WorldWideScience

Sample records for cell death apoptosis

  1. Picornaviruses and Apoptosis: Subversion of Cell Death.

    Science.gov (United States)

    Croft, Sarah N; Walker, Erin J; Ghildyal, Reena

    2017-09-19

    Infected cells can undergo apoptosis as a protective response to viral infection, thereby limiting viral infection. As viruses require a viable cell for replication, the death of the cell limits cellular functions that are required for virus replication and propagation. Picornaviruses are single-stranded RNA viruses that modify the host cell apoptotic response, probably in order to promote viral replication, largely as a function of the viral proteases 2A, 3C, and 3CD. These proteases are essential for viral polyprotein processing and also cleave cellular proteins. Picornavirus proteases cleave proapoptotic adaptor proteins, resulting in downregulation of apoptosis. Picornavirus proteases also cleave nucleoporins, disrupting the orchestrated manner in which signaling pathways use active nucleocytoplasmic trafficking, including those involved in apoptosis. In addition to viral proteases, the transmembrane 2B protein alters intracellular ion signaling, which may also modulate apoptosis. Overall, picornaviruses, via the action of virally encoded proteins, exercise intricate control over and subvert cell death pathways, specifically apoptosis, thereby allowing viral replication to continue. Copyright © 2017 Croft et al.

  2. What history tells us XXI. Apoptosis and programmed cell death

    Indian Academy of Sciences (India)

    2010-04-30

    Apr 30, 2010 ... Home; Journals; Journal of Biosciences; Volume 35; Issue 2. What history tells us XXI. Apoptosis and programmed cell death: when biological categories are blurred. Michel Morange. Series Volume 35 Issue 2 June 2010 pp 177-181 ...

  3. What history tells us XXI. Apoptosis and programmed cell death ...

    Indian Academy of Sciences (India)

    2010-04-30

    Apr 30, 2010 ... Home; Journals; Journal of Biosciences; Volume 35; Issue 2. What history tells us XXI. Apoptosis and programmed cell death: when biological categories are blurred. Michel Morange. Series Volume 35 Issue 2 June 2010 pp 177-181 ...

  4. Curcumin induces apoptosis-independent death in oesophageal cancer cells.

    LENUS (Irish Health Repository)

    O'Sullivan-Coyne, G

    2012-01-31

    BACKGROUND: Oesophageal cancer incidence is increasing and survival rates remain extremely poor. Natural agents with potential for chemoprevention include the phytochemical curcumin (diferuloylmethane). We have examined the effects of curcumin on a panel of oesophageal cancer cell lines. METHODS: MTT (3-(4,5-dimethyldiazol-2-yl)-2,5 diphenyl tetrazolium bromide) assays and propidium iodide staining were used to assess viability and DNA content, respectively. Mitotic catastrophe (MC), apoptosis and autophagy were defined by both morphological criteria and markers such as MPM-2, caspase 3 cleavage and monodansylcadaverine (MDC) staining. Cyclin B and poly-ubiquitinated proteins were assessed by western blotting. RESULTS: Curcumin treatment reduces viability of all cell lines within 24 h of treatment in a 5-50 muM range. Cytotoxicity is associated with accumulation in G2\\/M cell-cycle phases and distinct chromatin morphology, consistent with MC. Caspase-3 activation was detected in two out of four cell lines, but was a minor event. The addition of a caspase inhibitor zVAD had a marginal or no effect on cell viability, indicating predominance of a non-apoptotic form of cell death. In two cell lines, features of both MC and autophagy were apparent. Curcumin-responsive cells were found to accumulate poly-ubiquitinated proteins and cyclin B, consistent with a disturbance of the ubiquitin-proteasome system. This effect on a key cell-cycle checkpoint regulator may be responsible for the mitotic disturbances and consequent cytotoxicity of this drug. CONCLUSION: Curcumin can induce cell death by a mechanism that is not reliant on apoptosis induction, and thus represents a promising anticancer agent for prevention and treatment of oesophageal cancer.

  5. Curcumin induces apoptosis-independent death in oesophageal cancer cells.

    LENUS (Irish Health Repository)

    O'Sullivan-Coyne, G

    2009-10-06

    Background:Oesophageal cancer incidence is increasing and survival rates remain extremely poor. Natural agents with potential for chemoprevention include the phytochemical curcumin (diferuloylmethane). We have examined the effects of curcumin on a panel of oesophageal cancer cell lines.Methods:MTT (3-(4,5-dimethyldiazol-2-yl)-2,5 diphenyl tetrazolium bromide) assays and propidium iodide staining were used to assess viability and DNA content, respectively. Mitotic catastrophe (MC), apoptosis and autophagy were defined by both morphological criteria and markers such as MPM-2, caspase 3 cleavage and monodansylcadaverine (MDC) staining. Cyclin B and poly-ubiquitinated proteins were assessed by western blotting.Results:Curcumin treatment reduces viability of all cell lines within 24 h of treatment in a 5-50 muM range. Cytotoxicity is associated with accumulation in G2\\/M cell-cycle phases and distinct chromatin morphology, consistent with MC. Caspase-3 activation was detected in two out of four cell lines, but was a minor event. The addition of a caspase inhibitor zVAD had a marginal or no effect on cell viability, indicating predominance of a non-apoptotic form of cell death. In two cell lines, features of both MC and autophagy were apparent. Curcumin-responsive cells were found to accumulate poly-ubiquitinated proteins and cyclin B, consistent with a disturbance of the ubiquitin-proteasome system. This effect on a key cell-cycle checkpoint regulator may be responsible for the mitotic disturbances and consequent cytotoxicity of this drug.Conclusion:Curcumin can induce cell death by a mechanism that is not reliant on apoptosis induction, and thus represents a promising anticancer agent for prevention and treatment of oesophageal cancer.British Journal of Cancer advance online publication, 6 October 2009; doi:10.1038\\/sj.bjc.6605308 www.bjcancer.com.

  6. Apoptosis and Vocal Fold Disease: Clinically Relevant Implications of Epithelial Cell Death

    Science.gov (United States)

    Novaleski, Carolyn K.; Carter, Bruce D.; Sivasankar, M. Preeti; Ridner, Sheila H.; Dietrich, Mary S.; Rousseau, Bernard

    2017-01-01

    Purpose: Vocal fold diseases affecting the epithelium have a detrimental impact on vocal function. This review article provides an overview of apoptosis, the most commonly studied type of programmed cell death. Because apoptosis can damage epithelial cells, this article examines the implications of apoptosis on diseases affecting the vocal fold…

  7. Alternative pathways of programmed cell death are activated in cells with defective caspase-dependent apoptosis

    Czech Academy of Sciences Publication Activity Database

    Ondroušková, E.; Souček, Karel; Horváth, Viktor; Šmarda, J.

    2008-01-01

    Roč. 32, č. 4 (2008), s. 599-609 ISSN 0145-2126 R&D Projects: GA ČR(CZ) GA204/07/0834 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : apoptosis * autophagy * programmed cell death Subject RIV: BO - Biophysics Impact factor: 2.390, year: 2008

  8. Programmed cell death-10 enhances proliferation and protects malignant T cells from apoptosis

    DEFF Research Database (Denmark)

    Lauenborg, Britt; Kopp, Katharina; Krejsgaard, Thorbjørn

    2010-01-01

    The programmed cell death-10 (PDCD10; also known as cerebral cavernous malformation-3 or CCM3) gene encodes an evolutionarily conserved protein associated with cell apoptosis. Mutations in PDCD10 result in cerebral cavernous malformations, an important cause of cerebral hemorrhage. PDCD10...... of cutaneous T-cell lymphoma (Sezary syndrome) patients. PDCD10 is associated with protein phosphatase-2A, a regulator of mitogenesis and apoptosis in malignant T cells. Inhibition of oncogenic signal pathways [Jak3, Notch1, and nuclear factor-¿B (NF-¿B)] partly inhibits the constitutive PDCD10 expression......, whereas an activator of Jak3 and NF-¿B, interleukin-2 (IL-2), enhances PDCD10 expression. Functional data show that PDCD10 depletion by small interfering RNA induces apoptosis and decreases proliferation of the sensitive cells. To our knowledge, these data provide the first functional link between PDCD10...

  9. Depletion of the AP-1 repressor JDP2 induces cell death similar to apoptosis

    DEFF Research Database (Denmark)

    Lerdrup, Mads; Holmberg, Christian Henrik; Dietrich, Nikolaj

    2005-01-01

    depletion of JDP2 resulted in p53-independent cell death that resembles apoptosis and was evident at 72 h. The death mechanism was caspase dependent as the cells could be rescued by treatment with caspase inhibitor zVAD. Our studies suggest that JDP2 functions as a general survival protein, not only...

  10. VMP1 related autophagy and apoptosis in colorectal cancer cells: VMP1 regulates cell death

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Qinyi [Department of Ultrasonograph, Changshu No. 2 People’s Hospital, Changshu (China); Zhou, Hao; Chen, Yan [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou (China); Shen, Chenglong [Department of General Surgery, Changshu No. 2 People’s Hospital, Changshu (China); He, Songbing; Zhao, Hua; Wang, Liang [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou (China); Wan, Daiwei, E-mail: 372710369@qq.com [Department of Hepatobiliary Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou (China); Gu, Wen, E-mail: 505339704@qq.com [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou (China)

    2014-01-17

    Highlights: •This research confirmed VMP1 as a regulator of autophagy in colorectal cancer cell lines. •We proved the pro-survival role of VMP1-mediated autophagy in colorectal cancer cell lines. •We found the interaction between VMP1 and BECLIN1 also existing in colorectal cancer cell lines. -- Abstract: Vacuole membrane protein 1 (VMP1) is an autophagy-related protein and identified as a key regulator of autophagy in recent years. In pancreatic cell lines, VMP1-dependent autophagy has been linked to positive regulation of apoptosis. However, there are no published reports on the role of VMP1 in autophagy and apoptosis in colorectal cancers. Therefore, to address this gap of knowledge, we decided to interrogate regulation of autophagy and apoptosis by VMP1. We have studied the induction of autophagy by starvation and rapamycin treatment in colorectal cell lines using electron microscopy, immunofluorescence, and immunoblotting. We found that starvation-induced autophagy correlated with an increase in VMP1 expression, that VMP1 interacted with BECLIN1, and that siRNA mediated down-regulation of VMP1-reduced autophagy. Next, we examined the relationship between VMP1-dependent autophagy and apoptosis and found that VMP1 down-regulation sensitizes cells to apoptosis and that agents that induce apoptosis down-regulate VMP1. In conclusion, similar to its reported role in other cell types, VMP1 is an important regulator of autophagy in colorectal cell lines. However, in contrast to its role in pancreatic cell lines, in colorectal cancer cells, VMP1-dependent autophagy appears to be pro-survival rather than pro-cell death.

  11. Apoptosis-like yeast cell death in response to DNA damage and replication defects

    International Nuclear Information System (INIS)

    Burhans, William C.; Weinberger, Martin; Marchetti, Maria A.; Ramachandran, Lakshmi; D'Urso, Gennaro; Huberman, Joel A.

    2003-01-01

    In budding (Saccharomyces cerevisiae) and fission (Schizosaccharomyces pombe) yeast and other unicellular organisms, DNA damage and other stimuli can induce cell death resembling apoptosis in metazoans, including the activation of a recently discovered caspase-like molecule in budding yeast. Induction of apoptotic-like cell death in yeasts requires homologues of cell cycle checkpoint proteins that are often required for apoptosis in metazoan cells. Here, we summarize these findings and our unpublished results which show that an important component of metazoan apoptosis recently detected in budding yeast - reactive oxygen species (ROS) - can also be detected in fission yeast undergoing an apoptotic-like cell death. ROS were detected in fission and budding yeast cells bearing conditional mutations in genes encoding DNA replication initiation proteins and in fission yeast cells with mutations that deregulate cyclin-dependent kinases (CDKs). These mutations may cause DNA damage by permitting entry of cells into S phase with a reduced number of replication forks and/or passage through mitosis with incompletely replicated chromosomes. This may be relevant to the frequent requirement for elevated CDK activity in mammalian apoptosis, and to the recent discovery that the initiation protein Cdc6 is destroyed during apoptosis in mammals and in budding yeast cells exposed to lethal levels of DNA damage. Our data indicate that connections between apoptosis-like cell death and DNA replication or CDK activity are complex. Some apoptosis-like pathways require checkpoint proteins, others are inhibited by them, and others are independent of them. This complexity resembles that of apoptotic pathways in mammalian cells, which are frequently deregulated in cancer. The greater genetic tractability of yeasts should help to delineate these complex pathways and their relationships to cancer and to the effects of apoptosis-inducing drugs that inhibit DNA replication

  12. Diazene JK-279 induces apoptosis-like cell death in human cervical carcinoma cells.

    Science.gov (United States)

    Jakopec, S; Dubravcic, K; Polanc, S; Kosmrlj, J; Osmak, M

    2006-03-01

    Diazene N-phenyl-2-(2-pyridinyl)diazenecarboxamide (JK-279) is a newly synthesized compound, cytotoxic for several tumor cell lines and their drug-resistant sublines. In human cervical carcinoma cells (HeLa), this compound reduced intracellular glutathione content and increased sensitivity to cisplatin. The aim of the present study was to elucidate the molecular mechanisms involved in the cytotoxic effect of diazene JK-279 on HeLa cells. Cytotoxicity was determined by the MTT method. Flow cytometry analysis showed that diazene JK-279 induces G(2)/M phase arrest, mediated by the increase in p21 expression, and accompanied by an alteration in the expression of survivin. The highest concentration of JK-279 altered nuclear morphology in intact cells, showing "apoptosis-like" features. No cleavage of procaspase-3, procaspase-9 and PARP, or altered expression of apoptotic proteins Bcl-2 and Bax were detected. At the same time, PS externalization and internucleosomal DNA cleavage were observed. Partial necrosis was detected as well. Our results demonstrate that cytotoxicity of diazene JK-279 is mostly the consequence of caspase-independent cell death, which is in some aspects "apoptosis-like". Taking into account the multiplicity of mechanisms used by cancer cells to prevent apoptosis, the drugs (like diazene JK-279) that would activate alternative cell death pathways could provide a useful tool for new types of cancer therapy.

  13. Cell death by apoptosis following X-irradiation of the foetal and neonatal rat kidney

    International Nuclear Information System (INIS)

    Gobe, G.C.; Harmon, B.V.

    1988-01-01

    A light and electron microscopic study was undertaken to determine the type of cell death induced by X-irradiation in the developing kidney. Five-day-old Sprague-Dawley rats were exposed to a whole-body dose of either 2 or 5 Gy, and foetuses in the eighteenth day of development were exposed to a dose of 4 Gy. The kidneys were examined at 4, 8 and 24 h, and at 1 and 2 weeks post-irradiation. The dying cells from both control and treated kidneys showed the morphological features of apoptosis, a distinct form of cell death that has been identified in mammalian tissues under physiological as well as pathological conditions. Necrosis was not detected. Apoptosis was infrequent in control kidneys and insignificant in extent when compared with the proliferative activity of the cells of the superficial nephrons. There was a pronounced increase in apoptosis during the first day after irradiation. (author)

  14. Cellular zinc fluxes and the regulation of apoptosis/gene-directed cell death.

    Science.gov (United States)

    Truong-Tran, A Q; Ho, L H; Chai, F; Zalewski, P D

    2000-05-01

    The maintenance of discrete subcellular pools of zinc (Zn) is critical for the functional and structural integrity of cells. Among the important biological processes influenced by Zn is apoptosis, a process that is important in cellular homeostasis (an important cellular homeostatic process). It has also been identified as a major mechanism contributing to cell death in response to toxins and in disease, offering hope that novel therapies that target apoptotic pathways may be developed. Because Zn levels in the body can be increased in a relatively nontoxic manner, it may be possible to prevent or ameliorate degenerative disorders that are associated with high rates of apoptotic cell death. This review begins with brief introductions that address, first, the cellular biology of Zn, especially the critical labile Zn pools, and, second, the phenomenon of apoptosis. We then review the evidence relating Zn to apoptosis and address three major hypotheses: (1) that a specific pool or pools of intracellular labile Zn regulates apoptosis; (2) that systemic changes in Zn levels in the body, due to dietary factors, altered physiological states or disease, can influence cell susceptibility to apoptosis, and (3) that this altered susceptibility to apoptosis contributes to pathophysiological changes in the body. Other key issues are the identity of the molecular targets of Zn in the apoptotic cascade, the types of cells and tissues most susceptible to Zn-regulated apoptosis, the role of Zn as a coordinate regulator of mitosis and apoptosis and the apparent release of tightly bound intracellular pools of Zn during the later stages of apoptosis. This review concludes with a section highlighting areas of priority for future studies.

  15. Cell death control: the interplay of apoptosis and autophagy in the pathogenicity of Sclerotinia sclerotiorum.

    Directory of Open Access Journals (Sweden)

    Mehdi Kabbage

    Full Text Available Programmed cell death is characterized by a cascade of tightly controlled events that culminate in the orchestrated death of the cell. In multicellular organisms autophagy and apoptosis are recognized as two principal means by which these genetically determined cell deaths occur. During plant-microbe interactions cell death programs can mediate both resistant and susceptible events. Via oxalic acid (OA, the necrotrophic phytopathogen Sclerotinia sclerotiorum hijacks host pathways and induces cell death in host plant tissue resulting in hallmark apoptotic features in a time and dose dependent manner. OA-deficient mutants are non-pathogenic and trigger a restricted cell death phenotype in the host that unexpectedly exhibits markers associated with the plant hypersensitive response including callose deposition and a pronounced oxidative burst, suggesting the plant can recognize and in this case respond, defensively. The details of this plant directed restrictive cell death associated with OA deficient mutants is the focus of this work. Using a combination of electron and fluorescence microscopy, chemical effectors and reverse genetics, we show that this restricted cell death is autophagic. Inhibition of autophagy rescued the non-pathogenic mutant phenotype. These findings indicate that autophagy is a defense response in this necrotrophic fungus/plant interaction and suggest a novel function associated with OA; namely, the suppression of autophagy. These data suggest that not all cell deaths are equivalent, and though programmed cell death occurs in both situations, the outcome is predicated on who is in control of the cell death machinery. Based on our data, we suggest that it is not cell death per se that dictates the outcome of certain plant-microbe interactions, but the manner by which cell death occurs that is crucial.

  16. Montelukast Induces Apoptosis-Inducing Factor-Mediated Cell Death of Lung Cancer Cells

    Directory of Open Access Journals (Sweden)

    Ming-Ju Tsai

    2017-06-01

    Full Text Available Developing novel chemo-prevention techniques and advancing treatment are key elements to beating lung cancer, the most common cause of cancer mortality worldwide. Our previous cohort study showed that cysteinyl leukotriene receptor antagonists, mainly montelukast, decreased the lung cancer risk in asthma patients. In the current study, we conducted in vivo and in vitro experiments to demonstrate the inhibiting effect of montelukast on lung cancer and to investigate the underlying mechanisms. Using Lewis lung carcinoma-bearing mice, we showed that feeding montelukast significantly delayed the tumor growth in mice (p < 0.0001. Montelukast inhibited cell proliferation and colony formation and induced the cell death of lung cancer cells. Further investigation showed the down-regulation of B-cell lymphoma 2 (Bcl-2, up-regulation of Bcl-2 homologous antagonist/killer (Bak, and nuclear translocation of apoptosis-inducing factor (AIF in montelukast-treated lung cancer cells. Montelukast also markedly decreased the phosphorylation of several proteins, such as with no lysine 1 (WNK1, protein kinase B (Akt, extracellular signal-regulated kinase 1/2 (Erk1/2, MAPK/Erk kinase (MEK, and proline-rich Akt substrate of 40-kDa (PRAS40, which might contribute to cell death. In conclusion, montelukast induced lung cancer cell death via the nuclear translocation of AIF. This study confirmed the chemo-preventive effect of montelukast shown in our previous cohort study. The utility of montelukast in cancer prevention and treatment thus deserves further studies.

  17. Mulberry anthocyanins improves thyroid cancer progression mainly by inducing apoptosis and autophagy cell death

    Directory of Open Access Journals (Sweden)

    Hou-Long Long

    2018-05-01

    Full Text Available Dietary anthocyanin compounds have multiple biological effects, including antioxidant, anti-inflammatory, and anti-atherosclerotic characteristics. The present study evaluated the anti-tumor capacity of mulberry anthocyanins (MA in thyroid cancer cells. Our data showed that MA suppressed SW1736 and HTh-7 cell proliferation in a time- and dose-dependent manner. Meanwhile, flow cytometry results indicated that MA significantly increased SW1736 and HTh-7 cell apoptosis. We additionally observed that SW1736 and HTh-7 cell autophagy was markedly enhanced after MA treatment. Importantly, anthocyanin-induced cell death was largely abolished by 3-methyladenine (3-MA or chloroquine diphosphate salt (CQ treatment, suggesting that MA-induced SW1736 and HTh-7 cell death was partially dependent on autophagy. In addition, activation of protein kinase B (Akt, mammalian target of rapamycin (mTOR, and ribosomal protein S6 (S6 were significantly suppressed by anthocyanin exposure. In summary, MA may serve as an adjunctive therapy for thyroid cancer patients through induction of apoptosis and autophagy-dependent cell death. Keywords: Mulberry anthocyanins, Thyroid cancer, Apoptosis, Autophagic death

  18. Selenium Compounds, Apoptosis and Other Types of Cell Death: An Overview for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Juan Antonio Palop

    2012-08-01

    Full Text Available Selenium (Se is an essential trace element involved in different physiological functions of the human body and plays a role in cancer prevention and treatment. Induction of apoptosis is considered an important cellular event that can account for the cancer preventive effects of Se. The mechanisms of Se-induced apoptosis are associated with the chemical forms of Se and their metabolism as well as the type of cancer studied. So, some selenocompounds, such as SeO2 involve the activation of caspase-3 while sodium selenite induces apoptosis in the absence of the activation of caspases. Modulation of mitochondrial functions has been reported to play a key role in the regulation of apoptosis and also to be one of the targets of Se compounds. Other mechanisms for apoptosis induction are the modulation of glutathione and reactive oxygen species levels, which may function as intracellular messengers to regulate signaling pathways, or the regulation of kinase, among others. Emerging evidence indicates the overlaps between the apoptosis and other types of cell death such as autophagy. In this review we report different processes of cell death induced by Se compounds in cancer treatment and prevention.

  19. The fusarium mycotoxin deoxynivalenol can inhibit plant apoptosis-like programmed cell death.

    Directory of Open Access Journals (Sweden)

    Mark Diamond

    Full Text Available The Fusarium genus of fungi is responsible for commercially devastating crop diseases and the contamination of cereals with harmful mycotoxins. Fusarium mycotoxins aid infection, establishment, and spread of the fungus within the host plant. We investigated the effects of the Fusarium mycotoxin deoxynivalenol (DON on the viability of Arabidopsis cells. Although it is known to trigger apoptosis in animal cells, DON treatment at low concentrations surprisingly did not kill these cells. On the contrary, we found that DON inhibited apoptosis-like programmed cell death (PCD in Arabidopsis cells subjected to abiotic stress treatment in a manner independent of mitochondrial cytochrome c release. This suggested that Fusarium may utilise mycotoxins to suppress plant apoptosis-like PCD. To test this, we infected Arabidopsis cells with a wild type and a DON-minus mutant strain of F. graminearum and found that only the DON producing strain could inhibit death induced by heat treatment. These results indicate that mycotoxins may be capable of disarming plant apoptosis-like PCD and thereby suggest a novel way that some fungi can influence plant cell fate.

  20. 17-AAG sensitized malignant glioma cells to death-receptor mediated apoptosis.

    Science.gov (United States)

    Siegelin, Markus David; Habel, Antje; Gaiser, Timo

    2009-02-01

    17-AAG is a selective HSP90-inhibitor that exhibited therapeutic activity in cancer. In this study three glioblastoma cell lines (U87, LN229 and U251) were treated with 17-AAG, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or the combination of both. Treatment with subtoxic doses of 17-AAG in combination with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces rapid apoptosis in TRAIL-resistant glioma cells, suggesting that this combined treatment may offer an attractive strategy for treating gliomas. 17-AAG treatment down-regulated survivin through proteasomal degradation. In addition, over-expression of survivin attenuated cytotoxicity induced by the combination of 17-AAG and TRAIL. In summary, survivin is a key regulator of TRAIL-17-AAG mediated cell death in malignant glioma.

  1. Cell Death and Inflammatory Bowel Diseases: Apoptosis, Necrosis, and Autophagy in the Intestinal Epithelium

    Directory of Open Access Journals (Sweden)

    Tiago Nunes

    2014-01-01

    Full Text Available Cell death mechanisms have been associated with the development of inflammatory bowel diseases in humans and mice. Recent studies suggested that a complex crosstalk between autophagy/apoptosis, microbe sensing, and enhanced endoplasmic reticulum stress in the epithelium could play a critical role in these diseases. In addition, necroptosis, a relatively novel programmed necrosis-like pathway associated with TNF receptor activation, seems to be also present in the pathogenesis of Crohn’s disease and in specific animal models for intestinal inflammation. This review attempts to cover new data related to cell death mechanisms and inflammatory bowel diseases.

  2. Immunopathogenesis of Dengue Virus-Induced Redundant Cell Death: Apoptosis and Pyroptosis.

    Science.gov (United States)

    Suwanmanee, San; Luplertlop, Natthanej

    Dengue virus infection is a self-limited condition, which is of particular importance in tropical and subtropical regions and for which no specific treatment or effective vaccine is available. There are several hypotheses explaining dengue pathogenesis. These usually refer to host immune responses, including antibody-dependent enhancement, cytokine expression, and dengue virus particles including NS1 protein, which lead to cell death by both apoptosis and pyroptosis. A clear understanding of the pathogenesis should facilitate the development of vaccines and therapies. This review focuses on the immunopathogenesis in relation to clinical manifestations and patterns of cell death, focusing on the pathogenesis of severe dengue.

  3. Low dose rate radiation favors apoptosis as a mechanism of cell death

    International Nuclear Information System (INIS)

    Murtha, Albert D.; Rupnow, Brent; Knox, Susan J.

    1997-01-01

    Purpose/Objective: Radioimmunotherapy (RIT) has demonstrated promising results in the treatment of chemotherapy refractory non-Hodgkin's lymphoma. The radiation associated with this therapy is emitted in a continuous fashion at low dose rates (LDR). Results from studies comparing the relative efficacy of LDR radiation and high dose rate (HDR) radiation on malignant cell killing have been variable. This variability may be due in part to the relative contribution of different mechanisms of cell killing (apoptosis or necrosis) at different dose rates. Materials and Methods: In order to test this hypothesis, the relative efficacy of LDR (16.7 cGy/hr) and HDR radiation (422 cGy/min) were compared using a human B cell lymphoma cell line (PW) and a PW clone (c26) stably transfected to overexpress the anti-apoptotic gene Bcl-2. The endpoints evaluated included the relative amount of cell killing, the fraction of cell killing attributable to apoptosis versus necrosis, and the impact of Bcl-2 overexpression on both overall cell killing and the fraction of killing attributable to apoptosis. Results: HDR and LDR radiation resulted in similar overall cell killing in the PW wild type cell line. In contrast, killing of clone c26 cells was dose rate dependent. One third less killing was seen following LDR irradiation of c26 cells compared with equivalent doses of HDR radiation. Analysis of the relative mechanisms of killing following LDR irradiation revealed a relative increase in the proportion of killing attributable to apoptosis. Conclusion: These findings support the hypothesis that in PW cells, LDR radiation appears to be highly dependent on apoptosis as a mechanism of cell death. These findings may have implications for the selection of patients for RIT, and for the treatment of tumors that overexpress Bcl-2. They may also help form the basis for future rational design of effective combined modality therapies utilizing RIT

  4. Diffusion is capable of translating anisotropic apoptosis initiation into a homogeneous execution of cell death.

    LENUS (Irish Health Repository)

    Huber, Heinrich J

    2010-01-01

    ABSTRACT: BACKGROUND: Apoptosis is an essential cell death process throughout the entire life span of all metazoans and its deregulation in humans has been implicated in many proliferative and degenerative diseases. Mitochondrial outer membrane permeabilisation (MOMP) and activation of effector caspases are key processes during apoptosis signalling. MOMP can be subject to spatial coordination in human cancer cells, resulting in intracellular waves of cytochrome-c release. To investigate the consequences of these spatial anisotropies in mitochondrial permeabilisation on subsequent effector caspase activation, we devised a mathematical reaction-diffusion model building on a set of partial differential equations. RESULTS: Reaction-diffusion modelling suggested that even if strong spatial anisotropies existed during mitochondrial cytochrome c release, these would be eliminated by free diffusion of the cytosolic proteins that instantiate the apoptosis execution network. Experimentally, rapid sampling of mitochondrial permeabilisation and effector caspase activity in individual HeLa cervical cancer cells confirmed predictions of the reaction-diffusion model and demonstrated that the signalling network of apoptosis execution could efficiently translate spatial anisotropies in mitochondrial permeabilisation into a homogeneous effector caspase response throughout the cytosol. Further systems modelling suggested that a more than 10,000-fold impaired diffusivity would be required to maintain spatial anisotropies as observed during mitochondrial permeabilisation until the time effector caspases become activated. CONCLUSIONS: Multi-protein diffusion efficiently contributes to eliminating spatial asynchronies which are present during the initiation of apoptosis execution and thereby ensures homogeneous apoptosis execution throughout the entire cell body. For previously reported biological scenarios in which effector caspase activity was shown to be targeted selectively to

  5. Mitochondrion-mediated cell death: dissecting yeast apoptosis for a better understanding of neurodegeneration

    International Nuclear Information System (INIS)

    Braun, Ralf J.

