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Sample records for p53-mediated bax activation

  1. Differential induction of p53-mediated apoptosis in medulloblastomas and gliomas correlates with their ability to induce bax

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    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

  2. Activation of SAT1 engages polyamine metabolism with p53-mediated ferroptotic responses.

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    Ou, Yang; Wang, Shang-Jui; Li, Dawei; Chu, Bo; Gu, Wei

    2016-11-01

    Although p53-mediated cell-cycle arrest, senescence, and apoptosis remain critical barriers to cancer development, the emerging role of p53 in cell metabolism, oxidative responses, and ferroptotic cell death has been a topic of great interest. Nevertheless, it is unclear how p53 orchestrates its activities in multiple metabolic pathways into tumor suppressive effects. Here, we identified the SAT1 (spermidine/spermine N 1 -acetyltransferase 1) gene as a transcription target of p53. SAT1 is a rate-limiting enzyme in polyamine catabolism critically involved in the conversion of spermidine and spermine back to putrescine. Surprisingly, we found that activation of SAT1 expression induces lipid peroxidation and sensitizes cells to undergo ferroptosis upon reactive oxygen species (ROS)-induced stress, which also leads to suppression of tumor growth in xenograft tumor models. Notably, SAT1 expression is down-regulated in human tumors, and CRISPR-cas9-mediated knockout of SAT1 expression partially abrogates p53-mediated ferroptosis. Moreover, SAT1 induction is correlated with the expression levels of arachidonate 15-lipoxygenase (ALOX15), and SAT1-induced ferroptosis is significantly abrogated in the presence of PD146176, a specific inhibitor of ALOX15. Thus, our findings uncover a metabolic target of p53 involved in ferroptotic cell death and provide insight into the regulation of polyamine metabolism and ferroptosis-mediated tumor suppression.

  3. Fenofibrate inhibited pancreatic cancer cells proliferation via activation of p53 mediated by upregulation of LncRNA MEG3

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    Hu, Duanmin; Su, Cunjin; Jiang, Min; Shen, Yating; Shi, Aiming; Zhao, Fenglun; Chen, Ruidong; Shen, Zhu; Bao, Junjie; Tang, Wen

    2016-01-01

    There is still no suitable drug for pancreatic cancer treatment, which is one of the most aggressive human tumors. Maternally expressed gene 3 (MEG3), a LncRNA, has been suggested as a tumor suppressor in a range of human tumors. Studies found fenofibrate exerted anti-tumor roles in various human cancer cell lines. However, its role in pancreatic cancer remains unknown. The present study aimed to explore the impacts of fenofibrate on pancreatic cancer cell lines, and to investigate MEG3 role in its anti-tumor mechanisms. We used MTT assay to determine cells proliferation, genome-wide LncRNA microarray analysis to identify differently expressed LncRNAs, siRNA or pCDNA-MEG3 transfection to interfere or upregulate MEG3 expression, western blot to detect protein levels, real-time PCR to determine MEG3 level. Fenofibrate significantly inhibited proliferation of pancreatic cancer cells, increased MEG3 expression and p53 levels. Moreover, knockdown of MEG3 attenuated cytotoxicity induced by fenofibrate. Furthermore, overexpression of MEG3 induced cells death and increased p53 expression. Our results indicated fenofibrate inhibited pancreatic cancer cells proliferation via activation of p53 mediated by upregulation of MEG3. - Highlights: • We found that fenofibrate suppressed proliferation of pancreatic cancer cells. • We found fenofibrate increased LncRNA-MEG3 expression and p53 level in PANC-1 cells. • Inhibition of MEG3 expression attenuated anti-tumor effects of fenofibrate.

  4. Fenofibrate inhibited pancreatic cancer cells proliferation via activation of p53 mediated by upregulation of LncRNA MEG3

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    Hu, Duanmin [Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Su, Cunjin [Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Jiang, Min [Department of Breast Surgery, The First Affiliated Hospital of Soochow University, Suzhou 215004 (China); Shen, Yating [Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Shi, Aiming; Zhao, Fenglun [Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Chen, Ruidong [Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Shen, Zhu [Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Bao, Junjie, E-mail: baojjsdfey@sina.com [Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Tang, Wen, E-mail: sztangwen@163.com [Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China)

    2016-03-04

    There is still no suitable drug for pancreatic cancer treatment, which is one of the most aggressive human tumors. Maternally expressed gene 3 (MEG3), a LncRNA, has been suggested as a tumor suppressor in a range of human tumors. Studies found fenofibrate exerted anti-tumor roles in various human cancer cell lines. However, its role in pancreatic cancer remains unknown. The present study aimed to explore the impacts of fenofibrate on pancreatic cancer cell lines, and to investigate MEG3 role in its anti-tumor mechanisms. We used MTT assay to determine cells proliferation, genome-wide LncRNA microarray analysis to identify differently expressed LncRNAs, siRNA or pCDNA-MEG3 transfection to interfere or upregulate MEG3 expression, western blot to detect protein levels, real-time PCR to determine MEG3 level. Fenofibrate significantly inhibited proliferation of pancreatic cancer cells, increased MEG3 expression and p53 levels. Moreover, knockdown of MEG3 attenuated cytotoxicity induced by fenofibrate. Furthermore, overexpression of MEG3 induced cells death and increased p53 expression. Our results indicated fenofibrate inhibited pancreatic cancer cells proliferation via activation of p53 mediated by upregulation of MEG3. - Highlights: • We found that fenofibrate suppressed proliferation of pancreatic cancer cells. • We found fenofibrate increased LncRNA-MEG3 expression and p53 level in PANC-1 cells. • Inhibition of MEG3 expression attenuated anti-tumor effects of fenofibrate.

  5. Glaucarubinone sensitizes KB cells to paclitaxel by inhibiting ABC transporters via ROS-dependent and p53-mediated activation of apoptotic signaling pathways.

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    Karthikeyan, Subburayan; Hoti, Sugeerappa Laxmanappa; Nazeer, Yasin; Hegde, Harsha Vasudev

    2016-07-05

    Multidrug resistance (MDR) is considered to be the major contributor to failure of chemotherapy in oral squamous cell carcinoma (SCC). This study was aimed to explore the effects and mechanisms of glaucarubinone (GLU), one of the major quassinoids from Simarouba glauca DC, in potentiating cytotoxicity of paclitaxel (PTX), an anticancer drug in KB cells. Our data showed that the administration of GLU pre-treatment significantly enhanced PTX anti-proliferative effect in ABCB1 over-expressing KB cells. The Rh 123 drug efflux studies revealed that there was a significant transport function inhibition by GLU-PTX treatment. Interestingly, it was also found that this enhanced anticancer efficacy of GLU was associated with PTX-induced cell arrest in the G2/M phase of cell cycle. Further, the combined treatment of GLU-PTX had significant decrease in the expression levels of P-gp, MRPs, and BCRP in resistant KB cells at both mRNA and protein levels. Furthermore, the combination treatments showed significant reactive oxygen species (ROS) production, chromatin condensation and reduced mitochondrial membrane potential in resistant KB cells. The results from DNA fragmentation analysis also demonstrated the GLU induced apoptosis in KB cells and its synergy with PTX. Importantly, GLU and/or PTX triggered apoptosis through the activation of pro-apoptotic proteins such as p53, Bax, and caspase-9. Our findings demonstrated for the first time that GLU causes cell death in human oral cancer cells via the ROS-dependent suppression of MDR transporters and p53-mediated activation of the intrinsic mitochondrial pathway of apoptosis. Additionally, the present study also focussed on investigation of the protective effect of GLU and combination drugs in human normal blood lymphocytes. Normal blood lymphocytes assay indicated that GLU is able to induce selective toxicity in cancer cells and in silico molecular docking studies support the choice of GLU as ABC inhibitor to enhance PTX efficacy

  6. Ets-2 and p53 mediate cAMP-induced MMP-2 expression, activity and trophoblast invasion

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    Goldman Shlomit

    2009-11-01

    Full Text Available Abstract Background We have previously shown that Matrix metalloproteinase (MMP -2 is a key-enzyme in early trophoblast invasion and that Protein Kinase A (PKA increases MMP-2 expression and trophoblast invasion. The aim of this study was to examine MMP -2 regulation by PKA in invasive trophoblasts: JAR choriocarcinoma cell-line and 6-8 w first trimester trophoblasts. Methods The effect of Forskolin (PKA on MMP-2 expression was assessed by Northern Blot and RT-PCR. Possible transcription factors binding to consensus MMP-2 promoter sequences in response to Forskolin, were detected by EMSA binding assay and their expression assessed by western blot analysis. Antisense transfection of relevant transcription factors was performed and the inhibitory effect assessed on MMP-2 expression (RT-PCR, secretion (zymography and trophoblast invasiveness (transwell migration assay. Results We found that Forskolin increased MMP-2 mRNA in JAR cells within 24 hours, and induced binding to p53, Ets, C/EBP and AP-2. Transcription factors Ets-2, phospho- p53, C/EBP epsilon, C/EBP lambda and AP-2 alpha bound to their respective binding sequences in response to Forskolin and the expressions of these transcription factors were all elevated in Forskolin- treated cells. Inhibition of Ets-2 and p53 reduced MMP-2 expression, secretion and invasiveness of Forskolin treated cells. Conclusion MMP-2 is regulated by PKA through several binding sites and transcription factors including Ets-2, p53, C/EBP, C/EBP lambda and AP-2 alpha. Ets-2 and p53 mediate cAMP- induced trophoblast invasiveness, through regulation of MMP-2.

  7. 1800MHz Microwave Induces p53 and p53-Mediated Caspase-3 Activation Leading to Cell Apoptosis In Vitro.

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    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.

  8. Activations of Both Extrinsic and Intrinsic Pathways in HCT 116 Human Colorectal Cancer Cells Contribute to Apoptosis through p53-Mediated ATM/Fas Signaling by Emilia sonchifolia Extract, a Folklore Medicinal Plant

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    Yu-Hsuan Lan

    2012-01-01

    Full Text Available Emilia sonchifolia (L. DC (Compositae, an herbaceous plant found in Taiwan and India, is used as folk medicine. The clinical applications include inflammation, rheumatism, cough, cuts fever, dysentery, analgesic, and antibacteria. The activities of Emilia sonchifolia extract (ESE on colorectal cancer cell death have not been fully investigated. The purpose of this study explored the induction of apoptosis and its molecular mechanisms in ESE-treated HCT 116 human colorectal cancer cells in vitro. The methanolic ESE was characterized, and γ-humulene was formed as the major constituent (63.86%. ESE induced cell growth inhibition in a concentration- and time-dependent response by MTT assay. Apoptotic cells (DNA fragmentation, an apoptotic catachrestic were found after ESE treatment by TUNEL assay and DNA gel electrophoresis. Alternatively, ESE stimulated the activities of caspase-3, -8, and -9 and their specific caspase inhibitors protected against ESE-induced cytotoxicity. ESE promoted the mitochondria-dependent and death-receptor-associated protein levels. Also, ESE increased ROS production and upregulated the levels of ATM, p53, and Fas in HCT 116 cells. Strikingly, p53 siRNA reversed ESE-reduced viability involved in p53-mediated ATM/Fas signaling in HCT 116 cells. In summary, our result is the first report suggesting that ESE may be potentially efficacious in the treatment of colorectal cancer.

  9. Acetylation Is Crucial for p53-Mediated Ferroptosis and Tumor Suppression

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    Shang-Jui Wang

    2016-10-01

    Full Text Available Although previous studies indicate that loss of p53-mediated cell cycle arrest, apoptosis, and senescence does not completely abrogate its tumor suppression function, it is unclear how the remaining activities of p53 are regulated. Here, we have identified an acetylation site at lysine K98 in mouse p53 (or K101 for human p53. Whereas the loss of K98 acetylation (p53K98R alone has very modest effects on p53-mediated transactivation, simultaneous mutations at all four acetylation sites (p534KR: K98R+ 3KR[K117R+K161R+K162R] completely abolish its ability to regulate metabolic targets, such as TIGAR and SLC7A11. Notably, in contrast to p533KR, p534KR is severely defective in suppressing tumor growth in mouse xenograft models. Moreover, p534KR is still capable of inducing the p53-Mdm2 feedback loop, but p53-dependent ferroptotic responses are markedly abrogated. Together, these data indicate the critical role of p53 acetylation in ferroptotic responses and its remaining tumor suppression activity.

  10. p53-Mediated Molecular Control of Autophagy in Tumor Cells

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    Maria Mrakovcic

    2018-03-01

    Full Text Available Autophagy is an indispensable mechanism of the eukaryotic cell, facilitating the removal and renewal of cellular components and thereby balancing the cell’s energy consumption and homeostasis. Deregulation of autophagy is now regarded as one of the characteristic key features contributing to the development of tumors. In recent years, the suppression of autophagy in combination with chemotherapeutic treatment has been approached as a novel therapy in cancer treatment. However, depending on the type of cancer and context, interference with the autophagic machinery can either promote or disrupt tumorigenesis. Therefore, disclosure of the major signaling pathways that regulate autophagy and control tumorigenesis is crucial. To date, several tumor suppressor proteins and oncogenes have emerged as eminent regulators of autophagy whose depletion or mutation favor tumor formation. The mammalian cell “janitor” p53 belongs to one of these tumor suppressors that are most commonly mutated in human tumors. Experimental evidence over the last decade convincingly reports that p53 can act as either an activator or an inhibitor of autophagy depending on its subcellular localization and its mode of action. This finding gains particular significance as p53 deficiency or mutant variants of p53 that accumulate in the cytoplasm of tumor cells enable activation of autophagy. Accordingly, we recently identified p53 as a molecular hub that regulates autophagy and apoptosis in histone deacetylase inhibitor-treated uterine sarcoma cells. In light of this novel experimental evidence, in this review, we focus on p53 signaling as a mediator of the autophagic pathway in tumor cells.

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

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    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

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

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    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.

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

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    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.

  14. BAX channel activity mediates lysosomal disruption linked to Parkinson disease.

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    Bové, Jordi; Martínez-Vicente, Marta; Dehay, Benjamin; Perier, Celine; Recasens, Ariadna; Bombrun, Agnes; Antonsson, Bruno; Vila, Miquel

    2014-05-01

    Lysosomal disruption is increasingly regarded as a major pathogenic event in Parkinson disease (PD). A reduced number of intraneuronal lysosomes, decreased levels of lysosomal-associated proteins and accumulation of undegraded autophagosomes (AP) are observed in PD-derived samples, including fibroblasts, induced pluripotent stem cell-derived dopaminergic neurons, and post-mortem brain tissue. Mechanistic studies in toxic and genetic rodent PD models attribute PD-related lysosomal breakdown to abnormal lysosomal membrane permeabilization (LMP). However, the molecular mechanisms underlying PD-linked LMP and subsequent lysosomal defects remain virtually unknown, thereby precluding their potential therapeutic targeting. Here we show that the pro-apoptotic protein BAX (BCL2-associated X protein), which permeabilizes mitochondrial membranes in PD models and is activated in PD patients, translocates and internalizes into lysosomal membranes early following treatment with the parkinsonian neurotoxin MPTP, both in vitro and in vivo, within a time-frame correlating with LMP, lysosomal disruption, and autophagosome accumulation and preceding mitochondrial permeabilization and dopaminergic neurodegeneration. Supporting a direct permeabilizing effect of BAX on lysosomal membranes, recombinant BAX is able to induce LMP in purified mouse brain lysosomes and the latter can be prevented by pharmacological blockade of BAX channel activity. Furthermore, pharmacological BAX channel inhibition is able to prevent LMP, restore lysosomal levels, reverse AP accumulation, and attenuate mitochondrial permeabilization and overall nigrostriatal degeneration caused by MPTP, both in vitro and in vivo. Overall, our results reveal that PD-linked lysosomal impairment relies on BAX-induced LMP, and point to small molecules able to block BAX channel activity as potentially beneficial to attenuate both lysosomal defects and neurodegeneration occurring in PD.

  15. Modulation of the DNA repair system and ATR-p53 mediated apoptosis is relevant for tributyltin-induced genotoxic effects in human hepatoma G2 cells.

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    Li, Bowen; Sun, Lingbin; Cai, Jiali; Wang, Chonggang; Wang, Mengmeng; Qiu, Huiling; Zuo, Zhenghong

    2015-01-01

    The toxic effects of tributyltin (TBT) have been extensively documented in several types of cells, but the molecular mechanisms related to the genotoxic effects of TBT have still not been fully elucidated. Our study showed that exposure of human hepatoma G2 cells to 1-4 μmol/L TBT for 3 hr caused severe DNA damage in a concentration-dependent manner. Moreover, the expression levels of key DNA damage sensor genes such as the replication factor C, proliferating cell nuclear antigen and poly (ADP-ribose) polymerase-1 were inhabited in a concentration-dependent manner. We further demonstrated that TBT induced cell apoptosis via the p53-mediated pathway, which was most likely activated by the ataxia telangiectasia mutated and rad-3 related (ATR) protein kinase. The results also showed that cytochrome c, caspase-3, caspase-8, caspase-9, and the B-cell lymphoma 2 were involved in this process. Taken together, we demonstrated for the first time that the inhibition of the DNA repair system might be more responsible for TBT-induced genotoxic effects in cells. Then the generated DNA damage induced by TBT initiated ATR-p53-mediated apoptosis. Copyright © 2014. Published by Elsevier B.V.

  16. SCO2 induces p53-mediated apoptosis by Thr845 phosphorylation of ASK-1 and dissociation of the ASK-1-Trx complex.

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    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.

  17. Paracrine Apoptotic Effect of p53 Mediated by Tumor Suppressor Par-4

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    Ravshan Burikhanov

    2014-01-01

    Full Text Available The guardian of the genome, p53, is often mutated in cancer and may contribute to therapeutic resistance. Given that p53 is intact and functional in normal tissues, we harnessed its potential to inhibit the growth of p53-deficient cancer cells. Specific activation of p53 in normal fibroblasts selectively induced apoptosis in p53-deficient cancer cells. This paracrine effect was mediated by p53-dependent secretion of the tumor suppressor Par-4. Accordingly, the activation of p53 in normal mice, but not p53−/− or Par-4−/− mice, caused systemic elevation of Par-4, which induced apoptosis of p53-deficient tumor cells. Mechanistically, p53 induced Par-4 secretion by suppressing the expression of its binding partner, UACA, which sequesters Par-4. Thus, normal cells can be empowered by p53 activation to induce Par-4 secretion for the inhibition of therapy-resistant tumors.

  18. ARF and ATM/ATR cooperate in p53-mediated apoptosis upon oncogenic stress

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    Pauklin, Siim; Kristjuhan, Arnold; Maimets, Toivo; Jaks, Viljar

    2005-01-01

    Induction of apoptosis is pivotal for eliminating cells with damaged DNA or deregulated proliferation. We show that tumor suppressor ARF and ATM/ATR kinase pathways cooperate in the induction of apoptosis in response to elevated expression of c-myc, β-catenin or human papilloma virus E7 oncogenes. Overexpression of oncogenes leads to the formation of phosphorylated H2AX foci, induction of Rad51 protein levels and ATM/ATR-dependent phosphorylation of p53. Inhibition of ATM/ATR kinases abolishes both induction of Rad51 and phosphorylation of p53, and remarkably reduces the level of apoptosis induced by co-expression of oncogenes and ARF. However, the induction of apoptosis is downregulated in p53-/- cells and does not depend on activities of ATM/ATR kinases, indicating that efficient induction of apoptosis by oncogene activation depends on coordinated action of ARF and ATM/ATR pathways in the regulation of p53

  19. P53-mediated rapid induction of apoptosis conveys resistance to viral infection in Drosophila melanogaster.

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    Bo Liu

    2013-02-01

    Full Text Available Arthropod-borne pathogens account for millions of deaths each year. Understanding the genetic mechanisms controlling vector susceptibility to pathogens has profound implications for developing novel strategies for controlling insect-transmitted infectious diseases. The fact that many viruses carry genes that have anti-apoptotic activity has long led to the hypothesis that induction of apoptosis could be a fundamental innate immune response. However, the cellular mechanisms mediating the induction of apoptosis following viral infection remained enigmatic, which has prevented experimental verification of the functional significance of apoptosis in limiting viral infection in insects. In addition, studies with cultured insect cells have shown that there is sometimes a lack of apoptosis, or the pro-apoptotic response happens relatively late, thus casting doubt on the functional significance of apoptosis as an innate immunity. Using in vivo mosquito models and the native route of infection, we found that there is a rapid induction of reaper-like pro-apoptotic genes within a few hours following exposure to DNA or RNA viruses. Recapitulating a similar response in Drosophila, we found that this rapid induction of apoptosis requires the function of P53 and is mediated by a stress-responsive regulatory region upstream of reaper. More importantly, we showed that the rapid induction of apoptosis is responsible for preventing the expression of viral genes and blocking the infection. Genetic changes influencing this rapid induction of reaper-like pro-apoptotic genes led to significant differences in susceptibility to viral infection.

  20. Haploinsufficiency for Core Exon Junction Complex Components Disrupts Embryonic Neurogenesis and Causes p53-Mediated Microcephaly.

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    Hanqian Mao

    2016-09-01

    Full Text Available The exon junction complex (EJC is an RNA binding complex comprised of the core components Magoh, Rbm8a, and Eif4a3. Human mutations in EJC components cause neurodevelopmental pathologies. Further, mice heterozygous for either Magoh or Rbm8a exhibit aberrant neurogenesis and microcephaly. Yet despite the requirement of these genes for neurodevelopment, the pathogenic mechanisms linking EJC dysfunction to microcephaly remain poorly understood. Here we employ mouse genetics, transcriptomic and proteomic analyses to demonstrate that haploinsufficiency for each of the 3 core EJC components causes microcephaly via converging regulation of p53 signaling. Using a new conditional allele, we first show that Eif4a3 haploinsufficiency phenocopies aberrant neurogenesis and microcephaly of Magoh and Rbm8a mutant mice. Transcriptomic and proteomic analyses of embryonic brains at the onset of neurogenesis identifies common pathways altered in each of the 3 EJC mutants, including ribosome, proteasome, and p53 signaling components. We further demonstrate all 3 mutants exhibit defective splicing of RNA regulatory proteins, implying an EJC dependent RNA regulatory network that fine-tunes gene expression. Finally, we show that genetic ablation of one downstream pathway, p53, significantly rescues microcephaly of all 3 EJC mutants. This implicates p53 activation as a major node of neurodevelopmental pathogenesis following EJC impairment. Altogether our study reveals new mechanisms to help explain how EJC mutations influence neurogenesis and underlie neurodevelopmental disease.

  1. Loss of Atrx sensitizes cells to DNA damaging agents through p53-mediated death pathways.

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    Damiano Conte

    Full Text Available Prevalent cell death in forebrain- and Sertoli cell-specific Atrx knockout mice suggest that Atrx is important for cell survival. However, conditional ablation in other tissues is not associated with increased death indicating that diverse cell types respond differently to the loss of this chromatin remodeling protein. Here, primary macrophages isolated from Atrx(f/f mice were infected with adenovirus expressing Cre recombinase or β-galactosidase, and assayed for cell survival under different experimental conditions. Macrophages survive without Atrx but undergo rapid apoptosis upon lipopolysaccharide (LPS activation suggesting that chromatin reorganization in response to external stimuli is compromised. Using this system we next tested the effect of different apoptotic stimuli on cell survival. We observed that survival of Atrx-null cells were similar to wild type cells in response to serum withdrawal, anti-Fas antibody, C2 ceramide or dexamethasone treatment but were more sensitive to 5-fluorouracil (5-FU. Cell survival could be rescued by re-introducing Atrx or by removal of p53 demonstrating the cell autonomous nature of the effect and its p53-dependence. Finally, we demonstrate that multiple primary cell types (myoblasts, embryonic fibroblasts and neurospheres were sensitive to 5-FU, cisplatin, and UV light treatment. Together, our results suggest that cells lacking Atrx are more sensitive to DNA damaging agents and that this may result in enhanced death during development when cells are at their proliferative peak. Moreover, it identifies potential treatment options for cancers associated with ATRX mutations, including glioblastoma and pancreatic neuroendocrine tumors.

  2. RITA inhibits multiple myeloma cell growth through induction of p53-mediated caspase-dependent apoptosis and synergistically enhances nutlin-induced cytotoxic responses.

    Science.gov (United States)

    Saha, Manujendra N; Jiang, Hua; Mukai, Asuka; Chang, Hong

    2010-11-01

    Mutations or deletions of p53 are relatively rare in multiple myeloma (MM), at least in newly diagnosed patients. Thus, restoration of p53 tumor suppressor function in MM by blocking the inhibitory role of murine double minute 2 (MDM2) is a promising and applicable therapeutic strategy. RITA and nutlin are two new classes of small molecule MDM2 inhibitors that prevent the p53-MDM2 interaction. Earlier reports showed p53-dependent activity of RITA in solid tumors as well as in leukemias. We and others recently described nutlin-induced apoptosis in MM cells, but it remains unclear whether RITA exerts antimyeloma activity. Here, we found that RITA activates the p53 pathway and induces apoptosis in MM cell lines and primary MM samples, preferentially killing myeloma cells. The activation of p53 induced by RITA was mediated through modulation of multiple apoptotic regulatory proteins, including upregulation of a proapoptotic protein (NOXA), downregulation of an antiapoptotic protein, Mcl-1, and activation of caspases through extrinsic pathways. Moreover, a number of key p53-mediated apoptotic target genes were identified by gene expression profiling and further validated by quantitative real-time PCR. Importantly, the combination of RITA with nutlin displayed a strong synergism on growth inhibition with the combination index ranging from 0.56 to 0.82 in MM cells. Our data support further clinical evaluation of RITA as a potential novel therapeutic intervention in MM. ©2010 AACR.

  3. Targeting GRP75 improves HSP90 inhibitor efficacy by enhancing p53-mediated apoptosis in hepatocellular carcinoma.

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    Weiwei Guo

    Full Text Available Heat shock protein 90 (HSP90 inhibitors are potential drugs for cancer therapy. The inhibition of HSP90 on cancer cell growth largely through degrading client proteins, like Akt and p53, therefore, triggering cancer cell apoptosis. Here, we show that the HSP90 inhibitor 17-AAG can induce the expression of GRP75, a member of heat shock protein 70 (HSP70 family, which, in turn, attenuates the anti-growth effect of HSP90 inhibition on cancer cells. Additionally, 17-AAG enhanced binding of GRP75 and p53, resulting in the retention of p53 in the cytoplasm. Blocking GRP75 with its inhibitor MKT-077 potentiated the anti-tumor effects of 17-AAG by disrupting the formation of GRP75-p53 complexes, thereby facilitating translocation of p53 into the nuclei and leading to the induction of apoptosis-related genes. Finally, dual inhibition of HSP90 and GRP75 was found to significantly inhibit tumor growth in a liver cancer xenograft model. In conclusion, the GRP75 inhibitor MKT-077 enhances 17-AAG-induced apoptosis in HCCs and increases p53-mediated inhibition of tumor growth in vivo. Dual targeting of GRP75 and HSP90 may be a useful strategy for the treatment of HCCs.

  4. Estrogen-Related Receptor Alpha Confers Methotrexate Resistance via Attenuation of Reactive Oxygen Species Production and P53 Mediated Apoptosis in Osteosarcoma Cells

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    Peng Chen

    2014-01-01

    Full Text Available Osteosarcoma (OS is a malignant tumor mainly occurring in children and adolescents. Methotrexate (MTX, a chemotherapy agent, is widely used in treating OS. However, treatment failures are common due to acquired chemoresistance, for which the underlying molecular mechanisms are still unclear. In this study, we report that overexpression of estrogen-related receptor alpha (ERRα, an orphan nuclear receptor, promoted cell survival and blocked MTX-induced cell death in U2OS cells. We showed that MTX induced ROS production in MTX-sensitive U2OS cells while ERRα effectively blocked the ROS production and ROS associated cell apoptosis. Our further studies demonstrated that ERRα suppressed ROS induction of tumor suppressor P53 and its target genes NOXA and XAF1 which are mediators of P53-dependent apoptosis. In conclusion, this study demonstrated that ERRα plays an important role in the development of MTX resistance through blocking MTX-induced ROS production and attenuating the activation of p53 mediated apoptosis signaling pathway, and points to ERRα as a novel target for improving osteosarcoma therapy.

  5. Epstein-Barr virus nuclear antigen 3C stabilizes Gemin3 to block p53-mediated apoptosis.

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    Qiliang Cai

    2011-12-01

    Full Text Available The Epstein-Barr nuclear antigen 3C (EBNA3C, one of the essential latent antigens for Epstein-Barr virus (EBV-induced immortalization of primary human B lymphocytes in vitro, has been implicated in regulating cell proliferation and anti-apoptosis via interaction with several cellular and viral factors. Gemin3 (also named DDX20 or DP103 is a member of DEAD RNA helicase family which exhibits diverse cellular functions including DNA transcription, recombination and repair, and RNA metabolism. Gemin3 was initially identified as a binding partner to EBNA2 and EBNA3C. However, the mechanism by which EBNA3C regulates Gemin3 function remains unclear. Here, we report that EBNA3C directly interacts with Gemin3 through its C-terminal domains. This interaction results in increased stability of Gemin3 and its accumulation in both B lymphoma cells and EBV transformed lymphoblastoid cell lines (LCLs. Moreover, EBNA3C promotes formation of a complex with p53 and Gemin3 which blocks the DNA-binding affinity of p53. Small hairpin RNA based knockdown of Gemin3 in B lymphoma or LCL cells remarkably attenuates the ability of EBNA3C to inhibit the transcription activity of p53 on its downstream genes p21 and Bax, as well as apoptosis. These findings provide the first evidence that Gemin3 may be a common target of oncogenic viruses for driving cell proliferation and anti-apoptotic activities.

  6. Driving p53 Response to Bax Activation Greatly Enhances Sensitivity to Taxol by Inducing Massive Apoptosis

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    Paola De Feudis

    2000-05-01

    Full Text Available The proapoptotic gene bax is one of the downstream effectors of p53. The p53 binding site in the bax promoter is less responsive to p53 than the one in the growth arrest mediating gene p21. We introduced the bax gene under the control of 13 copies of a strong p53 responsive element into two ovarian cancer cell lines. The clones expressing bax under the control of p53 obtained from the wild-type (wt p53-expressing cell line A2780 were much more sensitive (500- to 1000-fold to the anticancer agent taxol than the parent cell line, with a higher percentage of cells undergoing apoptosis after drug treatment that was clearly p53-dependent and bax-mediated. Xenografts established in nude mice from one selected clone (A2780/C3 were more responsive to taxol than the parental line and the apoptotic response of A2780/C3 tumors was also increased after treatment. Introduction of the same plasmid into the p53 null SKOV3 cell line did not alter the sensitivity to taxol or the induction of apoptosis. In conclusion, driving the p53 response (after taxol treatment by activating the bax gene rather than the p21 gene results in induction of massive apoptosis, in vitro and in vivo, and greatly enhances sensitivity to the drug.

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

    OpenAIRE

    Kyoung-jin Min; Ju-Ock Nam; Taeg Kyu Kwon

    2017-01-01

    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 (...

  8. Kaempferol induces ATM/p53-mediated death receptor and mitochondrial apoptosis in human umbilical vein endothelial cells.

    Science.gov (United States)

    Lee, Chiu-Fang; Yang, Jai-Sing; Tsai, Fuu-Jen; Chiang, Ni-Na; Lu, Chi-Cheng; Huang, Yu-Syuan; Chen, Chun; Chen, Fu-An

    2016-05-01

    Kaempferol is a member of the flavonoid compounds found in vegetables and fruits. It is shown to exhibit biological impact and anticancer activity, but no report exists on the angiogenic effect of kaempferol and induction of cell apoptosis in vitro. In this study, we investigated the role of kaempferol on anti-angiogenic property and the apoptotic mechanism of human umbilical vein endothelial cells (HUVECs). Our results demonstrated that kaempferol decreased HUVEC viability in a time- and concentration-dependent manner. Kaempferol also induced morphological changes and sub-G1 phase cell population (apoptotic cells). Kaempferol triggered apoptosis of HUVECs as detecting by DNA fragmentation, comet assay and immunofluorescent staining for activated caspase-3. The caspase signals, including caspase-8, -9 and -3, were time-dependently activated in HUVECs after kaempferol exposure. Furthermore, pre-treatment with a specific inhibitor of caspase-8 (Z-IETD-FMK) significantly reduced the activity of caspase-8, -9 and -3, indicating that extrinsic pathway is a major signaling pathway in kaempferol-treated HUVECs. Importantly, kaempferol promoted reactive oxygen species (ROS) evaluated using flow cytometric assay in HUVECs. We further investigated the upstream extrinsic pathway and showed that kaempferol stimulated death receptor signals [Fas/CD95, death receptor 4 (DR4) and DR5] through increasing the levels of phosphorylated p53 and phosphorylated ATM pathways in HUVECs, which can be individually confirmed by N-acetylcysteine (NAC), ATM specific inhibitor (caffeine) and p53 siRNA. Based on these results, kaempferol-induced HUVEC apoptosis was involved in an ROS-mediated p53/ATM/death receptor signaling. Kaempferol might possess therapeutic effects on cancer treatment in anti-vascular targeting.

  9. Regulation of protein quality control by UBE4B and LSD1 through p53-mediated transcription.

    Directory of Open Access Journals (Sweden)

    Goran Periz

    2015-04-01

    Full Text Available Protein quality control is essential for clearing misfolded and aggregated proteins from the cell, and its failure is associated with many neurodegenerative disorders. Here, we identify two genes, ufd-2 and spr-5, that when inactivated, synergistically and robustly suppress neurotoxicity associated with misfolded proteins in Caenorhabditis elegans. Loss of human orthologs ubiquitination factor E4 B (UBE4B and lysine-specific demethylase 1 (LSD1, respectively encoding a ubiquitin ligase and a lysine-specific demethylase, promotes the clearance of misfolded proteins in mammalian cells by activating both proteasomal and autophagic degradation machineries. An unbiased search in this pathway reveals a downstream effector as the transcription factor p53, a shared substrate of UBE4B and LSD1 that functions as a key regulator of protein quality control to protect against proteotoxicity. These studies identify a new protein quality control pathway via regulation of transcription factors and point to the augmentation of protein quality control as a wide-spectrum antiproteotoxicity strategy.

  10. Induction of p53-mediated apoptosis in splenocytes and thymocytes of C57BL/6 mice exposed to perfluorooctane sulfonate (PFOS)

    International Nuclear Information System (INIS)

    Dong, Guang-Hui; Wang, Jing; Zhang, Ying-Hua; Liu, Miao-Miao; Wang, Da; Zheng, Li; Jin, Yi-He

    2012-01-01

    Perfluorooctane sulfonate (PFOS) is a persistent environmental contaminant found in human and wildlife tissues. It has been reported that PFOS can cause atrophy of the immune organs and apoptosis of immunocytes in rodents. However, the mechanism behind such cause is still unclear. To understand the model of cell death and its mechanism on lymphoid cells in vivo, we conducted a dose/response experiment in which 4 groups of male adult C57BL/6 mice (12 mice per group) were dosed daily by oral gavage with PFOS at 0, 0.0167, 0.0833, or 0.8333 mg/kg/day, yielding targeted Total Administered Dose (TAD) of 0, 1, 5, or 50 mg PFOS/kg, respectively, over 60 days. The results showed that spleen and thymus weight were significantly reduced in the highest PFOS-dose-group (TAD 50 mg PFOS/kg) compared to the control group, whereas liver weight was significantly increased. We analyzed the cell death via apoptosis with an annexin-V/propidium iodide assay by flow cytometry, and observed that both the percentage of apoptosis and the expression of the pro-apoptotic proteins p53 in splenocytes and thymocytes increased in a dose-related manner after PFOS treatment. We also observed that PFOS induced p53-dependent apoptosis through the cooperation between the Bcl-xl down regulation without changing the Bcl-2 and Bax expression. The down regulation of Bcl-xl was strongly indicating mitochondrial involvement in apoptosis. It is confirmed by the release of cytochrome c and activation of caspase-3. All of these findings establish an important role of p53 and mitochondrial function in PFOS induced toxic environment in the host. -- Highlights: ► PFOS immunotoxicity is caused by induction of apoptosis via the p53 activation. ► PFOS exposure can induce down regulation of Bcl-xl. ► Mitochondria are involved in PFOS-induced apoptosis. ► PFOS exposure can cause the release of cytochrome c and activation of caspase-3.

  11. Induction of p53-mediated apoptosis in splenocytes and thymocytes of C57BL/6 mice exposed to perfluorooctane sulfonate (PFOS)

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Guang-Hui, E-mail: ghdong@mail.cmu.edu.cn [School of Public Health, China Medical University, Shenyang 110001 (China); Wang, Jing [Department of Biostatistics, School of Public Health, Saint Louis University, Saint Louis, MO 63104 (United States); Zhang, Ying-Hua; Liu, Miao-Miao; Wang, Da [School of Public Health, China Medical University, Shenyang 110001 (China); Zheng, Li [Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Jin, Yi-He [School of Public Health, China Medical University, Shenyang 110001 (China); School of Environmental Science and Technology, Dalian University of Technology, Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, Dalian 116024 (China)

    2012-10-15

    Perfluorooctane sulfonate (PFOS) is a persistent environmental contaminant found in human and wildlife tissues. It has been reported that PFOS can cause atrophy of the immune organs and apoptosis of immunocytes in rodents. However, the mechanism behind such cause is still unclear. To understand the model of cell death and its mechanism on lymphoid cells in vivo, we conducted a dose/response experiment in which 4 groups of male adult C57BL/6 mice (12 mice per group) were dosed daily by oral gavage with PFOS at 0, 0.0167, 0.0833, or 0.8333 mg/kg/day, yielding targeted Total Administered Dose (TAD) of 0, 1, 5, or 50 mg PFOS/kg, respectively, over 60 days. The results showed that spleen and thymus weight were significantly reduced in the highest PFOS-dose-group (TAD 50 mg PFOS/kg) compared to the control group, whereas liver weight was significantly increased. We analyzed the cell death via apoptosis with an annexin-V/propidium iodide assay by flow cytometry, and observed that both the percentage of apoptosis and the expression of the pro-apoptotic proteins p53 in splenocytes and thymocytes increased in a dose-related manner after PFOS treatment. We also observed that PFOS induced p53-dependent apoptosis through the cooperation between the Bcl-xl down regulation without changing the Bcl-2 and Bax expression. The down regulation of Bcl-xl was strongly indicating mitochondrial involvement in apoptosis. It is confirmed by the release of cytochrome c and activation of caspase-3. All of these findings establish an important role of p53 and mitochondrial function in PFOS induced toxic environment in the host. -- Highlights: ► PFOS immunotoxicity is caused by induction of apoptosis via the p53 activation. ► PFOS exposure can induce down regulation of Bcl-xl. ► Mitochondria are involved in PFOS-induced apoptosis. ► PFOS exposure can cause the release of cytochrome c and activation of caspase-3.

  12. Anticancer copper(II) phosphorus dendrimers are potent proapoptotic Bax activators.

    Science.gov (United States)

    Mignani, Serge; El Brahmi, Nabil; Eloy, Laure; Poupon, Joel; Nicolas, Valérie; Steinmetz, Anke; El Kazzouli, Said; Bousmina, Mosto M; Blanchard-Desce, Mireille; Caminade, Anne-Marie; Majoral, Jean-Pierre; Cresteil, Thierry

    2017-05-26

    A multivalent phosphorus dendrimer 1G 3 and its corresponding Cu-complex, 1G 3 -Cu have been recently identified as agents retaining high antiproliferative potency. This antiproliferative capacity was preserved in cell lines overexpressing the efflux pump ABC B1, whereas cross-resistance was observed in ovarian cancer cell lines resistant to cisplatin. Theoretical 3D models were constructed: the dendrimers appear as irregularly shaped disk-like nano-objects of about 22 Å thickness and 49 Å diameter, which accumulated in cells after penetration by endocytosis. To get insight in their mode of action, cell death pathways have been examined in human cancer cell lines: early apoptosis was followed by secondary necrosis after multivalent phosphorus dendrimers exposure. The multivalent plain phosphorus dendrimer 1G 3 moderately activated caspase-3 activity, in contrast with the multivalent Cu-conjugated phosphorus dendrimer 1G 3 -Cu which strikingly reduced the caspase-3 content and activity. This decrease of caspase activity is not related to the presence of copper, since inorganic copper has no or little effect on caspase-3. Conversely the potent apoptosis activation could be related to a noticeable translocation of Bax to the mitochondria, resulting in the release of AIF into the cytosol, its translocation to the nucleus and a severe DNA fragmentation, without alteration of the cell cycle. The multivalent Cu-conjugated phosphorus dendrimer is more efficient than its non-complexed analog to activate this pathway in close relationship with the higher antiproliferative potency. Therefore, this multivalent Cu-conjugated phosphorus dendrimer 1G 3 -Cu can be considered as a new and promising first-in-class antiproliferative agent with a distinctive mode of action, inducing apoptosis tumor cell death through Bax activation pathway. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. Titanium dioxide induces apoptotic cell death through reactive oxygen species-mediated Fas upregulation and Bax activation

    Directory of Open Access Journals (Sweden)

    Yoon TH

    2012-03-01

    Full Text Available Ki-Chun Yoo1, Chang-Hwan Yoon1, Dongwook Kwon2, Kyung-Hwan Hyun1, Soo Jung Woo1, Rae-Kwon Kim1, Eun-Jung Lim1, Yongjoon Suh1, Min-Jung Kim1, Tae Hyun Yoon2, Su-Jae Lee11Laboratory of Molecular Biochemistry, 2Laboratory of Nanoscale Characterization and Environmental Chemistry, Department of Chemistry, Hanyang University, Seoul, Republic of KoreaBackground: Titanium dioxide (TiO2 has been widely used in many areas, including biomedicine, cosmetics, and environmental engineering. Recently, it has become evident that some TiO2 particles have a considerable cytotoxic effect in normal human cells. However, the molecular basis for the cytotoxicity of TiO2 has yet to be defined.Methods and results: In this study, we demonstrated that combined treatment with TiO2 nanoparticles sized less than 100 nm and ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-dependent upregulation of Fas and conformational activation of Bax in normal human cells. Treatment with P25 TiO2 nanoparticles with a hydrodynamic size distribution centered around 70 nm (TiO2P25–70 together with ultraviolet A irradiation-induced caspase-dependent apoptotic cell death, accompanied by transcriptional upregulation of the death receptor, Fas, and conformational activation of Bax. In line with these results, knockdown of either Fas or Bax with specific siRNA significantly inhibited TiO2-induced apoptotic cell death. Moreover, inhibition of reactive oxygen species with an antioxidant, N-acetyl-L-cysteine, clearly suppressed upregulation of Fas, conformational activation of Bax, and subsequent apoptotic cell death in response to combination treatment using TiO2P25–70 and ultraviolet A irradiation.Conclusion: These results indicate that sub-100 nm sized TiO2 treatment under ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-mediated upregulation of the death receptor, Fas, and activation of the preapoptotic protein

  14. A methoxyflavanone derivative from the Asian medicinal herb (Perilla frutescens) induces p53-mediated G2/M cell cycle arrest and apoptosis in A549 human lung adenocarcinoma.

    Science.gov (United States)

    Abd El-Hafeez, Amer Ali; Fujimura, Takashi; Kamei, Rikiya; Hirakawa, Noriko; Baba, Kenji; Ono, Kazuhisa; Kawamoto, Seiji

    2017-07-14

    Perilla frutescens is an Asian dietary herb consumed as an essential seasoning in Japanese cuisine as well as used for a Chinese medicine. Here, we report that a newly found methoxyflavanone derivative from P. frutescens (Perilla-derived methoxyflavanone, PDMF; 8-hydroxy-5,7-dimethoxyflavanone) shows carcinostatic activity on human lung adenocarcinoma, A549. We found that treatment with PDMF significantly inhibited cell proliferation and decreased viability through induction of G 2 /M cell cycle arrest and apoptosis. The PDMF stimulation induces phosphorylation of tumor suppressor p53 on Ser15, and increases its protein amount in conjunction with up-regulation of downstream cyclin-dependent kinase inhibitor p21 Cip1/Waf1 and proapoptotic caspases, caspase-9 and caspase-3. We also found that small interfering RNA knockdown of p53 completely abolished the PDMF-induced G 2 /M cell cycle arrest, and substantially abrogated its proapoptotic potency. These results suggest that PDMF represents a useful tumor-preventive phytochemical that triggers p53-driven G 2 /M cell cycle arrest and apoptosis.

  15. N-methylpurine DNA glycosylase inhibits p53-mediated cell cycle arrest and coordinates with p53 to determine sensitivity to alkylating agents.

    Science.gov (United States)

    Song, Shanshan; Xing, Guichun; Yuan, Lin; Wang, Jian; Wang, Shan; Yin, Yuxin; Tian, Chunyan; He, Fuchu; Zhang, Lingqiang

    2012-08-01

    Alkylating agents induce genome-wide base damage, which is repaired mainly by N-methylpurine DNA glycosylase (MPG). An elevated expression of MPG in certain types of tumor cells confers higher sensitivity to alkylation agents because MPG-induced apurinic/apyrimidic (AP) sites trigger more strand breaks. However, the determinant of drug sensitivity or insensitivity still remains unclear. Here, we report that the p53 status coordinates with MPG to play a pivotal role in such process. MPG expression is positive in breast, lung and colon cancers (38.7%, 43.4% and 25.3%, respectively) but negative in all adjacent normal tissues. MPG directly binds to the tumor suppressor p53 and represses p53 activity in unstressed cells. The overexpression of MPG reduced, whereas depletion of MPG increased, the expression levels of pro-arrest gene downstream of p53 including p21, 14-3-3σ and Gadd45 but not proapoptotic ones. The N-terminal region of MPG was specifically required for the interaction with the DNA binding domain of p53. Upon DNA alkylation stress, in p53 wild-type tumor cells, p53 dissociated from MPG and induced cell growth arrest. Then, AP sites were repaired efficiently, which led to insensitivity to alkylating agents. By contrast, in p53-mutated cells, the AP sites were repaired with low efficacy. To our knowledge, this is the first direct evidence to show that a DNA repair enzyme functions as a selective regulator of p53, and these findings provide new insights into the functional linkage between MPG and p53 in cancer therapy.

  16. Curcuma purpurascens BI. rhizome accelerates rat excisional wound healing: involvement of Hsp70/Bax proteins, antioxidant defense, and angiogenesis activity

    Science.gov (United States)

    Rouhollahi, Elham; Moghadamtousi, Soheil Zorofchian; Hajiaghaalipour, Fatemeh; Zahedifard, Maryam; Tayeby, Faezeh; Awang, Khalijah; Abdulla, Mahmood Ameen; Mohamed, Zahurin

    2015-01-01

    Purpose Curcuma purpurascens BI. is a member of Zingiberaceae family. The purpose of this study is to investigate the wound healing properties of hexane extract of C. purpurascens rhizome (HECP) against excisional wound healing in rats. Materials and methods Twenty four rats were randomly divided into 4 groups: A) negative control (blank placebo, acacia gum), B) low dose of HECP, C) high dose of HECP, and D) positive control, with 6 rats in each group. Full-thickness incisions (approximately 2.00 cm) were made on the neck area of each rat. Groups 1–4 were treated two-times a day for 20 days with blank placebo, HECP (100 mg/kg), HECP (200 mg/kg), and intrasite gel as a positive control, respectively. After 20 days, hematoxylin and eosin and Masson’s trichrome stainings were employed to investigate the histopathological alterations. Protein expressions of Bax and Hsp70 were examined in the wound tissues using immunohistochemistry analysis. In addition, levels of enzymatic antioxidants and malondialdehyde representing lipid peroxidation were measured in wound tissue homogenates. Results Macroscopic evaluation of wounds showed conspicuous elevation in wound contraction after topical administration of HECP at both doses. Moreover, histopathological analysis revealed noteworthy reduction in the scar width correlated with the enhanced collagen content and fibroblast cells, accompanied by a reduction of inflammatory cells in the granulation tissues. At the molecular level, HECP facilitates wound-healing process by downregulating Bax and upregulating Hsp70 protein at the wound site. The formation of new blood vessel was observed in Masson’s trichrome staining of wounds treated with HECP (100 and 200 mg/kg). In addition, HECP administration caused a significant surge in enzymatic antioxidant activities and a decline in lipid peroxidation. Conclusion These findings suggested that HECP accelerated wound-healing process in rats via antioxidant activity, angiogenesis

  17. IGF-1 protects against Aβ25-35-induced neuronal cell death via inhibition of PUMA expression and Bax activation.

    Science.gov (United States)

    Hou, Xunyao; Jin, Yan; Chen, Jian; Hong, Yan; Luo, Dingzhen; Yin, Qingqing; Liu, Xueping

    2017-01-10

    Amyloid-β-peptide (Aβ) is considered to be the toxic species in AD and causes cell death in the affected areas of patient's brain. Insulin-like growth factor 1 (IGF-1) has been reported to attenuate Aβ toxicity in neuronal cells. However, the molecular mechanisms involved in the neuroprotective function of IGF-1 remain largely unknown. In the present study, we for the first time demonstrated that IGF-1 protects against Aβ-induced neurotoxicity via inhibition of PUMA expression and Bax activation. We found that IGF-1 could activate Akt, which in turn inhibited Aβ-induced FOXO3a nuclear translocation and thus decreased the binding ability of FOXO3a to PUMA promoter, leading to decreased PUMA expression. In addition, IGF-1 inhibited the translocation of Bax to the mitochondria induced by Aβ. Notably, addition of wortmannin, a specific inhibitor of PI3K, significantly abolished the neuroprotective effect of IGF-1, suggesting that IGF-1 exerts its anti-apoptotic effect depend on PI3K activity. Our findings may provide new insights into molecular mechanisms mediated by IGF-1 in cell survival against Aβ-induced apoptosis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Cancer-selective death of human breast cancer cells by leelamine is mediated by bax and bak activation.

    Science.gov (United States)

    Sehrawat, Anuradha; Kim, Su-Hyeong; Hahm, Eun-Ryeong; Arlotti, Julie A; Eiseman, Julie; Shiva, Sruti S; Rigatti, Lora H; Singh, Shivendra V

    2017-02-01

    The present study is the first to report inhibition of breast cancer cell growth in vitro and in vivo and suppression of self-renewal of breast cancer stem cells (bCSC) by a pine bark component (leelamine). Except for a few recent publications in melanoma, anticancer pharmacology of this interesting phytochemical is largely elusive. Leelamine (LLM) dose-dependently inhibited viability of MDA-MB-231 (triple-negative), MCF-7 (estrogen receptor-positive), and SUM159 (triple-negative) human breast cancer cells in association with apoptotic cell death induction. To the contrary, a normal mammary epithelial cell line derived from fibrocystic breast disease and spontaneously immortalized (MCF-10A) was fully resistant to LLM-mediated cell growth inhibition and apoptosis induction. LLM also inhibited self-renewal of breast cancer stem cells. Apoptosis induction by LLM in breast cancer cells was accompanied by a modest increase in reactive oxygen species production, which was not due to inhibition of mitochondrial electron transport chain complexes. Nevertheless, ectopic expression of manganese superoxide dismutase conferred partial protection against LLM-induced cell death but only at a lower yet pharmacologically relevant concentration. Exposure of breast cancer cells to LLM resulted in (a) induction and/or activation of multidomain proapoptotic proteins Bax and Bak, (b) caspase-9 activation, and (c) cytosolic release of cytochrome c. Bax and Bak deficiency in immortalized fibroblasts conferred significant protection against cell death by LLM. Intraperitoneal administration of LLM (7.5 mg/kg; 5 times/wk) suppressed the growth of orthotopic SUM159 xenografts in mice without any toxicity. In conclusion, the present study provides critical preclinical data to warrant further investigation of LLM. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Ziyuglycoside I Inhibits the Proliferation of MDA-MB-231 Breast Carcinoma Cells through Inducing p53-Mediated G2/M Cell Cycle Arrest and Intrinsic/Extrinsic Apoptosis.

    Science.gov (United States)

    Zhu, Xue; Wang, Ke; Zhang, Kai; Zhang, Ting; Yin, Yongxiang; Xu, Fei

    2016-11-22

    Due to the aggressive clinical behavior, poor outcome, and lack of effective specific targeted therapies, triple-negative breast cancer (TNBC) has currently been recognized as one of the most malignant types of tumors. In the present study, we investigated the cytotoxic effect of ziyuglycoside I, one of the major components extracted from Chinese anti-tumor herbal Radix Sanguisorbae , on the TNBC cell line MDA-MB-231. The underlying molecular mechanism of the cytotoxic effect ziyuglycoside I on MDA-MB-231 cells was investigated with cell viability assay, flow cytometric analysis and Western blot. Compared to normal mammary gland Hs 578Bst cells, treatment of ziyuglycoside I resulted in a significant growth inhibitory effect on MDA-MB-231 cells. Ziyuglycoside I induced the G2/M phase arrest and apoptosis of MDA-MB-231 cells in a dose-dependent manner. These effects were found to be partially mediated through the up-regulation of p53 and p21 WAF1 , elevated Bax/Bcl-2 ratio, and the activation of both intrinsic (mitochondrial-initiated) and extrinsic (Fas/FasL-initiated) apoptotic pathways. Furthermore, the p53 specific siRNA attenuated these effects. Our study suggested that ziyuglycoside I-triggered MDA-MB-231 cell cycle arrest and apoptosis were probably mediated by p53. This suggests that ziyuglycoside I might be a potential drug candidate for treating TNBC.

  20. Antrodia camphorata Potentiates Neuroprotection against Cerebral Ischemia in Rats via Downregulation of iNOS/HO-1/Bax and Activated Caspase-3 and Inhibition of Hydroxyl Radical Formation

    Directory of Open Access Journals (Sweden)

    Po-Sheng Yang

    2015-01-01

    Full Text Available Antrodia camphorata (A. camphorata is a fungus generally used in Chinese folk medicine for treatment of viral hepatitis and cancer. Our previous study found A. camphorata has neuroprotective properties and could reduce stroke injury in cerebral ischemia animal models. In this study, we sought to investigate the molecular mechanisms of neuroprotective effects of A. camphorata in middle cerebral artery occlusion (MCAO rats. A selective occlusion of the middle cerebral artery (MCA with whole blood clots was used to induce ischemic stroke in rats and they were orally treated with A. camphorata (0.25 and 0.75 g/kg/day alone or combined with aspirin (5 mg/kg/day. To provide insight into the functions of A. camphorata mediated neuroprotection, the expression of Bax, inducible nitric oxide synthase (iNOS, haem oxygenase-1 (HO-1, and activated caspase-3 was determined by Western blot assay. Treatment of aspirin alone significantly reduced the expressions of HO-1 (P<0.001, iNOS (P<0.001, and Bax (P<0.01 in ischemic regions. The reduction of these expressions was more potentiated when rats treated by aspirin combined with A. camphorata (0.75 g/kg/day. Combination treatment also reduced apoptosis as measured by a significant reduction in active caspase-3 expression in the ischemic brain compared to MCAO group (P<0.01. Moreover, treatment of A. camphorata significantly (P<0.05 reduced fenton reaction-induced hydroxyl radical (OH• formation at a dose of 40 mg/mL. Taken together, A. camphorata has shown neuroprotective effects in embolic rats, and the molecular mechanisms may correlate with the downregulation of Bax, iNOS, HO-1, and activated caspase-3 and the inhibition of OH• signals.

  1. Oxcarbazepine causes neurocyte apoptosis and developing brain damage by triggering Bax/Bcl-2 signaling pathway mediated caspase 3 activation in neonatal rats.

    Science.gov (United States)

    Song, Y; Zhong, M; Cai, F-C

    2018-01-01

    Anti-epileptic drugs (AEDs) are the main methods for treatment of neonatal seizures; however, a few AEDs may cause developing brain damage of neonate. This study aims to investigate effects of oxcarbazepine (OXC) on developing brain damage of neonatal rats. Both of neonatal and adult rats were divided into 6 groups, including Control, OXC 187.5 mg/kg, OXC 281.25 mg/kg, OXC 375 mg/kg group, LEV and PHT group. Body weight and brain weight were evaluated. Hematoxylin and eosin (HE) and Nissl staining were used to observe neurocyte morphology and Nissl bodies, respectively. Apoptosis was examined using TUNEL assay, and caspase 8 activity was evaluated using spectrophotometer method. Cytochrome C-release was evaluated using flow cytometry. Western blot was used to examine Bax and Bcl-2 expression. OXC 375 mg/kg treatment significantly decreased brain weight compared to Control group in neonatal rats (P5 rats) (pOxcarbazepine at a concentration of 281.25 mg/kg or more causes neurocyte apoptosis and developing brain damage by triggering Bax/Bcl-2 signaling pathway mediated caspase 3 activation in neonatal rats.

  2. Patulin causes DNA damage leading to cell cycle arrest and apoptosis through modulation of Bax, p53 and p21/WAF1 proteins in skin of mice

    International Nuclear Information System (INIS)

    Saxena, Neha; Ansari, Kausar M.; Kumar, Rahul; Dhawan, Alok; Dwivedi, Premendra D.; Das, Mukul

    2009-01-01

    Patulin (PAT), a mycotoxin found in apples, grapes, oranges, pear and peaches, is a potent genotoxic compound. WHO has highlighted the need for the study of cutaneous toxicity of PAT as manual labour is employed during pre and post harvest stages, thereby causing direct exposure to skin. In the present study cutaneous toxicity of PAT was evaluated following topical application to Swiss Albino mice. Dermal exposure of PAT, to mice for 4 h resulted in a dose (40-160 μg/animal) and time (up to 6 h) dependent enhancement of ornithine decarboxylase (ODC), a marker enzyme of cell proliferation. The ODC activity was found to be normal after 12 and 24 h treatment of patulin. Topical application of PAT (160 μg/100 μl acetone) for 24-72 h caused (a) DNA damage in skin cells showing significant increase (34-63%) in olive tail moment, a parameter of Comet assay (b) significant G 1 and S-phase arrest along with induction of apoptosis (2.8-10 folds) as shown by annexin V and PI staining assay through flow cytometer. Moreover PAT leads to over expression of p 21/WAF1 (3.6-3.9 fold), pro apoptotic protein Bax (1.3-2.6) and tumor suppressor wild type p 53 (2.8-3.9 fold) protein. It was also shown that PAT induced apoptosis was mediated through mitochondrial intrinsic pathway as revealed through the release of cytochrome C protein in cytosol leading to enhancement of caspase-3 activity in skin cells of mice. These results suggest that PAT has a potential to induce DNA damage leading to p 53 mediated cell cycle arrest along with intrinsic pathway mediated apoptosis that may also be correlated with enhanced polyamine production as evident by induction of ODC activity, which may have dermal toxicological implications

  3. The ethanol extract of Scutellaria baicalensis and the active compounds induce cell cycle arrest and apoptosis including upregulation of p53 and Bax in human lung cancer cells

    International Nuclear Information System (INIS)

    Gao Jiayu; Morgan, Winston A.; Sanchez-Medina, Alberto; Corcoran, Olivia

    2011-01-01

    Despite a lack of scientific authentication, Scutellaria baicalensis is clinically used in Chinese medicine as a traditional adjuvant to chemotherapy of lung cancer. In this study, cytotoxicity assays demonstrated that crude ethanolic extracts of S. baicalensis were selectively toxic to human lung cancer cell lines A549, SK-LU-1 and SK-MES-1 compared with normal human lung fibroblasts. The active compounds baicalin, baicalein and wogonin did not exhibit such selectivity. Following exposure to the crude extracts, cellular protein expression in the cancer cell lines was assessed using 2D gel electrophoresis coupled with MALDI-TOF-MS/Protein Fingerprinting. The altered protein expression indicated that cell growth arrest and apoptosis were potential mechanisms of cytotoxicity. These observations were supported by PI staining cell cycle analysis using flow cytometry and Annexin-V apoptotic analysis by fluorescence microscopy of cancer cells treated with the crude extract and pure active compounds. Moreover, specific immunoblotting identification showed the decreased expression of cyclin A results in the S phase arrest of A549 whereas the G 0 /G 1 phase arrest in SK-MES-1 cells results from the decreased expression of cyclin D1. Following treatment, increased expression in the cancer cells of key proteins related to the enhancement of apoptosis was observed for p53 and Bax. These results provide further insight into the molecular mechanisms underlying the clinical use of this herb as an adjuvant to lung cancer therapy. - Research highlights: → Scutellaria baicalensis is a clinical adjuvant to lung cancer chemotherapy in China. → Scutellaria ethanol extracts selectively toxic to A549, SK-LU-1 and SK-MES-1. → Baicalin, baicalein and wogonin were toxic to all lung cancer cell lines. → Proteomics identified increased p53 and BAX in response to Scutellaria extracts.

  4. The apoptotic response in HCT116BAX-/- cancer cells becomes rapidly saturated with increasing expression of a GFP-BAX fusion protein

    International Nuclear Information System (INIS)

    Semaan, Sheila J; Nickells, Robert W

    2010-01-01

    Many chemotherapeutic agents promote tumor cell death by activating the intrinsic pathway of apoptosis. Intrinsic apoptosis involves permeabilization of the mitochondrial outer membrane and the release of cytochrome c, a process that is controlled by proteins of the BCL2 gene family. Chemoresistance is often associated with abnormalities in concentrations of BCL2 family proteins. Although stoichiometirc interactions between anti-apoptotic and BH3-only BCL2 family proteins have been well documented as affecting cell death, the association between changes in BAX concentration and intrinsic apoptosis are poorly understood. Exogenous GFP-murine Bax fusion constructs were transfected into BAX-deficient HCT116 cells. To titrate the expression of the fusion protein, GFP-BAX was cloned into a tetracycline sensitive expression cassette and cotransfected with a plasmid expressing the rtTA transcription factor into HCT116 BAX-/- cells. Linear expression of the fusion gene was induced with doxycycline and monitored by quantitative PCR and immunoblotting. Cell death was assayed by DAPI staining cells after exposure to indomethacin, and scoring nuclei for condensed chromatin and fragmented nuclei. HCT116 BAX-/- cells were resistant to indomethacin, but susceptibility could be recovered in cells expressing a GFP-BAX fusion protein. Titration of GFP-BAX expression revealed that the concentration of BAX required to induce a saturating apoptosis response from baseline, was rapidly achieved. Increased levels of GFP-BAX were unable to stimulate higher levels of cell death. Examination of GFP-BAX distribution before and after indomethacin treatment indicated that BAX protein did not form aggregates when present at sub-lethal concentrations. Within the limitations of this experimental system, BAX-dependent apoptosis in HCT116 cells exhibits an all-or-none response depending on the level of BAX protein present. The lack of BAX aggregation at sub-saturation levels suggests that the

  5. The apoptotic response in HCT116BAX-/- cancer cells becomes rapidly saturated with increasing expression of a GFP-BAX fusion protein

    Directory of Open Access Journals (Sweden)

    Semaan Sheila J

    2010-10-01

    Full Text Available Abstract Background Many chemotherapeutic agents promote tumor cell death by activating the intrinsic pathway of apoptosis. Intrinsic apoptosis involves permeabilization of the mitochondrial outer membrane and the release of cytochrome c, a process that is controlled by proteins of the BCL2 gene family. Chemoresistance is often associated with abnormalities in concentrations of BCL2 family proteins. Although stoichiometirc interactions between anti-apoptotic and BH3-only BCL2 family proteins have been well documented as affecting cell death, the association between changes in BAX concentration and intrinsic apoptosis are poorly understood. Methods Exogenous GFP-murine Bax fusion constructs were transfected into BAX-deficient HCT116 cells. To titrate the expression of the fusion protein, GFP-BAX was cloned into a tetracycline sensitive expression cassette and cotransfected with a plasmid expressing the rtTA transcription factor into HCT116BAX-/- cells. Linear expression of the fusion gene was induced with doxycycline and monitored by quantitative PCR and immunoblotting. Cell death was assayed by DAPI staining cells after exposure to indomethacin, and scoring nuclei for condensed chromatin and fragmented nuclei. Results HCT116BAX-/- cells were resistant to indomethacin, but susceptibility could be recovered in cells expressing a GFP-BAX fusion protein. Titration of GFP-BAX expression revealed that the concentration of BAX required to induce a saturating apoptosis response from baseline, was rapidly achieved. Increased levels of GFP-BAX were unable to stimulate higher levels of cell death. Examination of GFP-BAX distribution before and after indomethacin treatment indicated that BAX protein did not form aggregates when present at sub-lethal concentrations. Conclusion Within the limitations of this experimental system, BAX-dependent apoptosis in HCT116 cells exhibits an all-or-none response depending on the level of BAX protein present. The lack of

  6. Ginsenoside Rh2 Induces Human Hepatoma Cell Apoptosisvia Bax/Bak Triggered Cytochrome C Release and Caspase-9/Caspase-8 Activation

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    Xiao-Xi Guo

    2012-11-01

    Full Text Available Ginsenoside Rh2 (G-Rh2 has been shown to induce apoptotic cell death in a variety of cancer cells. However, the details of the signal transduction cascade involved in G-Rh2-induced cell death is unclear. In this manuscript we elucidate the molecular mechanism of G-Rh2-induced apoptosis in human hepatoma SK-HEP-1 cells by demonstrating that G-Rh2 causes rapid and dramatic translocation of both Bak and Bax, which subsequently triggers mitochondrial cytochrome c release and consequent caspase activation. Interestingly, siRNA-based gene inactivation of caspase-8 effectively delays caspase-9 activation and apoptosis induced by G-Rh2, indicating that caspase-8 also plays an important role in the G-Rh2-induced apoptosis program. Taken together, our results indicate that G-Rh2 employs a multi pro-apoptotic pathway to execute cancer cell death, suggesting a potential role for G-Rh2 as a powerful chemotherapeutic agent.

  7. Silver Nanoparticles Biosynthesized Using Achillea biebersteinii Flower Extract: Apoptosis Induction in MCF-7 Cells via Caspase Activation and Regulation of Bax and Bcl-2 Gene Expression

    Directory of Open Access Journals (Sweden)

    Javad Baharara

    2015-02-01

    Full Text Available Silver nanoparticles (Ag-NPs, the most popular nanoparticles, possess unique properties. Achillea biebersteinii is a plant of the Asteraceae family rich in active antitumor components. The aim of this research was the characterization and investigation of the cytotoxic properties of Ag-NPs synthesized using A. biebersteinii flower extract, on a human breast cancer cell line. The Ag-NPs were synthesized after approximately 180 min of reaction at 40 °C, then they were characterized by UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR, transmission electron microscopy (TEM and dynamic light scattering (DLS. The anti-apoptosis effect of Ag-NPs on the MCF-7 cell line was investigated by MTT assay, DAPI and acridine orange staining and caspase activity. The transcriptional expression of bax, bcl-2, caspase-3, -8 and -9 were also evaluated by RT-PCR. The TEM images revealed that the Ag-NPs morphology had a different shape. The DLS indicated that the average hydrodynamic diameter of the biosynthesized Ag-NPs was around 12 nm. By UV-visible spectroscopy the strongest absorbance peak was observed at 460 nm. The FTIR results also showed interaction between the plant extract and Ag-NPs due to the similarity in the peak patterns. The EDS results showed that Ag-NPs display an absorption peak at 3 keV, indicating the presence of the element silver. The Ag-NPs caused a dose-dependent decrease in cell viability, fragmentation in nucleic acid, inhibited the proliferation and induction of apoptosis on MCF-7 by suppressing specific cell cycle genes, and simulation programmed cell dead genes. Further investigation is required to establish the potential of this novel and promising approach in cancer therapy.

  8. Estrous cycle dependent changes in expression and distribution of Fas, Fas ligand, Bcl-2, Bax, and pro- and active caspase-3 in the rat ovary

    NARCIS (Netherlands)

    Slot, K.A.; Voorendt, M.; Boer-Brouwer, de M.; Vugt, van H.H.; Teerds, K.J.

    2006-01-01

    In the present investigation, the localization of proteins involved in ovarian apoptosis were studied throughout the estrous cycle in the presence of fluctuating hormone levels. Fas, Fas ligand, Bcl-2, Bax and caspase-3 mRNA expression and proteins were detected in all ovarian tissue extracts,

  9. A novel plant glutathione S-transferase/peroxidase suppresses Bax lethality in yeast

    DEFF Research Database (Denmark)

    Kampranis, S C; Damianova, R; Atallah, M

    2000-01-01

    The mammalian inducer of apoptosis Bax is lethal when expressed in yeast and plant cells. To identify potential inhibitors of Bax in plants we transformed yeast cells expressing Bax with a tomato cDNA library and we selected for cells surviving after the induction of Bax. This genetic screen allows...... for the identification of plant genes, which inhibit either directly or indirectly the lethal phenotype of Bax. Using this method a number of cDNA clones were isolated, the more potent of which encodes a protein homologous to the class theta glutathione S-transferases. This Bax-inhibiting (BI) protein was expressed...... in Escherichia coli and found to possess glutathione S-transferase (GST) and weak glutathione peroxidase (GPX) activity. Expression of Bax in yeast decreases the intracellular levels of total glutathione, causes a substantial reduction of total cellular phospholipids, diminishes the mitochondrial membrane...

  10. Expression of Bcl-2 and Bax in extrahepatic biliary tract carcinoma and dysplasia

    Science.gov (United States)

    Li, Sheng-Mian; Yao, Shu-Kun; Yamamura, Nobuyoshi; Nakamura, Toshitsugu

    2003-01-01

    AIM: To compare the difference of expression of Bcl-2 and Bax in extrahepatic biliary tract carcinoma and dysplasia, and to analyze the role of Bcl-2 and Bax proteins in the progression from dysplasia to carcinoma and to evaluate the correlation of Bcl-2/Bax protein expression with the biological behaviors. METHODS: Expressions of Bcl-2 and Bax were examined immunohistochemically in 27 cases of extrahepatic biliary tract carcinomas (bile duct carcinoma: n = 21, carcinoma of ampulla of Vater: n = 6), and 10 cases of atypical dysplasia. Five cases of normal biliary epithelial tissues were used as controls. A semiquantitative scoring system was used to assess the Bcl-2 and Bax reactivity. RESULTS: The expression of Bcl-2 was observed in 10 out of 27 (37.0%) invasive carcinomas, 1 out of 10 dysplasias, none out of 5 normal epithelial tissues. Bax expression rate was 74.1% (20/27) in invasive carcinoma, 30% (3/10) in dysplasia, and 40% (2/5) in normal biliary epithelium. Bcl-2 and Bax activities were more intense in carcinoma than in dysplasia, with no significant difference in Bcl-2 expression (P = 0.110), and significant difference in Bax expression (P = 0.038). Level of Bax expression was higher in invasive carcinoma than in dysplasia and normal tissue (P = 0.012). Bcl-2 expression was correlated to Bax expression (P = 0.0059). However, Bcl-2/Bax expression had no correlation with histological subtype, grade of differentiation, or level of invasion. CONCLUSION: Increased Bcl-2/Bax expression from dysplasia to invasive tumors supports the view that this is the usual route for the development of extrahepatic biliary tract carcinoma. Bcl-2/Bax may be involved, at least in part, in the apoptotic activity in extrahepatic biliary carcinoma. PMID:14606101

  11. Prognostic value of TP53 transcriptional activity on p21 and bax in patients with esophageal squamous cell carcinomas treated by definitive chemoradiotherapy

    International Nuclear Information System (INIS)

    Michel, Pierre; Magois, Karine; Robert, Valerie; Chiron, Anne; Lepessot, Florence; Bodenant, Corinne; Roque, Isabelle; Seng, Sok H.; Frebourg, Thierry; Paillot, Bernard

    2002-01-01

    Purpose: The aim of this study was to evaluate biologic factors on survival and clinical response after definitive concomitant chemoradiotherapy (CRT) in patients with esophageal squamous cell carcinoma (ESCC). Methods and Materials: TP53 protein hyperexpression (immunochemistry [IHC]) and functional assay (FA) of TP53, measuring the ability of TP53 to transactivate p21 and bax reporter systems, were performed in patients with ESCC treated by CRT. The impact of parameters studied on survival and clinical response to CRT was assessed. Results: Thirty-eight patients with ESCC were included. TP53 alterations were detected in 84.2% of cases with FA. All TP53 mutations abolished the transactivation of p21 and bax reporter systems. After CRT, complete response rate was 55.3%. The median survival of the population was 17.5 months. Serum albumin (p=0.002), weight loss <10% (p=0.005), and response to treatment (p<0.001) were significantly linked with survival. TP53 alteration in FA was not significantly predictive of response to CRT (p=0.132) nor survival (p=0.154). Conclusions: Our results suggest that wild-type TP53 in ESCC could be associated with good response to definitive CRT. However, the small rate of ESCC with wild-type TP53 suggests that systematic determination of TP53 status is not appropriate for the management of the ESCC population

  12. 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.

  13. 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

  14. Bax regulates neuronal Ca2+ homeostasis.

    Science.gov (United States)

    D'Orsi, Beatrice; Kilbride, Seán M; Chen, Gang; Perez Alvarez, Sergio; Bonner, Helena P; Pfeiffer, Shona; Plesnila, Nikolaus; Engel, Tobias; Henshall, David C; Düssmann, Heiko; Prehn, Jochen H M

    2015-01-28

    Excessive Ca(2+) entry during glutamate receptor overactivation ("excitotoxicity") induces acute or delayed neuronal death. We report here that deficiency in bax exerted broad neuroprotection against excitotoxic injury and oxygen/glucose deprivation in mouse neocortical neuron cultures and reduced infarct size, necrotic injury, and cerebral edema formation after middle cerebral artery occlusion in mice. Neuronal Ca(2+) and mitochondrial membrane potential (Δψm) analysis during excitotoxic injury revealed that bax-deficient neurons showed significantly reduced Ca(2+) transients during the NMDA excitation period and did not exhibit the deregulation of Δψm that was observed in their wild-type (WT) counterparts. Reintroduction of bax or a bax mutant incapable of proapoptotic oligomerization equally restored neuronal Ca(2+) dynamics during NMDA excitation, suggesting that Bax controlled Ca(2+) signaling independently of its role in apoptosis execution. Quantitative confocal imaging of intracellular ATP or mitochondrial Ca(2+) levels using FRET-based sensors indicated that the effects of bax deficiency on Ca(2+) handling were not due to enhanced cellular bioenergetics or increased Ca(2+) uptake into mitochondria. We also observed that mitochondria isolated from WT or bax-deficient cells similarly underwent Ca(2+)-induced permeability transition. However, when Ca(2+) uptake into the sarco/endoplasmic reticulum was blocked with the Ca(2+)-ATPase inhibitor thapsigargin, bax-deficient neurons showed strongly elevated cytosolic Ca(2+) levels during NMDA excitation, suggesting that the ability of Bax to support dynamic ER Ca(2+) handling is critical for cell death signaling during periods of neuronal overexcitation. Copyright © 2015 the authors 0270-6474/15/351706-17$15.00/0.

  15. Andrographolide reversed 5-FU resistance in human colorectal cancer by elevating BAX expression.

    Science.gov (United States)

    Wang, Weicheng; Guo, Wenjie; Li, Lele; Fu, Zan; Liu, Wen; Gao, Jian; Shu, Yongqian; Xu, Qiang; Sun, Yang; Gu, Yanhong

    2016-12-01

    5-FU is the first line therapy for colorectal cancer, however, treatment effect is often hampered by the development of drug resistance or toxicity at high doses. Andrographolide is a natural diterpenoid from Andrographis paniculata which has anti-bacterial, anti-antiviral and anti-inflammation activities. In the current study, we test the hypothesis that Andrographolide reverses 5-FU resistance in colorectal cancer and examine the underlying mechanism. In vitro and vivo studies indicated that Andrographolide treatment significantly re-sensitizes HCT116/5-FUR cells (HCT116 cells which are 5-FU resistant) to cytotoxicity of 5-FU. Mechanism analysis showed that Andrographolide/5-FU co-treatment elevated apoptosis level of HCT116/5-FUR cells with highly increased level of BAX. By using biotin-Andrographolide pull down and cellular thermal shift assay, we found out that Andrographolide can directly target to BAX. Andrographolide-BAX interaction prevented BAX degradation, enhancing mitochondria-mediated apoptosis thus reversed 5-FU resistance while BAX silence diminished this effect. Further, by analyzing patient samples who received 5-FU involved chemotherapy, we found that expression level of BAX is correlated with PFS. Our results here provide a novel combination treatment strategy, especially for patients with 5-FU-resistant tumors expressing low level of BAX. Meanwhile, we also proposed that BAX expression may be a predicted and prognosis marker of 5-FU involved chemotherapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Identification of Bax-Interacting Proteins in Oligodendrocyte Progenitors during Glutamate Excitotoxicity and Perinatal Hypoxia–Ischemia

    Directory of Open Access Journals (Sweden)

    Sopio Simonishvili

    2013-11-01

    Full Text Available OPC (oligodendrocyte progenitor cell death contributes significantly to the pathology and functional deficits following hypoxic-ischemic injury in the immature brain and to deficits resulting from demyelinating diseases, trauma and degenerative disorders in the adult CNS. Glutamate toxicity is a major cause of oligodendroglial death in diverse CNS disorders, and previous studies have demonstrated that AMPA/kainate receptors require the pro-apoptotic protein Bax in OPCs undergoing apoptosis. The goal of the present study was to define the pro-apoptotic and anti-apoptotic effectors that regulate Bax in healthy OPCs and after exposure to excess glutamate in vitro and following H–I (hypoxia–ischemia in the immature rat brain. We show that Bax associates with a truncated form of Bid, a BH3-only domain protein, subsequent to glutamate treatment. Furthermore, glutamate exposure reduces Bax association with the anti-apoptotic Bcl family member, Bcl-xL. Cell fractionation studies demonstrated that both Bax and Bid translocate from the cytoplasm to mitochondria during the early stages of cell death consistent with a role for Bid as an activator, whereas Bcl-xL, which normally complexes with both Bax and Bid, disassociates from these complexes when OPCs are exposed to excess glutamate. Bax remained unactivated in the presence of insulin-like growth factor-1, and the Bcl-xL complexes were protected. Our data similarly demonstrate loss of Bcl-xL–Bax association in white matter following H–I and implicate active Bad in Bax-mediated OPC death. To identify other Bax-binding partners, we used proteomics and identified cofilin as a Bax-associated protein in OPCs. Cofilin and Bax associated in healthy OPCs, whereas the Bax–cofilin association was disrupted during glutamate-induced OPC apoptosis.

  17. BAX protein expression and clinical outcome in epithelial ovarian cancer.

    Science.gov (United States)

    Tai, Y T; Lee, S; Niloff, E; Weisman, C; Strobel, T; Cannistra, S A

    1998-08-01

    Expression of the pro-apoptotic protein BAX sensitizes ovarian cancer cell lines to paclitaxel in vitro by enhancing the pathway of programmed cell death. The present study was performed to determine the relationship between BAX expression and clinical outcome in 45 patients with newly diagnosed ovarian cancer. BAX protein expression was analyzed by immunohistochemistry, and its relationship with clinical outcome was determined. Assessment of BAX mRNA transcript levels and mutational analysis of the BAX coding region were also performed. BAX protein was expressed at high levels (defined as > or = 50% of tumor cells positive) in tumor tissue from 60% of newly diagnosed patients. All patients whose tumors expressed high levels of BAX achieved a complete response (CR) to first-line chemotherapy that contained paclitaxel plus a platinum analogue, compared with 57% of patients in the low-BAX group (P = .036). After a median follow-up of 1.9 years, the median disease-free survival (DFS) of patients in the high-BAX group has not been reached, compared with a median DFS of 1.1 years for low-BAX expressors (P = .0061). BAX retained independent prognostic significance in multivariate analysis when corrected for stage and histology. BAX mRNA transcripts were easily detected in samples with low BAX protein expression, and no BAX mutations were identified. The correlation between high BAX levels and improved clinical outcome suggests that an intact apoptotic pathway is an important determinant of chemoresponsiveness in ovarian cancer patients who receive paclitaxel.

