line, βLox5. IFNγ primed βLox5 cells for apoptosis by elevating cell surface Fas. Consequently, βLox5 cells were killed by caspase-dependent apoptosis by agonistic activation of Fas, but only after priming with IFNγ. This beta cell line undergoes both apoptotic and necrotic cell death after incubation with the combination of the proinflammatory cytokines IFNγ and TNFα. Additionally, both caspase-dependent and -independent mechanisms that require proper mitochondrial function are involved. Mitochondrial contributions to βLox5 cell death were analyzed using mitochondrial DNA (mtDNA depleted βLox5 cells, or βLox5 ρ(0 cells. βLox5 ρ(0 cells are not sensitive to IFNγ and TNFα killing, indicating a direct role for the mitochondria in cytokine-induced cell death of the parental cell line. However, βLox5 ρ(0 cells are susceptible to Fas killing, implicating caspase-dependent extrinsic apoptotic death is the mechanism by which these human beta cells die after Fas ligation. These data support the hypothesis that immune mediators kill βLox5 cells by both mitochondrial-dependent intrinsic and caspase-dependent extrinsic pathways.

  2. Mitochondria are the primary target in the induction of apoptosis by chiral ruthenium(II) polypyridyl complexes in cancer cells.

    Science.gov (United States)

    Wang, Jin-Quan; Zhang, Ping-Yu; Qian, Chen; Hou, Xiao-Juan; Ji, Liang-Nian; Chao, Hui

    2014-03-01

    A series of novel chiral ruthenium(II) polypyridyl complexes (Δ-Ru1, Λ-Ru1, Δ-Ru2, Λ-Ru2, Δ-Ru3, Λ-Ru3) were synthesized and evaluated to determine their antiproliferative activities. Colocalization, inductively coupled plasma mass spectrometry, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay studies showed that these ruthenium(II) complexes accumulated preferentially in the mitochondria and exhibited cytotoxicity against various cancer cells in vitro. The complex Δ-Ru1 is of particular interest because it was found to have half-maximal inhibitory concentrations comparable to those of cisplatin and better activity than cisplatin against a cisplatin-resistant cell line, A549-CP/R. Δ-Ru1 induced alterations in the mitochondrial membrane potential and triggered intrinsic mitochondria-mediated apoptosis in HeLa cells, which involved the regulation of Bcl-2 family members and the activation of caspases. Taken together, these data suggest that Δ-Ru1 may be a novel mitochondria-targeting anticancer agent.

  3. Exogenous ether lipids predominantly target mitochondria

    DEFF Research Database (Denmark)

    Kuerschner, Lars; Richter, Doris; Hannibal-Bach, Hans Kristian

    2012-01-01

    Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high......, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria...

  4. 2,5-hexanedione induces bone marrow mesenchymal stem cell apoptosis via inhibition of Akt/Bad signal pathway.

    Science.gov (United States)

    Sun, Jingsong; Shi, Xiaoxia; Li, Shuangyue; Piao, Fengyuan

    2018-04-01

    2,5-Hexanedione (HD) is an important bioactive metabolite of n-hexane and mediates the neurotoxicity of parent compound. Studies show that HD induces apoptotic death of neural progenitor cells. However, its underlying mechanism remains unknown. Mesenchymal stem cells (MSCs) are multipotential stem cells with the ability to differentiate into various cell types and have been used as cell model for studying the toxic effects of chemicals on stem cells. In this study, we exposed rat bone marrow MSCs to 0, 10, 20, and 40 mM HD in vitro. Apoptosis and disruption of mitochondrial transmembrane potential were estimated by immunochemistry staining. The expression of Akt, Bad, phosphorylated Akt (p-Akt), and Bad (p-Bad) as well as cytochrome c in mitochondria and cytosol were examined by Western blot. Moreover, caspase 3 activity, viability, and death of cells were measured by spectrophotometry. Our results showed that HD induced cell apoptosis and increased caspase 3 activity. HD down-regulated the expression levels of p-Akt, p-Bad and induced MMP depolarization, followed by cytochrome c release. Moreover, HD led to a concentration-dependent increase in the MSCs death, which was relative to MSCs apoptosis. However, these toxic effects of HD on the MSCs were significantly mitigated in the presence of IGF, which could activate PI3 K/Akt pathway. These results indicated that HD induced mitochondria-mediated apoptosis in the MSCs via inhibiting Akt/Bad signaling pathway and apoptotic death of MSCs via the signaling pathway. These results might provide some clues for studying further the mechanisms of HD-induced stem cell apoptosis and adverse effect on neurogenesis. © 2017 Wiley Periodicals, Inc.

  5. Role of Bax in resveratrol-induced apoptosis of colorectal carcinoma cells

    International Nuclear Information System (INIS)

    Mahyar-Roemer, Mojgan; Köhler, Hans; Roemer, Klaus

    2002-01-01

    The natural plant polyphenol resveratrol present in some foods including grapes, wine, and peanuts, has been implicated in the inhibition, delay, and reversion of cellular events associated with heart diseases and tumorigenesis. Recent work has suggested that the cancer chemoprotective effect of the compound is primarily linked to its ability to induce cell division cycle arrest and apoptosis, the latter possibly through the activation of pro-apoptotic proteins such as Bax. The expression, subcellular localization, and importance of Bax for resveratrol-provoked apoptosis were assessed in human HCT116 colon carcinoma cells and derivatives with both bax alleles inactivated. Low to moderate concentrations of resveratrol induced co-localization of cellular Bax protein with mitochondria, collapse of the mitochondrial membrane potential, activation of caspases 3 and 9, and finally, apoptosis. In the absence of Bax, membrane potential collapse was delayed, and apoptosis was reduced but not absent. Resveratrol inhibited the formation of colonies by both HCT116 and HCT116 bax -/- cells. Resveratrol at physiological doses can induce a Bax-mediated and a Bax-independent mitochondrial apoptosis. Both can limit the ability of the cells to form colonies

  6. Prohibitin (PHB) acts as a potent survival factor against ceramide induced apoptosis in rat granulosa cells.

    Science.gov (United States)

    Chowdhury, Indrajit; Branch, Alicia; Olatinwo, Moshood; Thomas, Kelwyn; Matthews, Roland; Thompson, Winston E

    2011-08-29

    Ceramide is a key factor in inducing germ cell apoptosis by translocating from cumulus cells into the adjacent oocyte and lipid rafts through gap junctions. Therefore studies designed to elucidate the mechanistic pathways in ceramide induced granulosa cell (GC) apoptosis and follicular atresia may potentially lead to the development of novel lipid-based therapeutic strategies that will prevent infertility and premature menopause associated with chemo and/or radiation therapy in female cancer patients. Our previous studies have shown that Prohibitin (PHB) is intimately involved in GCs differentiation, atresia, and luteolysis. In the present study, we have examined the functional effects of loss-/gain-of-function of PHB using adenoviral technology in delaying apoptosis induced by the physiological ligand ceramide in rat GCs. Under these experimental conditions, exogenous ceramide C-8 (50 μM) augmented the expression of mitochondrial PHB and subsequently cause the physical destruction of GC by the release of mitochondrial cytochrome c and activation of caspase-3. In further studies, silencing of PHB expression by adenoviral small interfering RNA (shRNA) sensitized GCs to ceramide C8-induce apoptosis. In contrast, adenovirus (Ad) directed overexpression of PHB in GCs resulted in increased PHB content in mitochondria and delayed the onset of ceramide induced apoptosis in the infected GCs. Taken together, these results provide novel evidences that a critical level of PHB expression within the mitochondria plays a key intra-molecular role in GC fate by mediating the inhibition of apoptosis and may therefore, contribute significantly to ceramide induced follicular atresia. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. DNA damage-inducible transcript 4 (DDIT4) mediates methamphetamine-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes

    International Nuclear Information System (INIS)

    Chen, Rui; Wang, Bin; Chen, Ling; Cai, Dunpeng; Li, Bing; Chen, Chuanxiang; Huang, Enping; Liu, Chao; Lin, Zhoumeng; Xie, Wei-Bing; Wang, Huijun

    2016-01-01

    Methamphetamine (METH) is an amphetamine-like psychostimulant that is commonly abused. Previous studies have shown that METH can induce damages to the nervous system and recent studies suggest that METH can also cause adverse and potentially lethal effects on the cardiovascular system. Recently, we demonstrated that DNA damage-inducible transcript 4 (DDIT4) regulates METH-induced neurotoxicity. However, the role of DDIT4 in METH-induced cardiotoxicity remains unknown. We hypothesized that DDIT4 may mediate METH-induced autophagy and apoptosis in cardiomyocytes. To test the hypothesis, we examined DDIT4 protein expression in cardiomyocytes and in heart tissues of rats exposed to METH with Western blotting. We also determined the effects on METH-induced autophagy and apoptosis after silencing DDIT4 expression with synthetic siRNA with or without pretreatment of a mTOR inhibitor rapamycin in cardiomyocytes using Western blot analysis, fluorescence microscopy and TUNEL staining. Our results showed that METH exposure increased DDIT4 expression and decreased phosphorylation of mTOR that was accompanied with increased autophagy and apoptosis both in vitro and in vivo. These effects were normalized after silencing DDIT4. On the other hand, rapamycin promoted METH-induced autophagy and apoptosis in DDIT4 knockdown cardiomyocytes. These results suggest that DDIT4 mediates METH-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes. - Highlights: • METH exposure increases DDIT4 expression in cardiomyocytes. • DDIT4 mediates METH-induced autophagy and apoptosis in cardiomyocytes. • DDIT4 silencing protects cardiomyocytes against METH-caused autophagy and apoptosis.

  8. DNA damage-inducible transcript 4 (DDIT4) mediates methamphetamine-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Rui [Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, Guangzhou 510515 (China); Department of Forensic Medicine, Guangdong Medical University, Dongguan 523808 (China); Wang, Bin; Chen, Ling; Cai, Dunpeng; Li, Bing; Chen, Chuanxiang; Huang, Enping [Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, Guangzhou 510515 (China); Liu, Chao [Guangzhou Forensic Science Institute, Guangzhou 510030 (China); Lin, Zhoumeng [Institute of Computational Comparative Medicine and Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506 (United States); Xie, Wei-Bing, E-mail: xieweib@126.com [Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, Guangzhou 510515 (China); Wang, Huijun, E-mail: hjwang711@yahoo.cn [Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, Guangzhou 510515 (China)

    2016-03-15

    Methamphetamine (METH) is an amphetamine-like psychostimulant that is commonly abused. Previous studies have shown that METH can induce damages to the nervous system and recent studies suggest that METH can also cause adverse and potentially lethal effects on the cardiovascular system. Recently, we demonstrated that DNA damage-inducible transcript 4 (DDIT4) regulates METH-induced neurotoxicity. However, the role of DDIT4 in METH-induced cardiotoxicity remains unknown. We hypothesized that DDIT4 may mediate METH-induced autophagy and apoptosis in cardiomyocytes. To test the hypothesis, we examined DDIT4 protein expression in cardiomyocytes and in heart tissues of rats exposed to METH with Western blotting. We also determined the effects on METH-induced autophagy and apoptosis after silencing DDIT4 expression with synthetic siRNA with or without pretreatment of a mTOR inhibitor rapamycin in cardiomyocytes using Western blot analysis, fluorescence microscopy and TUNEL staining. Our results showed that METH exposure increased DDIT4 expression and decreased phosphorylation of mTOR that was accompanied with increased autophagy and apoptosis both in vitro and in vivo. These effects were normalized after silencing DDIT4. On the other hand, rapamycin promoted METH-induced autophagy and apoptosis in DDIT4 knockdown cardiomyocytes. These results suggest that DDIT4 mediates METH-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes. - Highlights: • METH exposure increases DDIT4 expression in cardiomyocytes. • DDIT4 mediates METH-induced autophagy and apoptosis in cardiomyocytes. • DDIT4 silencing protects cardiomyocytes against METH-caused autophagy and apoptosis.

  9. Apoptosis induced by penta-acetyl geniposide in C6 glioma cells is associated with JNK activation and Fas ligand induction

    International Nuclear Information System (INIS)

    Peng, C.-H.; Tseng, T.-H.; Huang, C.-N.; Hsu, S.-P.; Wang, C.-J.

    2005-01-01

    In our previous study, penta-acetyl geniposide ((AC) 5 GP) is suggested to induce tumor cell apoptosis through the specific activation of PKCδ. However, the downstream signal pathway of PKCδ has not yet been investigated. It was shown that JNK may play an important role in the regulation of apoptosis and could be a possible downstream signal of PKCδ isoforms. In the present study, we investigate whether JNK is involved in (AC) 5 GP induced apoptosis. The result reveals that (AC) 5 GP induces JNK activation and c-Jun phosphorylation thus stimulating the expression of Fas-L and Fas. Using SP600125 to block JNK activation shows that (AC) 5 GP-mediated apoptosis and related proteins expression are attenuated. Furthermore, we find that the (AC) 5 GP induces apoptosis through the activation of JNK/Jun/Fas L/Fas/caspase 8/caspase 3, a mitochondria-independent pathway. The JNK pathway is suggested to be the downstream signal of PKCδ, since rottlerin impedes (AC) 5 GP-induced JNK activation. Therefore, (AC) 5 GP mediates cell death via activation of PKCδ/JNK/FasL cascade signaling

  10. Mitochondrial translocation of Nur77 induced by ROS contributed to cardiomyocyte apoptosis in metabolic syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Aibin; Liu, Jingyi [Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi’an (China); Institute of Cardiovascular Disease, General Hospital of Beijing Command, PLA, Beijing (China); Liu, Peilin; Jia, Min; Wang, Han [Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi’an (China); Tao, Ling, E-mail: lingtao2006@gmail.com [Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi’an (China)

    2014-04-18

    Highlights: • Metabolic syndrome exacerbated MI/R induced injury accompanied by decreased Nur77. • ROS led to Nur77 translocation in metabolic syndrome. • Inhibiting relocation of Nur77 to mitochondria reduced ROS-induced cardiomyocyte injury in metabolic syndrome. - Abstract: Metabolic syndrome is a major risk factor for cardiovascular diseases, and increased cardiomyocyte apoptosis which contributes to cardiac dysfunction after myocardial ischemia/reperfusion (MI/R) injury. Nur77, a nuclear orphan receptor, is involved in such various cellular events as apoptosis, proliferation, and glucose and lipid metabolism in several cell types. Apoptosis is positively correlated with mitochondrial translocation of Nur77 in the cancer cells. However, the roles of Nur77 on cardiac myocytes in patients with metabolic syndrome remain unclear. The objective of this study was to determine whether Nur77 may contribute to cardiac apoptosis in patients with metabolic syndrome after I/R injury, and, if so, to identify the underlying molecular mechanisms responsible. We used leptin-deficient (ob/ob) mice to make metabolic syndrome models. In this report, we observed that, accompanied by the substantial decline in apoptosis inducer Nur77, MI/R induced cardiac dysfunction was manifested as cardiomyopathy and increased ROS. Using the neonatal rat cardiac myocytes cultured in a high-glucose and high-fat medium, we found that excessive H{sub 2}O{sub 2} led to the significant alteration in mitochondrial membrane potential and translocation of Nur77 from the nucleus to the mitochondria. However, inhibition of the relocation of Nur77 to mitochondria via Cyclosporin A reversed the changes in membrane potential mediated by H{sub 2}O{sub 2} and reduced myocardial cell injury. Therefore, these data provide a potential underlying mechanism for cardiac dysfunction in metabolic syndrome and the suppression of Nur77 translocation may provide an effective approach to reduce cardiac injury in the

  11. Mitochondrial translocation of Nur77 induced by ROS contributed to cardiomyocyte apoptosis in metabolic syndrome

    International Nuclear Information System (INIS)

    Xu, Aibin; Liu, Jingyi; Liu, Peilin; Jia, Min; Wang, Han; Tao, Ling

    2014-01-01

    Highlights: • Metabolic syndrome exacerbated MI/R induced injury accompanied by decreased Nur77. • ROS led to Nur77 translocation in metabolic syndrome. • Inhibiting relocation of Nur77 to mitochondria reduced ROS-induced cardiomyocyte injury in metabolic syndrome. - Abstract: Metabolic syndrome is a major risk factor for cardiovascular diseases, and increased cardiomyocyte apoptosis which contributes to cardiac dysfunction after myocardial ischemia/reperfusion (MI/R) injury. Nur77, a nuclear orphan receptor, is involved in such various cellular events as apoptosis, proliferation, and glucose and lipid metabolism in several cell types. Apoptosis is positively correlated with mitochondrial translocation of Nur77 in the cancer cells. However, the roles of Nur77 on cardiac myocytes in patients with metabolic syndrome remain unclear. The objective of this study was to determine whether Nur77 may contribute to cardiac apoptosis in patients with metabolic syndrome after I/R injury, and, if so, to identify the underlying molecular mechanisms responsible. We used leptin-deficient (ob/ob) mice to make metabolic syndrome models. In this report, we observed that, accompanied by the substantial decline in apoptosis inducer Nur77, MI/R induced cardiac dysfunction was manifested as cardiomyopathy and increased ROS. Using the neonatal rat cardiac myocytes cultured in a high-glucose and high-fat medium, we found that excessive H 2 O 2 led to the significant alteration in mitochondrial membrane potential and translocation of Nur77 from the nucleus to the mitochondria. However, inhibition of the relocation of Nur77 to mitochondria via Cyclosporin A reversed the changes in membrane potential mediated by H 2 O 2 and reduced myocardial cell injury. Therefore, these data provide a potential underlying mechanism for cardiac dysfunction in metabolic syndrome and the suppression of Nur77 translocation may provide an effective approach to reduce cardiac injury in the process

  12. The ER stress-mediated mitochondrial apoptotic pathway and MAPKs modulate tachypacing-induced apoptosis in HL-1 atrial myocytes.

    Directory of Open Access Journals (Sweden)

    Jiaojiao Shi

    Full Text Available Cell apoptosis is a contributing factor in the initiation, progression and relapse of atrial fibrillation (AF, a life-threatening illness accompanied with stroke and heart failure. However, the regulatory cascade of apoptosis is intricate and remains unidentified, especially in the setting of AF. The aim of this study was to explore the roles of endoplasmic reticulum (ER stress, mitochondrial apoptotic pathway (MAP, mitogen-activated protein kinases (MAPKs, and their cross-talking in tachypacing-induced apoptosis.HL-1 cells were cultured in the presence of tachypacing for 24 h to simulate atrial tachycardia remodeling. Results showed that tachypacing reduced cell viability measured by the cell counting kit-8, dissipated mitochondrial membrane potential detected by JC-1 staining and resulted in approximately 50% apoptosis examined by Hoechst staining and annexin V/propidium iodide staining. In addition, the proteins involved in ER stress, MAP and MAPKs were universally up-regulated or activated via phosphorylation, as confirmed by western blotting; and reversely silencing of ER stress, caspase-3 (the ultimate executor of MAP and MAPKs with specific inhibitors prior to pacing partially alleviated apoptosis. An inhibitor of ER stress was applied to further investigate the responses of mitochondria and MAPKs to ER stress, and results indicated that suppression of ER stress comprehensively but incompletely attenuated the activation of MAP and MAPKs aroused by tachypacing, with the exception of ERK1/2, one branch of MAPKs.Our study suggested tachypacing-induced apoptosis is regulated by ER stress-mediated MAP and MAPKs. Thus, the above three components are all promising anti-apoptotic targets in AF patients and ER stress appears to play a dominant role due to its comprehensive effects.

  13. Tributyltin induces apoptotic signaling in hepatocytes through pathways involving the endoplasmic reticulum and mitochondria

    International Nuclear Information System (INIS)

    Grondin, Melanie; Marion, Michel; Denizeau, Francine; Averill-Bates, Diana A.

    2007-01-01

    Tri-n-butyltin is a widespread environmental toxicant, which accumulates in the liver. This study investigates whether tri-n-butyltin induces pro-apoptotic signaling in rat liver hepatocytes through pathways involving the endoplasmic reticulum and mitochondria. Tri-n-butyltin activated the endoplasmic reticulum pathway of apoptosis, which was demonstrated by the activation of the protease calpain, its translocation to the plasma membrane, followed by cleavage of the calpain substrates, cytoskeletal protein vinculin, and caspase-12. Caspase-12 is localized to the cytoplasmic side of the endoplasmic reticulum and is involved in apoptosis mediated by the endoplasmic reticulum. Tri-n-butyltin also caused translocation of the pro-apoptotic proteins Bax and Bad from the cytosol to mitochondria, as well as changes in mitochondrial membrane permeability, events which can activate the mitochondrial death pathway. Tri-n-butyltin induced downstream apoptotic events in rat hepatocytes at the nuclear level, detected by chromatin condensation and by confocal microscopy using acridine orange. We investigated whether the tri-n-butyltin-induced pro-apoptotic events in hepatocytes could be linked to perturbation of intracellular calcium homeostasis, using confocal microscopy. Tri-n-butyltin caused changes in intracellular calcium distribution, which were similar to those induced by thapsigargin. Calcium was released from a subcellular compartment, which is likely to be the endoplasmic reticulum, into the cytosol. Cytosolic acidification, which is known to trigger apoptosis, also occurred and involved the Cl - /HCO 3 - exchanger. Pro-apoptotic events in hepatocytes were inhibited by the calcium chelator, Bapta-AM, and by a calpain inhibitor, which suggests that changes in intracellular calcium homeostasis are involved in tri-n-butyltin-induced apoptotic signaling in rat hepatocytes

  14. Glucocorticoid Induced Leucine Zipper inhibits apoptosis of cardiomyocytes by doxorubicin

    International Nuclear Information System (INIS)

    Aguilar, David; Strom, Joshua; Chen, Qin M.

    2014-01-01

    Doxorubicin (Dox) is an indispensable chemotherapeutic agent for the treatment of various forms of neoplasia such as lung, breast, ovarian, and bladder cancers. Cardiotoxicity is a major concern for patients receiving Dox therapy. Previous work from our laboratory indicated that glucocorticoids (GCs) alleviate Dox-induced apoptosis in cardiomyocytes. Here we have found Glucocorticoid-Induced Leucine Zipper (GILZ) to be a mediator of GC-induced cytoprotection. GILZ was found to be induced in cardiomyocytes by GC treatment. Knocking down of GILZ using siRNA resulted in cancelation of GC-induced cytoprotection against apoptosis by Dox treatment. Overexpressing GILZ by transfection was able to protect cells from apoptosis induced by Dox as measured by caspase activation, Annexin V binding and morphologic changes. Western blot analyses indicate that GILZ overexpression prevented cytochrome c release from mitochondria and cleavage of caspase-3. When bcl-2 family proteins were examined, we found that GILZ overexpression causes induction of the pro-survival protein Bcl-xL. Since siRNA against Bcl-xL reverses GC induced cytoprotection, Bcl-xL induction represents an important event in GILZ-induced cytoprotection. Our data suggest that GILZ functions as a cytoprotective gene in cardiomyocytes. - Highlights: • Corticosteroids act as a cytoprotective agent in cardiomyocytes • Corticosteroids induce GILZ expression in cardiomyocytes • Elevated GILZ results in resistance against apoptosis induced by doxorubicin • GILZ induces Bcl-xL protein without inducing Bcl-xL mRNA

  15. Caspase-12 is involved in stretch-induced apoptosis mediated endoplasmic reticulum stress.

    Science.gov (United States)

    Zhang, Qiang; Liu, Jianing; Chen, Shulan; Liu, Jing; Liu, Lijuan; Liu, Guirong; Wang, Fang; Jiang, Wenxin; Zhang, Caixia; Wang, Shuangyu; Yuan, Xiao

    2016-04-01

    It is well recognized that mandibular growth, which is caused by a variety of functional appliances, is considered to be the result of both neuromuscular and skeletal adaptations. Accumulating evidence has demonstrated that apoptosis plays an important role in the adaptation of skeletal muscle function. However, the underlying mechanism of apoptosis that is induced by stretch continues to be incompletely understood. Endoplasmic reticulum stress (ERS), a newly defined signaling pathway, initiates apoptosis. This study seeks to determine if caspase-12 is involved in stretch-induced apoptosis mediated endoplasmic reticulum stress in myoblast and its underlying mechanism. Apoptosis was assessed by Hochest staining, DAPI staining and annexin V binding and PI staining. ER chaperones, such as GRP78, CHOP and caspase-12, were determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Furthermore, caspase-12 inhibitor was used to value the mechanism of the caspase-12 pathway. Apoptosis of myoblast, which is subjected to cyclic stretch, was observed in a time-dependent manner. We found that GRP78 mRNA and protein were significantly increased and CHOP and caspase-12 were activated in myoblast that was exposed to cyclic stretch. Caspase-12 inhibition reduced stretch-induced apoptosis, and caspase-12 activated caspase-3 to induce apoptosis. We concluded that caspase-12 played an important role in stretch-induced apoptosis that is associated by endoplasmic reticulum stress by activating caspase-3.

  16. Study on the apoptosis mediated by cytochrome c and factors that affect the activation of bovine longissimus muscle during postmortem aging.

    Science.gov (United States)

    Zhang, Jiaying; Yu, Qunli; Han, Ling; Chen, Cheng; Li, Hang; Han, Guangxing

    2017-06-01

    This study investigates whether bovine longissimus muscle cell apoptosis occurs during postmortem aging and whether apoptosis is dependent on the mitochondria pathway. This study also determines the apoptosis process mediated by cytochrome c after its release from mitochondria and the factors that affect the activation processes. Results indicate that apoptotic nuclei were detected at 12 h postmortem. Cytochrome c release from the mitochondria to the cytoplasm activated the caspase-9 and caspase-3 at early postmortem aging and the activation of caspase-9 occurs before the activation of caspase-3. The pH level decreased during the first 48 h postmortem, whereas the mitochondria membrane permeability increased from 6 to 12 h. Results demonstrate that an apoptosis process of bovine muscle occurred during postmortem aging. Apoptosis was dependent on the mitochondria pathway and occurred at early postmortem aging. Increased mitochondria membrane permeability and low pH are necessary conditions for the release of cytochrome c during postmortem aging.

  17. Bcl-xL-mediated remodeling of rod and cone synaptic mitochondria after postnatal lead exposure: electron microscopy, tomography and oxygen consumption.

    Science.gov (United States)

    Perkins, Guy A; Scott, Ray; Perez, Alex; Ellisman, Mark H; Johnson, Jerry E; Fox, Donald A

    2012-01-01

    Postnatal lead exposure produces rod-selective and Bax-mediated apoptosis, decreased scotopic electroretinograms (ERGs), and scotopic and mesopic vision deficits in humans and/or experimental animals. Rod, but not cone, inner segment mitochondria were considered the primary site of action. However, photoreceptor synaptic mitochondria were not examined. Thus, our experiments investigated the structural and functional effects of environmentally relevant postnatal lead exposure on rod spherule and cone pedicle mitochondria and whether Bcl-xL overexpression provided neuroprotection. C57BL/6N mice pups were exposed to lead only during lactation via dams drinking water containing lead acetate. The blood [Pb] at weaning was 20.6±4.7 µg/dl, which decreased to the control value by 2 months. To assess synaptic mitochondrial structural differences and vulnerability to lead exposure, wild-type and transgenic mice overexpressing Bcl-xL in photoreceptors were used. Electron microscopy, three-dimensional electron tomography, and retinal and photoreceptor synaptic terminal oxygen consumption (QO(2)) studies were conducted in adult control, Bcl-xL, lead, and Bcl-xL/lead mice. The spherule and pedicle mitochondria in lead-treated mice were swollen, and the cristae structure was markedly changed. In the lead-treated mice, the mitochondrial cristae surface area and volume (abundance: measure correlated with ATP (ATP) synthesis) were decreased in the spherules and increased in the pedicles. Pedicles also had an increased number of crista segments per volume. In the lead-treated mice, the number of segments/crista and fraction of cristae with multiple segments (branching) similarly increased in spherule and pedicle mitochondria. Lead-induced remodeling of spherule mitochondria produced smaller cristae with more branching, whereas pedicle mitochondria had larger cristae with more branching and increased crista junction (CJ) diameter. Lead decreased dark- and light-adapted photoreceptor

  18. Advanced oxidation protein products induce chondrocyte apoptosis via receptor for advanced glycation end products-mediated, redox-dependent intrinsic apoptosis pathway.

    Science.gov (United States)

    Wu, Qian; Zhong, Zhao-Ming; Zhu, Si-Yuan; Liao, Cong-Rui; Pan, Ying; Zeng, Ji-Huan; Zheng, Shuai; Ding, Ruo-Ting; Lin, Qing-Song; Ye, Qing; Ye, Wen-Bin; Li, Wei; Chen, Jian-Ting

    2016-01-01

    Pro-inflammatory cytokine-induced chondrocyte apoptosis is a primary cause of cartilage destruction in the progression of rheumatoid arthritis (RA). Advanced oxidation protein products (AOPPs), a novel pro-inflammatory mediator, have been confirmed to accumulate in patients with RA. However, the effect of AOPPs accumulation on chondrocyte apoptosis and the associated cellular mechanisms remains unclear. The present study demonstrated that the plasma formation of AOPPs was enhanced in RA rats compared with normal. Then, chondrocyte were treated with AOPPs-modified rat serum albumin (AOPPs-RSA) in vitro. Exposure of chondrocyte to AOPPs activated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and increased expression of NADPH oxidase subunits, which was mediated by receptor for advanced glycation end products (RAGE), but not scavenger receptor CD36. Moreover, AOPPs challenge triggered NADPH oxidase-dependent ROS generation which induced mitochondrial dysfunction and endoplasmic reticulum stress resulted in activation of caspase family that eventually lead to apoptosis. Lastly, blockade of RAGE, instead of CD36, largely attenuated these signals. Our study demonstrated first time that AOPPs induce chondrocyte apoptosis via RAGE-mediated and redox-dependent intrinsic apoptosis pathway in vitro. These data implicates that AOPPs may represent a novel pathogenic factor that contributes to RA progression. Targeting AOPPs-triggered cellular mechanisms might emerge as a promising therapeutic option for patients with RA.

  19. Mast cell chymase induces smooth muscle cell apoptosis by disrupting NF-κB-mediated survival signaling

    International Nuclear Information System (INIS)

    Leskinen, Markus J.; Heikkilae, Hanna M.; Speer, Mei Y.; Hakala, Jukka K.; Laine, Mika; Kovanen, Petri T.; Lindstedt, Ken A.

    2006-01-01

    Chymase released from activated mast cells induces apoptosis of vascular smooth muscle cells (SMCs) in vitro by degrading the pericellular matrix component fibronectin, so causing disruption of focal adhesion complexes and Akt dephosphorylation, which are necessary for cell adhesion and survival. However, the molecular mechanisms of chymase-mediated apoptosis downstream of Akt have remained elusive. Here, we show by means of RT-PCR, Western blotting, EMSA, immunocytochemistry and confocal microscopy, that chymase induces SMC apoptosis by disrupting NF-κB-mediated survival signaling. Following chymase treatment, the translocation of active NF-κB/p65 to the nucleus was partly abolished and the amount of nuclear p65 was reduced. Pretreatment of SMCs with chymase also inhibited LPS- and IL-1β-induced nuclear translocation of p65. The chymase-induced degradation of p65 was mediated by active caspases. Loss of NF-κB-mediated transactivation resulted in downregulation of bcl-2 mRNA and protein expression, leading to mitochondrial swelling and release of cytochrome c. The apoptotic process involved activation of both caspase 9 and caspase 8. The results reveal that, by disrupting the NF-κB-mediated survival-signaling pathway, activated chymase-secreting mast cells can mediate apoptosis of cultured arterial SMCs. Since activated mast cells colocalize with apoptotic SMCs in vulnerable areas of human atherosclerotic plaques, they may participate in the weakening and rupture of atherosclerotic plaques

  20. Terpenoids Isolated From the Shoot of Plectranthus hadiensis Induces Apoptosis in Human Colon Cancer Cells Via the Mitochondria-Dependent Pathway.

    Science.gov (United States)

    Menon, Darsan B; Gopalakrishnan, V K

    2015-01-01

    The plant Plectranthus hadiensis is a rich source of many bioactive phytochemicals, especially terpenoids. The terpenoid fraction was isolated and phytochemical characterization was done using GC-MS. The aim of the present study was to find out the antiproliferative activity and the mechanism of cell death induction by the terpenoid fraction on human colon cancer cells (HCT-15). MTT assay was performed with different concentrations of the fraction (10, 20, and 50 µg/mL) to obtain IC50 value for 24 h to induce cell death. The induction of apoptosis were studied by Hoechst staining, acridine orange/ethidium bromide staining, Comet assay, DNA fragmentation, and caspase-3 activity assays. The mechanism of apoptosis induction was studied by expression analysis of antiapoptotic Bcl-2 and proapoptotic Bax using RT-PCR and also by Western blot analysis of proteins involved in the apoptotic pathway. The terpenoid fraction induced significant morphological changes and DNA fragmentation in the cells. Positive Hoechst staining and acridine orange/ethidium bromide staining indicated apoptosis induction by the fraction. DNA fragmentation, which is a characteristic feature of apoptosis, was also observed. Upregulation of caspase-3 activity and proapoptotic Bax, and the downregulation of antiapoptotic Bcl-2 and COX-2 confirmed that the apoptosis induction was via the mitochondria-dependent pathway.

  1. Thioredoxin-2 (TRX-2) is an essential gene regulating mitochondria-dependent apoptosis.

    Science.gov (United States)

    Tanaka, Toru; Hosoi, Fumihito; Yamaguchi-Iwai, Yuko; Nakamura, Hajime; Masutani, Hiroshi; Ueda, Shugo; Nishiyama, Akira; Takeda, Shunichi; Wada, Hiromi; Spyrou, Giannis; Yodoi, Junji

    2002-04-02

    Thioredoxin-2 (Trx-2) is a mitochondria-specific member of the thioredoxin superfamily. Mitochondria have a crucial role in the signal transduction for apoptosis. To investigate the biological significance of Trx-2, we cloned chicken TRX-2 cDNA and generated clones of the conditional Trx-2-deficient cells using chicken B-cell line, DT40. Here we show that TRX-2 is an essential gene and that Trx-2-deficient cells undergo apoptosis upon repression of the TRX-2 transgene, showing an accumulation of intracellular reactive oxygen species (ROS). Cytochrome c is released from mitochondria, while caspase-9 and caspase-3, but not caspase-8, are activated upon inhibition of the TRX-2 transgene. In addition, Trx-2 and cytochrome c are co-immunoprecipitated in an in vitro assay. These results suggest that mitochondrial Trx-2 is essential for cell viability, playing a crucial role in the scavenging ROS in mitochondria and regulating the mitochondrial apoptosis signaling pathway.

  2. Effect of dicycloplatin, a novel platinum chemotherapeutical drug, on inhibiting cell growth and inducing cell apoptosis.

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    Guang-quan Li

    Full Text Available Dicycloplatin, a new supramolecular platinum-based antitumor drug, has been approved by the State Food and Administration (SFDA of China. In this study, we investigated the anticancer activity of dicycloplatin in cancer cells and signaling pathways involved in dicycloplatin-induced apoptosis. Dicycloplatin inhibited the proliferation of cancer cells and increased the percentage of apoptosis in a concentration-dependent manner. Besides, some apoptosis related events were observed after treatment with dicycloplatin, including increase of reactive oxygen species (ROS, collapse of mitochondrial membrane potential (Δψm, release of cytochrome c from the mitochondria to the cytosol, upregulation of p53, which were accompanied by activation of caspase-9, caspase-3, caspase-8, and poly (ADP-ribose polymerase cleavage in a concentration-dependent manner. The role of apoptosis in dicycloplatin-mediated cell death was further confirmed by the concomitant treatment with caspase-8 or caspase-9 inhibitors, which inhibited apoptosis and PARP cleavage. Intracellular glutathione (GSH was also found to inhibit the cytotoxic effect of dicycloplatin. In conclusion, these findings suggest that dicycloplatin induces apoptosis through ROS stress-mediated death receptor pathway and mitochondrial pathway which is similar to carboplatin.

  3. A deficiency of apoptosis inducing factor (AIF in Harlequin mouse heart mitochondria paradoxically reduces ROS generation during ischemia-reperfusion

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    Qun eChen

    2014-07-01

    Full Text Available Background and Aims: AIF (apoptosis inducing factor is a flavin and NADH containing protein located within mitochondria required for optimal function of the respiratory chain. AIF may function as an antioxidant within mitochondria, yet when released from mitochondria it activates caspase-independent cell death. The Harlequin (Hq mouse has a markedly reduced content of AIF, providing an experimental model to query if the main role of AIF in the exacerbation of cell death is enhanced mitochondrial generation of reactive oxygen species (ROS or the activation of cell death programs. We asked if the ROS generation is altered in Hq heart mitochondria at baseline or following ischemia-reperfusion (IR.Methods: Buffer perfused mouse hearts underwent 30 min ischemia and 30 min reperfusion. Mitochondrial function including oxidative phosphorylation and H2O2 generation was measured. Immunoblotting was used to determine the contents of AIF and PAR [poly(ADP-ribose] in cell fractions.Results: There were no differences in the release of H2O2 between wild type (WT and Hq heart mitochondria at baseline. IR increased H2O2 generation from WT but not from Hq mitochondria compared to corresponding time controls. The complex I activity was decreased in WT but not in Hq mice following IR. The relocation of AIF from mitochondria to nucleus was increased in WT but not in Hq mice. IR activated PARP-1 only in WT mice. Cell injury was decreased in Hq mouse heart following in vitro IR.Conclusion: A deficiency of AIF within mitochondria does not increase ROS production during IR, indicating that AIF functions less as an antioxidant within mitochondria. The decreased cardiac injury in Hq mouse heart accompanied by less AIF translocation to the nucleus suggests that AIF relocation, rather than the AIF content within mitochondria, contributes to cardiac injury during IR.

  4. Tempo enhances heat-induced apoptosis by mitochondrial targeting of Bax

    International Nuclear Information System (INIS)

    Zhao, Q.-L.; Fujiwara, Y.; Kondo, T.

    2003-01-01

    A stable membrane-permeable nitroxide, Tempo, exerts an SOD-like antioxidant activity against ROS. Reportedly, Tempo inhibits ROS-induced thymocyte apoptosis, while 10 mM Tempo activates JNK1 to induce apoptosis in breast cancer cells. We have observed that nontoxic 5 mM Tempo enhances suboptimal hyperthermia (44 deg C/10 min)-induced apoptosis in U937 cells. Here we report the enhancing mechanism, focusing on activation and targeting of Bax to mitochondria and cytochrome c release. Methods: U937 cells were treated with either Tempo (5 mM, 37 deg C/10 min), heating (44 deg C/10 min), or Tempo-plus-heating, washed and incubated for various times up to 6 h, until assessing apoptosis, mitochondrial potential (ΔΨ>), and amount of superoxide by flow cytometry using Annexin V-FITC/PI, TMRM, and dihydroethidium, respectively. Bax, Bcl-2 and Bcl-XL, and cytochrome c were detected by western blotting, activated Bax was by immunoprecipitation, and ATP was by a luciferase assay. Bax targeting to and cytochrome c release from mitochorndria were also detected immunocytochemically under fluorescent microscopy. Results and Discussion: Treatment of U937 cells with 5 mM Tempo for 10 min at 37 deg C or suboptimal heating (44 deg C/ 10 min) alone did not induce apoptosis. The combined treatment with 5 mM Tempo and 44 deg C for 10 min dramatically induced ∼90% apoptosis in 6 h, as did the 44 deg C/30 min heating. During the enhanced apoptosis, cytochrome c release progressed. Although signals of Bcl-2, Bcl-XL and Bax in cell lysates were not altered, Bax was specifically activated and translocated to mitochondria after the combined treatment. Further, loss of ΔΨ>and decreases in superoxide and ATP progressed after the combined treatment, suggesting that the treatment may disturb mitochondrial electron transport. Thus, Tempo sensitizes the heat-induced apoptosis through (1) targeting of Bax to mitochondria and releasing cytochrome c, and (2) mitochondrial dysfunction

  5. Arsenic induces cell apoptosis in cultured osteoblasts through endoplasmic reticulum stress

    International Nuclear Information System (INIS)

    Tang, C.-H.; Chiu, Y.-C.; Huang, C.-F.; Chen, Y.-W.; Chen, P.-C.

    2009-01-01

    Osteoporosis is characterized by low bone mass resulting from an imbalance between bone resorption by osteoclasts and bone formation by osteoblasts. Therefore, decreased bone formation by osteoblasts may lead to the development of osteoporosis, and rate of apoptosis is responsible for the regulation of bone formation. Arsenic (As) exists ubiquitously in our environment and increases the risk of neurotoxicity, liver injury, peripheral vascular disease and cancer. However, the effect of As on apoptosis of osteoblasts is mostly unknown. Here, we found that As induced cell apoptosis in osteoblastic cell lines (including hFOB, MC3T3-E1 and MG-63) and mouse bone marrow stromal cells (M2-10B4). As also induced upregulation of Bax and Bak, downregulation of Bcl-2 and dysfunction of mitochondria in osteoblasts. As also triggered endoplasmic reticulum (ER) stress, as indicated by changes in cytosolic-calcium levels. We found that As increased the expression and activities of glucose-regulated protein 78 (GRP78) and calpain. Transfection of cells with GRP78 or calpain siRNA reduced As-mediated cell apoptosis in osteoblasts. Therefore, our results suggest that As increased cell apoptosis in cultured osteoblasts and increased the risk of osteoporosis.

  6. Regulation of apoptosis-inducing factor-mediated, cisplatin-induced apoptosis by Akt

    OpenAIRE

    Yang, X; Fraser, M; Abedini, M R; Bai, T; Tsang, B K

    2008-01-01

    Cisplatin is a first-line chemotherapeutic for ovarian cancer, although chemoresistance limits treatment success. Apoptosis, an important determinant of cisplatin sensitivity, occurs via caspase-dependent and -independent mechanisms. Activation of the protein kinase Akt, commonly observed in ovarian tumours, confers resistance to ovarian cancer cells via inhibition of caspase-dependent apoptosis. However, the effect of Akt on cisplatin-induced, caspase-independent apoptosis remains unclear. W...

  7. Melatonin Reverses Fas, E2F-1 and Endoplasmic Reticulum Stress Mediated Apoptosis and Dysregulation of Autophagy Induced by the Herbicide Atrazine in Murine Splenocytes.

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    Shweta Sharma

    Full Text Available Exposure to the herbicide Atrazine (ATR can cause immunotoxicity, apart from other adverse consequences for animal and human health. We aimed at elucidating the apoptotic mechanisms involved in immunotoxicity of ATR and their attenuation by Melatonin (MEL. Young Swiss mice were divided into control, ATR and MEL+ATR groups based on daily (x14 intraperitoneal administration of the vehicle (normal saline, ATR (100 mg/kg body weight and MEL (20 mg/kg body weight with ATR. Isolated splenocytes were processed for detection of apoptosis by Annexin V-FITC and TUNEL assays, and endoplasmic reticulum (ER stress by immunostaining. Key proteins involved in apoptosis, ER stress and autophagy were quantified by immunoblotting. ATR treatment resulted in Fas-mediated activation of caspases 8 and 3 and inactivation of PARP1 which were inhibited significantly by co-treatment with MEL. MEL also attenuated the ATR-induced, p53 independent mitochondrial apoptosis through upregulation of E2F-1 and PUMA and suppression of their downstream target Bax. An excessive ER stress triggered by ATR through overexpression of ATF-6α, spliced XBP-1, CREB-2 and GADD153 signals was reversed by MEL. MEL also reversed the ATR-induced impairment of autophagy which was indicated by a decline in BECN-1, along with significant enhancement in LC3B-II and p62 expressions. Induction of mitochondrial apoptosis, ER stress and autophagy dysregulation provide a new insight into the mechanism of ATR immunotoxicity. The cytoprotective role of MEL, on the other hand, was defined by attenuation of ER stress, Fas-mediated and p53 independent mitochondria-mediated apoptosis as well as autophagy signals.

  8. The Fas/Fas ligand death receptor pathway contributes to phenylalanine-induced apoptosis in cortical neurons.

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    Xiaodong Huang

    Full Text Available Phenylketonuria (PKU, an autosomal recessive disorder of amino acid metabolism caused by mutations in the phenylalanine hydroxylase (PAH gene, leads to childhood mental retardation by exposing neurons to cytotoxic levels of phenylalanine (Phe. A recent study showed that the mitochondria-mediated (intrinsic apoptotic pathway is involved in Phe-induced apoptosis in cultured cortical neurons, but it is not known if the death receptor (extrinsic apoptotic pathway and endoplasmic reticulum (ER stress-associated apoptosis also contribute to neurodegeneration in PKU. To answer this question, we used specific inhibitors to block each apoptotic pathway in cortical neurons under neurotoxic levels of Phe. The caspase-8 inhibitor Z-IETD-FMK strongly attenuated apoptosis in Phe-treated neurons (0.9 mM, 18 h, suggesting involvement of the Fas receptor (FasR-mediated cell death receptor pathway in Phe toxicity. In addition, Phe significantly increased cell surface Fas expression and formation of the Fas/FasL complex. Blocking Fas/FasL signaling using an anti-Fas antibody markedly inhibited apoptosis caused by Phe. In contrast, blocking the ER stress-induced cell death pathway with salubrinal had no effect on apoptosis in Phe-treated cortical neurons. These experiments demonstrate that the Fas death receptor pathway contributes to Phe-induced apoptosis and suggest that inhibition of the death receptor pathway may be a novel target for neuroprotection in PKU patients.

  9. Hepatoprotective properties of kombucha tea against TBHP-induced oxidative stress via suppression of mitochondria dependent apoptosis.

    Science.gov (United States)

    Bhattacharya, Semantee; Gachhui, Ratan; Sil, Parames C

    2011-06-01

    Kombucha, a fermented tea (KT) is claimed to possess many beneficial properties. Recent studies have suggested that KT prevents paracetamol and carbon tetrachloride-induced hepatotoxicity. We investigated the beneficial role of KT was against tertiary butyl hydroperoxide (TBHP) induced cytotoxicity and cell death in murine hepatocytes. TBHP is a well known reactive oxygen species (ROS) inducer, and it induces oxidative stress in organ pathophysiology. In our experiments, TBHP caused a reduction in cell viability, enhanced the membrane leakage and disturbed the intra-cellular antioxidant machineries while simultaneous treatment of the cells with KT and this ROS inducer maintained membrane integrity and prevented the alterations in the cellular antioxidant status. These findings led us to explore the detailed molecular mechanisms involved in the protective effect of KT. TBHP introduced apoptosis as the primary phenomena of cell death as evidenced by flow cytometric analyses. In addition, ROS generation, changes in the mitochondrial membrane potential, cytochrome c release, activation of caspases (3 and 9) and Apaf-1 were detected confirming involvement of mitochondrial pathway in this pathophysiology. Simultaneous treatment of KT with TBHP, on the other hand, protected the cells against oxidative injury and maintained their normal physiology. In conclusion, KT was found to modulate the oxidative stress induced apoptosis in murine hepatocytes probably due to its antioxidant activity and functioning via mitochondria dependent pathways and could be beneficial against liver diseases, where oxidative stress is known to play a crucial role. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Role of annexin A5 in cisplatin-induced toxicity in renal cells: molecular mechanism of apoptosis.

    Science.gov (United States)

    Jeong, Jin-Joo; Park, Nahee; Kwon, Yeo-Jung; Ye, Dong-Jin; Moon, Aree; Chun, Young-Jin

    2014-01-24

    Annexin A5 belongs to a large family of calcium-binding and phospholipid-binding proteins and may act as an endogenous regulator of various pathophysiological processes. There is increasing evidence that annexin A5 is related to cytotoxicity, but the precise function of this protein has yet to be elucidated. In this study, we aimed to verify the function of annexin A5 in the apoptosis of renal epithelial cells. Real-time PCR and Western blot analysis, together with immunofluorescence analysis, showed that the expression of annexin A5 significantly increased in the presence of cisplatin in both human and rat renal epithelial cells. With regard to the mechanism of cisplatin-induced apoptosis, apoptosis-inducing factor (AIF) release into the cytosol was observed, and the underlying mechanism was identified as voltage-dependent anion channel (VDAC) oligomerization. Mitochondrial membrane potential (Δψm) was found to be greatly disrupted in cisplatin-treated cells. Moreover, cisplatin strongly induced translocation of annexin A5 into mitochondria. To understand the functional significance of annexin A5 in renal cell death, we used a siRNA-mediated approach to knock down annexin A5. Annexin A5 depletion by siRNA led to decreased annexin A5 translocation into mitochondria and significantly reduced VDAC oligomerization and AIF release. Annexin A5 siRNA also increased cell viability compared with the control. Moreover, expression of annexin A5 was induced by other nephrotoxicants such as CdCl2 and bacitracin. Taken together, our data suggest that annexin A5 may play a crucial role in cisplatin-induced toxicity by mediating the mitochondrial apoptotic pathway via the induction and oligomerization of VDAC.

  11. BIM is the primary mediator of MYC-induced apoptosis in multiple solid tissues.

    Science.gov (United States)

    Muthalagu, Nathiya; Junttila, Melissa R; Wiese, Katrin E; Wolf, Elmar; Morton, Jennifer; Bauer, Barbara; Evan, Gerard I; Eilers, Martin; Murphy, Daniel J

    2014-09-11

    MYC is one of the most frequently overexpressed oncogenes in human cancer, and even modestly deregulated MYC can initiate ectopic proliferation in many postmitotic cell types in vivo. Sensitization of cells to apoptosis limits MYC's oncogenic potential. However, the mechanism through which MYC induces apoptosis is controversial. Some studies implicate p19ARF-mediated stabilization of p53, followed by induction of proapoptotic BH3 proteins NOXA and PUMA, whereas others argue for direct regulation of BH3 proteins, especially BIM. Here, we use a single experimental system to systematically evaluate the roles of p19ARF and BIM during MYC-induced apoptosis, in vitro, in vivo, and in combination with a widely used chemotherapeutic, doxorubicin. We find a common specific requirement for BIM during MYC-induced apoptosis in multiple settings, which does not extend to the p53-responsive BH3 family member PUMA, and find no evidence of a role for p19ARF during MYC-induced apoptosis in the tissues examined. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Qualitative and Quantitative Analysis of ROS-Mediated Oridonin-Induced Oesophageal Cancer KYSE-150 Cell Apoptosis by Atomic Force Microscopy.

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    Jiang Pi

    Full Text Available High levels of intracellular reactive oxygen species (ROS in cells is recognized as one of the major causes of cancer cell apoptosis and has been developed into a promising therapeutic strategy for cancer therapy. However, whether apoptosis associated biophysical properties of cancer cells are related to intracellular ROS functions is still unclear. Here, for the first time, we determined the changes of biophysical properties associated with the ROS-mediated oesophageal cancer KYSE-150 cell apoptosis using high resolution atomic force microscopy (AFM. Oridonin was proved to induce ROS-mediated KYSE-150 cell apoptosis in a dose dependent manner, which could be reversed by N-acetylcysteine (NAC pretreatment. Based on AFM imaging, the morphological damage and ultrastructural changes of KYSE-150 cells were found to be closely associated with ROS-mediated oridonin-induced KYSE-150 cell apoptosis. The changes of cell stiffness determined by AFM force measurement also demonstrated ROS-dependent changes in oridonin induced KYSE-150 cell apoptosis. Our findings not only provided new insights into the anticancer effects of oridonin, but also highlighted the use of AFM as a qualitative and quantitative nanotool to detect ROS-mediated cancer cell apoptosis based on cell biophysical properties, providing novel information of the roles of ROS in cancer cell apoptosis at nanoscale.

  13. A fraction from Petiveria alliacea induces apoptosis via a mitochondria-dependent pathway and regulates HSP70 expression

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    Susana Fiorentino

    2009-12-01

    Full Text Available To evaluate the biological activity of Petiveria alliacea extracts on tumoral cells in vitro. Materials and methods. P.alliaceafractions prepared by a bioguided purification protocol were characterized by their biological activities on two human tumoral cell lines.Morphological changes, cell viability, mitochondrial membrane depolarization, nuclear staining and activity on HSP70 were analyzed.Results. The present study demonstrates that P.alliacea fractions can induce apoptosis in a mitochondria-dependent pathway and downregulate HSP70 expression in vitro. The possible compounds present in P.alliacea responsible for the described biological activities wereidentified by dereplication methods. Conclusion. The present study provides new knowledge on the antitumoral properties of the plantspecies P. alliacea described in several ethnobotanical studies.

  14. Silver Nanoparticles Induce HePG-2 Cells Apoptosis Through ROS-Mediated Signaling Pathways

    Science.gov (United States)

    Zhu, Bing; Li, Yinghua; Lin, Zhengfang; Zhao, Mingqi; Xu, Tiantian; Wang, Changbing; Deng, Ning

    2016-04-01

    Recently, silver nanoparticles (AgNPs) have been shown to provide a novel approach to overcome tumors, especially those of hepatocarcinoma. However, the anticancer mechanism of silver nanoparticles is unclear. Thus, the purpose of this study was to estimate the effect of AgNPs on proliferation and activation of ROS-mediated signaling pathway on human hepatocellular carcinoma HePG-2 cells. A simple chemical method for preparing AgNPs with superior anticancer activity has been showed in this study. AgNPs were detected by transmission electronic microscopy (TEM) and energy dispersive X-ray (EDX). The size distribution and zeta potential of silver nanoparticles were detected by Zetasizer Nano. The average size of AgNPs (2 nm) observably increased the cellular uptake by endocytosis. AgNPs markedly inhibited the proliferation of HePG-2 cells through induction of apoptosis with caspase-3 activation and PARP cleavage. AgNPs with dose-dependent manner significantly increased the apoptotic cell population (sub-G1). Furthermore, AgNP-induced apoptosis was found dependent on the overproduction of reactive oxygen species (ROS) and affecting of MAPKs and AKT signaling and DNA damage-mediated p53 phosphorylation to advance HePG-2 cells apoptosis. Therefore, our results show that the mechanism of ROS-mediated signaling pathways may provide useful information in AgNP-induced HePG-2 cell apoptosis.

  15. Bid-Induced Release of AIF/EndoG from Mitochondria Causes Apoptosis of Macrophages during Infection with Leptospira interrogans

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    Wei-Lin Hu

    2017-11-01

    Full Text Available Leptospirosis is a global zoonotic infectious disease caused by pathogenic Leptospira species. Leptospire-induced macrophage apoptosis through the Fas/FasL-caspase-8/3 pathway plays an important role in the survival and proliferation of the pathogen in hosts. Although, the release of mitochondrial apoptosis-inducing factor (AIF and endonuclease G (EndoG in leptospire-infected macrophages has been described, the mechanisms linking caspase and mitochondrion-related host-cell apoptosis has not been determined. Here, we demonstrated that leptospire-infection induced apoptosis through mitochondrial damages in macrophages. Apoptosis was caused by the mitochondrial release and nuclear translocation of AIF and/or EndoG, leading to nuclear DNA fragmentation. However, the mitochondrion-related CytC-caspase-9/3 pathway was not activated. Next, we found that the release and translocation of AIF and/or EndoG was preceded by the activation of the BH3-interacting domain death agonist (Bid. Furthermore, our data demonstrated that caspase-8 was activated during the infection and caused the activation of Bid. Meanwhile, high reactive oxygen species (ROS trigged by the infection caused the dephosphorylation of Akt, which also activated Bid. In conclusion, Bid-mediated mitochondrial release of AIF and/or EndoG followed by nuclear translocation is a major mechanism of leptospire- induced apoptosis in macrophages, and this process is modulated by both caspase-8 and ROS-Akt signal pathways.

  16. Physcion induces mitochondria-driven apoptosis in colorectal cancer cells via downregulating EMMPRIN.

    Science.gov (United States)

    Chen, Xuehong; Gao, Hui; Han, Yantao; Ye, Junli; Xie, Jing; Wang, Chunbo

    2015-10-05

    Physcion, an anthraquinone derivative widely isolated and characterized from both terrestrial and marine sources, has anti-tumor effects on a variety of carcinoma cells, mainly through inhibition of cell proliferation, apoptosis induction and cell cycle arrest. However, little is known about the mechanisms underlying its role in tumor progression. In the present study, we investigated the molecular mechanisms involved in physcion-induced apoptosis in human colorectal cancer (CRC) lines HCT116. Our results showed that physcion inhibited tumor cell viability in a dose- and time-dependent manner, and induced cell apoptosis via intrinsic mitochondrial pathway. Our results also revealed that physcion treatment significantly inhibited extracelluar matrix metalloproteinase inducer (EMMPRIN) expression in HCT116 cells in a dose-dependent manner and overexpression of EMMPRIN protein markedly reduced physcion-induced cell apoptosis. Furthermore, our results strongly indicated the modulating effect of physcion on EMMPRIN is correlated with AMP-activated protein kinase (AMPK)/Hypoxia-inducible factor 1α (HIF-1α) signaling pathway. Our data provide the first experimental evidence that physcion induces mitochondrial apoptosis in CRC cells by downregulating of EMMPRIN via AMPK/HIF-1α signaling pathway and suggest a new mechanism to explain its anti-tumor effects. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. [Gefitineb inhibits the growth and induces the apoptosis of mouse I-10 Leydig testicular cancer cells in vitro].

    Science.gov (United States)

    Ji, Jie; Tong, Xu-hui; Zhang, Xin-yu; Gao, Qin; Li, Bei-bei; Wu, Xiao-xiang

    2015-09-01

    To observe the inhibitory effect of gefitineb on the proliferation and its inducing effect on the apoptosis of mouse I-10 Leydig testicular cancer cells in vitro. We treated I-10 Leydig testicular cancer cells of mice with gefitineb at 0, 1.25, 2.5, 5, 10, 20, and 40 µmol/L. Then we determined the inhibitory effect of gefitineb on the growth of the cells by MTT, detected their early and late apoptosis by Annexin V-FITC/propidium iodide double staining and Hoechst 33258 nuclear staining, respectively, and observed the expressions of apoptosis-related proteins Bcl-2, Bax and caspase 3/9 by Western blot. Compared with the blank control group, gefitineb significantly inhibited the proliferation of the I-10 cells at 10 and 20 µmol/L (P testicular cancer cells of mice and induce their apoptosis via the mitochondria-mediated apoptosis signaling pathway.

  18. LW6, a hypoxia-inducible factor 1 inhibitor, selectively induces apoptosis in hypoxic cells through depolarization of mitochondria in A549 human lung cancer cells.

    Science.gov (United States)

    Sato, Mariko; Hirose, Katsumi; Kashiwakura, Ikuo; Aoki, Masahiko; Kawaguchi, Hideo; Hatayama, Yoshiomi; Akimoto, Hiroyoshi; Narita, Yuichiro; Takai, Yoshihiro

    2015-09-01

    Hypoxia‑inducible factor 1 (HIF‑1) activates the transcription of genes that act upon the adaptation of cancer cells to hypoxia. LW6, an HIF‑1 inhibitor, was hypothesized to improve resistance to cancer therapy in hypoxic tumors by inhibiting the accumulation of HIF‑1α. A clear anti‑tumor effect under low oxygen conditions would indicate that LW6 may be an improved treatment strategy for cancer in hypoxia. In the present study, the HIF‑1 inhibition potential of LW6 on the growth and apoptosis of A549 lung cancer cells in association with oxygen availability was evaluated. LW6 was observed to inhibit the expression of HIF‑1α induced by hypoxia in A549 cells at 20 mM, independently of the von Hippel‑Lindau protein. In addition, at this concentration, LW6 induced hypoxia‑selective apoptosis together with a reduction in the mitochondrial membrane potential. The intracellular reactive oxygen species levels increased in LW6‑treated hypoxic A549 cells and LW6 induced a hypoxia‑selective increase of mitochondrial O2•‑. In conclusion, LW6 inhibited the growth of hypoxic A549 cells by affecting the mitochondria. The inhibition of the mitochondrial respiratory chain is suggested as a potentially effective strategy to target apoptosis in cancer cells.

  19. Functional analysis of molecular mechanisms of radiation induced apoptosis, that are not mediated by DNA damages

    International Nuclear Information System (INIS)

    Angermeier, Marita; Moertl, Simone

    2012-01-01

    The effects of low-dose irradiation pose new challenges on the radiation protection efforts. Enhanced cellular radiation sensitivity is displayed by disturbed cellular reactions and resulting damage like cell cycle arrest, DNA repair and apoptosis. Apoptosis serves as genetically determinate parameter for the individual radiation sensitivity. In the frame of the project the radiation-induced apoptosis was mechanistically investigated. Since ionizing radiation induced direct DNA damage and generates a reactive oxygen species, the main focus of the research was the differentiation and weighting of DNA damage mediated apoptosis and apoptosis caused by the reactive oxygen species (ROS).

  20. Connective tissue growth factor mediates TGF-β1-induced low-grade serous ovarian tumor cell apoptosis.

    Science.gov (United States)

    Cheng, Jung-Chien; Chang, Hsun-Ming; Leung, Peter C K

    2017-10-17

    Ovarian low-grade serous carcinoma (LGSC) is a rare disease and is now considered to be a distinct entity from high-grade serous carcinoma (HGSC), which is the most common and malignant form of epithelial ovarian cancer. Connective tissue growth factor (CTGF) is a secreted matricellular protein that has been shown to modulate many biological functions by interacting with multiple molecules in the microenvironment. Increasing evidence indicates that aberrant expression of CTGF is associated with cancer development and progression. Transforming growth factor-β1 (TGF-β1) is a well-known molecule that can strongly up-regulate CTGF expression in different types of normal and cancer cells. Our previous study demonstrated that TGF-β1 induces apoptosis of LGSC cells. However, the effect of TGF-β1 on CTGF expression in LGSC needs to be defined. In addition, whether CTGF mediates TGF-β1-induced LGSC cell apoptosis remains unknown. In the present study, we show that TGF-β1 treatment up-regulates CTGF expression by activating SMAD3 signaling in two human LGSC cell lines. Additionally, siRNA-mediated CTGF knockdown attenuates TGF-β1-induced cell apoptosis. Moreover, our results show that the inhibitory effect of the CTGF knockdown on TGF-β1-induced cell apoptosis is mediated by down-regulating SMAD3 expression. This study demonstrates an important role for CTGF in mediating the pro-apoptotic effects of TGF-β1 on LGCS.

  1. Multiple signal transduction pathways in okadaic acid induced apoptosis in HeLa cells

    International Nuclear Information System (INIS)

    Jayaraj, R.; Gupta, Nimesh; Rao, P.V. Lakshmana

    2009-01-01

    Okadaic acid (OA) is the major component of diarrhetic shell fish poisoning toxins and a potent inhibitor of protein phosphatase 1 and 2A. We investigated the signal transduction pathways involved in OA induced cell death in HeLa cells. OA induced cytotoxicity and apoptosis at IC50 of 100 nM. OA treatment resulted in time dependent increase in reactive oxygen species and depleted intracellular glutathione levels. Loss of mitochondrial membrane permeability led to translocation of bax, cytochrome-c and AIF from mitochondria to cytosol. The cells under fluorescence microscope showed typical apoptotic morphology with condensed chromatin, and nuclear fragmentation. We investigated the mitochondrial-mediated caspase cascade. The time dependent activation and cleavage of of bax, caspases-8, 10, 9, 3 and 7 was observed in Western blot analysis. In addition to caspase-dependent pathway AIF mediated caspase-independent pathway was involved in OA mediated cell death. OA also caused time dependent inhibition of protein phosphatase 2A activity and phosphorylation of p38 and p42/44 MAP kinases. Inhibitor studies with Ac-DEVO-CHO and Z-VAD-FMK could not prevent the phosphorylation of p38 and p42/44 MAP kinases. Our experiments with caspase inhibitors Ac-DEVD-CHO, Z-IETD-FMK and Z-VAD-FMK inhibited capsase-3, 8 cleavages but did not prevent OA-induced apoptosis and DNA fragmentation. Similarly, pretreatment with cyclosporin-A and N-acetylcysteine could not prevent the DNA fragmentation. In summary, the results of our study show that OA induces multiple signal transduction pathways acting either independently or simultaneously leading to apoptosis

  2. Mequindox-Induced Kidney Toxicity Is Associated With Oxidative Stress and Apoptosis in the Mouse

    Directory of Open Access Journals (Sweden)

    Qianying Liu

    2018-05-01

    Full Text Available Mequindox (MEQ, belonging to quinoxaline-di-N-oxides (QdNOs, is a synthetic antimicrobial agent widely used in China. Previous studies found that the kidney was one of the main toxic target organs of the QdNOs. However, the mechanisms underlying the kidney toxicity caused by QdNOs in vivo still remains unclear. The present study aimed to explore the molecular mechanism of kidney toxicity in mice after chronic exposure to MEQ. MEQ led to the oxidative stress, apoptosis, and mitochondrial damage in the kidney of mice. Meanwhile, MEQ upregulated Bax/Bcl-2 ratio, disrupted mitochondrial permeability transition pores, caused cytochrome c release, and a cascade activation of caspase, eventually induced apoptosis. The oxidative stress mediated by MEQ might led to mitochondria damage and apoptosis in a mitochondrial-dependent apoptotic pathway. Furthermore, upregulation of the Nrf2-Keap1 signaling pathway was also observed. Our findings revealed that the oxidative stress, mitochondrial dysfunction, and the Nrf2-Keap1 signaling pathway were associated with the kidney apoptosis induced by MEQ in vivo.

  3. A microtubule inhibitor, ABT-751, induces autophagy and delays apoptosis in Huh-7 cells

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Ren-Jie [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Department of Pathology, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan (China); Lin, Su-Shuan [Department of Pathology, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan (China); Wu, Wen-Ren [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Chen, Lih-Ren [Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Division of Physiology, Livestock Research Institute, Council of Agriculture, Taiwan (China); Li, Chien-Feng [Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Department of Pathology, Chi-Mei Medical Center, Tainan, Taiwan (China); National Institute of Cancer Research, National Health Research Institute, Tainan, Taiwan (China); Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Chen, Han-De; Chou, Chien-Ting; Chen, Ya-Chun [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Liang, Shih-Shin [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Chien, Shang-Tao [Department of Pathology, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan (China); Shiue, Yow-Ling, E-mail: ylshiue@mail.nsysu.edu.tw [Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan (China)

    2016-11-15

    The objective was to investigate the upstream mechanisms of apoptosis which were triggered by a novel anti-microtubule drug, ABT-751, in hepatocellular carcinoma-derived Huh-7 cells. Effects of ABT-751 were evaluated by immunocytochemistry, flow cytometric, alkaline comet, soft agar, immunoblotting, CytoID, green fluorescent protein-microtubule associated protein 1 light chain 3 beta detection, plasmid transfection, nuclear/cytosol fractionation, coimmunoprecipitation, quantitative reverse transcription-polymerase chain reaction, small-hairpin RNA interference and mitochondria/cytosol fractionation assays. Results showed that ABT-751 caused dysregulation of microtubule, collapse of mitochondrial membrane potential, generation of reactive oxygen species (ROS), DNA damage, G{sub 2}/M cell cycle arrest, inhibition of anchorage-independent cell growth and apoptosis in Huh-7 cells. ABT-751 also induced early autophagy via upregulation of nuclear TP53 and downregulation of the AKT serine/threonine kinase (AKT)/mechanistic target of rapamycin (MTOR) pathway. Through modulation of the expression levels of DNA damage checkpoint proteins and G{sub 2}/M cell cycle regulators, ABT-751 induced G{sub 2}/M cell cycle arrest. Subsequently, ABT-751 triggered apoptosis with marked downregulation of B-cell CLL/lymphoma 2, upregulation of mitochondrial BCL2 antagonist/killer 1 and BCL2 like 11 protein levels, and cleavages of caspase 8 (CASP8), CASP9, CASP3 and DNA fragmentation factor subunit alpha proteins. Suppression of ROS significantly decreased ABT-751-induced autophagic and apoptotic cells. Pharmacological inhibition of autophagy significantly increased the percentages of ABT-751-induced apoptotic cells. The autophagy induced by ABT-751 plays a protective role to postpone apoptosis by exerting adaptive responses following microtubule damage, ROS and/or impaired mitochondria. - Highlights: • An anti-microtubule agent, ABT-751, induces autophagy and apoptosis in Huh-7 cells.

  4. Apoptosis in Drosophila: which role for mitochondria?

    Science.gov (United States)

    Clavier, Amandine; Rincheval-Arnold, Aurore; Colin, Jessie; Mignotte, Bernard; Guénal, Isabelle

    2016-03-01

    It is now well established that the mitochondrion is a central regulator of mammalian cell apoptosis. However, the importance of this organelle in non-mammalian apoptosis has long been regarded as minor, mainly because of the absence of a crucial role for cytochrome c in caspase activation. Recent results indicate that the control of caspase activation and cell death in Drosophila occurs at the mitochondrial level. Numerous proteins, including RHG proteins and proteins of the Bcl-2 family that are key regulators of Drosophila apoptosis, constitutively or transiently localize in mitochondria. These proteins participate in the cell death process at different levels such as degradation of Diap1, a Drosophila IAP, production of mitochondrial reactive oxygen species or stimulation of the mitochondrial fission machinery. Here, we review these mitochondrial events that might have their counterpart in human.

  5. Hepatitis E Virus Induces Hepatocyte Apoptosis via Mitochondrial Pathway in Mongolian Gerbils

    Directory of Open Access Journals (Sweden)

    Yifei Yang

    2018-03-01

    Full Text Available Previous studies demonstrated that Mongolian gerbils can be infected by hepatitis E virus (HEV, which induces the hepatic injury. Here, the mitochondria in hepatocytes from HEV-infected gerbils were considerably swollen, thin cristae. After HEV infection, the activity of superoxide dismutase significantly decreased (p < 0.01, while malondialdehyde concentrations significantly increased, compared with those in the control group (p < 0.01. Adenosine triphosphatase levels decreased significantly in the hepatocyte of the inoculated groups, compared with those in control group (p < 0.05 at days 21, 28, 42 post-inoculation (dpi as well. Furthermore, the levels of ATP synthetase ATP5A1 significantly decreased during HEV infection, compared with those in the control group (p < 0.05. According to the TdT mediated dUTP nick end labeling (TUNEL detection, TUNEL positive hepatocytes increased in the inoculated group, compared with that in the control group (p < 0.05. Up-regulation of the mitochondrion-mediated apoptosis regulating proteins, Bax and Bcl-2, in the HEV-infected gerbils (p < 0.05 was observed. However, cytochrome c levels in mitochondria decreased, while this molecule was detected in the cytoplasm of the infected animals, in contrast to that in the control group. Apaf-1, and active caspase-9 and -3 levels were shown to be significantly higher in the inoculated group compared with those in the control group (p < 0.05. Taken together, our results demonstrated that HEV infection induces hepatocyte injuries and activity of the mitochondrial apoptotic pathway, which trigger the hepatocyte apoptosis in Mongolian gerbils.

  6. Menadione induces the formation of reactive oxygen species and depletion of GSH-mediated apoptosis and inhibits the FAK-mediated cell invasion.

    Science.gov (United States)

    Kim, Yun Jeong; Shin, Yong Kyoo; Sohn, Dong Suep; Lee, Chung Soo

    2014-09-01

    Menadione induces apoptosis in tumor cells. However, the mechanism of apoptosis in ovarian cancer cells exposed to menadione is not clear. In addition, it is unclear whether menadione-induced apoptosis is mediated by the depletion of glutathione (GSH) contents that is associated with the formation of reactive oxygen species. Furthermore, the effect of menadione on the invasion and migration of human epithelial ovarian cancer cells has not been studied. Therefore, we investigated the effects of menadione exposure on apoptosis, cell adhesion, and cell migration using the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. The results suggest that menadione may induce apoptotic cell death in ovarian carcinoma cell lines by activating the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The apoptotic effect of menadione appears to be mediated by the formation of reactive oxygen species and the depletion of GSH. Menadione inhibited fetal-bovine-serum-induced cell adhesion and migration of OVCAR-3 cells, possibly through the suppression the focal adhesion kinase (FAK)-dependent activation of cytoskeletal-associated components. Therefore, menadione might be beneficial in the treatment of epithelial ovarian adenocarcinoma and combination therapy.

  7. Bullatacin Triggered ABCB1-Overexpressing Cell Apoptosis via the Mitochondrial-Dependent Pathway

    Directory of Open Access Journals (Sweden)

    Yong-Ju Liang

    2009-01-01

    Full Text Available This paper was to explore bullatacin-mediated multidrug-resistant cell apoptosis at extremely low concentration. To investigate its precise mechanisms, the pathway of cell apoptosis induced by bullatacin was examined. Bullatacin causes an upregulation of ROS and a downregulation of ΔΨm in a concentration-dependent manner in ABCB1-overexpressing KBv200 cells. In addition, cleavers of caspase-9, caspase-3, and PARP were observed following the release of cytochrome c from mitochondria after bullatacin treatment. However, neither cleavage of caspase-8 nor change of expression level of bcl-2, bax and Fas was observed by the same treatment. Pretreating KBv200 cells with N-acetylcysteine, an antioxidant modulator, resulted in a significant reduction of ROS generation and cell apoptosis induced by bullatacin. Bullatacin-induced apoptosis was antagonized by z-LEHD-fmk, a caspase-9 inhibitor, but not by z-IETD-fmk, a caspase-8 inhibitor. These implied that apoptosis of KBv200 cells induced by bullatacin was associated with the mitochondria-dependent pathway that was limited to activation of apical caspase-9.

  8. Identification of RIP1 as a critical mediator of Smac mimetic-mediated sensitization of glioblastoma cells for Drozitumab-induced apoptosis.

    Science.gov (United States)

    Cristofanon, S; Abhari, B A; Krueger, M; Tchoghandjian, A; Momma, S; Calaminus, C; Vucic, D; Pichler, B J; Fulda, S

    2015-04-16

    This study aims at evaluating the combination of the tumor-necrosis-factor-related apoptosis-inducing ligand (TRAIL)-receptor 2 (TRAIL-R2)-specific antibody Drozitumab and the Smac mimetic BV6 in preclinical glioblastoma models. To this end, the effect of BV6 and/or Drozitumab on apoptosis induction and signaling pathways was analyzed in glioblastoma cell lines, primary glioblastoma cultures and glioblastoma stem-like cells. Here, we report that BV6 and Drozitumab synergistically induce apoptosis and reduce colony formation in several glioblastoma cell lines (combination indextrigger the formation of a cytosolic receptor-interacting protein (RIP) 1/Fas-associated via death domain (FADD)/caspase-8-containing complex and subsequent activation of caspase-8 and -3. BV6- and Drozitumab-induced apoptosis is blocked by the caspase inhibitor zVAD.fmk, pointing to caspase-dependent apoptosis. RNA interference-mediated silencing of RIP1 almost completely abolishes the BV6-conferred sensitization to Drozitumab-induced apoptosis, indicating that the synergism critically depends on RIP1 expression. In contrast, both necrostatin-1, a RIP1 kinase inhibitor, and Enbrel, a TNFα-blocking antibody, do not interfere with BV6/Drozitumab-induced apoptosis, demonstrating that apoptosis occurs independently of RIP1 kinase activity or an autocrine TNFα loop. In conclusion, the rational combination of BV6 and Drozitumab presents a promising approach to trigger apoptosis in glioblastoma, which warrants further investigation.

  9. Milestones and recent discoveries on cell death mediated by mitochondria and their interactions with biologically active amines.

    Science.gov (United States)

    Grancara, Silvia; Ohkubo, Shinji; Artico, Marco; Ciccariello, Mauro; Manente, Sabrina; Bragadin, Marcantonio; Toninello, Antonio; Agostinelli, Enzo

    2016-10-01

    Mitochondria represent cell "powerhouses," being involved in energy transduction from the electrochemical gradient to ATP synthesis. The morphology of their cell types may change, according to various metabolic processes or osmotic pressure. A new morphology of the inner membrane and mitochondrial cristae, significantly different from the previous one, has been proposed for the inner membrane and mitochondrial cristae, based on the technique of electron tomography. Mitochondrial Ca(2+) transport (the transporter has been isolated) generates reactive oxygen species and induces the mitochondrial permeability transition of both inner and outer mitochondrial membranes, leading to induction of necrosis and apoptosis. In the mitochondria of several cell types (liver, kidney, and heart), mitochondrial oxidative stress is an essential step in the induction of cell death, although not in brain, in which the phenomenon is caused by a different mechanism. Mitochondrial permeability transition drives both apoptosis and necrosis, whereas mitochondrial outer membrane permeability is characteristic of apoptosis. Adenine nucleotide translocase remains the most important component involved in membrane permeability, with the opening of the transition pore, although other proteins, such as ATP synthase or phosphate carriers, have been proposed. Intrinsic cell death is triggered by the release from mitochondria of proteic factors, such as cytochrome c, apoptosis inducing factor, and Smac/DIABLO, with the activation of caspases upon mitochondrial permeability transition or mitochondrial outer membrane permeability induction. Mitochondrial permeability transition induces the permeability of the inner membrane in sites in contact with the outer membrane; mitochondrial outer membrane permeability forms channels on the outer membrane by means of various stimuli involving Bcl-2 family proteins. The biologically active amines, spermine, and agmatine, have specific functions on mitochondria

  10. High glucose-induced Ca2+ overload and oxidative stress contribute to apoptosis of cardiac cells through mitochondrial dependent and independent pathways.