    2012-01-01

    Mitochondrial damage and dysfunction are common hallmarks for neurodegenerative disorders, including Alzheimer, Parkinson, Huntington diseases, and the motor neuron disorder amyotrophic lateral sclerosis. Damaged mitochondria pivotally contribute to neurotoxicity and neuronal cell death in these disorders, e.g., due to their inability to provide the high energy requirements for neurons, their generation of reactive oxygen species (ROS), and their induction of mitochondrion-mediated cell death pathways. Therefore, in-depth analyses of the underlying molecular pathways, including cellular mechanisms controlling the maintenance of mitochondrial function, is a prerequisite for a better understanding of neurodegenerative disorders. The yeast Saccharomyces cerevisiae is an established model for deciphering mitochondrial quality control mechanisms and the distinct mitochondrial roles during apoptosis and programmed cell death. Cell death upon expression of various human neurotoxic proteins has been characterized in yeast, revealing neurotoxic protein-specific differences. This review summarizes how mitochondria are affected in these neurotoxic yeast models, and how they are involved in the execution and prevention of cell death. I will discuss to which extent this mimics the situation in other neurotoxic model systems, and how this may contribute to a better understanding of the mitochondrial roles in the human disorders.

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

    OpenAIRE

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

    2017-01-01

    Andrographolide, a natural compound isolated from Andrographis paniculata, has been reported to possess antitumor activity. In the present study, the effect of andrographolide in human gastric cancer (GC) cells was investigated. Andrographolide induced cell death with apoptotic and non-apoptotic features. At a low concentration, andrographolide potentiated apoptosis and reduction of clonogenicity triggered by recombinant human tumor necrosis factor-related apoptosis-inducing ligand (rhTRAIL)....

  7. Study on apoptosis effect of human breast cancer cell MCF-7 induced by lycorine hydrochloride via death receptor pathway.

    Science.gov (United States)

    Ji, Yubin; Yu, Miao; Qi, Zheng; Cui, Di; Xin, Guosong; Wang, Bing; Jia, Weiling; Chang, Lin

    2017-05-01

    As research was conducted on the early apoptosis of human breast cancer cell MCF-7 caused by lycorine hydrochloride and the expression of the related apoptosis proteins. The early-period apoptosis rate of human breast cancer cell MCF-7 was tested with the AnnexinV/PI double staining and flow cytometry. The Western Blotting method was also used to detect the protein expression conditions of Fas, FasL, Caspase-8 and Bid. The results showed that the higher the dose, the higher the rate of apoptosis and that the rate of apoptosis was dependent on the dose; the relative protein activity of Fas, FasL, Caspase-8 and bid gradually rose with the increase of lycorine dosage and the activities revealed certain dose-independence. Results showed that lycorine hydrochloride could induce the apoptosis of human breast cancer cell MCF-7 through the death receptor pathway.

  8. Death penalty for keratinocytes: apoptosis versus cornification.

    Science.gov (United States)

    Lippens, S; Denecker, G; Ovaere, P; Vandenabeele, P; Declercq, W

    2005-11-01

    Homeostasis implies a balance between cell growth and cell death. This balance is essential for the development and maintenance of multicellular organisms. Homeostasis is controlled by several mechanisms including apoptosis, a process by which cells condemned to death are completely eliminated. However, in some cases, total destruction and removal of dead cells is not desirable, as when they fulfil a specific function such as formation of the skin barrier provided by corneocytes, also known as terminally differentiated keratinocytes. In this case, programmed cell death results in accumulation of functional cell corpses. Previously, this process has been associated with apoptotic cell death. In this overview, we discuss differences and similarities in the molecular regulation of epidermal programmed cell death and apoptosis. We conclude that despite earlier confusion, apoptosis and cornification occur through distinct molecular pathways, and that possibly antiapoptotic mechanisms are implicated in the terminal differentiation of keratinocytes.

  9. Targeting Death Receptor TRAIL-R2 by Chalcones for TRAIL-Induced Apoptosis in Cancer Cells

    Science.gov (United States)

    Szliszka, Ewelina; Jaworska, Dagmara; Kłósek, Małgorzata; Czuba, Zenon P.; Król, Wojciech

    2012-01-01

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in cancer cells without toxicity to normal cells. TRAIL binds to death receptors, TRAIL-R1 (DR4) and TRAIL-R2 (DR5) expressed on cancer cell surface and activates apoptotic pathways. Endogenous TRAIL plays an important role in immune surveillance and defense against cancer cells. However, as more tumor cells are reported to be resistant to TRAIL mediated death, it is important to search for and develop new strategies to overcome this resistance. Chalcones can sensitize cancer cells to TRAIL-induced apoptosis. We examined the cytotoxic and apoptotic effects of TRAIL in combination with four chalcones: chalcone, isobavachalcone, licochalcone A and xanthohumol on HeLa cancer cells. The cytotoxicity was measured by MTT and LDH assays. The apoptosis was detected using annexin V-FITC staining by flow cytometry and fluorescence microscopy. Death receptor expression was analyzed using flow cytometry. The decreased expression of death receptors in cancer cells may be the cause of TRAIL-resistance. Chalcones enhance TRAIL-induced apoptosis in HeLa cells through increased expression of TRAIL-R2. Our study has indicated that chalcones augment the antitumor activity of TRAIL and confirm their cancer chemopreventive properties. PMID:23203129

  10. Amphotericin B induces apoptosis-like programmed cell death in Naegleria fowleri and Naegleria gruberi.

    Science.gov (United States)

    Cárdenas-Zúñiga, Roberto; Silva-Olivares, Angélica; Villalba-Magdaleno, José D' Artagnan; Sánchez-Monroy, Virginia; Serrano-Luna, Jesús; Shibayama, Mineko

    2017-07-01

    Naegleria fowleri and Naegleria gruberi belong to the free-living amoebae group. It is widely known that the non-pathogenic species N. gruberi is usually employed as a model to describe molecular pathways in this genus, mainly because its genome has been recently described. However, N. fowleri is an aetiological agent of primary amoebic meningoencephalitis, an acute and fatal disease. Currently, the most widely used drug for its treatment is amphotericin B (AmB). It was previously reported that AmB has an amoebicidal effect in both N. fowleri and N. gruberi trophozoites by inducing morphological changes that resemble programmed cell death (PCD). PCD is a mechanism that activates morphological, biochemical and genetic changes. However, PCD has not yet been characterized in the genus Naegleria. The aim of the present work was to evaluate the typical markers to describe PCD in both amoebae. These results showed that treated trophozoites displayed several parameters of apoptosis-like PCD in both species. We observed ultrastructural changes, an increase in reactive oxygen species, phosphatidylserine externalization and a decrease in intracellular potassium, while DNA degradation was evaluated using the TUNEL assay and agarose gels, and all of these parameters are related to PCD. Finally, we analysed the expression of apoptosis-related genes, such as sir2 and atg8, in N. gruberi. Taken together, our results showed that AmB induces the morphological, biochemical and genetic changes of apoptosis-like PCD in the genus Naegleria.

  11. Apoptosis-Like Cell Death Induction and Aberrant Fibroblast Properties in Human Incisional Hernia Fascia

    Science.gov (United States)

    Diaz, Ramon; Quiles, Maria T.; Guillem-Marti, Jordi; Lopez-Cano, Manuel; Huguet, Pere; Ramon-y-Cajal, Santiago; Reventos, Jaume; Armengol, Manel; Arbos, Maria A.

    2011-01-01

    Incisional hernia often occurs following laparotomy and can be a source of serious problems. Although there is evidence that a biological cause may underlie its development, the mechanistic link between the local tissue microenvironment and tissue rupture is lacking. In this study, we used matched tissue-based and in vitro primary cell culture systems to examine the possible involvement of fascia fibroblasts in incisional hernia pathogenesis. Fascia biopsies were collected at surgery from incisional hernia patients and non-incisional hernia controls. Tissue samples were analyzed by histology and immunoblotting methods. Fascia primary fibroblast cultures were assessed at morphological, ultrastructural, and functional levels. We document tissue and fibroblast loss coupled to caspase-3 activation and induction of apoptosis-like cell-death mechanisms in incisional hernia fascia. Alterations in cytoskeleton organization and solubility were also observed. Incisional hernia fibroblasts showed a consistent phenotype throughout early passages in vitro, which was characterized by significantly enhanced cell proliferation and migration, reduced adhesion, and altered cytoskeleton properties, as compared to non-incisional hernia fibroblasts. Moreover, incisional hernia fibroblasts displayed morphological and ultrastructural alterations compatible with autophagic processes or lysosomal dysfunction, together with enhanced sensitivity to proapoptotic challenges. Overall, these data suggest an ongoing complex interplay of cell death induction, aberrant fibroblast function, and tissue loss in incisional hernia fascia, which may significantly contribute to altered matrix maintenance and tissue rupture in vivo. PMID:21641387

  12. Bee venom induces apoptosis through intracellular Ca2+ -modulated intrinsic death pathway in human bladder cancer cells.

    Science.gov (United States)

    Ip, Siu-Wan; Chu, Yung-Lin; Yu, Chun-Shu; Chen, Po-Yuan; Ho, Heng-Chien; Yang, Jai-Sing; Huang, Hui-Ying; Chueh, Fu-Shin; Lai, Tung-Yuan; Chung, Jing-Gung

    2012-01-01

    To focus on bee venom-induced apoptosis in human bladder cancer TSGH-8301 cells and to investigate its signaling pathway to ascertain whether intracellular calcium iron (Ca(2+)) is involved in this effect. Bee venom-induced cytotoxic effects, productions of reactive oxygen species and Ca(2+) and the level of mitochondrial membrane potential (ΔΨm) were analyzed by flow cytometry. Apoptosis-associated proteins were examined by Western blot analysis and confocal laser microscopy. Bee venom-induced cell morphological changes and decreased cell viability through the induction of apoptosis in TSGH-8301 cell were found. Bee venom promoted the protein levels of Bax, caspase-9, caspase-3 and endonuclease G. The enhancements of endoplasmic reticulum stress-related protein levels were shown in bee venom-provoked apoptosis of TSGH-8301 cells. Bee venom promoted the activities of caspase-3, caspase-8, and caspase-9, increased Ca(2+) release and decreased the level of ΔΨm. Co-localization of immunofluorescence analysis showed the releases of endonuclease G and apoptosis-inducing factor trafficking to nuclei for bee venom-mediated apoptosis. The images revealed evidence of nuclear condensation and formation of apoptotic bodies by 4',6-diamidino-2-phenylindole staining and DNA gel electrophoresis showed the DNA fragmentation in TSGH-8301 cells. Bee venom treatment induces both caspase-dependent and caspase-independent apoptotic death through intracellular Ca(2+) -modulated intrinsic death pathway in TSGH-8301 cells. © 2011 The Japanese Urological Association.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-25

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

  15. Cell-Centric View of Apoptosis and Apoptotic Cell Death-Inducing Antitumoral Strategies

    Directory of Open Access Journals (Sweden)

    Maria Dolores Boyano

    2011-03-01

    Full Text Available Programmed cell death and especially apoptotic cell death, occurs under physiological conditions and is also desirable under pathological circumstances. However, the more we learn about cellular signaling cascades, the less plausible it becomes to find restricted and well-limited signaling pathways. In this context, an extensive description of pathway-connections is necessary in order to point out the main regulatory molecules as well as to select the most appropriate therapeutic targets. On the other hand, irregularities in programmed cell death pathways often lead to tumor development and cancer-related mortality is projected to continue increasing despite the effort to develop more active and selective antitumoral compounds. In fact, tumor cell plasticity represents a major challenge in chemotherapy and improvement on anticancer therapies seems to rely on appropriate drug combinations. An overview of the current status regarding apoptotic pathways as well as available chemotherapeutic compounds provides a new perspective of possible future anticancer strategies.

  16. Cytotoxic hydrogen bridged ruthenium quinaldamide complexes showing induced cancer cell death by apoptosis.

    Science.gov (United States)

    Lord, Rianne M; Allison, Simon J; Rafferty, Karen; Ghandhi, Laura; Pask, Christopher M; McGowan, Patrick C

    2016-08-16

    This report presents the first known p-cymene ruthenium quinaldamide complexes which are stabilised by a hydrogen-bridging atom, [{(p-cym)Ru(II)X(N,N)}{H(+)}{(N,N)XRu(II)(p-cym)}][PF6] (N,N = functionalised quinaldamide and X = Cl or Br). These complexes are formed by a reaction of [p-cymRu(μ-X)2]2 with a functionalised quinaldamide ligand. When filtered over NH4PF6, and under aerobic conditions the equilibrium of NH4PF6 ⇔ NH3 + HPF6 enables incorporation of HPF6 and the stabilisation of two monomeric ruthenium complexes by a bridging H(+), which are counter-balanced by a PF6 counterion. X-ray crystallographic analysis is presented for six new structures with OO distances of 2.420(4)-2.448(15) Å, which is significant for strong hydrogen bonds. Chemosensitivity studies against HCT116, A2780 and cisplatin-resistant A2780cis human cancer cells showed the ruthenium complexes with a bromide ancillary ligand to be more potent than those with a chloride ligand. The 4'-fluoro compounds show a reduction in potency for both chloride and bromide complexes against all cell lines, but an increase in selectivity towards cancer cells compared to non-cancer ARPE-19 cells, with a selectivity index >1. Mechanistic studies showed a clear correlation between IC50 values and induction of cell death by apoptosis.

  17. α-Hispanolol sensitizes hepatocellular carcinoma cells to TRAIL-induced apoptosis via death receptor up-regulation

    International Nuclear Information System (INIS)

    Mota, Alba; Jiménez-Garcia, Lidia; Herránz, Sandra; Heras, Beatriz de las; Hortelano, Sonsoles

    2015-01-01

    Hispanolone derivatives have been previously described as anti-inflammatory and antitumoral agents. However, their effects on overcoming Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance remain to be elucidated. In this study, we analyzed the cytotoxic effects of the synthetic hispanolone derivative α-hispanolol (α-H) in several tumor cell lines, and we evaluated the induction of apoptosis, as well as the TRAIL-sensitizing potential of α-H in the hepatocellular carcinoma cell line HepG2. Our data show that α-H decreased cell viability in a dose-dependent manner in HeLa, MDA-MB231, U87 and HepG2 cell lines, with a more prominent effect in HepG2 cells. Interestingly, α-H had no effect on non-tumoral cells. α-H induced activation of caspase-8 and caspase-9 and also increased levels of the proapoptotic protein Bax, decreasing antiapoptotic proteins (Bcl-2, X-IAP and IAP-1) in HepG2 cells. Specific inhibition of caspase-8 abrogated the cascade of caspase activation, suggesting that the extrinsic pathway has a critical role in the apoptotic events induced by α-H. Furthermore, combined treatment of α-H with TRAIL enhanced apoptosis in HepG2 cells, activating caspase-8 and caspase-9. This correlated with up-regulation of both the TRAIL death receptor DR4 and DR5. DR4 or DR5 neutralizing antibodies abolished the effect of α-H on TRAIL-induced apoptosis, suggesting that sensitization was mediated through the death receptor pathway. Our results demonstrate that α-H induced apoptosis in the human hepatocellular carcinoma cell line HepG2 through activation of caspases and induction of the death receptor pathway. In addition, we describe a novel function of α-H as a sensitizer on TRAIL-induced apoptotic cell death in HepG2 cells. - Highlights: • α-Hispanolol induced apoptosis in the human hepatocellular carcinoma cell line HepG2. • α-Hispanolol induced activation of caspases and the death receptor pathway. • α-Hispanolol enhanced

  18. α-Hispanolol sensitizes hepatocellular carcinoma cells to TRAIL-induced apoptosis via death receptor up-regulation

    Energy Technology Data Exchange (ETDEWEB)

    Mota, Alba, E-mail: amota@iib.uam.es [Unidad de Terapias Farmacológicas, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid (Spain); Jiménez-Garcia, Lidia, E-mail: ljimenez@isciii.es [Unidad de Terapias Farmacológicas, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid (Spain); Herránz, Sandra, E-mail: sherranz@isciii.es [Unidad de Terapias Farmacológicas, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid (Spain); Heras, Beatriz de las, E-mail: lasheras@ucm.es [Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), Madrid (Spain); Hortelano, Sonsoles, E-mail: shortelano@isciii.es [Unidad de Terapias Farmacológicas, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid (Spain)

    2015-08-01

    Hispanolone derivatives have been previously described as anti-inflammatory and antitumoral agents. However, their effects on overcoming Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance remain to be elucidated. In this study, we analyzed the cytotoxic effects of the synthetic hispanolone derivative α-hispanolol (α-H) in several tumor cell lines, and we evaluated the induction of apoptosis, as well as the TRAIL-sensitizing potential of α-H in the hepatocellular carcinoma cell line HepG2. Our data show that α-H decreased cell viability in a dose-dependent manner in HeLa, MDA-MB231, U87 and HepG2 cell lines, with a more prominent effect in HepG2 cells. Interestingly, α-H had no effect on non-tumoral cells. α-H induced activation of caspase-8 and caspase-9 and also increased levels of the proapoptotic protein Bax, decreasing antiapoptotic proteins (Bcl-2, X-IAP and IAP-1) in HepG2 cells. Specific inhibition of caspase-8 abrogated the cascade of caspase activation, suggesting that the extrinsic pathway has a critical role in the apoptotic events induced by α-H. Furthermore, combined treatment of α-H with TRAIL enhanced apoptosis in HepG2 cells, activating caspase-8 and caspase-9. This correlated with up-regulation of both the TRAIL death receptor DR4 and DR5. DR4 or DR5 neutralizing antibodies abolished the effect of α-H on TRAIL-induced apoptosis, suggesting that sensitization was mediated through the death receptor pathway. Our results demonstrate that α-H induced apoptosis in the human hepatocellular carcinoma cell line HepG2 through activation of caspases and induction of the death receptor pathway. In addition, we describe a novel function of α-H as a sensitizer on TRAIL-induced apoptotic cell death in HepG2 cells. - Highlights: • α-Hispanolol induced apoptosis in the human hepatocellular carcinoma cell line HepG2. • α-Hispanolol induced activation of caspases and the death receptor pathway. • α-Hispanolol enhanced

  19. A systems level strategy for analyzing the cell death network: implication in exploring the apoptosis/autophagy connection.

    Science.gov (United States)

    Zalckvar, E; Yosef, N; Reef, S; Ber, Y; Rubinstein, A D; Mor, I; Sharan, R; Ruppin, E; Kimchi, A

    2010-08-01

    The mammalian cell death network comprises three distinct functional modules: apoptosis, autophagy and programmed necrosis. Currently, the field lacks systems level approaches to assess the extent to which the intermodular connectivity affects cell death performance. Here, we developed a platform that is based on single and double sets of RNAi-mediated perturbations targeting combinations of apoptotic and autophagic genes. The outcome of perturbations is measured both at the level of the overall cell death responses, using an unbiased quantitative reporter, and by assessing the molecular responses within the different functional modules. Epistatic analyses determine whether seemingly unrelated pairs of proteins are genetically linked. The initial running of this platform in etoposide-treated cells, using a few single and double perturbations, identified several levels of connectivity between apoptosis and autophagy. The knock down of caspase3 turned on a switch toward autophagic cell death, which requires Atg5 or Beclin-1. In addition, a reciprocal connection between these two autophagic genes and apoptosis was identified. By applying computational tools that are based on mining the protein-protein interaction database, a novel biochemical pathway connecting between Atg5 and caspase3 is suggested. Scaling up this platform into hundreds of perturbations potentially has a wide, general scope of applicability, and will provide the basis for future modeling of the cell death network.

  20. An assessment of norepinephrine mediated hypertrophy to apoptosis transition in cardiac cells: a signal for cell death.

    Science.gov (United States)

    Jain, Aditi; Atale, Neha; Kohli, Shrey; Bhattacharya, Susinjan; Sharma, Manish; Rani, Vibha

    2015-01-05

    Heart is an organ which is under a constant work load that generates numerous stress responses. Heart failure is associated with increased plasma norepinephrine (NE) and hypertrophic cell death. Within the current study we try to understand the concentration dependent molecular switch from hypertrophy to apoptosis under stress. The effect of increasing concentration of NE on cell death was studied using MTT assay based on which further experimental conditions were decided. Trypan Blue staining and TUNEL assay were done at selected concentrations of NE. Cellular and nuclear morphology at these concentrations was studied using Haematoxylin-Eosin, DAPI and PI stains. The molecular switch between hypertrophy and cell death was studied by expression analysis of β-MyHC and TNF-α. Rhodamine and DCFH-DA staining were done to evaluate the role of mitochondria and ROS under these conditions. Role of caspases under these transitions was also evaluated. NE shows steep falls in cell viability at 50 μM and 100 μM concentrations. The cellular and nuclear morphology is altered at these concentrations along with alterations at molecular level showing a shift from hypertrophy towards cell death. Altered mitochondrial membrane potential and increase in ROS support this which leads to caspase dependent activation of cell death. We show that at 50 μM NE, there occurs a transition from cellular hypertrophy towards death. This could be beneficial to prevent hypertrophy induced cardiac cell death and evaluating cardio protective therapeutic targets in vitro. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Caspase-2 mediates a Brucella abortus RB51-induced hybrid cell death having features of apoptosis and pyroptosis

    Directory of Open Access Journals (Sweden)

    Denise Nicole Bronner

    2013-11-01

    Full Text Available Programmed cell death (PCD can play a crucial role in tuning the immune response to microbial infection. Although PCD can occur in different forms, all are mediated by a family of proteases called caspases. Caspase-2 is the most conserved caspase; however its function in cell death is ill-defined. Previously we demonstrated that live attenuated cattle vaccine strain Brucella abortus RB51 induces caspase-2-mediated PCD of infected macrophages. However, the mechanism of caspase-2-mediated cell death pathway remained unclear. In this study, we found that caspase-2 mediated proinflammatory cell death of RB51-infected macrophages and regulated many genes in different PCD pathways. We show that the activation of proapoptotic caspases-3 and -8 was dependent upon caspase-2. Caspase-2 regulated mitochondrial cytochrome c release and TNFα production, both of which are known to activate caspase-3 and caspase-8, respectively. In addition to TNFα, RB51-induced caspase-1 and IL-1β production was also driven by caspase-2-mediated mitochondrial dysfunction. Interestingly, pore formation, a phenomenon commonly associated with caspase-1-mediated pyroptosis, occurred; however it did not contribute to RB51-induced proinflammatory cell death. Our data suggest that caspase-2 acts as an initiator caspase that mediates a novel RB51-induced hybrid cell death that simulates but differs from typical apoptosis and pyroptosis. The initiator role of the caspase-2-mediated cell death was also conserved in cellular stress-induced cell death of macrophages treated with etoposide, naphthalene, or anti-Fas. Caspase-2 also regulated caspase-3 and -8 activation, as well as cell death in macrophages treated with each of the three reagents. Taken together, our data has demonstrated that caspase-2 can play an important role in mediating a proinflammatory response and a hybrid cell death that demonstrates features of both apoptosis and pyroptosis.

  2. Ruthenium complexes with phenylterpyridine derivatives target cell membrane and trigger death receptors-mediated apoptosis in cancer cells.

    Science.gov (United States)

    Deng, Zhiqin; Gao, Pan; Yu, Lianling; Ma, Bin; You, Yuanyuan; Chan, Leung; Mei, Chaoming; Chen, Tianfeng

    2017-06-01

    Elucidation of the communication between metal complexes and cell membrane may provide useful information for rational design of metal-based anticancer drugs. Herein we synthesized a novel class of ruthenium (Ru) complexes containing phtpy derivatives (phtpy = phenylterpyridine), analyzed their structure-activity relationship and revealed their action mechanisms. The result showed that, the increase in the planarity of hydrophobic Ru complexes significantly enhanced their lipophilicity and cellular uptake. Meanwhile, the introduction of nitro group effectively improved their anticancer efficacy. Further mechanism studies revealed that, complex (2c), firstly accumulated on cell membrane and interacted with death receptors to activate extrinsic apoptosis signaling pathway. The complex was then transported into cell cytoplasm through transferrin receptor-mediated endocytosis. Most of the intracellular 2c accumulated in cell plasma, decreasing the level of cellular ROS, inducing the activation of caspase-9 and thus intensifying the apoptosis. At the same time, the residual 2c can translocate into cell nucleus to interact with DNA, induce DNA damage, activate p53 pathway and enhance apoptosis. Comparing with cisplatin, 2c possesses prolonged circulation time in blood, comparable antitumor ability and importantly, much lower toxicity in vivo. Taken together, this study uncovers the role of membrane receptors in the anticancer actions of Ru complexes, and provides fundamental information for rational design of membrane receptor targeting anticancer drugs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Critical role of p53 upregulated modulator of apoptosis in benzyl isothiocyanate-induced apoptotic cell death.

    Directory of Open Access Journals (Sweden)

    Marie Lue Antony

    Full Text Available Benzyl isothiocyanate (BITC, a constituent of edible cruciferous vegetables, decreases viability of cancer cells by causing apoptosis but the mechanism of cell death is not fully understood. The present study was undertaken to determine the role of Bcl-2 family proteins in BITC-induced apoptosis using MDA-MB-231 (breast, MCF-7 (breast, and HCT-116 (colon human cancer cells. The B-cell lymphoma 2 interacting mediator of cell death (Bim protein was dispensable for proapoptotic response to BITC in MCF-7 and MDA-MB-231 cells as judged by RNA interference studies. Instead, the BITC-treated MCF-7 and MDA-MB-231 cells exhibited upregulation of p53 upregulated modulator of apoptosis (PUMA protein. The BITC-mediated induction of PUMA was relatively more pronounced in MCF-7 cells due to the presence of wild-type p53 compared with MDA-MB-231 with mutant p53. The BITC-induced apoptosis was partially but significantly attenuated by RNA interference of PUMA in MCF-7 cells. The PUMA knockout variant of HCT-116 cells exhibited significant resistance towards BITC-induced apoptosis compared with wild-type HCT-116 cells. Attenuation of BITC-induced apoptosis in PUMA knockout HCT-116 cells was accompanied by enhanced G2/M phase cell cycle arrest due to induction of p21 and down regulation of cyclin-dependent kinase 1 protein. The BITC treatment caused a decrease in protein levels of Bcl-xL (MCF-7 and MDA-MB-231 cells and Bcl-2 (MCF-7 cells. Ectopic expression of Bcl-xL in MCF-7 and MDA-MB-231 cells and that of Bcl-2 in MCF-7 cells conferred protection against proapoptotic response to BITC. Interestingly, the BITC-treated MDA-MB-231 cells exhibited induction of Bcl-2 protein expression, and RNA interference of Bcl-2 in this cell line resulted in augmentation of BITC-induced apoptosis. The BITC-mediated inhibition of MDA-MB-231 xenograft growth in vivo was associated with the induction of PUMA protein in the tumor. In conclusion, the results of the present study

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

    Science.gov (United States)

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

    2017-05-01

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

  5. Caspase-2 mediates a Brucella abortus RB51-induced hybrid cell death having features of apoptosis and pyroptosis.

    Science.gov (United States)

    Bronner, Denise N; O'Riordan, Mary X D; He, Yongqun

    2013-01-01

    Programmed cell death (PCD) can play a crucial role in tuning the immune response to microbial infection. Although PCD can occur in different forms, all are mediated by a family of proteases called caspases. Caspase-2 is the most conserved caspase, however, its function in cell death is ill-defined. Previously we demonstrated that live attenuated cattle vaccine strain Brucella abortus RB51 induces caspase-2-mediated and caspase-1-independent PCD of infected macrophages. We also discovered that rough attenuated B. suis strain VTRS1 induces a caspase-2-mediated and caspase-1-independent proinflammatory cell death in infected macrophages, which was tentatively coined "caspase-2-mediated pyroptosis". However, the mechanism of caspase-2-mediated cell death pathway remained unclear. In this study, we found that caspase-2 mediated proinflammatory cell death of RB51-infected macrophages and regulated many genes in different PCD pathways. We show that the activation of proapoptotic caspases-3 and -8 was dependent upon caspase-2. Caspase-2 regulated mitochondrial cytochrome c release and TNFα production, both of which are known to activate caspase-3 and caspase-8, respectively. In addition to TNFα, RB51-induced caspase-1 and IL-1β production was also driven by caspase-2-mediated mitochondrial dysfunction. Interestingly, pore formation, a phenomenon commonly associated with caspase-1-mediated pyroptosis, occurred; however, unlike its role in S. typhimurium-induced pyroptosis, pore formation did not contribute to RB51-induced proinflammatory cell death. Our data suggest that caspase-2 acts as an initiator caspase that mediates a novel RB51-induced hybrid cell death that simulates but differs from typical non-proinflammatory apoptosis and caspase-1-mediated proinflammatory pyroptosis. The initiator role of the caspase-2-mediated cell death was also conserved in cellular stress-induced cell death of macrophages treated with etoposide, naphthalene, or anti-Fas. Caspase-2 also

  6. Inhibition of apoptosis blocks human motor neuron cell death in a stem cell model of spinal muscular atrophy.

    Directory of Open Access Journals (Sweden)

    Dhruv Sareen

    Full Text Available Spinal muscular atrophy (SMA is a genetic disorder caused by a deletion of the survival motor neuron 1 gene leading to motor neuron loss, muscle atrophy, paralysis, and death. We show here that induced pluripotent stem cell (iPSC lines generated from two Type I SMA subjects-one produced with lentiviral constructs and the second using a virus-free plasmid-based approach-recapitulate the disease phenotype and generate significantly fewer motor neurons at later developmental time periods in culture compared to two separate control subject iPSC lines. During motor neuron development, both SMA lines showed an increase in Fas ligand-mediated apoptosis and increased caspase-8 and-3 activation. Importantly, this could be mitigated by addition of either a Fas blocking antibody or a caspase-3 inhibitor. Together, these data further validate this human stem cell model of SMA, suggesting that specific inhibitors of apoptotic pathways may be beneficial for patients.

  7. Novel monofunctional platinum (II) complex Mono-Pt induces apoptosis-independent autophagic cell death in human ovarian carcinoma cells, distinct from cisplatin.