  18. All-trans retinoic acid inhibits KIT activity and induces apoptosis in gastrointestinal stromal tumor GIST-T1 cell line by affecting on the expression of survivin and Bax protein

    Directory of Open Access Journals (Sweden)

    Taguchi Takahiro

    2010-12-01

    Full Text Available Abstract Background Imatinib, a selective tyrosine kinase inhibitor, has been used as a standard first-line therapy for irresectable and metastasized gastrointestinal stromal tumor (GIST patients. Unfortunately, most patients responding to imatinib will eventually exhibit imatinib-resistance, the cause of which is not fully understood. The serious clinical problem of imatinib-resistance demands alternative therapeutic strategy. This study was conducted to investigate the effect of all-trans retinoic acid (ATRA on GIST cell lines. Methods Cell proliferation was determined by trypan blue dye exclusion test. Western blot analysis was performed to test the expression of activated KIT, its downstream proteins, and apoptosis associated proteins. The cytotoxic interactions of imatinib with ATRA were evaluated using the isobologram of Steel and Peckham. Results and conclusion In this work, for the first time we have demonstrated that ATRA affected on cell proliferation of GIST-T1 and GIST-882 cell line through inhibition of cell growth in a dose dependent manner and induced apoptosis. High dose of ATRA induced morphologic change in GIST-T1 cells, rounded-up cells, and activated the caspase-3 protein. In further examination, we found that the ATRA-induced apoptosis in GIST-T1 cells was accompanied by the down-regulated expression of survivin and up-regulated expression of Bax protein. Moreover, ATRA suppressed the activity of KIT protein in GIST-T1 cells and its downstream signal, AKT activity, but not MAPK activity. We also have demonstrated that combination of ATRA with imatinib showed additive effect by isobologram, suggesting that the combination of ATRA and imatinib may be a novel potential therapeutic option for GIST treatment. Furthermore, the scracht assay result suggested that ATRA was a potential reagent to prevent the invasion or metastasis of GIST cells.

  19. Increases in apoptosis, caspase activity and expression of p53 and bax, and the transition between two types of mitochondrion-rich cells, in the gills of the climbing perch, Anabas testudineus, during a progressive acclimation from freshwater to seawater

    Science.gov (United States)

    Ching, Biyun; Chen, Xiu L.; Yong, Jing H. A.; Wilson, Jonathan M.; Hiong, Kum C.; Sim, Eugene W. L.; Wong, Wai P.; Lam, Siew H.; Chew, Shit F.; Ip, Yuen K.

    2013-01-01

    This study aimed to test the hypothesis that branchial osmoregulatory acclimation involved increased apoptosis and replacement of mitochdonrion-rich cells (MRCs) in the climbing perch, Anabas testudineus, during a progressive acclimation from freshwater to seawater. A significant increase in branchial caspase-3/-7 activity was observed on day 4 (salinity 20), and an extensive TUNEL-positive apoptosis was detected on day 5 (salinity 25), indicating salinity-induced apoptosis had occurred. This was further supported by an up-regulation of branchial mRNA expression of p53, a key regulator of cell cycle arrest and apoptosis, between day 2 (salinity 10) and day 6 (seawater), and an increase in branchial p53 protein abundance on day 6. Seawater acclimation apparently activated both the extrinsic and intrinsic pathways, as reflected by significant increases in branchial caspase-8 and caspase-9 activities. The involvement of the intrinsic pathway was confirmed by the significant increase in branchial mRNA expression of bax between day 4 (salinity 20) and day 6 (seawater). Western blotting results revealed the presence of a freshwater Na+/K+-ATPase (Nka) α-isoform, Nka α1a, and a seawater isoform, Nka α1b, the protein abundance of which decreased and increased, respectively, during seawater acclimation. Immunofluorescence microscopy revealed the presence of two types of MRCs distinctly different in sizes, and confirmed that the reduction in Nka α1a expression, and the prominent increases in expression of Nka α1b, Na+:K+:2Cl− cotransporter 1, and cystic fibrosis transmembrane conductance regulator Cl− channel coincided with the salinity-induced apoptotic event. Since modulation of existing MRCs alone could not have led to extensive salinity-induced apoptosis, it is probable that some, if not all, freshwater-type MRCs could have been removed through increased apoptosis and subsequently replaced by seawater-type MRCs in the gills of A. testudineus during seawater

  20. Cycloheximide Can Induce Bax/Bak Dependent Myeloid Cell Death Independently of Multiple BH3-Only Proteins.

    Directory of Open Access Journals (Sweden)

    Katharine J Goodall

    Full Text Available Apoptosis mediated by Bax or Bak is usually thought to be triggered by BH3-only members of the Bcl-2 protein family. BH3-only proteins can directly bind to and activate Bax or Bak, or indirectly activate them by binding to anti-apoptotic Bcl-2 family members, thereby relieving their inhibition of Bax and Bak. Here we describe a third way of activation of Bax/Bak dependent apoptosis that does not require triggering by multiple BH3-only proteins. In factor dependent myeloid (FDM cell lines, cycloheximide induced apoptosis by a Bax/Bak dependent mechanism, because Bax-/-Bak-/- lines were profoundly resistant, whereas FDM lines lacking one or more genes for BH3-only proteins remained highly sensitive. Addition of cycloheximide led to the rapid loss of Mcl-1 but did not affect the expression of other Bcl-2 family proteins. In support of these findings, similar results were observed by treating FDM cells with the CDK inhibitor, roscovitine. Roscovitine reduced Mcl-1 abundance and caused Bax/Bak dependent cell death, yet FDM lines lacking one or more genes for BH3-only proteins remained highly sensitive. Therefore Bax/Bak dependent apoptosis can be regulated by the abundance of anti-apoptotic Bcl-2 family members such as Mcl-1, independently of several known BH3-only proteins.

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

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    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.

  2. A Single Nucleotide Polymorphism in the Bax Gene Promoter Affects Transcription and Influences Retinal Ganglion Cell Death

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    Sheila J Semaan

    2010-03-01

    Full Text Available Pro-apoptotic Bax is essential for RGC (retinal ganglion cell death. Gene dosage experiments in mice, yielding a single wild-type Bax allele, indicated that genetic background was able to influence the cell death phenotype. DBA/2J Bax+/− mice exhibited complete resistance to nerve damage after 2 weeks (similar to Bax −/− mice, but 129B6 Bax+/− mice exhibited significant cell loss (similar to wild-type mice. The different cell death phenotype was associated with the level of Bax expression, where 129B6 neurons had twice the level of endogenous Bax mRNA and protein as DBA/2J neurons. Sequence analysis of the Bax promoters between these strains revealed a single nucleotide polymorphism (T129B6 to CDBA/2J at position −515. A 1.5- to 2.5-fold increase in transcriptional activity was observed from the 129B6 promoter in transient transfection assays in a variety of cell types, including RGC5 cells derived from rat RGCs. Since this polymorphism occurred in a p53 half-site, we investigated the requirement of p53 for the differential transcriptional activity. Differential transcriptional activity from either 129B6 or DBA/2J Bax promoters were unaffected in p53−/− cells, and addition of exogenous p53 had no further effect on this difference, thus a role for p53 was excluded. Competitive electrophoretic mobility-shift assays identified two DNA-protein complexes that interacted with the polymorphic region. Those forming Complex 1 bound with higher affinity to the 129B6 polymorphic site, suggesting that these proteins probably comprised a transcriptional activator complex. These studies implicated quantitative expression of the Bax gene as playing a possible role in neuronal susceptibility to damaging stimuli.

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

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    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. The associated expression of Maspin and Bax proteins as a potential prognostic factor in intrahepatic cholangiocarcinoma

    International Nuclear Information System (INIS)

    Romani, Antonello A; Soliani, Paolo; Desenzani, Silvia; Borghetti, Angelo F; Crafa, Pellegrino

    2006-01-01

    Maspin, a member of the serpin family, is a suppressor of tumor growth, an inhibitor of angiogenesis and an inducer of apoptosis. Maspin induces apoptosis by increasing Bax, a member of the Bcl-2 family of apoptosis-regulating proteins. In this exploratory study, we investigated the associated expression of Maspin and Bax proteins as a potential prognostic factor in intrahepatic cholangiocarcinoma (IHCCA). Twenty-two paraffin-embedded samples were analyzed by immunohistochemical methods using Maspin, Bax and CD34 antibodies. Maspin was scored semiquantitatively (HSCORE). Apoptosis was assessed using an antibody against cleaved caspase-3. The strong relationship observed between the expression of Maspin and Bax, indicates that Bax is likely to be the key effector of Maspin-mediated induction of apoptosis as indicated by the activation of cleaved caspase-3. We categorized Maspin HSCORE by calculating the optimal cutpoint. A Maspin HSCORE above the cutpoint was inversely related with tumor dimension, depth of tumor and vascular invasion. Uni/multivariate analysis suggests that a Maspin HSCORE below the cutpoint significantly worsens the patients' prognosis. Tumors with Maspin HSCORE below the cutpoint had a shorter survival (11+/-5 months) than did patients with Maspin HSCORE above the cutpoint (27+/-4 months), whereas Kaplan-Meier analysis and logrank test showed no significant difference in overall survival between the patients. The associated expression of Maspin and Bax might delay tumor progression in IHCCA. Maspin above the cutpoint might counteract tumor development by increasing cell apoptosis, and by decreasing tumor mass and cell invasion. The combined expression of Maspin and Bax appears to influence the susceptibility of tumor cholangiocytes to apoptosis and thus may be involved in delaying IHCCA progression

  5. The p53-mediated cytotoxicity of photodynamic therapy of cancer: Recent advances

    International Nuclear Information System (INIS)

    Zawacka-Pankau, Joanna; Krachulec, Justyna; Grulkowski, Ireneusz; Bielawski, Krzysztof P.; Selivanova, Galina

    2008-01-01

    Photodynamic therapy (PDT) is a promising modality for the treatment of both pre-malignant and malignant lesions. The mechanism of action converges mainly on the generation of reactive oxygen species which damage cancer cells directly as well as indirectly acting on tumor vasculature. The exact mechanism of PDT action is not fully understood, which is a formidable barrier to its successful clinical application. Elucidation of the mechanisms of cancer cell elimination by PDT might help in establishing highly specific, non-genotoxic anti-cancer treatment of tomorrow. One of the candidate PDT targets is the well-known tumor suppressor p53 protein recognized as the guardian of the genome. Together with its family members, p73 and p63 proteins, p53 is involved in apoptosis induction upon stress stimuli. The wild-type and mutant p53-targeting chemotherapeutics are currently extensively investigated as a promising strategy for highly specific anti-cancer therapy. In photodynamic therapy porphyrinogenic sensitizers are the most widely used compounds due to their potent biophysical and biochemical properties. Recent data suggest that the p53 tumor suppressor protein might play a significant role in porphyrin-PDT-mediated cell death by direct interaction with the drug which leads to its accumulation and induction of p53-dependent cell death both in the dark and upon irradiation. In this review we describe the available evidence on the role of p53 in PDT

  6. P53-mediated rapid induction of apoptosis conveys resistance to viral infection in Drosophila melanogaster

    Science.gov (United States)

    Arthropod-borne pathogens account for millions of deaths each year. Understanding the genetic mechanisms controlling vector susceptibility to pathogens has profound implications for developing novel strategies for controlling insect transmitted infectious diseases. The fact that many viruses carry...

  7. Loss of anti-Bax function in Gerstmann-Sträussler-Scheinker syndrome-associated prion protein mutants.

    Directory of Open Access Journals (Sweden)

    Julie Jodoin

    2009-08-01

    Full Text Available Previously, we have shown the loss of anti-Bax function in Creutzfeldt Jakob disease (CJD-associated prion protein (PrP mutants that are unable to generate cytosolic PrP (CyPrP. To determine if the anti-Bax function of PrP modulates the manifestation of prion diseases, we further investigated the anti-Bax function of eight familial Gerstmann-Sträussler-Scheinker Syndrome (GSS-associated PrP mutants. These PrP mutants contained their respective methionine ((M or valine ((V at codon 129. All of the mutants lost their ability to prevent Bax-mediated chromatin condensation or DNA fragmentation in primary human neurons. In the breast carcinoma MCF-7 cells, the F198S(V, D202N(V, P102L(V and Q217R(V retained, whereas the P102L(M, P105L(V, Y145stop(M and Q212P(M PrP mutants lost their ability to inhibit Bax-mediated condensed chromatin. The inhibition of Bax-mediated condensed chromatin depended on the ability of the mutants to generate cytosolic PrP. However, except for the P102L(V, none of the mutants significantly inhibited Bax-mediated caspase activation. These results show that the cytosolic PrP generated from the GSS mutants is not as efficient as wild type PrP in inhibiting Bax-mediated cell death. Furthermore, these results indicate that the anti-Bax function is also disrupted in GSS-associated PrP mutants and is not associated with the difference between CJD and GSS.

  8. A BAX/BAK and cyclophilin D-independent intrinsic apoptosis pathway.

    Directory of Open Access Journals (Sweden)

    Sebastián Zamorano

    Full Text Available Most intrinsic death signals converge into the activation of pro-apoptotic BCL-2 family members BAX and BAK at the mitochondria, resulting in the release of cytochrome c and apoptosome activation. Chronic endoplasmic reticulum (ER stress leads to apoptosis through the upregulation of a subset of pro-apoptotic BH3-only proteins, activating BAX and BAK at the mitochondria. Here we provide evidence indicating that the full resistance of BAX and BAK double deficient (DKO cells to ER stress is reverted by stimulation in combination with mild serum withdrawal. Cell death under these conditions was characterized by the appearance of classical apoptosis markers, caspase-9 activation, release of cytochrome c, and was inhibited by knocking down caspase-9, but insensitive to BCL-X(L overexpression. Similarly, the resistance of BIM and PUMA double deficient cells to ER stress was reverted by mild serum withdrawal. Surprisingly, BAX/BAK-independent cell death did not require Cyclophilin D (CypD expression, an important regulator of the mitochondrial permeability transition pore. Our results suggest the existence of an alternative intrinsic apoptosis pathway emerging from a cross talk between the ER and the mitochondria.

  9. APAF1 is a key transcriptional target for p53 in the regulation of neuronal cell death

    DEFF Research Database (Denmark)

    Fortin, A; Cregan, S P; MacLaurin, J G

    2001-01-01

    p53 is a transcriptional activator which has been implicated as a key regulator of neuronal cell death after acute injury. We have shown previously that p53-mediated neuronal cell death involves a Bax-dependent activation of caspase 3; however, the transcriptional targets involved in the regulati...

  10. 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

  11. Proapoptotic Bak and Bax guard against fatal systemic and organ-specific autoimmune disease

    Science.gov (United States)

    Mason, Kylie D.; Lin, Ann; Robb, Lorraine; Josefsson, Emma C.; Henley, Katya J.; Gray, Daniel H. D.; Kile, Benjamin T.; Roberts, Andrew W.; Strasser, Andreas; Huang, David C. S.; Waring, Paul; O’Reilly, Lorraine A.

    2013-01-01

    Dysregulation of the “intrinsic” apoptotic pathway is associated with the development of cancer and autoimmune disease. Bak and Bax are two proapoptotic members of the Bcl-2 protein family with overlapping, essential roles in the intrinsic apoptotic pathway. Their activity is critical for the control of cell survival during lymphocyte development and homeostasis, best demonstrated by defects in thymic T-cell differentiation and peripheral lymphoid homeostasis caused by their combined loss. Because most bak−/−bax−/− mice die perinatally, the roles of Bax and Bak in immunological tolerance and prevention of autoimmune disease remain unclear. We show that mice reconstituted with a Bak/Bax doubly deficient hematopoietic compartment develop a fatal systemic lupus erythematosus-like autoimmune disease characterized by hypergammaglobulinemia, autoantibodies, lymphadenopathy, glomerulonephritis, and vasculitis. Importantly, these mice also develop a multiorgan autoimmune disease with autoantibodies against most solid glandular structures and evidence of glandular atrophy and necrotizing vasculitis. Interestingly, similar albeit less severe pathology was observed in mice containing a hematopoietic compartment deficient for only Bak, a phenotype reminiscent of the disease seen in patients with point mutations in BAK. These studies demonstrate a critical role for Bak and an ancillary role for Bax in safeguarding immunological tolerance and prevention of autoimmune disease. This suggests that direct activators of the intrinsic apoptotic pathway, such as BH3 mimetics, may be useful for treatment of diverse autoimmune diseases. PMID:23349374

  12. WNT signaling controls expression of pro-apoptotic BOK and BAX in intestinal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zeilstra, Jurrit; Joosten, Sander P.J. [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Wensveen, Felix M. [Department of Experimental Immunology, Academic Medical Center, Amsterdam (Netherlands); Dessing, Mark C.; Schuetze, Denise M. [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Eldering, Eric [Department of Experimental Immunology, Academic Medical Center, Amsterdam (Netherlands); Spaargaren, Marcel [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Pals, Steven T., E-mail: s.t.pals@amc.uva.nl [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands)

    2011-03-04

    Research highlights: {yields} Intestinal adenomas initiated by aberrant activation of the WNT pathway displayed an increased sensitivity to apoptosis. {yields} Expression profiling of apoptosis-related genes in Apc{sup Min/+} mice revealed the differential expression of pro-apoptotic Bok and Bax. {yields} APC-mutant adenomatous crypts in FAP patients showed strongly increased BAX immunoreactivity. {yields} Blocking of {beta}-catenin/TCF-4-mediated signaling in colon cancer cells reduced the expression of BOK and BAX. -- Abstract: In a majority of cases, colorectal cancer is initiated by aberrant activation of the WNT signaling pathway. Mutation of the genes encoding the WNT signaling components adenomatous polyposis coli or {beta}-catenin causes constitutively active {beta}-catenin/TCF-mediated transcription, driving the transformation of intestinal crypts to cancer precursor lesions, called dysplastic aberrant crypt foci. Deregulated apoptosis is a hallmark of adenomatous colon tissue. However, the contribution of WNT signaling to this process is not fully understood. We addressed this role by analyzing the rate of epithelial apoptosis in aberrant crypts and adenomas of the Apc{sup Min/+} mouse model. In comparison with normal crypts and adenomas, aberrant crypts displayed a dramatically increased rate of apoptotic cell death. Expression profiling of apoptosis-related genes along the crypt-villus axis and in Apc mutant adenomas revealed increased expression of two pro-apoptotic Bcl-2 family members in intestinal adenomas, Bok and Bax. Analysis of the colon of familial adenomatous polyposis (FAP) patients along the crypt-to-surface axis, and of dysplastic crypts, corroborated this expression pattern. Disruption of {beta}-catenin/TCF-4-mediated signaling in the colorectal cancer cell line Ls174T significantly decreased BOK and BAX expression, confirming WNT-dependent regulation in intestinal epithelial cells. Our results suggest a feedback mechanism by which

  13. WNT signaling controls expression of pro-apoptotic BOK and BAX in intestinal cancer

    International Nuclear Information System (INIS)

    Zeilstra, Jurrit; Joosten, Sander P.J.; Wensveen, Felix M.; Dessing, Mark C.; Schuetze, Denise M.; Eldering, Eric; Spaargaren, Marcel; Pals, Steven T.

    2011-01-01

    Research highlights: → Intestinal adenomas initiated by aberrant activation of the WNT pathway displayed an increased sensitivity to apoptosis. → Expression profiling of apoptosis-related genes in Apc Min/+ mice revealed the differential expression of pro-apoptotic Bok and Bax. → APC-mutant adenomatous crypts in FAP patients showed strongly increased BAX immunoreactivity. → Blocking of β-catenin/TCF-4-mediated signaling in colon cancer cells reduced the expression of BOK and BAX. -- Abstract: In a majority of cases, colorectal cancer is initiated by aberrant activation of the WNT signaling pathway. Mutation of the genes encoding the WNT signaling components adenomatous polyposis coli or β-catenin causes constitutively active β-catenin/TCF-mediated transcription, driving the transformation of intestinal crypts to cancer precursor lesions, called dysplastic aberrant crypt foci. Deregulated apoptosis is a hallmark of adenomatous colon tissue. However, the contribution of WNT signaling to this process is not fully understood. We addressed this role by analyzing the rate of epithelial apoptosis in aberrant crypts and adenomas of the Apc Min/+ mouse model. In comparison with normal crypts and adenomas, aberrant crypts displayed a dramatically increased rate of apoptotic cell death. Expression profiling of apoptosis-related genes along the crypt-villus axis and in Apc mutant adenomas revealed increased expression of two pro-apoptotic Bcl-2 family members in intestinal adenomas, Bok and Bax. Analysis of the colon of familial adenomatous polyposis (FAP) patients along the crypt-to-surface axis, and of dysplastic crypts, corroborated this expression pattern. Disruption of β-catenin/TCF-4-mediated signaling in the colorectal cancer cell line Ls174T significantly decreased BOK and BAX expression, confirming WNT-dependent regulation in intestinal epithelial cells. Our results suggest a feedback mechanism by which uncontrolled epithelial cell proliferation in the

  14. Zerumbone induced apoptosis in liver cancer cells via modulation of Bax/Bcl-2 ratio

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    Azimahtol Hawariah LP

    2007-04-01

    Full Text Available Abstract Background Zerumbone is a cytotoxic component isolated from Zingiber zerumbet Smith, a herbal plant which is also known as lempoyang. This new anticancer bioactive compound from Z. zerumbet was investigated for its activity and mechanism in human liver cancer cell lines. Results Zerumbone significantly showed an antiproliferative activity upon HepG2 cells with an IC50 of 3.45 ± 0.026 μg/ml. Zerumbone was also found to inhibit the proliferation of non-malignant Chang Liver and MDBK cell lines. However the IC50 obtained was higher compared to the IC50 for HepG2 cells (> 10 μg/ml. The extent of DNA fragmentation was evaluated by the Tdt-mediated dUTP nick end labelling assay which showed that, zerumbone significantly increased apoptosis in HepG2 cells in a time-course manner. In detail, the apoptotic process triggered by zerumbone involved the up-regulation of pro-apoptotic Bax protein and the suppression of anti-apoptotic Bcl-2 protein expression. The changes that occurred in the levels of this antagonistic proteins Bax/Bcl-2, was independent of p53 since zerumbone did not affect the levels of p53 although this protein exists in a functional form. Western blotting analysis for Bax protein was further confirmed qualitatively with an immunoassay that showed the distribution of Bax protein in zerumbone-treated cells. Conclusion Therefore, zerumbone was found to induce the apoptotic process in HepG2 cells through the up and down regulation of Bax/Bcl-2 protein independently of functional p53 activity.

  15. Mitochondrial ceramide-rich macrodomains functionalize Bax upon irradiation.

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    Hyunmi Lee

    Full Text Available Evidence indicates that Bax functions as a "lipidic" pore to regulate mitochondrial outer membrane permeabilization (MOMP, the apoptosis commitment step, through unknown membrane elements. Here we show mitochondrial ceramide elevation facilitates MOMP-mediated cytochrome c release in HeLa cells by generating a previously-unrecognized mitochondrial ceramide-rich macrodomain (MCRM, which we visualize and isolate, into which Bax integrates.MCRMs, virtually non-existent in resting cells, form upon irradiation coupled to ceramide synthase-mediated ceramide elevation, optimizing Bax insertion/oligomerization and MOMP. MCRMs are detected by confocal microscopy in intact HeLa cells and isolated biophysically as a light membrane fraction from HeLa cell lysates. Inhibiting ceramide generation using a well-defined natural ceramide synthase inhibitor, Fumonisin B1, prevented radiation-induced Bax insertion, oligomerization and MOMP. MCRM deconstruction using purified mouse hepatic mitochondria revealed ceramide alone is non-apoptogenic. Rather Bax integrates into MCRMs, oligomerizing therein, conferring 1-2 log enhanced cytochrome c release. Consistent with this mechanism, MCRM Bax isolates as high molecular weight "pore-forming" oligomers, while non-MCRM membrane contains exclusively MOMP-incompatible monomeric Bax.Our recent studies in the C. elegans germline indicate that mitochondrial ceramide generation is obligate for radiation-induced apoptosis, although a mechanism for ceramide action was not delineated. Here we demonstrate that ceramide, generated in the mitochondrial outer membrane of mammalian cells upon irradiation, forms a platform into which Bax inserts, oligomerizes and functionalizes as a pore. We posit conceptualization of ceramide as a membrane-based stress calibrator, driving membrane macrodomain organization, which in mitochondria regulates intensity of Bax-induced MOMP, and is pharmacologically tractable in vitro and in vivo.

  16. CoQ10 Augments Rosuvastatin Neuroprotective Effect in a Model of Global Ischemia via Inhibition of NF-κB/JNK3/Bax and Activation of Akt/FOXO3A/Bim Cues

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    Sarah A. Abd El-Aal

    2017-10-01

    Full Text Available Statins were reported to lower the Coenzyme Q10 (CoQ10 content upon their inhibition of HMG-CoA reductase enzyme and both are known to possess neuroprotective potentials; therefore, the aim is to assess the possible use of CoQ10 as an adds-on therapy to rosuvastatin to improve its effect using global I/R model. Rats were allocated into sham, I/R, rosuvastatin (10 mg/kg, CoQ10 (10 mg/kg and their combination. Drugs were administered orally for 7 days before I/R. Pretreatment with rosuvastatin and/or CoQ10 inhibited the hippocampal content of malondialdehyde, nitric oxide, and boosted glutathione and superoxide dismutase. They also opposed the upregulation of gp91phox, and p47phox subunits of NADPH oxidase. Meanwhile, both agents reduced content/expression of TNF-α, iNOS, NF-κBp65, ICAM-1, and MPO. Besides, all regimens abated cytochrome c, caspase-3 and Bax, but increased Bcl-2 in favor of cell survival. On the molecular level, they increased p-Akt and its downstream target p-FOXO3A, with the inhibition of the nuclear content of FOXO3A to downregulate the expression of Bim, a pro-apoptotic gene. Additionally, both treatments downregulate the JNK3/c-Jun signaling pathway. The effect of the combination regimen overrides that of either treatment alone. These effects were reflected on the alleviation of the hippocampal damage in CA1 region inflicted by I/R. Together, these findings accentuate the neuroprotective potentials of both treatments against global I/R by virtue of their rigorous multi-pronged actions, including suppression of hippocampal oxidative stress, inflammation, and apoptosis with the involvement of the Akt/FOXO3A/Bim and JNK3/c-Jun/Bax signaling pathways. The study also nominates CoQ10 as an adds-on therapy with statins.

  17. 7α-Hydroxy-β-Sitosterol from Chisocheton tomentosus Induces Apoptosis via Dysregulation of Cellular Bax/Bcl-2 Ratio and Cell Cycle Arrest by Downregulating ERK1/2 Activation

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    Mohammad Tasyriq

    2012-01-01

    Full Text Available In continuation of our interest towards the elucidation of apoptotic pathways of cytotoxic phytocompounds, we have embarked upon a study on the anticancer effects of 7α-hydroxy-β-sitosterol (CT1, a rare natural phytosterol oxide isolated from Chisocheton tomentosus. CT1 was found to be cytotoxic on three different human tumor cell lines with minimal effects on normal cell controls, where cell viability levels were maintained ≥80% upon treatment. Our results showed that cell death in MCF-7 breast tumor cells was achieved through the induction of apoptosis via downregulation of the ERK1/2 signaling pathway. CT1 was also found to increase proapoptotic Bax protein levels, while decreasing anti-apoptotic Bcl-2 protein levels, suggesting the involvement of the intrinsic pathway. Reduced levels of initiator procaspase-9 and executioner procaspase-3 were also observed following CT1 exposure, confirming the involvement of cytochrome c-mediated apoptosis via the mitochondrial pathway. These results demonstrated the cytotoxic and apoptotic ability of 7α-hydroxy-β-sitosterol and suggest its potential anti-cancer use particularly on breast adenocarcinoma cells.

  18. BAX/BAK–Independent Mitoptosis during Cell Death Induced by Proteasome Inhibition?

    OpenAIRE

    Lomonosova, Elena; Ryerse, Jan; Chinnadurai, G.

    2009-01-01

    Proteasome inhibitors induce rapid death of cancer cells. We show that in epithelial cancer cells, such death is associated with dramatic and simultaneous up-regulation of several BH3-only proteins, including BIK, BIM, MCL-1S, NOXA, and PUMA, as well as p53. Elevated levels of these proteins seem to be the result of direct inhibition of their proteasomal degradation, induction of transcription, and active translation. Subsequent cell death is independent of BAX, and probably BAK, and proceeds...

  19. The Octyl Ester of Ginsenoside Rh2 Induces Lysosomal Membrane Permeabilization via Bax Translocation

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    Fang Chen

    2016-04-01

    Full Text Available Ginsenoside Rh2 is a potential pharmacologically active metabolite of ginseng. Previously, we have reported that an octyl ester derivative of ginsenoside Rh2 (Rh2-O, has been confirmed to possess higher bioavailability and anticancer effect than Rh2 in vitro. In order to better assess the possibility that Rh2-O could be used as an anticancer compound, the underlying mechanism was investigated in this study. The present results revealed that lysosomal destabilization was involved in the early stage of cell apoptosis in HepG2 cells induced by Rh2-O. Rh2-O could induce an early lysosomal membrane permeabilization with the release of lysosomal protease cathepsins to the cytosol in HepG2 cells. The Cat B inhibitor (leu and Cat D inhibitor (pepA inhibited Rh2-O-induced HepG2 apoptosis as well as tBid production and Δφm depolarization, indicating that lysosomal permeabilization occurred upstream of mitochondrial dysfunction. In addition, Rh2-O induced a significant increase in the protein levels of DRAM1 and Bax (p < 0.05 in lysosomes of HepG2 cells. Knockdown of Bax partially inhibited Rh2-O-induced Cat D release from lysosomes. Thus it was concluded that Rh2-O induced apoptosis of HepG2 cells through activation of the lysosomal-mitochondrial apoptotic pathway involving the translocation of Bax to the lysosome.

  20. Apigenin induces apoptosis by targeting inhibitor of apoptosis proteins and Ku70–Bax interaction in prostate cancer

    Science.gov (United States)

    Shukla, Sanjeev; Fu, Pingfu; Gupta, Sanjay

    2014-01-01

    Dysfunction of the apoptotic pathway in prostate cancer cells confers apoptosis resistance towards various therapies. A novel strategy to overcome resistance is to directly target the apoptotic pathway in cancer cells. Apigenin, an anticancer agent, selectively toxic to cancer cells induces cell cycle arrest and apoptosis through mechanisms which are not fully explored. In the present study we provide novel insight into the mechanisms of apoptosis induction by apigenin. Treatment of androgen-refractory human prostate cancer PC-3 and DU145 cells with apigenin resulted in dose-dependent suppression of XIAP, c-IAP1, c-IAP2 and survivin protein levels. Apigenin treatment resulted in significant decrease in cell viability and apoptosis induction with the increase of cytochrome C in time-dependent manner. These effects of apigenin were accompanied by decrease in Bcl-xL and Bcl-2 and increase in the active form of Bax protein. The apigenin-mediated increase in Bax was due to dissociation of Bax from Ku70 which is essential for apoptotic activity of Bax. Apigenin treatment resulted in the inhibition of class I histone deacetylases and HDAC1 protein expression, thereby increasing the acetylation of Ku70 and the dissociation of Bax resulting in apoptosis of cancer cells. Furthermore, apigenin significantly reduced HDAC1 occupancy at the XIAP promoter, suggesting that histone deacetylation might be critical for XIAP downregulation. These results suggest that apigenin targets inhibitor of apoptosis proteins and Ku70–Bax interaction in the induction of apoptosis in prostate cancer cells and in athymic nude mouse xenograft model endorsing its in vivo efficacy. PMID:24563225

  1. Apoptosis, proliferation, Bax, Bcl-2 and p53 status prior to and after preoperative radiochemotherapy for locally advanced rectal cancer

    International Nuclear Information System (INIS)

    Tannapfel, Andrea; Nuesslein, Siegfried; Fietkau, Rainer; Katalinic, Alexander; Koeckerling, Ferdinand; Wittekind, Christian

    1998-01-01

    Purpose: To investigate the relationship between apoptotic cell death, proliferative activity, and the expression of apoptosis regulating proteins in rectal cancer prior to and after radiochemotherapy. Materials and Methods: In 32 patients dispositioned to receive preoperative radiochemotherapy for locally advanced rectal carcinoma, pretherapy biopsies and the final resected specimen after radiochemotherapy were available for analyses. Apoptotic cells were identified and quantified using in situ end labeling (ISEL) technique. The expression of the bax protein was assessed immunohistochemically. Additionally, double immunostaining was performed for apoptotic cells and bax expression. The proliferative activity was determined by immunohistochemical assessment of the Ki67 (MIB-1) and the proliferating cell nuclear antigen (PCNA). p53- and bcl-2 expression was analyzed immunohistochemically. A clinical-to-pathologic downstaging after radiochemotherapy was achieved in 25 of 32 patients (78%). During follow-up, tumor recurrence was observed in six cases. In one case, no residual tumor was detected after radiochemotherapy. Results: After radiochemotherapy, the apoptotic index increased significantly in almost every case examined. In contrast, the proliferative activity was significantly decreased in resected specimens as compared to biopsies. Bax immunostaining was detected in 12/31 (39%) biopsies and in 26/31 (84%) resected specimens. In the resected specimen, significantly more apoptotic cells that were bax-positive were found than in biopsies. Bcl-2 immunostaining occurred in 15/31 biopsies and 12/31 resected specimens, respectively. Tumors that were immunohistochemically negative for p53 (20/31 [65%]) generally exhibited a higher apoptotic index and a high expression level of bax than p53-positive tumors (11/31 [35%]). However, we did not find any correlation between the (pre- and post-therapeutic) rate of apoptosis or the level of bax expression and the degree of

  2. Reconstitution of the anti-apoptotic Bcl-2 protein into lipid membranes and biophysical evidence for its detergent-driven association with the pro-apoptotic Bax protein.

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    Marcus Wallgren

    Full Text Available The anti-apoptotic B-cell CLL/lymphoma-2 (Bcl-2 protein and its counterpart, the pro-apoptotic Bcl-2-associated X protein (Bax, are key players in the regulation of the mitochondrial pathway of apoptosis. However, how they interact at the mitochondrial outer membrane (MOM and there determine whether the cell will live or be sentenced to death remains unknown. Competing models have been presented that describe how Bcl-2 inhibits the cell-killing activity of Bax, which is common in treatment-resistant tumors where Bcl-2 is overexpressed. Some studies suggest that Bcl-2 binds directly to and sequesters Bax, while others suggest an indirect process whereby Bcl-2 blocks BH3-only proteins and prevents them from activating Bax. Here we present the results of a biophysical study in which we investigated the putative interaction of solubilized full-length human Bcl-2 with Bax and the scope for incorporating the former into a native-like lipid environment. Far-UV circular dichroism (CD spectroscopy was used to detect direct Bcl-2-Bax-interactions in the presence of polyoxyethylene-(23-lauryl-ether (Brij-35 detergent at a level below its critical micelle concentration (CMC. Additional surface plasmon resonance (SPR measurements confirmed this observation and revealed a high affinity between the Bax and Bcl-2 proteins. Upon formation of this protein-protein complex, Bax also prevented the binding of antimycin A2 (a known inhibitory ligand of Bcl-2 to the Bcl-2 protein, as fluorescence spectroscopy experiments showed. In addition, Bcl-2 was able to form mixed micelles with Triton X-100 solubilized neutral phospholipids in the presence of high concentrations of Brij-35 (above its CMC. Following detergent removal, the integral membrane protein was found to have been fully reconstituted into a native-like membrane environment, as confirmed by ultracentrifugation and subsequent SDS-PAGE experiments.

  3. 14-3-3theta protects against neurotoxicity in a cellular Parkinson's disease model through inhibition of the apoptotic factor Bax.

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    Sunny R Slone

    Full Text Available Disruption of 14-3-3 function by alpha-synuclein has been implicated in Parkinson's disease. As 14-3-3s are important regulators of cell death pathways, disruption of 14-3-3s could result in the release of pro-apoptotic factors, such as Bax. We have previously shown that overexpression of 14-3-3θ reduces cell loss in response to rotenone and MPP(+ in dopaminergic cell culture and reduces cell loss in transgenic C. elegans that overexpress alpha-synuclein. In this study, we investigate the mechanism for 14-3-3θ's neuroprotection against rotenone toxicity. While 14-3-3s can inhibit many pro-apoptotic factors, we demonstrate that inhibition of one factor in particular, Bax, is important to 14-3-3s' protection against rotenone toxicity in dopaminergic cells. We found that 14-3-3θ overexpression reduced Bax activation and downstream signaling events, including cytochrome C release and caspase 3 activation. Pharmacological inhibition or shRNA knockdown of Bax provided protection against rotenone, comparable to 14-3-3θ's neuroprotective effects. A 14-3-3θ mutant incapable of binding Bax failed to protect against rotenone. These data suggest that 14-3-3θ's neuroprotective effects against rotenone are at least partially mediated by Bax inhibition and point to a potential therapeutic role of 14-3-3s in Parkinson's disease.

  4. 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

  5. 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

  6. Apoptosis and Bax expression are increased by coal dust in the polycyclic aromatic hydrocarbon-exposed lung

    Energy Technology Data Exchange (ETDEWEB)

    Ghanem, M.M.; Battelli, L.A.; Mercer, R.R.; Scabilloni, J.F.; Kashon, M.L.; Ma, J.Y.C.; Nath, J.; Hubbs, A.F.

    2006-09-15

    Miners inhaling respirable coal dust (CD) frequently develop coal workers' pneumoconiosis. Many coal miners are also exposed to polycyclic aromatic hydrocarbon (PAH) components of diesel engine exhaust and cigarette smoke, which may contribute to lung disease in these workers. Recently, apoptosis was reported to play a critical role in the development of another pneumoconiosis of miners, silicosis. In addition, CID was reported to suppress cytochrome P450 1A1 (CYP1A1) induction by PAHs. We exposed rats intratracheally to 0.0, 2.5, 10.0, 20.0, or 40.0 mg/rat CD and, 11 days later, to intraperitoneal P-naphthoflavone (BNF), a PAH. In another group of rats exposed to CD and BNF, caspase activity was inhibited by injection of the pan-caspase inhibitor Q-VD-OPH (quinoline-Val-Asp (OMe)-CH{sub 2}-OPH). In rats exposed to BNF, CD exposure increased alveolar expression of the proapoptotic mediator Bax but decreased CYP1A1 induction relative to BNF exposure alone. Pan-caspase inhibition decreased CD-associated Bax expression and apoptosis but did not restore CYP1A1 activity. Further, CD-induced lung inflammation and alveolar epithelial cell hypertrophy and hyperplasia were not suppressed by caspase inhibition. It is concluded that combined BNF and CD exposure increased Bax expression and apoptosis in the lung, but Bax and apoptosis were not the major determinants of early lung injury in this model.

  7. Regulatory RNA Key Player in p53-Mediated Apoptosis in Embryonic Stem Cells | Center for Cancer Research

    Science.gov (United States)

    Embryonic stem cells (ESCs) must maintain the integrity of their genomes or risk passing potentially deleterious mutations on to numerous tissues. Thus, ESCs have a unique genome surveillance system and easily undergo apoptosis or differentiation when DNA damage is detected. The protein p53 is known to promote differentiation in mouse ESCs (mESCs), but its role in DNA

  8. Characterisation of the p53-mediated cellular responses evoked in primary mouse cells following exposure to ultraviolet radiation.

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    Gillian D McFeat

    Full Text Available Exposure to ultraviolet (UV light can cause significant damage to mammalian cells and, although the spectrum of damage produced varies with the wavelength of UV, all parts of the UV spectrum are recognised as being detrimental to human health. Characterising the cellular response to different wavelengths of UV therefore remains an important aim so that risks and their moderation can be evaluated, in particular in relation to the initiation of skin cancer. The p53 tumour suppressor protein is central to the cellular response that protects the genome from damage by external agents such as UV, thus reducing the risk of tumorigenesis. In response to a variety of DNA damaging agents including UV light, wild-type p53 plays a role in mediating cell-cycle arrest, facilitating apoptosis and stimulating repair processes, all of which prevent the propagation of potentially mutagenic defects. In this study we examined the induction of p53 protein and its influence on the survival of primary mouse fibroblasts exposed to different wavelengths of UV light. UVC was found to elevate p53 protein and its sequence specific DNA binding capacity. Unexpectedly, UVA treatment failed to induce p53 protein accumulation or sequence specific DNA binding. Despite this, UVA exposure of wild-type cells induced a p53 dependent G1 cell cycle arrest followed by a wave of p53 dependent apoptosis, peaking 12 hours post-insult. Thus, it is demonstrated that the elements of the p53 cellular response evoked by exposure to UV radiation are wavelength dependent. Furthermore, the interrelationship between various endpoints is complex and not easily predictable. This has important implications not only for understanding the mode of action of p53 but also for the use of molecular endpoints in quantifying exposure to different wavelengths of UV in the context of human health protection.

  9. BAX and tumor suppressor TRP53 are important in regulating mutagenesis in spermatogenic cells in mice.

    Science.gov (United States)

    Xu, Guogang; Vogel, Kristine S; McMahan, C Alex; Herbert, Damon C; Walter, Christi A

    2010-12-01

    During the first wave of spermatogenesis, and in response to ionizing radiation, elevated mutant frequencies are reduced to a low level by unidentified mechanisms. Apoptosis is occurring in the same time frame that the mutant frequency declines. We examined the role of apoptosis in regulating mutant frequency during spermatogenesis. Apoptosis and mutant frequencies were determined in spermatogenic cells obtained from Bax-null or Trp53-null mice. The results showed that spermatogenic lineage apoptosis was markedly decreased in Bax-null mice and was accompanied by a significantly increased spontaneous mutant frequency in seminiferous tubule cells compared to that of wild-type mice. Apoptosis profiles in the seminiferous tubules for Trp53-null were similar to control mice. Spontaneous mutant frequencies in pachytene spermatocytes and in round spermatids from Trp53-null mice were not significantly different from those of wild-type mice. However, epididymal spermatozoa from Trp53-null mice displayed a greater spontaneous mutant frequency compared to that from wild-type mice. A greater proportion of spontaneous transversions and a greater proportion of insertions/deletions 15 days after ionizing radiation were observed in Trp53-null mice compared to wild-type mice. Base excision repair activity in mixed germ cell nuclear extracts prepared from Trp53-null mice was significantly lower than that for wild-type controls. These data indicate that BAX-mediated apoptosis plays a significant role in regulating spontaneous mutagenesis in seminiferous tubule cells obtained from neonatal mice, whereas tumor suppressor TRP53 plays a significant role in regulating spontaneous mutagenesis between postmeiotic round spermatid and epididymal spermatozoon stages of spermiogenesis.

  10. Killing of Brain Tumor Cells by Hypoxia-Responsive Element Mediated Expression of BAX

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    Hangjun Ruan

    1999-11-01

    Full Text Available The presence of radioresistant hypoxic cells in human brain tumors limits the overall effectiveness of conventional fractionated radiation therapy. Tumor-specific therapies that target hypoxic cells are clearly needed. We have investigated the expression of suicide genes under hypoxia by a hypoxia-responsive element (HRE, which can be activated through hypoxia-inducible factor-1 (HIF-1. We transfected plasmids containing multiple copies of HIRE into U-87 MG and U-251 MG-NCI human brain tumor cells and tested their ability to induce LacZ gene expression under anoxia. Gene expression under anoxia versus oxia was increased about 12-fold for U-87 MG cells and about fourfold for U-251 MG-NCI cells. At intermediate hypoxic conditions, increased LacZ gene expression in U-87 MG cells was induced by the plasmid that contained three HREs, but not by the plasmid with two HREs. Lastly, when we placed a suicide gene BAX under the control of HREs, cells transfected with the BAX plasmids were preferentially killed through apoptosis under anoxia. Our studies demonstrate that HRE-regulated gene expression is active in brain tumor cells, and that the amount of increased gene expression obtained is dependent on the cell line, the HIRE copy number, and the degree of hypoxia.

  11. 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.

  12. Bax function in the absence of mitochondria in the primitive protozoan Giardia lamblia.

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    Adrian B Hehl

    Full Text Available Bax-induced permeabilization of the mitochondrial outer membrane and release of cytochrome c are key events in apoptosis. Although Bax can compromise mitochondria in primitive unicellular organisms that lack a classical apoptotic machinery, it is still unclear if Bax alone is sufficient for this, or whether additional mitochondrial components are required. The protozoan parasite Giardia lamblia is one of the earliest branching eukaryotes and harbors highly degenerated mitochondrial remnant organelles (mitosomes that lack a genome. Here we tested whether human Bax expressed in Giardia can be used to ablate mitosomes. We demonstrate that these organelles are neither targeted, nor compromised, by Bax. However, specialized compartments of the regulated secretory pathway are completely ablated by Bax. As a consequence, maturing cyst wall proteins that are sorted into these organelles are released into the cytoplasm, causing a developmental arrest and cell death. Interestingly, this ectopic cargo release is dependent on the carboxy-terminal 22 amino acids of Bax, and can be prevented by the Bax-inhibiting peptide Ku70. A C-terminally truncated Bax variant still localizes to secretory organelles, but is unable to permeabilize these membranes, uncoupling membrane targeting and cargo release. Even though mitosomes are too diverged to be recognized by Bax, off-target membrane permeabilization appears to be conserved and leads to cell death completely independently of mitochondria.

  13. Mode of cell death induced by the HSP90 inhibitor 17-AAG (tanespimycin) is dependent on the expression of pro-apoptotic BAX.

    Science.gov (United States)

    Powers, Marissa V; Valenti, Melanie; Miranda, Susana; Maloney, Alison; Eccles, Suzanne A; Thomas, George; Clarke, Paul A; Workman, Paul

    2013-11-01

    Inhibitors of the molecular chaperone heat shock protein 90 (HSP90) are of considerable current interest as targeted cancer therapeutic agents because of the ability to destabilize multiple oncogenic client proteins. Despite their resulting pleiotropic effects on multiple oncogenic pathways and hallmark traits of cancer, resistance to HSP90 inhibitors is possible and their ability to induce apoptosis is less than might be expected. Using an isogenic model for BAX knockout in HCT116 human colon carcinoma cells, we demonstrate the induction of BAX-dependent apoptosis at pharmacologically relevant concentrations of the HSP90 inhibitor 17-AAG both in vitro and in tumor xenografts in vivo. Removal of BAX expression by homologous recombination reduces apoptosis in vitro and in vivo but allows a lower level of cell death via a predominantly necrotic mechanism. Despite reducing apoptosis, the loss of BAX does not alter the overall sensitivity to 17-AAG in vitro or in vivo. The results indicate that 17-AAG acts predominantly to cause a cytostatic antiproliferative effect rather than cell death and further suggest that BAX status may not alter the overall clinical response to HSP90 inhibitors. Other agents may be required in combination to enhance tumor-selective killing by these promising drugs. In addition, there are implications for the use of apoptotic endpoints in the assessment of the activity of molecularly targeted agents.

  14. Melatonin promotes Bax sequestration to mitochondria reducing cell susceptibility to apoptosis via the lipoxygenase metabolite 5-hydroxyeicosatetraenoic acid

    KAUST Repository

    Radogna, Flavia

    2015-03-01

    Extra-neurological functions of melatonin include control of the immune system and modulation of apoptosis. We previously showed that melatonin inhibits the intrinsic apoptotic pathway in leukocytes via stimulation of high affinity MT1/MT2 receptors, thereby promoting re-localization of the anti-apoptotic Bcl-2 protein to mitochondria. Here we show that Bcl-2 sequesters pro-apoptotic Bax into mitochondria in an inactive form after melatonin treatment, thus reducing cell propensity to apoptosis. Bax translocation and the anti-apoptotic effect of melatonin are strictly dependent on the presence of Bcl-2, and on the 5-lipoxygenase (5-LOX) metabolite 5-hydroxyeicosatetraenoic acid (5-HETE), which we have previously shown to be produced as a consequence of melatonin binding to its low affinity target calmodulin. Therefore, the anti-apoptotic effect of melatonin requires the simultaneous, independent interaction with high (MT1/MT2) and low (calmodulin) affinity targets, eliciting two independent signal transduction pathways converging into Bax sequestration and inactivation. MT1/MT2 vs. lipoxygenase pathways are activated by 10-9 vs. 10-5M melatonin, respectively; the anti-apoptotic effect of melatonin is achieved at 10-5M, but drops to 10-9M upon addition of exogenous 5-HETE, revealing that lipoxygenase activation is the rate-limiting pathway. Therefore, in areas of inflammation with increased 5-HETE levels, physiological nanomolar concentrations of melatonin may suffice to maintain leukocyte viability.

  15. Paclitaxel-induced apoptosis is BAK-dependent, but BAX and BIM-independent in breast tumor.

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    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.

  16. Preparation and Photocatalytic Properties of Sr2−xBaxTa3O10−yNz Nanosheets

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    Tatsumi Ishihara

    2013-01-01

    Full Text Available Sr2−xBaxTa3O10−yNz (x = 0.0, 0.5, 1.0 nanosheets were prepared by exfoliating layered perovskite compounds (CsSr2−xBaxTa3O10−yNz. The Sr1.5Ba0.5Ta3O9.7N0.2 nanosheet showed the highest photocatalytic activity for H2 production from the water/methanol system among the Sr2−xBaxTa3O9.7N0.2 nanosheets prepared. In addition, Rh-loaded Sr1.5Ba0.5Ta3O9.6N0.3 nanosheet showed the photocatalytic activity for oxygen and hydrogen production from water. The ratio of hydrogen to oxygen evolved was around two. These results indicate that the Rh-loaded Sr1.5Ba0.5Ta3O9.6N0.3 nanosheet is a potential catalyst for photocatalytic water splitting.

  17. Expression and significance of Bax protein in model of radiation injury in mouse skin

    International Nuclear Information System (INIS)

    Feng Yizhong; Mo Yahong

    2002-01-01

    Objective: The study is to find some valuable criteria for diagnosis and treatment of radiation injury in skin. Methods: The expression of Bax protein was studied by SP immunohistochemistry in 40 cases of model of radiation injury in mouse skin. Their relationship relating to radiation dose was also investigated. Results: The expression rates of Bax were 30%, 30%, 70%, 70% in 5 Gy group, 15 Gy group, 30 Gy group, 45 Gy group respectively. There was no significant correlation between the expression of Bax and radiation groups. Conclusions: The experiment shows that radiation can increase the expression of Bax protein which might be related to poor healing in radiation skin injury

  18. Bcl-xL stimulates Bax relocation to mitochondria and primes cells to ABT-737.

    Science.gov (United States)

    Renault, Thibaud T; Teijido, Oscar; Missire, Florent; Ganesan, Yogesh Tengarai; Velours, Gisèle; Arokium, Hubert; Beaumatin, Florian; Llanos, Raul; Athané, Axel; Camougrand, Nadine; Priault, Muriel; Antonsson, Bruno; Dejean, Laurent M; Manon, Stéphen

    2015-07-01

    Bax cytosol-to-mitochondria translocation is a central event of the intrinsic pathway of apoptosis. Bcl-xL is an important regulator of this event and was recently shown to promote the retrotranslocation of mitochondrial Bax to the cytosol. The present study identifies a new aspect of the regulation of Bax localization by Bcl-xL: in addition to its role in Bax inhibition and retrotranslocation, we found that, like with Bcl-2, an increase of Bcl-xL expression levels led to an increase of Bax mitochondrial content. This finding was substantiated both in pro-lymphocytic FL5.12 cells and a yeast reporting system. Bcl-xL-dependent increase of mitochondrial Bax is counterbalanced by retrotranslocation, as we observed that Bcl-xLΔC, which is unable to promote Bax retrotranslocation, was more efficient than the full-length protein in stimulating Bax relocation to mitochondria. Interestingly, cells overexpressing Bcl-xL were more sensitive to apoptosis upon treatment with the BH3-mimetic ABT-737, suggesting that despite its role in Bax inhibition, Bcl-xL also primes mitochondria to permeabilization and cytochrome c release. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. 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

  20. Schiff Base Metal Derivatives Enhance the Expression of HSP70 and Suppress BAX Proteins in Prevention of Acute Gastric Lesion

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    Shahram Golbabapour

    2013-01-01

    Full Text Available Schiff base complexes have appeared to be promising in the treatment of different diseases and disorders and have drawn a lot of attention to their biological activities. This study was conducted to evaluate the regulatory effect of Schiff base metal derivatives on the expression of heat shock proteins (HSP 70 and BAX in protection against acute haemorrhagic gastric ulcer in rats. Rats were assigned to 6 groups of 6 rats: the normal control (Tween 20 5% v/v, 5 mL/kg, the positive control (Tween 20 5% v/v, 5 mL/kg, and four Schiff base derivative groups named Schiff_1, Schiff_2, Schiff_3, and Schiff_4 (25 mg/kg. After 1 h, all of the groups received ethanol 95% (5 mL/kg but the normal control received Tween 20 (Tween 20 5% v/v, 5 mL/kg. The animals were euthanized after 60 min and the stomachs were dissected for histology (H&E, immunohistochemistry, and western blot analysis against HSP70 and BAX proteins. The results showed that the Schiff base metal derivatives enhanced the expression of HSP70 and suppressed the expression of BAX proteins during their gastroprotection against ethanol-induced gastric lesion in rats.

  1. Schiff base metal derivatives enhance the expression of HSP70 and suppress BAX proteins in prevention of acute gastric lesion.

    Science.gov (United States)

    Golbabapour, Shahram; Gwaram, Nura Suleiman; Al-Obaidi, Mazen M Jamil; Soleimani, A F; Ali, Hapipah Mohd; Abdul Majid, Nazia

    2013-01-01

    Schiff base complexes have appeared to be promising in the treatment of different diseases and disorders and have drawn a lot of attention to their biological activities. This study was conducted to evaluate the regulatory effect of Schiff base metal derivatives on the expression of heat shock proteins (HSP) 70 and BAX in protection against acute haemorrhagic gastric ulcer in rats. Rats were assigned to 6 groups of 6 rats: the normal control (Tween 20 5% v/v, 5 mL/kg), the positive control (Tween 20 5% v/v, 5 mL/kg), and four Schiff base derivative groups named Schiff_1, Schiff_2, Schiff_3, and Schiff_4 (25 mg/kg). After 1 h, all of the groups received ethanol 95% (5 mL/kg) but the normal control received Tween 20 (Tween 20 5% v/v, 5 mL/kg). The animals were euthanized after 60 min and the stomachs were dissected for histology (H&E), immunohistochemistry, and western blot analysis against HSP70 and BAX proteins. The results showed that the Schiff base metal derivatives enhanced the expression of HSP70 and suppressed the expression of BAX proteins during their gastroprotection against ethanol-induced gastric lesion in rats.

  2. Mutational analysis of Bax and Bcl-2 in childhood acute lymphoblastic leukaemia

    NARCIS (Netherlands)

    Salomons, G. S.; Buitenhuis, C. K.; Martínez Muñoz, C.; Verwijs-Jassen, M.; Behrendt, H.; Zsiros, J.; Smets, L. A.

    1998-01-01

    In childhood acute lymphoblastic leukaemia there are large interpatient variations in levels of the apoptosis-regulating proteins Bax and Bcl-2, but the molecular basis for this variation is unknown. Point-mutations in bax have been reported in cell lines derived from haematological malignancies.

  3. Role of Apoptosis in the Development of Uterine Leiomyoma: Analysis of Expression Patterns of Bcl-2 and Bax in Human Leiomyoma Tissue With Clinical Correlations.

    Science.gov (United States)

    Csatlós, Éva; Máté, Szabolcs; Laky, Marcella; Rigó, János; Joó, József Gábor

    2015-07-01

    To describe gene expression patterns of the apoptotic regulatory genes Bcl and Bax in human uterine leiomyoma tissue. To investigate the relationship between alterations of gene expression patterns and several relevant clinical parameters. We obtained samples from 101 cases undergoing surgery for uterine leiomyoma for gene expression analysis of the Bcl-2 and Bax genes. Gene expression was quantified using RT-PCR technique. In the leiomyoma group, the Bcl-2 gene was significantly overexpressed compared with the control group although there was no such difference in the gene expression of Bax. Gene activity of Bcl-2 positively correlated with the tumor number in individual uterine leiomyoma cases. Although there was no significant correlation between the length of the cumulative lactation period before the development of uterine leiomyoma and Bcl-2 gene expression in the leiomyoma tissue, we observed a trend for a shorter cumulative lactation period to be associated with overexpression of the Bcl-2 gene. Overexpression of the antiapoptotic Bcl-2 gene appeared to be a factor in the development of uterine leiomyoma, whereas gene activity of the proapoptotic Bax gene did not seem to play a role in the process.

  4. Involvement of Bax and Bcl2 in Neuroprotective Effect of Curcumin in Kainic Acid-Induced Model of Temporal Lobe Epilepsy in Male Rat

    Directory of Open Access Journals (Sweden)

    zahra Kiasalari

    2016-04-01

    Full Text Available Background & objectives: Temporal lobe epilepsy is associated with neuronal apoptosis. Curcumin has antioxidant and anticonvulsant activities, therefore this study was conducted to assess involvement of Bax and Bcl2 in protective effect of curcumin in epileptic rats. Methods: 28 rats were divided into sham, curcumin-pretreated sham, epileptic (kainate, and curcumin-pretreated epileptic groups. Experimental model of epilepsy was induced by intrahippocampal administration of kainic acid. Rats received curcumin at a dose of 100 mg/kg. Finally, Nissl staining and Bax and Bcl2 immunohistochemistry were conducted on hippocampal sections and data were analyzed using one-way ANOVA and unpaired t-test. The p-value less than 0.05was considered statistically significant. Results: Induction of epilepsy was followed by a significant seizure and curcumin pretreatment significantly reduced seizure intensity (p<0.01. In addition, there were no significant differences between the groups in Nissl staining of CA3 area neurons. In addition, Bax positive neurons were observed in CA3 area in kainate group and significantly decreased in curcumin pretreated rats (p<0.05. Meanwhile, Bcl2 positive neurons were also moderately observed in kainate group and curcumin pretreatment significantly increased it (p<0.05. Conclusion: Curcumin pretreatment exhibits anticonvulsant activity in epileptic rats. It also decreases the expression of pro-apoptotic protein Bax and significantly enhances the expression of anti-apoptotic protein Bcl2 and hence could reduce neuronal apoptosis.

  5. Bax-mediated mitochondrial outer membrane permeabilization (MOMP), distinct from the mitochondrial permeability transition, is a key mechanism in diclofenac-induced hepatocyte injury: Multiple protective roles of cyclosporin A.

    Science.gov (United States)

    Siu, Woen Ping; Pun, Pamela Boon Li; Latchoumycandane, Calivarathan; Boelsterli, Urs A

    2008-03-15

    Diclofenac, a widely used nonsteroidal anti-inflammatory drug, has been associated with rare but severe cases of clinical hepatotoxicity. Diclofenac causes concentration-dependent cell death in human hepatocytes (after 24-48 h) by mitochondrial permeabilization via poorly defined mechanisms. To explore whether the cyclophilin D (CyD)-dependent mitochondrial permeability transition (mPT) and/or the mitochondrial outer membrane permeabilization (MOMP) was primarily involved in mediating cell death, we exposed immortalized human hepatocytes (HC-04) to apoptogenic concentrations of diclofenac (>500 microM) in the presence or absence of inhibitors of upstream mediators. The CyD inhibitor, cyclosporin A (CsA, 2 microM) fully inhibited diclofenac-induced cell injury, suggesting that mPT was involved. However, CyD gene silencing using siRNA left the cells susceptible to diclofenac toxicity, and CsA still protected the CyD-negative cells from lethal injury. Diclofenac induced early (9 h) activation of Bax and Bak and caused mitochondrial translocation of Bax, indicating that MOMP was involved in cell death. Inhibition of Bax protein expression by using siRNA significantly protected HC-04 from diclofenac-induced cell injury. Diclofenac also induced early Bid activation (tBid formation, 6 h), which is an upstream mechanism that initiates Bax activation and mitochondrial translocation. Bid activation was sensitive to the Ca2+ chelator, BAPTA. In conclusion, we found that Bax/Bak-mediated MOMP is a key mechanism of diclofenac-induced lethal cell injury in human hepatocytes, and that CsA can prevent MOMP through inhibition of Bax activation. These data support our concept that the Ca2+-Bid-Bax-MOMP axis is a critical pathway in diclofenac (metabolite)-induced hepatocyte injury.

  6. Bax-mediated mitochondrial outer membrane permeabilization (MOMP), distinct from the mitochondrial permeability transition, is a key mechanism in diclofenac-induced hepatocyte injury: Multiple protective roles of cyclosporin A

    International Nuclear Information System (INIS)

    Siu, W.P.; Pun, Pamela Boon Li; Latchoumycandane, Calivarathan; Boelsterli, Urs A.

    2008-01-01

    Diclofenac, a widely used nonsteroidal anti-inflammatory drug, has been associated with rare but severe cases of clinical hepatotoxicity. Diclofenac causes concentration-dependent cell death in human hepatocytes (after 24-48 h) by mitochondrial permeabilization via poorly defined mechanisms. To explore whether the cyclophilin D (CyD)-dependent mitochondrial permeability transition (mPT) and/or the mitochondrial outer membrane permeabilization (MOMP) was primarily involved in mediating cell death, we exposed immortalized human hepatocytes (HC-04) to apoptogenic concentrations of diclofenac (> 500 μM) in the presence or absence of inhibitors of upstream mediators. The CyD inhibitor, cyclosporin A (CsA, 2 μM) fully inhibited diclofenac-induced cell injury, suggesting that mPT was involved. However, CyD gene silencing using siRNA left the cells susceptible to diclofenac toxicity, and CsA still protected the CyD-negative cells from lethal injury. Diclofenac induced early (9 h) activation of Bax and Bak and caused mitochondrial translocation of Bax, indicating that MOMP was involved in cell death. Inhibition of Bax protein expression by using siRNA significantly protected HC-04 from diclofenac-induced cell injury. Diclofenac also induced early Bid activation (tBid formation, 6 h), which is an upstream mechanism that initiates Bax activation and mitochondrial translocation. Bid activation was sensitive to the Ca 2+ chelator, BAPTA. In conclusion, we found that Bax/Bak-mediated MOMP is a key mechanism of diclofenac-induced lethal cell injury in human hepatocytes, and that CsA can prevent MOMP through inhibition of Bax activation. These data support our concept that the Ca 2+ -Bid-Bax-MOMP axis is a critical pathway in diclofenac (metabolite)-induced hepatocyte injury

  7. The effect of radiation on bcl-2 and bax in hyperplastic prostatic tissues

    International Nuclear Information System (INIS)

    Ma Qingjie; Li Yuxin; Gu Xinquan; Cao Xia; Zhao Jie; Kong Xiangbo; Cai Shanyu

    2004-01-01

    Aim: To investigate the expressions of bcl-2 and bax in benign prostatic hyperplasia (BPH) and the effect of β-rays on bcl-2 and bax. Methods: The expressions of bcl-2 and bax are studied by means of immunohistochemical method in 9 normal prostate (NP) and 15 BPH and 35 patients treated with 90Sr/90Y Prostatic Hyperplasia Applicator. Results: The expressions of bcl-2 in epithelia of NP and BPH are higher than that in stroma P<0.01=. The expressions of bcl-2 in epithelia and stroma of BPH are higher than that in NP P<0.01=. The expressions of bax in epithelia of NP are higher than that in BPH P<0.05=. However ,the expressions of bcl-2 in epithelia and stroma of BPH are higher than bax P<0.01 =. Compared with the control group, the expressions of bcl-2 in epithelia and stroma of BPH treated with 90Sr/90Y Prostatic Hyperplasia Applicator decreased and the expressions of bax increased P<0.01=. Conclusion: bcl-2 gene and bax gene play an important role in the regulation of prostatic apoptosis and the treatment of β-rays can accelerate the apoptosis of prostatic tissues. (authors)

  8. Quantifying export production in the Southern Ocean: Implications for the Baxs proxy

    Science.gov (United States)

    Hernandez-Sanchez, Maria T.; Mills, Rachel A.; Planquette, HéLèNe; Pancost, Richard D.; Hepburn, Laura; Salter, Ian; Fitzgeorge-Balfour, Tania

    2011-12-01

    The water column and sedimentary Baxs distribution around the Crozet Plateau is used to decipher the controls and timing of barite formation and to evaluate how export production signals are recorded in sediments underlying a region of natural Fe fertilization within the Fe limited Southern Ocean. Export production estimated from preserved, vertical sedimentary Baxs accumulation rates are compared with published export fluxes assessed from an integrated study of the biological carbon pump to determine the validity of Baxs as a quantitative proxy under different Fe supply conditions typical of the Southern Ocean. Detailed assessment of the geochemical partitioning of Ba in sediments and the lithogenic end-member allows appropriate correction of the bulk Ba content and determination of the Baxs content of sediments and suspended particles. The upper water column distribution of Baxs is extremely heterogeneous spatially and temporally. Organic carbon/Baxs ratios in deep traps from the Fe fertilized region are similar to other oceanic settings allowing quantification of the inferred carbon export based on established algorithms. There appears to be some decoupling of POC and Ba export in the Fe limited region south of the Plateau. The export production across the Crozet Plateau inferred from the Baxs sedimentary proxy indicates that the Fe fertilized area to the north of the Plateau experiences enhanced export relative to equivalent Southern Ocean settings throughout the Holocene and that this influence may also have impacted the site to the south for significant periods. This interpretation is corroborated by alternative productivity proxies (opal accumulation, 231Paxs/230Thxs). Baxs can be used to quantify export production in complex settings such as naturally Fe-fertilized (volcanoclastic) areas, providing appropriate lithogenic correction is undertaken, and sediment focusing is corrected for along with evaluation of barite preservation.

  9. THE EXPRESSION AND CLINICAL VALUE OF APOPTOSIS CONTROL GENE Bcl-2 AND Bax IN BREAST CANCER

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jun; YAO Zhen-xiang; ZHANG Jing

    1999-01-01

    Objective: To study the expression and clinical value of apoptosis control gene bcl-2 and bax in breast cancer.Methods: Protein bax and bcl-2 in 41 breast cancers obtained from operations in our hospital in 1996 were detected using ABC immunohistochemical stain assay and compared with 10 cases with normal breast tissues.Results: The positive rate of bax in normal breast tissue was 90% and in breast cancer was 59%, with a significant statistical difference between them (P<0.05), but there was no statistical difference in bcl-2 protein expression. Among the 41 breast cancer, the group with lymph node metastasis (21 cases) had obviously low bax expression (43%) and high bcl-2 expression (76%), showing significant difference to the group without lymph node metastasis (P<0.05).Conclusion: The antiapoptosis function of bcl-2 was stronger than bax in breast cancer. Protein bax and bcl-2 assay may be useful in understanding the biological behaviors of breast cancer.

  10. Increase in intracellular PGE2 induces apoptosis in Bax-expressing colon cancer cell

    International Nuclear Information System (INIS)

    Lalier, Lisenn; Pedelaborde, François; Braud, Christophe; Menanteau, Jean; M Vallette, François; Olivier, Christophe

    2011-01-01

    NSAIDs exhibit protective properties towards some cancers, especially colon cancer. Yet, it is not clear how they play their protective role. PGE 2 is generally shown as the only target of the NSAIDs anticancerous activity. However, PGE 2 known targets become more and more manifold, considering both the molecular pathways involved and the target cells in the tumour. The role of PGE 2 in tumour progression thus appears complex and multipurpose. To gain understanding into the role of PGE 2 in colon cancer, we focused on the activity of PGE 2 in apoptosis in colon cancer cell lines. We observed that an increase in intracellular PGE 2 induced an apoptotic cell death, which was dependent on the expression of the proapoptotic protein Bax. This increase was induced by increasing PGE 2 intracellular concentration, either by PGE 2 microinjection or by the pharmacological inhibition of PGE 2 exportation and enzymatic degradation. We present here a new sight onto PGE 2 in colon cancer cells opening the way to a new prospective therapeutic strategy in cancer, alternative to NSAIDs

  11. Boron neutron capture therapy induces apoptosis of glioma cells through Bcl-2/Bax

    International Nuclear Information System (INIS)

    Wang, Peng; Zhen, Haining; Jiang, Xinbiao; Zhang, Wei; Cheng, Xin; Guo, Geng; Mao, Xinggang; Zhang, Xiang

    2010-01-01

    BPA-BNCT were significantly higher than those in Group B and Group C irradiated by [ 60 Co] γ-rays (P < 0.01). The clonogenicity of glioma cells was reduced by BPA-BNCT compared with cells treated in the reactor (Group F, G, H, I), and with the control cells (P < 0.01). Upon BPA-BNCT treatment, the Bax level increased in glioma cells, whereas Bcl-2 expression decreased. Compared with γ-ray and reactor neutron irradiation, a higher RBE can be achieved upon treatment of glioma cells with BNCT. Glioma cell apoptosis induced by BNCT may be related to activation of Bax and downregulation of Bcl-2

  12. Boron neutron capture therapy induces apoptosis of glioma cells through Bcl-2/Bax

    Directory of Open Access Journals (Sweden)

    Mao Xinggang

    2010-12-01

    BNCT may be related to activation of Bax and downregulation of Bcl-2.

  13. Ellagic acid protects against neuron damage in ischemic stroke through regulating the ratio of Bcl-2/Bax expression.

    Science.gov (United States)

    Liu, Qing-Shan; Deng, Ran; Li, Shuran; Li, Xu; Li, Keqin; Kebaituli, Gulibanumu; Li, Xueli; Liu, Rui

    2017-08-01

    An oxygen-glucose deprivation and reoxygenation model in primary cultured rat cortical neurons was developed for this study to investigate the effects of ellagic acid (EA), a low-molecular-weight polyphenol, on neuron cells and their function, and to evaluate whether EA can be safely utilized by humans as a functional food or therapeutic agent. Administration of EA significantly decreased the volume of cerebrum infarction and the neurological deficit scores of the rats; EA treatment also increased the number of Bcl-2-positive cells and the ratio of Bcl-2-positive to Bax-positive neurons in the semidarkness zone near the brain ischemic focus in the photothrombotic cerebral ischemia model. Treatment of EA resulted in increased neuron viability, cell nuclear integrity, and the ratio of Bcl-2/Bax expression in the primary cultured neuron model; EA treatment also lead to a decrease in the number of apoptotic cells. Our results therefore suggest a specific mechanism for the beneficial effects of EA, providing new insights into how it provides neuroprotection. To the best of our knowledge, these results represent new insights on the mechanisms of the brain cell protective activity of EA. Thus, EA may be used in functional foods or medicines to help treat nerve dysfunction, neurodegenerative disease, and aging.

  14. ERK1/2 signalling protects against apoptosis following endoplasmic reticulum stress but cannot provide long-term protection against BAX/BAK-independent cell death.

    Science.gov (United States)

    Darling, Nicola J; Balmanno, Kathryn; Cook, Simon J

    2017-01-01

    Disruption of protein folding in the endoplasmic reticulum (ER) causes ER stress. Activation of the unfolded protein response (UPR) acts to restore protein homeostasis or, if ER stress is severe or persistent, drive apoptosis, which is thought to proceed through the cell intrinsic, mitochondrial pathway. Indeed, cells that lack the key executioner proteins BAX and BAK are protected from ER stress-induced apoptosis. Here we show that chronic ER stress causes the progressive inhibition of the extracellular signal-regulated kinase (ERK1/2) signalling pathway. This is causally related to ER stress since reactivation of ERK1/2 can protect cells from ER stress-induced apoptosis whilst ERK1/2 pathway inhibition sensitises cells to ER stress. Furthermore, cancer cell lines harbouring constitutively active BRAFV600E are addicted to ERK1/2 signalling for protection against ER stress-induced cell death. ERK1/2 signalling normally represses the pro-death proteins BIM, BMF and PUMA and it has been proposed that ER stress induces BIM-dependent cell death. We found no evidence that ER stress increased the expression of these proteins; furthermore, BIM was not required for ER stress-induced death. Rather, ER stress caused the PERK-dependent inhibition of cap-dependent mRNA translation and the progressive loss of pro-survival proteins including BCL2, BCLXL and MCL1. Despite these observations, neither ERK1/2 activation nor loss of BAX/BAK could confer long-term clonogenic survival to cells exposed to ER stress. Thus, ER stress induces cell death by at least two biochemically and genetically distinct pathways: a classical BAX/BAK-dependent apoptotic response that can be inhibited by ERK1/2 signalling and an alternative ERK1/2- and BAX/BAK-independent cell death pathway.

  15. ERK1/2 signalling protects against apoptosis following endoplasmic reticulum stress but cannot provide long-term protection against BAX/BAK-independent cell death.

    Directory of Open Access Journals (Sweden)

    Nicola J Darling

    Full Text Available Disruption of protein folding in the endoplasmic reticulum (ER causes ER stress. Activation of the unfolded protein response (UPR acts to restore protein homeostasis or, if ER stress is severe or persistent, drive apoptosis, which is thought to proceed through the cell intrinsic, mitochondrial pathway. Indeed, cells that lack the key executioner proteins BAX and BAK are protected from ER stress-induced apoptosis. Here we show that chronic ER stress causes the progressive inhibition of the extracellular signal-regulated kinase (ERK1/2 signalling pathway. This is causally related to ER stress since reactivation of ERK1/2 can protect cells from ER stress-induced apoptosis whilst ERK1/2 pathway inhibition sensitises cells to ER stress. Furthermore, cancer cell lines harbouring constitutively active BRAFV600E are addicted to ERK1/2 signalling for protection against ER stress-induced cell death. ERK1/2 signalling normally represses the pro-death proteins BIM, BMF and PUMA and it has been proposed that ER stress induces BIM-dependent cell death. We found no evidence that ER stress increased the expression of these proteins; furthermore, BIM was not required for ER stress-induced death. Rather, ER stress caused the PERK-dependent inhibition of cap-dependent mRNA translation and the progressive loss of pro-survival proteins including BCL2, BCLXL and MCL1. Despite these observations, neither ERK1/2 activation nor loss of BAX/BAK could confer long-term clonogenic survival to cells exposed to ER stress. Thus, ER stress induces cell death by at least two biochemically and genetically distinct pathways: a classical BAX/BAK-dependent apoptotic response that can be inhibited by ERK1/2 signalling and an alternative ERK1/2- and BAX/BAK-independent cell death pathway.

  16. Bax/Bcl-2 expression ratio in prediction of response to breast cancer radiotherapy

    Directory of Open Access Journals (Sweden)

    Hosein Azimian

    2018-03-01

    Full Text Available Objective(s: Radiotherapy is one of the most effective modalities of cancer therapy, but clinical responses of individual patients varies considerably. To enhance treatment efficiency it is essential to implement an individual-based treatment. The aim of present study was to identify the mechanism of intrinsic apoptosis pathway on radiosensitivity and normal tissue complications caused by the radiotherapy. Materials and Methods: Peripheral blood mononuclear cells from ten breast cancer patients were exposed to 6MV X-rays to deliver 1 and 2 Gy. Expression levels of Bax, Bcl-2, and Bax/Bcl-2 ratio were examined by relative quantitative RT-PCR. All the patients received similar tangential irradiation of the whole breast and conventional fractionation. Skin dosimetry was done by GAFChromic EBT-3 film and clinical radiosensitivity was determined using the acute reactions to radiotherapy of the skin according to Radiation Therapy Oncology Group score. All statistical analyses were performed using GraphPad Prism, version 7.01. Results: In the in-vitro experiment, Bax and Bax/Bcl-2 ratios were significantly increased with 1 and 2 Gy doses (PP0.05 for all patients. Conclusion: Significant correlation between Bax/Bcl-2 ratio determined before radiation therapy and clinical response in the patients, can be used as a biomarker to identify radiosensitive individuals. However, further studies are required to validate radiation-induced apoptotic biomarkers.

  17. The studies on thyrocyte apoptosis and expression of Bcl-2 and Bax in Hashimoto's thyroiditis

    International Nuclear Information System (INIS)

    Zhao Yaping; Wang Jialing; Fan Zhiyong; Liu Zehong; Wu HeJun; Zhou Wei; Jia Meizhai

    2003-01-01

    To investigate the thyrocyte apoptosis, the expression of Bcl-2, Bax and the relationship between apoptosis and the pathogenesis in Hashimoto's thyroiditis (HT), 41 HT thyroid and 10 normal thyroid specimens were selected. The level of apoptosis was detected by TUNEL methods. The expression and distribution of Bcl-2 and Bax were detected using immunohistochemical methods and analyzed by Mias99 pathological image system. Immunohistochemical staining was carried out using S-P kit. The Result showed that an increased level of apoptosis was observed in Hashimoto's glands. The apoptosis mainly distributed in thyroid follicles destruction area. This was associated with increased Bax expression. The strongly positive Bcl-2 staining was observed in the thyrocyte of intact thyroid follicles. The ratios of positive granule area and total light density of Bcl-2 to those of Bax in HT thyroid follicle area were lower than those in normal thyroid. The apoptosis of thyrocyte induced by dysregulation of Bcl-2 and Bax may be involved in the pathogeneses of HT

  18. Ethanol Influences on Bax Associations with Mitochondrial Membrane Proteins in Neonatal Rat Cerebellum

    Science.gov (United States)

    Heaton, Marieta Barrow; Siler-Marsiglio, Kendra; Paiva, Michael; Kotler, Alexandra; Rogozinski, Jonathan; Kubovec, Stacey; Coursen, Mary; Madorsky, Vladimir

    2012-01-01

    These studies investigated interactions taking place at the mitochondrial membrane in neonatal rat cerebellum following ethanol exposure, and focused on interactions between pro-apoptotic Bax and proteins of the permeability transition pore (PTP), voltage-dependent anion channel (VDAC), and adenine nucleotide translocator (ANT), of the outer and inner mitochondrial membranes, respectively. Cultured cerebellar granule cells were used to assess the role of these interactions in ethanol neurotoxicity. Analyses were made at the age of maximal cerebellar ethanol vulnerability (P4), compared to the later age of relative resistance (P7), to determine whether differential ethanol sensitivity was mirrored by differences in these molecular interactions. We found that following ethanol exposure, Bax pro-apoptotic associations with both VDAC and ANT were increased, particularly at the age of greater ethanol sensitivity, and these interactions were sustained at this age for at least two hours post-exposure. Since Bax:VDAC interactions disrupt protective VDAC interactions with mitochondrial hexokinase (HXK), we also assessed VDAC:HXK associations following ethanol treatment, and found such interactions were altered by ethanol treatment, but only at two-hours post-exposure, and only in the P4, ethanol-sensitive cerebellum. Ethanol neurotoxicity in cultured neuronal preparations was abolished by pharmacological inhibition of both VDAC and ANT interactions with Bax, but not by a Bax channel blocker. Therefore, we conclude that at this age, within the constraints of our experimental model, a primary mode of Bax-induced initiation of the apoptosis cascade following ethanol insult involves interactions with proteins of the PTP complex, and not channel formation independent of PTP constituents. PMID:22767450

  19. TGFBR2 and BAX mononucleotide tract mutations, microsatellite instability, and prognosis in 1072 colorectal cancers.

    Directory of Open Access Journals (Sweden)

    Kaori Shima

    Full Text Available Mononucleotide tracts in the coding regions of the TGFBR2 and BAX genes are commonly mutated in microsatellite instability-high (MSI-high colon cancers. The receptor TGFBR2 plays an important role in the TGFB1 (transforming growth factor-β, TGF-β signaling pathway, and BAX plays a key role in apoptosis. However, a role of TGFBR2 or BAX mononucleotide mutation in colorectal cancer as a prognostic biomarker remains uncertain.We utilized a database of 1072 rectal and colon cancers in two prospective cohort studies (the Nurses' Health Study and the Health Professionals Follow-up Study. Cox proportional hazards model was used to compute mortality hazard ratio (HR, adjusted for clinical, pathological and molecular features including the CpG island methylator phenotype (CIMP, LINE-1 methylation, and KRAS, BRAF and PIK3CA mutations. MSI-high was observed in 15% (162/1072 of all colorectal cancers. TGFBR2 and BAX mononucleotide mutations were detected in 74% (117/159 and 30% (48/158 of MSI-high tumors, respectively. In Kaplan-Meier analysis as well as univariate and multivariate Cox regression analyses, compared to microsatellite stable (MSS/MSI-low cases, MSI-high cases were associated with superior colorectal cancer-specific survival [adjusted HR, 0.34; 95% confidence interval (CI, 0.20-0.57] regardless of TGFBR2 or BAX mutation status. Among MSI-high tumors, TGFBR2 mononucleotide mutation was associated with CIMP-high independent of other variables [multivariate odds ratio, 3.57; 95% CI, 1.66-7.66; p = 0.0011].TGFBR2 or BAX mononucleotide mutations are not associated with the patient survival outcome in MSI-high colorectal cancer. Our data do not support those mutations as prognostic biomarkers (beyond MSI in colorectal carcinoma.