    Science.gov (United States)

    Kumar, Sandeep; Kain, Vasundhara; Sitasawad, Sandhya L

    2012-07-01

    Cardiac cell apoptosis is the initiating factor of cardiac complications especially diabetic cardiomyopathy. Mitochondria are susceptible to the damaging effects of elevated glucose condition. Calcium overload and oxidative insult are the two mutually non-exclusive phenomena suggested to cause cardiac dysfunction. Here, we examined the effect of high-glucose induced calcium overload in calpain-1 mediated cardiac apoptosis in an in vitro setting. H9c2, rat ventricular myoblast cell line was treated with elevated glucose condition and the cellular consequences were studied. Intracellular calcium trafficking, ROS generation, calpain-1 activation and caspase-12 and caspase-9 pathway were studied using flow cytometry, confocal microscopy and Western blot analysis. High-glucose treatment resulted in increased intracellular calcium ([Ca2+]i) which was mobilized to the mitochondria. Concomitant intra-mitochondrial calcium ([Ca2+]m) increase resulted in enhanced reactive oxygen and nitrogen species generation. These events led to mitochondrial dysfunction and apoptosis. Cardiomyocyte death exhibited several classical markers of apoptosis, including activation of caspases, appearance of annexin V on the outer plasma membrane, increased population of cells with sub-G0/G1 DNA content and nuclear condensation. Key findings include elucidation of cell signaling mechanism of high-glucose induced calcium-dependent cysteine protease calpain-1 activation, which triggers non-conventional caspases as alternate mode of cell death. This information increases the understanding of cardiac cell death under hyperglycemic condition and can possibly be extended for designing new therapeutic strategies for diabetic cardiomyopathy. The novel findings of the study reveal that high glucose induces apoptosis by both mitochondria-dependent and independent pathways via concomitant rise in intracellular calcium. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Exogenous ether lipids predominantly target mitochondria.

    Directory of Open Access Journals (Sweden)

    Lars Kuerschner

    Full Text Available Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high amounts of ether-phosphatidylcholine and ether-phosphatidylethanolamine. Both lipids were specifically labeled using the corresponding lyso-ether lipids, which we established as supreme precursors for lipid tagging. Polyfosine, a fluorescent analogue of the anti-neoplastic ether lipid edelfosine, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria in ether lipid metabolism and intracellular ether lipid trafficking.

  12. Mitochondrial dysfunction in lyssavirus-induced apoptosis.

    Science.gov (United States)

    Gholami, Alireza; Kassis, Raïd; Real, Eléonore; Delmas, Olivier; Guadagnini, Stéphanie; Larrous, Florence; Obach, Dorothée; Prevost, Marie-Christine; Jacob, Yves; Bourhy, Hervé

    2008-05-01

    Lyssaviruses are highly neurotropic viruses associated with neuronal apoptosis. Previous observations have indicated that the matrix proteins (M) of some lyssaviruses induce strong neuronal apoptosis. However, the molecular mechanism(s) involved in this phenomenon is still unknown. We show that for Mokola virus (MOK), a lyssavirus of low pathogenicity, the M (M-MOK) targets mitochondria, disrupts the mitochondrial morphology, and induces apoptosis. Our analysis of truncated M-MOK mutants suggests that the information required for efficient mitochondrial targeting and dysfunction, as well as caspase-9 activation and apoptosis, is held between residues 46 and 110 of M-MOK. We used a yeast two-hybrid approach, a coimmunoprecipitation assay, and confocal microscopy to demonstrate that M-MOK physically associates with the subunit I of the cytochrome c (cyt-c) oxidase (CcO) of the mitochondrial respiratory chain; this is in contrast to the M of the highly pathogenic Thailand lyssavirus (M-THA). M-MOK expression induces a significant decrease in CcO activity, which is not the case with M-THA. M-MOK mutations (K77R and N81E) resulting in a similar sequence to M-THA at positions 77 and 81 annul cyt-c release and apoptosis and restore CcO activity. As expected, the reverse mutations, R77K and E81N, introduced in M-THA induce a phenotype similar to that due to M-MOK. These features indicate a novel mechanism for energy depletion during lyssavirus-induced apoptosis.

  13. Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways

    International Nuclear Information System (INIS)

    Nguyen Ngoc, Tam Dan; Son, Young-Ok; Lim, Shin-Saeng; Shi, Xianglin; Kim, Jong-Ghee; Heo, Jung Sun; Choe, Youngji; Jeon, Young-Mi; Lee, Jeong-Chae

    2012-01-01

    Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G 2 /M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45α. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-α or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ► The mode of NaF-induced cell death and the mechanisms involved were examined. ► NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ► NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ► JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ► ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

  14. Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Ngoc, Tam Dan [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Son, Young-Ok [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Lim, Shin-Saeng [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Kim, Jong-Ghee [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Heo, Jung Sun [Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Choe, Youngji [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Jeon, Young-Mi, E-mail: young@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Lee, Jeong-Chae, E-mail: leejc88@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2012-03-15

    Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G{sub 2}/M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45α. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-α or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ► The mode of NaF-induced cell death and the mechanisms involved were examined. ► NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ► NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ► JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ► ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

  15. Toxicity of Atorvastatin on Pancreas Mitochondria: A Justification for Increased Risk of Diabetes Mellitus.

    Science.gov (United States)

    Sadighara, Melina; Amirsheardost, Zahra; Minaiyan, Mohsen; Hajhashemi, Valiollah; Naserzadeh, Parvaneh; Salimi, Ahmad; Seydi, Enayatollah; Pourahmad, Jalal

    2017-02-01

    Statins (including atorvastatin) are a widely used class of drugs, and like all medications, they have a potential for adverse effects. Recently, it has been shown that statins also exert side effects on the pancreas. In vitro studies have suggested that this class of drugs induced a reduction in insulin secretion. Also, the use of statins is associated with a raised risk of diabetes mellitus (DM), but the mechanisms underlying statin-induced diabetes are poorly known. Literature data indicate that several statins are able to induce apoptosis signalling. This study was designed to examine the mechanism of atorvastatin on mitochondria obtained from rat pancreas. In our study, mitochondria were obtained from the pancreas and then exposed to atorvastatin and vehicle to investigate probable toxic effects. The results showed that atorvastatin (25, 50, 75, 100 and 125 μM) increased reactive oxygen species (ROS) production, mitochondrial swelling, collapse of mitochondrial membrane potential and cytochrome c release, the orchestrating factor for mitochondria-mediated apoptosis signalling. Atorvastatin also reduced the ATP levels. These results propose that the toxicity of atorvastatin on pancreas mitochondria is a key point for drug-induced apoptotic cell loss in the pancreas and therefore a justification for increased risk of DM. © 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  16. 3-Bromopyruvate induces apoptosis in breast cancer cells by downregulating Mcl-1 through the PI3K/Akt signaling pathway.

    Science.gov (United States)

    Liu, Zhe; Zhang, Yuan-Yuan; Zhang, Qian-Wen; Zhao, Su-Rong; Wu, Cheng-Zhu; Cheng, Xiu; Jiang, Chen-Chen; Jiang, Zhi-Wen; Liu, Hao

    2014-04-01

    The hexokinase inhibitor 3-bromopyruvate (3-BrPA) can inhibit glycolysis in tumor cells to reduce ATP production, resulting in apoptosis. However, as 3-BrPA is an alkylating agent, its cytotoxic action may be induced by other molecular mechanisms. The results presented here reveal that 3-BrPA-induced apoptosis is caspase independent. Further, 3-BrPA induces the generation of reactive oxygen species in MDA-MB-231 cells, leading to mitochondria-mediated apoptosis. These results suggest that caspase-independent apoptosis may be induced by the generation of reactive oxygen species. In this study, we also demonstrated that 3-BrPA induces apoptosis through the downregulation of myeloid cell leukemia-1 (Mcl-1) in MDA-MB-231 breast cancer cells. The results of Mcl-1 knockdown indicate that Mcl-1 plays an important role in 3-BrPA-induced apoptosis. Further, the upregulation of Mcl-1 expression in 3-BrPA-treated MDA-MB-231 cells significantly increases cell viability. In addition, 3-BrPA treatment resulted in the downregulation of p-Akt, suggesting that 3-BrPA may downregulate Mcl-1 through the phosphoinositide-3-kinase/Akt pathway. These findings indicate that 3-BrPA induces apoptosis in breast cancer cells by downregulating Mcl-1 through the phosphoinositide-3-kinase/Akt signaling pathway.

  17. Repercussion of mitochondria deformity induced by anti-Hsp90 drug 17AAG in human tumor cells

    KAUST Repository

    Vishal, Chaturvedi; Kumar, Jonnala Ujwal; Veera Brahmendra Swamy, Cherukuvada; Nandini, Rangaraj; Srinivas, Gunda; Kumaresan, Rathinam; Shashi, Singh; Sreedhar, Amere Subbarao

    2011-01-01

    Inhibiting Hsp90 chaperone roles using 17AAG induces cytostasis or apoptosis in tumor cells through destabilization of several mutated cancer promoting proteins. Although mitochondria are central in deciding the fate of cells, 17AAG induced effects

  18. TanshinoneIIA and cryptotanshinone protect against hypoxia-induced mitochondrial apoptosis in H9c2 cells.

    Directory of Open Access Journals (Sweden)

    Hyou-Ju Jin

    Full Text Available Mitochondrial apoptosis pathway is an important target of cardioprotective signalling. Tanshinones, a group of major bioactive compounds isolated from Salvia miltiorrhiza, have been reported with actions against inflammation, oxidative stress, and myocardial ischemia reperfusion injury. However, the actions of these compounds on the chronic hypoxia-related mitochondrial apoptosis pathway have not been investigated. In this study, we examined the effects and molecular mechanisms of two major tanshonones, tanshinone IIA (TIIA and cryptotanshinone (CT on hypoxia induced apoptosis in H9c2 cells. Cultured H9c2 cells were treated with TIIA and CT (0.3 and 3 μΜ 2 hr before and during an 8 hr hypoxic period. Chronic hypoxia caused a significant increase in hypoxia inducible factor 1α expression and the cell late apoptosis rate, which was accompanied with an increase in caspase 3 activity, cytochrome c release, mitochondria membrane potential and expression of pro-apoptosis proteins (Bax and Bak. TIIA and CT (0.3 and 3 μΜ, in concentrations without affecting the cell viability, significantly inhibited the late apoptosis and the changes of caspase 3 activity, cytochrome c release, and mitochondria membrane potential induced by chronic hypoxia. These compounds also suppressed the overexpression of Bax and reduced the ratio of Bax/Bcl-2. The results indicate that TIIA and CT protect against chronic hypoxia induced cell apoptosis by regulating the mitochondrial apoptosis signaling pathway, involving inhibitions of mitochondria hyperpolarization, cytochrome c release and caspase 3 activity, and balancing anti- and pro-apoptotic proteins in Bcl-2 family proteins.

  19. BID-dependent release of mitochondrial SMAC dampens XIAP-mediated immunity against Shigella

    Science.gov (United States)

    Andree, Maria; Seeger, Jens M; Schüll, Stephan; Coutelle, Oliver; Wagner-Stippich, Diana; Wiegmann, Katja; Wunderlich, Claudia M; Brinkmann, Kerstin; Broxtermann, Pia; Witt, Axel; Fritsch, Melanie; Martinelli, Paola; Bielig, Harald; Lamkemeyer, Tobias; Rugarli, Elena I; Kaufmann, Thomas; Sterner-Kock, Anja; Wunderlich, F Thomas; Villunger, Andreas; Martins, L Miguel; Krönke, Martin; Kufer, Thomas A; Utermöhlen, Olaf; Kashkar, Hamid

    2014-01-01

    The X-linked inhibitor of apoptosis protein (XIAP) is a potent caspase inhibitor, best known for its anti-apoptotic function in cancer. During apoptosis, XIAP is antagonized by SMAC, which is released from the mitochondria upon caspase-mediated activation of BID. Recent studies suggest that XIAP is involved in immune signaling. Here, we explore XIAP as an important mediator of an immune response against the enteroinvasive bacterium Shigella flexneri, both in vitro and in vivo. Our data demonstrate for the first time that Shigella evades the XIAP-mediated immune response by inducing the BID-dependent release of SMAC from the mitochondria. Unlike apoptotic stimuli, Shigella activates the calpain-dependent cleavage of BID to trigger the release of SMAC, which antagonizes the inflammatory action of XIAP without inducing apoptosis. Our results demonstrate how the cellular death machinery can be subverted by an invasive pathogen to ensure bacterial colonization. PMID:25056906

  20. BAK overexpression mediates p53-independent apoptosis inducing effects on human gastric cancer cells

    Directory of Open Access Journals (Sweden)

    Liu Jun

    2004-07-01

    Full Text Available Abstract Background BAK (Bcl-2 homologous antagonist/killer is a novel pro-apoptotic gene of the Bcl-2 family. It has been reported that gastric tumors have reduced BAK levels when compared with the normal mucosa. Moreover, mutations of the BAK gene have been identified in human gastrointestinal cancers, suggesting that a perturbation of BAK-mediated apoptosis may contribute to the pathogenesis of gastric cancer. In this study, we explored the therapeutic effects of gene transfer mediated elevations in BAK expression on human gastric cancer cells in vitro. Methods Eukaryotic expression vector for the BAK gene was constructed and transferred into gastric cancer cell lines, MKN-45 (wild-type p53 and MKN-28 (mutant-type p53. RT-PCR and Western Blotting detected cellular BAK gene expression. Cell growth activities were detected by MTT colorimetry and flow cytometry, while apoptosis was assayed by electronic microscopy and TUNEL. Western Blotting and colorimetry investigated cellular caspase-3 activities. Results BAK gene transfer could result in significant BAK overexpression, decreased in vitro growth, cell cycle G0/G1 arrest, and induced apoptosis in gastric cancer cells. In transferred cells, inactive caspase-3 precursor was cleaved into the active subunits p20 and p17, during BAK overexpression-induced apoptosis. In addition, this process occurred equally well in p53 wild-type (MKN-45, or in p53 mutant-type (MKN-28 gastric cancer cells. Conclusions The data presented suggests that overexpression of the BAK gene can lead to apoptosis of gastric cancer cells in vitro, which does not appear to be dependent on p53 status. The action mechanism of BAK mediated apoptosis correlates with activation of caspase-3. This could be served as a potential strategy for further development of gastric cancer therapies.

  1. BAK overexpression mediates p53-independent apoptosis inducing effects on human gastric cancer cells

    International Nuclear Information System (INIS)

    Tong, Qiang-Song; Zheng, Li-Duan; Wang, Liang; Liu, Jun; Qian, Wei

    2004-01-01

    BAK (Bcl-2 homologous antagonist/killer) is a novel pro-apoptotic gene of the Bcl-2 family. It has been reported that gastric tumors have reduced BAK levels when compared with the normal mucosa. Moreover, mutations of the BAK gene have been identified in human gastrointestinal cancers, suggesting that a perturbation of BAK-mediated apoptosis may contribute to the pathogenesis of gastric cancer. In this study, we explored the therapeutic effects of gene transfer mediated elevations in BAK expression on human gastric cancer cells in vitro. Eukaryotic expression vector for the BAK gene was constructed and transferred into gastric cancer cell lines, MKN-45 (wild-type p53) and MKN-28 (mutant-type p53). RT-PCR and Western Blotting detected cellular BAK gene expression. Cell growth activities were detected by MTT colorimetry and flow cytometry, while apoptosis was assayed by electronic microscopy and TUNEL. Western Blotting and colorimetry investigated cellular caspase-3 activities. BAK gene transfer could result in significant BAK overexpression, decreased in vitro growth, cell cycle G 0 /G 1 arrest, and induced apoptosis in gastric cancer cells. In transferred cells, inactive caspase-3 precursor was cleaved into the active subunits p20 and p17, during BAK overexpression-induced apoptosis. In addition, this process occurred equally well in p53 wild-type (MKN-45), or in p53 mutant-type (MKN-28) gastric cancer cells. The data presented suggests that overexpression of the BAK gene can lead to apoptosis of gastric cancer cells in vitro, which does not appear to be dependent on p53 status. The action mechanism of BAK mediated apoptosis correlates with activation of caspase-3. This could be served as a potential strategy for further development of gastric cancer therapies

  2. Activating transcription factor 6 mediates oxidized LDL-induced cholesterol accumulation and apoptosis in macrophages by up-regulating CHOP expression.

    Science.gov (United States)

    Yao, Shutong; Zong, Chuanlong; Zhang, Ying; Sang, Hui; Yang, Mingfeng; Jiao, Peng; Fang, Yongqi; Yang, Nana; Song, Guohua; Qin, Shucun

    2013-01-01

    This study was to explore whether activating transcription factor 6 (ATF6), an important sensor to endoplasmic reticulum (ER) stress, would mediate oxidized low-density lipoprotein (ox-LDL)- induced cholesterol accumulation and apoptosis in cultured macrophages and the underlying molecular mechanisms. Intracellular lipid droplets and total cholesterol levels were assayed by oil red O staining and enzymatic colorimetry, respectively. Cell viability and apoptosis were determined using MTT assay and AnnexinV-FITC apoptosis detection kit, respectively. The nuclear translocation of ATF6 in cells was detected by immunofluorescence analysis. Protein and mRNA levels were examined by Western blot analysis and real time-PCR, respectively. ATF6 siRNA was transfected to RAW264.7 cells by lipofectamin. Exposure of cells to ox-LDL induced glucose-regulated protein 78 (GRP78). C/EBP homologous protein (CHOP), a key-signaling component of ER stress-induced apoptosis, was up-regulated in ox-LDL-treated cells. ATF6, a factor that positively regulates CHOP expression, was activated by ox-LDL in a concentration- and time- dependent manner. The role of the ATF6-mediated ER stress pathway was further confirmed through the siRNA-mediated knockdown of ATF6, which attenuated ox-LDL-induced upregulation of CHOP, cholesterol accumulation and apoptosis in macrophages. In addition, the phosphorylation of double-stranded RNA-activated protein kinase-like endoplasmic reticulum kinase (PERK), another factor that positively regulates CHOP expression, was induced in the presence of ox-LDL, and PERK-specific siRNA also inhibited the ox-LDL-induced upregulation of CHOP and apoptosis in RAW264.7 cells. These results demonstrate that ER stress-related proteins, particularly ATF6 and its downstream molecule CHOP, are involved in ox-LDL-induced cholesterol accumulation and apoptosis in macrophages.

  3. Early Decrease in Respiration and Uncoupling Event Independent of Cytochrome c Release in PC12 Cells Undergoing Apoptosis

    Science.gov (United States)

    Berghella, Libera; Ferraro, Elisabetta

    2012-01-01

    Cytochrome c is a key molecule in mitochondria-mediated apoptosis. It also plays a pivotal role in cell respiration. The switch between these two functions occurs at the moment of its release from mitochondria. This process is therefore extremely relevant for the fate of the cell. Since cytochrome c mediates respiration, we studied the changes in respiratory chain activity during the early stages of apoptosis in order to contribute to unravel the mechanisms of cytochrome c release. We found that, during staurosporine (STS)- induced apoptosis in PC12 cells, respiration is affected before the release of cytochrome c, as shown by a decrease in the endogenous uncoupled respiration and an uncoupling event, both occurring independently of cytochrome c release. The decline in the uncoupled respiration occurs also upon Bcl-2 overexpression (which inhibits cytochrome c release), while the uncoupling event is inhibited by Bcl-2. We also observed that the first stage of nuclear condensation during STS-induced apoptosis does not depend on the release of cytochrome c into the cytosol and is a reversibile event. These findings may contribute to understand the mechanisms affecting mitochondria during the early stages of apoptosis and priming them for the release of apoptogenic factors. PMID:22666257

  4. Protective Effect of Edaravone against Carbon Monoxide Induced Apoptosis in Rat Primary Cultured Astrocytes

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    Xiaodan Xu

    2017-01-01

    Full Text Available Objective. To observe the protective effect of edaravone (Eda on astrocytes after prolonged exposure to carbon monoxide (CO and further to investigate the potential mechanisms of Eda against CO-induced apoptosis. Methods. The rat primary cultured astrocytes were cultured in vitro and exposed to 1% CO for 24 h after being cultured with different concentrations of Eda. MTT assay was used to detect the cytotoxicity of CO. Flow cytometry was used to detect the apoptosis rate, membrane potential of mitochondria, and ROS level. The mRNA and protein expressions of Bcl-2, Bax, and caspase-3 were assessed by real-time PCR and Western blotting analysis, respectively. Results. Eda can significantly suppress cytotoxicity of CO, and it can significantly increase membrane potential of mitochondria and Bcl-2 expressions and significantly suppress the apoptosis rate, ROS level, Bax, and caspase-3 expressions. Conclusion. Eda protects against CO-induced apoptosis in rat primary cultured astrocytes through decreasing ROS production and subsequently inhibiting mitochondrial apoptosis pathway.

  5. Regulation of apoptosis by resveratrol through JAK/STAT and mitochondria mediated pathway in human epidermoid carcinoma A431 cells

    International Nuclear Information System (INIS)

    Madan, Esha; Prasad, Sahdeo; Roy, Preeti; George, Jasmine; Shukla, Yogeshwer

    2008-01-01

    Resveratrol (trans-3,4',5-trihydroxystilbene), a polyphenolic phytoalexin present mainly in grapes, red wine and berries, is known to possess strong chemopreventive and anticancer properties. Here, we demonstrated the anti-proliferative and apoptosis-inducing activities of resveratrol in human epidermoid carcinoma A431 cells. Resveratrol has cytotoxic effects through inhibiting cellular proliferation of A431 cells, which leads to the induction of apoptosis, as evident by an increase in the fraction of cells in the sub-G 1 phase of the cell cycle and Annexin-V binding of externalized phosphatidylserine. Results revealed that inhibition of proliferation is associated with regulation of the JAK/STAT pathway, where resveratrol prevents phosphorylation of JAK, thereby inhibiting STAT1 phosphorylation. Furthermore, resveratrol treatment actively stimulated reactive oxygen species (ROS) and mitochondrial membrane depolarization. Consequently, an imbalance in the Bax/Bcl-2 ratio triggered the caspase cascade and subsequent cleavage of PARP, thereby shifting the balance in favor of apoptosis. These observations indicate that resveratrol treatment inhibits JAK/STAT-mediated gene transcription and induce the mitochondrial cell death pathway.

  6. The nonstructural protein NP1 of human bocavirus 1 induces cell cycle arrest and apoptosis in Hela cells

    International Nuclear Information System (INIS)

    Sun, Bin; Cai, Yingyue; Li, Yongshu; Li, Jingjing; Liu, Kaiyu; Li, Yi; Yang, Yongbo

    2013-01-01

    Human bocavirus type 1 (HBoV1) is a newly identified pathogen associated with human respiratory tract illnesses. Previous studies demonstrated that proteins of HBoV1 failed to cause cell death, which is considered as a possible common feature of bocaviruses. However, our work showed that the NP1 of HBoV1 induced apoptotic cell death in Hela cells in the absence of viral genome replication and expression of other viral proteins. Mitochondria apoptotic pathway was involved in the NP1-induced apoptosis that was confirmed by apoptotic characteristics including morphological changes, DNA fragmentation and caspase activation. We also demonstrated that the cell cycle of NP1-transfected Hela cells was transiently arrested at G2/M phase followed by rapid appearance of apoptosis and that the N terminal domain of NP1 was critical to its nuclear localization and function in apoptosis induction in Hela cells. These findings might provide alternative information for further study of mechanism of HBoV1 pathogenesis. - Highlights: ► NP1 protein of HBoV1 induced apoptosis in Hela cells was first reported. ► NP1 induced-apoptosis followed the cell cycle arrest at G2/M phase. ► The NP1 induced-apoptosis was mediated by mitochondrion apoptotic pathway. ► N terminal of NP1 was critical for apoptosis induction and nuclear localization

  7. The nonstructural protein NP1 of human bocavirus 1 induces cell cycle arrest and apoptosis in Hela cells

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Bin; Cai, Yingyue; Li, Yongshu [College of Life Science, Central China Normal University, Wuhan 430079, Hubei (China); Li, Jingjing [College of Life Science, Hubei Normal University, Huangshi 435002, Hubei (China); Liu, Kaiyu [College of Life Science, Central China Normal University, Wuhan 430079, Hubei (China); Li, Yi, E-mail: johnli2668@hotmail.com [College of Life Science, Central China Normal University, Wuhan 430079, Hubei (China); Bioengineering Department, Wuhan Bioengineering Institute, Wuhan 430415, Hubei (China); Yang, Yongbo, E-mail: yongboyang@mail.ccnu.edu.cn [College of Life Science, Central China Normal University, Wuhan 430079, Hubei (China)

    2013-05-25

    Human bocavirus type 1 (HBoV1) is a newly identified pathogen associated with human respiratory tract illnesses. Previous studies demonstrated that proteins of HBoV1 failed to cause cell death, which is considered as a possible common feature of bocaviruses. However, our work showed that the NP1 of HBoV1 induced apoptotic cell death in Hela cells in the absence of viral genome replication and expression of other viral proteins. Mitochondria apoptotic pathway was involved in the NP1-induced apoptosis that was confirmed by apoptotic characteristics including morphological changes, DNA fragmentation and caspase activation. We also demonstrated that the cell cycle of NP1-transfected Hela cells was transiently arrested at G2/M phase followed by rapid appearance of apoptosis and that the N terminal domain of NP1 was critical to its nuclear localization and function in apoptosis induction in Hela cells. These findings might provide alternative information for further study of mechanism of HBoV1 pathogenesis. - Highlights: ► NP1 protein of HBoV1 induced apoptosis in Hela cells was first reported. ► NP1 induced-apoptosis followed the cell cycle arrest at G2/M phase. ► The NP1 induced-apoptosis was mediated by mitochondrion apoptotic pathway. ► N terminal of NP1 was critical for apoptosis induction and nuclear localization.

  8. Overexpression of human kynurenine-3-monooxygenase protects against 3-hydroxykynurenine-mediated apoptosis through bidirectional nonlinear feedback.

    Science.gov (United States)

    Wilson, K; Auer, M; Binnie, M; Zheng, X; Pham, N T; Iredale, J P; Webster, S P; Mole, D J

    2016-04-14

    Kynurenine 3-monooxygenase (KMO) is a critical regulator of inflammation. The preferred KMO substrate, kynurenine, is converted to 3-hydroxykynurenine (3HK), and this product exhibits cytotoxicity through mechanisms that culminate in apoptosis. Here, we report that overexpression of human KMO with orthotopic localisation to mitochondria creates a metabolic environment during which the cell exhibits increased tolerance for exogenous 3HK-mediated cellular injury. Using the selective KMO inhibitor Ro61-8048, we show that KMO enzyme function is essential for cellular protection. Pan-caspase inhibition with Z-VAD-FMK confirmed apoptosis as the mode of cell death. By defining expression of pathway components upstream and downstream of KMO, we observed alterations in other key kynurenine pathway components, particularly tryptophan-2,3-dioxygenase upregulation, through bidirectional nonlinear feedback. KMO overexpression also increased expression of inducible nitric oxide synthase (iNOS). These changes in gene expression are functionally relevant, because siRNA knockdown of the pathway components kynureninase and quinolinate phosphoribosyl transferase caused cells to revert to a state of susceptibility to 3HK-mediated apoptosis. In summary, KMO overexpression, and importantly KMO activity, have metabolic repercussions that fundamentally affect resistance to cell stress.

  9. Mitochondrial translocation of Nur77 induced by ROS contributed to cardiomyocyte apoptosis in metabolic syndrome.

    Science.gov (United States)

    Xu, Aibin; Liu, Jingyi; Liu, Peilin; Jia, Min; Wang, Han; Tao, Ling

    2014-04-18

    Metabolic syndrome is a major risk factor for cardiovascular diseases, and increased cardiomyocyte apoptosis which contributes to cardiac dysfunction after myocardial ischemia/reperfusion (MI/R) injury. Nur77, a nuclear orphan receptor, is involved in such various cellular events as apoptosis, proliferation, and glucose and lipid metabolism in several cell types. Apoptosis is positively correlated with mitochondrial translocation of Nur77 in the cancer cells. However, the roles of Nur77 on cardiac myocytes in patients with metabolic syndrome remain unclear. The objective of this study was to determine whether Nur77 may contribute to cardiac apoptosis in patients with metabolic syndrome after I/R injury, and, if so, to identify the underlying molecular mechanisms responsible. We used leptin-deficient (ob/ob) mice to make metabolic syndrome models. In this report, we observed that, accompanied by the substantial decline in apoptosis inducer Nur77, MI/R induced cardiac dysfunction was manifested as cardiomyopathy and increased ROS. Using the neonatal rat cardiac myocytes cultured in a high-glucose and high-fat medium, we found that excessive H2O2 led to the significant alteration in mitochondrial membrane potential and translocation of Nur77 from the nucleus to the mitochondria. However, inhibition of the relocation of Nur77 to mitochondria via Cyclosporin A reversed the changes in membrane potential mediated by H2O2 and reduced myocardial cell injury. Therefore, these data provide a potential underlying mechanism for cardiac dysfunction in metabolic syndrome and the suppression of Nur77 translocation may provide an effective approach to reduce cardiac injury in the process. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Glutathione Depletion Induced by c-Myc Downregulation Triggers Apoptosis on Treatment with Alkylating Agents1

    Science.gov (United States)

    Biroccio, Annamaria; Benassi, Barbara; Fiorentino, Francesco; Zupi, Gabriella

    2004-01-01

    Abstract Here we investigate the mechanism(s) involved in the c-Myc-dependent drug response of melanoma cells. By using three M14-derived c-Myc low-expressing clones, we demonstrate that alkylating agents, cisplatin and melphalan, trigger apoptosis in the c-Myc antisense transfectants, but not in the parental line. On the contrary, topoisomerase inhibitors, adriamycin and camptothecin, induce apoptosis to the same extent regardless of c-Myc expression. Because we previously demonstrated that c-Myc downregulation decreases glutathione (GSH) content, we evaluated the role of GSH in the apoptosis induced by the different drugs. In control cells treated with one of the alkylating agents or the others, GSH depletion achieved by l-buthionine-sulfoximine preincubation opens the apoptotic pathway. The apoptosis proceeded through early Bax relocalization, cytochrome c release, and concomitant caspase-9 activation, whereas reactive oxygen species production and alteration of mitochondria membrane potential were late events. That GSH was determining in the c-Myc-dependent drug-induced apoptosis was demonstrated by altering the intracellular GSH content of the c-Myc low-expressing cells up to the level of controls. Indeed, GSH ethyl ester-mediated increase of GSH abrogated apoptosis induced by cisplatin and melphalan by inhibition of Bax/cytochrome c redistribution. The relationship among c-Myc, GSH content, and the response to alkylating agent has been also evaluated in the M14 Myc overexpressing clones as well as in the melanoma JR8 c-Myc antisense transfectants. All together, these results demonstrate that GSH plays a key role in governing c-Myc-dependent drug-induced apoptosis. PMID:15153331

  11. Mitochondria Superoxide Anion Production Contributes to Geranylgeraniol-Induced Death in Leishmania amazonensis

    Directory of Open Access Journals (Sweden)

    Milene Valéria Lopes

    2012-01-01

    Full Text Available Here we demonstrate the activity of geranylgeraniol, the major bioactive constituent from seeds of Bixa orellana, against Leishmania amazonensis. Geranylgeraniol was identified through 1H and 13C nuclear magnetic resonance imaging and DEPT. The compound inhibited the promastigote and intracellular amastigote forms, with IC50 of 11±1.0 and 17.5±0.7 μg/mL, respectively. This compound was also more toxic to parasites than to macrophages and did not cause lysis in human blood cells. Morphological and ultrastructural changes induced by geranylgeraniol were observed in the protozoan by electronic microscopy and included mainly mitochondria alterations and an abnormal chromatin condensation in the nucleus. These alterations were confirmed by Rh 123 and TUNEL assays. Additionally, geranylgeraniol induces an increase in superoxide anion production. Collectively, our in vitro studies indicate geranylgeraniol as a selective antileishmanial that appears to be mediated by apoptosis-like cell death.

  12. Jolkinolide B induces apoptosis of colorectal carcinoma through ROS-ER stress-Ca2+-mitochondria dependent pathway.

    Science.gov (United States)

    Zhang, Jing; Wang, Yang; Zhou, Ye; He, Qing-Yu

    2017-10-31

    Colorectal carcinoma (CRC) remains one of the leading causes of death in cancer-related diseases. In this study, we aimed to investigate the anticancer effect of Jolkinolide B (JB), a bioactive diterpenoid component isolated from the dried roots of Euphorbia fischeriana Steud, on CRC cells and its underlying mechanisms. We found that JB suppressed the cell viability and colony formation of CRC cells, HT29 and SW620. Annexin V/PI assay revealed that JB induced apoptosis in CRC cells, which was further confirmed by the increased expression of cleaved-caspase3 and cleaved-PARP. iTRAQ-based quantitative proteomics was performed to identify JB-regulated proteins in CRC cells. Gene Ontology (GO) analysis revealed that these JB-regulated proteins were mainly involved in ER stress response, which was evidenced by the expression of ER stress marker proteins, HSP90, Bip and PDI. Moreover, we found that JB provoked the generation of reactive oxygen species (ROS), and that inhibition of the ROS generation with N-acetyl L-cysteine could reverse the JB-induced apoptosis. Confocal microscopy and flow cytometry showed that JB treatment enhanced intracellular and mitochondrial Ca 2+ level and JC-1 assay revealed a loss of mitochondrial membrane potential in CRC after JB treatment. The mitochondrial Ca 2+ uptake and depolarization can be blocked by Ruthenium Red (RuRed), an inhibitor of mitochondrial Ca 2+ uniporter. Taken together, we demonstrated that JB exerts its anticancer effect by ER stress-Ca 2+ -mitochondria signaling, suggesting the promising chemotherapeutic potential of JB for the treatment of CRC.

  13. Cantharidin Induced Oral Squamous Cell Carcinoma Cell Apoptosis via the JNK-Regulated Mitochondria and Endoplasmic Reticulum Stress-Related Signaling Pathways.

    Directory of Open Access Journals (Sweden)

    Chin-Chuan Su

    Full Text Available Oral cancer is a subtype of head and neck cancer which represents 2.65% of all human malignancies. Most of oral cancer is histopathologically diagnosed as oral squamous cell carcinoma (OSCC. OSCC is characterized by a high degree of local invasion and a high rate of metastasis to the cervical lymph nodes. How to prevention and treatment of OSCC is important and imperative. Here, we investigated the therapeutic effect and molecular mechanism of cantharidin, an active compound isolated from blister beetles, on OSCC in vitro. Results showed that cantharidin significantly decreased cell viability in human tongue squamous carcinoma-derived SAS, CAL-27, and SCC-4 cell lines. The further mechanistic studies were carried out in SAS cells. Cantharidin also significantly increased apoptosis-related signals, including caspase-9, caspase-7 and caspase-3 proteins. Besides, cantharidin decreased mitochondrial transmembrane potential (MMP and induced cytochrome c and apoptosis inducing factor (AIF release. Cantharidin also increased Bax, Bid, and Bak protein expressions and decreased Bcl-2 protein expression. Cantharidin could also increase the endoplasmic reticulum (ER stress signals, including the expressions of phosphorylated eIF-2α and CHOP, but not Grp78 and Grp94. Furthermore, cantharidin reduced pro-caspase-12 protein expression. In signals of mitogen-activated protein kinases, cantharidin increased the phosphorylation of JNK, but not ERK and p38. Transfection of shRNA-JNK to OSCC cells effectively reversed the cantharidin-induced cell apoptotic signals, including the mitochondrial and ER stress-related signaling molecules. Taken together, these findings suggest that cantharidin induces apoptosis in OSCC cells via the JNK-regulated mitochondria and ER stress-related signaling pathways.

  14. Quercetogetin protects against cigarette smoke extract-induced apoptosis in epithelial cells by inhibiting mitophagy.

    Science.gov (United States)

    Son, Eun Suk; Kim, Se-Hee; Ryter, Stefan W; Yeo, Eui-Ju; Kyung, Sun Young; Kim, Yu Jin; Jeong, Sung Hwan; Lee, Chang Soo; Park, Jeong-Woong

    2018-04-01

    Recent studies demonstrate that the autophagy-dependent turnover of mitochondria (mitophagy) mediates pulmonary epithelial cell death in response to cigarette smoke extract (CSE) exposure, and contributes to emphysema development in vivo during chronic cigarette smoke (CS)-exposure, although the underlying mechanisms remain unclear. Here, we investigated the role of mitophagy in regulating apoptosis in CSE-exposed human lung bronchial epithelial cells. Furthermore, we investigated the potential of the polymethoxylated flavone antioxidant quercetogetin (QUE) to inhibit CSE-induced mitophagy-dependent apoptosis. Our results demonstrate that CSE induces mitophagy in epithelial cells via mitochondrial dysfunction, and causes increased expression levels of the mitophagy-regulator protein PTEN-induced putative kinase-1 (PINK1) and the mitochondrial fission protein dynamin-1-like protein (DRP-1). CSE induced epithelial cell death and increased the expression of the apoptosis-related proteins cleaved caspase-3, -8 and -9. Caspase-3 activity was significantly increased in Beas-2B cells exposed to CSE, and decreased by siRNA-dependent knockdown of DRP-1. Treatment of epithelial cells with QUE inhibited CSE-induced mitochondrial dysfunction and mitophagy by inhibiting phospho (p)-DRP-1 and PINK1 expression. QUE suppressed mitophagy-dependent apoptosis by inhibiting the expression of cleaved caspase-3, -8 and -9 and downregulating caspase activity in human bronchial epithelial cells. These findings suggest that QUE may serve as a potential therapeutic in CS-induced pulmonary diseases. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. A novel protein from edible fungi Cordyceps militaris that induces apoptosis

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    Ke-Chun Bai

    2018-01-01

    Full Text Available Cordyceps militaris is a dietary therapeutic fungus that is an important model species in Cordyceps research. In this study, we purified a novel protein from the fruit bodies of C. militaris and designated it as Cordyceps militaris protein (CMP. CMP has a molecular mass of 18.0 kDa and is not glycosylated. Interestingly, CMP inhibited cell viability in murine primary cells and other cell lines in a time- and dose-dependent manner. Using trypan blue staining and a lactate dehydrogenase release assay, we showed that CMP caused cell death in the murine hepatoma cell line BNL 1MEA.7R.1. Furthermore, the frequency of BNL 1MEA.7R.1 cells at the sub-G1 stage was increased by CMP. Apoptosis, as determined by Annexin V and propidium iodide analysis, indicated that CMP could mediate BNL 1MEA.7R.1 apoptosis, but not necrosis. After coincubation with CMP, a decrease in mitochondria potential was detected using 3,3′-dihexyloxacarbocyanine iodide. These results suggest that CMP is a harmful protein that induces apoptosis through a mitochondrion-dependent pathway. Stability experiments demonstrated that heat treatment and alkalization degraded CMP and further destroyed its cell-death-inducing ability, implying that cooking is necessary for food containing C. militaris.

  16. Caspase-independent cell death mediated by apoptosis-inducing factor (AIF) nuclear translocation is involved in ionizing radiation induced HepG2 cell death

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hengwen [Department of Radiation, Cancer Center of Guangdong General Hospital (Guangdong Academy of Medical Science), Guangzhou, 510080, Guangdong (China); Yang, Shana; Li, Jianhua [Department of Physiology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China); Zhang, Yajie [Department of Pathology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China); Gao, Dongsheng [Department of Oncology, Guangdong Medical College Affiliated Pengpai Memorial Hospital, Hai Feng, 516400, Gungdong (China); Zhao, Shenting, E-mail: zhaoshenting@126.com [Department of Physiology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China)

    2016-03-25

    Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. The aim of radiotherapy is to eradicate cancer cells with ionizing radiation. Except for the caspase-dependent mechanism, several lines of evidence demonstrated that caspase-independent mechanism is directly involved in the cell death responding to irradiation. For this reason, defining the contribution of caspase-independent molecular mechanisms represents the main goal in radiotherapy. In this study, we focused on the role of apoptosis-inducing factor (AIF), the caspase-independent molecular, in ionizing radiation induced hepatocellular carcinoma cell line (HepG2) cell death. We found that ionizing radiation has no function on AIF expression in HepG2 cells, but could induce AIF release from the mitochondria and translocate into nuclei. Inhibition of AIF could reduce ionizing radiation induced HepG2 cell death. These studies strongly support a direct relationship between AIF nuclear translocation and radiation induced cell death. What's more, AIF nuclear translocation is caspase-independent manner, but not caspase-dependent manner, in this process. These new findings add a further attractive point of investigation to better define the complex interplay between caspase-independent cell death and radiation therapy. - Highlights: • AIF nuclear translocation is involved in ionizing radiation induced hepatocellular carcinoma cell line HepG2 cell death. • AIF mediated cell death induced by ionizing radiation is caspase-independent. • Caspase-independent pathway is involved in ionzing radiation induced HepG2 cell death.

  17. Caspase-independent cell death mediated by apoptosis-inducing factor (AIF) nuclear translocation is involved in ionizing radiation induced HepG2 cell death

    International Nuclear Information System (INIS)

    Sun, Hengwen; Yang, Shana; Li, Jianhua; Zhang, Yajie; Gao, Dongsheng; Zhao, Shenting

    2016-01-01

    Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. The aim of radiotherapy is to eradicate cancer cells with ionizing radiation. Except for the caspase-dependent mechanism, several lines of evidence demonstrated that caspase-independent mechanism is directly involved in the cell death responding to irradiation. For this reason, defining the contribution of caspase-independent molecular mechanisms represents the main goal in radiotherapy. In this study, we focused on the role of apoptosis-inducing factor (AIF), the caspase-independent molecular, in ionizing radiation induced hepatocellular carcinoma cell line (HepG2) cell death. We found that ionizing radiation has no function on AIF expression in HepG2 cells, but could induce AIF release from the mitochondria and translocate into nuclei. Inhibition of AIF could reduce ionizing radiation induced HepG2 cell death. These studies strongly support a direct relationship between AIF nuclear translocation and radiation induced cell death. What's more, AIF nuclear translocation is caspase-independent manner, but not caspase-dependent manner, in this process. These new findings add a further attractive point of investigation to better define the complex interplay between caspase-independent cell death and radiation therapy. - Highlights: • AIF nuclear translocation is involved in ionizing radiation induced hepatocellular carcinoma cell line HepG2 cell death. • AIF mediated cell death induced by ionizing radiation is caspase-independent. • Caspase-independent pathway is involved in ionzing radiation induced HepG2 cell death.

  18. Caspase-8 acts as a key upstream executor of mitochondria during justicidin A-induced apoptosis in human hepatoma cells.

    Science.gov (United States)

    Su, Chun-Li; Huang, Lynn L H; Huang, Li-Min; Lee, Jenq-Chang; Lin, Chun-Nan; Won, Shen-Jeu

    2006-05-29

    Justicia procumbens is a traditional Taiwanese herbal remedy used to treat fever, pain, and cancer. Justicidin A, isolated from Justicia procumbens, has been reported to suppress in vitro growth of several tumor cell lines as well as hepatoma cells. In this study, justicidin A activated caspase-8 to increase tBid, disrupted mitochondrial membrane potential (Delta psi(m)), and caused the release of cytochrome c and Smac/DIABLO in Hep 3B and Hep G2 cells. Justicidin A also reduced Bcl-x(L) and increased Bax and Bak in mitochondria. Caspase-8 inhibitor (Z-IETD) attenuated the justicidin A-induced disruption of Delta psi(m). Growth of Hep 3B implanted in NOD-SCID mice was suppressed significantly by oral justicidin A (20 mg/kg/day). These results indicate that justicidin A-induced apoptosis in these cells proceeds via caspase-8 and is followed by mitochondrial disruption.

  19. Curcumin Analog DK1 Induces Apoptosis in Human Osteosarcoma Cells In Vitro through Mitochondria-Dependent Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Muhammad Nazirul Mubin Aziz

    2018-01-01

    Full Text Available Osteosarcoma is one of the primary malignant bone tumors that confer low survival rates for patients even with intensive regime treatments. Therefore, discovery of novel anti-osteosarcoma drugs derived from natural products that are not harmful to the normal cells remains crucial. Curcumin is one of the natural substances that have been extensively studied due to its anti-cancer properties and is pharmacologically safe considering its ubiquitous consumption for centuries. However, curcumin suffers from a poor circulating bioavailability, which has led to the development of a chemically synthesized curcuminoid analog, namely (Z-3-hydroxy-1-(2-hydroxyphenyl-3-phenylprop-2-en-1-one (DK1. In this study, the cytotoxic effects of the curcumin analog DK1 was investigated in both U-2OS and MG-63 osteosarcoma cell lines using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay and cell death was microscopically examined via acridine orange/propidium iodide (AO/PI double staining. Flow cytometer analysis including Annexin V/Fluorescein isothiocyanate (FITC, cell cycle analysis and JC-1 were adapted to determine the mode of cell death. Subsequently in order to determine the mechanism of cell death, quantitative polymerase chain reaction (qPCR and proteome profiling was carried out to measure the expression of several apoptotic-related genes and proteins. Results indicated that DK1 induced U-2 OS and MG-63 morphological changes and substantially reduced cell numbers through induction of apoptosis. Several apoptotic genes and proteins were steadily expressed after treatment with DK1; including caspase 3, caspase 9, and BAX, which indicated that apoptosis occurred through a mitochondria-dependent signaling pathway. In conclusion, DK1 could be considered as a potential candidate for an anti-osteosarcoma drug in the near future, contingent upon its ability to induce apoptosis in osteosarcoma cell lines.

  20. Dihydromyricetin induces mitochondria-mediated apoptosis in HepG2 cells through down-regulation of the Akt/Bad pathway.

    Science.gov (United States)

    Zhang, Zhuangwei; Zhang, Huiqin; Chen, Shiyong; Xu, Yan; Yao, Anjun; Liao, Qi; Han, Liyuan; Zou, Zuquan; Zhang, Xiaohong

    2017-02-01

    The plant flavonol dihydromyricetin (DHM) was reported to induce apoptosis in human hepatocarcinoma HepG2 cells. This study was undertaken to elucidate the underlying molecular mechanism of action of DHM. In the study, DHM down-regulated Akt expression and its phosphorylation at Ser473, up-regulated the levels of mitochondrial proapoptotic proteins Bax and Bad, and inhibited the phosphorylation of Bad at Ser136 and Ser112. It also inhibited the expression of the antiapoptotic protein Bcl-2 and enhanced the cleavage and activation of caspase-3 as well as the degradation of its downstream target poly(ADP-ribose) polymerase. Our results for the first time suggest that DHM-induced apoptosis in HepG2 cells may come about by the inhibition of the Akt/Bad signaling pathway and stimulation of the mitochondrial apoptotic pathway. Dihydromyricetin may be a promising therapeutic medication for hepatocellular carcinoma. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Shifting the balance of mitochondrial apoptosis: therapeutic perspectives

    International Nuclear Information System (INIS)

    Fulda, Simone

    2012-01-01

    Signaling via the intrinsic (mitochondrial) pathway of apoptosis represents one of the critical signal transduction cascades that control the regulation of cell death. This pathway is typically altered in human cancers, thereby providing a suitable target for therapeutic intervention. Members of the Bcl-2 family of proteins as well as cell survival signaling cascades such as the PI3K/Akt/mTOR pathway are involved in the regulation of mitochondria-mediated apoptosis. Therefore, further insights into the molecular mechanisms that form the basis for the control of mitochondria-mediated apoptosis will likely open new perspectives to bypass evasion of apoptosis and treatment resistance in human cancers.

  2. Shifting the balance of mitochondrial apoptosis: therapeutic perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Fulda, Simone, E-mail: simone.fulda@kgu.de [Institute for Experimental Cancer Research in Pediatrics, Goethe-University, Frankfurt (Germany)

    2012-10-08

    Signaling via the intrinsic (mitochondrial) pathway of apoptosis represents one of the critical signal transduction cascades that control the regulation of cell death. This pathway is typically altered in human cancers, thereby providing a suitable target for therapeutic intervention. Members of the Bcl-2 family of proteins as well as cell survival signaling cascades such as the PI3K/Akt/mTOR pathway are involved in the regulation of mitochondria-mediated apoptosis. Therefore, further insights into the molecular mechanisms that form the basis for the control of mitochondria-mediated apoptosis will likely open new perspectives to bypass evasion of apoptosis and treatment resistance in human cancers.

  3. Shifting the balance of mitochondrial apoptosis: therapeutic perspectives

    Directory of Open Access Journals (Sweden)

    Simone eFulda

    2012-10-01

    Full Text Available Signaling via the intrinsic (mitochondrial pathway of apoptosis represents one of the critical signal transduction cascades that control the regulation of cell death. This pathway is typically altered in human cancers, thereby providing a suitable target for therapeutic intervention. Members of the Bcl-2 family of proteins as well as cell survival signaling cascades such as the PI3K/Akt/mTOR pathway are involved in the regulation of mitochondria-mediated apoptosis. Therefore, further insights into the molecular mechanisms that form the basis for the control of mitochondria-mediated apoptosis will likely open new perspectives to bypass evasion of apoptosis and treatment resistance in human cancers.

  4. Nickel nanowires induced and reactive oxygen species mediated apoptosis in human pancreatic adenocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Kleve MG

    2011-07-01

    Full Text Available Md. Zakir Hossain1, Maurice G Kleve21Applied Biosciences (Bionanotechnology Research, Department of Applied Science, 2Molecular Biotechnology and Microscopy Laboratory, Department of Biology, University of Arkansas at Little Rock, Little Rock, Arkansas, USABackground: The ability to evade apoptosis is one of the key properties of cancer. The apoptogenic effect of nickel nanowires (Ni NWs on cancer cell lines has never been adequately addressed. Due to the unique physicochemical characteristics of Ni NWs, we envision the development of a novel anticancer therapeutics specifically for pancreatic cancer. Thus, we investigated whether Ni NWs induce ROS-mediated apoptosis in human pancreatic adenocarcinoma (Panc-1 cells. Methods: In this study Ni NWs were fabricated using the electrodeposition method. Synthesized Ni NWs were physically characterized by energy dispersive X-ray analysis, UV-Vis spectroscopy of NanoDrop 2000 (UV-Vis, magnetization study, scanning electron microscopy, and transmission electron microscopy. Assessment of morphological apoptotic characteristics by phase contrast microscopy (PCM, Ni-NWs-induced apoptosis staining with ethidium bromide (EB and acridine orange (AO followed by fluorescence microscopy (FM was performed. For molecular biological and biochemical characterization, Panc-1 cell culture and cytotoxic effect of Ni NWs were determined by using 3-(4, 5-dimethylthiazol-2-yl-2, 5-diphenyl tetrazolium bromide (MTT assay. Quantitative apoptosis was analyzed by flow cytometry staining with propidium iodide through cell cycle arrest and generation of ROS using 2', 7'-dichlorofluorescein diacetate fluorescence intensity. In all experiments, Panc-1 cancer cells without any treatment were used as the negative controls.Results: The intracellular uptake of Ni NWs through endocytosis by Panc-1 cells was observed by PCM. EB and AO staining of FM and MTT assay qualitatively and quantitatively confirmed the extent of apoptosis. Flow

  5. Iron-Mediated Lysosomal Membrane Permeabilization in Ethanol-Induced Hepatic Oxidative Damage and Apoptosis: Protective Effects of Quercetin

    Directory of Open Access Journals (Sweden)

    Yanyan Li

    2016-01-01

    Full Text Available Iron, in its free ferrous states, can catalyze Fenton reaction to produce OH∙, which is recognized as a crucial role in the pathogenesis of alcoholic liver diseases (ALD. As a result of continuous decomposition of iron-containing compounds, lysosomes contain a pool of redox-active iron. To investigate the important role of intralysosomal iron in alcoholic liver injury and the potential protection of quercetin, male C57BL/6J mice fed by Lieber De Carli diets containing ethanol (30% of total calories were cotreated by quercetin or deferoxamine (DFO for 15 weeks and ethanol-incubated mice primary hepatocytes were pretreated with FeCl3, DFO, and bafilomycin A1 at their optimal concentrations and exposure times. Chronic ethanol consumption caused an evident increase in lysosomal redox-active iron accompanying sustained oxidative damage. Iron-mediated ROS could trigger lysosomal membrane permeabilization (LMP and subsequent mitochondria apoptosis. The hepatotoxicity was attenuated by reducing lysosomal iron while being exacerbated by escalating lysosomal iron. Quercetin substantially alleviated the alcoholic liver oxidative damage and apoptosis by decreasing lysosome iron and ameliorating iron-mediated LMP, which provided a new prospective of the use of quercetin against ALD.

  6. Apoptosis of HeLa cells induced by a new targeting photosensitizer-based PDT via a mitochondrial pathway and ER stress

    Directory of Open Access Journals (Sweden)

    Li D

    2015-04-01

    Full Text Available Donghong Li,1 Lei Li,2 Pengxi Li,1 Yi Li,3 Xiangyun Chen1 1State Key Laboratory of Trauma, Burn and Combined Injury, The Second Department of Research Institute of Surgery, 2The First Department of Research Institute of Surgery, 3Cancer Center, Daping Hospital, Third Military Medical University, Chongqing, People’s Republic of China Abstract: Photodynamic therapy (PDT is emerging as a viable treatment for many cancers. To decrease the cutaneous photosensitivity induced by PDT, many attempts have been made to search for a targeting photosensitizer; however, few reports describe the molecular mechanism of PDT mediated by this type of targeting photosensitizer. The present study aimed to investigate the molecular mechanism of PDT induced by a new targeting photosensitizer (PS I, reported previously by us, on HeLa cells. Apoptosis is the primary mode of HeLa cell death in our system, and apoptosis occurs in a manner dependent on concentration, irradiation dose, and drug–light intervals. After endocytosis mediated by the folate receptor, PS I was primarily localized to the mitochondria and the endoplasmic reticulum (ER of HeLa cells. PS I PDT resulted in rapid increases in intracellular reactive oxygen species (ROS production and Ca2+ concentration, both of which reached a peak nearly simultaneously at 15 minutes, followed by the loss of mitochondrial membrane potential at 30 minutes, release of cytochrome c from mitochondria into the cytoplasm, downregulation of Bcl-2 expression, and upregulation of Bax expression. Meanwhile, activation of caspase-3, -9, and -12, as well as induction of C/EBP homologous protein (CHOP and glucose-regulated protein (GRP78, in HeLa cells after PS I PDT was also detected. These results suggest that apoptosis of HeLa cells induced by PS I PDT is not only triggered by ROS but is also regulated by Ca2+ overload. Mitochondria and the ER serve as the subcellular targets of PS I PDT, the effective activation of which

  7. Fisetin Induces Apoptosis Through p53-Mediated Up-Regulation of DR5 Expression in Human Renal Carcinoma Caki Cells.

    Science.gov (United States)

    Min, Kyoung-Jin; Nam, Ju-Ock; Kwon, Taeg Kyu

    2017-08-02

    Fisetin is a natural compound found in fruits and vegetables such as strawberries, apples, cucumbers, and onions. Since fisetin can elicit anti-cancer effects, including anti-proliferation and anti-migration, we investigated whether fisetin induced apoptosis in human renal carcinoma (Caki) cells. Fisetin markedly induced sub-G1 population and cleavage of poly (ADP-ribose) polymerase (PARP), which is a marker of apoptosis, and increased caspase activation. We found that pan-caspase inhibitor (z-VAD-fmk) inhibited fisetin-induced apoptosis. In addition, fisetin induced death receptor 5 (DR5) expression at the transcriptional level, and down-regulation of DR5 by siRNA blocked fisetin-induced apoptosis. Furthermore, fisetin induced p53 protein expression through up-regulation of protein stability, whereas down-regulation of p53 by siRNA markedly inhibited fisetin-induced DR5 expression. In contrast, fisetin induced up-regulation of CHOP expression and reactive oxygen species production, which had no effect on fisetin-induced apoptosis. Taken together, our study demonstrates that fisetin induced apoptosis through p53 mediated up-regulation of DR5 expression at the transcriptional level.

  8. Cytosolic NADP(+)-dependent isocitrate dehydrogenase regulates cadmium-induced apoptosis.

    Science.gov (United States)

    Shin, Seoung Woo; Kil, In Sup; Park, Jeen-Woo

    2010-04-01

    Cadmium ions have a high affinity for thiol groups. Therefore, they may disturb many cellular functions. We recently reported that cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) functions as an antioxidant enzyme to supply NADPH, a major source of reducing equivalents to the cytosol. Cadmium decreased the activity of IDPc both as a purified enzyme and in cultured cells. In the present study, we demonstrate that the knockdown of IDPc expression in HEK293 cells greatly enhances apoptosis induced by cadmium. Transfection of HEK293 cells with an IDPc small interfering RNA significantly decreased the activity of IDPc and enhanced cellular susceptibility to cadmium-induced apoptosis as indicated by the morphological evidence of apoptosis, DNA fragmentation and condensation, cellular redox status, mitochondria redox status and function, and the modulation of apoptotic marker proteins. Taken together, our results suggest that suppressing the expression of IDPc enhances cadmium-induced apoptosis of HEK293 cells by increasing disruption of the cellular redox status. Copyright 2009 Elsevier Inc. All rights reserved.

  9. Downregulation of Endogenous Hydrogen Sulfide Pathway Is Involved in Mitochondrion-Related Endothelial Cell Apoptosis Induced by High Salt

    Directory of Open Access Journals (Sweden)

    Yanfang Zong

    2015-01-01

    Full Text Available Background. The study aimed to investigate whether endogenous H2S pathway was involved in high-salt-stimulated mitochondria-related vascular endothelial cell (VEC apoptosis. Methods. Cultured human umbilical vein endothelial cells (HUVECs were used in the study. H2S content in the supernatant was detected. Western blot was used to detect expression of cystathionine gamma-lyase (CSE, cleaved-caspase-3, and mitochondrial and cytosolic cytochrome c (cytc. Fluorescent probes were used to quantitatively detect superoxide anion generation and measure the in situ superoxide anion generation in HUVEC. Mitochondrial membrane pore opening, mitochondrial membrane potential, and caspase-9 activities were measured. The cell apoptosis was detected by cell death ELISA and TdT-mediated dUTP nick end labeling (TUNEL methods. Results. High-salt treatment downregulated the endogenous VEC H2S/CSE pathway, in association with increased generation of oxygen free radicals, decreased mitochondrial membrane potential, enhanced the opening of mitochondrial membrane permeability transition pore and leakage of mitochondrial cytc, activated cytoplasmic caspase-9 and caspase-3 and subsequently induced VEC apoptosis. However, supplementation of H2S donor markedly inhibited VEC oxidative stress and mitochondria-related VEC apoptosis induced by high salt. Conclusion. H2S/CSE pathway is an important endogenous defensive system in endothelial cells antagonizing high-salt insult. The protective mechanisms for VEC damage might involve inhibiting oxidative stress and protecting mitochondrial injury.

  10. Curcumin inhibition of JNKs prevents dopaminergic neuronal loss in a mouse model of Parkinson’s disease through suppressing mitochondria dysfunction

    Directory of Open Access Journals (Sweden)

    Pan Jing

    2012-08-01

    Full Text Available Abstract Curcumin,a natural polyphenol obtained from turmeric,has been implicated to be neuroprotective in a variety of neurodegenerative disorders although the mechanism remains poorly understood. The results of our recent experiments indicated that curcumin could protect dopaminergic neurons from apoptosis in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP mouse model of Parkinson’s disease (PD. The death of dopaminergic neurons and the loss of dopaminergic axon in the striatum were significantly suppressed by curcumin in MPTP mouse model. Further studies showed that curcumin inhibited JNKs hyperphosphorylation induced by MPTP treatment. JNKs phosphorylation can cause translocation of Bax to mitochondria and the release of cytochrome c which both ultimately contribute to mitochondria-mediated apoptosis. These pro-apoptosis effect can be diminished by curcumin. Our experiments demonstrated that curcumin can prevent nigrostriatal degeneration by inhibiting the dysfunction of mitochondrial through suppressing hyperphosphorylation of JNKs induced by MPTP. Our results suggested that JNKs/mitochondria pathway may be a novel target in the treatment of PD patients.

  11. Apoptosis and autophagy induced by pyropheophorbide-α methyl ester-mediated photodynamic therapy in human osteosarcoma MG-63 cells.

    Science.gov (United States)

    Huang, Qiu; Ou, Yun-Sheng; Tao, Yong; Yin, Hang; Tu, Ping-Hua

    2016-06-01

    Pyropheophorbide-α methyl ester (MPPa) was a second-generation photosensitizer with many potential applications. Here, we explored the impact of MPPa-mediated photodynamic therapy (MPPa-PDT) on the apoptosis and autophagy of human osteosarcoma (MG-63) cells as well as the relationships between apoptosis and autophagy of the cells, and investigated the related molecular mechanisms. We found that MPPa-PDT demonstrated the ability to inhibit MG-63 cell viability in an MPPa concentration- and light dose-dependent manner, and to induce apoptosis via the mitochondrial apoptosis pathway. Additionally, MPPa-PDT could also induce autophagy of MG-63 cell. Meanwhile, the ROS scavenger N-acetyl-L-cysteine (NAC) and the Jnk inhibitor SP600125 were found to inhibit the MPPa-PDT-induced autophagy, and NAC could also inhibit Jnk phosphorylation. Furthermore, pretreatment with the autophagy inhibitor 3-methyladenine or chloroquine showed the potential in reducing the apoptosis rate induced by MPPa-PDT in MG-63 cells. Our results indicated that the mitochondrial pathway was involved in MPPa-PDT-induced apoptosis of MG-63 cells. Meanwhile the ROS-Jnk signaling pathway was involved in MPPa-PDT-induced autophagy, which further promoted the apoptosis in MG-63 cells.

  12. Capsaicin sensitizes TRAIL-induced apoptosis through Sp1-mediated DR5 up-regulation: Involvement of Ca2+ influx

    International Nuclear Information System (INIS)

    Moon, Dong-Oh; Kang, Chang-Hee; Kang, Sang-Hyuck; Choi, Yung-Hyun; Hyun, Jin-Won; Chang, Weon-Young; Kang, Hee-Kyoung; Koh, Young-Sang; Maeng, Young-Hee; Kim, Young-Ree; Kim, Gi-Young

    2012-01-01

    Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in various malignant cells, several cancers including human hepatocellular carcinoma (HCC) exhibit potent resistance to TRAIL-induced cell death. The aim of this study is to evaluate the anti-cancer potential of capsaicin in TRAIL-induced cancer cell death. As indicated by assays that measure phosphatidylserine exposure, mitochondrial activity and activation of caspases, capsaicin potentiated TRAIL-resistant cells to lead to cell death. In addition, we found that capsaicin induces the cell surface expression of TRAIL receptor DR5, but not DR4 through the activation Sp1 on its promoter region. Furthermore, we investigated that capsaicin-induced DR5 expression and apoptosis are inhibited by calcium chelator or inhibitors for calmodulin-dependent protein kinase. Taken together, our data suggest that capsaicin sensitizes TRAIL-mediated HCC cell apoptosis by DR5 up-regulation via calcium influx-dependent Sp1 activation. Highlights: ► Capsaicin sensitizes TRAIL-induced apoptosis through activation of caspases. ► Capsaicin induces expression of DR5 through Sp1 activation. ► Capsaicin activates calcium signaling pathway.

  13. 2'-Hydroxycinnamaldehyde induces apoptosis through HSF1-mediated BAG3 expression.

    Science.gov (United States)

    Nguyen, Hai-Anh; Kim, Soo-A

    2017-01-01

    BAG3, a member of BAG co-chaperone family, is induced by stressful stimuli such as heat shock and heavy metals. Through interaction with various binding partners, BAG3 is thought to play a role in cellular adaptive responses against stressful conditions in normal and neoplastic cells. 2'-Hydroxycinnamaldehyde (HCA) is a natural derivative of cinnamaldehyde and has antitumor activity in various cancer cells. In the present study, for the first time, we identified that HCA induced BAG3 expression and BAG3-mediated apoptosis in cancer cells. The apoptotic cell death induced by HCA was demonstrated by caspase-7, -9 and PARP activation, and confirmed by Annexin V staining in both SW480 and SW620 colon cancer cells. Notably, both the mRNA and protein levels of BAG3 were largely induced by HCA in a dose- and time-dependent manner. By showing transcription factor HSF1 activation, we demonstrated that HCA induces the expression of BAG3 through HSF1 activation. More importantly, knockdown of BAG3 expression using siRNA largely inhibited HCA-induced apoptosis, suggesting that BAG3 is actively involved in HCA-induced cancer cell death. Considering the importance of the stress response mechanism in cancer progression, our results strongly suggest that BAG3 could be a potential target for anticancer therapy.

  14. FOXO3-mediated up-regulation of Bim contributes to rhein-induced cancer cell apoptosis.

    Science.gov (United States)

    Wang, Jiao; Liu, Shu; Yin, Yancun; Li, Mingjin; Wang, Bo; Yang, Li; Jiang, Yangfu

    2015-03-01

    The anthraquinone compound rhein is a natural agent in the traditional Chinese medicine rhubarb. Preclinical studies demonstrate that rhein has anticancer activity. Treatment of a variety of cancer cells with rhein may induce apoptosis. Here, we report that rhein induces atypical unfolded protein response in breast cancer MCF-7 cells and hepatoma HepG2 cells. Rhein induces CHOP expression, eIF2α phosphorylation and caspase cleavage, while it does not induce glucose-regulated protein 78 (GRP78) expression in both MCF-7 and HepG2 cells. Meanwhile, rhein inhibits thapsigargin-induced GRP78 expression and X box-binding protein 1 splicing. In addition, rhein inhibits Akt phosphorylation and stimulates FOXO transactivation activity. Rhein induces Bim expression in MCF-7 and HepG2 cells, which can be abrogated by FOXO3a knockdown. Knockdown of FOXO3a or Bim abrogates rhein-induced caspase cleavage and apoptosis. The chemical chaperone 4-phenylbutyrate acid antagonizes the induction of FOXO activation, Bim expression and caspase cleavage by rhein, indicating that protein misfolding may be involved in triggering these deleterious effects. We conclude that FOXO3a-mediated up-regulation of Bim is a key mechanism underlying rhein-induced cancer cells apoptosis.

  15. Heat Shock Protein 70 Neutralizes Apoptosis-Inducing Factor

    Directory of Open Access Journals (Sweden)

    Guido Kroemer

    2001-01-01

    Full Text Available Programmed cell death (apoptosis is the physiological process responsible for the demise of superfluous, aged, damaged, mutated, and ectopic cells. Its normal function is essential both for embryonic development and for maintenance of adult tissue homeostasis. Deficient apoptosis participates in cancerogenesis, whereas excessive apoptosis leads to unwarranted cell loss accounting for disparate diseases including neurodegeneration and AIDS. One critical step in the process of apoptosis consists in the permeabilization of mitochondrial membranes, leading to the release of proteins which normally are secluded behind the outer mitochondrial membrane[1]. For example, cytochrome c, which is normally confined to the mitochondrial intermembrane space, is liberated from mitochondria and interacts with a cytosolic protein, Apaf-1, causing its oligomerization and constitution of the so-called apoptosome, a protein complex which activates a specific class of cysteine proteases, the caspases[2]. Another example concerns the so-called apoptosis-inducing factor (AIF, another mitochondrial intermembrane protein which can translocate to the nucleus where it induces chromatin condensation and DNA fragmentation[3].

  16. Silibinin induces mitochondrial NOX4-mediated endoplasmic reticulum stress response and its subsequent apoptosis

    International Nuclear Information System (INIS)

    Kim, Sang-Hun; Kim, Kwang-Youn; Yu, Sun-Nyoung; Seo, Young-Kyo; Chun, Sung-Sik; Yu, Hak-Sun; Ahn, Soon-Cheol

    2016-01-01

    Silibinin, a biologically active compound of milk thistle, has chemopreventive effects on cancer cell lines. Recently it was reported that silibinin inhibited tumor growth through activation of the apoptotic signaling pathway. Although various evidences showed multiple signaling pathways of silibinin in apoptosis, there were no reports to address the clear mechanism of ROS-mediated pathway in prostate cancer PC-3 cells. Several studies suggested that reactive oxygen species (ROS) play an important role in various signaling cascades, but the primary source of ROS was currently unclear. The effect of silibinin was investigated on cell growth of prostate cell lines by MTT assay. We examined whether silibinin induced apoptosis through production of ROS using flow cytometry. Expression of apoptosis-, endoplasmic reticulum (ER)-related protein and gene were determined by western blotting and RT-PCR, respectively. Results showed that silibinin triggered mitochondrial ROS production through NOX4 expression and finally led to induce apoptosis. In addition, mitochondrial ROS caused ER stress through disruption of Ca 2+ homeostasis. Co-treatment of ROS inhibitor reduced the silibinin-induced apoptosis through the inhibition of NOX4 expression, resulting in reduction of both Ca 2+ level and ER stress response. Taken together, silibinin induced mitochondrial ROS-dependent apoptosis through NOX4, which is associated with disruption of Ca 2+ homeostasis and ER stress response. Therefore, the regulation of NOX4, mitochondrial ROS producer, could be a potential target for the treatment of prostate cancer. The online version of this article (doi:10.1186/s12885-016-2516-6) contains supplementary material, which is available to authorized users

  17. Induction and regulation of tumor necrosis factor-related apoptosis-inducing ligand/Apo-2 ligand-mediated apoptosis in renal cell carcinoma.

    Science.gov (United States)

    Griffith, Thomas S; Fialkov, Jonathan M; Scott, David L; Azuhata, Takeo; Williams, Richard D; Wall, Nathan R; Altieri, Dario C; Sandler, Anthony D

    2002-06-01

    The lack of effective therapy for disseminated renal cell carcinoma (RCC) has stimulated the search for novel treatments including immunotherapeutic strategies. However, poor therapeutic responses and marked toxicity associated with immunological agents has limited their use. The tumor necrosis factor family member tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/Apo-2 ligand induces apoptosis in a variety of tumor cell types, while having little cytotoxic activity against normal cells. In this study the activation and regulation of TRAIL-induced apoptosis and TRAIL receptor expression in human RCC cell lines and pathologic specimens was examined. TRAIL induced caspase-mediated apoptotic death of RCC cells with variable sensitivities among the cell lines tested. Compared with TRAIL-sensitive RCC cell lines (A-498, ACHN, and 769-P), the TRAIL-resistant RCC cell line (786-O) expressed lesser amounts of the death-inducing TRAIL receptors, and greater amounts of survivin, an inhibitor of apoptosis. Incubation of 786-O with actinomycin D increased the expression of the death-inducing TRAIL receptors and, concomitantly, decreased the intracellular levels of survivin, resulting in TRAIL-induced apoptotic death. The link between survivin and TRAIL regulation was confirmed when an increase in TRAIL resistance was observed after overexpression of survivin in the TRAIL-sensitive, survivin-negative RCC line A-498. These findings, along with our observation that TRAIL receptors are expressed in RCC tumor tissue, suggest that TRAIL may be useful as a therapeutic agent for RCC and that survivin may partially regulate TRAIL-induced cell death.

  18. A receptor tyrosine kinase inhibitor, Tyrphostin A9 induces cancer cell death through Drp1 dependent mitochondria fragmentation

    International Nuclear Information System (INIS)

    Park, So Jung; Park, Young Jun; Shin, Ji Hyun; Kim, Eun Sung; Hwang, Jung Jin; Jin, Dong-Hoon; Kim, Jin Cheon; Cho, Dong-Hyung

    2011-01-01

    Highlights: → We screened and identified Tyrphostin A9, a receptor tyrosine kinase inhibitor as a strong mitochondria fission inducer. → Tyrphostin A9 treatment promotes mitochondria dysfunction and contributes to cytotoxicity in cancer cells. → Tyrphostin A9 induces apoptotic cell death through a Drp1-mediated pathway. → Our studies suggest that Tyrphostin A9 induces mitochondria fragmentation and apoptotic cell death via Drp1 dependently. -- Abstract: Mitochondria dynamics controls not only their morphology but also functions of mitochondria. Therefore, an imbalance of the dynamics eventually leads to mitochondria disruption and cell death. To identify specific regulators of mitochondria dynamics, we screened a bioactive chemical compound library and selected Tyrphostin A9, a tyrosine kinase inhibitor, as a potent inducer of mitochondrial fission. Tyrphostin A9 treatment resulted in the formation of fragmented mitochondria filament. In addition, cellular ATP level was decreased and the mitochondrial membrane potential was collapsed in Tyr A9-treated cells. Suppression of Drp1 activity by siRNA or over-expression of a dominant negative mutant of Drp1 inhibited both mitochondrial fragmentation and cell death induced by Tyrpohotin A9. Moreover, treatment of Tyrphostin A9 also evoked mitochondrial fragmentation in other cells including the neuroblastomas. Taken together, these results suggest that Tyrphostin A9 induces Drp1-mediated mitochondrial fission and apoptotic cell death.

  19. Fisetin Induces Apoptosis Through p53-Mediated Up-Regulation of DR5 Expression in Human Renal Carcinoma Caki Cells

    Directory of Open Access Journals (Sweden)

    Kyoung-jin Min

    2017-08-01

    Full Text Available Fisetin is a natural compound found in fruits and vegetables such as strawberries, apples, cucumbers, and onions. Since fisetin can elicit anti-cancer effects, including anti-proliferation and anti-migration, we investigated whether fisetin induced apoptosis in human renal carcinoma (Caki cells. Fisetin markedly induced sub-G1 population and cleavage of poly (ADP-ribose polymerase (PARP, which is a marker of apoptosis, and increased caspase activation. We found that pan-caspase inhibitor (z-VAD-fmk inhibited fisetin-induced apoptosis. In addition, fisetin induced death receptor 5 (DR5 expression at the transcriptional level, and down-regulation of DR5 by siRNA blocked fisetin-induced apoptosis. Furthermore, fisetin induced p53 protein expression through up-regulation of protein stability, whereas down-regulation of p53 by siRNA markedly inhibited fisetin-induced DR5 expression. In contrast, fisetin induced up-regulation of CHOP expression and reactive oxygen species production, which had no effect on fisetin-induced apoptosis. Taken together, our study demonstrates that fisetin induced apoptosis through p53 mediated up-regulation of DR5 expression at the transcriptional level.

  20. A novel polysaccharide from Ganoderma atrum exerts antitumor activity by activating mitochondria-mediated apoptotic pathway and boosting the immune system.

    Science.gov (United States)

    Zhang, Shenshen; Nie, Shaoping; Huang, Danfei; Feng, Yanling; Xie, Mingyong

    2014-02-19

    Ganoderma is a precious health-care edible medicinal fungus in China. A novel Ganoderma atrum polysaccharide (PSG-1) is the main bioactive component. We investigated the antitumor effect and molecular mechanisms of PSG-1. It exhibited no significant effect on cell proliferation directly. In contrast, administration of PSG-1 markedly suppressed tumor growth in CT26 tumor-bearing mice. It was observed that PSG-1 caused apoptosis in CT26 cells. Apoptosis was associated with loss of mitochondrial membrane potential, enhancement of mitochondrial cytochrome c release and intracellular ROS production, elevation of p53 and Bax expression, downregulation of Bcl-2, and the activation of caspase-9 and -3. Moreover, PSG-1 enhanced immune organ index and promoted lymphocyte proliferation as well as cytokine levels in serum. Taken together, our data indicate that PSG-1 has potential antitumor activity in vivo by inducing apoptosis via mitochondria-mediated apoptotic pathway and enhances host immune system function. Therefore, PSG-1 could be a safe and effective antitumor, bioactive agent or functional food.

  1. BID Mediates Oxygen-Glucose Deprivation-Induced Neuronal Injury in Organotypic Hippocampal Slice Cultures and Modulates Tissue Inflammation in a Transient Focal Cerebral Ischemia Model without Changing Lesion Volume

    DEFF Research Database (Denmark)

    Martin, Nellie Anne; Bonner, Helena; Elkjær, Maria Louise

    2016-01-01

    The BH3 interacting-domain death agonist (BID) is a pro-apoptotic protein involved in death receptor-induced and mitochondria-mediated apoptosis. Recently, it has also been suggested that BID is involved in the regulation of inflammatory responses in the central nervous system. We found that BID...

  2. 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to inhibit hepatocellular carcinoma cells

    International Nuclear Information System (INIS)

    Fu, Meili; Wan, Fuqiang; Li, Zhengling; Zhang, Fenghua

    2016-01-01

    The aim of the present study is to investigate the potential anti-hepatocellular carcinoma (HCC) cell activity by 4SC-202, a novel class I HDAC inhibitor (HDACi). The associated signaling mechanisms were also analyzed. We showed that 4SC-202 treatment induced potent cytotoxic and proliferation–inhibitory activities against established HCC cell lines (HepG2, HepB3, SMMC-7721) and patient-derived primary HCC cells. Further, adding 4SC-202 in HCC cells activated mitochondrial apoptosis pathway, which was evidenced by mitochondrial permeability transition pore (mPTP) opening, cytochrome C cytosol release and caspase-3/-9 activation. Inhibition of this apoptosis pathway, by caspase-3/-9 inhibitors, mPTP blockers, or by shRNA-mediated knockdown of cyclophilin-D (Cyp-D, a key component of mPTP), significantly attenuated 4SC-202-induced HCC cell death and apoptosis. Reversely, over-expression of Cyp-D enhanced 4SC-202's sensitivity in HCC cells. Further studies showed that 4SC-202 induced apoptosis signal-regulating kinase 1 (ASK1) activation, causing it translocation to mitochondria and physical association with Cyp-D. This mitochondrial ASK1-Cyp-D complexation appeared required for mediating 4SC-202-induced apoptosis activation. ASK1 stable knockdown by targeted-shRNAs largely inhibited 4SC-202-induced mPTP opening, cytochrome C release, and following HCC cell apoptotic death. Together, we suggest that 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to potently inhibit human HCC cells. - Highlights: • 4SC-202 exerts potent anti-proliferative and cytotoxic activity against established/primary HCC cells. • SC-202-induced anti-HCC cell activity relies on caspase-dependent apoptosis activation. • 4SC-202 activates Cyp-D-dependent mitochondrial apoptosis pathway in HCC cells. • 4SC-202 activates ASK1 in HCC cells, causing it translocation to mitochondria. • Mitochondrial ASK1-Cyp-D complexation mediates 4SC-202's activity in HCC cells.