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    Guo, Wen-Jie; Zhang, Yang-Miao; Zhang, Li; Huang, Bin; Tao, Fei-Fei; Chen, Wei; Guo, Zi-Jian; Xu, Qiang; Sun, Yang

    2013-07-01

    Failure to engage apoptosis appears to be a leading mechanism of resistance to traditional platinum drugs in patients with ovarian cancer. Therefore, an alternative strategy to induce cell death is needed for the chemotherapy of this apoptosis-resistant cancer. Here we report that autophagic cell death, distinct from cisplatin-induced apoptosis, is triggered by a novel monofunctional platinum (II) complex named Mono-Pt in human ovarian carcinoma cells. Mono-Pt-induced cell death has the following features: cytoplasmic vacuolation, caspase-independent, no nuclear fragmentation or chromatin condensation, and no apoptotic bodies. These characteristics integrally indicated that Mono-Pt, rather than cisplatin, initiated a nonapoptotic cell death in Caov-3 ovarian carcinoma cells. Furthermore, incubation of the cells with Mono-Pt but not with cisplatin produced an increasing punctate distribution of microtubule-associated protein 1 light chain 3 (LC3), and an increasing ratio of LC3-II to LC3-I. Mono-Pt also caused the formation of autophagic vacuoles as revealed by monodansylcadaverine staining and transmission electron microscopy. In addition, Mono-Pt-induced cell death was significantly inhibited by the knockdown of either BECN1 or ATG7 gene expression, or by autophagy inhibitors 3-methyladenine, chloroquine and bafilomycin A 1. Moreover, the effect of Mono-Pt involved the AKT1-MTOR-RPS6KB1 pathway and MAPK1 (ERK2)/MAPK3 (ERK1) signaling, since the MTOR inhibitor rapamycin increased, while the MAPK1/3 inhibitor U0126 decreased Mono-Pt-induced autophagic cell death. Taken together, our results suggest that Mono-Pt exerts anticancer effect via autophagic cell death in apoptosis-resistant ovarian cancer. These findings lead to increased options for anticancer platinum drugs to induce cell death in cancer.

  8. Apoptosis-inducing factor plays a critical role in caspase-independent, pyknotic cell death in hydrogen peroxide-exposed cells.

    Science.gov (United States)

    Son, Young-Ok; Jang, Yong-Suk; Heo, Jung-Sun; Chung, Wan-Tae; Choi, Ki-Choon; Lee, Jeong-Chae

    2009-06-01

    It has been proposed that continuously generated hydrogen peroxide (H(2)O(2)) inhibits typical apoptosis and instead initiates an alternate, apoptosis-inducing factor (AIF)-dependent process. Aside from the role of AIF, however, the detailed morphological characterization of H(2)O(2)-induced cell death is not complete. This study examined the cellular mechanism(s) by which the continuous presence of H(2)O(2) induces cell death. We also further analyzed the precise role of AIF by inhibiting its expression with siRNA. Exposure of cells to H(2)O(2) generated by glucose oxidase caused mitochondrion-mediated, caspase-independent cell death. In addition, H(2)O(2) exposure resulted in cell shrinkage and chromatin condensation without nuclear fragmentation, indicating that H(2)O(2) stimulates a pyknotic cell death. Further analysis of AIF-transfected cells clearly demonstrated that nuclear translocation of AIF is the most important event required for nuclear condensation, phosphatidyl serine translocation, and ultimately cell death in H(2)O(2)-exposed cells. Furthermore, ATP was rapidly and severely depleted in cells exposed to H(2)O(2) generated by glucose oxidase but not by H(2)O(2) added as a bolus. Suppression of the H(2)O(2)-mediated ATP depletion by 3-aminobenzamide led to a significant increase of nuclear fragmentation in glucose oxidase-exposed cells. Collectively, these findings suggest that an acute energy reduction by H(2)O(2) causes caspase-independent and AIF-dependent cell death.

  9. Death Receptor-Induced Apoptosis Signalling Regulation by Ezrin Is Cell Type Dependent and Occurs in a DISC-Independent Manner in Colon Cancer Cells.

    Science.gov (United States)

    Iessi, Elisabetta; Zischler, Luciana; Etringer, Aurélie; Bergeret, Marion; Morlé, Aymeric; Jacquemin, Guillaume; Morizot, Alexandre; Shirley, Sarah; Lalaoui, Najoua; Elifio-Esposito, Selene L; Fais, Stefano; Garrido, Carmen; Solary, Eric; Micheau, Olivier

    2015-01-01

    Ezrin belongs to the ERM (ezrin-radixin-moesin) protein family and has been demonstrated to regulate early steps of Fas receptor signalling in lymphoid cells, but its contribution to TRAIL-induced cell death regulation in adherent cancer cells remains unknown. In this study we report that regulation of FasL and TRAIL-induced cell death by ezrin is cell type dependant. Ezrin is a positive regulator of apoptosis in T-lymphoma cell line Jurkat, but a negative regulator in colon cancer cells. Using ezrin phosphorylation or actin-binding mutants, we provide evidence that negative regulation of death receptor-induced apoptosis by ezrin occurs in a cytoskeleton- and DISC-independent manner, in colon cancer cells. Remarkably, inhibition of apoptosis induced by these ligands was found to be tightly associated with regulation of ezrin phosphorylation on serine 66, the tumor suppressor gene WWOX and activation of PKA. Deficiency in WWOX expression in the liver cancer SK-HEP1 or the pancreatic Mia PaCa-2 cell lines as well as WWOX silencing or modulation of PKA activation by pharmacological regulators, in the colon cancer cell line SW480, abrogated regulation of TRAIL signalling by ezrin. Altogether our results show that death receptor pro-apoptotic signalling regulation by ezrin can occur downstream of the DISC in colon cancer cells.

  10. Andrographolide sensitizes cancer cells to TRAIL-induced apoptosis via p53-mediated death receptor 4 up-regulation.

    Science.gov (United States)

    Zhou, Jing; Lu, Guo-Dong; Ong, Chye-Sun; Ong, Choon-Nam; Shen, Han-Ming

    2008-07-01

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an important member of the tumor necrosis factor subfamily with great potential in cancer therapy. Andrographolide (Andro), a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, is known to possess potent anti-inflammatory and anticancer activities. Here, we showed that pretreatment with Andro significantly enhances TRAIL-induced apoptosis in various human cancer cell lines, including those TRAIL-resistant cells. Such sensitization is achieved through transcriptional up-regulation of death receptor 4 (DR4), a death receptor of TRAIL. In search of the molecular mechanisms responsible for DR4 up-regulation, we found that the tumor suppressor p53 plays an essential role in DR4 transcriptional activation. Andro is capable of activating p53 via increased p53 phosphorylation and protein stabilization, a process mediated by enhanced reactive oxygen species production and subsequent c-Jun NH(2)-terminal kinase activation. Pretreatment with an antioxidant (N-acetylcysteine) or a c-Jun NH(2)-terminal kinase inhibitor (SP600125) effectively prevented Andro-induced p53 activation and DR4 up-regulation and eventually blocked the Andro-induced sensitization on TRAIL-induced apoptosis. Taken together, these results present a novel anticancer effect of Andro and support its potential application in cancer therapy to overcome TRAIL resistance.

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

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    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.

  12. Early apoptosis and cell death induced by ATX-S10Na (II)-mediated photodynamic therapy are Bax- and p53-dependent in human colon cancer cells.

    Science.gov (United States)

    Mitsunaga, Makoto; Tsubota, Akihito; Nariai, Kohichi; Namiki, Yoshihisa; Sumi, Makoto; Yoshikawa, Tetsuya; Fujise, Kiyotaka

    2007-02-07

    To investigate the roles of Bax and p53 proteins in photosensitivity of human colon cancer cells by using lysosome-localizing photosensitizer, ATX-S10Na (II). HCT116 human colon cancer cells and Bax-null or p53-null isogenic derivatives were irradiated with a diode laser. Early apoptosis and cell death in response to photodynamic therapy were determined by MTT assays, annexin V assays, transmission electron microscopy assays, caspase assays and western blotting. Induction of early apoptosis and cell death was Bax- and p53-dependent. Bax and p53 were required for caspase-dependent apoptosis. The levels of anti-apoptotic Bcl-2 family proteins, Bcl-2 and Bcl-x(L), were decreased in Bax- and p53-independent manner. Our results indicate that early apoptosis and cell death of human colon cancer cells induced by photodynamic therapy with lysosome-localizing photosensitizer ATX-S10Na (II) are mediated by p53-Bax network and low levels of Bcl-2 and Bcl-x(L) proteins. Our results might help in formulating new therapeutic approaches in photodynamic therapy.

  13. ATG7 deficiency suppresses apoptosis and cell death induced by lysosomal photodamage

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    Kessel, David H.; Price, Michael; Reiners, Jr., John J.

    2012-01-01

    Photodynamic therapy (PDT) involves photosensitizing agents that, in the presence of oxygen and light, initiate formation of cytotoxic reactive oxygen species (ROS). PDT commonly induces both apoptosis and autophagy. Previous studies with murine hepatoma 1c1c7 cells indicated that loss of autophagy-related protein 7 (ATG7) inhibited autophagy and enhanced the cytotoxicity of photosensitizers that mediate photodamage to mitochondria or the endoplasmic reticulum. In this study, we examined two photosensitizing agents that target lysosomes: the chlorin NPe6 and the palladium bacteriopheophorbide WST11. Irradiation of wild-type 1c1c7 cultures loaded with either photosensitizer induced apoptosis and autophagy, with a blockage of autophagic flux. An ATG7- or ATG5-deficiency suppressed the induction of autophagy in PDT protocols using either photosensitizer. Whereas ATG5-deficient cells were quantitatively similar to wild-type cultures in their response to NPe6 and WST11 PDT, an ATG7-deficiency suppressed the apoptotic response (as monitored by analyses of chromatin condensation and procaspase-3/7 activation) and increased the LD50 light dose by > 5-fold (as monitored by colony-forming assays). An ATG7-deficiency did not prevent immediate lysosomal photodamage, as indicated by loss of the lysosomal pH gradient. However, unlike wild-type and ATG5-deficient cells, the lysosomes of ATG7-deficient cells recovered this gradient within 4 h of irradiation, and never underwent permeabilization (monitored as release of endocytosed 10-kDa dextran polymers). We propose that the efficacy of lysosomal photosensitizers is in part due to both promotion of autophagic stress and suppression of autophagic prosurvival functions. In addition, an effect of ATG7 unrelated to autophagy appears to modulate lysosomal photodamage. PMID:22889762

  14. Doxorubicin resistance mediated by cytoplasmic macrophage colony-stimulating factor is associated with switch from apoptosis to autophagic cell death in MCF-7 breast cancer cells

    Science.gov (United States)

    Zhang, Mengxia; Zhang, Hailiang; Tang, Fan; Wang, Yuhua; Mo, Zhongcheng; Lei, Xiaoyong

    2016-01-01

    Macrophage colony-stimulating factor is a vital factor in maintaining the biological function of monocyte–macrophage lineage. It is expressed in many tumor tissues and cancer cells. Recent findings indicate that macrophage colony-stimulating factor might contribute to chemoresistance, but the precise mechanisms are unclear. This study was to explore the effect of macrophage colony-stimulating factor on doxorubicin resistance in MCF-7 breast cancer cells and the possible mechanism. In the study, the human breast cancer cells, MCF-7, were transfected with macrophage colony-stimulating factor. We document that cytoplasmic macrophage colony-stimulating factor induces doxorubicin resistance and inhibits apoptosis in MCF-7 cells. Further studies demonstrated that cytoplasmic macrophage colony-stimulating factor-mediated apoptosis inhibition was dependent on the activation of PI3K/Akt/Survivin pathway. More importantly, we found that macrophage colony-stimulating factor-induced autophagic cell death in doxorubicin-treated MCF-7 cells. Taken together, we show for the first time that macrophage colony-stimulating factor-induced doxorubicin resistance is associated with the changes in cell death response with defective apoptosis and promotion of autophagic cell death. PMID:27439542

  15. Cell surface-bound TIMP3 induces apoptosis in mesenchymal Cal78 cells through ligand-independent activation of death receptor signaling and blockade of survival pathways.

    Directory of Open Access Journals (Sweden)

    Christina Koers-Wunrau

    Full Text Available BACKGROUND: The matrix metalloproteinases (MMPs and their endogenous regulators, the tissue inhibitor of metalloproteinases (TIMPs 1-4 are responsible for the physiological remodeling of the extracellular matrix (ECM. Among all TIMPs, TIMP3 appears to play a unique role since TIMP3 is a secreted protein and, unlike the other TIMP family members, is tightly bound to the ECM. Moreover TIMP3 has been shown to be able to induce apoptotic cell death. As little is known about the underlying mechanisms, we set out to investigate the pro-apoptotic effect of TIMP3 in human mesenchymal cells. METHODOLOGY/PRINCIPAL FINDINGS: Lentiviral overexpression of TIMP3 in mesenchymal cells led to a strong dose-dependent induction of ligand-independent apoptosis as reflected by a five-fold increase in caspase 3 and 7 activity compared to control (pLenti6/V5-GW/lacZ or uninfected cells, whereas exogenous TIMP3 failed to induce apoptosis. Concordantly, increased cleavage of death substrate PARP and the caspases 3 and 7 was observed in TIMP3 overexpressing cultures. Notably, activation of caspase-8 but not caspase-9 was observed in TIMP3-overexpressing cells, indicating a death receptor-dependent mechanism. Moreover, overexpression of TIMP3 led to a further induction of apoptosis after stimulation with TNF-alpha, FasL and TRAIL. Most interestingly, TIMP3-overexpression was associated with a decrease in phosphorylation of cRaf, extracellular signal-regulated protein kinase (Erk1/2, ribosomal S6 kinase (RSK1 and Akt and serum deprivation of TIMP3-overexpressing cells resulted in a distinct enhancement of apoptosis, pointing to an impaired signaling of serum-derived survival factors. Finally, heparinase treatment of heparan sulfate proteoglycans led to the release of TIMP3 from the surface of overexpressing cells and to a significant decrease in apoptosis indicating that the binding of TIMP3 is necessary for apoptosis induction. CONCLUSION: The results demonstrate that

  16. Andrographolide Analogue Induces Apoptosis and Autophagy Mediated Cell Death in U937 Cells by Inhibition of PI3K/Akt/mTOR Pathway.

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    Deepak Kumar

    Full Text Available Current chemotherapeutic agents based on apoptosis induction are lacking in desired efficacy. Therefore, there is continuous effort to bring about new dimension in control and gradual eradication of cancer by means of ever evolving therapeutic strategies. Various forms of PCD are being increasingly implicated in anti-cancer therapy and the complex interplay among them is vital for the ultimate fate of proliferating cells. We elaborated and illustrated the underlying mechanism of the most potent Andrographolide analogue (AG-4 mediated action that involved the induction of dual modes of cell death-apoptosis and autophagy in human leukemic U937 cells.AG-4 induced cytotoxicity was associated with redox imbalance and apoptosis which involved mitochondrial depolarisation, altered apoptotic protein expressions, activation of the caspase cascade leading to cell cycle arrest. Incubation with caspase inhibitor Z-VAD-fmk or Bax siRNA decreased cytotoxic efficacy of AG-4 emphasising critical roles of caspase and Bax. In addition, AG-4 induced autophagy as evident from LC3-II accumulation, increased Atg protein expressions and autophagosome formation. Pre-treatment with 3-MA or Atg 5 siRNA suppressed the cytotoxic effect of AG-4 implying the pro-death role of autophagy. Furthermore, incubation with Z-VAD-fmk or Bax siRNA subdued AG-4 induced autophagy and pre-treatment with 3-MA or Atg 5 siRNA curbed AG-4 induced apoptosis-implying that apoptosis and autophagy acted as partners in the context of AG-4 mediated action. AG-4 also inhibited PI3K/Akt/mTOR pathway. Inhibition of mTOR or Akt augmented AG-4 induced apoptosis and autophagy signifying its crucial role in its mechanism of action.Thus, these findings prove the dual ability of AG-4 to induce apoptosis and autophagy which provide a new perspective to it as a potential molecule targeting PCD for future cancer therapeutics.

  17. Andrographolide Analogue Induces Apoptosis and Autophagy Mediated Cell Death in U937 Cells by Inhibition of PI3K/Akt/mTOR Pathway.

    Science.gov (United States)

    Kumar, Deepak; Das, Bimolendu; Sen, Rupashree; Kundu, Priyanka; Manna, Alak; Sarkar, Avijit; Chowdhury, Chinmay; Chatterjee, Mitali; Das, Padma

    2015-01-01

    Current chemotherapeutic agents based on apoptosis induction are lacking in desired efficacy. Therefore, there is continuous effort to bring about new dimension in control and gradual eradication of cancer by means of ever evolving therapeutic strategies. Various forms of PCD are being increasingly implicated in anti-cancer therapy and the complex interplay among them is vital for the ultimate fate of proliferating cells. We elaborated and illustrated the underlying mechanism of the most potent Andrographolide analogue (AG-4) mediated action that involved the induction of dual modes of cell death-apoptosis and autophagy in human leukemic U937 cells. AG-4 induced cytotoxicity was associated with redox imbalance and apoptosis which involved mitochondrial depolarisation, altered apoptotic protein expressions, activation of the caspase cascade leading to cell cycle arrest. Incubation with caspase inhibitor Z-VAD-fmk or Bax siRNA decreased cytotoxic efficacy of AG-4 emphasising critical roles of caspase and Bax. In addition, AG-4 induced autophagy as evident from LC3-II accumulation, increased Atg protein expressions and autophagosome formation. Pre-treatment with 3-MA or Atg 5 siRNA suppressed the cytotoxic effect of AG-4 implying the pro-death role of autophagy. Furthermore, incubation with Z-VAD-fmk or Bax siRNA subdued AG-4 induced autophagy and pre-treatment with 3-MA or Atg 5 siRNA curbed AG-4 induced apoptosis-implying that apoptosis and autophagy acted as partners in the context of AG-4 mediated action. AG-4 also inhibited PI3K/Akt/mTOR pathway. Inhibition of mTOR or Akt augmented AG-4 induced apoptosis and autophagy signifying its crucial role in its mechanism of action. Thus, these findings prove the dual ability of AG-4 to induce apoptosis and autophagy which provide a new perspective to it as a potential molecule targeting PCD for future cancer therapeutics.

  18. Hibiscus sabdariffa leaf polyphenolic extract induces human melanoma cell death, apoptosis, and autophagy.

    Science.gov (United States)

    Chiu, Chun-Tang; Hsuan, Shu-Wen; Lin, Hui-Hsuan; Hsu, Cheng-Chin; Chou, Fen-Pi; Chen, Jing-Hsien

    2015-03-01

    Melanoma is the least common but most fatal form of skin cancer. Previous studies have indicated that an aqueous extract of Hibiscus sabdariffa leaves possess hypoglycemic, hypolipidemic, and antioxidant effects. In this study, we want to investigate the anticancer activity of Hibiscus leaf polyphenolic (HLP) extract in melanoma cells. First, HLP was exhibited to be rich in epicatechin gallate (ECG) and other polyphenols. Apoptotic and autophagic activities of HLP and ECG were further evaluated by DAPI stain, cell-cycle analysis, and acidic vascular organelle (AVO) stain. Our results revealed that both HLP and ECG induced the caspases cleavages, Bcl-2 family proteins regulation, and Fas/FasL activation in A375 cells. In addition, we also revealed that the cells presented AVO-positive after HLP treatments. HLP could increase the expressions of autophagy-related proteins autophagy-related gene 5 (ATG5), Beclin1, and light chain 3-II (LC3-II), and induce autophagic cell death in A375 cells. These data indicated that the anticancer effect of HLP, partly contributed by ECG, in A375 cells. HLP potentially could be developed as an antimelanoma agent. © 2015 Institute of Food Technologists®

  19. Green tea polyphenols induce cell death in breast cancer MCF-7 cells through induction of cell cycle arrest and mitochondrial-mediated apoptosis.

    Science.gov (United States)

    Liu, Shu-Min; Ou, Shi-Yi; Huang, Hui-Hua

    In order to study the molecular mechanisms of green tea polyphenols (GTPs) in treatment or prevention of breast cancer, the cytotoxic effects of GTPs on five human cell lines (MCF-7, A549, Hela, PC3, and HepG2 cells) were determined and the antitumor mechanisms of GTPs in MCF-7 cells were analyzed. The results showed that GTPs exhibited a broad spectrum of inhibition against the detected cancer cell lines, particularly the MCF-7 cells. Studies on the mechanisms revealed that the main modes of cell death induced by GTPs were cell cycle arrest and mitochondrial-mediated apoptosis. Flow cytometric analysis showed that GTPs mediated cell cycle arrest at both G1/M and G2/M transitions. GTP dose dependently led to apoptosis of MCF-7 cells via the mitochondrial pathways, as evidenced by induction of chromatin condensation, reduction of mitochondrial membrane potential (ΔΨ m ), improvement in the generation of reactive oxygen species (ROS), induction of DNA fragmentation, and activations of caspase-3 and caspase-9 in the present paper.

  20. Pw1/Peg3 is a potential cell death mediator and cooperates with Siah1a in p53-mediated apoptosis

    Science.gov (United States)

    Relaix, Frédéric; Wei, Xiao-jun; Li, Wei; Pan, Jianjing; Lin, Yahong; Bowtell, David D.; Sassoon, David A.; Wu, Xiangwei

    2000-01-01

    Induction of wild-type p53 in mouse fibroblasts causes cell cycle arrest at the G1 phase, whereas coexpression of p53 and the protooncogene c-myc induces apoptosis. Although p53 transcriptional activity generally is required for both pathways, the molecular components mediating p53-dependent apoptosis are not well understood. To identify factors that could mediate p53-induced cell death, we used a comparative RNA differential display procedure. We have identified Pw1/Peg3 as a gene product induced during p53/c-myc-mediated apoptosis. Pw1/Peg3 is not induced during p53-mediated G1 growth arrest nor by c-myc alone. Although it is not clear whether the induction of Pw1/Peg3 depends on p53 activity, we show that Pw1/Peg3 interacts with a p53-inducible gene product Siah1a. We demonstrate that coexpression of Pw1/Peg3 with Siah1a induces apoptosis independently of p53 whereas expression of Pw1/Peg3 or Siah1a separately has no effect on cell death. These data suggest that Siah1a and Pw1/Peg3 cooperate in the p53-mediated cell death pathway. Furthermore, we show that inhibiting Pw1/Peg3 activity blocks p53-induced apoptosis. The observation that Pw1/Peg3 is necessary for the p53 apoptotic response suggests a pivotal role for this gene in determining cell death versus survival. PMID:10681424

  1. Dual PI-3 kinase/mTOR inhibition impairs autophagy flux and induces cell death independent of apoptosis and necroptosis

    Science.gov (United States)

    Button, Robert W.; Vincent, Joseph H.; Strang, Conor J.; Luo, Shouqing

    2016-01-01

    The PI-3 kinase (PI-3K)/mTOR pathway is critical for cell growth and proliferation. Strategies of antagonising this signaling have proven to be detrimental to cell survival. This observation, coupled with the fact many tumours show enhanced growth signaling, has caused dual inhibitors of PI-3K and mTOR to be implicated in cancer treatment, and have thus been studied across various tumour models. Since PI-3K (class-I)/mTOR pathway negatively regulates autophagy, dual inhibitors of PI-3K/mTOR are currently believed to be autophagy activators. However, our present data show that the dual PI-3K/mTOR inhibition (DKI) potently suppresses autophagic flux. We further confirm that inhibition of Vps34/PI3KC3, the class-III PI-3K, causes the blockade to autophagosome-lysosome fusion. Our data suggest that DKI induces cell death independently of apoptosis and necroptosis, whereas autophagy perturbation by DKI may contribute to cell death. Given that autophagy is critical in cellular homeostasis, our study not only clarifies the role of a dual PI-3K/mTOR inhibitor in autophagy, but also suggests that its autophagy inhibition needs to be considered if such an agent is used in cancer chemotherapy. PMID:26814436

  2. Heat-modified citrus pectin induces apoptosis-like cell death and autophagy in HepG2 and A549 cancer cells.

    Directory of Open Access Journals (Sweden)

    Lionel Leclere

    Full Text Available Cancer is still one of the leading causes of death worldwide, and finding new treatments remains a major challenge. Previous studies showed that modified forms of pectin, a complex polysaccharide present in the primary plant cell wall, possess anticancer properties. Nevertheless, the mechanism of action of modified pectin and the pathways involved are unclear. Here, we show that citrus pectin modified by heat treatment induced cell death in HepG2 and A549 cells. The induced cell death differs from classical apoptosis because no DNA cleavage was observed. In addition, Z-VAD-fmk, a pan-caspase inhibitor, did not influence the observed cell death in HepG2 cells but appeared to be partly protective in A549 cells, indicating that heat-modified citrus pectin might induce caspase-independent cell death. An increase in the abundance of the phosphatidylethanolamine-conjugated Light Chain 3 (LC3 protein and a decrease in p62 protein abundance were observed in both cell types when incubated in the presence of heat-modified citrus pectin. These results indicate the activation of autophagy. To our knowledge, this is the first time that autophagy has been revealed in cells incubated in the presence of a modified form of pectin. This autophagy activation appears to be protective, at least for A549 cells, because its inhibition with 3-methyladenine increased the observed modified pectin-induced cytotoxicity. This study confirms the potential of modified pectin to improve chemotherapeutic cancer treatments.

  3. Heat-modified citrus pectin induces apoptosis-like cell death and autophagy in HepG2 and A549 cancer cells.

    Science.gov (United States)

    Leclere, Lionel; Fransolet, Maude; Cote, Francois; Cambier, Pierre; Arnould, Thierry; Van Cutsem, Pierre; Michiels, Carine

    2015-01-01

    Cancer is still one of the leading causes of death worldwide, and finding new treatments remains a major challenge. Previous studies showed that modified forms of pectin, a complex polysaccharide present in the primary plant cell wall, possess anticancer properties. Nevertheless, the mechanism of action of modified pectin and the pathways involved are unclear. Here, we show that citrus pectin modified by heat treatment induced cell death in HepG2 and A549 cells. The induced cell death differs from classical apoptosis because no DNA cleavage was observed. In addition, Z-VAD-fmk, a pan-caspase inhibitor, did not influence the observed cell death in HepG2 cells but appeared to be partly protective in A549 cells, indicating that heat-modified citrus pectin might induce caspase-independent cell death. An increase in the abundance of the phosphatidylethanolamine-conjugated Light Chain 3 (LC3) protein and a decrease in p62 protein abundance were observed in both cell types when incubated in the presence of heat-modified citrus pectin. These results indicate the activation of autophagy. To our knowledge, this is the first time that autophagy has been revealed in cells incubated in the presence of a modified form of pectin. This autophagy activation appears to be protective, at least for A549 cells, because its inhibition with 3-methyladenine increased the observed modified pectin-induced cytotoxicity. This study confirms the potential of modified pectin to improve chemotherapeutic cancer treatments.

  4. Chaetocin induces endoplasmic reticulum stress response and leads to death receptor 5-dependent apoptosis in human non-small cell lung cancer cells.

    Science.gov (United States)

    Liu, Xianfang; Guo, Sen; Liu, Xiangguo; Su, Ling

    2015-11-01

    Epigenetic abnormalities are associated with non-small cell lung cancer (NSCLC) initiation and progression. Epigenetic drugs are being studied and in clinical trials. However, the molecular mechanism underlying the apoptosis by the epigenetic agents remains unclear. SUV39H1 is an important methyl-transferase for lysine 9 on histone H3 and usually related to gene transcriptional suppression, and chaetocin acts as the inhibitor of SUV39H1. We demonstrated here that chaetocin effectively suppressed the growth of multiple lung cancer cells through inducing apoptosis in a death receptor 5 (DR5)-dependent manner. Chaetocin treatment activated endoplasmic reticulum (ER) stress which gave rise to the up-regulation of ATF3 and CHOP. Furthermore, ATF3 and CHOP contributed to the induction of DR5 and subsequent apoptosis. When SUV39H1 was silenced with siRNA, the expression of ATF3, CHOP and DR5 was elevated. Thereafter, knockdown of SUV39H1 induced apoptosis in NSCLC cells. In summary, chaetocin pharmacologically inhibits the activity of SUV39H1 which provokes ER stress and results in up-regulation of ATF3 and CHOP, leading to DR5-dependent apoptosis eventually. These findings provide a novel interpretation on the anti-neoplastic activity of epigenetic drugs as a new therapeutic approach in NSCLC.

  5. The SMAC mimetic BV6 induces cell death and sensitizes different cell lines to TNF-α and TRAIL-induced apoptosis.

    Science.gov (United States)

    El-Mesery, Mohamed; Shaker, Mohamed E; Elgaml, Abdelaziz

    2016-12-01

    The inhibitors of apoptosis proteins are implicated in promoting cancer cells survival and resistance toward immune surveillance and chemotherapy. Second mitochondria-derived activator of caspases (SMAC) mimetics are novel compounds developed to mimic the inhibitory effect of the endogenous SMAC/DIABLO on these IAPs. Here, we examined the potential effects of the novel SMAC mimetic BV6 on different human cancer cell lines. Our results indicated that BV6 was able to induce cell death in different human cancer cell lines. Mechanistically, BV6 dose dependently induced degradation of IAPs, including cIAP1 and cIAP2. This was coincided with activating the non-canonical NF -kappa B (NF-κB) pathway, as indicated by stabilizing NF-κB-inducing kinase (NIK) for p100 processing to p52. More interestingly, BV6 was able to sensitize some of the resistant cancer cell lines to apoptosis induced by the death ligands tumor necrosis factor-α (TNF-α) and TNF-related apoptosis-inducing ligand (TRAIL) that are produced by different cells of the immune system. Such cell death enhancement was mediated by inducing an additional cleavage of caspase-9 to augment that of caspase-8 induced by death ligands. This eventually led to more processing of the executioner caspase-3 and poly (ADP-ribose) polymerase (PARP). In conclusion, therapeutic targeting of IAPs by BV6 might be an effective approach to enhance cancer regression induced by immune system. Our data also open up the future possibility of using BV6 in combination with other antitumor therapies to overcome cancer drug resistance.

  6. The chalcone 2'-hydroxy-4',5'-dimethoxychalcone activates death receptor 5 pathway and leads to apoptosis in human nonsmall cell lung cancer cells.