  20. Differential Effects of Ethanol on c-Jun N-Terminal Kinase, 14-3-3 Proteins, and Bax in Postnatal Day 4 and Postnatal Day 7 Rat Cerebellum

    Science.gov (United States)

    Heaton, Marieta Barrow; Paiva, Michael; Kubovic, Stacey; Kotler, Alexandra; Rogozinski, Jonathan; Swanson, Eric; Madorsky, Vladimir; Posados, Michelle

    2011-01-01

    These studies investigated ethanol effects on upstream cellular elements and interactions which contribute to Bax-related apoptosis in neonatal rat cerebellum at ages of peak ethanol sensitivity (postnatal day 4 [P4]), compared to later ages of relative resistance (P7). Analyses were made of basal levels of the pro-apoptotic c-jun N-termimal kinase (JNK), Bax, and the 14-3-3 anchoring proteins, as well as the responsiveness of these substances to ethanol at P4 versus P7. Dimerization of Bax with 14-3-3 was also investigated at the two ages following ethanol treatment, a process which sequesters Bax in the cytosol, thus inhibiting its mitochondrial translocation and disruption of the mitochondrial membrane potential. Cultured cerebellar granule cells were used to examine the protective potential of JNK inhibition on ethanol-mediated cell death. Basal levels of JNK were significantly higher at P4 than P7, but no differences in the other proteins were found. Activated JNK, and cytosolic and mitochondrially-translocated Bax were increased in P4 but not P7 animals following ethanol exposure, while protective 14-3-3 proteins were increased only at P7. Ethanol treatment resulted in decreases in Bax:14-3-3 heterodimers at P4, but not at P7. Inhibition of JNK activity in vitro provided partial protection against ethanol neurotoxicity. Thus, differential temporal vulnerability to ethanol in this CNS region correlates with differences in both levels of apoptosis-related substances (e.g., JNK), and differential cellular responsiveness, favoring apoptosis at the most sensitive age and survival at the resistant age. The upstream elements contributing to this vulnerability can be targets for future therapeutic strategies. PMID:22169498

  1. The effect of N-nitrosodimethylamine (NDMA) on Bax and Mcl-1 expression in human neutrophils.

    Science.gov (United States)

    Jablonski, Jakub; Jablonska, Ewa; Leonik, Agnieszka

    2011-12-01

    In the present study we examined a role of pro-apoptotic Bax and anti-apoptotic Mcl-1 proteins, participating in the regulation of intrinsic apoptosis pathway in human neutrophils (PMNs) exposed to N-nitrosodimethylamine (NDMA), the environmental xenobiotic. For the purpose comparison, the same studies were conducted in autologous peripheral blood mononuclear cells (PBMCs). The production of cytochrome c by PMNs was also determined. A deficit of anti-apoptotic Mcl-1 and overexpression of the pro-apoptotic protein Bax suggest that the apoptosis process in human neutrophils exposed to NDMA is dependent on changes in the expression of these proteins. PMNs were more sensitive to NDMA than PBMCs.

  2. 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).

  3. Piracetam ameliorated oxygen and glucose deprivation-induced injury in rat cortical neurons via inhibition of oxidative stress, excitatory amino acids release and P53/Bax.

    Science.gov (United States)

    He, Zhi; Hu, Min; Zha, Yun-hong; Li, Zi-cheng; Zhao, Bo; Yu, Ling-ling; Yu, Min; Qian, Ying

    2014-05-01

    Our previous work has demonstrated that piracetam inhibited the decrease in amino acid content induced by chronic hypoperfusion, ameliorated the dysfunction of learning and memory in a hypoperfusion rat model, down-regulated P53, and BAX protein, facilitated the synaptic plasticity, and may be helpful in the treatment of vascular dementia. To explore the precise mechanism, the present study further evaluated effects of piracetam on Oxygen and glucose deprivation (OGD)-induced neuronal damage in rat primary cortical cells. The addition of piracetam to the cultured cells 12 h before OGD for 4 h significantly reduced neuronal damage as determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and lactate dehydrogenase release experiments. Piracetam also lowered the levels of malondialdehyde, nitrogen monoxidum, and xanthine oxidase which was increased in the OGD cells, and enhanced the activities of superoxide dismutase and glutathione peroxidase, which were decreased in the OGD cells. We also demonstrated that piracetam could decrease glutamate and aspartate release when cortical cells were subjected to OGD. Furthermore, Western blot study demonstrated that piracetam attenuated the increased expression of P53 and BAX protein in OGD cells. These observations demonstrated that piracetam reduced OGD-induced neuronal damage by inhibiting the oxidative stress and decreasing excitatory amino acids release and lowering P53/Bax protein expression in OGD cells.

  4. DHT inhibits the Aβ25-35-induced apoptosis by regulation of seladin-1, survivin, XIAP, bax, and bcl-xl expression through a rapid PI3-K/Akt signaling in C6 glial cell lines.

    Science.gov (United States)

    Bing, Lelin; Wu, Junfeng; Zhang, Jianfeng; Chen, Yinghui; Hong, Zhen; Zu, Hengbing

    2015-01-01

    Previous evidences indicate that androgen is neuroprotective in the brain. However, the underling mechanisms remain to be fully elucidated. Moreover, it is controversial whether dihydrotestosterone (DHT) modulates the expression of apoptosis-related effectors, such as survivin, XIAP, bax, and bcl-xl proteins mediated by the PI3-K/Akt pathway, which contributes to androgen neuroprotection. In this study using a C6 glial cell model, apoptotic cells were detected by flow cytometry. Akt, seladin-1, survivin, XIAP, bcl-xl, and bax protein expression is investigated by Western blot. After amyloid β-protein fragment (Aβ25-35) treatment, apoptotic cells at early (annexin V+, PI-) and late (annexin V+, PI+) stages were significantly increased. Apoptosis at early and late was obviously inhibited in the presence of DHT. The effect of DHT was markedly blocked by PI3-K inhibitor LY294002.To elicit the mechanism of DHT protection, the expression of seladin-1, survivin, XIAP, bax, and bcl-xl protein was determined in C6 cells treated with Aβ25-35, DHT, or LY294002. Aβ25-35 significantly downregulated the expression of seladin-1, survivin, XIAP, bcl-xl protein and upregulated the expression of bax protein. DHT significantly inhibited the expression of bax, seladin-1, survivin, XIAP, and bcl-xl protein induced by Aβ25-35. Further, we found the effect of DHT was significantly inhibited by LY294002. Collectively, in a C6 glial cell model, we firstly found that DHT inhibits Aβ25-35-induced apoptosis by a rapid nongenic PI-3K/Akt activation as well as regulation of seladin-1, survivin, XIAP, bcl-xl, and bax proteins.

  5. A Small-Molecule Inhibitor of Bax and Bak Oligomerization Prevents Genotoxic Cell Death and Promotes Neuroprotection.

    Science.gov (United States)

    Niu, Xin; Brahmbhatt, Hetal; Mergenthaler, Philipp; Zhang, Zhi; Sang, Jing; Daude, Michael; Ehlert, Fabian G R; Diederich, Wibke E; Wong, Eve; Zhu, Weijia; Pogmore, Justin; Nandy, Jyoti P; Satyanarayana, Maragani; Jimmidi, Ravi K; Arya, Prabhat; Leber, Brian; Lin, Jialing; Culmsee, Carsten; Yi, Jing; Andrews, David W

    2017-04-20

    Aberrant apoptosis can lead to acute or chronic degenerative diseases. Mitochondrial outer membrane permeabilization (MOMP) triggered by the oligomerization of the Bcl-2 family proteins Bax/Bak is an irreversible step leading to execution of apoptosis. Here, we describe the discovery of small-molecule inhibitors of Bax/Bak oligomerization that prevent MOMP. We demonstrate that these molecules disrupt multiple, but not all, interactions between Bax dimer interfaces thereby interfering with the formation of higher-order oligomers in the MOM, but not recruitment of Bax to the MOM. Small-molecule inhibition of Bax/Bak oligomerization allowed cells to evade apoptotic stimuli and rescued neurons from death after excitotoxicity, demonstrating that oligomerization of Bax is essential for MOMP. Our discovery of small-molecule Bax/Bak inhibitors provides novel tools for the investigation of the mechanisms leading to MOMP and will ultimately facilitate development of compounds inhibiting Bax/Bak in acute and chronic degenerative diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. The oxidized phospholipid PazePC promotes permeabilization of mitochondrial membranes by Bax

    Czech Academy of Sciences Publication Activity Database

    Lidman, M.; Pokorná, Šárka; Dingeldein, A. P. G.; Sparrman, T.; Wallgren, M.; Šachl, Radek; Hof, Martin; Gröbner, G.

    2016-01-01

    Roč. 1858, č. 6 (2016), s. 1288-1297 ISSN 0005-2736 R&D Projects: GA ČR GBP208/12/G016 Institutional support: RVO:61388955 Keywords : Apoptosis * Bax-protein * Calorimetry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.498, year: 2016

  7. Estradiol increases the Bax/Bcl-2 ratio and induces apoptosis in the anterior pituitary gland.

    Science.gov (United States)

    Zaldivar, Verónica; Magri, María Laura; Zárate, Sandra; Jaita, Gabriela; Eijo, Guadalupe; Radl, Daniela; Ferraris, Jimena; Pisera, Daniel; Seilicovich, Adriana

    2009-01-01

    Estrogens are recognized as acting as modulators of pituitary cell renewal, sensitizing cells to mitogenic and apoptotic signals, thus participating in anterior pituitary homeostasis during the estrous cycle. The balance of pro- and antiapoptotic proteins of the Bcl-2 family is known to regulate cell survival and apoptosis. In order to understand the mechanisms underlying apoptosis during the estrous cycle, we evaluated the expression of the proapoptotic protein Bax and the antiapoptotic proteins Bcl-2 and Bcl-xL in the anterior pituitary gland in cycling female rats as well as the influence of estradiol on the expression of these proteins in anterior pituitary cells of ovariectomized rats. As determined by Western blot, the expression of Bax was higher in anterior pituitary glands from rats at proestrus than at diestrus I, Bcl-2 protein levels showed no difference and Bcl-xL expression was lower, thus increasing the Bax/Bcl-2 ratio at proestrus. Assessed by annexin V binding and flow cytometry, the percentage of apoptotic anterior pituitary cells was higher in rats at proestrus than at diestrus I. Chronic estrogen treatment in ovariectomized rats enhanced the Bax/Bcl-2 ratio and induced apoptosis. Moreover, incubation of cultured anterior pituitary cells from ovariectomized rats with 17beta-estradiol for 24 h increased the Bax/Bcl-2 ratio, decreased Bcl-xL expression and induced apoptosis. Our results demonstrate that estradiol increases the ratio between proapoptotic and antiapoptotic proteins of the Bcl-2 family. This effect could participate in the sensitizing action of estrogens to proapoptotic stimuli and therefore be involved in the high apoptotic rate observed at proestrus in the anterior pituitary gland.

  8. The radiosensitivity of glioblastoma cell lines after hypoxia-induced Bax expression

    International Nuclear Information System (INIS)

    Chen, J.K.; Hu, L.J.; Kong, E.L.; Lamborn, K.R.; Deen, D.F.

    2003-01-01

    Full text: Radiation therapy is the most effective treatment after surgery for patients with malignant gliomas. However, the hypoxic cells exclusive to tumor tissue have proven resistant to both radiotherapy and many forms of chemotherapy. In order to specifically target these hypoxic cells, U-251 MG and U-87 MG human glioblastoma cells were stably transfected with constructs containing the suicide gene Bax under the regulation of nine copies of hypoxia-responsive elements (HREs). During hypoxia, the transcriptional complex hypoxia-inducible-factor 1 (HIF-1) binds to HRE and facilitates the transcription of downstream genes. Previously, hypoxia-induced Bax expression in transfected U-251 and U-87 clone cells has been shown to increase cell killing. The benefits of the gene therapy could be further expanded if Bax also acted to increase the sensitivity of these clone cells to radiation. To determine whether this was the case, parent and clone cells were irradiated with graded doses of X-rays under hypoxic conditions. These cells were then left hypoxic for varying durations of time, after which they were incubated for two weeks under aerated conditions to assay for clonogenic cell survival. After less than an hour under hypoxia, both U-251 and U-87 clone cells appeared significantly more sensitive to radiation than their respective parent cells. However, after longer amounts of time under anoxia, higher surviving fractions were found in each clone that were consistent with those of their respective parent cell line, showing that potentially lethal damage repair (PLDR) had occurred in the clone cells. Parent cells did not exhibit PLDR. Results are inconclusive at this point in time. Western blot analyses detailing the amount of Bax expression at each time point as well as further research exploring different durations of hypoxia will be necessary to reveal the nature of the correlation between Bax expression and radiosensitivity. Supported by NS-42927 and CA-85356

  9. Opposite role of Bax and BCL-2 in the anti-tumoral responses of the immune system

    International Nuclear Information System (INIS)

    Bougras, Gwenola; Cartron, Pierre-François; Gautier, Fabien; Martin, Stéphane; LeCabellec, Marité; Meflah, Khaled; Gregoire, Marc; Vallette, François M

    2004-01-01

    The relative role of anti apoptotic (i.e. Bcl-2) or pro-apoptotic (e.g. Bax) proteins in tumor progression is still not completely understood. The rat glioma cell line A15A5 was stably transfected with human Bcl-2 and Bax transgenes and the viability of theses cell lines was analyzed in vitro and in vivo. In vitro, the transfected cell lines (huBax A15A5 and huBcl-2 A15A5) exhibited different sensitivities toward apoptotic stimuli. huBax A15A5 cells were more sensitive and huBcl-2 A15A5 cells more resistant to apoptosis than mock-transfected A15A5 cells (pCMV A15A5). However, in vivo, in syngenic rat BDIX, these cell lines behaved differently, as no tumor growth was observed with huBax A15A5 cells while huBcl-2 A15A5 cells formed large tumors. The immune system appeared to be involved in the rejection of huBax A15A5 cells since i) huBax A15A5 cells were tumorogenic in nude mice, ii) an accumulation of CD8+ T-lymphocytes was observed at the site of injection of huBax A15A5 cells and iii) BDIX rats, which had received huBax A15A5 cells developed an immune protection against pCMV A15A5 and huBcl-2 A15A5 cells. We show that the expression of Bax and Bcl-2 controls the sensitivity of the cancer cells toward the immune system. This sensitization is most likely to be due to an increase in immune induced cell death and/or the amplification of an anti tumour immune response

  10. Effect of polysaccharides from Angelica sinensis on Bcl-2 and Bax protein expression of irradiated liver cells

    International Nuclear Information System (INIS)

    Sun Yuanlin; Tang Jian; Gu Xiaohong; Li Deyuan

    2009-01-01

    Objective: To investigate the effect of polysaccharides from Angelica sinensis (ASP3) on Bcl-2 and Bax protein expression of irradiated liver cells from mice. Methods: Bcl-2 and Bax protein expression of liver cells in vitro exposed to 2.0 Gy rays were examined by using immunohistochemistry method. Results: The expression of apoptosis-accelerating protein Bax in the irradiation group was enhanced obviously (70.83%), while apoptosis inhibiting protein Bcl-2 tended to decline (55.60%), with the statistically significant difference (P <0.01) compared with that of the control. ASP3 pretreatment could regulate Bcl-2 and Bax protein expression of liver cells, inhibiting Bax protein expression(64.14/58.37%) and increasing Bcl-2 protein expression(59.21%/ 67.45%). The differences between the high dosage (100 mg/L of ASP3) and the irradiation group were statistically significant (P<0.05). Conclusions: ASP3 pretreatment could prohibit the apoptosis of radiation- damaged liver cells due to abnormal expression of Bcl-2 and Bax, and reduce the cell apoptosis by increasing Bcl-2/Bax protein expression so as to enhance the radiation endurance of liver cells. (authors)

  11. 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.

  12. The BH3 α-Helical Mimic BH3-M6 Disrupts Bcl-XL, Bcl-2, and MCL-1 Protein-Protein Interactions with Bax, Bak, Bad, or Bim and Induces Apoptosis in a Bax- and Bim-dependent Manner*

    Science.gov (United States)

    Kazi, Aslamuzzaman; Sun, Jiazhi; Doi, Kenichiro; Sung, Shen-Shu; Takahashi, Yoshinori; Yin, Hang; Rodriguez, Johanna M.; Becerril, Jorge; Berndt, Norbert; Hamilton, Andrew D.; Wang, Hong-Gang; Sebti, Saïd M.

    2011-01-01

    A critical hallmark of cancer cell survival is evasion of apoptosis. This is commonly due to overexpression of anti-apoptotic proteins such as Bcl-2, Bcl-XL, and Mcl-1, which bind to the BH3 α-helical domain of pro-apoptotic proteins such as Bax, Bak, Bad, and Bim, and inhibit their function. We designed a BH3 α-helical mimetic BH3-M6 that binds to Bcl-XL and Mcl-1 and prevents their binding to fluorescently labeled Bak- or Bim-BH3 peptides in vitro. Using several approaches, we demonstrate that BH3-M6 is a pan-Bcl-2 antagonist that inhibits the binding of Bcl-XL, Bcl-2, and Mcl-1 to multi-domain Bax or Bak, or BH3-only Bim or Bad in cell-free systems and in intact human cancer cells, freeing up pro-apoptotic proteins to induce apoptosis. BH3-M6 disruption of these protein-protein interactions is associated with cytochrome c release from mitochondria, caspase-3 activation and PARP cleavage. Using caspase inhibitors and Bax and Bak siRNAs, we demonstrate that BH3-M6-induced apoptosis is caspase- and Bax-, but not Bak-dependent. Furthermore, BH3-M6 disrupts Bcl-XL/Bim, Bcl-2/Bim, and Mcl-1/Bim protein-protein interactions and frees up Bim to induce apoptosis in human cancer cells that depend for tumor survival on the neutralization of Bim with Bcl-XL, Bcl-2, or Mcl-1. Finally, BH3-M6 sensitizes cells to apoptosis induced by the proteasome inhibitor CEP-1612. PMID:21148306

  13. The BH3 alpha-helical mimic BH3-M6 disrupts Bcl-X(L), Bcl-2, and MCL-1 protein-protein interactions with Bax, Bak, Bad, or Bim and induces apoptosis in a Bax- and Bim-dependent manner.

    Science.gov (United States)

    Kazi, Aslamuzzaman; Sun, Jiazhi; Doi, Kenichiro; Sung, Shen-Shu; Takahashi, Yoshinori; Yin, Hang; Rodriguez, Johanna M; Becerril, Jorge; Berndt, Norbert; Hamilton, Andrew D; Wang, Hong-Gang; Sebti, Saïd M

    2011-03-18

    A critical hallmark of cancer cell survival is evasion of apoptosis. This is commonly due to overexpression of anti-apoptotic proteins such as Bcl-2, Bcl-X(L), and Mcl-1, which bind to the BH3 α-helical domain of pro-apoptotic proteins such as Bax, Bak, Bad, and Bim, and inhibit their function. We designed a BH3 α-helical mimetic BH3-M6 that binds to Bcl-X(L) and Mcl-1 and prevents their binding to fluorescently labeled Bak- or Bim-BH3 peptides in vitro. Using several approaches, we demonstrate that BH3-M6 is a pan-Bcl-2 antagonist that inhibits the binding of Bcl-X(L), Bcl-2, and Mcl-1 to multi-domain Bax or Bak, or BH3-only Bim or Bad in cell-free systems and in intact human cancer cells, freeing up pro-apoptotic proteins to induce apoptosis. BH3-M6 disruption of these protein-protein interactions is associated with cytochrome c release from mitochondria, caspase-3 activation and PARP cleavage. Using caspase inhibitors and Bax and Bak siRNAs, we demonstrate that BH3-M6-induced apoptosis is caspase- and Bax-, but not Bak-dependent. Furthermore, BH3-M6 disrupts Bcl-X(L)/Bim, Bcl-2/Bim, and Mcl-1/Bim protein-protein interactions and frees up Bim to induce apoptosis in human cancer cells that depend for tumor survival on the neutralization of Bim with Bcl-X(L), Bcl-2, or Mcl-1. Finally, BH3-M6 sensitizes cells to apoptosis induced by the proteasome inhibitor CEP-1612.

  14. p53-Dependent radiation-induced apoptosis in vivo: relationship to Bcl-2 and Bax expression

    International Nuclear Information System (INIS)

    Hasegawa, Masatoshi; Suzuki, Yoshiyuki; Furuta, Masaya; Yamakawa, Michitaka; Maebayashi, Katsuya; Hayakawa, Kayoko; Saito, Yoshihiro; Mitsuhashi, Norio; Niibe, Hideo

    1997-01-01

    Purpose: A close correlation between p53 protein expression and radiation-induced apoptosis has already been reported, however, Bcl-2 and Bax expression and the ratio of Bcl-2 to Bax have been also suggested to play an important role in the regulation of apoptotic cell death. In this study, we investigated the relationship between p53-dependent radiation-induced apoptosis and expression of Bcl-2 and Bax by using human tumors transplanted into nude mice. Materials and Methods: Three human tumors (an ependymoblastoma, a glioblastoma, and a small cell lung cancer) were subcutaneously transplanted into nude mice and irradiated with single doses of 1, 2, 5, or 10 Gy. The tumors were excised 1, 3, 6, 12, 24, and 48 hours after irradiation, fixed in 10% formalin for 24 hours, and embedded in paraffin. Slides were stained with hematoxylin and eosin for morphologic examination. Immunohistochemical studies were performed with mouse monoclonal antibodies to demonstrate p53, p21 (WAF-1), Bcl-2, and Bax expression. TdT-mediated dUTP-biotin nick-end labeling (TUNEL) and electron microscopic studies were performed to identify apoptosis, and PCR-SSCP analysis was used to evaluate p53 gene mutation. Results: All of the tumors showed only a few cells undergoing apoptosis before irradiation. Beginning several hours after irradiation, only the ependymoblastoma showed a large increase in the number of cells undergoing apoptosis, peaking at 6 hours after irradiation, and there was a clear dose-effect relationship. In contrast, the other tumors showed much less change following irradiation, and the dose-effect relationship was not as clear as in the ependymoblastoma. Immunohistochemically, the non-irradiated ependymoblastoma was negative for p53, p21, Bcl-2, and Bax. Following irradiation, however, many of the tumor cells became positive for p53 and p21, and a few cells became positive for bcl-2. In contrast, the glioblastoma and the small cell lung cancer were positive for p53 and Bcl-2

  15. Expanded polyglutamine embedded in the endoplasmic reticulum causes membrane distortion and coincides with Bax insertion

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Masashi; Li, Shimo; Itoh, Masanori; Wang, Miao-xing; Hayakawa, Miki; Islam, Saiful; Tana; Nakagawa, Kiyomi [Department of Neurobiology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan); Chen, Huayue [Department of Anatomy, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan); Nakagawa, Toshiyuki, E-mail: tnakagaw@gifu-u.ac.jp [Department of Neurobiology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan)

    2016-05-27

    The endoplasmic reticulum (ER) is important in various cellular functions, such as secretary and membrane protein biosynthesis, lipid synthesis, and calcium storage. ER stress, including membrane distortion, is associated with many diseases such as Huntington's disease. In particular, nuclear envelope distortion is related to neuronal cell death associated with polyglutamine. However, the mechanism by which polyglutamine causes ER membrane distortion remains unclear. We used electron microscopy, fluorescence protease protection assay, and alkaline treatment to analyze the localization of polyglutamine in cells. We characterized polyglutamine embedded in the ER membrane and noted an effect on morphology, including the dilation of ER luminal space and elongation of ER-mitochondria contact sites, in addition to the distortion of the nuclear envelope. The polyglutamine embedded in the ER membrane was observed at the same time as Bax insertion. These results demonstrated that the ER membrane may be a target of polyglutamine, which triggers cell death through Bax. -- Highlights: •We characterized polyglutamine embedded in the ER membrane. •The polyglutamine embedded in the ER membrane was observed at the same time as Bax insertion. •The ER membrane may be a target of polyglutamine, which triggers cell death.

  16. Caspase-3/-8/-9, Bax and Bcl-2 expression in the cerebellum, lymph nodes and leukocytes of dogs naturally infected with canine distemper virus.

    Science.gov (United States)

    Del Puerto, H L; Martins, A S; Moro, L; Milsted, A; Alves, F; Braz, G F; Vasconcelos, A C

    2010-01-26

    Canine distemper is an immunosuppressive disease caused by the canine distemper virus (CDV). Pathogenesis mainly involves the central nervous system and immunosuppression. Dogs naturally infected with CDV develop apoptotic cells in lymphoid tissues and the cerebellum, but this apoptotic mechanism is not well characterized. To better understand this process, we evaluated the expression of Bax, Bcl-2, and caspase-3, -8 and -9, by evaluating mRNA levels in the peripheral blood, lymph nodes and cerebellum of CDV-infected (CDV+) and uninfected (CDV-) dogs by real-time polymerase chain reaction (PCR). Blood samples from 12 CDV+ and 8 CDV- dogs, diagnosed by reverse transcription-PCR, were subjected to hematological analysis and apoptotic gene expression was evaluated using real-time-PCR. Tissues from the cerebellum and lymph nodes of four CDV+ and three CDV-dogs were also subjected to real time-PCR. No significant differences were found between CDV+ and CDV- dogs in the hemotological results or in the expression of caspase-3, -8, -9, Bax, and Bcl-2 in the peripheral blood. However, expression of Bax, caspase-3, -8 and -9 was significantly higher in the cerebellum of CDV+ compared to CDV- dogs. Expression of caspase-3 and -8 was significantly higher in the lymph nodes of CDV+ compared to CDV- dogs. We concluded that infection with CDV induces apoptosis in the cerebellum and lymph nodes in different ways. Lymph node apoptosis apparently occurs via caspase-3 activation, through the caspase-8 pathway, and cerebellum apoptosis apparently occurs via caspase-3 activation, through the caspase-8 and mitochondrial pathways.

  17. Gelsolin negatively regulates the activity of tumor suppressor p53 through their physical interaction in hepatocarcinoma HepG2 cells

    International Nuclear Information System (INIS)

    An, Joo-Hee; Kim, Jung-Woong; Jang, Sang-Min; Kim, Chul-Hong; Kang, Eun-Jin; Choi, Kyung-Hee

    2011-01-01

    Highlights: → The actin binding protein Gelsolin (GSN) interacts with transcription factor p53. → GSN interacts with transactivation- and DNA binding domains of p53. → GSN represses transactivity of p53 via inhibition of nuclear translocation of p53. → GSN inhibits the p53-mediated apoptosis in hepatocarcinoma HepG2 cells. -- Abstract: As a transcription factor, p53 modulates several cellular responses including cell-cycle control, apoptosis, and differentiation. In this study, we have shown that an actin regulatory protein, gelsolin (GSN), can physically interact with p53. The nuclear localization of p53 is inhibited by GSN overexpression in hepatocarcinoma HepG2 cells. Additionally, we demonstrate that GSN negatively regulates p53-dependent transcriptional activity of a reporter construct, driven by the p21-promoter. Furthermore, p53-mediated apoptosis was repressed in GSN-transfected HepG2 cells. Taken together, these results suggest that GSN binds to p53 and this interaction leads to the inhibition of p53-induced apoptosis by anchoring of p53 in the cytoplasm in HepG2 cells.

  18. Bax and Bak Do Not Exhibit Functional Redundancy in Mediating Radiation-Induced Endothelial Apoptosis in the Intestinal Mucosa

    International Nuclear Information System (INIS)

    Rotolo, Jimmy A.; Maj, Jerzy G.; Feldman, Regina; Ren, Decheng; Haimovitz-Friedman, Adriana; Cordon-Cardo, Carlos; Cheng, Emily H.-Y.; Kolesnick, Richard; Fuks, Zvi

    2008-01-01

    Purpose: To address in vivo the issue of whether Bax and Bak are functionally redundant in signaling apoptosis, capable of substituting for each other. Methods and Materials: Mice were exposed to whole-body radiation, and endothelial cell apoptosis was quantified using double immunostaining with TUNEL and anti-CD31 antibody. Crypt survival was determined at 3.5 days after whole-body radiation by the microcolony survival assay. Actuarial animal survival was calculated by the product-limit Kaplan-Meier method, and autopsies were performed to establish cause of death. Results: Radiation exposure of Bax- and Bak-deficient mice, both expressing a wild-type acid sphingomyelinase (ASMase) phenotype, indicated that Bax and Bak are both mandatory, though mutually independent, for the intestinal endothelial apoptotic response. However, neither affected epithelial apoptosis at crypt positions 4-5, indicating specificity toward endothelium. Furthermore, Bax deficiency and Bak deficiency each individually mimicked ASMase deficiency in inhibiting crypt lethality in the microcolony assay and in rescuing mice from the lethal gastrointestinal syndrome. Conclusions: The data indicate that Bax and Bak have nonredundant functional roles in the apoptotic response of the irradiated intestinal endothelium. The observation that Bax deficiency and Bak deficiency also protect crypts in the microcolony assay provides strong evidence that the microvascular apoptotic component is germane to the mechanism of radiation-induced damage to mouse intestines, regulating reproductive cell death of crypt stem cell clonogens

  19. Preclinical assessment of a new recombinant ADAMTS-13 drug product (BAX930) for the treatment of thrombotic thrombocytopenic purpura.

    Science.gov (United States)

    Kopić, A; Benamara, K; Piskernik, C; Plaimauer, B; Horling, F; Höbarth, G; Ruthsatz, T; Dietrich, B; Muchitsch, E-M; Scheiflinger, F; Turecek, M; Höllriegl, W

    2016-07-01

    Essentials ADAMTS-13-deficiency is a cause of thrombotic thrombocytopenic purpura (TTP). Preclinical safety of recombinant human ADAMTS-13 (BAX930) was shown in animal models. Preclinical efficacy of BAX930 was shown in a mouse model of TTP. BAX930 showed advantageous efficacy over fresh frozen plasma, the current standard of care. Click to hear Dr Cataland and Prof. Lämmle present a seminar on Thrombotic Thrombocytopenic Purpura (TTP): new Insights in Pathogenesis and Treatment Modalities. Background Thrombotic thrombocytopenic purpura (TTP) is a rare blood disorder characterized by microthrombosis in small blood vessels of the body, resulting in a low platelet count. Baxalta has developed a new recombinant ADAMTS-13 (rADAMTS-13) product (BAX930) for on-demand and prophylactic treatment of patients with hereditary TTP (hTTP). Objectives To evaluate the pharmacokinetics, efficacy and safety of BAX930 in different species, by use of an extensive preclinical program. Methods The prophylactic and therapeutic efficacies of BAX930 were tested in a previously established TTP mouse model. Pharmacokinetics were evaluated after single intravenous bolus injection in mice and rats, and after repeated dosing in cynomolgus monkeys. Toxicity was assessed in rats and monkeys, safety pharmacology in monkeys, and local tolerance in rabbits. Results BAX930 was shown to be efficacious, as demonstrated by a stabilized platelet count in ADAMTS-13 knockout mice that were thrombocytopenic when treated. Prophylactic efficacy was dose-dependent and comparable with that achieved by treatment with fresh frozen plasma, the mainstay of hTTP treatment. Therapeutic efficacy was treatment interval-dependent. Safety pharmacology evaluation did not show any deleterious effects of BAX930 on cardiovascular and respiratory functions in monkeys. The compound's pharmacokinetics were similar and dose-proportional in mice, rats, and monkeys. BAX930 was well tolerated in rats, monkeys, and rabbits, even

  20. Expressão da proteína Bax no tecido mamário normal de mulheres no menacme tratadas com raloxifeno Expression of Bax protein in normal tissue of premenopausal women treated with raloxifene

    Directory of Open Access Journals (Sweden)

    Ana Maria Furtado-Veloso

    2008-04-01

    Full Text Available OBJETIVO: avaliar a expressão do antígeno Bax no epitélio mamário normal de mulheres na pré-menopausa tratadas com raloxifeno. MÉTODOS: estudo randomizado duplo-cego, envolvendo 33 mulheres pré-menopáusicas com fibroadenoma. As pacientes foram divididas em dois grupos: Placebo, (n=18 e Raloxifeno 60 mg, (n=15. A medicação foi usada durante 22 dias, começando no primeiro dia do ciclo menstrual. Uma biópsia foi realizada no 23º dia do ciclo menstrual, durante a qual uma amostra do tecido mamário normal adjacente ao fibroadenoma foi coletada e submetida a estudo imuno-histoquímico utilizando o anticorpo policlonal anti-Bax para avaliar a expressão da proteína Bax. A imunorreação para a proteína Bax foi avaliada, levando-se em consideração a intensidade e a fração de células coradas, cuja combinação resultou em um escore final de 0 a 6. Os casos com escore final >3 foram classificados como positivos para proteína Bax. O teste do c2 foi usado para análise estatística dos dados (pPURPOSE: to evaluate the expression of Bax antigen in the normal mammary epithelium of premenopausal women treated with raloxifene. METHODS: a randomized double-blind study was conducted in 33 ovulatory premenopausal women with fibroadenoma. Patients were divided into two groups: Placebo, (n=18 and Raloxifene 60 mg, (n=15. The medication was used for 22 days, beginning on the first day of the menstrual cycle. An excisional biopsy was carried out on the 23rd day of the menstrual cycle and a sample of normal breast tissue adjacent to the fibroadenoma was collected and submitted to immunohistochemical study using anti-Bax polyclonal antibody to evaluate the expression of Bax protein. Immunoreaction for Bax was evaluated taking into consideration intensity and fraction of stained cells, whose combination resulted in a final score ranging from 0 to 6. Cases with a final score >3 were classified as positive for Bax. The c2 test was used for statistical

  1. 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

  2. Correlation of mammographical imaging signs with the expression of bcl-2 and bax proteins in breast cancer

    International Nuclear Information System (INIS)

    Zhang Yili; Du Hongwen; Zhang Yun; Zhang Yuelang; Kuang Fangjun; Guo Zuomin

    2004-01-01

    Objective: To discuss the correlation of mammographical imaging signs with the expression of bcl-2 and bax proteins in breast cancer for early diagnosis and forecast of its prognoses. Methods: Fifty-four breast cancers and 26 benign diseases were proved by pathologic methods and all cases underwent mammography. Immunohistochemical technique was used to measure the expression of bcl-2 and bax proteins in these tissues. The correlation of imaging signs with the expression of bcl-2 and bax proteins in breast cancer and benign lesion was analyzed. Results: The expression of bcl-2 or bax protein in the breast cancer was higher than that in breast benign diseases (χ 2 =15.116, 11.361, P 2 =10.358, 12.818, P 2 =10.996, 10.667, P 2 =10.405, P 2 =6.841, P<0.05). Conclusion: Some imaging signs of breast cancer were closely related to the expression of bcl-2 and bax proteins and these signs could reflect the biological behavior of tumor cells and prognoses. Therefore it could be helpful to the early diagnosis and treatment of breast cancer. (authors)

  3. Exhaustive Training Increases Uncoupling Protein 2 Expression and Decreases Bcl-2/Bax Ratio in Rat Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    W. Y. Liu

    2013-01-01

    Full Text Available This work investigates the effects of oxidative stress due to exhaustive training on uncoupling protein 2 (UCP2 and Bcl-2/Bax in rat skeletal muscles. A total of 18 Sprague-Dawley female rats were randomly divided into three groups: the control group (CON, the trained control group (TC, and the exhaustive trained group (ET. Malondialdehyde (MDA, superoxide dismutase (SOD, xanthine oxidase (XOD, ATPase, UCP2, and Bcl-2/Bax ratio in red gastrocnemius muscles were measured. Exhaustive training induced ROS increase in red gastrocnemius muscles, which led to a decrease in the cell antiapoptotic ability (Bcl-2/Bax ratio. An increase in UCP2 expression can reduce ROS production and affect mitochondrial energy production. Thus, oxidative stress plays a significant role in overtraining.

  4. MAGE-A inhibits apoptosis in proliferating myeloma cells through repression of Bax and maintenance of survivin.

    Science.gov (United States)

    Nardiello, Tricia; Jungbluth, Achim A; Mei, Anna; Diliberto, Maurizio; Huang, Xiangao; Dabrowski, Ania; Andrade, Valéria C C; Wasserstrum, Rebecca; Ely, Scott; Niesvizky, Ruben; Pearse, Roger; Coleman, Morton; Jayabalan, David S; Bhardwaj, Nina; Old, Lloyd J; Chen-Kiang, Selina; Cho, Hearn Jay

    2011-07-01

    The type I Melanoma Antigen GEnes (MAGEs) are commonly expressed in cancers, fueling speculation that they may be therapeutic targets with oncogenic potential. They form complexes with RING domain proteins that have E3 ubiquitin ligase activity and promote p53 degradation. MAGE-A3 was detected in tumor specimens from patients with multiple myeloma and its expression correlated with higher frequencies of Ki-67(+) malignant cells. In this report, we examine the mechanistic role of MAGE-A in promoting survival of proliferating multiple myeloma cells. The impact of MAGE-A3 expression on survival and proliferation in vivo was examined by immunohistochemical analysis in an independent set of tumor specimens segregated into two groups: newly diagnosed, untreated patients and patients who had relapsed after chemotherapy. The mechanisms of MAGE-A3 activity were investigated in vitro by silencing its expression by short hairpin RNA interference in myeloma cell lines and primary cells and assessing the resultant effects on proliferation and apoptosis. MAGE-A3 was detected in a significantly higher percentage of relapsed patients compared with newly diagnosed, establishing a novel correlation with progression of disease. Silencing of MAGE-A showed that it was dispensable for cell cycling, but was required for survival of proliferating myeloma cells. Loss of MAGE-A led to apoptosis mediated by p53-dependent activation of proapoptotic Bax expression and by reduction of survivin expression through both p53-dependent and -independent mechanisms. These data support a role for MAGE-A in the pathogenesis and progression of multiple myeloma by inhibiting apoptosis in proliferating myeloma cells through two novel mechanisms.

  5. Alteration of Bax-to-Bcl-2 ratio modulates the anticancer activity of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... regulation of cellular response to DNA-damage, cell cycle control and .... counted at different times of incubation using a Coulter counter model Z1 ... in a reverse transcription reaction mixture containing 1x PCR buffer,. 0.5 mM ...

  6. Interacciones hiperfinas en BaxSr1-xHfO3

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    López García, A.

    1999-10-01

    Full Text Available In order to determine the microscopic role of cation A in ABO3 perovskites the hyperfine interaction in the Sr1-xBaxHfO3 system using Perturbed Angular Correlation spectroscopy (PAC is studied. As a previous result the compositions x = 0.50 and 0.25 are shown. The PAC spectra were obtained in the temperature range from 20 to 1000ºC. In both compounds a phase transition to higher symmetry structure was observed at T≈400 and 200ºC, respectively. This structure is proposed to be cubic in both compositions. The results are compared with those obtained in SrHfO3 and BaHfO3.Con el fin de determinar el papel microscópico que juega el catión A en las perovskitas ABO3 se estudia la interacción hiperfina el sistema Sr1-xBaxHfO3 usando la espectroscopia Correlaciones Angulares Perturbadas (PAC en función de la temperatura y la composición. Como resultado previo se muestra en este trabajo, el estudio de las composiciones x = 0.5 y 0.75. Las medidas PAC se realizaron en el intervalo de temperaturas que va desde 20 a 1000ºC. Para x=0.50 y 0.75 se determinó una transición a una fase de mayor simetría a T≈400 y 200ºC, respectivamente. Se propone que esta fase de mayor simetría es cúbica en ambas composiciones. Los resultados obtenidos son comparados con los compuestos puros SrHfO3 y BaHfO3.

  7. Piperine attenuates UV-R induced cell damage in human keratinocytes via NF-kB, Bax/Bcl-2 pathway: An application for photoprotection.

    Science.gov (United States)

    Verma, Ankit; Kushwaha, Hari N; Srivastava, Ajeet K; Srivastava, Saumya; Jamal, Naseem; Srivastava, Kriti; Ray, Ratan Singh

    2017-07-01

    Chronic ultraviolet radiation (UV-R) exposure causes skin disorders like erythema, edema, hyperpigmentation, photoaging and photocarcinogenesis. Recent research trends of researchers have focused more attention on the identification and use of photo stable natural agents with photoprotective properties. Piperine (PIP), as a plant alkaloid, is an important constituent present in black pepper (Piper nigrum), used widely in ayurvedic and other traditional medicines and has broad pharmacological properties. The study was planned to photoprotective efficacy of PIP in human keratinocyte (HaCaT) cell line. We have assessed the UV-R induced activation of transcription factor NF-κB in coordination with cell death modulators (Bax/Bcl-2 and p21). The LC-MS/MS analysis revealed that PIP was photostable under UV-A/UV-B exposure. PIP (10μg/ml) attenuates the UV-R (A and B) induced phototoxicity of keratinocyte cell line through the restoration of cell viability, inhibition of ROS, and malondialdehyde generation. Further, PIP inhibited UV-R mediated DNA damage, prevented micronuclei formation, and reduced sub-G1 phase in cell cycle, which supported against photogenotoxicity. This study revealed that PIP pretreatment strongly suppressed UV-R induced photodamages. Molecular docking studies suggest that PIP binds at the active site of NF-κB, and thus, preventing its translocation to nucleus. In addition, transcriptional and translational analysis advocate the increased expression of NF-κB and concomitant decrease in IkB-α expression under UV-R exposed cells, favouring the apoptosis via Bax/Bcl-2 and p21 pathways. However, PIP induced expression of IkB-α suppress the NF-κB activity which resulted in suppression of apoptotic marker genes and proteins that involved in photoprotection. Therefore, we suggest the applicability of photostable PIP as photoprotective agent for human use. Copyright © 2017. Published by Elsevier B.V.

  8. Expression of Bax in yeast affects not only the mitochondria but also vacuolar integrity and intracellular protein traffic

    DEFF Research Database (Denmark)

    Dimitrova, Irina; Toby, Garabet G; Tili, Esmerina

    2004-01-01

    -transferase (BI-GST) leads to aggregation, but not fusion of the mitochondria. In addition, Bax affects the integrity of yeast vacuoles, resulting in the disintegration and eventual loss of the organelles, and the disruption of intracellular protein traffic. While Bcl-2 coexpression only partially corrects...

  9. Coenzyme Q10 Protects Hippocampal Neurons against Ischemia/ Reperfusion Injury via Modulation of BAX/Bcl-2 Expression

    Directory of Open Access Journals (Sweden)

    Mohammad Zamani

    2012-09-01

    Full Text Available Introduction: Preliminary studies have con.rmed reduction in cell death following treatment with antioxidants. According to this .nding we study the relationship between consumption of CoQ10 and expression of Bax and Bcl2 in hippocampus following ischemia/reperfusion as proteins involved in cell programmed death or apoptosis. Methods: We studied the protective role of CoQ10 against ischemia-reperfusion. Experimental design includes four groups:  intact, ischemic control, sham control and treatment group with CoQ10. The mice were pre-treated with CoQ10 for a week, then ischemia was induced by common carotid artery ligation and following the reduction in in.ammation (a week the mice was treated with CoQ10.  Nissl staining was applied for counting the necrotic cells of hippocampus and the western blot was performed to measure the Bax and Bcl2 expression.Results: Cell death was signi.cantly lower when mice were treated with CoQ10. Bax expression was signi.cantly high in the ischemic group but low in the treatment group, and the bcl2 expression was lower in the ischemic group than the treatment and the vehicle groups.Discussion: Ischemia for 15 minutes induced cell death in hippocampus with more potent effect on CA1. CoQ10 intake signi.cantly reduced cell death and prevented the expression of Bax while inducing an increase in expression of bcl2.

  10. Coenzyme Q10 Protects Hippocampal Neurons Against Ischemia/Reperfusion Injury via Modulation of BAX/Bcl-2 Expression

    Directory of Open Access Journals (Sweden)

    M Zamani

    2012-12-01

    Full Text Available Introduction : Preliminary studies confirmed reduction in cell death following treatment with antioxidants. According to this finding we study the relationship between consumption of CoQ10 and expression of bax and bcl2 in hippocampus following ischemia/reperfusion as proteins involved in cell programmed death or apoptosis.Material & methods : We studied the protective role of CoQ10 against Ischemia-Reperfusion. Experimental design includes four groups: intact, ischemic control, sham control and treatment groups with CoQ10. The mice treated with CoQ10 as Pre - Treatment for a week. Then, ischemia induced by common carotid artery ligation and following the reduction in inflammation (a week the mice post-treated with CoQ10.Nissl staining applied to counting necrotic cells of hippocampus and the western blotting performed to measurement the bax and bcl2 expression.Results :. Cell death was significantly lower when mice treated with CoQ10. Bax expression was significantly high in ischemic group but in treatment group was less and reversely the bcl2 expression in ischemic group was lower than treatment and vehicle groups.Conclusion : Ischemia for 15 minutes induced cell death in hippocampus with more potent effect on CA1. CoQ10 intake significantly reduced cell death and prevented the expression of bax while inducing an increase in expression of bcl2.

  11. Effect of Bcl-2/Bax gene expression on apoptosis of spermatogenic cells of mouse testes induced by low dose radiation

    International Nuclear Information System (INIS)

    Liu Guangwei; Wang Chunyan; Lu Zhe; Liu Shunchun; Gong Shouliang

    2003-01-01

    The different kinds of spermatogenic cells were separated using density gradient centrifugation and their apoptosis and Bcl-2 and Bax protein expression were measured with flow cytometry and immunohistochemical method, respectively. The results showed the apoptosis in all kinds of spermatogenic cells induced by low dose radiation (LDR) had a obvious regularity. When the doses were 0.025 and 0.05 Gy, spermatogonia apoptosis was dominant. With the increase of irradiation dose (0.075-0.2 Gy), spermatocytes also showed an apoptotic change, but the apoptotic percentage of spermatogonia was significantly higher than that of spermatocytes. Moreover, the apoptosis of spermatids and spermatozoa scarcely occurred after LDR. Bax protein was primarily expressed in spermatogonia and spermatocytes, and the former was significantly higher than that of the latter after LDR. With the increase of irradiation dose, Bax protein expression showed a upgrading tendency, but that of spermatids and spermatozoa scarcely occurred. Bcl-2 protein was primarily expressed in spermatids and spermatozoa, but the Bcl-2 protein expressions of spermatogonia and spermatocytes scarcely occurred after LDR. These results imply that the interacting regulation of Bcl-2 and Bax gene expression might be involved in selective apoptosis of spermatogenic cells induced by LDR, which provided an experimental evidence for further exploring the apoptotic mechanism of adaptive response of spermatogenic cells by LDR

  12. Reduced expression of bax in small cell lung cancer cells is not sufficient to induce cisplatin-resistance

    Directory of Open Access Journals (Sweden)

    Biagosch J

    2010-10-01

    Full Text Available Abstract Resistance to cisplatin in the course of chemotherapy contributes to the poor prognosis of small cell lung cancer (SCLC. B cell lymphoma-2 is the founding member of a large family of proteins that either promote or inhibit apoptosis. We aimed at investigating if the pro-apoptotic members Bad, Bax, Bim and Bid are involved in cisplatin-resistance. Cisplatin-resistance in the SCLC cell line H1339 was induced by repetitive exposure to cisplatin. Protein expression was quantified by Western Blot and immuno-fluorescence analysis. Protein expression was altered using siRNA interference. Four "cycles" of 0.5 μg/ml cisplatin led to partial cisplatin-resistance in H1339 cells. The expression of Bad, Bim and Bid was comparable in naïve and resistant cells while the expression of Bax was reduced in the resistant clone. But, reducing Bax expression in naïve cells did not lead to altered cisplatin sensitivity neither in H1339 nor in H187 SCLC cells. We conclude that the reduced Bax expression after exposure to cisplatin is not sufficient to induce cis-platin-resistance in SCLC cells.

  13. Hilar granule cells of the mouse dentate gyrus: effects of age, septotemporal location, strain, and selective deletion of the proapoptotic gene BAX.

    Science.gov (United States)

    Bermudez-Hernandez, Keria; Lu, Yi-Ling; Moretto, Jillian; Jain, Swati; LaFrancois, John J; Duffy, Aine M; Scharfman, Helen E

    2017-09-01

    The dentate gyrus (DG) principal cells are glutamatergic granule cells (GCs), and they are located in a compact cell layer. However, GCs are also present in the adjacent hilar region, but have been described in only a few studies. Therefore, we used the transcription factor prospero homeobox 1 (Prox1) to quantify GCs at postnatal day (PND) 16, 30, and 60 in a common mouse strain, C57BL/6J mice. At PND16, there was a large population of Prox1-immunoreactive (ir) hilar cells, with more in the septal than temporal hippocampus. At PND30 and 60, the size of the hilar Prox1-ir cell population was reduced. Similar numbers of hilar Prox1-expressing cells were observed in PND30 and 60 Swiss Webster mice. Prox1 is usually considered to be a marker of postmitotic GCs. However, many Prox1-ir hilar cells, especially at PND16, were not double-labeled with NeuN, a marker typically found in mature neurons. Most hilar Prox1-positive cells at PND16 co-expressed doublecortin (DCX) and calretinin, markers of immature GCs. Double-labeling with a marker of actively dividing cells, Ki67, was not detected. These results suggest that, surprisingly, a large population of cells in the hilus at PND16 are immature GCs (Type 2b and Type 3 cells). We also asked whether hilar Prox1-ir cell numbers are modifiable. To examine this issue, we conditionally deleted the proapoptotic gene BAX in Nestin-expressing cells at a time when there are numerous immature GCs in the hilus, PND2-8. When these mice were examined at PND60, the numbers of Prox1-ir hilar cells were significantly increased compared to control mice. However, deletion of BAX did not appear to change the proportion that co-expressed NeuN, suggesting that the size of the hilar Prox1-expressing population is modifiable. However, deleting BAX, a major developmental disruption, does not appear to change the proportion that ultimately becomes neurons.

  14. Clusterin Reduces Cold Ischemia-Reperfusion Injury in Heart Transplantation Through Regulation of NF-kB Signaling and Bax/Bcl-xL Expression

    Directory of Open Access Journals (Sweden)

    Guodong Liu

    2018-02-01

    Full Text Available Background/Aims: Ischemia-reperfusion (I/R injury is an unavoidable event occurring during heart transplantation and is a key factor in graft failure and the long-term survival rate of recipients. Therefore, there is an urgent need for the development of new therapies to prevent I/R injury. Clusterin is a hetero-dimeric glycoprotein with an antiapoptotic function. In this study, we investigated whether clusterin was cardioprotective in heart transplantation against I/R injury using an in vivo rat model and an in vitro cell culture system, and examined the underlying mechanisms of I/R injury. Methods: Heart grafts from wild-type C57BL/6 mice were preserved in UW solution (control or UW solution containing recombinant human apolipoprotein-J (hr clusterin for 24 h. The preserved hearts were implanted into recipient mice of the same strain as the donors for 72 h, and the heart grafts were then taken for histopathological and gene expression analyses. An in vitro ischemia reperfusion model using H9C2 cells or H9C2/clusterin cDNA cells was constructed. The expression of clusterin, p65, Bax, Bcl-xL, IL-1β, and TNF-α protein and mRNA in heart tissue and H9C2 cells was detected by western blot, reverse transcription-polymerase chain reaction (RT-PCR, and quantitative RT-PCR assays; IL-1β and TNF-α protein was detected by enzyme-linked immunosorbent assays; NF-kB activity was detected by an electrophoretic mobility shift assay; cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and flow cytometric analyses. Results: Cold I/R caused severe morphologic myocardial injury to heart grafts from wild-type C57BL/6 mice, whereas grafts from hr clusterin preservation showed less damage, as demonstrated by decreased cell apoptosis/death, decreased neutrophil infiltration, and the preservation of the normal structure of the heart. Clusterin reduced the expression of p65, pre-inflammatory IL-1β, and TNF-α, and

  15. Clusterin Reduces Cold Ischemia-Reperfusion Injury in Heart Transplantation Through Regulation of NF-kB Signaling and Bax/Bcl-xL Expression.

    Science.gov (United States)

    Liu, Guodong; Zhang, Hongmei; Hao, Fengyun; Hao, Jing; Pan, Lixiao; Zhao, Qing; Wo, Jinshan

    2018-01-01

    Ischemia-reperfusion (I/R) injury is an unavoidable event occurring during heart transplantation and is a key factor in graft failure and the long-term survival rate of recipients. Therefore, there is an urgent need for the development of new therapies to prevent I/R injury. Clusterin is a hetero-dimeric glycoprotein with an antiapoptotic function. In this study, we investigated whether clusterin was cardioprotective in heart transplantation against I/R injury using an in vivo rat model and an in vitro cell culture system, and examined the underlying mechanisms of I/R injury. Heart grafts from wild-type C57BL/6 mice were preserved in UW solution (control) or UW solution containing recombinant human apolipoprotein-J (hr clusterin) for 24 h. The preserved hearts were implanted into recipient mice of the same strain as the donors for 72 h, and the heart grafts were then taken for histopathological and gene expression analyses. An in vitro ischemia reperfusion model using H9C2 cells or H9C2/clusterin cDNA cells was constructed. The expression of clusterin, p65, Bax, Bcl-xL, IL-1β, and TNF-α protein and mRNA in heart tissue and H9C2 cells was detected by western blot, reverse transcription-polymerase chain reaction (RT-PCR), and quantitative RT-PCR assays; IL-1β and TNF-α protein was detected by enzyme-linked immunosorbent assays; NF-kB activity was detected by an electrophoretic mobility shift assay; cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and flow cytometric analyses. Cold I/R caused severe morphologic myocardial injury to heart grafts from wild-type C57BL/6 mice, whereas grafts from hr clusterin preservation showed less damage, as demonstrated by decreased cell apoptosis/death, decreased neutrophil infiltration, and the preservation of the normal structure of the heart. Clusterin reduced the expression of p65, pre-inflammatory IL-1β, and TNF-α, and the pro-apoptotic gene Bax, while it enhanced the

  16. Angiotensin II induces apoptosis in intestinal epithelial cells through the AT2 receptor, GATA-6 and the Bax pathway

    International Nuclear Information System (INIS)

    Sun, Lihua; Wang, Wensheng; Xiao, Weidong; Liang, Hongyin; Yang, Yang; Yang, Hua

    2012-01-01

    Highlights: ► Ang II-induced apoptosis in intestinal epithelial cell through AT2 receptor. ► The apoptosis process involves in the Bax/Bcl-2 intrinsic pathway. ► GATA-6 short hairpin RNA reduced Bax expression, but not Bcl-2. ► GATA-6 may play a critical role in apoptosis in response to the Ang II challenge. -- Abstract: Angiotensin II (Ang II) has been shown to play an important role in cell apoptosis. However, the mechanisms of Ang-II-induced apoptosis in intestinal epithelial cells are not fully understood. GATA-6 is a zinc finger transcription factor expressed in the colorectal epithelium, which directs cell proliferation, differentiation and apoptosis. In the present study we investigated the underlying mechanism of which GATA-6 affects Ang-II induced apoptosis in intestinal epithelial cells. The in vitro intestinal epithelial cell apoptosis model was established by co-culturing Caco-2 cells with Ang II. Pretreatment with Angiotensin type 2 (AT2) receptor antagonist, PD123319, significantly reduced the expression of Bax and prevented the Caco-2 cells apoptosis induced by Ang II. In addition, Ang II up-regulated the expression of GATA-6. Interestingly, GATA-6 short hairpin RNA prevented Ang II-induced intestinal epithelial cells apoptosis and reduced the expression of Bax, but not Bcl-2. Taken together, the present study suggests that Angiotensin II promotes apoptosis in intestinal epithelial cells through GATA-6 and the Bax pathway in an AT2 receptor-dependent manner.

  17. Low-frequency Electronic Transport Noise in La2-xBaxCuO4 Nanowires

    Science.gov (United States)

    Weis, Adam; Xin, Yizhou; van Harlingen, Dale

    2013-03-01

    In the pseudogap regime, high temperature superconductors often exhibit electronic structure, such as charge stripes. Charge stripes pinned to disorder have been predicted to contribute to low-frequency resistance fluctuations when sample dimensions are comparable to the size of stripe domains (Carlson, 2006). We are extending our previous studies of resistance fluctuations in YBa2Cu3O7-δ (Bonetti, 2004; Caplan, 2010) to thin films of La-based cuprates expected to have a more stable stripe phase, particularly in the regime near 1/8-filling. We present measurements of the low-frequency electronic transport in La2-xBaxCuO4 nanowires fabricated by pulsed laser deposition and lithographic techniques. We discuss temperature dependence of the power spectral density and its relevance to correlated electron phases above Tc. This research was supported by the DOE-DMS under grant DE-FG02-07ER46453, through the Frederick Seitz Materials Research Laboratory at the University of Illinois at Urbana-Champaign.

  18. BAX INHIBITOR-1 is required for full susceptibility of barley to powdery mildew.

    Science.gov (United States)

    Eichmann, Ruth; Bischof, Melanie; Weis, Corina; Shaw, Jane; Lacomme, Christophe; Schweizer, Patrick; Duchkov, Dimitar; Hensel, Götz; Kumlehn, Jochen; Hückelhoven, Ralph

    2010-09-01

    BAX INHIBITOR-1 (BI-1) is one of the few proteins known to have cross-kingdom conserved functions in negative control of programmed cell death. Additionally, barley BI-1 (HvBI-1) suppresses defense responses and basal resistance to the powdery mildew fungus Blumeria graminis f. sp. hordei and enhances resistance to cell death-provoking fungi when overexpressed in barley. Downregulation of HvBI-1 by transient-induced gene silencing or virus-induced gene silencing limited susceptibility to B. graminis f. sp. hordei, suggesting that HvBI-1 is a susceptibility factor toward powdery mildew. Transient silencing of BI-1 did not limit supersusceptibility induced by overexpression of MLO. Transgenic barley plants harboring an HvBI-1 RNA interference (RNAi) construct displayed lower levels of HvBI-1 transcripts and were less susceptible to powdery mildew than wild-type plants. At the cellular level, HvBI-1 RNAi plants had enhanced resistance to penetration by B. graminis f. sp. hordei. These data support a function of BI-1 in modulating cell-wall-associated defense and in establishing full compatibility of B. graminis f. sp. hordei with barley.

  19. Modification of the BAX System PCR assay for detecting Salmonella in beef, produce, and soy protein isolate. Performance Tested Method 100201.

    Science.gov (United States)

    Peng, Linda X; Wallace, Morgan; Andaloro, Bridget; Fallon, Dawn; Fleck, Lois; Delduco, Dan; Tice, George

    2011-01-01

    The BAX System PCR assay for Salmonella detection in foods was previously validated as AOAC Research Institute (RI) Performance Tested Method (PTM) 100201. New studies were conducted on beef and produce using the same media and protocol currently approved for the BAX System PCR assay for E. coli O157:H7 multiplex (MP). Additionally, soy protein isolate was tested for matrix extension using the U.S. Food and Drug Administration-Bacteriological Analytical Manual (FDA-BAM) enrichment protocols. The studies compared the BAX System method to the U.S. Department of Agriculture culture method for detecting Salmonella in beef and the FDA-BAM culture method for detecting Salmonella in produce and soy protein isolate. Method comparison studies on low-level inoculates showed that the BAX System assay for Salmonella performed as well as or better than the reference method for detecting Salmonella in beef and produce in 8-24 h enrichment when the BAX System E. coli O157:H7 MP media was used, and soy protein isolate in 20 h enrichment with lactose broth followed by 3 h regrowth in brain heart infusion broth. An inclusivity panel of 104 Salmonella strains with diverse serotypes was tested by the BAX System using the proprietary BAX System media and returned all positive results. Ruggedness factors involved in the enrichment phase were also evaluated by testing outside the specified parameters, and none of the factors examined affected the performance of the assay.

  20. Bcl-2 and bax expression and prostate cancer outcome in men treated with radiotherapy in Radiation Therapy Oncology Group protocol 86-10

    International Nuclear Information System (INIS)

    Khor, L.-Y.; De Silvio, Michelle; Li, Rile; McDonnell, Timothy J.; Hammond, M. Elizabeth H.; Sause, William T.; Pilepich, Miljenko V.; Okunieff, Paul; Sandler, Howard M.; Pollack, Alan

    2006-01-01

    Purpose: Bcl-2 and bax are proteins with opposing roles in apoptosis regulation; yet abnormal expression of either has been associated with failure after radiotherapy (RT). In this study we examined bcl-2 and bax expression as predictive markers in men treated with radiotherapy ± androgen deprivation on Radiation Therapy Oncology Group (RTOG) protocol 86-10. Experimental Design: Suitable archival diagnostic tissue was obtained from 119 (26%) patients for bcl-2 analysis and 104 (23%) patients for bax analysis. Cox proportional hazards multivariate analysis was used to determine the relationship of abnormal bcl-2 and bax expression to the end points of local failure, distant metastasis, cause-specific mortality, and overall mortality. Bcl-2 overexpression was classified as any tumor cell cytoplasmic staining and altered bax expression was classified as greater or lesser cytoplasmic staining intensity of tumor cells as compared with adjacent normal prostate epithelium. Results: The study cohort exhibited bcl-2 overexpression in 26% (n = 30) of cases and abnormal bax expression in 47% (n = 49) of cases. A borderline significant relationship was observed between abnormal bax expression and higher Gleason score (p = 0.08). In univariate and multivariate analyses, there was no statistically significant relationship seen between abnormal bcl-2 or bax expression and outcome. Conclusions: Abnormal bcl-2 and bax expression were not related to any of the end points tested. The cohort examined was comprised of patients with locally advanced disease and it is possible that these markers may be of greater value in men with earlier-stage prostate cancer

  1. [Effects of blueberry on apoptosis and expression of Bcl-2 and Bax in HSC-T6].

    Science.gov (United States)

    Lu, Shuang; Cheng, Mingliang; Yang, Demeng; Liu, Yang; Guan, Li; Wu, Jun

    2015-08-18

    To investigate the effects of blueberry on the apoptosis, expression of Bcl-2 and Bax in rat hepatic stellate cell (HSC-T6). 10% blueberry serum at low, middle and high dose, 10% Fu-Fang-Bie-Jia-Ruan-Gan tablet serum and 10% saline serum were prepared by method of serum pharmacology. Subcultured HSC-T6 was divided into saline serum control group, blueberry serum at low, middle, high dose and Fu-Fang-Bie-Jia-Ruan-Gan tablet serum group, and then was respectively incubated at different dose of 10% blueberry serum, 10% Fu-Fang-Bie-Jia-Ruan-Gan tablet serum and 10% saline serum for 72 hours.Apoptosis of HSC-T6 was detected using flow cytometry with annexin V FITC/PI double staining. The expression of Bcl-2 and Bax in HSC-T6 were examined using immunocytochemistry and Western blotting, respectively. There was no significant difference for HSC-T6 Bax protein expression in the low, middle and high dose blueberry serum groups, compared with saline serum control group, respectively.In the high-dose blueberry serum group HSC-T6 early and total apoptosis rate increased significantly compared with the saline serum control group (5.55% ± 0.98% vs 2.53% ± 0.46%, 7.01% ± 1.05% vs 2.96% ± 0.81%, both Pblueberry serum group showed no significant difference with the saline serum control group. Blueberry can induce HSC-T6 apoptosis by down-regulating Bcl-2 expression and decreasing the ratio of Bcl-2/Bax in HSC-T6 cells, so it may have potential interference effects on hepatic fibrosis.

  2. Mutations in TGFbeta-RII and BAX mediate tumor progression in the later stages of colorectal cancer with microsatellite instability

    International Nuclear Information System (INIS)

    Yashiro, Masakazu; Hirakawa, Kosei; Boland, C Richard

    2010-01-01

    Microsatellite instability (MSI) occurs in 15% of colorectal cancers (CRC). The genetic targets for mutation in the MSI phenotype include somatic mutations in the transforming growth factor beta receptor typeII (TGFbetaRII), BAX, hMSH3 and hMSH6. It is not clear how mutations of these genes mediate tumor progression in the MSI pathway, and the temporal sequence of these mutations remains uncertain. In this study, early stage CRCs were examined for frameshift mutations in these target genes, and compared with late stage tumors and CRC cell lines. We investigated 6 CRC cell lines and 71 sporadic CRCs, including 61 early stage cancers and 10 late stage cancers. Mutations of repetitive mononucleotide tracts in the coding regions of TGFbetaRII, BAX, hMSH3, hMSH6, IGFIIR and Fas antigen were identified by direct sequencing. Thirteen (18.3%) of 71 CRC, including 9/61 (14.7%) early stage cancers and 4/10 (40%) late stage cancers, were identified as MSI and analyzed for frameshift mutations. No mutation in the target genes was observed in any of the 9 early stage MSI CRCs. In contrast, frameshift mutations of TGFbetaRII, BAX, hMSH3 and hMSH6 were present in 3/4 late stage MSI tumors. There is a statistical association (p = 0.014) between mutation in any one gene and tumor stage. TGFbetaRII, BAX, hMSH3 and hMSH6 mutations are relatively late events in the genesis of MSI CRCs. The frameshift mutations in these target genes might mediate progression from early to late stage cancer, rather than mediating the adenoma to carcinoma transition

  3. The effect of octreotide and bromocriptine on expression of a pro-apoptotic Bax protein in rat prolactinoma.

    Directory of Open Access Journals (Sweden)

    Jolanta Kunert-Radek

    2004-03-01

    Full Text Available It is well established that disruption of apoptosis may lead to tumor initiation, progression or metastasis. It is also well documented that many anticancer drugs induce apoptosis. In the earlier studies, the dopamine D2 receptor agonist bromocriptine (BC and somatostatin analog octreotide (OCT were found to inhibit the growth of the estrogen-induced rat prolactinoma. Our previous investigations, applying the TUNEL method showed the involvement of the pro-apoptotic effect in the action of BC, and to a lesser degree, in the action of OCT. The aim of the present study was to investigate whether the pro-apoptotic action of these drugs involves the increased expression of Bax--a member of Bcl-2 protein family which is known to play an important role in the regulation of apoptosis. Male four-week Fisher 344 rats were used in the experiment. Capsules containing diethylstilboestrol (DES were implanted subcutaneously. Six weeks after the implantation the rats were given OCT (2 x 25 microg/animal/24, BC (3 mg/kg b.w./24 h or OCT and BC at the above doses for 10 days. Bax expression was detected by immunohistochemistry. Prolactin (PRL in blood serum was measured by radioimmunoassay (RIA. It has been found that both OCT and BC, alone or in combination, significantly reduce the tumor weight. Both OCT and BC suppressed PRL levels, but the inhibitory effect of BC was stronger than that of OCT. It has been found that the treatment with OCT and BC, alone or in combination, causes a significant increase in Bax expression in the rat prolactinoma cells. Our findings indicate that anti-tumoral action of bromocriptine and to some extent the action of octreotide in the experimental rat prolactinoma is connected with the induction of apoptosis and is associated with increased Bax expression.

  4. An Integrative Analysis Reveals a Central Role of P53 Activation via MDM2 in Zika Virus Infection Induced Cell Death

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    Yue Teng

    2017-07-01

    Full Text Available Zika virus (ZIKV infection is an emerging global threat that is suspected to be associated with fetal microcephaly. However, the molecular mechanisms underlying ZIKV disease pathogenesis in humans remain elusive. Here, we investigated the human protein interaction network associated with ZIKV infection using a systemic virology approach, and reconstructed the transcriptional regulatory network to analyze the mechanisms underlying ZIKV-elicited microcephaly pathogenesis. The bioinformatics findings in this study show that P53 is the hub of the genetic regulatory network for ZIKV-related and microcephaly-associated proteins. Importantly, these results imply that the ZIKV capsid protein interacts with mouse double-minute-2 homolog (MDM2, which is involved in the P53-mediated apoptosis pathway, activating the death of infected neural cells. We also found that synthetic mimics of the ZIKV capsid protein induced cell death in vitro and in vivo. This study provides important insight into the relationship between ZIKV infection and brain diseases.

  5. Apoptosis Induction by Targeting Interferon Gamma Receptor 2 (IFNgammaR2) in Prostate Cancer: Ligand (IFNgamma) Independent Novel Function of IFNgammaR2 as a Bax Inhibitor

    Science.gov (United States)

    2016-10-01

    Cisplatin (2uM, 30 hrs) PN (5uM, 55hrs) + Cisplatin (2uM, 30 hrs) •  Thorough studies are needed to examine the unknown mechanism of IFNgR2 and Bax as well as...mouse xenograft model. Task3: To determine the mechanism of increased IFNγR2 expression in PCa. We found that NFkB inhibitor suppressed IFNγR2 expression...suggesting that hyper-activation of NFkB may be one of the mechanisms of IFNγR2 overexpression in PCa. These results support our hypothesis that

  6. Borax-induced apoptosis in HepG2 cells involves p53, Bcl-2, and Bax.

    Science.gov (United States)

    Wei, Y; Yuan, F J; Zhou, W B; Wu, L; Chen, L; Wang, J J; Zhang, Y S

    2016-06-21

    Borax, a boron compound and a salt of boric acid, is known to inhibit the growth of tumor cells. HepG2 cells have been shown to be clearly susceptible to the anti-proliferative effects of borax. However, the specific mechanisms regulating this effect are poorly understood. This study aimed to investigate the pathways underlying the growth inhibition induced by borax in HepG2 cells. The effects of borax on HepG2 cell viability were characterized using MTT. Apoptosis was also verified by annexin V/propidium iodide staining. JC-1 dye and western blotting techniques were used to measure mitochondrial membrane potential and p53, Bax, and Bcl-2 protein expression, respectively. Relevant mRNA levels were measured by qRT-PCR. Borax inhibited the proliferation of HepG2 cells in a time- and dose-dependent manner in vitro. The apoptotic process triggered by borax involved the upregulation of p53 and Bax and the downregulation of Bcl-2, which was confirmed by a change in the mitochondrial membrane potential. These results elucidate a borax-induced apoptotic pathway in HepG2 cells that involves the upregulation of p53 and Bax and the downregulation of Bcl-2.

  7. Ginkgo biloba extract mitigates liver fibrosis and apoptosis by regulating p38 MAPK, NF-κB/IκBα, and Bcl-2/Bax signaling

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    Wang YY

    2015-12-01

    Full Text Available Yuanyuan Wang, Rong Wang, Yujie Wang, Ruqin Peng, Yan Wu, Yongfang Yuan Department of Pharmacy, Shanghai 9th People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China Background: Liver fibrosis is the consequence of diverse liver injuries and can eventually develop into liver cirrhosis. Ginkgo biloba extract (GBE is an extract from dried ginkgo leaves that has many pharmacological effects because of its various ingredients and has been shown to be hepatoprotective. Purpose and methods: Aimed to investigate the underlying protective mechanisms of GBE on carbon tetrachloride (CCl4-induced liver fibrosis in rats. Male Sprague Dawley rats were randomly divided into four groups: control group (C, model group (M, low-dose group (L, and high-dose group (H. Liver fibrosis was induced by CCl4 groups M, L, and H: group C was administered saline. In addition, GBE at different doses was used to treat groups L and H. Results: The results of hematoxylin and eosin staining, Masson’s trichrome staining, a liver function index, and a liver fibrosis index showed that GBE application noticeably mitigated fibrosis and improved the function of the liver. The western blotting and immunohistochemistry analyses indicated that GBE reduced liver fibrosis not only by inhibiting p38 MAPK and NF-κBp65 via inhibition of IκBα degradation but also by inhibiting hepatocyte apoptosis via downregulation of Bax, upregulation of Bcl-2, and subsequent inhibition of caspase-3 activation. Inflammation-associated factors and hepatic stellate cell (HSC-activation markers further demonstrated that GBE could effectively inhibit HSC activation and inflammation as a result of its regulation of p38 MAPK and nuclear factor-kappa B/IκBα signaling. Conclusion: Our findings indicated a novel role for GBE in the treatment of liver fibrosis. The potential mechanisms may be associated with the following signaling pathways: 1 the p38 MAPK

  8. Overexpression of BAX INHIBITOR-1 Links Plasma Membrane Microdomain Proteins to Stress.

    Science.gov (United States)

    Ishikawa, Toshiki; Aki, Toshihiko; Yanagisawa, Shuichi; Uchimiya, Hirofumi; Kawai-Yamada, Maki

    2015-10-01

    BAX INHIBITOR-1 (BI-1) is a cell death suppressor widely conserved in plants and animals. Overexpression of BI-1 enhances tolerance to stress-induced cell death in plant cells, although the molecular mechanism behind this enhancement is unclear. We recently found that Arabidopsis (Arabidopsis thaliana) BI-1 is involved in the metabolism of sphingolipids, such as the synthesis of 2-hydroxy fatty acids, suggesting the involvement of sphingolipids in the cell death regulatory mechanism downstream of BI-1. Here, we show that BI-1 affects cell death-associated components localized in sphingolipid-enriched microdomains of the plasma membrane in rice (Oryza sativa) cells. The amount of 2-hydroxy fatty acid-containing glucosylceramide increased in the detergent-resistant membrane (DRM; a biochemical counterpart of plasma membrane microdomains) fraction obtained from BI-1-overexpressing rice cells. Comparative proteomics analysis showed quantitative changes of DRM proteins in BI-1-overexpressing cells. In particular, the protein abundance of FLOTILLIN HOMOLOG (FLOT) and HYPERSENSITIVE-INDUCED REACTION PROTEIN3 (HIR3) markedly decreased in DRM of BI-1-overexpressing cells. Loss-of-function analysis demonstrated that FLOT and HIR3 are required for cell death by oxidative stress and salicylic acid, suggesting that the decreased levels of these proteins directly contribute to the stress-tolerant phenotypes in BI-1-overexpressing rice cells. These findings provide a novel biological implication of plant membrane microdomains in stress-induced cell death, which is negatively modulated by BI-1 overexpression via decreasing the abundance of a set of key proteins involved in cell death. © 2015 American Society of Plant Biologists. All Rights Reserved.

  9. Distribution of 99Tcm-rh-Annexin vin tumor and expression relationship of bcl-2, bax after a single dose of chemotherapy

    International Nuclear Information System (INIS)

    Zhang Xin; Li Yaming; Zhang Yanjun; Tao Li; Zhu Yi; Yang Chun; Ji Xiaopeng; Zhao Ming; Tian Aijuan; Zhang Jianying; Zhao Zhenzhen

    2007-01-01

    The expression of bcl-2 and bax after the single dose of chemotherapy with 99 Tc m -rh-Annexin V as the tracer of tumor apoptosis imaging is studied. tumor cell apoptosis is examined by TUNEL methods, and the expression of bcl-2 and bax in tumor are determined by immunohistochemical methods. Single dose of chemotherapy significantly increased the tumor uptake of 99 Tc m -rh-annexin V and the positive number of TUNEL, as well as the expression of bax (P 99 Tc m -rh-annexin V in tumor reflectes not only the degree of apoptosis of tumor cells, but also the change of bax expression after the single dose of chemotherapy. (authors)

  10. Bax/Mcl-1 balance affects neutrophil survival in intermittent hypoxia and obstructive sleep apnea: effects of p38MAPK and ERK1/2 signaling.

    Science.gov (United States)

    Dyugovskaya, Larissa; Polyakov, Andrey; Cohen-Kaplan, Victoria; Lavie, Peretz; Lavie, Lena

    2012-10-22

    Prolonged neutrophil survival is evident in various cardiovascular and respiratory morbidities, in hypoxic conditions in-vitro and in patients with obstructive sleep apnea (OSA) characterized by nightly intermittent hypoxia (IH). This may lead to persistent inflammation, tissue injury and dysfunction. We therefore investigated by a translational approach the potential contribution of the intrinsic stress-induced mitochondrial pathway in extending neutrophil survival under IH conditions. Thus, neutrophils of healthy individuals treated with IH in-vitro and neutrophils of OSA patients undergoing nightly IH episodes in-vivo were investigated. Specifically, the balance between pro-apoptotic Bax and anti-apoptotic Mcl-1 protein expression, and the potential involvement of p38MAPK and ERK1/2 signaling pathways in the control of Mcl-1 expression were investigated. Purified neutrophils were exposed to IH and compared to normoxia and to sustained hypoxia (SH) using a BioSpherix-OxyCycler C42 system. Bax and Mcl-1 levels, and p38MAPK and ERK1/2 phosphorylation were determined by western blotting. Also, Bax/Mcl-1 expression and Bax translocation to the mitochondria were assessed by confocal microscopy in pre-apoptotic neutrophils, before the appearance of apoptotic morphology. Co-localization of Bax and mitochondria was quantified by LSM 510 CarlZeiss MicroImaging using Manders Overlap Coefficient. A paired two-tailed t test, with Bonferroni correction for multiple comparisons, was used for statistical analysis. Compared to normoxia, IH and SH up-regulated the anti-apoptotic Mcl-1 by about 2-fold, down-regulated the pro-apoptotic Bax by 41% and 27%, respectively, and inhibited Bax co-localization with mitochondria before visible morphological signs of apoptosis were noted. IH induced ERK1/2 and p38MAPKs phosphorylation, whereas SH induced only p38MAPK phosphorylation. Accordingly, both ERK and p38MAPK inhibitors attenuated the IH-induced Mcl-1 increase. In SH, only p38MAPK

  11. Involvement of Bax and Bcl-2 in Induction of Apoptosis by Essential Oils of Three Lebanese Salvia Species in Human Prostate Cancer Cells

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    Alessandra Russo

    2018-01-01

    Full Text Available Prostate cancer is one of the most common forms of cancer in men, and research to find more effective and less toxic drugs has become necessary. In the frame of our ongoing program on traditionally used Salvia species from the Mediterranean Area, here we report the biological activities of Salvia aurea, S. judaica and S. viscosa essential oils against human prostate cancer cells (DU-145. The cell viability was measured by 3(4,5-dimethyl-thiazol-2-yl2,5-diphenyl-tetrazolium bromide (MTT test and lactate dehydrogenase (LDH release was used to quantify necrosis cell death. Genomic DNA, caspase-3 activity, expression of cleaved caspase-9, B-cell lymphoma 2 (Bcl-2 and Bcl-2 associated X (Bax proteins were analyzed in order to study the apoptotic process. The role of reactive oxygen species in cell death was also investigated. We found that the three essential oils, containing caryophyllene oxide as a main constituent, are capable of reducing the growth of human prostate cancer cells, activating an apoptotic process and increasing reactive oxygen species generation. These results suggest it could be profitable to further investigate the effects of these essential oils for their possible use as anticancer agents in prostate cancer, alone or in combination with chemotherapy agents.