  3. 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to inhibit hepatocellular carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Meili, E-mail: fumeilidrlinyi@tom.com [Department of Infectious Disease, Linyi People' s Hospital, Linyi 276000 (China); Wan, Fuqiang [Department of Head and Neck Surgery, Linyi Tumor Hospital, Linyi 276000 (China); Li, Zhengling [Department of Nursing, Tengzhou Central People' s Hospital, Tengzhou 277500 (China); Zhang, Fenghua [Department of Operating Room, Linyi People' s Hospital, Linyi 276000 (China)

    2016-03-04

    The aim of the present study is to investigate the potential anti-hepatocellular carcinoma (HCC) cell activity by 4SC-202, a novel class I HDAC inhibitor (HDACi). The associated signaling mechanisms were also analyzed. We showed that 4SC-202 treatment induced potent cytotoxic and proliferation–inhibitory activities against established HCC cell lines (HepG2, HepB3, SMMC-7721) and patient-derived primary HCC cells. Further, adding 4SC-202 in HCC cells activated mitochondrial apoptosis pathway, which was evidenced by mitochondrial permeability transition pore (mPTP) opening, cytochrome C cytosol release and caspase-3/-9 activation. Inhibition of this apoptosis pathway, by caspase-3/-9 inhibitors, mPTP blockers, or by shRNA-mediated knockdown of cyclophilin-D (Cyp-D, a key component of mPTP), significantly attenuated 4SC-202-induced HCC cell death and apoptosis. Reversely, over-expression of Cyp-D enhanced 4SC-202's sensitivity in HCC cells. Further studies showed that 4SC-202 induced apoptosis signal-regulating kinase 1 (ASK1) activation, causing it translocation to mitochondria and physical association with Cyp-D. This mitochondrial ASK1-Cyp-D complexation appeared required for mediating 4SC-202-induced apoptosis activation. ASK1 stable knockdown by targeted-shRNAs largely inhibited 4SC-202-induced mPTP opening, cytochrome C release, and following HCC cell apoptotic death. Together, we suggest that 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to potently inhibit human HCC cells. - Highlights: • 4SC-202 exerts potent anti-proliferative and cytotoxic activity against established/primary HCC cells. • SC-202-induced anti-HCC cell activity relies on caspase-dependent apoptosis activation. • 4SC-202 activates Cyp-D-dependent mitochondrial apoptosis pathway in HCC cells. • 4SC-202 activates ASK1 in HCC cells, causing it translocation to mitochondria. • Mitochondrial ASK1-Cyp-D complexation mediates 4SC-202's activity in HCC cells.

  4. Hypoxia-induced p53 modulates both apoptosis and radiosensitivity via AKT

    Science.gov (United States)

    Leszczynska, Katarzyna B.; Foskolou, Iosifina P.; Abraham, Aswin G.; Anbalagan, Selvakumar; Tellier, Céline; Haider, Syed; Span, Paul N.; O’Neill, Eric E.; Buffa, Francesca M.; Hammond, Ester M.

    2015-01-01

    Restoration of hypoxia-induced apoptosis in tumors harboring p53 mutations has been proposed as a potential therapeutic strategy; however, the transcriptional targets that mediate hypoxia-induced p53-dependent apoptosis remain elusive. Here, we demonstrated that hypoxia-induced p53-dependent apoptosis is reliant on the DNA-binding and transactivation domains of p53 but not on the acetylation sites K120 and K164, which, in contrast, are essential for DNA damage–induced, p53-dependent apoptosis. Evaluation of hypoxia-induced transcripts in multiple cell lines identified a group of genes that are hypoxia-inducible proapoptotic targets of p53, including inositol polyphosphate-5-phosphatase (INPP5D), pleckstrin domain–containing A3 (PHLDA3), sulfatase 2 (SULF2), B cell translocation gene 2 (BTG2), cytoplasmic FMR1-interacting protein 2 (CYFIP2), and KN motif and ankyrin repeat domains 3 (KANK3). These targets were also regulated by p53 in human cancers, including breast, brain, colorectal, kidney, bladder, and melanoma cancers. Downregulation of these hypoxia-inducible targets associated with poor prognosis, suggesting that hypoxia-induced apoptosis contributes to p53-mediated tumor suppression and treatment response. Induction of p53 targets, PHLDA3, and a specific INPP5D transcript mediated apoptosis in response to hypoxia through AKT inhibition. Moreover, pharmacological inhibition of AKT led to apoptosis in the hypoxic regions of p53-deficient tumors and consequently increased radiosensitivity. Together, these results identify mediators of hypoxia-induced p53-dependent apoptosis and suggest AKT inhibition may improve radiotherapy response in p53-deficient tumors. PMID:25961455

  5. Betulinic acid-induced mitochondria-dependent cell death is counterbalanced by an autophagic salvage response

    NARCIS (Netherlands)

    Potze, L.; Mullauer, F. B.; Colak, S.; Kessler, J. H.; Medema, J. P.

    2014-01-01

    Betulinic acid (BetA) is a plant-derived pentacyclic triterpenoid that exerts potent anti-cancer effects in vitro and in vivo. It was shown to induce apoptosis via a direct effect on mitochondria. This is largely independent of proapoptotic BAK and BAX, but can be inhibited by cyclosporin A (CsA),

  6. Organometallic Gold(III) Complexes Similar to Tetrahydroisoquinoline Induce ER-Stress-Mediated Apoptosis and Pro-Death Autophagy in A549 Cancer Cells.

    Science.gov (United States)

    Huang, Ke-Bin; Wang, Feng-Yang; Tang, Xiao-Ming; Feng, Hai-Wen; Chen, Zhen-Feng; Liu, Yan-Cheng; Liu, You-Nian; Liang, Hong

    2018-04-26

    Agents inducing both apoptosis and autophagic death can be effective chemotherapeutic drugs. In our present work, we synthesized two organometallic gold(III) complexes harboring C^N ligands that structurally resemble tetrahydroisoquinoline (THIQ): Cyc-Au-1 (AuL 1 Cl 2 , L 1 = 3,4-dimethoxyphenethylamine) and Cyc-Au-2 (AuL 2 Cl 2 , L 2 = methylenedioxyphenethylamine). In screening their in vitro activity, we found both gold complexes exhibited lower toxicity, lower resistance factors, and better anticancer activity than those of cisplatin. The organometallic gold(III) complexes accumulate in mitochondria and induce elevated ROS and an ER stress response through mitochondrial dysfunction. These effects ultimately result in simultaneous apoptosis and autophagy. Importantly, compared to cisplatin, Cyc-Au-2 exhibits lower toxicity and better anticancer activity in a murine tumor model. To the best of our knowledge, Cyc-Au-2 is the first organometallic Au(III) compound that induces apoptosis and autophagic death. On the basis of our results, we believe Cyc-Au-2 to be a promising anticancer agent or lead compound for further anticancer drug development.

  7. Paraoxon induces apoptosis in EL4 cells via activation of mitochondrial pathways.

    Science.gov (United States)

    Saleh, A M; Vijayasarathy, C; Masoud, L; Kumar, L; Shahin, A; Kambal, A

    2003-07-01

    The toxicity of organophosphorus compounds, such as paraoxon (POX), is due to their anticholinesterase action. Recently, we have shown that, at noncholinergic doses (1 to 10 nM), POX (the bioactive metabolite of parathion) causes apoptotic cell death in murine EL4 T-lymphocytic leukemia cell line through activation of caspase-3. In this study, by employing caspase-specific inhibitors, we extend our observations to elucidate the sequence of events involved in POX-stimulated apoptosis. Pretreatment of EL4 cells with the caspase-9-specific inhibitor zLEHD-fmk attenuated POX-induced apoptosis in a dose-dependent manner, whereas the caspase-8 inhibitor zIETD-fmk had no effect. Furthermore, the activation of caspase-9, -8, and -3 in response to POX treatment was completely inhibited in the presence of zLEHD-fmk, implicating the involvement of caspase 9-dependent mitochondrial pathways in POX-stimulated apoptosis. Indeed, under both in vitro and in vivo conditions, POX triggered a dose- and time-dependent translocation of cytochrome c from mitochondria into the cytosol, as assessed by Western blot analysis. Investigation of the mechanism of cytochrome c release revealed that POX disrupted mitochondrial transmembrane potential. Neither this effect nor cytchrome c release was dependent on caspase activation, since the general inhibitor of the caspase family zVAD-fmk did not influence both processes. Finally, POX treatment also resulted in a time-dependent up-regulation and translocation of the proapoptotic molecule Bax to mitochondria. Inhibition of this event by zVAD-fmk suggests that the activation and translocation of Bax to mitochondria is subsequent to activation of the caspase cascades. The results indicate that POX induces apoptosis in EL4 cells through a direct effect on mitochondria by disrupting its transmembrane potential, causing the release of cytochrome c into the cytosol and subsequent activation of caspase-9. Inhibition of this specific pathway might provide

  8. Autoregulatory Feedback Mechanism of P38MAPK/Caspase-8 in Photodynamic Therapy-Hydrophilic/Lipophilic Tetra-α-(4-carboxyphenoxy Phthalocyanine Zinc-Induced Apoptosis of Human Hepatocellular Carcinoma Bel-7402 Cells

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2014-01-01

    Full Text Available Photodynamic therapy (PDT is a novel and promising antitumor treatment. Our previous study showed that hydrophilic/lipophilic tetra-α-(4-carboxyphenoxy phthalocyanine zinc- (TαPcZn- mediated PDT (TαPcZn-PDT inhibits the proliferation of human hepatocellular carcinoma Bel-7402 cells by triggering apoptosis and arresting cell cycle. However, mechanisms of TαPcZn-PDT-induced apoptosis of Bel-7402 cells have not been fully clarified. In the present study, therefore, effect of TαPcZn-PDT on apoptosis, P38MAPK, p-P38MAPK, Caspase-8, Caspase-3, Bcl-2, Bid, Cytochrome c, and mitochondria membrane potential in Bel-7402 cells without or with P38MAPK inhibitor SB203580 or Caspase-8 inhibitor Ac-IEFD-CHO was investigated by haematoxylin and eosin (HE staining assay, flow cytometry analysis of annexin V-FITC/propidium iodide (PI double staining cells and 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine iodide (JC-1, and immunoblot assay. We found that TαPcZn-PDT resulted in apoptosis induction, activation of P38MAPK, Caspase-8, Caspase-3, and Bid, downregulation of Bcl-2, release of Cytochrome c from mitochondria, and disruption of mitochondrial membrane potential in TαPcZn-PDT-treated Bel-7402 cells. In contrast, SB203580 or Ac-IEFD-CHO attenuated induction of apoptosis, activation of P38MAPK, Caspase-8, Caspase-3, and Bid, downregulation of Bcl-2, release of Cytochrome c from mitochondria, and disruption of mitochondrial membrane potential in TαPcZn-PDT-treated Bel-7402 cells. Taken together, we conclude that Caspase-3, Bcl-2, Bid, and mitochondria are involved in autoregulatory feedback of P38MAPK/Caspase-8 during TαPcZn-PDT-induced apoptosis of Bel-7402 cells.

  9. Cardioprotection by modulation of mitochondrial respiration during ischemia–reperfusion: Role of apoptosis-inducing factor

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Aijun [Department of Internal Medicine (Division of Cardiology), Virginia Commonwealth University, Richmond, VA 23298 (United States); Department of Anesthesiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030 (China); Szczepanek, Karol; Hu, Ying [Department of Internal Medicine (Division of Cardiology), Virginia Commonwealth University, Richmond, VA 23298 (United States); Lesnefsky, Edward J. [Department of Internal Medicine (Division of Cardiology), Virginia Commonwealth University, Richmond, VA 23298 (United States); Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298 (United States); Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA 23298 (United States); McGuire Department of Veterans Affairs Medical Center, Richmond, VA 23249 (United States); Chen, Qun, E-mail: qchen8@vcu.edu [Department of Internal Medicine (Division of Cardiology), Virginia Commonwealth University, Richmond, VA 23298 (United States)

    2013-06-14

    Highlights: •Blockade of electron transport prevents the loss of AIF from mitochondria during IR. •Blockade of electron transport decreases caspase-independent cell death during IR. •Mitochondrial AIF content is down-regulated in Harlequin mice. •Blockade of electron transport protects Harlequin mouse hearts during IR. •Amobarbital protection is partially dependent on mitochondrial AIF content. -- Abstract: The transient, reversible blockade of electron transport (BET) during ischemia or at the onset of reperfusion protects mitochondria and decreases cardiac injury. Apoptosis inducing factor (AIF) is located within the mitochondrial intermembrane space. A release of AIF from mitochondria into cytosol and nucleus triggers caspase-independent cell death. We asked if BET prevents the loss of AIF from mitochondria as a mechanism of protection in the buffer perfused heart. BET during ischemia with amobarbital, a rapidly reversible inhibitor of mitochondrial complex I, attenuated a release of AIF from mitochondria into cytosol, in turn decreasing the formation of cleaved and activated PARP-1. These results suggest that BET-mediated protection may occur through prevention of the loss of AIF from mitochondria during ischemia–reperfusion. In order to further clarify the role of mitochondrial AIF in BET-mediated protection, Harlequin (Hq) mice, a genetic model with mitochondrial AIF deficiency, were used to test whether BET could still decrease cell injury in Hq mouse hearts during reperfusion. BET during ischemia protected Hq mouse hearts against ischemia–reperfusion injury and improved mitochondrial function in these hearts during reperfusion. Thus, cardiac injury can still be decreased in the presence of down-regulated mitochondrial AIF content. Taken together, BET during ischemia protects both hearts with normal mitochondrial AIF content and hearts with mitochondrial AIF deficiency. Although preservation of mitochondrial AIF content plays a key role in

  10. Cardioprotection by modulation of mitochondrial respiration during ischemia–reperfusion: Role of apoptosis-inducing factor

    International Nuclear Information System (INIS)

    Xu, Aijun; Szczepanek, Karol; Hu, Ying; Lesnefsky, Edward J.; Chen, Qun

    2013-01-01

    Highlights: •Blockade of electron transport prevents the loss of AIF from mitochondria during IR. •Blockade of electron transport decreases caspase-independent cell death during IR. •Mitochondrial AIF content is down-regulated in Harlequin mice. •Blockade of electron transport protects Harlequin mouse hearts during IR. •Amobarbital protection is partially dependent on mitochondrial AIF content. -- Abstract: The transient, reversible blockade of electron transport (BET) during ischemia or at the onset of reperfusion protects mitochondria and decreases cardiac injury. Apoptosis inducing factor (AIF) is located within the mitochondrial intermembrane space. A release of AIF from mitochondria into cytosol and nucleus triggers caspase-independent cell death. We asked if BET prevents the loss of AIF from mitochondria as a mechanism of protection in the buffer perfused heart. BET during ischemia with amobarbital, a rapidly reversible inhibitor of mitochondrial complex I, attenuated a release of AIF from mitochondria into cytosol, in turn decreasing the formation of cleaved and activated PARP-1. These results suggest that BET-mediated protection may occur through prevention of the loss of AIF from mitochondria during ischemia–reperfusion. In order to further clarify the role of mitochondrial AIF in BET-mediated protection, Harlequin (Hq) mice, a genetic model with mitochondrial AIF deficiency, were used to test whether BET could still decrease cell injury in Hq mouse hearts during reperfusion. BET during ischemia protected Hq mouse hearts against ischemia–reperfusion injury and improved mitochondrial function in these hearts during reperfusion. Thus, cardiac injury can still be decreased in the presence of down-regulated mitochondrial AIF content. Taken together, BET during ischemia protects both hearts with normal mitochondrial AIF content and hearts with mitochondrial AIF deficiency. Although preservation of mitochondrial AIF content plays a key role in

  11. Singlet oxygen mediated apoptosis by anthrone involving lysosomes and mitochondria at ambient UV exposure

    Energy Technology Data Exchange (ETDEWEB)

    Mujtaba, Syed Faiz [Photobiology Division, (CSIR)-Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India); College of Pharmacy, Faculty of Pharmaceutical Sciences, Pt. B.D.S University of Health Sciences, Rohtak, Haryana (India); Dwivedi, Ashish; Yadav, Neera [Photobiology Division, (CSIR)-Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India); Ray, R.S., E-mail: ratanray.2011@rediffmail.com [Photobiology Division, (CSIR)-Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India); Singh, Gajendra [College of Pharmacy, Faculty of Pharmaceutical Sciences, Pt. B.D.S University of Health Sciences, Rohtak, Haryana (India)

    2013-05-15

    Highlights: ► Photomodification of anthrone at ambient environmental intensities of UV-radiation. ► Phototoxicity of anthrone through type-II photodynamic reaction by generating {sup 1}O{sub 2}. ► Role of DNA damage and lipid peroxidation in anthrone phototoxicity. ► Apototic cell death and involvement of lysosomes and mitochondria. ► Up-regulation of p21 and bax concomitantly down regulation of bcl2 genes expression. -- Abstract: Anthrone a tricyclic aromatic hydrocarbon which is toxic environmental pollutant comes in the environment through photooxidation of anthracene. We have studied the photomodification of anthrone under environmental conditions. Anthrone generates reactive oxygen species (ROS) like {sup 1}O{sub 2} through Type-II photodynamic reaction. Significant intracellular ROS generation was measured through dichlorohydrofluorescein fluorescence intensity. The generation of {sup 1}O{sub 2} was further substantiated by using specific quencher like sodium azide. UV induced photodegradation of 2-deoxyguanosine and photoperoxidation of linoleic acid accorded the involvement of {sup 1}O{sub 2} in the manifestation of anthrone phototoxicity. Phototoxicity of anthrone was done on human keratinocytes (HaCaT) through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and neutral red uptake assays. Anthrone induced cell cycle arrest (G2/M-phase) and DNA damage in a concentration dependent manner. We found apoptosis as a pattern of cell death which was confirmed through sub-G1 fraction, morphological changes, caspase-3 activation, acridine orange/ethidium bromide staining and phosphatidylserine translocation. Mitochondrial depolarization and lysosomal destabilization was parallel to apoptotic process. Our RT-PCR results strongly supports our view point of apoptotic cell death through up-regulation of pro-apoptotic genes p21 and Bax, and down regulation of anti-apoptotic gene Bcl{sub 2}. Therefore, much attention should be paid to concomitant

  12. Degradation of Epidermal Growth Factor Receptor Mediates Dasatinib-Induced Apoptosis in Head and Neck Squamous Cell Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Yu-Chin Lin

    2012-06-01

    Full Text Available Epidermal growth factor receptor (EGFR is an important oncoprotein that promotes cell growth and proliferation. Dasatinib, a bcr-abl inhibitor, has been approved clinically for the treatment of chronic myeloid leukemia and demonstrated to be effective against solid tumors in vitro through Src inhibition. Here, we disclose that EGFR degradation mediated dasatinib-induced apoptosis in head and neck squamous cell carcinoma (HNSCC cells. HNSCC cells, including Ca9-22, FaDu, HSC3, SAS, SCC-25, and UMSCC1, were treated with dasatinib, and cell viability, apoptosis, and underlying signal transduction were evaluated. Dasatinib exhibited differential sensitivities against HNSCC cells. Growth inhibition and apoptosis were correlated with its inhibition on Akt, Erk, and Bcl-2, irrespective of Src inhibition. Accordingly, we found that down-regulation of EGFR was a determinant of dasatinib sensitivity. Lysosome inhibitor reversed dasatinib-induced EGFR down-regulation, and c-cbl activity was increased by dasatinib, indicating that dasatinib-induced EGFR down-regulation might be through c-cbl-mediated lysosome degradation. Increased EGFR activation by ligand administration rescued cells from dasatinib-induced apoptosis, whereas inhibition of EGFR enhanced its apoptotic effect. Estrogen receptor α (ERα was demonstrated to play a role in Bcl-2 expression, and dasatinib inhibited ERα at the pretranslational level. ERα was associated with EGFR in dasatinib-treated HNSCC cells. Furthermore, the xenograft model showed that dasatinib inhibited HSC3 tumor growth through in vivo down-regulation of EGFR and ERα. In conclusion, degradation of EGFR is a novel mechanism responsible for dasatinib-induced apoptosis in HNSCC cells.

  13. Fem1b, a proapoptotic protein, mediates proteasome inhibitor-induced apoptosis of human colon cancer cells.

    Science.gov (United States)

    Subauste, M Cecilia; Sansom, Owen J; Porecha, Nehal; Raich, Natacha; Du, Liqin; Maher, Joseph F

    2010-02-01

    In the treatment of colon cancer, the development of resistance to apoptosis is a major factor in resistance to therapy. New molecular approaches to overcome apoptosis resistance, such as selectively upregulating proapoptotic proteins, are needed in colon cancer therapy. In a mouse model with inactivation of the adenomatous polyposis coli (Apc) tumor suppressor gene, reflecting the pathogenesis of most human colon cancers, the gene encoding feminization-1 homolog b (Fem1b) is upregulated in intestinal epithelium following Apc inactivation. Fem1b is a proapoptotic protein that interacts with apoptosis-inducing proteins Fas, tumor necrosis factor receptor-1 (TNFR1), and apoptotic protease activating factor-1 (Apaf-1). Increasing Fem1b expression induces apoptosis of cancer cells, but effects on colon cancer cells have not been reported. Fem1b is a homolog of feminization-1 (FEM-1), a protein in Caenorhabditis elegans that is regulated by proteasomal degradation, but whether Fem1b is likewise regulated by proteasomal degradation is unknown. Herein, we found that Fem1b protein is expressed in primary human colon cancer specimens, and in malignant SW620, HCT-116, and DLD-1 colon cancer cells. Increasing Fem1b expression, by transfection of a Fem1b expression construct, induced apoptosis of these cells. We found that proteasome inhibitor treatment of SW620, HCT-116, and DLD-1 cells caused upregulation of Fem1b protein levels, associated with induction of apoptosis. Blockade of Fem1b upregulation with morpholino antisense oligonucleotide suppressed the proteasome inhibitor-induced apoptosis of these cells. In conclusion, the proapoptotic protein Fem1b is downregulated by the proteasome in malignant colon cancer cells and mediates proteasome inhibitor-induced apoptosis of these cells. Therefore, Fem1b could represent a novel molecular target to overcome apoptosis resistance in therapy of colon cancer.

  14. Lysosomal ceramide generated by acid sphingomyelinase triggers cytosolic cathepsin B-mediated degradation of X-linked inhibitor of apoptosis protein in natural killer/T lymphoma cell apoptosis

    OpenAIRE

    Taniguchi, M; Ogiso, H; Takeuchi, T; Kitatani, K; Umehara, H; Okazaki, T

    2015-01-01

    We previously reported that IL-2 deprivation induced acid sphingomyelinase-mediated (ASM-mediated) ceramide elevation and apoptosis in an NK/T lymphoma cell line KHYG-1. However, the molecular mechanism of ASM?ceramide-mediated apoptosis during IL-2 deprivation is poorly understood. Here, we showed that IL-2 deprivation induces caspase-dependent apoptosis characterized by phosphatidylserine externalization, caspase-8, -9, and -3 cleavage, and degradation of X-linked inhibitor of apoptosis pro...

  15. Capsaicin binds to prohibitin 2 and displaces it from the mitochondria to the nucleus

    International Nuclear Information System (INIS)

    Kuramori, Chikanori; Azuma, Motoki; Kume, Kanako; Kaneko, Yuki; Inoue, Atsushi; Yamaguchi, Yuki; Kabe, Yasuaki; Hosoya, Takamitsu; Kizaki, Masahiro; Suematsu, Makoto; Handa, Hiroshi

    2009-01-01

    Capsaicin is widely used as a food additive and as an analgesic agent. Besides its well-known role in nociception, which is mediated by vanilloid receptor 1 specifically expressed in dorsal root ganglion neurons, capsaicin has also been considered as a potential anticancer agent, as it inhibits cell proliferation and induces apoptosis in various types of cancer cells. Here we identified a new molecular target of capsaicin from human myeloid leukemia cells. We show that capsaicin binds to prohibitin (PHB) 2, which is normally localized to the inner mitochondrial membrane, and induces its translocation to the nucleus. PHB2 is implicated in the maintenance of mitochondrial morphology and the control of apoptosis. We also provide evidence suggesting that capsaicin causes apoptosis directly through the mitochondria and that PHB2 contributes to capsaicin-induced apoptosis at multiple levels. This work will serve as an important foundation for further understanding of anticancer activity of capsaicin.

  16. Verocytotoxin-induced apoptosis of human microvascular endothelial cells.

    Science.gov (United States)

    Pijpers, A H; van Setten, P A; van den Heuvel, L P; Assmann, K J; Dijkman, H B; Pennings, A H; Monnens, L A; van Hinsbergh, V W

    2001-04-01

    The pathogenesis of the epidemic form of hemolytic uremic syndrome is characterized by endothelial cell damage. In this study, the role of apoptosis in verocytotoxin (VT)-mediated endothelial cell death in human glomerular microvascular endothelial cells (GMVEC), human umbilical vein endothelial cells, and foreskin microvascular endothelial cells (FMVEC) was investigated. VT induced apoptosis in GMVEC and human umbilical vein endothelial cells when the cells were prestimulated with the inflammatory mediator tumor necrosis factor-alpha (TNF-alpha). FMVEC displayed strong binding of VT and high susceptibility to VT under basal conditions, which made them suitable for the study of VT-induced apoptosis without TNF-alpha interference. On the basis of functional (flow cytometry and immunofluorescence microscopy using FITC-conjugated annexin V and propidium iodide), morphologic (transmission electron microscopy), and molecular (agarose gel electrophoresis of cellular DNA fragments) criteria, it was documented that VT induced programmed cell death in microvascular endothelial cells in a dose- and time-dependent manner. Furthermore, whereas partial inhibition of protein synthesis by VT was associated with a considerable number of apoptotic cells, comparable inhibition of protein synthesis by cycloheximide was not. This suggests that additional pathways, independent of protein synthesis inhibition, may be involved in VT-mediated apoptosis in microvascular endothelial cells. Specific inhibition of caspases by Ac-Asp-Glu-Val-Asp-CHO, but not by Ac-Tyr-Val-Ala-Asp-CHO, was accompanied by inhibition of VT-induced apoptosis in FMVEC and TNF-alpha-treated GMVEC. These data indicate that VT can induce apoptosis in human microvascular endothelial cells.

  17. Cr(VI) induces mitochondrial-mediated and caspase-dependent apoptosis through reactive oxygen species-mediated p53 activation in JB6 Cl41 cells

    International Nuclear Information System (INIS)

    Son, Young-Ok; Hitron, J. Andrew; Wang Xin; Chang Qingshan; Pan Jingju; Zhang Zhuo; Liu Jiankang; Wang Shuxia; Lee, Jeong-Chae; Shi Xianglin

    2010-01-01

    Cr(VI) compounds are known to cause serious toxic and carcinogenic effects. Cr(VI) exposure can lead to a severe damage to the skin, but the mechanisms involved in the Cr(VI)-mediated toxicity in the skin are unclear. The present study examined whether Cr(VI) induces cell death by apoptosis or necrosis using mouse skin epidermal cell line, JB6 Cl41 cells. We also investigated the cellular mechanisms of Cr(VI)-induced cell death. This study showed that Cr(VI) induced apoptotic cell death in a dose-dependent manner, as demonstrated by the appearance of cell shrinkage, the migration of cells into the sub-G1 phase, the increase of Annexin V positively stained cells, and the formation of nuclear DNA ladders. Cr(VI) treatment resulted in the increases of mitochondrial membrane depolarization and caspases activation. Electron spin resonance (ESR) and fluorescence analysis revealed that Cr(VI) increased intracellular levels of reactive oxygen species (ROS) such as hydrogen peroxide and superoxide anion radical in dose-dependent manner. Blockage of p53 by si-RNA transfection suppressed mitochondrial changes of Bcl-2 family composition, mitochondrial membrane depolarization, caspase activation and PARP cleavage, leading to the inhibition of Cr(VI)-induced apoptosis. Further, catalase treatment prevented p53 phosphorylation stimulated by Cr(VI) with the concomitant inhibition of caspase activation. These results suggest that Cr(VI) induced a mitochondrial-mediated and caspase-dependent apoptosis in skin epidermal cells through activation of p53, which are mainly mediated by reactive oxidants generated by the chemical.

  18. Glycidamide inhibits progesterone production through reactive oxygen species-induced apoptosis in R2C Rat Leydig Cells.

    Science.gov (United States)

    Li, Mingwei; Sun, Jianxia; Zou, Feiyan; Bai, Shun; Jiang, Xinwei; Jiao, Rui; Ou, Shiyi; Zhang, Hui; Su, Zhijian; Huang, Yadong; Bai, Weibin

    2017-10-01

    The food contaminant acrylamide (AA) is usually recognized as a probable human carcinogen. In addition, AA has also been found able to induce male infertility in animals. Interestingly, resent research work revealed that the toxic effect of AA on the ability of male reproduction in vivo may due to glycidamide (GA) which is the metabolite of AA. In this study, R2C Leydig cells was used to investigate the toxic effects of GA on progesterone production. GA caused dose-dependent inhibition on the cell growth, with IC 25 , IC 50, and IC 75 values found at 0.635, 0.872, and 1.198 mM, respectively. The results of single cell gel/Comet assay showed that GA significantly induced early-phase cell apoptosis, reduced progesterone production, as well as decreasing the protein expression of steroidogenic acute regulatory (StAR) in R2C cells. Furthermore, GA induced overproduction of intracellular reactive oxygen species (ROS), upregulated Bax expression, decreased mitochondrial membrane potential, and triggered mitochondria-mediated cell apoptosis. Consequently, the downstream effector caspase-3 was activated, resulting in Leydig cells apoptosis. Overall, our results showed that GA could damage R2C Leydig cells by the lesion of the ability of progesterone genesis and inducing cells apoptosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Ionizing radiation and nitric oxide donor sensitize Fas-induced apoptosis via up-regulation of Fas in human cervical cancer cells

    International Nuclear Information System (INIS)

    Park, In Chul; Woo, Sang Hyeok; Park, Myung Jin; Lee, Hyung Chahn; Lee Su Jae; Hong, Young Joon; Lee, Seung Hoon; Hong, Seok II; Rhee, Chang Hun

    2004-01-01

    Fas/CD95/Apo1 is a transmembrane receptor known to trigger apoptotic cell death in several cell types. In the present study, we showed that ionizing radiation (IR) and NO donor, S-nitroso-N-acetyl-penicillamine (SNAP), sensitized Fas-induced apoptotic cell death of HeLa human cervical cancers. Suboptimal dose of IR and SNAP up-regulated cell-surface Fas antigen, detected by FACScan using FITC-anti-Fas antibody. When combined with IR or SNAP, agonistic anti-Fas antibody CH-11 resulted in marked enhancement of apoptosis. This sensitization was completely abrogated by anti-Fas neutralizing antibody ZB4. During the IR and SNAP sensitized Fas-induced apoptosis, mitochondria permeabilization, cytochrome c release, and DNA fragmentation were detected. Furthermore, combined treatment of IR and SNAP additively up-regulated the surface Fas protein expression and sensitized Fas-induced apoptosis. Our finding demonstrate that sensitization of HeLa cervical cells to Fas-mediated apoptosis by IR and NO donor is most likely due to the up-regulation of Fas expression and also provides a means with which to sensitize tumors to the killing effects of cancer therapy via the Fas receptor

  20. Lysosomal ceramide generated by acid sphingomyelinase triggers cytosolic cathepsin B-mediated degradation of X-linked inhibitor of apoptosis protein in natural killer/T lymphoma cell apoptosis.

    Science.gov (United States)

    Taniguchi, M; Ogiso, H; Takeuchi, T; Kitatani, K; Umehara, H; Okazaki, T

    2015-04-09

    We previously reported that IL-2 deprivation induced acid sphingomyelinase-mediated (ASM-mediated) ceramide elevation and apoptosis in an NK/T lymphoma cell line KHYG-1. However, the molecular mechanism of ASM-ceramide-mediated apoptosis during IL-2 deprivation is poorly understood. Here, we showed that IL-2 deprivation induces caspase-dependent apoptosis characterized by phosphatidylserine externalization, caspase-8, -9, and -3 cleavage, and degradation of X-linked inhibitor of apoptosis protein (XIAP). IL-2 re-supplementation rescued apoptosis via inhibition of XIAP degradation without affecting caspase cleavage. However, IL-2 deprivation induced ceramide elevation via ASM in lysosomes and activated lysosomal cathepsin B (CTSB) but not cathepsin D. A CTSB inhibitor CA-074 Me and knockdown of CTSB inhibited ceramide-mediated XIAP degradation and apoptosis. Inhibition of ceramide accumulation in lysosomes using an ASM inhibitor, desipramine, decreased cytosolic activation of CTSB by inhibiting its transfer into cytosol from the lysosome. Knockdown of ASM also inhibited XIAP degradation and apoptosis. Furthermore, cell permeable N-acetyl sphingosine (C2-ceramide), which increases mainly endogenous d18:1/16:0 and d18:1/24:1 ceramide-like IL-2 deprivation, induced caspase-dependent apoptosis with XIAP degradation through CTSB. These findings suggest that lysosomal ceramide produced by ASM mediates XIAP degradation by activation of cytosolic CTSB and caspase-dependent apoptosis. The ASM-ceramide-CTSB signaling axis is a novel pathway of ceramide-mediated apoptosis in IL-2-deprived NK/T lymphoma cells.

  1. Platelet-derived growth factor (PDGF)-signaling mediates radiation-induced apoptosis in human prostate cancer cells with loss of p53 function

    International Nuclear Information System (INIS)

    Kim, Harold E.; Han, Sue J.; Kasza, Thomas; Han, Richard; Choi, Hyeong-Seon; Palmer, Kenneth C.; Kim, Hyeong-Reh C.

    1997-01-01

    Platelet-derived growth factor (PDGF) signals a diversity of cellular responses in vitro, including cell proliferation, survival, transformation, and chemotaxis. PDGF functions as a 'competence factor' to induce a set of early response genes expressed in G 1 including p21 WAF1/CIP1 , a functional mediator of the tumor suppressor gene p53 in G 1 /S checkpoint. For PDGF-stimulated cells to progress beyond G 1 and transit the cell cycle completely, progression factors in serum such as insulin and IGF-1 are required. We have recently shown a novel role of PDGF in inducing apoptosis in growth-arrested murine fibroblasts. The PDGF-induced apoptosis is rescued by insulin, suggesting that G 1 /S checkpoint is a critical determinant for PDGF-induced apoptosis. Because recent studies suggest that radiation-induced signal transduction pathways interact with growth factor-mediated signaling pathways, we have investigated whether activation of the PDGF-signaling facilitates the radiation-induced apoptosis in the absence of functional p53. For this study we have used the 125-IL cell line, a mutant p53-containing, highly metastatic, and hormone-unresponsive human prostate carcinoma cell line. PDGF signaling is constitutively activated by transfection with a p28 v-sis expression vector, which was previously shown to activate PDGF α- and β- receptors. Although the basal level of p21 WAF1/CIP1 expression and radiation-induced apoptosis were not detectable in control 125-IL cells as would be predicted in mutant p53-containing cells, activation of PDGF-signaling induced expression of p21 WAF1/CIP1 and radiation-induced apoptosis. Our study suggests that the level of 'competence' growth factors including PDGF may be one of the critical determinants for radiation-induced apoptosis, especially in cells with loss of p53 function at the site of radiotherapy in vivo

  2. Host and Viral Factors in HIV-Mediated Bystander Apoptosis

    Science.gov (United States)

    Garg, Himanshu; Joshi, Anjali

    2017-01-01

    Human immunodeficiency virus (HIV) infections lead to a progressive loss of CD4 T cells primarily via the process of apoptosis. With a limited number of infected cells and vastly disproportionate apoptosis in HIV infected patients, it is believed that apoptosis of uninfected bystander cells plays a significant role in this process. Disease progression in HIV infected individuals is highly variable suggesting that both host and viral factors may influence HIV mediated apoptosis. Amongst the viral factors, the role of Envelope (Env) glycoprotein in bystander apoptosis is well documented. Recent evidence on the variability in apoptosis induction by primary patient derived Envs underscores the role of Env glycoprotein in HIV disease. Amongst the host factors, the role of C-C Chemokine Receptor type 5 (CCR5), a coreceptor for HIV Env, is also becoming increasingly evident. Polymorphisms in the CCR5 gene and promoter affect CCR5 cell surface expression and correlate with both apoptosis and CD4 loss. Finally, chronic immune activation in HIV infections induces multiple defects in the immune system and has recently been shown to accelerate HIV Env mediated CD4 apoptosis. Consequently, those factors that affect CCR5 expression and/or immune activation in turn indirectly regulate HIV mediated apoptosis making this phenomenon both complex and multifactorial. This review explores the complex role of various host and viral factors in determining HIV mediated bystander apoptosis. PMID:28829402

  3. A novel benzofuran derivative, ACDB, induces apoptosis of human chondrosarcoma cells through mitochondrial dysfunction and endoplasmic reticulum stress.

    Science.gov (United States)

    Su, Chen-Ming; Chen, Chien-Yu; Lu, Tingting; Sun, Yi; Li, Weimin; Huang, Yuan-Li; Tsai, Chun-Hao; Chang, Chih-Shiang; Tang, Chih-Hsin

    2016-12-13

    Chondrosarcoma is one of the bone tumor with high mortality in respond to poor radiation and chemotherapy treatment. Here, we analyze the antitumor activity of a novel benzofuran derivative, 2-amino-3-(2-chlorophenyl)-6-(4-dimethylaminophenyl)benzofuran-4-yl acetate (ACDB), in human chondrosarcoma cells. ACDB increased the cell apoptosis of human chondrosarcomas without harm in chondrocytes. ACDB also enhanced endoplasmic reticulum (ER) stress, which was characterized by varieties in the cytosolic calcium levels and induced the expression of glucose-regulated protein (GRP) and calpain. Furthermore, the ACDB-induced chondrosarcoma apoptosis was associated with the upregulation of the B cell lymphoma-2 (Bcl-2) family members including pro- and anti-apoptotic proteins, downregulation of dysfunctional mitochondria that released cytochrome C, and subsequent activation of caspases-3. In addition, the ACDB-mediated cellular apoptosis was suppressed by transfecting cells with glucose-regulated protein (GRP) and calpain siRNA or treating cells with ER stress chelators and caspase inhibitors. Interestingly, animal experiments illustrated a reduction in the tumor volume following ACDB treatment. Together, these results suggest that ACDB may be a novel tumor suppressor of chondrosarcoma, and this study demonstrates that the novel antitumor agent, ACDB, induced apoptosis by mitochondrial dysfunction and ER stress in human chondrosarcoma cells in vitro and in vivo.

  4. E2F-1 induces melanoma cell apoptosis via PUMA up-regulation and Bax translocation

    International Nuclear Information System (INIS)

    Hao, Hongying; Dong, Yanbin; Bowling, Maria T; Gomez-Gutierrez, Jorge G; Zhou, H Sam; McMasters, Kelly M

    2007-01-01

    PUMA is a pro-apoptotic Bcl-2 family member that has been shown to be involved in apoptosis in many cell types. We sought to ascertain whether induction of PUMA plays a crucial role in E2F-1-induced apoptosis in melanoma cells. PUMA gene and protein expression levels were detected by real-time PCR and Western blot in SK-MEL-2 and HCT116 cell lines after Ad-E2F-1 infection. Activation of the PUMA promoter by E2F-1 overexpression was detected by dual luciferase reporter assay. E2F-1-induced Bax translocation was shown by immunocytochemistry. The induction of caspase-9 activity was measured by caspase-9 colorimetric assay kit. Up-regulation of the PUMA gene and protein by E2F-1 overexpression was detected by real-time PCR and Western blot analysis in the SK-MEL-2 melanoma cell line. In support of this finding, we found six putative E2F-1 binding sites within the PUMA promoter. Subsequent dual luciferase reporter assay showed that E2F-1 expression could increase the PUMA gene promoter activity 9.3 fold in SK-MEL-2 cells. The role of PUMA in E2F-1-induced apoptosis was further investigated in a PUMA knockout cell line. Cell viability assay showed that the HCT116 PUMA-/- cell line was more resistant to Ad-E2F-1-mediated cell death than the HCT116 PUMA+/+ cell line. Moreover, a 2.2-fold induction of the PUMA promoter was also noted in the HCT116 PUMA+/+ colon cancer cell line after Ad-E2F-1 infection. Overexpression of a truncated E2F-1 protein that lacks the transactivation domain failed to up-regulate PUMA promoter, suggesting that PUMA may be a transcriptional target of E2F-1. E2F-1-induced cancer cell apoptosis was accompanied by Bax translocation from the cytosol to mitochondria and the induction of caspase-9 activity, suggesting that E2F-1-induced apoptosis is mediated by PUMA through the cytochrome C/Apaf-1-dependent pathway. Our studies strongly demonstrated that E2F-1 induces melanoma cell apoptosis via PUMA up-regulation and Bax translocation. The signaling

  5. ING1 induces apoptosis through direct effects at the mitochondria

    DEFF Research Database (Denmark)

    Bose, P; Thakur, S; Thalappilly, S

    2013-01-01

    The ING family of tumor suppressors acts as readers and writers of the histone epigenetic code, affecting DNA repair, chromatin remodeling, cellular senescence, cell cycle regulation and apoptosis. The best characterized member of the ING family, ING1,interacts with the proliferating cell nuclear....... Bioinformatic analysis of the yeast interactome indicates that yeast ING proteins interact with 64 mitochondrial proteins. Also, sequence analysis of ING1 reveals the presence of a BH3-like domain. These data suggest a model in which stress-induced cytoplasmic relocalization of ING1 by14-3-3 induces ING1-BAX...

  6. Excessive apoptosis and defective autophagy contribute to developmental testicular toxicity induced by fluoride

    International Nuclear Information System (INIS)

    Zhang, Shun; Niu, Qiang; Gao, Hui; Ma, Rulin; Lei, Rongrong; Zhang, Cheng; Xia, Tao; Li, Pei; Xu, Chunyan; Wang, Chao; Chen, Jingwen; Dong, Lixing; Zhao, Qian; Wang, Aiguo

    2016-01-01

    testicular damage. • The abnormal apoptosis is mediated by both Fas and mitochondrial pathways. • The autophagy defect is caused by impaired degradation but not increased formation. - Both Fas- and mitochondria-mediated apoptosis, and impaired autophagy are involved in testicular damage of rats developmentally exposed to fluoride.

  7. Induction of apoptosis in human multiple myeloma cell lines by ebselen via enhancing the endogenous reactive oxygen species production.

    Science.gov (United States)

    Zhang, Liang; Zhou, Liwei; Du, Jia; Li, Mengxia; Qian, Chengyuan; Cheng, Yi; Peng, Yang; Xie, Jiayin; Wang, Dong

    2014-01-01

    Ebselen a selenoorganic compound showing glutathione peroxidase like activity is an anti-inflammatory and antioxidative agent. Its cytoprotective activity has been investigated in recent years. However, experimental evidence also shows that ebselen causes cell death in several cancer cell types whose mechanism has not yet been elucidated. In this study, we examined the effect of ebselen on multiple myeloma (MM) cell lines in vitro. The results showed that ebselen significantly enhanced the production of reactive oxygen species (ROS) accompanied by cell viability decrease and apoptosis rate increase. Further studies revealed that ebselen can induce Bax redistribution from the cytosol to mitochondria leading to mitochondrial membrane potential ΔΨm changes and cytochrome C release from the mitochondria to cytosol. Furtherly, we found that exogenous addition of N-acetyl cysteine (NAC) completely diminished the cell damage induced by ebselen. This result suggests that relatively high concentration of ebselen can induce MM cells apoptosis in culture by enhancing the production of endogenous ROS and triggering mitochondria mediated apoptotic pathway.

  8. Ursodeoxycholic Acid Induces Death Receptor-mediated Apoptosis in Prostate Cancer Cells

    Science.gov (United States)

    Lee, Won Sup; Jung, Ji Hyun; Panchanathan, Radha; Yun, Jeong Won; Kim, Dong Hoon; Kim, Hye Jung; Kim, Gon Sup; Ryu, Chung Ho; Shin, Sung Chul; Hong, Soon Chan; Choi, Yung Hyun; Jung, Jin-Myung

    2017-01-01

    Background Bile acids have anti-cancer properties in a certain types of cancers. We determined anticancer activity and its underlying molecular mechanism of ursodeoxycholic acid (UDCA) in human DU145 prostate cancer cells. Methods Cell viability was measured with an MTT assay. UDCA-induced apoptosis was determined with flow cytometric analysis. The expression levels of apoptosis-related signaling proteins were examined with Western blotting. Results UDCA treatment significantly inhibited cell growth of DU145 in a dose-dependent manner. It induced cellular shrinkage and cytoplasmic blebs and accumulated the cells with sub-G1 DNA contents. Moreover, UDCA activated caspase 8, suggesting that UDCA-induced apoptosis is associated with extrinsic pathway. Consistent to this finding, UDCA increased the expressions of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor, death receptor 4 (DR4) and death receptor 5 (DR5), and TRAIL augmented the UDCA-induced cell death in DU145 cells. In addition, UDCA also increased the expressions of Bax and cytochrome c and decreased the expression of Bcl-xL in DU145 cells. This finding suggests that UDCA-induced apoptosis may be involved in intrinsic pathway. Conclusions UDCA induces apoptosis via extrinsic pathway as well as intrinsic pathway in DU145 prostate cancer cells. UDCA may be a promising anti-cancer agent against prostate cancer. PMID:28382282

  9. Mpv17 in mitochondria protects podocytes against mitochondrial dysfunction and apoptosis in vivo and in vitro.

    Science.gov (United States)

    Casalena, Gabriela; Krick, Stefanie; Daehn, Ilse; Yu, Liping; Ju, Wenjun; Shi, Shaolin; Tsai, Su-yi; D'Agati, Vivette; Lindenmeyer, Maja; Cohen, Clemens D; Schlondorff, Detlef; Bottinger, Erwin P

    2014-06-01

    Mitochondrial dysfunction is increasingly recognized as contributing to glomerular diseases, including those secondary to mitochondrial DNA (mtDNA) mutations and deletions. Mitochondria maintain cellular redox and energy homeostasis and are a major source of intracellular reactive oxygen species (ROS) production. Mitochondrial ROS accumulation may contribute to stress-induced mitochondrial dysfunction and apoptosis and thereby to glomerulosclerosis. In mice, deletion of the gene encoding Mpv17 is associated with glomerulosclerosis, but the underlying mechanism remains poorly defined. Here we report that Mpv17 localizes to mitochondria of podocytes and its expression is reduced in several glomerular injury models and in human focal segmental glomerulosclerosis (FSGS) but not in minimal change disease. Using models of mild or severe nephrotoxic serum nephritis (NTSN) in Mpv17(+/+) wild-type (WT) and Mpv17(-/-) knockout mice, we found that Mpv17 deficiency resulted in increased proteinuria (mild NTSN) and renal insufficiency (severe NTSN) compared with WT. These lesions were associated with increased mitochondrial ROS generation and mitochondrial injury such as oxidative DNA damage. In vitro, podocytes with loss of Mpv17 function were characterized by increased susceptibility to apoptosis and ROS injury including decreased mitochondrial function, loss of mtDNA content, and change in mitochondrial configuration. In summary, the inner mitochondrial membrane protein Mpv17 in podocytes is essential for the maintenance of mitochondrial homeostasis and protects podocytes against oxidative stress-induced injury both in vitro and in vivo. Copyright © 2014 the American Physiological Society.

  10. The signalling axis mediating neuronal apoptosis in response to [Pt(O,O'-acac)(γ-acac)(DMS)].

    Science.gov (United States)

    Muscella, Antonella; Calabriso, Nadia; Vetrugno, Carla; Fanizzi, Francesco Paolo; De Pascali, Sandra Angelica; Marsigliante, Santo

    2011-06-01

    It was previously shown that [Pt(O,O'-acac)(γ-acac)(DMS)] induces apoptosis in various cancer cells and exerts antimetastatic responses in vitro. In rats, [Pt(O,O'-acac)(γ-acac)(DMS)] reaches the central nervous system in quantities higher than cisplatin causing less excitotoxicity. The aim of the present paper was to investigate whether [Pt(O,O'-acac)(γ-acac)(DMS)] is able to exert cytotoxic effects on SH-SY5Y human neuroblastoma cell line, and to study the intracellular transduction mechanisms underlying these effects. Here we have demonstrated that [Pt(O,O'-acac)(γ-acac)(DMS)] was more effective than cisplatin in provoking apoptosis characterized by: (a) mitochondria depolarization, (b) decrease of Bcl-2 expression and increase of BAX expressions with cytosol-to-mitochondria translocation, (c) activation of caspase-7 and -9 and (d) generation of reactive oxygen species (ROS). [Pt(O,O'-acac)(γ-acac)(DMS)] provoked the activation of the following signalling kinases that were interacting with each other: PKC-δ and -ɛ, ERK1/2, p38MAPK, JNK1/2, NF-κB, c-src and FAK. We found that ROS generated by NADPH oxidase was responsible for the [Pt(O,O'-acac)(γ-acac)(DMS)]-mediated PKC-δ and -ɛ activation and consequential phosphorylation of all MAPKs. [Pt(O,O'-acac)(γ-acac)(DMS)]-induced mitochondrial apoptosis was blocked when p38MAPK and JNK1/2 were inhibited, whilst the effects on Bax/Bcl-2 mRNA and protein levels were blocked inhibiting NF-κB. NF-κB nuclear translocation was blocked inhibiting MEK1/2 activity. In addition to the induction of apoptosis [Pt(O,O'-acac)(γ-acac)(DMS)] downregulated pro-survival pathway. Survival inhibition started from mitochondrial ROS generation which induced c-src, FAK and Akt activation. In conclusion, our results suggest that [Pt(O,O'-acac)(γ-acac)(DMS)] may be considered a promising compound for the treatment of neuroblastoma. Further studies are warranted to explore in detail the therapeutic potential of this compound

  11. The Voltage-dependent Anion Channel 1 Mediates Amyloid β Toxicity and Represents a Potential Target for Alzheimer Disease Therapy.

    Science.gov (United States)

    Smilansky, Angela; Dangoor, Liron; Nakdimon, Itay; Ben-Hail, Danya; Mizrachi, Dario; Shoshan-Barmatz, Varda

    2015-12-25

    The voltage-dependent anion channel 1 (VDAC1), found in the mitochondrial outer membrane, forms the main interface between mitochondrial and cellular metabolisms, mediates the passage of a variety of molecules across the mitochondrial outer membrane, and is central to mitochondria-mediated apoptosis. VDAC1 is overexpressed in post-mortem brains of Alzheimer disease (AD) patients. The development and progress of AD are associated with mitochondrial dysfunction resulting from the cytotoxic effects of accumulated amyloid β (Aβ). In this study we demonstrate the involvement of VDAC1 and a VDAC1 N-terminal peptide (VDAC1-N-Ter) in Aβ cell penetration and cell death induction. Aβ directly interacted with VDAC1 and VDAC1-N-Ter, as monitored by VDAC1 channel conductance, surface plasmon resonance, and microscale thermophoresis. Preincubated Aβ interacted with bilayer-reconstituted VDAC1 and increased its conductance ∼ 2-fold. Incubation of cells with Aβ resulted in mitochondria-mediated apoptotic cell death. However, the presence of non-cell-penetrating VDAC1-N-Ter peptide prevented Aβ cellular entry and Aβ-induced mitochondria-mediated apoptosis. Likewise, silencing VDAC1 expression by specific siRNA prevented Aβ entry into the cytosol as well as Aβ-induced toxicity. Finally, the mode of Aβ-mediated action involves detachment of mitochondria-bound hexokinase, induction of VDAC1 oligomerization, and cytochrome c release, a sequence of events leading to apoptosis. As such, we suggest that Aβ-mediated toxicity involves mitochondrial and plasma membrane VDAC1, leading to mitochondrial dysfunction and apoptosis induction. The VDAC1-N-Ter peptide targeting Aβ cytotoxicity is thus a potential new therapeutic strategy for AD treatment. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. RIG-I-like receptor-induced IRF3 mediated pathway of apoptosis (RIPA: a new antiviral pathway

    Directory of Open Access Journals (Sweden)

    Saurabh Chattopadhyay

    2016-11-01

    Full Text Available Abstract The innate immune response is the first line of host defense to eliminate viral infection. Pattern recognition receptors in the cytosol, such as RIG-I-like receptors (RLR and Nod-like receptors (NLR, and membrane bound Toll like receptors (TLR detect viral infection and initiate transcription of a cohort of antiviral genes, including interferon (IFN and interferon stimulated genes (ISGs, which ultimately block viral replication. Another mechanism to reduce viral spread is through RIPA, the RLR-induced IRF3-mediated pathway of apoptosis, which causes infected cells to undergo premature death. The transcription factor IRF3 can mediate cellular antiviral responses by both inducing antiviral genes and triggering apoptosis through the activation of RIPA. The mechanism of IRF3 activation in RIPA is distinct from that of transcriptional activation; it requires linear polyubiquitination of specific lysine residues of IRF3. Using RIPA-active, but transcriptionally inactive, IRF3 mutants, it was shown that RIPA can prevent viral replication and pathogenesis in mice.

  13. Dynamic movement of cytochrome c from mitochondria into cytosol and peripheral circulation in massive hepatic cell injury.

    Science.gov (United States)

    Kobayashi, Yoshinori; Mori, Masaaki; Naruto, Takuya; Kobayashi, Naoki; Sugai, Toshiyuki; Imagawa, Tomoyuki; Yokota, Shumpei

    2004-12-01

    In the process of apoptosis, it is known that the transition of cytochrome c from mitochondria into the cytosol occurs, and tumor necrosis factor (TNF)-alpha is one of the molecules responsible for this event. But in the state of hypercytokine induced by D-galactosamine (D-GaIN)/Lipopolysaccharide (LPS), the localization of cytochrome c is little known. Rats were administrated with D-GaIN(700 mg/kg)/LPS(200 microg/kg). Blood and tissue samples were collected and examined for levels of pro-inflammatory cytokines, the apoptosis of liver cells, and the localization of cytochrome c. Before administration of D-GaIN/LPS, cytochrome c was definitely localized in the mitochondria. At 2 h after simultaneous administration of D-GaIN/LPS, cytochrome c had accumulated in the cytosol following abrupt increases of plasma TNF-alpha. Massive cell destruction due to apoptosis proved by Terminal deoxynucleo-tidyl transferase-mediated dUTP nick end labeling staining was observed in liver tissue 4 h later and markedly increased levels of cytochrome c were detected in the plasma 12 h after D-GaIN/LPS administration. Liver injury induced by simultaneous administration of D-GaIN/LPS was closely associated with the production of TNF-alpha, and also with the dynamic movement of cytochrome c from the mitochondria into the cytosol, and then into the systemic circulation. The detection of plasma cytochrome c levels may be a useful clinical tool for the detection of apoptosis in vivo.

  14. A Smac-mimetic sensitizes prostate cancer cells to TRAIL-induced apoptosis via modulating both IAPs and NF-kappaB

    International Nuclear Information System (INIS)

    Dai, Yao; Liu, Meilan; Tang, Wenhua; Li, Yongming; Lian, Jiqin; Lawrence, Theodore S; Xu, Liang

    2009-01-01

    Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising agent for human cancer therapy, prostate cancer still remains resistant to TRAIL. Both X-linked inhibitor of apoptosis (XIAP) and nuclear factor-kappaB function as key negative regulators of TRAIL signaling. In this study, we evaluated the effect of SH122, a small molecule mimetic of the second mitochondria-derived activator of caspases (Smac), on TRAIL-induced apoptosis in prostate cancer cells. The potential of Smac-mimetics to bind XIAP or cIAP-1 was examined by pull-down assay. Cytotoxicity of TRAIL and/or Smac-mimetics was determined by a standard cell growth assay. Silencing of XIAP or cIAP-1 was achieved by transient transfection of short hairpin RNA. Apoptosis was detected by Annexin V-PI staining followed by flow cytometry and by Western Blot analysis of caspases, PARP and Bid. NF-kappaB activation was determined by subcellular fractionation, real time RT-PCR and reporter assay. SH122, but not its inactive analog, binds to XIAP and cIAP-1. SH122 significantly sensitized prostate cancer cells to TRAIL-mediated cell death. Moreover, SH122 enhanced TRAIL-induced apoptosis via both the death receptor and the mitochondrial pathway. Knockdown of both XIAP and cIAP-1 sensitized cellular response to TRAIL. XIAP-knockdown attenuated sensitivity of SH122 to TRAIL-induced cytotoxicity, confirming that XIAP is an important target for IAP-inhibitor-mediated TRAIL sensitization. SH122 also suppressed TRAIL-induced NF-kappaB activation by preventing cytosolic IkappaB-alpha degradation and RelA nuclear translocation, as well as by suppressing NF-kappaB target gene expression. These results demonstrate that SH122 sensitizes human prostate cancer cells to TRAIL-induced apoptosis by mimicking Smac and blocking both IAPs and NF-kappaB. Modulating IAPs may represent a promising approach to overcoming TRAIL-resistance in human prostate cancer with constitutively active NF-kappaB signaling

  15. Role of apoptosis and necrosis in cell death induced by nanoparticle-mediated photothermal therapy

    International Nuclear Information System (INIS)

    Pattani, Varun P.; Shah, Jay; Atalis, Alexandra; Sharma, Anirudh; Tunnell, James W.

    2015-01-01

    Current cancer therapies can cause significant collateral damage due to a lack of specificity and sensitivity. Therefore, we explored the cell death pathway response to gold nanorod (GNR)-mediated photothermal therapy as a highly specific cancer therapeutic to understand the role of apoptosis and necrosis during intense localized heating. By developing this, we can optimize photothermal therapy to induce a maximum of ‘clean’ cell death pathways, namely apoptosis, thereby reducing external damage. GNRs were targeted to several subcellular localizations within colorectal tumor cells in vitro, and the cell death pathways were quantitatively analyzed after photothermal therapy using flow cytometry. In this study, we found that the cell death response to photothermal therapy was dependent on the GNR localization. Furthermore, we demonstrated that nanorods targeted to the perinuclear region irradiated at 37.5 W/cm 2 laser fluence rate led to maximum cell destruction with the ‘cleaner’ method of apoptosis, at similar percentages as other anti-cancer targeted therapies. We believe that this indicates the therapeutic potential for GNR-mediated photothermal therapy to treat cancer effectively without causing damage to surrounding tissue

  16. Role of apoptosis and necrosis in cell death induced by nanoparticle-mediated photothermal therapy

    Energy Technology Data Exchange (ETDEWEB)

    Pattani, Varun P., E-mail: varun.pattani@utexas.edu; Shah, Jay; Atalis, Alexandra; Sharma, Anirudh; Tunnell, James W. [The University of Texas at Austin, Department of Biomedical Engineering (United States)

    2015-01-15

    Current cancer therapies can cause significant collateral damage due to a lack of specificity and sensitivity. Therefore, we explored the cell death pathway response to gold nanorod (GNR)-mediated photothermal therapy as a highly specific cancer therapeutic to understand the role of apoptosis and necrosis during intense localized heating. By developing this, we can optimize photothermal therapy to induce a maximum of ‘clean’ cell death pathways, namely apoptosis, thereby reducing external damage. GNRs were targeted to several subcellular localizations within colorectal tumor cells in vitro, and the cell death pathways were quantitatively analyzed after photothermal therapy using flow cytometry. In this study, we found that the cell death response to photothermal therapy was dependent on the GNR localization. Furthermore, we demonstrated that nanorods targeted to the perinuclear region irradiated at 37.5 W/cm{sup 2} laser fluence rate led to maximum cell destruction with the ‘cleaner’ method of apoptosis, at similar percentages as other anti-cancer targeted therapies. We believe that this indicates the therapeutic potential for GNR-mediated photothermal therapy to treat cancer effectively without causing damage to surrounding tissue.

  17. Prion protein with Y145STOP mutation induces mitochondria-mediated apoptosis and PrP-containing deposits in vitro

    International Nuclear Information System (INIS)

    Hachiya, Naomi S.; Watanabe, Kota; Kawabata, Makiko Y.; Jozuka, Akiko; Kozuka, Yoshimichi; Sakasegawa, Yuji; Kaneko, Kiyotoshi

    2005-01-01

    A pathogenic truncation of an amber mutation at codon 145 (Y145STOP) in Gerstmann-Straussler-Scheinker disease (GSS) was investigated through the real-time imaging in living cells, by utilizing GFP-PrP constructs. GFP-PrP(1-144) exhibited an aberrant localization to mitochondria in mouse neuroblastoma neuro2a (N2a) and HpL3-4 cells, a hippocampal cell line established from prnp gene-ablated mice, whereas full-length GFP-PrP did not. The aberrant mitochondrial localization was also confirmed by Western blot analysis. Since GFP-PrP(1-121), as previously reported, and full-length GFP-PrP do not exhibit such mitochondrial localization, the mitochondrial localization of GFP-PrP(1-144) requires not only PrP residues 121-144 (in human sequence) but also COOH-terminal truncation in the current experimental condition. Subsequently, the GFP-PrP(1-144) induced a change in the mitochondrial innermembrane potential (ΔΨ m ), release of cytochrome c from the intermembrane space into the cytosol, and DNA fragmentation in these cells. Non-fluorescent PrP(1-144) also induced the DNA fragmentation in N2a and HpL3-4 cells after the proteasomal inhibition. These data may provide clues as to the molecular mechanism of the neurotoxic property of Y145STOP mutation. Furthermore, immunoelectron microscopy revealed numerous electron-dense deposits in mitochondria clusters of GFP-PrP(1-144)-transfected N2a cells, whereas no deposit was detected in the cells transfected with full-length GFP-PrP. Co-localization of GFP/PrP-immunogold particles with porin-immunogold particles as a mitochondrial marker was observed in such electron-dense vesicular foci, resembling those found in autophagic vacuoles forming secondary lysosomes. Whether such electron-dense deposits may serve as a seed for the growth of amyloid plaques, a characteristic feature of GSS with Y145STOP, awaits further investigations

  18. Evaluation of the neuronal apoptotic pathways involved in cytoskeletal disruption-induced apoptosis.

    Science.gov (United States)

    Jordà, Elvira G; Verdaguer, Ester; Jimenez, Andrés; Arriba, S Garcia de; Allgaier, Clemens; Pallàs, Mercè; Camins, Antoni

    2005-08-01

    The cytoskeleton is critical to neuronal functioning and survival. Cytoskeletal alterations are involved in several neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. We studied the possible pathways involved in colchicine-induced apoptosis in cerebellar granule neurons (CGNs). Although colchicine evoked an increase in caspase-3, caspase-6 and caspase-9 activation, selective caspase inhibitors did not attenuate apoptosis. Inhibitors of other cysteine proteases such as PD150606 (a calpain-specific inhibitor), Z-Phe-Ala fluoromethyl ketone (a cathepsins-inhibitors) and N(alpha)-p-tosyl-l-lysine chloromethyl ketone (serine-proteases inhibitor) also had no effect on cell death/apoptosis induced by colchicine. However, BAPTA-AM 10 microM (intracellular calcium chelator) prevented apoptosis mediated by cytoskeletal alteration. These data indicate that calcium modulates colchicine-induced apoptosis in CGNs. PARP-1 inhibitors did not prevent apoptosis mediated by colchicine. Finally, colchicine-induced apoptosis in CGNs was attenuated by kenpaullone, a cdk5 inhibitor. Kenpaullone and indirubin also prevented cdk5/p25 activation mediated by colchicine. These findings indicate that cytoskeletal alteration can compromise cdk5 activation, regulating p25 formation and suggest that cdk5 inhibitors attenuate apoptosis mediated by cytoskeletal alteration. The present data indicate the potential therapeutic value of drugs that prevent the formation of p25 for the treatment of neurodegenerative disorders.

  19. BL-038, a Benzofuran Derivative, Induces Cell Apoptosis in Human Chondrosarcoma Cells through Reactive Oxygen Species/Mitochondrial Dysfunction and the Caspases Dependent Pathway.

    Science.gov (United States)

    Liu, Ju-Fang; Chen, Chien-Yu; Chen, Hsien-Te; Chang, Chih-Shiang; Tang, Chih-Hsin

    2016-09-07

    Chondrosarcoma is a highly malignant cartilage-forming bone tumor that has the capacity to invade locally and cause distant metastasis. Moreover, chondrosarcoma is intrinsically resistant to conventional chemotherapy or radiotherapy. The novel benzofuran derivative, BL-038 (2-amino-3-(2,6-dichlorophenyl)-6-(4-methoxyphenyl)benzofuran-4-yl acetate), has been evaluated for its anticancer effects in human chondrosarcoma cells. BL-038 caused cell apoptosis in two human chondrosarcoma cell lines, JJ012 and SW1353, but not in primary chondrocytes. Treatment of chondrosarcoma with BL-038 also induced reactive oxygen species (ROS) production. Furthermore, BL-038 decreased mitochondrial membrane potential (MMP) and changed mitochondrial-related apoptosis, by downregulating the anti-apoptotic activity members (Bcl-2, Bcl-xL) and upregulating pro-apoptotic members (Bax, Bak) of the B-cell lymphoma 2 (Bcl-2) family of proteins, key regulators of the apoptotic machinery in cells. These results demonstrate that in human chondrosarcoma cells, the apoptotic and cytotoxic effects of BL-038 are mediated by the intrinsic mitochondria-mediated apoptotic pathway, which in turn causes the release of cytochrome c, the activation of caspase-9 and caspase-3, and the cleavage of poly (ADP-ribose) polymerase (PARP), to elicit apoptosis response. Our results show that the benzofuran derivative BL-038 induces apoptosis in chondrosarcoma cells.

  20. Influenza virus induces apoptosis via BAD-mediated mitochondrial dysregulation.

    Science.gov (United States)

    Tran, Anh T; Cortens, John P; Du, Qiujiang; Wilkins, John A; Coombs, Kevin M

    2013-01-01

    Influenza virus infection results in host cell death and major tissue damage. Specific components of the apoptotic pathway, a signaling cascade that ultimately leads to cell death, are implicated in promoting influenza virus replication. BAD is a cell death regulator that constitutes a critical control point in the intrinsic apoptosis pathway, which occurs through the dysregulation of mitochondrial outer membrane permeabilization and the subsequent activation of downstream apoptogenic factors. Here we report a novel proviral role for the proapoptotic protein BAD in influenza virus replication. We show that influenza virus-induced cytopathology and cell death are considerably inhibited in BAD knockdown cells and that both virus replication and viral protein production are dramatically reduced, which suggests that virus-induced apoptosis is BAD dependent. Our data showed that influenza viruses induced phosphorylation of BAD at residues S112 and S136 in a temporal manner. Viral infection also induced BAD cleavage, late in the viral life cycle, to a truncated form that is reportedly a more potent inducer of apoptosis. We further demonstrate that knockdown of BAD resulted in reduced cytochrome c release and suppression of the intrinsic apoptotic pathway during influenza virus replication, as seen by an inhibition of caspases-3, caspase-7, and procyclic acidic repetitive protein (PARP) cleavage. Our data indicate that influenza viruses carefully modulate the activation of the apoptotic pathway that is dependent on the regulatory function of BAD and that failure of apoptosis activation resulted in unproductive viral replication.

  1. Cytotoxic effects and apoptosis induction of enrofloxacin in hepatic cell line of grass carp (Ctenopharyngodon idellus).

    Science.gov (United States)

    Liu, Bo; Cui, Yanting; Brown, Paul B; Ge, Xianping; Xie, Jun; Xu, Pao

    2015-12-01

    We determined the effect of enrofloxacin on the lactate dehydrogenase (LDH) release, reactive oxygen species (ROS), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), malondialdehyde (MDA), mitochondria membrane potential (ΔΨm) and apoptosis in the hepatic cell line of grass carp (Ctenopharyngodon idellus). Cultured cells were treated with different concentrations of enrofloxacin (12.5-200 ug/mL) for 24 h. We found that the cytotoxic effect of enrofloxacin was mediated by apoptosis, and that this apoptosis occurred in a dose-dependent manner. The doses of 50,100 and 200 μg/mL enrofloxacin increased the LDH release and MDA concentration, induced cell apoptosis and reduced the ΔΨm compared to the control. The highest dose of 200 ug/mL enrofloxacin also significantly induced apoptosis accompanied by ΔΨm disruption and ROS generation and significantly reduced T-AOC and increased MDA concentration compared to the control. Our results suggest that the dose of 200 ug/mL enrofloxacin exerts its cytotoxic effect and produced ROS via apoptosis by affecting the mitochondria of the hepatic cells of grass carp. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Sulforaphane reverses glucocorticoid-induced apoptosis in osteoblastic cells through regulation of the Nrf2 pathway

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    Lin H

    2014-07-01

    Full Text Available Hao Lin,1,* Bo Wei,1,* Guangsheng Li,1 Jinchang Zheng,1 Jiecong Sun,1 Jiaqi Chu,2 Rong Zeng,1 Yanru Niu21Department of Spinal Surgery, Affiliated Hospital of Guangdong Medical College, Zhanjiang, People’s Republic of China; 2Laboratory Institute of Minimally Invasive Orthopedic Surgery, Affiliated Hospital of Guangdong Medical College, Zhanjiang, People’s Republic of China *These authors contributed equally to this work Abstract: Apoptosis of osteoblasts triggered by high-dose glucocorticoids (GCs has been identified as a major cause of osteoporosis. However, the underlying molecular mechanisms accounting for this action remain elusive, which has impeded the prevention and cure of this side effect. Sulforaphane (SFP is a naturally occurring isothiocyanate that has huge health benefits for humans. In this study, by using osteoblastic MC3T3-E1 cells as a model, we demonstrate the protective effects of SFP against dexamethasone (Dex-induced apoptosis and elucidate the underlying molecular mechanisms. The results show that SFP could effectively inhibit the Dex-induced growth inhibition and release of lactate dehydrogenase in MC3T3-E1 cells. Treatment with Dex induced caspase-dependent apoptosis in MC3T3-E1 cells, as evidenced by an increase in the Sub-G1 phase, chromatin condensation, and deoxyribonucleic acid fragmentation, which were significantly suppressed by coincubation with SFP. Mitochondria-mediated apoptosis pathway contributed importantly to Dex-induced apoptosis, as revealed by the activation of caspase-3/-9 and subsequent cleavage of poly adenosine diphosphate ribose polymerase, which was also effectively blocked by SFP. Moreover, treatments of Dex strongly induced overproduction of reactive oxygen species and inhibited the expression of nuclear factor erythroid 2-related factor 2 (Nrf2 and the downstream effectors HO1 and NQO1. However, cotreatment with SFP effectively reversed this action of Dex. Furthermore, silencing of Nrf2 by

  3. Brucein D, a Naturally Occurring Tetracyclic Triterpene Quassinoid, Induces Apoptosis in Pancreatic Cancer through ROS-Associated PI3K/Akt Signaling Pathway

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    Zheng-Quan Lai

    2017-12-01

    Full Text Available Brucein D (BD, a major active quassinoid in Brucea javanica, has exhibited pronounced anticancer activities. However, the biologic mechanisms have not been fully explored. In this study, BD exhibited more potent cytotoxic effect on pancreatic cancer (PanCa cell lines, while exerted weaker cytotoxic effects on GES-1 cells (non-tumorigenic. BD was shown to elicit apoptosis through inducing both the intrinsic and extrinsic mitochondria-mediated caspase activations. Furthermore, the BD-induced apoptotic effects were dependent on the accumulated reactive oxygen species (ROS and inactivation of PI3K/Akt signaling pathway. Pretreatment with tempol completely prevented the cellular apoptosis induced by BD, and recovered the inactivation of AKT, which suggested ROS essentially involved in BD-elicited apoptosis and down-regulation of PI3K/Akt pathway. In addition, the results obtained from orthotopic xenograft in nude mice were congruent with those of the in vitro investigations. These results support the notion that BD held good potential to be further developed into an effective pharmaceutical agent for the treatment of PanCa.

  4. Cadmium-induced apoptosis through the mitochondrial pathway in rainbow trout hepatocytes: involvement of oxidative stress

    International Nuclear Information System (INIS)

    Risso-de Faverney, C.; Orsini, N.; Sousa, G. de; Rahmani, R.

    2004-01-01

    Cadmium (Cd) induces oxidative stress and apoptosis in trout hepatocytes. We therefore investigated the involvement of the mitochondrial pathway in the initiation of apoptosis and the possible role of oxidative stress in that process. This study demonstrates that hepatocyte exposure to Cd (2, 5 and 10 μM) triggers significant caspase-3, but also caspase-8 and -9 activation in a dose-dependent manner. Western-blot analysis of hepatocyte mitochondrial and cytosolic fractions revealed that cytochrome c (Cyt c) was released in the cytosol in a dose-dependent manner, whereas the pro-apoptotic protein Bax was redistributed to mitochondria after 24 and 48 h exposure. We also found that the expression of anti-apoptotic protein Bcl-xL, known to be regulated under mild oxidative stress to protect cells from apoptosis, did not change after 3 and 6 h exposure to Cd, then increased after 24 and 48 h exposure to 10 μM Cd. In the second part of this work, two antioxidant agents, 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) (100 μM) and N-acetylcysteine (NAC, 100 μM) were used to determine the involvement of reactive oxygen species (ROS) in Cd-induced apoptosis. Simultaneously exposing trout hepatocytes to Cd and TEMPO or NAC significantly reduced caspase-3 activation after 48 h and had a suppressive effect on caspase-8 and -9 also, mostly after 24 h. Lastly, the presence of either one of these antioxidants in the treatment medium also attenuated Cd-induced Cyt c release in cytosol and the level of Bax in the mitochondria after 24 and 48 h, while high Bcl-xL expression was observed. Taken together, these data clearly evidenced the key role of mitochondria in the cascade of events leading to trout hepatocyte apoptosis in response to Cd and the relationship that exists between oxidative stress and cell death

  5. Nitric oxide and bcl-2 mediated the apoptosis induced by nickel(II) in human T hybridoma cells

    International Nuclear Information System (INIS)

    Guan Fuqin; Zhang Dongmei; Wang Xinchang; Chen Junhui

    2007-01-01

    Although effects of nickel(II) on the immune system have long been recognized, little is known about the effects of nickel(II) on the induction of apoptosis and related signaling events in T cells. In the present study, we investigated the roles and signaling pathways of nickel(II) in the induction of apoptosis in a human T cell line jurkat. The results showed that the cytotoxic effects of Ni involved significant morphological changes and chromosomal condensation (Hoechst 33258 staining). Analyses of hypodiploid cells and FITC-Annexin V and PI double staining showed significant increase of apoptosis in jurkat cells 6, 12 and 24 h after nickel(II) treatment. Flow cytometry analysis also revealed that the loss of mitochondrial membrane potential (MMP) occurred concomitantly with the onset of NiCl 2 -induced apoptosis. Induction of apoptotic cell death by nickel was mediated by reduction of bcl-2 expression. Furthermore, nickel stimulated the generation of nitric oxide (NO). These results suggest that nickel(II) chloride induces jurkat cells apoptosis via nitric oxide generation, mitochondrial depolarization and bcl-2 suppression

  6. Cuprous oxide nanoparticles selectively induce apoptosis of tumor cells

    Science.gov (United States)

    Wang, Ye; Zi, Xiao-Yuan; Su, Juan; Zhang, Hong-Xia; Zhang, Xin-Rong; Zhu, Hai-Ying; Li, Jian-Xiu; Yin, Meng; Yang, Feng; Hu, Yi-Ping

    2012-01-01

    In the rapid development of nanoscience and nanotechnology, many researchers have discovered that metal oxide nanoparticles have very useful pharmacological effects. Cuprous oxide nanoparticles (CONPs) can selectively induce apoptosis and suppress the proliferation of tumor cells, showing great potential as a clinical cancer therapy. Treatment with CONPs caused a G1/G0 cell cycle arrest in tumor cells. Furthermore, CONPs enclosed in vesicles entered, or were taken up by mitochondria, which damaged their membranes, thereby inducing apoptosis. CONPs can also produce reactive oxygen species (ROS) and initiate lipid peroxidation of the liposomal membrane, thereby regulating many signaling pathways and influencing the vital movements of cells. Our results demonstrate that CONPs have selective cytotoxicity towards tumor cells, and indicate that CONPs might be a potential nanomedicine for cancer therapy. PMID:22679374

  7. Ultraviolet-Ray-Induced Sea Cucumber (Stichopus japonicus) Melting Is Mediated by the Caspase-Dependent Mitochondrial Apoptotic Pathway.

    Science.gov (United States)

    Su, Li; Yang, Jing-Feng; Fu, Xi; Dong, Liang; Zhou, Da-Yong; Sun, Li-Ming; Gong, Zhenwei

    2018-01-10

    Sea cucumber body-wall melting occurs under certain circumstances. We have shown that apoptosis but not autolysis plays a critical role in the initial stage. However, it is still unclear how apoptosis is triggered in this process. In this study, we examined the levels of reactive oxygen species (ROS), the levels of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax) proteins, the depolarization of mitochondrial transmembrane potentials, and cytochrome c (Cyt c) release during sea cucumber melting induced by ultraviolet (UV) exposure. We also investigated the contribution of caspase in this process by injecting a pan-caspase inhibitor. Our data showed that UV exposure stimulates ROS production, dysfunction of mitochondria, and the release of Cyt c in sea cucumber coelomic fluid cells and body walls. We found a decrease of Bcl-2 and increase of Bax in the mitochondria after UV exposure. We also demonstrated that these changes are associated with elevated caspase-9 and -3 activity. Finally, our data showed that the inhibition of caspases-9 and -3 using an inhibitor suppresses UV-induced sea cucumber melting. These results suggest that apoptosis during sea cucumber melting is mediated by mitochondrial dysfunction and follows the activation of the caspase-signaling pathway. This study presents a novel insight into the mechanism of sea cucumber melting.