    Science.gov (United States)

    Yang, Lina; Su, Ling; Cao, Congmei; Xu, Linyan; Zhong, Diansheng; Xu, Lijia; Liu, Xiangguo

    2013-06-01

    Natural chalcones have been proved to inhibit cancer cells with therapeutic potential, but the underlying molecular mechanism is still largely unexplored. Here, we identified a novel chalcone, 2'-hydroxy-4',5'-dimethoxychalcone (HDMC) and demonstrated that HDMC induced apoptosis in various nonsmall cell lung cancer cells. Further study showed that HDMC elevated cellular reactive oxygen species (ROS) levels, thus inducing expressions of ATF4 and C/EBP homologous protein (CHOP). Then, death receptor 5 (DR5) was upregulated through ATF4-CHOP axis and eventually resulted in apoptosis. We also found that downregulation of c-FLIPL contributed to HDMC-induced apoptosis. In conclusion, HDMC induces apoptosis in human nonsmall cell lung cancer cells via activation of DR5 signaling pathway, and ROS-mediated ATF4-CHOP axis is involved in the process. Our results further supported the potential for HDMC to be developed as a new antitumor agent for cancer therapy or chemoprevention. Copyright © 2013 International Union of Biochemistry and Molecular Biology, Inc.

  7. 1-Nitropyrene (1-NP) induces apoptosis and apparently a non-apoptotic programmed cell death (paraptosis) in Hepa1c1c7 cells

    International Nuclear Information System (INIS)

    Asare, Nana; Landvik, Nina E.; Lagadic-Gossmann, Dominique; Rissel, Mary; Tekpli, Xavier; Ask, Kjetil; Lag, Marit; Holme, Jorn A.

    2008-01-01

    Mechanistic studies of nitro-PAHs (polycyclic aromatic hydrocarbons) of interest might help elucidate which chemical characteristics are most important in eliciting toxic effects. 1-Nitropyrene (1-NP) is the predominant nitrated PAH emitted in diesel exhaust. 1-NP-exposed Hepa1c1c7 cells exhibited marked changes in cellular morphology, decreased proliferation and different forms of cell death. A dramatic increase in cytoplasmic vacuolization was observed already after 6 h of exposure and the cells started to round up at 12 h. The rate of cell proliferation was markedly reduced at 24 h and apoptotic as well as propidium iodide (PI)-positive cells appeared. Electron microscopic examination revealed that the vacuolization was partly due to mitochondria swelling. The caspase inhibitor Z-VAD-FMK inhibited only the apoptotic cell death and Nec-1 (an inhibitor of necroptosis) exhibited no inhibitory effects on either cell death or vacuolization. In contrast, cycloheximide markedly reduced both the number of apoptotic and PI-positive cells as well as the cytoplasmic vacuolization, suggesting that 1-NP induced paraptotic cell death. All the MAPKs; ERK1/2, p38 and JNK, appear to be involved in the death process since marked activation was observed upon 1-NP exposure, and their inhibitors partly reduced the induced cell death. The ERK1/2 inhibitor PD 98057 completely blocked the induced vacuolization, whereas the other MAPKs inhibitors only had minor effects on this process. These findings suggest that 1-NP may cause apoptosis and paraptosis. In contrast, the corresponding amine (1-aminopyrene) elicited only minor apoptotic and necrotic cell death, and cells with characteristics typical of paraptosis were absent

  8. Both the caspase CSP-1 and a caspase-independent pathway promote programmed cell death in parallel to the canonical pathway for apoptosis in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Daniel P Denning

    Full Text Available Caspases are cysteine proteases that can drive apoptosis in metazoans and have critical functions in the elimination of cells during development, the maintenance of tissue homeostasis, and responses to cellular damage. Although a growing body of research suggests that programmed cell death can occur in the absence of caspases, mammalian studies of caspase-independent apoptosis are confounded by the existence of at least seven caspase homologs that can function redundantly to promote cell death. Caspase-independent programmed cell death is also thought to occur in the invertebrate nematode Caenorhabditis elegans. The C. elegans genome contains four caspase genes (ced-3, csp-1, csp-2, and csp-3, of which only ced-3 has been demonstrated to promote apoptosis. Here, we show that CSP-1 is a pro-apoptotic caspase that promotes programmed cell death in a subset of cells fated to die during C. elegans embryogenesis. csp-1 is expressed robustly in late pachytene nuclei of the germline and is required maternally for its role in embryonic programmed cell deaths. Unlike CED-3, CSP-1 is not regulated by the APAF-1 homolog CED-4 or the BCL-2 homolog CED-9, revealing that csp-1 functions independently of the canonical genetic pathway for apoptosis. Previously we demonstrated that embryos lacking all four caspases can eliminate cells through an extrusion mechanism and that these cells are apoptotic. Extruded cells differ from cells that normally undergo programmed cell death not only by being extruded but also by not being engulfed by neighboring cells. In this study, we identify in csp-3; csp-1; csp-2 ced-3 quadruple mutants apoptotic cell corpses that fully resemble wild-type cell corpses: these caspase-deficient cell corpses are morphologically apoptotic, are not extruded, and are internalized by engulfing cells. We conclude that both caspase-dependent and caspase-independent pathways promote apoptotic programmed cell death and the phagocytosis of cell

  9. The Fas-Associated Death Domain Protein (FADD) is Required in Apoptosis and TLR-induced Proliferative Responses in B Cells1

    Science.gov (United States)

    Imtiyaz, Hongxia Z.; Rosenberg, Stephen; Zhang, Yuhang; Rahman, Ziaur S. M.; Hou, Ying-Ju; Manser, Tim L.; Zhang, Jianke

    2011-01-01

    The Fas-associated death domain protein FADD/Mort1 is a signaling adaptor protein which mediates the activation of caspase 8 during death receptor-induced apoptosis. Disruption of FADD in germ cells results in death receptor-independent embryonic lethality in mice. Previous studies indicated that in addition to its function in apoptosis, FADD is also required in peripheral T cell homeostasis and TCR-induced proliferative responses. In this report, we generated B cell-specific FADD-deficient mice and showed that deletion of FADD at the pro-B cell stage had minor effects on B cell development in the bone marrow, and resulted in increased splenic and lymph node B cell numbers and decreased peritoneal B1 cell numbers. As in T cells, a FADD deficiency inhibited Fas-induced apoptosis in B cells. However, B cell proliferative responses induced by stimulation of the BCR and CD40 using anti-IgM or anti-CD40 antibodies were unaffected by the absence of FADD. Further analyses revealed that FADD-deficient B cells were defective in proliferative responses induced by treatments with dsRNA and LPS which stimulate TLR3 and TLR4 respectively. Therefore, in addition to its apoptotic function, FADD also plays a role in TLR3- and TLR4-induced proliferative responses in B cells. PMID:16709845

  10. Balance of life and death in alveolar epithelial type II cells: proliferation, apoptosis, and the effects of cyclic stretch on wound healing.

    Science.gov (United States)

    Crosby, Lynn M; Luellen, Charlean; Zhang, Zhihong; Tague, Larry L; Sinclair, Scott E; Waters, Christopher M

    2011-10-01

    After acute lung injury, repair of the alveolar epithelium occurs on a substrate undergoing cyclic mechanical deformation. While previous studies showed that mechanical stretch increased alveolar epithelial cell necrosis and apoptosis, the impact of cell death during repair was not determined. We examined epithelial repair during cyclic stretch (CS) in a scratch-wound model of primary rat alveolar type II (ATII) cells and found that CS altered the balance between proliferation and cell death. We measured cell migration, size, and density; intercellular gap formation; cell number, proliferation, and apoptosis; cytoskeletal organization; and focal adhesions in response to scratch wounding followed by CS for up to 24 h. Under static conditions, wounds were closed by 24 h, but repair was inhibited by CS. Wounding stimulated cell motility and proliferation, actin and vinculin redistribution, and focal adhesion formation at the wound edge, while CS impeded cell spreading, initiated apoptosis, stimulated cytoskeletal reorganization, and attenuated focal adhesion formation. CS also caused significant intercellular gap formation compared with static cells. Our results suggest that CS alters several mechanisms of epithelial repair and that an imbalance occurs between cell death and proliferation that must be overcome to restore the epithelial barrier.

  11. 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.

  12. Water-Soluble Dinitrosyl Iron Complex (DNIC): a Nitric Oxide Vehicle Triggering Cancer Cell Death via Apoptosis.

    Science.gov (United States)

    Wu, Shou-Cheng; Lu, Chung-Yen; Chen, Yi-Lin; Lo, Feng-Chun; Wang, Ting-Yin; Chen, Yu-Jen; Yuan, Shyng-Shiou; Liaw, Wen-Feng; Wang, Yun-Ming

    2016-09-19

    Nitric oxide (NO) is an important cellular signaling molecule that modulates various physiological activities. Angiogenesis-promoting activities of NO-donor drugs have been explored in both experimental and clinical studies. In this study, a structurally well characterized and water-soluble neutral {Fe(NO)2}(9) DNIC [(S(CH2)2OH)(S(CH2)2NH3)Fe(NO)2] (DNIC 2) was synthesized to serve as a NO-donor species. The antitumor activity of DNIC 2 was determined by MTT assay, confocal imaging, and Annexin-V/PI staining. The IC50 values of DNIC 2 were 18.8, 42.9, and 38.6 μM for PC-3, SKBR-3, and CRL5866 tumor cells, respectively. Moreover, DNIC 2 promoted apoptotic cell death via activation of apoptosis-associated proteins and inhibition of survival associated proteins. In particular, DNIC 2 treatment suppressed PC-3 tumor growth by 2.34- and 19.3-fold at 7 and 21 days, in comparison with the control group. These results indicate that water-soluble DNIC 2 may serve as a promising drug for cancer therapy.

  13. Triclosan demonstrates synergic effect with amphotericin B and fluconazole and induces apoptosis-like cell death in Cryptococcus neoformans

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    Elaheh eMovahed

    2016-03-01

    Full Text Available Objectives: Cryptococcus neoformans is an opportunistic fungus that causes fatal meningoencephalitis especially in AIDS patients. There is an increasing need for discovery of new anti-cryptococcal drugs due to emergence of resistance cases in recent years. In this study, we aim to elucidate the antifungal effect of triclosan against C. neoformans.Methods: Minimal inhibitory concentration (MIC of triclosan in different C. neoformans strains was first examined. The in vitro interactions between triclosan and two standard anti-fungal drugs (amphotericin B and fluconazole were further evaluated by microdilution checkerboard assay. Mechanism of triclosan fungicidal activity was then investigated by viewing the cell morphology under transmission electron microscope.Results: We reported that triclosan potently inhibited the growth of C. neoformans. A combination of triclosan with amphotericin B or with fluconazole enhanced their fungicidal effects. Triclosan-treated C. neoformans displayed characteristics such as nuclear chromatin condensation, extensive intracellular vacuolation and mitochondrial swelling, indicating that triclosan triggered apoptosis-like cell death.Conclusion: In summary, our report suggests triclosan as an independent drug or synergent for C. neoformans treatment.

  14. Immunohistochemical detection of Ki67 in breast cancer correlates with transcriptional regulation of genes related to apoptosis and cell death.

    Science.gov (United States)

    Tan, Puay-Hoon; Bay, Boon-Huat; Yip, George; Selvarajan, Sathiyamoorthy; Tan, Patrick; Wu, Jeanie; Lee, Chee-How; Li, Kuo-Bin

    2005-03-01

    Ki67 is a nuclear protein that is tightly linked to the cell cycle. It is a marker of cell proliferation and has been used to stratify good and poor prognostic categories in invasive breast cancer. Its correlation with gene expression patterns has not been fully elucidated. In this study, Ki67 immunohistochemistry using the MIB-1 antibody was performed on sections cut from 21 formalin-fixed, paraffin-embedded invasive breast cancers. Scoring was determined as nil (no immunostaining), low (10% or less immunopositivity) or high (>10% immunoreactive cells) respectively. The relationship of Ki67 immunohistochemical detection with clinicopathologic parameters was evaluated. Using Affymetrix U133A GeneChips, expression profiles for these tumors were generated and correlated with Ki67 immunohistochemical findings. Analysis of variance was used to define genes that were differentially regulated between the groups. Real-time polymerase chain reaction (PCR) was used to confirm the presence of a downregulated gene. Our results showed high, low and nil Ki67 immunostaining in nine (43%), six (28.5%) and six (28.5%) invasive breast cancers respectively, with increased Ki67 protein expression correlating with high histologic grade (P=0.02), mitotic score (P=0.001) and estrogen receptor immunonegativity (P=0.002). Expression profiling trends of the Ki67 gene mirrored the observed proportions of immunostained cells when the Ki67 immunoscore was >10%. Genes related to apoptosis and cell death (bcl2, MAP2K4, TNF10) were noted to be downregulated in tumors that disclosed >40% Ki67 immunostaining (Pbreast cancers.

  15. Snake venom toxin from vipera lebetina turanica induces apoptosis of colon cancer cells via upregulation of ROS- and JNK-mediated death receptor expression

    International Nuclear Information System (INIS)

    Park, Mi Hee; Jo, MiRan; Won, Dohee; Song, Ho Sueb; Han, Sang Bae; Song, Min Jong; Hong, Jin Tae

    2012-01-01

    Abundant research suggested that the cancer cells avoid destruction by the immune system through down-regulation or mutation of death receptors. Therefore, it is very important that finding the agents that increase the death receptors of cancer cells. In this study, we demonstrated that the snake venom toxin from Vipera lebetina turanica induce the apoptosis of colon cancer cells through reactive oxygen species (ROS) and c-Jun N-terminal kinases (JNK) dependent death receptor (DR4 and DR5) expression. We used cell viability assays, DAPI/TUNEL assays, as well as western blot for detection of apoptosis related proteins and DRs to demonstrate that snake venom toxin-induced apoptosis is DR4 and DR5 dependent. We carried out transient siRNA knockdowns of DR4 and DR5 in colon cancer cells. We showed that snake venom toxin inhibited growth of colon cancer cells through induction of apoptosis. We also showed that the expression of DR4 and DR5 was increased by treatment of snake venom toxin. Moreover, knockdown of DR4 or DR5 reversed the effect of snake venom toxin. Snake venom toxin also induced JNK phosphorylation and ROS generation, however, pretreatment of JNK inhibitor and ROS scavenger reversed the inhibitory effect of snake venom toxin on cancer cell proliferation, and reduced the snake venom toxin-induced upregulation of DR4 and DR5 expression. Our results indicated that snake venom toxin could inhibit human colon cancer cell growth, and these effects may be related to ROS and JNK mediated activation of death receptor (DR4 and DR5) signals

  16. Nitric oxide-induced cell death in developing oligodendrocytes is associated with mitochondrial dysfunction and apoptosis-inducing factor translocation.

    Science.gov (United States)

    Baud, Olivier; Li, Jianrong; Zhang, Yumin; Neve, Rachael L; Volpe, Joseph J; Rosenberg, Paul A

    2004-10-01

    Reactive nitrogen species are thought to be involved in both hypoxic-ischemic and cytokine-induced brain injury, including periventricular leukomalacia (PVL), the major pathological substrate of cerebral palsy in premature infants. PVL appears to be the result of perinatal inflammatory events and hypoxic-ischemic injury to the cerebral white matter. The chronic disturbance of myelination resulting from PVL suggests that developing oligodendrocytes (OLs) are involved in its pathogenesis. We hypothesized that nitric oxide (NO) could participate in the pathogenesis of PVL through a toxic effect on developing OLs. Using primary cultures of highly enriched OLs we found that NO is toxic to developing OLs (O4+, O1-, MBP-), with an EC50 value of 236 +/- 125 microm of DETANOnoate. Peroxynitrite formation does not appear to be involved in NO toxicity in developing OLs, as determined by the failure of peroxynitrite scavengers as well as superoxide dismutase overexpression to prevent NO-induced toxicity. Similarly, several pathways involving PARP, excitotoxicity, guanylyl cyclase and caspase activation were not related to NO toxicity to developing OLs. NO toxicity to OLs resulted in ATP depletion and loss of mitochondrial membrane potential (DeltaPsi) in developing OLs. Apoptosis-inducing factor (AIF) has been shown to be involved in caspase-independent cell death, and we found that AIF translocated from mitochondria into the nucleus upon NO exposure. In conclusion, we suggest that the vulnerability of developing OLs to NO involves mitochondrial dysfunction and translocation of AIF from mitochondria to nuclei.

  17. Cyproterone acetate enhances TRAIL-induced androgen-independent prostate cancer cell apoptosis via up-regulation of death receptor 5.

    Science.gov (United States)

    Chen, Linjie; Wolff, Dennis W; Xie, Yan; Lin, Ming-Fong; Tu, Yaping

    2017-03-07

    Virtually all prostate cancer deaths occur due to obtaining the castration-resistant phenotype after prostate cancer cells escaped from apoptosis and/or growth suppression initially induced by androgen receptor blockade. TNF-related apoptosis-inducing ligand (TRAIL) was an attractive cancer therapeutic agent due to its minimal toxicity to normal cells and remarkable apoptotic activity in tumor cells. However, most localized cancers including prostate cancer are resistant to TRAIL-induced apoptosis, thereby creating a therapeutic challenge of inducing TRAIL sensitivity in cancer cells. Herein the effects of cyproterone acetate, an antiandrogen steroid, on the TRAIL-induced apoptosis of androgen receptor-negative prostate cancer cells are reported. Cell apoptosis was assessed by both annexin V/propidium iodide labeling and poly (ADP-ribose) polymerase cleavage assays. Gene and protein expression changes were determined by quantitative real-time PCR and western blot assays. The effect of cyproterone acetate on gene promoter activity was determined by luciferase reporter assay. Cyproterone acetate but not AR antagonist bicalutamide dramatically increased the susceptibility of androgen receptor-negative human prostate cancer PC-3 and DU145 cells to TRAIL-induced apoptosis but no effects on immortalized human prostate stromal PS30 cells and human embryonic kidney HEK293 cells. Further investigation of the TRAIL-induced apoptosis pathway revealed that cyproterone acetate exerted its effect by selectively increasing death receptor 5 (DR5) mRNA and protein expression. Cyproterone acetate treatment also increased DR5 gene promoter activity, which could be abolished by mutation of a consensus binding domain of transcription factor CCAAT-enhancer-binding protein homologous protein (CHOP) in the DR5 gene promoter. Cyproterone acetate increases CHOP expression in a concentration and time-dependent manner and endoplasmic reticulum stress reducer 4-phenylbutyrate could block

  18. The myb-related gene stonewall induces both hyperplasia and cell death in Drosophila: rescue of fly lethality by coexpression of apoptosis inducers.

    Science.gov (United States)

    Brun, S; Rincheval-Arnold, A; Colin, J; Risler, Y; Mignotte, B; Guénal, I

    2006-10-01

    We carried out gain-of-function mutagenesis screening and identified a mutant in which GAL4 induction led to both hyperplasia and apoptosis. The gene involved was identified as stonewall (stwl), a myb-related gene involved in germ cell proliferation and differentiation during oogenesis. As observed with dmyb, the ectopic expression of stwl(UY823) inhibited endoreplication in salivary glands. We also found that stwl(UY823) overexpression, like overexpression of the wild-type gene, activated G1/S transition and apoptosis. The apoptosis triggered by stwl(UY823) expression is correlated to induction of the proapoptotic gene reaper. Finally, the death of flies induced by ectopic stwl(UY823) expression is efficiently prevented in vivo by triggering cell death in stwl(UY823)-expressing cells. Our results suggest that stwl(UY823) kills flies by causing inappropriate cell cycle entry, and that triggering the death of these overproliferating cells or slowing their proliferation restores viability.

  19. Alternative Pathways of Cancer Cell Death by Rottlerin: Apoptosis versus Autophagy

    Czech Academy of Sciences Publication Activity Database

    Torricelli, C.; Salvadori, S.; Valacchi, G.; Souček, Karel; Slabáková, Eva; Muscettola, M.; Volpi, N.; Maioli, E.

    2012-01-01

    Roč. 2012, NOV (2012), s. 1-11 /AN 980658/ ISSN 1741-427X R&D Projects: GA ČR(CZ) GPP301/12/P407 Institutional support: RVO:68081707 Keywords : PKC-DELTA * KAPPA-B * CARCINOMA CELLS Subject RIV: BO - Biophysics Impact factor: 1.722, year: 2012

  20. Neutrophils are resistant to Yersinia YopJ/P-induced apoptosis and are protected from ROS-mediated cell death by the type III secretion system.

    Directory of Open Access Journals (Sweden)

    Justin L Spinner

    2010-02-01

    Full Text Available The human innate immune system relies on the coordinated activity of macrophages and polymorphonuclear leukocytes (neutrophils or PMNs for defense against bacterial pathogens. Yersinia spp. subvert the innate immune response to cause disease in humans. In particular, the Yersinia outer protein YopJ (Y. pestis and Y. pseudotuberculosis and YopP (Y. enterocolitica rapidly induce apoptosis in murine macrophages and dendritic cells. However, the effects of Yersinia Yop J/P on neutrophil fate are not clearly defined.In this study, we utilized wild-type and mutant strains of Yersinia to test the contribution of YopJ and YopP on induction of apoptosis in human monocyte-derived macrophages (HMDM and neutrophils. Whereas YopJ and YopP similarly induced apoptosis in HMDMs, interaction of human neutrophils with virulence plasmid-containing Yersinia did not result in PMN caspase activation, release of LDH, or loss of membrane integrity greater than PMN controls. In contrast, interaction of human PMNs with the virulence plasmid-deficient Y. pestis strain KIM6 resulted in increased surface exposure of phosphatidylserine (PS and cell death. PMN reactive oxygen species (ROS production was inhibited in a virulence plasmid-dependent but YopJ/YopP-independent manner. Following phagocytic interaction with Y. pestis strain KIM6, inhibition of PMN ROS production with diphenyleneiodonium chloride resulted in a reduction of PMN cell death similar to that induced by the virulence plasmid-containing strain Y. pestis KIM5.Our findings showed that Yersinia YopJ and/or YopP did not induce pronounced apoptosis in human neutrophils. Furthermore, robust PMN ROS production in response to virulence plasmid-deficient Yersinia was associated with increased PMN cell death, suggesting that Yersinia inhibition of PMN ROS production plays a role in evasion of the human innate immune response in part by limiting PMN apoptosis.

  1. α-TEA-induced death receptor dependent apoptosis involves activation of acid sphingomyelinase and elevated ceramide-enriched cell surface membranes

    Directory of Open Access Journals (Sweden)

    Xiong Ailian

    2010-10-01

    Full Text Available Abstract Background Alpha-tocopherol ether-linked acetic acid (α-TEA, an analog of vitamin E (RRR-alpha-tocopherol, is a potent and selective apoptosis-inducing agent for human cancer cells in vivo and in vitro. α-TEA induces apoptosis via activation of extrinsic death receptors Fas (CD95 and DR5, JNK/p73/Noxa pathways, and suppression of anti-apoptotic mediators Akt, ERK, c-FLIP and survivin in breast, ovarian and prostate cancer cells. Results In this study, we demonstrate that α-TEA induces the accumulation of cell surface membrane ceramide, leading to co-localization with Fas, DR5, and FADD, followed by activation of caspases-8 and -9 and apoptosis in human MDA-MB-231 breast cancer cells. α-TEA treatment leads to increased acid sphingomyelinase (ASMase activity by 30 min, peaking at 4 hrs, which is correlated with ASMase translocation from cytosol to the cell surface membrane. Functional knockdown of ASMase with either the chemical inhibitor, desipramine, or siRNA markedly reduces α-TEA-induced cell surface membrane accumulation of ceramide and its co-localization with Fas, DR5, and FADD, cleavage of caspases-8 and -9 and apoptosis, suggesting an early and critical role for ASMase in α-TEA-induced apoptosis. Consistent with cell culture data, immunohistochemical analyses of tumor tissues taken from α-TEA treated nude mice bearing MDA-MB-231 xenografts show increased levels of cell surface membrane ceramide in comparison to tumor tissues from control animals. Conclusion Taken together, these studies demonstrate that ASMase activation and membrane ceramide accumulation are early events contributing to α-TEA-induced apoptosis in vitro and perhaps in vivo.

  2. Endothelial apoptosis in pulmonary hypertension is controlled by a microRNA/programmed cell death 4/caspase-3 axis

    NARCIS (Netherlands)

    White, Kevin; Dempsie, Yvonne; Caruso, Paola; Wallace, Emma; McDonald, Robert A; Stevens, Hannah; Hatley, Mark E; Van Rooij, Eva; Morrell, Nicholas W; MacLean, Margaret R; Baker, Andrew H

    Pulmonary endothelial cell apoptosis is a transient, yet defining pathogenic event integral to the onset of many pulmonary vascular diseases such as pulmonary hypertension (PH). However, there is a paucity of information concerning the molecular pathway(s) that control pulmonary arterial endothelial

  3. Silibinin induces apoptosis via calpain-dependent AIF nuclear translocation in U87MG human glioma cell death

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    Kim Yong K

    2011-04-01

    Full Text Available Abstract Background Silibinin, a natural polyphenolic flavonoid, has been reported to induce cell death in various cancer cell types. However, the molecular mechanism is not clearly defined. Our previous study showed that silibinin induces glioma cell death and its effect was effectively prevented by calpain inhibitor. The present study was therefore undertaken to examine the role of calpain in the silibinin-induced glioma cell death. Methods U87MG cells were grown on well tissue culture plates and cell viability was measured by MTT assay. ROS generation and △ψm were estimated using the fluorescence dyes. PKC activation and Bax expression were measured by Western blot analysis. AIF nuclear translocation was determined by Western blot and immunocytochemistry. Results Silibinin induced activation of calpain, which was blocked by EGTA and the calpain inhibitor Z-Leu-Leu-CHO. Silibinin caused ROS generation and its effect was inhibited by calpain inhibitor, the general PKC inhibitor GF 109203X, the specific PKCδ inhibitor rottlerin, and catalase. Silibinin-induce cell death was blocked by calpain inhibitor and PKC inhibitors. Silibinin-induced PKCδ activation and disruption of △ψm were prevented by the calpain inhibitor. Silibinin induced AIF nuclear translocation and its effect was prevented by calpain inhibitor. Transfection of vector expressing microRNA of AIF prevented the silibinin-induced cell death. Conclusions Silibinin induces apoptotic cell death through a calpain-dependent mechanism involving PKC, ROS, and AIF nuclear translocation in U87MG human glioma cells.

  4. The Amaryllidaceae Isocarbostyril Narciclasine Induces Apoptosis By Activation of the Death Receptor and/or Mitochondrial Pathways in Cancer Cells But Not in Normal Fibroblasts

    Directory of Open Access Journals (Sweden)

    Patrick Dumont

    2007-09-01

    Full Text Available Our study has shown that the Amaryllidaceae isocarbostyril narciclasine induces marked apoptosismediated cytotoxic effects in human cancer cells but not in normal fibroblasts by triggering the activation of the initiator caspases of the death receptor pathway (caspase-8 and caspase-10 at least in human MCF-7 breast and PC-3 prostate carcinoma cells. The formation of the Fas and death receptor 4 (DR4 death-inducing signaling complex was clearly evidenced in MCF-7 and PC-3 cancer cells. Caspase-8 was found to interact with Fas and DR4 receptors on narciclasine treatment. However, narciclasine-induced downstream apoptotic pathways in MCF-7 cells diverged from those in PC-3 cells, where caspase-8 directly activated effector caspases such as caspase-3 in the absence of any further release of mitochondrial proapoptotic effectors. In contrast, in MCF-7 cells, the apoptotic process was found to require an amplification step that is mitochondria-dependent, with Bid processing, release of cytochrome c, caspase-9 activation. It is postulated that the high selectivity of narciclasine to cancer cells might be linked, at least in part, to this activation of the death receptor pathway. Normal human fibroblasts appear approximately 250-fold less sensitive to narciclasine, which does not induce apoptosis in these cells probably due to the absence of death receptor pathway activation.

  5. Involvement of apoptosis and autophagy in the death of RPMI 8226 multiple myeloma cells by two enantiomeric sigma receptor ligands.

    Science.gov (United States)

    Korpis, Katharina; Weber, Frauke; Brune, Stefanie; Wünsch, Bernhard; Bednarski, Patrick J

    2014-01-01

    Over-expression of σ receptors by many tumor cell lines makes ligands for these receptors attractive as potential chemotherapeutic drugs. Enantiomeric piperazines (S)-4 and (R)-4 were prepared as potential σ-receptor ligands in a chiral pool synthesis starting from (S)- and (R)-aspartate. Both compounds showed high affinities for the σ₁ and σ₂ receptors. In the human multiple myeloma cell line RPMI 8226, a line expressing high levels of σ receptors, both compounds inhibited cell proliferation with IC₅₀ values in the low μM range. No chiral differentiation between either the σ receptor binding affinity or the cytotoxicity of the two enantiomers was observed. Both compounds induced apoptosis, which was evidenced by nuclear condensation, binding of annexin-V to phosphatidylserine in the outer leaf of the cell membrane, cleavage products of poly(ADP-ribose) polymerase-1 (PARP-1) and caspase-8 as well as the expression of bcl₂ family members bax, bad and bid. However, apoptosis appeared to be caspase independent. Increased levels of the phosphorylated form of the microtubule associated protein light chain 3-II (LC3-II), an autophagosome marker, gave evidence that both compounds induced autophagy. However, further data (e.g., treatment with wortmannin) indicate that autophagy is incomplete and not cytoprotective. Lipid peroxidation (LPO) was observed in RPMI 8226 cells treated with the two compounds, and the lipid antioxidant α-tocopherol attenuated LPO. Interestingly, α-tocopherol reduced significantly both apoptosis and autophagy induced by the compounds. These results provide evidence that, by initiating LPO and changes in mitochondrial membrane potential, both compounds induce apoptosis and autophagy in RPMI 8226 cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Luffa echinata Roxb. Induces Human Colon Cancer Cell (HT-29 Death by Triggering the Mitochondrial Apoptosis Pathway

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    Yan Yu

    2012-05-01

    Full Text Available The antiproliferative properties and cell death mechanism induced by the extract of the fruits of Luffa echinata Roxb. (LER were investigated. The methanolic extract of LER inhibited the proliferation of human colon cancer cells (HT-29 in both dose-dependent and time-dependent manners and caused a significant increase in the population of apoptotic cells. In addition, obvious shrinkage and destruction of the monolayer were observed in LER-treated cells, but not in untreated cells. Analysis of the cell cycle after treatment of HT-29 cells with various concentrations indicated that LER extracts inhibited the cellular proliferation of HT-29 cells via G2/M phase arrest of the cell cycle. The Reactive oxygen species (ROS level determination revealed that LER extracts induced apoptotic cell death via ROS generation. In addition, LER treatment led to a rapid drop in mitochondrial membrane potential (MMP as a decrease in fluorescence. The transcripts of several apoptosis-related genes were investigated by RT-PCR analysis. The caspase-3 transcripts of HT-29 cells significantly accumulated and the level of Bcl-XL mRNA was decreased after treatment with LER extract. Furthermore, the ratio of mitochondria-dependent apoptosis genes (Bax and Bcl-2 was sharply increased from 1.6 to 54.1. These experiments suggest that LER has anticancer properties via inducing the apoptosis in colon cancer cells, which provided the impetus for further studies on the therapeutic potential of LER against human colon carcinoma.