  12. Flavanols from evening primrose (Oenothera paradoxa) defatted seeds inhibit prostate cells invasiveness and cause changes in Bcl-2/Bax mRNA ratio.

    Science.gov (United States)

    Lewandowska, Urszula; Szewczyk, Karolina; Owczarek, Katarzyna; Hrabec, Zbigniew; Podsędek, Anna; Koziołkiewicz, Maria; Hrabec, Elżbieta

    2013-03-27

    In this study, we assessed the influence of an evening primrose flavanol preparation (EPFP) on proliferation and invasiveness of human prostate cancer cells (DU 145) and immortalized prostate epithelial cells (PNT1A). We report for the first time that EPFP reduces DU 145 cell proliferation (IC50 = 97 μM GAE for 72 h incubation) and invasiveness (by 24% versus control at 75 μM GAE). EPFP strongly inhibited PNT1A invasiveness in a concentration-dependent manner (by 67% versus control at 75 μM GAE) and did not cause a reduction in their proliferation. Furthermore, EPFP inhibited the activities of MMP-2 and MMP-9 secreted to culture medium by PNT1A cells by 84% and 34% versus control at 100 μM GAE, respectively. In the case of DU 145, MMP-9 activity at 100 μM GAE was reduced by 37% versus control. Moreover, the evening primrose seed flavanols suppressed the expression of selected genes (MMP-1, MMP-9, MMP-14, c-Fos, c-Jun, and VEGF) and also caused favorable changes in Bcl-2/Bax mRNA ratio which render DU 145 cells more sensitive to apoptosis-triggering agents. An additional confirmation of the proapoptotic activity of EPFP toward DU 145 was visualization of characteristic apoptotic bodies by DAPI staining. In conclusion, this study suggests that EPFP may increase apoptosis and reduce angiogenesis of prostate cancer cells.

  13. Lycopene modulates cholinergic dysfunction, Bcl-2/Bax balance, and antioxidant enzymes gene transcripts in monosodium glutamate (E621) induced neurotoxicity in a rat model.

    Science.gov (United States)

    Sadek, Kadry; Abouzed, Tarek; Nasr, Sherif

    2016-04-01

    The effect of monosodium glutamate (MSG) on brain tissue and the relative ability of lycopene to avert these neurotoxic effects were investigated. Thirty-two male Wistar rats were distributed into 4 groups: group I, untreated (placebo); group II, injected with MSG (5 mg·kg(-1)) s.c.; group III, gastrogavaged with lycopene (10 mg·kg(-1)) p.o.; and group IV received MSG with lycopene with the same mentioned doses for 30 days. The results showed that MSG induced elevation in lipid peroxidation marker and perturbation in the antioxidant homeostasis and increased the levels of brain and serum cholinesterase (ChE), total creatine phosphokinase (CPK), creatine phosphokinase isoenzymes BB (CPK-BB), and lactate dehydrogenase (LDH). Glutathione S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT) activities and gene expression were increased and glutathione content was reduced in the MSG-challenged rats, and these effects were ameliorated by lycopene. Furthermore, MSG induced apoptosis in brain tissues reflected in upregulation of pro-apoptotic Bax while lycopene upregulated the anti-apoptotic Bcl-2. Our results indicate that lycopene appears to be highly effective in relieving the toxic effects of MSG by inhibiting lipid peroxidation and inducing modifications in the activity of cholinesterase and antioxidant pathways. Interestingly, lycopene protects brain tissue by inhibiting apoptosis signaling induced by MSG.

  14. In-house validation study of the DuPont Qualicon BAX system Q7 instrument with the BAX system PCR Assay for Salmonella (modification of AOAC Official Method 2003.09 and AOAC Research Institute Performance-Tested Method 100201).

    Science.gov (United States)

    Tice, George; Andaloro, Bridget; White, H Kirk; Bolton, Lance; Wang, Siqun; Davis, Eugene; Wallace, Morgan

    2009-01-01

    In 2006, DuPont Qualicon introduced the BAX system Q7 instrument for use with its assays. To demonstrate the equivalence of the new and old instruments, a validation study was conducted using the BAX system PCR Assay for Salmonella, AOAC Official Method 2003.09, on three food types. The foods were simultaneously analyzed with the BAX system Q7 instrument and either the U.S. Food and Drug Administration Bacteriological Analytical Manual or the U.S. Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook reference method for detecting Salmonella. Comparable performance between the BAX system and the reference methods was observed. Of the 75 paired samples analyzed, 39 samples were positive by both the BAX system and reference methods, and 36 samples were negative by both the BAX system and reference methods, demonstrating 100% correlation. Inclusivity and exclusivity for the BAX system Q7 instrument were also established by testing 50 Salmonella strains and 20 non-Salmonella isolates. All Salmonella strains returned positive results, and all non-Salmonella isolates returned a negative response.

  15. Long noncoding RNA TUG1 is a diagnostic factor in lung adenocarcinoma and suppresses apoptosis via epigenetic silencing of BAX.

    Science.gov (United States)

    Liu, Huan; Zhou, Guizhi; Fu, Xin; Cui, Haiyan; Pu, Guangrui; Xiao, Yao; Sun, Wei; Dong, Xinhua; Zhang, Libin; Cao, Sijia; Li, Guiqin; Wu, Xiaowei; Yang, Xu

    2017-11-24

    Lung cancer is one of the leading causes of cancer-related mortality, and responds badly to existing treatment. Thus, it is of urgent need to identify novel diagnostic markers and therapeutic targets. Increasing evidences have indicated that long non-coding RNAs (lncRNAs) play an important role in initiation and progression of lung cancer. However, the role of lncRNA Taurine upregulated 1 (TUG1) in lung adenocarcinoma (LAD) progression is not well known. In this study, we determined the diagnostic value of TUG1 in LAD patients, and further uncovered the underlying functional mechanism. Our results showed that TUG1 was significantly upregulated in LAD cells and serum samples. Receiver operator characteristic (ROC) analysis suggested a relatively higher area under the curve (AUC) of TUG1 (0.756) contrast to cyfra21-1 (0.619). In addition, high TUG1 level was associated with enhanced tumor size, degree of differentiation, lymph node metastases, distant metastasis and TNM stage. Cell functional assays showed that knockdown of TUG1 suppressed LAD cell viability and promoted cell apoptosis. We then sought to reveal the underlying regulatory mechanism, and the pro-apoptotic protein BAX was then identified as the downstream target of TUG1. Gain and loss functional assays showed that inhibition of BAX reversed the induced apoptosis by TUG1 knockdown. Finally, RNA immunoprecipitation and Chromatin immunoprecipitation revealed that TUG1 suppressed BAX expression through physically interacting with EZH2. In conclusion, lncRNA TUG1 is a promising diagnostic marker for LAD patients and suppression of TUG1 levels could be a future direction to promote the prognosis of LAD patients.

  16. Electromagnetic radiation at 900 MHz induces sperm apoptosis through bcl-2, bax and caspase-3 signaling pathways in rats.

    Science.gov (United States)

    Liu, Qi; Si, Tianlei; Xu, Xiaoyun; Liang, Fuqiang; Wang, Lufeng; Pan, Siyi

    2015-08-04

    The decreased reproductive capacity of men is an important factor contributing to infertility. Accumulating evidence has shown that Electromagnetic radiation potentially has negative effects on human health. However, whether radio frequency electromagnetic radiation (RF-EMR) affects the human reproductive system still requires further investigation. Therefore, The present study investigates whether RF-EMR at a frequency of 900 MHz can trigger sperm cell apoptosis and affect semen morphology, concentration, and microstructure. Twenty four rats were exposed to 900 MHz electromagnetic radiation with a special absorption rate of 0.66 ± 0.01 W/kg for 2 h/d. After 50d, the sperm count, morphology, apoptosis, reactive oxygen species (ROS), and total antioxidant capacity (TAC), representing the sum of enzymatic and nonenzymatic antioxidants, were investigated. Western blotting and reverse transcriptase PCR were used to determine the expression levels of apoptosis-related proteins and genes, including bcl-2, bax, cytochrome c, and capase-3. In the present study, the percentage of apoptotic sperm cells in the exposure group was significantly increased by 91.42% compared with the control group. Moreover, the ROS concentration in exposure group was increased by 46.21%, while the TAC was decreased by 28.01%. Radiation also dramatically decreased the protein and mRNA expression of bcl-2 and increased that of bax, cytochrome c, and capase-3. RF-EMR increases the ROS level and decreases TAC in rat sperm. Excessive oxidative stress alters the expression levels of apoptosis-related genes and triggers sperm apoptosis through bcl-2, bax, cytochrome c and caspase-3 signaling pathways.

  17. Safety of PEGylated recombinant human full-length coagulation factor VIII (BAX 855) in the overall context of PEG and PEG conjugates.

    Science.gov (United States)

    Stidl, R; Fuchs, S; Bossard, M; Siekmann, J; Turecek, P L; Putz, M

    2016-01-01

    BAX 855 is a PEGylated human full-length recombinant factor VIII (rFVIII) based on licensed rFVIII (ADVATE). The applied PEGylation technology has been optimized to retain functionality of the FVIII molecule, improve its pharmacokinetic properties and allow less frequent injections while maintaining efficacy. The aim of this study was to confirm that the excellent safety profile of ADVATE remains unchanged after PEGylation. Non-clinical safety studies with BAX 855 and its respective unbound polyethylene glycol (PEG) were conducted in several species. The distribution of a single dose of radiolabelled BAX 855 was further investigated in rats. Publically available safety data on PEG alone and PEGylated biomolecules were summarized and reviewed for specific safety findings attributable to PEG or PEGylated biopharmaceuticals. Safety pharmacology studies in rabbits and macaques and repeated dose toxicity studies in rats and macaques identified no safety issues. Results of a distribution study in rats administered radiolabelled BAX 855 showed that radioactivity was completely excreted; urine was the major elimination route. A 28-day study in rats dosed with the unbound PEG constituent (PEG2ru20KCOOH) of BAX 855 showed no adverse or non-adverse effects. Safety data for PEG and PEG-protein conjugates indicate no safety concerns associated with PEG at clinically relevant dose levels. Although vacuolation of certain cell types has been reported in mammals, no such vacuolation was observed with BAX 855 or with the unbound PEG constituent. Non-clinical safety evaluation of PEG and BAX 855 identified no safety signals; the compound is now in clinical development for the treatment of patients with haemophilia A. © 2015 Baxalta Innovations GmbH. Haemophilia Published by John Wiley & Sons Ltd.

  18. Bcl-2, Bax, and c-Fos expression correlates to RPE cell apoptosis induced by UV-light and daunorubicin

    DEFF Research Database (Denmark)

    Liang, Y G; Jorgensen, A G; Kaestel, C G

    2000-01-01

    PURPOSE. The aim of this study was to determine the role of Bcl-2, Bcl-X L, Bax, and c-Fos in regulation of apoptosis, induced by ultraviolet-light A (UV-A) and daunorubicin (DNR), in retinal pigment epithelium (RPE) cells grown on bovine extracellular matrix (ECM)-coated or uncoated plastic dishes....... METHODS. Apoptosis in confluent RPE cells cultured on ECM-coated or uncoated dishes was induced by UV-A or DNR. Apoptosis was detected by 7-amino-actinomycin D labeling followed by flow cytometry and by terminal deoxy-transferase mediated X-dUTP nick end labeling (TUNEL). Cellular expression of Bcl-2, Bcl......-X L, Bax, and c-Fos was determined by the use of antibodies and flow cytometry, Western blot analysis, and immunocytochemical staining. RESULTS. Both UV-A and DNR induce apoptosis in human RPE cells in vitro. Human fetal RPE cells grown on ECM-coated dishes were significantly more resistant to UV...

  19. Inhibition of Xenograft tumor growth by gold nanoparticle-DNA oligonucleotide conjugates-assisted delivery of BAX mRNA.

    Directory of Open Access Journals (Sweden)

    Ji-Hyun Yeom

    Full Text Available Use of non-biological agents for mRNA delivery into living systems in order to induce heterologous expression of functional proteins may provide more advantages than the use of DNA and/or biological vectors for delivery. However, the low efficiency of mRNA delivery into live animals, using non-biological systems, has hampered the use of mRNA as a therapeutic molecule. Here, we show that gold nanoparticle-DNA oligonucleotide (AuNP-DNA conjugates can serve as universal vehicles for more efficient delivery of mRNA into human cells, as well as into xenograft tumors generated in mice. Injections of BAX mRNA loaded on AuNP-DNA conjugates into xenograft tumors resulted in highly efficient mRNA delivery. The delivered mRNA directed the efficient production of biologically functional BAX protein, a pro-apoptotic factor, consequently inhibiting tumor growth. These results demonstrate that mRNA delivery by AuNP-DNA conjugates can serve as a new platform for the development of safe and efficient gene therapy.

  20. The Impact of Adenosine Fast Induction of Myocardial Arrest during CABG on Myocardial Expression of Apoptosis-Regulating Genes Bax and Bcl-2

    Directory of Open Access Journals (Sweden)

    Ahmed Shalaby

    2009-01-01

    Full Text Available Background. We studied the effect of fast induction of cardiac arrest with denosine on myocardial bax and bcl-2 expression. Methods and Results. 40 elective CABG patients were allocated into two groups. The adenosine group (n=20 received 250 μg/kg adenosine into the aortic root followed by blood potassium cardioplegia. The control group received potassium cardioplegia in blood. Bcl-2 and bax were measured. Bax was reduced in the postoperative biopsies (1.38 versus 0.47, P=.002 in the control group. Bcl-2 showed a reducing tendency (0.14 versus 0.085, P=.07. After the adenosine treatment, the expression of both bax (0.52 versus 0.59, P=.4 and bcl-2 (0.104 versus 0.107, P=.4 remained unaltered after the operation. Conclusion. Open heart surgery is associated with rapid reduction in the expression of apoptosis regulating genes bax and bcl-2. Fast Adenosine induction abolished changes in their expression.

  1. Immunohistochemical expression of p53, BCL-2, BAX and VEGFR1 proteins in nephroblastomas A expressão imuno-histoquímica das proteínas p53, BCL-2, BAX e VEGFR1 em nefroblastomas

    Directory of Open Access Journals (Sweden)

    Ana Paula Percicote

    2013-02-01

    Full Text Available INTRODUCTION: Nephroblastoma or Wilms' tumor is the most frequent renal cancer in children. Although its prognosis is favorable for most patients, it may relapse or have a fatal outcome. The characterization of risk groups by applying immunohistochemical biomarkers aims to adapt the treatment to its corresponding group as well as to reduce relapses and fatal outcome. p53, B-cell lymphoma 2 (BCL-2, BCL-2 associated protein X (BAX and vascular endothelial growth factor receptor 1 (VEGFR1 are among the most widely studied biomarkers, which are related to the apoptotic pathway, DNA repair and neovascularization. OBJECTIVE: The objective of this study is to assess the immunohistochemical expression of p53, BCL-2, BAX and VEGFR1 in samples of human nephroblastoma and to correlate them with clinicopathological prognostic factors. MATERIAL AND METHODS: Twenty-nine surgical specimens of nephroblastoma diagnosed from 1994 to 2007 were selected from the Anatomopathological Service of two hospitals in Curitiba. The immunohistochemical analysis of tissue microarrays was performed through immunoperoxidase staining and the yielded results were compared with clinicopathological prognostic factors. RESULTS: The major immunohistochemical expression of VEGFR1 in blastema and epithelium presented positive association with the risk group. Hence this may be related to higher vascular neoplastic invasion apparently caused by the endothelial growth factor, which maximizes the chances of metastasis and ultimately changes tumor staging, risk group and clinical evolution. CONCLUSIONS: The immunohistochemical expression of VEGFR1 substantiated a directly proportional association with the nephroblastoma risk group.INTRODUÇÃO: O nefroblastoma, ou tumor de Wilms, é a neoplasia renal mais frequente na infância. Embora o prognóstico seja favorável para a maioria dos pacientes, muitos evoluem para recidiva ou óbito. A caracterização de grupos de risco por meio de

  2. Anomalous metallic state with strong charge fluctuations in BaxTi8O16 +δ revealed by hard x-ray photoemission spectroscopy

    Science.gov (United States)

    Dash, S.; Kajita, T.; Okawa, M.; Saitoh, T.; Ikenaga, E.; Saini, N. L.; Katsufuji, T.; Mizokawa, T.

    2018-04-01

    We have studied a charge-orbital driven metal-insulator transition (MIT) in hollandite-type BaxTi8O16 +δ by means of hard x-ray photoemission spectroscopy (HAXPES). The Ti 2 p HAXPES indicates strong Ti3 +/Ti4 + charge fluctuation in the metallic phase above the MIT temperature. The metallic phase is characterized by a power-law spectral function near the Fermi level which would be a signature of bad metal with non-Drude polaronic behavior. The power-law spectral shape is associated with the large Seebeck coefficient of the metallic phase in BaxTi8O16 +δ .

  3. Determination of stoichiometry and concentration of trace elements in thin BaxSr1-xTiO3 perovskite layers.

    Science.gov (United States)

    Becker, J S; Boulyga, S F

    2001-07-01

    This paper describes an analytical procedure for determining the stoichiometry of BaxSr1-xTiO3 perovskite layers using inductively coupled plasma mass spectrometry (ICP-MS). The analytical results of mass spectrometry measurements are compared to those of X-ray fluorescence analysis (XRF). The performance and the limits of solid-state mass spectrometry analytical methods for the surface analysis of thin BaxSr1-xTiO3 perovskite layers sputtered neutral mass spectrometry (SNMS)--are investigated and discussed.

  4. Bax/Mcl-1 balance affects neutrophil survival in intermittent hypoxia and obstructive sleep apnea: effects of p38MAPK and ERK1/2 signaling

    Directory of Open Access Journals (Sweden)

    Dyugovskaya Larissa

    2012-10-01

    Full Text Available Abstract Background Prolonged neutrophil survival is evident in various cardiovascular and respiratory morbidities, in hypoxic conditions in-vitro and in patients with obstructive sleep apnea (OSA characterized by nightly intermittent hypoxia (IH. This may lead to persistent inflammation, tissue injury and dysfunction. We therefore investigated by a translational approach the potential contribution of the intrinsic stress-induced mitochondrial pathway in extending neutrophil survival under IH conditions. Thus, neutrophils of healthy individuals treated with IH in-vitro and neutrophils of OSA patients undergoing nightly IH episodes in-vivo were investigated. Specifically, the balance between pro-apoptotic Bax and anti-apoptotic Mcl-1 protein expression, and the potential involvement of p38MAPK and ERK1/2 signaling pathways in the control of Mcl-1 expression were investigated. Methods Purified neutrophils were exposed to IH and compared to normoxia and to sustained hypoxia (SH using a BioSpherix-OxyCycler C42 system. Bax and Mcl-1 levels, and p38MAPK and ERK1/2 phosphorylation were determined by western blotting. Also, Bax/Mcl-1 expression and Bax translocation to the mitochondria were assessed by confocal microscopy in pre-apoptotic neutrophils, before the appearance of apoptotic morphology. Co-localization of Bax and mitochondria was quantified by LSM 510 CarlZeiss MicroImaging using Manders Overlap Coefficient. A paired two-tailed t test, with Bonferroni correction for multiple comparisons, was used for statistical analysis. Results Compared to normoxia, IH and SH up-regulated the anti-apoptotic Mcl-1 by about 2-fold, down-regulated the pro-apoptotic Bax by 41% and 27%, respectively, and inhibited Bax co-localization with mitochondria before visible morphological signs of apoptosis were noted. IH induced ERK1/2 and p38MAPKs phosphorylation, whereas SH induced only p38MAPK phosphorylation. Accordingly, both ERK and p38MAPK inhibitors attenuated

  5. Bax/Tubulin/Epithelial-Mesenchymal Pathways Determine the Efficacy of Silybin Analog HM015k in Colorectal Cancer Cell Growth and Metastasis

    Directory of Open Access Journals (Sweden)

    Haneen Amawi

    2018-05-01

    Full Text Available The inhibition of apoptosis, disruption of cellular microtubule dynamics, and over-activation of the epithelial mesenchymal transition (EMT, are involved in the progression, metastasis, and resistance of colorectal cancer (CRC to chemotherapy. Therefore, the design of a molecule that can target these pathways could be an effective strategy to reverse CRC progression and metastasis. In this study, twelve novel silybin derivatives, HM015a-HM015k (15a−15k and compound 17, were screened for cytotoxicity in CRC cell lines. Compounds HM015j and HM015k (15k and 15j significantly decreased cell proliferation, inhibited colony formation, and produced cell cycle arrest in CRC cells. Furthermore, 15k significantly induced the formation of reactive oxygen species and apoptosis. It induced the cleavage of the intrinsic apoptotic protein (Bax p21 to its more efficacious fragment, p18. Compound 15k also inhibited tubulin expression and disrupted its structure. Compound 15k significantly decreased metastatic LOVO cell migration and invasion. Furthermore, 15k reversed mesenchymal morphology in HCT116 and LOVO cells. Additionally, 15k significantly inhibited the expression of the mesenchymal marker N-cadherin and upregulated the expression of the epithelial marker, E-cadherin. Compound 15k inhibited the expression of key proteins known to induce EMT (i.e., DVL3, β-catenin, c-Myc and upregulated the anti-metastatic protein, cyclin B1. Overall, in vitro, 15k significantly inhibited CRC progression and metastasis by inhibiting apoptosis, tubulin activity and the EMT pathways. Overall, these data suggest that compound 15k should be tested in vivo in a CRC animal model for further development.

  6. Effects of aspartame on hsp70, bcl-2 and bax expression in immune organs of Wistar albino rats

    Science.gov (United States)

    Choudhary, Arbind Kumar; Devi, Rathinasamy Sheela

    2016-01-01

    Abstract Aspartame, a “first generation sweetener”, is widely used in a variety of foods, beverages, and medicine. The FDA has determined the acceptable daily intake (ADI) value of aspartame to be 50 mg/kg·day, while the JECFA (Joint FAO/WHO Expert Committee on Food Additives) has set this value at 40 mg/kg of body weight/day. Safety issues have been raised about aspartame due to its metabolites, specifically toxicity from methanol and/or its systemic metabolites formaldehyde and formic acid. The immune system is now recognized as a target organ for many xenobiotics, such as drugs and chemicals, which are able to trigger unwanted apoptosis or to alter the regulation of apoptosis. Our previous studies has shown that oral administration of aspartame [40 mg/(kg·day)] or its metabolites for 90 days increased oxidative stress in immune organs of Wistar albino rats. In this present study, we aimed to clarify whether aspartame consumption over a longer period (90-days) has any effect on the expression of hsp70, bcl-2 and bax at both mRNA transcript and protein expression levels in immune organs. We observed that oral administration of aspartame for 90 days did not cause any apparent DNA fragmentation in immune organs of aspartame treated animals; however, there was a significant increase in hsp70 expression, apart from significant alteration in bcl-2 and bax at both mRNA transcript and protein expression level in the immune organs of aspartame treated animals compared to controls. Hence, the results indicated that hsp70 levels increased in response to oxidative injury induced by aspartame metabolites; however, these metabolites did not induce apoptosis in the immune organs. Furthermore, detailed analyses are needed to elucidate the precise molecular mechanisms involved in these changes. PMID:27845306

  7. BaxSr1-xTi1.02O3 metal-insulator-metal capacitors on planarized alumina substrates

    NARCIS (Netherlands)

    Tiggelman, M.P.J.; Reimann, K.; Klee, M.; Mauczok, R.; Keur, W.; Hueting, Raymond Josephus Engelbart

    2010-01-01

    Nanocrystalline barium strontium titanate (BaxSr1−xTi1.02O3) thin films with a barium content of x=0.8, 0.9 and 1 have been fabricated in a metal–insulator–metal configuration on glass-planarized alumina substrates. Cost-effective processing measures have been utilized by using poly-crystalline

  8. Characterization of Bc1-2, Bc1-xL, and Bax Pore Formation and Their Role in Apoptosis Regulation

    Science.gov (United States)

    2002-01-01

    Bcl-2, Bcl-xL, and Bax Pore Formation and Their Role in Apoptosis Regulation PRINCIPAL INVESTIGATOR: Frank Stenner -Liewen, Ph.D. Sharon Schendel, Ph.D...AUTHOR(S) Frank Stenner -Liewen, Ph.D. Sharon Schendel, Ph.D. John C. Reed, M.D., Ph.D. 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING

  9. Effects of Helicobacter pylori infection on the expressions of Bax and Bcl-2 in patients with chronic gastritis and gastric cancer.

    Science.gov (United States)

    Bartchewsky, Waldemar; Martini, Mariana R; Squassoni, Aline C; Alvarez, Marisa C; Ladeira, Marcelo S P; Salvatore, Daisy M F; Trevisan, Miriam A; Pedrazzoli, José; Ribeiro, Marcelo L

    2010-01-01

    The aim of the present study is to evaluate the influence of Helicobacter pylori on Bax and Bcl-2 mRNA and protein levels in patients with chronic gastritis and gastric cancer. The study included 217 patients, of which 26 were uninfected; 127 had chronic gastritis and were H. pylori-positive, and 64 had gastric cancer. Bacterial genotypes were evaluated by PCR, and the expression values were determined by quantitative real-time PCR and immunohistochemistry. Our data showed that the up-regulationary effects of H. pylori infection on the pro-apoptotic gene, Bax, were stronger than its induction of Bcl-2; this effect may increase apoptosis in patients with chronic gastritis. In patients with gastric cancer, the up-regulation of the anti-apoptotic gene, Bcl-2, counteracted the pro-apoptotic effects of Bax, leading to a deregulation of apoptosis-associated gene expression, favoring cell proliferation. Thus, the disturbance in Bax and Bcl-2 balance, induced by H. pylori, might be important in gastric cancer development.

  10. Synthesis and characterization of BaxMgyAl2O4: Eu,Dy nanophosphors prepared using solution-combustion method

    CSIR Research Space (South Africa)

    Kebede, MA

    2011-07-01

    Full Text Available Europium-doped barium magnesium aluminate (BaxMgyAl2O4:Eu) phosphors were obtained at low temperature using the solution-combustion of corresponding metal nitrate-urea solution mixtures. The particle sizes, morphology, structural and luminescent...

  11. BH3-only protein Bim inhibits activity of antiapoptotic members of Bcl-2 family when expressed in yeast.

    Science.gov (United States)

    Juhásová, Barbora; Mentel, Marek; Bhatia-Kiššová, Ingrid; Zeman, Igor; Kolarov, Jordan; Forte, Michael; Polčic, Peter

    2011-09-02

    Proteins of the Bcl-2 family regulate programmed cell death in mammals by promoting the release of cytochrome c from mitochondria in response to various proapoptotic stimuli. The mechanism by which BH3-only members of the family activate multidomain proapoptotic proteins Bax and Bak to form a pore in mitochondrial membranes remains under dispute. We report that cell death promoting activity of BH3-only protein Bim can be reconstituted in yeast when both Bax and antiapoptotic protein Bcl-X(L) are present, suggesting that Bim likely activates Bax indirectly by inhibiting antiapoptotic proteins. Copyright © 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  12. 1800 MHz mobile phone irradiation induced oxidative and nitrosative stress leads to p53 dependent Bax mediated testicular apoptosis in mice, Mus musculus.

    Science.gov (United States)

    Shahin, Saba; Singh, Surya P; Chaturvedi, Chandra M

    2018-09-01

    Present study was carried out to investigate the effect of long-term mobile phone radiation exposure in different operative modes (Dialing, Receiving, and Stand-by) on immature male mice. Three-week old male mice were exposed to mobile phone (1800 MHz) radiation for 3 hr/day for 120 days in different operative modes. To check the changes/alteration in testicular histoarchitecture and serum testosterone level, HE staining and ELISA was performed respectively. Further, we have checked the redox status (ROS, NO, MDA level, and antioxidant enzymes: SOD, CAT, and GPx) by biochemical estimation, alteration in the expression of pro-apoptotic proteins (p53 and Bax), active executioner caspase-3, full length/uncleaved PARP-1 (DNA repair enzyme), anti-apoptotic proteins (Bcl-2 and Bcl-x L ) in testes by immunofluorescence and cytosolic cytochrome-c by Western blot. Decreased seminiferous tubule diameter, sperm count, and viability along with increased germ cells apoptosis and decreased serum testosterone level, was observed in the testes of all the mobile phone exposed mice compared with control. We also observed that, mobile phone radiation exposure in all the three different operative modes alters the testicular redox status via increasing ROS, NO, and MDA level, and decreasing antioxidant enzymes levels leading to enhanced apoptosis of testicular cells by increasing the expression of pro-apoptotic and apoptotic proteins along with decreasing the expression of anti-apoptotic protein. On the basis of results, it is conclude that long-term mobile phone radiation exposure induced oxidative stress leads to apoptosis of testicular cells and thus impairs testicular function. © 2018 Wiley Periodicals, Inc.

  13. Tubeimoside-1 induces glioma apoptosis through regulation of Bax/Bcl-2 and the ROS/Cytochrome C/Caspase-3 pathway

    Directory of Open Access Journals (Sweden)

    Jia G

    2015-01-01

    Full Text Available Geng Jia,1,* Qiang Wang,2,* Rong Wang,2,* Danni Deng,2 Lian Xue,2 Naiyuan Shao,1 Yi Zhang,1 Xiwei Xia,1 Feng Zhi,2 Yilin Yang1,2 1Department of Neurosurgery, Third Affiliated Hospital of Soochow University, Jiangsu, People’s Republic of China; 2Modern Medical Research Center, Third Affiliated Hospital of Soochow University, Jiangsu, People’s Republic of China * These authors contributed equally to this workBackground: Tubeimoside-1 (TBMS1 is a natural compound isolated from tubeimoside, which has been widely used as a traditional Chinese herbal medicine. The purpose of the present study is to investigate the anti-tumor effect and the underling mechanism of TBMS1 on glioma cancer cells.Methods: The MTT assay was performed to evaluate the effect of TBMS1 on glioma cell proliferation. The fluorescent microscopy and flow cytometry analysis were performed to evaluate the effect of TBMS1 on glioma cell apoptosis. The Western blot analysis was used to evaluate the protein change.Results: TBMS1 inhibited glioma cancer cell proliferation in a dose- and time-dependent manner. Fluorescent microscopy and flow cytometry analysis demonstrated that TBMS1 induced glioma cell apoptosis in a concentration-dependent manner. Western blotting showed that TBMS1 induced apoptosis by increasing the expression of Bax and downregulating the level of Bcl-2. Furthermore, we found that TBMS1 induced apoptosis by increasing the concentration of reactive oxygen species through the release of Cytochrome C and activation of Caspase-3.Conclusion: These findings indicate that TBMS1 may be developed as a possible therapeutic agent for the management of glioma. Keywords: Tubeimoside-1, glioma, proliferation, apoptosis

  14. Photobiomodulation on Bax and Bcl-2 Proteins and SIRT1/PGC-1α Axis mRNA Expression Levels of Aging Rat Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    Fang-Hui Li

    2014-01-01

    Full Text Available Objective. This study aimed to analyze the effects of low level laser irradiation (LLLI on Bax and IGF-1 and Bcl-2 protein contents and SIRT1/PGC-1α axis mRNA expression levels to prevent sarcopenia in aged rats. Material and Methods. Twenty female Sprague Dawley rats (18 months old were randomly divided into two groups (n=10 per group: control (CON and LLLI groups. The gallium-aluminum-arsenium (GaAlAs laser irradiation at 810 nm was used in the single point contact mode (3.75 J/cm2; 0.4 cm2; 125 mW/cm2; 30 s. Bax, Bcl-2, and IGF-1 proteins and SIRT1/PGC-1α axis mRNA expression were assessed 24 h after LLLI on gastrocnemius in aged rat. Results. Gastrocnemius muscle weights, gastrocnemius mass/body mass, Bcl-2/BAX ratio, Bcl-2 protein, IGF-1 protein, and the mRNA contents in SIRT1, PGC-1α, NRF1, TMF, and SOD2 were significantly (P<0.05 increased by LLLI compared to CON group without LLLI. However, levels of BAX protein and caspase 3 mRNA were significantly attenuated by LLLI compared to CON group (P<0.05. Conclusion. LLLI at 810 nm inhibits sarcopenia associated with upregulation of Bcl-2/BAX ratio and IGF-1 and SIRT1/PGC-1α axis mRNA expression in aged rats. This indicates that LLLI has potential to decrease progression of myocyte apoptosis in sarcopenic muscles.

  15. Melatonin may play a role in modulation of bax and bcl-2 expression levels to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis

    International Nuclear Information System (INIS)

    Mohseni, Mehran; Mihandoost, Ehsan; Shirazi, Alireza; Sepehrizadeh, Zargham; Bazzaz, Javad Tavakkoly; Ghazi-khansari, Mahmoud

    2012-01-01

    The close relationship between free radicals effects and apoptosis process has been proved. Melatonin has been reported as a direct free radical scavenger. We investigated the capability of melatonin in the modification of radiation-induced apoptosis and apoptosis-associated upstream regulators expression in rat peripheral blood lymphocytes. Rats were irradiated with a single whole body Cobalt 60-gamma radiation dose of 8 Gy at a dose rate of 101 cGy/min with or without melatonin pretreatments at different concentrations of 10 and 100 mg/kg body weight. The rats were divided into eight groups of control, irradiation-only, vehicle-only, vehicle plus irradiation, 10 mg/kg melatonin alone, 10 mg/kg melatonin plus irradiation, 100 mg/kg melatonin alone and 100 mg/kg melatonin plus irradiation. Rats were given an intraperitoneal (IP) injection of melatonin or the same volume of vehicle alone 1 h prior to irradiation. Blood samples were taken 4, 24, 48 and 72 h after irradiation for evaluation of flow cytometric analysis of apoptotic lymphocytes using Annexin V/PI assay and measurement of bax and bcl-2 expression using quantitative real-time PCR (RT 2 qPCR). Irradiation-only and vehicle plus irradiation showed an increase in the percentage of apoptotic lymphocytes significantly different from control group (P < 0.01), while melatonin pretreatments in a dose-dependent manner reduced it as compared with the irradiation-only and vehicle plus irradiation groups (P < 0.01) in all time points. This reduced apoptosis by melatonin was related to the downregulation of bax, upregulation of bcl-2, and therefore reduction of bax/bcl-2 ratio. Our results suggest that melatonin in these doses may provide modulation of bax and bcl-2 expression as well as bax/bcl-2 ratio to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis.

  16. Melatonin may play a role in modulation of bax and bcl-2 expression levels to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Mohseni, Mehran [Department of Radiology and Medical Physics, Faculty of Paramedicine, Kashan University of Medical Sciences, Kashan (Iran, Islamic Republic of); Mihandoost, Ehsan, E-mail: mihandoost.e@gmail.com [Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Shirazi, Alireza [Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sepehrizadeh, Zargham [Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Bazzaz, Javad Tavakkoly [Department of Medical Genetics, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ghazi-khansari, Mahmoud [Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2012-10-15

    The close relationship between free radicals effects and apoptosis process has been proved. Melatonin has been reported as a direct free radical scavenger. We investigated the capability of melatonin in the modification of radiation-induced apoptosis and apoptosis-associated upstream regulators expression in rat peripheral blood lymphocytes. Rats were irradiated with a single whole body Cobalt 60-gamma radiation dose of 8 Gy at a dose rate of 101 cGy/min with or without melatonin pretreatments at different concentrations of 10 and 100 mg/kg body weight. The rats were divided into eight groups of control, irradiation-only, vehicle-only, vehicle plus irradiation, 10 mg/kg melatonin alone, 10 mg/kg melatonin plus irradiation, 100 mg/kg melatonin alone and 100 mg/kg melatonin plus irradiation. Rats were given an intraperitoneal (IP) injection of melatonin or the same volume of vehicle alone 1 h prior to irradiation. Blood samples were taken 4, 24, 48 and 72 h after irradiation for evaluation of flow cytometric analysis of apoptotic lymphocytes using Annexin V/PI assay and measurement of bax and bcl-2 expression using quantitative real-time PCR (RT{sup 2}qPCR). Irradiation-only and vehicle plus irradiation showed an increase in the percentage of apoptotic lymphocytes significantly different from control group (P < 0.01), while melatonin pretreatments in a dose-dependent manner reduced it as compared with the irradiation-only and vehicle plus irradiation groups (P < 0.01) in all time points. This reduced apoptosis by melatonin was related to the downregulation of bax, upregulation of bcl-2, and therefore reduction of bax/bcl-2 ratio. Our results suggest that melatonin in these doses may provide modulation of bax and bcl-2 expression as well as bax/bcl-2 ratio to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis.

  17. Probucol Attenuates Cyclophosphamide-induced Oxidative Apoptosis, p53 and Bax Signal Expression in Rat Cardiac Tissues

    Directory of Open Access Journals (Sweden)

    Yousif A. Asiri

    2010-01-01

    Full Text Available Cyclophosphamide (CP is a widely used drug in cancer chemotherapy and immunosuppression, which could cause toxicity of the normal cells due to its toxic metabolites. Probucol, a cholesterol-lowering drug, acts as potential inhibitor of DNA damage and shows to protect against doxorubicin-induced cardiomyopathy by enhancing the endogenous antioxidant system including glutathione peroxidase, catalase and superoxide dismutase. This study examined the possible protective effects of probucol, a lipid-lowering compound with strong antioxidant properties, against CPinduced cardiotoxicity. This objective could be achieved through studying the gene expression-based on the possible protective effects of probucol against CP-induced cardiac failure in rats. Adult male Wistar albino rats were assigned into four treatment groups: Animals in the first (control and second (probucol groups were injected intraperitoneally with corn oil and probucol (61 mg/kg/day, respectively, for two weeks. Animals in the third (CP and fourth (probucol plus CP groups were injected with the same doses of corn oil and probucol (61 mg/kg/day, respectively, for one week before and one week after a single dose of CP (200 mg/kg, I.P.. The p53, Bax, Bcl2 and oxidative genes signal expression were measured by real time PCR. CP-induced cardiotoxicity was clearly observed by a significant increase in serum creatine phosphokinase isoenzyme (CK-MB (117%, lactate dehydrogenase (LDH (64%, free (69% and esterified cholesterol (42% and triglyceride (69% compared to control group. In cardiac tissues, CP significantly increases the mRNA expression levels of apoptotic genes, p53 with two-fold and Bax with 1.6-fold, and decreases the anti-apoptotic gene Bcl2 with 0.5-fold. Moreover, CP caused downregulation of antioxidant genes, glutathione peroxidase, catalase, and superoxide dismutase and increased the lipid peroxidation and decreased adenosine triphosphate (ATP (40% and ATP/ADP (44% in cardiac

  18. Effect of nerve injury on the number of dorsal root ganglion neurons and autotomy behavior in adult Bax-deficient mice

    Directory of Open Access Journals (Sweden)

    Lyu C

    2017-08-01

    Full Text Available Chuang Lyu,1,2 Gong-Wei Lyu,3 Aurora Martinez,4 Tie-Jun Sten Shi4 1State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People’s Republic of China; 2Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden; 3Department of Neurology, 1st Hospital of Harbin Medical University, Harbin, People’s Republic of China; 4Department of Biomedicine, University of Bergen, Bergen, Norway Background: The proapoptotic molecule BAX, plays an important role in mitochondrial apoptotic pathway. Dorsal root ganglion (DRG neurons depend on neurotrophic factors for survival at early developmental stages. Withdrawal of neurotrophic factors will induce apoptosis in DRG neurons, but this type of cell death can be delayed or prevented in neonatal Bax knockout (KO mice. In adult animals, evidence also shows that DRG neurons are less dependent upon neurotrophic factors for survival. However, little is known about the effect of Bax deletion on the survival of normal and denervated DRG neurons in adult mice. Methods: A unilateral sciatic nerve transection was performed in adult Bax KO mice and wild-type (WT littermates. Stereological method was employed to quantify the number of lumbar-5 DRG neurons 1 month post-surgery. Nerve injury-induced autotomy behavior was also examined on days 1, 3, and 7 post-surgery. Results: There were significantly more neurons in contralateral DRGs of KO mice as compared with WT mice. The number of neurons was reduced in ipsilateral DRGs in both KO and WT mice. No changes in size distributions of DRG neuron profiles were detected before or after nerve injury. Injury-induced autotomy behavior developed much earlier and was more serious in KO mice. Conclusion: Although postnatal death or loss of DRG neurons is partially prevented by Bax deletion, this effect cannot interfere with long-term nerve injury-induced neuronal loss. The exaggerated self

  19. Role of the lattice dynamics in La2-xBaxCuO4 superconductor based on DFT method

    Directory of Open Access Journals (Sweden)

    A Tavana

    2010-09-01

    Full Text Available Electron-phonon coupling parameters are calculated for La2-x BaxCuO4 cuprate superconductor in a wide range of dopings, from undoped to overdoped compounds. In this study we aim to study the quality of such calculations based on DFT method so, the results of σ GGA+U electronic structure calculations are also investigated. The obtained value for electron-phonon coupling is in the same order of previous calculations but, the value obtained for the Hubbard U parameter shows that, such methods are poor in the estimation of electronic correlations to decide about the role of phonons in these compounds based on their results. Moreover, existence of several structural phase transitions with temperature and doping, lead to larger error in these calculations. Based on the calculated phonon dispersions, structural phase transitions can be resulted which shows the ability of DFT in the study of structural properties and the weakness of the strongly correlations in this properties.

  20. Relationship between bcl-2, bax, beclin-1, and cathepsin-D proteins during postovulatory follicular regression in fish ovary.

    Science.gov (United States)

    Morais, Roberto D V S; Thomé, Ralph G; Santos, Hélio B; Bazzoli, Nilo; Rizzo, Elizete

    2016-04-01

    In fish ovaries, postovulatory follicles (POFs) are key biomarkers of breeding and provide an interesting model for studying the relationship between autophagy and apoptosis. In this study, we investigated the immunohistochemical expression of autophagic and apoptotic proteins to improve the knowledge on the mechanisms regulating ovarian remodeling after spawning. Females from three neotropical fish species kept in captivity were submitted to hormonal induction. After ova stripping, ovarian sections were sampled daily until 5 days postspawning (dps). Similar events of POF regression were detected by histology, terminal transferase-mediated dUTP nick-end labeling (TUNEL), and electron microscopy in the three species: follicular cells hypertrophy, progressive disintegration of the basement membrane, gradual closing of the follicular lumen, theca thickening, and formation of large autophagic vacuoles preceding apoptosis of the follicular cells. Autophagic and apoptotic proteins were assessed by immunohistochemistry. Morphometric analysis of the immunolabeling revealed a more intense reaction for bcl-2 and beclin-1 (BECN1) in POFs at 0 to 1 dps and for bax at 2 to 3 dps (P family, BECN1, and cathepsin-D can be involved in the regulation of ovarian remodeling in teleost fish. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Displacement-type ferroelectric transition with magnetic Mn ions in perovskite Sr1-xBaxMnO3

    Science.gov (United States)

    Sakai, Hideaki; Fujioka, Jun; Fukuda, Tatsuo; Okuyama, Daisuke; Hashizume, Daisuke; Kagawa, Fumitaka; Nakao, Hironori; Murakami, Youich; Arima, Takahisa; Baron, Alfred Q. R.; Taguchi, Yasujiro; Tokura, Yoshinori

    2012-02-01

    Almost all the proper ferroelectrics with a perovskite structure discovered so far have no d-electrons in the off-center transition metal site, as exemplified by BaTiO3 and Pb(Zr,Ti)O3. This empirical d^0 rule is incompatible with the emergence of magnetism and has significantly restricted the variety of multiferroic materials. In this work, we have discovered a displacement-type ferroelectric transition originating from off-center Mn^4+ ions in antiferromagnetic Mott insulators Sr1-xBaxMnO3. As Ba concentration increases, the perovskite lattice shows the typical soft mode dynamics, and the ferroelectricity shows up for x .45. In addition to the large polarization and high transition temperature comparable to BaTiO3, we demonstrate that the magnetic order suppresses the ferroelectric lattice dilation by ˜70% and increases the soft-phonon energy by ˜50%, indicating gigantic magnetoelectric effects [1]. This work was supported by the FIRST program on ``Quantum Science on Strong Correlation''. [4pt] [1] H. Sakai et al., Phys. Rev. Lett. 107, 137601 (2011).

  2. Mdm2 is a novel activator of ApoCIII promoter which is antagonized by p53 and SHP inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhihong; Zhang, Yuxia [Departments of Medicine and Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84132 (United States); Wang, Li, E-mail: l.wang@hsc.utah.edu [Departments of Medicine and Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84132 (United States)

    2012-01-13

    Highlights: Black-Right-Pointing-Pointer Mdm2 enhances HNF4{alpha} activation of the ApoCIII promoter via interaction with HNF4{alpha}. Black-Right-Pointing-Pointer p53 antagonizes the effect of Mdm2 activation of the ApoCIII promoter. Black-Right-Pointing-Pointer SHP strengthens p53 inhibition but abolishes Mdm2 activation of the ApoCIII promoter. Black-Right-Pointing-Pointer Mdm2 alters the enrichment of HNF4{alpha}, p53 and SHP to the ApoCIII promoter. -- Abstract: We examined the effect of Mdm2 on regulation of the ApoCIII promoter and its cross-talk with p53 and nuclear receptor SHP. Overexpression of Mdm2 markedly enhanced ApoCIII promoter activity by HNF4{alpha}. A direct association of Mdm2 protein with the HNF4{alpha} protein was observed by co-immunoprecipitation. Ectopic expression of p53 decreased HNF4{alpha} activation of the ApoCIII promoter and antagonized the effect of Mdm2. Co-expression of SHP further strengthened p53 inhibition and abolished Mdm2 activation of the ApoCIII promoter. Mdm2 inhibited p53-mediated enrichment of HNF4{alpha} to the ApoCIII promoter while simultaneously reducing p53 binding and increasing recruitment of SHP to the ApoCIII promoter. The results from this study implicate a potentially important function of Mdm2 in regulation of lipoprotein metabolism.

  3. Mdm2 is a novel activator of ApoCIII promoter which is antagonized by p53 and SHP inhibition

    International Nuclear Information System (INIS)

    Yang, Zhihong; Zhang, Yuxia; Wang, Li

    2012-01-01

    Highlights: ► Mdm2 enhances HNF4α activation of the ApoCIII promoter via interaction with HNF4α. ► p53 antagonizes the effect of Mdm2 activation of the ApoCIII promoter. ► SHP strengthens p53 inhibition but abolishes Mdm2 activation of the ApoCIII promoter. ► Mdm2 alters the enrichment of HNF4α, p53 and SHP to the ApoCIII promoter. -- Abstract: We examined the effect of Mdm2 on regulation of the ApoCIII promoter and its cross-talk with p53 and nuclear receptor SHP. Overexpression of Mdm2 markedly enhanced ApoCIII promoter activity by HNF4α. A direct association of Mdm2 protein with the HNF4α protein was observed by co-immunoprecipitation. Ectopic expression of p53 decreased HNF4α activation of the ApoCIII promoter and antagonized the effect of Mdm2. Co-expression of SHP further strengthened p53 inhibition and abolished Mdm2 activation of the ApoCIII promoter. Mdm2 inhibited p53-mediated enrichment of HNF4α to the ApoCIII promoter while simultaneously reducing p53 binding and increasing recruitment of SHP to the ApoCIII promoter. The results from this study implicate a potentially important function of Mdm2 in regulation of lipoprotein metabolism.

  4. Ab-initio study of structural, elastic, electronic and thermodynamic properties of BaxSr1−xS ternary alloys

    Directory of Open Access Journals (Sweden)

    Chelli S.

    2015-12-01

    Full Text Available The structural, elastic, electronic and thermodynamic properties of BaxSr1−xS ternary alloys have been investigated using the full-potential (linearized augmented plane wave method. The ground state properties, such as lattice constant, bulk modulus and elastic constants, are in good agreement with numerous experimental and theoretical data. The dependence of the lattice parameters, bulk modulus and band gap on the composition x was analyzed. Deviation of the lattice constant from Vegard’s law and the bulk modulus from linear concentration dependence (LCD was observed. The microscopic origins of the gap bowing were explained by using the approach of Zunger et al. The thermodynamic stability of BaxSr1−xS alloy was investigated by calculating the excess enthalpy of mixing, ΔHm and the calculated phase diagram showed a broad miscibility gap with a critical temperature.

  5. An Assay of Bax and Bcl2 Expression in Mice Hippocampus Following Ischemia-Reperfusion Treatment with CoQ10

    Directory of Open Access Journals (Sweden)

    Jalal Hassanshahi

    2013-10-01

    Full Text Available Introduction: Preliminary studies confirmed reduction of cell death following treatment with antioxidants. According to this finding we investigated the relationship between consumption of CoQ10 and expression of bax and bcl2 in hippocampus ischemia that this expression related to cell programmed death.Material and Methods: We studied the protective role of CoQ10 against ischemia-reperfusion. Experimental design includes four groups: intact (N=7, ischemic control (N=7, sham control (N=7 and treatment groups with CoQ10 (N=7. The mice (treatment group treated with CoQ10 as Pre-Treatment for a week. Then, ischemia induced by common carotid artery ligation and following the reduction in inflammation (a week the treatment group post-treated with CoQ10 for a week. Nissl staining applied to counting necrotic cells of hippocampus and the western blotting performed to measurement the bax and bcl2 expression. Tunnel kit was used to quantify apoptotic cell death while to short term memory scale, we apply Y-maze.Results: Cell death was significantly lower when mice treated with CoQ10. Bax expression was significantly high in ischemic group but in treatment group was less and reversely the bcl2 expression in ischemic group was lower than treatment and vehicle groups. The memory test results were consistent with cell death results. Conclusion: Ischemia for 15 minutes induced cell death in hippocampus with more potent effect on CA1. CoQ10 intake significantly reduced cell death and decreased memory loss. with prevent of expression of bax and increase in expression of bcl2.

  6. Cycloheximide and actinomycin D delay death and affect bcl-2, bax, and Ice gene expression in astrocytes under in vitro ischemia.

    Science.gov (United States)

    Yu, Albert Cheung Hoi; Yung, Hon Wa; Hui, Michael Hung Kit; Lau, Lok Ting; Chen, Xiao Qian; Collins, Richard A

    2003-10-15

    An in vitro ischemia model was established and the effect of the metabolic inhibitors cycloheximide (CHX) and actinomycin D (ActD) on apoptosis in astrocytes under ischemia studied. CHX decreased by 75% the number of cells dying after 6 hr of ischemia compared with control cultures. TdT-mediated dUTP nick end labelling (TUNEL) staining of comparable cultures was reduced by 40%. ActD decreased cell death by 60% compared with controls. The number of TUNEL-positive cells was reduced by 38%. The nuclear shrinkage in TUNEL-positive astrocytes in control cultures did not occur in ActD-treated astrocytes, indicating that nuclear shrinkage and DNA fragmentation during apoptosis are two unrelated processes. Expression of bcl-2 (alpha and beta), bax, and Ice in astrocytes under similar ischemic conditions, as measured by quantitative reverse transcription-polymerase chain reaction, indicated that ischemia down-regulated bcl-2 (alpha and beta) and bax. Ice was initially down-regulated from 0 to 4 hr, before returning to control levels after 8 hr of ischemia. ActD decreased the expression of these genes. CHX reduced the expression of bcl-2 (alpha and beta) but increased bax and Ice expression. It is hypothesized that the balance of proapoptotic (Bad, Bax) and antiapoptotic (Bcl-2, Bcl-Xl) proteins determines apoptosis. The data suggest that the ratio of Bcl-2/Bad in astrocytes following ActD and CHX treatment does not decrease as much in untreated cells during ischemia. Our data indicate that it is the ratio of Bcl-2 family members that plays a critical role in determining ischemia-induced apoptosis. It is also important to note that ischemia-induced apoptosis involves the regulation of RNA and protein synthesis. Copyright 2003 Wiley-Liss, Inc.

  7. Disturbance of Bcl-2, Bax, Caspase-3, Ki-67 and C-myc expression in acute and subchronic exposure to benzo(a)pyrene in cervix.

    Science.gov (United States)

    Gao, Meili; Li, Yongfei; Ji, Xiaoying; Xue, Xiaochang; Chen, Lan; Feng, Guodong; Zhang, Huqin; Wang, Huichun; Shah, Walayat; Hou, Zhanwu; Kong, Yu

    2016-03-01

    Epidemiological studies have demonstrated that cigarette smoking is an important cofactor or an independent risk factor for the development of cervical cancer. Benzo(a)pyrene (BaP) is one of the most potent tobacco smoke carcinogens in tobacco smoke. BaP induced DNA damage and over expression in p53 cervical tissue of mice as demonstrated in our previous study. Here we present the findings of exposure to BaP on the expression of Bcl-2, C-myc, Ki-67, Caspase-3 and Bax genes in mouse cervix. Acute intraperitoneal administration of BaP (12.5, 25, 50, 100mg/kg body weight) to ICR female mice induced a significant increase in Bcl-2, C-myc, Ki-67 mRNA and protein level till 72h except in Bcl-2 at 24h with 12.5, 25, 50mg/kg as well as at 48h with 12.5mg/kg body weight post treatment. A significant increase was also seen in Caspase-3 and Bax mRNA and protein level with peak level at 24h and gradual decrease till 72h, however, the expression of caspase-3 increased while that of Bax decreased with increasing dose of Bap after 24h. In sub chronic intraperitoneal and oral gavage administration of BaP (2.5, 5, 10mg/kg body weight), similar significant increase was observed for all the examined genes as compared to the control and vehicle groups, however the expression of Bax decreased in a dose dependent manner. The findings of this study will help in further understanding the molecular mechanism of BaP induced carcinogenesis of cervical cancer. Copyright © 2015 Elsevier GmbH. All rights reserved.

  8. Phosphorylation and nuclear accumulation are distinct events contributing to the activation of p53

    International Nuclear Information System (INIS)

    O'Hagan, Heather M.; Ljungman, Mats

    2004-01-01

    It has been recently shown that ionizing radiation (IR) and the mRNA synthesis inhibitor 5,6-dichloro-1-b-D-ribofuranosylbenzimidazole (DRB) act in synergy to induce p53-mediated transactivation of reporter plasmids in human cells [Oncogene 19 (2000) 3829]. We have extended these studies and show that ionizing radiation and DRB also act in synergy to induce ATM-mediated phosphorylation of the ser15 site of p53 and enhance the expression of endogenous p21 protein. Examination of the localization of p53 revealed that while DRB did not induce phosphorylation of the ser15 site of p53 but efficiently accumulated p53 in the nucleus, ionizing radiation induced phosphorylation of the ser15 site of p53 without prolonged nuclear accumulation. Importantly, the combination of DRB and IR resulted in a strong accumulation of phosphorylated p53 in the nucleus that was more persistent then p53 accumulation after IR alone. Furthermore, the nuclear export inhibitor leptomycin B showed a similar synergy with IR as did DRB regarding ser15 phosphorylation of p53 and p21 induction. These results suggest that the synergistic activation of the p53 response by the combination treatment is due to the activation of two distinct pathways where DRB causes the prolonged nuclear accumulation of p53 while ionizing radiation activates p53 by ATM-mediated phosphorylation

  9. Pushing the size limit of de novo structure ensemble prediction guided by sparse SDSL-EPR restraints to 200 residues: The monomeric and homodimeric forms of BAX

    Science.gov (United States)

    Fischer, Axel W.; Bordignon, Enrica; Bleicken, Stephanie; García-Sáez, Ana J.; Jeschke, Gunnar; Meiler, Jens

    2016-01-01

    Structure determination remains a challenge for many biologically important proteins. In particular, proteins that adopt multiple conformations often evade crystallization in all biologically relevant states. Although computational de novo protein folding approaches often sample biologically relevant conformations, the selection of the most accurate model for different functional states remains a formidable challenge, in particular, for proteins with more than about 150 residues. Electron paramagnetic resonance (EPR) spectroscopy can obtain limited structural information for proteins in well-defined biological states and thereby assist in selecting biologically relevant conformations. The present study demonstrates that de novo folding methods are able to accurately sample the folds of 192-residue long soluble monomeric Bcl-2-associated X protein (BAX). The tertiary structures of the monomeric and homodimeric forms of BAX were predicted using the primary structure as well as 25 and 11 EPR distance restraints, respectively. The predicted models were subsequently compared to respective NMR/X-ray structures of BAX. EPR restraints improve the protein-size normalized root-mean-square-deviation (RMSD100) of the most accurate models with respect to the NMR/crystal structure from 5.9 Å to 3.9 Å and from 5.7 Å to 3.3 Å, respectively. Additionally, the model discrimination is improved, which is demonstrated by an improvement of the enrichment from 5% to 15% and from 13% to 21%, respectively. PMID:27129417

  10. AMP-activated protein kinase phosphorylates CtBP1 and down-regulates its activity

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae-Hwan; Choi, Soo-Youn; Kang, Byung-Hee; Lee, Soon-Min [National Creative Research Center for Epigenome Reprogramming Network, Departments of Biomedical Sciences and Biochemistry and Molecular Biology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Park, Hyung Soon; Kang, Gum-Yong; Bang, Joo Young [Center for Biomedical Mass Spectrometry, Diatech Korea Co., Ltd., Seoul (Korea, Republic of); Cho, Eun-Jung [National Research Laboratory for Chromatin Dynamics, College of Pharmacy, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Youn, Hong-Duk, E-mail: hdyoun@snu.ac.kr [National Creative Research Center for Epigenome Reprogramming Network, Departments of Biomedical Sciences and Biochemistry and Molecular Biology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); WCU Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence and Technology, Seoul National University, Seoul (Korea, Republic of)

    2013-02-01

    Highlights: ► AMPK phosphorylates CtBP1 on serine 158. ► AMPK-mediated phosphorylation of CtBP1 causes the ubiquitination and nuclear export of CtBP1. ► AMPK downregulates the CtBP1-mediated repression of Bax transcription. -- Abstract: CtBP is a transcriptional repressor which plays a significant role in the regulation of cell proliferation and tumor progression. It was reported that glucose withdrawal causes induction of Bax due to the dissociation of CtBP from the Bax promoter. However, the precise mechanism involved in the regulation of CtBP still remains unclear. In this study, we found that an activated AMP-activated protein kinase (AMPK) phosphorylates CtBP1 on Ser-158 upon metabolic stresses. Moreover, AMPK-mediated phosphorylation of CtBP1 (S158) attenuates the repressive function of CtBP1. We also confirmed that triggering activation of AMPK by various factors resulted in an increase of Bax gene expression. These findings provide connections of AMPK with CtBP1-mediated regulation of Bax expression for cell death under metabolic stresses.

  11. The Wheat Bax Inhibitor-1 Protein Interacts with an Aquaporin TaPIP1 and Enhances Disease Resistance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Pan-Pan Lu

    2018-01-01

    Full Text Available Bax inhibitor-1 (BI-1 is an endoplasmic reticulum (ER-resident cell death suppressor evolutionarily conserved in eukaryotes. The ability of BI-1 to inhibit the biotic and abiotic stresses have been well-studied in Arabidopsis, while the functions of wheat BI-1 are largely unknown. In this study, the wheat BI-1 gene TaBI-1.1 was isolated by an RNA-seq analysis of Fusarium graminearum (Fg-treated wheat. TaBI-1.1 expression was induced by a salicylic acid (SA treatment and down-regulated by an abscisic acid (ABA treatment. Based on β-glucuronidase (GUS staining, TaBI-1.1 was expressed in mature leaves and roots but not in the hypocotyl or young leaves. Constitutive expression of TaBI-1.1 in Arabidopsis enhanced its resistance to Pseudomonas syringae pv. Tomato (Pst DC3000 infection and induced SA-related gene expression. Additionally, TaBI-1.1 transgenic Arabidopsis exhibited an alleviation of damage caused by high concentrations of SA and decreased the sensitivity to ABA. Consistent with the phenotype, the RNA-seq analysis of 35S::TaBI-1.1 and Col-0 plants showed that TaBI-1.1 was involved in biotic stresses. These results suggested that TaBI-1.1 positively regulates SA signals and plays important roles in the response to biotic stresses. In addition, TaBI-1.1 interacted with the aquaporin TaPIP1, and both them were localized to ER membrane. Furthermore, we demonstrated that TaPIP1 was up-regulated by SA treatment and TaPIP1 transgenic Arabidopsis enhanced the resistance to Pst DC3000 infection. Thus, the interaction between TaBI-1.1 and TaPIP1 on the ER membrane probably occurs in response to SA signals and defense response.

  12. Inhibition of p53 acetylation by INHAT subunit SET/TAF-Iβ represses p53 activity.

    Science.gov (United States)

    Kim, Ji-Young; Lee, Kyu-Sun; Seol, Jin-Ee; Yu, Kweon; Chakravarti, Debabrata; Seo, Sang-Beom

    2012-01-01

    The tumor suppressor p53 responds to a wide variety of cellular stress signals. Among potential regulatory pathways, post-translational modifications such as acetylation by CBP/p300 and PCAF have been suggested for modulation of p53 activity. However, exactly how p53 acetylation is modulated remains poorly understood. Here, we found that SET/TAF-Iβ inhibited p300- and PCAF-mediated p53 acetylation in an INHAT (inhibitor of histone acetyltransferase) domain-dependent manner. SET/TAF-Iβ interacted with p53 and repressed transcription of p53 target genes. Consequently, SET/TAF-Iβ blocked both p53-mediated cell cycle arrest and apoptosis in response to cellular stress. Using different apoptosis analyses, including FACS, TUNEL and BrdU incorporation assays, we also found that SET/TAF-Iβ induced cellular proliferation via inhibition of p53 acetylation. Furthermore, we observed that apoptotic Drosophila eye phenotype induced by either dp53 overexpression or UV irradiation was rescued by expression of dSet. Inhibition of dp53 acetylation by dSet was observed in both cases. Our findings provide new insights into the regulation of stress-induced p53 activation by HAT-inhibiting histone chaperone SET/TAF-Iβ.

  13. Residues in the alternative reading frame tumor suppressor that influence its stability and p53-independent activities

    International Nuclear Information System (INIS)

    Tommaso, Anne di; Hagen, Jussara; Tompkins, Van; Muniz, Viviane; Dudakovic, Amel; Kitzis, Alain; Ladeveze, Veronique; Quelle, Dawn E.

    2009-01-01

    The Alternative Reading Frame (ARF) protein suppresses tumorigenesis through p53-dependent and p53-independent pathways. Most of ARF's anti-proliferative activity is conferred by sequences in its first exon. Previous work showed specific amino acid changes occurred in that region during primate evolution, so we programmed those changes into human p14ARF to assay their functional impact. Two human p14ARF residues (Ala 14 and Thr 31 ) were found to destabilize the protein while two others (Val 24 and Ala 41 ) promoted more efficient p53 stabilization and activation. Despite those effects, all modified p14ARF forms displayed robust p53-dependent anti-proliferative activity demonstrating there are no significant biological differences in p53-mediated growth suppression associated with simian versus human p14ARF residues. In contrast, p53-independent p14ARF function was considerably altered by several residue changes. Val 24 was required for p53-independent growth suppression whereas multiple residues (Val 24 , Thr 31 , Ala 41 and His 60 ) enabled p14ARF to block or reverse the inherent chromosomal instability of p53-null MEFs. Together, these data pinpoint specific residues outside of established p14ARF functional domains that influence its expression and signaling activities. Most intriguingly, this work reveals a novel and direct role for p14ARF in the p53-independent maintenance of genomic stability.

  14. Low-level overexpression of p53 promotes warfarin-induced calcification of porcine aortic valve interstitial cells by activating Slug gene transcription.

    Science.gov (United States)

    Gao, Li; Ji, Yue; Lu, Yan; Qiu, Ming; Shen, Yejiao; Wang, Yaqing; Kong, Xiangqing; Shao, Yongfeng; Sheng, Yanhui; Sun, Wei

    2018-03-09

    The most frequently used oral anti-coagulant warfarin has been implicated in inducing calcification of aortic valve interstitial cells (AVICs), whereas the mechanism is not fully understood. The low-level activation of p53 is found to be involved in osteogenic transdifferentiation and calcification of AVICs. Whether p53 participates in warfarin-induced AVIC calcification remains unknown. In this study, we investigated the role of low-level p53 overexpression in warfarin-induced porcine AVIC (pAVIC) calcification. Immunostaining, quantitative PCR, and Western blotting revealed that p53 was expressed in human and pAVICs and that p53 expression was slightly increased in calcific human aortic valves compared with non-calcific valves. Terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling staining indicated that apoptosis slightly increased in calcific aortic valves than in non-calcific valves. Warfarin treatment led to a low-level increase of p53 mRNA and protein in both pAVICs and mouse aortic valves. Low-level overexpression of p53 in pAVICs via an adenovirus vector did not affect pAVIC apoptosis but promoted warfarin-induced calcium deposition and expression of osteogenic markers. shRNA-mediated p53 knockdown attenuated the pAVIC calcium deposition and osteogenic marker expression. Moreover, ChIP and luciferase assays showed that p53 was recruited to the slug promoter and activated slug expression in calcific pAVICs. Of note, overexpression of Slug increased osteogenic marker Runx2 expression, but not pAVIC calcium deposition, and Slug knockdown attenuated pAVIC calcification and p53-mediated pAVIC calcium deposition and expression of osteogenic markers. In conclusion, we found that p53 plays an important role in warfarin induced pAVIC calcification, and increased slug transcription by p53 is required for p53-mediated pAVIC calcification. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Selective functional activity measurement of a PEGylated protein with a modification-dependent activity assay.

    Science.gov (United States)

    Weber, Alfred; Engelmaier, Andrea; Mohr, Gabriele; Haindl, Sonja; Schwarz, Hans Peter; Turecek, Peter L

    2017-01-05

    BAX 855 (ADYNOVATE) is a PEGylated recombinant factor VIII (rFVIII) that showed prolonged circulatory half-life compared to unmodified rFVIII in hemophilic patients. Here, the development and validation of a novel assay is described that selectively measures the activity of BAX 855 as cofactor for the serine protease factor IX, which actives factor X. This method type, termed modification-dependent activity assay, is based on PEG-specific capture of BAX 855 by an anti-PEG IgG preparation, followed by a chromogenic FVIII activity assay. The assay principle enabled sensitive measurement of the FVIII cofactor activity of BAX 855 down to the pM-range without interference by non-PEGylated FVIII. The selectivity of the capture step, shown by competition studies to primarily target the terminal methoxy group of PEG, also allowed assessment of the intactness of the attached PEG chains. Altogether, the modification-dependent activity not only enriches, but complements the group of methods to selectively, accurately, and precisely measure a PEGylated drug in complex biological matrices. In contrast to all other methods described so far, it allows measurement of the biological activity of the PEGylated protein. Data obtained demonstrate that this new method principle can be extended to protein modifications other than PEGylation and to a variety of functional activity assays. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Lithium chloride attenuates mitomycin C induced necrotic cell death in MDA-MB-231 breast cancer cells via HMGB1 and Bax signaling.

    Science.gov (United States)

    Razmi, Mahdieh; Rabbani-Chadegani, Azra; Hashemi-Niasari, Fatemeh; Ghadam, Parinaz

    2018-07-01

    The clinical use of potent anticancer drug mitomycin C (MMC) has limited due to side effects and resistance of cancer cells. The aim of this study was to investigate whether lithium chloride (LiCl), as a mood stabilizer, can affect the sensitivity of MDA-MB-231 breast cancer cells to mitomycin C. The cells were exposed to various concentrations of mitomycin C alone and combined with LiCl and the viability determined by trypan blue and MTT assays. Proteins were analyzed by western blot and mRNA expression of HMGB1 MMP9 and Bcl-2 were analyzed by RT-PCR. Flow cytometry was used to determine the cell cycle arrest and percent of apoptotic and necrotic cells. Concentration of Bax assessed by ELISA. Exposure of the cells to mitomycin C revealed IC 50 value of 20 μM, whereas pretreatment of the cells with LiCl induced synergistic cytotoxicity and IC 50 value declined to 5 μM. LiCl combined with mitomycin C significantly down-regulated HMGB1, MMP9 and Bcl-2 gene expression but significantly increased the level of Bax protein. In addition, the content of HMGB1 in the nuclei decreased and pretreatment with LiCl reduced the content of HMGB1 release induced by MMC. LiCl increased mitomycin C-induced cell shrinkage and PARP fragmentation suggesting induction of apoptosis in these cells. LiCl prevented mitomycin C-induced necrosis and changed the cell death arrest at G2/M-phase. Taking all together, it is suggested that LiCl efficiently enhances mitomycin C-induced apoptosis and HMGB1, Bax and Bcl-2 expression may play a major role in this process, the findings that provide a new therapeutic strategy for LiCl in combination with mitomycin C. Copyright © 2018 Elsevier GmbH. All rights reserved.

  17. The BH3 mimetic ABT-737 targets selective Bcl-2 proteins and efficiently induces apoptosis via Bak/Bax if Mcl-1 is neutralized

    OpenAIRE

    van Delft, Mark F.; Wei, Andrew H.; Mason, Kylie D.; Vandenberg, Cassandra J.; Chen, Lin; Czabotar, Peter E.; Willis, Simon N.; Scott, Clare L.; Day, Catherine L.; Cory, Suzanne; Adams, Jerry M.; Roberts, Andrew W.; Huang, David C.S.

    2006-01-01

    Since apoptosis is impaired in malignant cells overexpressing pro-survival Bcl-2 proteins, drugs mimicking their natural antagonists, BH3-only proteins, might overcome chemoresistance. Of seven putative BH3 mimetics tested, only ABT-737 triggered Bax/Bak-mediated apoptosis. Despite its high affinity for Bcl-2, Bcl-xL and Bcl-w, many cell types proved refractory to ABT-737. We show that this resistance reflects its inability to target another pro-survival relative, Mcl-1. Down-regulation of Mc...

  18. Structural and energetical studies of the adsorption of para and meta-isomers of xylene on pre-hydrated zeolite BaX. Characterization by neutron diffraction and temperature programmed desorption; Etude structurale et energetique de l'adsorption des isomeres para- et meta- du xylene dans la zeolithe BaX prehydratee. Caracterisation par diffraction des neutrons et thermodesorption programmee

    Energy Technology Data Exchange (ETDEWEB)

    Pichon, Ch.

    1999-10-19

    The separation of p-xylene from C{sub 8} aromatics is performed industrially by selective adsorption on zeolitic materials. FAU-type zeolites are currently used for this separation and especially the partially hydrated BaX. The aim of this work is to characterize from a structural (by low temperature neutron powder diffraction) and an energetical (by temperature programmed desorption) point of view, the adsorption of para- and meta- isomers of xylene, for different fillings, as pure substances as well as mixtures, on pre-hydrated zeolite BaX. The influence of the water pre-adsorption on xylene adsorption selectivity is carefully discussed. The crystalline structure of the zeolite BaX (framework and compensation of charge cations) and of the adsorbed phase (water, p- and m-xylene molecules) are completely characterized by neutron diffraction. The location and the distribution of water and xylene molecules on their adsorption sites is especially followed as a function of the filling of the zeolite and of the composition of the adsorbed phase. Microscopic measurements were correlated to the energetical analysis (at a macroscopic level) in order to obtain a consistent description of adsorption phenomenon and to propose a possible origin for adsorption selectivity.

  19. Persea declinata (Bl. Kosterm Bark Crude Extract Induces Apoptosis in MCF-7 Cells via G0/G1 Cell Cycle Arrest, Bcl-2/Bax/Bcl-xl Signaling Pathways, and ROS Generation

    Directory of Open Access Journals (Sweden)

    Putri Narrima

    2014-01-01

    Full Text Available Persea declinata (Bl. Kosterm is a member of the Lauraceae family, widely distributed in Southeast Asia. It is from the same genus with avocado (Persea americana Mill, which is widely consumed as food and for medicinal purposes. In the present study, we examined the anticancer properties of Persea declinata (Bl. Kosterm bark methanolic crude extract (PDM. PDM exhibited a potent antiproliferative effect in MCF-7 human breast cancer cells, with an IC50 value of 16.68 µg/mL after 48 h of treatment. We observed that PDM caused cell cycle arrest and subsequent apoptosis in MCF-7 cells, as exhibited by increased population at G0/G1 phase, higher lactate dehydrogenase (LDH release, and DNA fragmentation. Mechanistic studies showed that PDM caused significant elevation in ROS production, leading to perturbation of mitochondrial membrane potential, cell permeability, and activation of caspases-3/7. On the other hand, real-time PCR and Western blot analysis showed that PDM treatment increased the expression of the proapoptotic molecule, Bax, but decreased the expression of prosurvival proteins, Bcl-2 and Bcl-xL, in a dose-dependent manner. These findings imply that PDM could inhibit proliferation in MCF-7 cells via cell cycle arrest and apoptosis induction, indicating its potential as a therapeutic agent worthy of further development.

  20. BAX-mediated cell death affects early germ cell loss and incidence of testicular teratomas in Dnd1(Ter/Ter) mice.

    Science.gov (United States)

    Cook, Matthew S; Coveney, Douglas; Batchvarov, Iordan; Nadeau, Joseph H; Capel, Blanche

    2009-04-15

    A homozygous nonsense mutation (Ter) in murine Dnd1 (Dnd1(Ter/Ter)) results in a significant early loss of primordial germ cells (PGCs) prior to colonization of the gonad in both sexes and all genetic backgrounds tested. The same mutation also leads to testicular teratomas only on the 129Sv/J background. Male mutants on other genetic backgrounds ultimately lose all PGCs with no incidence of teratoma formation. It is not clear how these PGCs are lost or what factors directly control the strain-specific phenotype variation. To determine the mechanism underlying early PGC loss we crossed Dnd1(Ter/Ter) embryos to a Bax-null background and found that germ cells were partially rescued. Surprisingly, on a mixed genetic background, rescued male germ cells also generated fully developed teratomas at a high rate. Double-mutant females on a mixed background did not develop teratomas, but were fertile and produced viable off-spring. However, when Dnd1(Ter/Ter) XX germ cells developed in a testicular environment they gave rise to the same neoplastic clusters as mutant XY germ cells in a testis. We conclude that BAX-mediated apoptosis plays a role in early germ cell loss and protects from testicular teratoma formation on a mixed genetic background.

  1. Enhanced thermoelectric figure-of-merit in environmentally benign BaxSr2-xTiCoO6 double perovskites

    Science.gov (United States)

    Saxena, Mandvi; Roy, Pinku; Acharya, Megha; Bose, Imon; Tanwar, Khagesh; Maiti, Tanmoy

    2016-12-01

    Environmental friendly, non-toxic double perovskite BaxSr2-xTiCoO6 compositions with 0 ≤ x ≤ 0.2 were synthesized using solid-state reaction route for high temperature thermoelectric (TE) applications. XRD and SEM studies confirmed the presence of single-phase solid solution with highly dense microstructure for all the oxide compositions. Temperature dependent electrical conductivity measurement showed semiconductor to metal (M-S) transition in these double perovskites. Incorporation of barium in Sr2TiCoO6 pushed M-S transition to higher temperature making it a potential candidate for high temperature TE applications. Conductivity behaviors of these oxides were explained by small polaron model. Furthermore, these oxides exhibit a glass like behavior resulting in low thermal conductivity. Low temperature dielectric measurement revealed relaxor ferroelectric behavior in these oxides below room temperature. Transition of these relaxors into a glassy state beyond Burns temperature (TD) was found responsible for having low thermal conductivity in these oxides. Maximum dimensionless TE figure-of-merit ZT = 0.29 at 1223 K was achieved for BaxSr2-xTiCoO6 composition with x = 0.2.

  2. 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.

  3. Bmi1 is down-regulated in the aging brain and displays antioxidant and protective activities in neurons.

    Directory of Open Access Journals (Sweden)

    Mohamed Abdouh

    Full Text Available Aging increases the risk to develop several neurodegenerative diseases, although the underlying mechanisms are poorly understood. Inactivation of the Polycomb group gene Bmi1 in mice results in growth retardation, cerebellar degeneration, and development of a premature aging-like phenotype. This progeroid phenotype is characterized by formation of lens cataracts, apoptosis of cortical neurons, and increase of reactive oxygen species (ROS concentrations, owing to p53-mediated repression of antioxidant response (AOR genes. Herein we report that Bmi1 expression progressively declines in the neurons of aging mouse and human brains. In old brains, p53 accumulates at the promoter of AOR genes, correlating with a repressed chromatin state, down-regulation of AOR genes, and increased oxidative damages to lipids and DNA. Comparative gene expression analysis further revealed that aging brains display an up-regulation of the senescence-associated genes IL-6, p19(Arf and p16(Ink4a, along with the pro-apoptotic gene Noxa, as seen in Bmi1-null mice. Increasing Bmi1 expression in cortical neurons conferred robust protection against DNA damage-induced cell death or mitochondrial poisoning, and resulted in suppression of ROS through activation of AOR genes. These observations unveil that Bmi1 genetic deficiency recapitulates aspects of physiological brain aging and that Bmi1 over-expression is a potential therapeutic modality against neurodegeneration.

  4. Caspase Activation and Aberrant Cell Growth in a p53+/+ Cell Line from a Li-Fraumeni Syndrome Family

    Directory of Open Access Journals (Sweden)

    Zaki A. Sherif

    2015-01-01

    Full Text Available Wild-type p53 is well known to induce cell cycle arrest and apoptosis to block aberrant cell growth. However, p53’s unique role in apoptosis and cell proliferation in Li-Fraumeni Syndrome (LFS has not been well elucidated. The aim of this study is to characterize the activity of wild-type p53 protein in LFS family dominated by a germline negative mutant p53. As expected, etoposide-treated wild-type p53-containing cell lines, LFS 2852 and control Jurkat, showed a greater rate of caspase- and annexin V-induced apoptotic cell death compared to the p53-mutant LFS 2673 cell line although mitochondrial and nuclear assays could not detect apoptosis in these organelles. The most intriguing part of the observation was the abnormal proliferation rate of the wild-type p53-containing cell line, which grew twice as fast as 2673 and Jurkat cells. This is important because apoptosis inducers acting through the mitochondrial death pathway are emerging as promising drugs against tumors where the role of p53 is not only to target gene regulation but also to block cell proliferation. This study casts a long shadow on the possible dysregulation of p53 mediators that enable cell proliferation. The deregulation of proliferation pathways represents an important anticancer therapeutic strategy for patients with the LFS phenotype.