  8. Electroacupuncture inhibits apoptosis in annulus fibrosis cells through suppression of the mitochondria-dependent pathway in a rat model of cervical intervertebral disc degradation

    Directory of Open Access Journals (Sweden)

    Jun Liao

    2012-01-01

    Full Text Available The purpose of this study was to investigate whether treatment with electroacupuncture (EA inhibited mitochondria-dependent apoptosis in annulus fibrosis (AF cells in a rat model of cervical intervertebral disc degradation induced by unbalanced dynamic and static forces. Forty Sprague-Dawley rats were used in this study, of which 30 underwent surgery to induce cervical intervertebral disc degradation, 10 rats received EA at acupoints Dazhui (DU 14 and Shousanli (LI 10. TUNEL staining was measured to assess apoptosis in AF cells, immunohistochemistry was used to examine Bcl-2 and Bax expression, colorimetric assays were used to determine caspase 9 and caspase 3 activities and RT-PCR and western blotting were used to assess the mRNA and protein expression of Crk and ERK2. Treatment with EA reduced the number of AF-positive cells in TUNEL staining, increased Bcl-2-positive cells and decreased Bax-positive cells in immunohistochemical staining, significantly inhibited the activation of caspases-9 and -3, and enhanced the mRNA and protein expression of Crk and ERK2. Our data show that EA inhibits AF cell apoptosis via the mitochondria-dependent pathway and up-regulates Crk and ERK2 expression. These results suggest that treatment with may be a good alternative therapy for preventing cervical spondylosis.

  9. [Apoptosis and pathological process].

    Science.gov (United States)

    Rami, Mukhammed Salim Iusef

    2007-01-01

    Apoptosis (programmed cell death) occurs normally for maitenance of tissue homeostasis and play an important role in morphogenesis, embriogenesis and tissue growth. On the other hand, apoptosis may be involved in different pathological processes such as malignancy, infectious diseases and autoimmune disorders. Apoptosis is regulated by various mediators. Caspases, death receptors, mitochondria, Bcl-2 protoncogenes and tumor supressor genes are considered to be the most important of them. Advance in apoptosis regulation research suggests enormouse facilities for therapy of wide range of human illnesses.

  10. Hypoxia-induced p53 modulates both apoptosis and radiosensitivity via AKT

    NARCIS (Netherlands)

    Leszczynska, K.B.; Foskolou, I.P.; Abraham, A.G.; Anbalagan, S.; Tellier, C.; Haider, S.; Span, P.N.; O'Neill, E.E.; Buffa, F.M.; Hammond, E.M.

    2015-01-01

    Restoration of hypoxia-induced apoptosis in tumors harboring p53 mutations has been proposed as a potential therapeutic strategy; however, the transcriptional targets that mediate hypoxia-induced p53-dependent apoptosis remain elusive. Here, we demonstrated that hypoxia-induced p53-dependent

  11. Tannic Acid Induces Endoplasmic Reticulum Stress-Mediated Apoptosis in Prostate Cancer.

    Science.gov (United States)

    Nagesh, Prashanth K B; Hatami, Elham; Chowdhury, Pallabita; Kashyap, Vivek K; Khan, Sheema; Hafeez, Bilal B; Chauhan, Subhash C; Jaggi, Meena; Yallapu, Murali M

    2018-03-07

    Endoplasmic reticulum (ER) stress is an intriguing target with significant clinical importance in chemotherapy. Interference with ER functions can lead to the accumulation of unfolded proteins, as detected by transmembrane sensors that instigate the unfolded protein response (UPR). Therefore, controlling induced UPR via ER stress with natural compounds could be a novel therapeutic strategy for the management of prostate cancer. Tannic acid (a naturally occurring polyphenol) was used to examine the ER stress mediated UPR pathway in prostate cancer cells. Tannic acid treatment inhibited the growth, clonogenic, invasive, and migratory potential of prostate cancer cells. Tannic acid demonstrated activation of ER stress response (Protein kinase R-like endoplasmic reticulum kinase (PERK) and inositol requiring enzyme 1 (IRE1)) and altered its regulatory proteins (ATF4, Bip, and PDI) expression. Tannic acid treatment affirmed upregulation of apoptosis-associated markers (Bak, Bim, cleaved caspase 3, and cleaved PARP), while downregulation of pro-survival proteins (Bcl-2 and Bcl-xL). Tannic acid exhibited elevated G₁ population, due to increase in p18 INK4C and p21 WAF1/CIP1 expression, while cyclin D1 expression was inhibited. Reduction of MMP2 and MMP9, and reinstated E-cadherin signifies the anti-metastatic potential of this compound. Altogether, these results demonstrate that tannic acid can promote apoptosis via the ER stress mediated UPR pathway, indicating a potential candidate for cancer treatment.

  12. Roles of dynamin-related protein 1 in the regulation of mitochondrial fission and apoptosis in response to UV stimuli

    Science.gov (United States)

    Zhang, Zhenzhen; Feng, Jie; Wu, Shengnan

    2011-03-01

    Mitochondria are dynamic structures that frequently divide and fuse with one another to form interconnecting network. This network disintegrates into punctiform organelles during apoptosis. However, it remains unclear whether this event has a significant impact on the rate of cell death or only accompanies apoptosis as an epiphenomenon. In this study, we investigate the role of dynamin-related protein 1 (Drp1), a large GTPase that mediates outer mitochondrial membrane fission, in mitochondrial morphology and apoptosis in response to UV irradiation in human lung adenocarcinoma cells (ASTC-a-1) and HeLa cells. Using time-lapse fluorescent imaging, we find that Drp1 primarily distributes in cytosol under physiological conditions. After UV treatment, Drp1 translocates from cytosol to mitochondria, indicating the enhancement of Drp1 mitochondrial accumulation. Down-regulation of Drp1 by shRNA inhibits UV-induced apoptosis. Our results suggest that Drp1 is involved in the regulation of transition from a reticulo-tubular to a punctiform mitochondrial phenotype and mitochondrial fission plays an important role in UV-induced apoptosis.

  13. 1-Benzyl-2-Phenylbenzimidazole (BPB, a Benzimidazole Derivative, Induces Cell Apoptosis in Human Chondrosarcoma through Intrinsic and Extrinsic Pathways

    Directory of Open Access Journals (Sweden)

    Ju-Fang Liu

    2012-12-01

    Full Text Available In this study, we investigated the anticancer effects of a new benzimidazole derivative, 1-benzyl-2-phenyl -benzimidazole (BPB, in human chondrosarcoma cells. BPB-mediated apoptosis was assessed by the MTT assay and flow cytometry analysis. The in vivo efficacy was examined in a JJ012 xenograft model. Here we found that BPB induced apoptosis in human chondrosarcoma cell lines (JJ012 and SW1353 but not in primary chondrocytes. BPB induced upregulation of Bax, Bad and Bak, downregulation of Bcl-2, Bid and Bcl-XL and dysfunction of mitochondria in chondrosarcoma. In addition, BPB also promoted cytosolic releases AIF and Endo G. Furthermore, it triggered extrinsic death receptor-dependent pathway, which was characterized by activating Fas, FADD and caspase-8. Most importantly, animal studies revealed a dramatic 40% reduction in tumor volume after 21 days of treatment. Thus, BPB may be a novel anticancer agent for the treatment of chondrosarcoma.

  14. Trichomonas vaginalis Induces SiHa Cell Apoptosis by NF-κB Inactivation via Reactive Oxygen Species

    Science.gov (United States)

    Quan, Juan-Hua; Kang, Byung-Hun; Yang, Jung-Bo; Rhee, Yun-Ee; Noh, Heung-Tae; Choi, In-Wook; Cha, Guang-Ho; Yuk, Jae-Min

    2017-01-01

    Trichomonas vaginalis induces apoptosis in host cells through various mechanisms; however, little is known about the relationship between apoptosis, reactive oxygen species (ROS), and NF-κB signaling pathways in the cervical mucosal epithelium. Here, we evaluated apoptotic events, ROS production, and NF-κB activity in T. vaginalis-treated cervical mucosal epithelial SiHa cells, with or without specific inhibitors, using fluorescence microscopy, DNA fragmentation assays, subcellular fractionation, western blotting, and luciferase reporter assay. SiHa cells treated with live T. vaginalis at a multiplicity of infection of 5 (MOI 5) for 4 h produced intracellular and mitochondrial ROS in a parasite-load-dependent manner. Incubation with T. vaginalis caused DNA fragmentation, cleavage of caspase 3 and PARP, and release of cytochrome c into the cytoplasm. T. vaginalis-treated SiHa cells showed transient early NF-κB p65 nuclear translocation, which dramatically dropped at 4 h after treatment. Suppression of NF-κB activity was dependent on parasite burden. However, treatment with the ROS scavenger, N-acetyl-C-cysteine (NAC), reversed the effect of T. vaginalis on apoptosis and NF-κB inactivation in SiHa cells. Taken together, T. vaginalis induces apoptosis in human cervical mucosal epithelial cells by parasite-dose-dependent ROS production through an NF-κB-regulated, mitochondria-mediated pathway. PMID:29410962

  15. Trichomonas vaginalis Induces SiHa Cell Apoptosis by NF-κB Inactivation via Reactive Oxygen Species

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    Juan-Hua Quan

    2017-01-01

    Full Text Available Trichomonas vaginalis induces apoptosis in host cells through various mechanisms; however, little is known about the relationship between apoptosis, reactive oxygen species (ROS, and NF-κB signaling pathways in the cervical mucosal epithelium. Here, we evaluated apoptotic events, ROS production, and NF-κB activity in T. vaginalis-treated cervical mucosal epithelial SiHa cells, with or without specific inhibitors, using fluorescence microscopy, DNA fragmentation assays, subcellular fractionation, western blotting, and luciferase reporter assay. SiHa cells treated with live T. vaginalis at a multiplicity of infection of 5 (MOI 5 for 4 h produced intracellular and mitochondrial ROS in a parasite-load-dependent manner. Incubation with T. vaginalis caused DNA fragmentation, cleavage of caspase 3 and PARP, and release of cytochrome c into the cytoplasm. T. vaginalis-treated SiHa cells showed transient early NF-κB p65 nuclear translocation, which dramatically dropped at 4 h after treatment. Suppression of NF-κB activity was dependent on parasite burden. However, treatment with the ROS scavenger, N-acetyl-C-cysteine (NAC, reversed the effect of T. vaginalis on apoptosis and NF-κB inactivation in SiHa cells. Taken together, T. vaginalis induces apoptosis in human cervical mucosal epithelial cells by parasite-dose-dependent ROS production through an NF-κB-regulated, mitochondria-mediated pathway.

  16. Tetrandrine Induces Apoptosis in Human Nasopharyngeal Carcinoma NPC-TW 039 Cells by Endoplasmic Reticulum Stress and Ca2+/Calpain Pathways.

    Science.gov (United States)

    Liu, Kuo-Ching; Lin, Ya-Jing; Hsiao, Yung-Ting; Lin, Meng-Liang; Yang, Jiun-Long; Huang, Yi-Ping; Chu, Yung-Lin; Chung, Jing-Gung

    2017-11-01

    Tetrandrine is an alkaloid extracted from a traditional China medicine plant, and is considered part of food therapy as well. In addition, it has been widely reported to induce apoptotic cell death in many human cancer cells. However, the mechanism of Tetrandrine on human nasopharyngeal carcinoma cells (NPC) is still questioned. In our study, we examined whether Tetrandrine can induce apoptosis of NPC-TW 039 cells. We found that cell morphology was changed after treatment with different concentrations of Tetrandrine. Further, we indicated that the NPC-TW 039 cells viability decreased in a Tetrandrine dose-dependent manner. We also found that tetrandrine induced cell cycle arrest in G 0 /G 1 phase. Tetrandrine induced DNA condensation by DAPI staining as well. In addition, we found that Tetrandrine induced Ca 2+ release in the cytosol. At the same time, endoplasmic reticulum (ER) stress occurred. Then we used western blotting to examine the protein expression which is associated with mitochondria-mediated apoptotic pathways and caspase-dependent pathways. To further examine whether Ca 2+ was released or not with Tetrandrine induced-apoptosis, we used the chelator of Ca 2+ and showed that cell viability increased. At the same time, caspase-3 expression was decreased. Furthermore, confocal microscopy examination revealed that Tetrandrine induced expression of ER stress-related proteins GADD153 and GRP78. Our results indicate that Tetrandrine induces apoptosis through calcium-mediated ER stress and caspase pathway in NPC-TW 039 cells. In conclusion, Tetrandrine may could be used for treatment of human nasopharyngeal carcinoma in future. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  17. Esculetin Ameliorates Carbon Tetrachloride-Mediated Hepatic Apoptosis in Rats

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    Chuan-Sung Chiu

    2011-06-01

    Full Text Available Esculetin (ESC is a coumarin that is present in several plants such as Fraxinus rhynchophylla and Artemisia capillaris. Our previous study found that FR ethanol extract (FREtOH significantly ameliorated rats’ liver function. This study was intended to investigate the protective mechanism of ESC in hepatic apoptosis in rats induced by carbon tetrachloride. Rat hepatic apoptosis was induced by oral administration of CCl4. All rats were administered orally with CCl4 (20%, 0.5 mL/rat twice a week for 8 weeks. Rats in the ESC groups were treated daily with ESC, and silymarin group were treated daily with silymarin. Serum alanine aminotransferase (ALT, aspartate aminotransferase (AST as well as the activities of the anti-oxidative enzymes glutathione peroxidase (GPx, superoxide dismutase (SOD, and catalase in the liver were measured. In addition, expression of liver apoptosis proteins and anti-apoptotic proteins were detected. ESC (100, 500 mg/kg significantly reduced the elevated activities of serum ALT and AST caused by CCl4 and significantly increased the activities of catalase, GPx and SOD. Furthermore, ESC (100, 500 mg/kg significantly decreased the levels of the proapoptotic proteins (t-Bid, Bak and Bad and significantly increased the levels of the anti-apoptotic proteins (Bcl-2 and Bcl-xL. ESC inhibited the release of cytochrome c from mitochondria. In addition, the levels of activated caspase-9 and activated caspase-3 were significantly decreased in rats treated with ESC than those in rats treated with CCl4 alone. ESC significantly reduced CCl4-induced hepatic apoptosis in rats.

  18. The Efficacy of Dandelion Root Extract in Inducing Apoptosis in Drug-Resistant Human Melanoma Cells

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    S. J. Chatterjee

    2011-01-01

    Full Text Available Notoriously chemoresistant melanoma has become the most prevalent form of cancer for the 25–29 North American age demographic. Standard treatment after early detection involves surgical excision (recurrence is possible, and metastatic melanoma is refractory to immuno-, radio-, and most harmful chemotherapies. Various natural compounds have shown efficacy in killing different cancers, albeit not always specifically. In this study, we show that dandelion root extract (DRE specifically and effectively induces apoptosis in human melanoma cells without inducing toxicity in noncancerous cells. Characteristic apoptotic morphology of nuclear condensation and phosphatidylserine flipping to the outer leaflet of the plasma membrane of A375 human melanoma cells was observed within 48 hours. DRE-induced apoptosis activates caspase-8 in A375 cells early on, demonstrating employment of an extrinsic apoptotic pathway to kill A375 cells. Reactive Oxygen Species (ROS generated from DRE-treated isolated mitochondria indicates that natural compounds in DRE can also directly target mitochondria. Interestingly, the relatively resistant G361 human melanoma cell line responded to DRE when combined with the metabolism interfering antitype II diabetic drug metformin. Therefore, treatment with this common, yet potent extract of natural compounds has proven novel in specifically inducing apoptosis in chemoresistant melanoma, without toxicity to healthy cells.

  19. [Advances in Parvovirus Non-structural Protein NS1 Induced Apoptosis].

    Science.gov (United States)

    Tu, Mengyu; Liu, Fei; Chen, Shun; Wang, Mingshu; Cheng, Anchun

    2015-11-01

    Until now, more than seventeen parvovirus have been reported which can infect mammals and poultries. The infected cells appeared different properties of apoptosis and death, present a typical cytopathic effect. NS1 is a major nonstructural protein of parvovirus, with a conservative structure and function, which plays an important role in the viral life cycle. In addition to the influence on viral replication, the NS1 also participates in apoptosis induced by viruses. Parvovirus induced apoptosis which is mainly mediated by mitochondrial pathway, this review summarized the latest research progresses of parvovirus induced apoptosis.

  20. Regulatory mechanisms of apoptosis in regularly dividing cells

    Directory of Open Access Journals (Sweden)

    Ribal S Darwish

    2010-08-01

    Full Text Available Ribal S DarwishDepartment of Anesthesiology, Division of Critical Care Medicine, University of Maryland Medical Center, Baltimore, Maryland, USAAbstract: The balance between cell survival and death is essential for normal development and homeostasis of organisms. Apoptosis is a distinct type of cell death with ultrastructural features that are consistent with an active, inherently controlled process. Abnormalities and ­dysregulation of apoptosis contribute to the pathophysiology of multiple disease processes. Apoptosis is strictly regulated by several positive and negative feedback mechanisms that regulate cell death and determine the final outcome after cell exposure to apoptotic stimuli. Mitochondria and caspases are central components of the regulatory mechanisms of ­apoptosis. Recently, noncaspase pathways of apoptosis have been explored through the studies of ­apoptosis-inducing factor and endonuclease G. Multiple difficulties in the apoptosis research relate to apoptosis detection and imaging. This article reviews current understanding of the regulatory mechanisms of apoptosis.Keywords: caspases, apoptosis-inducing factor, apoptosis inhibitory proteins, cytochrome c, mitochondria 

  1. Acrylamide induces immunotoxicity through reactive oxygen species production and caspase-dependent apoptosis in mice splenocytes via the mitochondria-dependent signaling pathways.

    Science.gov (United States)

    Zamani, Ehsan; Shaki, Fatemeh; AbedianKenari, Saeid; Shokrzadeh, Mohammad

    2017-10-01

    Acrylamide (AA), a well-known food neo-contamination, can be produced during food preparing at high temperature. The immunotoxicity of AA have been revealed in the experimental animals. In this study, we explored the molecular mechanism responsible for the immunotoxicity of AA. The mice splenocytes exposed to AA concentrations (0,5,10 and 25 mM) and apoptosis cell death was measured through Annexin V/Propidium Iodide staining by flow cytometry method. The role of extrinsic and intrinsic pathways were evaluated respectively by activity of caspase-8 and-9. Furthermore, the spleen mitochondria were obtained using differential centrifugation from mice and mitochondrial toxicity endpoints were determined after AA exposure. Exposure of splenocytes to AA increased the splenocytes' apoptotic cell death. Also, increased activation of both caspase-8 and-9 were observed in mice splenocytes after AA exposure. Treatment of isolated mitochondria with AA lead to disturbance in activity of complex I and III of mitochondrial electron transfer chain that result in increased reactive oxygen species (ROS) production, lipid peroxidation and glutathione oxidation. These events were accompanied by mitochondrial membrane swelling, collapse of mitochondrial membrane potential and significant falling of mitochondrial activity. AA-mediated mitochondrial dysfunction along with mitochondrial oxidative damage seems to be critical events leading to activation of caspase cascade and apoptotic cell death in spleen that finally can attenuate immune system's function. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. Genetic Signatures of HIV-1 Envelope-mediated Bystander Apoptosis

    Science.gov (United States)

    Joshi, Anjali; Lee, Raphael T. C.; Mohl, Jonathan; Sedano, Melina; Khong, Wei Xin; Ng, Oon Tek; Maurer-Stroh, Sebastian; Garg, Himanshu

    2014-01-01

    The envelope (Env) glycoprotein of HIV is an important determinant of viral pathogenesis. Several lines of evidence support the role of HIV-1 Env in inducing bystander apoptosis that may be a contributing factor in CD4+ T cell loss. However, most of the studies testing this phenomenon have been conducted with laboratory-adapted HIV-1 isolates. This raises the question of whether primary Envs derived from HIV-infected patients are capable of inducing bystander apoptosis and whether specific Env signatures are associated with this phenomenon. We developed a high throughput assay to determine the bystander apoptosis inducing activity of a panel of primary Envs. We tested 38 different Envs for bystander apoptosis, virion infectivity, neutralizing antibody sensitivity, and putative N-linked glycosylation sites along with a comprehensive sequence analysis to determine if specific sequence signatures within the viral Env are associated with bystander apoptosis. Our studies show that primary Envs vary considerably in their bystander apoptosis-inducing potential, a phenomenon that correlates inversely with putative N-linked glycosylation sites and positively with virion infectivity. By use of a novel phylogenetic analysis that avoids subtype bias coupled with structural considerations, we found specific residues like Arg-476 and Asn-425 that were associated with differences in bystander apoptosis induction. A specific role of these residues was also confirmed experimentally. These data demonstrate for the first time the potential of primary R5 Envs to mediate bystander apoptosis in CD4+ T cells. Furthermore, we identify specific genetic signatures within the Env that may be associated with the bystander apoptosis-inducing phenotype. PMID:24265318

  3. Interaction of caveolin-1 with Ku70 inhibits Bax-mediated apoptosis.

    Directory of Open Access Journals (Sweden)

    Huafei Zou

    Full Text Available Caveolin-1, the structural protein component of caveolae, acts as a scaffolding protein that functionally regulates signaling molecules. We show that knockdown of caveolin-1 protein expression enhances chemotherapeutic drug-induced apoptosis and inhibits long-term survival of colon cancer cells. In vitro studies demonstrate that caveolin-1 is a novel Ku70-binding protein, as shown by the binding of the scaffolding domain of caveolin-1 (amino acids 82-101 to the caveolin-binding domain (CBD of Ku70 (amino acids 471-478. Cell culture data show that caveolin-1 binds Ku70 after treatment with chemotherapeutic drugs. Mechanistically, we found that binding of caveolin-1 to Ku70 inhibits the chemotherapeutic drug-induced release of Bax from Ku70, activation of Bax, translocation of Bax to mitochondria and apoptosis. Potentiation of apoptosis by knockdown of caveolin-1 protein expression is greatly reduced in the absence of Bax expression. Finally, we found that overexpression of wild type Ku70, but not a mutant form of Ku70 that cannot bind to caveolin-1 (Ku70 Φ→A, limits the chemotherapeutic drug-induced Ku70/Bax dissociation and apoptosis. Thus, caveolin-1 acts as an anti-apoptotic protein in colon cancer cells by binding to Ku70 and inhibiting Bax-dependent cell death.

  4. Involvement of VDAC, Bax and ceramides in the efflux of AIF from mitochondria during curcumin-induced apoptosis.

    NARCIS (Netherlands)

    Scharstuhl, A.; Mutsaers, H.A.M.; Pennings, S.W.C.; Russel, F.G.M.; Wagener, F.A.D.T.G.

    2009-01-01

    BACKGROUND: We previously identified curcumin as a potent inducer of fibroblast apoptosis, which could be used to treat hypertrophic scar formation. Here we investigated the underlying mechanism of this process. PRINCIPAL FINDINGS: Curcumin-induced apoptosis could not be blocked by

  5. Induction of Apoptosis in Human Multiple Myeloma Cell Lines by Ebselen via Enhancing the Endogenous Reactive Oxygen Species Production

    Directory of Open Access Journals (Sweden)

    Liang Zhang

    2014-01-01

    Full Text Available Ebselen a selenoorganic compound showing glutathione peroxidase like activity is an anti-inflammatory and antioxidative agent. Its cytoprotective activity has been investigated in recent years. However, experimental evidence also shows that ebselen causes cell death in several cancer cell types whose mechanism has not yet been elucidated. In this study, we examined the effect of ebselen on multiple myeloma (MM cell lines in vitro. The results showed that ebselen significantly enhanced the production of reactive oxygen species (ROS accompanied by cell viability decrease and apoptosis rate increase. Further studies revealed that ebselen can induce Bax redistribution from the cytosol to mitochondria leading to mitochondrial membrane potential ΔΨm changes and cytochrome C release from the mitochondria to cytosol. Furtherly, we found that exogenous addition of N-acetyl cysteine (NAC completely diminished the cell damage induced by ebselen. This result suggests that relatively high concentration of ebselen can induce MM cells apoptosis in culture by enhancing the production of endogenous ROS and triggering mitochondria mediated apoptotic pathway.

  6. Vitamin E and Lycopene Reduce Coal Burning Fluorosis-induced Spermatogenic Cell Apoptosis via Oxidative Stress-mediated JNK and ERK Signaling Pathways.

    Science.gov (United States)

    Tian, Yuan; Xiao, Yuehai; Wang, Bolin; Sun, Chao; Tang, Kaifa; Sun, Fa

    2017-12-22

    Although fluoride has been widely used in toothpaste, mouthwash, and drinking water to prevent dental caries, the excessive intake of fluoride can cause fluorosis which is associated with dental, skeletal, and soft tissue fluorosis. Recent evidences have drawn the attention to its adverse effects on male reproductive system that include spermatogenesis defect, sperm count loss, and sperm maturation impairment. Fluoride induces oxidative stress through the activation of mitogen activated protein kinase (MAPK) cascade which can lead to cell apoptosis. Vitamin E (VE) and lycopene are two common anti-oxidants, being protective to reactive oxygen species (ROS)-induced toxic effects. However, whether and how these two anti-oxidants prevent fluoride-induced spermatogenic cell apoptosis are largely unknown. In the present study, a male rat model for coal burning fluorosis was established and the histological lesions and spermatogenic cell apoptosis in rat testes were observed. The decreased expression of clusterin, a heterodimeric glycoprotein reported to regulate spermatogenic cell apoptosis, is detected in fluoride-treated rat testes. Interestingly, the co-administration with VE or lycopene reduced fluorosis-mediated testicular toxicity and rescued clusterin expression. Further, fluoride caused the enhanced Jun N-terminal kinase (JNK) and extracellular signal-regulated protein kinase (ERK) phosphorylation, which was reduced by VE or lycopene. Thus, VE and lycopene prevent coal burning fluorosis-induced spermatogenic cell apoptosis through the suppression of oxidative stress-mediated JNK and ERK signaling pathway, which could be an alternative therapeutic strategy for the treatment of fluorosis. ©2017 The Author(s).

  7. Cadmium induces Ca2+ mediated, calpain-1/caspase-3-dependent apoptosis in primary cultured rat proximal tubular cells.

    Science.gov (United States)

    Wang, Hong; Zhai, Nianhui; Chen, Ying; Xu, Haibin; Huang, Kehe

    2017-07-01

    Calcium, as a ubiquitous second messenger, governs a large array of cellular processes and is necessary for cell survival. More recently, it was observed that the cytosolic Ca 2+ concentration ([Ca 2+ ] c ) elevation could induce apoptosis in primary cultured rat proximal tubular (rPT) cells exposed to cadmium (Cd), but the concrete mechanism is still unclear. This study was designed to investigate the signal pathway involved in [Ca 2+ ] c elevation-mediated apoptosis. The results confirmed the elevation of [Ca 2+ ] c by confocal microscopy and enhancement of the apoptosis by Hoechst 33258 staining and flow cytometer when rPT cells were exposed to Cd for 12h. Then we demonstrated that Cd enhanced the protein levels of active calpain-1 and caspase-3 in rPT cells. Pretreatment with a cytosolic Ca 2+ chelator, 1,2-Bis (2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM), markedly blocked the up-regulation of active calpain-1 and caspase-3 and inhibited the apoptosis induced by Cd. Further, rPT cells were pretreated with a cell-permeable selective calpain-1 inhibitor, 3-(4-iodophenyl)-2-mercapto-(Z)-2-propenoic acid (PD150606) and caspase-3 inhibitor, N-Acetyl-Asp-Glu-Val-Asp-CHO (Ac-DEVD-CHO), respectively. PD150606 significantly attenuated the up-regulation of active caspase-3 and the apoptosis induced by Cd. As expected, inhibition of active caspase-3 by Ac-DEVD-CHO decreased the apoptosis induced by Cd. Taken together, it could be concluded that [Ca 2+ ] c elevation did act as a pro-apoptotic signal in Cd-induced cytotoxicity of rPT cells, triggered calpain-1 and caspase-3 activation in turn, and induced apoptosis of rPT cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. [Ursodeoxycholic acid induced apoptosis of human hepatoma cells HepG2 and SMMC-7721 bymitochondrial-mediated pathway].

    Science.gov (United States)

    Wu, Duan; Zhou, Jianyin; Yin, Zhenyu; Liu, Pingguo; Zhao, Yilin; Liu, Jianming; Wang, Xiaomin

    2014-12-02

    To explore the effects and underlying mechanisms of ursodeoxycholic acid on human hepatoma cells. HepG2 and SMMC-7721 HCC cell lines were respectively treated with ursodeoxycholic acid. And cell proliferation, apoptosis and the expression of Bax/Bcl-2 gene were detected by methyl thiazolyl tetrazolium (MTT), inverted microscopy, fluorescent microscopy, flow cytometry and Western blot. Ursodeoxycholic acid significantly inhibited the proliferation of human hepatoma cells in a concentration- and time-dependent manner. The half maximal inhibitory concentrations (IC50) of HepG2 and SMMC-7721 were 397.3 and 387.7 µg/ml respectively after a 48-hour treatment of 400 µg /ml ursodeoxycholic acid. And it also induced the apoptosis of HepG2 and SMMC-7721 cells, up-regulated Bax gene and down-regulated Bcl-2 gene. Ursodeoxycholic acid inhibits the proliferation of hepatoma cells and induce apoptosis by mitochondrial-mediated pathway.

  9. Lithium protects ethanol-induced neuronal apoptosis

    International Nuclear Information System (INIS)

    Zhong Jin; Yang Xianlin; Yao Weiguo; Lee Weihua

    2006-01-01

    Lithium is widely used for the treatment of bipolar disorder. Recent studies have demonstrated its neuroprotective effect. Ethanol is a potent neurotoxin that is particularly harmful to the developing nervous system. In this study, we evaluated lithium's neuroprotection against ethanol-induced apoptosis. Transient exposure of infant mice to ethanol caused apoptotic cell death in brain, which was prevented significantly by administering a low dose of lithium 15 min later. In cultured cerebellar granule neurons, ethanol-induced apoptosis and activation of caspase-3/9, both of which were prevented by lithium. However, lithium's protection is not mediated by its commonly known inhibition of glycogen synthase3β, because neither ethanol nor lithium has significant effects on the phosphorylation of Akt (ser473) or GSK3β (ser9). In addition, the selective GSK-3β inhibitor SB-415286 was unable to prevent ethanol-induced apoptosis. These data suggest lithium may be used as a potential preventive measure for ethanol-induced neurological deficits

  10. Trichodermin induces cell apoptosis through mitochondrial dysfunction and endoplasmic reticulum stress in human chondrosarcoma cells

    International Nuclear Information System (INIS)

    Su, Chen-Ming; Wang, Shih-Wei; Lee, Tzong-Huei; Tzeng, Wen-Pei; Hsiao, Che-Jen; Liu, Shih-Chia; Tang, Chih-Hsin

    2013-01-01

    Chondrosarcoma is the second most common primary bone tumor, and it responds poorly to both chemotherapy and radiation treatment. Nalanthamala psidii was described originally as Myxosporium in 1926. This is the first study to investigate the anti-tumor activity of trichodermin (trichothec-9-en-4-ol, 12,13-epoxy-, acetate), an endophytic fungal metabolite from N. psidii against human chondrosarcoma cells. We demonstrated that trichodermin induced cell apoptosis in human chondrosarcoma cell lines (JJ012 and SW1353 cells) instead of primary chondrocytes. In addition, trichodermin triggered endoplasmic reticulum (ER) stress protein levels of IRE1, p-PERK, GRP78, and GRP94, which were characterized by changes in cytosolic calcium levels. Furthermore, trichodermin induced the upregulation of Bax and Bid, the downregulation of Bcl-2, and the dysfunction of mitochondria, which released cytochrome c and activated caspase-3 in human chondrosarcoma. In addition, animal experiments illustrated reduced tumor volume, which led to an increased number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells and an increased level of cleaved PARP protein following trichodermin treatment. Together, this study demonstrates that trichodermin is a novel anti-tumor agent against human chondrosarcoma cells both in vitro and in vivo via mitochondrial dysfunction and ER stress. - Highlights: • Trichodermin induces chondrosarcoma apoptosis. • ER stress is involved in trichodermin-induced cell death. • Trichodermin induces chondrosarcoma death in vivo.

  11. Trichodermin induces cell apoptosis through mitochondrial dysfunction and endoplasmic reticulum stress in human chondrosarcoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Su, Chen-Ming [Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan (China); Wang, Shih-Wei [Department of Medicine, Mackay Medical College, New Taipei City, Taiwan (China); Lee, Tzong-Huei [Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan (China); Tzeng, Wen-Pei [Graduate Institute of Sports and Health, National Changhua University of Education, Changhua, Taiwan (China); Hsiao, Che-Jen [School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Liu, Shih-Chia [Department of Orthopaedics, Mackay Memorial Hospital, Taipei, Taiwan (China); Tang, Chih-Hsin, E-mail: chtang@mail.cmu.edu.tw [Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan (China); Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan (China); Department of Biotechnology, College of Health Science, Asia University, Taichung, Taiwan (China)

    2013-10-15

    Chondrosarcoma is the second most common primary bone tumor, and it responds poorly to both chemotherapy and radiation treatment. Nalanthamala psidii was described originally as Myxosporium in 1926. This is the first study to investigate the anti-tumor activity of trichodermin (trichothec-9-en-4-ol, 12,13-epoxy-, acetate), an endophytic fungal metabolite from N. psidii against human chondrosarcoma cells. We demonstrated that trichodermin induced cell apoptosis in human chondrosarcoma cell lines (JJ012 and SW1353 cells) instead of primary chondrocytes. In addition, trichodermin triggered endoplasmic reticulum (ER) stress protein levels of IRE1, p-PERK, GRP78, and GRP94, which were characterized by changes in cytosolic calcium levels. Furthermore, trichodermin induced the upregulation of Bax and Bid, the downregulation of Bcl-2, and the dysfunction of mitochondria, which released cytochrome c and activated caspase-3 in human chondrosarcoma. In addition, animal experiments illustrated reduced tumor volume, which led to an increased number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells and an increased level of cleaved PARP protein following trichodermin treatment. Together, this study demonstrates that trichodermin is a novel anti-tumor agent against human chondrosarcoma cells both in vitro and in vivo via mitochondrial dysfunction and ER stress. - Highlights: • Trichodermin induces chondrosarcoma apoptosis. • ER stress is involved in trichodermin-induced cell death. • Trichodermin induces chondrosarcoma death in vivo.

  12. Ectopic overexpression of LAPTM5 results in lysosomal targeting and induces Mcl-1 down-regulation, Bak activation, and mitochondria-dependent apoptosis in human HeLa cells.

    Directory of Open Access Journals (Sweden)

    Do Youn Jun

    Full Text Available Human lysosomal-associated protein multispanning membrane 5 (LAPTM5 was identified by an ordered differential display-polymerase chain reaction (ODD-PCR as an up-regulated cDNA fragment during 12-O-tetradecanoylphorbol 13-acetate (TPA-induced differentiation of U937 cells into monocytes/macrophages. After TPA-treatment, the levels of LAPTM5 mRNA and protein increased and reached a maximum at 18-36 h. In healthy human tissues, LAPTM5 mRNA was expressed at high levels in hematopoietic cells and tissues, at low levels in the lung and fetal liver, and was not detected in other non-hematopoietic tissues. LAPTM5 mRNA was detected in immature malignant cells of myeloid lineage, such as K562, HL-60, U937, and THP-1 cells, and in unstimulated peripheral T cells, but was absent or barely detectable in lymphoid malignant or non-hematopoietic malignant cells. The LAPTM5 level in HL-60 cells increased more significantly during TPA-induced monocyte/macrophage differentiation than during DMSO-induced granulocyte differentiation. Ectopic expression of GFP-LAPTM5 or LAPTM5 in HeLa cells exhibited the localization of LAPTM5 to the lysosome. In HeLa cells overexpressing LAPTM5, the Mcl-1 and Bid levels declined markedly and apoptosis was induced via Bak activation, Δψm loss, activation of caspase-9, -8 and -3, and PARP degradation without accompanying necrosis. However, these LAPTM5-induced apoptotic events except for the decline of Bid level were completely abrogated by concomitant overexpression of Mcl-1. The pan-caspase inhibitor (z-VAD-fmk could suppress the LAPTM5-induced apoptotic sub-G1 peak by ~40% but failed to block the induced Δψm loss, whereas the broad-range inhibitor of cathepsins (Cathepsin Inhibitor I could suppress the LAPTM5-induced apoptotic sub-G1 peak and Δψm loss, by ~22% and ~23%, respectively, suggesting that the LAPTM5-mediated Δψm loss was exerted at least in part in a cathepsin-dependent manner. Together, these results

  13. Ectopic overexpression of LAPTM5 results in lysosomal targeting and induces Mcl-1 down-regulation, Bak activation, and mitochondria-dependent apoptosis in human HeLa cells

    Science.gov (United States)

    Jun, Do Youn; Kim, Hyejin; Jang, Won Young; Lee, Ji Young; Fukui, Kiyoshi; Kim, Young Ho

    2017-01-01

    Human lysosomal-associated protein multispanning membrane 5 (LAPTM5) was identified by an ordered differential display-polymerase chain reaction (ODD-PCR) as an up-regulated cDNA fragment during 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced differentiation of U937 cells into monocytes/macrophages. After TPA-treatment, the levels of LAPTM5 mRNA and protein increased and reached a maximum at 18–36 h. In healthy human tissues, LAPTM5 mRNA was expressed at high levels in hematopoietic cells and tissues, at low levels in the lung and fetal liver, and was not detected in other non-hematopoietic tissues. LAPTM5 mRNA was detected in immature malignant cells of myeloid lineage, such as K562, HL-60, U937, and THP-1 cells, and in unstimulated peripheral T cells, but was absent or barely detectable in lymphoid malignant or non-hematopoietic malignant cells. The LAPTM5 level in HL-60 cells increased more significantly during TPA-induced monocyte/macrophage differentiation than during DMSO-induced granulocyte differentiation. Ectopic expression of GFP-LAPTM5 or LAPTM5 in HeLa cells exhibited the localization of LAPTM5 to the lysosome. In HeLa cells overexpressing LAPTM5, the Mcl-1 and Bid levels declined markedly and apoptosis was induced via Bak activation, Δψm loss, activation of caspase-9, -8 and -3, and PARP degradation without accompanying necrosis. However, these LAPTM5-induced apoptotic events except for the decline of Bid level were completely abrogated by concomitant overexpression of Mcl-1. The pan-caspase inhibitor (z-VAD-fmk) could suppress the LAPTM5-induced apoptotic sub-G1 peak by ~40% but failed to block the induced Δψm loss, whereas the broad-range inhibitor of cathepsins (Cathepsin Inhibitor I) could suppress the LAPTM5-induced apoptotic sub-G1 peak and Δψm loss, by ~22% and ~23%, respectively, suggesting that the LAPTM5-mediated Δψm loss was exerted at least in part in a cathepsin-dependent manner. Together, these results demonstrate that

  14. Regorafenib inhibits colorectal tumor growth through PUMA-mediated apoptosis

    Science.gov (United States)

    Chen, Dongshi; Wei, Liang; Yu, Jian; Zhang, Lin

    2014-01-01

    Purpose Regorafenib, a multi-kinase inhibitor targeting the Ras/Raf/MEK/ERK pathway, has recently been approved for the treatment of metastatic colorectal cancer (CRC). However, the mechanisms of action of regorafenib in CRC cells have been unclear. We investigated how regorafenib suppresses CRC cell growth and potentiates effects of other chemotherapeutic drugs. Experimental Design We determined whether and how regorafenib induces the expression of PUMA, a p53 target and a critical mediator of apoptosis in CRC cells. We also investigated whether PUMA is necessary for the killing and chemosensitization effects of regorafenib in CRC cells. Furthermore, xenograft tumors were used to test if PUMA mediates the in vivo antitumor, antiangiogenic and chemosensitization effects of regorafenib. Results We found that regorafenib treatment induces PUMA in CRC cells irrespective of p53 status through the NF-κB pathway following ERK inhibition and glycogen synthase kinase 3β (GSK3β) activation. Upregulation of PUMA is correlated with apoptosis induction in different CRC cell lines. PUMA is necessary for regorafenib-induced apoptosis in CRC cells. Chemosensitization by regorafenib is mediated by enhanced PUMA induction through different pathways. Furthermore, deficiency in PUMA abrogates the in vivo antitumor, antiangiogenic and chemosensitization effects of regorafenib. Conclusions Our results demonstrate a key role of PUMA in mediating the anticancer effects of regorafenib in CRC cells. They suggest that PUMA induction can be used as an indicator of regorafenib sensitivity, and also provide a rationale for manipulating the apoptotic machinery to improve the therapeutic efficacy of regorafenib and other targeted drugs. PMID:24763611

  15. Silkworm Pupa Protein Hydrolysate Induces Mitochondria-Dependent Apoptosis and S Phase Cell Cycle Arrest in Human Gastric Cancer SGC-7901 Cells

    Directory of Open Access Journals (Sweden)

    Xiaotong Li

    2018-03-01

    Full Text Available Silkworm pupae (Bombyx mori are a high-protein nutrition source consumed in China since more than 2 thousand years ago. Recent studies revealed that silkworm pupae have therapeutic benefits to treat many diseases. However, the ability of the compounds of silkworm pupae to inhibit tumourigenesis remains to be elucidated. Here, we separated the protein of silkworm pupae and performed alcalase hydrolysis. Silkworm pupa protein hydrolysate (SPPH can specifically inhibit the proliferation and provoke abnormal morphologic features of human gastric cancer cells SGC-7901 in a dose- and time-dependent manner. Moreover, flow cytometry indicated that SPPH can induce apoptosis and arrest the cell-cycle in S phase. Furthermore, SPPH was shown to provoke accumulation of reactive oxygen species (ROS and depolarization of mitochondrial membrane potential. Western blotting analysis indicated that SPPH inhibited Bcl-2 expression and promoted Bax expression, and subsequently induced apoptosis-inducing factor and cytochrome C release, which led to the activation of initiator caspase-9 and executioner caspase-3, cleavage of poly (ADP-ribose polymerase (PARP, eventually caused cell apoptosis. Moreover, SPPH-induced S-phase arrest was mediated by up-regulating the expression of E2F1 and down-regulating those of cyclin E, CDK2 and cyclin A2. Transcriptome sequencing and gene set enrichment analysis (GSEA also revealed that SPPH treatment could affect gene expression and pathway regulation related to tumourigenesis, apoptosis and cell cycle. In summary, our results suggest that SPPH could specifically suppress cell growth of SGC-7901 through an intrinsic apoptotic pathway, ROS accumulation and cell cycle arrest, and silkworm pupae have a potential to become a source of anticancer agents in the future.

  16. The efficacy and mechanism of apoptosis induction by hypericin-mediated sonodynamic therapy in THP-1 macrophages

    Directory of Open Access Journals (Sweden)

    Li XS

    2015-01-01

    sonodynamic therapy (SDT group. Both ROS generation and MDA levels were significantly reduced by the ROS scavenger N-acetyl cysteine (NAC and the singlet oxygen scavenger sodium azide. Most of the loss of ΔΨm was inhibited by pretreatment with NAC, sodium azide, and the mPTP inhibitor cyclosporin A (CsA. mPTP opening was induced upon SDT but was reduced by pretreatment with bongkrekic acid, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid disodium, CsA, and NAC. Western blot analyses revealed translocation of BAX and cytochrome C, downregulated expression of Bcl-2, and upregulated expression of cleaved caspase-9, cleaved caspase-3, and cleaved poly(ADP-ribose polymerase in the SDT group, which were reversed by NAC.Conclusion: HY mediated SDT-induced apoptosis in THP-1 macrophages via ROS generation. Then, the proapoptotic factor BAX translocated from the cytosol to the mitochondria, increasing the ratio of BAX/Bcl-2, and the mPTP opened to release cytochrome C. This study demonstrated the great potential of HY-mediated SDT for treating atherosclerosis. Keywords: apoptosis, hypericin, sonodynamic therapy, mitochondria–caspase pathway, atherosclerosis

  17. Thymic Atrophy and Apoptosis of CD4+CD8+ Thymocytes in the Cuprizone Model of Multiple Sclerosis

    DEFF Research Database (Denmark)

    Solti, Izabella; Kvell, Krisztian; Talaber, Gergely

    2015-01-01

    Previous studies on the degenerative animal model of multiple sclerosis suggested that the copper-chelator cuprizone might directly suppress T-cell functions. Peripheral T-cell function in the cuprizone model has already been explored; therefore, in the present study, we investigated, for the first...... mitochondria, myelin-bodies, large lipid droplets, and large lysosomes in the thymi of cuprizone-treated mice. Some of these features were similar to those in physiological and steroid-induced accelerated aging. According to our results, apoptosis was mainly of mitochondrial origin mediated by both caspase-3......- and apoptosis inducing factor-mediated mechanisms. Additionally, mitogen activated protein kinase activation and increased pro-apoptotic B cell lymphoma-2 family protein expression were the major underlying processes. Our results do not indicate a functional relationship between cuprizone-induced thymus...

  18. Bim is a crucial regulator of apoptosis induced by Mycobacterium tuberculosis

    Science.gov (United States)

    Aguiló, N; Uranga, S; Marinova, D; Martín, C; Pardo, J

    2014-01-01

    Mycobacterium tuberculosis, the causative agent of tuberculosis, induces apoptosis in infected macrophages in vitro and in vivo. However, the molecular mechanism controlling this process is not known. In order to study the involvement of the mitochondrial apoptotic pathway in M. tuberculosis-induced apoptosis, we analysed cell death in M. tuberculosis-infected embryonic fibroblasts (MEFs) derived from different knockout mice for genes involved in this route. We found that apoptosis induced by M. tuberculosis is abrogated in the absence of Bak and Bax, caspase 9 or the executioner caspases 3 and 7. Notably, we show that MEF deficient in the BH3-only BCL-2-interacting mediator of cell death (Bim) protein were also resistant to this process. The relevance of these results has been confirmed in the mouse macrophage cell line J774, where cell transfection with siRNA targeting Bim impaired apoptosis induced by virulent mycobacteria. Notably, only infection with a virulent strain, but not with attenuated ESX-1-defective strains, such as Bacillus Calmette-Guerin and live-attenuated M. tuberculosis vaccine strain MTBVAC, induced Bim upregulation and apoptosis, probably implicating virulence factor early secreted antigenic target 6-kDa protein in this process. Our results suggest that Bim upregulation and apoptosis is mediated by the p38MAPK-dependent pathway. Our findings show that Bim is a master regulator of apoptosis induced by M. tuberculosis. PMID:25032866

  19. N-Acetyl Cysteine Depletes Reactive Oxygen Species and Prevents Dental Monomer-Induced Intrinsic Mitochondrial Apoptosis In Vitro in Human Dental Pulp Cells.

    Directory of Open Access Journals (Sweden)

    Yang Jiao

    Full Text Available To investigate the involvement of intrinsic mitochondrial apoptosis in dental monomer-induced cytotoxicity and the influences of N-acetyl cysteine (NAC on this process.Human dental pulp cells (hDPCs were exposed to several dental monomers in the absence or presence of NAC, and cell viability, intracellular redox balance, morphology and function of mitochondria and key indicators of intrinsic mitochondrial apoptosis were evaluated using various commercial kits.Dental monomers exerted dose-dependent cytotoxic effects on hDPCs. Concomitant to the over-production of reactive oxygen species (ROS and depletion of glutathione (GSH, differential changes in activities of superoxide dismutase, glutathione peroxidase, and catalase were detected. Apoptosis, as indicated by positive Annexin V/propidium iodide (PI staining and activation of caspase-3, was observed after dental monomer treatment. Dental monomers impaired the morphology and function of mitochondria, and induced intrinsic mitochondrial apoptosis in hDPCs via up-regulation of p53, Bax and cleaved caspase-3, and down-regulation of Bcl-2. NAC restored cell viability, relieved oxidative stress and blocked the apoptotic effects of dental monomers.Dental monomers induced oxidative stress and mitochondrial intrinsic apoptosis in hDPCs. NAC could reduce the oxidative stress and thus protect hDPCs against dental monomer-induced apoptosis.

  20. Xylopine Induces Oxidative Stress and Causes G2/M Phase Arrest, Triggering Caspase-Mediated Apoptosis by p53-Independent Pathway in HCT116 Cells

    Directory of Open Access Journals (Sweden)

    Luciano de Souza Santos

    2017-01-01

    Full Text Available Xylopine is an aporphine alkaloid that has cytotoxic activity to cancer cells. In this study, the underlying mechanism of xylopine cytotoxicity was assessed in human colon carcinoma HCT116 cells. Xylopine displayed potent cytotoxicity in different cancer cell lines in monolayer cultures and in a 3D model of cancer multicellular spheroids formed from HCT116 cells. Typical morphology of apoptosis, cell cycle arrest in the G2/M phase, increased internucleosomal DNA fragmentation, loss of the mitochondrial transmembrane potential, and increased phosphatidylserine externalization and caspase-3 activation were observed in xylopine-treated HCT116 cells. Moreover, pretreatment with a caspase-3 inhibitor (Z-DEVD-FMK, but not with a p53 inhibitor (cyclic pifithrin-α, reduced xylopine-induced apoptosis, indicating induction of caspase-mediated apoptosis by the p53-independent pathway. Treatment with xylopine also caused an increase in the production of reactive oxygen/nitrogen species (ROS/RNS, including hydrogen peroxide and nitric oxide, but not superoxide anion, and reduced glutathione levels were decreased in xylopine-treated HCT116 cells. Application of the antioxidant N-acetylcysteine reduced the ROS levels and xylopine-induced apoptosis, indicating activation of ROS-mediated apoptosis pathway. In conclusion, xylopine has potent cytotoxicity to different cancer cell lines and is able to induce oxidative stress and G2/M phase arrest, triggering caspase-mediated apoptosis by the p53-independent pathway in HCT116 cells.

  1. Beta-irradiation used for systemic radioimmunotherapy induces apoptosis and activates apoptosis pathways in leukaemia cells

    International Nuclear Information System (INIS)

    Friesen, Claudia; Lubatschofski, Annelie; Debatin, Klaus-Michael; Kotzerke, Joerg; Buchmann, Inga; Reske, Sven N.

    2003-01-01

    Beta-irradiation used for systemic radioimmunotherapy (RIT) is a promising treatment approach for high-risk leukaemia and lymphoma. In bone marrow-selective radioimmunotherapy, beta-irradiation is applied using iodine-131, yttrium-90 or rhenium-188 labelled radioimmunoconjugates. However, the mechanisms by which beta-irradiation induces cell death are not understood at the molecular level. Here, we report that beta-irradiation induced apoptosis and activated apoptosis pathways in leukaemia cells depending on doses, time points and dose rates. After beta-irradiation, upregulation of CD95 ligand and CD95 receptor was detected and activation of caspases resulting in apoptosis was found. These effects were completely blocked by the broad-range caspase inhibitor zVAD-fmk. In addition, irradiation-mediated mitochondrial damage resulted in perturbation of mitochondrial membrane potential, caspase-9 activation and cytochrome c release. Bax, a death-promoting protein, was upregulated and Bcl-x L , a death-inhibiting protein, was downregulated. We also found higher apoptosis rates and earlier activation of apoptosis pathways after gamma-irradiation in comparison to beta-irradiation at the same dose rate. Furthermore, irradiation-resistant cells were cross-resistant to CD95 and CD95-resistant cells were cross-resistant to irradiation, indicating that CD95 and irradiation used, at least in part, identical effector pathways. These findings demonstrate that beta-irradiation induces apoptosis and activates apoptosis pathways in leukaemia cells using both mitochondrial and death receptor pathways. Understanding the timing, sequence and molecular pathways of beta-irradiation-mediated apoptosis may allow rational adjustment of chemo- and radiotherapeutic strategies. (orig.)

  2. [TRPM8 mediates PC-12 neuronal cell apoptosis induced by oxygen-glucose deprivation through cAMP-PKA/UCP4 signaling].

    Science.gov (United States)

    Li, Hong-Wei; Zhou, Bin; Zhang, Hai-Hong

    2016-08-20

    To explore the molecular mechanism responsible for apoptosis of PC-12 neuronal cells induced by oxygen-glucose deprivation (OGD). PC12 cells were exposed to OGD for 24 h to simulate ischemia-reperfusion injury. Flow cytometry was employed detect the cell apoptosis, and the expresions of TRPM8, UCP4, cAMP and PKA in the exposed cells were detected with RT-PCR and Western blotting. The changes in the expressions of Bax, Bcl-2, cAMP, PKA and UCP4 proteins were detected in the exposed cells in resposne to inhibition of TRPM8 and cAMP-PKA signal or over-expression of UCP4. OGD for 24 induced obvious apoptosis in PC-12 cells and caused TRPM8 over-expression and inhibition of UCP4 and cAMP-PKA signaling. Inhibiting TRPM8 expression reduced the cell apoptosis and up-regulated cAMP, p-PKA and UCP4 in the cells exposed to OGD. In cells exposed to OGD, inhibition of TRPM8 and cAMP-PKA signaling suppressed the expressio of UCP4 and increased the cell apoptosis. TRPM8 mediates OGD-induced PC12 cell apoptosis through cAMP-PKA/UCP4 signaling.

  3. Role of mitochondria-associated hexokinase II in cancer cell death induced by 3-Bromopyruvate

    Science.gov (United States)

    Chen, Zhao; Zhang, Hui; Lu, Weiqin; Huang, Peng

    2009-01-01

    Summary It has long been observed that cancer cells rely more on glycolysis to generate ATP and actively use certain glycolytic metabolic intermediates for biosynthesis. Hexokinase II (HKII) is a key glycolytic enzyme that plays a role in the regulation of the mitochondria-initiated apoptotic cell death. As a potent inhibitor of hexokinase, 3-bromopyruvate (3-BrPA) is known to inhibit cancer cell energy metabolism and trigger cell death, supposedly through depletion of cellular ATP. The current study showed that 3-BrPA caused a covalent modification of HKII protein and directly triggered its dissociation from mitochondria, leading to a specific release of apoptosis-inducing factor (AIF) from the mitochondria to cytosol and eventual cell death. Co-immunoprecipitation revealed a physical interaction between HKII and AIF. Using a competitive peptide of HKII, we showed that the dissociation of hexokinase II from mitochondria alone could cause apoptotic cell death, especially in the mitochondria-deficient ρ0 cells that highly express HKII. Interestingly, the dissociation of HKII itself did no directly affect the mitochondrial membrane potential, ROS generation, and oxidative phosphorylation. Our study suggests that the physical association between HKII and AIF is important for the normal localization of AIF in the mitochondria, and disruption of this protein complex by 3-BrPA leads to their release from the mitochondria and eventual cell death. PMID:19285479

  4. Repercussion of mitochondria deformity induced by anti-Hsp90 drug 17AAG in human tumor cells

    KAUST Repository

    Vishal, Chaturvedi

    2011-06-07

    Inhibiting Hsp90 chaperone roles using 17AAG induces cytostasis or apoptosis in tumor cells through destabilization of several mutated cancer promoting proteins. Although mitochondria are central in deciding the fate of cells, 17AAG induced effects on tumor cell mitochondria were largely unknown. Here, we show that Hsp90 inhibition with 17AAG first affects mitochondrial integrity in different human tumor cells, neuroblastoma, cervical cancer and glial cells. Using human neuroblastoma tumor cells, we found the early effects associated with a change in mitochondrial membrane potential, elongation and engorgement of mitochondria because of an increased matrix vacuolization. These effects are specific to Hsp90 inhibition as other chemotherapeutic drugs did not induce similar mitochondrial deformity. Further, the effects are independent of oxidative damage and cytoarchitecture destabilization since cytoskeletal disruptors and mitochondrial metabolic inhibitors also do not induce similar deformity induced by 17AAG. The 1D PAGE LC MS/ MS mitochondrial proteome analysis of 17AAG treated human neuroblastoma cells showed a loss of 61% proteins from membrane, metabolic, chaperone and ribonucleoprotein families. About 31 unmapped protein IDs were identified from proteolytic processing map using Swiss-Prot accession number, and converted to the matching gene name searching the ExPASy proteomics server. Our studies display that Hsp90 inhibition effects at first embark on mitochondria of tumor cells and compromise mitochondrial integrity. the author(s), publisher and licensee Libertas Academica Ltd.

  5. Mechanisms of methicillin-resistant Staphylococcus aureus pneumonia-induced intestinal epithelial apoptosis.

    Science.gov (United States)

    Perrone, Erin E; Jung, Enjae; Breed, Elise; Dominguez, Jessica A; Liang, Zhe; Clark, Andrew T; Dunne, W Michael; Burd, Eileen M; Coopersmith, Craig M

    2012-07-01

    Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia-induced sepsis is a common cause of morbidity in the intensive care unit. Although pneumonia is initiated in the lungs, extrapulmonary manifestations occur commonly. In light of the key role the intestine plays in the pathophysiology of sepsis, we sought to determine whether MRSA pneumonia induces intestinal injury. FVB/N mice were subjected to MRSA or sham pneumonia and killed 24 h later. Septic animals had a marked increase in intestinal epithelial apoptosis by both hematoxylin-eosin and active caspase 3 staining. Methicillin-resistant S. aureus-induced intestinal apoptosis was associated with an increase in the expression of the proapoptotic proteins Bid and Bax and the antiapoptotic protein Bcl-xL in the mitochondrial pathway. In the receptor-mediated pathway, MRSA pneumonia induced an increase in Fas ligand but decreased protein levels of Fas, FADD, pFADD, TNF-R1, and TRADD. To assess the functional significance of these changes, MRSA pneumonia was induced in mice with genetic manipulations in proteins in either the mitochondrial or receptor-mediated pathways. Both Bid-/- mice and animals with intestine-specific overexpression of Bcl-2 had decreased intestinal apoptosis compared with wild-type animals. In contrast, Fas ligand-/- mice had no alterations in apoptosis. To determine if these findings were organism-specific, similar experiments were performed in mice subjected to Pseudomonas aeruginosa pneumonia. Pseudomonas aeruginosa induced gut apoptosis, but unlike MRSA, this was associated with increased Bcl-2 and TNF-R1 and decreased Fas. Methicillin-resistant S. aureus pneumonia thus induces organism-specific changes in intestinal apoptosis via changes in both the mitochondrial and receptor-mediated pathways, although the former may be more functionally significant.

  6. Hypercholesterolemia aggravates myocardial ischemia reperfusion injury via activating endoplasmic reticulum stress-mediated apoptosis.

    Science.gov (United States)

    Wu, Nan; Zhang, Xiaowen; Jia, Pengyu; Jia, Dalin

    2015-12-01

    The effect of hypercholesterolemia on myocardial ischemia reperfusion injury (MIRI) is in controversy and the underlying mechanism is still not well understood. In the present study, we firstly detected the effects of hypercholesterolemia on MIRI and the role of endoplasmic reticulum (ER) stress-mediated apoptosis pathway in this process. The infarct size was determined by TTC staining, and apoptosis was measured by the TUNEL method. The marker proteins of ER stress response and ER stress-mediated apoptosis pathway were detected by Western blot. The results showed that high cholesterol diet-induced hypercholesterolemia significantly increased the myocardial infarct size, the release of myocardium enzyme and the ratio of apoptosis, but did not affect the recovery of cardiac function. Moreover, hypercholesterolemia also remarkably up-regulated the expressions of ER stress markers (glucose-regulated protein 78 and calreticulin) and critical molecules in ER stress-mediated apoptosis pathway (CHOP, caspase 12, phospho-JNK). In conclusion, our study demonstrated that hypercholesterolemia enhanced myocardial vulnerability/sensitivity to ischemia reperfusion injury involved in aggravation the ER stress and activation of ER stress-mediated apoptosis pathway and it gave us a new insight into the underlying mechanisms associated with hypercholesterolemia-induced exaggerated MIRI and also provided a novel target for preventing MIRI in the presence of hypercholesterolemia. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Andrographolide Analogue Induces Apoptosis and Autophagy Mediated Cell Death in U937 Cells by Inhibition of PI3K/Akt/mTOR Pathway.

    Directory of Open Access Journals (Sweden)

    Deepak Kumar

    Full Text Available Current chemotherapeutic agents based on apoptosis induction are lacking in desired efficacy. Therefore, there is continuous effort to bring about new dimension in control and gradual eradication of cancer by means of ever evolving therapeutic strategies. Various forms of PCD are being increasingly implicated in anti-cancer therapy and the complex interplay among them is vital for the ultimate fate of proliferating cells. We elaborated and illustrated the underlying mechanism of the most potent Andrographolide analogue (AG-4 mediated action that involved the induction of dual modes of cell death-apoptosis and autophagy in human leukemic U937 cells.AG-4 induced cytotoxicity was associated with redox imbalance and apoptosis which involved mitochondrial depolarisation, altered apoptotic protein expressions, activation of the caspase cascade leading to cell cycle arrest. Incubation with caspase inhibitor Z-VAD-fmk or Bax siRNA decreased cytotoxic efficacy of AG-4 emphasising critical roles of caspase and Bax. In addition, AG-4 induced autophagy as evident from LC3-II accumulation, increased Atg protein expressions and autophagosome formation. Pre-treatment with 3-MA or Atg 5 siRNA suppressed the cytotoxic effect of AG-4 implying the pro-death role of autophagy. Furthermore, incubation with Z-VAD-fmk or Bax siRNA subdued AG-4 induced autophagy and pre-treatment with 3-MA or Atg 5 siRNA curbed AG-4 induced apoptosis-implying that apoptosis and autophagy acted as partners in the context of AG-4 mediated action. AG-4 also inhibited PI3K/Akt/mTOR pathway. Inhibition of mTOR or Akt augmented AG-4 induced apoptosis and autophagy signifying its crucial role in its mechanism of action.Thus, these findings prove the dual ability of AG-4 to induce apoptosis and autophagy which provide a new perspective to it as a potential molecule targeting PCD for future cancer therapeutics.

  8. Hydroxychavicol, a Piper betle leaf component, induces apoptosis of CML cells through mitochondrial reactive oxygen species-dependent JNK and endothelial nitric oxide synthase activation and overrides imatinib resistance.

    Science.gov (United States)

    Chakraborty, Jayashree B; Mahato, Sanjit K; Joshi, Kalpana; Shinde, Vaibhav; Rakshit, Srabanti; Biswas, Nabendu; Choudhury Mukherjee, Indrani; Mandal, Labanya; Ganguly, Dipyaman; Chowdhury, Avik A; Chaudhuri, Jaydeep; Paul, Kausik; Pal, Bikas C; Vinayagam, Jayaraman; Pal, Churala; Manna, Anirban; Jaisankar, Parasuraman; Chaudhuri, Utpal; Konar, Aditya; Roy, Siddhartha; Bandyopadhyay, Santu

    2012-01-01

    Alcoholic extract of Piper betle (Piper betle L.) leaves was recently found to induce apoptosis of CML cells expressing wild type and mutated Bcr-Abl with imatinib resistance phenotype. Hydroxy-chavicol (HCH), a constituent of the alcoholic extract of Piper betle leaves, was evaluated for anti-CML activity. Here, we report that HCH and its analogues induce killing of primary cells in CML patients and leukemic cell lines expressing wild type and mutated Bcr-Abl, including the T315I mutation, with minimal toxicity to normal human peripheral blood mononuclear cells. HCH causes early but transient increase of mitochondria-derived reactive oxygen species. Reactive oxygen species-dependent persistent activation of JNK leads to an increase in endothelial nitric oxide synthase-mediated nitric oxide generation. This causes loss of mitochondrial membrane potential, release of cytochrome c from mitochondria, cleavage of caspase 9, 3 and poly-adenosine diphosphate-ribose polymerase leading to apoptosis. One HCH analogue was also effective in vivo in SCID mice against grafts expressing the T315I mutation, although to a lesser extent than grafts expressing wild type Bcr-Abl, without showing significant bodyweight loss. Our data describe the role of JNK-dependent endothelial nitric oxide synthase-mediated nitric oxide for anti-CML activity of HCH and this molecule merits further testing in pre-clinical and clinical settings. © 2011 Japanese Cancer Association.

  9. Asiatic acid attenuates methamphetamine-induced neuroinflammation and neurotoxicity through blocking of NF-kB/STAT3/ERK and mitochondria-mediated apoptosis pathway.

    Science.gov (United States)

    Park, Ji-Hyun; Seo, Young Ho; Jang, Jung-Hee; Jeong, Chul-Ho; Lee, Sooyeun; Park, Byoungduck

    2017-12-11

    Methamphetamine (METH) is a commonly abused drug that may result in neurotoxic effects. Recent studies have suggested that involvement of neuroinflammatory processes in brain dysfunction is induced by misuse of this drug. However, the mechanism underlying METH-induced inflammation and neurotoxicity in neurons is still unclear. In this study, we investigated whether asiatic acid (AA) effected METH-mediated neuroinflammation and neurotoxicity in dopaminergic neuronal cells. And we further determined whether the effect involved in the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and signal transducer and activator of transcription (STAT)3 and extracellular signal-regulated kinase (ERK) pathway. We used the human dopaminergic neuroblastoma SH-SY5Y cell line, murine microglial BV2 cell line, and primary culture of rat embryo mesencephalic neurons. Pro-inflammatory cytokine production was monitored by ELISA and RT/real-time PCR. The cell cycle distribution and mitochondrial membrane integrity was analyzed by flow cytometry. We used immunoblotting, DNA-binding activity, and immunofluorescence staining to analyze the effect of AA on activation of the NF-κB, STAT3, MAPK-ERK, and apoptosis signaling pathways. METH induced TNF receptor (TNFR) expression and led to morphological changes of cells. Additionally, this drug increased pro-inflammatory cytokine (TNFα and IL-6) expression. AA significantly suppressed METH-induced TNFR expression in concentration dependent. Increased secretion of TNFα and IL-6 was inhibited in METH-stimulated neuronal cells by AA administration. AA showed significant protection against METH-induced translocation of NF-κB/STAT3 and ERK phosphorylation. AA inhibited METH-induced proteolytic fragmentation of caspase-3 and PARP. The pro-apoptotic protein Bax was significantly decreased, while the anti-apoptotic protein Bcl-xL was increased by AA treatment in METH-stimulated cells. A similar protective effect of AA on

  10. Eosinophil Resistance to Glucocorticoid-Induced Apoptosis is Mediated by the Transcription Factor NFIL3

    Science.gov (United States)

    Pazdrak, Konrad; Moon, Young; Straub, Christof; Stafford, Susan; Kurosky, Alexander

    2016-01-01

    The mainstay of asthma therapy, glucocorticoids (GCs) exert their therapeutic effects through the inhibition of inflammatory signaling and induction of eosinophil apoptosis. However, laboratory and clinical observations of GC-resistant asthma suggest that GCs' effects on eosinophil viability may depend on the state of eosinophil activation. In the present study we demonstrate that eosinophils stimulated with IL-5 show impaired prop-aptoptotic response to GCs. We sought to determine the contribution of GC-mediated transactivating (TA) and transrepressing (TR) pathways in modulation of activated eosinophils' response to GC by comparing their response to the selective GC receptor (GR) agonist Compound A (CpdA) devoid of TA activity to that upon treatment with Dexamethasone (Dex). IL-5-activated eosinophils showed contrasting responses to CpdA and Dex, as IL-5-treated eosinophils showed no increase in apoptosis compared to cells treated with Dex alone, while CpdA elicited an apoptotic response regardless of IL-5 stimulation. Proteomic analysis revealed that both Nuclear Factor IL-3 (NFIL3) and Map Kinase Phosphatase 1 (MKP1) were inducible by IL-5 and enhanced by Dex; however, CpdA had no effect on NFIL3 and MKP1 expression. We found that inhibiting NFIL3 with specific siRNA or by blocking the IL-5-inducible Pim-1 kinase abrogated the protective effect of IL-5 on Dex-induced apoptosis, indicating crosstalk between IL-5 anti-apoptotic pathways and GR-mediated TA signaling occurring via the NFIL3 molecule. Collectively, these results indicate that 1) GCs' TA pathway may support eosinophil viability in IL-5-stimulated cells through synergistic upregulation of NFIL3; and 2) functional inhibition of IL-5 signaling (anti-Pim1) or the use of selective GR agonists that don't upregulate NFIL3 may be effective strategies for the restoring pro-apoptotic effect of GCs on IL-5-activated eosinophils. PMID:26880402

  11. Immune-relevant thrombocytes of common carp undergo parasite-induced nitric oxide-mediated apoptosis.

    Science.gov (United States)

    Fink, Inge R; Ribeiro, Carla M S; Forlenza, Maria; Taverne-Thiele, Anja; Rombout, Jan H W M; Savelkoul, Huub F J; Wiegertjes, Geert F

    2015-06-01

    Common carp thrombocytes account for 30-40% of peripheral blood leukocytes and are abundant in the healthy animals' spleen, the thrombopoietic organ. We show that, ex vivo, thrombocytes from healthy carp express a large number of immune-relevant genes, among which several cytokines and Toll-like receptors, clearly pointing at immune functions of carp thrombocytes. Few studies have described the role of fish thrombocytes during infection. Carp are natural host to two different but related protozoan parasites, Trypanoplasma borreli and Trypanosoma carassii, which reside in the blood and tissue fluids. We used the two parasites to undertake controlled studies on the role of fish thrombocytes during these infections. In vivo, but only during infection with T. borreli, thrombocytes were massively depleted from the blood and spleen leading to severe thrombocytopenia. Ex vivo, addition of nitric oxide induced a clear and rapid apoptosis of thrombocytes from healthy carp, supporting a role for nitric oxide-mediated control of immune-relevant thrombocytes during infection with T. borreli. The potential advantage for parasites to selectively deplete the host of thrombocytes via nitric oxide-induced apoptosis is discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. The Green Tea Component (--Epigallocatechin-3-Gallate Sensitizes Primary Endothelial Cells to Arsenite-Induced Apoptosis by Decreasing c-Jun N-Terminal Kinase-Mediated Catalase Activity.

    Directory of Open Access Journals (Sweden)

    Jee-Youn Kim

    Full Text Available The green tea component (--epigallocatechin-3-gallate (EGCG has been shown to sensitize many different types of cancer cells to anticancer drug-induced apoptosis, although it protects against non-cancerous primary cells against toxicity from certain conditions such as exposure to arsenic (As or ultraviolet irradiation. Here, we found that EGCG promotes As-induced toxicity of primary-cultured bovine aortic endothelial cells (BAEC at doses in which treatment with each chemical alone had no such effect. Increased cell toxicity was accompanied by an increased condensed chromatin pattern and fragmented nuclei, cleaved poly(ADP-ribose polymerase (PARP, activity of the pro-apoptotic enzymes caspases 3, 8 and 9, and Bax translocation into mitochondria, suggesting the involvement of an apoptotic signaling pathway. Fluorescence activated cell sorting analysis revealed that compared with EGCG or As alone, combined EGCG and As (EGCG/As treatment significantly induced production of reactive oxygen species (ROS, which was accompanied by decreased catalase activity and increased lipid peroxidation. Pretreatment with N-acetyl-L-cysteine or catalase reversed EGCG/As-induced caspase activation and EC toxicity. EGCG/As also increased the phosphorylation of c-Jun N-terminal kinase (JNK, which was not reversed by catalase. However, pretreatment with the JNK inhibitor SP600125 reversed all of the observed effects of EGCG/As, suggesting that JNK may be the most upstream protein examined in this study. Finally, we also found that all the observed effects by EGCG/As are true for other types of EC tested. In conclusion, this is firstly to show that EGCG sensitizes non-cancerous EC to As-induced toxicity through ROS-mediated apoptosis, which was attributed at least in part to a JNK-activated decrease in catalase activity.

  13. The Green Tea Component (-)-Epigallocatechin-3-Gallate Sensitizes Primary Endothelial Cells to Arsenite-Induced Apoptosis by Decreasing c-Jun N-Terminal Kinase-Mediated Catalase Activity.

    Science.gov (United States)

    Kim, Jee-Youn; Choi, Ji-Young; Lee, Hyeon-Ju; Byun, Catherine Jeonghae; Park, Jung-Hyun; Park, Jae Hoon; Cho, Ho-Seong; Cho, Sung-Jin; Jo, Sangmee Ahn; Jo, Inho

    2015-01-01

    The green tea component (-)-epigallocatechin-3-gallate (EGCG) has been shown to sensitize many different types of cancer cells to anticancer drug-induced apoptosis, although it protects against non-cancerous primary cells against toxicity from certain conditions such as exposure to arsenic (As) or ultraviolet irradiation. Here, we found that EGCG promotes As-induced toxicity of primary-cultured bovine aortic endothelial cells (BAEC) at doses in which treatment with each chemical alone had no such effect. Increased cell toxicity was accompanied by an increased condensed chromatin pattern and fragmented nuclei, cleaved poly(ADP-ribose) polymerase (PARP), activity of the pro-apoptotic enzymes caspases 3, 8 and 9, and Bax translocation into mitochondria, suggesting the involvement of an apoptotic signaling pathway. Fluorescence activated cell sorting analysis revealed that compared with EGCG or As alone, combined EGCG and As (EGCG/As) treatment significantly induced production of reactive oxygen species (ROS), which was accompanied by decreased catalase activity and increased lipid peroxidation. Pretreatment with N-acetyl-L-cysteine or catalase reversed EGCG/As-induced caspase activation and EC toxicity. EGCG/As also increased the phosphorylation of c-Jun N-terminal kinase (JNK), which was not reversed by catalase. However, pretreatment with the JNK inhibitor SP600125 reversed all of the observed effects of EGCG/As, suggesting that JNK may be the most upstream protein examined in this study. Finally, we also found that all the observed effects by EGCG/As are true for other types of EC tested. In conclusion, this is firstly to show that EGCG sensitizes non-cancerous EC to As-induced toxicity through ROS-mediated apoptosis, which was attributed at least in part to a JNK-activated decrease in catalase activity.

  14. Apoptosis in mammalian oocytes: a review.

    Science.gov (United States)

    Tiwari, Meenakshi; Prasad, Shilpa; Tripathi, Anima; Pandey, Ashutosh N; Ali, Irfan; Singh, Arvind K; Shrivastav, Tulsidas G; Chaube, Shail K

    2015-08-01

    Apoptosis causes elimination of more than 99% of germ cells from cohort of ovary through follicular atresia. Less than 1% of germ cells, which are culminated in oocytes further undergo apoptosis during last phases of oogenesis and depletes ovarian reserve in most of the mammalian species including human. There are several players that induce apoptosis directly or indirectly in oocytes at various stages of meiotic cell cycle. Premature removal of encircling granulosa cells from immature oocytes, reduced levels of adenosine 3',5'-cyclic monophosphate and guanosine 3',5'-cyclic monophosphate, increased levels of calcium (Ca(2+)) and oxidants, sustained reduced level of maturation promoting factor, depletion of survival factors, nutrients and cell cycle proteins, reduced meiotic competency, increased levels of proapoptotic as well as apoptotic factors lead to oocyte apoptosis. The BH3-only proteins also act as key regulators of apoptosis in oocyte within the ovary. Both intrinsic (mitochondria-mediated) as well as extrinsic (cell surface death receptor-mediated) pathways are involved in oocyte apoptosis. BID, a BH3-only protein act as a bridge between both apoptotic pathways and its cleavage activates cell death machinery of both the pathways inside the follicular microenvironment. Oocyte apoptosis leads to the depletion of ovarian reserve that directly affects reproductive outcome of various mammals including human. In this review article, we highlight some of the important players and describe the pathways involved during oocyte apoptosis in mammals.