  7. Human T-Cell Leukemia Virus Type 1 Tax-Deregulated Autophagy Pathway and c-FLIP Expression Contribute to Resistance against Death Receptor-Mediated Apoptosis

    Science.gov (United States)

    Wang, Weimin; Zhou, Jiansuo; Shi, Juan; Zhang, Yaxi; Liu, Shilian

    2014-01-01

    ABSTRACT The human T-cell leukemia virus type 1 (HTLV-1) Tax protein is considered to play a central role in the process that leads to adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-1 Tax-expressing cells show resistance to apoptosis induced by Fas ligand (FasL) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). The regulation of Tax on the autophagy pathway in HeLa cells and peripheral T cells was recently reported, but the function and underlying molecular mechanism of the Tax-regulated autophagy are not yet well defined. Here, we report that HTLV-1 Tax deregulates the autophagy pathway, which plays a protective role during the death receptor (DR)-mediated apoptosis of human U251 astroglioma cells. The cellular FLICE-inhibitory protein (c-FLIP), which is upregulated by Tax, also contributes to the resistance against DR-mediated apoptosis. Both Tax-induced autophagy and Tax-induced c-FLIP expression require Tax-induced activation of IκB kinases (IKK). Furthermore, Tax-induced c-FLIP expression is regulated through the Tax-IKK-NF-κB signaling pathway, whereas Tax-triggered autophagy depends on the activation of IKK but not the activation of NF-κB. In addition, DR-mediated apoptosis is correlated with the degradation of Tax, which can be facilitated by the inhibitors of autophagy. IMPORTANCE Our study reveals that Tax-deregulated autophagy is a protective mechanism for DR-mediated apoptosis. The molecular mechanism of Tax-induced autophagy is also illuminated, which is different from Tax-increased c-FLIP. Tax can be degraded via manipulation of autophagy and TRAIL-induced apoptosis. These results outline a complex regulatory network between and among apoptosis, autophagy, and Tax and also present evidence that autophagy represents a new possible target for therapeutic intervention for the HTVL-1 related diseases. PMID:24352466

  8. Apoptosis in inner ear sensory hair cells

    Directory of Open Access Journals (Sweden)

    Seth Morrill

    2017-12-01

    Full Text Available Apoptosis, or controlled cell death, is a normal part of cellular lifespan. Cell death of cochlear hair cells causes deafness; an apoptotic process that is not well understood. Worldwide, 1.3 billion humans suffer some form of hearing loss, while 360 million suffer debilitating hearing loss as a direct result of the absence of these cochlear hair cells (Worldwide Hearing, 2014. Much is known about apoptosis in other systems and in other cell types thanks to studies done since the mid-20th century. Here we review current literature on apoptosis in general, and causes of deafness and cochlear hair cells loss as a result of apoptosis. The family of B-cell lymphoma (Bcl proteins are among the most studied and characterized. We will review current literature on the Bcl2 and Bcl6 protein interactions in relation to apoptosis and their possible roles in vulnerability and survival of cochlear hair cells.

  9. Research of ALA combined with HpD-PDT which induced s180 ascitic tumor cells, death or apoptosis on cytology

    Science.gov (United States)

    Zhu, Jing; Yan, Min; Zhang, Hui-Guo; Li, Enling; Luo, Hongyu

    2005-07-01

    To ascertain the adequate dosage of ALA combined with HpD-PDT which induced tumor cell death or apoptosis on cytology. And to study the different effect of ALA-PDT and HPD-PDT used only. Rat ascitic tumor cells(S180) were randomly divided into several groups and incubated with ALA(20μg/ml 、40μg/ml、80μg/ml 、160μg/ml)、HPD(2.5μg/ml、5μg/ml、10μg/ml)and their combination dosages. 630nm light (total output 2W) was delivered to tumor cells at a constant fluence rate: 200mw/cm2 and a constant irradiated time period: 20 minutes. We set 3 groups (no photosensitizers or no irradiation or neither) to be the control groups. We used inversion microscopy to observe the morphological change of tumor cells and flow cytometry technology to detect the death or apoptosis of tumor cells during the experiment. ..

  10. Protein synthesis persists during necrotic cell death.

    NARCIS (Netherlands)

    Saelens, X.; Festjens, N.; Parthoens, E.; Overberghe, I. van; Kalai, M.; Kuppeveld, F.J.M. van; Vandenabeele, P.

    2005-01-01

    Cell death is an intrinsic part of metazoan development and mammalian immune regulation. Whereas the molecular events orchestrating apoptosis have been characterized extensively, little is known about the biochemistry of necrotic cell death. Here, we show that, in contrast to apoptosis, the

  11. Water-Soluble Coenzyme Q10 Inhibits Nuclear Translocation of Apoptosis Inducing Factor and Cell Death Caused by Mitochondrial Complex I Inhibition

    Directory of Open Access Journals (Sweden)

    Haining Li

    2014-07-01

    Full Text Available The objectives of the study were to explore the mechanism of rotenone-induced cell damage and to examine the protective effects of water-soluble Coenzyme Q10 (CoQ10 on the toxic effects of rotenone. Murine hippocampal HT22 cells were cultured with mitochondrial complex I inhibitor rotenone. Water-soluble CoQ10 was added to the culture media 3 h prior to the rotenone incubation. Cell viability was determined by alamar blue, reactive oxygen species (ROS production by dihydroethidine (DHE and mitochondrial membrane potential by tetramethyl rhodamine methyl ester (TMRM. Cytochrome c, caspase-9 and apoptosis-inducing factor (AIF were measured using Western blotting after 24 h rotenone incubation. Rotenone caused more than 50% of cell death, increased ROS production, AIF nuclear translocation and reduction in mitochondrial membrane potential, but failed to cause mitochondrial cytochrome c release and caspase-9 activation. Pretreatment with water-soluble CoQ10 enhanced cell viability, decreased ROS production, maintained mitochondrial membrane potential and prevented AIF nuclear translocation. The results suggest that rotenone activates a mitochondria-initiated, caspase-independent cell death pathway. Water-soluble CoQ10 reduces ROS accumulation, prevents the fall of mitochondrial membrane potential, and inhibits AIF translocation and subsequent cell death.

  12. The role of death-associated protein 3 in apoptosis, anoikis and human cancer.

    Science.gov (United States)

    Wazir, Umar; Orakzai, Mona Maw; Khanzada, Zubair S; Jiang, Wen G; Sharma, Anup K; Kasem, Abdul; Mokbel, Kefah

    2015-01-01

    Death-associated protein 3 (DAP3) is a molecule with a significant role in the control of both apoptosis and anoikis. Apoptosis is the predominant type of programmed cell death (PCD) which may occur in response to irreparable damage to DNA, or in response to induction by inflammatory cells. Anoikis is subset of apoptosis which occurs in epithelial cells in response to detachment from the surrounding matrix. Both apoptosis and anoikis are of interest in the context of carcinogenesis. In this review, we shall discuss apoptosis and anoikis, and the recent literature regarding the role of DAP3 in both these pathways.

  13. Long-term blue light exposure induces RGC-5 cell death in vitro: involvement of mitochondria-dependent apoptosis, oxidative stress, and MAPK signaling pathways.

    Science.gov (United States)

    Huang, Chen; Zhang, Pei; Wang, Wei; Xu, Yongsheng; Wang, Minshu; Chen, Xiaoyong; Dong, Xuran

    2014-06-01

    The mechanism of blue light-induced retinal ganglion cell (RGC) injury is poorly understood. In this study, we established a patented light-emitting diode-based system to study the effects of long-term blue light exposure under culture conditions on RGC-5 cells. Long-term blue light exposure significantly reduced cell viability in a time-dependent manner and induced apoptosis and necrosis in RGC-5 cells. Long-term blue light exposure marked an increase in the expression of Bax and active Caspase-3 (p17), which was accompanied by Bcl-2 down-regulation, and displayed features of the mitochondria-dependent apoptosis pathway. Blue light exposure also increased the generation of reactive oxygen species (ROS), and was a strong inducer of ROS-sensitive protein nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression. Moreover, blue light exposure constitutively activated p38 mitogen-activated protein kinases and c-Jun NH2-terminal kinase (JNK), as well as induced the phosphorylation of extracellular signal-regulated kinase in the early phase, in blue light-exposed RGC-5 cells. The protein expression of c-jun and c-fos was further enhanced after RGC-5 cells were exposed to blue light. Taken together, these findings indicated that blue light induced RGC-5 cell line death in dependence upon exposure duration. The potential mechanisms for this phenomenon might be via activated mitochondria-dependent apoptosis, increased ROS production and protein expressions of Nrf2 and HO-1, and activated JNK/p38 MAPK signaling pathways.

  14. Caspases in yeast apoptosis-like death: facts and artefacts

    Czech Academy of Sciences Publication Activity Database

    Váchová, Libuše; Palková, Z.

    2007-01-01

    Roč. 7, - (2007), s. 12-21 ISSN 1567-1356 R&D Projects: GA ČR GA525/05/0297; GA MŠk(CZ) LC531 Institutional research plan: CEZ:AV0Z50200510 Keywords : caspases and metacaspases * apoptosis and programmed cell death in yeast * saccharomyces cerevisiae Subject RIV: EE - Microbiology, Virology Impact factor: 2.812, year: 2007

  15. Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

    Science.gov (United States)

    Galluzzi, Lorenzo; Vitale, Ilio; Aaronson, Stuart A; Abrams, John M; Adam, Dieter; Agostinis, Patrizia; Alnemri, Emad S; Altucci, Lucia; Amelio, Ivano; Andrews, David W; Annicchiarico-Petruzzelli, Margherita; Antonov, Alexey V; Arama, Eli; Baehrecke, Eric H; Barlev, Nickolai A; Bazan, Nicolas G; Bernassola, Francesca; Bertrand, Mathieu J M; Bianchi, Katiuscia; Blagosklonny, Mikhail V; Blomgren, Klas; Borner, Christoph; Boya, Patricia; Brenner, Catherine; Campanella, Michelangelo; Candi, Eleonora; Carmona-Gutierrez, Didac; Cecconi, Francesco; Chan, Francis K-M; Chandel, Navdeep S; Cheng, Emily H; Chipuk, Jerry E; Cidlowski, John A; Ciechanover, Aaron; Cohen, Gerald M; Conrad, Marcus; Cubillos-Ruiz, Juan R; Czabotar, Peter E; D'Angiolella, Vincenzo; Dawson, Ted M; Dawson, Valina L; De Laurenzi, Vincenzo; De Maria, Ruggero; Debatin, Klaus-Michael; DeBerardinis, Ralph J; Deshmukh, Mohanish; Di Daniele, Nicola; Di Virgilio, Francesco; Dixit, Vishva M; Dixon, Scott J; Duckett, Colin S; Dynlacht, Brian D; El-Deiry, Wafik S; Elrod, John W; Fimia, Gian Maria; Fulda, Simone; García-Sáez, Ana J; Garg, Abhishek D; Garrido, Carmen; Gavathiotis, Evripidis; Golstein, Pierre; Gottlieb, Eyal; Green, Douglas R; Greene, Lloyd A; Gronemeyer, Hinrich; Gross, Atan; Hajnoczky, Gyorgy; Hardwick, J Marie; Harris, Isaac S; Hengartner, Michael O; Hetz, Claudio; Ichijo, Hidenori; Jäättelä, Marja; Joseph, Bertrand; Jost, Philipp J; Juin, Philippe P; Kaiser, William J; Karin, Michael; Kaufmann, Thomas; Kepp, Oliver; Kimchi, Adi; Kitsis, Richard N; Klionsky, Daniel J; Knight, Richard A; Kumar, Sharad; Lee, Sam W; Lemasters, John J; Levine, Beth; Linkermann, Andreas; Lipton, Stuart A; Lockshin, Richard A; López-Otín, Carlos; Lowe, Scott W; Luedde, Tom; Lugli, Enrico; MacFarlane, Marion; Madeo, Frank; Malewicz, Michal; Malorni, Walter; Manic, Gwenola; Marine, Jean-Christophe; Martin, Seamus J; Martinou, Jean-Claude; Medema, Jan Paul; Mehlen, Patrick; Meier, Pascal; Melino, Sonia; Miao, Edward A; Molkentin, Jeffery D; Moll, Ute M; Muñoz-Pinedo, Cristina; Nagata, Shigekazu; Nuñez, Gabriel; Oberst, Andrew; Oren, Moshe; Overholtzer, Michael; Pagano, Michele; Panaretakis, Theocharis; Pasparakis, Manolis; Penninger, Josef M; Pereira, David M; Pervaiz, Shazib; Peter, Marcus E; Piacentini, Mauro; Pinton, Paolo; Prehn, Jochen H M; Puthalakath, Hamsa; Rabinovich, Gabriel A; Rehm, Markus; Rizzuto, Rosario; Rodrigues, Cecilia M P; Rubinsztein, David C; Rudel, Thomas; Ryan, Kevin M; Sayan, Emre; Scorrano, Luca; Shao, Feng; Shi, Yufang; Silke, John; Simon, Hans-Uwe; Sistigu, Antonella; Stockwell, Brent R; Strasser, Andreas; Szabadkai, Gyorgy; Tait, Stephen W G; Tang, Daolin; Tavernarakis, Nektarios; Thorburn, Andrew; Tsujimoto, Yoshihide; Turk, Boris; Vanden Berghe, Tom; Vandenabeele, Peter; Vander Heiden, Matthew G; Villunger, Andreas; Virgin, Herbert W; Vousden, Karen H; Vucic, Domagoj; Wagner, Erwin F; Walczak, Henning; Wallach, David; Wang, Ying; Wells, James A; Wood, Will; Yuan, Junying; Zakeri, Zahra; Zhivotovsky, Boris; Zitvogel, Laurence; Melino, Gerry; Kroemer, Guido

    2018-03-01

    Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field.

  16. HA14-1 selectively induces apoptosis in Bcl-2-overexpressing leukemia/lymphoma cells, and enhances cytarabine-induced cell death.

    Science.gov (United States)

    Lickliter, J D; Wood, N J; Johnson, L; McHugh, G; Tan, J; Wood, F; Cox, J; Wickham, N W

    2003-11-01

    The Bcl-2 oncoprotein is commonly overexpressed in hematological malignancy, where it promotes the survival of neoplastic cells. Recently, a small molecule (HA14-1) was reported to bind the surface pocket of Bcl-2 that mediates antiapoptotic interactions, triggering apoptosis in a Bcl-2-transfected cell line. We investigated the activity of this compound in a panel of malignant hematopoietic cell lines. Consistent with its proposed role as a Bcl-2 inhibitor, HA14-1 was most cytotoxic in lines expressing high levels of Bcl-2. In addition, at lower concentrations (5-12.5 muM), the compound predominantly triggered apoptosis. However, at concentrations two-fold higher than this and above, increasing primary necrosis was observed, suggesting the onset of interactions supplementary to Bcl-2 inhibition. In experiments on primary cells, 25 muM HA14-1 induced extensive apoptosis in acute leukemic blasts, but also suppressed normal hematopoietic colony formation to <50% of baseline. Importantly, low-concentration HA14-1 (5 muM) was nontoxic to normal colony-forming cells, whereas it enhanced the cytotoxicity of the antileukemia drug cytarabine in Bcl-2-positive lymphoblastic leukemia cells. In conclusion, our results indicate that HA14-1 at low concentration selectively triggers apoptosis in malignant hematopoietic cells that overexpress Bcl-2. Agents of this class may have particular utility in combination with cytotoxic chemotherapy drugs.

  17. Epigenetic regulation of microRNA-128a expression contributes to the apoptosis-resistance of human T-cell leukaemia jurkat cells by modulating expression of fas-associated protein with death domain (FADD).

    Science.gov (United States)

    Yamada, Nami; Noguchi, Shunsuke; Kumazaki, Minami; Shinohara, Haruka; Miki, Kohei; Naoe, Tomoki; Akao, Yukihiro

    2014-03-01

    Increased expression of miR-128a is often observed in acute lymphoblastic leukaemia (ALL) compared with its expression in acute myeloid leukaemia (AML). The objective of this study was to investigate the role of miR-128a, especially that in the Fas-signalling pathway, in T-cell leukaemia cells. The role of miR-128a in Fas-mediated apoptosis was examined by using Fas-activating antibody (CH-11)-susceptible Jurkat cells and -resistant Jurkat/R cells. Whereas ectopic expression of miR-128a conferred Fas-resistance on Jurkat cells by directly targeting Fas-associated protein with death domain (FADD), antagonizing miR-128a expression sensitized Jurkat/R cells to the Fas-mediated apoptosis through derepression of FADD expression. Myeloid leukaemia HL60 and K562 cells were also CH-11-resistant, sharing a similar resistant mechanism with Jurkat/R cells. Furthermore, CH-11 induced demethylation of the promoter region of miR-128a with resultant up-regulation of miR-128a expression in Jurkat/R cells, which was shown to be a mechanism for the resistance ofJurkat/R cells to Fas-mediated apoptosis. Our results indicate that the induction of miR-128a expression by DNA demethylation is a novel mechanism of resistance to Fas-mediated apoptosis.

  18. Mitochondrial disfunction and apoptosis in leukemia cells

    Directory of Open Access Journals (Sweden)

    Annamaria PALLAG

    2008-05-01

    Full Text Available Apoptosis or programmed cell death is a process which involves the intentional degradation of the cell from the inside, the participation of the mitochondria to propagate the apoptotic signal, the alteration of the phospholipid cell membrane composition, the perturbation and alteration of the cell metabolism.The antineoplastic drugs is inducing the apoptotic process in the sensitive cells.It have been studied acute lymphoblastic leukemia cells. Using Annexin V-PE Apoptosis Detection Kit and flow cytometer, the amount of cells undergoing apoptosis, in various stages of the antineoplasic treatment, was detected. At the same time, were monitored, the serum level of malondialdehyde. The results obtained confirm the alteration of the mitochondrial metabolism. We can observed the mitochondrial dysfunction role in cell apoptosis.

  19. Aloe-emodin Induces Apoptosis in Human Liver HL-7702 Cells through Fas Death Pathway and the Mitochondrial Pathway by Generating Reactive Oxygen Species.

    Science.gov (United States)

    Dong, Xiaoxv; Fu, Jing; Yin, Xingbin; Yang, Chunjing; Ni, Jian

    2017-06-01

    Aloe-emodin (1,8-dihydroxy-3-hydroxymethyl-anthraquinone) is one of the primary active compounds in total rhubarb anthraquinones isolated from some traditional medicinal plants such as Rheum palmatum L. and Cassia occidentalis, which induce hepatotoxicity in rats. Thus, the aim of this study was to determine the potential cytotoxic effects and the underlying mechanism of aloe-emodin on human normal liver HL-7702 cells. The CCK-8 assays demonstrated that aloe-emodin decreased the viability of HL-7702 cells in a dose-dependent and time-dependent manner. Aloe-emodin induced S and G2/M phase cell cycle arrest in HL-7702 cells. This apoptosis was further investigated by flow cytometry and nuclear morphological changes by DAPI staining, respectively. Moreover, aloe-emodin provoked the production of intracellular reactive oxygen species and the depolarization of mitochondrial membrane potential (MMP). Further studies by western blot indicated that aloe-emodin dose-dependently up-regulated the levels of Fas, p53, p21, Bax/Bcl-2 ratio, and cleaved caspase-3, -8, -9, and subsequent cleavage of poly(ADP-ribose)polymerase (PARP). Taken together, these results suggest that aloe-emodin inhibits cell proliferation of HL-7702 cells and induces cell cycle arrest and caspase-dependent apoptosis via both Fas death pathway and the mitochondrial pathway by generating reactive oxygen species, indicating that aloe-emodin should be taken into account in the risk assessment for human exposure. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  20. Up-regulated Ectonucleotidases in Fas-Associated Death Domain Protein- and Receptor-Interacting Protein Kinase 1-Deficient Jurkat Leukemia Cells Counteract Extracellular ATP/AMP Accumulation via Pannexin-1 Channels during Chemotherapeutic Drug-Induced Apoptosis.

    Science.gov (United States)

    Boyd-Tressler, Andrea M; Lane, Graham S; Dubyak, George R

    2017-07-01

    Pannexin-1 (Panx1) channels mediate the efflux of ATP and AMP from cancer cells in response to induction of extrinsic apoptosis by death receptors or intrinsic apoptosis by chemotherapeutic agents. We previously described the accumulation of extracellular ATP /AMP during chemotherapy-induced apoptosis in Jurkat human leukemia cells. In this study, we compared how different signaling pathways determine extracellular nucleotide pools in control Jurkat cells versus Jurkat lines that lack the Fas-associated death domain (FADD) or receptor-interacting protein kinase 1 (RIP1) cell death regulatory proteins. Tumor necrosis factor- α induced extrinsic apoptosis in control Jurkat cells and necroptosis in FADD-deficient cells; treatment of both lines with chemotherapeutic drugs elicited similar intrinsic apoptosis. Robust extracellular ATP/AMP accumulation was observed in the FADD-deficient cells during necroptosis, but not during apoptotic activation of Panx1 channels. Accumulation of extracellular ATP/AMP was similarly absent in RIP1-deficient Jurkat cells during apoptotic responses to chemotherapeutic agents. Apoptotic activation triggered equivalent proteolytic gating of Panx1 channels in all three Jurkat cell lines. The differences in extracellular ATP/AMP accumulation correlated with cell-line-specific expression of ectonucleotidases that metabolized the released ATP/AMP. CD73 mRNA, and α β -methylene-ADP-inhibitable ecto-AMPase activity were elevated in the FADD-deficient cells. In contrast, the RIP1-deficient cells were defined by increased expression of tartrate-sensitive prostatic acid phosphatase as a broadly acting ectonucleotidase. Thus, extracellular nucleotide accumulation during regulated tumor cell death involves interplay between ATP/AMP efflux pathways and different cell-autonomous ectonucleotidases. Differential expression of particular ectonucleotidases in tumor cell variants will determine whether chemotherapy-induced activation of Panx1 channels

  1. Oxygen-glucose deprivation enhancement of cell death/apoptosis in PC12 cells and hippocampal neurons correlates with changes in neuronal excitatory amino acid neurotransmitter signaling and potassium currents.

    Science.gov (United States)

    Wang, Yu-Xiang; Zhang, Feng; Ma, Xue-Ling; He, Cong-Cong; Tian, Kun; Wang, Hong-Gang; An, Di; Heng, Bin; Xie, Lai-Hua; Liu, Yan-Qiang

    2016-05-25

    Neuronal death is a pathophysiological process that is often caused by hypoxia/ischemia. However, the causes of hypoxia/ischemia-induced neuronal death are debated, and additional experimental data are needed to resolve this debate. In the present study, we applied oxygen-glucose deprivation (OGD) to PC12 cells and hippocampal neurons to establish a hypoxia/ischemia model. We evaluated the effects of OGD on cell death/apoptosis and on the levels of two excitatory amino acid neurotransmitters, aspartic acid and glutamic acid, in both hippocampal neurons and the medium used to culture the hippocampal neurons. We also evaluated GluR2 expression in hippocampal neurons as well as the effects of OGD on whole-cell potassium currents in PC12 cells and hippocampal neurons. Our experimental results showed that OGD significantly decreased cell viability and markedly enhanced apoptosis in PC12 cells and hippocampal neurons. OGD treatment for 3 h increased the levels of Asp and Glu in the medium used to culture hippocampal neurons, but decreased both the levels of Asp and Glu and GluR2 expression in hippocampal neurons. Furthermore, OGD altered the electrophysiological properties of voltage-dependent potassium channels in PC12 cells and hippocampal neurons in different ways; OGD decreased the voltage-dependent potassium current in PC12 cells, but increased this current in hippocampal neurons. On the basis of these results, we concluded that OGD enhanced neuronal cell death/apoptosis in addition to altering neuronal excitatory amino acid neurotransmitter signaling and whole-cell voltage-dependent potassium currents.

  2. Quercetin enhances TRAIL-mediated apoptosis in colon cancer cells by inducing the accumulation of death receptors in lipid rafts

    Czech Academy of Sciences Publication Activity Database

    Psahoulia, F.H.; Drosopoulos, K.G.; Doubravská, Lenka; Anděra, Ladislav; Pintzas, A.

    2007-01-01

    Roč. 6, č. 9 (2007), s. 2591-2599 ISSN 1535-7163 R&D Projects: GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50520514 Keywords : TRAIL * apoptosis * lipid rafts Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.800, year: 2007

  3. ROS-induced toxicity: exposure of 3T3, RAW264.7, and MCF7 cells to superparamagnetic iron oxide nanoparticles results in cell death by mitochondria-dependent apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Hui-Chen, E-mail: d93548008@ntu.edu.tw; Chen, Chung-Ming, E-mail: chung@ntu.edu.tw [National Taiwan University, Institute of Biomedical Engineering (China); Hsieh, Wen-Yuan, E-mail: hsiehw@itri.org.tw [Industrial Technology Research Institute, Biomedical Technology and Device Research Labs (China); Chen, Ching-Yun, E-mail: chingyun523@gmail.com; Liu, Chia-Ching, E-mail: d95548005@ntu.edu.tw; Lin, Feng-Huei, E-mail: double@ntu.edu.tw [National Taiwan University, Institute of Biomedical Engineering (China)

    2015-02-15

    Superparamagnetic nanoparticles (Fe{sub 3}O{sub 4}, SPIO) have been used as magnetic resonance imaging enhancers for years. However, bio-safety issues concerning nanoparticles remain largely unexplored. Of particular concern is the possible cellular impact of nanoparticles during SPIO uptake and subsequent oxidative stress. SPIO causes cell death by apoptosis via a little understood mitochondrial pathway. To more closely examine this process, three kinds of cells—3T3, RAW264.7, and MCF7—were treated with SPIO coated with polyethylene glycol (SPIO-PEG) and monitored by transmission electron microscopy (TEM), using cytotoxicity evaluation, mitochondrial activity, reactive oxygen species (ROS) generation, and Annexin V assay. TEM revealed that SPIO-PEG nanoparticles surrounded the cellular endosome membrane, creating a bulge in the endosome. Compared to 3T3 cells, greater numbers of SPIO-PEG nanoparticles infiltrated the mitochondria of RAW264.7 and MCF7 cells. SPIO-PEG residency is associated with boosted ROS, with elevated levels of mitochondrial activity, and advancement of cell apoptosis. Furthermore, correlation analysis showed that a polynomial model demonstrates a better fit than a linear model in MCF7, implying that cytotoxicity may have alternative impacts on cell death at different concentrations. Thus, we believe that MCF7 cell death results from the apoptosis pathway triggered by mitochondria, and we find lower cytotoxicity in 3T3. We propose that optimal levels of SPIO-PEG nanoparticles lead to increased levels of ROS and a resulting oxidative stress environment which will kill only cancer cells while sparing normal cells. This finding has great potential for use in cancer therapies in the future.

  4. ROS-induced toxicity: exposure of 3T3, RAW264.7, and MCF7 cells to superparamagnetic iron oxide nanoparticles results in cell death by mitochondria-dependent apoptosis

    Science.gov (United States)

    Hsieh, Hui-Chen; Chen, Chung-Ming; Hsieh, Wen-Yuan; Chen, Ching-Yun; Liu, Chia-Ching; Lin, Feng-Huei

    2015-02-01

    Superparamagnetic nanoparticles (Fe3O4, SPIO) have been used as magnetic resonance imaging enhancers for years. However, bio-safety issues concerning nanoparticles remain largely unexplored. Of particular concern is the possible cellular impact of nanoparticles during SPIO uptake and subsequent oxidative stress. SPIO causes cell death by apoptosis via a little understood mitochondrial pathway. To more closely examine this process, three kinds of cells—3T3, RAW264.7, and MCF7—were treated with SPIO coated with polyethylene glycol (SPIO-PEG) and monitored by transmission electron microscopy (TEM), using cytotoxicity evaluation, mitochondrial activity, reactive oxygen species (ROS) generation, and Annexin V assay. TEM revealed that SPIO-PEG nanoparticles surrounded the cellular endosome membrane, creating a bulge in the endosome. Compared to 3T3 cells, greater numbers of SPIO-PEG nanoparticles infiltrated the mitochondria of RAW264.7 and MCF7 cells. SPIO-PEG residency is associated with boosted ROS, with elevated levels of mitochondrial activity, and advancement of cell apoptosis. Furthermore, correlation analysis showed that a polynomial model demonstrates a better fit than a linear model in MCF7, implying that cytotoxicity may have alternative impacts on cell death at different concentrations. Thus, we believe that MCF7 cell death results from the apoptosis pathway triggered by mitochondria, and we find lower cytotoxicity in 3T3. We propose that optimal levels of SPIO-PEG nanoparticles lead to increased levels of ROS and a resulting oxidative stress environment which will kill only cancer cells while sparing normal cells. This finding has great potential for use in cancer therapies in the future.