  5. Loss of p53 induces cell proliferation via Ras-independent activation of the Raf/Mek/Erk signaling pathway

    Science.gov (United States)

    Drosten, Matthias; Sum, Eleanor Y. M.; Lechuga, Carmen G.; Simón-Carrasco, Lucía; Jacob, Harrys K. C.; García-Medina, Raquel; Huang, Sidong; Beijersbergen, Roderick L.; Bernards, Rene; Barbacid, Mariano

    2014-01-01

    The Ras family of small GTPases constitutes a central node in the transmission of mitogenic stimuli to the cell cycle machinery. The ultimate receptor of these mitogenic signals is the retinoblastoma (Rb) family of pocket proteins, whose inactivation is a required step to license cell proliferation. However, little is known regarding the molecular events that connect Ras signaling with the cell cycle. Here, we provide genetic evidence to illustrate that the p53/p21 Cdk-interacting protein 1 (Cip1)/Rb axis is an essential component of the Ras signaling pathway. Indeed, knockdown of p53, p21Cip1, or Rb restores proliferative properties in cells arrested by ablation of the three Ras loci, H-, N- and K-Ras. Ras signaling selectively inactivates p53-mediated induction of p21Cip1 expression by inhibiting acetylation of specific lysine residues in the p53 DNA binding domain. Proliferation of cells lacking both Ras proteins and p53 can be prevented by reexpression of the human p53 ortholog, provided that it retains an active DNA binding domain and an intact lysine residue at position 164. These results unveil a previously unidentified role for p53 in preventing cell proliferation under unfavorable mitogenic conditions. Moreover, we provide evidence that cells lacking Ras and p53 proteins owe their proliferative properties to the unexpected retroactivation of the Raf/Mek/Erk cascade by a Ras-independent mechanism. PMID:25288756

  6. Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

    International Nuclear Information System (INIS)

    Yu, Zhendong; Wang, Hao; Zhang, Libin; Tang, Aifa; Zhai, Qinna; Wen, Jianxiang; Yao, Li; Li, Pengfei

    2009-01-01

    CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

  7. Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zhendong, E-mail: zdyu@hotmail.com [Department of Clinical laboratory, Peking University Shenzhen Hospital, Guangdong (China); Wang, Hao [Department of pathology, The Chinese University of Hong Kong, Hong Kong (China); Zhang, Libin; Tang, Aifa; Zhai, Qinna; Wen, Jianxiang; Yao, Li [Department of Clinical laboratory, Peking University Shenzhen Hospital, Guangdong (China); Li, Pengfei, E-mail: lipengfei@cuhk.edu.hk [Department of pathology, The Chinese University of Hong Kong, Hong Kong (China)

    2009-09-04

    CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

  8. Suppression of chondrosarcoma cells by 15-deoxy-Δ12,14-prostaglandin J2 is associated with altered expression of Bax/Bcl-xL and p21

    International Nuclear Information System (INIS)

    Shen, Zheng-Nan; Nishida, Keiichiro; Doi, Hideyuki; Oohashi, Toshitaka; Hirohata, Satoshi; Ozaki, Toshifumi; Yoshida, Aki; Ninomiya, Yoshifumi; Inoue, Hajime

    2005-01-01

    We previously reported that 15-deoxy-Δ 12,14 -prostaglandin J 2 (15d-PGJ 2 ), the most potent agonist for peroxisome proliferator-activated receptor γ (PPARγ), induces apoptosis of human chondrosarcoma cell line OUMS-27. The current study aimed to explore the mechanism of 15d-PGJ 2 -induced apoptosis and inhibition of cell proliferation in OUMS-27 cells. The preliminary results of cDNA microarray analysis showed the down-regulation of anti-apoptotic Bcl-xL and up-regulation of pro-apoptotic Bax in the process of 15d-PGJ 2 -induced apoptosis. These changes were further confirmed at mRNA and protein levels by RT-PCR and Western blot analysis, respectively. Among cyclin-dependent kinase inhibitors, p21 was induced and up-regulated by 15d-PGJ 2 , but p16 and p27 were not changed, suggesting that the involvement of p21 in inhibition of cell proliferation. Activation of caspase-3 by 15d-PGJ 2 was partly, but not completely, blocked by PPARγ antagonist (GW9662) suggesting the 15d-PGJ 2 exerted its effect by PPARγ-dependent and -independent pathways. Interestingly, immunohistochemical study on human chondrosarcoma samples revealed that Bcl-xL is frequently expressed by tumor cells. The results of the current study suggest that the potential ability of 15d-PGJ 2 in regulation of cell cycle and inhibition of Bcl-xL expression might be beneficial in the development of novel pharmacological agents for chondrosarcoma

  9. On the Sr1−xBaxFeO2F Oxyfluoride Perovskites: Structure and Magnetism from Neutron Diffraction and Mössbauer Spectroscopy

    Science.gov (United States)

    García-Ramos, Crisanto A.; Retuerto, María; Alonso, José Antonio

    2016-01-01

    Four oxyfluorides of the title series (x = 0.00, 0.25, 0.50, 0.75) have been stabilized by topotactic treatment of perovskite precursors Sr1−xBaxFeO3−δ prepared by soft-chemistry procedures, yielding reactive materials that can easily incorporate a substantial amount of F atoms at moderate temperatures, thus avoiding the stabilization of competitive SrF2 and BaF2 parasitic phases. XRD and Neutron Powder Diffraction (NPD) measurements assess the phase purity and yield distinct features concerning the unit cell parameters’ variation, the Sr and Ba distribution, the stoichiometry of the anionic sublattice and the anisotropic displacement factors for O and F atoms. The four oxyfluorides are confirmed to be cubic in all of the compositional range, the unit cell parameters displaying Vergard’s law. All of the samples are magnetically ordered above room temperature; the magnetic structure is always G-type antiferromagnetic, as shown from NPD data. The ordered magnetic moments are substantially high, around 3.5 μB, even at room temperature (RT). Temperature-dependent Mössbauer data allow identifying Fe3+ in all of the samples, thus confirming the Sr1−xBaxFeO2F stoichiometry. The fit of the magnetic hyperfine field vs. temperature curve yields magnetic ordering TN temperatures between 740 K (x = 0.00) and 683 K (x = 0.75). These temperatures are substantially higher than those reported before for some of the samples, assessing for stronger Fe-Fe superexchange interactions for these specimens prepared by fluorination of citrate precursors in mild conditions. PMID:28774089

  10. The effects of escitalopram on myocardial apoptosis and the expression of Bax and Bcl-2 during myocardial ischemia/reperfusion in a model of rats with depression.

    Science.gov (United States)

    Wang, Yiming; Zhang, Hongming; Chai, Fangxian; Liu, Xingde; Berk, Michael

    2014-12-04

    Major depressive disorder (MDD) is an independent risk factor for coronary heart disease (CHD), and influences the occurrence and prognosis of cardiovascular events. Although there is evidence that antidepressants may be cardioprotective after acute myocardial infarction (AMI) comorbid with MDD, the operative pathophysiological mechanisms remain unclear. Our aim was therefore to explore the molecular mechanisms of escitalopram on myocardial apoptosis and the expression of Bax and Bcl-2 in a rat model of depression during myocardial ischemia/reperfusion (I/R). Rats were divided randomly into 3 groups (n = 8): D group (depression), DI/R group (depression with myocardial I/R) and escitalopram + DI/R group. The rats in all three groups underwent the same chronic mild stress and separation for 21 days, at the same time, in the escitalopram + DI/R group, rats were administered escitalopram by gavage (10 mg/kg/day). Ligation of the rat's left anterior descending branch was done in the myocardial I/R model. Following which behavioral tests were done. The size of the myocardial infarction was detected using 1.5% TTC dye. The Tunel method was used to detect apoptotic myocardial cells, and both the Rt-PCR method and immunohistochemical techniques were used to detect the expression of Bcl-2 and Bax. Compared with the D and DI/R groups, rats in Escitalopram + DI/R group showed significantly increased movements and sucrose consumption (P escitalopram + DI/R group was significantly decreased (P escitalopram + DI/R groups (P escitalopram + DI/R group were significantly decreased (P escitalopram + DI/R group (P escitalopram. This suggests that clinically escitalopram may have a direct cardioprotective after acute myocardial infarction.

  11. On the Sr1−xBaxFeO2F Oxyfluoride Perovskites: Structure and Magnetism from Neutron Diffraction and Mössbauer Spectroscopy

    Directory of Open Access Journals (Sweden)

    Crisanto A. García-Ramos

    2016-11-01

    Full Text Available Four oxyfluorides of the title series (x = 0.00, 0.25, 0.50, 0.75 have been stabilized by topotactic treatment of perovskite precursors Sr1−xBaxFeO3−δ prepared by soft-chemistry procedures, yielding reactive materials that can easily incorporate a substantial amount of F atoms at moderate temperatures, thus avoiding the stabilization of competitive SrF2 and BaF2 parasitic phases. XRD and Neutron Powder Diffraction (NPD measurements assess the phase purity and yield distinct features concerning the unit cell parameters’ variation, the Sr and Ba distribution, the stoichiometry of the anionic sublattice and the anisotropic displacement factors for O and F atoms. The four oxyfluorides are confirmed to be cubic in all of the compositional range, the unit cell parameters displaying Vergard’s law. All of the samples are magnetically ordered above room temperature; the magnetic structure is always G-type antiferromagnetic, as shown from NPD data. The ordered magnetic moments are substantially high, around 3.5 μB, even at room temperature (RT. Temperature-dependent Mössbauer data allow identifying Fe3+ in all of the samples, thus confirming the Sr1−xBaxFeO2F stoichiometry. The fit of the magnetic hyperfine field vs. temperature curve yields magnetic ordering TN temperatures between 740 K (x = 0.00 and 683 K (x = 0.75. These temperatures are substantially higher than those reported before for some of the samples, assessing for stronger Fe-Fe superexchange interactions for these specimens prepared by fluorination of citrate precursors in mild conditions.

  12. Adsorption of xylene para- and meta- isomers in NaX and BaX zeolites. Study of properties-structure relations; Adsorption des isomeres para- et meta- du xylene dans les zeolithes NaX et BaX. Etude des relations proprietes-structure

    Energy Technology Data Exchange (ETDEWEB)

    Descours, A.

    1997-02-14

    The separation of para-xylene from C8 aromatics is performed industrially bu adsorption process on zeolitic molecular sieves. The sorption properties of these zeolites are strongly linked to their structure, and their comprehension require an accurate knowledge of the interactions between sorbate molecules and zeolitic structure. The aim of this work is to characterise from a structural point of view the adsorption of para- and meta-xylenes in BaX and NaX zeolites. The former is selective for para-xylene, and the latter has not selective properties for para- and meta-isomers of xylene. For each zeolite, the adsorption of pure para-xylene and meta-xylene or a mixture of the two isomers, is investigated as a function of coverage. Powder neutron diffraction is used to determine the crystalline structure of these zeolites and the different crystallographic adsorption sites of the molecules. The influence of coverage on sorbate-sorbent and sorbate-sorbate interactions is investigated. Infrared spectroscopy allows to determine the chemical environment of the sorbate molecules at low coverage or when the coverage increases, and is particularly effective for the study of the binary mixture of xylenes. This study is performed by sorbing a mixture of xylene isomers, or by sorbing these isomers successively. Infrared studies and crystallographic analysis are compared in order to get a consistent description of adsorption mechanism of xylene isomers for both zeolites as a function of coverage. The role of coverage, of cation type, an the presence of the two xylene isomers is the super-cages is essential. For both zeolites, the increase of coverage actually leads to steric hindrances between sorbed molecules and molecular rearrangements. These reorganizations are connected to the cationic distribution of NaX and BaX zeolites. The sorbed molecules are connected to the cationic distribution of NaX and BaX zeolites. The sorbed molecules are particularly confined in BaX zeolite

  13. Abrogation of Wip1 expression by RITA-activated p53 potentiates apoptosis induction via activation of ATM and inhibition of HdmX

    Science.gov (United States)

    Spinnler, C; Hedström, E; Li, H; de Lange, J; Nikulenkov, F; Teunisse, A F A S; Verlaan-de Vries, M; Grinkevich, V; Jochemsen, A G; Selivanova, G

    2011-01-01

    Inactivation of the p53 tumour suppressor, either by mutation or by overexpression of its inhibitors Hdm2 and HdmX is the most frequent event in cancer. Reactivation of p53 by targeting Hdm2 and HdmX is therefore a promising strategy for therapy. However, Hdm2 inhibitors do not prevent inhibition of p53 by HdmX, which impedes p53-mediated apoptosis. Here, we show that p53 reactivation by the small molecule RITA leads to efficient HdmX degradation in tumour cell lines of different origin and in xenograft tumours in vivo. Notably, HdmX degradation occurs selectively in cancer cells, but not in non-transformed cells. We identified the inhibition of the wild-type p53-induced phosphatase 1 (Wip1) as the major mechanism important for full engagement of p53 activity accomplished by restoration of the ataxia telangiectasia mutated (ATM) kinase-signalling cascade, which leads to HdmX degradation. In contrast to previously reported transactivation of Wip1 by p53, we observed p53-dependent repression of Wip1 expression, which disrupts the negative feedback loop conferred by Wip1. Our study reveals that the depletion of both HdmX and Wip1 potentiates cell death due to sustained activation of p53. Thus, RITA is an example of a p53-reactivating drug that not only blocks Hdm2, but also inhibits two important negative regulators of p53 – HdmX and Wip1, leading to efficient elimination of tumour cells. PMID:21546907

  14. Abrogation of Wip1 expression by RITA-activated p53 potentiates apoptosis induction via activation of ATM and inhibition of HdmX.

    Science.gov (United States)

    Spinnler, C; Hedström, E; Li, H; de Lange, J; Nikulenkov, F; Teunisse, A F A S; Verlaan-de Vries, M; Grinkevich, V; Jochemsen, A G; Selivanova, G

    2011-11-01

    Inactivation of the p53 tumour suppressor, either by mutation or by overexpression of its inhibitors Hdm2 and HdmX is the most frequent event in cancer. Reactivation of p53 by targeting Hdm2 and HdmX is therefore a promising strategy for therapy. However, Hdm2 inhibitors do not prevent inhibition of p53 by HdmX, which impedes p53-mediated apoptosis. Here, we show that p53 reactivation by the small molecule RITA leads to efficient HdmX degradation in tumour cell lines of different origin and in xenograft tumours in vivo. Notably, HdmX degradation occurs selectively in cancer cells, but not in non-transformed cells. We identified the inhibition of the wild-type p53-induced phosphatase 1 (Wip1) as the major mechanism important for full engagement of p53 activity accomplished by restoration of the ataxia telangiectasia mutated (ATM) kinase-signalling cascade, which leads to HdmX degradation. In contrast to previously reported transactivation of Wip1 by p53, we observed p53-dependent repression of Wip1 expression, which disrupts the negative feedback loop conferred by Wip1. Our study reveals that the depletion of both HdmX and Wip1 potentiates cell death due to sustained activation of p53. Thus, RITA is an example of a p53-reactivating drug that not only blocks Hdm2, but also inhibits two important negative regulators of p53 - HdmX and Wip1, leading to efficient elimination of tumour cells.

  15. Maternal exposure to titanium dioxide nanoparticles during pregnancy and lactation alters offspring hippocampal mRNA BAX and Bcl-2 levels, induces apoptosis and decreases neurogenesis.

    Science.gov (United States)

    Ebrahimzadeh Bideskan, Alireza; Mohammadipour, Abbas; Fazel, Alireza; Haghir, Hossein; Rafatpanah, Houshang; Hosseini, Mahmoud; Rajabzadeh, Aliakbar

    2017-07-05

    The usage of Titanium dioxide nanoparticles (TiO 2 -NPs) covers a vast area in different fields ranging from cosmetics and food to the production of drugs. Maternal exposure to TiO 2 -NPs during developmental period has been associated with hippocampal injury and with a decrease in learning and memory status of the offspring. However, little is known about its injury mechanism. This paper describes the in vivo neurotoxic effects of TiO 2 -NPs on rat offspring hippocampus during developmental period. Pregnant and lactating Wistar rats received intragastric TiO 2 -NPs (100mg/kg body weight) daily from gestational day (GD) 2 to (GD) 21 and postnatal day (PD) 2 to (PD) 21 respectively. Animals in the control groups received an equal volume of distilled water via gavage. At the end of the treatment process, offspring were deeply anesthetized and sacrificed. Then brains of each group were collected and sections of the rat offspring's brains were stained using TUNEL staining (for detection of apoptotic cells) and immunostaining (for neurogenesis). Moreover, the right hippocampus (n=6 per each group) were removed from the right hemisphere for evaluating the expression of Bax and Bcl-2 level. Results of histopatological examination by TUNEL staining showed that maternal exposure to TiO 2 -NPs during pregnancy and lactation periods increased apoptotic cells significantly (P<0.01) in the offspring hippocampus. The immunolabeling of double cortin (DCX) protein as neurogenesis marker also showed that TiO 2 -NPs reduced neurogenesis in the hippocampus of the offspring (P<0.05). Moreover, in comparison with the control group, the mRNA levels of Bax and Bcl-2 in the TiO 2 -NPs group significantly increased and decreased, respectively (P<0.01). These findings provide strong evidence that maternal exposure to TiO 2 -NPs significantly impact hippocampal neurogenesis and apoptosis in the offspring. The potential impact of nanoparticle exposure for millions of pregnant mothers and

  16. [Distribution of Pathogenic Bacteria and Its Influence on Expression of BCL-2 and BAX Protein after HSCT in the Patients with Hematological Malignancies].

    Science.gov (United States)

    Su, Gui-Ping; Dai, Yan; Huang, Lai-Quan; Jiang, Yi-Zhi; Geng, Liang-Quan; Ding, Kai-Yang; Huang, Dong-Ping

    2016-06-01

    To investigate the distribution of pathogenic bacteria in the patients with hematologic malignancies received hematopoietic stem cell transplantation (HSCT) and its influence on the expression of BCL-2 and BAX proteins. The clinical data of 64 patients with malignant lymphoma (ML) received auto-HSCT from January 2011 to December 2015 in our hospital were analyzed. On basis of post-treansplant infection, the patients were divided into infection group (36 cases) and non-infection group (28 cases). The distribution of pathogenic bacteria in 2 groups was identified, the T lymphocyte subsets of peripheral blood, expression level of apoptotic proteins and C-reaction protein (CRP) in 2 group were detected. Thirty-six strains of pathogenic bacteria were isolated from 36 case of hematological malignancy after HSCT, including 24 strains of Gram-negative bacteria (66.67%) with predominamce of klebsiella pneumoniae (19.44%). The periperal blood CD4+ (t=2.637, Ppathogenic bacteria infecting ML patients after HSCT were mainly Gram-negative bacteria. The post-transplant infection can promote the expression up-regulation of related inflammatory factors and apoptotic proteins. The pathogens may be involved in cell apoptisis that provides a new strategy to treat the hematologic malignancies.

  17. Composition-control of magnetron-sputter-deposited (BaxSr1-x)Ti1+yO3+z thin films for voltage tunable devices

    Science.gov (United States)

    Im, Jaemo; Auciello, O.; Baumann, P. K.; Streiffer, S. K.; Kaufman, D. Y.; Krauss, A. R.

    2000-01-01

    Precise control of composition and microstructure is critical for the production of (BaxSr1-x)Ti1+yO3+z (BST) dielectric thin films with the large dependence of permittivity on electric field, low losses, and high electrical breakdown fields that are required for successful integration of BST into tunable high-frequency devices. Here, we present results on composition-microstructure-electrical property relationships for polycrystalline BST films produced by magnetron-sputter deposition, that are appropriate for microwave and millimeter-wave applications such as varactors and frequency triplers. Films with controlled compositions were grown from a stoichiometric Ba0.5Sr0.5TiO3 target by control of the background processing gas pressure. It was determined that the (Ba+Sr)/Ti ratios of these BST films could be adjusted from 0.73 to 0.98 by changing the total (Ar+O2) process pressure, while the O2/Ar ratio did not strongly affect the metal ion composition. Film crystalline structure and dielectric properties as a function of the (Ba+Sr)/Ti ratio are discussed. Optimized BST films yielded capacitors with low dielectric losses (0.0047), among the best reported for sputtered BST, while still maintaining tunabilities suitable for device applications.

  18. No dramatic age-related loss of hair cells and spiral ganglion neurons in Bcl-2 over-expression mice or Bax null mice

    Directory of Open Access Journals (Sweden)

    Ohlemiller Kevin K

    2010-07-01

    Full Text Available Abstract Age-related decline of neuronal function is associated with age-related structural changes. In the central nervous system, age-related decline of cognitive performance is thought to be caused by synaptic loss instead of neuronal loss. However, in the cochlea, age-related loss of hair cells and spiral ganglion neurons (SGNs is consistently observed in a variety of species, including humans. Since age-related loss of these cells is a major contributing factor to presbycusis, it is important to study possible molecular mechanisms underlying this age-related cell death. Previous studies suggested that apoptotic pathways were involved in age-related loss of hair cells and SGNs. In the present study, we examined the role of Bcl-2 gene in age-related hearing loss. In one transgenic mouse line over-expressing human Bcl-2, there were no significant differences between transgenic mice and wild type littermate controls in their hearing thresholds during aging. Histological analysis of the hair cells and SGNs showed no significant conservation of these cells in transgenic animals compared to the wild type controls during aging. These data suggest that Bcl-2 overexpression has no significant effect on age-related loss of hair cells and SGNs. We also found no delay of age-related hearing loss in mice lacking Bax gene. These findings suggest that age-related hearing loss is not through an apoptotic pathway involving key members of Bcl-2 family.

  19. Structural and ferroelectric properties of Sr1−xBaxBi2Nb2O9 thin films obtained by dip-coating

    Directory of Open Access Journals (Sweden)

    Y. González-Abreu

    2017-10-01

    Full Text Available The paper presents the structural and ferroelectric results for Sr1−xBaxBi2Nb2O9(x=0.30; 0.85 thin films, which were obtained by using dip-coating. The solutions containing the desirable ions were prepared from the powders of the previous studied ceramic samples. The films were deposited at room temperature on Fluorine-doped Tin Oxide (FTO substrates and submitted to a heat treatment for crystallization. The films were characterized by using scanning microscopy electronic, energy dispersive spectroscopy and ellipsometry. Hysteresis ferroelectric loops were obtained, at room temperature, by using a Sawyer-Tower circuit at several frequencies. A well-defined grain structure was observed for both compositions. The energy dispersive spectroscopy (EDS measurements revealed the presence of the corresponding elements from the chemical composition of the ceramic systems. The band-gap energy was around 3.3eV for both samples. Typical hysteresis loops for normal and relaxor ferroelectrics were obtained for x=0.30 and 0.85, respectively.

  20. cAMP signalling of Bordetella adenylate cyclase toxin through the SHP-1 phosphatase activates the BimEL-Bax pro-apoptotic cascade in phagocytes

    Czech Academy of Sciences Publication Activity Database

    Ahmad, Jawid Nazir; Černý, Ondřej; Linhartová, Irena; Mašín, Jiří; Osička, Radim; Šebo, Peter

    2016-01-01

    Roč. 18, č. 3 (2016), s. 384-398 ISSN 1462-5814 R&D Projects: GA ČR GA13-14547S; GA ČR(CZ) GAP302/11/0580; GA ČR GAP302/12/0460 Institutional support: RVO:61388971 Keywords : FORKHEAD TRANSCRIPTION FACTOR * HUMAN T- CELL S * DENDRITIC CELL S Subject RIV: EE - Microbiology, Virology Impact factor: 4.554, year: 2016

  1. Bid truncation, Bid/Bax targeting to the mitochondria, and caspase activation associated with neutrophil apoptosis are inhibited by granulocyte colony-stimulating factor

    NARCIS (Netherlands)

    Maianski, Nikolai A.; Roos, Dirk; Kuijpers, Taco W.

    2004-01-01

    Neutrophil apoptosis constitutes a way of managing neutrophil-mediated reactions. It allows coping with infections, but avoiding overt bystander tissue damage. Using digitonin-based subcellular fractionation and Western blotting, we found that spontaneous apoptosis of human neutrophils (after

  2. Structural Insight into the Critical Role of the N-Terminal Region in the Catalytic Activity of Dual-Specificity Phosphatase 26.

    Directory of Open Access Journals (Sweden)

    Eun-Young Won

    Full Text Available Human dual-specificity phosphatase 26 (DUSP26 is a novel target for anticancer therapy because its dephosphorylation of the p53 tumor suppressor regulates the apoptosis of cancer cells. DUSP26 inhibition results in neuroblastoma cell cytotoxicity through p53-mediated apoptosis. Despite the previous structural studies of DUSP26 catalytic domain (residues 61-211, DUSP26-C, the high-resolution structure of its catalytically active form has not been resolved. In this study, we determined the crystal structure of a catalytically active form of DUSP26 (residues 39-211, DUSP26-N with an additional N-terminal region at 2.0 Å resolution. Unlike the C-terminal domain-swapped dimeric structure of DUSP26-C, the DUSP26-N (C152S monomer adopts a fold-back conformation of the C-terminal α8-helix and has an additional α1-helix in the N-terminal region. Consistent with the canonically active conformation of its protein tyrosine phosphate-binding loop (PTP loop observed in the structure, the phosphatase assay results demonstrated that DUSP26-N has significantly higher catalytic activity than DUSP26-C. Furthermore, size exclusion chromatography-multiangle laser scattering (SEC-MALS measurements showed that DUSP26-N (C152S exists as a monomer in solution. Notably, the crystal structure of DUSP26-N (C152S revealed that the N-terminal region of DUSP26-N (C152S serves a scaffolding role by positioning the surrounding α7-α8 loop for interaction with the PTP-loop through formation of an extensive hydrogen bond network, which seems to be critical in making the PTP-loop conformation competent for phosphatase activity. Our study provides the first high-resolution structure of a catalytically active form of DUSP26, which will contribute to the structure-based rational design of novel DUSP26-targeting anticancer therapeutics.

  3. Deregulated expression of A1, Bcl-2, Bcl-xL, and Mcl-1 antiapoptotic proteins and Bid, Bad, and Bax proapoptotic genes in polycythemia vera patients

    Directory of Open Access Journals (Sweden)

    Elainy Patricia Lino Gasparotto

    2011-12-01

    Full Text Available Apoptosis deregulation might have a role in the pathophysiology of polycythemia vera (PV. This study evaluated Bcl-2 molecule expression in CD34+ cells and leukocytes in 12 PV patients. Gene expression was investigated by real time PCR using SybrGreen Quantitect kit and protein expression was evaluated by western-blotting. JAK2 V617F mutation was detected according to Baxter et al (2005. CD34+ cells from PV patients presented higher levels of A1 and Mcl-1 expression (median: 22.6 and 5.2, respectively in comparison with controls (0.9 and 0.5, p=0.004 and p=0.020; while Bcl-2 and Bcl-xL expression decreased in PV patients (0.18 and 1.19 compared with controls (1.39 and 2.01, p=0.006 and p=0.020. CD34+ cells in PV patients showed an elevated Bid expression (14.4 in comparison with healthy subjects (1.0; p=0.002. Patients' leukocytes showed an A1 augmentation (7.41, p=0.001 and a reduced expression of Bax (0.19; p=0.040 and Bad (0.2; p=0.030. There was no correlation between JAK2 V617F allele burden and molecular expression. PV patients showed alterations in Bcl-2 members' expression, which may interfere with control of apoptotic machinery and contribute to disease pathogenesis.A desregulação da apoptose parece participar da fisiopatologia da policitemia vera (PV. Este estudo avaliou a expressão das moléculas da família Bcl-2 em células hematopoéticas CD34 + e leucócitos de 12 pacientes com PV. Foram realizados: a quantificação da expressão gênica por PCR em tempo real utilizando kit Sybrgreen Quantitect, avaliação da expressão de proteínas por western-blot e detecção da mutação JAK2 V617F segundo Baxter et al. (2005. Células CD34 + dos pacientes com PV apresentaram maior expressão de A1 e Mcl-1 (mediana: 22,6 e 5,2, respectivamente em comparação com controles (0,9 e 0,5, p = 0,004 e p = 0,020 e expressão de Bcl-2 e Bcl-xL diminuída nestes pacientes (0,18 e 1,19 em relação aos controles (1,39 e 2,01, p = 0,006 e p = 0

  4. The influence of sleep deprivation on expression of apoptosis regulatory proteins p53, bcl-2 and bax following rat tongue carcinogenesis induced by 4-nitroquinoline 1-oxide

    Directory of Open Access Journals (Sweden)

    Juliana Noguti

    2013-01-01

    Full Text Available Background: The aim of this study was to evaluate whether paradoxical sleep deprivation could affects the mechanisms and pathways essentials for cancer cells in tongue cancer induced by 4-nitroquinole 1-oxide in Wistar rats. Materials and Methods: For this purpose, the animals were distributed into 4 groups of 5 animals each treated with 50 ppm 4 nitroquinoline 1 oxide (4 NQO solution through their drinking water for 4 and 12 weeks. The animals were submitted to paradoxical sleep deprivation (PSD for 72 h using the modified multiple platform method, which consisted of placing 5 mice in a cage (41 × 34 × 16 cm containing 10 circular platforms (3.5 cm in diameter with water 1 cm below the upper surface. The investigations were conducted using immunohistochemistry of p53, Bax and Bcl-2 proteins related to apoptosis and its pathways. Statistical analysis was performed by Kruskal-Wallis non-parametric test followed by the Dunn′s test using SPSS software pack (version 1.0. P value < 0.05 was considered for statistic significance. Results: Although no histopathological abnormalities were induced in the epithelium after 4 weeks of carcinogen exposure in all groups, in 12 weeks were observed pre-neoplasic lesions. Data analysis revealed statistically significant differences ( P < 0.05 in 4 weeks group for p53 and for bcl-2 and for all immunomarkers after 12 weeks of 4NQO administration. Conclusion: Our results reveal that sleep deprivation exerted alterations in proteins associated with proliferation and apoptosis in carcinogenesis.

  5. Occupational health hazards of trichloroethylene among workers in relation to altered mRNA expression of cell cycle regulating genes (p53, p21, bax and bcl-2 and PPARA

    Directory of Open Access Journals (Sweden)

    Meenu Varshney

    2015-01-01

    Full Text Available Trichloroethylene (TCE is widely used as a metal degreaser in industrial processes. The present study reports on the effects of TCE exposure on workers employed in the lock industries. To ensure exposure of the workers to TCE, its toxic metabolites, trichloroacetic acid (TCA, dichloroacetic acid (DCA and trichloroethanol (TCEOH were detected in the plasma of the subjects through solid phase microextraction-gas chromatography-electron capture detection. TCA, DCA and TCEOH were detected in the range of 0.004–2.494 μg/mL, 0.01–3.612 μg/mL and 0.002–0.617 μg/mL, respectively. Quantitative reverse transcription polymerase chain reaction analysis revealed up-regulated expression of p53 (2.4-fold; p < 0.05, p21 (2-fold; p < 0.01, bax (2.9-fold; p < 0.01 mRNAs and down-regulated expression of bcl-2 (67%; p < 0.05 mRNAs, indicating DNA damaging potential of these metabolites. No effects were observed on the levels of p16 and c-myc mRNAs. Further, as TCA and DCA, the ligand of peroxisome proliferator activated receptor alpha (PPARA, are involved in the process of hepatocarcinogenesis in rodents, we examined expression of PPARA mRNA and let-7c miRNA in the workers. No statistically significant differences in expression of PPARA mRNA and let-7c miRNA in patients were observed as compared to values in controls. Dehydroepiandosterone sulfate (DHEAS is a reported endogenous ligand of PPARA so its competitive role was also studied. We observed decreased levels of DHEAS hormone in the subjects. Hence, its involvement in mediation of the observed changes in the levels of various mRNAs analyzed in this study appears unlikely.

  6. PEG-b-PCL polymeric nano-micelle inhibits vascular angiogenesis by activating p53-dependent apoptosis in zebrafish.

    Science.gov (United States)

    Zhou, Tian; Dong, Qinglei; Shen, Yang; Wu, Wei; Wu, Haide; Luo, Xianglin; Liao, Xiaoling; Wang, Guixue

    Micro/nanoparticles could cause adverse effects on cardiovascular system and increase the risk for cardiovascular disease-related events. Nanoparticles prepared from poly(ethylene glycol) (PEG)- b -poly( ε -caprolactone) (PCL), namely PEG- b -PCL, a widely studied biodegradable copolymer, are promising carriers for the drug delivery systems. However, it is unknown whether polymeric PEG- b -PCL nano-micelles give rise to potential complications of the cardiovascular system. Zebrafish were used as an in vivo model to evaluate the effects of PEG- b -PCL nano-micelle on cardiovascular development. The results showed that PEG- b -PCL nano-micelle caused embryo mortality as well as embryonic and larval malformations in a dose-dependent manner. To determine PEG- b -PCL nano-micelle effects on embryonic angiogenesis, a critical process in zebrafish cardiovascular development, growth of intersegmental vessels (ISVs) and caudal vessels (CVs) in flk1-GFP transgenic zebrafish embryos using fluorescent stereomicroscopy were examined. The expression of fetal liver kinase 1 (flk1), an angiogenic factor, by real-time quantitative polymerase chain reaction (qPCR) and in situ whole-mount hybridization were also analyzed. PEG- b -PCL nano-micelle decreased growth of ISVs and CVs, as well as reduced flk1 expression in a concentration-dependent manner. Parallel to the inhibitory effects on angiogenesis, PEG- b -PCL nano-micelle exposure upregulated p53 pro-apoptotic pathway and induced cellular apoptosis in angiogenic regions by qPCR and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assay. This study further showed that inhibiting p53 activity, either by pharmacological inhibitor or RNA interference, could abrogate the apoptosis and angiogenic defects caused by PEG- b -PCL nano-micelles, indicating that PEG- b -PCL nano-micelle inhibits angiogenesis by activating p53-mediated apoptosis. This study indicates that polymeric PEG- b -PCL nano-micelle could

  7. Materials science and integration bases for fabrication of (BaxSr1-x)TiO3 thin film capacitors with layered Cu-based electrodes

    Science.gov (United States)

    Fan, W.; Kabius, B.; Hiller, J. M.; Saha, S.; Carlisle, J. A.; Auciello, O.; Chang, R. P. H.; Ramesh, R.

    2003-11-01

    The synthesis and fundamental material properties of layered TiAl/Cu/Ta electrodes were investigated to achieve the integration of Cu electrodes with high-dielectric constant (κ) oxide thin films for application to the fabrication of high-frequency devices. The Ta layer is an excellent diffusion barrier to inhibit deleterious Cu diffusion into the Si substrate, while the TiAl layer provides an excellent barrier against oxygen diffusion into the Cu layer to inhibit Cu oxidation during the growth of the high-κ layer in an oxygen atmosphere. Polycrystalline (BaxSr1-x)TiO3 (BST) thin films were grown on the Cu-based bottom electrode by rf magnetron sputtering at temperatures in the range 400-600 °C in oxygen, to investigate the performance of BST/Cu-based capacitors. Characterization of the Cu-based layered structure using surface analytical methods showed that two amorphous oxide layers were formed on both sides of the TiAl barrier, such that the oxide layer on the free surface of the TiAl layer correlates with TiAlOx, while the oxide layer at the TiAl/Cu interface is an Al2O3-rich layer. This double amorphous barrier layer structure effectively prevents oxygen penetration towards the underlying Cu and Ta layers. The TiAlOx interfacial layer, which has a relatively low dielectric constant compared with BST, reduced the total capacitance of the BST thin film capacitors. In addition, the layered electrode-oxide interface roughening observed during the growth of BST films at high temperature, due to copper grain growth, resulted in large dielectric loss on the fabricated BST capacitors. These problems were solved by growing the BST layer at 450 °C followed by a rapid thermal annealing at 700 °C. This process significantly reduced the thickness of the TiAlOx layer and interface roughness resulting in BST capacitors exhibiting properties suitable for the fabrication of high-performance high-frequency devices. In summary, relatively high dielectric constant (280), low

  8. Genetic progression in microsatellite instability high (MSI-H) colon cancers correlates with clinico-pathological parameters: A study of the TGRbetaRII, BAX, hMSH3, hMSH6, IGFIIR and BLM genes.

    Science.gov (United States)

    Calin, G A; Gafà, R; Tibiletti, M G; Herlea, V; Becheanu, G; Cavazzini, L; Barbanti-Brodano, G; Nenci, I; Negrini, M; Lanza, G

    2000-05-20

    Colon carcinomas with microsatellite mutator phenotype exhibit specific genetic and clinico-pathological features. This report describes the analysis of 63 "microsatellite instability-high" (MSI-H) tumors for the presence of mutations in microsatellites located in the coding regions (CDRs) of 6 genes: TGFbetaRII, BAX, hMSH3, hMSH6, IGFIIR, and BLM. The following frequencies of mutations were detected: TGFbetaRII (70%), BAX (54%), hMSH3 (36.5%), IGFIIR (22%), hMSH6 (17.5%), and BLM (16%). The overall picture revealed combinations of mutations suggestive of a progressive order of accumulation, with mutations of TGFbetaRII and BAX first, followed by frameshifts in hMSH3, hMSH6, IGFIIR, and BLM. Correlations with 12 clinico-pathological parameters revealed that tumors with frameshifts in 1 or 2 CDRs were significantly better differentiated than tumors with frameshifts in more than 2 CDRs. We also found that mutations in the hMSH3 gene were significantly associated with decreased wall invasiveness and aneuploidy, and frameshifts in the BLM gene were significantly associated with the mucinous histotype. A trend toward an association between hMSH3 and IGFIIR with the medullary and conventional adenocarcinoma histotypes, respectively, was seen. Our results strengthen the concept that mutations in target genes have a role in the tumorigenic process of MSI-H tumors, and indicate that frameshifts in microsatellites located in CDRs occur in a limited number of combinations that could determine distinct clinico-pathological traits. Copyright 2000 Wiley-Liss, Inc.

  9. The effect of the ginger on the apoptosis of hippochampal cells according to the expression of BAX and Cyclin D1 genes and histological characteristics of brain in streptozotocin male diabetic rats.

    Science.gov (United States)

    Molahosseini, A; Taghavi, M M; Taghipour, Z; Shabanizadeh, A; Fatehi, F; Kazemi Arababadi, M; Eftekhar Vaghefe, S H

    2016-10-31

    Diabetes is the most common endocrine disorder in humans with multiple complications including nervous system damages. The aim of the present study was to determine the effect of ginger extract on apoptosis of the neurons of hippocampus, via evaluation of BAX and Cyclin D1 and also histological analysis, in male diabetic rats. In this experimental study, 60 Wistar rats (220 ± 30gr) were conducted in 5 groups as follow: diabetic group treated with saline (group 1), normal group treated with saline (group 2), diabetic group treated with ginger (group 3), diabetic group treated with ginger-insulin (group 4), diabetic group treated with insulin (group 5). STZ (60 mg/kg) was intraperitoneally used to induce the diabetes. Expression levels of BAX and Cyclin D1 were examined using Real-Time PCR technique and the normality of neurons was evaluated using H&E staining method. The results showed that blood glucose level significantly decreased in group 4 when compared to group 1. In molecular analysis, there was no significant difference between groups regarding the expression of BAX gens, while, the expression of Cyclin D1 were significantly decreased in group 4 compared with group 1. Histological analysis revealed that pathological symptoms were lower in group 4 than the other diabetic groups. The results of present study showed that the ginger in addition to lowering blood sugar level, changes the expression of Cyclin D1 gene and histological characteristics in a positive manner. This means that the ginger may protects neurons of the hippocampus from apoptosis in diabetic patients.

  10. Metabolic oxidative stress elicited by the copper(II) complex [Cu(isaepy)2] triggers apoptosis in SH-SY5Y cells through the induction of the AMP-activated protein kinase/p38MAPK/p53 signalling axis: evidence for a combined use with 3-bromopyruvate in neuroblastoma treatment.

    Science.gov (United States)

    Filomeni, Giuseppe; Cardaci, Simone; Da Costa Ferreira, Ana Maria; Rotilio, Giuseppe; Ciriolo, Maria Rosa

    2011-08-01

    We have demonstrated previously that the complex bis[(2-oxindol-3-ylimino)-2-(2-aminoethyl)pyridine-N,N']copper(II), named [Cu(isaepy)(2)], induces AMPK (AMP-activated protein kinase)-dependent/p53-mediated apoptosis in tumour cells by targeting mitochondria. In the present study, we found that p38(MAPK) (p38 mitogen-activated protein kinase) is the molecular link in the phosphorylation cascade connecting AMPK to p53. Transfection of SH-SY5Y cells with a dominant-negative mutant of AMPK resulted in a decrease in apoptosis and a significant reduction in phospho-active p38(MAPK) and p53. Similarly, reverse genetics of p38(MAPK) yielded a reduction in p53 and a decrease in the extent of apoptosis, confirming an exclusive hierarchy of activation that proceeds via AMPK/p38(MAPK)/p53. Fuel supplies counteracted [Cu(isaepy)(2)]-induced apoptosis and AMPK/p38(MAPK)/p53 activation, with glucose being the most effective, suggesting a role for energetic imbalance in [Cu(isaepy)(2)] toxicity. Co-administration of 3BrPA (3-bromopyruvate), a well-known inhibitor of glycolysis, and succinate dehydrogenase, enhanced apoptosis and AMPK/p38(MAPK)/p53 signalling pathway activation. Under these conditions, no toxic effect was observed in SOD (superoxide dismutase)-overexpressing SH-SY5Y cells or in PCNs (primary cortical neurons), which are, conversely, sensitized to the combined treatment with [Cu(isaepy)(2)] and 3BrPA only if grown in low-glucose medium or incubated with the glucose-6-phosphate dehydrogenase inhibitor dehydroepiandrosterone. Overall, the results suggest that NADPH deriving from the pentose phosphate pathway contributes to PCN resistance to [Cu(isaepy)(2)] toxicity and propose its employment in combination with 3BrPA as possible tool for cancer treatment. © The Authors Journal compilation © 2011 Biochemical Society

  11. Improved antitumor activity and reduced cardiotoxicity of epirubicin using hepatocyte-targeted nanoparticles combined with tocotrienols against hepatocellular carcinoma in mice.

    Science.gov (United States)

    Nasr, Magda; Nafee, Noha; Saad, Hoda; Kazem, Amani

    2014-09-01

    Hepatocellular carcinoma (HCC) is the third most common cause of cancer death worldwide. Epirubicin (EPI), an anthracycline derivative, is one of the main line treatments for HCC. However, serious side effects including cardiomyopathy and congestive heart failure limit its long term administration. Our main goal is to develop a delivery strategy that ensures improved efficacy of the chemotherapeutic agent together with reduced cardiotoxicity. In this context, EPI was loaded in chitosan-PLGA nanoparticles linked with asialofetuin (EPI-NPs) selectively targeting hepatocytes. In an attempt to reduce cardiotoxicity, targeted EPI-NPs were coadministered with tocotrienols. EPI-NPs significantly enhanced the antiproliferative effect compared to free EPI as studied on Hep G2 cell line. Nanoencapsulated EPI injected in HCC mouse model revealed higher p53-mediated apoptosis and reduced angiogenesis in the tumor. Combined therapy of EPI-NPs with tocotrienols further enhanced apoptosis and reduced VEGF level in a dose dependent manner. Assessment of cardiotoxicity indicated that EPI-NPs diminished the high level of proinflammatory cytokine tumor necrosis factor-α (TNF-α) as well as oxidative stress-induced cardiotoxicity as manifested by reduced level of lipid peroxidation products (TBARS) and nitric oxide (NO). EPI-NPs additionally restored the diminished level of superoxide dismutase (SOD) and reduced glutathione (GSH) in the heart. Interestingly, tocotrienols provided both antitumor activity and higher protection against oxidative stress and inflammation induced by EPI in the heart. This hepatocyte-targeted biodegradable nanoparticle/tocotrienol combined therapy represents intriguing therapeutic strategy for EPI providing not only superior efficacy but also higher safety levels. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Synergistic Effect of Subtoxic-dose Cisplatin and TRAIL to Mediate Apoptosis by Down-regulating Decoy Receptor 2 and Up-regulating Caspase-8, Caspase-9 and Bax Expression on NCI-H460 and A549 Cells

    Directory of Open Access Journals (Sweden)

    Xiaoyan Zhang

    2013-05-01

    Full Text Available Objective(s: Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL can selectively induce apoptosis in tumor cells, more than half of tumors including non-small cell lung cancer (NSCLC exhibit TRAIL-resistance. The purpose of this study was to determine whether subtoxic-dose cisplatin and TRAIL could synergistically enhance apoptosis on NSCLC cells and investigate its underlying mechanisms. Materials and Methods:NCI-H460 and A549 cells were treated with TRAIL alone, cisplatin alone or combination treatment in this study. The cytotoxicity was evaluated according to Sulforhodamine B assay, and apoptosis was examined using Hoechst 33342 staining and flow cytometry. The mRNA and protein levels of TRAIL receptors and apoptotic proteins including caspase-8, caspase-9, Bcl-2 and Bax were determined by RT-PCR and Western blotting, respectively. Results:Our results showed that NCI-H460 cells were sensitive to TRAIL, whereas A549 cells were resistant. However, subtoxic-dose cisplatin could enhance the both cells to TRAIL-mediated cell proliferation inhibition and apoptosis. The underlying mechanisms might be associated with the down-regulation of DcR2 and up-regulation of Caspase-8, Caspase-9 and Bax. Conclusion:Subtoxic-dose cisplatin could enhance both TRAIL- sensitive and TRAIL- resistant NSCLC cells to TRAIL-mediated apoptosis. These findings motivated further studies to evaluate such a combinatory therapeutic strategy against NSCLC in the animal models.

  13. A comparison of the effects of tributyltin chloride and triphenyltin chloride on cell proliferation, proapoptotic p53, Bax, and antiapoptotic Bcl-2 protein levels in human breast cancer MCF-7 cell line.

    Science.gov (United States)

    Fickova, Maria; Macho, Ladislav; Brtko, Julius

    2015-06-01

    In recent years it was disclosed, that numerous organotin(IV) derivatives have remarkable cytotoxicity against several types of cancer cells. The property to inhibit cell growth makes these compounds promising for antitumor therapy, as the clinical effectiveness of cisplatin is limited by drug resistance and significant side effects. Tributyltin and triphenyltin are known as endocrine disruptors. Moreover, the compounds exert their toxicity in mammals predominantly through nuclear receptor signaling. Here we present the effects of tributyltin chloride (TBT-Cl) and triphenyltin chloride (TPT-Cl) on cell proliferation, expression of proapoptotic p53, Bax, and antiapoptotic Bcl-2 proteins in human breast cancer MCF-7 cell line. Dose and time dependent (24, 48 and 72 h) cell expositions have demonstrated TBT-Cl as more effective in inhibiting MCF-7 cell proliferation than TPT-Cl. Short time treatment with TBT-Cl displayed marked stimulation of p53 protein expression when compared to TPT-Cl. Both organotin compounds displayed similar mild enhancement of Bax protein expression. The 24h exposition of TPT-Cl induced substantial diminution of Bcl-2 protein expression in comparison with both, untreated cells and TBT-Cl treated cells. Our observations indicate that TBT-Cl and TPT-Cl have different antiproliferative potency and distinct impact on expression of apoptosis marker proteins. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Evaluation of bax, bcl-2, p21 and p53 genes expression variations on cerebellum of BALB/c mice before and after birth under mobile phone radiation exposure.

    Science.gov (United States)

    Ghatei, Najmeh; Nabavi, Ariane Sadr; Toosi, Mohammad Hossein Bahreyni; Azimian, Hosein; Homayoun, Mansour; Targhi, Reza Ghasemnezhad; Haghir, Hossein

    2017-09-01

    The increasing rate of over using cell phones has been considerable in youths and pregnant women. We examined the effect of mobile phones radiation on genes expression variation on cerebellum of BALB/c mice before and after of the birth. In this study, a mobile phone jammer, which is an instrument to prevent receiving signals between cellular phones and base transceiver stations (two frequencies 900 and 1800 MHz) for exposure was used and twelve pregnant mice (BALB/c) divided into two groups (n=6), first group irradiated in pregnancy period (19th day), the second group did not irradiate in pregnancy period. After childbirth, offspring were classified into four groups (n=4): Group1: control, Group 2: B1 (Irradiated after birth), Group 3: B2 (Irradiated in pregnancy period and after birth), Group 4: B3 (Irradiated in pregnancy period). When maturity was completed (8-10 weeks old), mice were dissected and cerebellum was isolated. The expression level of bax , bcl-2, p21 and p53 genes examined by real-time reverse transcription polymerase chain reaction (Real-Time RT- PCR). The data showed that mobile phone radio waves were ineffective on the expression level of bcl-2 and p53 genes) P >0.05(. Also gene expression level of bax decreased and gene expression level of p21 increased comparing to the control group ( P mobile phone radiations did not induce apoptosis in cells of the cerebellum and the injured cells can be repaired by cell cycle arrest.

  15. Caractérisation structurale de l'adsorption des isomères para- et meta- du xylène dans la zéolithe de type faujasite BaX Structural Characterization of Para- and Meta- Xylene in Bax Zeolite

    Directory of Open Access Journals (Sweden)

    Mellot C.

    2006-11-01

    Full Text Available La séparation du para-xylène des isomères aromatiques en C8 est réalisée industriellement grâce à l'adsorption sur tamis moléculaire zéolithique. Une amélioration des propriétés de séparation des tamis, et en particulier de leur sélectivité, nécessite, entre autres, une bonne connaissance des interactions entre les molécules d'adsorbat et la structure zéolithique. Pour ce faire, nous avons fait appel à deux techniques de caractérisation physico-chimique : la diffraction des neutrons et la spectroscopie infrarouge. Nous avons étudié une zéolithe BaX de type faujasite sur laquelle nous avons adsorbé, à l'état de corps purs, les isomères para- et méta- du xylène. Cette zéolithe est connue industriellement pour ses propriétés sélectives performantes pour le paraxylène. Les analyses ont été réalisées en considérant tout d'abord un faible taux de remplissage, voisin d'une molécule par supercage de zéolithe, et ensuite à saturation où la zéolithe contient sensiblement trois molécules par supercage. La diffraction des neutrons permet, à basse température, de localiser les molécules dans la zéolithe et de préciser leur interaction avec le cation Ba²+. La spectroscopie infrarouge permet une étude des caractéristiques vibrationnelles de l'adsorbat en fonction du taux de recouvrement. Une synthèse des résultats obtenus à l'aide de ces deux méthodes d'investigation nous a permis de dégager un modèle de remplissage des supercages pour les deux isomères considérés. Ainsi, des différences significatives sont mises en évidence. En ce qui concerne le para-xylène, pour un taux de remplissage inférieur à deux molécules par supercage, les molécules de para-xylène viennent se positionner au voisinage des cations en site SII de la supercage. La troisième molécule de para-xylène introduite dans la zéolithe n'est pas en interaction avec un cation Ba²+ et sera localisée dans un nouveau site F

  16. Overexpression of p53 activated by small activating RNA suppresses the growth of human prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Ge Q

    2016-01-01

    Full Text Available Qiangqiang Ge,1,* Chenghe Wang,2,* Yajun Ruan,1,* Zhong Chen,1 Jihong Liu,1 Zhangqun Ye1 1Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 2Department of Urology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: Previous research has reported that a particular double-stranded RNA, named dsP53-285, has the capacity to induce expression of the tumor suppressor gene TP53 in chimpanzee cells by targeting its promoter. Usually, it is the wild-type p53 protein, rather than mutants, which exhibits potent cancer-inhibiting effects. In addition, nonhuman primates, such as chimpanzees, share almost identical genome sequences with humans. This prompted us to speculate whether dsP53-285 can trigger wild-type p53 protein expression in human prostate cancer (PCa cells and consequently suppress cell growth. The human PCa cell lines LNCaP and DU145 were transfected with dsP53-285 for 72 hours. Compared with the dsControl and mock transfection groups, expression of both p53 messenger RNA and p53 protein was significantly enhanced after dsP53-285 transfection, and this enhancement was followed by upregulation of p21, which indirectly indicated that dsP53-285 induced wild-type p53 expression. Moreover, overexpression of wild-type p53 mediated by dsP53-285 downregulated the expression of Cyclin D1 and cyclin-dependent kinase 4/6, thereby inducing PCa cell cycle arrest in G0/G1 phase and then inhibiting cell proliferation and clonogenicity. More importantly, dsP53-285 suppressed PCa cells mainly by modulating wild-type p53 expression. In conclusion, our study provides evidence that dsP53-285 can significantly stimulate wild-type p53 expression in the human PCa cell lines LNCaP and DU145 and can exert potent antitumor effects. Keywords: p53, small activating RNA, prostate

  17. Bax/Bcl-2 protein expression ratio and leukocyte function are related to reduction of Walker-256 tumor growth after β-hydroxy-β-methylbutyrate (HMB) administration in Wistar rats.

    Science.gov (United States)

    Kuczera, Diogo; Paro de Oliveira, Heloísa Helena; Fonseca Guimarães, Fernando de Souza; de Lima, Carina; Alves, Luciana; Machado, Andressa Franzói; Coelho, Isabela; Yamaguchi, Adriana; Donatti, Lucélia; Naliwaiko, Katya; Fernandes, Luiz Claudio; Nunes, Everson Araújo

    2012-01-01

    This study investigated the mechanisms by which β-hydroxy-β-methylbutyrate (HMB) administration in rats reduces Walker-256 tumor growth. Male Wistar rats were supplemented with HMB (76 mg/kg/day) (HW), or a placebo (W), during 8 wk by gavage. At the 6th wk, rats were inoculated with a suspension of Walker 256 tumor cells (3 × 10(7)/mL). Fifteen days after inoculation, the HW group showed higher glycemia (109.4 ± 5.53 vs. 89.87 ± 7.02 mg/dL, P HMB-treated rats displayed a 36.9% decrement in rates of proliferation ex vivo and a significant increase in the Bax/Bcl-2 protein expression ratio in comparison to those extracted from the placebo-treated rats (P HMB supplementation decreases tumor burden by modifying the inner environment of tumor cells and by interfering with blood leukocyte function.

  18. Distinct radioprotective activities of major heat shock proteins in irradiated mammalian cells

    International Nuclear Information System (INIS)

    Kabakov, Alexander; Malyutina, Yana; Kudryavtsev, Vladimir

    2008-01-01

    Full text: Several years ago we have suggested that heat shock proteins (Hsps) can be involved in cellular and tissue mechanisms of protection from ionizing radiation. At present, the accumulated experimental data do allow us to characterize three major mammalian Hsps, Hsp70, Hsp27 and Hsp90, as specific endogenous radioprotectors which are able to prevent or minimize cell death resulting from the radiation exposure. It follows from the many findings that the radioprotective effect of these Hsps is particularly manifested in their ability to attenuate apoptosis in various normal and tumor cells irradiated in vivo or in vitro. The obtained data already enable to suggest three main mechanisms of the radioprotection conferred by the excess Hsps: 1) Modulation of the intracellular signaling so that the apoptotic signal transduction is blocked, whereas the 'cell survival' signal transduction is stimulated; 2) Suppression of the radiation-associated free radical generation and apoptosis induced by reactive oxygen species (ROS); 3) Attenuation of the genotoxic impact of ionizing radiation. The latter suggested mechanism seems particularly intriguing and implies that the excess Hsps can somehow contribute to protection/repair of genomic DNA from radiation-induced damage. According to our recent results, Hsp90 is indeed involved in the post-irradiation repair of nuclear DNA, while excess Hsp70 can beneficially affect the p53-mediated DNA damage response in irradiated cells to ensure their long-term survival and recovery. As for Hsp27, we found that its accumulation in target cells increases their radioresistance by enhancing the irradiation-responsive activation of anti apoptotic pathways. While the Hsp70 and Hsp27 seem to perform different functions in irradiated cells, the synergistic enhancement of radioprotection was clearly observed in the cells enriched by the both the Hsps. In vivo, such radioprotective activities of the major mammalian Hsps may play a role in

  19. Inhibition of nuclear factor-kappaB or Bax prevents endoplasmic reticulum stress- but not nitric oxide-mediated apoptosis in INS-1E cells

    DEFF Research Database (Denmark)

    Tonnesen, Morten F; Grunnet, Lars G; Friberg, Josefine

    2009-01-01

    . Exposure of INS-1E cells to TG or SNAP caused caspase-3 cleavage and apoptosis. Both TG and SNAP induced activation of the proapoptotic transcription factor CCAAT/enhancer-binding protein homologous protein (CHOP). However, other classical ER stress-induced markers such as up-regulation of ER chaperone Bip...

  20. Identification of human ferritin, heavy polypeptide 1 (FTH1) and yeast RGI1 (YER067W) as pro-survival sequences that counteract the effects of Bax and copper in Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Eid, Rawan [Department of Chemistry and Chemical Engineering, Royal Military College, Kingston, Ontario (Canada); Department of Biology, Queen' s University, Kingston, Ontario (Canada); Boucher, Eric [Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec (Canada); Gharib, Nada [Department of Chemistry and Chemical Engineering, Royal Military College, Kingston, Ontario (Canada); Khoury, Chamel [Department of Chemistry and Chemical Engineering, Royal Military College, Kingston, Ontario (Canada); Department of Biology, Queen' s University, Kingston, Ontario (Canada); Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec (Canada); Arab, Nagla T.T. [Department of Chemistry and Chemical Engineering, Royal Military College, Kingston, Ontario (Canada); Department of Biology, Queen' s University, Kingston, Ontario (Canada); Murray, Alistair [Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec (Canada); Young, Paul G. [Department of Biology, Queen' s University, Kingston, Ontario (Canada); Mandato, Craig A. [Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec (Canada); Greenwood, Michael T., E-mail: michael.greenwood@rmc.ca [Department of Chemistry and Chemical Engineering, Royal Military College, Kingston, Ontario (Canada)

    2016-03-01

    Ferritin is a sub-family of iron binding proteins that form multi-subunit nanotype iron storage structures and prevent oxidative stress induced apoptosis. Here we describe the identification and characterization of human ferritin, heavy polypeptide 1 (FTH1) as a suppressor of the pro-apoptotic murine Bax sequence in yeast. In addition we demonstrate that FTH1 is a general pro-survival sequence since it also prevents the cell death inducing effects of copper when heterologously expressed in yeast. Although ferritins are phylogenetically widely distributed and are present in most species of Bacteria, Archaea and Eukarya, ferritin is conspicuously absent in most fungal species including Saccharomyces cerevisiae. An in silico analysis of the yeast proteome lead to the identification of the 161 residue RGI1 (YER067W) encoded protein as a candidate for being a yeast ferritin. In addition to sharing 20% sequence identity with the 183 residue FTH1, RGI1 also has similar pro-survival properties as ferritin when overexpressed in yeast. Analysis of recombinant protein by SDS-PAGE and by electron microscopy revealed the expected formation of higher-order structures for FTH1 that was not observed with Rgi1p. Further analysis revealed that cells overexpressing RGI1 do not show increased resistance to iron toxicity and do not have enhanced capacity to store iron. In contrast, cells lacking RGI1 were found to be hypersensitive to the toxic effects of iron. Overall, our results suggest that Rgi1p is a novel pro-survival protein whose function is not related to ferritin but nevertheless it may have a role in regulating yeast sensitivity to iron stress. - Highlights: • Human ferritin, heavy polypeptide 1 (FTH1) was identified as a suppressor of the pro-apoptotic Bax in yeast. • Based on its similarity to ferritin we examined Rgi1p/YER067W for potential ferritin like functions. • Like human H-ferritin, RGI1 confers increased resistance to apoptotic inducing stresses in yeast.

  1. Identification of human ferritin, heavy polypeptide 1 (FTH1) and yeast RGI1 (YER067W) as pro-survival sequences that counteract the effects of Bax and copper in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Eid, Rawan; Boucher, Eric; Gharib, Nada; Khoury, Chamel; Arab, Nagla T.T.; Murray, Alistair; Young, Paul G.; Mandato, Craig A.; Greenwood, Michael T.

    2016-01-01

    Ferritin is a sub-family of iron binding proteins that form multi-subunit nanotype iron storage structures and prevent oxidative stress induced apoptosis. Here we describe the identification and characterization of human ferritin, heavy polypeptide 1 (FTH1) as a suppressor of the pro-apoptotic murine Bax sequence in yeast. In addition we demonstrate that FTH1 is a general pro-survival sequence since it also prevents the cell death inducing effects of copper when heterologously expressed in yeast. Although ferritins are phylogenetically widely distributed and are present in most species of Bacteria, Archaea and Eukarya, ferritin is conspicuously absent in most fungal species including Saccharomyces cerevisiae. An in silico analysis of the yeast proteome lead to the identification of the 161 residue RGI1 (YER067W) encoded protein as a candidate for being a yeast ferritin. In addition to sharing 20% sequence identity with the 183 residue FTH1, RGI1 also has similar pro-survival properties as ferritin when overexpressed in yeast. Analysis of recombinant protein by SDS-PAGE and by electron microscopy revealed the expected formation of higher-order structures for FTH1 that was not observed with Rgi1p. Further analysis revealed that cells overexpressing RGI1 do not show increased resistance to iron toxicity and do not have enhanced capacity to store iron. In contrast, cells lacking RGI1 were found to be hypersensitive to the toxic effects of iron. Overall, our results suggest that Rgi1p is a novel pro-survival protein whose function is not related to ferritin but nevertheless it may have a role in regulating yeast sensitivity to iron stress. - Highlights: • Human ferritin, heavy polypeptide 1 (FTH1) was identified as a suppressor of the pro-apoptotic Bax in yeast. • Based on its similarity to ferritin we examined Rgi1p/YER067W for potential ferritin like functions. • Like human H-ferritin, RGI1 confers increased resistance to apoptotic inducing stresses in yeast.

  2. In vitro anti-inflammatory and anti-cancer activities of Cuscuta reflexa Roxb.

    Science.gov (United States)

    Suresh, V; Sruthi, V; Padmaja, B; Asha, V V

    2011-04-12

    To determine anti-inflammatory and anti-cancer activities of Cuscuta reflexa in cell lines (in vitro). Anti-inflammatory activity of the water extract was analysed in vitro using lipopolysaccharide (LPS) induced inflammatory reactions in murine macrophage cell line RAW264.7. The expression of COX-2 and TNF-α genes involved in inflammation was analysed by SQ RT-PCR. EMSA was conducted to analyse the influence of the extract on NF-κB signalling. Anti-cancer activity was analysed on Hep3B cells by MTT assay, DAPI staining, annexin V staining and SQ-RT PCR analysis of BAX, Bcl-2, p53 and survivin. The extract down regulated LPS induced over expression of TNF-α and COX-2 in RAW264.7 cells; blocked NF-κB binding to its motifs and induced apoptosis in Hep3B cells as evidenced from MTT, DAPI staining and annexin V staining assays. The extract up regulated pro-apoptotic factors BAX and p53, and down regulated anti-apoptotic factors Bcl-2 and survivin. The study showed that Cuscuta reflexa inhibits LPS induced inflammatory responses in RAW264.7 cells through interplay of TNF-α, COX-2 and NF-κB signalling. It induced apoptosis in Hep3B cells through the up regulation of p53, BAX and down regulation of Bcl-2 and survivin. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  3. Caspase activity and expression of cell death genes during development of human preimplantation embryos.

    Science.gov (United States)

    Spanos, S; Rice, S; Karagiannis, P; Taylor, D; Becker, D L; Winston, R M L; Hardy, K

    2002-09-01

    It has been observed that apoptosis occurs in human blastocysts. In other types of cell, the characteristic morphological changes seen in apoptotic cells are executed by caspases, which are regulated by the BCL-2 family of proteins. This study investigated whether these components of the apoptotic cascade are present throughout human preimplantation development. Developing and arrested two pronucleate embryos at all stages were incubated with a fluorescently tagged caspase inhibitor that binds only to active caspases, fixed, counterstained with 4,6-diamidino-2-phenylindole (DAPI) to assess nuclear morphology and examined using confocal microscopy. Active caspases were detected only after compaction, at the morula and blastocyst stages, and were frequently associated with apoptotic nuclei. Occasional labelling was seen in arrested embryos. Expression of proapoptotic BAX and BAD and anti-apoptotic BCL-2 was examined in single embryos using RT-PCR and immunohistochemistry. BAX and BCL-2 mRNAs were expressed throughout development, whereas BAD mRNA was expressed mainly after compaction. Simultaneous expression of BAX and BCL-2 proteins within individual embryos was confirmed using immunohistochemistry. The onset of caspase activity and BAD expression after compaction correlates with the previously reported appearance of apoptotic nuclei. As in other types of cell, human embryos express common molecular components of the apoptotic cascade, although apoptosis appears to be suppressed before compaction and differentiation.

  4. Anomalous atomic displacement parameters and local dynamics in the Curie range of a Pb-free relaxor ferroelectric system (Bi1-xBax)(Fe1-xTix)O3(0.36 ≤ x ≤ 0.50)

    Science.gov (United States)

    Singh, Anar; Moriyoshi, Chikako; Kuroiwa, Yoshihiro; Pandey, Dhananjai

    2018-04-01

    We report here the relaxor ferroelectric (RFE) behaviour in a multiferroic solid solution system, (Bi1-xBax)(Fe1-xTix)O3, at a critical disorder level of xC ˜ 0.35 in BiFeO3 and 0.65 (i.e., 1-xC = 0.35) in BaTiO3 similar to the 1:2 ratio of Mg2+ and Nb5+ in the canonical RFE Pb(Mg1/3Nb2/3)O3. This Pb-free system, like canonical Pb-based RFEs, does not exhibit macroscopic symmetry breaking and shows only the signatures of ergodicity breaking at Vogel-Fulcher freezing temperature (TVF). The atomic displacement parameters (ADPs) of Fe3+/Ti4+ and O2-, obtained using high wave vector (Q) and high-resolution synchrotron x-ray diffraction data as a function of temperature, show anomalous diffuse peaks in the Curie range. It is shown that the diffuse peak in ADPs is due to softening of the vibrational frequencies of the B-O chain (B = Fe3+/Ti4+ and O = O2-) below the Burns temperature (TB) followed by hardening below the characteristic temperature (T'm), which corresponds to a peak in the dielectric permittivity (ɛ').

  5. Phase coexistence and magnetic behavior in the low-dimensional hexagonal cobaltites BaxA1-xCoO3-δ (A = Mg or Ca and 0 ⩽ x ⩽ 0.20)

    Science.gov (United States)

    Oliveira, M. P.; Mercena, S. G.; Meneses, C. T.; Jesus, C. B. R.; Pagliuso, P. G.; Duque, J. G. S.

    2018-04-01

    In this work, we report on X-ray diffraction and magnetization measurements carried out in the low-dimensional hexagonal cobaltites BaxA1-xCoO3-δ (A = Mg or Ca, 0 ⩽ x ⩽ 0.20 and δ = 0 or 0.4). Polycrystalline samples have been synthesized by solid-state reaction. The Rietveld refinements of the X-ray diffraction patterns show clearly a phase coexistence of both BaCoO2.6 and BaCoO3 hexagonal polytype structures (space group: P63/mmc), which is dependent on both the dopant ion and doping level. At low temperatures (T 0.10 the low temperature hysteresis is not observed anymore. The field-dependence of ZFC-FC curves taken for the sample grown with x = 0 show a displacement of the peak position into low temperature region. Except for the sample grown with x = 0.20, the MvsH loops taken at T = 2 K show multiple steps in the field region ranging - 15 ⩽ H ⩽ 15 kOe . Finally, the saturation magnetization values are consistent with a low-spin state for the Co2+ or Co4+ ions.

  6. Ethyl acetate extract of Chinese medicinal herb Sarcandra glabra induces growth inhibition on human leukemic HL-60 cells, associated with cell cycle arrest and up-regulation of pro-apoptotic Bax/Bcl-2 ratio.

    Science.gov (United States)

    Li, W Y; Chiu, Lawrence C M; Lam, W S; Wong, W Y; Chan, Y T; Ho, Y P; Wong, Elaine Y L; Wong, Y S; Ooi, Vincent E C

    2007-02-01

    Sarcandra glabra (Thunb.) Nakai, colloquially known as Caoshanhu, is a Chinese medicinal herb with reported anti-tumor, anti-inflammatory, anti-viral and non-specific immunoenhancing properties. Although the plant has been clinically used for treating a variety of diseases, its bioactive ingredients are largely unknown and its mode of action has never been investigated. In this study, the anti-tumor property of ethyl acetate (EA) extract of S. glabra was investigated by determining its in vitro growth-inhibitory effects on a panel of human cancer cell lines of different histotypes. Growth inhibition of the EA extract on the cancer cells seemed to be selective, and the leukemic HL-60 was found to be the most responsive after 48 h of treatment (IC50=58 microg/ml). Flow cytometric studies further illustrated that the extract might interfere with DNA replication and thus arrested the cell cycle at S phase in the leukemic cells, followed by DNA fragmentation and loss of phospholipid asymmetry in the plasma membrane after 72 h of treatment. Concurrently, the pro-apoptotic Bax/Bcl-2 ratio was also up-regulated by more than 178% of the control level. All these findings suggested that the extract had initiated apoptosis to kill the leukemic cells. Results from this pioneer study help to establish a scientific foundation for future research and development of the bioactive ingredients in EA extract of S. glabra as efficacious anti-cancer agents.

  7. AMP-activated protein kinase couples 3-bromopyruvate-induced energy depletion to apoptosis via activation of FoxO3a and upregulation of proapoptotic Bcl-2 proteins.

    Science.gov (United States)

    Bodur, Cagri; Karakas, Bahriye; Timucin, Ahmet Can; Tezil, Tugsan; Basaga, Huveyda

    2016-11-01

    Most tumors primarily rely on glycolysis rather than mitochondrial respiration for ATP production. This phenomenon, also known as Warburg effect, renders tumors more sensitive to glycolytic disturbances compared to normal cells. 3-bromopyruvate is a potent inhibitor of glycolysis that shows promise as an anticancer drug candidate. Although investigations revealed that 3-BP triggers apoptosis through ATP depletion and subsequent AMPK activation, the underlying molecular mechanisms coupling AMPK to apoptosis are poorly understood. We showed that 3-BP leads to a rapid ATP depletion which was followed by growth inhibition and Bax-dependent apoptosis in HCT116 cells. Apoptosis was accompanied with activation of caspase-9 and -3 while pretreatment with a general caspase inhibitor attenuated cell death. AMPK, p38, JNK, and Akt were phosphorylated immediately upon treatment. Pharmacological inhibition and silencing of AMPK largely inhibited 3-BP-induced apoptosis and reversed phosphorylation of JNK. Transcriptional activity of FoxO3a was dramatically increased subsequent to AMPK-mediated phosphorylation of FoxO3a at Ser413. Cell death analysis of cells transiently transfected with wt or AMPK-phosphorylation-deficient FoxO3 expression plasmids verified the contributory role of AMPK-FoxO3a axis in 3-BP-induced apoptosis. In addition, expression of proapoptotic Bcl-2 proteins Bim and Bax were upregulated in an AMPK-dependent manner. Bim was transcriptionally activated in association with FoxO3a activity, while Bax upregulation was abolished in p53-null cells. Together, these data suggest that AMPK couples 3-BP-induced metabolic disruption to intrinsic apoptosis via modulation of FoxO3a-Bim axis and Bax expression. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  8. Evaluation of In Vitro Anticancer Activity of Ocimum Basilicum, Alhagi Maurorum, Calendula Officinalis and Their Parasite Cuscuta Campestris

    OpenAIRE

    Behbahani, Mandana

    2014-01-01

    The present investigation was carried out to study the relationship between presence of cytotoxic compounds in Ocimum basilicum, Alhagi maurorum, Calendula officinalis and their parasite Cuscuta campestris. The cytotoxic activity of the pure compounds was performed by MTT assay against breast cancer cell lines (MCF-7 and MDA-MB-231) and normal breast cell line (MCF 10A). The induction of apoptosis was measured by the expression levels of p53, bcl-2, bax and caspase-3 genes using quantitative ...

  9. Roles of some antioxidants in modulation of cardiac myopathy induced by sodium nitrite via down-regulation of mRNA expression of NF-κB, Bax, and flt-1 and suppressing DNA damage

    Directory of Open Access Journals (Sweden)

    Laila Mohamed Fadda

    2018-02-01

    Full Text Available The underlying pathology of cardiac damage involves various molecular and signaling pathways. Therefore, this study aimed to explore the role of Quercetin (Querc, alone or in combination with Melatonin (Melat against cardiac damage induced by sodium nitrite (Sod nit, as well as to elucidate different signaling pathways. Querc and Melat were injected intraperitoneally (i.p., followed by induction of hypoxia in rats by using a single dose of Sod nit (60 mg/kg, s.c.. Treatment with Sod nit significantly decreased hemoglobin (Hb levels in blood. Pretreatment of hypoxic rats with Querc and/or Melat elevated the declined Hb concentration. The forementioned antioxidants also successfully ameliorated the alteration of heat shock protein 70 (HSP-70 and markers of cardiac injury, including troponin T (Trop. T, creatine kinase-MB (CK-MB, tumor necrosis factor-α (TNF α, and C-reactive protein (CRP in the rats serum. Furthermore, RT-PCR revealed that these antioxidants successfully modulated mRNA expression of NF-κB, Bax, Bcl-2, and flt-1. They also regulated vascular endothelial growth factor (VEGF, the apoptosis marker caspase 3, and oxidative DNA damage in cardiac tissue, compared to Sod nit-intoxicated rats. The present biochemical results are reinforced by histopathological examination. In Conclusion: The results reflected that treatment with Querc in combination with Melat was most effective in improving Sod nit-toxicity induced cardiac damage, thus confirming the promising role of this combination as an effective treatment for cardiac damage induced by other cardio-toxic agents.

  10. Anti-hepatoma activity of a novel compound glaucocalyxin H in vivo and in vitro.

    Science.gov (United States)

    Hai, Guangfan; Zhang, Chong; Jia, Yanlong; Bai, Suping; Han, Jinfen; Guo, Lanqing; Cui, Taizhen; Niu, Bingxuan; Huang, Feng; Song, Yu

    2015-06-01

    Glaucocalyxin H (GLH) is a new compound isolated from a traditional Chinese medical herb Isodon japonica var. glaucocalyx which has been used for folk medicine. This study was carried out for the first time to investigate the potential role of GLH in anti-hepatoma activity and underlying mechanisms in it. GLH could inhibit the growth of tumor in mice and induce HepG2 cells to death as assessed by the tumor reduction assay, toxic assay, morphological change, and survival rate assay. Many antitumor drugs originated from plants could inhibit the growth of tumor by inducing cells to apoptosis. The morphological changes of HepG2 cells treated with different concentrations of GLH under fluorescence and electron microscope and apoptotic rates were detected to verify its effect on apoptosis. As shown in the study, GLH could induce HepG2 cells to apoptosis in a dose-dependent manner. Bcl2 and Bax proteins played important roles in apoptosis and the disequilibrium between Bcl2 and Bax might result in apoptosis. The expression of Bax protein was upregulated and Bcl2 protein was downregulated in HepG2 cells treated with GLH assessed by Western blotting, and they were in a dose-dependent manner. Taken together, GLH can inhibit the growth of hepatoma cells in vivo and in vitro by inducing cell apoptosis due to the decreased Bcl2 and increased Bax proteins suggesting that GLH could be a potential candidate as an anti-hepatoma agent for the therapeutic treatment of hepatoma.

  11. The neuroprotective action of pyrroloquinoline quinone against glutamate-induced apoptosis in hippocampal neurons is mediated through the activation of PI3K/Akt pathway

    International Nuclear Information System (INIS)

    Zhang Qi; Shen Mi; Ding Mei; Shen Dingding; Ding Fei

    2011-01-01

    Pyrroloquinoline quinone (PQQ), a cofactor in several enzyme-catalyzed redox reactions, possesses a potential capability of scavenging reactive oxygen species (ROS) and inhibiting cell apoptosis. In this study, we investigated the effects of PQQ on glutamate-induced cell death in primary cultured hippocampal neurons and the possible underlying mechanisms. We found that glutamate-induced apoptosis in cultured hippocampal neurons was significantly attenuated by the ensuing PQQ treatment, which also inhibited the glutamate-induced increase in Ca2+ influx, caspase-3 activity, and ROS production, and reversed the glutamate-induced decrease in Bcl-2/Bax ratio. The examination of signaling pathways revealed that PQQ treatment activated the phosphorylation of Akt and suppressed the glutamate-induced phosphorylation of c-Jun N-terminal protein kinase (JNK). And inhibition of phosphatidylinositol-3-kinase (PI3K)/Akt cascade by LY294002 and wortmannin significantly blocked the protective effects of PQQ, and alleviated the increase in Bcl-2/Bax ratio. Taken together, our results indicated that PQQ could protect primary cultured hippocampal neurons against glutamate-induced cell damage by scavenging ROS, reducing Ca2+ influx, and caspase-3 activity, and suggested that PQQ-activated PI3K/Akt signaling might be responsible for its neuroprotective action through modulation of glutamate-induced imbalance between Bcl-2 and Bax. - Research Highlights: →PQQ attenuated glutamate-induced cell apoptosis of cultured hippocampal neurons. →PQQ inhibited glutamate-induced Ca 2+ influx and caspase-3 activity. →PQQ reduced glutamate-induced increase in ROS production. →PQQ affected phosphorylation of Akt and JNK signalings after glutamate injury. →PI3K/Akt was required for neuroprotection of PQQ by modulating Bcl-2/Bax ratio.

  12. Impact of a product-specific reference standard for the measurement of a PEGylated rFVIII activity: the Swiss Multicentre Field Study.

    Science.gov (United States)

    Bulla, O; Poncet, A; Alberio, L; Asmis, L M; Gähler, A; Graf, L; Nagler, M; Studt, J-D; Tsakiris, D A; Fontana, P

    2017-07-01

    Measuring factor VIII (FVIII) activity can be challenging when it has been modified, such as when FVIII is pegylated to increase its circulating half-life. Use of a product-specific reference standard may help avoid this issue. Evaluate the impact of using a product-specific reference standard for measuring the FVIII activity of BAX 855 - a pegylated FVIII - in eight of Switzerland's main laboratories. Factor VIII-deficient plasma, spiked with five different concentrations of BAX 855, plus a control FVIII sample, was sent to the participating laboratories. They measured FVIII activity by using either with a one-stage (OSA) or the chromogenic assay (CA) against their local or a product-specific reference standard. When using a local reference standard, there was an overestimation of BAX 855 activity compared to the target concentrations, both with the OSA and CA. The use of a product-specific reference standard reduced this effect: mean recovery ranged from 127.7% to 213.5% using the OSA with local reference standards, compared to 110% to 183.8% with a product-specific reference standard, and from 146.3% to 182.4% using the CA with local reference standards compared to 72.7% to 103.7% with a product-specific reference standard. In this in vitro study, the type of reference standard had a major impact on the measurement of BAX 855 activity. Evaluation was more accurate and precise when using a product-specific reference standard. © 2017 John Wiley & Sons Ltd.

  13. Dopaminergic Neuron-Specific Deletion of p53 Gene Attenuates Methamphetamine Neurotoxicity.

    Science.gov (United States)

    Lu, Tao; Kim, Paul P; Greig, Nigel H; Luo, Yu

    2017-08-01

    p53 plays an essential role in the regulation of cell death in dopaminergic (DA) neurons and its activation has been implicated in the neurotoxic effects of methamphetamine (MA). However, how p53 mediates MA neurotoxicity remains largely unknown. In this study, we examined the effect of DA-specific p53 gene deletion in DAT-p53KO mice. Whereas in vivo MA binge exposure reduced locomotor activity in wild-type (WT) mice, this was significantly attenuated in DAT-p53KO mice and associated with significant differences in the levels of the p53 target genes BAX and p21 between WT and DAT-p53KO. Notably, DA-specific deletion of p53 provided protection of substantia nigra pars reticulata (SNpr) tyrosine hydroxylase (TH) positive fibers following binge MA, with DAT-p53KO mice having less decline of TH protein levels in striatum versus WT mice. Whereas DAT-p53KO mice demonstrated a consistently higher density of TH fibers in striatum compared to WT mice at 10 days after MA exposure, DA neuron counts within the substantia nigra pars compacta (SNpc) were similar. Finally, supportive of these results, administration of a p53-specific inhibitor (PFT-α) provided a similarly protective effect on MA binge-induced behavioral deficits. Neither DA specific p53 deletion nor p53 pharmacological inhibition affected hyperthermia induced by MA binge. These findings demonstrate a specific contribution of p53 activation in behavioral deficits and DA neuronal terminal loss by MA binge exposure.