  15. Pivotal roles of p53 transcription-dependent and -independent pathways in manganese-induced mitochondrial dysfunction and neuronal apoptosis

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    Wan, Chunhua [Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong 226019 Jiangsu (China); Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong 226019 Jiangsu (China); Ma, Xa; Shi, Shangshi [Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019 Jiangsu (China); Zhao, Jianya; Nie, Xiaoke [Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong 226019 Jiangsu (China); Han, Jingling; Xiao, Jing; Wang, Xiaoke [Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019 Jiangsu (China); Jiang, Shengyang [Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong 226019 Jiangsu (China); Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong 226019 Jiangsu (China); Jiang, Junkang, E-mail: Jiang_junkang@163.com [Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019 Jiangsu (China); Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong 226019 Jiangsu (China)

    2014-12-15

    Chronic exposure to excessive manganese (Mn) has been known to lead to neuronal loss and a clinical syndrome resembling idiopathic Parkinson's disease (IPD). p53 plays an integral role in the development of various human diseases, including neurodegenerative disorders. However, the role of p53 in Mn-induced neuronal apoptosis and neurological deficits remains obscure. In the present study, we showed that p53 was critically involved in Mn-induced neuronal apoptosis in rat striatum through both transcription-dependent and -independent mechanisms. Western blot and immunohistochemistrical analyses revealed that p53 was remarkably upregulated in the striatum of rats following Mn exposure. Coincidentally, increased level of cleaved PARP, a hallmark of apoptosis, was observed. Furthermore, using nerve growth factor (NGF)-differentiated PC12 cells as a neuronal cell model, we showed that Mn exposure decreased cell viability and induced apparent apoptosis. Importantly, p53 was progressively upregulated, and accumulated in both the nucleus and the cytoplasm. The cytoplasmic p53 had a remarkable distribution in mitochondria, suggesting an involvement of p53 mitochondrial translocation in Mn-induced neuronal apoptosis. In addition, Mn-induced impairment of mitochondrial membrane potential (ΔΨm) could be partially rescued by pretreatment with inhibitors of p53 transcriptional activity and p53 mitochondrial translocation, Pifithrin-α (PFT-α) and Pifithrin-μ (PFT-μ), respectively. Moreover, blockage of p53 activities with PFT-α and PFT-μ significantly attenuated Mn-induced reactive oxidative stress (ROS) generation and mitochondrial H{sub 2}O{sub 2} production. Finally, we observed that pretreatment with PFT-α and PFT-μ ameliorated Mn-induced apoptosis in PC12 cells. Collectively, these findings implicate that p53 transcription-dependent and -independent pathways may play crucial roles in the regulation of Mn-induced neuronal death. - Highlights: • p53 is

  16. Pivotal roles of p53 transcription-dependent and -independent pathways in manganese-induced mitochondrial dysfunction and neuronal apoptosis

    International Nuclear Information System (INIS)

    Wan, Chunhua; Ma, Xa; Shi, Shangshi; Zhao, Jianya; Nie, Xiaoke; Han, Jingling; Xiao, Jing; Wang, Xiaoke; Jiang, Shengyang; Jiang, Junkang

    2014-01-01

    Chronic exposure to excessive manganese (Mn) has been known to lead to neuronal loss and a clinical syndrome resembling idiopathic Parkinson's disease (IPD). p53 plays an integral role in the development of various human diseases, including neurodegenerative disorders. However, the role of p53 in Mn-induced neuronal apoptosis and neurological deficits remains obscure. In the present study, we showed that p53 was critically involved in Mn-induced neuronal apoptosis in rat striatum through both transcription-dependent and -independent mechanisms. Western blot and immunohistochemistrical analyses revealed that p53 was remarkably upregulated in the striatum of rats following Mn exposure. Coincidentally, increased level of cleaved PARP, a hallmark of apoptosis, was observed. Furthermore, using nerve growth factor (NGF)-differentiated PC12 cells as a neuronal cell model, we showed that Mn exposure decreased cell viability and induced apparent apoptosis. Importantly, p53 was progressively upregulated, and accumulated in both the nucleus and the cytoplasm. The cytoplasmic p53 had a remarkable distribution in mitochondria, suggesting an involvement of p53 mitochondrial translocation in Mn-induced neuronal apoptosis. In addition, Mn-induced impairment of mitochondrial membrane potential (ΔΨm) could be partially rescued by pretreatment with inhibitors of p53 transcriptional activity and p53 mitochondrial translocation, Pifithrin-α (PFT-α) and Pifithrin-μ (PFT-μ), respectively. Moreover, blockage of p53 activities with PFT-α and PFT-μ significantly attenuated Mn-induced reactive oxidative stress (ROS) generation and mitochondrial H 2 O 2 production. Finally, we observed that pretreatment with PFT-α and PFT-μ ameliorated Mn-induced apoptosis in PC12 cells. Collectively, these findings implicate that p53 transcription-dependent and -independent pathways may play crucial roles in the regulation of Mn-induced neuronal death. - Highlights: • p53 is robustly

  17. Autophagy activation promotes removal of damaged mitochondria and protects against renal tubular injury induced by albumin overload.

    Science.gov (United States)

    Tan, Jin; Wang, Miaohong; Song, Shuling; Miao, Yuyang; Zhang, Qiang

    2018-01-10

    Proteinuria (albuminuria) is an important cause of aggravating tubulointerstitial injury. Previous studies have shown that autophagy activation can alleviate renal tubular epithelial cell injury caused by urinary protein, but the mechanism is not clear. Here, we investigated the role of clearance of damaged mitochondria in this protective effect. We found that albumin overload induces a significant increase in turnover of LC3-II and decrease in p62 protein level in renal proximal tubular (HK-2) cells in vitro. Albumin overload also induces an increase in mitochondrial damage. ALC, a mitochondrial torpent, alleviates mitochondrial damage induced by albumin overload and also decreases autophagy, while mitochondrial damage revulsant CCCP further increases autophagy. Furthermore, pretreatment of HK-2 cells with rapamycin reduced the amount of damaged mitochondria and the level of apoptosis induced by albumin overload. In contrast, blocking autophagy with chloroquine exerted an opposite effect. Taken together, our results indicated autophagy activation promotes removal of damaged mitochondria and protects against renal tubular injury caused by albumin overload. This further confirms previous research that autophagy activation is an adaptive response in renal tubular epithelial cells after urinary protein overload.

  18. Xanthurenic acid translocates proapoptotic Bcl-2 family proteins into mitochondria and impairs mitochondrial function

    Directory of Open Access Journals (Sweden)

    Hess Otto M

    2004-04-01

    Full Text Available Abstract Background Xanthurenic acid is an endogenous molecule produced by tryptophan degradation, produced in the cytoplasm and mitochondria. Its accumulation can be observed in aging-related diseases, e.g. senile cataract and infectious disease. We previously reported that xanthurenic acid provokes apoptosis, and now present a study of the response of mitochondria to xanthurenic acid. Results Xanthurenic acid at 10 or 20 μM in culture media of human aortic smooth muscle cells induces translocation of the proteins Bax, Bak, Bclxs, and Bad into mitochondria. In 20 μM xanthurenic acid, Bax is also translocated to the nucleus. In isolated mitochondria xanthurenic acid leads to Bax and Bclxs oligomerization, accumulation of Ca2+, and increased oxygen consumption. Conclusion Xanthurenic acid interacts directly with Bcl-2 family proteins, inducing mitochondrial pathways of apoptosis and impairing mitochondrial functions.

  19. Curcumin attenuates oxidative stress induced NFκB mediated inflammation and endoplasmic reticulum dependent apoptosis of splenocytes in diabetes.

    Science.gov (United States)

    Rashid, Kahkashan; Chowdhury, Sayantani; Ghosh, Sumit; Sil, Parames C

    2017-11-01

    The present study was aimed to determine the curative role of curcumin against diabetes induced oxidative stress and its associated splenic complications. Diabetes was induced in the experimental rats via the intraperitoneal administration of a single dose of STZ (65mgkg -1 body weight). Increased blood glucose and intracellular ROS levels along with decreased body weight, the activity of cellular antioxidant enzymes and GSH/GSSG ratio were observed in the diabetic animals. Histological assessment showed white pulp depletion and damaged spleen anatomy in these animals. Oral administration of curcumin at a dose of 100mgkg -1 body weight daily for 8weeks, however, restored these alterations. Investigation of the mechanism of hyperglycemia induced oxidative stress mediated inflammation showed upregulation of inflammatory cytokines, chemokines, adhesion molecules and increased translocation of NFκB into the nucleus. Moreover, ER stress dependent cell death showed induction of eIF2α and CHOP mediated signalling pathways as well as increment in the expression of GRP78, Caspase-12, Calpain-1, phospho JNK, phospho p38 and phospho p53 in the diabetic group. Alteration of Bax/Bcl-2 ratio; disruption of mitochondrial membrane potential, release of cytochrome-C from mitochondria and upregulation of caspase 3 along with the formation of characteristic DNA ladder in the diabetic animals suggest the involvement of mitochondria dependent apoptotic pathway in the splenic cells. Treatment with curcumin could, however, protect cells from inflammatory damage and ER as well as mitochondrial apoptotic death by restoring the alterations of these parameters. Our results suggest that curcumin has the potential to act as an anti-diabetic, anti-oxidant, anti-inflammatory and anti-apoptotic therapeutic against diabetes mediated splenic damage. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Radiation-induced apoptosis

    International Nuclear Information System (INIS)

    Ohyama, Harumi

    1995-01-01

    Apoptosis is an active process of gene-directed cellular self-destruction that can be induced in many cell types via numerous physiological and pathological stimuli. We found that interphasedeath of thymocytes is a typical apoptosis showing the characteristic features of apoptosis including cell shrinkage, chromatin condensation and DNA degradation. Moderate dose of radiation induces extensive apoptosis in rapidly proliferating cell population such as the epithelium of intestinal crypt. Recent reports indicate that the ultimate form of radiation-induced mitotic death in several cells is also apoptosis. One of the hallmarks of apoptosis is the enzymatic internucleosomal degradation of chromatin DNA. We identified an endonuclease responsible for the radiation-induced DNA degradation in rat thymocytes. The death-sparing effects of interrupting RNA and protein synthesis suggested a cell genetic program for apoptosis. Apoptosis of thymocytes initiated by DNA damage, such as radiation and radio mimetic substance, absolutely requires the protein of p53 cancer suppresser gene. The cell death induced by glucocorticoid, or aging, has no such requirement. Expression of oncogene bcl-2 rescues cells from the apoptosis. Massive apoptosis in radiosensitive cells induced by higher dose radiation may be fatal. It is suggested that selective apoptotic elimination of cells would play an important role for protection against carcinogenesis and malformation through removal of cells with unrepaired radiation-induced DNA damages. Data to evaluate the significance of apoptosis in the radiation risk are still poor. Further research should be done in order to clarify the roles of the cell death on the acute and late effects of irradiation. (author)

  1. Valsartan reduces AT1-AA-induced apoptosis through suppression oxidative stress mediated ER stress in endothelial progenitor cells.

    Science.gov (United States)

    Wang, Z-C; Qi, J; Liu, L-M; Li, J; Xu, H-Y; Liang, B; Li, B

    2017-03-01

    Valsartan has been reported to have the function of treating hypertension and improving the prognosis of patients. Many studies indicated that valsartan can also increase angiotensin II, andosterone and plasma renin activity (PRA). Autoantibodies against the angiotensin II type 1 receptor (AT1-AA) have been showed to increase reactive oxygen species (ROS) and calcium (Ca2+) and result in apoptosis in vascular smooth muscle cells. In this study, we attempted to explore the effect of valsartan on AT1-AA-induced apoptosis in endothelial progenitor cells. Endothelial progenitor cells (EPCs) were cultured. The cytotoxicity was determined by MTT assay. EPCs apoptosis was determined by DAPI staining and flow cytometry. Reactive oxygen species, intracellular calcium concentration and calpain activity were measured using Fluostar Omega Spectrofluorimeter. The expression of p-ERK, p-eIF-2a, CHOP, Bcl-2 and caspase-3 were detected by Western blot. MTT assays showed valsartan significantly inhibited AT1-AA- induced decline of the viability of EPCs. DAPI staining and flow cytometry results indicated valsartan inhibited AT1-AA-induced decline of the viability of EPCs via inhibiting AT1-AA-induced apoptosis. Furthermore, the increasing of reactive oxygen species, intracellular calcium and calpain activity induced by AT1-AA in EPCs were also recovered after pre-treated with valsartan. Meanwhile, the upregulation of p-ERK, p-eIF-2a and CHOP, downregulation of Bcl-2, and activation of Caspase-3 caused by AT1-AA were reversed after pre-incubated with valsartan. Valsartan could inhibit AT1-AA-induced apoptosis through inhibiting oxidative stress mediated ER stress in EPCs.

  2. Dose-dependent folic acid and memantine treatments promote synergistic or additive protection against Aβ(25-35) peptide-induced apoptosis in SH-SY5Y cells mediated by mitochondria stress-associated death signals.

    Science.gov (United States)

    Chen, Ta-Fu; Tang, Ming-Chi; Chou, Chia-Hui; Chiu, Ming-Jang; Huang, R-F S

    2013-12-01

    Increased dietary folic acid (FA) is associated with reduced risks of Alzheimer's disease (AD). The AD drug memantine (Mn) has had limited therapeutic effects for the treatment of patients with moderate to severe AD. This study investigated whether and the underlying mechanisms by which the combination of Mn and FA may have synergistic or additive effects in protecting against amyloid-β(25-35) peptide (Aβ)-induced neurocytotoxicity. Aβ treatment of human neuroblastoma SH-SY5Y cells significantly induced a 6-fold increase of apoptotic cells compared with the Aβ-untreated group. Preincubation of Aβ-exposed cells with FA (500 μM) or Mn (20 μM) caused a 22% and 10% reduction of apoptotic cells, respectively, whereas the combo-treatments at such doses synergistically alleviated Aβ-induced apoptosis by 60% (P<0.05). The apoptotic protection by the combo-treatments coincided with attenuating Aβ-elicited mitochondrial (mt) membrane depolarization and abolishing Aβ-induced mt cytochrome c release to the cytosol. Increased levels of FA at 1000 μM in combination with 20 μM Mn exerted an additive protection against Aβ(25-35)-induced-apoptosis as compared to the isolate Mn group (P<0.05). The combo-treatments reversed Aβ-elicited mt membrane depolarization, attenuated Aβ-elicited mt cytochrome c release to the cytosol, and diminished Aβ-promoted superoxide generation. The apoptotic-protection by such combo-treatments was partially abolished by carbonyl cyanide 3-chlorophenylhydrazone (mt membrane potential uncoupler) and sodium azide (mt cytochrome c oxidase inhibitor). Taken together, the data demonstrated that dose-dependent FA and Mn synergistically or additively protected SH-SY5Y cells against Aβ-induced apoptosis, which was partially, if not completely, mediated by mt stress-associated death signals. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Extracellular anti-angiogenic proteins augment an endosomal protein trafficking pathway to reach mitochondria and execute apoptosis in HUVECs.

    Science.gov (United States)

    Chen, Mo; Qiu, Tao; Wu, Jiajie; Yang, Yang; Wright, Graham D; Wu, Min; Ge, Ruowen

    2018-03-09

    Classic endocytosis destinations include the recycling endosome returning to the plasma membrane or the late endosome (LE) merging with lysosomes for cargo degradation. However, the anti-angiogenic proteins angiostatin and isthmin, are endocytosed and trafficked to mitochondria (Mito) to execute apoptosis of endothelial cells. How these extracellular proteins reach mitochondria remains a mystery. Through confocal and super-resolution fluorescent microscopy, we demonstrate that angiostatin and isthmin are trafficked to mitochondria through the interaction between LE and Mito. Using purified organelles, the LE-Mito interaction is confirmed through in vitro lipid-fusion assay, as well as single vesicle total internal reflection fluorescent microscopy. LE-Mito interaction enables the transfer of not only lipids but also proteins from LE to Mito. Angiostatin and isthmin augment this endosomal protein trafficking pathway and make use of it to reach mitochondria to execute apoptosis. Cell fractionation and biochemical analysis identified that the cytosolic scaffold protein Na+/H+ exchanger regulatory factor 1 (NHERF1) associated with LE and the t-SNARE protein synaptosome-associated protein 25 kDa (SNAP25) associated with Mito form an interaction complex to facilitate LE-Mito interaction. Proximity ligation assay coupled with fluorescent microscopy showed that both NHERF1 and SNAP25 are located at the contacting face between LE and Mito. RNAi knockdown of either NHERF1 or SNAP25 suppressed not only the mitochondrial trafficking of angiostatin and isthmin but also their anti-angiogenic and pro-apoptotic functions. Hence, this study reveals a previously unrealized endosomal protein trafficking pathway from LE to Mito that allows extracellular proteins to reach mitochondria and execute apoptosis.

  4. Deoxyelephantopin from Elephantopus scaber L. induces cell-cycle arrest and apoptosis in the human nasopharyngeal cancer CNE cells

    International Nuclear Information System (INIS)

    Su, Miaoxian; Chung, Hau Yin; Li, Yaolan

    2011-01-01

    Highlights: → Deoxyelephantopin (ESD) inhibited cell proliferation in the human nasopharyngeal cancer CNE cells. → ESD induced cell cycle arrest in S and G2/M phases via modulation of cell cycle regulatory proteins. → ESD triggered apoptosis by dysfunction of mitochondria and induction of both intrinsic and extrinsic apoptotic signaling pathways. → ESD also triggered Akt, ERK, and JNK signaling pathways. -- Abstract: Deoxyelephantopin (ESD), a naturally occurring sesquiterpene lactone present in the Chinese medicinal herb, Elephantopus scaber L. exerted anticancer effects on various cultured cancer cells. However, the cellular mechanisms by which it controls the development of the cancer cells are unavailable, particularly the human nasopharyngeal cancer CNE cells. In this study, we found that ESD inhibited the CNE cell proliferation. Cell cycle arrest in S and G2/M phases was also found. Western blotting analysis showed that modulation of cell cycle regulatory proteins was responsible for the ESD-induced cell cycle arrest. Besides, ESD also triggered apoptosis in CNE cells. Dysfunction in mitochondria was found to be associated with the ESD-induced apoptosis as evidenced by the loss of mitochondrial membrane potential (ΔΨm), the translocation of cytochrome c, and the regulation of Bcl-2 family proteins. Despite the Western blotting analysis showed that both intrinsic and extrinsic apoptotic pathways (cleavage of caspases-3, -7, -8, -9, and -10) were triggered in the ESD-induced apoptosis, additional analysis also showed that the induction of apoptosis could be achieved by the caspase-independent manner. Besides, Akt, ERK and JNK pathways were found to involve in ESD-induced cell death. Overall, our findings provided the first evidence that ESD induced cell cycle arrest, and apoptosis in CNE cells. ESD could be a potential chemotherapeutic agent in the treatment of nasopharyngeal cancer (NPC).

  5. Deoxyelephantopin from Elephantopus scaber L. induces cell-cycle arrest and apoptosis in the human nasopharyngeal cancer CNE cells

    Energy Technology Data Exchange (ETDEWEB)

    Su, Miaoxian [Biology Programme (Formally Biology Dept.), School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR (China); Chung, Hau Yin, E-mail: anthonychung@cuhk.edu.hk [Biology Programme (Formally Biology Dept.), School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR (China); Food and Nutritional Sciences Programme, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR (China); Li, Yaolan [Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou (China); Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drug Research, Guangzhou (China)

    2011-07-29

    Highlights: {yields} Deoxyelephantopin (ESD) inhibited cell proliferation in the human nasopharyngeal cancer CNE cells. {yields} ESD induced cell cycle arrest in S and G2/M phases via modulation of cell cycle regulatory proteins. {yields} ESD triggered apoptosis by dysfunction of mitochondria and induction of both intrinsic and extrinsic apoptotic signaling pathways. {yields} ESD also triggered Akt, ERK, and JNK signaling pathways. -- Abstract: Deoxyelephantopin (ESD), a naturally occurring sesquiterpene lactone present in the Chinese medicinal herb, Elephantopus scaber L. exerted anticancer effects on various cultured cancer cells. However, the cellular mechanisms by which it controls the development of the cancer cells are unavailable, particularly the human nasopharyngeal cancer CNE cells. In this study, we found that ESD inhibited the CNE cell proliferation. Cell cycle arrest in S and G2/M phases was also found. Western blotting analysis showed that modulation of cell cycle regulatory proteins was responsible for the ESD-induced cell cycle arrest. Besides, ESD also triggered apoptosis in CNE cells. Dysfunction in mitochondria was found to be associated with the ESD-induced apoptosis as evidenced by the loss of mitochondrial membrane potential ({Delta}{Psi}m), the translocation of cytochrome c, and the regulation of Bcl-2 family proteins. Despite the Western blotting analysis showed that both intrinsic and extrinsic apoptotic pathways (cleavage of caspases-3, -7, -8, -9, and -10) were triggered in the ESD-induced apoptosis, additional analysis also showed that the induction of apoptosis could be achieved by the caspase-independent manner. Besides, Akt, ERK and JNK pathways were found to involve in ESD-induced cell death. Overall, our findings provided the first evidence that ESD induced cell cycle arrest, and apoptosis in CNE cells. ESD could be a potential chemotherapeutic agent in the treatment of nasopharyngeal cancer (NPC).

  6. Single-cell analysis of dihydroartemisinin-induced apoptosis through reactive oxygen species-mediated caspase-8 activation and mitochondrial pathway in ASTC-a-1 cells using fluorescence imaging techniques

    Science.gov (United States)

    Lu, Ying-Ying; Chen, Tong-Sheng; Wang, Xiao-Ping; Li, Li

    2010-07-01

    Dihydroartemisinin (DHA), a front-line antimalarial herbal compound, has been shown to possess promising anticancer activity with low toxicity. We have previously reported that DHA induced caspase-3-dependent apoptosis in human lung adenocarcinoma cells. However, the cellular target and molecular mechanism of DHA-induced apoptosis is still poorly defined. We use confocal fluorescence microscopy imaging, fluorescence resonance energy transfer, and fluorescence recovery after photobleaching techniques to explore the roles of DHA-elicited reactive oxygen species (ROS) in the DHA-induced Bcl-2 family proteins activation, mitochondrial dysfunction, caspase cascade, and cell death. Cell Counting Kit-8 assay and flow cytometry analysis showed that DHA induced ROS-mediated apoptosis. Confocal imaging analysis in a single living cell and Western blot assay showed that DHA triggered ROS-dependent Bax translocation, mitochondrial membrane depolarization, alteration of mitochondrial morphology, cytochrome c release, caspase-9, caspase-8, and caspase-3 activation, indicating the coexistence of ROS-mediated mitochondrial and death receptor pathway. Collectively, our findings demonstrate for the first time that DHA induces cell apoptosis by triggering ROS-mediated caspase-8/Bid activation and the mitochondrial pathway, which provides some novel insights into the application of DHA as a potential anticancer drug and a new therapeutic strategy by targeting ROS signaling in lung adenocarcinoma therapy in the future.

  7. Protective Effects of Hesperidin (Citrus Flavonone on High Glucose Induced Oxidative Stress and Apoptosis in a Cellular Model for Diabetic Retinopathy

    Directory of Open Access Journals (Sweden)

    Wayne Young Liu

    2017-12-01

    Full Text Available The aim of this study was to investigate the protective effects and mechanisms of hesperidin, a plant based active flavanone found in citrus fruits, under the oxidative stress and apoptosis induced by high levels of glucose in retinal ganglial cells (RGCs. RGC-5 cells were pretreated with hesperidin (12.5, 25, or 50 μmol/L for 6 h followed by exposure to high (33.3 mmol/L d-glucose for 48 h. The 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay was adopted to evaluate cell viability. Mitochondrial function was estimated by measuring the mitochondrial membrane potential (ΔΨm. A fluorescent probe was employed to evaluate the intercellular production of reactive oxygen species (ROS. Colorimetric assay kits were used to evaluate lipid peroxidation, antioxidant enzyme activities, and protein carbonyls formation. The expression of apoptosis-related proteins and mitogen-activated protein kinase (MAPK were measured with Western blotting. Hesperidin inhibited high glucose-mediated cell loss and restored mitochondrial function including a reversion of ΔΨm loss and cytochrome c release. Treated with hesperidin, high glucose-induced increase in ROS, malondialdehyde, and protein carbonyl levels were blocked in RGC-5 cells. Hesperidin was found to elevate the activities of superoxide dismutase, catalase, glutathione peroxidase, and to recover glutathione levels. Hesperidin inhibited high glucose-induced cell apoptosis by attenuating the downregulation of caspase-9, caspase-3, and Bax/Bcl-2. Furthermore, the phosphorylation of c-Jun N-terminal kinases (JNK and p38 MAPK triggered by high glucose were attenuated in RGC-5 cells after their incubation with hesperdin. We concluded that hesperidin may protect RGC-5 cells from high glucose-induced injury since it owns the properties of antioxidant action and blocks mitochondria-mediated apoptosis.

  8. 17-AAG sensitized malignant glioma cells to death-receptor mediated apoptosis.

    Science.gov (United States)

    Siegelin, Markus David; Habel, Antje; Gaiser, Timo

    2009-02-01

    17-AAG is a selective HSP90-inhibitor that exhibited therapeutic activity in cancer. In this study three glioblastoma cell lines (U87, LN229 and U251) were treated with 17-AAG, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or the combination of both. Treatment with subtoxic doses of 17-AAG in combination with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces rapid apoptosis in TRAIL-resistant glioma cells, suggesting that this combined treatment may offer an attractive strategy for treating gliomas. 17-AAG treatment down-regulated survivin through proteasomal degradation. In addition, over-expression of survivin attenuated cytotoxicity induced by the combination of 17-AAG and TRAIL. In summary, survivin is a key regulator of TRAIL-17-AAG mediated cell death in malignant glioma.

  9. Calreticulin is a fine tuning molecule in epibrassinolide-induced apoptosis through activating endoplasmic reticulum stress in colon cancer cells.

    Science.gov (United States)

    Obakan-Yerlikaya, Pinar; Arisan, Elif Damla; Coker-Gurkan, Ajda; Adacan, Kaan; Ozbey, Utku; Somuncu, Berna; Baran, Didem; Palavan-Unsal, Narcin

    2017-06-01

    Epibrassinolide (EBR), a member of brassinostreoids plant hormones with cell proliferation promoting role in plants, is a natural polyhydroxysteroid with structural similarity to steroid hormones of vertebrates. EBR has antiproliferative and apoptosis-inducing effect in various cancer cells. Although EBR has been shown to affect survival and mitochondria-mediated apoptosis pathways in a p53-independent manner, the exact molecular targets of EBR are still under investigation. Our recent SILAC (Stable Isotope Labeling by Amino Acids in Cell Culture) data showed that the most significantly altered protein after EBR treatment was calreticulin (CALR). CALR, a chaperone localized in endoplasmic reticulum (ER) lumen, plays role in protein folding and buffering Ca 2+ ions. The alteration of CALR may cause ER stress and unfolded protein response correspondingly the induction of apoptosis. Unfolded proteins are conducted to 26S proteasomal degradation following ubiquitination. Our study revealed that EBR treatment caused ER stress and UPR by altering CALR expression causing caspase-dependent apoptosis in HCT 116, HT29, DLD-1, and SW480 colon cancer cells. Furthermore, 48 h EBR treatment did not caused UPR in Fetal Human Colon cells (FHC) and Mouse Embryonic Fibroblast cells (MEF). In addition our findings showed that HCT 116 colon cancer cells lacking Bax and Puma expression still undergo UPR and related apoptosis. CALR silencing and rapamycin co-treatment prevented EBR-induced UPR and apoptosis, whereas 26S proteasome inhibition further increased the effect of EBR in colon cancer cells. All these findings showed that EBR is an ER stress and apoptotic inducer in colon cancer cells without affecting non-malignant cells. © 2017 Wiley Periodicals, Inc.

  10. Isoorientin induces apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cancer cells

    International Nuclear Information System (INIS)

    Yuan, Li; Wang, Jing; Xiao, Haifang; Xiao, Chunxia; Wang, Yutang; Liu, Xuebo

    2012-01-01

    Isoorientin induced apoptosis in HepG2 cells. ► Isoorientin disordered mitochondrial function and inhibited PI3K/AKt pathway. ► PI3K/Akt pathway mediated mitochondrial dysfunction via Bcl-2 family members. ► Isoorientin stimulated the intracellular ROS and NO generation in HepG2 cells. ► ROS and NO initiated mitochondria dysfunction and involved in PI3K/Akt pathway.

  11. Concanavalin A: A potential anti-neoplastic agent targeting apoptosis, autophagy and anti-angiogenesis for cancer therapeutics

    International Nuclear Information System (INIS)

    Li, Wen-wen; Yu, Jia-ying; Xu, Huai-long; Bao, Jin-ku

    2011-01-01

    Highlights: → ConA induces cancer cell death targeting apoptosis and autophagy. → ConA inhibits cancer cell angiogenesis. → ConA is utilized in pre-clinical and clinical trials. -- Abstract: Concanavalin A (ConA), a Ca 2+ /Mn 2+ -dependent and mannose/glucose-binding legume lectin, has drawn a rising attention for its remarkable anti-proliferative and anti-tumor activities to a variety of cancer cells. ConA induces programmed cell death via mitochondria-mediated, P73-Foxo1a-Bim apoptosis and BNIP3-mediated mitochondrial autophagy. Through IKK-NF-κB-COX-2, SHP-2-MEK-1-ERK, and SHP-2-Ras-ERK anti-angiogenic pathways, ConA would inhibit cancer cell survival. In addition, ConA stimulates cell immunity and generates an immune memory, resisting to the same genotypic tumor. These biological findings shed light on new perspectives of ConA as a potential anti-neoplastic agent targeting apoptosis, autophagy and anti-angiogenesis in pre-clinical or clinical trials for cancer therapeutics.

  12. Human retinal pigment epithelial cell-induced apoptosis in activated T cells

    DEFF Research Database (Denmark)

    Jørgensen, A; Wiencke, A K; la Cour, M

    1998-01-01

    human retinal pigment epithelial (RPE) cells can induce apoptosis in activated T cells. METHODS: Fas ligand (FasL) expression was detected by flow cytometry and immunohistochemistry. Cultured RPE cells were cocultured with T-cell lines and peripheral blood lymphocytes for 6 hours to 2 days. Induction...... of apoptosis was detected by 7-amino-actinomycin D and annexin V staining. RESULTS: Retinal pigment epithelial cells expressed FasL and induced apoptosis in activated Fas+ T cells. Blocking of Fas-FasL interaction with antibody strongly inhibited RPE-mediated T-cell apoptosis. Retinal pigment epithelial cells...... induced apoptosis in several activated T-cell populations and T-cell lines, including T-cell antigen receptor (TCR)-CD3-negative T-cell lines. In contrast, RPE cells induced little or no apoptosis in resting peripheral T cells. Major histocompatibility complex (MHC) class II monoclonal antibodies, which...

  13. MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells

    International Nuclear Information System (INIS)

    Yu, Teng; Ji, Jiang; Guo, Yong-li

    2013-01-01

    Highlights: •Curcumin activates MST1 in melanoma cells. •MST1 mediates curcumin-induced apoptosis of melanoma cells. •ROS production is involved in curcumin-induced MST1 activation. •MST1 mediates curcumin-induced JNK activation in melanoma cells. •MST1 mediates curcumin-induced Foxo3a nuclear translocation and Bim expression. -- Abstract: Different groups including ours have shown that curcumin induces melanoma cell apoptosis, here we focused the role of mammalian Sterile 20-like kinase 1 (MST1) in it. We observed that curcumin activated MST1-dependent apoptosis in cultured melanoma cells. MST1 silencing by RNA interference (RNAi) suppressed curcumin-induced cell apoptosis, while MST1 over-expressing increased curcumin sensitivity. Meanwhile, curcumin induced reactive oxygen species (ROS) production in melanoma cells, and the ROS scavenger, N-acetyl-cysteine (NAC), almost blocked MST1 activation to suggest that ROS might be required for MST1 activation by curcumin. c-Jun N-terminal protein kinase (JNK) activation by curcumin was dependent on MST1, since MST1 inhibition by RNAi or NAC largely inhibited curcumin-induced JNK activation. Further, curcumin induced Foxo3 nuclear translocation and Bim-1 (Foxo3 target gene) expression in melanoma cells, such an effect by curcumin was inhibited by MST1 RNAi. In conclusion, we suggested that MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells

  14. MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Teng, E-mail: tengyu33@yahoo.com [Department of Dermatology, Shandong Ji-ning No. 1 People’s Hospital, Shandong Province 272011 (China); Ji, Jiang [Department of Dermatology, The Second Hospital Affiliated of Soochow University, SuZhou, Jiangsu Province 215000 (China); Guo, Yong-li [Department of Oncology, Shandong Ji-ning No. 1 People’s Hospital, Shandong Province 272011 (China)

    2013-11-08

    Highlights: •Curcumin activates MST1 in melanoma cells. •MST1 mediates curcumin-induced apoptosis of melanoma cells. •ROS production is involved in curcumin-induced MST1 activation. •MST1 mediates curcumin-induced JNK activation in melanoma cells. •MST1 mediates curcumin-induced Foxo3a nuclear translocation and Bim expression. -- Abstract: Different groups including ours have shown that curcumin induces melanoma cell apoptosis, here we focused the role of mammalian Sterile 20-like kinase 1 (MST1) in it. We observed that curcumin activated MST1-dependent apoptosis in cultured melanoma cells. MST1 silencing by RNA interference (RNAi) suppressed curcumin-induced cell apoptosis, while MST1 over-expressing increased curcumin sensitivity. Meanwhile, curcumin induced reactive oxygen species (ROS) production in melanoma cells, and the ROS scavenger, N-acetyl-cysteine (NAC), almost blocked MST1 activation to suggest that ROS might be required for MST1 activation by curcumin. c-Jun N-terminal protein kinase (JNK) activation by curcumin was dependent on MST1, since MST1 inhibition by RNAi or NAC largely inhibited curcumin-induced JNK activation. Further, curcumin induced Foxo3 nuclear translocation and Bim-1 (Foxo3 target gene) expression in melanoma cells, such an effect by curcumin was inhibited by MST1 RNAi. In conclusion, we suggested that MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells.

  15. Photo-oxidative damage to isolated rat liver mitochondria induced by phenothiazines

    Directory of Open Access Journals (Sweden)

    T. RODRIGUES

    2009-01-01

    Full Text Available

    Photosensitization is a well-known side-effect of phenothiazines that could involve photochemically promoted oxidative damage to mitochondria, leading to the impairment of metabolic functions and apoptosis. In this work, for the first time, we investigated the effects of photoexcited thioridazine (TR, trifluoperazine (TFP and fluphenazine (FP on isolated rat liver mitochondria. Under UV irradiation, the presence of these phenothiazines led to a dose-dependent lack of the respiratory control ratio. These effects were not accompanied by significant swelling and oxidation of protein thiol groups but were accompanied by lipid peroxidation. Lycopene and sorbate, well-known quenchers of singlet oxygen and triplet species, respectively, were ineffective at protecting mitochondrial lipids against the damage promoted by the excited phenothiazines, suggesting that photochemically-produced cation radicals were the prooxidant species. Corroborating this proposal, butylated hydroxytoluene (BHT completely inhibited the lipid peroxidation induced by UV irradiation in the presence of phenothiazines. These novel results make a significant contribution to the understanding of the photochemical properties of phenothiazines in biological systems. Keywords: Trifluoperazine, thioridazine, fluphenazine, rat liver mitochondria, oxidative stress, photochemistry, photodamage, respiratory chain.

  16. The proapoptotic activity of C-terminal domain of apoptosis-inducing factor (AIF is separated from its N-terminal

    Directory of Open Access Journals (Sweden)

    YONG ZHANG

    2009-01-01

    Full Text Available Apoptosis-inducing factor (AIF is a mitochondrial flavoprotein that mediates both NADH-oxidizing and caspase-independent apoptosis. Further, the proapoptotic activity of AIF is located in the C-terminus of AIF, although the precise minimum sequence responsible for apoptosis induction remains to be investigated. In the present study, we generated two truncated AIFs, AIFΔ1-480-FLAG, which is a FLAG-tagged C-terminal peptide comprising amino acids from 481 to 613, and AIF360-480 containing amino acids from 360 to 480 of AIF. We used confocal microscopy to demonstrate that both the truncated proteins are expressed and located in the cytoplasm of transfected cells. AIFΔ1-480 but not AIF360-480 induces apoptosis in transfected cells. We also found that the expression of AIFΔ1-480 could initiate the release of cytochrome c from the mitochondria. The suppression of caspase-9 via siRNA blocked the proapoptotic activity of AIFΔ1-480. Therefore, AIFΔ 1-480 is sufficient for inducing caspase-9-dependent apoptotic signaling, probably by promoting the release of cytochrome c. At last, we generated a chimeric immuno-AIFΔ 1-480 protein, which comprised an HER2 antibody, a Pseudomonas exotoxin A translocation domain and AIFΔ 1-480. Human Jurkat cells transfected with the immuno-AIFΔl-480 gene could express and secrete the chimeric protein, which selectively recognize and kill HER2-overexpressing tumor cells. Our study demonstrates the feasibility of the immuno-AIFΔl-480 gene as a novel approach to treating HER2-overexpressing cancers.

  17. Interdependence of Bad and Puma during ionizing-radiation-induced apoptosis.

    Science.gov (United States)

    Toruno, Cristhian; Carbonneau, Seth; Stewart, Rodney A; Jette, Cicely

    2014-01-01

    Ionizing radiation (IR)-induced DNA double-strand breaks trigger an extensive cellular signaling response that involves the coordination of hundreds of proteins to regulate DNA repair, cell cycle arrest and apoptotic pathways. The cellular outcome often depends on the level of DNA damage as well as the particular cell type. Proliferating zebrafish embryonic neurons are highly sensitive to IR-induced apoptosis, and both p53 and its transcriptional target puma are essential mediators of the response. The BH3-only protein Puma has previously been reported to activate mitochondrial apoptosis through direct interaction with the pro-apoptotic Bcl-2 family proteins Bax and Bak, thus constituting the role of an "activator" BH3-only protein. This distinguishes it from BH3-only proteins like Bad that are thought to indirectly promote apoptosis through binding to anti-apoptotic Bcl-2 family members, thereby preventing the sequestration of activator BH3-only proteins and allowing them to directly interact with and activate Bax and Bak. We have shown previously that overexpression of the BH3-only protein Bad in zebrafish embryos supports normal embryonic development but greatly sensitizes developing neurons to IR-induced apoptosis. While Bad has previously been shown to play only a minor role in promoting IR-induced apoptosis of T cells in mice, we demonstrate that Bad is essential for robust IR-induced apoptosis in zebrafish embryonic neural tissue. Moreover, we found that both p53 and Puma are required for Bad-mediated radiosensitization in vivo. Our findings show the existence of a hierarchical interdependence between Bad and Puma whereby Bad functions as an essential sensitizer and Puma as an essential activator of IR-induced mitochondrial apoptosis specifically in embryonic neural tissue.

  18. Isthmin targets cell-surface GRP78 and triggers apoptosis via induction of mitochondrial dysfunction.

    Science.gov (United States)

    Chen, M; Zhang, Y; Yu, V C; Chong, Y-S; Yoshioka, T; Ge, R

    2014-05-01

    Isthmin (ISM) is a secreted 60-kDa protein that potently induces endothelial cell (EC) apoptosis. It suppresses tumor growth and angiogenesis in mice when stably overexpressed in cancer cells. Although αvβ5 integrin serves as a low-affinity receptor for ISM, the mechanism by which ISM mediates antiangiogenesis and apoptosis in ECs remain to be fully resolved. In this work, we report the identification of cell-surface glucose-regulated protein 78 kDa (GRP78) as a high-affinity receptor for ISM (Kd=8.6 nM). We demonstrated that ISM-GRP78 interaction triggers apoptosis not only in activated ECs but also in cancer cells expressing high level of cell-surface GRP78. Normal cells and benign tumor cells tend to express low level of cell-surface GRP78 and are resistant to ISM-induced apoptosis. Upon binding to GRP78, ISM is internalized into ECs through clathrin-dependent endocytosis that is essential for its proapoptotic activity. Once inside the cell, ISM co-targets with GRP78 to mitochondria where it interacts with ADP/ATP carriers on the inner membrane and blocks ATP transport from mitochondria to cytosol, thereby causing apoptosis. Hence, ISM is a novel proapoptotic ligand that targets cell-surface GRP78 to trigger apoptosis by inducing mitochondrial dysfunction. The restricted and high-level expression of cell-surface GRP78 on cancer cells and cancer ECs make them uniquely susceptible to ISM-targeted apoptosis. Indeed, systemic delivery of recombinant ISM potently suppressed subcutaneous 4T1 breast carcinoma and B16 melanoma growth in mice by eliciting apoptosis selectively in the cancer cells and cancer ECs. Together, this work reveals a novel ISM-GRP78 apoptosis pathway and demonstrates the potential of ISM as a cancer-specific and dual-targeting anticancer agent.

  19. Isthmin targets cell-surface GRP78 and triggers apoptosis via induction of mitochondrial dysfunction

    Science.gov (United States)

    Chen, M; Zhang, Y; Yu, V C; Chong, Y-S; Yoshioka, T; Ge, R

    2014-01-01

    Isthmin (ISM) is a secreted 60-kDa protein that potently induces endothelial cell (EC) apoptosis. It suppresses tumor growth and angiogenesis in mice when stably overexpressed in cancer cells. Although αvβ5 integrin serves as a low-affinity receptor for ISM, the mechanism by which ISM mediates antiangiogenesis and apoptosis in ECs remain to be fully resolved. In this work, we report the identification of cell-surface glucose-regulated protein 78 kDa (GRP78) as a high-affinity receptor for ISM (Kd=8.6 nM). We demonstrated that ISM-GRP78 interaction triggers apoptosis not only in activated ECs but also in cancer cells expressing high level of cell-surface GRP78. Normal cells and benign tumor cells tend to express low level of cell-surface GRP78 and are resistant to ISM-induced apoptosis. Upon binding to GRP78, ISM is internalized into ECs through clathrin-dependent endocytosis that is essential for its proapoptotic activity. Once inside the cell, ISM co-targets with GRP78 to mitochondria where it interacts with ADP/ATP carriers on the inner membrane and blocks ATP transport from mitochondria to cytosol, thereby causing apoptosis. Hence, ISM is a novel proapoptotic ligand that targets cell-surface GRP78 to trigger apoptosis by inducing mitochondrial dysfunction. The restricted and high-level expression of cell-surface GRP78 on cancer cells and cancer ECs make them uniquely susceptible to ISM-targeted apoptosis. Indeed, systemic delivery of recombinant ISM potently suppressed subcutaneous 4T1 breast carcinoma and B16 melanoma growth in mice by eliciting apoptosis selectively in the cancer cells and cancer ECs. Together, this work reveals a novel ISM-GRP78 apoptosis pathway and demonstrates the potential of ISM as a cancer-specific and dual-targeting anticancer agent. PMID:24464222

  20. Dissection of pathways leading to antigen receptor-induced and Fas/CD95-induced apoptosis in human B cells

    NARCIS (Netherlands)

    Lens, S. M.; den Drijver, B. F.; Pötgens, A. J.; Tesselaar, K.; van Oers, M. H.; van Lier, R. A.

    1998-01-01

    To dissect intracellular pathways involved in B cell Ag receptor (BCR)-mediated and Fas-induced human B cell death, we isolated clones of the Burkitt lymphoma cell line Ramos with different apoptosis sensitivities. Selection for sensitivity to Fas-induced apoptosis also selected for clones with

  1. Bifidobacterial recombinant thymidine kinase-ganciclovir gene therapy system induces FasL and TNFR2 mediated antitumor apoptosis in solid tumors

    International Nuclear Information System (INIS)

    Wang, Changdong; Ma, Yongping; Hu, Qiongwen; Xie, Tingting; Wu, Jiayan; Zeng, Fan; Song, Fangzhou

    2016-01-01

    Directly targeting therapeutic suicide gene to a solid tumor is a hopeful approach for cancer gene therapy. Treatment of a solid tumor by an effective vector for a suicide gene remains a challenge. Given the lack of effective treatments, we constructed a bifidobacterial recombinant thymidine kinase (BF-rTK) -ganciclovir (GCV) targeting system (BKV) to meet this requirement and to explore antitumor mechanisms. Bifidobacterium (BF) or BF-rTK was injected intratumorally with or without ganciclovir in a human colo320 intestinal xenograft tumor model. The tumor tissues were analyzed using apoptosis antibody arrays, real time PCR and western blot. The colo320 cell was analyzed by the gene silencing method. Autophagy and necroptosis were also detected in colo320 cell. Meanwhile, three human digestive system xenograft tumor models (colorectal cancer colo320, gastric cancer MKN-45 and liver cancer SSMC-7721) and a breast cancer (MDA-MB-231) model were employed to validate the universality of BF-rTK + GCV in solid tumor gene therapy. The survival rate was evaluated in three human cancer models after the BF-rTK + GCV intratumor treatment. The analysis of inflammatory markers (TNF-α) in tumor indicated that BF-rTK + GCV significantly inhibited TNF-α expression. The results suggested that BF-rTK + GCV induced tumor apoptosis without autophagy and necroptosis occurrence. The apoptosis was transduced by multiple signaling pathways mediated by FasL and TNFR2 and mainly activated the mitochondrial control of apoptosis via Bid and Bim, which was rescued by silencing Bid or/and Bim. However, BF + GCV only induced apoptosis via Fas/FasL signal pathway accompanied with increased P53 expression. We further found that BF-rTK + GCV inhibited the expression of the inflammatory maker of TNF-α. However, BF-rTK + GCV did not result in necroptosis and autophagy. BF-rTK + GCV induced tumor apoptosis mediated by FasL and TNFR2 through the mitochondrial control of apoptosis via Bid and Bim

  2. HIV-1 protease-induced apoptosis

    Czech Academy of Sciences Publication Activity Database

    Rumlová, Michaela; Křížová, Ivana; Keprová, Alena; Hadravová, Romana; Doležal, Michal; Strohalmová, Karolína; Pichová, Iva; Hájek, Miroslav; Ruml, T.

    2014-01-01

    Roč. 11, May 20 (2014), 37/1-37/15 ISSN 1742-4690 R&D Projects: GA ČR GA204/09/1388 Institutional support: RVO:61388963 Keywords : HIV protease * BCA3 * AKIP-1 * apoptosis * mitochondria Subject RIV: EE - Microbiology, Virology Impact factor: 4.185, year: 2014 http://www.retrovirology.com/content/11/1/37

  3. Evaluation of a curcumin analog as an anti-cancer agent inducing ER stress-mediated apoptosis in non-small cell lung cancer cells

    International Nuclear Information System (INIS)

    Liu, Zhiguo; Wang, Yi; Sun, Yusheng; Ren, Luqing; Huang, Yi; Cai, Yuepiao; Weng, Qiaoyou; Shen, Xueqian; Li, Xiaokun; Liang, Guang

    2013-01-01

    Recent advances have highlighted the importance of the endoplasmic reticulum (ER) in cell death processes. Pharmacological interventions that effectively enhance tumor cell death through activating ER stress have attracted a great deal of attention for anti-cancer therapy. A bio-evaluation on 113 curcumin analogs against four cancer cell lines was performed through MTT assay. Furthermore, real time cell assay and flow cytometer were used to evaluate the apoptotic induction of (1E,4E)-1,5-bis(5-bromo-2-ethoxyphenyl)penta-1,4-dien-3-one (B82). Western blot, RT-qPCR, and siRNA were then utilized to confirm whether B82-induced apoptosis is mediated through activating ER stress pathway. Finally, the in vivo anti-tumor effect of B82 was evaluated. B82 exhibited strong anti-tumor activity in non-small cell lung cancer (NSCLC) H460 cells. Treatment with B82 significantly induced apoptosis in H460 cells in vitro and inhibited H460 tumor growth in vivo. Further studies demonstrated that the B82-induced apoptosis is mediated by activating ER stress both in vitro and in vivo. A new monocarbonyl analog of curcumin, B82, exhibited anti-tumor effects on H460 cells via an ER stress-mediated mechanism. B82 could be further explored as a potential anticancer agent for the treatment of NSCLC

  4. NF-κB and JNK mediated apoptosis and G0/G1 arrest of HeLa cells induced by rubiarbonol G, an arborinane-type triterpenoid from Rubia yunnanensis.

    Science.gov (United States)

    Zeng, Guang-Zhi; Wang, Zhe; Zhao, Li-Mei; Fan, Jun-Ting; Tan, Ning-Hua

    2018-06-28

    0 /G 1 arrest in HeLa cells. These results indicated that RG induces mitochondria-mediated apoptosis and G 0 /G 1 cell cycle arrest by activation of JNK signaling as well as inactivation of NF-κB pathway in HeLa cells, which suggests that RG is one of the key active ingredients accounting for the anti-tumor effect of R. yunnanensis. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Multiple metabolic hits converge on CD36 as novel mediator of tubular epithelial apoptosis in diabetic nephropathy.

    Directory of Open Access Journals (Sweden)

    Katalin Susztak

    2005-02-01

    Full Text Available Diabetic nephropathy (DNP is a common complication of type 1 and type 2 diabetes mellitus and the most common cause of kidney failure. While DNP manifests with albuminuria and diabetic glomerulopathy, its progression correlates best with tubular epithelial degeneration (TED and interstitial fibrosis. However, mechanisms leading to TED in DNP remain poorly understood.We found that expression of scavenger receptor CD36 coincided with proximal tubular epithelial cell (PTEC apoptosis and TED specifically in human DNP. High glucose stimulated cell surface expression of CD36 in PTECs. CD36 expression was necessary and sufficient to mediate PTEC apoptosis induced by glycated albumins (AGE-BSA and CML-BSA and free fatty acid palmitate through sequential activation of src kinase, and proapoptotic p38 MAPK and caspase 3. In contrast, paucity of expression of CD36 in PTECs in diabetic mice with diabetic glomerulopathy was associated with normal tubular epithelium and the absence of tubular apoptosis. Mouse PTECs lacked CD36 and were resistant to AGE-BSA-induced apoptosis. Recombinant expression of CD36 in mouse PTECs conferred susceptibility to AGE-BSA-induced apoptosis.Our findings suggest a novel role for CD36 as an essential mediator of proximal tubular apoptosis in human DNP. Because CD36 expression was induced by glucose in PTECs, and because increased CD36 mediated AGE-BSA-, CML-BSA-, and palmitate-induced PTEC apoptosis, we propose a two-step metabolic hit model for TED, a hallmark of progression in DNP.

  6. Withaferin A Induces ROS-Mediated Paraptosis in Human Breast Cancer Cell-Lines MCF-7 and MDA-MB-231.

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    Kamalini Ghosh

    Full Text Available Advancement in cancer therapy requires a better understanding of the detailed mechanisms that induce death in cancer cells. Besides apoptosis, themode of other types of cell death has been increasingly recognized in response to therapy. Paraptosis is a non-apoptotic alternative form of programmed cell death, morphologically distinct from apoptosis and autophagy. In the present study, Withaferin-A (WA induced hyperpolarization of mitochondrial membrane potential and formation of many cytoplasmic vesicles. This was due to progressive swelling and fusion of mitochondria and dilation of endoplasmic reticulum (ER, forming large vacuolar structures that eventually filled the cytoplasm in human breast cancer cell-lines MCF-7 and MDA-MB-231. The level of indigenous paraptosis inhibitor, Alix/AIP-1 (Actin Interacting Protein-1 was down-regulated by WA treatment. Additionally, prevention of WA-induced cell death and vacuolation on co-treatment with protein-synthesis inhibitor indicated requirement of de-novo protein synthesis. Co-treatment with apoptosis inhibitor resulted in significant augmentation of WA-induced death in MCF-7 cells, while partial inhibition in MDA-MB-231 cells; implyingthat apoptosis was not solely responsible for the process.WA-mediated cytoplasmic vacuolationcould not be prevented by autophagy inhibitor wortmanninas well, claiming this process to be a non-autophagic one. Early induction of ROS (Reactive Oxygen Speciesby WA in both the cell-lines was observed. ROS inhibitorabrogated the effect of WA on: cell-death, expression of proliferation-associated factor andER-stress related proteins,splicing of XBP-1 (X Box Binding Protein-1 mRNA and formation of paraptotic vacuoles.All these results conclusively indicate thatWA induces deathin bothMCF-7 and MDA-MB-231 cell lines byROS-mediated paraptosis.

  7. Isolation and identification of gene mediating radiation-induced apoptosis in human leukemia U937 cells

    International Nuclear Information System (INIS)

    Tong Xin; Luo Ying; Dong Yan; Sun Zhixian

    1998-01-01

    Objective: Increasing evidences suggest that Caspase family proteases play an important role in the effector mechanism of apoptotic cell death. Radiation (IR) can induce apoptosis in tumor cells, so it is very important to isolate and identify the member of the Caspase family proteases involved in IR-induced apoptosis, and this would contribute to the understanding of the mechanism responsible for apoptosis execution. Methods: A PCR approach to isolate genes for IR-induced apoptosis was developed. The approach used degenerated oligonucleotide encoding the highly conserved peptides that were present in all known Caspases. Results: Protease inhibitors special for Caspases could block the apoptotic cell death caused by IR, and Caspase-3 was isolated from irradiated human leukemia U937 cells. Conclusion: Caspases involve in IR-induced apoptosis, and Caspase-3 is the pivotal element of IR-induced apoptosis

  8. Transcutaneous application of carbon dioxide (CO2 induces mitochondrial apoptosis in human malignant fibrous histiocytoma in vivo.

    Directory of Open Access Journals (Sweden)

    Yasuo Onishi

    Full Text Available Mitochondria play an essential role in cellular energy metabolism and apoptosis. Previous studies have demonstrated that decreased mitochondrial biogenesis is associated with cancer progression. In mitochondrial biogenesis, peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α regulates the activities of multiple nuclear receptors and transcription factors involved in mitochondrial proliferation. Previously, we showed that overexpression of PGC-1α leads to mitochondrial proliferation and induces apoptosis in human malignant fibrous histiocytoma (MFH cells in vitro. We also demonstrated that transcutaneous application of carbon dioxide (CO(2 to rat skeletal muscle induces PGC-1α expression and causes an increase in mitochondrial proliferation. In this study, we utilized a murine model of human MFH to determine the effect of transcutaneous CO(2 exposure on PGC-1α expression, mitochondrial proliferation and cellular apoptosis. PGC-1α expression was evaluated by quantitative real-time PCR, while mitochondrial proliferation was assessed by immunofluorescence staining and the relative copy number of mitochondrial DNA (mtDNA was assessed by real-time PCR. Immunofluorescence staining and DNA fragmentation assays were used to examine mitochondrial apoptosis. We also evaluated the expression of mitochondrial apoptosis related proteins, such as caspases, cytochorome c and Bax, by immunoblot analysis. We show that transcutaneous application of CO(2 induces PGC-1α expression, and increases mitochondrial proliferation and apoptosis of tumor cells, significantly reducing tumor volume. Proteins involved in the mitochondrial apoptotic cascade, including caspase 3 and caspase 9, were elevated in CO(2 treated tumors compared to control. We also observed an enrichment of cytochrome c in the cytoplasmic fraction and Bax protein in the mitochondrial fraction of CO(2 treated tumors, highlighting the involvement of mitochondria in apoptosis

  9. Curcumin induces apoptosis of upper aerodigestive tract cancer cells by targeting multiple pathways.

    Directory of Open Access Journals (Sweden)

    A R M Ruhul Amin

    Full Text Available Curcumin, a natural compound isolated from the Indian spice "Haldi" or "curry powder", has been used for centuries as a traditional remedy for many ailments. Recently, the potential use of curcumin in cancer prevention and therapy urges studies to uncover the molecular mechanisms associated with its anti-tumor effects. In the current manuscript, we investigated the mechanism of curcumin-induced apoptosis in upper aerodigestive tract cancer cell lines and showed that curcumin-induced apoptosis is mediated by the modulation of multiple pathways such as induction of p73, and inhibition of p-AKT and Bcl-2. Treatment of cells with curcumin induced both p53 and the related protein p73 in head and neck and lung cancer cell lines. Inactivation of p73 by dominant negative p73 significantly protected cells from curcumin-induced apoptosis, whereas ablation of p53 by shRNA had no effect. Curcumin treatment also strongly inhibited p-AKT and Bcl-2 and overexpression of constitutively active AKT or Bcl-2 significantly inhibited curcumin-induced apoptosis. Taken together, our findings suggest that curcumin-induced apoptosis is mediated via activating tumor suppressor p73 and inhibiting p-AKT and Bcl-2.

  10. Lycopene protects human SH-SY5Y neuroblastoma cells against hydrogen peroxide-induced death via inhibition of oxidative stress and mitochondria-associated apoptotic pathways

    Science.gov (United States)

    FENG, CHUNSHENG; LUO, TIANFEI; ZHANG, SHUYAN; LIU, KAI; ZHANG, YANHONG; LUO, YINAN; GE, PENGFEI

    2016-01-01

    Oxidative stress, which is characterized by excessive production of reactive oxygen species (ROS), is a common pathway that results in neuronal injury or death due to various types of pathological stress. Although lycopene has been identified as a potent antioxidant, its effect on hydrogen peroxide (H2O2)-induced neuronal damage remains unclear. In the present study, pretreatment with lycopene was observed to protect SH-SY5Y neuroblastoma cells against H2O2-induced death via inhibition of apoptosis resulting from activation of caspase-3 and translocation of apoptosis inducing factor (AIF) to the nucleus. Furthermore, the over-produced ROS, as well as the reduced activities of anti-oxidative enzymes, superoxide dismutase and catalase, were demonstrated to be alleviated by lycopene. Additionally, lycopene counteracted H2O2-induced mitochondrial dysfunction, which was evidenced by suppression of mitochondrial permeability transition pore opening, attenuation of the decline of the mitochondrial membrane potential, and inhibition of the increase of Bax and decrease of Bcl-2 levels within the mitochondria. The release of cytochrome c and AIF from the mitochondria was also reduced. These results indicate that lycopene is a potent neuroprotectant against apoptosis, oxidative stress and mitochondrial dysfunction, and could be administered to prevent neuronal injury or death. PMID:27035331

  11. Cudraflavone C Induces Apoptosis of A375.S2 Melanoma Cells through Mitochondrial ROS Production and MAPK Activation.

    Science.gov (United States)

    Lee, Chiang-Wen; Yen, Feng-Lin; Ko, Horng-Huey; Li, Shu-Yu; Chiang, Yao-Chang; Lee, Ming-Hsueh; Tsai, Ming-Horng; Hsu, Lee-Fen

    2017-07-13

    Melanoma is the most malignant form of skin cancer and is associated with a very poor prognosis. The aim of this study was to evaluate the apoptotic effects of cudraflavone C on A375.S2 melanoma cells and to determine the underlying mechanisms involved in apoptosis. Cell viability was determined using the MTT and real-time cytotoxicity assays. Flow cytometric evaluation of apoptosis was performed after staining the cells with Annexin V-FITC and propidium iodide. The mitochondrial membrane potential was evaluated using the JC-1 assay. Cellular ROS production was measured using the CellROX assay, while mitochondrial ROS production was evaluated using the MitoSOX assay. It was observed that cudraflavone C inhibited growth in A375.S2 melanoma cells, and promoted apoptosis via the mitochondrial pathway mediated by increased mitochondrial ROS production. In addition, cudraflavone C induced phosphorylation of MAPKs (p38, ERK, and JNK) and up-regulated the expression of apoptotic proteins (Puma, Bax, Bad, Bid, Apaf-1, cytochrome C, caspase-9, and caspase-3/7) in A375.S2 cells. Pretreatment of A375.S2 cells with MitoTEMPOL (a mitochondria-targeted antioxidant) attenuated the phosphorylation of MAPKs, expression of apoptotic proteins, and the overall progression of apoptosis. In summary, cudraflavone C induced apoptosis in A375.S2 melanoma cells by increasing mitochondrial ROS production; thus, activating p38, ERK, and JNK; and increasing the expression of apoptotic proteins. Therefore, cudraflavone C may be regarded as a potential form of treatment for malignant melanoma.

  12. SCO2 induces p53-mediated apoptosis by Thr845 phosphorylation of ASK-1 and dissociation of the ASK-1-Trx complex.

    Science.gov (United States)

    Madan, Esha; Gogna, Rajan; Kuppusamy, Periannan; Bhatt, Madan; Mahdi, Abbas Ali; Pati, Uttam

    2013-04-01

    p53 prevents cancer via cell cycle arrest, apoptosis, and the maintenance of genome stability. p53 also regulates energy-generating metabolic pathways such as oxidative phosphorylation (OXPHOS) and glycolysis via transcriptional regulation of SCO2 and TIGAR. SCO2, a cytochrome c oxidase assembly factor, is a metallochaperone which is involved in the biogenesis of cytochrome c oxidase subunit II. Here we have shown that SCO2 functions as an apoptotic protein in tumor xenografts, thus providing an alternative pathway for p53-mediated apoptosis. SCO2 increases the generation of reactive oxygen species (ROS) and induces dissociation of the protein complex between apoptosis signal-regulating kinase 1 (ASK-1) (mitogen-activated protein kinase kinase kinase [MAPKKK]) and its cellular inhibitor, the redox-active protein thioredoxin (Trx). Furthermore, SCO2 induces phosphorylation of ASK-1 at the Thr(845) residue, resulting in the activation of the ASK-1 kinase pathway. The phosphorylation of ASK-1 induces the activation of mitogen-activated protein kinase kinases 4 and 7 (MAP2K4/7) and MAP2K3/6, which switches the c-Jun N-terminal protein kinase (JNK)/p38-dependent apoptotic cascades in cancer cells. Exogenous addition of the SCO2 gene to hypoxic cancer cells and hypoxic tumors induces apoptosis and causes significant regression of tumor xenografts. We have thus discovered a novel apoptotic function of SCO2, which activates the ASK-1 kinase pathway in switching "on" an alternate mode of p53-mediated apoptosis. We propose that SCO2 might possess a novel tumor suppressor function via the ROS-ASK-1 kinase pathway and thus could be an important candidate for anticancer gene therapy.

  13. Fluoxetine and the mitochondria: A review of the toxicological aspects.

    Science.gov (United States)

    de Oliveira, Marcos Roberto

    2016-09-06

    Fluoxetine (a selective serotonin reuptake inhibitor (SSRI)) is used as an antidepressant by modulating the levels of serotonin in the synaptic cleft. Nevertheless, fluoxetine also induces undesirable effects, such as anxiety, sexual dysfunction, sleep disturbances, and gastrointestinal impairments. Fluoxetine has been viewed as an agent that may interfere with cell fate by triggering apoptosis. On the other hand, fluoxetine intake has been associated with increased cancer risk. Nonetheless, data remain contradictory and no conclusions were taken. Several studies demonstrated that fluoxetine interacts with mitochondria triggering apoptosis and/or altering mitochondrial function by modulating the activity of respiratory chain components and enzymes of the Krebs cycle. Furthermore, fluoxetine affects mitochondria-related redox parameters in different experimental models. In this review, data demonstrating the effects of fluoxetine upon mammalian mitochondria are described and discussed, as well as several unsolved questions in this field of research are addressed. A separate section deals with future needs regarding the research involving the impact of fluoxetine treatment upon mitochondria and mitochondria-related signaling. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Mitochondria, Energy and Cancer: The Relationship with Ascorbic Acid

    Science.gov (United States)

    González, Michael J.; Rosario-Pérez, Glorivee; Guzmán, Angélica M.; Miranda-Massari, Jorge R.; Duconge, Jorge; Lavergne, Julio; Fernandez, Nadia; Ortiz, Norma; Quintero, Ana; Mikirova, Nina; Riordan, Neil H.; Ricart, Carlos M.

    2012-01-01

    Ascorbic Acid (AA) has been used in the prevention and treatment of cancer with reported effectiveness. Mitochondria may be one of the principal targets of ascorbate's cellular activity and it may play an important role in the development and progression of cancer. Mitochondria, besides generating adenosine triphosphate (ATP), has a role in apoptosis regulation and in the production of regulatory oxidative species that may be relevant in gene expression. At higher concentrations AA may increase ATP production by increasing mitochondrial electron flux, also may induce apoptotic cell death in tumor cell lines, probably via its pro-oxidant action In contrast, at lower concentrations AA displays antioxidant properties that may prevent the activation of oxidant-induced apoptosis. These concentration dependent activities of ascorbate may explain in part the seemingly contradictory results that have been reported previously. PMID:23565030

  15. Sequential activation of proteases in radiation induced apoptosis

    International Nuclear Information System (INIS)

    Watters, D.; Waterhouse, N.

    1997-01-01

    Full text: Significant advances have been made in recent years in unraveling the molecular mechanisms of apoptosis particularly in relation to Fas- and TNF-mediated cell death, however there are considerable gaps in our knowledge of the processes involved in apoptosis induced by ionizing radiation. We have used the degradation of specific proteolytic targets in a pair of isogenic Burkitt's Iymphoma cells lines (BL30A, sensitive and BL30K resistant) to study the sequence of events in the execution of radiation-induced apoptosis. Fodrin can be cleaved to fragments of 150 kDa and 120 kDa. In the case of Fas-mediated apoptosis both cleavages are inhibited by the caspase inhibitor zVAD-fmk at 10 μM, a concentration which inhibits all the hallmarks of apoptosis. However in radiation-induced apoptosis, inhibition of the clevage of fodrin to the 150 kDa fragment requires 100 μM zVAD-fink while apoptosis itself is inhibited at 10 μM. This suggests that different enzymes are responsible for the generation of the 150 kDa fragment in the two models of apoptosis. Fodrin has been reported to be cleaved by μ-calpain to a 150 kDa fragment however, the involvement of μ-calpain in apoptosis has not yet been established. In murine fodrin there is a caspase cleavage site within 1 kDa of the calpain cleavage site. In vitro studies using purified enzymes showed that only caspase-3 and μ-calpain could cleave fodrin in untreated cell extracts to the same sized fragments as seen during apoptosis in vivo. We provide evidence for the early activation of μ-calpain after ionizing radiation in the sensitive BL30A cell line, and show that the time course of μ-calpain activation parallels that of the appearance of the 150 kDa fragment. Caspase-3 is activated much later and is likely to be responsible for the generation of the 120 kDa fragment. μ-Calpain was not activated in the resistant cell line. Based on these results we propose a model for the proteolytic cascade in radiation-induced

  16. Andrographolide induces apoptotic and non-apoptotic death and enhances tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis in gastric cancer cells

    OpenAIRE

    Lim, Sung-Chul; Jeon, Ho Jong; Kee, Keun Hong; Lee, Mi Ja; Hong, Ran; Han, Song Iy

    2017-01-01

    Andrographolide, a natural compound isolated from Andrographis paniculata, has been reported to possess antitumor activity. In the present study, the effect of andrographolide in human gastric cancer (GC) cells was investigated. Andrographolide induced cell death with apoptotic and non-apoptotic features. At a low concentration, andrographolide potentiated apoptosis and reduction of clonogenicity triggered by recombinant human tumor necrosis factor-related apoptosis-inducing ligand (rhTRAIL)....

  17. Curcumin Induced Human Gastric Cancer BGC-823 Cells Apoptosis by ROS-Mediated ASK1-MKK4-JNK Stress Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Tao Liang

    2014-09-01

    Full Text Available The signaling mediated by stress-activated MAP kinases (MAPK, c-Jun N-terminal kinase (JNK has well-established importance in cancer. In the present report, we investigated the effects of curcumin on the signaling pathway in human gastric cancer BGC-823 cells. Curcumin induced reactive oxygen species (ROS production and BGC-823 cells apoptosis. Inhibition of ROS generation by antioxidant (NAC or Trion significantly prevented curcumin-mediated apoptosis. Notably, we observed that curcumin activated ASK1, a MAPKKK that is oxidative stress sensitive and responsible to phosphorylation of JNK via triggering cascades, up-regulated an upstream effector of the JNK, MKK4, and phosphorylated JNK protein expression in BGC-823 cells. However, curcumin induced ASK1-MKK4-JNK signaling was attenuated by NAC. All the findings confirm the possibility that oxidative stress-activated ASK1-MKK4-JNK signaling cascade promotes the apoptotic response in curcumin-treated BGC-823 cells.

  18. Differential induction of p53-mediated apoptosis in medulloblastomas and gliomas correlates with their ability to induce bax

    International Nuclear Information System (INIS)

    Shu, H.-K.G.; Furman, Felix; Dee, Suzanne; Israel, Mark A.

    1997-01-01

    Purpose/Objective: Medulloblastoma cell lines readily undergo a p53-mediated apoptosis following exposure to ionizing radiation, while glioma cell lines do not undergo significant levels of apoptosis following irradiation. This study attempts to define some of the molecular events that characterize the differential ability medulloblastomas and gliomas to undergo radiation-induced apoptosis. Materials and Methods: The medulloblastoma cell lines D283 and D341 and the glioma cell lines U87, U343 and U563 were used in this study. All five cell lines were confirmed to have a wild type p53 by their ability to induce p21 protein levels and to undergo a cell-cycle arrest in G1 following treatment with ionizing radiation. Also, 3 clonal derivatives of D283 were used. Two of the clones were derived following transfection with an expression plasmid containing a dominant negative mutant p53 (Arg175 --> His) expressed from the CMV promoter (D283/53.6 and D283/53.7), while the remaining clone was derived following transfection with that same expression plasmid without mutant p53 (D283/vec). All irradiation experiments were performed on Phillips RT-250 X-ray unit using 250 Kvp X-rays. In each case, 5 Gy of ionizing radiation was given at a dose rate of 250 cGy/minute. Apoptosis was quantitated by staining fixed cells with propidium iodide and determining the percentage of cells with subdiploid DNA content by flow cytometry. Northern blot analysis was performed using standard methods. Results: The D283 and D341 cell lines exhibited a significant induction of apoptosis when assayed 2 days following treatment with radiation while the U87, U343 and U563 cell lines displayed only minimal induction of apoptosis when assayed following treatment at that time. RNA was prepared from the different cell lines that were unirradiated, 6 hours or 24 hours post-irradiation. Northern blots were made of the total RNAs and probed for bax, bcl-2 and bcl-x mRNA. This analysis detected no significant

  19. Gentamicin-induced apoptosis in LLC-PK1 cells: Involvement of lysosomes and mitochondria

    International Nuclear Information System (INIS)

    Servais, Helene; Van Der Smissen, Patrick; Thirion, Gaetan; Van der Essen, Gauthier; Van Bambeke, Francoise; Tulkens, Paul M.; Mingeot-Leclercq, Marie-Paule

    2005-01-01

    Gentamicin accumulates in lysosomes and induces apoptosis in kidney proximal tubules and renal cell lines. Using LLC-PK1 cells, we have examined the concentration- and time-dependency of the effects exerted by gentamicin (1-3 mM; 0-3 days) on (i) lysosomal stability; (ii) activation of mitochondrial pathway; (iii) occurrence of apoptosis (concentrations larger than 3 mM caused extensive necrosis as assessed by the measurement of lactate dehydrogenase release). Within 2 h, gentamicin induced a partial relocalization [from lysosomes to cytosol] of the weak organic base acridine orange. We thereafter observed (a) a loss of mitochondrial membrane potential (as from 10 h, based on spectrophotometric and confocal microscopy using JC1 probe) and (b) the release of cytochrome c from granules to cytosol, and the activation of caspase-9 (as from 12 h; evidenced by Western blot analysis). Increase in caspase-3 activity (assayed with Ac-DEVD-AFC in the presence of z-VAD-fmk]) and appearance of fragmented nuclei (DAPI staining) was then detected as from 16 to 24 h together with nuclear fragmentation. Gentamicin produces a fast (within 4 h) release of calcein from negatively-charged liposomes at pH 5.4, which was slowed down by raising the pH to 7.4, or when phosphatidylinositol was replaced by cardiolipin (to mimic the inner mitochondrial membrane). The present data provide temporal evidence that gentamicin causes apoptosis in LLC-PK1 with successive alteration of the permeability of lysosomes, triggering of the mitochondrial pathway, and activation of caspase-3

  20. The neem limonoids azadirachtin and nimbolide induce cell cycle arrest and mitochondria-mediated apoptosis in human cervical cancer (HeLa) cells.

    Science.gov (United States)

    Priyadarsini, R Vidya; Murugan, R Senthil; Sripriya, P; Karunagaran, D; Nagini, S

    2010-06-01

    Limonoids from the neem tree (Azadirachta indica) have attracted considerable research attention in recent years owing to their potent antioxidant and anti-proliferative effects. The present study was designed to investigate the cellular and molecular mechanisms by which azadirachtin and nimbolide exert cytotoxic effects in the human cervical cancer (HeLa) cell line. Both azadirachtin and nimbolide significantly suppressed the viability of HeLa cells in a dose-dependent manner by inducing cell cycle arrest at G0/G1 phase accompanied by p53-dependent p21 accumulation and down-regulation of the cell cycle regulatory proteins cyclin B, cyclin D1 and PCNA. Characteristic changes in nuclear morphology, presence of a subdiploid peak and annexin-V staining pointed to apoptosis as the mode of cell death. Increased generation of reactive oxygen species with decline in the mitochondrial transmembrane potential and release of cytochrome c confirmed that the neem limonoids transduced the apoptotic signal via the mitochondrial pathway. Altered expression of the Bcl-2 family of proteins, inhibition of NF-kappaB activation and over-expression of caspases and survivin provide compelling evidence that azadirachtin and nimbolide induce a shift of balance toward a pro-apoptotic phenotype. Antioxidants such as azadirachtin and nimbolide that can simultaneously arrest the cell cycle and target multiple molecules involved in mitochondrial apoptosis offer immense potential as anti-cancer therapeutic drugs.

  1. ROS accumulation by PEITC selectively kills ovarian cancer cells via UPR-mediated apoptosis

    Directory of Open Access Journals (Sweden)

    Yoon-hee eHong

    2015-07-01

    Full Text Available Unfolded protein response (UPR is crucial for both survival and death of mammalian cells, which is regulated by reactive oxygen species (ROS and nutrient depletion. In this study, we demonstrated the effect of ROS-accumulation, induced by β-phenethyl isothiocyanate (PEITC, on UPR mediated apoptosis in ovarian cancer cells. We used ovarian cancer cell lines, PA-1 and SKOV-3, with different p53 status (wild- and null- type, respectively. PEITC caused increased ROS-accumulation and inhibited proliferation selectively in ovarian cancer cells, and glutathione (GSH depletion in SKOV-3. However, PEITC did not cause any effect in normal ovarian epithelial cells and peripheral blood mononuclear cells. After 48 h of PEITC treatment (5 µM, apoptotic cell death was shown to increase significantly in the ovarian cancer cells and not in the normal cells. The key regulator of UPR-mediated apoptosis, CHOP/GADD153 and ER resident chaperone BiP/GRP78 were parallely up-regulated with activation of two major sensors of the UPR (PERK and ATF-6 in PA-1; PERK, and IRE1α in SKOV-3 in response to ROS accumulation induced by PEITC (5 µM. ROS scavenger, N-acetyl-cysteine (NAC, attenuated the effect of PEITC on UPR signatures (P-PERK, IRE1α, CHOP/GADD153, and BiP/GRP78, suggesting the involvement of ROS in UPR-mediated apoptosis. Altogether, PEITC induces UPR-mediated apoptosis in ovarian cancer cells via accumulation of ROS in a cancer-specific manner.

  2. JNK1 protects against glucolipotoxicity-mediated beta-cell apoptosis

    DEFF Research Database (Denmark)

    Prause, Michala; Christensen, Dan Ploug; Billestrup, Nils

    2014-01-01

    Pancreatic β-cell dysfunction is central to type 2 diabetes pathogenesis. Prolonged elevated levels of circulating free-fatty acids and hyperglycemia, also termed glucolipotoxicity, mediate β-cell dysfunction and apoptosis associated with increased c-Jun N-terminal Kinase (JNK) activity. Endoplas......Pancreatic β-cell dysfunction is central to type 2 diabetes pathogenesis. Prolonged elevated levels of circulating free-fatty acids and hyperglycemia, also termed glucolipotoxicity, mediate β-cell dysfunction and apoptosis associated with increased c-Jun N-terminal Kinase (JNK) activity....... Endoplasmic reticulum (ER) and oxidative stress are elicited by palmitate and high glucose concentrations further potentiating JNK activity. Our aim was to determine the role of the JNK subtypes JNK1, JNK2 and JNK3 in palmitate and high glucose-induced β-cell apoptosis. We established insulin-producing INS1...... INS1 cells showed increased apoptosis and cleaved caspase 9 and 3 compared to non-sense shRNA expressing control INS1 cells when exposed to palmitate and high glucose associated with increased CHOP expression, ROS formation and Puma mRNA expression. JNK2 shRNA expressing INS1 cells did not affect...

  3. Cuprous oxide nanoparticles selectively induce apoptosis of tumor cells

    Directory of Open Access Journals (Sweden)

    Wang Y

    2012-05-01

    Full Text Available Ye Wang,1,2,* Xiao-Yuan Zi,1,* Juan Su,1 Hong-Xia Zhang,1 Xin-Rong Zhang,3 Hai-Ying Zhu,1 Jian-Xiu Li,1 Meng Yin,3 Feng Yang,3 Yi-Ping Hu,11Department of Cell Biology, 2School of Clinical Medicine, 3Department of Pharmaceuticals, Second Military Medical University, Shanghai, People's Republic of China*Authors contributed equally.Abstract: In the rapid development of nanoscience and nanotechnology, many researchers have discovered that metal oxide nanoparticles have very useful pharmacological effects. Cuprous oxide nanoparticles (CONPs can selectively induce apoptosis and suppress the proliferation of tumor cells, showing great potential as a clinical cancer therapy. Treatment with CONPs caused a G1/G0 cell cycle arrest in tumor cells. Furthermore, CONPs enclosed in vesicles entered, or were taken up by mitochondria, which damaged their membranes, thereby inducing apoptosis. CONPs can also produce reactive oxygen species (ROS and initiate lipid peroxidation of the liposomal membrane, thereby regulating many signaling pathways and influencing the vital movements of cells. Our results demonstrate that CONPs have selective cytotoxicity towards tumor cells, and indicate that CONPs might be a potential nanomedicine for cancer therapy.Keywords: nanomedicine, selective cytotoxicity, apoptosis, cell cycle arrest, mitochondrion-targeted nanomaterials

  4. Emamectin benzoate induces ROS-mediated DNA damage and apoptosis in Trichoplusia Tn5B1-4 cells.

    Science.gov (United States)

    Luan, Shaorong; Yun, Xinming; Rao, Wenbing; Xiao, Ciying; Xu, Zhikang; Lang, Jialin; Huang, Qingchun

    2017-08-01

    Emamectin benzoate (EMB), a novel macrocyclic lactone insecticide, possesses high efficacy and beneficial selective toxicity in agriculture, but so far the EMB-induced cytotoxic action in arthropod insect remains unclear. The present studies were carried out to characterize the property of EMB on the induction of reactive oxygen species (ROS)-mediated DNA damage and apoptosis in Trichoplusia Tn5B1-4 cell model. Following the exposure to EMB at 2.5, 5, 10 or 15 μM, the cells changed to be round, suspended and aggregated, and the decline of cell proliferating ability and cell viability was positively related with the exposure time. Median inhibitory concentration (IC 50 ) of EMB on cell viability was 3.72 μM during 72 h exposure. Apoptosis was induced in 29.8% (24 h) and 39.5% (48 h) of the cells by EMB at 15 μM, showing chromatin condensation in nuclei. The content of ROS in the cells increased rapidly as the concentration of EMB increased, and the pre-incubation of the cells with vitamin E significantly reduced the ROS accumulation. In the treatment of 15 μM EMB, the migrated cell nucleus with DNA strand breaks appeared a teardrop, pear-shaped, or large fan-like tail, and 63.1% of γH2AX-positive cells contained more than four foci, accompanying with high expression level of caspase-3 in time-dependent manner, which consequently led to cell apoptotic death. These evidences in ROS-mediated DNA damage and cell apoptosis induced by EMB may be helpful for deep understanding the cytotoxic action of EMB based on cell model. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. The nitric oxide-sensitive p21Ras-ERK pathway mediates S-nitrosoglutathione-induced apoptosis

    International Nuclear Information System (INIS)

    Tsujita, Maristela; Batista, Wagner L.; Ogata, Fernando T.; Stern, Arnold; Monteiro, Hugo P.; Arai, Roberto J.