  5. Quinovic acid glycosides purified fraction from Uncaria tomentosa induces cell death by apoptosis in the T24 human bladder cancer cell line.

    Science.gov (United States)

    Dietrich, Fabrícia; Kaiser, Samuel; Rockenbach, Liliana; Figueiró, Fabrício; Bergamin, Letícia Scussel; da Cunha, Fernanda Monte; Morrone, Fernanda Bueno; Ortega, George González; Battastini, Ana Maria Oliveira

    2014-05-01

    Bladder cancer is the second most prevalent malignancy in the genitourinary tract and remains a therapeutic challenge. In the search for new treatments, researchers have attempted to find compounds with low toxicity. With this goal in mind, Uncaria tomentosa is noteworthy because the bark and root of this species are widely used in traditional medicine and in adjuvant therapy for the treatment of numerous diseases. The objective of this study was to investigate the antitumor effect of one purified bioactive fraction of U.tomentosa bark on cell proliferation in two human bladder cancer cell lines, T24 and RT4. Quinovic acid glycosides purified fraction (QAPF) of U.tomentosa decreased the growth and viability of both T24 and RT4 cell lines. In T24 cells, QAPF induced apoptosis by activating caspase-3 and NF-κB. Further study showed that this fraction does not induce cell cycle arrest and does not alter PTEN and ERK levels. In conclusion, we demonstrated that QAPF of U.tomentosa has a potent inhibitory effect on the growth of human bladder cancer cell lines by inducing apoptosis through modulation of NF-κB, and we suggest that QAPF may become a potential therapeutic agent for the prevention and/or treatment of this cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Femtosecond near-infrared laser pulses elicit generation of reactive oxygen species in mammalian cells leading to apoptosis-like death.

    Science.gov (United States)

    Tirlapur, U K; König, K; Peuckert, C; Krieg, R; Halbhuber, K J

    2001-02-01

    Two-photon excitation-based near-infrared (NIR) laser scanning microscopy is currently emerging as a new and versatile alternative to conventional confocal laser scanning microscopy, particularly for vital cell imaging in life sciences. Although this innovative microscopy has several advantages such as highly localized excitation, higher penetration depth, reduced photobleaching and photodamage, and improved signal to noise ratio, it has, however, recently been evidenced that high-power NIR laser irradiation can drastically inhibit cell division and induce cell death. In the present study we have investigated the cellular responses of unlabeled rat kangaroo kidney epithelium (PtK2) cells to NIR femtosecond laser irradiation. We demonstrate that NIR 170-fs laser pulses operating at 80-MHz pulse repetition frequency and at mean power of > or = 7 mW evoke generation of reactive oxygen species (ROS) such as H2O2 that can be visualized in situ by standard in vivo cytochemical analysis using Ni-3,3'-diaminobenzidine (Ni-DAB) as well as with a recently developed fluorescent probe Jenchrom px blue. The formation of the Ni-DAB reaction product as well as that of Jenchrom was relatively more pronounced when irradiated cells were incubated in alkaline solution (pH 8) than in those incubated in acidic solution (pH 6), suggesting peroxisomal localization of these reaction products. Two-photon time-lapse imaging of the internalization of the cell impermeate fluorescent dye propidium iodide revealed that the integrity of the plasma membrane of NIR irradiated cells is drastically compromised. Visualization of the nuclei with DNA-specific fluorescent probes such as 4',6-diamidino-2-phenylindole 24 h postirradiation further provided tangible evidence that the nuclei of these cells undergo several deformations and eventual fragmentation. That these NIR irradiated cells die by apoptosis has been established by in situ detection of DNA strand breaks using the terminal deoxynucleotidyl

  7. Programmed cell death in plants.

    Science.gov (United States)

    Fomicheva, A S; Tuzhikov, A I; Beloshistov, R E; Trusova, S V; Galiullina, R A; Mochalova, L V; Chichkova, N V; Vartapetian, A B

    2012-12-01

    The modern concepts of programmed cell death (PCD) in plants are reviewed as compared to PCD (apoptosis) in animals. Special attention is focused on considering the potential mechanisms of implementation of this fundamental biological process and its participants. In particular, the proteolytic enzymes involved in PCD in animals (caspases) and plants (phytaspases) are compared. Emphasis is put on elucidation of both common features and substantial differences of PCD implementation in plants and animals.

  8. Euphorbia formosana Root Extract Induces Apoptosis by Caspase-Dependent Cell Death via Fas and Mitochondrial Pathway in THP-1 Human Leukemic Cells

    Directory of Open Access Journals (Sweden)

    Yann-Lii Leu

    2013-02-01

    Full Text Available Acute myeloid leukemia (AML, a very rare type of cancer, generally affects patients over 50 years old. While clinical drugs to treat advanced stages of AML exist, the disease becomes increasingly resistant to therapies. Euphorbia formosana Hayata (EF is a native Taiwanese medicinal plant used to treat rheumatism, liver cirrhosis, herpes zoster, scabies, and photoaging, along with tumor suppression. However, the mechanisms by which it suppresses tumors have not been explored. Here, we provide molecular evidence that a hot-water extract of Euphorbia formosana (EFW selectively inhibited the growth of human leukemic cancer cells more than other solid human cancer cell lines. Most importantly, the plant extract had limited toxicity toward healthy peripheral blood mononuclear cells (PBMCs. After THP-1 leukemic cells were treated with 50–100 µg/mL EFW for one day, the S phase DNA content of the cells increased, while treatment with 200–400 µg/mL caused the cells to accumulate in the G0/G1 phase. Notably, EFW did not affect A-549 lung cancer cells. The effectiveness of EFW against THP-1 cells may be through caspase-dependent apoptosis in leukemic cells, which is mediated through the Fas and mitochondrial pathways. The potent antileukemic activity of EFW in vitro warrants further investigation of this plant to treat leukemias and other malignancies.

  9. Euphorbia formosana root extract induces apoptosis by caspase-dependent cell death via Fas and mitochondrial pathway in THP-1 human leukemic cells.

    Science.gov (United States)

    Hsieh, Yi-Jen; Chang, Chih-Jui; Wan, Chin-Feng; Chen, Chin-Piao; Chiu, Yi-Han; Leu, Yann-Lii; Peng, Kou-Cheng

    2013-02-01

    Acute myeloid leukemia (AML), a very rare type of cancer, generally affects patients over 50 years old. While clinical drugs to treat advanced stages of AML exist, the disease becomes increasingly resistant to therapies. Euphorbia formosana Hayata (EF) is a native Taiwanese medicinal plant used to treat rheumatism, liver cirrhosis, herpes zoster, scabies, and photoaging, along with tumor suppression. However, the mechanisms by which it suppresses tumors have not been explored. Here, we provide molecular evidence that a hot-water extract of Euphorbia formosana (EFW) selectively inhibited the growth of human leukemic cancer cells more than other solid human cancer cell lines. Most importantly, the plant extract had limited toxicity toward healthy peripheral blood mononuclear cells (PBMCs). After THP-1 leukemic cells were treated with 50-100 µg/mL EFW for one day, the S phase DNA content of the cells increased, while treatment with 200-400 µg/mL caused the cells to accumulate in the G0/G1 phase. Notably, EFW did not affect A-549 lung cancer cells. The effectiveness of EFW against THP-1 cells may be through caspase-dependent apoptosis in leukemic cells, which is mediated through the Fas and mitochondrial pathways. The potent antileukemic activity of EFW in vitro warrants further investigation of this plant to treat leukemias and other malignancies.

  10. Different mechanisms between premitotic apoptosis and postmitotic apoptosis in X-irradiated U937 cells

    International Nuclear Information System (INIS)

    Shinomiya, Nariyoshi; Kuno, Yukie; Yamamoto, Fuyumi; Fukasawa, Masashi; Okumura, Atsushi; Uefuji, Megumi; Rokutanda, Makoto

    2000-01-01

    Purpose: Apoptosis is currently being evaluated for its importance as a pathway of radiation-induced cell death. However, the difference in the mechanisms between premitotic and postmitotic apoptosis following X-irradiation remains not well understood. We show here that the human monoblastoid cell line U937 can be induced to undergo these two different types of apoptosis. Methods and Materials: U937 cells were irradiated at a dose of 5 or 20 Gy, and the DNA fragmentation rate was measured by both flow cytometric analysis and gel electrophoresis. Activation of caspase-3 was detected by Western blot analysis and fluorogenic assay using acetyl-Asp-Glu-Val-Asp-7-amino-4-methyl-coumarin (Ac-DEVD-AMC). Detection of mitochondrial transmembrane potential (no. DELTAno. no. PSIno. ) was performed by using Rho123. Chasing of S-phase fraction following X-irradiation was performed after labeling with 5-bromo-2'-deoxyuridine (BrdU). Thymidine was used for synchronization of the cells. Inhibition of caspase-3 activity was achieved by Acetyl-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-CHO). Results: Time courses of the apoptotic rates, caspase activation, and no. DELTAno. no. PSIno. indicated that two different types of cell death were induced by the different X-ray doses. High-dose X-ray (20 Gy) induced a rapid and strong apoptosis, whereas low-dose X-ray (5 Gy) induced a slow and mild apoptosis. Cell-cycle analyses revealed that there was cell death before cell division in the former apoptosis but the cells must be dying after cell division in the latter apoptosis. By means of cell-cycle synchronization, the S-phase cells proved to be the most sensitive fraction to premitotic apoptosis, but an obvious difference in the susceptibility to cell death among the cell-cycle phases was not observed in postmitotic apoptosis. Ac-DEVD-CHO treatment effectively blocked caspase activity and premitotic apoptosis, but it failed to block postmitotic apoptosis. Conclusions: Irradiation of U937 cells at

  11. Apoptosis-Dependent and Apoptosis-Independent Functions of Bim in Prostate Cancer Cells

    National Research Council Canada - National Science Library

    Tang, Dean; Liu, Junwei

    2005-01-01

    ... (death, survival, proliferation/division, etc.). Our hypothesis is that, under normal, unstimulated conditions, with its apoptotic function blocked, the upregulated Bim in PCa cells plays an apoptosis-independent function...

  12. Apoptosis-Dependent and Apoptosis-Independent Functions Bim in Prostate Cancer Cells

    National Research Council Canada - National Science Library

    Liu, Junwei

    2004-01-01

    ... (death, survival, proliferation/division, etc). Our hypothesis is that, under normal, unstimulated conditions, with its apoptotic function blocked, the upregulated Bim in PCa cells play an apoptosis-independent function...

  13. [Methuosis: a novel type of cell death].

    Science.gov (United States)

    Cai, Hongbing; Liu, Jinkun; Fan, Qin; Li, Xin

    2013-12-01

    Cell death is a major physiological or pathological phenomenon in life activities. The classic forms of cell death include apoptosis, necrosis, and autophagy. Recently, a novel type of cell death has been observed and termed as methuosis, in which excessive stimuli can induce cytoplasmic uptake and accumulation of small bubbles that gradually merge into giant vacuoles, eventually leading to decreased cellular metabolic activity, cell membrane rupture and cell death. In this article, we describe the nomenclature, morphological characteristics and underlying mechanisms of methuosis, compare methuosis with autophagy, oncosis and paraptosis, and review the related researches.

  14. Staphylococcus aureus alpha-toxin induces apoptosis in peripheral blood mononuclear cells : role of endogenous tumour necrosis factor-alpha and the mitochondrial death pathway

    NARCIS (Netherlands)

    Haslinger, Bettina; Strangfeld, Katrin; Peters, Georg; Schulze-Osthoff, Klaus; Sinha, Bhanu

    2003-01-01

    Staphylococcus aureus infections can result in septic and toxic shock with depletion of immune cells and massive cytokine production. Recently, we showed that, in S. aureus-infected Jurkat T cells, alpha-toxin is the major mediator of caspase activation and apoptosis. Here, we investigated the

  15. Title of paper: the induction of P-53 independent programmed cell death (apoptosis) with ionizing radiation and 5-fluorouracil (5-FU) in the HT-29 human colon carcinoma cell line

    International Nuclear Information System (INIS)

    Blackstock, A. Wm.; Gill, Misha; Hess, Suzanne M.; Fisher, Robert W.; Leadon, Steven A.; Tepper, Joel E.

    1996-01-01

    Purpose/Objective: The role of programmed cell death (apoptosis) as a cellular response to cancer therapy such as radiation or chemotherapy is the subject of much study, and manipulation of the apoptotic response in tumor cells may be valuable in the treatment of a variety of cancers. Both p53 dependent and independent apoptotic pathways have been identified; p53 is mutated in at least 50 % of human cancers and a majority of radiation resistant tumors contain p53 mutations. This study is designed to examine the induction of programmed cell death in a human colon carcinoma cell line that possesses two mutated p53 alleles. Ionizing radiation alone, or in combination with the chemotherapeutic drug 5-fluorouracil (5-FU), were used to elicit the apoptotic response. This study will focus on whether these treatments can induce a significant apoptotic response in cells that have mutated p53 alleles. Materials and Methods: HT-29 cells were assessed for clonogenic survival after being plated at a variety of densities, and treated with single graded doses of radiation (0, 1, 2, 4, 6, 8, 10 Gy) either alone or immediately prior to a 24 hour exposure to 5-FU (2 ug/ml). The extent of radiation and 5-FU-induced apoptosis was determined in the HT-29 cell line after single doses of 0, 2, 5, and 10 Gy either alone or immediately prior to a 24 hour incubation in 5-FU (2 ug/ml). Three separate assays were used to evaluate the apoptotic response. Cells undergoing apoptosis undergo gross morphological changes including a condensation of chromatin, membrane blebbing, and an eventual release of membrane bound cytoplasmic fragments. Hematoxylin and eosin staining were used to visualize some of these morphological changes. Another characteristic of the apoptotic response is the activation of an endonuclease that cleaves DNA into specific fragments. Accordingly, an ELISA cell death assay (Boehringer Mannheim, Indianapolis IN) was used to quantitate cytoplasmic histone-associated DNA

  16. p53 protein or BID protein select the route to either apoptosis (programmed cell death) or to cell cycle arrest opposing carcinogenesis after DNA damage by ROS.

    Science.gov (United States)

    Wiseman, Alan

    2006-01-01

    p53 is a tumour-suppressor protein of human cells that prevents their entry into the route to carcinogenesis. Furthermore, p53 protein acts at the p53-response loci in genomic DNA to facilitate the switch-on of genes that can be expressed by the biosynthesis of routing-proteins for apoptosis or stalling of cellular proliferation (via cell cycle progression checkpoint arrests). Moreover, oxidative stress by reactive oxygen species (ROS) such as the hydroxyl radical (*OH) produced by ionizing radiation (carcinogenic) triggers p53 activation in response to the damage of DNA (followed by initiation of DNA-repair mechanisms). Phosphorylation of the BID protein may lead to the recovery from DNA-damage by ROS.

  17. Glutathione in Cancer Cell Death

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, Angel L. [Department of Physiology, Faculty of Medicine and Odontology, University of Valencia, 17 Av. Blasco Ibanez, 46010 Valencia (Spain); Mena, Salvador [Green Molecular SL, Pol. Ind. La Coma-Parc Cientific, 46190 Paterna, Valencia (Spain); Estrela, Jose M., E-mail: jose.m.estrela@uv.es [Department of Physiology, Faculty of Medicine and Odontology, University of Valencia, 17 Av. Blasco Ibanez, 46010 Valencia (Spain)

    2011-03-11

    Glutathione (L-γ-glutamyl-L-cysteinyl-glycine; GSH) in cancer cells is particularly relevant in the regulation of carcinogenic mechanisms; sensitivity against cytotoxic drugs, ionizing radiations, and some cytokines; DNA synthesis; and cell proliferation and death. The intracellular thiol redox state (controlled by GSH) is one of the endogenous effectors involved in regulating the mitochondrial permeability transition pore complex and, in consequence, thiol oxidation can be a causal factor in the mitochondrion-based mechanism that leads to cell death. Nevertheless GSH depletion is a common feature not only of apoptosis but also of other types of cell death. Indeed rates of GSH synthesis and fluxes regulate its levels in cellular compartments, and potentially influence switches among different mechanisms of death. How changes in gene expression, post-translational modifications of proteins, and signaling cascades are implicated will be discussed. Furthermore, this review will finally analyze whether GSH depletion may facilitate cancer cell death under in vivo conditions, and how this can be applied to cancer therapy.

  18. Glutathione in Cancer Cell Death

    International Nuclear Information System (INIS)

    Ortega, Angel L.; Mena, Salvador; Estrela, Jose M.

    2011-01-01

    Glutathione (L-γ-glutamyl-L-cysteinyl-glycine; GSH) in cancer cells is particularly relevant in the regulation of carcinogenic mechanisms; sensitivity against cytotoxic drugs, ionizing radiations, and some cytokines; DNA synthesis; and cell proliferation and death. The intracellular thiol redox state (controlled by GSH) is one of the endogenous effectors involved in regulating the mitochondrial permeability transition pore complex and, in consequence, thiol oxidation can be a causal factor in the mitochondrion-based mechanism that leads to cell death. Nevertheless GSH depletion is a common feature not only of apoptosis but also of other types of cell death. Indeed rates of GSH synthesis and fluxes regulate its levels in cellular compartments, and potentially influence switches among different mechanisms of death. How changes in gene expression, post-translational modifications of proteins, and signaling cascades are implicated will be discussed. Furthermore, this review will finally analyze whether GSH depletion may facilitate cancer cell death under in vivo conditions, and how this can be applied to cancer therapy

  19. Apoptosis-like death in bacteria induced by HAMLET, a human milk lipid-protein complex.

    Directory of Open Access Journals (Sweden)

    Anders P Hakansson

    Full Text Available BACKGROUND: Apoptosis is the primary means for eliminating unwanted cells in multicellular organisms in order to preserve tissue homeostasis and function. It is characterized by distinct changes in the morphology of the dying cell that are orchestrated by a series of discrete biochemical events. Although there is evidence of primitive forms of programmed cell death also in prokaryotes, no information is available to suggest that prokaryotic death displays mechanistic similarities to the highly regulated programmed death of eukaryotic cells. In this study we compared the characteristics of tumor and bacterial cell death induced by HAMLET, a human milk complex of alpha-lactalbumin and oleic acid. METHODOLOGY/PRINCIPAL FINDINGS: We show that HAMLET-treated bacteria undergo cell death with mechanistic and morphologic similarities to apoptotic death of tumor cells. In Jurkat cells and Streptococcus pneumoniae death was accompanied by apoptosis-like morphology such as cell shrinkage, DNA condensation, and DNA degradation into high molecular weight fragments of similar sizes, detected by field inverse gel electrophoresis. HAMLET was internalized into tumor cells and associated with mitochondria, causing a rapid depolarization of the mitochondrial membrane and bound to and induced depolarization of the pneumococcal membrane with similar kinetic and magnitude as in mitochondria. Membrane depolarization in both systems required calcium transport, and both tumor cells and bacteria were found to require serine protease activity (but not caspase activity to execute cell death. CONCLUSIONS/SIGNIFICANCE: Our results suggest that many of the morphological changes and biochemical responses associated with apoptosis are present in prokaryotes. Identifying the mechanisms of bacterial cell death has the potential to reveal novel targets for future antimicrobial therapy and to further our understanding of core activation mechanisms of cell death in eukaryote cells.

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

    Science.gov (United States)

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

    2018-04-26

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

  1. Hyperthermia: an effective strategy to induce apoptosis in cancer cells.

    Science.gov (United States)

    Ahmed, Kanwal; Tabuchi, Yoshiaki; Kondo, Takashi

    2015-11-01

    Heat has been used as a medicinal and healing modality throughout human history. The combination of hyperthermia (HT) with radiation and anticancer agents has been used clinically and has shown positive results to a certain extent. However, the clinical results of HT treatment alone have been only partially satisfactory. Cell death following HT treatment is a function of both temperature and treatment duration. HT induces cancer cell death through apoptosis; the degree of apoptosis and the apoptotic pathway vary in different cancer cell types. HT-induced reactive oxygen species production are responsible for apoptosis in various cell types. However, the underlying mechanism of signal transduction and the genes related to this process still need to be elucidated. In this review, we summarize the molecular mechanism of apoptosis induced by HT, enhancement of heat-induced apoptosis, and the genetic network involved in HT-induced apoptosis.

  2. Programmed cell death

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The purpose of this conference to provide a multidisciplinary forum for exchange of state-of-the-art information on the role programmed cell death plays in normal development and homeostasis of many organisms. This volume contains abstracts of papers in the following areas: invertebrate development; immunology/neurology; bcl-2 family; biochemistry; programmed cell death in viruses; oncogenesis; vertebrate development; and diseases.

  3. Cellular response after irradiation: Cell cycle control and apoptosis

    International Nuclear Information System (INIS)

    Siles, E.; Valenzuela, M.T.; Nunez, M.I.; Guerrero, R.; Villalobos, M.; Ruiz de Almodovar, J.M.

    1997-01-01

    The importance of apoptotic death was assessed in a set of experiments, involving eight human tumour cell lines (breast cancer, bladder carcinoma, medulloblastoma). Various aspects of the quantitative study of apoptosis and methods based on the detection of DNA fragmentation (in situ tailing and comet assay) are described and discussed. Data obtained support the hypothesis that apoptosis is not crucial for cellular radiosensitivity and that the relationship between p53 functionality or clonogenic survival and apoptosis may bee cell type specific. (author)

  4. Autophagy induces apoptosis and death of T lymphocytes in the spleen of pigs infected with CSFV.

    Science.gov (United States)

    Gou, Hongchao; Zhao, Mingqiu; Fan, Shuangqi; Yuan, Jin; Liao, Jiedan; He, Wencheng; Xu, Hailuan; Chen, Jinding

    2017-10-19

    Lymphocyte depletion and immunosuppression are typical clinical characteristics of pigs infected with classical swine fever virus (CSFV). The apoptosis of virus-infected and bystander cells plays a role in the immunopathology of classical swine fever (CSF). Here, we offer the first evidence that autophagy is involved in apoptosis and death of T lymphocytes in the spleen of pigs infected with CSFV. Using immunohistochemical assays, we observed that more LC3II-positive cells appear in the T-cell zone of spleens. Spleen cell apoptosis was demonstrated using flow cytometry and TUNEL staining. Confocal immunofluorescence revealed that partial LC3II-positive cells were simultaneously TUNEL-positive. By cultivating spleen cells ex vivo, we demonstrated that the inhibition of autophagy by 3-MA treatment inhibited apoptosis and death of T lymphocytes caused by CSFV infection but did not have this effect  on B lymphocytes. Further observations demonstrated that uninfected cells in the spleen were also undergoing autophagy in vivo. In summary, these results linked autophagy with the apoptosis and cell death of splenic T cells, providing a new outlook to understand the mechanism of T lymphocyte depletion and immunosuppression during CSF.

  5. The regulation of apoptotic cell death

    Directory of Open Access Journals (Sweden)

    Amarante-Mendes G.P.

    1999-01-01

    Full Text Available Apoptosis is a fundamental biological phenomenon in which the death of a cell is genetically and biochemically regulated. Different molecules are involved in the regulation of the apoptotic process. Death receptors, coupled to distinct members of the caspases as well as other adapter molecules, are involved in the initiation of the stress signals (The Indictment. Members of the Bcl-2 family control at the mitochondrial level the decision between life and death (The Judgement. The effector caspases are responsible for all morphological and biochemical changes related to apoptosis including the "eat-me" signals perceived by phagocytes and neighboring cells (The Execution. Finally, apoptosis would have little biological significance without the recognition and removal of the dying cells (The Burial.

  6. The regulation of apoptotic cell death

    Directory of Open Access Journals (Sweden)

    G.P. Amarante-Mendes

    1999-09-01

    Full Text Available Apoptosis is a fundamental biological phenomenon in which the death of a cell is genetically and biochemically regulated. Different molecules are involved in the regulation of the apoptotic process. Death receptors, coupled to distinct members of the caspases as well as other adapter molecules, are involved in the initiation of the stress signals (The Indictment. Members of the Bcl-2 family control at the mitochondrial level the decision between life and death (The Judgement. The effector caspases are responsible for all morphological and biochemical changes related to apoptosis including the "eat-me" signals perceived by phagocytes and neighboring cells (The Execution. Finally, apoptosis would have little biological significance without the recognition and removal of the dying cells (The Burial.

  7. Acrolein-Induced Oxidative Stress and Cell Death Exhibiting Features of Apoptosis in the Yeast Saccharomyces cerevisiae Deficient in SOD1.

    Science.gov (United States)

    Kwolek-Mirek, Magdalena; Zadrąg-Tęcza, Renata; Bednarska, Sabina; Bartosz, Grzegorz

    2015-04-01

    The yeast Saccharomyces cerevisiae is a useful eukaryotic model to study the toxicity of acrolein, an important environmental toxin and endogenous product of lipid peroxidation. The study was aimed at elucidation of the cytotoxic effect of acrolein on the yeast deficient in SOD1, Cu, Zn-superoxide dismutase which is hypersensitive to aldehydes. Acrolein generated within the cell from its precursor allyl alcohol caused growth arrest and cell death of the yeast cells. The growth inhibition involved an increase in production of reactive oxygen species and high level of protein carbonylation. DNA condensation and fragmentation, exposition of phosphatidylserine at the cell surface as well as decreased dynamic of actin microfilaments and mitochondria disintegration point to the induction of apoptotic-type cell death besides necrotic cell death.

  8. Kaempferol Sensitizes Human Ovarian Cancer Cells-OVCAR-3 and SKOV-3 to Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)-Induced Apoptosis via JNK/ERK-CHOP Pathway and Up-Regulation of Death Receptors 4 and 5.

    Science.gov (United States)

    Zhao, Yingmei; Tian, Binqiang; Wang, Yong; Ding, Haiying

    2017-10-26

    BACKGROUND Ovarian cancer is the most common gynecological malignancies in women, with high mortality rates worldwide. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor (TNF) superfamily which preferentially induces apoptosis of cancer cells. However, acquired resistance to TRAIL hampers its therapeutic application. Identification of compounds that sensitize cancer cells to TRAIL is vital in combating resistance to TRAIL. The effect of kaempferol, a flavonoid enhancing TRAIL-induced apoptosis in ovarian cancer cells, was investigated in this study. MATERIAL AND METHODS The cytotoxic effects of TRAIL (25 ng/mL) and kaempferol (20-100 µM) on human ovarian cancer cells OVCAR-3 and SKOV-3 were assessed. Effect of kaempferol on the expression patterns of cell survival proteins (Bcl-xL, Bcl-2, survivin, XIAP, c-FLIP) and apoptotic proteins (caspase-3, caspase-8, caspase-9, Bax) were studied. The influence of kaempferol on expression of DR4 and DR5 death receptors on the cell surface and protein and mRNA levels was also analyzed. Apoptosis following silencing of DR5 and CHOP by small interfering RNA (siRNA), and activation of MAP kinases were analyzed as well. RESULTS Kaempferol enhanced apoptosis and drastically up-regulated DR4, DR5, CHOP, JNK, ERK1/2, p38 and apoptotic protein expression with decline in the expression of anti-apoptotic proteins. Further transfection with siRNA specific to CHOP and DR5 indicated the involvement of CHOP in DR5 up-regulation and also the contribution of DR5 in kaempferol-enhanced TRAIL-induced apoptosis. CONCLUSIONS Kaempferol sensitized ovarian cancer cells to TRAIL-induced apoptosis via up-regulation of DR4 and DR5 through ERK/JNK/CHOP pathways.

  9. Morphological classification of plant cell deaths

    DEFF Research Database (Denmark)

    van Doorn, W.G.; Beers, E.P.; Dangl, J.L.

    2011-01-01

    Programmed cell death (PCD) is an integral part of plant development and of responses to abiotic stress or pathogens. Although the morphology of plant PCD is, in some cases, well characterised and molecular mechanisms controlling plant PCD are beginning to emerge, there is still confusion about...... the classification of PCD in plants. Here we suggest a classification based on morphological criteria. According to this classification, the use of the term 'apoptosis' is not justified in plants, but at least two classes of PCD can be distinguished: vacuolar cell death and necrosis. During vacuolar cell death......, the cell contents are removed by a combination of autophagy-like process and release of hydrolases from collapsed lytic vacuoles. Necrosis is characterised by early rupture of the plasma membrane, shrinkage of the protoplast and absence of vacuolar cell death features. Vacuolar cell death is common during...

  10. Epidermal cell death in frogs with chytridiomycosis

    Directory of Open Access Journals (Sweden)

    Laura A. Brannelly

    2017-02-01

    Full Text Available Background Amphibians are declining at an alarming rate, and one of the major causes of decline is the infectious disease chytridiomycosis. Parasitic fungal sporangia occur within epidermal cells causing epidermal disruption, but these changes have not been well characterised. Apoptosis (planned cell death can be a damaging response to the host but may alternatively be a mechanism of pathogen removal for some intracellular infections. Methods In this study we experimentally infected two endangered amphibian species Pseudophryne corroboree and Litoria verreauxii alpina with the causal agent of chytridiomycosis. We quantified cell death in the epidermis through two assays: terminal transferase-mediated dUTP nick end-labelling (TUNEL and caspase 3/7. Results Cell death was positively associated with infection load and morbidity of clinically infected animals. In infected amphibians, TUNEL positive cells were concentrated in epidermal layers, correlating to the localisation of infection within the skin. Caspase activity was stable and low in early infection, where pathogen loads were light but increasing. In animals that recovered from infection, caspase activity gradually returned to normal as the infection cleared. Whereas, in amphibians that did not recover, caspase activity increased dramatically when infection loads peaked. Discussion Increased cell death may be a pathology of the fungal parasite, likely contributing to loss of skin homeostatic functions, but it is also possible that apoptosis suppression may be used initially by the pathogen to help establish infection. Further research should explore the specific mechanisms of cell death and more specifically apoptosis regulation during fungal infection.

  11. Matrine induces caspase-independent program cell death in hepatocellular carcinoma through bid-mediated nuclear translocation of apoptosis inducing factor.