  14. The cyclin-dependent kinase inhibitor 5, 6-dichloro-1-beta-D-ribofuranosylbenzimidazole induces nongenotoxic, DNA replication-independent apoptosis of normal and leukemic cells, regardless of their p53 status

    International Nuclear Information System (INIS)

    Turinetto, Valentina; Porcedda, Paola; Orlando, Luca; De Marchi, Mario; Amoroso, Antonio; Giachino, Claudia

    2009-01-01

    Current chemotherapy of human cancers focuses on the DNA damage pathway to induce a p53-mediated cellular response leading to either G1 arrest or apoptosis. However, genotoxic treatments may induce mutations and translocations that result in secondary malignancies or recurrent disease. In addition, about 50% of human cancers are associated with mutations in the p53 gene. Nongenotoxic activation of apoptosis by targeting specific molecular pathways thus provides an attractive therapeutic approach. Normal and leukemic cells were evaluated for their sensitivity to 5, 6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) through cell viability and caspase activation tests. The apoptotic pathway induced by DRB was analysed by immunfluorescence and immunoblot analysis. H2AX phosphorylation and cell cycle analysis were performed to study the dependance of apoptosis on DNA damage and DNA replication, respectively. To investigate the role of p53 in DRB-induced apoptosis, specific p53 inhibitors were used. Statistical analysis on cell survival was performed with the test of independence. Here we report that DRB, an inhibitor of the transcriptional cyclin-dependent kinases (CDKs) 7 and 9, triggers DNA replication-independent apoptosis in normal and leukemic human cells regardless of their p53 status and without inducing DNA damage. Our data indicate that (i) in p53-competent cells, apoptosis induced by DRB relies on a cytosolic accumulation of p53 and subsequent Bax activation, (ii) in the absence of p53, it may rely on p73, and (iii) it is independent of ATM and NBS1 proteins. Notably, even apoptosis-resistant leukemic cells such as Raji were sensitive to DRB. Our results indicate that DRB represents a potentially useful cancer chemotherapeutic strategy that employs both the p53-dependent and -independent apoptotic pathways without inducing genotoxic stress, thereby decreasing the risk of secondary malignancies

  15. Chemoprevention by Probiotics During 1,2-Dimethylhydrazine-Induced Colon Carcinogenesis in Rats.

    Science.gov (United States)

    Walia, Sohini; Kamal, Rozy; Dhawan, D K; Kanwar, S S

    2018-04-01

    Probiotics are believed to have properties that lower the risk of colon cancer. However, the mechanisms by which they exert their beneficial effects are relatively unknown. To assess the impact of probiotics in preventing induction of colon carcinogenesis in rats. The rats were divided into six groups viz., normal control, Lactobacillus plantarum (AdF10)-treated, Lactobacillus rhamnosus GG (LGG)-treated, 1,2-dimethylhydrazine (DMH)-treated, L. plantarum (AdF10) + DMH-treated and L. rhamnosus GG (LGG) + DMH-treated. Both the probiotics were supplemented daily at a dose of 2 × 10 10 cells per day. DMH at a dose of 30 mg/kg body weight was administered subcutaneously twice a week for the first 4 weeks and then once every week for a duration of 16 weeks. Glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and catalase as protein expression of genes involved in apoptosis were assessed during DMH-induced colon carcinogenesis in rats. DMH treatment decreased the activity of GSH, GPx, GST, SOD and catalase. However, AdF10 and LGG supplementation to DMH-treated rats significantly increased the activity of these enzymes. Further, DMH treatment revealed alterations in the protein expressions of various genes involved in the p53-mediated apoptotic pathway such as p53, p21, Bcl-2, Bax, caspase-9 and caspase-3, which, however, were shifted towards normal control levels upon simultaneous supplementation with probiotics. The present study suggests that probiotics can provide protection against oxidative stress and apoptotic-related protein disregulation during experimentally induced colon carcinogenesis.

  16. Heat shock factor-1 modulates p53 activity in the transcriptional response to DNA damage

    Science.gov (United States)

    Logan, Ian R.; McNeill, Hesta V.; Cook, Susan; Lu, Xiaohong; Meek, David W.; Fuller-Pace, Frances V.; Lunec, John; Robson, Craig N.

    2009-01-01

    Here we define an important role for heat shock factor 1 (HSF1) in the cellular response to genotoxic agents. We demonstrate for the first time that HSF1 can complex with nuclear p53 and that both proteins are co-operatively recruited to p53-responsive genes such as p21. Analysis of natural and synthetic cis elements demonstrates that HSF1 can enhance p53-mediated transcription, whilst depletion of HSF1 reduces the expression of p53-responsive transcripts. We find that HSF1 is required for optimal p21 expression and p53-mediated cell-cycle arrest in response to genotoxins while loss of HSF1 attenuates apoptosis in response to these agents. To explain these novel properties of HSF1 we show that HSF1 can complex with DNA damage kinases ATR and Chk1 to effect p53 phosphorylation in response to DNA damage. Our data reveal HSF1 as a key transcriptional regulator in response to genotoxic compounds widely used in the clinical setting, and suggest that HSF1 will contribute to the efficacy of these agents. PMID:19295133

  17. Angelica sinensis polysaccharides promotes apoptosis in human breast cancer cells via CREB-regulated caspase-3 activation

    International Nuclear Information System (INIS)

    Zhou, Wei-Jie; Wang, Sheng; Hu, Zhuang; Zhou, Zhen-Yu; Song, Cai-Juan

    2015-01-01

    Angelica sinensis polysaccharide (ASP) is purified from the fresh roots of Angelica sinensis (AS). This traditional Chinese medicine has been used for thousands of years for treating gynecological diseases and used in functional foods for the prevention and treatment of various diseases, such as inflammation and cancer. The antitumor activity of ASP is related to its biological activities, because it suppresses a variety of pro-proliferative or anti-apoptotic factors that are dramatically expressed in cancer cells of given types. In this study, we show that angelica sinensis polysaccharide induced apoptosis in breast cancer cells of T47D over-expressing the Cyclic AMP response element binding protein (CREB), inducing apoptosis-related signaling pathway activity. The result also found that ASP caused cell death was linked to caspase activity, accompanied by the loss of mitochondrial membrane potential, cytochrome c release, and Bax translocation from the cytosol to the mitochondria. We found that ASP significantly affected the poly-ADP-ribose polymerase (PARP), Bcl-2 Associated X Protein (Bax), Bcl-2, Bcl-xL and apoptotic protease activating facter-1 (Apaf1) protein expression in a dose- and time-dependent manner. DAPI staining and Flow cytometry were used to analyze apoptosis. The nude mice xenograft model was used to evaluate the antitumor effect of ASP in vivo. ASP has profound antitumor effect on T47D cells, probably by inducing apoptosis through CREB signaling pathway. Thus, these results suggest that ASP would be a promising therapeutic agent for breast cancer. - Highlights: • CREB and Caspase-3 signaling pathways are involved in the ASP induced breast cancer cells apoptosis. • ROCK1/Mlc signaling pathway plays a critical role in this ASP-mediated apoptosis. • Angelica sinensis polysaccharide (ASP) affected the PARP, Bax, Bcl-2, Bcl-xL and Apaf1 protein expression. • The activation of CREB and ROCK1 promotes caspase-3 activation and apoptosis induced

  18. Angelica sinensis polysaccharides promotes apoptosis in human breast cancer cells via CREB-regulated caspase-3 activation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Wei-Jie; Wang, Sheng [Department of Breast and Thyroid Surgery, Huaihe Hospital, Henan University, Kaifeng 475000 (China); Hu, Zhuang, E-mail: zhuanghu475000@sina.com [Department of Breast and Thyroid Surgery, Huaihe Hospital, Henan University, Kaifeng 475000 (China); Zhengzhou Center for Disease Control and Prevention, Zhengzhou 475000 (China); Zhou, Zhen-Yu; Song, Cai-Juan [Department of Breast and Thyroid Surgery, Huaihe Hospital, Henan University, Kaifeng 475000 (China); Zhengzhou Center for Disease Control and Prevention, Zhengzhou 475000 (China)

    2015-11-20

    Angelica sinensis polysaccharide (ASP) is purified from the fresh roots of Angelica sinensis (AS). This traditional Chinese medicine has been used for thousands of years for treating gynecological diseases and used in functional foods for the prevention and treatment of various diseases, such as inflammation and cancer. The antitumor activity of ASP is related to its biological activities, because it suppresses a variety of pro-proliferative or anti-apoptotic factors that are dramatically expressed in cancer cells of given types. In this study, we show that angelica sinensis polysaccharide induced apoptosis in breast cancer cells of T47D over-expressing the Cyclic AMP response element binding protein (CREB), inducing apoptosis-related signaling pathway activity. The result also found that ASP caused cell death was linked to caspase activity, accompanied by the loss of mitochondrial membrane potential, cytochrome c release, and Bax translocation from the cytosol to the mitochondria. We found that ASP significantly affected the poly-ADP-ribose polymerase (PARP), Bcl-2 Associated X Protein (Bax), Bcl-2, Bcl-xL and apoptotic protease activating facter-1 (Apaf1) protein expression in a dose- and time-dependent manner. DAPI staining and Flow cytometry were used to analyze apoptosis. The nude mice xenograft model was used to evaluate the antitumor effect of ASP in vivo. ASP has profound antitumor effect on T47D cells, probably by inducing apoptosis through CREB signaling pathway. Thus, these results suggest that ASP would be a promising therapeutic agent for breast cancer. - Highlights: • CREB and Caspase-3 signaling pathways are involved in the ASP induced breast cancer cells apoptosis. • ROCK1/Mlc signaling pathway plays a critical role in this ASP-mediated apoptosis. • Angelica sinensis polysaccharide (ASP) affected the PARP, Bax, Bcl-2, Bcl-xL and Apaf1 protein expression. • The activation of CREB and ROCK1 promotes caspase-3 activation and apoptosis induced

  19. Disruption of the 5S RNP-Mdm2 interaction significantly improves the erythroid defect in a mouse model for Diamond-Blackfan anemia.

    OpenAIRE

    Jaako, Pekka; Debnath, Shubhranshu; Olsson, Karin; Zhang, Y; Flygare, Johan; Lindström, M S; Bryder, David; Karlsson, Stefan

    2015-01-01

    Diamond-Blackfan anemia (DBA) is a congenital erythroid hypoplasia caused by haploinsufficiency of genes encoding ribosomal proteins (RPs). Perturbed ribosome biogenesis in DBA has been shown to induce a p53-mediated ribosomal stress response. However, the mechanisms of p53 activation and its relevance for the erythroid defect remain elusive. Previous studies have indicated that activation of p53 is caused by the inhibition of Mdm2, the main negative regulator of p53, by the 5S ribonucleoprot...

  20. Signaling Pathways in Pathogenesis of Diamond Blackfan Anemia

    Science.gov (United States)

    2014-10-01

    Allergy and Infectious Diseases. This research was funded by NIH National Heart , Lung, and Blood Institute grant R01 HL097561, a St. Baldrick’s Foundation...with anemia, congenital malformations and cancer. p53 mediates many features of DBA, but the mechanism of p53 activation remains unclear. Another...frequently mutated RP in DBA (Boria et al., 2010; Draptchinskaia et al., 1999; Farrar et al., 2011). DBA is associated with anemia, malformations and

  1. Pattern of MAP kinases p44/42 and JNK activation by non-lethal doses of tributyltin in human natural killer cells

    Energy Technology Data Exchange (ETDEWEB)

    Aluoch, Aloice O. [Tennessee State University, Department of Biological Sciences, Nashville, TN (United States); Odman-Ghazi, Sabah O.; Whalen, Margaret M. [Tennessee State University, Department of Chemistry, Nashville, TN (United States)

    2007-04-15

    Tributyltin (TBT) has been shown to disrupt the ability of natural killer (NK) cells to destroy tumor targets in vitro even at exposures of 25 nM for 24 h, but cell viability was not significantly impacted. Thus, evaluation of intracellular molecular events that regulate cell viability in TBT exposed NK cells are of interest. It has been suggested that activation of the mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), may promote apoptosis while activation of the MAPK p44/42 may be crucial in mediating anti-apoptotic stimuli. However, it is well established that increases in pro-apoptotic BCL-2 family members, such as Bax, results in cell death. We have set out to study the effects of a range of TBT concentrations on the MAPKs, JNK and p44/42. Additionally, we examined the effects of TBT on the levels of pro-apoptotic proteins Bax and p53 as well as anti-apoptotic protein Bcl-2. The results show that 300-25 nM TBT activated JNK within 10 min. MAPK p44/42 was also activated by 300-50 nM TBT within 10 min. These data show that while 300-200 nM TBT activates p44/42 significantly more than JNK, the pattern of 100-25 nM TBT activation of these MAPKs may be similar. TBT exposure alters neither pro-apoptotic proteins Bax and p53 nor anti-apoptotic protein Bcl-2 levels at any exposure studied. The results suggest that exposure to TBT activated the anti-apoptotic regulatory p44/42 pathway to a greater extent than the pro-apoptotic JNK pathway, which may explain to some extent how NK cell viability is maintained. (orig.)

  2. The effects of combining ionizing radiation and adenoviral p53 therapy in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Li Jianhua; Lax, Stuart A.; Kim, John; Klamut, Henry; Liu Feifei

    1999-01-01

    Purpose: Nasopharyngeal carcinoma (NPC) is a malignant disease of the head/neck region, with a 5-year survival level of approximately 65%. To explore gene therapy as a novel approach which might improve outcome, we have shown previously that introduction of human recombinant wild-type p53 mediated by the adenoviral vector (Ad5CMV-p53) was cytotoxic in two human nasopharyngeal carcinoma (NPC) cell lines (CNE-1 and CNE-2Z). The current work was designed to determine whether this strategy, combined with ionizing radiation (XRT), was more effective than either treatment alone. Methods and Materials: CNE-1, CNE-2Z, and a normal human nasopharyngeal fibroblast strain, KS1, were infected with 2- and 6-plaque-forming units (pfu)/cell of Ad5CMV-p53, respectively. These doses were iso-effective for β-galactosidase activity in the CNE-1 and CNE-2Z cells. XRT was administered 24 h post-infection, and Western blot analyses were conducted for p53, p21 WAF1/CIP1 , bax, and bcl-2 2 days after XRT. Cell survival was assessed using a clonogenic assay. Presence of DNA ladders reflecting apoptosis was detected using DNA agarose gel electrophoresis, and cell cycle was analyzed using flow cytometry. Results: The combination of Ad5CMV-p53 plus XRT (2, 4, and 6 Gy) resulted in an approximately 1-log greater level of cytotoxicity compared to that observed with XRT alone for both NPC cell lines. The two modalities appear to be interacting in a synergistic manner in cancer cells, but not in KS1 fibroblasts. XRT alone stimulated minimal p53 expression in control cells; Ad5CMV-p53 alone induced significant recombinant p53 expression, which was not further enhanced by the addition of XRT. Similar observations were made for p21 WAF1/CIP1 expression. No changes were observed for bax or bcl-2 expression with any of these treatments. Apoptosis was induced following 4 Gy of XRT alone, but was observed after only 2 Gy when combined with Ad5CMV-p53. Cell cycle analysis indicated that Ad5CMV-p53

  3. Inability of p53-reactivating compounds Nutlin-3 and RITA to overcome p53 resistance in tumor cells deficient in p53Ser46 phosphorylation.

    Science.gov (United States)

    Ma, Teng; Yamada, Shumpei; Ichwan, Solachuddin J A; Iseki, Sachiko; Ohtani, Kiyoshi; Otsu, Megumi; Ikeda, Masa-Aki

    2012-01-20

    The p53 tumor suppressor protein plays key roles in protecting cells from tumorigenesis. Phosphorylation of p53 at Ser46 (p53Ser46) is considered to be a crucial modification regulating p53-mediated apoptosis. Because the activity of p53 is impaired in most human cancers, restoration of wild-type p53 (wt-p53) function by its gene transfer or by p53-reactivating small molecules has been extensively investigated. The p53-reactivating compounds Nutlin-3 and RITA activate p53 in the absence of genotoxic stress by antagonizing the action of its negative regulator Mdm2. Although controversial, Nutlin-3 was shown to induce p53-mediated apoptosis in a manner independent of p53 phosphorylation. Recently, RITA was shown to induce apoptosis by promoting p53Ser46 phosphorylation. Here we examined whether Nutlin-3 or RITA can overcome resistance to p53-mediated apoptosis in p53-resistant tumor cell lines lacking the ability to phosphorylate p53Ser46. We show that Nutlin-3 did not rescue the apoptotic defect of a Ser46 phosphorylation-defective p53 mutant in p53-sensitive tumor cells, and that RITA neither restored p53Ser46 phosphorylation nor induced apoptosis in p53Ser46 phosphorylation-deficient cells retaining wt-p53. Furthermore, treatment with Nutlin-3 or RITA together with adenoviral p53 gene transfer also failed to induce apoptosis in p53Ser46 phosphorylation-deficient cells either expressing or lacking wt-p53. These results indicate that neither Nutlin-3 nor RITA in able to induce p53-mediated apoptosis in the absence of p53Ser46 phosphorylation. Thus, the dysregulation of this phosphorylation in tumor cells may be a critical factor that limits the efficacy of these p53-based cancer therapies. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Altholactone Inhibits NF-κB and STAT3 Activation and Induces Reactive Oxygen Species-Mediated Apoptosis in Prostate Cancer DU145 Cells

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    Chunwa Jiang

    2017-02-01

    Full Text Available Altholactone, a natural compound isolated from Goniothalamus spp., has demonstrated anti-inflammatory and anticancer activities, but its molecular mechanisms are still not fully defined. Nuclear factor kappa B (NF-κB and signal transducer and activator of transcription 3 (STAT3 play pivotal roles in the cell survival of many human tumors. The objective of this study was to elucidate the mechanism of action of altholactone against prostate cancer DU145 cells and to evaluate whether its effects are mediated by inhibition of NF-κB and STAT3 activity. Altholactone inhibited proliferation of DU145 cells and induced cell cycle arrest in S phase and triggered apoptosis. Reporter assays revealed that altholactone repressed p65- and TNF-α-enhanced NF-κB transcriptional activity and also inhibited both constitutive and IL-6-induced transcriptional activity of STAT3. Consistent with this, altholactone down-regulated phosphorylation of STAT3 and moreover, decreased constitutively active mutant of STAT3 (STAT3C-induced transcriptional activity. Altholactone treatment also results in down-regulation of STAT3 target genes such as survivin, and Bcl-2 followed by up regulation of pro-apoptotic Bax protein. However, pre-treatment with the antioxidant N-acetylcysteine (NAC significantly inhibited the activation of Bax and prevented down-regulation of STAT3 target genes. Collectively, our findings suggest that altholactone induces DU145 cells death through inhibition of NF-κB and STAT3 activity.

  5. Acrolein-exposed normal human lung fibroblasts in vitro: cellular senescence, enhanced telomere erosion, and degradation of Werner's syndrome protein.

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    Jang, Jun-Ho; Bruse, Shannon; Huneidi, Salam; Schrader, Ronald M; Monick, Martha M; Lin, Yong; Carter, A Brent; Klingelhutz, Aloysius J; Nyunoya, Toru

    2014-09-01

    Acrolein is a ubiquitous environmental hazard to human health. Acrolein has been reported to activate the DNA damage response and induce apoptosis. However, little is known about the effects of acrolein on cellular senescence. We examined whether acrolein induces cellular senescence in cultured normal human lung fibroblasts (NHLF). We cultured NHLF in the presence or absence of acrolein and determined the effects of acrolein on cell proliferative capacity, senescence-associated β-galactosidase activity, the known senescence-inducing pathways (e.g., p53, p21), and telomere length. We found that acrolein induced cellular senescence by increasing both p53 and p21. The knockdown of p53 mediated by small interfering RNA (siRNA) attenuated acrolein-induced cellular senescence. Acrolein decreased Werner's syndrome protein (WRN), a member of the RecQ helicase family involved in DNA repair and telomere maintenance. Acrolein-induced down-regulation of WRN protein was rescued by p53 knockdown or proteasome inhibition. Finally, we found that acrolein accelerated p53-mediated telomere shortening. These results suggest that acrolein induces p53-mediated cellular senescence accompanied by enhanced telomere attrition and WRN protein down-regulation.

  6. Docosahexaenoic Acid (DHA) Provides Neuroprotection in Traumatic Brain Injury Models via Activating Nrf2-ARE Signaling.

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    Zhu, Wei; Ding, Yuexia; Kong, Wei; Li, Tuo; Chen, Hongguang

    2018-04-16

    In this study, we explored the neuroprotective effects of docosahexaenoic acid (DHA) in traumatic brain injury (TBI) models. In this study, we first confirmed that DHA was neuroprotective against TBI via the NSS test and Morris water maze experiment. Western blot was conducted to identify the expression of Bax, caspase-3, and Bcl-2. And the cell apoptosis of the TBI models was validated by TUNEL staining. Relationships between nuclear factor erythroid 2-related factor 2-antioxidant response element (Nrf2-ARE) pathway-related genes and DHA were explored by RT-PCR and Western blot. Rats of the DHA group performed remarkably better than those of the TBI group in both NSS test and water maze experiment. DHA conspicuously promoted the expression of Bcl-2 and diminished that of cleaved caspase-3 and Bax, indicating the anti-apoptotic role of DHA. Superoxide dismutase (SOD) activity and cortical malondialdehyde content, glutathione peroxidase (GPx) activity were renovated in rats receiving DHA treatment, implying that the neuroprotective influence of DHA was derived from lightening the oxidative stress caused by TBI. Moreover, immunofluorescence and Western blot experiments revealed that DHA facilitated the translocation of Nrf2 to the nucleus. DHA administration also notably increased the expression of the downstream factors NAD(P)H:quinone oxidoreductase (NQO-1) and heme oxygenase 1(HO-1). DHA exerted neuroprotective influence on the TBI models, potentially through activating the Nrf2- ARE pathway.

  7. Activating Nrf-2 signaling depresses unilateral ureteral obstruction-evoked mitochondrial stress-related autophagy, apoptosis and pyroptosis in kidney.

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    Shue Dong Chung

    Full Text Available Exacerbated oxidative stress and inflammation may induce three types of programmed cell death, autophagy, apoptosis and pyroptosis in unilateral ureteral obstruction (UUO kidney. Sulforaphane activating NF-E2-related nuclear factor erythroid-2 (Nrf-2 signaling may ameliorate UUO-induced renal damage. UUO was induced in the left kidney of female Wistar rats. The level of renal blood flow, cortical and medullary oxygen tension and reactive oxygen species (ROS was evaluated. Fibrosis, ED-1 (macrophage/monocyte infiltration, oxidative stress, autophagy, apoptosis and pyroptosis were evaluated by immunohistochemistry and Western blot in UUO kidneys. Effects of sulforaphane, an Nrf-2 activator, on Nrf-2- and mitochondrial stress-related proteins and renal injury were examined. UUO decreased renal blood flow and oxygen tension and increased renal ROS, 3-nitrotyrosine stain, ED-1 infiltration and fibrosis. Enhanced renal tubular Beclin-1 expression started at 4 h UUO and further enhanced at 3d UUO, whereas increased Atg-5-Atg12 and LC3-II expression were found at 3d UUO. Increased renal Bax/Bcl-2 ratio, caspase 3 and PARP fragments, apoptosis formation associated with increased caspase 1 and IL-1β expression for pyroptosis formation were started from 3d UUO. UUO reduced nuclear Nrf-2 translocation, increased cytosolic and inhibitory Nrf-2 expression, increased cytosolic Bax translocation to mitochondrial and enhanced mitochondrial Cytochrome c release into cytosol of the UUO kidneys. Sulforaphane significantly increased nuclear Nrf-2 translocation and decreased mitochondrial Bax translocation and Cytochrome c release into cytosol resulting in decreased renal injury. In conclusion, sulforaphane via activating Nrf-2 signaling preserved mitochondrial function and suppressed UUO-induced renal oxidative stress, inflammation, fibrosis, autophagy, apoptosis and pyroptosis.

  8. The Coordinated P53 and Estrogen Receptor Cis-Regulation at an FLT1 Promoter SNP Is Specific to Genotoxic Stress and Estrogenic Compound

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    Langen, Jan-Stephan; Schoenfelder, Gilbert; Resnick, Michael A.; Inga, Alberto

    2010-01-01

    Background Recently, we established that a C>T single nucleotide polymorphism (SNP) in the promoter of the VEGF receptor FLT1 gene generates a ½ site p53 response element (RE-T) that results in p53 responsiveness of the promoter. The transcriptional control required an estrogen receptor (ER) ½ site response element (ERE1) 225 nt upstream to the RE-T. Methodology/Principal Findings Here we report the identification of a second ER ½ site (ERE2) located 145 bp downstream of the RE-T and establish that both EREs can impact p53-mediated transactivation of FLT1-T in a manner that is cell type and ER level dependent. Gene reporter assays and ChIP experiments conducted in the breast cancer-derived MCF7 cells revealed that the ERE2 site was sufficient for p53-mediated ERα recruitment and transactivation of the FLT1-T promoter/reporter construct. Surprisingly, unlike the case for other p53 target promoters, p53-mediated transactivation of FLT1-T constructs or expression of the endogenous FLT1 gene, as well as binding of p53 and ER at the promoter constructs, was inducible by doxorubicin but not by 5-fluorouracil. Furthermore, ER activity at FLT1-T was differentially affected by ER ligands, compared to a control TFF1/pS2 ER target promoter. The p53-related transcription factors (TFs) p73 and p63 had no effect on FLT1 transactivation. Conclusions/Significance We establish a new dimension to the p53 master regulatory network where p53-mediated transcription from a ½ site RE can be determined by ER binding at one or more cis-acting EREs in manner that is dependent on level of ER protein, the type of ER ligand and the specific p53-inducing agent. PMID:20422012

  9. Caspase activity and apoptotic signaling in proliferating C2C12 cells following cisplatin or A23187 exposure

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    Darin Bloemberg

    2016-06-01

    Full Text Available Investigating cell death signaling using cell culture is commonly performed to examine the effects of novel pharmaceuticals or to further characterize discrete cellular signaling pathways. Here, we provide data regarding the cell death response to either cisplatin or A23187 in sub-confluent C2C12 cells, by utilizing several concentrations and incubation times for each chemical. These data include an assessment of the activation of the proteolytic enzymes caspase-3, caspase-8, caspase-9, calpain, and cathepsin B/L. Additionally, the expression of the apoptosis-regulating proteins Bax, Bcl2, and p53 are presented.

  10. Effects of low dose radiation on differentiation, activation and apoptosis of thymocytes in mice

    International Nuclear Information System (INIS)

    Su Xu; Zhang Yingchun; Wan Hong; Liu Shuzheng

    1997-01-01

    Objective: To elucidate the possible mechanism of immunoenhancement after low dose radiation (LDR), the differentiation, activation and apoptosis of thymocytes following low dose irradiation were studied. Method: Kunming mice were whole-body irradiated (WBI) with low dose X-rays. The expressions of CD4, CD8, TCR, CD3, IL-2R, (Ca 2+ ) i , Bcl-2 Bax and apoptosis of thymocytes were analyzed by flow cytometry. Results: It was found that the ratio of T H /T S showed no significant changes after LDR. Thymocyte apoptosis was not increased after LDR. The increase of Bcl-2/Bax ratio after LDR might be one of its mechanisms. LDR could expedites the process of differentiation of, and facilitate the signal transduction in, thymocytes. Conclusion: The results indicate that the mechanism of immunoenhancement might be related to the expedition of the maturation, differentiation and activation of thymocytes, thus up-regulating the capability of supplying more mature T lymphocytes to the periphery by the thymus after LDR

  11. Anticancer Activity of a Hexapeptide from Skate (Raja porosa Cartilage Protein Hydrolysate in HeLa Cells

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    Xin Pan

    2016-08-01

    Full Text Available In this study, the hexapeptide Phe-Ile-Met-Gly-Pro-Tyr (FIMGPY, which has a molecular weight of 726.9 Da, was separated from skate (Raja porosa cartilage protein hydrolysate using ultrafiltration and chromatographic methods, and its anticancer activity was evaluated in HeLa cells. Methylthiazolyldiphenyl-tetrazolium bromide (MTT assay indicated that FIMGPY exhibited high, dose-dependent anti-proliferation activities in HeLa cells with an IC50 of 4.81 mg/mL. Acridine orange/ethidium bromide (AO/EB fluorescence staining and flow cytometry methods confirmed that FIMGPY could inhibit HeLa cell proliferation by inducing apoptosis. Western blot assay revealed that the Bax/Bcl-2 ratio and relative intensity of caspase-3 in HeLa cells treated with 7-mg/mL FIMGPY were 2.63 and 1.83, respectively, significantly higher than those of the blank control (p < 0.01. Thus, FIMGPY could induce apoptosis by upregulating the Bax/Bcl-2 ratio and caspase-3 activation. Using a DNA ladder method further confirmed that the anti-proliferation activity of FIMGPY was attributable to its role in inducing apoptosis. These results suggest that FIMGPY from skate cartilage protein hydrolysate may have applications as functional foods and nutraceuticals for the treatment and prevention of cancer.

  12. Evaluation of in vitro anticancer activity of Ocimum basilicum, Alhagi maurorum, Calendula officinalis and their parasite Cuscuta campestris.

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    Behbahani, Mandana

    2014-01-01

    The present investigation was carried out to study the relationship between presence of cytotoxic compounds in Ocimum basilicum, Alhagi maurorum, Calendula officinalis and their parasite Cuscuta campestris. The cytotoxic activity of the pure compounds was performed by MTT assay against breast cancer cell lines (MCF-7 and MDA-MB-231) and normal breast cell line (MCF 10A). The induction of apoptosis was measured by the expression levels of p53, bcl-2, bax and caspase-3 genes using quantitative Real Time PCR. Three active fractions were detected by nuclear magnetic resonance as lutein, lupeol and eugenol, respectively, in C. officinalis, A. maurorum and O. basilicum. These compounds and their epoxidized forms were also detected in their parasite C. campestris. The cytotoxic activity of lutein epoxide, lupeol epoxide and eugenol epoxide was significantly more than lutein, lupeol and eugenol. The mRNA expression level of p53, caspase-3 and bax genes were increased in both cancer cells treated with all pure compounds. However, bcl-2 gene expression decreased in treated breast cancer cells. In conclusion, all the data indicated that the epoxide forms of lupeol, lutein and eugenol are potential drug candidates for inducing apoptosis in human breast cancer cells.

  13. Evaluation of in vitro anticancer activity of Ocimum basilicum, Alhagi maurorum, Calendula officinalis and their parasite Cuscuta campestris.

    Directory of Open Access Journals (Sweden)

    Mandana Behbahani

    Full Text Available The present investigation was carried out to study the relationship between presence of cytotoxic compounds in Ocimum basilicum, Alhagi maurorum, Calendula officinalis and their parasite Cuscuta campestris. The cytotoxic activity of the pure compounds was performed by MTT assay against breast cancer cell lines (MCF-7 and MDA-MB-231 and normal breast cell line (MCF 10A. The induction of apoptosis was measured by the expression levels of p53, bcl-2, bax and caspase-3 genes using quantitative Real Time PCR. Three active fractions were detected by nuclear magnetic resonance as lutein, lupeol and eugenol, respectively, in C. officinalis, A. maurorum and O. basilicum. These compounds and their epoxidized forms were also detected in their parasite C. campestris. The cytotoxic activity of lutein epoxide, lupeol epoxide and eugenol epoxide was significantly more than lutein, lupeol and eugenol. The mRNA expression level of p53, caspase-3 and bax genes were increased in both cancer cells treated with all pure compounds. However, bcl-2 gene expression decreased in treated breast cancer cells. In conclusion, all the data indicated that the epoxide forms of lupeol, lutein and eugenol are potential drug candidates for inducing apoptosis in human breast cancer cells.

  14. Galectin-3 silencing inhibits epirubicin-induced ATP binding cassette transporters and activates the mitochondrial apoptosis pathway via β-catenin/GSK-3β modulation in colorectal carcinoma.

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    Yung-Kuo Lee

    Full Text Available Multidrug resistance (MDR, an unfavorable factor compromising the treatment efficacy of anticancer drugs, involves the upregulation of ATP binding cassette (ABC transporters and induction of galectin-3 signaling. Galectin-3 plays an anti-apoptotic role in many cancer cells and regulates various pathways to activate MDR. Thus, the inhibition of galectin-3 has the potential to enhance the efficacy of the anticancer drug epirubicin. In this study, we examined the effects and mechanisms of silencing galectin-3 via RNA interference (RNAi on the β-catenin/GSK-3β pathway in human colon adenocarcinoma Caco-2 cells. Galectin-3 knockdown increased the intracellular accumulation of epirubicin in Caco-2 cells; suppressed the mRNA expression of galectin-3, β-catenin, cyclin D1, c-myc, P-glycoprotein (P-gp, MDR-associated protein (MRP 1, and MRP2; and downregulated the protein expression of P-gp, cyclin D1, galectin-3, β-catenin, c-Myc, and Bcl-2. Moreover, galectin-3 RNAi treatment significantly increased the mRNA level of GSK-3β, Bax, caspase-3, and caspase-9; remarkably increased the Bax-to-Bcl-2 ratio; and upregulated the GSK-3β and Bax protein expressions. Apoptosis was induced by galectin-3 RNAi and/or epirubicin as demonstrated by chromatin condensation, a higher sub-G1 phase proportion, and increased caspase-3 and caspase-9 activity, indicating an intrinsic/mitochondrial apoptosis pathway. Epirubicin-mediated resistance was effectively inhibited via galectin-3 RNAi treatment. However, these phenomena could be rescued after galectin-3 overexpression. We show for the first time that the silencing of galectin-3 sensitizes MDR cells to epirubicin by inhibiting ABC transporters and activating the mitochondrial pathway of apoptosis through modulation of the β-catenin/GSK-3β pathway in human colon cancer cells.

  15. Allergen-Removed Rhus verniciflua Extract Induces Ovarian Cancer Cell Death via JNK Activation.

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    Kang, Se-Hui; Hwang, In-Hu; Son, Eunju; Cho, Chong-Kwan; Choi, Jong-Soon; Park, Soo-Jung; Jang, Byeong-Churl; Lee, Kyung-Bok; Lee, Zee-Won; Lee, Jong Hoon; Yoo, Hwa-Seung; Jang, Ik-Soon

    2016-01-01

    Nuclear factor-[Formula: see text]B (NF-[Formula: see text]B)/Rel transcription factors are best known for their central roles in promoting cell survival in cancer. NF-[Formula: see text]B antagonizes tumor necrosis factor (TNF)-[Formula: see text]-induced apoptosis through a process involving attenuation of the c-Jun-N-terminal kinase (JNK). However, the role of JNK activation in apoptosis induced by negative regulation of NF-[Formula: see text]B is not completely understood. We found that allergen-removed Rhus verniciflua Stokes (aRVS) extract-mediated NF-[Formula: see text]B inhibition induces apoptosis in SKOV-3 ovarian cancer cells via the serial activation of caspases and SKOV-3 cells are most specifically suppressed by aRVS. Here, we show that in addition to activating caspases, aRVS extract negatively modulates the TNF-[Formula: see text]-mediated I[Formula: see text]B/NF-[Formula: see text]B pathway to promote JNK activation, which results in apoptosis. When the cytokine TNF-[Formula: see text] binds to the TNF receptor, I[Formula: see text]B dissociates from NF-[Formula: see text]B. As a result, the active NF-[Formula: see text]B translocates to the nucleus. aRVS extract (0.5[Formula: see text]mg/ml) clearly prevented NF-[Formula: see text]B from mobilizing to the nucleus, resulting in the upregulation of JNK phosphorylation. This subsequently increased Bax activation, leading to marked aRVS-induced apoptosis, whereas the JNK inhibitor SP600125 in aRVS extract treated SKOV-3 cells strongly inhibited Bax. Bax subfamily proteins induced apoptosis through caspase-3. Thus, these results indicate that aRVS extract contains components that inhibit NF-[Formula: see text]B signaling to upregulate JNK activation in ovarian cancer cells and support the potential of aRVS as a therapeutic agent for ovarian cancer.

  16. Hippocampal mitogen-activated protein kinase activation is associated with intermittent hypoxia in a rat model of obstructive sleep apnea syndrome.

    Science.gov (United States)

    Zhao, Ya-Ning; Wang, Hong-Yang; Li, Jian-Min; Chen, Bao-Yuan; Xia, Guo; Zhang, Pan-Pan; Ge, Yan-Lei

    2016-01-01

    Obstructive sleep apnea syndrome (OSAS), characterized by intermittent hypoxia/re‑oxygenation, may impair the cerebral system. Although mitogen‑activated protein kinase (MAPK) signaling was observed to have a key role in hypoxia‑induced brain injury, the intracellular events and their underlying mechanisms for intermittent hypoxia/re‑oxygenation-associated damage to hippocamal MAPKs, including extracellular signal‑regulated kinase (ERK)1/2, P38MAPK and c‑Jun N‑terminal kinase (JNK) remain to be elucidated and require further investigation. A total of five rats in each sub‑group were exposed to intermittent hypoxia or continued hypoxia for 2, 4, 6 or 8 weeks. Histological, immunohistochemical and biological analyses were performed to assess nerve cell injury in the hippocampus. Surviving CA1 pyramidal cells were identified by hematoxylin and eosin staining. The levels of phosphorylated ERK1/2, P38MAPK and JNK were detected by western blotting. B‑cell lymphoma 2 (Bcl‑2) and Bcl‑2‑associated X protein (Bax) in neural cells were examined by immunohistochemistry. The malondialdehyde (MDA) contents and superoxide dismutase (SOD) activities were measured by thiobarbituric acid and xanthine oxidation methods, respectively. Under continued hypoxia, the levels of phospho‑ERK1/2 peaked at the fourth week and then declined, whereas phospho‑P38MAPK and JNK were detected only in the late stages. By contrast, under intermittent hypoxia, ERK1/2, P38MAPK and JNK were activated at all time-points assessed (2, 4, 6 and 8 weeks). The levels of phospho‑ERK1/2, P38MAPK and JNK were all higher in the intermittent hypoxia groups than those in the corresponding continued hypoxia groups. Bcl‑2 was mainly increased and reached the highest level at six weeks in the continued hypoxia group. Of note, Bcl‑2 rapidly increased to the peak level at four weeks, followed by a decrease to the lowest level at the eighth week in the intermittent hypoxia group. Bax was

  17. THE EFFECT OF CURCUMIN ON SECRETORY ACTIVITY, PROLIFERATION AND APOPTOSIS OF THE PORCINE OVARIAN GRANULOSA CELLS

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    Attila Kádasi

    2012-08-01

    Full Text Available The aim of this in vitro study was to examine the effect of natural plant (Curcuma longa molecule curcumin on secretory activity, proliferation and apoptosis of porcine granulosa cells. The secretion of steroid hormones (progesterone, testosterone, accumulation of PCNA (marker of proliferation and bax (marker of apoptosis in granulosa cells of swine ovaries after curcumin treatment at the doses 0, 1, 10, 100 μg.mL-1 was determined by RIA and immunocytochemistry. It was observed that, addition of curcumin stimulated progesterone (at doses 1 and 10 μg.mL-1, but not 100 μg.mL-1 and testosterone at (100 μg.mL-1 but not 1 and 10 μg.mL-1 release. The number of cells contained PCNA was down-regulated by curcumin administration (at dose of 10 μg.mL-1, but not of 1 and 100 μg.mL-1. Bax expression was stimulated by curcumin at all doses added. Our results suggest a direct effect of curcumin on ovarian functions: steroidogenesis, proliferation and apoptosis. This could suggest antireproductive properties of curcumin in swine ovaries.

  18. The natural triterpene maslinic acid induces apoptosis in HT29 colon cancer cells by a JNK-p53-dependent mechanism

    International Nuclear Information System (INIS)

    Reyes-Zurita, Fernando J; Pachón-Peña, Gisela; Lizárraga, Daneida; Rufino-Palomares, Eva E; Cascante, Marta; Lupiáñez, José A

    2011-01-01

    Maslinic acid, a pentacyclic triterpene found in the protective wax-like coating of the leaves and fruit of Olea europaea L., is a promising agent for the prevention of colon cancer. We have shown elsewhere that maslinic acid inhibits cell proliferation to a significant extent and activates mitochondrial apoptosis in colon cancer cells. In our latest work we have investigated further this compound's apoptotic molecular mechanism. We used HT29 adenocarcinoma cells. Changes genotoxicity were analyzed by single-cell gel electrophoresis (comet assay). The cell cycle was determined by flow cytometry. Finally, changes in protein expression were examined by western blotting. Student's t-test was used for statistical comparison. HT29 cells treated with maslinic acid showed significant increases in genotoxicity and cell-cycle arrest during the G0/G1 phase after 72 hours' treatment and an apoptotic sub-G0/G1 peak after 96 hours. Nevertheless, the molecular mechanism for this cytotoxic effect of maslinic acid has never been properly explored. We show here that the anti-tumoral activity of maslinic acid might proceed via p53-mediated apoptosis by acting upon the main signaling components that lead to an increase in p53 activity and the induction of the rest of the factors that participate in the apoptotic pathway. We found that in HT29 cells maslinic acid activated the expression of c-Jun NH2-terminal kinase (JNK), thus inducing p53. Treatment of tumor cells with maslinic acid also resulted in an increase in the expression of Bid and Bax, repression of Bcl-2, release of cytochrome-c and an increase in the expression of caspases -9, -3, and -7. Moreover, maslinic acid produced belated caspase-8 activity, thus amplifying the initial mitochondrial apoptotic signaling. All these results suggest that maslinic acid induces apoptosis in human HT29 colon-cancer cells through the JNK-Bid-mediated mitochondrial apoptotic pathway via the activation of p53. Thus we propose

  19. Non-secreted clusterin isoforms are translated in rare amounts from distinct human mRNA variants and do not affect Bax-mediated apoptosis or the NF-κB signaling pathway.

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    Hans Prochnow

    Full Text Available Clusterin, also known as apolipoprotein J, is expressed from a variety of tissues and implicated in pathological disorders such as neurodegenerative diseases, ischemia and cancer. In contrast to secretory clusterin (sCLU, which acts as an extracellular chaperone, the synthesis, subcellular localization and function(s of intracellular CLU isoforms is currently a matter of intense discussion. By investigating human CLU mRNAs we here unravel mechanisms leading to the synthesis of distinct CLU protein isoforms and analyze their subcellular localization and their impact on apoptosis and on NF-κB-activity. Quantitative PCR-analyses revealed the expression of four different stress-inducible CLU mRNA variants in non-cancer and cancer cell lines. In all cell lines variant 1 represents the most abundant mRNA, whereas all other variants collectively account for no more than 0.34% of total CLU mRNA, even under stressed conditions. Overexpression of CLU cDNAs combined with in vitro mutagenesis revealed distinct translational start sites including a so far uncharacterized non-canonical CUG start codon. We show that all exon 2-containing mRNAs encode sCLU and at least three non-glycosylated intracellular isoforms, CLU1‑449, CLU21‑449 and CLU34‑449, which all reside in the cytosol of unstressed and stressed HEK‑293 cells. The latter is the only form expressed from an alternatively spliced mRNA variant lacking exon 2. Functional analysis revealed that none of these cytosolic CLU forms modulate caspase-mediated intrinsic apoptosis or significantly affects TNF-α-induced NF-κB-activity. Therefore our data challenge some of the current ideas regarding the physiological functions of CLU isoforms in pathologies.

  20. Anticancer activity of Pupalia lappacea on chronic myeloid leukemia K562 cells.

    Science.gov (United States)

    Ravi, Alvala; Alvala, Mallika; Sama, Venkatesh; Kalle, Arunasree M; Irlapati, Vamshi K; Reddy, B Madhava

    2012-12-05

    Cancer is one of the most prominent human diseases which has enthused scientific and commercial interest in the discovery of newer anticancer agents from natural sources. Here we demonstrated the anticancer activity of ethanolic extract of aerial parts of Pupalia lappacea (L) Juss (Amaranthaceae) (EAPL) on Chronic Myeloid Leukemia K562 cells. Antiproliferative activity of EAPL was determined by MTT assay using carvacrol as a positive control. Induction of apoptosis was studied by annexin V, mitochondrial membrane potential, caspase activation and cell cycle analysis using flow cytometer and modulation in protein levels of p53, PCNA, Bax and Bcl2 ratio, cytochrome c and cleavage of PARP were studied by Western blot analysis. The standardization of the extract was performed through reverse phase-HPLC using Rutin as biomarker. The results showed dose dependent decrease in growth of K562 cells with an IC50 of 40 ± 0.01 μg/ml by EAPL. Induction of apoptosis by EAPL was dose dependent with the activation of p53, inhibition of PCNA, decrease in Bcl2/Bax ratio, decrease in the mitochondrial membrane potential resulting in release of cytochrome c, activation of multicaspase and cleavage of PARP. Further HPLC standardization of EAPL showed presence 0.024% of Rutin. Present study significantly demonstrates anticancer activity of EAPL on Chronic Myeloid Leukemia (K562) cells which can lead to potential therapeutic agent in treating cancer. Rutin, a known anti cancer compound is being reported and quantified for the first time from EAPL.

  1. 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

  2. Opposite effects of Ha-Ras and Ki-Ras on radiation-induced apoptosis via differential activation of PI3K/Akt and Rac/p38 mitogen-activated protein kinase signaling

    International Nuclear Information System (INIS)

    Choi, J.-A.; Kang, C.-M.; Lee, Y.-S.; Lee, S.-J.; Bae, S.-W.; Cho, C.-K.

    2003-01-01

    It has been well known that Ras signaling is involved in various cellular processes, including proliferation, differentiation, and apoptosis. However, distinct cellular functions of Ras isozymes are not fully understood. Here we show the opposing roles of Ha-Ras and Ki-Ras genes in the modulation of cell sensitivity to ionizing radiation. Overexpression of active isoform of Ha-Ras (12V-Ha- Ras) in Rat2 cells increases resistance to the ionizing radiation. Constitutive activation of phosphoinositide-3-kinase (PI3K) and Akt is detected specifically in 12V-Ha-Ras-overexpressing cells. The specific PI3K inhibitor LY294002 inhibits PI3K/Akt signaling and potentiates the radiation-induced apoptosis, suggesting that activation of PI3K/Akt signaling pathway is involved in the increased radio-resistance in cells overexpressing 12V-Ha-Ras. Overexpression of activated Ki-Ras (12V-Ki-Ras), on the other hand, markedly increases radiation sensitivity. The p38 mitogen-activated protein (MAP) kinase activity is selectively enhanced by ionizing radiation in cells overexpressing 12V-Ki-Ras. The specific p38 MAP kinase inhibitor, PD169316, or dominant-negative p38 MAP kinase decreases radiation-induced cell death. We further show that the mechanism that underlies potentiation of cell death in cells overexpressing 12V-Ki-Ras involves Bax translocation to the mitochondrial membrane. Elevated Bax translocation following ionizing irradiation in 12V-Ki-Ras-overexpressing cells is completely inhibited by PD169316 or dominant-negative p38 MAP kinase. In addition, introduction of cells with RacN17, a dominant negative mutant of Rac, resulted in a marked inhibition of radiation-induced Bax translocation and apoptotic cell death as well as p38 MAP kinase activation. Taken together, these findings explain the opposite effects of Ha-Ras and Ki-Ras on modulation of radio-sensitivity, and suggest that differential activation of PI3K/Akt and Rac/p38 MAP kinase signaling by Ha-Ras and Ki-Ras may

  3. Disruption of redox homeostasis in liver function and activation of apoptosis on consumption of aspartame in folate deficient rat model

    Directory of Open Access Journals (Sweden)

    Ashok Iyaswamy

    2017-06-01

    Full Text Available This study assesses the effect of long-term intake of aspartame on liver function and apoptosis signaling pathway in the Wistar albino rats. Several reports have suggested that methanol is one of the major metabolites of Aspartame. Non-primate animals are usually resistant to methanol-induced metabolic acidosis due to high levels of hepatic folate content; hence a folate deficiency model was induced by treating animals with methotrexate (MTX prior to aspartame exposure. The aspartame treated MTX animals exhibited a marked significant increase in hepatic alanine transaminase (ALT, aspartate transaminase (AST, alkaline phosphatase (ALP and lactic acid dehydrogenase (LDH activity compared to controls. Aspartame treated MTX animals additionally exhibited down-regulation of genes namely B-cell lymphoma 2 (Bcl2 expression and up-regulation of Bcl-2-associated X protein (Bax, Fas-associated protein with death domain (FADD and Caspase 3, 9 genes and apoptotic protein expression, indicating the augmentation of hepatic apoptosis. Nuclear condensation, micro vacuole formation in the cytoplasm and necrosis were observed in the liver of the aspartame treated animals on histopathology evaluation. Additionally, Immunohistochemical analysis revealed a significant increase in positive cells expressing Fas, FADD, Bax and Caspase 9 protein, indicating an increase in apoptotic protein expression in the liver. Thus, Aspartame may act as a chemical stressor which alters the functional status of liver, leading to hepatotoxicity.

  4. Troxerutin Reduces Kidney Damage against BDE-47-Induced Apoptosis via Inhibiting NOX2 Activity and Increasing Nrf2 Activity

    Directory of Open Access Journals (Sweden)

    Qun Shan

    2017-01-01

    Full Text Available 2,2,4,4-Tetrabromodiphenyl ether (BDE-47, one of the persistent organic pollutants, seriously influences the quality of life; however, its pathological mechanism remains unclear. Troxerutin is a flavonoid with pharmacological activity of antioxidation and anti-inflammation. In the present study, we investigated troxerutin against BDE-47-induced kidney cell apoptosis and explored the underlying mechanism. The results show that troxerutin reduced renal cell apoptosis and urinary protein secretion in BDE-47-treated mice. Western blot analysis shows that troxerutin supplement enhanced the ratio of Bcl-2/Bax; inhibited the release of cytochrome c from mitochondria, the activation of procaspase-9 and procaspase-3, and the cleavage of PARP; and reduced FAS, FASL, and caspase-8 levels induced by BDE-47. In addition, troxerutin decreased the production of reactive oxygen species (ROS and increased the activities of antioxidative enzymes. Furthermore, troxerutin blunted Nrf2 ubiquitylation, enhanced the activity of Nrf2, decreased the activity of NOX2, and ameliorated kidney oxidant status of BDE-47-treated mice. Together, these results confirm that troxerutin could alleviate the cytotoxicity of BDE-47 through antioxidation and antiapoptosis, which suggests that its protective mechanism is involved in the inhibition of apoptosis via suppressing NOX2 activity and increasing Nrf2 signaling pathway.

  5. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. 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

  8. Menadione triggers cell death through ROS-dependent mechanisms involving PARP activation without requiring apoptosis.

    Science.gov (United States)

    Loor, Gabriel; Kondapalli, Jyothisri; Schriewer, Jacqueline M; Chandel, Navdeep S; Vanden Hoek, Terry L; Schumacker, Paul T

    2010-12-15

    Low levels of reactive oxygen species (ROS) can function as redox-active signaling messengers, whereas high levels of ROS induce cellular damage. Menadione generates ROS through redox cycling, and high concentrations trigger cell death. Previous work suggests that menadione triggers cytochrome c release from mitochondria, whereas other studies implicate the activation of the mitochondrial permeability transition pore as the mediator of cell death. We investigated menadione-induced cell death in genetically modified cells lacking specific death-associated proteins. In cardiomyocytes, oxidant stress was assessed using the redox sensor RoGFP, expressed in the cytosol or the mitochondrial matrix. Menadione elicited rapid oxidation in both compartments, whereas it decreased mitochondrial potential and triggered cytochrome c redistribution to the cytosol. Cell death was attenuated by N-acetylcysteine and exogenous glutathione or by overexpression of cytosolic or mitochondria-targeted catalase. By contrast, no protection was observed in cells overexpressing Cu,Zn-SOD or Mn-SOD. Overexpression of antiapoptotic Bcl-X(L) protected against staurosporine-induced cell death, but it failed to confer protection against menadione. Genetic deletion of Bax and Bak, cytochrome c, cyclophilin D, or caspase-9 conferred no protection against menadione-induced cell death. However, cells lacking PARP-1 showed a significant decrease in menadione-induced cell death. Thus, menadione induces cell death through the generation of oxidant stress in multiple subcellular compartments, yet cytochrome c, Bax/Bak, caspase-9, and cyclophilin D are dispensable for cell death in this model. These studies suggest that multiple redundant cell death pathways are activated by menadione, but that PARP plays an essential role in mediating each of them. Copyright © 2010 Elsevier Inc. All rights reserved.

  9. Neurotrophin receptors expression and JNK pathway activation in human astrocytomas

    Directory of Open Access Journals (Sweden)

    Maraziotis Theodore

    2007-10-01

    Full Text Available Abstract Background Neurotrophins are growth factors that regulate cell growth, differentiation and apoptosis in the nervous system. Their diverse actions are mediated through two different transmembrane – receptor signaling systems: Trk receptor tyrosine kinases (TrkA, TrkB, TrkC and p75NTR neurotrophin receptor. Trk receptors promote cell survival and differentiation while p75NTR induces, in most cases, the activity of JNK-p53-Bax apoptosis pathway or suppresses intracellular survival signaling cascades. Robust Trk activation blocks p75NTR -induced apoptosis by suppressing the JNK-p53-Bax pathway. The aim of this exploratory study was to investigate the expression levels of neurotrophin receptors, Trks and p75NTR, and the activation of JNK pathway in human astrocytomas and in adjacent non-neoplastic brain tissue. Methods Formalin-fixed paraffin-embedded serial sections from 33 supratentorial astrocytomas (5 diffuse fibrillary astrocytomas, WHO grade II; 6 anaplastic astrocytomas, WHO grade III; 22 glioblastomas multiforme, WHO grade IV were immunostained following microwave pretreatment. Polyclonal antibodies against TrkA, TrkB, TrkC and monoclonal antibodies against p75NTR and phosphorylated forms of JNK (pJNK and c-Jun (pc-Jun were used. The labeling index (LI, defined as the percentage of positive (labeled cells out of the total number of tumor cells counted, was determined. Results Moderate to strong, granular cytoplasmic immunoreactivity for TrkA, TrkB and TrkC receptors was detected in greater than or equal to 10% of tumor cells in the majority of tumors independently of grade; on the contrary, p75NTR receptor expression was found in a small percentage of tumor cells (~1% in some tumors. The endothelium of tumor capillaries showed conspicuous immunoreactivity for TrkB receptor. Trk immunoreactivity seemed to be localized in some neurons and astrocytes in non-neoplastic tissue. Phosphorylated forms of JNK (pJNK and c-Jun (pc-Jun were

  10. Neurotrophin receptors expression and JNK pathway activation in human astrocytomas

    International Nuclear Information System (INIS)

    Assimakopoulou, Martha; Kondyli, Maria; Gatzounis, George; Maraziotis, Theodore; Varakis, John

    2007-01-01

    Neurotrophins are growth factors that regulate cell growth, differentiation and apoptosis in the nervous system. Their diverse actions are mediated through two different transmembrane – receptor signaling systems: Trk receptor tyrosine kinases (TrkA, TrkB, TrkC) and p75 NTR neurotrophin receptor. Trk receptors promote cell survival and differentiation while p75 NTR induces, in most cases, the activity of JNK-p53-Bax apoptosis pathway or suppresses intracellular survival signaling cascades. Robust Trk activation blocks p75 NTR -induced apoptosis by suppressing the JNK-p53-Bax pathway. The aim of this exploratory study was to investigate the expression levels of neurotrophin receptors, Trks and p75 NTR , and the activation of JNK pathway in human astrocytomas and in adjacent non-neoplastic brain tissue. Formalin-fixed paraffin-embedded serial sections from 33 supratentorial astrocytomas (5 diffuse fibrillary astrocytomas, WHO grade II; 6 anaplastic astrocytomas, WHO grade III; 22 glioblastomas multiforme, WHO grade IV) were immunostained following microwave pretreatment. Polyclonal antibodies against TrkA, TrkB, TrkC and monoclonal antibodies against p75 NTR and phosphorylated forms of JNK (pJNK) and c-Jun (pc-Jun) were used. The labeling index (LI), defined as the percentage of positive (labeled) cells out of the total number of tumor cells counted, was determined. Moderate to strong, granular cytoplasmic immunoreactivity for TrkA, TrkB and TrkC receptors was detected in greater than or equal to 10% of tumor cells in the majority of tumors independently of grade; on the contrary, p75 NTR receptor expression was found in a small percentage of tumor cells (~1%) in some tumors. The endothelium of tumor capillaries showed conspicuous immunoreactivity for TrkB receptor. Trk immunoreactivity seemed to be localized in some neurons and astrocytes in non-neoplastic tissue. Phosphorylated forms of JNK (pJNK) and c-Jun (pc-Jun) were significantly co-expressed in a tumor

  11. Activated charcoal filter effectively reduces p-benzosemiquinone ...

    Indian Academy of Sciences (India)

    Prakash

    is irreversible and currently there is no effective treatment aimed at curing this fatal ..... overexpression of Bax, a member of the Bcl-2 family. After treatment with ..... consequences of smoking: nicotine addiction: a report of the. Surgeon General ...

  12. B cell lymphoma-2 (BCL-2) homology domain 3 (BH3) mimetics demonstrate differential activities dependent upon the functional repertoire of pro- and anti-apoptotic BCL-2 family proteins.

    Science.gov (United States)

    Renault, Thibaud T; Elkholi, Rana; Bharti, Archana; Chipuk, Jerry E

    2014-09-19

    The B cell lymphoma-2 (BCL-2) family is the key mediator of cellular sensitivity to apoptosis during pharmacological interventions for numerous human pathologies, including cancer. There is tremendous interest to understand how the proapoptotic BCL-2 effector members (e.g. BCL-2-associated X protein, BAX) cooperate with the BCL-2 homology domain only (BH3-only) subclass (e.g. BCL-2 interacting mediator of death, BIM; BCL-2 interacting-domain death agonist, BID) to induce mitochondrial outer membrane permeabilization (MOMP) and apoptosis and whether these mechanisms may be pharmacologically exploited to enhance the killing of cancer cells. Indeed, small molecule inhibitors of the anti-apoptotic BCL-2 family members have been designed rationally. However, the success of these "BH3 mimetics" in the clinic has been limited, likely due to an incomplete understanding of how these drugs function in the presence of multiple BCL-2 family members. To increase our mechanistic understanding of how BH3 mimetics cooperate with multiple BCL-2 family members in vitro, we directly compared the activity of several BH3-mimetic compounds (i.e. ABT-263, ABT-737, GX15-070, HA14.1, TW-37) in biochemically defined large unilamellar vesicle model systems that faithfully recapitulate BAX-dependent mitochondrial outer membrane permeabilization. Our investigations revealed that the presence of BAX, BID, and BIM differentially regulated the ability of BH3 mimetics to derepress proapoptotic molecules from anti-apoptotic proteins. Using mitochondria loaded with fluorescent BH3 peptides and cells treated with inducers of cell death, these differences were supported. Together, these data suggest that although the presence of anti-apoptotic BCL-2 proteins primarily dictates cellular sensitivity to BH3 mimetics, additional specificity is conferred by proapoptotic BCL-2 proteins. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Indirect induction of endothelial cell injury by PU- or PTFE-mediated activation of monocytes.

    Science.gov (United States)

    Liu, Xin; Xue, Yang; Sun, Jiao

    2010-01-01

    Polyurethanes (PUs) and polytetrafluoroethylene (PTFE) are widely used for making cardiovascular devices, but thrombus formation on the surfaces of these devices is inevitable. Since endothelial injury can lead to thrombosis, most of the studies on PUs or PTFE focused on their damage to endothelial cells. However, few studies have attempted to clarify whether the use of foreign objects as biomaterials can cause endothelial injury by activating the innate immune system. In this study, we aimed to investigate the roles of PU- or PTFE-stimulated immune cells in endothelial-cell injury. First, monocytes (THP-1 cells) were stimulated with PU or PTFE for 24 h and, subsequently, human umbilical vein endothelial cells (HUVECs) were treated with the supernatants of the stimulated cells for 24 h. We measured the generation of intracellular reactive oxygen species (ROS) from THP-1 cells treated with PU and PTFE for 24 h, meanwhile hydrogen dioxide (H(2)O(2)), tumor necrosis factor (TNF)-α and interleukin (IL)-1β in the supernatants were also detected. Then, we assessed the apoptosis rate of the HUVECs and determined the expression of NO, inducible nitric oxide synthase (iNOS), and apoptosis-related proteins (p53, Bax, Bcl-2) in the HUVECs. The results showed that large amounts of ROS and low levels of pro-inflammatory cytokines (TNF-α and IL-1β) were produced by the stimulated THP-1 cells. After culturing with the supernatants of the PU- or PTFE-stimulated THP-1 cells, the apoptosis rate, NO production and expression of iNOS, p53 and Bax in the HUVECs were up-regulated, while Bcl-2 expression was down-regulated. In conclusion, the release of ROS by PU- or PTFE-treated THP-1 cells may induce iNOS expression and cause apoptosis in HUVECs via the p53, Bax and Bcl-2 proteins. These data provide the interesting finding that endothelial injury in the process of biomaterial-induced thrombosis can be initiated through the release of soluble mediators by monocytes.

  14. Relaxin attenuates aristolochic acid induced human tubular epithelial cell apoptosis in vitro by activation of the PI3K/Akt signaling pathway.

    Science.gov (United States)

    Xie, Xiang-Cheng; Zhao, Ning; Xu, Qun-Hong; Yang, Xiu; Xia, Wen-Kai; Chen, Qi; Wang, Ming; Fei, Xiao

    2017-06-01

    Aristolochic acid nephropathy remains a leading cause of chronic kidney disease (CKD), however few treatment strategies exist. Emerging evidence has shown that H2 relaxin (RLX) possesses powerful antifibrosis and anti-apoptotic properties, therefore we aimed to investigate whether H2 relaxin can be employed to reduce AA-induced cell apoptosis. Human proximal tubular epithelial (HK-2) cells exposed to AA-I were treated with or without administration of H2 RLX. Cell viability was examined using the WST-8 assay. Apoptotic morphologic alterations were observed using the Hoechst 33342 staining method. Apoptosis was detected using flow cytometry. The expression of caspase 3, caspase 8, caspase 9, ERK1/2, Bax, Bcl-2, and Akt proteins was determined by Western blot. Co-treatment with RLX reversed the increased apoptosis observed in the AA-I only treated group. RLX restored expression of phosphorylated Akt which found to be decreased in the AA-I only treated cells. RLX co-treatment led to a decrease in the Bax/Bcl-2 ratio as well as the cleaved form of caspase-3 compared to the AA-I only treated cells. This anti-apoptotic effect of RLX was attenuated by co-administration of the Akt inhibitor LY294002. The present study demonstrated H2 RLX can decrease AA-I induced apoptosis through activation of the PI3K/Akt signaling pathway.

  15. Morus alba Leaf Lectin (MLL) Sensitizes MCF-7 Cells to Anoikis by Inhibiting Fibronectin Mediated Integrin-FAK Signaling through Ras and Activation of P38 MAPK

    Science.gov (United States)

    Saranya, Jayaram; Shilpa, Ganesan; Raghu, Kozhiparambil G.; Priya, Sulochana

    2017-01-01

    Lectins are a unique class of carbohydrate binding proteins/glycoproteins, and many of them possess anticancer properties. They can induce cell cycle arrest and apoptosis, inhibit protein synthesis, telomerase activity and angiogenesis in cancer cells. In the present study, we have demonstrated the effect of Morus alba leaf lectin (MLL) on anoikis induction in MCF-7 cells. Anoikis induction in cancer cells has a significant role in preventing early stage metastasis. MLL treatment in monolayers of MCF-7 cells caused significant detachment of cells in a time and concentration dependent manner. The detached cells failed to re-adhere and grew even to culture plates coated with different matrix proteins. DNA fragmentation, membrane integrity studies, annexin V staining, caspase 9 activation and upregulation of Bax/Bad confirmed that the detached cells underwent apoptosis. Upregulation of matrix metalloproteinase 9 (MMP-9) caused a decrease in fibronectin (FN) production which facilitated the cells to detach by blocking the FN mediated downstream signaling. On treatment with MLL, we have observed downregulation of integrin expression, decreased phosphorylation of focal adhesion kinase (FAK), loss in FAK-integrin interaction and active Ras. MLL treatment downregulated the levels of phosphorylated Akt and PI3K. Also, we have studied the effect of MLL on two stress activated protein kinases p38 MAPK and JNK. p38 MAPK activation was found to be elevated, but there was no change in the level of JNK. Thus our study substantiated the possible antimetastatic effect of MLL by inducing anoikis in MCF-7 cells by activation of caspase 9 and proapoptotic Bax/Bad by blockage of FN mediated integrin/FAK signaling and partly by activation of p38 MAPK. PMID:28223935

  16. Ischemic preconditioning negatively regulates plenty of SH3s-mixed lineage kinase 3-Rac1 complex and c-Jun N-terminal kinase 3 signaling via activation of Akt.

    Science.gov (United States)

    Zhang, Q-G; Han, D; Xu, J; Lv, Q; Wang, R; Yin, X-H; Xu, T-L; Zhang, G-Y

    2006-12-01

    Activation of Akt/protein kinase B has been recently reported to play an important role in ischemic tolerance. We here demonstrate that the decreased protein expression and phosphorylation of phosphatase and tensin homolog deleted from chromosome 10 (PTEN) underlie the increased Akt-Ser-473 phosphorylation in the hippocampal CA1 subfield in ischemic preconditioning (IPC). Co-immunoprecipitation analysis reveals that Akt physically interacts with Rac1, a small Rho family GTPase required for mixed lineage kinase 3 (MLK3) autophosphorylation, and both this interaction and Rac1-Ser-71 phosphorylation induced by Akt are promoted in preconditioned rats. In addition, we show that Akt activation results in the disassembly of the plenty of SH3s (POSH)-MLK3-Rac1 signaling complex and down-regulation of the activation of MLK3/c-Jun N-terminal kinase (JNK) pathway. Akt activation results in decreased serine phosphorylation of 14-3-3, a cytoplasmic anchor of Bax, and prevents ischemia-induced mitochondrial translocation of Bax, release of cytochrome c, and activation of caspase-3. The expression of Fas ligand is also decreased in the CA1 region. Akt activation protects against apoptotic neuronal death as shown in TUNEL staining following IPC. Intracerebral infusion of LY294002 before IPC reverses the increase in Akt phosphorylation and the decrease in JNK signaling activation, as well as the neuroprotective action of IPC. Our results suggest that activation of pro-apoptotic MLK3/JNK3 cascade can be suppressed through activating anti-apoptotic phosphoinositide 3-kinase/Akt pathway induced by a sublethal ischemic insult, which provides a functional link between Akt and the JNK family of stress-activated kinases in ischemic tolerance.

  17. Acrolein-Exposed Normal Human Lung Fibroblasts in Vitro: Cellular Senescence, Enhanced Telomere Erosion, and Degradation of Werner’s Syndrome Protein

    Science.gov (United States)

    Jang, Jun-Ho; Bruse, Shannon; Huneidi, Salam; Schrader, Ronald M.; Monick, Martha M.; Lin, Yong; Carter, A. Brent; Klingelhutz, Aloysius J.

    2014-01-01

    Background: Acrolein is a ubiquitous environmental hazard to human health. Acrolein has been reported to activate the DNA damage response and induce apoptosis. However, little is known about the effects of acrolein on cellular senescence. Objectives: We examined whether acrolein induces cellular senescence in cultured normal human lung fibroblasts (NHLF). Methods: We cultured NHLF in the presence or absence of acrolein and determined the effects of acrolein on cell proliferative capacity, senescence-associated β-galactosidase activity, the known senescence-inducing pathways (e.g., p53, p21), and telomere length. Results: We found that acrolein induced cellular senescence by increasing both p53 and p21. The knockdown of p53 mediated by small interfering RNA (siRNA) attenuated acrolein-induced cellular senescence. Acrolein decreased Werner’s syndrome protein (WRN), a member of the RecQ helicase family involved in DNA repair and telomere maintenance. Acrolein-induced down-regulation of WRN protein was rescued by p53 knockdown or proteasome inhibition. Finally, we found that acrolein accelerated p53-mediated telomere shortening. Conclusions: These results suggest that acrolein induces p53-mediated cellular senescence accompanied by enhanced telomere attrition and WRN protein down-regulation. Citation: Jang JH, Bruse S, Huneidi S, Schrader RM, Monick MM, Lin Y, Carter AB, Klingelhutz AJ, Nyunoya T. 2014. Acrolein-exposed normal human lung fibroblasts in vitro: cellular senescence, enhanced telomere erosion, and degradation of Werner’s syndrome protein. Environ Health Perspect 122:955–962; http://dx.doi.org/10.1289/ehp.1306911 PMID:24747221

  18. Anti-TNF-alpha antibody attenuates subarachnoid hemorrhage-induced apoptosis in the hypothalamus by inhibiting the activation of Erk

    Directory of Open Access Journals (Sweden)

    Ma L

    2018-02-01

    Full Text Available Ling Ma,1 Yong Jiang,2 Yanan Dong,2 Jun Gao,2 Bin Du,2 Dianwei Liu2 1Department of Clinical Laboratory, The Second Hospital of Shandong University, Jinan, Shandong, People’s Republic of China; 2Department of Neurosurgery, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong, People’s Republic of China Background: Subarachnoid hemorrhage (SAH can induce apoptosis in many regions of the brain including the cortex and hippocampus. However, few studies have focused on apoptosis in the hypothalamus after SAH. Although some antiapoptotic strategies have been developed for SAH, such as anti-tumor necrosis factor-alpha (TNF-α antibody, the molecular mechanisms underlying this condition have yet to be elucidated. Therefore, the purpose of this study was to evaluate whether SAH could induce apoptosis in the hypothalamus and identify the potential molecular mechanisms underlying the actions of anti-TNF-α antibody, as a therapeutic regimen, upon apoptosis. Materials and methods: SAH was induced in a rat model. Thirty minutes prior to SAH, anti-TNF-α antibody or U0126, an extracellular signal-regulated kinase (Erk inhibitor, was microinjected into the left lateral cerebral ventricle. In addition, phorbol-12-myristate-13-acetate was injected intraperitoneally immediately after the anti-TNF-α antibody microinjection. Then, real-time polymerase chain reaction, Western blotting and immunohistochemistry were used to detect the expression of caspase-3, bax, bcl-2, phosphorylated Erk (p-Erk and Erk. Finally, anxiety-like behavior was identified by using open field. Results: Levels of caspase-3, bax and bcl-2, all showed a temporary rise after SAH in the hypothalamus, indicating the induction of apoptosis in this brain region. Interestingly, we found that the microinjection of anti-TNF-α antibody could selectively block the elevated levels of bax, suggesting the potential role of anti-TNF-α antibody in the inhibition of SAH

  19. Valsartan ameliorates ageing-induced aorta degeneration via angiotensin II type 1 receptor-mediated ERK activity

    Science.gov (United States)

    Shan, HaiYan; Zhang, Siyang; Li, Xuelian; yu, Kai; Zhao, Xin; Chen, Xinyue; Jin, Bo; Bai, XiaoJuan

    2014-01-01

    Angiotensin II (Ang II) plays important roles in ageing-related disorders through its type 1 receptor (AT1R). However, the role and underlying mechanisms of AT1R in ageing-related vascular degeneration are not well understood. In this study, 40 ageing rats were randomly divided into two groups: ageing group which received no treatment (ageing control), and valsartan group which took valsartan (selective AT1R blocker) daily for 6 months. 20 young rats were used as adult control. The aorta structure were analysed by histological staining and electron microscopy. Bcl-2/Bax expression in aorta was analysed by immunohistochemical staining, RT-PCR and Western blotting. The expressions of AT1R, AT2R and mitogen-activated protein kinases (MAPKs) were detected. Significant structural degeneration of aorta in the ageing rats was observed, and the degeneration was remarkably ameliorated by long-term administration of valsartan. With ageing, the expression of AT1R was elevated, the ratio of Bcl-2/Bax was decreased and meanwhile, an important subgroup of MAPKs, extracellular signal-regulated kinase (ERK) activity was elevated. However, these changes in ageing rats could be reversed to some extent by valsartan. In vitro experiments observed consistent results as in vivo study. Furthermore, ERK inhibitor could also acquire partial effects as valsartan without affecting AT1R expression. The results indicated that AT1R involved in the ageing-related degeneration of aorta and AT1R-mediated ERK activity was an important mechanism underlying the process. PMID:24548645

  20. Hesperidin produces cardioprotective activity via PPAR-γ pathway in ischemic heart disease model in diabetic rats.

    Directory of Open Access Journals (Sweden)

    Yogeeta O Agrawal

    Full Text Available The present study investigated the effect of hesperidin, a natural flavonoid, in cardiac ischemia and reperfusion (I/R injury in diabetic rats. Male Wistar rats with diabetes were divided into five groups and were orally administered saline once daily (IR-sham and IR-control, Hesperidin (100 mg/kg/day; IR-Hesperidin, GW9962 (PPAR-γ receptor antagonist, or combination of both for 14 days. On the 15th day, in the IR-control and IR-treatment groups, rats were subjected to left anterior descending (LAD coronary artery occlusion for 45 minutes followed by a one-hour reperfusion. Haemodynamic parameters were recorded and rats were sacrificed; hearts were isolated for biochemical, histopathological, ultrastructural and immunohistochemistry. In the IR-control group, significant ventricular dysfunctions were observed along with enhanced expression of pro-apoptotic protein Bax. A decline in cardiac injury markers lactate dehydrogenase activity, CK-MB and increased content of thiobarbituric acid reactive substances, a marker of lipid peroxidation, and TNF-α were observed. Hesperidin pretreatment significantly improved mean arterial pressure, reduced left ventricular end-diastolic pressure, and improved both inotropic and lusitropic function of the heart (+LVdP/dt and -LVdP/dt as compared to IR-control. Furthermore, hesperidin treatment significantly decreased the level of thiobarbituric acid reactive substances and reversed the activity of lactate dehydrogenase towards normal value. Hesperidin showed anti-apoptotic effects by upregulating Bcl-2 protein and decreasing Bax protein expression. Additionally, histopathological and ultrastructural studies reconfirmed the protective action of hesperidin. On the other hand, GW9662, selective PPAR-γ receptor antagonist, produced opposite effects and attenuated the hesperidin induced improvements. The study for the first time evidence the involvement of PPAR-γ pathway in the cardioprotective activity of

  1. Administration of Tauroursodeoxycholic Acid Attenuates Early Brain Injury via Akt Pathway Activation

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    Dongdong Sun

    2017-07-01

    Full Text Available Traumatic brain injury (TBI is one of the leading causes of trauma-induced mortality and disability, and emerging studies have shown that endoplasmic reticulum (ER stress plays an important role in the pathophysiology of TBI. Tauroursodeoxycholic acid (TUDCA, a hydrophilic bile acid, has been reported to act as an ER stress inhibitor and chemical chaperone and to have the potential to attenuate apoptosis and inflammation. To study the effects of TUDCA on brain injury, we subjected mice to TBI with a controlled cortical impact (CCI device. Using western blotting, we first examined TBI-induced changes in the expression levels of GRP78, an ER stress marker, p-PERK, PERK, p-eIF2a, eIF2a, ATF4, p-Akt, Akt, Pten, Bax, Bcl-2, Caspase-12 and CHOP, as well as changes in the mRNA levels of Akt, GRP78, Caspase-12 and CHOP using RT-PCR. Neuronal cell death was assessed by a terminal deoxynucleotidyl transferase (TdT-mediated dUTP nick end-labeling (TUNEL assay, and CHOP expression in neuronal cells was detected by double-immunofluorescence staining. Neurological and motor deficits were assessed by modified neurological severity scores (mNSS and beam balance and beam walking tests, and brain water content was also assessed. Our results indicated that ER stress peaked at 72 h after TBI and that TUDCA abolished ER stress and inhibited p-PERK, p-eIF2a, ATF4, Pten, Caspase-12 and CHOP expression levels. Moreover, our results show that TUDCA also improved neurological function and alleviated brain oedema. Additionally, TUDCA increased p-Akt expression and the Bcl-2/Bax ratio. However, the administration of the Akt inhibitor MK2206 or siRNA targeting of Akt abolished the beneficial effects of TUDCA. Taken together, our results indicate that TUDCA may attenuate early brain injury via Akt pathway activation.

  2. Infección por el virus de la Lengua azul: activación de señales celulares que inducen apoptosis Bluetongue virus infection: signaling pathway activated during apoptosis

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    E. Mortola

    2009-09-01

    Full Text Available El virus de la Lengua azul (VLA es un ARN virus de doble cadena que induce apoptosis tanto en cultivos celulares como en tejidos blanco. Con el fin de dilucidar el mecanismo de apoptosis en la infección por el VLA, en el presente trabajo examinamos en detalle, por la técnica de Western blot, las señales celulares de caspasas, Bax, citocromo c, Smac/DIABLO y factor nuclear kappa B (NF-kB que se activan en la infección viral. Hemos comprobado que luego de la infección in vitro con el VLA, se detectó la activación de la caspasa 8 y con ello el mecanismo extrínseco de la apoptosis. También detectamos por primera vez no sólo la activación de miembros de la familia Bcl-2 (Bax, sino también la liberación del citocromo c y la proteína Smac/DIABLO, confirmando que en la infección por el VLA está involucrado el mecanismo secuencial intrínseco de la apoptosis. Asimismo, demostramos que la infección por el VLA activa el NF-kB y que la apoptosis es sustancialmente reducida mediante la inhibición del mismo. La activación de las señales celulares tales como Bax, citocromo c, Smac/DIABLO y NF-kB presentados en este trabajo, esclarecen los mecanismos apoptóticos durante la infección por el VLA para una mayor comprensión del papel primario que juega la apoptosis en la patogénesis del virus.Bluetongue (BTV is a double-stranded RNA virus that induces apoptosis both in mammalian cell cultures and in target tissues. To elucidate the apoptosis pathways in BTV infection, we have examined in detail the apoptosis mechanism by examination of caspases, Bax, cytochrome c, Smac/DIABLO and NF-kB signalling pathways. In this report, after cell infection with BTV, the activation of caspase 8 was detected, proving the extrinsic receptor binding apoptotic pathway. Apoptosis followed a sequential pathway involving the detection of activated Bcl-2 family members. Furthermore, its translocation to the mitochondria, as well as the release of cytochrome c and

  3. Induction of Tca8113 tumor cell apoptosis by icotinib is associated with reactive oxygen species mediated p38-MAPK activation.

    Science.gov (United States)

    Yang, Cailing; Yan, Jianguo; Yuan, Guoyan; Zhang, Yinghua; Lu, Derong; Ren, Mingxin; Cui, Weigang

    2014-08-01

    Icotinib, a selective EGFR tyrosine kinase inhibitor (EGFR-TKI), has been shown to exhibit anti-tumor activity against several tumor cell lines. However, the exact molecular mechanism of icotinib's anti-tumor effect remains unknown. This study aims to examine the zytotoxic effect of icotinib on Tca8113 cells and its potential molecular mechanism. Icotinib significantly resulted in dose-dependent cell death as determined by MTT assay, accompanied by increased levels of Bax and DNA fragmentation. Icotinib could also induce Reactive Oxygen Species (ROS) generation. Further studies confirmed that scavenging of reactive oxygen species by N-acetyl-L-cysteine (NAC), and pharmacological inhibition of MAPK reversed icotinib-induced apoptosis in Tca8113 cells. Our data provide evidence that icotinib induces apoptosis, possibly via ROS-mediated MAPK pathway in Tca8113 cells.

  4. Synthesis and In Vitro Antiproliferative Activity of Novel Phenyl Ring-Substituted 5-Alkyl-12(H-quino[3,4-b][1,4]benzothiazine Derivatives

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    Andrzej Zięba

    2016-11-01

    Full Text Available A novel series of tetracyclic quinobenzothiazine derivatives was synthetized. Compounds containing a substituent (hydroxyl, methyl, phenyl, piperidyl, or piperazinyl in positions 9 and 11 were obtained by cyclization of suitable 4-aminoquinolinium-3-thiolates. Quinobenzothiazine 10-O-substituted derivatives were obtained by alkylating the hydroxyl group in position 10 of the parent (quinobenzothiazine system. Antiproliferative activity of the synthesized compounds was studied using cultured neoplastic cells (MDA-MB-231, SNB-19, and C-32 cell lines. Four selected compounds were investigated in more detail for cytotoxicity and antiproliferative effect. Transcriptional activity of genes regulating cell cycle (TP53, apoptosis (BAX, BCL-2, as well as proliferation (H3 were assessed. Finally, the ability of the selected compounds to bind DNA was checked in the presence of ethidium bromide.