    2008-01-01

    p21Ras protein plays a critical role in cellular signaling that induces either cell cycle progression or apoptosis. Nitric oxide (NO) has been consistently reported to activate p21Ras through the redox sensitive cysteine residue (118). In this study, we demonstrated that the p21Ras-ERK pathway regulates THP-1 monocyte/macrophage apoptosis induced by S-nitrosoglutathione (SNOG). This was apparent from studies in THP-1 cells expressing NO-insensitive p21Ras (p21Ras C118S ) where the pro-apoptotic action of SNOG was almost abrogated. Three major MAP kinase pathways (ERK, JNK, and p38) that are downstream to p21Ras were investigated. It was observed that only the activation of ERK1/2 MAP kinases by SNOG in THP-1 cells was attributable to p21Ras. The inhibition of the ERK pathway by PD98059 markedly attenuated apoptosis in SNOG-treated THP-1 cells, but had a marginal effect on SNOG-treated THP-1 cells expressing NO-insensitive p21Ras. The inhibition of the JNK and p38 pathways by selective inhibitors had no marked effects on the percentage of apoptosis. The induction of p21Waf1 expression by SNOG was observed in THP-1 cells harboring mutant and wild-type p21Ras, however in cells expressing mutant Ras, the expression of p21Waf1 was significantly attenuated. The treatment of THP-1 cells expressing wild-type p21Ras with PD98059 resulted in significant attenuation of p21Waf1 expression. These results indicate that the redox sensitive p21Ras-ERK pathway plays a critical role in sensing and delivering the pro-apoptotic signaling mediated by SNOG

  6. USP22 Induces Cisplatin Resistance in Lung Adenocarcinoma by Regulating γH2AX-Mediated DNA Damage Repair and Ku70/Bax-Mediated Apoptosis

    Directory of Open Access Journals (Sweden)

    Aman Wang

    2017-05-01

    Full Text Available Resistance to platinum-based chemotherapy is one of the most important reasons for treatment failure in advanced non-small cell lung cancer, but the underlying mechanism is extremely complex and unclear. The present study aimed to investigate the correlation of ubiquitin-specific peptidase 22 (USP22 with acquired resistance to cisplatin in lung adenocarcinoma. In this study, we found that overexpression of USP22 could lead to cisplatin resistance in A549 cells. USP22 and its downstream proteins γH2AX and Sirt1 levels are upregulated in the cisplatin- resistant A549/CDDP cell line. USP22 enhances DNA damage repair and induce cisplatin resistance by promoting the phosphorylation of histone H2AX via deubiquitinating histone H2A. In addition, USP22 decreases the acetylation of Ku70 by stabilizing Sirt1, thus inhibiting Bax-mediated apoptosis and inducing cisplatin resistance. The cisplatin sensitivity in cisplatin-resistant A549/CDDP cells was restored by USP22 inhibition in vivo and vitro. In summary, our findings reveal the dual mechanism of USP22 involvement in cisplatin resistance that USP22 can regulate γH2AX-mediated DNA damage repair and Ku70/Bax-mediated apoptosis. USP22 is a potential target in cisplatin-resistant lung adenocarcinoma and should be considered in future therapeutic practice.

  7. Ceramides in Alzheimer’s Disease: Key Mediators of Neuronal Apoptosis Induced by Oxidative Stress and Aβ Accumulation

    Directory of Open Access Journals (Sweden)

    Maja Jazvinšćak Jembrek

    2015-01-01

    Full Text Available Alzheimer’s disease (AD, the most common chronic and progressive neurodegenerative disorder, is characterized by extracellular deposits of amyloid β-peptides (Aβ and intracellular deposits of hyperphosphorylated tau (phospho-tau protein. Ceramides, the major molecules of sphingolipid metabolism and lipid second messengers, have been associated with AD progression and pathology via Aβ generation. Enhanced levels of ceramides directly increase Aβ through stabilization of β-secretase, the key enzyme in the amyloidogenic processing of Aβ precursor protein (APP. As a positive feedback loop, the generated oligomeric and fibrillar Aβ induces a further increase in ceramide levels by activating sphingomyelinases that catalyze the catabolic breakdown of sphingomyelin to ceramide. Evidence also supports important role of ceramides in neuronal apoptosis. Ceramides may initiate a cascade of biochemical alterations, which ultimately leads to neuronal death by diverse mechanisms, including depolarization and permeabilization of mitochondria, increased production of reactive oxygen species (ROS, cytochrome c release, Bcl-2 depletion, and caspase-3 activation, mainly by modulating intracellular signalling, particularly along the pathways related to Akt/PKB kinase and mitogen-activated protein kinases (MAPKs. This review summarizes recent findings related to the role of ceramides in oxidative stress-driven neuronal apoptosis and interplay with Aβ in the cascade of events ending in neuronal degeneration.

  8. Feline immunodeficiency virus envelope glycoprotein mediates apoptosis in activated PBMC by a mechanism dependent on gp41 function

    International Nuclear Information System (INIS)

    Garg, Himanshu; Joshi, Anjali; Tompkins, Wayne A.

    2004-01-01

    Feline Immunodeficiency Virus (FIV) is a lentivirus that causes immunodeficiency in cats, which parallels HIV-1-induced immunodeficiency in humans. It has been established that HIV envelope (Env) glycoprotein mediates T cell loss via a mechanism that requires CXCR4 binding. The Env glycoprotein of FIV, similar to HIV, requires CXCR4 binding for viral entry, as well as inducing membrane fusion leading to syncytia formation. However, the role of FIV Env in T cell loss and the molecular mechanisms governing this process have not been elucidated. We studied the role of Env glycoprotein in FIV-mediated T cell apoptosis in an in vitro model. Our studies demonstrate that membrane-expressed FIV Env induces apoptosis in activated feline peripheral blood mononuclear cells (PBMC) by a mechanism that requires CXCR4 binding, as the process was inhibited by CXCR4 antagonist AMD3100 in a dose-dependent manner. Interestingly, studies regarding the role of CD134, the recently identified primary receptor of FIV, suggest that binding to CD134 may not be important for induction of apoptosis in PBMC. However, inhibiting Env-mediated fusion post CXCR4 binding by FIV gp41-specific fusion inhibitor also inhibited apoptosis. Under similar conditions, a fusion-defective gp41 mutant was unable to induce apoptosis in activated PBMC. Our findings are the first report suggesting the potential of FIV Env to mediate apoptosis in bystander cells by a process that is dependent on gp41 function

  9. Mitochondria As the Target for the Modulatory Effect of Curcumin in Oxaliplatin-induced Toxicity in Isolated Rat Liver Mitochondria.

    Science.gov (United States)

    Waseem, Mohammad; Parvez, Suhel; Tabassum, Heena

    2017-01-01

    To explore hepatoprotective action of curcumin (CMN, a bioflavonoid) on oxaliplatin (Oxa)-triggered mitochondrial oxidative stress and respiratory chain complexes in liver of rats. Oxa is a ubiquitously utilized platinum-based chemotherapeutic agent commonly used for the treatment of colorectal cancer. Mitochondria have recently emerged as targets for anticancer drugs in several kinds of toxicity including hepatotoxicity that can lead to neoplastic disease. There is a dearth of evidence involving the role of mitochondria in mediating Oxa-evoked hepatotoxicity and its underlying mechanism is still debatable. The study was performed in mitochondria isolated from liver of Wistar rats. Oxa (200 μg/mL) and CMN (5 μmol) were incubated under in vitro conditions. Oxa evoked a significant increase in the membrane lipid peroxidation (LPO) levels, protein carbonyl (PC) contents, decrease in reduced glutathione (GSH) and nonprotein thiol (NP-SH) levels. Oxa also caused a marked decline in the activities of enzymatic antioxidants and respiratory chain enzymes (I, II, III and V) in liver mitochondria. CMN pre-treatment significantly prevented the activities of enzymatic antioxidants and mitochondrial respiratory chain enzymes. CMN also restored the LPO and PC contents, GSH and NP-SH levels in liver mitochondria. CMN intake might be effective in regulation of Oxa-evoked mitotoxicity during chemotherapy. Moreover, it is included in the armamentarium for anticancer agent-induced oxidative stress. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

  10. Apoptosis-promoted tumorigenesis: γ-irradiation-induced thymic lymphomagenesis requires Puma-driven leukocyte death

    OpenAIRE

    Michalak, Ewa M.; Vandenberg, Cassandra J.; Delbridge, Alex R.D.; Wu, Li; Scott, Clare L.; Adams, Jerry M.; Strasser, Andreas

    2010-01-01

    Although tumor development requires impaired apoptosis, we describe a novel paradigm of apoptosis-dependent tumorigenesis. Because DNA damage triggers apoptosis through p53-mediated induction of BH3-only proteins Puma and Noxa, we explored their roles in γ-radiation-induced thymic lymphomagenesis. Surprisingly, whereas Noxa loss accelerated it, Puma loss ablated tumorigenesis. Tumor suppression by Puma deficiency reflected its protection of leukocytes from γ-irradiation-induced death, because...

  11. Exogenous and Endogeneous Disialosyl Ganglioside GD1b Induces Apoptosis of MCF-7 Human Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Sun-Hyung Ha

    2016-04-01

    Full Text Available Gangliosides have been known to play a role in the regulation of apoptosis in cancer cells. This study has employed disialyl-ganglioside GD1b to apoptosis in human breast cancer MCF-7 cells using exogenous treatment of the cells with GD1b and endogenous expression of GD1b in MCF-7 cells. First, apoptosis in MCF-7 cells was observed after treatment of GD1b. Treatment of MCF-7 cells with GD1b reduced cell growth rates in a dose and time dependent manner during GD1b treatment, as determined by XTT assay. Among the various gangliosides, GD1b specifically induced apoptosis of the MCF-7 cells. Flow cytometry and immunofluorescence assays showed that GD1b specifically induces apoptosis in the MCF-7 cells with Annexin V binding for apoptotic actions in early stage and propidium iodide (PI staining the nucleus of the MCF-7 cells. Treatment of MCF-7 cells with GD1b activated apoptotic molecules such as processed forms of caspase-8, -7 and PARP (Poly(ADP-ribose polymerase, without any change in the expression of mitochondria-mediated apoptosis molecules such as Bax and Bcl-2. Second, to investigate the effect of endogenously produced GD1b on the regulation of cell function, UDP-gal: β1,3-galactosyltransferase-2 (GD1b synthase, Gal-T2 gene has been transfected into the MCF-7 cells. Using the GD1b synthase-transfectants, apoptosis-related signal proteins linked to phenotype changes were examined. Similar to the exogenous GD1b treatment, the cell growth of the GD1b synthase gene-transfectants was significantly suppressed compared with the vector-transfectant cell lines and transfection activated the apoptotic molecules such as processed forms of caspase-8, -7 and PARP, but not the levels of expression of Bax and Bcl-2. GD1b-induced apoptosis was blocked by caspase inhibitor, Z-VAD. Therefore, taken together, it was concluded that GD1b could play an important role in the regulation of breast cancer apoptosis.

  12. Simultaneous modulation of the intrinsic and extrinsic pathways by simvastatin in mediating prostate cancer cell apoptosis

    International Nuclear Information System (INIS)

    Goc, Anna; Kochuparambil, Samith T; Al-Husein, Belal; Al-Azayzih, Ahmad; Mohammad, Shuaib; Somanath, Payaningal R

    2012-01-01

    Recent studies suggest the potential benefits of statins as anti-cancer agents. Mechanisms by which statins induce apoptosis in cancer cells are not clear. We previously showed that simvastatin inhibit prostate cancer cell functions and tumor growth. Molecular mechanisms by which simvastatin induce apoptosis in prostate cancer cells is not completely understood. Effect of simvastatin on PC3 cell apoptosis was compared with docetaxel using apoptosis, TUNEL and trypan blue viability assays. Protein expression of major candidates of the intrinsic pathway downstream of simvastatin-mediated Akt inactivation was analyzed. Gene arrays and western analysis of PC3 cells and tumor lysates were performed to identify the candidate genes mediating extrinsic apoptosis pathway by simvastatin. Data indicated that simvastatin inhibited intrinsic cell survival pathway in PC3 cells by enhancing phosphorylation of Bad, reducing the protein expression of Bcl-2, Bcl-xL and cleaved caspases 9/3. Over-expression of PC3 cells with Bcl-2 or DN-caspase 9 did not rescue the simvastatin-induced apoptosis. Simvastatin treatment resulted in increased mRNA and protein expression of molecules such as TNF, Fas-L, Traf1 and cleaved caspase 8, major mediators of intrinsic apoptosis pathway and reduced protein levels of pro-survival genes Lhx4 and Nme5. Our study provides the first report that simvastatin simultaneously modulates intrinsic and extrinsic pathways in the regulation of prostate cancer cell apoptosis in vitro and in vivo, and render reasonable optimism that statins could become an attractive anti-cancer agent

  13. Quinacrine induces apoptosis in human leukemia K562 cells via p38 MAPK-elicited BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression

    International Nuclear Information System (INIS)

    Changchien, Jung-Jung; Chen, Ying-Jung; Huang, Chia-Hui; Cheng, Tian-Lu; Lin, Shinne-Ren; Chang, Long-Sen

    2015-01-01

    Although previous studies have revealed the anti-cancer activity of quinacrine, its effect on leukemia is not clearly resolved. We sought to explore the cytotoxic effect and mechanism of quinacrine action in human leukemia K562 cells. Quinacrine induced K562 cell apoptosis accompanied with ROS generation, mitochondrial depolarization, and down-regulation of BCL2L1 and BCL2. Upon exposure to quinacrine, ROS-mediated p38 MAPK activation and ERK inactivation were observed in K562 cells. Quinacrine-induced cell death and mitochondrial depolarization were suppressed by the p38MAPK inhibitor SB202190 and constitutively active MEK1 over-expression. Activation of p38 MAPK was shown to promote BCL2 degradation. Further, ERK inactivation suppressed c-Jun-mediated transcriptional expression of BCL2L1. Over-expression of BCL2L1 and BCL2 attenuated quinacrine-evoked mitochondrial depolarization and rescued the viability of quinacrine-treated cells. Taken together, our data indicate that quinacrine-induced K562 cell apoptosis is mediated through mitochondrial alterations triggered by p38 MAPK-mediated BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression. - Highlights: • Quinacrine induces K562 cell apoptosis via down-regulation of BCL2 and BCL2L1. • Quinacrine induces p38 MAPK activation and ERK inactivation in K562 cells. • Quinacrine elicits p38 MAPK-mediated BCL2 down-regulation. • Quinacrine suppresses ERK/c-Jun-mediated BCL2L1 expression

  14. Androgen-Sensitized Apoptosis of HPr-1AR Human Prostate Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Congcong Chen

    Full Text Available Androgen receptor (AR signaling is crucial to the development and homeostasis of the prostate gland, and its dysregulation mediates common prostate pathologies. The mechanisms whereby AR regulates growth suppression and differentiation of luminal epithelial cells in the prostate gland and proliferation of malignant versions of these cells have been investigated in human and rodent adult prostate. However, the cellular stress response of human prostate epithelial cells is not well understood, though it is central to prostate health and pathology. Here, we report that androgen sensitizes HPr-1AR and RWPE-AR human prostate epithelial cells to cell stress agents and apoptotic cell death. Although 5α-dihydrotestosterone (DHT treatment alone did not induce cell death, co-treatment of HPr-1AR cells with DHT and an apoptosis inducer, such as staurosporine (STS, TNFt, or hydrogen peroxide, synergistically increased cell death in comparison to treatment with each apoptosis inducer by itself. We found that the synergy between DHT and apoptosis inducer led to activation of the intrinsic/mitochondrial apoptotic pathway, which is supported by robust cleavage activation of caspase-9 and caspase-3. Further, the dramatic depolarization of the mitochondrial membrane potential that we observed upon co-treatment with DHT and STS is consistent with increased mitochondrial outer membrane permeabilization (MOMP in the pro-apoptotic mechanism. Interestingly, the synergy between DHT and apoptosis inducer was abolished by AR antagonists and inhibitors of transcription and protein synthesis, suggesting that AR mediates pro-apoptotic synergy through transcriptional regulation of MOMP genes. Expression analysis revealed that pro-apoptotic genes (BCL2L11/BIM and AIFM2 were DHT-induced, whereas pro-survival genes (BCL2L1/BCL-XL and MCL1 were DHT-repressed. Hence, we propose that the net effect of these AR-mediated expression changes shifts the balance of BCL2-family proteins

  15. The protective effect of lipid emulsion in preventing bupivacaine-induced mitochondrial injury and apoptosis of H9C2 cardiomyocytes.

    Science.gov (United States)

    Chen, Zhe; Jin, Zhousheng; Xia, Yun; Zhao, Shishi; Xu, Xuzhong; Papadimos, Thomas J; Wang, Quanguang

    2017-11-01

    Lipid emulsion (LE) has been shown to be effective in the resuscitation of bupivacaine-induced cardiac arrest, but the precise mechanism of this action has not been fully elucidated. Pursuant to this lack of information on the mechanism in which LE protects the myocardium during bupivacaine-induced toxicity, we explored mitochondrial function and cell apoptosis. H9C2 cardiomyocytes were used in study. Cells were randomly divided in different groups and were cultivated 6 h, 12 h, and 24 h. The mitochondria were extracted and mitochondrial ATP content was measured, as was mitochondrial membrane potential, the concentration of calcium ion (Ca2+), and the activity of Ca2+-ATP enzyme (Ca2+-ATPase). Cells from groups Bup1000, LE group, and Bup1000LE were collected to determine cell viability, cell apoptosis, and electron microscopy scanning of mitochondrial ultrastructure (after 24 h). We found that LE can reverse the inhibition of the mitochondrial function induced by bupivacaine, regulate the concentration of calcium ion in mitochondria, resulting in the protection of myocardial cells from toxicity induced by bupivacaine.

  16. Paclitaxel-induced apoptosis is BAK-dependent, but BAX and BIM-independent in breast tumor.

    Directory of Open Access Journals (Sweden)

    Anna V Miller

    Full Text Available Paclitaxel (Taxol-induced cell death requires the intrinsic cell death pathway, but the specific participants and the precise mechanisms are poorly understood. Previous studies indicate that a BH3-only protein BIM (BCL-2 Interacting Mediator of cell death plays a role in paclitaxel-induced apoptosis. We show here that BIM is dispensable in apoptosis with paclitaxel treatment using bim(-/- MEFs (mouse embryonic fibroblasts, the bim(-/- mouse breast tumor model, and shRNA-mediated down-regulation of BIM in human breast cancer cells. In contrast, both bak (-/- MEFs and human breast cancer cells in which BAK was down-regulated by shRNA were more resistant to paclitaxel. However, paclitaxel sensitivity was not affected in bax(-/- MEFs or in human breast cancer cells in which BAX was down-regulated, suggesting that paclitaxel-induced apoptosis is BAK-dependent, but BAX-independent. In human breast cancer cells, paclitaxel treatment resulted in MCL-1 degradation which was prevented by a proteasome inhibitor, MG132. A Cdk inhibitor, roscovitine, blocked paclitaxel-induced MCL-1 degradation and apoptosis, suggesting that Cdk activation at mitotic arrest could induce subsequent MCL-1 degradation in a proteasome-dependent manner. BAK was associated with MCL-1 in untreated cells and became activated in concert with loss of MCL-1 expression and its release from the complex. Our data suggest that BAK is the mediator of paclitaxel-induced apoptosis and could be an alternative target for overcoming paclitaxel resistance.

  17. Induction of apoptosis by pinostrobin in human cervical cancer cells: Possible mechanism of action.

    Directory of Open Access Journals (Sweden)

    Alka Jaudan

    Full Text Available Pinostrobin (PN is a naturally occurring dietary bioflavonoid, found in various medicinal herbs/plants. Though anti-cancer potential of many such similar constituents has been demonstrated, critical biochemical targets and exact mechanism for their apoptosis-inducing actions have not been fully elucidated. The present study was aimed to investigate if PN induced apoptosis in cervical cancer cells (HeLa of human origin. It is demonstrated that PN at increasing dose effectivity reduced the cell viability as well as GSH and NO2- levels. Condensed nuclei with fragmented chromatin and changes in mitochondrial matrix morphology clearly indicated the role of mitochondria in PN induced apoptosis. A marked reduction in mitochondrial membrane potential and increased ROS production after PN treatment showed involvement of free radicals, which in turn further augment ROS levels. PN treatment resulted in DNA damage, which could have been triggered by an increase in ROS levels. Decrease in apoptotic cells in the presence of caspase 3 inhibitor in PN-treated cells suggested that PN induced apoptosis via caspase dependent pathways. Additionally, a significant increase in the expression of proteins of extrinsic (TRAIL R1/DR4, TRAIL R2/DR5, TNF RI/TNFRSF1A, FADD, Fas/TNFRSF6 and intrinsic pathway (Bad, Bax, HTRA2/Omi, SMAC/Diablo, cytochrome C, Pro-Caspase-3, Cleaved Caspase-3 was observed in the cells exposed to PN. Taken together, these observations suggest that PN efficiently induces apoptosis through ROS mediated extrinsic and intrinsic dependent signaling pathways, as well as ROS mediated mitochondrial damage in HeLa cells.

  18. Induction of apoptosis by plumbagin through reactive oxygen species-mediated inhibition of topoisomerase II

    International Nuclear Information System (INIS)

    Kawiak, Anna; Piosik, Jacek; Stasilojc, Grzegorz; Gwizdek-Wisniewska, Anna; Marczak, Lukasz; Stobiecki, Maciej; Bigda, Jacek; Lojkowska, Ewa

    2007-01-01

    Reactive oxygen species (ROS) have been recognized as key molecules, which can selectively modify proteins and therefore regulate cellular signalling including apoptosis. Plumbagin, a naphthoquinone exhibiting antitumor activity, is known to generate ROS and has been found to inhibit the activity of topoisomerase II (Topo II) through the stabilization of the Topo II-DNA cleavable complex. The objective of this research was to clarify the role of ROS and Topo II inhibition in the induction of apoptosis mediated by plumbagin. As determined by the comet assay, plumbagin induced DNA cleavage in HL-60 cells, whereas in a cell line with reduced Topo II activity-HL-60/MX2, the level of DNA damage was significantly decreased. The onset of DNA strand break formation in HL-60 cells was delayed in comparison with the generation of intracellular ROS. In HL-60/MX2 cells, ROS were generated at a similar rate, whereas a significant reduction in the level of DNA damage was detected. The pretreatment of cells with N-acetylcysteine (NAC) attenuated plumbagin-induced DNA damage, pointing out to the involvement of ROS generation in cleavable complex formation. These results suggest that plumbagin-induced ROS does not directly damage DNA but requires the involvement of Topo II. Furthermore, experiments carried out using light spectroscopy indicated no direct interactions between plumbagin and DNA. The induction of apoptosis was significantly delayed in HL-60/MX2 cells indicating the involvement of Topo II inhibition in plumbagin-mediated apoptosis. Thus, these findings strongly suggest ROS-mediated inhibition of Topo II as an important mechanism contributing to the apoptosis-inducing properties of plumbagin

  19. Apoptosis and Necrosis in the Liver

    Science.gov (United States)

    Guicciardi, Maria Eugenia; Malhi, Harmeet; Mott, Justin L.; Gores, Gregory J.

    2013-01-01

    Because of its unique function and anatomical location, the liver is exposed to a multitude of toxins and xenobiotics, including medications and alcohol, as well as to infection by hepatotropic viruses, and therefore, is highly susceptible to tissue injury. Cell death in the liver occurs mainly by apoptosis or necrosis, with apoptosis also being the physiologic route to eliminate damaged or infected cells and to maintain tissue homeostasis. Liver cells, especially hepatocytes and cholangiocytes, are particularly susceptible to death receptor-mediated apoptosis, given the ubiquitous expression of the death receptors in the organ. In a quite unique way, death receptor-induced apoptosis in these cells is mediated by both mitochondrial and lysosomal permeabilization. Signaling between the endoplasmic reticulum and the mitochondria promotes hepatocyte apoptosis in response to excessive free fatty acid generation during the metabolic syndrome. These cell death pathways are partially regulated by microRNAs. Necrosis in the liver is generally associated with acute injury (i.e., ischemia/reperfusion injury) and has been long considered an unregulated process. Recently, a new form of “programmed” necrosis (named necroptosis) has been described: the role of necroptosis in the liver has yet to be explored. However, the minimal expression of a key player in this process in the liver suggests this form of cell death may be uncommon in liver diseases. Because apoptosis is a key feature of so many diseases of the liver, therapeutic modulation of liver cell death holds promise. An updated overview of these concepts is given in this article. PMID:23720337

  20. PAR-1 mediated apoptosis of breast cancer cells by V. cholerae hemagglutinin protease.

    Science.gov (United States)

    Ray, Tanusree; Pal, Amit

    2016-05-01

    Bacterial toxins have emerged as promising agents in cancer treatment strategy. Hemagglutinin (HAP) protease secreted by Vibrio cholerae induced apoptosis in breast cancer cells and regresses tumor growth in mice model. The success of novel cancer therapies depends on their selectivity for cancer cells with limited toxicity for normal tissues. Increased expression of Protease Activated Receptor-1 (PAR-1) has been reported in different malignant cells. In this study we report that HAP induced activation and over expression of PAR-1 in breast cancer cells (EAC). Immunoprecipitation studies have shown that HAP specifically binds with PAR-1. HAP mediated activation of PAR-1 caused nuclear translocation of p50-p65 and the phosphorylation of p38 which triggered the activation of NFκB and MAP kinase signaling pathways. These signaling pathways enhanced the cellular ROS level in malignant cells that induced the intrinsic pathway of cell apoptosis. PAR-1 mediated apoptosis by HAP of malignant breast cells without effecting normal healthy cells in the same environment makes it a good therapeutic agent for treatment of cancer.

  1. Apoptosis signaling and radiation protection

    International Nuclear Information System (INIS)

    Morita, Akinori; Suzuki, Norio; Hosoi, Yoshio

    2005-01-01

    Radiation protection by apoptosis control is the suppression of cell death in highly radiosensitive tissues. This paper describes the outline of radiation-induced apoptosis framework, apoptosis-concerned target molecules possibly related to apoptosis by radiation and their inhibitors. Although there are intrinsic (via mitochondria) and extrinsic (via death receptor) pathways in apoptosis, this review mainly mentions the former which is more important in radiation-induced apoptosis. Those molecules known at present in the apoptosis are caspase, Bcl-2 family and p53. Caspase, a group of cystein proteases, initiates apoptosis but its inhibition is known not always to result in apoptosis suppression, suggesting the existence of caspase-independent pathways. Bcl-2 family involves apoptosis-suppressing (possessing BH domains) and -promoting (lacking BH domains or possessing BH3 domain alone/BH3-only protein) groups. Two p53-transcription-dependent and one -independent pathways in p53-induced apoptosis are known and p53 can be a most possible target molecule since it positions at the start of apoptosis. Authors have found a vanadate inactivates p53. Inhibitors affecting upstream molecules of apoptosis will be the most useful candidate for apoptosis suppression/radiation protection. (S.I.) 106 refs

  2. Norcantharidin (NCTD) induces mitochondria mediated apoptosis in ...

    African Journals Online (AJOL)

    Norcantharidin (NCTD), a demethylated form of cantharidin, is now in used as a routine anticancer drug. However, the detailed mechanisms underlying this process are generally unclear. The aims of this study were to evaluate the apoptotic effects and molecular mechanisms of NCTD. MTT assay was used to determine the ...

  3. TGEV nucleocapsid protein induces cell cycle arrest and apoptosis through activation of p53 signaling

    International Nuclear Information System (INIS)

    Ding, Li; Huang, Yong; Du, Qian; Dong, Feng; Zhao, Xiaomin; Zhang, Wenlong; Xu, Xingang; Tong, Dewen

    2014-01-01

    Highlights: • TGEV N protein reduces cell viability by inducing cell cycle arrest and apoptosis. • TGEV N protein induces cell cycle arrest and apoptosis by regulating p53 signaling. • TGEV N protein plays important roles in TGEV-induced cell cycle arrest and apoptosis. - Abstract: Our previous studies showed that TGEV infection could induce cell cycle arrest and apoptosis via activation of p53 signaling in cultured host cells. However, it is unclear which viral gene causes these effects. In this study, we investigated the effects of TGEV nucleocapsid (N) protein on PK-15 cells. We found that TGEV N protein suppressed cell proliferation by causing cell cycle arrest at the S and G2/M phases and apoptosis. Characterization of various cellular proteins that are involved in regulating cell cycle progression demonstrated that the expression of N gene resulted in an accumulation of p53 and p21, which suppressed cyclin B1, cdc2 and cdk2 expression. Moreover, the expression of TGEV N gene promoted translocation of Bax to mitochondria, which in turn caused the release of cytochrome c, followed by activation of caspase-3, resulting in cell apoptosis in the transfected PK-15 cells following cell cycle arrest. Further studies showed that p53 inhibitor attenuated TGEV N protein induced cell cycle arrest at S and G2/M phases and apoptosis through reversing the expression changes of cdc2, cdk2 and cyclin B1 and the translocation changes of Bax and cytochrome c induced by TGEV N protein. Taken together, these results demonstrated that TGEV N protein might play an important role in TGEV infection-induced p53 activation and cell cycle arrest at the S and G2/M phases and apoptosis occurrence

  4. Arsenic-induced alteration in intracellular calcium homeostasis induces head kidney macrophage apoptosis involving the activation of calpain-2 and ERK in Clarias batrachus

    International Nuclear Information System (INIS)

    Banerjee, Chaitali; Goswami, Ramansu; Datta, Soma; Rajagopal, R.; Mazumder, Shibnath

    2011-01-01

    We had earlier shown that exposure to arsenic (0.50 μM) caused caspase-3 mediated head kidney macrophage (HKM) apoptosis involving the p38-JNK pathway in Clarias batrachus. Here we examined the roles of calcium (Ca 2+ ) and extra-cellular signal-regulated protein kinase (ERK), the other member of MAPK-pathway on arsenic-induced HKM apoptosis. Arsenic-induced HKM apoptosis involved increased expression of ERK and calpain-2. Nifedipine, verapamil and EGTA pre-treatment inhibited the activation of calpain-2, ERK and reduced arsenic-induced HKM apoptosis as evidenced from reduced caspase-3 activity, Annexin V-FITC-propidium iodide and Hoechst 33342 staining. Pre-incubation with ERK inhibitor U 0126 inhibited the activation of calpain-2 and interfered with arsenic-induced HKM apoptosis. Additionally, pre-incubation with calpain-2 inhibitor also interfered with the activation of ERK and inhibited arsenic-induced HKM apoptosis. The NADPH oxidase inhibitor apocynin and diphenyleneiodonium chloride also inhibited ERK activation indicating activation of ERK in arsenic-exposed HKM also depends on signals from NADPH oxidase pathway. Our study demonstrates the critical role of Ca 2+ homeostasis on arsenic-induced HKM apoptosis. We suggest that arsenic-induced alteration in intracellular Ca 2+ levels initiates pro-apoptotic ERK and calpain-2; the two pathways influence each other positively and induce caspase-3 mediated HKM apoptosis. Besides, our study also indicates the role of ROS in the activation of ERK pathway in arsenic-induced HKM apoptosis in C. batrachus. - Highlights: → Altered Ca 2+ homeostasis leads to arsenic-induced HKM apoptosis. → Calpain-2 plays a critical role in the process. → ERK is pro-apoptotic in arsenic-induced HKM apoptosis. → Arsenic-induced HKM apoptosis involves cross talk between calpain-2 and ERK.

  5. Single-prolonged stress induces apoptosis in dorsal raphe nucleus in the rat model of posttraumatic stress disorder

    Directory of Open Access Journals (Sweden)

    Liu Dongjuan

    2012-11-01

    Full Text Available Abstract Introduction Post-traumatic stress disorder (PTSD is an anxiety disorder that develops after exposure to a life-threatening traumatic experience. Meta-analyses of the brainstem showed that midsagittal area of the pons was significantly reduced in patients with PTSD, suggesting a potential apoptosis in dorsal raphe nucleus after single-prolonged stress (SPS. The aim of this study is to investigate whether SPS induces apoptosis in dorsal raphe nucleus in PTSD rats, which may be a possible mechanism of reduced volume of pons and density of gray matter. Methods In this study, rats were randomly divided into 1d, 7d and 14d groups after SPS along with the control group. The apoptosis rate was determined using annexin V-FITC/PI double-labeled flow cytometry (FCM. Levels of Cytochrome c (Cyt-C was examined by Western blotting. Expression of Cyt-C on mitochondria in the dorsal raphe nucleus neuron was determined by enzymohistochemistry under transmission electron microscopy (TEM. The change of thiamine monophosphatase (TMP levels was assessed by enzymohistochemistry under light microscope and TEM. Morphological changes of the ultrastructure of the dorsal raphe nucleus neuron were determined by TEM. Results Apoptotic morphological alterations were observed in dorsal raphe nucleus neuron for all SPS-stimulate groups of rats. The apoptosis rates were significantly increased in dorsal raphe nucleus neuron of SPS rats, along with increased release of cytochrome c from the mitochondria into the cytoplasm, increased expression of Cyt-C and TMP levels in the cytoplasm, which reached to the peak of increase 7 days of SPS. Conclusions The results indicate that SPS induced Cyt-C released from mitochondria into cytosol and apoptosis in dorsal raphe nucleus neuron of rats. Increased TMP in cytoplasm facilitated the clearance of apoptotic cells. We propose that this presents one of the mechanisms that lead to reduced volume of pons and gray matter associated

  6. Activating transcription factor 4 underlies the pathogenesis of arsenic trioxide-mediated impairment of macrophage innate immune functions

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Ritesh K.; Li, Changzhao [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL (United States); Wang, Yong [Department of Medicine, University of Alabama at Birmingham, Birmingham, AL (United States); Weng, Zhiping; Elmets, Craig A. [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL (United States); Harrod, Kevin S. [Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL (United States); Deshane, Jessy S., E-mail: treena@uab.edu [Department of Medicine, University of Alabama at Birmingham, Birmingham, AL (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL (United States)

    2016-10-01

    Chronic arsenic exposure to humans is considered immunosuppressive with augmented susceptibility to several infectious diseases. The exact molecular mechanisms, however, remain unknown. Earlier, we showed the involvement of unfolded protein response (UPR) signaling in arsenic-mediated impairment of macrophage functions. Here, we show that activating transcription factor 4 (ATF4), a UPR transcription factor, regulates arsenic trioxide (ATO)-mediated dysregulation of macrophage functions. In ATO-treated ATF4{sup +/+} wild-type mice, a significant down-regulation of CD11b expression was associated with the reduced phagocytic functions of peritoneal and lung macrophages. This severe immuno-toxicity phenotype was not observed in ATO-treated ATF4{sup +/−} heterozygous mice. To confirm these observations, we demonstrated in Raw 264.7 cells that ATF4 knock-down rescues ATO-mediated impairment of macrophage functions including cytokine production, bacterial engulfment and clearance of engulfed bacteria. Sustained activation of ATF4 by ATO in macrophages induces apoptosis, while diminution of ATF4 expression protects against ATO-induced apoptotic cell death. Raw 264.7 cells treated with ATO also manifest dysregulated Ca{sup ++} homeostasis. ATO induces Ca{sup ++}-dependent calpain-1 and caspase-12 expression which together regulated macrophage apoptosis. Additionally, apoptosis was also induced by mitochondria-regulated pathway. Restoring ATO-impaired Ca{sup ++} homeostasis in ER/mitochondria by treatments with the inhibitors of inositol 1,4,5-trisphosphate receptor (IP3R) and voltage-dependent anion channel (VDAC) attenuate innate immune functions of macrophages. These studies identify a novel role for ATF4 in underlying pathogenesis of macrophage dysregulation and immuno-toxicity of arsenic. - Highlights: • ATF4 regulates arsenic-mediated impairment in macrophage functions. • Arsenic-mediated alterations in pulmonary macrophage are diminished in ATF4{sup +/−} mice

  7. Activating transcription factor 4 underlies the pathogenesis of arsenic trioxide-mediated impairment of macrophage innate immune functions

    International Nuclear Information System (INIS)

    Srivastava, Ritesh K.; Li, Changzhao; Wang, Yong; Weng, Zhiping; Elmets, Craig A.; Harrod, Kevin S.; Deshane, Jessy S.; Athar, Mohammad

    2016-01-01

    Chronic arsenic exposure to humans is considered immunosuppressive with augmented susceptibility to several infectious diseases. The exact molecular mechanisms, however, remain unknown. Earlier, we showed the involvement of unfolded protein response (UPR) signaling in arsenic-mediated impairment of macrophage functions. Here, we show that activating transcription factor 4 (ATF4), a UPR transcription factor, regulates arsenic trioxide (ATO)-mediated dysregulation of macrophage functions. In ATO-treated ATF4 +/+ wild-type mice, a significant down-regulation of CD11b expression was associated with the reduced phagocytic functions of peritoneal and lung macrophages. This severe immuno-toxicity phenotype was not observed in ATO-treated ATF4 +/− heterozygous mice. To confirm these observations, we demonstrated in Raw 264.7 cells that ATF4 knock-down rescues ATO-mediated impairment of macrophage functions including cytokine production, bacterial engulfment and clearance of engulfed bacteria. Sustained activation of ATF4 by ATO in macrophages induces apoptosis, while diminution of ATF4 expression protects against ATO-induced apoptotic cell death. Raw 264.7 cells treated with ATO also manifest dysregulated Ca ++ homeostasis. ATO induces Ca ++ -dependent calpain-1 and caspase-12 expression which together regulated macrophage apoptosis. Additionally, apoptosis was also induced by mitochondria-regulated pathway. Restoring ATO-impaired Ca ++ homeostasis in ER/mitochondria by treatments with the inhibitors of inositol 1,4,5-trisphosphate receptor (IP3R) and voltage-dependent anion channel (VDAC) attenuate innate immune functions of macrophages. These studies identify a novel role for ATF4 in underlying pathogenesis of macrophage dysregulation and immuno-toxicity of arsenic. - Highlights: • ATF4 regulates arsenic-mediated impairment in macrophage functions. • Arsenic-mediated alterations in pulmonary macrophage are diminished in ATF4 +/− mice. • Changes in macrophage

  8. The phytopathogenic virulent effector protein RipI induces apoptosis in budding yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Deng, Meng-Ying; Sun, Yun-Hao; Li, Pai; Fu, Bei; Shen, Dong; Lu, Yong-Jun

    2016-10-01

    Virulent protein toxins secreted by the bacterial pathogens can cause cytotoxicity by various molecular mechanisms to combat host cell defense. On the other hand, these proteins can also be used as probes to investigate the defense pathway of host innate immunity. Ralstonia solanacearum, one of the most virulent bacterial phytopathogens, translocates more than 70 effector proteins via type III secretion system during infection. Here, we characterized the cytotoxicity of effector RipI in budding yeast Saccharomyce scerevisiae, an alternative host model. We found that over-expression of RipI resulted in severe growth defect and arginine (R) 117 within the predicted integrase motif was required for inhibition of yeast growth. The phenotype of death manifested the hallmarks of apoptosis. Our data also revealed that RipI-induced apoptosis was independent of Yca1 and mitochondria-mediated apoptotic pathways because Δyca1 and Δaif1 were both sensitive to RipI as compared with the wild type. We further demonstrated that RipI was localized in the yeast nucleus and the N-terminal 1-174aa was required for the localization. High-throughput RNA sequencing analysis showed that upon RipI over-expression, 101 unigenes of yeast ribosome presented lower expression level, and 42 GO classes related to the nucleus or recombination were enriched with differential expression levels. Taken together, our data showed that a nuclear-targeting effector RipI triggers yeast apoptosis, potentially dependent on its integrase function. Our results also provided an alternative strategy to dissect the signaling pathway of cytotoxicity induced by the protein toxins. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Ginsenoside Rb1 Protects Neonatal Rat Cardiomyocytes from Hypoxia/Ischemia Induced Apoptosis and Inhibits Activation of the Mitochondrial Apoptotic Pathway

    Directory of Open Access Journals (Sweden)

    Xu Yan

    2014-01-01

    Full Text Available Aim. To investigate the effect of Ginsenoside Rb1 (GS-Rb1 on hypoxia/ischemia (H/I injury in cardiomyocytes in vitro and the mitochondrial apoptotic pathway mediated mechanism. Methods. Neonatal rat cardiomyocytes (NRCMs for the H/I groups were kept in DMEM without glucose and serum, and were placed into a hypoxic jar for 24 h. GS-Rb1 at concentrations from 2.5 to 40 µM was given during hypoxic period for 24 h. NRCMs injury was determined by MTT and lactate dehydrogenase (LDH leakage assay. Cell apoptosis, ROS accumulation, and mitochondrial membrane potential (MMP were assessed by flow cytometry. Cytosolic translocation of mitochondrial cytochrome c and Bcl-2 family proteins were determined by Western blot. Caspase-3 and caspase-9 activities were determined by the assay kit. Results. GS-Rb1 significantly reduced cell death and LDH leakage induced by H/I. It also reduced H/I induced NRCMs apoptosis induced by H/I, in accordance with a minimal reactive oxygen species (ROS burst. Moreover, GS-Rb1 markedly decreased the translocation of cytochrome c from the mitochondria to the cytosol, increased the Bcl-2/ Bax ratio, and preserved mitochondrial transmembrane potential (ΔΨm. Its administration also inhibited activities of caspase-9 and caspase-3. Conclusion. Administration of GS-Rb1 during H/I in vitro is involved in cardioprotection by inhibiting apoptosis, which may be due to inhibition of the mitochondrial apoptotic pathway.

  10. Cigarette smoke causes caspase-independent apoptosis of bronchial epithelial cells from asthmatic donors.

    Directory of Open Access Journals (Sweden)

    Fabio Bucchieri

    Full Text Available Epidemiologic studies have demonstrated important links between air pollution and asthma. Amongst these pollutants, environmental cigarette smoke is a risk factor both for asthma pathogenesis and exacerbation. As the barrier to the inhaled environment, the bronchial epithelium is a key structure that is exposed to cigarette smoke.Since primary bronchial epithelial cells (PBECs from asthmatic donors are more susceptible to oxidant-induced apoptosis, we hypothesized that they would be susceptible to cigarette smoke-induced cell death.PBECs from normal and asthmatic donors were exposed to cigarette smoke extract (CSE; cell survival and apoptosis were assessed by fluorescence-activated cell sorting, and protective effects of antioxidants evaluated. The mechanism of cell death was evaluated using caspase inhibitors and immunofluorescent staining for apoptosis-inducing factor (AIF.Exposure of PBEC cultures to CSE resulted in a dose-dependent increase in cell death. At 20% CSE, PBECs from asthmatic donors exhibited significantly more apoptosis than cells from non-asthmatic controls. Reduced glutathione (GSH, but not ascorbic acid (AA, protected against CSE-induced apoptosis. To investigate mechanisms of CSE-induced apoptosis, caspase-3 or -9 inhibitors were tested, but these failed to prevent apoptosis; in contrast, CSE promoted nuclear translocation of AIF from the mitochondria. GSH reduced the number of nuclear-AIF positive cells whereas AA was ineffective.Our results show that PBECs from asthmatic donors are more susceptible to CSE-induced apoptosis. This response involves AIF, which has been implicated in DNA damage and ROS-mediated cell-death. Epithelial susceptibility to CSE may contribute to the impact of environmental tobacco smoke in asthma.

  11. JALUR MOLEKULER MEKANISME APOPTOSIS

    Directory of Open Access Journals (Sweden)

    Yani Corvianindya Rahayu

    2015-07-01

    Full Text Available Apoptosis or programmed cell death is a normal condition for development and live multicellular organism. Apoptosis is a morphological phenomenon that plays an important role in physiologic processes during fetal development and in adult. Mitochondria play an important role in apoptosis. Mitochondria can do apoptosis directly. Mitochondria has 2 family of protein Bcl-2. Bcl-2 and Bcl-XL are anti apoptosis while Bad an Bax are pro apoptosis. There are 3 different mechanism to receptors at the cell surface and a third may be triggered by dangerous agent that different from two ways before. Apoptosis also need caspase as cell death executor. Study of apoptosis still done especially in case of disease. Some disease have known related with disturbing of apoptosis mechanism for example cancer and auto immune. This article reviews about molecular mechanism of apoptosis for understanding disease and future therapy.

  12. A new brominated chalcone derivative suppresses the growth of gastric cancer cells in vitro and in vivo involving ROS mediated up-regulation of DR5 and 4 expression and apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Saiyang; Li, Tingyu; Zhang, Yanbing; Xu, Hongde; Li, Yongchun [School of Pharmaceutical Sciences, Key Laboratory of State Ministry of Education, Key Laboratory of Henan province for Drug Quality Control and Evaluation, Collaborative Innovation Center of New Drug Research and Safety Evaluation, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001 (China); Zi, Xiaolin [Department of Urology, University of California, Irvine, Orange (United States); Department of Pharmacology, University of California, Irvine, Orange (United States); Department of Pharmaceutical Sciences, University of California, Irvine, Orange (United States); Yu, Haiyang [Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin Key Laboratory of TCM Chemistry and Analysis, Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 312 Anshanxi Road, Nankai District, Tianjin 300193 (China); Li, Jinfeng [Kidney Transplantation, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe Road, Erqi District, Zhengzhou, Henan 450001 (China); Jin, Cheng-Yun, E-mail: cyjin@zzu.edu.cn [School of Pharmaceutical Sciences, Key Laboratory of State Ministry of Education, Key Laboratory of Henan province for Drug Quality Control and Evaluation, Collaborative Innovation Center of New Drug Research and Safety Evaluation, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001 (China); Liu, Hong-Min, E-mail: liuhm@zzu.edu.cn [School of Pharmaceutical Sciences, Key Laboratory of State Ministry of Education, Key Laboratory of Henan province for Drug Quality Control and Evaluation, Collaborative Innovation Center of New Drug Research and Safety Evaluation, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001 (China)

    2016-10-15

    A new series of 20 brominated chalcone derivatives were designed, synthesized, and investigated for their effects against the growth of four cancer cell lines (EC109, SKNSH, HepG2, MGC803). Among them, compound 19 which given chemical name of H72, was the most potent one on gastric cancer cell lines (i.e. MGC803, HGC27, SGC7901) with IC{sub 50s} ranged from 3.57 to 5.61 μM. H72 exhibited less cytotoxicity to non-malignant gastric epithelial cells GES-1. H72 treatment of MGC803 and HGC27 induced generation of reactive oxygen species (ROS) leading to activation of caspase 9/3 cascade and mitochondria mediated apoptosis. H72 also up-regulated the expression of DR5, DR4 and Bim{sub EL}, and down-regulated the expression of Bid, Bcl-xL, and XIAP. N-acetyl cysteine (NAC), a ROS scavenger completely blocked these effects of H72 in MGC803 cells. Intraperitoneal administration of H72 significantly inhibited the growth of MGC803 cells in vivo in a xenograft mouse model without observed toxicity. These results indicated that H72 is a lead brominated chalcone derivate and deserves further investigation for prevention and treatment of gastric cancer. - Highlights: • 20 brominated chalcone derivatives were designed and synthesized. • H72 caused potent cytotoxic activity against MGC803 and less against GES1. • H72 led to activation of caspase 9/3 cascade and mitochondria mediated apoptosis. • H72 induced generation of reactive oxygen species (ROS). • H72 significantly inhibited the growth of MGC803 cells in vivo.

  13. Penta-acetyl geniposide-induced apoptosis involving transcription of NGF/p75 via MAPK-mediated AP-1 activation in C6 glioma cells

    International Nuclear Information System (INIS)

    Peng, C.-H.; Huang, C.-N.; Hsu, S.-P.; Wang, C.-J.

    2007-01-01

    We have demonstrated the herbal derivative penta-acetyl geniposide ((Ac) 5 GP) induces C6 glioma cell apoptosis through the critical sphingomyelinase (SMase)/nerve growth factor (NGF)/p75 and its downstream signals. It has been reported mitogen-activated protein kinase (MAPK) mediates NGF synthesis induced by SMase activation. In this study, ERK, p38 and JNK are shown to mediate (Ac) 5 GP-induced glioma cell apoptosis and elevation of NGF and p75. Treatment of PD98059 (ERK-specific inhibitor), SB203580 (p38 MAPK inhibitor) and SP600125 (JNK inhibitor) decreases the elevation of NGF and p75 mRNA induced by (Ac) 5 GP, indicating possible transcription regulation via MAPKs. The results of nuclear extract blotting and EMSA further confirm (Ac) 5 GP maximally increases AP-1 and NF-κB DNA binding at 6 h. Inhibition of ERK, p38 and JNK block the activation of AP-1 and NF-κB, suggesting these MAPKs are involved in (Ac) 5 GP-induced transcription regulation. We thereby used RT-PCR to analyze cells treated with (Ac) 5 GP, with or without AP-1 or NF-κB inhibitors. AP-1 inhibitor NDGA decreases NGF/p75 and expression of FasL and caspase 3 induced by (Ac) 5 GP, suggesting the importance of AP-1 in mediating NGF/p75 and their downstream apoptotic signals. However, FasL and caspase 3 do not change with the NF-κB inhibitor PDTC; NF-κB might be linked to other cellular events. Overall, we demonstrate that MAPK mediates (Ac) 5 GP-induced activation of AP-1, promoting the transcription of NGF/p75 and downstream apoptotic signals. These results further highlight the potential therapeutic effects of (Ac) 5 GP in chemoprevention or as an anti-tumor agent

  14. Changes in mitochondrial dynamics during ceramide-induced cardiomyocyte early apoptosis.

    Science.gov (United States)

    Parra, Valentina; Eisner, Veronica; Chiong, Mario; Criollo, Alfredo; Moraga, Francisco; Garcia, Alejandra; Härtel, Steffen; Jaimovich, Enrique; Zorzano, Antonio; Hidalgo, Cecilia; Lavandero, Sergio

    2008-01-15

    In cells, mitochondria are organized as a network of interconnected organelles that fluctuate between fission and fusion events (mitochondrial dynamics). This process is associated with cell death. We investigated whether activation of apoptosis with ceramides affects mitochondrial dynamics and promotes mitochondrial fission in cardiomyocytes. Neonatal rat cardiomyocytes were incubated with C(2)-ceramide or the inactive analog dihydro-C(2)-ceramide for up to 6 h. Three-dimensional images of cells loaded with mitotracker green were obtained by confocal microscopy. Dynamin-related protein-1 (Drp-1) and mitochondrial fission protein 1 (Fis1) distribution and levels were studied by immunofluorescence and western blot. Mitochondrial membrane potential (DeltaPsi(m)) and cytochrome c (cyt c) distribution were used as indexes of early activation of apoptosis. Cell viability and DNA fragmentation were determined by propidium iodide staining/flow cytometry, whereas cytotoxicity was evaluated by lactic dehydrogenase activity. To decrease the levels of the mitochondrial fusion protein mitofusin 2, we used an antisense adenovirus (AsMfn2). C(2)-ceramide, but not dihydro-C(2)-ceramide, promoted rapid fragmentation of the mitochondrial network in a concentration- and time-dependent manner. C(2)-ceramide also increased mitochondrial Drp-1 and Fis1 content, Drp-1 colocalization with Fis1, and caused early activation of apoptosis. AsMfn2 accentuated the decrease in DeltaPsi(m) and cyt c redistribution induced by C(2)-ceramide. Doxorubicin, which induces cardiomyopathy and apoptosis through ceramide generation, also stimulated mitochondrial fragmentation. Ceramides stimulate mitochondrial fission and this event is associated with early activation of cardiomyocyte apoptosis.

  15. BH3-only protein Bim is associated with the degree of Helicobacter pylori-induced gastritis and is localized to the mitochondria of inflammatory cells in the gastric mucosa.

    Science.gov (United States)

    Akazawa, Yuko; Matsuda, Katsuya; Isomoto, Hajime; Matsushima, Kayoko; Kido, Yoko; Urabe, Shigetoshi; Yamaghchi, Naoyuki; Ohnita, Ken; Takeshima, Fuminao; Kondo, Hisayoshi; Tsugawa, Hitoshi; Suzuki, Hidekazu; Moss, Joel; Nakao, Kazuhiko; Nakashima, Masahiro

    2015-09-01

    BH3-only protein, Bim, is a pro-apoptotic protein that mediates mitochondria-dependent cell death. However, the role of Bim in Helicobacter pylori-associated gastritis remains unclear. This study aimed to assess the cellular localization of Bim and its possible role in H. pylori-induced gastritis. The study was conducted on biopsy specimens obtained from 80 patients who underwent upper gastrointestinal endoscopy (H. pylori-negative: n=30, positive: n=50). Association between Bim mRNA expression and severity of gastritis was evaluated and the localization of Bim was examined by immunofluorescence. Bim mRNA expression was positively correlated with the degree of gastritis, as defined by the Sydney system. Immunohistochemical analysis confirmed increased Bim expression in H. pylori-infected gastric mucosa compared with uninfected mucosa in both humans and mice. Bim localized in myeloperoxidase- and CD138-positive cells of H. pylori-infected lamina propria and submucosa of the gastric tract, indicating that this protein is predominantly expressed in neutrophils and plasma cells. In contrast, Bim did not localize in CD20-, CD3-, or CD68-positive cells. Bim was expressed in the mitochondria, where it was partially co-localized with activated Bax and cleaved-PARP. In conclusion, Bim is expressed in neutrophils and plasma cells in H. pylori-associated gastritis, where it may participate in the termination of inflammatory response by causing mitochondria-mediated apoptosis in specific leucocytes. Copyright © 2015 Elsevier GmbH. All rights reserved.

  16. Involvement of p38 MAPK- and JNK-modulated expression of Bcl-2 and Bax in Naja nigricollis CMS-9-induced apoptosis of human leukemia K562 cells.

    Science.gov (United States)

    Chen, Ying-Jung; Liu, Wen-Hsin; Kao, Pei-Hsiu; Wang, Jeh-Jeng; Chang, Long-Sen

    2010-06-15

    CMS-9, a phospholipase A(2) (PLA(2)) isolated from Naja nigricollis venom, induced apoptosis of human leukemia K562 cells, characterized by mitochondrial depolarization, modulation of Bcl-2 family members, cytochrome c release and activation of caspases 9 and 3. Moreover, an increase in intracellular Ca2+ concentration and the production of reactive oxygen species (ROS) was noted. Pretreatment with BAPTA-AM (Ca2+ chelator) and N-acetylcysteine (NAC, ROS scavenger) proved that Ca2+ was an upstream event in inducing ROS generation. Upon exposure to CMS-9, activation of p38 MAPK and JNK was observed in K562 cells. BAPTA-AM or NAC abrogated CMS-9-elicited p38 MAPK and JNK activation, and rescued viability of CMS-9-treated K562 cells. SB202190 (p38 MAPK inhibitor) and SP600125 (JNK inhibitor) suppressed CMS-9-induced dissipation of mitochondrial membrane potential, Bcl-2 down-regulation, Bax up-regulation and increased mitochondrial translocation of Bax. Inactivation of PLA(2) activity reduced drastically the cytotoxicity of CMS-9, and a combination of lysophosphatidylcholine and stearic acid mimicked the cytotoxic effects of CMS-9. Taken together, our data suggest that CMS-9-induced apoptosis of K562 cells is catalytic activity-dependent and is mediated through mitochondria-mediated death pathway triggered by Ca2+/ROS-evoked p38 MAPK and JNK activation. 2010 Elsevier Ltd. All rights reserved.

  17. Iodinated contrast media induce neutrophil apoptosis through a mitochondrial and caspase mediated pathway.

    LENUS (Irish Health Repository)

    Fanning, N F

    2012-02-03

    Iodinated contrast media (ICM) can induce apoptosis (programmed cell death) in renal, myocardial and endothelial cells. Following intravascular injection, circulating immune cells are exposed to high concentrations of ICM. As neutrophils constitutively undergo apoptosis we hypothesized that ICM may adversely affect neutrophil survival. Our aim was to investigate the effect of ICM on neutrophil apoptosis. Neutrophils were isolated from healthy subjects and cultured in vitro with ionic (diatrizoate and ioxaglate) and non-ionic (iohexol and iotrolan) ICM. The effect of ICM on neutrophil apoptosis in both unstimulated and lipopolysaccharide-stimulated neutrophils was determined by annexin V flow cytometry. The influence of physicochemical properties of the different ICM on apoptosis of neutrophils was also studied. We further investigated the effects of ICM on key intracellular signal pathways, including p38 mitogen-activated protein kinase (MAPK) by Western blotting, and mitochondrial depolarization and caspase activity by flow cytometry. Isoiodine concentrations (20 mg ml(-1)) of ionic (diatrizoate 69.6+\\/-2.9%; ioxaglate 58.9+\\/-2.0%) and non-ionic (iohexol 57.3+\\/-2.9%; iotrolan 57.1+\\/-2.6%) ICM significantly induced neutrophil apoptosis over control levels (47.7+\\/-1.4%). The apoptotic effect of ICM was influenced by their chemical structure, with ionic ICM having a more significant (p<0.01) apoptotic effect than non-ionic ICM (p<0.05). Furthermore, ICM reversed the anti-apoptotic effect of lipopolysaccharide (1000 ng ml(-1)) treated neutrophils to control levels (23.0+\\/-3.5% to 61.2+\\/-5.3%; n=4; p<0.05). These agents induce apoptosis through a p38 MAPK independent pathway that results in mitochondrial depolarization, and is dependent on caspase activation. As neutrophils play a central role in host response to infection and injury, ICM, through induction of neutrophil apoptosis, could have a significant deleterious effect on host immune defence and

  18. EspC, an Autotransporter Protein Secreted by Enteropathogenic Escherichia coli, Causes Apoptosis and Necrosis through Caspase and Calpain Activation, Including Direct Procaspase-3 Cleavage

    Directory of Open Access Journals (Sweden)

    Antonio Serapio-Palacios

    2016-06-01

    Full Text Available Enteropathogenic Escherichia coli (EPEC has the ability to antagonize host apoptosis during infection through promotion and inhibition of effectors injected by the type III secretion system (T3SS, but the total number of these effectors and the overall functional relationships between these effectors during infection are poorly understood. EspC produced by EPEC cleaves fodrin, paxillin, and focal adhesion kinase (FAK, which are also cleaved by caspases and calpains during apoptosis. Here we show the role of EspC in cell death induced by EPEC. EspC is involved in EPEC-mediated cell death and induces both apoptosis and necrosis in epithelial cells. EspC induces apoptosis through the mitochondrial apoptotic pathway by provoking (i a decrease in the expression levels of antiapoptotic protein Bcl-2, (ii translocation of the proapoptotic protein Bax from cytosol to mitochondria, (iii cytochrome c release from mitochondria to the cytoplasm, (iv loss of mitochondrial membrane potential, (v caspase-9 activation, (vi cleavage of procaspase-3 and (vii an increase in caspase-3 activity, (viii PARP proteolysis, and (ix nuclear fragmentation and an increase in the sub-G1 population. Interestingly, EspC-induced apoptosis was triggered through a dual mechanism involving both independent and dependent functions of its EspC serine protease motif, the direct cleavage of procaspase-3 being dependent on this motif. This is the first report showing a shortcut for induction of apoptosis by the catalytic activity of an EPEC protein. Furthermore, this atypical intrinsic apoptosis appeared to induce necrosis through the activation of calpain and through the increase of intracellular calcium induced by EspC. Our data indicate that EspC plays a relevant role in cell death induced by EPEC.

  19. Involvement of caspase-dependent and -independent apoptotic pathways in cisplatin-induced apoptosis

    Science.gov (United States)

    Liu, Lei; Zhang, Yingjie; Wang, Xianwang

    2009-02-01

    Cisplatin, an efficient anticancer agent, can trigger multiple apoptotic pathways in cancer cells. However, the signal transduction pathways in response to cisplatin-based chemotherapy are complicated, and the mechanism is not fully understood. In current study, we showed that, during cisplatin-induced apoptosis of human lung adenocarcinoma cells, both the caspase-dependent and -independent pathways were activated. Herein, we reported that after cisplatin treatment, the activities of caspase-9/-3 were sharply increased; pre-treatment with Z-LEHD-fmk (inhibitor of caspase-9), Z-DEVD-fmk (inhibitor of caspase-3), and Z-VAD-fmk (a pan-caspase inhibitor) increased cell viability and decreased apoptosis, suggesting that caspase-mediated apoptotic pathway was activated following cisplatin treatment. Confocal imaging of the cells transfected with AIF-GFP demonstrated that AIF release occurred about 9 h after cisplatin treatment. The event proceeded progressively over time, coinciding with a nuclear translocation and lasting for more than 2 hours. Down-regulation of AIF by siRNA also significantly increased cell viability and decreased apoptosis, these results suggested that AIF-mediated caspase-independent apoptotic pathway was involved in cispatin-induced apoptosis. In conclusion, the current study demonstrated that both caspase-dependent and -independent apoptotic pathways were involved in cisplatin-induced apoptosis in human lung adenocarcinoma cells.

  20. Mitochondrial shape governs BAX-induced membrane permeabilization and apoptosis.

    Science.gov (United States)

    Renault, Thibaud T; Floros, Konstantinos V; Elkholi, Rana; Corrigan, Kelly-Ann; Kushnareva, Yulia; Wieder, Shira Y; Lindtner, Claudia; Serasinghe, Madhavika N; Asciolla, James J; Buettner, Christoph; Newmeyer, Donald D; Chipuk, Jerry E

    2015-01-08

    Proapoptotic BCL-2 proteins converge upon the outer mitochondrial membrane (OMM) to promote mitochondrial outer membrane permeabilization (MOMP) and apoptosis. Here we investigated the mechanistic relationship between mitochondrial shape and MOMP and provide evidence that BAX requires a distinct mitochondrial size to induce MOMP. We utilized the terminal unfolded protein response pathway to systematically define proapoptotic BCL-2 protein composition after stress and then directly interrogated their requirement for a productive mitochondrial size. Complementary biochemical, cellular, in vivo, and ex vivo studies reveal that Mfn1, a GTPase involved in mitochondrial fusion, establishes a mitochondrial size that is permissive for proapoptotic BCL-2 family function. Cells with hyperfragmented mitochondria, along with size-restricted OMM model systems, fail to support BAX-dependent membrane association and permeabilization due to an inability to stabilize BAXα9·membrane interactions. This work identifies a mechanistic contribution of mitochondrial size in dictating BAX activation, MOMP, and apoptosis. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Role of mitochondria in parvovirus pathology.

    Directory of Open Access Journals (Sweden)

    Jonna Nykky

    Full Text Available Proper functioning of the mitochondria is crucial for the survival of the cell. Viruses are able to interfere with mitochondrial functions as they infect the host cell. Parvoviruses are known to induce apoptosis in infected cells, but the role of the mitochondria in parvovirus induced cytopathy is only partially known. Here we demonstrate with confocal and electron microscopy that canine parvovirus (CPV associated with the mitochondrial outer membrane from the onset of infection. During viral entry a transient depolarization of the mitochondrial transmembrane potential and increase in ROS level was detected. Subsequently, mitochondrial homeostasis was normalized shortly, as detected by repolarization of the mitochondrial membrane and decrease of ROS. Indeed, activation of cell survival signalling through ERK1/2 cascade was observed early in CPV infected cells. At 12 hours post infection, concurrent with the expression of viral non-structural protein 1, damage to the mitochondrial structure and depolarization of its membrane were apparent. Results of this study provide additional insight of parvovirus pathology and also more general information of virus-mitochondria association.

  2. Involvement of Bcl-xL degradation and mitochondrial-mediated apoptotic pathway in pyrrolizidine alkaloids-induced apoptosis in hepatocytes

    International Nuclear Information System (INIS)

    Ji Lili; Chen Ying; Liu Tianyu; Wang Zhengtao

    2008-01-01

    Pyrrolizidine alkaloids (PAs) are natural hepatotoxins with worldwide distribution in more than 6000 high plants including medicinal herbs or teas. The aim of this study is to investigate the signal pathway involved in PAs-induced hepatotoxicity. Our results showed that clivorine, isolated from Ligularia hodgsonii Hook, decreased cell viability and induced apoptosis in L-02 cells and mouse hepatocytes. Western-blot results showed that clivorine induced caspase-3/-9 activation, mitochondrial release of cytochrome c and decreased anti-apoptotic Bcl-xL in a time (8-48 h)- and concentration (1-100 μM)-dependent manner. Furthermore, inhibitors of pan-caspase, caspase-3 and caspase-9 significantly inhibited clivorine-induced apoptosis and rescued clivorine-decreased cell viability. Polyubiquitination of Bcl-xL was detected after incubation with 100 μM clivorine for 40 h in the presence of proteasome specific inhibitor MG132, indicating possible degradation of Bcl-xL protein. Furthermore, pretreatment with MG132 or calpain inhibitor I for 2 h significantly enhanced clivorine-decreased Bcl-xL level and cell viability. All the other tested PAs such as senecionine, isoline and monocrotaline decreased mouse hepatocytes viability in a concentration-dependent manner. Clivorine (10 μM) induced caspase-3 activation and decreased Bcl-xL was also confirmed in mouse hepatocytes. Meanwhile, another PA senecionine isolated from Senecio vulgaris L also induced apoptosis, caspase-3 activation and decreased Bcl-xL in mouse hepatocytes. In conclusion, our results suggest that PAs may share the same hepatotoxic signal pathway, which involves degradation of Bcl-xL protein and thus leading to the activation of mitochondrial-mediated apoptotic pathway

  3. Mitochondria-targeting nanomedicine: An effective and potent strategy against aminoglycosides-induced ototoxicity.

    Science.gov (United States)

    Zhou, Shuang; Sun, Yanhui; Kuang, Xiao; Hou, Shanshan; Yang, YinXian; Wang, Zhenjie; Liu, Hongzhuo

    2018-04-21

    We report a proof-of-concept for the development of mitochondria-targeting nanoparticles (NPs) loaded with geranylgeranylacetone (GGA) to protect against a wide range of gentamicin-induced ototoxicity symptoms in a zebrafish model. The polymeric NPs were functionalized with a mitochondrial-homing peptide (d‑Arg‑Dmt‑Orn‑Phe‑NH 2 ) and exhibited greater mitochondrial uptake and lower gentamicin uptake in hair cells via mechanotransduction (MET) channels and tuned machinery in the hair bundle than the ordinary NPs did. Blockade of MET channels rapidly reversed this effect, indicating the reversible responses of hair cells to the targeting NPs were mediated by MET channels. Pretreatment of hair cells with mitochondria-targeting GGA-loaded NPs exhibited a superior acute or chronic protective efficacy against subsequent exposure to gentamicin compared with unmodified formulations. Mitochondrial delivery regulating the death pathway of hair cells appeared to cause the therapeutic failure of untargeted NPs. Thus, peptide-directed mitochondria-targeting NPs may represent a novel therapeutic strategy for mitochondrial dysfunction-linked diseases. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Oxaliplatin-induced Oxidative Stress Provokes Toxicity in Isolated Rat Liver Mitochondria.

    Science.gov (United States)

    Tabassum, Heena; Waseem, Mohammad; Parvez, Suhel; Qureshi, M Irfan

    2015-11-01

    Oxaliplatin is a widely employed platinum-derived chemotherapeutic agent commonly used for the treatment of colorectal cancer. Unfortunately, the benefit of this important drug is compromised by severe side effects such as neuropathy, ototoxicity, gastrointestinal toxicity, and hematological toxicity. Recently, few studies have also suggested the occurrence of hepatotoxicity in oxaliplatin-treated patients. Mitochondria have emerged as targets for anticancer drugs in various kinds of toxicity including hepatotoxicity that can lead to neoplastic disease. Oxidative stress is a well-established biomarker of mitochondrial toxicity. The purpose of this study was to investigate the dose-dependent damage caused by oxaliplatin on isolated liver mitochondria under in vitro conditions. The study was conducted in mitochondria isolated from liver of Wistar rats. Oxaliplatin was incubated with mitochondria in a dose-dependent manner under in vitro conditions. Oxidative stress indexes, non-enzymatic and enzymatic antioxidants were evaluated, looking at the overall armamentarium against the toxicity induced by oxaliplatin. Oxaliplatin caused a significant rise in the mitochondrial oxidative stress indexes lipid peroxidation and protein carbonyl. Alterations in the levels of non-enzymatic antioxidants and activities of enzymatic antioxidants were also observed. Oxidative stress plays an important role in the mitochondrial toxicity of oxaliplatin. The integrity of the hepatic tissue is compromised by the reactive oxygen species-mediated lipid peroxidation and protein carbonyl formation. Copyright © 2015 IMSS. Published by Elsevier Inc. All rights reserved.

  5. Dose dependent activation of retinoic acid-inducible gene-I promotes both proliferation and apoptosis signals in human head and neck squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Jingzhou Hu

    Full Text Available The retinoic-acid-inducible gene (RIG-like receptor (RLR family proteins are major pathogen reorganization receptors (PRR responsible for detection of viral RNA, which initiates antiviral response. Here, we evaluated the functional role of one RLR family member, RIG-I, in human head and neck squamous cell carcinoma (HNSCC. RIG-I is abundantly expressed both in poorly-differentiated primary cancer and lymph node metastasis, but not in normal adjacent tissues. Activation of RIG-I by transfection with low dose of 5'-triphosphate RNA (3p-RNA induces low levels of interferon and proinflammatory cytokines and promotes NF-κB- and Akt-dependent cell proliferation, migration and invasion. In contrast, activation of RIG-I by a high dose of 3p-RNA induces robust mitochondria-derived apoptosis accompanied by decreased activation of Akt, which is independent of the interferon and TNFα receptor, but can be rescued by over-expression of constitutively active Akt. Furthermore, co-immunoprecipitation experiments indicate that the CARD domain of RIG-I is essential for inducing apoptosis by interacting with caspase-9. Together, our results reveal a dual role of RIG-I in HNSCC through regulating activation of Akt, in which RIG-I activation by low-dose viral dsRNA increases host cell survival, whereas higher level of RIG-I activation leads to apoptosis. These findings highlight the therapeutic potential of dsRNA mediated RIG-I activation in the treatment of HNSCC.

  6. Glycogen synthase kinase-3β facilitates cell apoptosis induced by high fluence low-power laser irradiation through acceleration of Bax translocation

    Science.gov (United States)

    Huang, Lei; Wu, Shengnan; Xing, Da

    2011-03-01

    Glycogen synthase kinase-3β (GSK-3β) is a critical activator of cell apoptosis induced by a diverse array of insults. However, the effects of GSK-3β on the human lung adenocarcinoma cell (ASTC-a-1) apoptosis induced by high fluence low-power laser irradiation (HF-LPLI) are not clear. Here, we showed that GSK-3β was constantly translocated from cytoplasm to nucleus and activated during HF-LPLI-induced cell apoptosis. In addition, we found that co-overexpression of YFP-GSK-3β and CFP-Bax in ASTC-a-1 cells accelerated both Bax translocations to mitochondria and cell apoptosis, compared to the cells expressed CFP-Bax only under HF-LPLI treatment, indicating that GSK-3β facilitated ASTC-a-1 cells apoptosis through acceleration mitochondrial translocation of Bax. Our results demonstrate that GSK-3β exerts some of its pro-apoptotic effects in ASTC-a-1 cells by regulating the mitochondrial localization of Bax, a key component of the intrinsic apoptotic cascade.

  7. Demethoxycurcumin Retards Cell Growth and Induces Apoptosis in Human Brain Malignant Glioma GBM 8401 Cells

    Directory of Open Access Journals (Sweden)

    Tzuu-Yuan Huang

    2012-01-01

    Full Text Available Demethoxycurcumin (DMC; a curcumin-related demethoxy compound has been recently shown to display antioxidant and antitumor activities. It has also produced a potent chemopreventive action against cancer. In the present study, the antiproliferation (using the MTT assay, DMC was found to have cytotoxic activities against GBM 8401 cell with IC50 values at 22.71 μM and induced apoptosis effects of DMC have been investigated in human brain malignant glioma GBM 8401 cells. We have studied the mitochondrial membrane potential (MMP, DNA fragmentation, caspase activation, and NF-κB transcriptional factor activity. By these approaches, our results indicated that DMC has produced an inhibition of cell proliferation as well as the activation of apoptosis in GBM 8401 cells. Both effects were observed to increase in proportion with the dosage of DMC treatment, and the apoptosis was induced by DMC in human brain malignant glioma GBM 8401 cells via mitochondria- and caspase-dependent pathways.

  8. Noxa/Mcl-1 Balance Regulates Susceptibility of Cells to Camptothecin-Induced Apoptosis

    Directory of Open Access Journals (Sweden)

    Yide Mei

    2007-10-01

    Full Text Available Although camptothecin (CPT has been reported to induce apoptosis in various cancer cells, the molecular details of this regulation remain largely unknown. In this study, we demonstrate that 131-113-only protein Noxa is upregulated during CPT-induced apoptosis, which is independent of p53. In addition, we show that phosphatidylinositol 3-kinase (PI3K/Akt signaling pathway is responsible for Noxa's induction. Luciferase assay, cAMP response element binding protein (CREB knockdown experiments further demonstrate that CREB is involved in the transcriptional upregulation of Noxa. Moreover, blocking Noxa expression using specific small interfering ribonucleic acid (siRNA significantly reduces the apoptosis in response to CPT, indicating that Noxa is an essential mediator for CPT-induced apoptosis. Interestingly, antiapoptotic Mcl-1 was also upregulated through PI3K/Akt signaling pathway upon CPT treatment. Using immunoprecipitation assay, Noxa was found to interact with Mcl-1 in the presence or absence of CPT. Knockdown of Mcl-1 expression by short hairpin ribonucleic acid (shRNA was shown to potentiate CPT-induced apoptosis. Consistently, ectopic overexpression of Mcl-1 rescued cells from apoptosis induced by CPT. Cells coexpressing Noxa, Mcl-1 at different ratio correlates well with the extent of apoptosis, suggesting that the balance between Noxa, Mcl-1 may determine the susceptibility of HeLa cells to CPT-induced apoptosis.

  9. Punica granatum (pomegranate) leaves extract induces apoptosis through mitochondrial intrinsic pathway and inhibits migration and invasion in non-small cell lung cancer in vitro.

    Science.gov (United States)

    Li, Yali; Yang, Fangfang; Zheng, Weidong; Hu, Mingxing; Wang, Juanxiu; Ma, Sisi; Deng, Yuanle; Luo, Yi; Ye, Tinghong; Yin, Wenya

    2016-05-01

    Most conventional treatments on non-small cell lung carcinoma always accompany with awful side effects, and the incidence and mortality rates of this cancer are increasing rapidly worldwide. The objective of this study was to examine the anticancer effects of extract of Punica granatum (pomegranate) leaves extract (PLE) on the non-small cell lung carcinoma cell line A549, H1299 and mouse Lewis lung carcinoma cell line LL/2 in vitro, and explore its mechanisms of action. Our results have shown that PLE inhibited cell proliferation in non-small cell lung carcinoma cell line in a concentration- and time-dependent manner. Flow cytometry (FCM) assay showed that PLE affected H1299 cell survival by arresting cell cycle progression in G2/M phase in a dose-dependent manner and inducing apoptosis. Moreover, PLE could also decrease the reactive oxygen species (ROS) and the mitochondrial membrane potential (ΔYm), indicating that PLE may induce apoptosis via mitochondria-mediated apoptotic pathway. Furthermore, PLE blocked H1299 cell migration and invasion, and the reduction of matrix metalloproteinase (MMP) MMP-2 and MMP-9 expression were also observed in vitro. These results suggested that PLE could be an effective and safe chemotherapeutic agent in non-small cell lung carcinoma treatment by inhibiting proliferation, inducing apoptosis, cell cycle arrest and impairing cell migration and invasion. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  10. Anthraquinone G503 Induces Apoptosis in Gastric Cancer Cells through the Mitochondrial Pathway

    Science.gov (United States)

    Li, Shuai; Duan, Junting; Ye, Fang; Li, Hanxiang; She, Zhigang; Gao, Guoquan; Yang, Xia

    2014-01-01

    G503 is an anthraquinone compound isolated from the secondary metabolites of a mangrove endophytic fungus from the South China Sea. The present study elucidates the anti-tumor activity and the underlying mechanism of G503. Cell viability assay performed in nine cancer cell lines and two normal cell lines demonstrated that the gastric cancer cell line SGC7901 is the most G503-sensitive cancer cells. G503 induced SGC7901 cell death via apoptosis. G503 exposure activated caspases-3, -8 and -9. Pretreatment with the pan-caspase inhibitor Z-VAD-FMK and caspase-9 inhibitor Z-LEHD-FMK, but not caspase-8 inbibitor Z-IETD-FMK, attenuated the effect of G503. These results suggested that the intrinsic mitochondrial apoptosis pathway, rather than the extrinsic pathway, was involved in G503-induced apoptosis. Furthermore, G503 increased the ratio of Bax to Bcl-2 in the mitochondria and decreased the ratio in the cytosol. G503 treatment resulted in mitochondrial depolarization, cytochrome c release and the subsequent cleavage of caspase -9 and -3. Moreover, it is reported that the endoplasmic reticulum apoptosis pathway may also be activated by G503 by inducing capase-4 cleavage. In consideration of the lower 50% inhibitory concentration for gastric cancer cells, G503 may serve as a promising candidate for gastric cancer chemotherapy. PMID:25268882

  11. Calcium and Superoxide-Mediated Pathways Converge to Induce Nitric Oxide-Dependent Apoptosis in Mycobacterium fortuitum-Infected Fish Macrophages.