    Science.gov (United States)

    Zhou, Huan; Xu, Minying; Gao, Ya; Deng, Zhigang; Cao, Hanwei; Zhang, Wenqing; Wang, Qiao; Zhang, Bing; Song, Gang; Zhan, Yanyan; Hu, Tianhui

    2014-03-16

    Matrine, a clinical drug in China, has been used to treat viral hepatitis, cardiac arrhythmia and skin inflammations. Matrine also exhibits chemotherapeutic potential through its ability to trigger cancer cell death. However, the mechanisms involved are still largely unknown. The objective of this study was to investigate the major determinant for the cell death induced by matrine in human hepatocellular carcinoma. We use human hepatocellular carcinoma cell line HepG2 and human hepatocellular carcinoma xenograft in nude mice as models to study the action of matrine in hepatocellular cancers. We found that caspase-dependent and -independent Program Cell Death (PCD) occurred in matrine-treated HepG2 cells, accompanied by the decreasing of mitochondrial transmembrane potential and the increasing ROS production. Further studies showed that AIF released from the mitochondria to the nucleus, and silencing of AIF reduced the caspase-independent PCD induced by matrine. What's more, AIF nuclear translocation, and the subsequent cell death as well, was prevented by Bid inhibitor BI-6C9, Bid-targeted siRNA and ROS scavenger Tiron. In the in vivo study, matrine significantly attenuated tumor growth with AIF release from mitochondria into nucleus in nude mice. These data imply that matrine potently induce caspase-independent PCD in HepG2 cells through Bid-mediated AIF translocation.

  12. Mechanisms of Virus-Induced Neural Cell Death

    National Research Council Canada - National Science Library

    Tyler, Kenneth

    2002-01-01

    Virtually all known neurotropic viruses are capable of killing infected cells by inducing a specific pattern of cell death known as apoptosis, yet the mechanism by which this occurs and its relevance...

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  14. Mipu1 Protects H9c2 Myogenic Cells from Hydrogen Peroxide-Induced Apoptosis through Inhibition of the Expression of the Death Receptor Fas

    Directory of Open Access Journals (Sweden)

    Guiliang Wang

    2014-10-01

    Full Text Available Mipu1 (myocardial ischemic preconditioning upregulated protein 1, a novel rat gene recently identified in our lab, was expressed abundantly and predominantly in the brain and heart and upregulated in myocardium during myocardial ischemia/reperfusion in rats. In our previous study we found that Mipu1 was an evolutionarily conserved zinc finger-containing transcription factor. However, whether Mipu1 confers myocardial protection remains unknown. In this study, H9c2 myogenic cells were treated with hydrogen peroxide (H2O2 to simulate oxidative stress during myocardial ischemia-reperfusion injury. The expression of Mipu1 at mRNA and protein levels was detected by RT-PCR and Western blotting analysis. To study the effect of Mipu1 on apoptosis and expression of Fas induced by H2O2, full-length Mipu1 cDNA and Mipu1-RNAi plasmids were transiently transfected into H9c2 myogenic cells, and flow cytometry was used to quantitate the percentage of apoptotic cells. The expression of Fas was analyzed by Western blotting assay. The DNA binding and transcription activities of Mipu1 to the Fas promoter were detected by chromatin immunoprecipitation and luciferase reporter assays. The results showed that exposure of H9c2 myogenic cells to H2O2 resulted in a dose- and time-dependent increase in Mipu1 mRNA and protein levels; Mipu1 over-expression inhibited H2O2-induced apoptosis and upregulation of Fas induced by H2O2 in H9c2 myogenic cells; and knockdown of Mipu1 by RNAi promoted apoptosis and upregulation of Fas induced by H2O2. The chromatin immunoprecipition and reporter assays showed the DNA binding and transcription suppressor activities of Mipu1 to Fas promoter region. These results indicate that Mipu1 protected H9c2 myogenic cells from H2O2-induced apoptosis through inhibiting the expression of Fas.

  15. Endoplasmic reticulum involvement in yeast cell death

    International Nuclear Information System (INIS)

    Nicanor Austriaco, O.

    2012-01-01

    Yeast cells undergo programed cell death (PCD) with characteristic markers associated with apoptosis in mammalian cells including chromatin breakage, nuclear fragmentation, reactive oxygen species generation, and metacaspase activation. Though significant research has focused on mitochondrial involvement in this phenomenon, more recent work with both Saccharomyces cerevisiae and Schizosaccharomyces pombe has also implicated the endoplasmic reticulum (ER) in yeast PCD. This minireview provides an overview of ER stress-associated cell death (ER-SAD) in yeast. It begins with a description of ER structure and function in yeast before moving to a discussion of ER-SAD in both mammalian and yeast cells. Three examples of yeast cell death associated with the ER will be highlighted here including inositol starvation, lipid toxicity, and the inhibition of N-glycosylation. It closes by suggesting ways to further examine the involvement of the ER in yeast cell death.

  16. Deletion of apoptosis signal-regulating kinase 1 (ASK1 protects pancreatic beta-cells from stress-induced death but not from glucose homeostasis alterations under pro-inflammatory conditions.

    Directory of Open Access Journals (Sweden)

    Emilie Pepin

    Full Text Available Type 2 diabetes is characterized by pancreatic beta-cell dysfunction and is associated with low-grade inflammation. Recent observations suggest that apoptosis signal-regulating kinase 1 (ASK1 is involved in beta-cell death in response to different stressors. In this study, we tested whether ASK1 deficiency protects beta-cells from glucolipotoxic conditions and cytokines treatment or from glucose homeostasis alteration induced by endotoxemia.Insulin secretion was neither affected upon shRNA-mediated downregulation of ASK1 in MIN6 cells nor in islets from ASK1-deficient mice. ASK1 silencing in MIN6 cells and deletion in islets did not prevent the deleterious effect of glucolipotoxic conditions or cytokines on insulin secretion. However, it protected MIN6 cells from death induced by ER stress or palmitate and islets from short term caspase activation in response to cytokines. Moreover, endotoxemia induced by LPS infusion increased insulin secretion during hyperglycemic clamps but the response was similar in wild-type and ASK1-deficient mice. Finally, insulin sensitivity in the presence of LPS was not affected by ASK1-deficiency.Our study demonstrates that ASK1 is not involved in beta-cell function and dysfunction but controls stress-induced beta-cell death.

  17. Activation of apoptosis signal-regulating kinase 1 is a key factor in paraquat-induced cell death : modulation by the Nrf2/Trx axis

    NARCIS (Netherlands)

    Niso-Santano, Mireia; González-Polo, Rosa A; Bravo-San Pedro, José M; Gómez-Sánchez, Rubén; Lastres-Becker, Isabel; Ortiz-Ortiz, Miguel A; Soler, Germán; Morán, José M; Cuadrado, Antonio; Fuentes, José M

    2010-01-01

    Although oxidative stress is fundamental to the etiopathology of Parkinson disease, the signaling molecules involved in transduction after oxidant exposure to cell death are ill-defined, thus making it difficult to identify molecular targets of therapeutic relevance. We have addressed this question

  18. 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.)

  19. Death Receptor-Mediated Cell Death and Proinflammatory Signaling in Nonalcoholic SteatohepatitisSummary

    Directory of Open Access Journals (Sweden)

    Petra Hirsova

    2015-01-01

    Full Text Available Nonalcoholic fatty liver disease (NAFLD is becoming a public health problem worldwide. A subset of patients develop an inflammatory disease, nonalcoholic steatohepatitis (NASH, characterized by steatosis, hepatocellular death, macrophage and neutrophil accumulation, and varying stages of fibrosis. Hepatocyte cell death triggers the cellular inflammatory response, therefore reducing cell death may be salutary in the steatohepatitis disease process. Recently, a better understanding of hepatocyte apoptosis in NASH has been obtained and new information regarding other cell death modes such as necroptosis and pyroptosis has been reported. Hepatocyte lipotoxicity is often triggered by death receptors. In addition to causing apoptosis, death receptors have been shown to mediate proinflammatory signaling, suggesting that apoptosis in this context is not an immunologically silent process. Here, we review recent developments in our understanding of hepatocyte cell death by death receptors and its mechanistic link to inflammation in NASH. We emphasize how proapoptotic signaling by death receptors may induce the release of proinflammatory extracellular vesicles, thereby recruiting and activating macrophages and promoting the steatohepatitis process. Potential therapeutic strategies are discussed based on this evolving information. Keywords: Apoptosis, Caspase Inhibitor, Cell Death, Death Receptors, Exosomes, Extracellular Vesicles, Fibrosis, Inflammation, Inflammasome, Microvesicles, Necroptosis, Pyroptosis

  20. Plasma membrane changes during programmed cell deaths.

    Science.gov (United States)

    Zhang, Yingying; Chen, Xin; Gueydan, Cyril; Han, Jiahuai

    2018-01-01

    Ruptured and intact plasma membranes are classically considered as hallmarks of necrotic and apoptotic cell death, respectively. As such, apoptosis is usually considered a non-inflammatory process while necrosis triggers inflammation. Recent studies on necroptosis and pyroptosis, two types of programmed necrosis, revealed that plasma membrane rupture is mediated by MLKL channels during necroptosis but depends on non-selective gasdermin D (GSDMD) pores during pyroptosis. Importantly, the morphology of dying cells executed by MLKL channels can be distinguished from that executed by GSDMD pores. Interestingly, it was found recently that secondary necrosis of apoptotic cells, a previously believed non-regulated form of cell lysis that occurs after apoptosis, can be programmed and executed by plasma membrane pore formation like that of pyroptosis. In addition, pyroptosis is associated with pyroptotic bodies, which have some similarities to apoptotic bodies. Therefore, different cell death programs induce distinctive reshuffling processes of the plasma membrane. Given the fact that the nature of released intracellular contents plays a crucial role in dying/dead cell-induced immunogenicity, not only membrane rupture or integrity but also the nature of plasma membrane breakdown would determine the fate of a cell as well as its ability to elicit an immune response. In this review, we will discuss recent advances in the field of apoptosis, necroptosis and pyroptosis, with an emphasis on the mechanisms underlying plasma membrane changes observed on dying cells and their implication in cell death-elicited immunogenicity.

  1. Chemical -induced apoptotic cell death in tomato cells : involvement of caspase-like proteases

    NARCIS (Netherlands)

    Jong, de A.J.; Hoeberichts, F.A.; Yakimova, E.T.; Maximova, E.; Woltering, E.J.

    2000-01-01

    A new system to study programmed cell death in plants is described. Tomato (Lycopersicon esculentum Mill.) suspension cells were induced to undergo programmed cell death by treatment with known inducers of apoptosis in mammalian cells. This chemical-induced cell death was accompanied by the

  2. Molecular Cell Biology of Apoptosis and Necroptosis in Cancer.

    Science.gov (United States)

    Dillon, Christopher P; Green, Douglas R

    Cell death is a major mechanism to eliminate cells in which DNA is damaged, organelles are stressed, or oncogenes are overexpressed, all events that would otherwise predispose cells to oncogenic transformation. The pathways that initiate and execute cell death are complex, genetically encoded, and subject to significant regulation. Consequently, while these pathways are often mutated in malignancy, there is considerable interest in inducing cell death in tumor cells as therapy. This chapter addresses our current understanding of molecular mechanisms contributing to two cell death pathways, apoptotic cell death and necroptosis, a regulated form of necrotic cell death. Apoptosis can be induced by a wide variety of signals, leading to protease activation that dismantles the cell. We discuss the physiological importance of each apoptosis pathway and summarize their known roles in cancer suppression and the current efforts at targeting each pathway therapeutically. The intricate mechanistic link between death receptor-mediated apoptosis and necroptosis is described, as well as the potential opportunities for utilizing necroptosis in the treatment of malignancy.

  3. Diversity of cell death pathways: insight from the fly ovary.

    Science.gov (United States)

    Jenkins, Victoria K; Timmons, Allison K; McCall, Kimberly

    2013-11-01

    Multiple types of cell death exist including necrosis, apoptosis, and autophagic cell death. The Drosophila ovary provides a valuable model to study the diversity of cell death modalities, and we review recent progress to elucidate these pathways. At least five distinct types of cell death occur in the ovary, and we focus on two that have been studied extensively. Cell death of mid-stage egg chambers occurs through a novel caspase-dependent pathway that involves autophagy and triggers phagocytosis by surrounding somatic epithelial cells. For every egg, 15 germline nurse cells undergo developmental programmed cell death, which occurs independently of most known cell death genes. These forms of cell death are strikingly similar to cell death observed in the germlines of other organisms. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Radiation-Induced Apoptosis in Breast Cancer Cells.

    Science.gov (United States)

    1995-09-21

    This project is designed to investigate the possible role of apoptosis as a mode of cell death in irradiated and tamoxifen-treated breast cancer cells and to study the potential for using therapeutic manipulations to enhance this cell killing as a means of improving radiation therapy for treatment of breast cancer.

  5. Mechanisms of Betulinic acid‐induced cell death

    NARCIS (Netherlands)

    Potze, L.

    2015-01-01

    The scope of this thesis was to investigate the mechanisms by which BetA induces cell death in cancer cells in more detail. At the start of the studies described in this thesis several questions urgently needed an answer. Although BetA induces cell death via apoptosis, when blocking this form of

  6. [Taurine induces apoptosis in pulmonary artery smooth muscle cells].

    Science.gov (United States)

    Zhang, Xiaodan; Sheng, Jiejing; Zhang, Caixiaz; Zhao, Fenghua

    2012-03-01

    To study the effect of taurine on apoptosis in PASMCs, and whether the death-receptor pathway act in the mechanism. Culture the PASMCs, and divided the cells into control, SD. Acridine orange(AO) assay and western-blot analysis on the expression of Bax, Bcl-2, Procaspase-3 and Fas were used to study the mechanism. A major finding of this study is that the Tau effects many apoptosis index, such as increasing the expression of Bax and Fas, decreasing the expression of Procaspase-3, and Bcl-2, accrescencing the mitochondrial depolarization, causing the nuclear shrinkage, all these datas demonstrated that Tau induced the apoptosis in pulmonary artery smooth muscle cells through mitochondrial-dependent pathway. Tau induces the apoptosis in pulmonary artery smooth muscle cells through death-receptor.

  7. Programmed cell death: Superman meets Dr Death.

    Science.gov (United States)

    Meier, Pascal; Silke, John

    2003-12-01

    This year's Cold Spring Harbor meeting on programmed cell death (September 17-21, 2003), organised by Craig Thompson and Junying Yuan, was proof that the 'golden age' of research in this field is far from over. There was a flurry of fascinating insights into the regulation of diverse apoptotic pathways and unexpected non-apoptotic roles for some of the key apoptotic regulators and effectors. In addition to their role in cell death, components of the apoptotic molecular machinery are now known to also function in a variety of essential cellular processes, such as regulating glucose homeostasis, lipid metabolism, cell proliferation and differentiation.

  8. Multiple mediators of plant programmed cell death : interplay of conserved cell death mechanisms and plant-specific regulators

    NARCIS (Netherlands)

    Hoeberichts, F.A.; Woltering, E.J.

    2002-01-01

    Programmed cell death (PCD) is a process aimed at the removal of redundant, misplaced, or damaged cells and it is essential to the development and maintenance of multicellular organisms. In contrast to the relatively well-described cell death pathway in animals, often referred to as apoptosis,

  9. P2X7 Cell Death Receptor Activation and Mitochondrial Impairment in Oxaliplatin-Induced Apoptosis and Neuronal Injury: Cellular Mechanisms and In Vivo Approach.

    Directory of Open Access Journals (Sweden)

    France Massicot

    Full Text Available Limited information is available regarding the cellular mechanisms of oxaliplatin-induced painful neuropathy during exposure of patients to this drug. We therefore determined oxidative stress in cultured cells and evaluated its occurrence in C57BL/6 mice. Using both cultured neuroblastoma (SH-SY5Y and macrophage (RAW 264.7 cell lines and also brain tissues of oxaliplatin-treated mice, we investigated whether oxaliplatin (OXA induces oxidative stress and apoptosis. Cultured cells were treated with 2-200 µM OXA for 24 h. The effects of pharmacological inhibitors of oxidative stress or inflammation (N-acetyl cysteine, ibuprofen, acetaminophen were also tested. Inhibitors were added 30 min before OXA treatment and then in combination with OXA for 24 h. In SH-SY5Y cells, OXA caused a significant dose-dependent decrease in viability, a large increase in ROS and NO production, lipid peroxidation and mitochondrial impairment as assessed by a drop in mitochondrial membrane potential, which are deleterious for the cell. An increase in levels of negatively charged phospholipids such as cardiolipin but also phosphatidylserine and phosphatidylinositol, was also observed. Additionally, OXA caused concentration-dependent P2X7 receptor activation, increased chromatin condensation and caspase-3 activation associated with TNF-α and IL-6 release. The majority of these toxic effects were equally observed in Raw 264.7 which also presented high levels of PGE2. Pretreatment of SH-SY5Y cells with pharmacological inhibitors significantly reduced or blocked all the neurotoxic OXA effects. In OXA-treated mice (28 mg/kg cumulated dose significant cold hyperalgesia and oxidative stress in the tested brain areas were shown. Our study suggests that targeting P2X7 receptor activation and mitochondrial impairment might be a potential therapeutic strategy against OXA-induced neuropathic pain.

  10. Induction of apoptosis by eugenol in human breast cancer cells

    International Nuclear Information System (INIS)

    Vidhya, N.; Niranjali Devaraj, S.

    2011-01-01

    In the present study, potential anticancer effect of eugenol on inhibition of cell proliferation and induction of apoptosis in human MCF-7 breast cancer cells was investigated. Induction of cell death by eugenol was evaluated following MTT assay and monitoring lactate dehydrogenase released into the culture medium for cell viability and cytotoxicity, giemsa staining for morphological alterations, fluorescence microscopy analysis of cells using ethidium bromide and acridine orange and quantitation of DNA fragments for induction of apoptosis. Effect of eugenol on intracellular redox status of the human breast cancer cells was assessed by determining the level of glutathione and lipid peroxidation products (TBARS). Eugenol treatment inhibited the growth and proliferation of human MCF-7 breast cancer cells through induction of cell death, which was dose and time dependent. Microscopic examination of eugenol treated cells showed cell shrinkage, membrane blebbing and apoptotic body formation. Further, eugenol treatment also depleted the level of intracellular glutathione and increased the level of lipid peroxidation. The dose dependent increase in the percentage of apoptotic cells and DNA fragments suggested that apoptosis was involved in eugenol induced cell death and apoptosis might have played a role in the chemopreventive action of eugenol. (author)

  11. Biisofraxidin on Apoptosis of Human Gastric Cancer BGC-823 Cells

    African Journals Online (AJOL)

    Conclusion: 3,3′-Biisofraxidin significantly induces the apoptosis of BGC-823 cells in vitro and in vivo ... Plant material. Sarcandrae Herba (SH) was obtained from. Chengdu international trade city in 2013 and identified by Jian-Tao Wu. A voucher specimen ..... induced by p65 prevents doxorubicin-induced cell death.

  12. Apoptosis transcriptional mechanism of feline infectious peritonitis virus infected cells.

    Science.gov (United States)

    Shuid, Ahmad Naqib; Safi, Nikoo; Haghani, Amin; Mehrbod, Parvaneh; Haron, Mohd Syamsul Reza; Tan, Sheau Wei; Omar, Abdul Rahman

    2015-11-01

    Apoptosis has been postulated to play an important role during feline infectious peritonitis virus (FIPV) infection; however, its mechanism is not well characterized. This study is focused on apoptosis and transcriptional profiling of FIPV-infected cells following in vitro infection of CRFK cells with FIPV 79-1146 WSU. Flow cytometry was used to determine mode of cell death in first 42 h post infection (hpi). FIPV infected cells underwent early apoptosis at 9 hpi (p apoptosis at 12 hpi (p apoptosis cluster (80 down-regulated and 51 up-regulated) along with increase of apoptosis, p53, p38 MAPK, VEGF and chemokines/cytokines signaling pathways were probably involved in apoptosis process. Six of the de-regulated genes expression (RASSF1, BATF2, MAGEB16, PDCD5, TNFα and TRAF2) and TNFα protein concentration were analyzed by RT-qPCR and ELISA, respectively, at different time-points. Up-regulations of both pro-apoptotic (i.e. PDCD5) and anti-apoptotic (i.e. TRAF2) were detected from first hpi and continuing to deregulate during apoptosis process in the infected cells.

  13. Patterns of cell death in the perinatal mouse forebrain

    OpenAIRE

    Mosley, Morgan; Shah, Charisma; Morse, Kiriana A.; Miloro, Stephen A.; Holmes, Melissa M.; Ahern, Todd H.; Forger, Nancy G.

    2016-01-01

    The importance of cell death in brain development has long been appreciated, but many basic questions remain, such as what initiates or terminates the cell death period. One obstacle has been the lack of quantitative data defining exactly when cell death occurs. We recently created a “cell death atlas,” using the detection of activated caspase-3 (AC3) to quantify apoptosis in the postnatal mouse ventral forebrain and hypothalamus, and found that the highest rates of cell death were seen at th...

  14. High expression of markers of apoptosis in Langerhans cell histiocytosis

    DEFF Research Database (Denmark)

    Petersen, Bodil Laub; Lundegaard, Pia Rengtved; Bank, M I

    2003-01-01

    53 and the number of cells in apoptosis detected with TUNEL. Langerhans cell histiocytosis cells showed strong expression of p53 and in some cases co-expression of Fas and Fas-L. The expression of Fas-L was significantly higher in infiltrates from patients with single-system disease. The actual...... number of pathological Langerhans cells in apoptosis as estimated by TUNEL was low. CONCLUSIONS: The low number of TUNEL-reactive cells can be explained by the rapid turnover of apoptotic cells in the tissue, not leaving the apoptotic cells long enough in the tissue to be detected. The co......-expression of Fas and Fas-L in some Langerhans cells can lead to an autocrine apoptotic shortcut, mediating the death of the double-positive cells. Our findings suggest that apoptosis mediated through the Fas/Fas-L pathway may contribute to the spontaneous regression of lesions in single-system disease. A delicate...

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

    Directory of Open Access Journals (Sweden)

    Xiaodong Huang

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

  16. Contrast agents and renal cell apoptosis.

    Science.gov (United States)

    Romano, Giulia; Briguori, Carlo; Quintavalle, Cristina; Zanca, Ciro; Rivera, Natalia V; Colombo, Antonio; Condorelli, Gerolama

    2008-10-01

    Contrast media (CM) induce a direct toxic effect on renal tubular cells. This toxic effect may have a role in the pathophysiology of contrast nephropathy. We evaluated (i) the cytotoxicity of CM [both low-osmolality (LOCM) and iso-osmolality (IOCM)], of iodine alone, and of an hyperosmolar solution (mannitol 8%) on human embryonic kidney (HEK 293), porcine proximal renal tubular (LLC-PK1), and canine Madin-Darby distal tubular renal (MDCK) cells; and (ii) the effectiveness of various antioxidant compounds [n-acetylcysteine (NAC), ascorbic acid and sodium bicarbonate] in preventing CM cytotoxicity. The cytotoxicity of CM was assessed at different time points, with different methods: cell viability, DNA laddering, flow cytometry, and caspase activation. Both LOCM and IOCM produced a concentration- and time-dependent increase in cell death as assessed by the different methods. On the contrary, iodine alone and hyperosmolar solution did not induce any significant cytotoxic effect. There was not any significant difference in the cytotoxic effect between LOCM and IOCM. Furthermore, both LOCM and IOCM caused a marked increase in caspase-3 and -9 activities and poly(ADP-ribose) fragmentation, while no effect on caspase-8/-10 was observed, thus indicating that the CM activated apoptosis mainly through the intrinsic pathway. Both CM induced an increase in protein expression levels of pro-apoptotic members of the Bcl2 family (Bim and Bad). NAC and ascorbic acid but not sodium bicarbonate had a dose-dependent protective effect on renal cells after 3 h incubation with high dose (200 mg iodine/mL) of both LOCM and IOCM. Both LOCM and IOCM induce a dose-dependent renal cell apoptosis. NAC and ascorbic acid but not sodium bicarbonate prevent this contrast-induced apoptosis.

  17. Cell cycle regulation and radiation-induced cell death

    International Nuclear Information System (INIS)

    Favaudon, V.

    2000-01-01

    Tight control of cell proliferation is mandatory to prevent cancer formation as well as to normal organ development and homeostasis. This occurs through checkpoints that operate in both time and space and are involved in the control of numerous pathways including DNA replication and transcription, cell cycle progression, signal transduction and differentiation. Moreover, evidence has accumulated to show that apoptosis is tightly connected with the regulation of cell cycle progression. In this paper we describe the main pathways that determine checkpoints in the cell cycle and apoptosis. It is also recalled that in solid tumors radiation-induced cell death occurs most frequently through non-apoptotic mechanisms involving oncosis, and mitotic or delayed cell death. (author)

  18. Noisy-threshold control of cell death

    Directory of Open Access Journals (Sweden)

    Vilar Jose MG

    2010-11-01

    Full Text Available Abstract Background Cellular responses to death-promoting stimuli typically proceed through a differentiated multistage process, involving a lag phase, extensive death, and potential adaptation. Deregulation of this chain of events is at the root of many diseases. Improper adaptation is particularly important because it allows cell sub-populations to survive even in the continuous presence of death conditions, which results, among others, in the eventual failure of many targeted anticancer therapies. Results Here, I show that these typical responses arise naturally from the interplay of intracellular variability with a threshold-based control mechanism that detects cellular changes in addition to just the cellular state itself. Implementation of this mechanism in a quantitative model for T-cell apoptosis, a prototypical example of programmed cell death, captures with exceptional accuracy experimental observations for different expression levels of the oncogene Bcl-xL and directly links adaptation with noise in an ATP threshold below which cells die. Conclusions These results indicate that oncogenes like Bcl-xL, besides regulating absolute death values, can have a novel role as active controllers of cell-cell variability and the extent of adaptation.

  19. Dimethyl sulfoxide potentiates death receptor-mediated apoptosis in the human myeloid leukemia U937 cell line through enhancement of mitochondrial membrane depolarization

    Czech Academy of Sciences Publication Activity Database

    Vondráček, Jan; Souček, Karel; Sheard, M. A.; Chramostová, Kateřina; Andrysík, Zdeněk; Hofmanová, Jiřina; Kozubík, Alois

    2006-01-01

    Roč. 30, č. 1 (2006), s. 81-89 ISSN 0145-2126 R&D Projects: GA ČR(CZ) GA524/03/0766 Institutional research plan: CEZ:AV0Z50040507 Keywords : human myeloid leukemia * DMSO * apoptosis Subject RIV: BO - Biophysics Impact factor: 2.483, year: 2006

  20. Biochemical events in naturally occurring forms of cell death.

    Science.gov (United States)

    Fesus, L

    1993-08-09

    Several molecular elements of programmed cell death and apoptosis have recently been revealed. The function of gene products which deliver the lethal 'hit' is still not known. Well-characterized and newly discovered cell surface structures (e.g. antigen receptors, FAS/APO-1), as well as transcriptional factors (steroid receptor, c-myc, P53, retinoblastoma protein and others), have been implicated in the initiation of the death pathway. Negative regulators of the process (ced-9 gene product in programmed death of cells in Caenorhabditis elegans and bcl-2 protein in apoptosis) have been described. Biochemical mechanisms responsible for the silent nature of natural deaths of cells include their rapid engulfment (mainly through integrin receptors), transglutaminase-catalyzed cross-linking of cellular proteins, and fragmentation of DNA. Several lines of evidence suggest that distinct molecular mechanisms may operate in various forms of natural cell death.

  1. Programmed cell death for defense against anomaly and tumor formation

    International Nuclear Information System (INIS)

    Kondo, Sohei; Norimura, Toshiyuki; Nomura, Taisei

    1995-01-01

    Cell death after exposure to low-level radiation is often considered evidence that radiation is poisonous, however small the dose. Evidence has been accumulating to support the notion that cell death after low-level exposure to radiation results from activation of suicidal genes open-quote programmed cell death close-quote or open-quote apoptosis close-quote - for the health of the whole body. This paper gives experimental evidence that embryos of fruit flies and mouse fetuses have potent defense mechanisms against teratogenic or tumorigenic injury caused by radiation and carcinogens, which function through programmed cell death

  2. Suppression of ICE and Apoptosis in Mammary Epithelial Cells by Extracellular Matrix

    Energy Technology Data Exchange (ETDEWEB)

    Boudreau, Nancy; Sympson, C. J.; Werb, Zena; Bissell, Mina J.

    1994-12-01

    Apoptosis (programmed cell death) plays a major role in development and tissue regeneration. Basement membrane extracellular matrix (ECM), but not fibronectin or collagen, was shown to suppress apoptosis of mammary epithelial cells in tissue culture and in vivo. Apoptosis was induced by antibodies to beta 1 integrins or by overexpression of stromelysin-1, which degrades ECM. Expression of interleukin-1 beta converting enzyme (ICE) correlated with the loss of ECM, and inhibitors of ICE activity prevented apoptosis. These results suggest that ECM regulates apoptosis in mammary epithelial cells through an integrin-dependent negative regulation of ICE expression.

  3. Ionizing radiation induces apoptosis in hematopoietic stem and progenitor cells

    International Nuclear Information System (INIS)

    Meng, A.; Zhou, D.; Geiger, H.; Zant, G.V.