  5. Biochemical responses and mitochondrial mediated activation of apoptosis on long-term effect of aspartame in rat brain

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    Iyaswamy Ashok

    2014-01-01

    Full Text Available Aspartame, an artificial sweetener, is very widely used in many foods and beverages. But there are controversies about its metabolite which is marked for its toxicity. Hence it is believed to be unsafe for human use. Previous studies have reported on methanol exposure with involvements of free radicals on excitotoxicity of neuronal apoptosis. Hence, this present study is proposed to investigate whether or not chronic aspartame (FDA approved Daily Acceptable Intake (ADI,40 mg/kg bwt administration could release methanol, and whether or not it can induce changes in brain oxidative stress status and gene and protein expression of anti-apoptotic Bcl-2 and pro-apoptotic Bax and caspase-3 in the rat brain region. To mimic the human methanol metabolism, Methotrexate (MTX-treated Wistar strain male albino rats were used and after the oral administration of aspartame, the effects were studied along with controls and MTX-treated controls. Aspartame exposure resulted with a significant increase in the enzymatic activity in protein carbonyl, lipid peroxidation levels, superoxide dismutase, glutathione-S-transferase, glutathione peroxidase and catalase activity in (aspartame MTX-treated animals and with a significant decrease in reduced glutathione, glutathione reductase and protein thiol, pointing out the generation of free radicals. The gene and protein expression of pro apoptotic marker Bax showed a marked increase whereas the anti-apoptotic marker Bcl-2 decreased markedly indicating the aspartame is harmful at cellular level. It is clear that long term aspartame exposure could alter the brain antioxidant status, and can induce apoptotic changes in brain.

  6. Locomotor activity of rats with SCI is improved by dexmedetomidine by targeting the expression of inflammatory factors.

    Science.gov (United States)

    Wang, Wei-Guo; Wang, Lin; Jiao, Zhen-Hua; Xue, Bin; Xu, Zhan-Wang

    2018-04-26

    Dexmedetomidine, a well‑known selective α‑2 adrenoceptor agonist, inhibits the apoptosis of neurons and protects other organs from oxidative damage. In the present study, the effect of dexmedetomidine on spinal cord injury (SCI) in a rat model was investigated. The SCI rat model was prepared using the weight‑drop method, and the effect of dexmedetomidine on locomotor activity was analyzed using the Basso, Beattie and Bresnahan (BBB) rating scale. Western blot analysis was used to observe changes in the expression of apoptosis‑related proteins, including B‑cell lymphoma 2 (Bcl‑2) and Bcl‑2‑associated X protein (Bax). The results revealed that treatment of the SCI rats with dexmedetomidine at a dose of 50 mg/kg significantly prevented the formation of edema in the tissues of the spinal cord. Dexmedetomidine also inhibited the SCI‑induced accumulation of neutrophils in the spinal cord. The BBB scores were significantly increased (PSCI treated with dexmedetomidine after 10 days. The results of grid walking test revealed a marked decrease in the number of missteps following 10 days of dexmedetomidine treatment. The expression levels of tumor necrosis factor (TNF)‑α and interleukin (IL)‑1β were significantly reduced (PSCI exerted an inhibitory effect on the SCI‑induced increase in the expression of Bax. The expression of Bcl‑2 was increased in the dexmedetomidine treated rats, compared with that in the control group. Taken together, dexmedetomidine improved the locomotor activity of the rats through the inhibition of edema, reduction in the expression levels of TNF‑α and IL‑1β, and inhibition of the induction of apoptosis. Therefore, dexmedetomidine may be of therapeutic importance for patients with SCI.

  7. Biochemical responses and mitochondrial mediated activation of apoptosis on long-term effect of aspartame in rat brain.

    Science.gov (United States)

    Ashok, Iyaswamy; Sheeladevi, Rathinasamy

    2014-01-01

    Aspartame, an artificial sweetener, is very widely used in many foods and beverages. But there are controversies about its metabolite which is marked for its toxicity. Hence it is believed to be unsafe for human use. Previous studies have reported on methanol exposure with involvements of free radicals on excitotoxicity of neuronal apoptosis. Hence, this present study is proposed to investigate whether or not chronic aspartame (FDA approved Daily Acceptable Intake (ADI),40 mg/kg bwt) administration could release methanol, and whether or not it can induce changes in brain oxidative stress status and gene and protein expression of anti-apoptotic Bcl-2 and pro-apoptotic Bax and caspase-3 in the rat brain region. To mimic the human methanol metabolism, Methotrexate (MTX)-treated Wistar strain male albino rats were used and after the oral administration of aspartame, the effects were studied along with controls and MTX-treated controls. Aspartame exposure resulted with a significant increase in the enzymatic activity in protein carbonyl, lipid peroxidation levels, superoxide dismutase, glutathione-S-transferase, glutathione peroxidase and catalase activity in (aspartame MTX)-treated animals and with a significant decrease in reduced glutathione, glutathione reductase and protein thiol, pointing out the generation of free radicals. The gene and protein expression of pro apoptotic marker Bax showed a marked increase whereas the anti-apoptotic marker Bcl-2 decreased markedly indicating the aspartame is harmful at cellular level. It is clear that long term aspartame exposure could alter the brain antioxidant status, and can induce apoptotic changes in brain.

  8. Synergistic effect of fisetin combined with sorafenib in human cervical cancer HeLa cells through activation of death receptor-5 mediated caspase-8/caspase-3 and the mitochondria-dependent apoptotic pathway.

    Science.gov (United States)

    Lin, Ming-Te; Lin, Chia-Liang; Lin, Tzu-Yu; Cheng, Chun-Wen; Yang, Shun-Fa; Lin, Chu-Liang; Wu, Chih-Chien; Hsieh, Yi-Hsien; Tsai, Jen-Pi

    2016-05-01

    Combining antitumor agents with bioactive compounds is a potential strategy for improving the effect of chemotherapy on cancer cells. The goal of this study was to elucidate the antitumor effect of the flavonoid, fisetin, combined with the multikinase inhibitor, sorafenib, against human cervical cancer cells in vitro and in vivo. The combination of fisetin and sorafenib synergistically induced apoptosis in HeLa cells, which is accompanied by a marked increase in loss of mitochondrial membrane potential. Apoptosis induction was achieved by caspase-3 and caspase-8 activation which increased the ratio of Bax/Bcl-2 and caused the subsequent cleavage of PARP level while disrupting the mitochondrial membrane potential in HeLa cells. Decreased Bax/Bcl-2 ratio level and mitochondrial membrane potential were also observed in siDR5-treated HeLa cells. In addition, in vivo studies revealed that the combined fisetin and sorafenib treatment was clearly superior to sorafenib treatment alone using a HeLa xenograft model. Our study showed that the combination of fisetin and sorafenib exerted better synergistic effects in vitro and in vivo than either agent used alone against human cervical cancer, and this synergism was based on apoptotic potential through a mitochondrial- and DR5-dependent caspase-8/caspase-3 signaling pathway. This combined fisetin and sorafenib treatment represents a novel therapeutic strategy for further clinical developments in advanced cervical cancer.

  9. Surviving the crash: T-cell homeostasis

    Indian Academy of Sciences (India)

    TOSHIBA

    The formation of higher order apoptotic structures at the mitochondrion precedes cellular collapse dead. Tracking bax multimerization at mitochondria wildtype. Bax active -6A7. Nucleus – H33342. Apoptotic T-cells ...

  10. The Antioxidant, Anti-Inflammatory and Anti-Apoptotic Activities of the Bauhinia Championii Flavone are Connected with Protection Against Myocardial Ischemia/Reperfusion Injury.

    Science.gov (United States)

    Jian, Jie; Xuan, Feifei; Qin, Feizhang; Huang, Renbin

    2016-01-01

    Previous studies have demonstrated that Bauhinia championii flavone (BCF) exhibits anti-oxidative, anti-hypoxic and anti-stress properties. This study was designed to investigate whether BCF has a cardioprotective effect against myocardial ischemia/reperfusion (I/R) injuries in rats and to shed light on its possible mechanism. The model of I/R was established by ligating the left anterior descending coronary artery for 30 min, then reperfusing for 180 min. Hemodynamic changes were continuously monitored. The content of malondialdehyde (MDA) as well as the lactate dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were assessed. The release of interleukin-6 (IL-6) was measured by enzyme-linked immunosorbent assay (ELISA). Apoptosis of cardiomyocytes was determined by caspase-3 activity and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The expression of TLR4, NF-x03BA;Bp65, Bcl-2 and Bax were detected by western blotting. Pretreatment with BCF significantly reduced the serum levels of LDH, MDA and IL-6, but increased the activities of SOD and GSH-Px. It also attenuated myocardial infarct size, reduced the apoptosis rate and preserved cardiac function. Furthermore, BCF inhibited caspase-3 activity and the expression of TLR4, phosphorylated NF-x03BA;Bp65 and Bax, but enhanced the expression of Bcl-2. These results provide substantial evidence that BCF exerts a protective effect on myocardial I/R injury, which may be attributed to attenuating lipid peroxidation, the inflammatory response and apoptosis. © 2016 The Author(s) Published by S. Karger AG, Basel.

  11. Polyphenolic Extract of Euphorbia supina Attenuates Manganese-Induced Neurotoxicity by Enhancing Antioxidant Activity through Regulation of ER Stress and ER Stress-Mediated Apoptosis

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    Entaz Bahar

    2017-01-01

    Full Text Available Manganese (Mn is an important trace element present in human body, which acts as an enzyme co-factor or activator in various metabolic reactions. While essential in trace amounts, excess levels of Mn in human brain can produce neurotoxicity, including idiopathic Parkinson’s disease (PD-like extrapyramidal manganism symptoms. This study aimed to investigate the protective role of polyphenolic extract of Euphorbia supina (PPEES on Mn-induced neurotoxicity and the underlying mechanism in human neuroblastoma SKNMC cells and Sprague-Dawley (SD male rat brain. PPEES possessed significant amount of total phenolic and flavonoid contents. PPEES also showed significant antioxidant activity in 1,1-diphenyl-2-picrylhydrazyl (DPPH radical scavenging and reducing power capacity (RPC assays. Our results showed that Mn treatment significantly reduced cell viability and increased lactate dehydrogenase (LDH level, which was attenuated by PPEES pretreatment at 100 and 200 µg/mL. Additionally, PPEES pretreatment markedly attenuated Mn-induced antioxidant status alteration by resolving the ROS, MDA and GSH levels and SOD and CAT activities. PPEES pretreatment also significantly attenuated Mn-induced mitochondrial membrane potential (ΔΨm and apoptosis. Meanwhile, PPEES pretreatment significantly reversed the Mn-induced alteration in the GRP78, GADD34, XBP-1, CHOP, Bcl-2, Bax and caspase-3 activities. Furthermore, administration of PPEES (100 and 200 mg/kg to Mn exposed rats showed improvement of histopathological alteration in comparison to Mn-treated rats. Moreover, administration of PPEES to Mn exposed rats showed significant reduction of 8-OHdG and Bax immunoreactivity. The results suggest that PPEES treatment reduces Mn-induced oxidative stress and neuronal cell loss in SKNMC cells and in the rat brain. Therefore, PPEES may be considered as potential treat-ment in Mn-intoxicated patients.

  12. Design and synthesis of novel C14-urea-tetrandrine derivatives with potent anti-cancer activity.

    Science.gov (United States)

    Lan, Junjie; Huang, Lan; Lou, Huayong; Chen, Chao; Liu, Tangjingjun; Hu, Shengcao; Yao, Yao; Song, Junrong; Luo, Jun; Liu, Yazhou; Xia, Bin; Xia, Lei; Zeng, Xueyi; Ben-David, Yaacov; Pan, Weidong

    2018-01-01

    Tetrandrine is a dibenzyltetrahydroisoquinoline alkaloid, isolated from traditional Chinese medicinal plant Stephania tetrandra, with anti-tumor activity. Our previous study identified several derivatives of tetrandrine showing better activities than parental compound against human hepatocellular carcinoma cells. To increase diversity and cytotoxic activities of the original compound, a series of novel 14-urea-tetrandrine derivatives were synthesized through structural modification of tetrandrine. These derivaties demonstrated a moderate to strong anti-proliferative activities against human cell lines HEL and K562 (Leukemia), prostate (PC3), breast (MDA-MB-231) and melanoma (WM9). Compound 4g showed strongest cytotoxic effect against PC3 cells with IC 50 value of 0.64 μM, which was 12-fold, 31-fold and 26-fold lower than the parental tetrandrine, 5-fluorouracil and cisplatin, respectively. Preliminary structure-activity relationship study indicated that urea subsititution was the key pharmacophore for the enhancement of their antitumor activities. Induction of apoprosis by 4g was associated with the activation of pro-apoptotic protein BAX and inhibition of antiapoptosis proteins survivin as well as Bcl-2. Moreover, activation of caspases led to increase cleavage of PARP, which further accelerates apoptotic cell death. These results reveal that the compound 4g may be used as a potential anticancer drug candidate. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. Mesenchymal Stem Cell-Conditioned Medium Modulates Apoptotic and Stress-Related Gene Expression, Ameliorates Maturation and Allows for the Development of Immature Human Oocytes after Artificial Activation

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    Hakimeh Akbari

    2017-12-01

    Full Text Available The aim of the present study was to determine whether mesenchymal stem cell-conditioned medium (MSC-CM modulates apoptotic and stress-related gene expression, and ameliorates maturation and developmental potential of immature human oocytes after artificial activation. A total of 247 surplus immature germinal vesicle (GV oocytes obtained from infertile women were allocated into two in vitro maturation (IVM groups: 1: GV oocytes (n = 116 matured in vitro (fIVM, and 2: GV oocytes (n = 131 that were vitrified, then in vitro matured (vIVM. Also, two maturation media were used: Alpha-minimum essential medium (α-MEM and human umbilical cord-derived MSCs (hUCM. After 36 h of incubation, the IVM oocytes were examined for nuclear maturation. In IVM-matured oocytes, cytoplasmic maturation was evaluated after artificial activation through Ionomycin. Moreover, the quantitative expressions of B-cell CLL/lymphoma 2 (BCL2, BCL2-associated X protein (BAX, superoxide dismutase (SOD, and Heat shock proteins (HSP70 in matured oocytes were assessed by quantitative Real-time polymerase chain reaction (qRT-PCR and compared with fresh and vitrified in vivo matured oocytes, which were used as fIVM and vIVM controls, respectively. The highest maturation rate was found in hUCM in fIVM, and the lowest maturation rate was found using α-MEM in vIVM (85.18% and 71.42%, respectively. The cleavage rate in fIVM was higher than that in vIVM (83.4% vs. 72.0%. In addition, the cleavage rate in α-MEM was lower than that in the hUCM (66.0% vs. 89.4%. Furthermore, the difference between parthenote embryo arrested in 4–8 cells (p < 0.04 and the quality of embryo arrested in 8-cell (p < 0.007 were significant. The developmental stages of parthenote embryos in hUCM versus α-MEM were as follows: 2–4 cell (89.45% vs. 66.00%, respectively, 4–8 cell (44.31% vs. 29.11%, respectively, morula (12.27% vs. 2.63%, respectively, and blastocysts (2.5% vs. 0%, respectively. The messenger

  14. Mitochondrial-mediated apoptosis in lymphoma cells by the diterpenoid lactone Andrographolide, the active component of Andrographis paniculata

    Science.gov (United States)

    Yang, Shuo; Evens, Andrew M.; Prachand, Sheila; Singh, Amareshwar T.K; Bhalla, Savita; David, Kevin; Gordon, Leo I.

    2010-01-01

    Purpose Andrographolide is a diterpenoid lactone isolated from Andrographis paniculata (King of Bitters), an herbal medicine used in Asia. It has been reported to have anti-inflammatory, antihypertensive, anti-viral and immune-stimulant properties. Furthermore, it has been shown to inhibit cancer cell proliferation and induce apoptosis in leukemia and solid tumor cell lines. Experimental Design We studied the Burkitt p53 mutated Ramos cell line, the mantle-cell lymphoma (MCL) line Granta, the follicular lymphoma (FL) cell line HF-1 and the diffuse large B-cell lymphoma (DLBCL) cell line SUDHL4, as well as primary cells from patients with FL, DLBCL, and MCL. Results We found that andrographolide resulted in dose- and time-dependent cell death as measured by MTT. Andrographolide significantly increased reactive oxygen species (ROS) production in all cell lines. To determine mechanism of cell death, we measured apoptosis by Annexin-V/propidium iodide (PI) in the presence and absence of the antioxidant N-acetyl-L-cysteine (NAC), the glutathione-depleting agent buthionine sulfoxamine (BSO), or caspase inhibitors. We found that apoptosis was greatly enhanced by BSO, blocked by NAC, and accompanied by PARP cleavage and activation of caspases 3, 8 and 9. We measured BAX conformational change, and mitochondrial membrane potential, and using mouse embryonic fibroblast (MEF) Bax/Bak double knockouts (MEFBax−/−/Bak−/−), we found that apoptosis was mediated through mitochondrial pathways, but dependent on caspases in both cell lines and in patient samples. Conclusions Andrographolide caused ROS-dependent apoptosis in lymphoma cell lines and in primary tumor samples, which was enhanced by depletion of GSH and inhibited by NAC or the pan-caspase inhibitor Z-VAD-FMK. Further studies of diterpenoid lactones in lymphoma are warranted. PMID:20798229

  15. Low-Dose Ethanol Preconditioning Protects Against Oxygen-Glucose Deprivation/Reoxygenation-Induced Neuronal Injury By Activating Large Conductance, Ca2+-Activated K+ Channels In Vitro

    Institute of Scientific and Technical Information of China (English)

    Fang Su; An-Chen Guo; Wei-Wei Li; Yi-Long Zhao; Zheng-Yi Qu; Yong-Jun Wang; Qun Wang; Yu-Lan Zhu

    2017-01-01

    Increasing evidence suggests that low to moderate ethanol ingestion protects against the deleterious effects of subsequent ischemia/reperfusion;however,the underlying mechanism has not been elucidated.In the present study,we showed that expression of the neuronal large-conductance,Ca2+-activated K+ channel (BKCa) α-subunit was upregulated in cultured neurons exposed to oxygen-glucose deprivatior/reoxygenation (OGD/R) compared with controls.Preconditioning with low-dose ethanol (10 mmol/L) increased cell survival rate in neurons subjected to OGD/R,attenuated the OGD/R-induced elevation of cytosolic Ca2+ levels,and reduced the number of apoptotic neurons.Western blots revealed that ethanol preconditioning upregulated expression of the anti-apoptotic protein Bcl-2 and downregulated the pro-apoptotic protein Bax.The protective effect of ethanol preconditioning was antagonized by a BKCa channel inhibitor,paxilline.Inside-out patches in primary neurons also demonstrated the direct activation of the BKCa channel by 10 mmol/L ethanol.The above results indicated that low-dose ethanol preconditioning exerts its neuroprotective effects by attenuating the elevation of cytosolic Ca2+ and preventing neuronal apoptosis,and this is mediated by BKCa channel activation.

  16. Low-Dose Ethanol Preconditioning Protects Against Oxygen-Glucose Deprivation/Reoxygenation-Induced Neuronal Injury By Activating Large Conductance, Ca2+-Activated K+ Channels In Vitro.

    Science.gov (United States)

    Su, Fang; Guo, An-Chen; Li, Wei-Wei; Zhao, Yi-Long; Qu, Zheng-Yi; Wang, Yong-Jun; Wang, Qun; Zhu, Yu-Lan

    2017-02-01

    Increasing evidence suggests that low to moderate ethanol ingestion protects against the deleterious effects of subsequent ischemia/reperfusion; however, the underlying mechanism has not been elucidated. In the present study, we showed that expression of the neuronal large-conductance, Ca 2+ -activated K + channel (BK Ca ) α-subunit was upregulated in cultured neurons exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) compared with controls. Preconditioning with low-dose ethanol (10 mmol/L) increased cell survival rate in neurons subjected to OGD/R, attenuated the OGD/R-induced elevation of cytosolic Ca 2+ levels, and reduced the number of apoptotic neurons. Western blots revealed that ethanol preconditioning upregulated expression of the anti-apoptotic protein Bcl-2 and downregulated the pro-apoptotic protein Bax. The protective effect of ethanol preconditioning was antagonized by a BK Ca channel inhibitor, paxilline. Inside-out patches in primary neurons also demonstrated the direct activation of the BK Ca channel by 10 mmol/L ethanol. The above results indicated that low-dose ethanol preconditioning exerts its neuroprotective effects by attenuating the elevation of cytosolic Ca 2+ and preventing neuronal apoptosis, and this is mediated by BK Ca channel activation.

  17. Chemical Characterization and Antitumor Activities of Polysaccharide Extracted from Ganoderma lucidum

    Directory of Open Access Journals (Sweden)

    Zengenni Liang

    2014-05-01

    Full Text Available Ganoderma lucidum polysaccharide (GLP is a biologically active substance reported to possess anti-tumor ability. Nonetheless, the mechanisms of GLP-stimulated apoptosis are still unclear. This study aims to determine the inhibitory and apoptosis-inducing effects of GLP on HCT-116 cells. We found that GLP reduced cell viability on HCT-116 cells in a time- and dose-dependent manner, which in turn, induced cell apoptosis. The observed apoptosis was characterized by morphological changes, DNA fragmentation, mitochondrial membrane potential decrease, S phase population increase, and caspase-3 and -9 activation. Furthermore, inhibition of c-Jun N-terminal kinase (JNK by SP600125 led to a dramatic decrease of the GLP-induced apoptosis. Western blot analysis unveiled that GLP up-regulated the expression of Bax/Bcl-2, caspase-3 and poly (ADP-ribose polymerase (PARP. These results demonstrate that apoptosis stimulated by GLP in human colorectal cancer cells is associated with activation of mitochondrial and mitogen-activated protein kinase (MAPK pathways.

  18. Regulation of ROS in transmissible gastroenteritis virus-activated apoptotic signaling

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Li [College of Veterinary Medicine, Northwest A and F University, Yangling, Shaanxi 712100 (China); College of Life Sciences, Hainan Normal University, Haikou, Hainan 571158 (China); Zhao, Xiaomin; Huang, Yong; Du, Qian; Dong, Feng; Zhang, Hongling; Song, Xiangjun; Zhang, Wenlong [College of Veterinary Medicine, Northwest A and F University, Yangling, Shaanxi 712100 (China); Tong, Dewen, E-mail: dwtong@nwsuaf.edu.cn [College of Veterinary Medicine, Northwest A and F University, Yangling, Shaanxi 712100 (China)

    2013-12-06

    Highlights: •TGEV infection induced ROS accumulation. •ROS accumulation is involved in TGEV-induced mitochondrial integrity impairment. •ROS is associated with p53 activation and apoptosis occurrence in TGEV-infected cells. -- Abstract: Transmissible gastroenteritis virus (TGEV), an enteropathogenic coronavirus, causes severe lethal watery diarrhea and dehydration in piglets. Previous studies indicate that TGEV infection induces cell apoptosis in host cells. In this study, we investigated the roles and regulation of reactive oxygen species (ROS) in TGEV-activated apoptotic signaling. The results showed that TGEV infection induced ROS accumulation, whereas UV-irradiated TGEV did not promote ROS accumulation. In addition, TGEV infection lowered mitochondrial transmembrane potential in PK-15 cell line, which could be inhibited by ROS scavengers, pyrrolidinedithiocarbamic (PDTC) and N-acetyl-L-cysteine (NAC). Furthermore, the two scavengers significantly inhibited the activation of p38 MAPK and p53 and further blocked apoptosis occurrence through suppressing the TGEV-induced Bcl-2 reduction, Bax redistribution, cytochrome c release and caspase-3 activation. These results suggest that oxidative stress pathway might be a key element in TGEV-induced apoptosis and TGEV pathogenesis.

  19. Chemical Characterization and Antitumor Activities of Polysaccharide Extracted from Ganoderma lucidum

    Science.gov (United States)

    Liang, Zengenni; Yi, Youjin; Guo, Yutong; Wang, Rencai; Hu, Qiulong; Xiong, Xingyao

    2014-01-01

    Ganoderma lucidum polysaccharide (GLP) is a biologically active substance reported to possess anti-tumor ability. Nonetheless, the mechanisms of GLP-stimulated apoptosis are still unclear. This study aims to determine the inhibitory and apoptosis-inducing effects of GLP on HCT-116 cells. We found that GLP reduced cell viability on HCT-116 cells in a time- and dose-dependent manner, which in turn, induced cell apoptosis. The observed apoptosis was characterized by morphological changes, DNA fragmentation, mitochondrial membrane potential decrease, S phase population increase, and caspase-3 and -9 activation. Furthermore, inhibition of c-Jun N-terminal kinase (JNK) by SP600125 led to a dramatic decrease of the GLP-induced apoptosis. Western blot analysis unveiled that GLP up-regulated the expression of Bax/Bcl-2, caspase-3 and poly (ADP-ribose) polymerase (PARP). These results demonstrate that apoptosis stimulated by GLP in human colorectal cancer cells is associated with activation of mitochondrial and mitogen-activated protein kinase (MAPK) pathways. PMID:24857920

  20. Sesquiterpenes with TRAIL-resistance overcoming activity from Xanthium strumarium.

    Science.gov (United States)

    Karmakar, Utpal K; Ishikawa, Naoki; Toume, Kazufumi; Arai, Midori A; Sadhu, Samir K; Ahmed, Firoj; Ishibashi, Masami

    2015-08-01

    The ability of TRAIL to selectively induce apoptosis in cancer cells while sparing normal cells makes it an attractive target for the development of new cancer therapy. In search of bioactive natural products for overcoming TRAIL-resistance from natural resources, we previously reported a number of active compounds. In our screening program on natural resources targeting overcoming TRAIL-resistance, activity-guided fractionations of the extract of Xanthium strumarium led to the isolation of five sesquiterpene compounds (1-5). 11α,13-dihydroxanthinin (2) and 11α,13-dihydroxanthuminol (3) were first isolated from natural resources and xanthinosin (1), desacetylxanthanol (4), and lasidiol p-methoxybenzoate (5) were known compounds. All compounds (1-5) showed potent TRAIL-resistance overcoming activity at 8, 20, 20, 16, and 16 μM, respectively, in TRAIL-resistant AGS cells. Compounds 1 and 5 enhanced the levels of apoptosis inducing proteins DR4, DR5, p53, CHOP, Bax, cleaved caspase-3, cleaved caspase-8, and cleaved caspase-9 and also decreased the levels of cell survival protein Bcl-2 in TRAIL-resistant AGS cells in a dose-dependent manner. Compound 1 also enhanced the levels of DR4 and DR5 proteins in a time-dependent manner. Thus, compounds 1 and 5 were found to induce both extrinsic and intrinsic apoptotic cell death. Compound 1 also exhibit TRAIL-resistance overcoming activity in DLD1, DU145, HeLa, and MCF7 cells but did not decrease viability in non-cancer HEK293 cells up to 8 μM. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Sirtuin7 is involved in protecting neurons against oxygen-glucose deprivation and reoxygenation-induced injury through regulation of the p53 signaling pathway.

    Science.gov (United States)

    Lv, Jianrui; Tian, Junbin; Zheng, Guoxi; Zhao, Jing

    2017-10-01

    Sirtuin7 (SIRT7) is known to regulate apoptosis and stress responses. So far, very little is known about the role of SIRT7 in cerebral ischemia/reperfusion injury. In this study, we aimed to investigate the potential role of SIRT7 in regulating oxygen-glucose deprivation and reoxygenation (OGD/R)-induced injury in neurons. We found a significant increase of SIRT7 expression in neurons in response to OGD/R treatment. Knockdown of SIRT7 aggravated OGD/R-induced injury. Knockdown of SIRT7 augmented the levels of total and acetylated p53 protein. Moreover, knockdown of SIRT7 markedly increased the transcriptional activity of p53 toward apoptosis and activated the p53-mediated proapoptotic signaling pathway. By contrast, overexpression of SIRT7 showed the opposite effects. Taken together, the results of our study suggest that SIRT7 is involved in protecting neurons against OGD/R-induced injury, possibly through regulation of the p53-mediated proapoptotic signaling pathway, indicating a potential therapeutic target for cerebral ischemia/reperfusion injury. © 2017 Wiley Periodicals, Inc.

  2. Differential immunotoxic effects of ethanol on murine EL-4 lymphoma and normal lymphocytes is mediated through increased ROS production and activation of p38MAPK.

    Science.gov (United States)

    Premachandran, Sudha; Khan, Nazir M; Thakur, Vikas S; Shukla, Jyoti; Poduval, T B

    2012-08-01

    Ethanol has been used to achieve thymic depletion in myasthenia gravis patients. Ethanol (95%) has also been used widely in the therapy of many tumors including hepatocellular carcinoma. In light of these findings, we delineated the differential immunotoxic behavior and mechanism of lower concentration of ethanol towards murine EL-4 lymphoma and its normal counterpart lymphocytes. EL-4 lymphoma and normal lymphocytes were cultured with ethanol (0%-5%) for 6 h and cytotoxicity was measured by various methods. EL-4 cells treated with ethanol showed concentration-dependent loss of viability at 2%-5% ethanol concentration and exhibit proliferative arrest at preG1 stage. Acridine-orange and ethidium-bromide staining indicated that ethanol induced death in EL-4 cells, by induction of both apoptosis and necrosis which was further supported by findings of DNA-fragmentation and trypan blue dye exclusion test. However, treatment of lymphocytes with similar concentration of ethanol did not show any death-associated parameters. Furthermore, ethanol induced significantly higher ROS generation in EL-4 cells as compared to lymphocytes and caused PARP cleavage and activation of apoptotic proteins like p53 and Bax, in EL-4 cells and not in normal lymphocytes. In addition, ethanol exposure to EL-4 cells led to phosphorylation of p38MAPK, and upregulation of death receptor Fas (CD95). Taken together, these results suggest that ethanol upto a concentration of 5% caused no significant immunotoxicity towards normal lymphocytes and induced cell death in EL-4 cells via phosphorylation of p38MAPK and regulation of p53 leading to further activation of both extrinsic (Fas) and intrinsic (Bax) apoptotic markers.

  3. Active Teachers - Active Students

    DEFF Research Database (Denmark)

    as an initiative from the Polytechnic in Nantes, France and the University the Los Andes in Bogota, Colombia. The objective was to start a world wide collaboration allowing teachers in engineering to learn from each other about their experiences with active learning. In this thirteenth edition, ALE joins forces...... with the International Research Symposium on Problem Based Learning (IRSPB) and the International Symposium on Project Approaches in Engineering Education (PAEE) to organise the first International Joint Conference on the Learner in Engineering Education (IJCLEE 2015) hosted by Mondragon University, in San Sebastian...

  4. Is activation analysis still active?

    International Nuclear Information System (INIS)

    Chai Zhifang

    2001-01-01

    This paper reviews some aspects of neutron activation analysis (NAA), covering instrumental neutron activation analysis (INAA), k 0 method, prompt gamma-ray neutron activation analysis (PGNAA), radiochemical neutron activation analysis (RNAA) and molecular activation analysis (MAA). The comparison of neutron activation analysis with other analytical techniques are also made. (author)

  5. Cytotoxic and apoptosis-inducing activity of C21 steroids from the roots of Cynanchum atratum.

    Science.gov (United States)

    Zhang, Jian; Ma, Lin; Wu, Zheng-Feng; Yu, Shu-Le; Wang, Lei; Ye, Wen-Cai; Zhang, Qing-Wen; Yin, Zhi-Qi

    2017-06-01

    Two new (1-2) and two known C 21 steroids (3-4) were isolated from the roots of Cynanchum atratum. Their structures were elucidated by detailed 1D and 2D spectroscopic. The MTT assay showed that compounds 1-4 displayed obvious cytotoxic activities against HepG2 cells with IC 50 values ranging from 10.19μM to 76.12μM. Compounds 1-3 also exhibited cytotoxic effects in A549 cells with IC 50 values of 30.87-95.39μM. Compound 3 showed the antiproliferative activity via G0/G1 cell cycle arrest and proapoptosis in HepG2 cells by Flowcytometry analysis. Western blotting analysis revealed that compound 3 could induce HepG2 cell apoptosis via the mitochondrial pathway by downregulating Bcl-2 expression, upregulating Bax protein expression, and activating caspase-9 and caspase-3. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. 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.

  7. 25-OCH3-PPD induces the apoptosis of activated t-HSC/Cl-6 cells via c-FLIP-mediated NF-κB activation.

    Science.gov (United States)

    Wu, Yan-ling; Wan, Ying; Jin, Xue-Jun; OuYang, Bing-Qing; Bai, Ting; Zhao, Yu-Qing; Nan, Ji-Xing

    2011-11-15

    25-OCH(3)-PPD is a dammarane-type triterpene sapogenin isolated from the roots, leaves and seeds of Panax notoginseng, which has shown anti-tumor effects in several human cancer lines. In this study, we evaluated the effects of 25-OCH(3)-PPD on apoptosis of activated t-HSC/Cl-6 cells induced by tumor necrosis factor-α (TNF-α). The inhibitory effects of eleven compounds isolated from Panax ginseng and P. notoginseng were detected in activated t-HSC/Cl-6 cells. 25-OCH(3)-PPD produced a significant inhibitory effect on activated t-HSC/Cl-6 cells. However, 25-OCH(3)-PPD showed almost no effect on the cell viability of Chang liver cells, a type of normal human hepatic cell line. Therefore, we aimed to determine the anti-fibrotic potential of 25-OCH(3)-PPD and to characterize the signal transduction pathways involved in activated HSCs. 25-OCH(3)-PPD decreased the fibrosis markers, including α-smooth muscle actin (α-SMA), transforming growth factor β-1 (TGF-β1) and tissue inhibitors of metalloproteinases-1 (TIMP-1). 25-OCH(3)-PPD elevated the level of cellular GSH in activated HSCs, which demonstrated that 25-OCH(3)-PPD might inhibit HSC activation by its antioxidant capacity. Further analyses revealed that 25-OCH(3)-PPD increased the levels of cleaved caspase-3, decreased the ratio of Bcl-2/Bax and the expression of survivin via c-FLIP-mediated NF-κB activation and shed light on the regulation of apoptosis. Therefore, 25-OCH(3)-PPD may prove to be an excellent candidate agent for the therapy of hepatic fibrosis. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  8. Curcumin protects neurons against oxygen-glucose deprivation/reoxygenation-induced injury through activation of peroxisome proliferator-activated receptor-γ function.

    Science.gov (United States)

    Liu, Zun-Jing; Liu, Hong-Qiang; Xiao, Cheng; Fan, Hui-Zhen; Huang, Qing; Liu, Yun-Hai; Wang, Yu

    2014-11-01

    The turmeric derivative curcumin protects against cerebral ischemic injury. We previously demonstrated that curcumin activates peroxisome proliferator-activated receptor-γ (PPARγ), a ligand-activated transcription factor involved in both neuroprotective and anti-inflammatory signaling pathways. This study tested whether the neuroprotective effects of curcumin against oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury of rat cortical neurons are mediated (at least in part) by PPARγ. Curcumin (10 μM) potently enhanced PPARγ expression and transcriptional activity following OGD/R. In addition, curcumin markedly increased neuronal viability, as evidenced by decreased lactate dehydrogenase release and reduced nitric oxide production, caspase-3 activity, and apoptosis. These protective effects were suppressed by coadministration of the PPARγ antagonist 2-chloro-5-nitrobenzanilide (GW9662) and by prior transfection of a small-interfering RNA (siRNA) targeting PPARγ, treatments that had no toxic effects on healthy neurons. Curcumin reduced OGD/R-induced accumulation of reactive oxygen species and inhibited the mitochondrial apoptosis pathway, as indicated by reduced release of cytochrome c and apoptosis-inducing factor and maintenance of both the mitochondrial membrane potential and the Bax/Bcl-2 ratio. Again, GW9662 or PPARγ siRNA transfection mitigated the protective effects of curcumin on mitochondrial function. Curcumin suppressed IκB kinase phosphorylation and IκB degradation, thereby inhibiting nuclear factor-κ B (NF-κB) nuclear translocation, effects also blocked by GW9662 or PPARγ siRNA. Immunoprecipitation experiments revealed that PPARγ interacted with NF-κB p65 and inhibited NF-κB activation. The present study provides strong evidence that at least some of the neuroprotective effects of curcumin against OGD/R are mediated by PPARγ activation. Copyright © 2014 Wiley Periodicals, Inc.

  9. Anti-proliferative and apoptosis-inducing activity of lycopene against three subtypes of human breast cancer cell lines

    Science.gov (United States)

    Takeshima, Mikako; Ono, Misaki; Higuchi, Takako; Chen, Chen; Hara, Takayuki; Nakano, Shuji

    2014-01-01

    Although lycopene, a major carotenoid component of tomatoes, has been suggested to attenuate the risk of breast cancer, the underlying preventive mechanism remains to be determined. Moreover, it is not known whether there are any differences in lycopene activity among different subtypes of human breast cancer cells. Using ER/PR positive MCF-7, HER2-positive SK-BR-3 and triple-negative MDA-MB-468 cell lines, we investigated the cellular and molecular mechanism of the anticancer activity of lycopene. Lycopene treatment for 168 consecutive hours exhibited a time-dependent and dose-dependent anti-proliferative activity against these cell lines by arresting the cell cycle at the G0/G1 phase at physiologically achievable concentrations found in human plasma. The greatest growth inhibition was observed in MDA-MB-468 where the sub-G0/G1 apoptotic population was significantly increased, with demonstrable cleavage of PARP. Lycopene induced strong and sustained activation of the ERK1/2, with concomitant cyclin D1 suppression and p21 upregulation in these three cell lines. In triple negative cells, lycopene inhibited the phosphorylation of Akt and its downstream molecule mTOR, followed by subsequent upregulation of proapoptotic Bax without affecting anti-apoptotic Bcl-xL. Taken together, these data indicate that the predominant anticancer activity of lycopene in MDA-MB-468 cells suggests a potential role of lycopene for the prevention of triple negative breast cancer. PMID:24397737

  10. Evidence of the gastroprotective and anti-Helicobacter pylori activities of β-mangostin isolated from Cratoxylum arborescens (vahl blume

    Directory of Open Access Journals (Sweden)

    Sidahmed HMA

    2016-01-01

    Full Text Available Heyam Mohamed Ali Sidahmed,1 Najihah Mohd Hashim,1 Syam Mohan,2 Siddig Ibrahim Abdelwahab,2 Manal Mohamed Elhassan Taha,2 Firouzeh Dehghan,3 Maizatulakmal Yahayu,4 Gwendoline Cheng Lian Ee,5 Mun Fai Loke,6 Jamuna Vadivelu6 1Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia; 2Medical Research Center, Jazan University, Jazan, Saudi Arabia; 3Department of Exercise Science, Sports Centre, University of Malaya, Kuala Lumpur, 4Department of Bioproduct Research and Innovation, Institute of Bioproduct Development (IBD, Universiti Teknologi Malaysia (UTM, Johor Bahru, 5Department of Chemistry, Faculty of Science, Universiti Putra Malaysia (UPM, Serdang, 6Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia Purpose: β-Mangostin (BM from Cratoxylum arborescens demonstrated various pharmacological activities such as anticancer and anti-inflammatory. In this study, we aimed to investigate its antiulcer activity against ethanol ulcer model in rats. Materials and methods: BM was isolated from C. arborescens. Gastric acid output, ulcer index, gross evaluation, mucus production, histological evaluation using hematoxylin and eosin and periodic acid–Schiff staining and immunohistochemical localization for heat shock protein 70 (HSP70 and Bax proteins were investigated. Possible involvement of reduced glutathione, lipid peroxidation, prostaglandin E2, antioxidant enzymes, superoxide dismutase and catalase enzymes, radical scavenging, nonprotein sulfhydryl compounds, and anti-Helicobacter pylori were investigated. Results: BM showed antisecretory activity against the pylorus ligature model. The pretreatment with BM protect gastric mucosa from ethanol damaging effect as seen by the improved gross and histological appearance. BM significantly reduced the ulcer area formation, the submucosal edema, and the leukocytes infiltration compared to the ulcer control. The compound

  11. Serenoa repens extracts promote hair regeneration and repair of hair loss mouse models by activating TGF-β and mitochondrial signaling pathway.

    Science.gov (United States)

    Zhu, H-L; Gao, Y-H; Yang, J-Q; Li, J-B; Gao, J

    2018-06-01

    Plenty of plant extracts have been used for treating hair loss. This study aims to investigate the effects of liposterolic extracts of Serenoa repens (LSESr) on hair cell growth and regeneration of hair, and clarify the associated mechanisms. Human keratinocyte cells (HACAT) were cultured, incubated with dihydrotestosterone (DHT) and treated with LSESr. Cell viability was examined by using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H- tetrazolium bromide (MTT) assay. Hair loss C57BL/6 mouse model was established by inducing with DHT. Hair growth, density, and thickness were evaluated. Back skin samples were collected and stained with hematoxylin and eosin (HE) assay. B-cell lymphoma-2 (Bcl-2), Bcl-2 associated protein X (Bax), cleaved caspase 3 and transforming growth factor β2 (TGF-β2) were examined using Western blot assay. LSESr treatment significantly increased HACAT cell viabilities compared to DHT-only treated cells (p<0.05). LSESr treatment post injection of DHT significantly converted skin color from pink to gray and increased hair density, weight and thickness compared to DHT-only treated mice (p<0.05). LSESr treatment significantly triggered follicle growth and decreased inflammatory response. LSESr treatment significantly decreased TGF-β2 and cleaved caspase 3 expression of hair loss mouse models compared to that of DHT treated mice (p<0.05). LSESr treatment significantly enhanced Bcl-2 expression and reduced Bax expression compared to that of DHT treated mice (p<0.05). Meanwhile, effects of LSESr were substantial even achieving to the potential of finasteride. LSESr promoted the hair regeneration and repair of hair loss mouse models by activating TGF-β signaling and mitochondrial signaling pathway.

  12. Antiproliferative Activity of Phenylpropanoids Isolated from Lagotis brevituba Maxim.

    Science.gov (United States)

    Xiang, Yuan; Jing, Zhao; Haixia, Wang; Ruitao, Yu; Huaixiu, Wen; Zenggen, Liu; Lijuan, Mei; Yiping, Wang; Yanduo, Tao

    2017-10-01

    The aim of the present study was to evaluate the antiproliferative effect of phenylpropanoids isolated from the n-BuOH-soluble fraction of an ethanolic extract of Lagotis brevituba Maxim. The phenylpropanoids were identified as echinacoside, lagotioside, glucopyranosyl(1-6)martynoside, plantamoside, and verbascoside. Three of the compounds, lagotioside, glucopyranosyl(1-6)martynoside, and plantamoside, were isolated from L. brevituba for the first time. The antiproliferative activity of the isolates was evaluated in human gastric carcinoma (MGC-803), human colorectal carcinoma (HCT116), human hepatocellar carcinoma (HepG2), and human lung cancer (HCT116) cells using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Plantamoside showed promising activity against MGC-803 cells, with a half maximal inhibitory concentration value of 37.09 μM. The mechanism of the pro-apoptosis effect of plantamoside was then evaluated in MGC-803 cells. Changes in cell morphology, including disorganization of the architecture of actin microfilaments and formation of apoptotic bodies, together with cell cycle arrest in G2/M phases, were observed after treatment of plantamoside. The antiproliferative and pro-apoptotic effects were associated with a decrease in the ratio of Bcl-2/Bax and reduced mitochondrial membrane potential, which was accompanied by the release of reactive oxygen species and Ca 2+ into the cytoplasm. Taken together, the results indicated that plantamoside promotes apoptosis via a mitochondria-dependent mechanism. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  13. Molecular mechanism behind the synergistic activity of diphenylmethyl selenocyanate and Cisplatin against murine tumor model.

    Science.gov (United States)

    Chakraborty, Pramita; Roy, Somnath Singha; Bhattacharya, Sudin

    2015-01-01

    Various preclinical, clinical and epidemiological studies have already well established the cancer chemopreventive and chemoprotective potential of selenium compounds. In addition to its protective efficacy, recent studies have also proved the abilities of selenium compounds to induce cell death specifically in malignant cells. Therefore, our intention is to improve the therapeutic efficacy of an alkylating agent, cisplatin, by the adjuvant use of an organoselenium compound, diphenylmethyl selenocyanate (DMSE). It was observed that combined treatment decreased the tumor burden significantly through reactive oxygen species generation and modulation of antioxidant and detoxifying enzyme system in tumor cells. These activities ultimately led to significant DNA damage and apoptosis in tumor cells. Study of the molecular pathway disclosed that the adjuvant treatment caused induction of p53, Bax and suppressed Bcl-2 followed by the activation of caspase cascade. Furthermore, a concomitant decrease in cisplatin-induced nephrotoxicity and hematopoietic toxicity by DMSE might also have enhanced the efficacy of cisplatin and provided survival advantage to the host. Results suggested that the combination treatment with DMSE and cisplatin may offer potential therapeutic benefit, and utilization of cisplatin in cancer chemotherapy exempt of its limitations.

  14. Novel Radiolytic Rotenone Derivative, Rotenoisin B with Potent Anti-Carcinogenic Activity in Hepatic Cancer Cells

    Directory of Open Access Journals (Sweden)

    Srilatha Badaboina

    2015-07-01

    Full Text Available Rotenone, isolated from roots of derris plant, has been shown to possess various biological activities, which lead to attempting to develop a potent drug against several diseases. However, recent studies have demonstrated that rotenone has the potential to induce several adverse effects such as a neurodegenerative disease. Radiolytic transformation of the rotenone with gamma-irradiation created a new product, named rotenoisin B. The present work was designed to investigate the anticancer activity of rotenoisin B with low toxicity and its molecular mechanism in hepatic cancer cells compared to a parent compound, rotenone. Our results showed rotenoisin B inhibited hepatic cancer cells’ proliferation in a dose dependent manner and increased in apoptotic cells. Interestingly, rotenoisin B showed low toxic effects on normal cells compared to rotenone. Mitochondrial transmembrane potential has been decreased, which leads to cytochrome c release. Down regulation of anti-apoptotic Bcl-2 levels as well as the up regulation of proapoptotic Bax levels were observed. The cleaved PARP (poly ADP-ribose polymerase level increased as well. Moreover, phosphorylation of extracellular signal regulated kinase (ERK and p38 slightly up regulated and intracellular reactive oxygen species (ROS increased as well as cell cycle arrest predominantly at the G2/M phase observed. These results suggest that rotenoisin B might be a potent anticancer candidate similar to rotenone in hepatic cancer cells with low toxicity to normal cells even at high concentrations compared to rotenone.

  15. 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.

  16. Acetaldehyde Induces Cytotoxicity of SH-SY5Y Cells via Inhibition of Akt Activation and Induction of Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Tingting Yan

    2016-01-01

    Full Text Available Excessive alcohol consumption can lead to brain tissue damage and cognitive dysfunction. It has been shown that heavy drinking is associated with an earlier onset of neurodegenerative diseases such as Alzheimer’s disease. Acetaldehyde, the most toxic metabolite of ethanol, is speculated to mediate the brain tissue damage and cognitive dysfunction induced by the chronic excessive consumption of alcohol. However, the exact mechanisms by which acetaldehyde induces neurotoxicity are not totally understood. In this study, we investigated the cytotoxic effects of acetaldehyde in SH-SY5Y cells and found that acetaldehyde induced apoptosis of SH-SY5Y cells by downregulating the expression of antiapoptotic Bcl-2 and Bcl-xL and upregulating the expression of proapoptotic Bax. Acetaldehyde treatment led to a significant decrease in the levels of activated Akt and cyclic AMP-responsive element binding protein (CREB. In addition, acetaldehyde induced the activation of p38 mitogen-activated protein kinase (MAPK while inhibiting the activation of extracellular signal-regulated kinases (ERKs, p44/p42MAPK. Meanwhile, acetaldehyde treatment caused an increase in the production of reactive oxygen species and elevated the oxidative stress in SH-SY5Y cells. Therefore, acetaldehyde induces cytotoxicity of SH-SY5Y cells via promotion of apoptotic signaling, inhibition of cell survival pathway, and induction of oxidative stress.

  17. Silybin-mediated inhibition of Notch signaling exerts antitumor activity in human hepatocellular carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Song Zhang

    Full Text Available Hepatocellular carcinoma (HCC is a global health burden that is associated with limited treatment options and poor patient prognoses. Silybin (SIL, an antioxidant derived from the milk thistle plant (Silybum marianum, has been reported to exert hepatoprotective and antitumorigenic effects both in vitro and in vivo. While SIL has been shown to have potent antitumor activity against various types of cancer, including HCC, the molecular mechanisms underlying the effects of SIL remain largely unknown. The Notch signaling pathway plays crucial roles in tumorigenesis and immune development. In the present study, we assessed the antitumor activity of SIL in human HCC HepG2 cells in vitro and in vivo and explored the roles of the Notch pathway and of the apoptosis-related signaling pathway on the activity of SIL. SIL treatment resulted in a dose- and time-dependent inhibition of HCC cell viability. Additionally, SIL exhibited strong antitumor activity, as evidenced not only by reductions in tumor cell adhesion, migration, intracellular glutathione (GSH levels and total antioxidant capability (T-AOC but also by increases in the apoptotic index, caspase3 activity, and reactive oxygen species (ROS. Furthermore, SIL treatment decreased the expression of the Notch1 intracellular domain (NICD, RBP-Jκ, and Hes1 proteins, upregulated the apoptosis pathway-related protein Bax, and downregulated Bcl2, survivin, and cyclin D1. Notch1 siRNA (in vitro or DAPT (a known Notch1 inhibitor, in vivo further enhanced the antitumor activity of SIL, and recombinant Jagged1 protein (a known Notch ligand in vitro attenuated the antitumor activity of SIL. Taken together, these data indicate that SIL is a potent inhibitor of HCC cell growth that targets the Notch signaling pathway and suggest that the inhibition of Notch signaling may be a novel therapeutic intervention for HCC.

  18. Exposure to Cerium Oxide Nanoparticles Is Associated With Activation of Mitogen-activated Protein Kinases Signaling and Apoptosis in Rat Lungs

    Directory of Open Access Journals (Sweden)

    Kevin M. Rice

    2015-05-01

    Full Text Available Objectives: With recent advances in nanoparticle manufacturing and applications, potential exposure to nanoparticles in various settings is becoming increasing likely. No investigation has yet been performed to assess whether respiratory tract exposure to cerium oxide (CeO2 nanoparticles is associated with alterations in protein signaling, inflammation, and apoptosis in rat lungs. Methods: Specific-pathogen-free male Sprague-Dawley rats were instilled with either vehicle (saline or CeO2 nanoparticles at a dosage of 7.0 mg/kg and euthanized 1, 3, 14, 28, 56, or 90 days after exposure. Lung tissues were collected and evaluated for the expression of proteins associated with inflammation and cellular apoptosis. Results: No change in lung weight was detected over the course of the study; however, cerium accumulation in the lungs, gross histological changes, an increased Bax to Bcl-2 ratio, elevated cleaved caspase-3 protein levels, increased phosphorylation of p38 MAPK, and diminished phosphorylation of ERK-1/2-MAPK were detected after CeO2 instillation (p<0.05. Conclusions: Taken together, these data suggest that high-dose respiratory exposure to CeO2 nanoparticles is associated with lung inflammation, the activation of signaling protein kinases, and cellular apoptosis, which may be indicative of a long-term localized inflammatory response.

  19. Activation of peroxisome proliferator-activated receptor-γ (PPARγ) induces cell death through MAPK-dependent mechanism in osteoblastic cells

    International Nuclear Information System (INIS)

    Kim, Sung Hun; Yoo, Chong Il; Kim, Hui Taek; Park, Ji Yeon; Kwon, Chae Hwa; Keun Kim, Yong

    2006-01-01

    The present study was undertaken to determine the role of the mitogen-activated protein kinase (MAPK) subfamilies in cell death induced by PPARγ agonists in osteoblastic cells. Ciglitazone and troglitazone, PPARγ agonists, resulted in a concentration- and time-dependent cell death, which was largely attributed to apoptosis. But a PPARα agonist ciprofibrate did not affect the cell death. Ciglitazone caused reactive oxygen species (ROS) generation and ciglitazone-induced cell death was prevented by antioxidants, suggesting an important role of ROS generation in the ciglitazone-induced cell death. ROS generation and cell death induced by ciglitazone were inhibited by the PPARγ antagonist GW9662. Ciglitazone treatment caused activation of extracellular signal-regulated kinase (ERK) and p38. Activation of ERK was dependent on epidermal growth factor receptor (EGFR) and that of p38 was independent. Ciglitazone-induced cell death was significantly prevented by PD98059, an inhibitor of ERK upstream kinase MEK1/2, and SB203580, a p38 inhibitor. Ciglitazone treatment increased Bax expression and caused a loss of mitochondrial membrane potential, and its effect was prevented by N-acetylcysteine, PD98059, and SB203580. Ciglitazone induced caspase activation, which was prevented by PD98059 and SB203580. The general caspase inhibitor z-DEVD-FMK and the specific inhibitor of caspases-3 DEVD-CHO exerted the protective effect against the ciglitazone-induced cell death. The EGFR inhibitors AG1478 and suramin protected against the ciglitazone-induced cell death. Taken together, these findings suggest that the MAPK signaling pathways play an active role in mediating the ciglitazone-induced cell death of osteoblasts and function upstream of a mitochondria-dependent mechanism. These data may provide a novel insight into potential therapeutic strategies for treatment of osteoporosis

  20. Activated Charcoal

    Science.gov (United States)

    Common charcoal is made from peat, coal, wood, coconut shell, or petroleum. “Activated charcoal” is similar to common charcoal, but is made especially for use as a medicine. To make activated charcoal, manufacturers heat common ...

  1. Beneficial effect of prolonged heme oxygenase 1 activation in a rat model of chronic heart failure

    Directory of Open Access Journals (Sweden)

    Massimo Collino

    2013-07-01

    We and others have previously demonstrated that heme oxygenase 1 (HO-1 induction by acute hemin administration exerts cardioprotective effects. Here, we developed a rat model of heart failure to investigate whether a long-term induction of HO-1 by chronic hemin administration exerted protective effects. Sprague Dawley rats that underwent permanent ligation of the left coronary artery were closely monitored for survival rate analysis and sacrificed on day 28 post-operation. Administration of hemin (4 mg/kg body weight every other day for 4 weeks induced a massive increase in HO-1 expression and activity, as shown by the increased levels of the two main metabolic products of heme degradation, bilirubin and carbon monoxide (CO. These effects were associated with significant improvement in survival and reduced the extension of myocardial damage. The ischemic hearts of the hemin-treated animals displayed reduced oxidative stress and apoptosis in comparison with the non-treated rats, as shown by the decreased levels of lipid peroxidation, free-radical-induced DNA damage, caspase-3 activity and Bax expression. Besides, chronic HO-1 activation suppressed the elevated levels of myeloperoxidase (MPO activity, interleukin 1β (IL-1β production and tumor necrosis factor-α (TNFα production that were evoked by the ischemic injury, and increased the plasma level of the anti-inflammatory cytokine IL-10. Interestingly, HO-1 inhibitor zinc protoporphyrin IX (ZnPP-IX; 1 mg/kg lowered bilirubin and CO concentrations to control values, thus abolishing all the cardioprotective effects of hemin. In conclusion, the results demonstrate that chronic HO-1 activation by prolonged administration of hemin improves survival and exerts protective effects in a rat model of myocardial ischemia by exerting a potent antioxidant activity and disrupting multiple levels of the apoptotic and inflammatory cascade.

  2. Beneficial effect of prolonged heme oxygenase 1 activation in a rat model of chronic heart failure.

    Science.gov (United States)

    Collino, Massimo; Pini, Alessandro; Mugelli, Niccolò; Mastroianni, Rosanna; Bani, Daniele; Fantozzi, Roberto; Papucci, Laura; Fazi, Marilena; Masini, Emanuela

    2013-07-01

    We and others have previously demonstrated that heme oxygenase 1 (HO-1) induction by acute hemin administration exerts cardioprotective effects. Here, we developed a rat model of heart failure to investigate whether a long-term induction of HO-1 by chronic hemin administration exerted protective effects. Sprague Dawley rats that underwent permanent ligation of the left coronary artery were closely monitored for survival rate analysis and sacrificed on day 28 post-operation. Administration of hemin (4 mg/kg body weight) every other day for 4 weeks induced a massive increase in HO-1 expression and activity, as shown by the increased levels of the two main metabolic products of heme degradation, bilirubin and carbon monoxide (CO). These effects were associated with significant improvement in survival and reduced the extension of myocardial damage. The ischemic hearts of the hemin-treated animals displayed reduced oxidative stress and apoptosis in comparison with the non-treated rats, as shown by the decreased levels of lipid peroxidation, free-radical-induced DNA damage, caspase-3 activity and Bax expression. Besides, chronic HO-1 activation suppressed the elevated levels of myeloperoxidase (MPO) activity, interleukin 1β (IL-1β) production and tumor necrosis factor-α (TNFα) production that were evoked by the ischemic injury, and increased the plasma level of the anti-inflammatory cytokine IL-10. Interestingly, HO-1 inhibitor zinc protoporphyrin IX (ZnPP-IX; 1 mg/kg) lowered bilirubin and CO concentrations to control values, thus abolishing all the cardioprotective effects of hemin. In conclusion, the results demonstrate that chronic HO-1 activation by prolonged administration of hemin improves survival and exerts protective effects in a rat model of myocardial ischemia by exerting a potent antioxidant activity and disrupting multiple levels of the apoptotic and inflammatory cascade.

  3. Perfluorononanoic acid-induced apoptosis in rat spleen involves oxidative stress and the activation of caspase-independent death pathway

    International Nuclear Information System (INIS)

    Fang, Xuemei; Feng, Yixing; Wang, Jianshe; Dai, Jiayin

    2010-01-01

    Perfluoroalkyl acid (PFAA)-induced apoptosis has been reported in many cell types. However, minimal information on its mode of action is available. This study explored the possible involvement of apoptotic signaling pathways in a nine-carbon-chain length PFAA-perfluorononanoic acid (PFNA)-induced splenocyte apoptosis. After a 14-day exposure to PFNA, rat spleens showed dose-dependent levels of apoptosis. The production of pro-inflammatory and anti-inflammatory cytokines was significantly increased and decreased, respectively. However, protein levels of tumor necrosis factor receptor 1 (TNFR1), fas-associated protein with death domain (FADD), caspase 8 and caspase 3, which are involved in inflammation-related and caspase-dependent apoptosis, were discordant. Peroxisome proliferator-activated receptors alpha (PPARα) and PPARγ genes expression was up-regulated in rats treated with 3 or 5 mg/kg/day of PFNA, and the level of hydrogen peroxide (H 2 O 2 ) increased concurrently in rats treated with the highest dose. Moreover, superoxide dismutase (SOD) activity and Bcl-2 protein levels were dramatically decreased in spleens after treatment with 3 and 5 mg/kg/day of PFNA. However, protein levels of Bax were unchanged. Apoptosis-inducing factor (AIF), an initiator of caspase-independent apoptosis, was significantly increased in all PFNA-dosed rats. Thus, oxidative stress and the activation of a caspase-independent apoptotic signaling pathway contributed to PFNA-induced apoptosis in rat splenocytes.

  4. Active fragments from pro- and antiapoptotic BCL-2 proteins have distinct membrane behavior reflecting their functional divergence.

    Directory of Open Access Journals (Sweden)

    Yannis Guillemin

    Full Text Available BACKGROUND: The BCL-2 family of proteins includes pro- and antiapoptotic members acting by controlling the permeabilization of mitochondria. Although the association of these proteins with the outer mitochondrial membrane is crucial for their function, little is known about the characteristics of this interaction. METHODOLOGY/PRINCIPAL FINDINGS: Here, we followed a reductionist approach to clarify to what extent membrane-active regions of homologous BCL-2 family proteins contribute to their functional divergence. Using isolated mitochondria as well as model lipid Langmuir monolayers coupled with Brewster Angle Microscopy, we explored systematically and comparatively the membrane activity and membrane-peptide interactions of fragments derived from the central helical hairpin of BAX, BCL-xL and BID. The results show a connection between the differing abilities of the assayed peptide fragments to contact, insert, destabilize and porate membranes and the activity of their cognate proteins in programmed cell death. CONCLUSION/SIGNIFICANCE: BCL-2 family-derived pore-forming helices thus represent structurally analogous, but functionally dissimilar membrane domains.

  5. Essential Oil from Cryptomeria japonica Induces Apoptosis in Human Oral Epidermoid Carcinoma Cells via Mitochondrial Stress and Activation of Caspases

    Directory of Open Access Journals (Sweden)

    Ji-Young Kim

    2012-03-01

    Full Text Available Cryptomeria japonica D. Don (C. japonica has been used in traditional medicines from Asia for a variety of indications, including liver ailments, and an antitussive, and for its antiulcer activities. We examined the cell viability and apoptosis of KB cells treated with C. japonica essential oil at several concentrations for 12 h by MTT assay, Hoechst-33258 dye staining, DNA fragmentation, flow cytometry (cell cycle, and Western blotting for mitochondria stress, activation of caspases, and poly (ADP-ribose polymerase. The essential oil induced the apoptosis of KB cells in a dose-dependent manner, which was verified by DNA fragmentation, appearance of apoptotic bodies, and the sub-G1 ratio. The essential oil also induced rapid and transient caspase-3 activity and cleavage of PARP of the KB cells. Treating the cells with the oil also caused changes in the mitochondrial level of the Bcl-2 family proteins such as Bcl-2 and Bax, thereby inducing the release of cytochrome c into the cytosol. The essential oil of C. japonica may have potential as a cancer chemopreventive and therapeutic agent.

  6. Astragalin: A Bioactive Phytochemical with Potential Therapeutic Activities

    Directory of Open Access Journals (Sweden)

    Ammara Riaz

    2018-01-01

    Full Text Available Natural products, an infinite treasure of bioactive chemical entities, persist as an inexhaustible resource for discovery of drugs. This review article intends to emphasize on one of the naturally occurring flavonoids, astragalin (kaempferol 3-glucoside, which is a bioactive constituent of various traditional medicinal plants such as Cuscuta chinensis. This multifaceted compound is well known for its diversified pharmacological applications such as anti-inflammatory, antioxidant, neuroprotective, cardioprotective, antiobesity, antiosteoporotic, anticancer, antiulcer, and antidiabetic properties. It carries out the aforementioned activities by the regulation and modulation of various molecular targets such as transcription factors (NF-κB, TNF-α, and TGF-β1, enzymes (iNOS, COX-2, PGE2, MMP-1, MMP-3, MIP-1α, COX-2, PGE-2, HK2, AChe, SOD, DRP-1, DDH, PLCγ1, and GPX, kinases (JNK, MAPK, Akt, ERK, SAPK, IκBα, PI3K, and PKCβ2, cell adhesion proteins (E-cadherin, vimentin PAR-2, and NCam, apoptotic and antiapoptotic proteins (Beclin-1, Bcl-2, Bax, Bcl-xL, cytochrome c, LC3A/B, caspase-3, caspase-9, procaspase-3, procaspase-8, and IgE, and inflammatory cytokines (SOCS-3, SOCS-5, IL-1β, IL-4, IL-6, IL-8, IL-13, MCP-1, CXCL-1, CXCL-2, and IFN-γ. Although researchers have reported multiple pharmacological applications of astragalin in various diseased conditions, further experimental investigations are still mandatory to fully understand its mechanism of action. It is contemplated that astragalin could be subjected to structural optimization to ameliorate its chemical accessibility, to optimize its absorption profiles, and to synthesize its more effective analogues which will ultimately lead towards potent drug candidates.

  7. Active ageing

    Directory of Open Access Journals (Sweden)

    Frode F. Jacobsen

    2017-09-01

    Full Text Available Background: The concept of active ageing has been gaining prominence in the Nordic countries and beyond. This has been reflected in policy papers in Norway and other Nordic nations. Aims: The aim of this article is to analyse the topic of active ageing in five Norwegian White Papers (2002 to 2015 and discuss those policy documents in context of relevant research literature. Methods: A qualitative document analyses is employed focusing on how active ageing, and ageing in general, is described and which concepts are employed. No ethical approval was needed. Findings: The general theme of ageing and the specific theme of active ageing are increasingly prominent in the Norwegian White Papers studied. In all documents, some assumptions regarding ageing and active ageing seem implicit, such as independence being more important than (interdependence. ‘Productive’ activities like participation in working life are stressed, while others, like reading, watching TV or watching children playing in the street, are ignored. Conclusions: The policy documents demonstrate that the topic of active ageing is growing in importance. The documents increasingly seem to stress ‘productive’ activities – those related to working life, voluntary work or sports and physical training. They exclude activities that are meaningful for many older people, like watching their grandchildren play or reading books. Implications for practice: Practitioners in older people’s care could consider reflecting on: Government documents dealing with their own practice The prevalent concept of active ageing The trend of active ageing as a facilitating or hindering factor for good care work How present discourse on active ageing may influence their attitude towards frail older persons How they wish to relate to active ageing in their own practice

  8. Maspin Enhances the Anticancer Activity of Curcumin in Hormone-refractory Prostate Cancer Cells.

    Science.gov (United States)

    Cheng, Wan-Li; Huang, Chien-Yu; Tai, Cheng-Jeng; Chang, Yu-Jia; Hung, Chin-Sheng

    2018-02-01

    Androgen deprivation therapy remains the principal treatment for patients with advanced prostate cancer, though, most patients will eventually develop hormone-refractory prostate cancer (HRPC). Androgen ablation mediated maspin-induction has been identified in cancer patients. However, the role of maspin on the anticancer activity of curcumin derived from turmeric (Curcuma longa) in HRPC cells has not been elucidated. The anticancer action of curcumin in hormone-independent prostate cancer cells (DU145, and PC-3) was determined by measures of cell survival rate. The cause of maspin silencing on the anti-tumor abilities of curcumin in PC-3 cells was evaluated by measures of cell survival rate, cell-cycle distribution, and apoptosis signaling analysis. Our present study showed that PC-3 cells (with higher maspin expression) were more sensitive than DU145 cells to curcumin treatment (with lower maspin expression). RNA interference-mediated maspin silencing reduced curcumin sensitivity of PC-3 cells, as evidenced by reduced apoptotic cell death. After exposure to curcumin, maspin-knockdown cells showed lower expression levels of pro-apoptotic proteins, Bad and Bax, as compared with control cells. Maspin can enhance the sensitivity of HRPC cells to curcumin treatment. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  9. AKT delays the early-activated apoptotic pathway in UVB-irradiated keratinocytes via BAD translocation.

    Science.gov (United States)

    Claerhout, Sofie; Decraene, David; Van Laethem, An; Van Kelst, Sofie; Agostinis, Patrizia; Garmyn, Marjan

    2007-02-01

    Upon irradiation with a high dose of UVB, keratinocytes undergo apoptosis as a protective mechanism. In previous work, we demonstrated the existence of an early-activated UVB-induced apoptotic pathway in growth factor-depleted human keratinocytes, which can be substantially delayed by the exclusive supplementation of IGF-1. We now show that in human keratinocytes, IGF-1 inhibits the onset of UVB-triggered apoptosis through a transcriptional independent, AKT-mediated mechanism, involving BAD serine 136 phosphorylation. Our results show that the early UVB-induced apoptosis in growth factor-depleted human keratinocytes is exclusively triggered through the mitochondrial pathway. It is accompanied by BAX translocation, cytochrome c release, and procaspase-9 cleavage, but not by procaspase-8 or BID cleavage. In human keratinocytes, IGF-1 supplementation inhibits these events in a transcription-independent manner. Both IGF-1 supplementation and the transduction of a membrane-targeted form of AKT result in a shift of the BH3-only protein BAD from the mitochondria to the cytoplasm, paralleled by an increase of AKT-specific Ser136 phospho-BAD bound to 14-3-3zeta protein. These data indicate that AKT-induced BAD phosphorylation and its subsequent cytoplasmic sequestration by 14-3-3zeta is a major mechanism responsible for the postponement of UVB-induced apoptosis in human keratinocytes.

  10. Functional Characterisation of Anticancer Activity in the Aqueous Extract of Helicteres angustifolia L. Roots.

    Directory of Open Access Journals (Sweden)

    Kejuan Li

    Full Text Available Helicteres angustifolia L. is a shrub that forms a common ingredient of several cancer treatment recipes in traditional medicine system both in China and Laos. In order to investigate molecular mechanisms of its anticancer activity, we prepared aqueous extract of Helicteres angustifolia L. Roots (AQHAR and performed several in vitro assays using human normal fibroblasts (TIG-3 and osteosarcoma (U2OS. We found that AQHAR caused growth arrest/apoptosis of U2OS cells in a dose-dependent manner. It showed no cytotoxicity to TIG-3 cells at doses up to 50 μg/ml. Biochemical, imaging and cell cycle analyses revealed that it induces ROS signaling and DNA damage response selectively in cancer cells. The latter showed upregulation of p53, p21 and downregulation of Cyclin B1 and phospho-Rb. Furthermore, AQHAR-induced apoptosis was mediated by increase in pro-apoptotic proteins including cleaved PARP, caspases and Bax. Anti-apoptotic protein Bcl-2 showed decrease in AQHAR-treated U2OS cells. In vivo xenograft tumor assays in nude mice revealed dose-dependent suppression of tumor growth and lung metastasis with no toxicity to the animals suggesting that AQHAR could be a potent and safe natural drug for cancer treatment.

  11. 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.)

  12. Physical Activity

    DEFF Research Database (Denmark)

    Andersen, Lars Bo; Anderssen, Sigmund Alfred; Wisløff, Ulrik

    2014-01-01

    Andersen LB, Anderssen SA, Wisløff U, Hellénius M-L, Fogelholm M, Ekelund U. (Expert Group) Nordic Nutrition Recommendations 2012. Integrating nutrition and physical activity. Chapter: Physical Activity p. 195-217.Nordic Counsil of Ministers.......Andersen LB, Anderssen SA, Wisløff U, Hellénius M-L, Fogelholm M, Ekelund U. (Expert Group) Nordic Nutrition Recommendations 2012. Integrating nutrition and physical activity. Chapter: Physical Activity p. 195-217.Nordic Counsil of Ministers....

  13. Novel curcumin analogue 14p protects against myocardial ischemia reperfusion injury through Nrf2-activating anti-oxidative activity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Weixin [Department of Cardiology, The 5th Affiliated Hospital of Wenzhou Medical University, Lishui, Zhejiang (China); Chemical Biology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang (China); Wu, Mingchai [Department of Pharmacy, The Third Affiliated Hospital of Wenzhou Medical University, Wenzou, Zhejiang (China); Tang, Longguang; Pan, Yong; Liu, Zhiguo [Chemical Biology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang (China); Zeng, Chunlai [Department of Cardiology, The 5th Affiliated Hospital of Wenzhou Medical University, Lishui, Zhejiang (China); Wang, Jingying [Chemical Biology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang (China); Wei, Tiemin, E-mail: lswtm@sina.com [Department of Cardiology, The 5th Affiliated Hospital of Wenzhou Medical University, Lishui, Zhejiang (China); Liang, Guang, E-mail: wzmcliangguang@163.com [Chemical Biology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang (China)

    2015-01-15

    Background: Alleviating the oxidant stress associated with myocardial ischemia reperfusion has been demonstrated as a potential therapeutic approach to limit ischemia reperfusion (I/R)-induced cardiac damage. Curcumin, a natural compound with anti-oxidative activity, exerts beneficial effect against cardiac I/R injury, but poor chemical and metabolic stability. Previously, we have designed and synthesized a series of mono-carbonyl analogues of curcumin (MACs) with high stability. This study aims to find new anti-oxidant MACs and to demonstrate their effects and mechanisms against I/R-induced heart injury. Methods: H9c2 cells challenged with H{sub 2}O{sub 2} or TBHP were used for in vitro bio-screening and mechanistic studies. The MDA, H{sub 2}O{sub 2} and SOD levels in H9C2 cells were determined, and the cell viability was assessed by MTT assay. Myocardial I/R mouse models administrated with or without the compound were used for in vivo studies. Results: The in vitro cell-based screening showed that curcumin analogues 8d and 14p exhibited strong anti-oxidative effects. Pre-treatment of H9c2 cells with 14p activated Nrf2 signaling pathway, attenuated H{sub 2}O{sub 2}-increased MDA and SOD level, followed by the inhibition of TBHP-induced cell death and Bax/Bcl-2–caspase-3 pathway activation. Silencing Nrf2 significantly reversed the protective effects of 14p. In in vivo animal model of myocardial I/R, administration of low dose 14p (10 mg/kg) reduced infarct size and myocardial apoptosis to the same extent as the high dose curcumin (100 mg/kg). Conclusion: These data support the novel curcumin analogue 14p as a promising antioxidant to decrease oxidative stress and limit myocardial ischemia reperfusion injury via activating Nrf2. - Highlights: • Mono-carbonyl analogue of curcumin, 14p, exhibited better chemical stability. • Compound 14p inhibited TBHP-induced apoptosis through activating Nrf2 in vitro. • Compound 14p limited myocardial ischemia

  14. Activity report

    International Nuclear Information System (INIS)

    1990-11-01

    The Department of Physics and Measurement Technology, Biology and Chemistry (IFM) presents every year a progress report containing a brief description of activities in research and education within the department. The report is intended as an information for colleagues and institutions. The present report contains activities for the academic year July 1989 to June 1990

  15. ATM phosphorylation of Mdm2 Ser394 regulates the amplitude and duration of the DNA damage response in mice

    Science.gov (United States)

    Gannon, Hugh S.; Woda, Bruce A.; Jones, Stephen N.

    2012-01-01

    Summary DNA damage induced by ionizing radiation (IR) activates the ATM kinase, which subsequently stabilizes and activates the p53 tumor suppressor protein. Although phosphorylation of p53 by ATM was found previously to modulate p53 levels and transcriptional activities in vivo, it does not appear to be a major regulator of p53 stability. We have utilized mice bearing altered Mdm2 alleles to demonstrate that ATM phosphorylation of Mdm2 serine 394 is required for robust p53 stabilization and activation after DNA damage. In addition, we demonstrate that dephosphorylation of Mdm2 Ser394 regulates attenuation of the p53-mediated response to DNA damage. Therefore, the phosphorylation status of Mdm2 Ser394 governs p53 protein levels and functions in cells undergoing DNA damage. PMID:22624716

  16. Bioactives in cactus (Opuntia ficus-indica) stems possess potent antioxidant and pro-apoptotic activities through COX-2 involvement.

    Science.gov (United States)

    Kim, Jinhee; Soh, Soon Yil; Shin, Juha; Cho, Chi-Woung; Choi, Young Hee; Nam, Sang-Yong

    2015-10-01

    Bioactives extracted from cactus (Opuntia ficus-indica) stems were investigated for their chemopreventive activities using human cancer cells in vitro. The bioactives present in crude extracts were detected and quantified using high-performance liquid chromatography. Among all the extracts, such as hexane, ethyl acetate (EtOAc), acetone, methanol (MeOH), and MeOH:water (80:20), the MeOH extract had the highest amount of polyphenolic compounds and the acetone extract exhibited the most potent effect at scavenging the 2,2,-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS(•+) ) radical. In addition, most of the extracts, with the exception of hexane, exhibited significant cytotoxicity in human SW480 colon and MCF7 breast cancer cells. Overall, the SW480 cells were more sensitive than the MCF7 cells to the cytotoxic effect of the O. ficus-indica extracts (OFEs). Cell death by OFE treatment caused significant inhibition of cyclooxygenase-2 and increased the Bax/Bcl2 ratio in both SW480 and MCF7 cell lines. However, degradation of poly (ADP-ribose) polymerase was significantly increased by OFE only in the MCF7 cells, thereby inducing apoptosis. These findings demonstrate the health-benefit roles, including anti-oxidative and anti-proliferative activities as well as pro-apoptotic effects, of bioactive compounds in OFEs, suggesting a chemopreventive role in human cancer cells. © 2014 Society of Chemical Industry.

  17. Anticancer Activity of a Hexapeptide from Skate (Raja porosa) Cartilage Protein Hydrolysate in HeLa Cells.

    Science.gov (United States)

    Pan, Xin; Zhao, Yu-Qin; Hu, Fa-Yuan; Chi, Chang-Feng; Wang, Bin

    2016-08-16

    In this study, the hexapeptide Phe-Ile-Met-Gly-Pro-Tyr (FIMGPY), which has a molecular weight of 726.9 Da, was separated from skate (Raja porosa) cartilage protein hydrolysate using ultrafiltration and chromatographic methods, and its anticancer activity was evaluated in HeLa cells. Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay indicated that FIMGPY exhibited high, dose-dependent anti-proliferation activities in HeLa cells with an IC50 of 4.81 mg/mL. Acridine orange/ethidium bromide (AO/EB) fluorescence staining and flow cytometry methods confirmed that FIMGPY could inhibit HeLa cell proliferation by inducing apoptosis. Western blot assay revealed that the Bax/Bcl-2 ratio and relative intensity of caspase-3 in HeLa cells treated with 7-mg/mL FIMGPY were 2.63 and 1.83, respectively, significantly higher than those of the blank control (p skate cartilage protein hydrolysate may have applications as functional foods and nutraceuticals for the treatment and prevention of cancer.

  18. Pinus densiflora leaf essential oil induces apoptosis via ROS generation and activation of caspases in YD-8 human oral cancer cells.

    Science.gov (United States)

    Jo, Jeong-Rang; Park, Ju Sung; Park, Yu-Kyoung; Chae, Young Zoo; Lee, Gyu-Hee; Park, Gy-Young; Jang, Byeong-Churl

    2012-04-01

    The leaf of Pinus (P.) densiflora, a pine tree widely distributed in Asian countries, has been used as a traditional medicine. In the present study, we investigated the anticancer activity of essential oil, extracted by steam distillation, from the leaf of P. densiflora in YD-8 human oral squamous cell carcinoma (OSCC) cells. Treatment of YD-8 cells with P. densiflora leaf essential oil (PLEO) at 60 µg/ml for 8 h strongly inhibited proliferation and survival and induced apoptosis. Notably, treatment with PLEO led to generation of ROS, activation of caspase-9, PARP cleavage, down-regulation of Bcl-2, and phosphorylation of ERK-1/2 and JNK-1/2 in YD-8 cells. Treatment with PLEO, however, did not affect the expression of Bax, XIAP and GRP78. Importantly, pharmaco-logical inhibition studies demonstrated that treatment with vitamin E (an anti-oxidant) or z-VAD-fmk (a pan-caspase inhibitor), but not with PD98059 (an ERK-1/2 inhibitor) or SP600125 (a JNK-1/2 inhibitor), strongly suppressed PLEO-induced apoptosis in YD-8 cells and reduction of their survival. Vitamin E treatment further blocked activation of caspase-9 and Bcl-2 down-regulation induced by PLEO. Thus, these results demonstrate firstly that PLEO has anti-proliferative, anti-survival and pro-apoptotic effects on YD-8 cells and the effects are largely due to the ROS-dependent activation of caspases.