    Science.gov (United States)

    Datta, Debika; Khatri, Preeti; Banerjee, Chaitali; Singh, Ambika; Meena, Ramavatar; Saha, Dhira Rani; Raman, Rajagopal; Rajamani, Paulraj; Mitra, Abhijit; Mazumder, Shibnath

    2016-01-01

    Mycobacterium fortuitum causes 'mycobacteriosis' in wide range of hosts although the mechanisms remain largely unknown. Here we demonstrate the role of calcium (Ca+2)-signalling cascade on M. fortuitum-induced apoptosis in headkidney macrophages (HKM) of Clarias sp. M. fortuitum could trigger intracellular-Ca+2 influx leading to the activation of calmodulin (CaM), protein kinase C alpha (PKCα) and Calmodulin kinase II gamma (CaMKIIg). Gene silencing and inhibitor studies established the role of CaM in M. fortuitum pathogenesis. We noted that CaMKIIg activation is regulated by CaM as well as PKCα-dependent superoxide anions. This is altogether first report of oxidised CaMKIIg in mycobacterial infections. Our studies with targeted-siRNA and pharmacological inhibitors implicate CaMKIIg to be pro-apoptotic and critical for the activation of extra-cellular signal regulated kinase 1/2 (ERK1/2). Inhibiting the ERK1/2 pathway attenuated nitric oxide synthase 2 (NOS2)-induced nitric oxide (NO) production. Conversely, inhibiting the NOS2-NO axis by specific-siRNA and inhibitors down-regulated ERK1/2 activation suggesting the crosstalk between ERK1/2 and NO is essential for pathogenesis induced by the bacterium. Silencing the NOS2-NO axis enhanced intracellular bacterial survival and attenuated caspase-8 mediated activation of caspase-3 in the infected HKM. Our findings unveil hitherto unknown mechanism of M. fortuitum pathogenesis. We propose that M. fortuitum triggers intracellular Ca+2 elevations resulting in CaM activation and PKCα-mediated superoxide generation. The cascade converges in common pathway mediated by CaMKIIg resulting in the activation of ERK1/2-NOS2 axis. The crosstalk between ERK1/2 and NO shifts the balance in favour of caspase dependent apoptosis of M. fortuitum-infected HKM.

  12. Human T-Cell Leukemia Virus Type 1 Tax-Deregulated Autophagy Pathway and c-FLIP Expression Contribute to Resistance against Death Receptor-Mediated Apoptosis

    Science.gov (United States)

    Wang, Weimin; Zhou, Jiansuo; Shi, Juan; Zhang, Yaxi; Liu, Shilian

    2014-01-01

    ABSTRACT The human T-cell leukemia virus type 1 (HTLV-1) Tax protein is considered to play a central role in the process that leads to adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-1 Tax-expressing cells show resistance to apoptosis induced by Fas ligand (FasL) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). The regulation of Tax on the autophagy pathway in HeLa cells and peripheral T cells was recently reported, but the function and underlying molecular mechanism of the Tax-regulated autophagy are not yet well defined. Here, we report that HTLV-1 Tax deregulates the autophagy pathway, which plays a protective role during the death receptor (DR)-mediated apoptosis of human U251 astroglioma cells. The cellular FLICE-inhibitory protein (c-FLIP), which is upregulated by Tax, also contributes to the resistance against DR-mediated apoptosis. Both Tax-induced autophagy and Tax-induced c-FLIP expression require Tax-induced activation of IκB kinases (IKK). Furthermore, Tax-induced c-FLIP expression is regulated through the Tax-IKK-NF-κB signaling pathway, whereas Tax-triggered autophagy depends on the activation of IKK but not the activation of NF-κB. In addition, DR-mediated apoptosis is correlated with the degradation of Tax, which can be facilitated by the inhibitors of autophagy. IMPORTANCE Our study reveals that Tax-deregulated autophagy is a protective mechanism for DR-mediated apoptosis. The molecular mechanism of Tax-induced autophagy is also illuminated, which is different from Tax-increased c-FLIP. Tax can be degraded via manipulation of autophagy and TRAIL-induced apoptosis. These results outline a complex regulatory network between and among apoptosis, autophagy, and Tax and also present evidence that autophagy represents a new possible target for therapeutic intervention for the HTVL-1 related diseases. PMID:24352466

  13. Toll-like receptor 9 is required for opioid-induced microglia apoptosis.

    Directory of Open Access Journals (Sweden)

    Lei He

    2011-04-01

    Full Text Available Opioids have been widely applied in clinics as one of the most potent pain relievers for centuries, but their abuse has deleterious physiological effects beyond addiction. However, the underlying mechanism by which microglia in response to opioids remains largely unknown. Here we show that morphine induces the expression of Toll-like receptor 9 (TLR9, a key mediator of innate immunity and inflammation. Interestingly, TLR9 deficiency significantly inhibited morphine-induced apoptosis in microglia. Similar results were obtained when endogenous TLR9 expression was suppressed by the TLR9 inhibitor CpGODN. Inhibition of p38 MAPK by its specific inhibitor SB203580 attenuated morphine-induced microglia apoptosis in wild type microglia. Morphine caused a dramatic decrease in Bcl-2 level but increase in Bax level in wild type microglia, but not in TLR9 deficient microglia. In addition, morphine treatment failed to induce an increased levels of phosphorylated p38 MAPK and MAP kinase kinase 3/6 (MKK3/6, the upstream MAPK kinase of p38 MAPK, in either TLR9 deficient or µ-opioid receptor (µOR deficient primary microglia, suggesting an involvement of MAPK and µOR in morphine-mediated TLR9 signaling. Moreover, morphine-induced TLR9 expression and microglia apoptosis appears to require μOR. Collectively, these results reveal that opioids prime microglia to undergo apoptosis through TLR9 and µOR as well. Taken together, our data suggest that inhibition of TLR9 and/or blockage of µOR is capable of preventing opioid-induced brain damage.

  14. Fast neutrons-induced apoptosis is Fas-independent in lymphoblastoid cells

    International Nuclear Information System (INIS)

    Fischer, Barbara; Benzina, Sami; Jeannequin, Pierre; Dufour, Patrick; Bergerat, Jean-Pierre; Denis, Jean-Marc; Gueulette, John; Bischoff, Pierre L.

    2005-01-01

    We have previously shown that ionizing radiation-induced apoptosis in human lymphoblastoid cells differs according to their p53 status, and that caspase 8-mediated cleavage of BID is involved in the p53-dependent pathway. In the present study, we investigated the role of Fas signaling in caspase 8 activation induced by fast neutrons irradiation in these cells. Fas and FasL expression was assessed by flow cytometry and by immunoblot. We also measured Fas aggregation after irradiation by fluorescence microscopy. We found a decrease of Fas expression after irradiation, but no change in Fas ligand expression. We also showed that, in contrast to the stimulation of Fas by an agonistic antibody, Fas aggregation did not occur after irradiation. Altogether, our data strongly suggest that fast neutrons induced-apoptosis is Fas-independent, even in p53-dependent apoptosis

  15. Dopamine-induced apoptosis of lactotropes is mediated by the short isoform of D2 receptor.

    Science.gov (United States)

    Radl, Daniela Betiana; Ferraris, Jimena; Boti, Valeria; Seilicovich, Adriana; Sarkar, Dipak Kumar; Pisera, Daniel

    2011-03-25

    Dopamine, through D2 receptor (D2R), is the major regulator of lactotrope function in the anterior pituitary gland. Both D2R isoforms, long (D2L) and short (D2S), are expressed in lactotropes. Although both isoforms can transduce dopamine signal, they differ in the mechanism that leads to cell response. The administration of D2R agonists, such as cabergoline, is the main pharmacological treatment for prolactinomas, but resistance to these drugs exists, which has been associated with alterations in D2R expression. We previously reported that dopamine and cabergoline induce apoptosis of lactotropes in primary culture in an estrogen-dependent manner. In this study we used an in vivo model to confirm the permissive action of estradiol in the apoptosis of anterior pituitary cells induced by D2R agonists. Administration of cabergoline to female rats induced apoptosis, measured by Annexin-V staining, in anterior pituitary gland from estradiol-treated rats but not from ovariectomized rats. To evaluate the participation of D2R isoforms in the apoptosis induced by dopamine we used lactotrope-derived PR1 cells stably transfected with expression vectors encoding D2L or D2S receptors. In the presence of estradiol, dopamine induced apoptosis, determined by ELISA and TUNEL assay, only in PR1-D2S cells. To study the role of p38 MAPK in apoptosis induced by D2R activation, anterior pituitary cells from primary culture or PR1-D2S were incubated with an inhibitor of the p38 MAPK pathway (SB203850). SB203580 blocked the apoptotic effect of D2R activation in lactotropes from primary cultures and PR1-D2S cells. Dopamine also induced p38 MAPK phosphorylation, determined by western blot, in PR1-D2S cells and estradiol enhanced this effect. These data suggest that, in the presence of estradiol, D2R agonists induce apoptosis of lactotropes by their interaction with D2S receptors and that p38 MAPK is involved in this process.

  16. Light induces translocation of NF-κB p65 to the mitochondria and suppresses expression of cytochrome c oxidase subunit III (COX III) in the rat retina

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Hiroshi, E-mail: htomita@iwate-u.ac.jp [Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551 (Japan); Soft-Path Engineering Research Center (SPERC), Faculty of Science and Engineering, Iwate University, Morioka 020-8551 (Japan); Clinical Research, Innovation and Education Center, Tohoku University Hospital, 1-1 Seiryo, Aoba, Sendai, Miyagi 980-8574 (Japan); Tabata, Kitako, E-mail: ktabata@iwate-u.ac.jp [Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551 (Japan); Takahashi, Maki, E-mail: mqdelta@iwate-u.ac.jp [Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551 (Japan); Nishiyama, Fumiaki, E-mail: t2114018@iwate-u.ac.jp [Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551 (Japan); Sugano, Eriko, E-mail: sseriko@iwate-u.ac.jp [Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551 (Japan); Soft-Path Engineering Research Center (SPERC), Faculty of Science and Engineering, Iwate University, Morioka 020-8551 (Japan)

    2016-05-13

    The transcription factor nuclear factor kappaB (NF-κB) plays various roles in cell survival, apoptosis, and inflammation. In the rat retina, NF-κB activity increases after exposure to damaging light, resulting in degeneration of photoreceptors. Here, we report that in dark-adapted rats exposed for 6 h to bright white light, the p65 subunit of retinal NF-κB translocates to the mitochondria, an event associated with a decrease in expression of cytochrome c oxidase subunit III (COX III). However, sustained exposure for 12 h depleted p65 from the mitochondria, and enhanced COX III expression. Treatment with the protective antioxidant PBN prior to light exposure prevents p65 depletion in the mitochondria and COX III upregulation during prolonged exposure, and apoptosis in photoreceptor cells. These results indicate that COX III expression is sensitive to the abundance of NF-κB p65 in the mitochondria, which, in turn, is affected by exposure to damaging light. - Highlights: • Damaging light exposure of the retina induces NF-κB p65 mitochondrial translocation. • NF-κB p65 mitochondrial translocation is associated with the decrease of COX III expression. • Prolonged light exposure depletes mitochondrial p65 resulting in the increase in COX III expression. • NF-κB p65 and COX III expression play an important role in the light-induced photoreceptor degeneration.

  17. Light induces translocation of NF-κB p65 to the mitochondria and suppresses expression of cytochrome c oxidase subunit III (COX III) in the rat retina

    International Nuclear Information System (INIS)

    Tomita, Hiroshi; Tabata, Kitako; Takahashi, Maki; Nishiyama, Fumiaki; Sugano, Eriko

    2016-01-01

    The transcription factor nuclear factor kappaB (NF-κB) plays various roles in cell survival, apoptosis, and inflammation. In the rat retina, NF-κB activity increases after exposure to damaging light, resulting in degeneration of photoreceptors. Here, we report that in dark-adapted rats exposed for 6 h to bright white light, the p65 subunit of retinal NF-κB translocates to the mitochondria, an event associated with a decrease in expression of cytochrome c oxidase subunit III (COX III). However, sustained exposure for 12 h depleted p65 from the mitochondria, and enhanced COX III expression. Treatment with the protective antioxidant PBN prior to light exposure prevents p65 depletion in the mitochondria and COX III upregulation during prolonged exposure, and apoptosis in photoreceptor cells. These results indicate that COX III expression is sensitive to the abundance of NF-κB p65 in the mitochondria, which, in turn, is affected by exposure to damaging light. - Highlights: • Damaging light exposure of the retina induces NF-κB p65 mitochondrial translocation. • NF-κB p65 mitochondrial translocation is associated with the decrease of COX III expression. • Prolonged light exposure depletes mitochondrial p65 resulting in the increase in COX III expression. • NF-κB p65 and COX III expression play an important role in the light-induced photoreceptor degeneration.

  18. Antioxidant enzyme gene delivery to protect from HIV-1 gp120-induced neuronal apoptosis.

    Science.gov (United States)

    Agrawal, L; Louboutin, J-P; Reyes, B A S; Van Bockstaele, E J; Strayer, D S

    2006-12-01

    Human immunodeficiency virus-1 (HIV-1) infection in the central nervous system (CNS) may lead to neuronal loss and progressively deteriorating CNS function: HIV-1 gene products, especially gp120, induce free radical-mediated apoptosis. Reactive oxygen species (ROS), are among the potential mediators of these effects. Neurons readily form ROS after gp120 exposure, and so might be protected from ROS-mediated injury by antioxidant enzymes such as Cu/Zn-superoxide dismutase (SOD1) and/or glutathione peroxidase (GPx1). Both enzymes detoxify oxygen free radicals. As they are highly efficient gene delivery vehicles for neurons, recombinant SV40-derived vectors were used for these studies. Cultured mature neurons derived from NT2 cells and primary fetal neurons were transduced with rSV40 vectors carrying human SOD1 and/or GPx1 cDNAs, then exposed to gp120. Apoptosis was measured by terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay. Transduction efficiency of both neuron populations was >95%, as assayed by immunostaining. Transgene expression was also ascertained by Western blotting and direct assays of enzyme activity. Gp120 induced apoptosis in a high percentage of unprotected NT2-N. Transduction with SV(SOD1) and SV(GPx1) before gp120 challenge reduced neuronal apoptosis by >90%. Even greater protection was seen in cells treated with both vectors in sequence. Given singly or in combination, they protect neuronal cells from HIV-1-gp120 induced apoptosis. We tested whether rSV40 s can deliver antioxidant enzymes to the CNS in vivo: intracerebral injection of SV(SOD1) or SV(GPx1) into the caudate putamen of rat brain yielded excellent transgene expression in neurons. In vivo transduction using SV(SOD1) also protected neurons from subsequent gp120-induced apoptosis after injection of both into the caudate putamen of rat brain. Thus, SOD1 and GPx1 can be delivered by SV40 vectors in vitro or in vivo. This approach may merit consideration for

  19. Nitric oxide from both exogenous and endogenous sources activates mitochondria-dependent events and induces insults to human chondrocytes.

    Science.gov (United States)

    Wu, Gong-Jhe; Chen, Tyng-Guey; Chang, Huai-Chia; Chiu, Wen-Ta; Chang, Chia-Chen; Chen, Ruei-Ming

    2007-08-15

    During inflammation, overproduction of nitric oxide (NO) can damage chondrocytes. In this study, we separately evaluated the toxic effects of exogenous and endogenous NO on human chondrocytes and their possible mechanisms. Human chondrocytes were exposed to sodium nitroprusside (SNP), an NO donor, or a combination of lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) as the exogenous and endogenous sources of NO, respectively. Administration of SNP or a combination of LPS and IFN-gamma in human chondrocytes increased cellular NO levels but decreased cell viability. Exposure to exogenous or endogenous NO significantly induced apoptosis of human chondrocytes. When treated with exogenous or endogenous NO, the mitochondrial membrane potential time-dependently decreased. Exposure to exogenous or endogenous NO significantly enhanced cellular reactive oxygen species (ROS) and cytochrome c (Cyt c) levels. Administration of exogenous or endogenous NO increased caspase-3 activity and consequently induced DNA fragmentation. Suppression of caspase-3 activation by Z-DEVD-FMK decreased NO-induced DNA fragmentation and cell apoptosis. Similar to SNP, exposure of human chondrocytes to S-nitrosoglutathione (GSNO), another NO donor, caused significant increases in Cyt c levels, caspase-3 activity, and DNA fragmentation, and induced cell apoptosis. Pretreatment with N-monomethyl arginine (NMMA), an inhibitor of NO synthase, significantly decreased cellular NO levels, and lowered endogenous NO-induced alterations in cellular Cyt c amounts, caspase-3 activity, DNA fragmentation, and cell apoptosis. Results of this study show that NO from exogenous and endogenous sources can induce apoptotic insults to human chondrocytes via a mitochondria-dependent mechanism.

  20. Ofloxacin induces apoptosis in microencapsulated juvenile rabbit chondrocytes by caspase-8-dependent mitochondrial pathway

    International Nuclear Information System (INIS)

    Sheng Zhiguo; Cao Xiaojuan; Peng Shuangqing; Wang Changyong; Li Qianqian; Wang Yimei; Liu Mifeng

    2008-01-01

    Quinolones (QNs)-induced arthropathy is an important toxic effect in immature animals leading to restriction of their therapeutic use in pediatrics. However, the exact mechanism still remains unclear. Recently, we have demonstrated that ofloxacin, a typical QN, induces apoptosis of alginate microencapsulated juvenile rabbit joint chondrocytes by disturbing the β 1 integrin functions and inactivating the ERK/MAPK signaling pathway. In this study, we extend our initial observations to further elucidate the mechanism(s) of ofloxacin-induced apoptosis by utilizing specific caspase inhibitors. Pretreatment with both caspase-9-specific inhibitor zLEHD-fmk and caspase-8 inhibitor zIETD-fmk attenuated ofloxacin-induced apoptosis and activation of caspase-3 of chondrocyte in a concentration-dependent manner, as determined by fluorescent dye staining, enzyme activity assay and immunoblotting. Furthermore, the activation of caspase-9, -8 and -3 stimulated by ofloxacin was significantly inhibited in the presence of zIETD-fmk while pretreatment with zLEHD-fmk only blocked the activation of caspase-9 and -3. Ofloxacin also stimulated a concentration-dependent translocation of cytochrome c from mitochondria into the cytosol and a decrease of mitochondrial transmembrane potential, which was completely inhibited by zIETD-fmk. In addition, ofloxacin was found to increase the level of Bax, tBid, p53 in a concentration- and time-dependent manner. Taken together, The current results indicate that the caspase-8-dependent mitochondrial pathway is primarily involved in the ofloxacin-induced apoptosis of microencapsulated juvenile rabbit joint chondrocytes

  1. β-Sitosterol targets Trx/Trx1 reductase to induce apoptosis in A549 cells via ROS mediated mitochondrial dysregulation and p53 activation.

    Science.gov (United States)

    Rajavel, Tamilselvam; Packiyaraj, Pandian; Suryanarayanan, Venkatesan; Singh, Sanjeev Kumar; Ruckmani, Kandasamy; Pandima Devi, Kasi

    2018-02-01

    β-Sitosterol (BS), a major bioactive constituent present in plants and vegetables has shown potent anticancer effect against many human cancer cells, but the underlying mechanism remain elusive on NSCLC cancers. We found that BS significantly inhibited the growth of A549 cells without harming normal human lung and PBMC cells. Further, BS treatment triggered apoptosis via ROS mediated mitochondrial dysregulation as evidenced by caspase-3 & 9 activation, Annexin-V/PI positive cells, PARP inactivation, loss of MMP, Bcl-2-Bax ratio alteration and cytochrome c release. Moreover, generation of ROS species and subsequent DNA stand break were found upon BS treatment which was reversed by addition of ROS scavenger (NAC). Indeed BS treatment increased p53 expression and its phosphorylation at Ser15, while silencing the p53 expression by pifithrin-α, BS induced apoptosis was reduced in A549 cells. Furthermore, BS induced apoptosis was also observed in NCI-H460 cells (p53 wild) but not in the NCI-H23 cells (p53 mutant). Down-regulation of Trx/Trx1 reductase contributed to the BS induced ROS accumulation and mitochondrial mediated apoptotic cell death in A549 and NCI-H460 cells. Taken together, our findings provide evidence for the novel anti-cancer mechanism of BS which could be developed as a promising chemotherapeutic drug against NSCLC cancers.

  2. H2O2 INDUCES APOPTOSIS OF RABBIT CHONDROCYTES VIA BOTH THE EXTRINSIC AND THE CASPASE-INDEPENDENT INTRINSIC PATHWAYS

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    CAIPING ZHUANG

    2013-07-01

    Full Text Available Osteoarthritis (OA, one of the most common joint diseases with unknown etiology, is characterized by the progressive destruction of articular cartilage and the apoptosis of chondrocytes. The purpose of this study is to elucidate the molecular mechanisms of H2O2-mediated rabbit chondrocytes apoptosis. CCK-8 assay showed that H2O2 treatment induced a remarkable reduction of cell viability, which was further verified by the remarkable phosphatidylserine externalization after H2O2 treatment for 1 h, the typical characteristics of apoptosis. H2O2 treatment induced a significant dysfunction of mitochondrial membrane potential (ΔΨm, but did not induce casapse-9 activation, indicating that H2O2 treatment induced caspase-independent intrinsic apoptosis that was further verified by the fact that silencing of AIF but not inhibiting caspase-9 potently prevented H2O2-induced apoptosis. H2O2 treatment induced a significant increase of caspase-8 and -3 activation, and inhibition of caspase-8 or -3 significantly prevented H2O2-induced apoptosis, suggesting that the extrinsic pathway played an important role. Collectively, our findings demonstrate that H2O2 induces apoptosis via both the casapse-8-mediated extrinsic and the caspase-independent intrinsic apoptosis pathways in rabbit chondrocytes.

  3. Saponin 1 induces apoptosis and suppresses NF-κB-mediated survival signaling in glioblastoma multiforme (GBM.

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    Juan Li

    Full Text Available Saponin 1 is a triterpeniod saponin extracted from Anemone taipaiensis, a traditional Chinese medicine against rheumatism and phlebitis. It has also been shown to exhibit significant anti-tumor activity against human leukemia (HL-60 cells and human hepatocellular carcinoma (Hep-G2 cells. Herein we investigated the effect of saponin 1 in human glioblastoma multiforme (GBM U251MG and U87MG cells. Saponin 1 induced significant growth inhibition in both glioblastoma cell lines, with a 50% inhibitory concentration at 24 h of 7.4 µg/ml in U251MG cells and 8.6 µg/ml in U87MG cells, respectively. Nuclear fluorescent staining and electron microscopy showed that saponin 1 caused characteristic apoptotic morphological changes in the GBM cell lines. Saponin 1-induced apoptosis was also verified by DNA ladder electrophoresis and flow cytometry. Additionally, immunocytochemistry and western blotting analyses revealed a time-dependent decrease in the expression and nuclear location of NF-κB following saponin 1 treatment. Western blotting data indicated a significant decreased expression of inhibitors of apoptosis (IAP family members,(e.g., survivin and XIAP by saponin 1. Moreover, saponin 1 caused a decrease in the Bcl-2/Bax ratio and initiated apoptosis by activating caspase-9 and caspase-3 in the GBM cell lines. These findings indicate that saponin 1 inhibits cell growth of GBM cells at least partially by inducing apoptosis and inhibiting survival signaling mediated by NF-κB. In addition, in vivo study also demonstrated an obvious inhibition of saponin 1 treatment on the tumor growth of U251MG and U87MG cells-produced xenograft tumors in nude mice. Given the minimal toxicities of saponin 1 in non-neoplastic astrocytes, our results suggest that saponin 1 exhibits significant in vitro and in vivo anti-tumor efficacy and merits further investigation as a potential therapeutic agent for GBM.

  4. Saponin 1 Induces Apoptosis and Suppresses NF-κB-Mediated Survival Signaling in Glioblastoma Multiforme (GBM)

    Science.gov (United States)

    Tang, Chi; Li, Bo; Wang, Yuangang; Gao, Zhenhui; Luo, Peng; Yin, Anan; Wang, Xiaoyang; Cheng, Guang; Fei, Zhou

    2013-01-01

    Saponin 1 is a triterpeniod saponin extracted from Anemone taipaiensis, a traditional Chinese medicine against rheumatism and phlebitis. It has also been shown to exhibit significant anti-tumor activity against human leukemia (HL-60 cells) and human hepatocellular carcinoma (Hep-G2 cells). Herein we investigated the effect of saponin 1 in human glioblastoma multiforme (GBM) U251MG and U87MG cells. Saponin 1 induced significant growth inhibition in both glioblastoma cell lines, with a 50% inhibitory concentration at 24 h of 7.4 µg/ml in U251MG cells and 8.6 µg/ml in U87MG cells, respectively. Nuclear fluorescent staining and electron microscopy showed that saponin 1 caused characteristic apoptotic morphological changes in the GBM cell lines. Saponin 1-induced apoptosis was also verified by DNA ladder electrophoresis and flow cytometry. Additionally, immunocytochemistry and western blotting analyses revealed a time-dependent decrease in the expression and nuclear location of NF-κB following saponin 1 treatment. Western blotting data indicated a significant decreased expression of inhibitors of apoptosis (IAP) family members,(e.g., survivin and XIAP) by saponin 1. Moreover, saponin 1 caused a decrease in the Bcl-2/Bax ratio and initiated apoptosis by activating caspase-9 and caspase-3 in the GBM cell lines. These findings indicate that saponin 1 inhibits cell growth of GBM cells at least partially by inducing apoptosis and inhibiting survival signaling mediated by NF-κB. In addition, in vivo study also demonstrated an obvious inhibition of saponin 1 treatment on the tumor growth of U251MG and U87MG cells-produced xenograft tumors in nude mice. Given the minimal toxicities of saponin 1 in non-neoplastic astrocytes, our results suggest that saponin 1 exhibits significant in vitro and in vivo anti-tumor efficacy and merits further investigation as a potential therapeutic agent for GBM. PMID:24278406

  5. Inhibitory Effect of Lycopene on Amyloid-β-Induced Apoptosis in Neuronal Cells.

    Science.gov (United States)

    Hwang, Sinwoo; Lim, Joo Weon; Kim, Hyeyoung

    2017-08-16

    Alzheimer's disease (AD) is a fatal neurodegenerative disease. Brain amyloid-β deposition is a crucial feature of AD, causing neuronal cell death by inducing oxidative damage. Reactive oxygen species (ROS) activate NF-κB, which induces expression of Nucling. Nucling is a pro-apoptotic factor recruiting the apoptosome complex. Lycopene is an antioxidant protecting from oxidative stress-induced cell damage. We investigated whether lycopene inhibits amyloid-β-stimulated apoptosis through reducing ROS and inhibiting mitochondrial dysfunction and NF-κB-mediated Nucling expression in neuronal SH-SY5Y cells. We prepared cells transfected with siRNA for Nucling or nontargeting control siRNA to determine the role of Nucling in amyloid-β-induced apoptosis. The amyloid-β increased intracellular and mitochondrial ROS levels, apoptotic indices (p53, Bax/Bcl-2 ratio, caspase-3 cleavage), NF-kB activation and Nucling expression, while cell viability, mitochondrial membrane potential, and oxygen consumption rate decreased in SH-SY5Y cells. Lycopene inhibited these amyloid-β-induced alterations. However, amyloid-β did not induce apoptosis, determined by cell viability and apoptotic indices (p53, Bax/Bcl-2 ratio, caspase-3 cleavage), in the cells transfected with siRNA for Nucling. Lycopene inhibited apoptosis by reducing ROS, and by inhibiting mitochondrial dysfunction and NF-κB-target gene Nucling expression in neuronal cells. Lycopene may be beneficial for preventing oxidative stress-mediated neuronal death in patients with neurodegeneration.

  6. Nicotine induces resistance to chemotherapy by modulating mitochondrial signaling in lung cancer.

    Science.gov (United States)

    Zhang, Jingmei; Kamdar, Opal; Le, Wei; Rosen, Glenn D; Upadhyay, Daya

    2009-02-01

    Continued smoking causes tumor progression and resistance to therapy in lung cancer. Carcinogens possess the ability to block apoptosis, and thus may induce development of cancers and resistance to therapy. Tobacco carcinogens have been studied widely; however, little is known about the agents that inhibit apoptosis, such as nicotine. We determine whether mitochondrial signaling mediates antiapoptotic effects of nicotine in lung cancer. A549 cells were exposed to nicotine (1 muM) followed by cisplatin (35 muM) plus etoposide (20 muM) for 24 hours. We found that nicotine prevented chemotherapy-induced apoptosis, improved cell survival, and caused modest increases in DNA synthesis. Inhibition of mitogen-activated protein kinase (MAPK) and Akt prevented the antiapoptotic effects of nicotine and decreased chemotherapy-induced apoptosis. Small interfering RNA MAPK kinase-1 blocked antiapoptotic effects of nicotine, whereas small interfering RNA MAPK kinase-2 blocked chemotherapy-induced apoptosis. Nicotine prevented chemotherapy-induced reduction in mitochondrial membrane potential and caspase-9 activation. Antiapoptotic effects of nicotine were blocked by mitochondrial anion channel inhibitor, 4,4'diisothiocyanatostilbene-2,2'disulfonic acid. Chemotherapy enhanced translocation of proapoptotic Bax to the mitochondria, whereas nicotine blocked these effects. Nicotine up-regulated Akt-mediated antiapoptotic X-linked inhibitor of apoptosis protein and phosphorylated proapoptotic Bcl2-antagonist of cell death. The A549-rho0 cells, which lack mitochondrial DNA, demonstrated partial resistance to chemotherapy-induced apoptosis, but blocked the antiapoptotic effects of nicotine. Accordingly, we provide evidence that nicotine modulates mitochondrial signaling and inhibits chemotherapy-induced apoptosis in lung cancer. The mitochondrial regulation of nicotine imposes an important mechanism that can critically impair the treatment of lung cancer, because many cancer

  7. Lysophosphatidic acid rescues bone mesenchymal stem cells from hydrogen peroxide-induced apoptosis.

    Science.gov (United States)

    Wang, Xian-Yun; Fan, Xue-Song; Cai, Lin; Liu, Si; Cong, Xiang-Feng; Chen, Xi

    2015-03-01

    The increase of reactive oxygen species in infracted heart significantly reduces the survival of donor mesenchymal stem cells, thereby attenuating the therapeutic efficacy for myocardial infarction. In our previous study, we demonstrated that lysophosphatidic acid (LPA) protects bone marrow-derived mesenchymal stem cells (BMSCs) against hypoxia and serum deprivation-induced apoptosis. However, whether LPA protects BMSCs from H2O2-induced apoptosis was not examined. In this study, we report that H2O2 induces rat BMSC apoptosis whereas LPA pre-treatment effectively protects BMSCs from H2O2-induced apoptosis. LPA protection of BMSC from the induced apoptosis is mediated mostly through LPA3 receptor. Furthermore, we found that membrane G protein Gi2 and Gi3 are involved in LPA-elicited anti-apoptotic effects through activation of ERK1/2- and PI3 K-pathways. Additionally, H2O2 increases levels of type II of light chain 3B (LC3B II), an autophagy marker, and H2O2-induced autophagy thus protected BMSCs from apoptosis. LPA further increases the expression of LC3B II in the presence of H2O2. In contrast, autophagy flux inhibitor bafilomycin A1 has no effect on LPA's protection of BMSC from H2O2-induced apoptosis. Taken together, our data suggest that LPA rescues H2O2-induced apoptosis mainly by interacting with Gi-coupled LPA3, resulting activation of the ERK1/2- and PI3 K/AKT-pathways and inhibition caspase-3 cleavage, and LPA protection of BMSCs against the apoptosis is independent of it induced autophagy.

  8. Hematoporphyrin monomethyl ether-mediated photodynamic therapy selectively kills sarcomas by inducing apoptosis.

    Directory of Open Access Journals (Sweden)

    Hui Zeng

    Full Text Available We investigated the antitumor effect and mechanism of hematoporphyrin monomethyl ether-mediated photodynamic therapy (HMME-PDT in sarcomas. Intracellular uptake of HMME by osteosarcoma cells (LM8 and K7 was time- and dose-dependent, while this was not observed for myoblast cells (C2C12 and fibroblast cells (NIH/3T3. HMME-PDT markedly inhibited the proliferation of sarcoma cell lines (LM8, MG63, Saos-2, SW1353, TC71, and RD (P<0.05, and the killing effect was improved with increased HMME concentration and energy intensity. Flow cytometry analysis revealed that LM8, MG63, and Saos-2 cells underwent apoptosis after treatment with HMME-PDT. Additionally, apoptosis was induced after HMME-PDT in a three-dimensional culture of osteosarcoma cells. Hoechst 33342 staining confirmed apoptosis. Cell death caused by PDT was rescued by an irreversible inhibitor (Z-VAD-FMK of caspase. However, cell viability was not markedly decreased compared with the HMME-PDT group. Expression levels of caspase-1, caspase-3, caspase-6, caspase-9, and poly (ADP-ribose polymerase (PARP proteins were markedly up-regulated in the treatment groups and increased with HMME concentration as determined by western blot analysis. In vivo, tumor volume markedly decreased at 7-16 days post-PDT. Hematoxylin and eosin staining revealed widespread necrotic and infiltrative inflammatory cells in the HMME-PDT group. Immunohistochemistry analysis also showed that caspase-1, caspase-3, caspase-6, caspase-9, and PARP proteins were significantly increased in the HMME-PDT group. These results indicate that HMME-PDT has a potent killing effect on osteosarcoma cells in vitro and significantly inhibits tumor growth in vivo, which is associated with the caspase-dependent pathway.

  9. Ghrelin ameliorates the human alveolar epithelial A549 cell apoptosis induced by lipopolysaccharide

    International Nuclear Information System (INIS)

    Huang, Chunrong; Zheng, Haichong; He, Wanmei; Lu, Guifang; Li, Xia; Deng, Yubin; Zeng, Mian

    2016-01-01

    Ghrelin is a gastric acyl-peptide that plays an inhibitory role in cell apoptosis. Herein we investigate the protective effects of ghrelin in LPS-induced apoptosis of human alveolar epithelial A549 cells, along with the possible molecular mechanisms. LPS exposure impaired cell viability and increased apoptosis of A549 cells significantly in concentration- and time-dependent manners embodied in increased Bax and cleaved caspase-3 production, coupled with decreased Bcl-2 levels. Simultaneously, LPS remarkably decreased the expression of phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) and extracellular signal-regulated kinas (ERK) in A549 cells. However, ghrelin'pretreatment ameliorated LPS-caused alterations in the ratio of Bax/Bcl-2 and cleaved caspase-3 expression, whereas activated the PI3K/Akt and ERK signaling. These results demonstrate that ghrelin lightens LPS-induced apoptosis of human alveolar epithelial cells partly through activating the PI3K/Akt and ERK pathway and thereby might benefit alleviating septic ALI. -- Graphical abstract: Ghrelin ameliorates the human alveolar epithelial A549 cells apoptosis induced by lipopolysaccharide partly through activating the PI3K/Akt and ERK pathway. Display Omitted -- Highlights: •It has been observed that LPS insult significantly increased apoptosis in A549 cells. •Both Akt and ERK signaling are critical adapter molecules to mediate the ghrelin-mediated proliferative effect. •Ghrelin may have a therapeutic effect in the prevention of LPS-induced apoptosis.

  10. Ghrelin ameliorates the human alveolar epithelial A549 cell apoptosis induced by lipopolysaccharide

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chunrong; Zheng, Haichong; He, Wanmei; Lu, Guifang; Li, Xia [Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080 (China); Deng, Yubin, E-mail: dengyub@mail.sysu.edu.cn [Research Center of Translational Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080 (China); Zeng, Mian, E-mail: zengmian2004@163.com [Department of Medical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080 (China)

    2016-05-20

    Ghrelin is a gastric acyl-peptide that plays an inhibitory role in cell apoptosis. Herein we investigate the protective effects of ghrelin in LPS-induced apoptosis of human alveolar epithelial A549 cells, along with the possible molecular mechanisms. LPS exposure impaired cell viability and increased apoptosis of A549 cells significantly in concentration- and time-dependent manners embodied in increased Bax and cleaved caspase-3 production, coupled with decreased Bcl-2 levels. Simultaneously, LPS remarkably decreased the expression of phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) and extracellular signal-regulated kinas (ERK) in A549 cells. However, ghrelin'pretreatment ameliorated LPS-caused alterations in the ratio of Bax/Bcl-2 and cleaved caspase-3 expression, whereas activated the PI3K/Akt and ERK signaling. These results demonstrate that ghrelin lightens LPS-induced apoptosis of human alveolar epithelial cells partly through activating the PI3K/Akt and ERK pathway and thereby might benefit alleviating septic ALI. -- Graphical abstract: Ghrelin ameliorates the human alveolar epithelial A549 cells apoptosis induced by lipopolysaccharide partly through activating the PI3K/Akt and ERK pathway. Display Omitted -- Highlights: •It has been observed that LPS insult significantly increased apoptosis in A549 cells. •Both Akt and ERK signaling are critical adapter molecules to mediate the ghrelin-mediated proliferative effect. •Ghrelin may have a therapeutic effect in the prevention of LPS-induced apoptosis.

  11. Amyloid-β triggers the release of neuronal hexokinase 1 from mitochondria.

    Directory of Open Access Journals (Sweden)

    Leonardo M Saraiva

    2010-12-01

    Full Text Available Brain accumulation of the amyloid-β peptide (Aβ and oxidative stress underlie neuronal dysfunction and memory loss in Alzheimer's disease (AD. Hexokinase (HK, a key glycolytic enzyme, plays important pro-survival roles, reducing mitochondrial reactive oxygen species (ROS generation and preventing apoptosis in neurons and other cell types. Brain isozyme HKI is mainly associated with mitochondria and HK release from mitochondria causes a significant decrease in enzyme activity and triggers oxidative damage. We here investigated the relationship between Aβ-induced oxidative stress and HK activity. We found that Aβ triggered HKI detachment from mitochondria decreasing HKI activity in cortical neurons. Aβ oligomers further impair energy metabolism by decreasing neuronal ATP levels. Aβ-induced HKI cellular redistribution was accompanied by excessive ROS generation and neuronal death. 2-deoxyglucose blocked Aβ-induced oxidative stress and neuronal death. Results suggest that Aβ-induced cellular redistribution and inactivation of neuronal HKI play important roles in oxidative stress and neurodegeneration in AD.

  12. Human gastric signet ring carcinoma (KATO-III) cell apoptosis induced by Vitex agnus-castus fruit extract through intracellular oxidative stress.

    Science.gov (United States)

    Ohyama, Kunio; Akaike, Takenori; Imai, Masahiko; Toyoda, Hiroo; Hirobe, Chieko; Bessho, Toshio

    2005-07-01

    We have previously reported that an ethanol extract of the dried ripe fruit of Vitex agnus-castus (Vitex) displays cytotoxic activity against certain kinds of human cancer cell line resulting in the induction of apoptosis. In this paper, we investigate the molecular mechanism of apoptosis induced by Vitex using a human gastric signet ring carcinoma cell line, KATO-III. DNA fragmentation was observed in Vitex-treated KATO-III cells in a time- and dose-dependent manner. DNA fragmentation was accompanied by the following phenomena: elevation in the level of hemeoxygenase-1 protein and thioredoxin reductase mRNA; repression of Mn-superoxide dismutase and catalase mRNAs; release of cytochrome c from mitochondria into the cytosol; activation of caspases-8, -9 and -3; decrease in the level of Bcl-2, Bcl-XL and Bid protein; increase in the level of Bad protein. The intracellular oxidized state, measured using 2',7'-dichlorofluorescin diacetate, increased after Vitex treatment. While the amount of intracellular GSH decreased significantly after treatment with Vitex, the level of GSSG was unaffected. Furthermore, no significant perturbation in the amount of proteins/mRNAs related to glutathione metabolism could be detected. These apoptotic alterations induced by exposure to Vitex were blocked by the presence of an anti-oxidative reagent, N-acetyl-l-cysteine, or the addition of exogenous GSH. Our results demonstrate that intracellular oxidative stress and mitochondrial membrane damage is responsible for Vitex-induced apoptosis, which may be mediated by a diminution of reduced type glutathione within the cell.

  13. Bisphenol A induces spermatocyte apoptosis in rare minnow Gobiocypris rarus

    International Nuclear Information System (INIS)

    Zhang, Yingying; Cheng, Mengqian; Wu, Lang; Zhang, Guo; Wang, Zaizhao

    2016-01-01

    Highlights: • Adult male G. rarus were exposed to 225 μg/L BPA for 7, 21 and 63 days. • BPA could induce spermatocyte apoptosis in rare minnow testis. • The mitochondrial apoptotic pathway participated in the germ cell apoptosis. • The spermatocyte apoptosis was likely initiated by BPA induced meiosis arrest. - Abstract: Bisphenol A (BPA) is an endocrine disruptor, and could induce germ cells apoptosis in the testis of mammals. But whether it could affect fish in the same mechanism has not’ been studied till now. In the present study, to investigate the influence of BPA on testis germ cells in fish, adult male rare minnow Gobiocypris rarus were exposed to 225 μg L"−"1 (0.99 μM) BPA for 1, 3 and 9 weeks. Through TdT-mediated dUTP nick end labeling (TUNEL) and transmission electron microscope (TEM) analysis, we found that the amount of apoptotic spermatocytes significantly increased in a time dependent manner following BPA exposure. Western Blot results showed that the ratio of Bcl2/Bax, the important apoptosis regulators in intrinsic mitochondrial apoptotic pathway, was significantly decreased. qPCR showed that mRNA expression of several genes in mitochondrial apoptotic pathway including bcl2, bax, casp9, cytc and mcl1b were significantly changed following BPA exposure. In addition, mRNA expression of meiosis regulation genes (kpna7 and wee2), and genes involved in both apoptosis and meiosis (birc5, ccna1, and gsa1a) were also affected by BPA. Taken together, the present study demonstrated that BPA could induce spermatocytes apoptosis in rare minnow testis, and the apoptosis was probably under regulation of intrinsic mitochondrial apoptotic pathway. Moreover, the spermatocyte apoptosis was likely initiated by BPA induced meiosis arrest.

  14. Bisphenol A induces spermatocyte apoptosis in rare minnow Gobiocypris rarus

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yingying; Cheng, Mengqian; Wu, Lang; Zhang, Guo; Wang, Zaizhao, E-mail: zzwang@nwsuaf.edu.cn

    2016-10-15

    Highlights: • Adult male G. rarus were exposed to 225 μg/L BPA for 7, 21 and 63 days. • BPA could induce spermatocyte apoptosis in rare minnow testis. • The mitochondrial apoptotic pathway participated in the germ cell apoptosis. • The spermatocyte apoptosis was likely initiated by BPA induced meiosis arrest. - Abstract: Bisphenol A (BPA) is an endocrine disruptor, and could induce germ cells apoptosis in the testis of mammals. But whether it could affect fish in the same mechanism has not’ been studied till now. In the present study, to investigate the influence of BPA on testis germ cells in fish, adult male rare minnow Gobiocypris rarus were exposed to 225 μg L{sup −1} (0.99 μM) BPA for 1, 3 and 9 weeks. Through TdT-mediated dUTP nick end labeling (TUNEL) and transmission electron microscope (TEM) analysis, we found that the amount of apoptotic spermatocytes significantly increased in a time dependent manner following BPA exposure. Western Blot results showed that the ratio of Bcl2/Bax, the important apoptosis regulators in intrinsic mitochondrial apoptotic pathway, was significantly decreased. qPCR showed that mRNA expression of several genes in mitochondrial apoptotic pathway including bcl2, bax, casp9, cytc and mcl1b were significantly changed following BPA exposure. In addition, mRNA expression of meiosis regulation genes (kpna7 and wee2), and genes involved in both apoptosis and meiosis (birc5, ccna1, and gsa1a) were also affected by BPA. Taken together, the present study demonstrated that BPA could induce spermatocytes apoptosis in rare minnow testis, and the apoptosis was probably under regulation of intrinsic mitochondrial apoptotic pathway. Moreover, the spermatocyte apoptosis was likely initiated by BPA induced meiosis arrest.

  15. Mitochondrion-mediated cell death: dissecting yeast apoptosis for a better understanding of neurodegeneration

    Energy Technology Data Exchange (ETDEWEB)

    Braun, Ralf J., E-mail: ralf.braun@uni-bayreuth.de [Institut für Zellbiologie, Universität Bayreuth, Bayreuth (Germany)

    2012-11-28

    Mitochondrial damage and dysfunction are common hallmarks for neurodegenerative disorders, including Alzheimer, Parkinson, Huntington diseases, and the motor neuron disorder amyotrophic lateral sclerosis. Damaged mitochondria pivotally contribute to neurotoxicity and neuronal cell death in these disorders, e.g., due to their inability to provide the high energy requirements for neurons, their generation of reactive oxygen species (ROS), and their induction of mitochondrion-mediated cell death pathways. Therefore, in-depth analyses of the underlying molecular pathways, including cellular mechanisms controlling the maintenance of mitochondrial function, is a prerequisite for a better understanding of neurodegenerative disorders. The yeast Saccharomyces cerevisiae is an established model for deciphering mitochondrial quality control mechanisms and the distinct mitochondrial roles during apoptosis and programmed cell death. Cell death upon expression of various human neurotoxic proteins has been characterized in yeast, revealing neurotoxic protein-specific differences. This review summarizes how mitochondria are affected in these neurotoxic yeast models, and how they are involved in the execution and prevention of cell death. I will discuss to which extent this mimics the situation in other neurotoxic model systems, and how this may contribute to a better understanding of the mitochondrial roles in the human disorders.

  16. Mitochondrion-mediated cell death: dissecting yeast apoptosis for a better understanding of neurodegeneration

    International Nuclear Information System (INIS)

    Braun, Ralf J.

    2012-01-01

    Mitochondrial damage and dysfunction are common hallmarks for neurodegenerative disorders, including Alzheimer, Parkinson, Huntington diseases, and the motor neuron disorder amyotrophic lateral sclerosis. Damaged mitochondria pivotally contribute to neurotoxicity and neuronal cell death in these disorders, e.g., due to their inability to provide the high energy requirements for neurons, their generation of reactive oxygen species (ROS), and their induction of mitochondrion-mediated cell death pathways. Therefore, in-depth analyses of the underlying molecular pathways, including cellular mechanisms controlling the maintenance of mitochondrial function, is a prerequisite for a better understanding of neurodegenerative disorders. The yeast Saccharomyces cerevisiae is an established model for deciphering mitochondrial quality control mechanisms and the distinct mitochondrial roles during apoptosis and programmed cell death. Cell death upon expression of various human neurotoxic proteins has been characterized in yeast, revealing neurotoxic protein-specific differences. This review summarizes how mitochondria are affected in these neurotoxic yeast models, and how they are involved in the execution and prevention of cell death. I will discuss to which extent this mimics the situation in other neurotoxic model systems, and how this may contribute to a better understanding of the mitochondrial roles in the human disorders.

  17. Diclofenac inhibits tumor necrosis factor-α-induced nuclear factor-κB activation causing synergistic hepatocyte apoptosis.

    Science.gov (United States)

    Fredriksson, Lisa; Herpers, Bram; Benedetti, Giulia; Matadin, Quraisha; Puigvert, Jordi C; de Bont, Hans; Dragovic, Sanja; Vermeulen, Nico P E; Commandeur, Jan N M; Danen, Erik; de Graauw, Marjo; van de Water, Bob

    2011-06-01

    Drug-induced liver injury (DILI) is an important clinical problem. It involves crosstalk between drug toxicity and the immune system, but the exact mechanism at the cellular hepatocyte level is not well understood. Here we studied the mechanism of crosstalk in hepatocyte apoptosis caused by diclofenac and the proinflammatory cytokine tumor necrosis factor α (TNF-α). HepG2 cells were treated with diclofenac followed by TNF-α challenge and subsequent evaluation of necrosis and apoptosis. Diclofenac caused a mild apoptosis of HepG2 cells, which was strongly potentiated by TNF-α. A focused apoptosis machinery short interference RNA (siRNA) library screen identified that this TNF-α-mediated enhancement involved activation of caspase-3 through a caspase-8/Bid/APAF1 pathway. Diclofenac itself induced sustained activation of c-Jun N-terminal kinase (JNK) and inhibition of JNK decreased both diclofenac and diclofenac/TNF-α-induced apoptosis. Live cell imaging of GFPp65/RelA showed that diclofenac dampened the TNF-α-mediated nuclear factor kappaB (NF-κB) translocation oscillation in association with reduced NF-κB transcriptional activity. This was associated with inhibition by diclofenac of the TNF-α-induced phosphorylation of the inhibitor of NF-κB alpha (IκBα). Finally, inhibition of IκB kinase β (IKKβ) with BMS-345541 as well as stable lentiviral short hairpin RNA (shRNA)-based knockdown of p65/RelA sensitized hepatocytes towards diclofenac/TNF-α-induced cytotoxicity. Together, our data suggest a model whereby diclofenac-mediated stress signaling suppresses TNF-α-induced survival signaling routes and sensitizes cells to apoptosis. Copyright © 2011 American Association for the Study of Liver Diseases.

  18. Generation of reactive oxygen species by a novel berberine–bile acid analog mediates apoptosis in hepatocarcinoma SMMC-7721 cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qingyong, E-mail: li_qingyong@126.com [Key Laboratory of Forest Plant Ecology (Northeast Forestry University), Ministry of Education (China); Zhang, Li; Zu, Yuangang; Liu, Tianyu; Zhang, Baoyou; He, Wuna [Key Laboratory of Forest Plant Ecology (Northeast Forestry University), Ministry of Education (China)

    2013-04-19

    Graphical abstract: - Highlights: • Anticancer effects of B4, a novel berberine–bile acid analog, were tested. • B4 inhibited cell proliferation in hepatocellular carcinoma cells. • It also stimulated mitochondrial ROS production and membrane depolarization. • Effects of B4 were inhibited by a non-specific ROS scavenger. • Regulation of ROS generation may be a strategy for treating hepatic carcinoma. - Abstract: 2,3-Methenedioxy-9-O-(3′α,7′α-dihydroxy-5′β-cholan-24′-propy-lester) berberine (B4) is a novel berberine–bile acid analog synthesized in our laboratory. Previously, we showed that B4 exerted greater cytotoxicity than berberine in several human cancer cell lines. Therefore, we further evaluated the mechanism governing its anticancer actions in hepatocellular carcinoma SMMC-7721 cells. B4 inhibited the proliferation of SMMC-7721 cells, and stimulated reactive oxygen species (ROS) production and mitochondrial membrane depolarization; anti-oxidant capacity was reduced. B4 also induced the release of cytochrome c from the mitochondria to the cytosol and an increase in poly ADP-ribose polymerase (PARP) cleavage products, reflective of caspase-3 activation. Moreover, B4 induced the nuclear translocation of apoptosis-inducing factor (AIF) and a rise in DNA fragmentation. Pretreatment with the anti-oxidant N-acetylcysteine (NAC) inhibited B4-mediated effects, including cytotoxicity, ROS production, mitochondrial membrane depolarization increase in intracellular Ca{sup 2+}, cytochrome c release, PARP cleavage, and AIF translocation. Our data suggest that B4 induces ROS-triggered caspase-dependent and caspase-independent apoptosis pathways in SMMC-7721 cells and that ROS production may be a specific potential strategy for treating hepatic carcinoma.

  19. Mitochondrial Dysfunction Causes Oxidative Stress and Tapetal Apoptosis in Chemical Hybridization Reagent-Induced Male Sterility in Wheat

    Directory of Open Access Journals (Sweden)

    Shuping Wang

    2018-01-01

    Full Text Available Male sterility in plants has been strongly linked to mitochondrial dysfunction. Chemical hybridization agent (CHA-induced male sterility is an important tool in crop heterosis. Therefore, it is important to better understand the relationship between mitochondria and CHA-induced male sterility in wheat. This study reports on the impairment of mitochondrial function duo to CHA-SQ-1, which occurs by decreasing cytochrome oxidase and adenosine triphosphate synthase protein levels and theirs activities, respiratory rate, and in turn results in the inhibition of the mitochondrial electron transport chain (ETC, excessive production of reactive oxygen species (ROS and disruption of the alternative oxidase pathway. Subsequently, excessive ROS combined with MnSOD defects results in damage to the mitochondrial membrane, followed by ROS release into the cytoplasm. The microspores underwent severe oxidative stress during pollen development. Furthermore, chronic oxidative stress, together with the overexpression of type II metacaspase, triggered premature tapetal apoptosis, which resulted in pollen abortion. Accordingly, we propose a metabolic pathway for mitochondrial-mediated male sterility in wheat, which provides information on the molecular events underlying CHA-SQ-1-induced abortion of anthers and may serve as an additional guide to the practical application of hybrid breeding.

  20. Pharmacological targeting of HSP90 with 17-AAG induces apoptosis of myogenic cells through activation of the intrinsic pathway.

    Science.gov (United States)

    Wagatsuma, Akira; Takayama, Yuzo; Hoshino, Takayuki; Shiozuka, Masataka; Yamada, Shigeru; Matsuda, Ryoichi; Mabuchi, Kunihiko

    2017-12-16

    We have shown that pharmacological inhibition of HSP90 ATPase activity induces apoptosis of myoblasts during their differentiation. However, the signaling pathways remain not fully characterized. We report that pharmacological targeting of HSP90 with 17-AAG activates the intrinsic pathway including caspase-dependent and caspase-independent pathways. 17-AAG induces the typical apoptotic phenotypes including PARP cleavage, chromatin condensation, and nuclear fragmentation with mitochondrial release of cytochrome c, Smac/DIABLO, procaspase-9 processing, and caspase-3 activation. AIF and EndoG redistribute from the mitochondria into the cytosol and are partially translocated to the nucleus in 17-AAG-treated cells. These results suggest that caspase-dependent and caspase-independent pathways should be considered in apoptosis of myogenic cells induced by inhibition of HSP90 ATPase activity.

  1. Dopamine-induced apoptosis of lactotropes is mediated by the short isoform of D2 receptor.

    Directory of Open Access Journals (Sweden)

    Daniela Betiana Radl

    Full Text Available Dopamine, through D2 receptor (D2R, is the major regulator of lactotrope function in the anterior pituitary gland. Both D2R isoforms, long (D2L and short (D2S, are expressed in lactotropes. Although both isoforms can transduce dopamine signal, they differ in the mechanism that leads to cell response. The administration of D2R agonists, such as cabergoline, is the main pharmacological treatment for prolactinomas, but resistance to these drugs exists, which has been associated with alterations in D2R expression. We previously reported that dopamine and cabergoline induce apoptosis of lactotropes in primary culture in an estrogen-dependent manner. In this study we used an in vivo model to confirm the permissive action of estradiol in the apoptosis of anterior pituitary cells induced by D2R agonists. Administration of cabergoline to female rats induced apoptosis, measured by Annexin-V staining, in anterior pituitary gland from estradiol-treated rats but not from ovariectomized rats. To evaluate the participation of D2R isoforms in the apoptosis induced by dopamine we used lactotrope-derived PR1 cells stably transfected with expression vectors encoding D2L or D2S receptors. In the presence of estradiol, dopamine induced apoptosis, determined by ELISA and TUNEL assay, only in PR1-D2S cells. To study the role of p38 MAPK in apoptosis induced by D2R activation, anterior pituitary cells from primary culture or PR1-D2S were incubated with an inhibitor of the p38 MAPK pathway (SB203850. SB203580 blocked the apoptotic effect of D2R activation in lactotropes from primary cultures and PR1-D2S cells. Dopamine also induced p38 MAPK phosphorylation, determined by western blot, in PR1-D2S cells and estradiol enhanced this effect. These data suggest that, in the presence of estradiol, D2R agonists induce apoptosis of lactotropes by their interaction with D2S receptors and that p38 MAPK is involved in this process.

  2. Gallic acid prevents nonsteroidal anti-inflammatory drug-induced gastropathy in rat by blocking oxidative stress and apoptosis.

    Science.gov (United States)

    Pal, Chinmay; Bindu, Samik; Dey, Sumanta; Alam, Athar; Goyal, Manish; Iqbal, Mohd Shameel; Maity, Pallab; Adhikari, Susanta S; Bandyopadhyay, Uday

    2010-07-15

    Nonsteroidal anti-inflammatory drug (NSAID)-induced oxidative stress plays a critical role in gastric mucosal cell apoptosis and gastropathy. NSAIDs induce the generation of hydroxyl radical ((*)OH) through the release of free iron, which plays an important role in developing gastropathy. Thus, molecules having both iron-chelating and antiapoptotic properties will be beneficial in preventing NSAID-induced gastropathy. Gallic acid (GA), a polyphenolic natural product, has the capacity to chelate free iron. Here, we report that GA significantly prevents, as well as heals, NSAID-induced gastropathy. In vivo, GA blocks NSAID-mediated mitochondrial oxidative stress by preventing mitochondrial protein carbonyl formation, lipid peroxidation, and thiol depletion. In vitro, GA scavenges free radicals and blocks (*)OH-mediated oxidative damage. GA also attenuates gastric mucosal cell apoptosis in vivo as well as in vitro in cultured gastric mucosal cells as evident from the TUNEL assay. GA prevents NSAID-induced activation of caspase-9, a marker for the mitochondrial pathway of apoptosis, and restores NSAID-mediated collapse of the mitochondrial transmembrane potential and dehydrogenase activity. Thus, the inhibition of mitochondrial oxidative stress by GA is associated with the inhibition of NSAID-induced mitochondrial dysfunction and activation of apoptosis in gastric mucosal cells, which are responsible for gastric injury or gastropathy. Copyright 2010 Elsevier Inc. All rights reserved.

  3. 1800MHz Microwave Induces p53 and p53-Mediated Caspase-3 Activation Leading to Cell Apoptosis In Vitro.

    Directory of Open Access Journals (Sweden)

    Fuqiang Xing

    Full Text Available Recent studies have reported that exposure of mammalian cells to microwave radiation may have adverse effects such as induction of cell apoptosis. However, the molecular mechanisms underlying microwave induced mammalian cell apoptosis are not fully understood. Here, we report a novel mechanism: exposure to 1800MHz microwave radiation induces p53-dependent cell apoptosis through cytochrome c-mediated caspase-3 activation pathway. We first measured intensity of microwave radiation from several electronic devices with an irradiation detector. Mouse NIH/3T3 and human U-87 MG cells were then used as receivers of 1800MHz electromagnetic radiation (EMR at a power density of 1209 mW/m2. Following EMR exposure, cells were analyzed for viability, intracellular reactive oxygen species (ROS generation, DNA damage, p53 expression, and caspase-3 activity. Our analysis revealed that EMR exposure significantly decreased viability of NIH/3T3 and U-87 MG cells, and increased caspase-3 activity. ROS burst was observed at 6 h and 48 h in NIH/3T3 cells, while at 3 h in U-87 MG cells. Hoechst 33258 staining and in situ TUNEL assay detected that EMR exposure increased DNA damage, which was significantly restrained in the presence of N-acetyl-L-cysteine (NAC, an antioxidant. Moreover, EMR exposure increased the levels of p53 protein and p53 target gene expression, promoted cytochrome c release from mitochondrion, and increased caspase-3 activity. These events were inhibited by pretreatment with NAC, pifithrin-α (a p53 inhibitor and caspase inhibitor. Collectively, our findings demonstrate, for the first time, that 1800MHz EMR induces apoptosis-related events such as ROS burst and more oxidative DNA damage, which in turn promote p53-dependent caspase-3 activation through release of cytochrome c from mitochondrion. These findings thus provide new insights into physiological mechanisms underlying microwave-induced cell apoptosis.

  4. Apoptosis-like death, an extreme SOS response in Escherichia coli.

    Science.gov (United States)

    Erental, Ariel; Kalderon, Ziva; Saada, Ann; Smith, Yoav; Engelberg-Kulka, Hanna

    2014-07-15

    In bacteria, SOS is a global response to DNA damage, mediated by the recA-lexA genes, resulting in cell cycle arrest, DNA repair, and mutagenesis. Previously, we reported that Escherichia coli responds to DNA damage via another recA-lexA-mediated pathway resulting in programmed cell death (PCD). We called it apoptosis-like death (ALD) because it is characterized by membrane depolarization and DNA fragmentation, which are hallmarks of eukaryotic mitochondrial apoptosis. Here, we show that ALD is an extreme SOS response that occurs only under conditions of severe DNA damage. Furthermore, we found that ALD is characterized by additional hallmarks of eukaryotic mitochondrial apoptosis, including (i) rRNA degradation by the endoribonuclease YbeY, (ii) upregulation of a unique set of genes that we called extensive-damage-induced (Edin) genes, (iii) a decrease in the activities of complexes I and II of the electron transport chain, and (iv) the formation of high levels of OH˙ through the Fenton reaction, eventually resulting in cell death. Our genetic and molecular studies on ALD provide additional insight for the evolution of mitochondria and the apoptotic pathway in eukaryotes. Importance: The SOS response is the first described and the most studied bacterial response to DNA damage. It is mediated by a set of two genes, recA-lexA, and it results in DNA repair and thereby in the survival of the bacterial culture. We have shown that Escherichia coli responds to DNA damage by an additional recA-lexA-mediated pathway resulting in an apoptosis-like death (ALD). Apoptosis is a mode of cell death that has previously been reported only in eukaryotes. We found that E. coli ALD is characterized by several hallmarks of eukaryotic mitochondrial apoptosis. Altogether, our results revealed that recA-lexA is a DNA damage response coordinator that permits two opposite responses: life, mediated by the SOS, and death, mediated by the ALD. The choice seems to be a function of the degree

  5. Physalis peruviana extract induces apoptosis in human Hep G2 cells through CD95/CD95L system and the mitochondrial signaling transduction pathway.

    Science.gov (United States)

    Wu, Shu-Jing; Ng, Lean-Teik; Lin, Doung-Liang; Huang, Shan-Ney; Wang, Shyh-Shyan; Lin, Chun-Ching

    2004-11-25

    Physalis species is a popular folk medicine used for treating cancer, leukemia, hepatitis and other diseases. Studies have shown that the ethanol extract of Physalis peruviana (EEPP) inhibits growth and induces apoptotic death of human Hep G2 cells in culture, whereas proliferation of the mouse BALB/C normal liver cells was not affected. In this study, we performed detailed studies to define the molecular mechanism of EEPP-induced apoptosis in Hep G2 cells. The results further confirmed that EEPP inhibited cell proliferation in a dose- and time-dependent manner. At 50 microg/ml, EEPP significantly increased the accumulation of the sub-G1 peak (hypoploid) and the portion of apoptotic annexin V positive cells. EEPP was found to trigger apoptosis through the release of cytochrome c, Smac/DIABLO and Omi/HtrA2 from mitochondria to cytosol and consequently resulted in caspase-3 activation. Pre-treatment with a general caspase inhibitor (z-VAD-fmk) prevented cytochrome c release. After 48 h of EEPP treatment, the apoptosis of Hep G2 cells was found to associate with an elevated p53, and CD95 and CD95L proteins expression. Furthermore, a marked down-regulation of the expression of the Bcl-2, Bcl-XL and XIAP, and up-regulation of the Bax and Bad proteins were noted. Taken together, the present results suggest that EEPP-induced Hep G2 cell apoptosis was possibly mediated through the CD95/CD95L system and the mitochondrial signaling transduction pathway.

  6. The role of apoptosis in MCLR-induced developmental toxicity in zebrafish embryos

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Cheng [College of Fisheries, Huazhong Agricultural University, Wuhan 430070 (China); Sun, Hong [Hubei Maternal and Child Health Hospital, Wuhan 430070 (China); Xie, Ping [Donghu Experimental Station of Lake Ecosystems, State Key Laboratory for Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072 (China); Wang, Jianghua; Zhang, Guirong; Chen, Nan [College of Fisheries, Huazhong Agricultural University, Wuhan 430070 (China); Yan, Wei, E-mail: Yanwei75126@163.com [Institute of Agricultural Quality Standards and Testing Technology, Hubei Academy of Agricultural Sciences, Wuhan 430064 (China); Li, Guangyu, E-mail: ligy2001@163.com [College of Fisheries, Huazhong Agricultural University, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China)

    2014-04-01

    Highlights: • MCLR-induced apoptosis in the heart of developing embryos leads to the growth delay in zebrafish. • MCLR-triggered apoptosis might be induced by ROS. • P53–Bax–Bcl-2 and caspase-dependent apoptotic pathway contribute greatly to MCLR-induced apoptosis. Abstract: We previously demonstrated that cyanobacteria-derived microcystin–leucine–arginine (MCLR) is able to induce developing toxicity, such as malformation, growth delay and also decreased heart rates in zebrafish embryos. However, the molecular mechanisms by which MCLR induces its toxicity during the development of zebrafish remain largely unknown. Here, we evaluate the role of apoptosis in MCLR-induced developmental toxicity. Zebrafish embryos were exposed to various concentrations of MCLR (0, 0.2, 0.5, 2, and 5.0 mg L⁻¹ for 96 h, at which time reactive oxygen species (ROS) was significantly induced in the 2 and 5.0 mg L⁻¹ MCLR exposure groups. Acridine orange (AO) staining and terminal deoxynucleotide transferase-mediated deoxy-UTP nick end labelling (TUNEL) assay showed that MCLR exposure resulted in cell apoptosis. To test the apoptotic pathway, the expression pattern of several apoptotic-related genes was examined for the level of enzyme activity, gene and protein expression, respectively. The overall results demonstrate that MCLR induced ROS which consequently triggered apoptosis in the heart of developing zebrafish embryos. Our results also indicate that the p53–Bax–Bcl-2 pathway and the caspase-dependent apoptotic pathway play major roles in MCLR-induced apoptosis in the developing embryos.

  7. Noxa/Mcl-1 Balance Regulates Susceptibility of Cells to Camptothecin-Induced Apoptosis1

    Science.gov (United States)

    Mei, Yide; Xie, Chongwei; Xie, Wei; Tian, Xu; Li, Mei; Wu, Mian

    2007-01-01

    Although camptothecin (CPT) has been reported to induce apoptosis in various cancer cells, the molecular details of this regulation remain largely unknown. In this study, we demonstrate that BH3-only protein Noxa is upregulated during CPT-induced apoptosis, which is independent of p53. In addition, we show that phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway is responsible for Noxa's induction. Luciferase assay and cAMP response element binding protein (CREB) knockdown experiments further demonstrate that CREB is involved in the transcriptional upregulation of Noxa. Moreover, blocking Noxa expression using specific small interfering ribonucleic acid (siRNA) significantly reduces the apoptosis in response to CPT, indicating that Noxa is an essential mediator for CPT-induced apoptosis. Interestingly, antiapoptotic Mcl-1 was also upregulated through PI3K/Akt signaling pathway upon CPT treatment. Using immunoprecipitation assay, Noxa was found to interact with Mcl-1 in the presence or absence of CPT. Knockdown of Mcl-1 expression by short hairpin ribonucleic acid (shRNA) was shown to potentiate CPT-induced apoptosis. Consistently, ectopic overexpression of Mcl-1 rescued cells from apoptosis induced by CPT. Cells coexpressing Noxa and Mcl-1 at different ratio correlates well with the extent of apoptosis, suggesting that the balance between Noxa and Mcl-1 may determine the susceptibility of HeLa cells to CPT-induced apoptosis. PMID:17971907

  8. Angiotensin II protects primary rat hepatocytes against bile salt-induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Golnar Karimian

    Full Text Available UNLABELLED: Angiotensin II (AT-II is a pro-fibrotic compound that acts via membrane-bound receptors (AT-1R/AT-2R and thereby activates hepatic stellate cells (HSCs. AT-II receptor blockers (ARBs are thus important candidates in the treatment of liver fibrosis. However, multiple case reports suggest that AT-1R blockers may induce hepatocyte injury. Therefore, we investigated the effect of AT-II and its receptor blockers on cytokine-, oxidative stress- and bile salt-induced cell death in hepatocytes. Primary rat hepatocytes were exposed to TNF-α/Actinomycin D, the ROS-generating agent menadione or the bile salts: glycochenodeoxycholic acid (GCDCA and tauro-lithocholic acid-3 sulfate (TLCS, to induce apoptosis. AT-II (100 nmol/L was added 10 minutes prior to the cell death-inducing agent. AT-1R antagonists (Sartans and the AT-2R antagonist PD123319 were used at 1 µmol/L. Apoptosis (caspase-3 activity, acridine orange staining and necrosis (Sytox green staining were quantified. Expression of CHOP (marker for ER stress and AT-II receptor mRNAs were quantified by Q-PCR. AT-II dose-dependently reduced GCDCA-induced apoptosis of hepatocytes (-50%, p<0.05 without inducing necrosis. In addition, AT-II reduced TLCS-induced apoptosis of hepatocytes (-50%, p<0.05. However, AT-II did not suppress TNF/Act-D and menadione-induced apoptosis. Only the AT-1R antagonists abolished the protective effect of AT-II against GCDCA-induced apoptosis. AT-II increased phosphorylation of ERK and a significant reversal of the protective effect of AT-II was observed when signaling kinases, including ERK, were inhibited. Moreover, AT-II prevented the GCDCA-induced expression of CHOP (the marker of the ER-mediated apoptosis. CONCLUSION: Angiotensin II protects hepatocytes from bile salt-induced apoptosis through a combined activation of PI3-kinase, MAPKs, PKC pathways and inhibition of bile salt-induced ER stress. Our results suggest a mechanism for the observed hepatocyte

  9. Activation of P2X7-mediated apoptosis Inhibits DMBA/TPA-induced formation of skin papillomas and cancer in mice

    International Nuclear Information System (INIS)

    Fu, Wen; Gorodeski, George I; McCormick, Tom; Qi, Xiaoping; Luo, Liping; Zhou, Lingyin; Li, Xin; Wang, Bing-Cheng; Gibbons, Heidi E; Abdul-Karim, Fadi W

    2009-01-01

    augmented calcium influx were depended on the expression of the P2X 7 receptor, while the BzATP-induced apoptosis depended on calcium influx. (h) The BzATP-induced apoptosis could be blocked by co-treatment with inhibitors of caspase-9 and caspase-3, but not of caspase-8. (a) P2X 7 -dependent apoptosis is an important mechanism that controls the development and progression of epidermal neoplasia in the mouse. (b) The P2X 7 -dependent apoptosis is mediated by calcium influx via P2X 7 pores, and involves the caspase-9 (mitochondrial) pathway. (c) The diminished pro-apoptotic effect of BzATP in mouse cancer keratinocytes is possibly the result of low expression of the P2X 7 receptor. (d) Activation of P2X 7 -dependent apoptosis, e.g. with BzATP could be a novel chemotherapeutic growth-preventive modality for papillomas and epithelial cancers in vivo

  10. Involvement of TR3/Nur77 translocation to the endoplasmic reticulum in ER stress-induced apoptosis

    International Nuclear Information System (INIS)

    Liang Bin; Song Xuhong; Liu Gefei; Li Rui; Xie Jianping; Xiao Lifeng; Du Mudan; Zhang Qiaoxia; Xu Xiaoyuan; Gan Xueqiong; Huang Dongyang

    2007-01-01

    Nuclear orphan receptor TR3/Nur77/NGFI-B is a novel apoptotic effector protein that initiates apoptosis largely by translocating from the nucleus to the mitochondria, causing the release of cytochrome c. However, it is possible that TR3 translocates to other organelles. The present study was designed to determine the intracellular localization of TR3 following CD437-induced nucleocytoplasmic translocation and the mechanisms involved in TR3-induced apoptosis. In human neuroblastoma SK-N-SH cells and human esophageal squamous carcinoma EC109 and EC9706 cells, 5 μM CD437 induced translocation of TR3 to the endoplasmic reticulum (ER). This distribution was confirmed by immunofluorescence analysis, subcellular fractionation analysis and coimmunoprecipitation analysis. The translocated TR3 interacted with ER-targeting Bcl-2; initiated an early release of Ca 2+ from ER; resulted in ER stress and induced apoptosis through ER-specific caspase-4 activation, together with induction of mitochondrial stress and subsequent activation of caspase-9. Our results identified a novel distribution of TR3 in the ER and defined two parallel mitochondrial- and ER-based pathways that ultimately result in apoptotic cell death

  11. Osteoblasts Protect AML Cells from SDF-1-Induced Apoptosis

    Science.gov (United States)

    Kremer, Kimberly N.; Dudakovic, Amel; McGee-Lawrence, Meghan E.; Philips, Rachael L.; Hess, Allan D.; Smith, B. Douglas; van Wijnen, Andre J.; Karp, Judith E.; Kaufmann, Scott H.; Westendorf, Jennifer J.; Hedin, Karen E.

    2014-01-01

    The bone marrow provides a protective environment for acute myeloid leukemia (AML) cells that often allows leukemic stem cells to survive standard chemotherapeutic regimens. Targeting these leukemic stem cells within the bone marrow is critical for preventing relapse. We recently demonstrated that SDF-1, a chemokine abundant in the bone marrow, induces apoptosis in AML cell lines and in patient samples expressing high levels of its receptor, CXCR4. Here we show that a subset of osteoblast lineage cells within the bone marrow can protect AML cells from undergoing apoptosis in response to the SDF-1 naturally present in that location. In co-culture systems, osteoblasts at various stages of differentiation protected AML cell lines and patient isolates from SDF-1-induced apoptosis. The differentiation of the osteoblast cell lines, MC3T3 and W-20-17, mediated this protection via a cell contact-independent mechanism. In contrast, bone marrow-derived mesenchymal cells, the precursors of osteoblasts, induced apoptosis in AML cells via a CXCR4-dependent mechanism and failed to protect AML cells from exogenously added SDF-1. These results indicate that osteoblasts in the process of differentiation potently inhibit the SDF-1-driven apoptotic pathway of CXCR4-expressing AML cells residing in the bone marrow. Drugs targeting this protective mechanism could potentially provide a new approach to treating AML by enhancing the SDF-1-induced apoptosis of AML cells residing within the bone marrow microenvironment. PMID:24851270

  12. Resveratrol-Sensitized UVA Induced Apoptosis in Human Keratinocytes through Mitochondrial Oxidative Stress and Pore Opening

    Science.gov (United States)

    Boyer, Jean Z; Jandova, Jana; Janda, Jaroslav; Vleugels, Frank R; Elliott, David; Sligh, James E

    2012-01-01

    Resveratrol (3, 5, 4′-trihydroxy- trans- stilbene), a polyphenol compound, is derived from natural products such as the skin of red grapes, blueberries and cranberries. Resveratrol not only exhibits antioxidant, cardioprotection, and anti-aging properties, but can also inhibit cancer cell growth and induce apoptosis. It has been shown that resveratrol inhibits the activation of Nf-kB and subsequently down regulates the expression of Nf-kB regulated genes such as interleukin-2 and Bcl-2, leading to cell cycle arrest and increased apoptosis in multiple myeloma cells. In the skin, resveratrol has been reported to sensitize keratinocytes to UVA induced apoptosis. However, the effect of resveratrol on opening of the mitochondrial permeability transition pore has not been previously examined. Our data show that UVA (14J/cm2) along with resveratrol causes massive oxidative stress in mitochondria. As a consequence of oxidative stress, the mitochondrial membrane potential decreases which results in opening of the mitochondrial pores ultimately leading to apoptosis in human keratinocytes. These results may have clinical implications for development of future chemotherapeutic treatment for tumors of the skin. PMID:22673012

  13. Short-chain fatty acids induced autophagy serves as an adaptive strategy for retarding mitochondria-mediated apoptotic cell death

    OpenAIRE

    Tang, Y; Chen, Y; Jiang, H; Nie, D

    2010-01-01

    Short-chain fatty acids (SCFAs) are the major by-products of bacterial fermentation of undigested dietary fibers in the large intestine. SCFAs, mostly propionate and butyrate, inhibit proliferation and induce apoptosis in colon cancer cells, but clinical trials had mixed results regarding the anti-tumor activities of SCFAs. Herein we demonstrate that propionate and butyrate induced autophagy in human colon cancer cells to dampen apoptosis whereas inhibition of autophagy potentiated SCFA induc...

  14. Apoptosis induced by lipid-associated membrane proteins from Mycoplasma hyopneumoniae in a porcine lung epithelial cell line with the involvement of caspase 3 and the MAPK pathway.

    Science.gov (United States)

    Ni, B; Bai, F F; Wei, Y; Liu, M J; Feng, Z X; Xiong, Q Y; Hua, L Z; Shao, G Q

    2015-09-25

    Lipid-associated membrane proteins (LAMPs) are important in the pathogenicity of the Mycoplasma genus of bacteria. We investigated whether Mycoplasma hyopneumoniae LAMPs have pathogenic potential by inducing apoptosis in a St. Jude porcine lung epithelial cell line (SJPL). LAMPs from a pathogenic strain of M. hyopneumoniae (strain 232) were used in the research. Our investigation made use of diamidino-phenylindole (DAPI) and acridine orange/ethidium bromide (AO/EB) staining, terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) analysis, and Annexin-V-propidium iodide staining. After LAMP treatment for 24 h, typical changes were induced, chromosomes were concentrated, apoptotic bodies were observed, the 3'-OH groups of cleaved genomes were exposed, and the percentage of apoptotic cells reached 36.5 ± 11.66%. Caspase 3 and caspase 8 were activated and cytochrome c (cyt c) was released from the mitochondria into the cytoplasm; poly ADP ribose polymerase (PARP) was digested into two fragments; p38 mitogen-activated protein kinase (MAPK) was phosphorylated; and the expression of pro-apoptosis protein Bax increased while the anti-apoptosis protein Bcl-2 decreased. LAMPs also stimulated SJPL cells to produce nitric oxide (NO) and superoxide. This study demonstrated that LAMPs from M. hyopneumoniae can induce apoptosis in SJPL cells through the activation of caspase 3, caspase 8, cyt c, Bax, and p38 MAPK, thereby contributing to our understanding of the pathogenesis of M. hyopneumoniae, which should improve the treatment of M. hyopneumoniae infections.

  15. Interferon-β-induced activation of c-Jun NH2-terminal kinase mediates apoptosis through up-regulation of CD95 in CH31 B lymphoma cells

    International Nuclear Information System (INIS)

    Takada, Eiko; Shimo, Kuniaki; Hata, Kikumi; Abiake, Maira; Mukai, Yasuo; Moriyama, Masami; Heasley, Lynn; Mizuguchi, Junichiro

    2005-01-01

    Type I interferon (IFN)-induced antitumor action is due in part to apoptosis, but the molecular mechanisms underlying IFN-induced apoptosis remain largely unresolved. In the present study, we demonstrate that IFN-β induced apoptosis and the loss of mitochondrial membrane potential (ΔΨm) in the murine CH31 B lymphoma cell line, and this was accompanied by the up-regulation of CD95, but not CD95-ligand (CD95-L), tumor necrosis factor (TNF), or TNF-related apoptosis-inducing ligand (TRAIL). Pretreatment with anti-CD95-L mAb partially prevented the IFN-β-induced loss of ΔΨm, suggesting that the interaction of IFN-β-up-regulated CD95 with CD95-L plays a crucial role in the induction of fratricide. IFN-β induced a sustained activation of c-Jun NH 2 -terminal kinase 1 (JNK1), but not extracellular signal-regulated kinases (ERKs). The IFN-β-induced apoptosis and loss of ΔΨm were substantially compromised in cells overexpressing a dominant-negative form of JNK1 (dnJNK1), and it was slightly enhanced in cells carrying a constitutively active JNK construct, MKK7-JNK1 fusion protein. The IFN-β-induced up-regulation of CD95 together with caspase-8 activation was also abrogated in the dnJNK1 cells while it was further enhanced in the MKK7-JNK1 cells. The levels of cellular FLIP (c-FLIP), competitively interacting with caspase-8, were down-regulated by stimulation with IFN-β but were reversed by the proteasome inhibitor lactacystin. Collectively, the IFN-β-induced sustained activation of JNK mediates apoptosis, at least in part, through up-regulation of CD95 protein in combination with down-regulation of c-FLIP protein

  16. Human retinal pigment epithelial cell-induced apoptosis in activated T cells

    DEFF Research Database (Denmark)

    Jørgensen, A; Wiencke, A K; la Cour, M

    1998-01-01

    PURPOSE: The immune privilege of the eye has been thought to be dependent on physical barriers and absence of lymphatic vessels. However, the immune privilege may also involve active immunologic processes, as recent studies have indicated. The purpose of the present study was to investigate whether...... human retinal pigment epithelial (RPE) cells can induce apoptosis in activated T cells. METHODS: Fas ligand (FasL) expression was detected by flow cytometry and immunohistochemistry. Cultured RPE cells were cocultured with T-cell lines and peripheral blood lymphocytes for 6 hours to 2 days. Induction...... of apoptosis was detected by 7-amino-actinomycin D and annexin V staining. RESULTS: Retinal pigment epithelial cells expressed FasL and induced apoptosis in activated Fas+ T cells. Blocking of Fas-FasL interaction with antibody strongly inhibited RPE-mediated T-cell apoptosis. Retinal pigment epithelial cells...

  17. The role of cPLA2 in Methylglyoxal-induced cell apoptosis of HUVECs

    International Nuclear Information System (INIS)

    Yuan, Jie; Zhu, Chao; Hong, Yali; Sun, Zongxing; Fang, Xianjun; Wu, Biao; Li, Shengnan

    2017-01-01

    Methylglyoxal (MGO), a highly reactive dicarbonyl compound, is mainly formed as a byproduct of glycolysis. Elevated MGO level is known to induce apoptosis of vascular endothelial cells, which is implicated with progression of atherosclerosis and diabetic complications. However, the underlying mechanisms have not been exhaustively investigated yet. Here, we further characterized the mechanisms how MGO induced apoptosis in human umbilical vein endothelial cells (HUVECs). Our data revealed that cytosolic phospholipase A2 (cPLA2) played an important role in MGO-induced cell apoptosis. It was found that MGO could increase both the activity and expression of cPLA2. Inhibition of cPLA2 by Pyrrophenone (PYR) or siRNA significantly attenuated the MGO-induced apoptosis. Additionally, MGO time-dependently decreased the phosphorylation of nuclear factor κB (NF-κB). Pretreatment of the cells with NF-κB inhibitor, BAY11-7082, further increased MGO-induced apoptosis of HUVECs, indicating that NF-κB played a survival role in this MGO-induced apoptosis. Furthermore, in the presence of si-cPLA2 or PYR, MGO no longer decreased NF-κB phosphorylation. Beyond that, the antioxidant N-acetyl cysteine (NAC) could reverse the changes of both cPLA2 and NF-κB caused by MGO. p38, the upstream of cPLA2, was also significantly phosphorylated by MGO. However, p38 inhibitor failed to reverse the apoptosis induced by MGO. This study gives an important insight into the downstream signaling mechanisms of MGO, cPLA2-NF-κB, in endothelial apoptosis. - Highlights: • cPLA2 participated in MGO-induced HUVECs apoptosis. • Inhibition of NF-κB was involved in MGO-cPLA2-mediated cell apoptosis. • Antioxidant NAC attenuated MGO-induced cPLA2 activation and cell apoptosis.

  18. The role of cPLA2 in Methylglyoxal-induced cell apoptosis of HUVECs

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Jie; Zhu, Chao; Hong, Yali; Sun, Zongxing; Fang, Xianjun [Jiangsu Provincial Key Lab of Cardiovascular Diseases and Molecular intervention, Department of Pharmacology, Nanjing Medical University, Nanjing 210029 (China); Wu, Biao, E-mail: wubiao@ncu.edu.cn [Department of Surgery, The First Affiliated Hospital, Nanchang University (China); Li, Shengnan, E-mail: snli@njmu.edu.cn [Jiangsu Provincial Key Lab of Cardiovascular Diseases and Molecular intervention, Department of Pharmacology, Nanjing Medical University, Nanjing 210029 (China)

    2017-05-15

    Methylglyoxal (MGO), a highly reactive dicarbonyl compound, is mainly formed as a byproduct of glycolysis. Elevated MGO level is known to induce apoptosis of vascular endothelial cells, which is implicated with progression of atherosclerosis and diabetic complications. However, the underlying mechanisms have not been exhaustively investigated yet. Here, we further characterized the mechanisms how MGO induced apoptosis in human umbilical vein endothelial cells (HUVECs). Our data revealed that cytosolic phospholipase A2 (cPLA2) played an important role in MGO-induced cell apoptosis. It was found that MGO could increase both the activity and expression of cPLA2. Inhibition of cPLA2 by Pyrrophenone (PYR) or siRNA significantly attenuated the MGO-induced apoptosis. Additionally, MGO time-dependently decreased the phosphorylation of nuclear factor κB (NF-κB). Pretreatment of the cells with NF-κB inhibitor, BAY11-7082, further increased MGO-induced apoptosis of HUVECs, indicating that NF-κB played a survival role in this MGO-induced apoptosis. Furthermore, in the presence of si-cPLA2 or PYR, MGO no longer decreased NF-κB phosphorylation. Beyond that, the antioxidant N-acetyl cysteine (NAC) could reverse the changes of both cPLA2 and NF-κB caused by MGO. p38, the upstream of cPLA2, was also significantly phosphorylated by MGO. However, p38 inhibitor failed to reverse the apoptosis induced by MGO. This study gives an important insight into the downstream signaling mechanisms of MGO, cPLA2-NF-κB, in endothelial apoptosis. - Highlights: • cPLA2 participated in MGO-induced HUVECs apoptosis. • Inhibition of NF-κB was involved in MGO-cPLA2-mediated cell apoptosis. • Antioxidant NAC attenuated MGO-induced cPLA2 activation and cell apoptosis.

  19. Apoptosis-like death in bacteria induced by HAMLET, a human milk lipid-protein complex.

    Science.gov (United States)

    Hakansson, Anders P; Roche-Hakansson, Hazeline; Mossberg, Ann-Kristin; Svanborg, Catharina

    2011-03-10

    Apoptosis is the primary means for eliminating unwanted cells in multicellular organisms in order to preserve tissue homeostasis and function. It is characterized by distinct changes in the morphology of the dying cell that are orchestrated by a series of discrete biochemical events. Although there is evidence of primitive forms of programmed cell death also in prokaryotes, no information is available to suggest that prokaryotic death displays mechanistic similarities to the highly regulated programmed death of eukaryotic cells. In this study we compared the characteristics of tumor and bacterial cell death induced by HAMLET, a human milk complex of alpha-lactalbumin and oleic acid. We show that HAMLET-treated bacteria undergo cell death with mechanistic and morphologic similarities to apoptotic death of tumor cells. In Jurkat cells and Streptococcus pneumoniae death was accompanied by apoptosis-like morphology such as cell shrinkage, DNA condensation, and DNA degradation into high molecular weight fragments of similar sizes, detected by field inverse gel electrophoresis. HAMLET was internalized into tumor cells and associated with mitochondria, causing a rapid depolarization of the mitochondrial membrane and bound to and induced depolarization of the pneumococcal membrane with similar kinetic and magnitude as in mitochondria. Membrane depolarization in both systems required calcium transport, and both tumor cells and bacteria were found to require serine protease activity (but not caspase activity) to execute cell death. Our results suggest that many of the morphological changes and biochemical responses associated with apoptosis are present in prokaryotes. Identifying the mechanisms of bacterial cell death has the potential to reveal novel targets for future antimicrobial therapy and to further our understanding of core activation mechanisms of cell death in eukaryote cells.

  20. Gallic Acid Induces Apoptosis in Human Gastric Adenocarcinoma Cells.

    Science.gov (United States)

    Tsai, Chung-Lin; Chiu, Ying-Ming; Ho, Tin-Yun; Hsieh, Chin-Tung; Shieh, Dong-Chen; Lee, Yi-Ju; Tsay, Gregory J; Wu, Yi-Ying

    2018-04-01

    Gastric cancer is one of the most common malignant cancers with a poor prognosis and high mortality rate worldwide. Current treatment of gastric cancer includes surgery and chemotherapy as the main modalities, but the potentially severe side-effects of chemotherapy present a considerable challenge. Gallic acid is a trihydroxybenzoic acid found to exert an anticancer effect against a variety of cancer cells. The purpose of this study was to determine the anti-cancer activity of Galla chinensis and its main component gallic acid on human gastric adenocarcinoma cells. MTT assay and cell death ELISA were used to determine the apoptotic effect of Gallic Chinensis and gallic acid on human gastric adenocarcinoma cells. To determine the pathway and relevant components by which gallic acid-induced apoptosis is mediated through, cells were transfected with siRNA (Fas, FasL, DR5, p53) using Lipofectamine 2000. Reults: Gallic Chinensis and gallic acid induced apoptosis of human gastric adenocarcinoma cells. Gallic acid induced up-regulation of Fas, FasL, and DR5 expression in AGS cells. Transfection of cells with Fas, FasL, or DR5 siRNA reduced gallic acid-induced cell death. In addition, p53 was shown to be involved in gallic acid-mediated Fas, FasL, and DR5 expression as well as cell apoptosis in AGS cells. These results suggest that gallic acid has a potential role in the treatment of gastric cancer. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  1. Romo1 expression contributes to oxidative stress-induced death of lung epithelial cells

    International Nuclear Information System (INIS)

    Shin, Jung Ar; Chung, Jin Sil; Cho, Sang-Ho; Kim, Hyung Jung; Yoo, Young Do

    2013-01-01

    Highlights: •Romo1 mediates oxidative stress-induced mitochondrial ROS production. •Romo1 induction by oxidative stress plays an important role in oxidative stress-induced apoptosis. •Romo1 overexpression correlates with epithelial cell death in patients with IPF. -- Abstract: Oxidant-mediated death of lung epithelial cells due to cigarette smoking plays an important role in pathogenesis in lung diseases such as idiopathic pulmonary fibrosis (IPF). However, the exact mechanism by which oxidants induce epithelial cell death is not fully understood. Reactive oxygen species (ROS) modulator 1 (Romo1) is localized in the mitochondria and mediates mitochondrial ROS production through complex III of the mitochondrial electron transport chain. Here, we show that Romo1 mediates mitochondrial ROS production and apoptosis induced by oxidative stress in lung epithelial cells. Hydrogen peroxide (H 2 O 2 ) treatment increased Romo1 expression, and Romo1 knockdown suppressed the cellular ROS levels and cell death triggered by H 2 O 2 treatment. In immunohistochemical staining of lung tissues from patients with IPF, Romo1 was mainly localized in hyperplastic alveolar and bronchial epithelial cells. Romo1 overexpression was detected in 14 of 18 patients with IPF. TUNEL-positive alveolar epithelial cells were also detected in most patients with IPF but not in normal controls. These findings suggest that Romo1 mediates apoptosis induced by oxidative stress in lung epithelial cells

  2. Romo1 expression contributes to oxidative stress-induced death of lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jung Ar [Department of Internal Medicine, Yonsei University College of Medicine, Yonsei University Health System, Seoul 135-270 (Korea, Republic of); Chung, Jin Sil [Laboratory of Molecular Cell Biology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of); Cho, Sang-Ho [Department of Pathology, Pochon CHA University, College of Medicine, Gyeonggi-do (Korea, Republic of); Kim, Hyung Jung, E-mail: khj57@yuhs.ac.kr [Department of Internal Medicine, Yonsei University College of Medicine, Yonsei University Health System, Seoul 135-270 (Korea, Republic of); Yoo, Young Do, E-mail: ydy1130@korea.ac.kr [Laboratory of Molecular Cell Biology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of)

    2013-09-20

    Highlights: •Romo1 mediates oxidative stress-induced mitochondrial ROS production. •Romo1 induction by oxidative stress plays an important role in oxidative stress-induced apoptosis. •Romo1 overexpression correlates with epithelial cell death in patients with IPF. -- Abstract: Oxidant-mediated death of lung epithelial cells due to cigarette smoking plays an important role in pathogenesis in lung diseases such as idiopathic pulmonary fibrosis (IPF). However, the exact mechanism by which oxidants induce epithelial cell death is not fully understood. Reactive oxygen species (ROS) modulator 1 (Romo1) is localized in the mitochondria and mediates mitochondrial ROS production through complex III of the mitochondrial electron transport chain. Here, we show that Romo1 mediates mitochondrial ROS production and apoptosis induced by oxidative stress in lung epithelial cells. Hydrogen peroxide (H{sub 2}O{sub 2}) treatment increased Romo1 expression, and Romo1 knockdown suppressed the cellular ROS levels and cell death triggered by H{sub 2}O{sub 2} treatment. In immunohistochemical staining of lung tissues from patients with IPF, Romo1 was mainly localized in hyperplastic alveolar and bronchial epithelial cells. Romo1 overexpression was detected in 14 of 18 patients with IPF. TUNEL-positive alveolar epithelial cells were also detected in most patients with IPF but not in normal controls. These findings suggest that Romo1 mediates apoptosis induced by oxidative stress in lung epithelial cells.

  3. Asiatic acid attenuates methamphetamine-induced neuroinflammation and neurotoxicity through blocking of NF-kB/STAT3/ERK and mitochondria-mediated apoptosis pathway

    OpenAIRE

    Park, Ji-Hyun; Seo, Young Ho; Jang, Jung-Hee; Jeong, Chul-Ho; Lee, Sooyeun; Park, Byoungduck

    2017-01-01

    Background Methamphetamine (METH) is a commonly abused drug that may result in neurotoxic effects. Recent studies have suggested that involvement of neuroinflammatory processes in brain dysfunction is induced by misuse of this drug. However, the mechanism underlying METH-induced inflammation and neurotoxicity in neurons is still unclear. In this study, we investigated whether asiatic acid (AA) effected METH-mediated neuroinflammation and neurotoxicity in dopaminergic neuronal cells. And we fu...

  4. Ciglitazone induces caspase-independent apoptosis via p38-dependent AIF nuclear translocation in renal epithelial cells

    International Nuclear Information System (INIS)

    Kwon, Chae Hwa; Yoon, Chang Soo; Kim, Yong Keun

    2008-01-01

    Peroxisome proliferator-activated receptor γ (PPARγ) agonists have been reported to induce apoptosis in a variety of cell types including renal proximal epithelial cells. However, the underlying mechanism of cell death induced by PPARγ agonists has not been clearly defined in renal proximal tubular cells. This study was therefore undertaken to determine the mechanism by which ciglitazone, a synthetic PPARγ agonist, induces apoptosis in opossum kidney (OK) cells, an established renal epithelial cell line. Ciglitazone treatment induced apoptotic cell death in a dose- and time-dependent manner. Ciglitazone caused a transient activation of ERK and sustained activation of p38 MAP kinase. Ciglitazone-mediated cell death was attenuated by the p38 inhibitor SB203580 and transfection of dominant-negative form of p38, but not by the MEK inhibitor U0126, indicating that p38 MAP kinase activation is involved in the ciglitazone-induced cell death. Although ciglitazone-induced caspase-3 activation, the ciglitazone-mediated cell death was not affected by the caspase-3 inhibitor DEVD-CHO. Ciglitazone-induced mitochondrial membrane depolarization and apoptosis-inducing factor (AIF) nuclear translocation and these effects were prevented by the p38 inhibitor. These results suggest that ciglitazone induces caspase-independent apoptosis through p38 MAP kinase-dependent AIF nuclear translocation in OK renal epithelial cells

  5. Knockdown of HIF-1α and IL-8 induced apoptosis of hepatocellular carcinoma triggers apoptosis of vascular endothelial cells.

    Science.gov (United States)

    Choi, Sung Hoon; Park, Jun Yong; Kang, Wonseok; Kim, Seung Up; Kim, Do Young; Ahn, Sang Hoon; Ro, Simon Wonsang; Han, Kwang-Hyub

    2016-01-01

    A local hypoxic microenvironment is one of the most important characteristics of solid tumors. Hypoxia inducible factor-1α (HIF-1α) and Interleukin-8 (IL-8) activate tumor survival from hypoxic-induced apoptosis in each pathway. This study aimed to evaluate whether knockdown of HIF-1α and IL-8 induced apoptosis of the hepatocellular carcinoma (HCC) and endothelial cell lines. HCC cell lines were infected with adenovirus-expressing shRNA for HIF-1α and IL-8 and maintained under hypoxic conditions (1% O2, 24 h). The expression levels of HIF-1α and both apoptotic and growth factors were examined by real-time quantitative PCR and western blot. We also investigated apoptosis by TUNEL assay (FACS and Immunofluorescence) and measured the concentration of cytochrome C. Inhibition of HIF-1α and IL-8 up-regulated the expression of apoptotic factors while downregulating anti-apoptotic factors simultaneously. Knockdown of HIF-1α and IL-8 increased the concentration of cytochrome C and enhanced DNA fragmentation in HCC cell lines. Moreover, culture supernatant collected from the knockdown of HIF-1α and IL-8 in HCC cell lines induced apoptosis in human umbilical vein endothelial cells under hypoxia, and the expression of variable apoptotic ligand increased from HCC cell lines, time-dependently. These data suggest that adenovirus-mediated knockdown of HIF-1α and IL-8 induced apoptosis in HCC cells and triggered apoptosis of vascular endothelial cells.

  6. Globular Adiponectin Inhibits the Apoptosis of Mesenchymal Stem Cells Induced by Hypoxia and Serum Deprivation via the AdipoR1-Mediated Pathway

    Directory of Open Access Journals (Sweden)

    Xia-Qiu Tian

    2016-02-01

    Full Text Available Background/Aims: Poor viability of transplanted mesenchymal stem cells (MSCs within the ischemic heart limits their therapeutic potential for cardiac repair. Globular adiponectin (gAPN exerts anti-apoptotic effects on several types of stem cells. Herein, we investigated the effect of gAPN on the MSCs against apoptosis induced by hypoxia and serum deprivation (H/SD. Methods: MSCs exposed to H/SD conditions were treated with different concentrations of gAPN. To identify the main type of receptor, MSCs were transfected with siRNA targeting adiponectin receptor 1 or 2 (AdipoR1 or AdipoR2. To elucidate the downstream pathway, MSCs were pre-incubated with AMPK inhibitor Compound C. Apoptosis, caspase-3 activity and mitochondrial membrane potential were evaluated. Results: H/SD-induced MSCs apoptosis and caspase-3 activation were attenuated by gAPN in a concentration-dependent manner. gAPN increased Bcl-2 and decreased Bax expressions. The loss of mitochondrial membrane potential induced by H/SD was also abolished by gAPN. The protective effect of gAPN was significantly attenuated after the knockdown of AdipoR1 rather than AdipoR2. Moreover, Compound C partly suppressed the anti-apoptotic effect of gAPN. Conclusions: gAPN inhibits H/SD-induced apoptosis in MSCs via AdipoR1-mediated pathway, possibly linked to the activation of AMPK. gAPN may be a novel survival factor for MSCs in the ischemic engraftment environment.

  7. Globular Adiponectin Inhibits the Apoptosis of Mesenchymal Stem Cells Induced by Hypoxia and Serum Deprivation via the AdipoR1-Mediated Pathway.

    Science.gov (United States)

    Tian, Xia-Qiu; Yang, Yue-Jin; Li, Qing; Huang, Pei-Sen; Li, Xiang-Dong; Jin, Chen; Qi, Kang; Jiang, Lei-Pei; Chen, Gui-Hao

    2016-01-01

    Poor viability of transplanted mesenchymal stem cells (MSCs) within the ischemic heart limits their therapeutic potential for cardiac repair. Globular adiponectin (gAPN) exerts anti-apoptotic effects on several types of stem cells. Herein, we investigated the effect of gAPN on the MSCs against apoptosis induced by hypoxia and serum deprivation (H/SD). MSCs exposed to H/SD conditions were treated with different concentrations of gAPN. To identify the main type of receptor, MSCs were transfected with siRNA targeting adiponectin receptor 1 or 2 (AdipoR1 or AdipoR2). To elucidate the downstream pathway, MSCs were pre-incubated with AMPK inhibitor Compound C. Apoptosis, caspase-3 activity and mitochondrial membrane potential were evaluated. H/SD-induced MSCs apoptosis and caspase-3 activation were attenuated by gAPN in a concentration-dependent manner. gAPN increased Bcl-2 and decreased Bax expressions. The loss of mitochondrial membrane potential induced by H/SD was also abolished by gAPN. The protective effect of gAPN was significantly attenuated after the knockdown of AdipoR1 rather than AdipoR2. Moreover, Compound C partly suppressed the anti-apoptotic effect of gAPN. gAPN inhibits H/SD-induced apoptosis in MSCs via AdipoR1-mediated pathway, possibly linked to the activation of AMPK. gAPN may be a novel survival factor for MSCs in the ischemic engraftment environment. © 2016 The Author(s) Published by S. Karger AG, Basel.

  8. A chimeric antigen receptor for TRAIL-receptor 1 induces apoptosis in various types of tumor cells.

    Science.gov (United States)

    Kobayashi, Eiji; Kishi, Hiroyuki; Ozawa, Tatsuhiko; Hamana, Hiroshi; Nakagawa, Hidetoshi; Jin, Aishun; Lin, Zhezhu; Muraguchi, Atsushi

    2014-10-31

    Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and its associated receptors (TRAIL-R/TR) are attractive targets for cancer therapy because TRAIL induces apoptosis in tumor cells through TR while having little cytotoxicity on normal cells. Therefore, many agonistic monoclonal antibodies (mAbs) specific for TR have been produced, and these induce apoptosis in multiple tumor cell types. However, some TR-expressing tumor cells are resistant to TR-specific mAb-induced apoptosis. In this study, we constructed a chimeric antigen receptor (CAR) of a TRAIL-receptor 1 (TR1)-specific single chain variable fragment (scFv) antibody (TR1-scFv-CAR) and expressed it on a Jurkat T cell line, the KHYG-1 NK cell line, and human peripheral blood lymphocytes (PBLs). We found that the TR1-scFv-CAR-expressing Jurkat cells killed target cells via TR1-mediated apoptosis, whereas TR1-scFv-CAR-expressing KHYG-1 cells and PBLs killed target cells not only via TR1-mediated apoptosis but also via CAR signal-induced cytolysis, resulting in cytotoxicity on a broader range if target cells than with TR1-scFv-CAR-expressing Jurkat cells. The results suggest that TR1-scFv-CAR could be a new candidate for cancer gene therapy. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Akt interacts directly with Smad3 to regulate the sensitivity to TGF-beta induced apoptosis.

    Science.gov (United States)

    Conery, Andrew R; Cao, Yanna; Thompson, E Aubrey; Townsend, Courtney M; Ko, Tien C; Luo, Kunxin

    2004-04-01

    Transforming growth factor beta (TGF-beta) induces both apoptosis and cell-cycle arrest in some cell lines, but only growth arrest in others. It is not clear how this differential response to TGF-beta is specified. Smad proteins are critical mediators of TGF-beta signalling. After stimulation by TGF-beta, Smad2 and Smad3 become phosphorylated by the activated TGF-beta receptor kinases, oligomerize with Smad4, translocate to the nucleus and regulate the expression of TGF-beta target genes. Here we report that the sensitivity to TGF-beta induced apoptosis is regulated by crosstalk between the Akt/PKB serine/threonine kinase and Smad3 through a mechanism that is independent of Akt kinase activity. Akt interacts directly with unphosphorylated Smad3 to sequester it outside the nucleus, preventing its phosphorylation and nuclear translocation. This results in inhibition of Smad3-mediated transcription and apoptosis. Furthermore, the ratio of Smad3 to Akt correlates with the sensitivity of cells to TGF-beta induced apoptosis. Alteration of this ratio changes the apoptotic, but not the growth-inhibitory, responses of cells to TGF-beta. These findings identify an important determinant of sensitivity to TGF-beta-induced apoptosis that involves crosstalk between the TGF-beta and phosphatidylinositol-3-OH kinase (PI(3)K) pathways.

  10. N-(1-Pyrenyl Maleimide Induces Bak Oligomerization and Mitochondrial Dysfunction in Jurkat Cells

    Directory of Open Access Journals (Sweden)

    Pei-Rong Huang

    2015-01-01

    Full Text Available N-(1-pyrenyl maleimide (NPM is a fluorescent reagent that is frequently used as a derivatization agent for the detection of thio-containing compounds. NPM has been shown to display a great differential cytotoxicity against hematopoietic cancer cells. In this study, the molecular mechanism by which NPM induces apoptosis was examined. Here, we show that treatment of Jurkat cells with NPM leads to Bak oligomerization, loss of mitochondrial membrane potential (Δψm, and release of cytochrome C from mitochondria to cytosol. Induction of Bak oligomerization appears to play a critical role in NPM-induced apoptosis, as downregulation of Bak by shRNA significantly prevented NPM-induced apoptosis. Inhibition of caspase 8 by Z-IETD-FMK and/or depletion of Bid did not affect NPM-induced oligomerization of Bak. Taken together, these results suggest that NPM-induced apoptosis is mediated through a pathway that is independent of caspase-8 activation.

  11. Similar to spironolactone, oxymatrine is protective in aldosterone-induced cardiomyocyte injury via inhibition of calpain and apoptosis-inducing factor signaling.

    Directory of Open Access Journals (Sweden)

    Ting-Ting Xiao

    Full Text Available Accumulating evidence indicates that oxymatrine (OMT possesses variously pharmacological properties, especially on the cardiovascular system. We previously demonstrated that activated calpain/apoptosis-inducing factor (AIF-mediated pathway was the key molecular mechanism in aldosterone (ALD induces cardiomyocytes apoptosis. In the present study, we extended the experimentation by investigating the effect of OMT on cardiomyocytes exposed to ALD, as compared to spironolactone (Spiro, a classical ALD receptor antagonist. Cardiomyocytes were pre-incubated with OMT, Spiro or vehicle for 1 h, and then, cardiomyocytes were exposed to ALD 24 h. The cell injury was evaluated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay and lactate dehydrogenase (LDH leakage ratio. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL assay, annexin V/PI staining, and relative caspase-3 activity assay. Furthermore, expression of pro-apoptotic proteins including truncated Bid (tBid, calpain and AIF were evaluated by western blot analysis. ALD stimulation increased cardiomyocytes apoptosis, caspase-3 activity and protein expression of calpain, tBid and AIF in the cytosol (p<0.05. Pre-incubated with cardiomyocytes injury and increased caspase-3 activity were significantly attenuated (p<0.05. Furthermore, OMT suppressed ALD-induced high expression of calpain and AIF. And these effects of OMT could be comparable to Spiro. These findings indicated that OMT might be a potential cardioprotective-agent against excessive ALD-induced cardiotoxicity, at least in part, mediated through inhibition of calpain/AIF signaling.

  12. Cardiovascular Disease, Mitochondria, and Traditional Chinese Medicine

    Directory of Open Access Journals (Sweden)

    Jie Wang

    2015-01-01

    Full Text Available Recent studies demonstrated that mitochondria play an important role in the cardiovascular system and mutations of mitochondrial DNA affect coronary artery disease, resulting in hypertension, atherosclerosis, and cardiomyopathy. Traditional Chinese medicine (TCM has been used for thousands of years to treat cardiovascular disease, but it is not yet clear how TCM affects mitochondrial function. By reviewing the interactions between the cardiovascular system, mitochondrial DNA, and TCM, we show that cardiovascular disease is negatively affected by mutations in mitochondrial DNA and that TCM can be used to treat cardiovascular disease by regulating the structure and function of mitochondria via increases in mitochondrial electron transport and oxidative phosphorylation, modulation of mitochondrial-mediated apoptosis, and decreases in mitochondrial ROS. However further research is still required to identify the mechanism by which TCM affects CVD and modifies mitochondrial DNA.

  13. Tumor necrosis factor-α attenuates starvation-induced apoptosis through upregulation of ferritin heavy chain in hepatocellular carcinoma cells

    International Nuclear Information System (INIS)

    Kou, Xingrui; Zhao, Qiudong; Zhao, Xue; Li, Rong; Wei, Lixin; Wu, Mengchao; Jing, Yingying; Deng, Weijie; Sun, Kai; Han, Zhipeng; Ye, Fei; Yu, Guofeng; Fan, Qingmin; Gao, Lu

    2013-01-01

    Tumor microenviroment is characteristic of inflammation, ischemia and starvation of nutrient. TNF-α, which is an extraordinarily pleiotropic cytokine, could be an endogenous tumor promoter in some tumor types. The basic objective of this study was to investigate the effects of TNF-α on the cell viability and apoptosis of hepatocellular carcinoma cells under serum starvation, and to identify the molecular mechanisms involved. For this purpose, five different concentrations of TNF-α and two different serum settings (serum-cultured and serum-deprived) were used to investigate the effects of TNF-α on the cell viability and apoptosis of Hep3B and SMMC-7721 cells. TNF-α (10 ng/ml) attenuated serum starvation-induced apoptosis of hepatocellular carcinoma cells, and autophagy conferred this process. BAY11-7082, a specific inhibitor of NF-κB, reversed the suppression of serum starvation-induced apoptosis by TNF-α. Moreover, TNF-α-induced NF-κB transactivation was suppressed by autophagy inhibitor 3-MA. In addition, TNF-α up-regulated Ferritin heavy chain (FHC) transiently by NF-κB activation and FHC levels were correlated with the TNF-α-induced protection against serum starvation-mediated apoptosis of hepatocellular carcinoma cells. Furthermore, FHC-mediated inhibition of apoptosis depended on suppressing ROS accumulation. Our findings suggested that autophagy conferred the TNF-α protection against serum starvation-mediated apoptosis of hepatocellular carcinoma cells, the mechanism involved with the activation of the TNF-α/ NF-κB /FHC signaling pathway

  14. Critical role of p53 upregulated modulator of apoptosis in benzyl isothiocyanate-induced apoptotic cell death.

    Directory of Open Access Journals (Sweden)

    Marie Lue Antony

    Full Text Available Benzyl isothiocyanate (BITC, a constituent of edible cruciferous vegetables, decreases viability of cancer cells by causing apoptosis but the mechanism of cell death is not fully understood. The present study was undertaken to determine the role of Bcl-2 family proteins in BITC-induced apoptosis using MDA-MB-231 (breast, MCF-7 (breast, and HCT-116 (colon human cancer cells. The B-cell lymphoma 2 interacting mediator of cell death (Bim protein was dispensable for proapoptotic response to BITC in MCF-7 and MDA-MB-231 cells as judged by RNA interference studies. Instead, the BITC-treated MCF-7 and MDA-MB-231 cells exhibited upregulation of p53 upregulated modulator of apoptosis (PUMA protein. The BITC-mediated induction of PUMA was relatively more pronounced in MCF-7 cells due to the presence of wild-type p53 compared with MDA-MB-231 with mutant p53. The BITC-induced apoptosis was partially but significantly attenuated by RNA interference of PUMA in MCF-7 cells. The PUMA knockout variant of HCT-116 cells exhibited significant resistance towards BITC-induced apoptosis compared with wild-type HCT-116 cells. Attenuation of BITC-induced apoptosis in PUMA knockout HCT-116 cells was accompanied by enhanced G2/M phase cell cycle arrest due to induction of p21 and down regulation of cyclin-dependent kinase 1 protein. The BITC treatment caused a decrease in protein levels of Bcl-xL (MCF-7 and MDA-MB-231 cells and Bcl-2 (MCF-7 cells. Ectopic expression of Bcl-xL in MCF-7 and MDA-MB-231 cells and that of Bcl-2 in MCF-7 cells conferred protection against proapoptotic response to BITC. Interestingly, the BITC-treated MDA-MB-231 cells exhibited induction of Bcl-2 protein expression, and RNA interference of Bcl-2 in this cell line resulted in augmentation of BITC-induced apoptosis. The BITC-mediated inhibition of MDA-MB-231 xenograft growth in vivo was associated with the induction of PUMA protein in the tumor. In conclusion, the results of the present study

  15. Stearoyl-CoA Desaturase-1 Protects Cells against Lipotoxicity-Mediated Apoptosis in Proximal Tubular Cells

    Directory of Open Access Journals (Sweden)

    Tamaki Iwai

    2016-11-01

    Full Text Available Saturated fatty acid (SFA-related lipotoxicity is a pathogenesis of diabetes-related renal proximal tubular epithelial cell (PTEC damage, closely associated with a progressive decline in renal function. This study was designed to identify a free fatty acid (FFA metabolism-related enzyme that can protect PTECs from SFA-related lipotoxicity. Among several enzymes involved in FFA metabolism, we identified stearoyl-CoA desaturase-1 (SCD1, whose expression level significantly decreased in the kidneys of high-fat diet (HFD-induced diabetic mice, compared with non-diabetic mice. SCD1 is an enzyme that desaturates SFAs, converting them to monounsaturated fatty acids (MUFAs, leading to the formation of neutral lipid droplets. In culture, retrovirus-mediated overexpression of SCD1 or MUFA treatment significantly ameliorated SFA-induced apoptosis in PTECs by enhancing intracellular lipid droplet formation. In contrast, siRNA against SCD1 exacerbated the apoptosis. Both overexpression of SCD1 and MUFA treatment reduced SFA-induced apoptosis via reducing endoplasmic reticulum stress in cultured PTECs. Thus, HFD-induced decrease in renal SCD1 expression may play a pathogenic role in lipotoxicity-induced renal injury, and enhancing SCD1-mediated desaturation of SFA and subsequent formation of neutral lipid droplets may become a promising therapeutic target to reduce SFA-induced lipotoxicity. The present study provides a novel insight into lipotoxicity in the pathogenesis of diabetic nephropathy.

  16. Taurine Pretreatment Prevents Isoflurane-Induced Cognitive Impairment by Inhibiting ER Stress-Mediated Activation of Apoptosis Pathways in the Hippocampus in Aged Rats.

    Science.gov (United States)

    Zhang, Yanan; Li, Dongliang; Li, Haiou; Hou, Dailiang; Hou, Jingdong

    2016-10-01

    Isoflurane, a commonly used inhalation anesthetic, may induce neurocognitive deficits, especially in elderly patients after surgery. Recent study demonstrated that isoflurane caused endoplasmic reticulum (ER) stress and subsequent neuronal apoptosis in the brain, contributing to cognitive deficits. Taurine, a major intracellular free amino acid, has been shown to inhibit ER stress and neuronal apoptosis in several neurological disorders. Here, we examined whether taurine can prevent isoflurane-induced ER stress and cognitive impairment in aged rats. Thirty minutes prior to a 4-h 1.3 % isoflurane exposure, aged rats were treated with vehicle or taurine at low, middle and high doses. Aged rats without any treatment served as control. The brains were harvested 6 h after isoflurane exposure for molecular measurements, and behavioral study was performed 2 weeks later. Compared with control, isoflurane increased expression of hippocampal ER stress biomarkers including glucose-regulated protein 78, phosphorylated (P-) inositol-requiring enzyme 1, P-eukaryotic initiation factor 2-α (EIF2α), activating transcription factor 4 (ATF-4), cleaved ATF-6 and C/EBP homologous protein, along with activation of apoptosis pathways as indicated by decreased B cell lymphoma 2 (BCL-2)/BCL2-associated X protein, increased expressions of cytochrome-c and cleaved caspase-3. Taurine pretreatment dose-dependently inhibited isoflurane-induced increase in expression of ER stress biomarkers except for P-EIF2α and ATF-4, and reversed isoflurane-induced changes in apoptosis-related proteins. Moreover, isoflurane caused spatial working memory deficits in aged rats, which were prevented by taurine pretreatment. The results indicate that taurine pretreatment prevents anesthetic isoflurane-induced cognitive impairment by inhibiting ER stress-mediated activation of apoptosis pathways in the hippocampus in aged rats.

  17. Inflammation induction of Dickkopf-1 mediates chondrocyte apoptosis in osteoarthritic joint.

    Science.gov (United States)

    Weng, L-H; Wang, C-J; Ko, J-Y; Sun, Y-C; Su, Y-S; Wang, F-S

    2009-07-01

    Dysregulated Wnt signaling appears to modulate chondrocyte fate and joint disorders. Dickkopf-1 (DKK1) regulates the pathogenesis of skeletal tissue by inhibiting Wnt actions. This study examined whether DKK1 expression is linked to chondrocyte fate in osteoarthritis (OA). Articular cartilage specimens harvested from nine patients with knee OA and from six controls with femoral neck fracture were assessed for DKK1, interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), Bad, Bax, Bcl2 and caspase-3 expression by real time-polymerase chain reaction (RT-PCR) and immunohistochemistry. Apoptotic chondrocytes were detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labelling (TUNEL) and 4', 6-dianidino-2-phenylindole dihydrochloride (DAPI) staining. Human chondrocyte cultures were treated with recombinant IL-1beta and monoclonal DKK1 antibody to determine whether DKK1 impairs chondrocyte survival. Expression of DKK1 correlated with inflammatory cytokine levels (IL-1beta and TNF-alpha expressions), proapoptosis regulators (Bad and caspase-3 expressions) and TUNEL staining in OA cartilage tissues. The IL-1beta induced expressions of DKK1, Bax, Bad and caspase-3-dependent apoptosis of chondrocyte cultures. Neutralization of DKK1 by monoclonal DKK1 antibody significantly abrogated IL-1beta-mediated caspase-3 cleavage and apoptosis and reversed chondrocyte proliferation. Recombinant DKK1 treatment impaired chondrocyte growth and promoted apoptosis. By suppressing nuclear beta-catenin accumulation and Akt phosphorylation, DKK1 mediated IL-1beta promotion of chondrocyte apoptosis. Chondrocyte apoptosis correlates with joint OA. Expression of DKK1 contributes to cartilage deterioration and is a potent factor in OA pathogenesis. Attenuating DKK1 may reduce cartilage deterioration in OA.

  18. Fisetin inhibits cellular proliferation and induces mitochondria-dependent apoptosis in human gastric cancer cells.

    Science.gov (United States)

    Sabarwal, Akash; Agarwal, Rajesh; Singh, Rana P

    2017-02-01

    The anticancer effects of fisetin, a dietary agent, are largely unknown against human gastric cancer. Herein, we investigated the mechanisms of fisetin-induced inhibition of growth and survival of human gastric carcinoma AGS and SNU-1 cells. Fisetin (25-100 μM) caused significant decrease in the levels of G1 phase cyclins and CDKs, and increased the levels of p53 and its S15 phosphorylation in gastric cancer cells. We also observed that growth suppression and death of non-neoplastic human intestinal FHs74int cells were minimally affected by fisetin. Fisetin strongly increased apoptotic cells and showed mitochondrial membrane depolarization in gastric cancer cells. DNA damage was observed as early as 3 h after fisetin treatment which was accompanied with gamma-H2A.X(S139) phosphorylation and cleavage of PARP. Fisetin-induced apoptosis was observed to be independent of p53. DCFDA and MitoSOX analyses showed an increase in mitochondrial ROS generation in time- and dose-dependent fashion. It also increased cellular nitrite and superoxide generation. Pre-treatment with N-acetyl cysteine (NAC) inhibited ROS generation and also caused protection from fisetin-induced DNA damage. The formation of comets were observed in only fisetin treated cells which was blocked by NAC pre-treatment. Further investigation of the source of ROS, using mitochondrial respiratory chain (MRC) complex inhibitors, suggested that fisetin caused ROS generation specifically through complex I. Collectively, these results for the first time demonstrated that fisetin possesses anticancer potential through ROS production most likely via MRC complex I leading to apoptosis in human gastric carcinoma cells. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. D-saccharic acid-1,4-lactone ameliorates alloxan-induced diabetes mellitus and oxidative stress in rats through inhibiting pancreatic beta-cells from apoptosis via mitochondrial dependent pathway

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Semantee [Department of Life Sciences and Biotechnology, Jadavpur University, 188, Raja S C Mullick Road, Kolkata 700 032 (India); Manna, Prasenjit [Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata-700054 (India); Gachhui, Ratan [Department of Life Sciences and Biotechnology, Jadavpur University, 188, Raja S C Mullick Road, Kolkata 700 032 (India); Sil, Parames C., E-mail: parames@bosemain.boseinst.ac.in [Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata-700054 (India)

    2011-12-15

    Oxidative stress plays a vital role in diabetic complications. To suppress the oxidative stress mediated damage in diabetic pathophysiology, a special focus has been given on naturally occurring antioxidants present in normal diet. D-saccharic acid 1,4-lactone (DSL), a derivative of D-glucaric acid, is present in many dietary plants and is known for its detoxifying and antioxidant properties. The aim of the present study was to evaluate the beneficial role of DSL against alloxan (ALX) induced diabetes in the pancreas tissue of Swiss albino rats. A dose-dependent study for DSL (20-120 mg/kg body weight) was carried out to find the effective dose of the compound in ALX-induced diabetic rats. ALX exposure elevated the blood glucose, glycosylated Hb, decreased the plasma insulin and disturbed the intra-cellular antioxidant machineries whereas oral administration of DSL at a dose of 80 mg/kg body weight restored these alterations close to normal. Investigating the mechanism of the protective activity of DSL we observed that it prevented the pancreatic {beta}-cell apoptosis via mitochondria-dependent pathway. Results showed decreased mitochondrial membrane potential, enhanced cytochrome c release in the cytosol and reciprocal regulation of Bcl-2 family proteins in the diabetic rats. These events were also found to be associated with increased level of Apaf-1, caspase 9, and caspase 3 that ultimately led to pancreatic {beta}-cell apoptosis. DSL treatment, however, counteracted these changes. In conclusion, DSL possesses the capability of ameliorating the oxidative stress in ALX-induced diabetes and thus could be a promising approach in lessening diabetic complications. Highlights: Black-Right-Pointing-Pointer Oxidative stress is suggested as a key event in the pathogenesis of diabetes. Black-Right-Pointing-Pointer D-saccharic acid 1,4-lactone (DSL) reduces the alloxan-induced diabetes mellitus. Black-Right-Pointing-Pointer DSL normalizes cellular antioxidant machineries

  20. D-saccharic acid-1,4-lactone ameliorates alloxan-induced diabetes mellitus and oxidative stress in rats through inhibiting pancreatic beta-cells from apoptosis via mitochondrial dependent pathway

    International Nuclear Information System (INIS)

    Bhattacharya, Semantee; Manna, Prasenjit; Gachhui, Ratan; Sil, Parames C.

    2011-01-01

    Oxidative stress plays a vital role in diabetic complications. To suppress the oxidative stress mediated damage in diabetic pathophysiology, a special focus has been given on naturally occurring antioxidants present in normal diet. D-saccharic acid 1,4-lactone (DSL), a derivative of D-glucaric acid, is present in many dietary plants and is known for its detoxifying and antioxidant properties. The aim of the present study was to evaluate the beneficial role of DSL against alloxan (ALX) induced diabetes in the pancreas tissue of Swiss albino rats. A dose-dependent study for DSL (20–120 mg/kg body weight) was carried out to find the effective dose of the compound in ALX-induced diabetic rats. ALX exposure elevated the blood glucose, glycosylated Hb, decreased the plasma insulin and disturbed the intra-cellular antioxidant machineries whereas oral administration of DSL at a dose of 80 mg/kg body weight restored these alterations close to normal. Investigating the mechanism of the protective activity of DSL we observed that it prevented the pancreatic β-cell apoptosis via mitochondria-dependent pathway. Results showed decreased mitochondrial membrane potential, enhanced cytochrome c release in the cytosol and reciprocal regulation of Bcl-2 family proteins in the diabetic rats. These events were also found to be associated with increased level of Apaf-1, caspase 9, and caspase 3 that ultimately led to pancreatic β-cell apoptosis. DSL treatment, however, counteracted these changes. In conclusion, DSL possesses the capability of ameliorating the oxidative stress in ALX-induced diabetes and thus could be a promising approach in lessening diabetic complications. Highlights: ► Oxidative stress is suggested as a key event in the pathogenesis of diabetes. ► D-saccharic acid 1,4-lactone (DSL) reduces the alloxan-induced diabetes mellitus. ► DSL normalizes cellular antioxidant machineries disturbed due to alloxan toxicity. ► DSL inhibits pancreatic β-cells apoptosis

  1. NSAIDs, Mitochondria and Calcium Signaling: Special Focus on Aspirin/Salicylates

    Directory of Open Access Journals (Sweden)

    Yoshihiro Suzuki

    2010-05-01

    Full Text Available Aspirin (acetylsalicylic acid is a well-known nonsteroidal anti-inflammatory drug (NSAID that has long been used as an anti-pyretic and analgesic drug. Recently, much attention has been paid to the chemopreventive and apoptosis-inducing effects of NSAIDs in cancer cells. These effects have been thought to be primarily attributed to the inhibition of cyclooxygenase activity and prostaglandin synthesis. However, recent studies have demonstrated unequivocally that certain NSAIDs, including aspirin and its metabolite salicylic acid, exert their anti-inflammatory and chemopreventive effects independently of cyclooxygenase activity and prostaglandin synthesis inhibition. It is becoming increasingly evident that two potential common targets of NSAIDs are mitochondria and the Ca2+ signaling pathway. In this review, we provide an overview of the current knowledge regarding the roles of mitochondria and Ca2+ in the apoptosis-inducing effects as well as some side effects of aspirin, salicylates and other NSAIDs, and introducing the emerging role of L-type Ca2+ channels, a new Ca2+ entry pathway in non-excitable cells that is up-regulated in human cancer cells.

  2. Arsenic trioxide (AT) is a novel human neutrophil pro-apoptotic agent: effects of catalase on AT-induced apoptosis, degradation of cytoskeletal proteins and de novo protein synthesis.

    Science.gov (United States)

    Binet, François; Cavalli, Hélène; Moisan, Eliane; Girard, Denis

    2006-02-01

    The anti-cancer drug arsenic trioxide (AT) induces apoptosis in a variety of transformed or proliferating cells. However, little is known regarding its ability to induce apoptosis in terminally differentiated cells, such as neutrophils. Because neutropenia has been reported in some cancer patients after AT treatment, we hypothesised that AT could induce neutrophil apoptosis, an issue that has never been investigated. Herein, we found that AT-induced neutrophil apoptosis and gelsolin degradation via caspases. AT did not increase neutrophil superoxide production and did not induce mitochondrial generation of reactive oxygen species. AT-induced apoptosis in PLB-985 and X-linked chronic granulomatous disease (CGD) cells (PLB-985 cells deficient in gp91(phox) mimicking CGD) at the same potency. Addition of catalase, an inhibitor of H2O2, reversed AT-induced apoptosis and degradation of the cytoskeletal proteins gelsolin, alpha-tubulin and lamin B1. Unexpectedly, AT-induced de novo protein synthesis, which was reversed by catalase. Cycloheximide partially reversed AT-induced apoptosis. We conclude that AT induces neutrophil apoptosis by a caspase-dependent mechanism and via de novo protein synthesis. H2O2 is of major importance in AT-induced neutrophil apoptosis but its production does not originate from nicotinamide adenine dinucleotide phosphate dehydrogenase activation and mitochondria. Cytoskeletal structures other than microtubules can now be considered as novel targets of AT.

  3. SIRT1 sensitizes hepatocellular carcinoma cells expressing hepatitis B virus X protein to oxidative stress-induced apoptosis

    International Nuclear Information System (INIS)

    Srisuttee, Ratakorn; Koh, Sang Seok; Malilas, Waraporn; Moon, Jeong; Cho, Il-Rae; Jhun, Byung Hak; Horio, Yoshiyuki; Chung, Young-Hwa

    2012-01-01

    Highlights: ► Up-regulation of SIRT1 protein and activity sensitizes Hep3B-HBX cells to oxidative stress-induced apoptosis. ► Nuclear localization of SIRT1 is not required for oxidation-induced apoptosis. ► Ectopic expression and enhanced activity of SIRT1 attenuate JNK phosphorylation. ► Inhibition of SIRT1 activity restores resistance to oxidation-induced apoptosis through JNK activation. -- Abstract: We previously showed that SIRT1 deacetylase inhibits proliferation of hepatocellular carcinoma cells expressing hepatitis B virus (HBV) X protein (HBX), by destabilization of β-catenin. Here, we report another role for SIRT1 in HBX-mediated resistance to oxidative stress. Ectopic expression and enhanced activity of SIRT1 sensitize Hep3B cells stably expressing HBX to oxidative stress-induced apoptosis. SIRT1 mutant analysis showed that nuclear localization of SIRT1 is not required for sensitization of oxidation-mediated apoptosis. Furthermore, ectopic expression of SIRT1 and treatment with resveratrol (a SIRT1 activator) attenuated JNK phosphorylation, which is a prerequisite for resistance to oxidative stress-induced apoptosis. Conversely, suppression of SIRT1 activity with nicotinamide inhibited the effect of resveratrol on JNK phosphorylation, leading to restoration of resistance to oxidation-induced apoptosis. Taken together, these results suggest that up-regulation of SIRT1 under oxidative stress may be a therapeutic strategy for treatment of hepatocellular carcinoma cells related to HBV through inhibition of JNK activation.

  4. SIRT1 sensitizes hepatocellular carcinoma cells expressing hepatitis B virus X protein to oxidative stress-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Srisuttee, Ratakorn [WCU, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Koh, Sang Seok [Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, University of Science and Technology, Daejeon 305-333 (Korea, Republic of); Department of Functional Genomics, University of Science and Technology, Daejeon 305-333 (Korea, Republic of); Malilas, Waraporn; Moon, Jeong; Cho, Il-Rae [WCU, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Jhun, Byung Hak [Department of Applied Nanoscience, Pusan National University, Busan 609-735 (Korea, Republic of); Horio, Yoshiyuki [Department of Pharmacology, Sapporo Medical University, Sapporo 060-8556 (Japan); Chung, Young-Hwa, E-mail: younghc@pusan.ac.kr [WCU, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)

    2012-12-07

    Highlights: Black-Right-Pointing-Pointer Up-regulation of SIRT1 protein and activity sensitizes Hep3B-HBX cells to oxidative stress-induced apoptosis. Black-Right-Pointing-Pointer Nuclear localization of SIRT1 is not required for oxidation-induced apoptosis. Black-Right-Pointing-Pointer Ectopic expression and enhanced activity of SIRT1 attenuate JNK phosphorylation. Black-Right-Pointing-Pointer Inhibition of SIRT1 activity restores resistance to oxidation-induced apoptosis through JNK activation. -- Abstract: We previously showed that SIRT1 deacetylase inhibits proliferation of hepatocellular carcinoma cells expressing hepatitis B virus (HBV) X protein (HBX), by destabilization of {beta}-catenin. Here, we report another role for SIRT1 in HBX-mediated resistance to oxidative stress. Ectopic expression and enhanced activity of SIRT1 sensitize Hep3B cells stably expressing HBX to oxidative stress-induced apoptosis. SIRT1 mutant analysis showed that nuclear localization of SIRT1 is not required for sensitization of oxidation-mediated apoptosis. Furthermore, ectopic expression of SIRT1 and treatment with resveratrol (a SIRT1 activator) attenuated JNK phosphorylation, which is a prerequisite for resistance to oxidative stress-induced apoptosis. Conversely, suppression of SIRT1 activity with nicotinamide inhibited the effect of resveratrol on JNK phosphorylation, leading to restoration of resistance to oxidation-induced apoptosis. Taken together, these results suggest that up-regulation of SIRT1 under oxidative stress may be a therapeutic strategy for treatment of hepatocellular carcinoma cells related to HBV through inhibition of JNK activation.

  5. CD40-mediated apoptosis in murine B-lymphoma lines containing mutated p53

    DEFF Research Database (Denmark)

    Hollmann, Annette C; Gong, Qiaoke; Owens, Trevor

    2002-01-01

    Crosslinking CD40 induces normal B-cells to proliferate and differentiate but causes many tumor cell lines to undergo apoptosis. As p53 is required for many apoptotic pathways, we analyzed the effects of CD40 ligation and their correlation with p53 function in four murine B-lymphoma lines. A20...... of detectable p21 mRNA in A20 and M12 cells. P21 mRNA was increased to detectable levels in M12 cells upon CD40 ligation; however, blocking this effect with the p53 inhibitor pifithrin had no effect on CD40-mediated apoptosis. Sequencing showed that p53 in A20 and M12 cells contained point mutations leading...... to amino acid substitutions in DNA binding regions, but was unmutated in WEHI231 and WEHI 279. These results suggest that CD40-mediated apoptosis can occur in the absence of functional p53....

  6. Thromboxane synthase suppression induces lung cancer cell apoptosis via inhibiting NF-κB

    International Nuclear Information System (INIS)

    Leung, Kin Chung; Li, Ming-Yue; Leung, Billy C.S.; Hsin, Michael K.Y.; Mok, Tony S.K.; Underwood, Malcolm J.; Chen, George G.

    2010-01-01

    Accumulating evidence shows that the inhibition of thromboxane synthase (TXS) induced apoptosis in cancer cells. TXS inhibitor 1-Benzylimidzole (1-BI) can trigger apoptosis in lung cancer cells but the mechanism is not fully defined. In this study, lung cancer cells were treated with 1-BI. In this study, the level of reactive oxygen species (ROS) was measured and NF-κB activity was determined in human lung cancer cells. The roles of ROS and NF-κB in 1-BI-mediated cell death were analyzed. The results showed that 1-BI induced ROS generation but decreased the activity of NF-κB by reducing phosphorylated IκBα (p-IκBα) and inhibiting the translocation of p65 into the nucleus. In contrast to 1-BI, antioxidant N-acetyl cysteine (NAC) stimulated cell proliferation and significantly protected the cells from 1-BI-mediated cell death by neutralizing ROS. Collectively, apoptosis induced by 1-BI is associated with the over-production of ROS and the reduction of NF-κB. Antioxidants can significantly block the inhibitory effect of 1-BI.

  7. A non-toxic fluorogenic dye for mitochondria labeling.

    Science.gov (United States)

    Han, Junyan; Han, Myung Shin; Tung, Ching-Hsuan

    2013-11-01

    Mitochondria, powerhouses of cells, are responsible for many critical cellular functions, such as cell energy metabolism, reactive oxygen species production, and apoptosis regulation. Monitoring mitochondria morphology in live cells temporally and spatially could help with the understanding of the mechanisms of mitochondrial functional regulation and the pathogenesis of mitochondria-related diseases. A novel non-cytotoxic fluorogenic compound, AcQCy7, was developed as a mitochondria-specific dye. AcQCy7 emitted no fluorescent signal outside of cells, but it became fluorescent after intracellular hydrolysis of the acetyl group. The hydrolyzed fluorescent product was well retained in mitochondria, enabling long-lasting fluorescence imaging of mitochondria without cell washing. A 2-day culture study using AcQCy7 showed no sign of cytotoxicity, whereas a commonly used mitochondria-staining probe, Mitochondria Tracker Green, caused significant cell death even at a much lower concentration. Apoptosis-causing mitochondria fission was monitored clearly in real time by AcQCy7. A simple add-and-read mitochondria specific dye AcQCy7 has been validated in various cell models. Bright mitochondria specific fluorescent signal in treated cells lasted several days without noticeable toxicity. The probe AcQCy7 has been proofed to be a non-toxic agent for long-term mitochondria imaging. © 2013.

  8. The fate of paternal mitochondria in marmoset pre-implantation embryos.

    Science.gov (United States)

    Luetjens, C M; Wesselmann, R

    2008-06-01

    Sperm-derived mitochondria are integrated into the oocyte at fertilization but seem to vanish during the early cleavage phase. The developmental potential of pre-implantation embryos seems to be closely related to their ability to induce degeneration of these mitochondria, but the mechanisms underlying their loss of function are not yet understood. This study focuses on the fate of paternal mitochondria in pre-implantation embryos. Stimulation, collection and in vitro culture of oocytes from Callithrix jacchus, allows the study of the destiny of paternal mitochondria by utilizing immunostaining of pre-implantation embryos, fluorescence and laserscanning microscopy. Live pre-implantation embryos were stained with a fluorescence indicator reflecting mitochondrial membrane potential. Evidence indicating the loss of mitochondrial function was not found nor that apoptosis pathways were involved in the disappearance of paternally derived mitochondria. These findings may have implications for mitochondrially inherited diseases and could lead to new strategies for improving assisted reproduction.

  9. The Non-structural Protein of Crimean-Congo Hemorrhagic Fever Virus Disrupts the Mitochondrial Membrane Potential and Induces Apoptosis*

    Science.gov (United States)

    Barnwal, Bhaskar; Karlberg, Helen; Mirazimi, Ali; Tan, Yee-Joo

    2016-01-01

    Viruses have developed distinct strategies to overcome the host defense system. Regulation of apoptosis in response to viral infection is important for virus survival and dissemination. Like other viruses, Crimean-Congo hemorrhagic fever virus (CCHFV) is known to regulate apoptosis. This study, for the first time, suggests that the non-structural protein NSs of CCHFV, a member of the genus Nairovirus, induces apoptosis. In this report, we demonstrated the expression of CCHFV NSs, which contains 150 amino acid residues, in CCHFV-infected cells. CCHFV NSs undergoes active degradation during infection. We further demonstrated that ectopic expression of CCHFV NSs induces apoptosis, as reflected by caspase-3/7 activity and cleaved poly(ADP-ribose) polymerase, in different cell lines that support CCHFV replication. Using specific inhibitors, we showed that CCHFV NSs induces apoptosis via both intrinsic and extrinsic pathways. The minimal active region of the CCHFV NSs protein was determined to be 93–140 amino acid residues. Using alanine scanning, we demonstrated that Leu-127 and Leu-135 are the key residues for NSs-induced apoptosis. Interestingly, CCHFV NSs co-localizes in mitochondria and also disrupts the mitochondrial membrane potential. We also demonstrated that Leu-127 and Leu-135 are important residues for disruption of the mitochondrial membrane potential by NSs. Therefore, these results indicate that the C terminus of CCHFV NSs triggers mitochondrial membrane permeabilization, leading to activation of caspases, which, ultimately, leads to apoptosis. Given that multiple factors contribute to apoptosis during CCHFV infection, further studies are needed to define the involvement of CCHFV NSs in regulating apoptosis in infected cells. PMID:26574543

  10. Activation of P2X7-mediated apoptosis Inhibits DMBA/TPA-induced formation of skin papillomas and cancer in mice

    Directory of Open Access Journals (Sweden)

    Fu Wen

    2009-04-01

    BzATP. (g Pore formation and the augmented calcium influx were depended on the expression of the P2X7 receptor, while the BzATP-induced apoptosis depended on calcium influx. (h The BzATP-induced apoptosis could be blocked by co-treatment with inhibitors of caspase-9 and caspase-3, but not of caspase-8. Conclusion (a P2X7-dependent apoptosis is an important mechanism that controls the development and progression of epidermal neoplasia in the mouse. (b The P2X7-dependent apoptosis is mediated by calcium influx via P2X7 pores, and involves the caspase-9 (mitochondrial pathway. (c The diminished pro-apoptotic effect of BzATP in mouse cancer keratinocytes is possibly the result of low expression of the P2X7 receptor. (d Activation of P2X7-dependent apoptosis, e.g. with BzATP could be a novel chemotherapeutic growth-preventive modality for papillomas and epithelial cancers in vivo.

  11. Raf-1/CK2 and RhoA/ROCK signaling promote TNF-α-mediated endothelial apoptosis via regulating vimentin cytoskeleton.

    Science.gov (United States)

    Yang, Lifeng; Tang, Lian; Dai, Fan; Meng, Guoliang; Yin, Runting; Xu, Xiaole; Yao, Wenjuan

    2017-08-15

    Both RhoA/ROCK and Raf-1/CK2 pathway play essential roles in cell proliferation, apoptosis, differentiation, and multiple other common cellular functions. We previously reported that vimentin is responsible for TNF-α-induced cell apoptosis. Herein, we investigated the regulation of RhoA/ROCK and Raf-1/CK2 signaling on vimentin filaments and endothelial apoptosis mediated by TNF-α. Treatment with TNF-α significantly induced the activation of RhoA and ROCK, and the expression of ROCK1. RhoA deficiency could obviously inhibit ROCK activation and ROCK1 expression induced by TNF-α. Both RhoA deficiency and ROCK activity inhibition (Y-27632) greatly inhibited endothelial apoptosis and preserved cell viability in TNF-α-induced human umbilical vein endothelial cells (HUVECs). Also vimentin phosphorylation and the remodeling of vimentin or phospho-vimentin induced by TNF-α were obviously attenuated by RhoA suppression and ROCK inhibition. TNF-α-mediated vimentin cleavage was significantly inhibited by RhoA suppression and ROCK inhibition through decreasing the activation of caspase3 and 8. Furthermore, TNF-α treatment greatly enhanced the activation of Raf-1. Suppression of Raf-1 or CK2 by its inhibitor (GW5074 or TBB) blocked vimentin phosphorylation, remodeling and endothelial apoptosis, and preserved cell viability in TNF-α-induced HUVECs. However, Raf-1 inhibition showed no significant effect on TNF-α-induced ROCK expression and activation, suggesting that the regulation of Raf-1/CK2 signaling on vimentin was independent of ROCK. Taken together, these results indicate that both RhoA/ROCK and Raf-1/CK2 pathway are responsible for TNF-α-mediated endothelial cytotoxicity via regulating vimentin cytoskeleton. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. The E3 ubiquitin ligases β-TrCP and FBXW7 cooperatively mediates GSK3-dependent Mcl-1 degradation induced by the Akt inhibitor API-1, resulting in apoptosis.

    Science.gov (United States)

    Ren, Hui; Koo, Junghui; Guan, Baoxiang; Yue, Ping; Deng, Xingming; Chen, Mingwei; Khuri, Fadlo R; Sun, Shi-Yong

    2013-11-22

    The novel Akt inhibitor, API-1, induces apoptosis through undefined mechanisms. The current study focuses on revealing the mechanisms by which API-1 induces apoptosis. API-1 rapidly and potently reduced the levels of Mcl-1 primarily in API-1-senstive lung cancer cell lines. Ectopic expression of Mcl-1 protected cells from induction of apoptosis by API-1. API-1 treatment decreased the half-life of Mcl-1, whereas inhibition of the proteasome with MG132 rescued Mcl-1 reduction induced by API-1. API-1 decreased Mcl-1 levels accompanied with a rapid increase in Mcl-1 phosphorylation (S159/T163). Moreover, inhibition of GSK3 inhibited Mcl-1 phosphorylation and reduction induced by API-1 and antagonized the effect of API-1 on induction of apoptosis. Knockdown of either FBXW7 or β-TrCP alone, both of which are E3 ubiquitin ligases involved in Mcl-1 degradation, only partially rescued Mcl-1 reduction induced by API-1. However, double knockdown of both E3 ubiquitin ligases enhanced the rescue of API-1-induced Mcl-1 reduction. API-1 induces GSK3-dependent, β-TrCP- and FBXW7-mediated Mcl-1 degradation, resulting in induction of apoptosis.

  13. Autophagy capacity and sub-mitochondrial heterogeneity shape Bnip3-induced mitophagy regulation of apoptosis.

    Science.gov (United States)

    Choe, Sehyo Charley; Hamacher-Brady, Anne; Brady, Nathan Ryan

    2015-08-08

    Mitochondria are key regulators of apoptosis. In response to stress, BH3-only proteins activate pro-apoptotic Bcl2 family proteins Bax and Bak, which induce mitochondrial outer membrane permeabilization (MOMP). While the large-scale mitochondrial release of pro-apoptotic proteins activates caspase-dependent cell death, a limited release results in sub-lethal caspase activation which promotes tumorigenesis. Mitochondrial autophagy (mitophagy) targets dysfunctional mitochondria for degradation by lysosomes, and undergoes extensive crosstalk with apoptosis signaling, but its influence on apoptosis remains undetermined. The BH3-only protein Bnip3 integrates apoptosis and mitophagy signaling at different signaling domains. Bnip3 inhibits pro-survival Bcl2 members via its BH3 domain and activates mitophagy through its LC3 Interacting Region (LIR), which is responsible for binding to autophagosomes. Previously, we have shown that Bnip3-activated mitophagy prior to apoptosis induction can reduce mitochondrial activation of caspases, suggesting that a reduction to mitochondrial levels may be pro-survival. An outstanding question is whether organelle dynamics and/or recently discovered subcellular variations of protein levels responsible for both MOMP sensitivity and crosstalk between apoptosis and mitophagy can influence the cellular apoptosis decision event. To that end, here we undertook a systems biology analysis of mitophagy-apoptosis crosstalk at the level of cellular mitochondrial populations. Based on experimental findings, we developed a multi-scale, hybrid model with an individually adaptive mitochondrial population, whose actions are determined by protein levels, embedded in an agent-based model (ABM) for simulating subcellular dynamics and local feedback via reactive oxygen species signaling. Our model, supported by experimental evidence, identified an emergent regulatory structure within canonical apoptosis signaling. We show that the extent of mitophagy is

  14. Albumin-bound fatty acids but not albumin itself alter redox balance in tubular epithelial cells and induce a peroxide-mediated redox-sensitive apoptosis

    Science.gov (United States)

    Ruggiero, Christine; Elks, Carrie M.; Kruger, Claudia; Cleland, Ellen; Addison, Kaity; Noland, Robert C.

    2014-01-01

    Albuminuria is associated with metabolic syndrome and diabetes. It correlates with the progression of chronic kidney disease, particularly with tubular atrophy. The fatty acid load on albumin significantly increases in obesity, presenting a proinflammatory environment to the proximal tubules. However, little is known about changes in the redox milieu during fatty acid overload and how redox-sensitive mechanisms mediate cell death. Here, we show that albumin with fatty acid impurities or conjugated with palmitate but not albumin itself compromised mitochondrial and cell viability, membrane potential and respiration. Fatty acid overload led to a redox imbalance which deactivated the antioxidant protein peroxiredoxin 2 and caused a peroxide-mediated apoptosis through the redox-sensitive pJNK/caspase-3 pathway. Transfection of tubular cells with peroxiredoxin 2 was protective and mitigated apoptosis. Mitochondrial fatty acid entry and ceramide synthesis modulators suggested that mitochondrial β oxidation but not ceramide synthesis may modulate lipotoxic effects on tubular cell survival. These results suggest that albumin overloaded with fatty acids but not albumin itself changes the redox environment in the tubules, inducing a peroxide-mediated redox-sensitive apoptosis. Thus, mitigating circulating fatty acid levels may be an important factor in both preserving redox balance and preventing tubular cell damage in proteinuric diseases. PMID:24500687

  15. Hyperthermia-induced apoptosis

    NARCIS (Netherlands)

    Nijhuis, E.H.A.

    2008-01-01

    This thesis describes a number of studies that investigated several aspects of heat-induced apoptosis in human lymphoid malignancies. Cells harbour both pro- and anti-apoptotic proteins and the balance between these proteins determines whether a cell is susceptible to undergo apoptosis. In this

  16. Apoptosis-Inducing Factor (AIF in Physiology and Disease: The Tale of a Repented Natural Born Killer

    Directory of Open Access Journals (Sweden)

    Daniele Bano

    2018-04-01

    Full Text Available Apoptosis-inducing factor (AIF is a mitochondrial oxidoreductase that contributes to cell death programmes and participates in the assembly of the respiratory chain. Importantly, AIF deficiency leads to severe mitochondrial dysfunction, causing muscle atrophy and neurodegeneration in model organisms as well as in humans. The purpose of this review is to describe functions of AIF and AIF-interacting proteins as regulators of cell death and mitochondrial bioenergetics. We describe how AIF deficiency induces pathogenic processes that alter metabolism and ultimately compromise cellular homeostasis. We report the currently known AIFM1 mutations identified in humans and discuss the variability of AIFM1-related disorders in terms of onset, organ involvement and symptoms. Finally, we summarize how the study of AIFM1-linked pathologies may help to further expand our understanding of rare inherited forms of mitochondrial diseases. Keywords: Apoptosis-inducing factor (AIF, Cell death, Mitochondria, Mitochondrial diseases, Oxidative phosphorylation (OXPHOS

  17. Nuclear thioredoxin-1 is required to suppress cisplatin-mediated apoptosis of MCF-7 cells

    International Nuclear Information System (INIS)

    Chen, Xiao-Ping; Liu, Shou; Tang, Wen-Xin; Chen, Zheng-Wang

    2007-01-01

    Different cell line with increased thioredoxin-1 (Trx-1) showed a decreased or increased sensitivity to cell killing by cisplatin. Recently, several studies found that the subcellular localization of Trx-1 is closely associated with its functions. In this study, we explored the association of the nuclear Trx-1 with the cisplatin-mediated apoptosis of breast cancer cells MCF-7. Firstly, we found that higher total Trx-1 accompanied by no change of nuclear Trx-1 can not influence apoptosis induced by cisplatin in MCF-7 cells transferred with Trx-1 cDNA. Secondly, higher nuclear Trx-1 accompanied by no change of total Trx-1 can protect cells from apoptosis induced by cisplatin. Thirdly, high nuclear Trx-1 involves in the cisplatin-resistance in cisplatin-resistive cells. Meanwhile, we found that the mRNA level of p53 is closely correlated with the level of nuclear Trx-1. In summary, we concluded that the nuclear Trx-1 is required to resist apoptosis of MCF-7 cells induced by cisplatin, probably through up-regulating the anti-apoptotic gene, p53

  18. A Recombinant Fragment of Human Surfactant Protein D induces Apoptosis in Pancreatic Cancer Cell Lines via Fas-Mediated Pathway.

    Science.gov (United States)

    Kaur, Anuvinder; Riaz, Muhammad Suleman; Murugaiah, Valarmathy; Varghese, Praveen Mathews; Singh, Shiv K; Kishore, Uday

    2018-01-01

    Human surfactant protein D (SP-D) is a potent innate immune molecule, which is emerging as a key molecule in the recognition and clearance of altered and non-self targets. Previous studies have shown that a recombinant fragment of human SP-D (rfhSP-D) induced apoptosis via p53-mediated apoptosis pathway in an eosinophilic leukemic cell line, AML14.3D10. Here, we report the ability of rfhSP-D to induce apoptosis via TNF-α/Fas-mediated pathway regardless of the p53 status in human pancreatic adenocarcinoma using Panc-1 (p53 mt ), MiaPaCa-2 (p53 mt ), and Capan-2 (p53 wt ) cell lines. Treatment of these cell lines with rfhSP-D for 24 h caused growth arrest in G1 cell cycle phase and triggered transcriptional upregulation of pro-apoptotic factors such as TNF-α and NF-κB. Translocation of NF-κB from the cytoplasm into the nucleus of pancreatic cancer cell lines was observed via immunofluorescence microscopy following treatment with rfhSP-D as compared to the untreated cells. The rfhSP-D treatment caused upregulation of pro-apoptotic marker Fas, as analyzed via qPCR and western blot, which then triggered caspase cascade, as evident from cleavage of caspase 8 and 3 analyzed via western blot at 48 h. The cell number following the rfhSP-D treatment was reduced in the order of Panc-1 (~67%) > MiaPaCa-2 (~60%) > Capan-2 (~35%). This study appears to suggest that rfhSP-D can potentially be used to therapeutically target pancreatic cancer cells irrespective of their p53 phenotype.

  19. Atrazine-induced apoptosis of splenocytes in BALB/C mice

    Directory of Open Access Journals (Sweden)

    Zheng Jing

    2011-10-01

    Full Text Available Abstract Background Atrazine (2-chloro-4-ethytlamino-6-isopropylamine-1,3,5-triazine; ATR, is the most commonly applied broad-spectrum herbicide in the world. Unintentional overspray of ATR poses an immune function health hazard. The biomolecular mechanisms responsible for ATR-induced immunotoxicity, however, are little understood. This study presents on our investigation into the apoptosis of splenocytes in mice exposed to ATR as we explore possible immunotoxic mechanisms. Methods Oral doses of ATR were administered to BALB/C mice for 21 days. The histopathology, lymphocyte apoptosis and the expression of apoptosis-related proteins from the Fas/Fas ligand (FasL apoptotic pathway were examined from spleen samples. Results Mice administered ATR exhibited a significant decrease in spleen and thymus weight. Electron microscope histology of ultrathin sections of spleen revealed degenerative micromorphology indicative of apoptosis of splenocytes. Flow cytometry revealed that the percentage of apoptotic lymphocytes increased in a dose-dependent manner after ATR treatment. Western blots identified increased expression of Fas, FasL and active caspase-3 proteins in the treatment groups. Conclusions ATR is capable of inducing splenocytic apoptosis mediated by the Fas/FasL pathway in mice, which could be the potential mechanism underlying the immunotoxicity of ATR.

  20. The novel Akt inhibitor API-1 induces c-FLIP degradation and synergizes with TRAIL to augment apoptosis independent of Akt inhibition.

    Science.gov (United States)

    Li, Bo; Ren, Hui; Yue, Ping; Chen, Mingwei; Khuri, Fadlo R; Sun, Shi-Yong

    2012-04-01

    API-1 (pyrido[2,3-d]pyrimidines) is a novel small-molecule inhibitor of Akt, which acts by binding to Akt and preventing its membrane translocation and has promising preclinical antitumor activity. In this study, we reveal a novel function of API-1 in regulation of cellular FLICE-inhibitory protein (c-FLIP) levels and TRAIL-induced apoptosis, independent of Akt inhibition. API-1 effectively induced apoptosis in tested cancer cell lines including activation of caspase-8 and caspase-9. It reduced the levels of c-FLIP without increasing the expression of death receptor 4 (DR4) or DR5. Accordingly, it synergized with TRAIL to induce apoptosis. Enforced expression of ectopic c-FLIP did not attenuate API-1-induced apoptosis but inhibited its ability to enhance TRAIL-induced apoptosis. These data indicate that downregulation of c-FLIP mediates enhancement of TRAIL-induced apoptosis by API-1 but is not sufficient for API-1-induced apoptosis. API-1-induced reduction of c-FLIP could be blocked by the proteasome inhibitor MG132. Moreover, API-1 increased c-FLIP ubiquitination and decreased c-FLIP stability. These data together suggest that API-1 downregulates c-FLIP by facilitating its ubiquitination and proteasome-mediated degradation. Because other Akt inhibitors including API-2 and MK2206 had minimal effects on reducing c-FLIP and enhancement of TRAIL-induced apoptosis, it is likely that API-1 reduces c-FLIP and enhances TRAIL-induced apoptosis independent of its Akt-inhibitory activity. 2012 AACR