  19. Essential Oil Derived From Eupatorium adenophorum Spreng. Mediates Anticancer Effect by Inhibiting STAT3 and AKT Activation to Induce Apoptosis in Hepatocellular Carcinoma

    Directory of Open Access Journals (Sweden)

    Hao Chen

    2018-05-01

    Full Text Available Eupatorium adenophorum Spreng. (EA is a well-known noxious invasive species. Gas chromatography-mass spectrometry (GC-MS analysis revealed that the essential oil derived from EA (EAEO is mainly composed of sesquiterpenes. However, the pharmacological value of EAEO in hepatocellular carcinoma (HCC remains largely unexplored. Herein, we investigated the anti-HCC activities of EAEO, and explored the potential mechanisms of EAEO-induced apoptosis. An MTT assay showed that EAEO inhibited HCC cell proliferation with little toxicity on normal liver cells. Wound healing and FACS assays revealed that EAEO suppressed HCC cell migration and arrested cell cycle, respectively. Moreover, EAEO promoted in vitro HCC cell apoptosis, and EAEO treatment inhibited HepG2 xenografts growth and enhanced apoptotic nucleus of xenografts in HepG2-bearing nude mice. Mechanistically, EAEO significantly decreased the ratio of Bcl-2/Bax and resulted in the activation of caspase-9 and -3. EAEO also reduced the expression of Grp78, which in turn relieved the inhibition of caspase-12 and -7. Meanwhile, EAEO suppressed the phosphorylation of STAT3 and AKT, indicative of its anti-HCC potential. In summary, we determined that EAEO treatment promoted HCC apoptosis via activation of the apoptotic signaling pathway in mitochondria and endoplasmic reticulum, as well as repressed the activity of STAT3 and AKT in HCC cells.

  20. Melatonin Inhibits Neural Cell Apoptosis and Promotes Locomotor Recovery via Activation of the Wnt/β-Catenin Signaling Pathway After Spinal Cord Injury.

    Science.gov (United States)

    Shen, Zhaoliang; Zhou, Zipeng; Gao, Shuang; Guo, Yue; Gao, Kai; Wang, Haoyu; Dang, Xiaoqian

    2017-08-01

    The spinal cord is highly sensitive to spinal cord injury (SCI) by external mechanical damage, resulting in irreversible neurological damage. Activation of the Wnt/β-catenin signaling pathway can effectively reduce apoptosis and protect against SCI. Melatonin, an indoleamine originally isolated from bovine pineal tissue, exerts neuroprotective effects after SCI through activation of the Wnt/β-catenin signaling pathway. In this study, we demonstrated that melatonin exhibited neuroprotective effects on neuronal apoptosis and supported functional recovery in a rat SCI model by activating the Wnt/β-catenin signaling pathway. We found that melatonin administration after SCI significantly upregulated the expression of low-density lipoprotein receptor related protein 6 phosphorylation (p-LRP-6), lymphoid enhancer factor-1 (LEF-1) and β-catenin protein in the spinal cord. Melatonin enhanced motor neuronal survival in the spinal cord ventral horn and improved the locomotor functions of rats after SCI. Melatonin administration after SCI also reduced the expression levels of Bax and cleaved caspase-3 in the spinal cord and the proportion of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) positive cells, but increased the expression level of Bcl-2. These results suggest that melatonin attenuated SCI by activating the Wnt/β-catenin signaling pathway.

  1. Infection with E1B-mutant adenovirus stabilizes p53 but blocks p53 acetylation and activity through E1A

    DEFF Research Database (Denmark)

    Savelyeva, I.; Dobbelstein, M.

    2011-01-01

    to the suppression of p21 transcription. Depending on the E1A conserved region 3, E1B-defective adenovirus impaired the ability of the transcription factor Sp1 to bind the p21 promoter. Moreover, the amino terminal region of E1A, binding the acetyl transferases p300 and CREB-binding protein, blocked p53 K382...... accumulation of p53, without obvious defects in p53 localization, phosphorylation, conformation and oligomerization. Nonetheless, p53 completely failed to induce its target genes in this scenario, for example, p21/CDKN1A, Mdm2 and PUMA. Two regions of the E1A gene products independently contributed...... acetylation in infected cells. Mutating either of these E1A regions, in addition to E1B, partially restored p21 mRNA levels. Our findings argue that adenovirus attenuates p53-mediated p21 induction, through at least two E1B-independent mechanisms. Other virus species and cancer cells may employ analogous...

  2. Treatment of porcine donor cells and reconstructed embryos with the antioxidant melatonin enhances cloning efficiency.

    Science.gov (United States)

    Pang, Yun-Wei; An, Lei; Wang, Peng; Yu, Yong; Yin, Qiu-Dan; Wang, Xiao-Hong; Xin-Zhang; Qian-Zhang; Yang, Mei-Ling; Min-Guo; Wu, Zhong-Hong; Tian, Jian-Hui

    2013-05-01

    This study was conducted to investigate the effect of melatonin during the culture of donor cells and cloned embryos on the in vitro developmental competence and quality of cloned porcine embryos. At concentrations of 10(-6 )M or 10(-8) M, melatonin significantly enhanced the proliferation of porcine fetal fibroblasts (PFFs), and the blastocyst rate was significantly increased in the 10(-10) M melatonin-treated donor cell group. Cloned embryo development was also improved in embryo culture medium that was supplemented with 10(-9) M or 10(-12) M melatonin. When both donor cells and cloned embryos were treated with melatonin, the cleavage rate and total cell number of blastocysts were not significantly affected; however, the blastocyst rate was increased significantly (20.0% versus 11.7%). TUNEL assays showed that combined melatonin treatment reduced the rate of apoptotic nuclei (3.6% versus 6.1%). Gene expression analysis of the apoptosis-related genes BAX, BCL2L1, and p53 showed that the expression of BCL2L1 was significantly elevated 2.7-fold relative to the control group, while the expression of BAX and p53 was significantly decreased by 3.7-fold and 23.2-fold, respectively. In addition, we detected the expression of two melatonin receptors (MT1 and MT2) in PFFs but not in porcine cloned embryos. We conclude that exogenous melatonin enhances the development of porcine cloned embryos and improves embryo quality by inhibiting p53-mediated apoptotic pathway. The proliferation of PFFs may be mediated by receptor binding, but the beneficial effects of melatonin on embryonic development may be receptor-independent, possibly through melatonin's ability to directly scavenge free radicals. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  3. Mitochondrial targeted curcumin exhibits anticancer effects through disruption of mitochondrial redox and modulation of TrxR2 activity.

    Science.gov (United States)

    Jayakumar, Sundarraj; Patwardhan, Raghavendra S; Pal, Debojyoti; Singh, Babita; Sharma, Deepak; Kutala, Vijay Kumar; Sandur, Santosh Kumar

    2017-12-01

    Mitocurcumin is a derivative of curcumin, which has been shown to selectively enter mitochondria. Here we describe the anti-tumor efficacy of mitocurcumin in lung cancer cells and its mechanism of action. Mitocurcumin, showed 25-50 fold higher efficacy in killing lung cancer cells as compared to curcumin as demonstrated by clonogenic assay, flow cytometry and high throughput screening assay. Treatment of lung cancer cells with mitocurcumin significantly decreased the frequency of cancer stem cells. Mitocurcumin increased the mitochondrial reactive oxygen species (ROS), decreased the mitochondrial glutathione levels and induced strand breaks in the mitochondrial DNA. As a result, we observed increased BAX to BCL-2 ratio, cytochrome C release into the cytosol, loss of mitochondrial membrane potential and increased caspase-3 activity suggesting that mitocurcumin activates the intrinsic apoptotic pathway. Docking studies using mitocurcumin revealed that it binds to the active site of the mitochondrial thioredoxin reductase (TrxR2) with high affinity. In corroboration with the above finding, mitocurcumin decreased TrxR activity in cell free as well as the cellular system. The anti-cancer activity of mitocurcumin measured in terms of apoptotic cell death and the decrease in cancer stem cell frequency was accentuated by TrxR2 overexpression. This was due to modulation of TrxR2 activity to NADPH oxidase like activity by mitocurcumin, resulting in higher ROS accumulation and cell death. Thus, our findings reveal mitocurcumin as a potent anticancer agent with better efficacy than curcumin. This study also demonstrates the role of TrxR2 and mitochondrial DNA damage in mitocurcumin mediated killing of cancer cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. 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

  5. Tumor Suppressor p53 Stimulates the Expression of Epstein-Barr Virus Latent Membrane Protein 1.

    Science.gov (United States)

    Wang, Qianli; Lingel, Amy; Geiser, Vicki; Kwapnoski, Zachary; Zhang, Luwen

    2017-10-15

    Epstein-Barr virus (EBV) is associated with multiple human malignancies. EBV latent membrane protein 1 (LMP1) is required for the efficient transformation of primary B lymphocytes in vitro and possibly in vivo The tumor suppressor p53 plays a seminal role in cancer development. In some EBV-associated cancers, p53 tends to be wild type and overly expressed; however, the effects of p53 on LMP1 expression is not clear. We find LMP1 expression to be associated with p53 expression in EBV-transformed cells under physiological and DNA damaging conditions. DNA damage stimulates LMP1 expression, and p53 is required for the stimulation. Ectopic p53 stimulates endogenous LMP1 expression. Moreover, endogenous LMP1 blocks DNA damage-mediated apoptosis. Regarding the mechanism of p53-mediated LMP1 expression, we find that interferon regulatory factor 5 (IRF5), a direct target of p53, is associated with both p53 and LMP1. IRF5 binds to and activates a LMP1 promoter reporter construct. Ectopic IRF5 increases the expression of LMP1, while knockdown of IRF5 leads to reduction of LMP1. Furthermore, LMP1 blocks IRF5-mediated apoptosis in EBV-infected cells. All of the data suggest that cellular p53 stimulates viral LMP1 expression, and IRF5 may be one of the factors for p53-mediated LMP1 stimulation. LMP1 may subsequently block DNA damage- and IRF5-mediated apoptosis for the benefits of EBV. The mutual regulation between p53 and LMP1 may play an important role in EBV infection and latency and its related cancers. IMPORTANCE The tumor suppressor p53 is a critical cellular protein in response to various stresses and dictates cells for various responses, including apoptosis. This work suggests that an Epstein-Bar virus (EBV) principal viral oncogene is activated by cellular p53. The viral oncogene blocks p53-mediated adverse effects during viral infection and transformation. Therefore, the induction of the viral oncogene by p53 provides a means for the virus to cope with infection and

  6. [Active euthanasia].

    Science.gov (United States)

    Folker, A P; Hvidt, N

    1995-02-20

    The growing interest in the subject of active euthanasia in connection with the debate regarding legalization of such practices in Denmark necessitates taking a definite standpoint. The difference in concept between active and passive euthanasia is stressed, and the Dutch guidelines are reviewed. The article discusses how far the patient's autonomy should go, as it regards the consideration of self-determination as being too narrow a criterion in itself. The discussion on the quality of life is included, and the consequences of the process of expulsion as a sociological concept are considered--the risk of a patient feeling guilty for being alive and therefore feeling compelled to request active euthanasia. The changed function of the physician is underlined, and it is discussed whether active euthansia will cause a breach of confidence between the physician and his patient. In connection with the debate the following tendencies in society are emphasized: lack of clarity, increasing medicalization and utilitarian priorities.

  7. Active colloids

    International Nuclear Information System (INIS)

    Aranson, Igor S

    2013-01-01

    A colloidal suspension is a heterogeneous fluid containing solid microscopic particles. Colloids play an important role in our everyday life, from food and pharmaceutical industries to medicine and nanotechnology. It is useful to distinguish two major classes of colloidal suspensions: equilibrium and active, i.e., maintained out of thermodynamic equilibrium by external electric or magnetic fields, light, chemical reactions, or hydrodynamic shear flow. While the properties of equilibrium colloidal suspensions are fairly well understood, active colloids pose a formidable challenge, and the research is in its early exploratory stage. One of the most remarkable properties of active colloids is the possibility of dynamic self-assembly, a natural tendency of simple building blocks to organize into complex functional architectures. Examples range from tunable, self-healing colloidal crystals and membranes to self-assembled microswimmers and robots. Active colloidal suspensions may exhibit material properties not present in their equilibrium counterparts, e.g., reduced viscosity and enhanced self-diffusivity, etc. This study surveys the most recent developments in the physics of active colloids, both in synthetic and living systems, with the aim of elucidation of the fundamental physical mechanisms governing self-assembly and collective behavior. (physics of our days)

  8. Activated CD4+ T cells enhance radiation effect through the cooperation of interferon-γ and TNF-α

    International Nuclear Information System (INIS)

    Wang, Yixiang; Radfar, Soroosh; Khong, Hung T

    2010-01-01

    Approaches that enhance radiation effect may lead to improved clinical outcome and decrease toxicity. Here we investigated whether activated CD4+ T cells (aCD4) can serve as an effective radiosensitizer. CD4+ T cells were activated with anti-CD3 and anti-CD28 mAbs. Hela cells were presensitized with aCD4 or conditioned supernatant (aCD4S) or recombinant cytokines for 2 days, followed γ-irradiation. The treated cells were cultured for an additional 2 to 5 days for cell proliferation, cell cycle, and western blot assays. For confirmation, other cancer cell lines were also used. Presensitization of tumor cells with aCD4 greatly increased tumor cell growth inhibition. Soluble factors secreted from activated CD4 + T cells were primarily responsible for the observed effect. IFN-γ seemed to play a major role. TNF-α, though inactive by itself, significantly augmented the radiosensitizing activity of IFN-γ. aCD4S, but not IFN-γ or IFN-γ/TNF-α combination, was found to enhance the γ-irradiation-induced G2/M phase arrest. Bax expression was highly upregulated in Hela cells presensitized with aCD4S followed by γ-irradiation. The radio-sensitizing activity of aCD4 is not uniquely observed with Hela cell line, but also seen with other cancer cell lines of various histology. Our findings suggest possible molecular and cellular mechanisms that may help explain the radio-sensitization effect of activated lymphocytes, and may provide an improved strategy in the treatment of cancer with radiotherapy

  9. Impact of aromaticity on anticancer activity of polypyridyl ruthenium(II) complexes: synthesis, structure, DNA/protein binding, lipophilicity and anticancer activity.

    Science.gov (United States)

    Čanović, Petar; Simović, Ana Rilak; Radisavljević, Snežana; Bratsos, Ioannis; Demitri, Nicola; Mitrović, Marina; Zelen, Ivanka; Bugarčić, Živadin D

    2017-10-01

    With the aim of assessing how the aromaticity of the inert chelating ligand can influence the activity of ruthenium(II) polypyridyl complexes, two new monofunctional ruthenium(II) complexes, [Ru(Cl-Ph-tpy)(phen)Cl]Cl (1) and [Ru(Cl-Ph-tpy)(o-bqdi)Cl]Cl (2) (where Cl-Ph-tpy = 4'-(4-chlorophenyl)-2,2':6',2″-terpyridine, phen = 1,10-phenanthroline, o-bqdi = o-benzoquinonediimine), were synthesized. All complexes were fully characterized by elemental analysis and spectroscopic techniques (IR, UV-Vis, 1D and 2D NMR, XRD). Their chemical behavior in aqueous solution was studied by UV-Vis and NMR spectroscopy showing that both compounds are relatively labile leading to the formation of the corresponding aqua species 1a and 2a. 1 H NMR spectroscopy studies performed on complexes 1 and 2 demonstrated that after the hydrolysis of the Cl ligand, they are capable to interact with guanine derivatives (i.e., 9-methylguanine (9MeG) and 5'-GMP) through the N7, forming monofunctional adduct. The kinetics and the mechanism of the reaction of complexes 1 and 2 with the biologically more relevant 5'-GMP ligand were studied by UV-Vis spectroscopy. DNA/protein interactions of the complexes have been examined by photophysical studies, which demonstrated a bifunctional binding mode of the complexes with DNA and the complexes strongly quench the fluorescence intensity of bovine serum albumin (BSA) through the mechanism of both static and dynamic quenching. Complexes 1 and 2 strongly induced apoptosis of treated cancer cells with high percentages of apoptotic cells and negligible percentage of necrotic cells. In addition, both ruthenium complexes decreased Bcl-2/Bax ratio causing cytochrome c mitochondrial release, the activation of caspase-3 and induction of apoptosis.

  10. Valerian inhibits rat hepatocarcinogenesis by activating GABA(A receptor-mediated signaling.

    Directory of Open Access Journals (Sweden)

    Anna Kakehashi

    Full Text Available Valerian is widely used as a traditional medicine to improve the quality of sleep due to interaction of several active components with the γ-aminobutyric acid (GABA A receptor (GABA(AR system. Recently, activation of GABA signaling in stem cells has been reported to suppress cell cycle progression in vivo. Furthermore, possible inhibitory effects of GABA(AR agonists on hepatocarcinogenesis have been reported. The present study was performed to investigate modulating effects of Valerian on hepatocarcinogenesis using a medium-term rat liver bioassay. Male F344 rats were treated with one of the most powerful Valerian species (Valeriana sitchensis at doses of 0, 50, 500 and 5000 ppm in their drinking water after initiation of hepatocarcinogenesis with diethylnitrosamine (DEN. Formation of glutathione S-transferase placental form positive (GST-P(+ foci was significantly inhibited by Valerian at all applied doses compared with DEN initiation control rats. Generation of 8-hydroxy-2'-deoxyguanosine in the rat liver was significantly suppressed by all doses of Valerian, likely due to suppression of Nrf2, CYP7A1 and induction of catalase expression. Cell proliferation was significantly inhibited, while apoptosis was induced in areas of GST-P(+ foci of Valerian groups associated with suppression of c-myc, Mafb, cyclin D1 and induction of p21(Waf1/Cip1, p53 and Bax mRNA expression. Interestingly, expression of the GABA(AR alpha 1 subunit was observed in GST-P(+ foci of DEN control rats, with significant elevation associated with Valerian treatment. These results indicate that Valerian exhibits inhibitory effects on rat hepatocarcinogenesis by inhibiting oxidative DNA damage, suppressing cell proliferation and inducing apoptosis in GST-P(+ foci by activating GABA(AR-mediated signaling.

  11. Physics activities

    International Nuclear Information System (INIS)

    1997-09-01

    As we move into the 21st Century, nuclear technology is on the verge of rejuvenation in advanced Member States and of expansion in developing Member States. The principal responsibilities of the IAEA are transferring technologies, co-ordinating scientific research, managing specialized projects and maintaining analytical quality control. The IAEA physics activities provide assistance with nuclear instrumentation, promote more effective utilization of research reactors and accelerators, and facilitate global co-operation in nuclear fusion research. These activities will help Member States improve their standards of living through the benefits of nuclear technology. This booklet presents a brief profile on the physics activities and involvement in these fields of the Physics Section, IAEA

  12. Sulforaphane Ameliorates Bladder Dysfunction through Activation of the Nrf2-ARE Pathway in a Rat Model of Partial Bladder Outlet Obstruction

    Directory of Open Access Journals (Sweden)

    Chong Liu

    2016-01-01

    Full Text Available Purpose. We evaluated the effect of sulforaphane (SFN treatment on the function and changes of expression of Nrf2-ARE pathway in the bladder of rats with bladder outlet obstruction (BOO. Materials and Methods. A total of 18 male Sprague-Dawley rats at age of 8 weeks were divided into 3 groups (6 of each: the sham operated group, the BOO group, and the BOO+SFN group. We examined histological alterations and the changes of oxidative stress markers and the protein expression of the Nrf2-ARE pathway. Results. We found that SFN treatment could prolong micturition interval and increase bladder capacity and bladder compliance. However, the peak voiding pressure was lower than BOO group. SFN treatment can ameliorate the increase of collagen fibers induced by obstruction. SFN treatment also increased the activity of SOD, GSH-Px, and CAT compared to the other groups. The level of bladder cell apoptosis was decreased in BOO rats with SFN treatment. Moreover, SFN could reduce the ratio of Bax/Bcl-2 expression. Furthermore, SFN could activate the Nrf2 expression with elevation of its target antioxidant proteins. Conclusions. The sulforaphane-mediated decrease of oxidative stress and activation of the Nrf2-ARE pathway may ameliorate bladder dysfunction caused by bladder outlet obstruction.

  13. Sulforaphane Ameliorates Bladder Dysfunction through Activation of the Nrf2-ARE Pathway in a Rat Model of Partial Bladder Outlet Obstruction

    Science.gov (United States)

    Liu, Chong; Xu, Huan; Fu, Shi; Chen, Yanbo; Chen, Qi; Cai, Zhikang; Zhou, Juan; Wang, Zhong

    2016-01-01

    Purpose. We evaluated the effect of sulforaphane (SFN) treatment on the function and changes of expression of Nrf2-ARE pathway in the bladder of rats with bladder outlet obstruction (BOO). Materials and Methods. A total of 18 male Sprague-Dawley rats at age of 8 weeks were divided into 3 groups (6 of each): the sham operated group, the BOO group, and the BOO+SFN group. We examined histological alterations and the changes of oxidative stress markers and the protein expression of the Nrf2-ARE pathway. Results. We found that SFN treatment could prolong micturition interval and increase bladder capacity and bladder compliance. However, the peak voiding pressure was lower than BOO group. SFN treatment can ameliorate the increase of collagen fibers induced by obstruction. SFN treatment also increased the activity of SOD, GSH-Px, and CAT compared to the other groups. The level of bladder cell apoptosis was decreased in BOO rats with SFN treatment. Moreover, SFN could reduce the ratio of Bax/Bcl-2 expression. Furthermore, SFN could activate the Nrf2 expression with elevation of its target antioxidant proteins. Conclusions. The sulforaphane-mediated decrease of oxidative stress and activation of the Nrf2-ARE pathway may ameliorate bladder dysfunction caused by bladder outlet obstruction. PMID:27433291

  14. Anaplasma phagocytophilum inhibits human neutrophil apoptosis via upregulation of bfl-1, maintenance of mitochondrial membrane potential and prevention of caspase 3 activation.

    Science.gov (United States)

    Ge, Yan; Yoshiie, Kiyotaka; Kuribayashi, Futoshi; Lin, Mingqun; Rikihisa, Yasuko

    2005-01-01

    The inhibition of neutrophil apoptosis plays a central role in human granulocytic anaplasmosis. Intracellular signalling pathways through which the obligatory intracellular bacterium Anaplasma phagocytophilum inhibits the spontaneous apoptosis of human peripheral blood neutrophils were investigated. bfl-1 mRNA levels in uninfected neutrophils after 12 h in culture were reduced to approximately 5-25% of 0 h levels, but remained high in infected neutrophils. The eukaryotic RNA synthesis inhibitor, actinomycin D, prevented the maintenance of bfl-1 mRNA levels by A. phagocytophilum. Differences in mcl-1, bax, bcl-w, bad or bak mRNA levels in infected versus uninfected neutrophils were not remarkable. By using mitochondrial fluorescent dyes, Mitotracker Red and JC-1, it was found that most uninfected neutrophils lost mitochondrial membrane potential after 10-12 h incubation, whereas A. phagocytophilum-infected neutrophils maintained high membrane potential. Caspase 3 activity and the degree of apoptosis were lower in dose-dependent manner in A. phagocytophilum-infected neutrophils at 16 h post infection, as compared to uninfected neutrophils. Anti-active caspase 3 antibody labelling showed less positively stained population in infected neutrophils compared to those in uninfected neutrophils after 12 h incubation. These results suggest that A. phagocytophilum inhibits human neutrophil apoptosis via transcriptional upregulation of bfl-1 and inhibition of mitochondria-mediated activation of caspase 3.

  15. Near infrared radiation protects against oxygen-glucose deprivation-induced neurotoxicity by down-regulating neuronal nitric oxide synthase (nNOS) activity in vitro.

    Science.gov (United States)

    Yu, Zhanyang; Li, Zhaoyu; Liu, Ning; Jizhang, Yunneng; McCarthy, Thomas J; Tedford, Clark E; Lo, Eng H; Wang, Xiaoying

    2015-06-01

    Near infrared radiation (NIR) has been shown to be neuroprotective against neurological diseases including stroke and brain trauma, but the underlying mechanisms remain poorly understood. In the current study we aimed to investigate the hypothesis that NIR may protect neurons by attenuating oxygen-glucose deprivation (OGD)-induced nitric oxide (NO) production and modulating cell survival/death signaling. Primary mouse cortical neurons were subjected to 4 h OGD and NIR was applied at 2 h reoxygenation. OGD significantly increased NO level in primary neurons compared to normal control, which was significantly ameliorated by NIR at 5 and 30 min post-NIR. Neither OGD nor NIR significantly changed neuronal nitric oxide synthase (nNOS) mRNA or total protein levels compared to control groups. However, OGD significantly increased nNOS activity compared to normal control, and this effect was significantly diminished by NIR. Moreover, NIR significantly ameliorated the neuronal death induced by S-Nitroso-N-acetyl-DL-penicillamine (SNAP), a NO donor. Finally, NIR significantly rescued OGD-induced suppression of p-Akt and Bcl-2 expression, and attenuated OGD-induced upregulation of Bax, BAD and caspase-3 activation. These results suggest NIR may protect against OGD at least partially through reducing NO production by down-regulating nNOS activity, and modulating cell survival/death signaling.

  16. Regulatory activities

    International Nuclear Information System (INIS)

    2001-01-01

    This publication, compiled in 8 chapters, presents the regulatory system developed by the Nuclear Regulatory Authority (NRA) of the Argentine Republic. The following activities and developed topics in this document describe: the evolution of the nuclear regulatory activity in Argentina; the Argentine regulatory system; the nuclear regulatory laws and standards; the inspection and safeguards of nuclear facilities; the emergency systems; the environmental systems; the environmental monitoring; the analysis laboratories on physical and biological dosimetry, prenatal irradiation, internal irradiation, radiation measurements, detection techniques on nuclear testing, medical program on radiation protection; the institutional relations with national and international organization; the training courses and meeting; the technical information

  17. NF-Y loss triggers p53 stabilization and apoptosis in HPV18-positive cells by affecting E6 transcription.

    Science.gov (United States)

    Benatti, Paolo; Basile, Valentina; Dolfini, Diletta; Belluti, Silvia; Tomei, Margherita; Imbriano, Carol

    2016-07-19

    The expression of the high risk HPV18 E6 and E7 oncogenic proteins induces the transformation of epithelial cells, through the disruption of p53 and Rb function. The binding of cellular transcription factors to cis-regulatory elements in the viral Upstream Regulatory Region (URR) stimulates E6/E7 transcription. Here, we demonstrate that the CCAAT-transcription factor NF-Y binds to a non-canonical motif within the URR and activates viral gene expression. In addition, NF-Y indirectly up-regulates HPV18 transcription through the transactivation of multiple cellular transcription factors. NF-YA depletion inhibits the expression of E6 and E7 genes and re-establishes functional p53. The activation of p53 target genes in turn leads to apoptotic cell death. Finally, we show that NF-YA loss sensitizes HPV18-positive cells toward the DNA damaging agent Doxorubicin, via p53-mediated transcriptional response.

  18. Identity Activities

    Science.gov (United States)

    2016-08-03

    in reaction to their environment. They reflect an individual’s internal or external, conscious or subconscious , overt or covert, voluntary or...identity activities under a range of legal authorities, policy constraints, transnational threats, regional concerns and biases , and most likely...Biography. A baseline and descriptive analytic product that supports the development of the behavioral influences analysis ( BIA ) individual behavioral

  19. Active instruments

    DEFF Research Database (Denmark)

    Lim, Miguel Antonio; Ørberg, Jakob Williams

    2017-01-01

    themselves. We draw on two multi-year field studies of India and Denmark to investigate how national reforms and developments within the ranking industry interact in often surprising ways. Rankings do not always do what policy makers expect. We (1) highlight the activity of rankers in these two countries, (2...

  20. Active house

    DEFF Research Database (Denmark)

    Eriksen, Kurt Emil; Olesen, Gitte Gylling Hammershøj

    Formålet med dette abstrakt er at illustrere, at huse kan være konstrueret til at basere sig udelukkende på vedvarende energikilder og samtidig være CO2-neutrale og producere mere energi end de forbruger. Active House Visionen undersøger disse muligheder i otte demonstration huse i fem forskellige...

  1. Apoptosis by [Pt(O,O'-acac)(γ-acac)(DMS)] requires PKC-δ mediated p53 activation in malignant pleural mesothelioma.

    Science.gov (United States)

    Muscella, Antonella; Vetrugno, Carla; Cossa, Luca Giulio; Antonaci, Giovanna; Barca, Amilcare; De Pascali, Sandra Angelica; Fanizzi, Francesco Paolo; Marsigliante, Santo

    2017-01-01

    Mesothelioma cancer cells have epithelioid or sarcomatoid morphology. The worst prognosis is associated with sarcomatoid phenotype and resistance to therapy is affected by cells heterogeneity. We recently showed that in ZL55 mesothelioma cell line of epithelioid origin [Pt(O,O'-acac)(γ-acac)(DMS)] (Ptac2S) has an antiproliferative effect in vitro and in vivo. Aim of this work was to extend the study on the effects of Ptac2S on ZL34 cell line, representative of sarcomatoid mesothelioma. ZL34 cells were used to assay the antitumor activity of Ptac2S in a mouse xenograft model in vivo. Then, both ZL34 and ZL55 cells were used in order to assess the involvement of p53 protein in (a) the processes underlying the sensitivity to chemotherapy and (b) the activation of various transduction proteins involved in apoptosis/survival processes. Ptac2S increases ZL34 cell death in vivo compared with cisplatin and, in vitro, Ptac2S was more efficacious than cisplatin in inducing apoptosis. In Ptac2S-treated ZL34 and ZL55 cells, p53 regulated gene products of apoptotic BAX and anti-apoptotic Bcl-2 proteins via transcriptional activation. Ptac2S activated PKC-δ and PKC-ε; their inhibition by PKC-siRNA decreased the apoptotic death of cells. PKC-δ was responsible for JNK1/2 activation that has a role in p53 activation. In addition, PKC-ε activation provoked phosphorylation of p38MAPK, concurring to apoptosis. In ZL34 cells, Ptac2S also activated PKC-α thus provoking ERK1/2 activation; inhibition of PKC-α, or ERK1/2, increased Ptac2S cytotoxicity. Results confirm that Ptac2S is a promising therapeutic agent for malignant mesothelioma, giving a substantial starting point for its further validation.

  2. Formulation of vitamin D encapsulated cinnamon oil nanoemulsion: Its potential anti-cancerous activity in human alveolar carcinoma cells.

    Science.gov (United States)

    Meghani, Nikita; Patel, Pal; Kansara, Krupa; Ranjan, Shivendu; Dasgupta, Nandita; Ramalingam, Chidambaram; Kumar, Ashutosh

    2018-06-01

    Cinnamon oil is used for medicinal purpose since ancient time because of its antioxidant activity. Oil-in-water nanoemulsion (NE) of cinnamon oil was formulated using cinnamon oil, nonionic surfactant Tween 80 and water by ultrasonication technique. Phase diagram was constructed to investigate the influence of oil, water and surfactant concentration. Vitamin D encapsulated cinnamon oil NE was fabricated by wash out method followed by ultrasonication in similar fashion. The hydrodynamic size of cinnamon oil NE and vitamin D encapsulated cinnamon oil NE was observed as 40.52 and 48.96 nm in complete DMEM F12 media respectively. We focused on the cytotoxic and genotoxic responses of NEs in A549 cells in concentration dependent manner. We observed that both NEs induce DNA damage along with corresponding increase in micronucleus frequency that is evident from the comet and CBMN assay. Both the NEs arrested the cell cycle progression in G0/G1 phase, showed increased expression of Bax, capase-3 and caspase-9 and decrease expression of BcL2 proteins along with significant (p oil as carrier for lipophilic nutraceutical like vitamin D. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Tetrandrine, an Activator of Autophagy, Induces Autophagic Cell Death via PKC-α Inhibition and mTOR-Dependent Mechanisms

    Directory of Open Access Journals (Sweden)

    Vincent Kam Wai Wong

    2017-06-01

    Full Text Available Emerging evidence suggests the therapeutic role of autophagic modulators in cancer therapy. This study aims to identify novel traditional Chinese medicinal herbs as potential anti-tumor agents through autophagic induction, which finally lead to autophagy mediated-cell death in apoptosis-resistant cancer cells. Using bioactivity-guided purification, we identified tetrandrine (Tet from herbal plant, Radix stephaniae tetrandrae, as an inducer of autophagy. Across a number of cancer cell lines, we found that breast cancer cells treated with tetrandrine show an increase autophagic flux and formation of autophagosomes. In addition, tetrandrine induces cell death in a panel of apoptosis-resistant cell lines that are deficient for caspase 3, caspase 7, caspase 3 and 7, or Bax-Bak respectively. We also showed that tetrandrine-induced cell death is independent of necrotic cell death. Mechanistically, tetrandrine induces autophagy that depends on mTOR inactivation. Furthermore, tetrandrine induces autophagy in a calcium/calmodulin-dependent protein kinase kinase-β (CaMKK-β, 5′ AMP-activated protein kinase (AMPK independent manner. Finally, by kinase profiling against 300 WT kinases and computational molecular docking analysis, we showed that tetrandrine is a novel PKC-α inhibitor, which lead to autophagic induction through PKC-α inactivation. This study provides detailed insights into the novel cytotoxic mechanism of an anti-tumor compound originated from the herbal plant, which may be useful in promoting autophagy mediated- cell death in cancer cell that is resistant to apoptosis.

  4. In Vitro and In Vivo Antitumor Activity of [Pt(O,O'-acac)(γ-acac)(DMS)] in Malignant Pleural Mesothelioma.

    Science.gov (United States)

    Muscella, Antonella; Vetrugno, Carla; Cossa, Luca Giulio; Antonaci, Giovanna; De Nuccio, Francesco; De Pascali, Sandra Angelica; Fanizzi, Francesco Paolo; Marsigliante, Santo

    2016-01-01

    Malignant pleural mesothelioma (MPM) is an aggressive malignancy highly resistant to chemotherapy. There is an urgent need for effective therapy inasmuch as resistance, intrinsic and acquired, to conventional therapies is common. Among Pt(II) antitumor drugs, [Pt(O,O'-acac)(γ-acac)(DMS)] (Ptac2S) has recently attracted considerable attention due to its strong in vitro and in vivo antiproliferative activity and reduced toxicity. The purpose of this study was to examine the efficacy of Ptac2S treatment in MPM. We employed the ZL55 human mesothelioma cell line in vitro and in a murine xenograft model in vivo, to test the antitumor activity of Ptac2S. Cytotoxicity assays and Western blottings of different apoptosis and survival proteins were thus performed. Ptac2S increases MPM cell death in vitro and in vivo compared with cisplatin. Ptac2S was more efficacious than cisplatin also in inducing apoptosis characterized by: (a) mitochondria depolarization, (b) increase of bax expression and its cytosol-to-mitochondria translocation and decrease of Bcl-2 expression, (c) activation of caspase-7 and -9. Ptac2S activated full-length PKC-δ and generated a PKC-δ fragment. Full-length PKC-δ translocated to the nucleus and membrane, whilst PKC-δ fragment concentrated to mitochondria. Ptac2S was also responsible for the PKC-ε activation that provoked phosphorylation of p38. Both PKC-δ and PKC-ε inhibition (by PKC-siRNA) reduced the apoptotic death of ZL55 cells. Altogether, our results confirm that Ptac2S is a promising therapeutic agent for malignant mesothelioma, providing a solid starting point for its validation as a suitable candidate for further pharmacological testing.

  5. Active particles

    CERN Document Server

    Degond, Pierre; Tadmor, Eitan

    2017-01-01

    This volume collects ten surveys on the modeling, simulation, and applications of active particles using methods ranging from mathematical kinetic theory to nonequilibrium statistical mechanics. The contributing authors are leading experts working in this challenging field, and each of their chapters provides a review of the most recent results in their areas and looks ahead to future research directions. The approaches to studying active matter are presented here from many different perspectives, such as individual-based models, evolutionary games, Brownian motion, and continuum theories, as well as various combinations of these. Applications covered include biological network formation and network theory; opinion formation and social systems; control theory of sparse systems; theory and applications of mean field games; population learning; dynamics of flocking systems; vehicular traffic flow; and stochastic particles and mean field approximation. Mathematicians and other members of the scientific commu...

  6. Active solar information dissemination activities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    The principal objective of the project has been the development of an information dissemination strategy for the UK active solar heating industry. The project has also aimed to prepare the industry for the implementation of such a strategy and to produce initial information materials to support the early stages of the implementation process. (author)

  7. Design and synthesis of thienopyrimidine urea derivatives with potential cytotoxic and pro-apoptotic activity against breast cancer cell line MCF-7.

    Science.gov (United States)

    Abdelhaleem, Eman F; Abdelhameid, Mohammed K; Kassab, Asmaa E; Kandeel, Manal M

    2018-01-01

    A series of novel tetrahydrobenzothieno[2,3-d]pyrimidine urea derivatives was synthesized according to fragment-based design strategy. They were evaluated for their anticancer activity against MCF-7 cell line. Three compounds 9c, 9d and 11b showed 1.5-1.03 folds more potent anticancer activity than doxorubicin. In this study, a promising multi-sited enzyme small molecule inhibitor 9c, which showed the most potent anti-proliferative activity, was identified. The anti-proliferative activity of this compound appears to correlate well with its ability to inhibit topoisomerase II (IC 50  = 9.29 μM). Moreover, compound 9c showed excellent VEGFR-2 inhibitory activity, at the sub-micromolar level with IC 50 value 0.2 μM, which is 2.1 folds more potent than sorafenib. Moreover, activation of damage response pathway of the DNA leads to cell cycle arrest at G2/M phase, accumulation of cells in pre-G1 phase and annexin-V and propidium iodide staining, indicating that cell death proceeds through an apoptotic mechanism. Compound 9c showed potent pro-apoptotic effect through induction of the intrinsic mitochondrial pathway of apoptosis. This mechanistic pathway was confirmed by a significant increase in the expression of the tumor suppressor gene p53, elevation in Bax/BCL-2 ratio and a significant increase in the level of active caspase-3. Quantitative structure-activity relationship (QSAR) studies delivered equations of five 3D descriptors with R 2  = 0.814. This QSAR model provides an effective technique for understanding the observed antitumor properties and thus could be adopted for developing effective lead structures. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  8. 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.

  9. Melatonin Activates Endoplasmic Reticulum Stress and Apoptosis in Rats with Diethylnitrosamine-Induced Hepatocarcinogenesis.

    Directory of Open Access Journals (Sweden)

    Andrea Janz Moreira

    Full Text Available Hepatocellular carcinoma (HCC is one of the most lethal human cancers worldwide because of its high incidence, its metastatic potential and the low efficacy of conventional treatment. Inactivation of apoptosis is implicated in tumour progression and chemotherapy resistance, and has been linked to the presence of endoplasmic reticulum stress. Melatonin, the main product of the pineal gland, exerts anti-proliferative, pro-apoptotic and anti-angiogenic effects in HCC cells, but these effects still need to be confirmed in animal models. Male Wistar rats in treatment groups received diethylnitrosamine (DEN 50 mg/kg intraperitoneally twice/once a week for 18 weeks. Melatonin was given in drinking water at 1 mg/kg/d, beginning 5 or 12 weeks after the start of DEN administration. Melatonin improved survival rates and successfully attenuated liver injury, as shown by histopathology, decreased levels of serum transaminases and reduced expression of placental glutathione S-transferase. Furthermore, melatonin treatment resulted in a significant increase of caspase 3, 8 and 9 activities, polyadenosine diphosphate (ADP ribose polymerase (PARP cleavage, and Bcl-associated X protein (Bax/Bcl-2 ratio. Cytochrome c, p53 and Fas-L protein concentration were also significantly enhanced by melatonin. Melatonin induced an increased expression of activating transcription factor 6 (ATF6, C/EBP-homologous protein (CHOP and immunoglobulin heavy chain-binding protein (BiP, while cyclooxygenase (COX-2 expression decreased. Data obtained suggest that induction of apoptosis and ER stress contribute to the beneficial effects of melatonin in rats with DEN-induced HCC.

  10. Study of gel grown mixed crystals of Bax Ca ((IO3) 4

    Indian Academy of Sciences (India)

    The growth of mixed crystals of BaCa1–(IO3)4 were carried out with simple gel method. The effect of various parameters such as pH of gel solution, gel concentration, gel setting time, concentration of reactants on the growth was studied. Crystals having different morphologies and habits were obtained. The grown ...

  11. Boron neutron capture therapy induces apoptosis of glioma cells through Bcl-2/Bax

    OpenAIRE

    Wang, Peng; Zhen, Haining; Jiang, Xinbiao; Zhang, Wei; Cheng, Xin; Guo, Geng; Mao, Xinggang; Zhang, Xiang

    2010-01-01

    Abstract Background Boron neutron capture therapy (BNCT) is an alternative treatment modality for patients with glioma. The aim of this study was to determine whether induction of apoptosis contributes to the main therapeutic efficacy of BNCT and to compare the relative biological effect (RBE) of BNCT, γ-ray and reactor neutron irradiation. Methods The neutron beam was obtained from the Xi'an Pulsed Reactor (XAPR) and γ-rays were obtained from [60Co] γ source of the Fourth Military Medical Un...

  12. Barium aluminides BaxAl5(x=3,3.5,4)

    International Nuclear Information System (INIS)

    Jehle, Michael; Scherer, Harald; Wendorff, Marco; Roehr, Caroline

    2009-01-01

    Three aluminides of the series Ba x Al 5 (x=3,3.5,4) were synthesized from stoichiometric ratios of the elements in Ta crucibles. The crystal structure of the new compound Ba 7 Al 10 was determined using single crystal X-ray data (space group R3-barm, a=604.23(9), c=4879.0(12)pm, Z=3, R1=0.0325). The compound exhibits Al Kagome (3.6.3.6.) nets in which half of the triangles form the basis of trigonal bipyramids Al 5 . The apical Al are thus three-bonded assuming a charge of -2 ( 27 Al-NMR chemical shift δ=660pm), whereas the Al atoms of the basal triangle (i.e. of the Kagome net) are four-bonded and thus of formal charge -1(δ=490ppm). The total charge of the anion is thus exactly compensated by the Ba cations, i.e. the compound can be interpreted as an electron precise Zintl phase, exhibiting a distinct pseudo-band gap at the Fermi level of the calculated tDOS. According to the total formula, the structure displays a combination the stacking sequences of Ba 3 Al 5 and Ba 4 Al 5 , the structures of which have been redetermined with current methods (both hexagonal with space group P6 3 /mmc; Ba 3 Al 5 : a=606.55(7), c=1461.8(2)pm, Z=2, R1=0.0239; Ba 4 Al 5 : a=609.21(7), c=1775.8(3)pm, Z=2, R1=0.0300). These three compounds with slightly different electron counts but similar polyanions allow to compare the bond lengths, the electronic structures and the overall bonding situation in dependence of positive or negative deviation of the electron count in relation to the novel formally electron precise Zintl compound Ba 7 Al 10 . - Al 5 layers of Kagome nets in the new binary electron precise Zintl compound Ba 3.5 Al 5 , also found in Ba 3 Al 5 and Ba 4 Al 5 .

  13. Field dependent dielectric behaviour of BaxSr1-xTiO3 perovskites

    International Nuclear Information System (INIS)

    Kukreti, Ashish; Ashok Kumar; Naithani, U.C.

    2008-01-01

    Using the method of double time thermal Green's function and Kubo formalism, a general expression has been derived for the electric field dependence of the complex dielectric constant of Ba x Sr 1-x TiO 3 ferroelectric crystal in the paraelectric phase from the Silverman-Joseph Hamiltonian augmented with fourth order phonon co-ordinates. The change of mass as well as harmonic force constant between impurity atom and host lattice atoms are taken into account. The frequency, temperature and electric field dependent dielectric constant of Ba x Sr 1-x TiO 3 crystal has been discussed. Dielectric constant increases with increase of applied field. The results are compared with previous experimental and theoretical results. (author)

  14. The critical properties of the BaxSr1-xTiO3 solid solution

    International Nuclear Information System (INIS)

    Saber, M.; Ainane, A.; Essaoudi, I.; Baerner, K.; Gonzalez, J.

    2009-01-01

    Within the framework of the transverse spin -1/2 Ising model and by using the effective field theory with a probability distribution technique that accounts for the self-spin correlations, we have studied the critical properties of the Ba x Sr 1-x TiO 3 system. In particular, we have studied the polarization as function of both the temperature T and the Ba concentration x, the critical temperature T c (x) as function of x, and also the dielectric susceptibility χ(T,x) for different values of the strength of the applied electric field E

  15. Apoptotic Bax at Oxidatively Stressed Mitochondrial Membranes: Lipid Dynamics and Permeabilization

    Czech Academy of Sciences Publication Activity Database

    Dilgendein, A. P.; Pokorná, Šárka; Lidman, M.; Sparrman, T.; Šachl, Radek; Hof, Martin; Gröbner, G.

    2017-01-01

    Roč. 112, č. 10 (2017), s. 2147-2158 ISSN 0006-3495 R&D Projects: GA ČR(CZ) GBP208/12/G016 Institutional support: RVO:61388955 Keywords : LOW-FREQUENCY MOTION * OXIDIZED PHOSPHOLIPIDS * BILAYER-MEMBRANES Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 3.656, year: 2016

  16. Fas-Induced Apoptosis of Renal Cell Carcinoma is Mediated by Apoptosis Signal-Regulating Kinase 1 via Mitochondrial Damage-Dependent Caspase-8 Activation

    Directory of Open Access Journals (Sweden)

    Mohamed Hassan

    2009-01-01

    Full Text Available Renal cell carcinoma (RCC is a prototype of a chemo refractory tumour. It remains the most lethal of the common urologic cancers and is highly resistant to conventional therapy. Here, we confirmed the efficiency of anti-Fas monoclonal antibody (CH11 as alternative therapeutic approach for the treatment of RCC and investigated the molecular mechanism(s, whereby CH11 induces apoptosis of RCC cells. The present study shows an essential role for apoptosis signal-regulating kinase 1 (ASK1, together with both c-jun-N-terminal kinase (JNK and p38 pathways, and caspase-8 in this process. Furthermore, CH11-dependent induction of the ASK1–JNK/p38 pathways was found to activate the transcription factors AP-1 and ATF-2, and FADD-caspase-8-Bid signalling, resulting in the translocation of both Bax and Bak proteins, and subsequently mitochondrial dysregulation that is characterized by the loss of mitochondrial membrane potential (ΔΨm, cytochrome c release and cleavage of caspase-9, caspase-3 and PARP. Thus, the described molecular mechanisms of CH11-induced apoptosis suggest the reliability of Fas activation as an alternative therapeutic approach for the treatment of patients with advanced renal cell carcinoma.

  17. Isoegomaketone induces apoptosis in SK-MEL-2 human melanoma cells through mitochondrial apoptotic pathway via activating the PI3K/Akt pathway.

    Science.gov (United States)

    Kwon, Soon-Jae; Lee, Ju-Hye; Moon, Kwang-Deog; Jeong, Il-Yun; Yee, Sung-Tae; Lee, Mi-Kyung; Seo, Kwon-Il

    2014-11-01

    Isoegomaketone (IK) is a major biologically active component of Perilla frutescens. In this study, we investigated the contribution of reactive oxygen species (ROS) to IK-induced apoptosis in human melanoma SK-MEL-2 cells. We found that IK inhibited the proliferation of SK-MEL-2 human melanoma cells in a dose-dependent manner. IK also induced sub-G1 DNA accumulation, formation of apoptotic bodies, nuclear condensation, and a DNA ladder in SK-MEL-2 cells. IK also induced activation of caspase-3 and -9, whereas caspase‑8 was unaffected. Further, N-acetyl-L-cysteine (NAC, ROS scavenger) treatment to SK-MEL-2 cells significantly reduced IK-induced cell death. Pretreatment of NAC to SK-MEL-2 cells followed by 100 µM IK reduced the protein levels of Bax and cytochrome c as well as PARP cleavage, whereas the protein level of Bcl-2 increased. Moreover, IK inhibited the phosphorylation of AKT/mTOR protein and cell proliferation induced by LY294002, a PI3K inhibitor. In conclusion, IK-induced ROS generation regulates cell growth inhibition and it induces apoptosis through caspase‑dependent and -independent pathways via modulation of PI3K/AKT signaling in SK-MEL-2 cells.

  18. Chocolate active

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    There is a table of current radioactivity values for various foods and mushrooms. A special accent is on milk and chocolate. Chocolate sorts with more powdered milk are more active. Finally there is a chapter on radionucleides contained in the Chernobyl fallout, other than cesium 137, cesium 134 and strontium 90. The amounts of ruthenium 106, antimony 125, cerium 144, silver 110 m, cesium 134, strontium 90 and plutonium 239 relative to cesium 137 in soil samples in autumn 1987 are given. Special emphasis is on ruthenium 'hot particles' and on plutonium. (qui)

  19. 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.

  20. Methylprednisolone promotes recovery of neurological function after spinal cord injury: association with Wnt/β-catenin signaling pathway activation

    Science.gov (United States)

    Lu, Gong-biao; Niu, Fu-wen; Zhang, Ying-chun; Du, Lin; Liang, Zhi-yuan; Gao, Yuan; Yan, Ting-zhen; Nie, Zhi-kui; Gao, Kai

    2016-01-01

    Some studies have indicated that the Wnt/β-catenin signaling pathway is activated following spinal cord injury, and expression levels of specific proteins, including low-density lipoprotein receptor related protein-6 phosphorylation, β-catenin, and glycogen synthase kinase-3β, are significantly altered. We hypothesized that methylprednisolone treatment contributes to functional recovery after spinal cord injury by inhibiting apoptosis and activating the Wnt/β-catenin signaling pathway. In the current study, 30 mg/kg methylprednisolone was injected into rats with spinal cord injury immediately post-injury and at 1 and 2 days post-injury. Basso, Beattie, and Bresnahan scores showed that methylprednisolone treatment significantly promoted locomotor functional recovery between 2 and 6 weeks post-injury. The number of surviving motor neurons increased, whereas the lesion size significantly decreased following methylprednisolone treatment at 7 days post-injury. Additionally, caspase-3, caspase-9, and Bax protein expression levels and the number of apoptotic cells were reduced at 3 and 7 days post-injury, while Bcl-2 levels at 7 days post-injury were higher in methylprednisolone-treated rats compared with saline-treated rats. At 3 and 7 days post-injury, methylprednisolone up-regulated expression and activation of the Wnt/β-catenin signaling pathway, including low-density lipoprotein receptor related protein-6 phosphorylation, β-catenin, and glycogen synthase kinase-3β phosphorylation. These results indicate that methylprednisolone-induced neuroprotection may correlate with activation of the Wnt/β-catenin signaling pathway. PMID:28123427

  1. Theissenolactone C Exhibited Ocular Protection of Endotoxin-Induced Uveitis by Attenuating Ocular Inflammatory Responses and Glial Activation

    Directory of Open Access Journals (Sweden)

    Fan-Li Lin

    2018-04-01

    Full Text Available The aim of this study was to investigate the effects of a natural component, theissenolactone C (LC53, on the ocular inflammation of experimental endotoxin-induced uveitis (EIU and its related mechanisms in microglia. Evaluation of the severity of anterior uveitis indicated that LC53 treatment significantly decreased iridal hyperemia and restored the clinical scores. Additionally, the deficient retina functions of electroretinography were improved by LC53. LC53 significantly reduced levels of tumor necrosis factor (TNF-α, monocyte chemoattractant protein-1, protein leakage and activation of matrix metalloproteinases in the anterior section during EIU. Moreover, LC53 treatment decreased the oxidative stress as well as neuroinflammatory reactivities of GFAP and Iba-1 in the posterior section. Furthermore, LC53 decreased the phosphorylation of p65, expression of HSP90, Bax, and cleaved-caspase-3 in EIU. According to the microglia studies, LC53 significantly abrogated the productions of TNF-α, PGE2, NO and ROS, as well as inducible NO synthase and cyclooxygenase-2 expression in LPS-stimulated microglial BV2 cells. The microglial activation of IKKβ, p65 phosphorylation and nuclear phosphorylated p65 translocation were strongly attenuated by LC53. On the other hand, LC53 exhibited the inhibitory effects on JNK and ERK MAPKs activation. Our findings indicated that LC53 exerted the ocular-protective effect through its inhibition on neuroinflammation, glial activation, and apoptosis in EIU, suggesting a therapeutic potential with down-regulation of the NF-κB signaling for uveitis and retinal inflammatory diseases.

  2. Hydrogen inhalation reduced epithelial apoptosis in ventilator-induced lung injury via a mechanism involving nuclear factor-kappa B activation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chien-Sheng [Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Division of Thoracic Surgery, Department of Surgery, Taipei-Veterans General Hospital and National Yang-Ming University School of Medicine, Taipei, Taiwan (China); Kawamura, Tomohiro; Peng, Ximei [Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Tochigi, Naobumi [Department of Pathology, University of Pittsburgh Medical Center, PA (United States); Shigemura, Norihisa [Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Billiar, Timothy R. [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Nakao, Atsunori, E-mail: anakao@imap.pitt.edu [Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Toyoda, Yoshiya [Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States)

    2011-05-06

    Highlights: {yields} Hydrogen is a regulatory molecule with antiinflammatory and antiapoptotic protective effects. {yields} There is very limited information on the pathways regulated in vivo by the hydrogen. {yields} Antiapoptotic abilities of hydrogen were explained by upregulation of the antiapoptotic gene. {yields} NF{kappa}B activation during hydrogen treatment was correlated with elevated antiapoptotic protein. {yields} NF{kappa}B activation associated with increase Bcl-2 may contribute to cytoprotection of hydrogen. -- Abstract: We recently demonstrated the inhalation of hydrogen gas, a novel medical therapeutic gas, ameliorates ventilator-induced lung injury (VILI); however, the molecular mechanisms by which hydrogen ameliorates VILI remain unclear. Therefore, we investigated whether inhaled hydrogen gas modulates the nuclear factor-kappa B (NF{kappa}B) signaling pathway. VILI was generated in male C57BL6 mice by performing a tracheostomy and placing the mice on a mechanical ventilator (tidal volume of 30 ml/kg or 10 ml/kg without positive end-expiratory pressure). The ventilator delivered either 2% nitrogen or 2% hydrogen in balanced air. NF{kappa}B activation, as indicated by NF{kappa}B DNA binding, was detected by electrophoretic mobility shift assays and enzyme-linked immunosorbent assay. Hydrogen gas inhalation increased NF{kappa}B DNA binding after 1 h of ventilation and decreased NF{kappa}B DNA binding after 2 h of ventilation, as compared with controls. The early activation of NF{kappa}B during hydrogen treatment was correlated with elevated levels of the antiapoptotic protein Bcl-2 and decreased levels of Bax. Hydrogen inhalation increased oxygen tension, decreased lung edema, and decreased the expression of proinflammatory mediators. Chemical inhibition of early NF{kappa}B activation using SN50 reversed these protective effects. NF{kappa}B activation and an associated increase in the expression of Bcl-2 may contribute, in part, to the

  3. Hydrogen inhalation reduced epithelial apoptosis in ventilator-induced lung injury via a mechanism involving nuclear factor-kappa B activation

    International Nuclear Information System (INIS)

    Huang, Chien-Sheng; Kawamura, Tomohiro; Peng, Ximei; Tochigi, Naobumi; Shigemura, Norihisa; Billiar, Timothy R.; Nakao, Atsunori; Toyoda, Yoshiya

    2011-01-01

    Highlights: → Hydrogen is a regulatory molecule with antiinflammatory and antiapoptotic protective effects. → There is very limited information on the pathways regulated in vivo by the hydrogen. → Antiapoptotic abilities of hydrogen were explained by upregulation of the antiapoptotic gene. → NFκB activation during hydrogen treatment was correlated with elevated antiapoptotic protein. → NFκB activation associated with increase Bcl-2 may contribute to cytoprotection of hydrogen. -- Abstract: We recently demonstrated the inhalation of hydrogen gas, a novel medical therapeutic gas, ameliorates ventilator-induced lung injury (VILI); however, the molecular mechanisms by which hydrogen ameliorates VILI remain unclear. Therefore, we investigated whether inhaled hydrogen gas modulates the nuclear factor-kappa B (NFκB) signaling pathway. VILI was generated in male C57BL6 mice by performing a tracheostomy and placing the mice on a mechanical ventilator (tidal volume of 30 ml/kg or 10 ml/kg without positive end-expiratory pressure). The ventilator delivered either 2% nitrogen or 2% hydrogen in balanced air. NFκB activation, as indicated by NFκB DNA binding, was detected by electrophoretic mobility shift assays and enzyme-linked immunosorbent assay. Hydrogen gas inhalation increased NFκB DNA binding after 1 h of ventilation and decreased NFκB DNA binding after 2 h of ventilation, as compared with controls. The early activation of NFκB during hydrogen treatment was correlated with elevated levels of the antiapoptotic protein Bcl-2 and decreased levels of Bax. Hydrogen inhalation increased oxygen tension, decreased lung edema, and decreased the expression of proinflammatory mediators. Chemical inhibition of early NFκB activation using SN50 reversed these protective effects. NFκB activation and an associated increase in the expression of Bcl-2 may contribute, in part, to the cytoprotective effects of hydrogen against apoptotic and inflammatory signaling pathway

  4. Staying Active: Physical Activity and Exercise

    Science.gov (United States)

    ... Events Advocacy For Patients About ACOG Staying Active: Physical Activity and Exercise Home For Patients Search FAQs Staying ... Exercise FAQ045, November 2016 PDF Format Staying Active: Physical Activity and Exercise Women's Health What are the benefits ...

  5. Halal Activism

    DEFF Research Database (Denmark)

    Fischer, Johan

    2016-01-01

    The purpose of this article is to further our understanding of contemporary Muslim consumer activism in Malaysia with a particular focus on halal (in Arabic, literally “permissible” or “lawful”) products and services. Muslim activists and organisations promote halal on a big scale in the interface...... zones between new forms of Islamic revivalism, the ethnicised state and Muslim consumer culture. Organisations such as the Muslim Consumers Association of Malaysia play an important role in pushing and protecting halal in Malaysia, that is, halal activists constantly call on the state to tighten halal...... in particular historical/national settings and that these issues should be explored in the interfaces between Islam, the state and market. More specifically, this article examines the above issues building on ethnography from fieldwork with three Muslim organisations in Malaysia....

  6. Prolactin-induced neuroprotection against glutamate excitotoxicity is mediated by the reduction of [Ca2+]i overload and NF-κB activation

    Science.gov (United States)

    Rivero-Segura, Nadia A.; Flores-Soto, Edgar; García de la Cadena, Selene; Coronado-Mares, Isabel; Gomez-Verjan, Juan C.; Ferreira, Diana G.; Cabrera-Reyes, Erika Alejandra; Lopes, Luísa V.; Massieu, Lourdes

    2017-01-01

    Prolactin (PRL) is a peptidic hormone that displays pleiotropic functions in the organism including different actions in the brain. PRL exerts a neuroprotective effect against excitotoxicity produced by glutamate (Glu) or kainic acid in both in vitro and in vivo models. It is well known that Glu excitotoxicity causes cell death through apoptotic or necrotic pathways due to intracellular calcium ([Ca2+] i) overload. Therefore, the aim of the present study was to assess the molecular mechanisms by which PRL maintains cellular viability of primary cultures of rat hippocampal neurons exposed to Glu excitotoxicity. We determined cell viability by monitoring mitochondrial activity and using fluorescent markers for viable and dead cells. The intracellular calcium level was determined by a fluorometric assay and proteins involved in the apoptotic pathway were determined by immunoblot. Our results demonstrated that PRL afforded neuroprotection against Glu excitotoxicity, as evidenced by a decrease in propidium iodide staining and by the decrease of the LDH activity. In addition, the MTT assay shows that PRL maintains normal mitochondrial activity even in neurons exposed to Glu. Furthermore, the Glu-induced intracellular [Ca2+]i overload was attenuated by PRL. These data correlate with the reduction found in the level of active caspase-3 and the pro-apoptotic ratio (Bax/Bcl-2). Concomitantly, PRL elicited the nuclear translocation of the transcriptional factor NF-κB, which was detected by immunofluorescence and confocal microscopy. To our knowledge, this is the first report demonstrating that PRL prevents Glu excitotoxicity by a mechanism involving the restoration of the intracellular calcium homeostasis and mitochondrial activity, as well as an anti-apoptotic action possibly mediated by the activity of NF-κB. Overall, the current results suggest that PRL could be of potential therapeutic advantage in the treatment of neurodegenerative diseases. PMID:28475602

  7. Tob1 induces apoptosis and inhibits proliferation, migration and invasion of gastric cancer cells by activating Smad4 and inhibiting β‑catenin signaling.

    Science.gov (United States)

    Kundu, Juthika; Wahab, S M Riajul; Kundu, Joydeb Kumar; Choi, Yoon-La; Erkin, Ozgur Cem; Lee, Hun Seok; Park, Sang Gyu; Shin, Young Kee

    2012-09-01

    Transducer of ErbB-2.1 (Tob1), a tumor suppressor protein, is inactivated in a variety of cancers including stomach cancer. However, the role of Tob1 in gastric carcinogenesis remains elusive. The present study aimed to investigate whether Tob1 could inhibit gastric cancer progression in vitro, and to elucidate its underlying molecular mechanisms. We found differential expression of Tob1 in human gastric cancer (MKN28, AGS and MKN1) cells. The overexpression of Tob1 induced apoptosis in MKN28 and AGS cells, which was associated with sub-G1 arrest, activation of caspase-3, induction of Bax, inhibition of Bcl-2 and cleavage of poly (ADP-ribose) polymerase (PARP). In addition, Tob1 inhibited proliferation, migration and invasion, which were reversed in MKN1 and AGS cells transfected with Tob1 siRNA. Overexpression of Tob1 in MKN28 and AGS cells induced the expression of Smad4, leading to the increased expression and the promoter activity of p15, which was diminished by silencing of Tob1 using specific siRNA. Tob1 decreased the phosphorylation of Akt and glycogen synthase kinase-3β (GSK3β) in MKN28 and AGS cells, resulting in the reduced protein expression and the transcriptional activity of β‑catenin, which in turn decreased the expression of cyclin D1, cyclin-dependent kinase-4 (CDK4), urokinase plasminogen activator receptor (uPAR) and peroxisome proliferator and activator receptor-δ (PPARδ). Conversely, silencing of Tob1 induced the phosphorylation of Akt and GSK-3β, and increased the expression of β‑catenin and its target genes. Collectively, our study demonstrates that the overexpression of Tob1 inhibits gastric cancer progression by activating Smad4- and inhibiting β‑catenin-mediated signaling pathways.

  8. Beta-mangostin from Cratoxylum arborescens activates the intrinsic apoptosis pathway through reactive oxygen species with downregulation of the HSP70 gene in the HL60 cells associated with a G0/G1 cell-cycle arrest.

    Science.gov (United States)

    Omer, Fatima Abdelmutaal Ahmed; Hashim, Najihah Binti Mohd; Ibrahim, Mohamed Yousif; Dehghan, Firouzeh; Yahayu, Maizatulakmal; Karimian, Hamed; Salim, Landa Zeenelabdin Ali; Mohan, Syam

    2017-11-01

    Xanthones are phytochemical compounds found in a number of fruits and vegetables. Characteristically, they are noted to be made of diverse properties based on their biological, biochemical, and pharmacological actions. Accordingly, the apoptosis mechanisms induced by beta-mangostin, a xanthone compound isolated from Cratoxylum arborescens in the human promyelocytic leukemia cell line (HL60) in vitro, were examined in this study. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was done to estimate the cytotoxicity effect of β-mangostin on the HL60 cell line. Acridine orange/propidium iodide and Hoechst 33342 dyes and Annexin V tests were conducted to detect the apoptosis features. Caspase-3 and caspase-9 activities; reactive oxygen species; real-time polymerase chain reaction for Bcl-2, Bax, caspase-3, and caspase-9 Hsp70 genes; and western blot for p53, cytochrome c, and pro- and cleavage-caspase-3 and caspase-9 were assessed to examine the apoptosis mechanism. Cell-cycle analysis conducted revealed that β-mangostin inhibited the growth of HL60 at 58 µM in 24 h. The administration of β-mangostin with HL60 caused cell morphological changes related to apoptosis which increased the number of early and late apoptotic cells. The β-mangostin-catalyzed apoptosis action through caspase-3, caspase-7, and caspase-9 activation overproduced reactive oxygen species which downregulated the expression of antiapoptotic genes Bcl-2 and HSP70. Conversely, the expression of the apoptotic genes Bax, caspase-3, and caspase-9 were upregulated. Meanwhile, at the protein level, β-mangostin activated the formation of cleaved caspase-3 and caspase-9 and also upregulated the p53. β-mangostin arrested the cell cycle at the G 0 /G 1 phase. Overall, the results for β-mangostin showed an antiproliferative effect in HL60 via stopping the cell cycle at the G 0 /G 1 phase and prompted the intrinsic apoptosis pathway.

  9. Anti-proliferative effect of RCE-4 from Reineckia carnea on human cervical cancer HeLa cells by inhibiting the PI3K/Akt/mTOR signaling pathway and NF-κB activation.

    Science.gov (United States)

    Bai, Caihong; Yang, Xiaojiao; Zou, Kun; He, Haibo; Wang, Junzhi; Qin, Huilin; Yu, Xiaoqin; Liu, Chengxiong; Zheng, Juyan; Cheng, Fan; Chen, Jianfeng

    2016-06-01

    Cervical cancer is the second leading cause of cancer deaths in women worldwide. In recent years, the studies find that inflammation is a critical component of tumor progression, and the ideal therapeutic methods should be aimed at the inflammation reaction triggers. (1β,3β,5β,25S)-spirostan-1,3-diol1-[α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranoside] (RCE-4) was the main active composition of Reineckia carnea (Andr.) Kunth. It significantly induced apoptosis in cervical cancer Caski cells through the mitochondrial pathway in our previous studies; however, its underlying mechanism remains poorly understood. This study aimed to further evaluate the effect of RCE-4 on human cervical cancer HeLa cells. Based on this observation, we investigated the anti-cervical cancer effect of RCE-4 by modulating phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway, nuclear factor-kappa B (NF-κB) activation, and inflammation-related key factors in HeLa cells. The results indicated that the HeLa cell was the most sensitive with an IC50 of 7.01 μM; RCE-4 significantly promoted the release of cellular lactate dehydrogenase (LDH); increased DNA fragmentation and apoptosis; reduced PI3K, Akt, mTOR, and NF-κBp65 phosphorylation levels; increased the Bax and cleaved poly (ADP-ribose) polymerase (PARP) protein levels; suppressed Bcl-2 protein expression; elevated the Bax/Bcl-2 expression ratio; and decreased the interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) mRNA expressions in HeLa cells in a concentration-dependent manner. These findings suggest that RCE-4 exerted beneficially anti-cervical cancer effect on HeLa cells, mainly inhibiting PI3K/Akt/mTOR signaling pathway phosphorylation and NF-κB activation, promoting HeLa cell apoptosis. Graphical abstract Anti-tumor effect of RCE-4 on HeLa cells.

  10. Active sharing

    CERN Multimedia

    2012-01-01

    The big news this week is, of course, the conclusions from the LHC performance workshop held in Chamonix from 6 to 10 February . The main recommendation, endorsed by CERN’s Machine Advisory Committee and adopted by the Management, is that the LHC will run at 4 TeV per beam this year. You can find all the details from Chamonix in the slides presented on Wednesday at the summary session, which leaves me free to talk about another important development coming up soon.   In ten days time, a new kind of gathering will be taking place in Geneva, bringing together two previously separate conferences, one driven by physics, the other by the medical community, but both looking to apply physics to the advancement of health. The merger of the International Conference for Translational Research in Radio-Oncology and CERN’s workshop on Physics for Health in Europe (ICTR-PHE) makes for a very eclectic mix. Presentations range from active shielding for interplanetary flight to the rather...

  11. Active Segmentation.

    Science.gov (United States)

    Mishra, Ajay; Aloimonos, Yiannis

    2009-01-01

    The human visual system observes and understands a scene/image by making a series of fixations. Every fixation point lies inside a particular region of arbitrary shape and size in the scene which can either be an object or just a part of it. We define as a basic segmentation problem the task of segmenting that region containing the fixation point. Segmenting the region containing the fixation is equivalent to finding the enclosing contour- a connected set of boundary edge fragments in the edge map of the scene - around the fixation. This enclosing contour should be a depth boundary.We present here a novel algorithm that finds this bounding contour and achieves the segmentation of one object, given the fixation. The proposed segmentation framework combines monocular cues (color/intensity/texture) with stereo and/or motion, in a cue independent manner. The semantic robots of the immediate future will be able to use this algorithm to automatically find objects in any environment. The capability of automatically segmenting objects in their visual field can bring the visual processing to the next level. Our approach is different from current approaches. While existing work attempts to segment the whole scene at once into many areas, we segment only one image region, specifically the one containing the fixation point. Experiments with real imagery collected by our active robot and from the known databases 1 demonstrate the promise of the approach.

  12. PKI 166 induced redox signalling and apoptosis through activation of p53, MAP kinase and caspase pathway in epidermoid carcinoma.

    Science.gov (United States)

    Das, Subhasis; Dey, Kaushik Kumar; Bharti, Rashmi; MaitiChoudhury, Sujata; Maiti, Sukumar; Mandal, Mahitosh

    2012-01-01

    Cellular redox changes have emerged as a pivotal and proximal event in cancer. PKI 166 is used to determine the effects of redox sensitive inhibition of EGFR, metastasis and apoptosis in epidermoid carcinoma. Cytotoxicity study of PKI 166 (IC50 1.0 microM) treated A431 cells were performed by MTT assay for 48 and 72 hrs. Morphological analysis of PKI 166 treated A431 cells for 48 hrs. revealed the cell shrinkage, loss of filopodia and lamellipodia by phase contrast and SEM images in dose dependent manner. It has cytotoxic effects through inhibiting cellular proliferation, leads to the induction of apoptosis, as increased fraction of sub-G1 phase of the cell cycle, chromatin condensation and DNA ladder. It inhibited cyclin-D1 and cyclin-E expression and induced p53, p21 expression in dose dependent manner. Consequently, an imbalance of Bax/Bcl-2 ratio triggered caspase cascade and subsequent cleavage of PARP, thereby shifting the balance in favour of apoptosis. PKI 166 treatment actively stimulated reactive oxygen species (ROS) and mitochondrial membrane depolarization. It inhibited some metastatic properties of A431 cells supressing colony formation by soft agar assay and inhibition of MMP 9 activity by gelatin zymography and western blot analysis. PKI 166 inhibited growth factor induced phosphorylation of EGFR, Akt, MAPK, JNK and colony formation in A431 cells. Thus the inhibition of proliferation was associated with redox regulation of the caspase cascade, EGFR, Akt/PI3K, MAPK/ ERK and JNK pathway. On the other hand, increased antioxidant activity leads to decreased ROS generation inhibit the anti-proliferative and apoptotic properties of PKI 166 in A431 cells. These observations indicated PKI 166 induced redox signalling dependent inhibition of cell proliferation, metastatic properties and induction of apoptotic potential in epidermoid carcinoma.

  13. Oxidative stress and hepatic stellate cell activation are key events in arsenic induced liver fibrosis in mice

    International Nuclear Information System (INIS)

    Ghatak, Subhadip; Biswas, Ayan; Dhali, Gopal Krishna; Chowdhury, Abhijit; Boyer, James L.; Santra, Amal

    2011-01-01

    Arsenic is an environmental toxicant and carcinogen. Exposure to arsenic is associated with development of liver fibrosis and portal hypertension through ill defined mechanisms. We evaluated hepatic fibrogenesis after long term arsenic exposure in a murine model. BALB/c mice were exposed to arsenic by daily gavages of 6 μg/gm body weight for 1 year and were evaluated for markers of hepatic oxidative stress and fibrosis, as well as pro-inflammatory, pro-apoptotic and pro-fibrogenic factors at 9 and 12 months. Hepatic NADPH oxidase activity progressively increased in arsenic exposure with concomitant development of hepatic oxidative stress. Hepatic steatosis with occasional collection of mononuclear inflammatory cells and mild portal fibrosis were the predominant liver lesion observed after 9 months of arsenic exposure, while at 12 months, the changes included mild hepatic steatosis, inflammation, necrosis and significant fibrosis in periportal areas. The pathologic changes in the liver were associated with markers of hepatic stellate cells (HSCs) activation, matrix reorganization and fibrosis including α-smooth muscle actin, transforming growth factor-β1, PDGF-Rβ, pro-inflammatory cytokines and enhanced expression of tissue inhibitor of metalloproteinase-1 and pro(α) collagen type I. Moreover, pro-apoptotic protein Bax was dominantly expressed and Bcl-2 was down-regulated along with increased number of TUNEL positive hepatocytes in liver of arsenic exposed mice. Furthermore, HSCs activation due to increased hepatic oxidative stress observed after in vivo arsenic exposure was recapitulated in co-culture model of isolated HSCs and hepatocytes exposed to arsenic. These findings have implications not only for the understanding of the pathology of arsenic related liver fibrosis but also for the design of preventive strategies in chronic arsenicosis.

  14. Axin1 up-regulated 1 accelerates stress-induced cardiomyocytes apoptosis through activating Wnt/β-catenin signaling.

    Science.gov (United States)

    Ye, Xing; Lin, Junyi; Lin, Zebin; Xue, Aimin; Li, Liliang; Zhao, Ziqin; Liu, Li; Shen, Yiwen; Cong, Bin

    2017-10-15

    Stress-induced cardiomyocyte apoptosis contributes to the pathogenesis of a variety of cardiovascular diseases, but how stress induces cardiomyocyte apoptosis remains largely unclear. The present study aims to investigate the effects of Axin1 up-regulated 1 (Axud1), a novel pro-apoptotic protein, on the cardiomyocyte survival and the underlying mechanisms. To this end, a rat model under restraint stress (RS) was established and in vitro stress-induced cardiomyocytes culture was achieved. Our data showed that Axud1 was upregulated in the rat myocardia after exposure to RS. Anti-apoptotic Bcl-2 was decreased, whereas pro-apoptotic Bax and Cleaved caspase-3 (Cc3) were increased in a time-dependent manner. The Wnt/β-catenin signaling was observed to be interestingly activated in heart undergoing RS. In addition, the treatment of norepinephrine (NE) to in vitro cardiomyocytes increased Axud1 level and induced cell apoptosis. Wnt/β-catenin signaling was consistently activated. Knockdown of Axud1 using specific siRNA blunted NE-induced cardiomyocytes apoptosis and also inactivated the Wnt/β-catenin signaling. XAV-939, an inhibitor of Wnt/β-catenin signaling, partially reversed the pro-apoptotic effect of NE. In conclusion, Axud1 accelerated stress-induced cardiomyocytes apoptosis through activation of Wnt/β-catenin signaling pathway. Our data provided novel evidence that therapeutic strategies against Axud1 or Wnt/β-catenin signaling might be promising in relation to RS-induced myocardial injury. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Oxidative stress caused by activation of NADPH oxidase 4 promotes contrast-induced acute kidney injury.

    Directory of Open Access Journals (Sweden)

    Bo Young Jeong

    Full Text Available Contrast-induced acute kidney injury (CIAKI is a leading cause of acute kidney injury following radiographic procedures. Intrarenal oxidative stress plays a critical role in CIAKI. Nicotinamide adenine dinucleotide 3-phosphate (NADPH oxidases (Noxs are important sources of reactive oxygen species (ROS. Among the various types of Noxs, Nox4 is expressed predominantly in the kidney in rodents. Here, we evaluated the role of Nox4 and benefit of Nox4 inhibition on CIAKI using in vivo and in vitro models. HK-2 cells were treated with iohexol, with or without Nox4 knockdown, or the most specific Nox1/4 inhibitor (GKT137831. Effects of Nox4 inhibition on CIAKI mice were examined. Expression of Nox4 in HK-2 cells was significantly increased following iohexol exposure. Silencing of Nox4 rescued the production of ROS, downregulated pro-inflammatory markers (particularly phospho-p38 implicated in CIAKI, and reduced Bax and caspase 3/7 activity, which resulted in increased cellular survival in iohexol-treated HK-2 cells. Pretreatment with GKT137831 replicated these effects by decreasing levels of phospho-p38. In a CIAKI mouse model, even though the improvement of plasma blood urea nitrogen was unclear, pretreatment with GKT137831 resulted in preserved structure, reduced expression of 8-hydroxy-2'-deoxyguanosine (8OHdG and kidney injury molecule-1 (KIM-1, and reduced number of TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells. These results suggest Nox4 as a key source of reactive oxygen species responsible for CIAKI and provide a novel potential option for prevention of CIAKI.

  16. Novel molecular, cytotoxical, and immunological study on promising and selective anticancer activity of Mung bean sprouts

    Directory of Open Access Journals (Sweden)

    Hafidh Rand R

    2012-11-01

    Full Text Available Abstract Background The anticancer and immunomodulatory activity of mung bean sprouts (MBS and the underlying mechanisms against human cervical and hepatocarcinoma cancer cells were explored. Methods MBS cytotoxicity and MBS-induced anticancer cytokines, TNF-α and IFN-β from cancer cells, and immunological cytokines, IL-4, IFN-γ, and IL-10 from peripheral mononuclear cells (PMNC were assessed by MTS and ELISA assays. Apoptotic cells were investigated by flow cytometry. The expression level of apoptotic genes (Bax, BCL-2, Capsases 7–9 and cell cycle regulatory genes (cyclin D, E, and A and tumor suppressor proteins (p27, p21, and p53 was assessed by real-time qPCR in the cancer cells treated with extract IC50. Results The cytotoxicity on normal human cells was significantly different from HeLa and HepG2 cells, 163.97 ± 5.73, 13.3 ± 0.89, and 14.04 ± 1.5 mg/ml, respectively. The selectivity index (SI was 12.44 ± 0.83 for HeLa and 11.94 ± 1.2 for HepG2 cells. Increased levels of TNF-α and IFN-β were observed in the treated HeLa and HepG2 culture supernatants when compared with untreated cells. MBS extract was shown to be an immunopolarizing agent by inducing IFNγ and inhibiting IL-4 production by PBMC; this leads to triggering of CMI and cellular cytotoxicity. The extract induced apoptosis, in a dose and time dependent manner, in treated HeLa and HepG2, but not in untreated, cells (P Conclusion MBS extract was shown to be a potent anticancer agent granting new prospects of anticancer therapy using natural products.

  17. IASS Activity

    Science.gov (United States)

    Hojaev, Alisher S.; Ibragimova, Elvira M.

    2015-08-01

    It’s well known, astronomy in Uzbekistan has ancient roots and traditions (e.g., Mirzo Ulugh Beg, Abū al-Rayhān al-Bīrūnī, Abū ‘Abdallāh al-Khwārizmī) and astronomical heritage carefully preserved. Nowadays uzbek astronomers play a key role in scientific research but also in OAD and Decadal Plan activity in the Central Asia region. International Aerospace School (IASS) is an amazing and wonderful event held annually about 30 years. IASS is unique project in the region, and at the beginning we spent the Summer and Winter Schools. At present in the summer camp we gather about 50 teenage and undergraduate students over the country and abroad (France, Malaysia, Turkey, Azerbaijan, Pakistan, Russia, etc.). They are selected on the basis of tests of astronomy and space issues. During two weeks of IASS camp the invited scientists, cosmonauts and astronauts as well as other specialists give lectures and engage in practical exercises with IASS students in astronomy, including daily observations of the Sun and night sky observations with meniscus telescope, space research and exploration, aerospace modelling, preparation and presentation of original projects. This is important that IASS gives not theoretical grounds only but also practically train the students and the hands-on training is the major aims of IASS. Lectures and practice in the field of astronomy carried out with the direct involvement and generous assistance of Uranoscope Association (Paris, France). The current 26-th IASS is planned to held in July 2015.

  18. Activation Energy

    Science.gov (United States)

    Gadeken, Owen

    2002-01-01

    Teaming is so common in today's project management environment that most of us assume it comes naturally. We further assume that when presented with meaningful and challenging work, project teams will naturally engage in productive activity to complete their tasks. This assumption is expressed in the simple (but false) equation: Team + Work = Teamwork. Although this equation appears simple and straightforward, it is far from true for most project organizations whose r