    2003-01-01

    The aims of this study was to determine if ionizing radiation (IR) induces apoptosis in hematopoietic stem (HSC) and progenitor cells. Lin-cells were isolated from mouse bone marrow (BM) and pretreated with vehicle or 100 μM z-VAD 1 h prior to exposure to 4 Gy IR. The apoptotic and/or necrotic responses of these cells to IR were analyzed by measuring the annexin V and/or 7-AAD staining in HSC and progenitor populations using flow cytometry, and hematopoietic function of these cells was determined by CAFC assay. Exposure of Lin-cells to IR selectively decreased the numbers of HSC and progenitors in association with an increase in apoptosis in a time-dependent manner. Pretreatment of Lin- cells with z-VAD significantly inhibited IR-induced apoptosis and the decrease in the numbers of HSC and progenitors. However, IR alone or in combination with z-VAD did not lead to a significant increase in necrotic cell death in either HSC or progenitors. In addition, pretreatment of BM cells with z-VAD significantly attenuated IR-induced reduction in the frequencies of day-7, -28 and -35 CAFC. Exposure of HSC and progenitors to IR induces apoptosis. The induction of HSC and progenitor apoptosis contributes to IR-induced suppression of their hematopoietic function

  4. Cell renewal and apoptosis in macrostomum sp. [Lignano].

    Science.gov (United States)

    Nimeth, K; Ladurner, P; Gschwentner, R; Salvenmoser, W; Rieger, R

    2002-01-01

    In platyhelminths, all cell renewal is accomplished by totipotent stem cells (neoblasts). Tissue maintenance is achieved in a balance between cell proliferation and apoptosis. It is known that in Macrostomum sp. the epidermis undergoes extensive cell renewal. Here we show that parenchymal cells also exhibit a high rate of cell turnover. We demonstrate cell renewal using continuous 5'bromo-2-deoxyuridine (BrdU) exposure. About one-third of all cells are replaced after 14 days. The high level of replacement requires an equivalent removal of cells by apoptosis. Cell death is characterized using a combination of three methods: (1). terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL), (2). specific binding of phosphatidyl-serine to fluorescent-labelled annexin V and (3). identification of apoptotic stages by ultrastructure. The number of cells observed in apoptosis is insufficient to explain the homeostasis of tissues in Macrostomum. Apoptosis-independent mechanisms may play an additional role in tissue dynamics.

  5. Characterized mechanism of alpha-mangostin-induced cell death: caspase-independent apoptosis with release of endonuclease-G from mitochondria and increased miR-143 expression in human colorectal cancer DLD-1 cells.

    Science.gov (United States)

    Nakagawa, Yoshihito; Iinuma, Munekazu; Naoe, Tomoki; Nozawa, Yoshinori; Akao, Yukihiro

    2007-08-15

    alpha-Mangostin, a xanthone from the pericarps of mangosteen (Garcinia mangostana Linn.), was evaluated for in vitro cytotoxicity against human colon cancer DLD-1 cells. The number of viable cells was consistently decreased by the treatment with alpha-mangostin at more than 20 microM. The cytotoxic effect of 20 microM alpha-mangostin was found to be mainly due to apoptosis, as indicated by morphological findings. Western blotting, the results of an apoptosis inhibition assay using caspase inhibitors, and the examination of caspase activity did not demonstrate the activation of any of the caspases tested. However, endonuclease-G released from mitochondria with the decreased mitochondrial membrane potential was shown. The levels of phospho-Erk1/2 were increased in the early phase until 1h after the start of treatment and thereafter decreased, and increased again in the late phase. On the other hand, the level of phospho-Akt was sharply reduced with the process of apoptosis after 6h of treatment. Interestingly, the level of microRNA-143, which negatively regulates Erk5 at translation, gradually increased until 24h following the start of treatment. We also examined the synergistic growth suppression in DLD-1 cells by the combined treatment of the cells with alpha-mangostin and 5-FU which is one of the most effective chemotherapeutic agents for colorectal adenocarcinoma. The co-treatment with alpha-mangostin and 5-FU, both at 2.5 microM, augmented growth inhibition compared with the treatment with 5 microM of alpha-mangostin or 5 microM 5-FU alone. These findings indicate unique mechanisms of alpha-mangostin-induced apoptosis and its action as an effective chemosensitizer.

  6. Delayed cell death signaling in traumatized central nervous system: hypoxia.

    Science.gov (United States)

    Chu, Danielle; Qiu, JingXin; Grafe, Marjorie; Fabian, Roderick; Kent, Thomas A; Rassin, David; Nesic, Olivera; Werrbach-Perez, Karin; Perez-Polo, Regino

    2002-02-01

    There are two different ways for cells to die: necrosis and apoptosis. Cell death has traditionally been described as necrotic or apoptotic based on morphological criteria. There are controversy about the respective roles of apoptosis and necrosis in cell death resulting from trauma to the central nervous system (CNS). An evaluation of work published since 1997 in which electron microscopy was applied to ascertain the role of apoptosis and necrosis in: spinal cord injury, stroke, and hypoxia/ischemia (H/I) showed evidence for necrosis and apoptosis based on DNA degradation, presence of histones in cytoplasm, and morphological evidence in spinal cord. In the aftermath of stroke, many of the biochemical markers for apoptosis were present but the morphological determinations suggested that necrosis is the major source of post-traumatic cell death. This was not the case in H/I where both biochemical assays and the morphological studies gave more consistent results in a manner similar to the spinal cord injury studies. After H/I, major factors affecting cell death outcomes are DNA damage and repair processes, expression of bcl-like gene products and inflammation-triggered cytokine production.

  7. VEGF masks BNIP3-mediated apoptosis of hypoxic endothelial cells.

    Science.gov (United States)

    Jurasz, Paul; Yurkova, Natasha; Kirshenbaum, Lorrie; Stewart, Duncan J

    2011-05-01

    Hypoxia results in the apoptotic death of myocytes, neurons, and epithelial cells, through the actions of Bcl-2 and Nineteen kilodalton Interacting Protein-3 (BNIP3). On the contrary, endothelial cells are especially adept at surviving conditions of oxygen deprivation via up-regulation of vascular endothelial growth factor (VEGF) the most potent endothelial survival factor. Both VEGF and BNIP3 expression are transcriptionally regulated by hypoxia inducible factor and may antagonize each other's affects in endothelial cells (ECs). Since factors that promote and inhibit apoptosis may be expressed at the same time in endothelial cells under hypoxic conditions, we decided to investigate whether VEGF and BNIP3 have opposing actions in endothelial cells. Human microvascular endothelial cells were exposed to hypoxic conditions in a Billups-Rothenburg chamber. Under hypoxic conditions BNIP3 expression by endothelial cells increased as measured by real-time PCR and immunoblot. After 48 h of hypoxia, EC apoptosis was assessed by flow cytometry and was lower than in corresponding normoxia serum starved controls. The increase in EC survival under hypoxic conditions corresponded with an increase in the expression of VEGF. Under normoxic conditions adenoviral BNIP3 over-expression promoted apoptosis of ECs; however, recombinant VEGF (100 pg/ml) antagonized the BNIP3 apoptosis promoting affects. SiRNA knockdown of VEGF expression by hypoxic ECs resulted in increased apoptosis with a concomitant increase in BNIP3 expression. SiRNA knockdown of BNIP3 expression by hypoxic ECs reduced the increase in EC apoptosis as a result of VEGF knockdown. We conclude that under hypoxic conditions VEGF counteracts and masks the apoptosis promoting affects of BNIP3.

  8. Transformation by oncogenic RAS sensitizes human colon cells to TRAIL-induced apoptosis by up-regulating death receptor 4 and death receptor 5 through a MEK-dependent pathway

    Czech Academy of Sciences Publication Activity Database

    Drosopoulos, K.G.; Roberts, M.L.; Čermák, Lukáš; Sasazuki, T.; Shirasawa, S.; Anděra, Ladislav; Pintzas, A.

    2005-01-01

    Roč. 280, č. 24 (2005), s. 22856-22867 ISSN 0021-9258 R&D Projects: GA AV ČR(CZ) KSK5020115; GA AV ČR(CZ) KJB5052407 Keywords : TRAIL * Ras * apoptosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.854, year: 2005

  9. Ouabain enhances ADPKD cell apoptosis via the intrinsic pathway

    Directory of Open Access Journals (Sweden)

    Gustavo eBlanco

    2016-03-01

    Full Text Available Progression of autosomal dominant polycystic kidney disease (ADPKD is highly influenced by factors circulating in blood. We have shown that the hormone ouabain enhances several characteristics of the ADPKD cystic phenotype, including the rate of cell proliferation, fluid secretion and the capacity of the cells to form cysts. In this work, we found that physiological levels of ouabain (3nM also promote programmed cell death of renal epithelial cells obtained from kidney cysts of patients with ADPKD (ADPKD cells. This was determined by Alexa Fluor 488 labeled-Annexin-V staining and TUNEL assay, both biochemical markers of apoptosis. Ouabain-induced apoptosis also takes place when ADPKD cell growth is blocked; suggesting that the effect is not secondary to the stimulatory actions of ouabain on cell proliferation. Ouabain alters the expression of BCL family of proteins, reducing BCL-2 and increasing BAX expression levels, anti- and pro-apoptotic mediators respectively. In addition, ouabain caused the release of cytochrome c from mitochondria. Moreover, ouabain activates caspase-3, a key executioner caspase in the cell apoptotic pathway, but did not affect caspase-8. This suggests that ouabain triggers ADPKD cell apoptosis by stimulating the intrinsic, but not the extrinsic pathway of programmed cell death. The apoptotic effects of ouabain are specific for ADPKD cells and do not occur in normal human kidney cells (NHK cells. Taken together with our previous observations, these results show that ouabain causes an imbalance in cell growth/death, to favor growth of the cystic cells. This event, characteristic of ADPKD, further suggests the importance of ouabain as a circulating factor that promotes ADPKD progression.

  10. METHYLMERCURY BUT NOT MERCURIC CHLORIDE INDUCES APOPTOTIC CELL DEATH IN PC12 CELLS.

    Science.gov (United States)

    Normal development of the nervous system requires the process of apoptosis, a form of programmed cell death, to remove superfluous neurons. Abnormal patterns of apoptosis may be a consequence of exposure to environmental neurotoxicants leading to a disruption in the tightly regul...

  11. Coxsackievirus A16 infection induces neural cell and non-neural cell apoptosis in vitro.

    Directory of Open Access Journals (Sweden)

    Zhaolong Li

    Full Text Available Coxsackievirus A16 (CA16 is one of the main causative pathogens of hand, foot and mouth disease (HFMD. Viral replication typically results in host cell apoptosis. Although CA16 infection has been reported to induce apoptosis in the human rhabdomyosarcoma (RD cell line, it remains unclear whether CA16 induces apoptosis in diverse cell types, especially neural cells which have important clinical significance. In the current study, CA16 infection was found to induce similar apoptotic responses in both neural cells and non-neural cells in vitro, including nuclear fragmentation, DNA fragmentation and phosphatidylserine translocation. CA16 generally is not known to lead to serious neurological symptoms in vivo. In order to further clarify the correlation between clinical symptoms and cell apoptosis, two CA16 strains from patients with different clinical features were investigated. The results showed that both CA16 strains with or without neurological symptoms in infected patients led to neural and muscle cell apoptosis. Furthermore, mechanistic studies showed that CA16 infection induced apoptosis through the same mechanism in both neural and non-neural cells, namely via activation of both the mitochondrial (intrinsic pathway-related caspase 9 protein and the Fas death receptor (extrinsic pathway-related caspase 8 protein. Understanding the mechanisms by which CA16 infection induces apoptosis in both neural and non-neural cells will facilitate a better understanding of CA16 pathogenesis.

  12. MYC, Cell Competition, and Cell Death in Cancer: The Inseparable Triad.

    Science.gov (United States)

    Di Giacomo, Simone; Sollazzo, Manuela; Paglia, Simona; Grifoni, Daniela

    2017-04-17

    Deregulation of MYC family proteins in cancer is associated with a global reprogramming of gene expression, ultimately promoting glycolytic pathways, cell growth, and proliferation. It is well known that MYC upregulation triggers cell-autonomous apoptosis in normal tissues, while frankly malignant cells develop resistance to apoptotic stimuli, partly resulting from MYC addiction. As well as inducing cell-autonomous apoptosis, MYC upregulation is able to trigger non cell-autonomous apoptotic death through an evolutionarily conserved mechanism known as "cell competition". With regard to this intimate and dual relationship between MYC and cell death, recent evidence obtained in Drosophila models of cancer has revealed that, in early tumourigenesis, MYC upregulation guides the clonal expansion of mutant cells, while the surrounding tissue undergoes non-cell autonomous death. Apoptosis inhibition in this context was shown to restrain tumour growth and to restore a wild-type phenotype. This suggests that cell-autonomous and non cell-autonomous apoptosis dependent on MYC upregulation may shape tumour growth in different ways, soliciting the need to reconsider the role of cell death in cancer in the light of this new level of complexity. Here we review recent literature about MYC and cell competition obtained in Drosophila , with a particular emphasis on the relevance of cell death to cell competition and, more generally, to cancer. Possible implications of these findings for the understanding of mammalian cancers are also discussed.

  13. Cord blood stem cell-mediated induction of apoptosis in glioma downregulates X-linked inhibitor of apoptosis protein (XIAP.

    Directory of Open Access Journals (Sweden)

    Venkata Ramesh Dasari

    2010-07-01

    Full Text Available XIAP (X-linked inhibitor of apoptosis protein is one of the most important members of the apoptosis inhibitor family. XIAP is upregulated in various malignancies, including human glioblastoma. It promotes invasion, metastasis, growth and survival of malignant cells. We hypothesized that downregulation of XIAP by human umbilical cord blood mesenchymal stem cells (hUCBSC in glioma cells would cause them to undergo apoptotic death.We observed the effect of hUCBSC on two malignant glioma cell lines (SNB19 and U251 and two glioma xenograft cell lines (4910 and 5310. In co-cultures of glioma cells with hUCBSC, proliferation of glioma cells was significantly inhibited. This is associated with increased cytotoxicity of glioma cells, which led to glioma cell death. Stem cells induced apoptosis in glioma cells, which was evaluated by TUNEL assay, FACS analyses and immunoblotting. The induction of apoptosis is associated with inhibition of XIAP in co-cultures of hUCBSC. Similar results were obtained by the treatment of glioma cells with shRNA to downregulate XIAP (siXIAP. Downregulation of XIAP resulted in activation of caspase-3 and caspase-9 to trigger apoptosis in glioma cells. Apoptosis is characterized by the loss of mitochondrial membrane potential and upregulation of mitochondrial apoptotic proteins Bax and Bad. Cell death of glioma cells was marked by downregulation of Akt and phospho-Akt molecules. We observed similar results under in vivo conditions in U251- and 5310-injected nude mice brains, which were treated with hUCBSC. Under in vivo conditions, Smac/DIABLO was found to be colocalized in the nucleus, showing that hUCBSC induced apoptosis is mediated by inhibition of XIAP and activation of Smac/DIABLO.Our results indicate that downregulation of XIAP by hUCBSC treatment induces apoptosis, which led to the death of the glioma cells and xenograft cells. This study demonstrates the therapeutic potential of XIAP and hUCBSC to treat malignant

  14. Programmed cell death - strategy for maintenance cellular organisms homeostasis.

    Science.gov (United States)

    Godlewski, Mirosław; Kobylińska, Agnieszka

    2016-12-20

    Programmed cell death (PCD) is a cellular suicide process, commonly found in organisms, that is important for elimination unnecessary and damaged cells during development and adaptation to abiotic and biotic environmental stresses. PCD is a complex and precise, genetically controlled cellular process, in opposite to non-programmed death, necrosis, in which cells are "killed" by strong abiotic factors. This article shows: the occurrence of PCD during animals and plants ontogenesis, classification of cell death types in these organisms with description of autophagy, apoptosis and necrotic cell death and with discussion on plant cell death by apoptosis. The role of Bcl-2 protein and other proteins involved in the regulation of apoptosis induction and detection in the plant's (whose genomes do not encode these proteins) proteins of analogous function is also discussed. The paper also presents the effects of the expression of animals pro- and anti-apoptotic genes transformed into yeast and plants, and the use of transformed yeast as model to identify in cDNA libraries animal and plant genes involved in regulation of the induction and course of the PCD.

  15. Programmed cell death – strategy for maintenance cellular organisms homeostasis

    Directory of Open Access Journals (Sweden)

    Mirosław Godlewski

    2016-12-01

    Full Text Available Programmed cell death (PCD is a cellular suicide process, commonly found in organisms, that is important for elimination unnecessary and damaged cells during development and adaptation to abiotic and biotic environmental stresses. PCD is a complex and precise, genetically controlled cellular process, in opposite to non-programmed death, necrosis, in which cells are “killed” by strong abiotic factors. This article shows: the occurrence of PCD during animals and plants ontogenesis, classification of cell death types in these organisms with description of autophagy, apoptosis and necrotic cell death and with discussion on plant cell death by apoptosis. The role of Bcl-2 protein and other proteins involved in the regulation of apoptosis induction and detection in the plant’s (whose genomes do not encode these proteins proteins of analogous function is also discussed. The paper also presents the effects of the expression of animals pro- and anti-apoptotic genes transformed into yeast and plants, and the use of transformed yeast as model to identify in cDNA libraries animal and plant genes involved in regulation of the induction and course of the PCD.

  16. Cell-in-Cell Death Is Not Restricted by Caspase-3 Deficiency in MCF-7 Cells

    Science.gov (United States)

    Wang, Shan; He, Meifang; Li, Linmei; Liang, Zhihua; Zou, Zehong

    2016-01-01

    Purpose Cell-in-cell structures are created by one living cell entering another homotypic or heterotypic living cell, which usually leads to the death of the internalized cell, specifically through caspase-dependent cell death (emperitosis) or lysosome-dependent cell death (entosis). Although entosis has attracted great attention, its occurrence is controversial, because one cell line used in its study (MCF-7) is deficient in caspase-3. Methods We investigated this issue using MCF-7 and A431 cell lines, which often display cell-in-cell invasion, and have different levels of caspase-3 expression. Cell-in-cell death morphology, microstructures, and signaling pathways were compared in the two cell lines. Results Our results confirmed that MCF-7 cells are caspase-3 deficient with a partial deletion in the CASP-3 gene. These cells underwent cell death that lacked typical apoptotic properties after staurosporine treatment, whereas caspase-3-sufficient A431 cells displayed typical apoptosis. The presence of caspase-3 was related neither to the lysosome-dependent nor to the caspase-dependent cell-in-cell death pathway. However, the existence of caspase-3 was associated with a switch from lysosome-dependent cell-in-cell death to the apoptotic cell-in-cell death pathway during entosis. Moreover, cellular hypoxia, mitochondrial swelling, release of cytochrome C, and autophagy were observed in internalized cells during entosis. Conclusion The occurrence of caspase-independent entosis is not a cell-specific process. In addition, entosis actually represents a cellular self-repair system, functioning through autophagy, to degrade damaged mitochondria resulting from cellular hypoxia in cell-in-cell structures. However, sustained autophagy-associated signal activation, without reduction in cellular hypoxia, eventually leads to lysosome-dependent intracellular cell death. PMID:27721872

  17. Xylodiol from Xylopia langsdorfiana induces apoptosis in HL60 cells

    Directory of Open Access Journals (Sweden)

    Marianna Vieira S. Castello-Branco

    2011-08-01

    Full Text Available An atisane diterpene was isolated from Xylopia langsdorfiana St. Hilaire & Tulasne, Annonaceae, leaves, ent-atisane-7α,16α-diol (xylodiol. Preliminary study showed that xylodiol was cytotoxic and induced differentiation on human leukemia cell lines. However, the molecular mechanisms of xylodiol-mediated cytotoxicity have not been fully defined. Thus, we investigated the anti-tumor effect of xylodiol in human leukemia HL60 cell line. Xylodiol induced apoptosis and necrosis. HL60 cells treated with xylodiol showed biochemical changes characteristic of apoptosis, including caspases-8, -9 and -3 activation and loss of mitochondrial transmembrane potential (∆ Ψm. However, there was a condensation rather than swelling of mitochondria. Moreover, the formation of condensed mitochondria and the loss of ∆ Ψm occurred downstream of caspase activation. Cyclosporine A did not protect HL60 cells from the cytotoxic effects of xylodiol, suggesting that the loss of ∆ Ψm is a late event in xylodiol-induced apoptosis. Oxidative stress was involved in xylodiol-induced apoptosis. Thus, we conclude that activated caspases cleave cellular proteins resulting in mitochondrial damage leading to mitochondrial condensation, loss of ∆ Ψm and ROS release from the mitochondria. ROS can further induce and maintain a collapse of ∆ Ψm leading to cellular damage through oxidation of lipids and proteins resulting in apoptotic cell death.

  18. Methuosis: Nonapoptotic Cell Death Associated with Vacuolization of Macropinosome and Endosome Compartments

    OpenAIRE

    Maltese, William A.; Overmeyer, Jean H.

    2014-01-01

    Apoptosis is the most widely recognized form of physiological programmed cell death. During the past three decades, various nonapoptotic forms of cell death have gained increasing attention, largely because of their potential importance in pathological processes, toxicology, and cancer therapy. A recent addition to the panoply of cell death phenotypes is methuosis. The neologism is derived from the Greek methuo (to drink to intoxication) because the hallmark of this form of cell death is disp...

  19. Helicobacter pylori enhances tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis in human gastric epithelial cells

    Science.gov (United States)

    Wu, Yi-Ying; Tsai, Hwei-Fang; Lin, We-Cheng; Chou, Ai-Hsiang; Chen, Hui-Ting; Yang, Jyh-Chin; Hsu, Ping-I; Hsu, Ping-Ning

    2004-01-01

    AIM: To investigate the relations between tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and Helicobacter pylori (H pylori) infection in apoptosis of gastric epithelial cells and to assess the expression of TRAIL on the surface of infiltrating T-cells in H pylori-infected gastric mucosa. METHODS: Human gastric epithelial cell lines and primary gastric epithelial cells were co-cultured with H pylori in vitro, then recombinant TRAIL proteins were added to the culture. Apoptosis of gastric epithelial cells was determined by a specific ELISA for cell death. Infiltrating lymphocytes were isolated from H pylori-infected gastric mucosa, and expression of TRAIL in T cells was analyzed by flow cytometry. RESULTS: The apoptosis of gastric epithelial cell lines and primary human gastric epithelial cells was mildly increased by interaction with either TRAIL or H pylori alone. Interestingly, the apoptotic indices were markedly elevated when gastric epithelial cells were incubated with both TRAIL and H pylori (Control vs TRAIL and H pylori: 0.51 ± 0.06 vs 2.29 ± 0.27, P = 0.018). A soluble TRAIL receptor (DR4-Fc) could specifically block the TRAIL-mediated apoptosis. Further studies demonstrated that infiltrating T-cells in gastric mucosa expressed TRAIL on their surfaces, and the induction of TRAIL sensitivity by H pylori was dependent upon direct cell contact of viable bacteria, but not CagA and VacA of H pylori. CONCLUSION: H pylori can sensitize human gastric epithelial cells and enhance susceptibility to TRAIL-mediated apoptosis. Modulation of host cell sensitivity to apoptosis by bacterial interaction adds a new dimension to the immunopathogenesis of H pylori infection. PMID:15285015

  20. Colorectal Cancer Stem Cells and Cell Death

    Energy Technology Data Exchange (ETDEWEB)

    Catalano, Veronica [Department of Surgical and Oncological Sciences, University of Palermo, Via Liborio Giuffrè 5, 90127 Palermo, PA (Italy); Gaggianesi, Miriam [Department of Surgical and Oncological Sciences, University of Palermo, Via Liborio Giuffrè 5, 90127 Palermo, PA (Italy); Department of Cellular and Molecular Oncology, IRCCS Fondazione Salvatore Maugeri, Via Salvatore Maugeri, 27100 Pavia, PV (Italy); Spina, Valentina; Iovino, Flora [Department of Surgical and Oncological Sciences, University of Palermo, Via Liborio Giuffrè 5, 90127 Palermo, PA (Italy); Dieli, Francesco [Departement of Biopathology and Medicine Biotechnologies, University of Palermo, Via Liborio Giuffrè 5, 90127 Palermo, PA (Italy); Stassi, Giorgio, E-mail: giorgio.stassi@unipa.it [Department of Surgical and Oncological Sciences, University of Palermo, Via Liborio Giuffrè 5, 90127 Palermo, PA (Italy); Department of Cellular and Molecular Oncology, IRCCS Fondazione Salvatore Maugeri, Via Salvatore Maugeri, 27100 Pavia, PV (Italy); Todaro, Matilde [Department of Surgical and Oncological Sciences, University of Palermo, Via Liborio Giuffrè 5, 90127 Palermo, PA (Italy)

    2011-04-11

    Nowadays it is reported that, similarly to other solid tumors, colorectal cancer is sustained by a rare subset of cancer stem–like cells (CSCs), which survive conventional anticancer treatments, thanks to efficient mechanisms allowing escape from apoptosis, triggering tumor recurrence. To improve patient outcomes, conventional anticancer therapies have to be replaced with specific approaches targeting CSCs. In this review we provide strong support that BMP4 is an innovative therapeutic approach to prevent colon cancer growth increasing differentiation markers expression and apoptosis. Recent data suggest that in colorectal CSCs, protection from apoptosis is achieved by interleukin-4 (IL-4) autocrine production through upregulation of antiapoptotic mediators, including survivin. Consequently, IL-4 neutralization could deregulate survivin expression and localization inducing chemosensitivity of the colon CSCs pool.

  1. Analysis of Residual DSBs in Ataxia-Telangiectasia Lymphoblast Cells Initiating Apoptosis

    Directory of Open Access Journals (Sweden)

    Teresa Anglada

    2016-01-01

    Full Text Available In order to examine the relationship between accumulation of residual DNA double-strand breaks (DSBs and cell death, we have used a control and an ATM (Ataxia-Telangiectasia Mutated defective cell line, as Ataxia-Telangiectasia (AT cells tend to accumulate residual DSBs at long times after damage infliction. After irradiation, AT cells showed checkpoint impairment and a fraction of cells displayed an abnormal centrosome number and tetraploid DNA content, and this fraction increased along with apoptosis rates. At all times analyzed, AT cells displayed a significantly higher rate of radiation-induced apoptosis than normal cells. Besides apoptosis, 70–85% of the AT viable cells (TUNEL-negative carried ≥10 γH2AX foci/cell, while only 12–27% of normal cells did. The fraction of AT and normal cells undergoing early and late apoptosis were isolated by flow cytometry and residual DSBs were concretely scored in these populations. Half of the γH2AX-positive AT cells undergoing early apoptosis carried ≥10 γH2AX foci/cell and this fraction increased to 75% in late apoptosis. The results suggest that retention of DNA damage-induced γH2AX foci is an indicative of lethal DNA damage, as cells undergoing apoptosis are those accumulating more DSBs. Scoring of residual γH2AX foci might function as a predictive tool to assess radiation-induced apoptosis.

  2. Cell death programs in Yersinia immunity and pathogenesis

    Directory of Open Access Journals (Sweden)

    Naomi Hannah Philip

    2012-11-01

    Full Text Available Cell death plays a central role in host-pathogen interactions, as it can eliminate the pathogen’s replicative niche and provide pro-inflammatory signals necessary for an effective immune response; conversely, cell death can allow pathogens to eliminate immune cells and evade anti-microbial effector mechanisms. In response to developmental signals or cell-intrinsic stresses, the executioner caspases-3 and -7 mediate apoptotic cell death, which is generally viewed as immunologically silent or immunosuppressive. A proinflammatory form of cell death that requires caspase-1, termed pyroptosis, is activated in response to microbial products within the host cytosol or disruption of cellular membranes by microbial pathogens. Infection by the bacterial pathogen Yersinia has features of both apoptosis and pyroptosis. Cell death and caspase-1 processing in Yersinia-infected cells occur in response to inhibition of NF-κB and MAPK signaling by the Yersinia virulence factor YopJ. However, the molecular basis of YopJ-induced cell death, and the role of different death pathways in anti-Yersinia immune responses remain enigmatic. Here, we discuss the role that cell death may play in inducing specific pro-inflammatory signals that shape innate and adaptive immune responses against Yersinia infection.

  3. DNA damage and mitochondria dysfunction in cell apoptosis induced by nonthermal air plasma

    Science.gov (United States)

    Kim, G. J.; Kim, W.; Kim, K. T.; Lee, J. K.

    2010-01-01

    Nonthermal plasma is known to induce animal cell death but the mechanism is not yet clear. Here, cellular and biochemical regulation of cell apoptosis is demonstrated for plasma treated cells. Surface type nonthermal air plasma triggered apoptosis of B16F10 mouse melanoma cancer cells causing DNA damage and mitochondria dysfunction. Plasma treatment activated caspase-3, apoptosis executioner. The plasma treated cells also accumulated gamma-H2A.X, marker for DNA double strand breaks, and p53 tumor suppressor gene as a response to DNA damage. Interestingly, cytochrome C was released from mitochondria and its membrane potential was changed significantly.

  4. Mechanisms of apoptosis modulation and their contribution to genomic instability in tumor cells

    OpenAIRE

    Vukicevic, Vladimir

    2004-01-01

    The concept of programmed cell death has been increasingly considered from various aspects since early 1970’s. Primarily, knowledge of apoptosis referred to morphological changes in which chromatin is condensed and increasingly fragmented, revealed as small structure in the nucleus. The membrane shrinks and the cell becomes dense as can be seen by flow cytometry. Interestingly, similar modes of cell deletion were observed in nematodes indicating that apoptosis is a highly conserved machinery....

  5. Apoptosis and systemic autoimmunity: the dendritic cell connection

    Directory of Open Access Journals (Sweden)

    AA Manfredi

    2009-12-01

    Full Text Available Much effort has been devoted in recent years to the events linking recognition and disposal of apoptotic cells to sustained immunity towards the antigens they contain. Programmed death via apoptosis indeed provides most of the raw material the immune system exploits to establish self tolerance, i.e. to learn how to distinguish between self constituents and foreign antigens, belonging to invading pathogens. In parallel, events occurring during cell death may enable a restricted array of molecules endowed with diverse structure, function and intracellular distribution to satisfy the requirement to evoke and maintain autoimmune responses. Dendritic cells (DCs, the most potent antigen presenting cells, appear to play a crucial role. Here we will discuss some of the constrains regulating the access of dying cells’ antigens to DCs, as well as censorship mechanisms that prevent their maturation and the full explication of their antigen presenting function.

  6. A tomato metacaspase gene is upregulated during programmed cell death in Botrytis cinerea-infected leaves

    NARCIS (Netherlands)

    Hoeberichts, F.A.; Have, ten A.; Woltering, E.J.

    2003-01-01

    Programmed cell death (PCD) in plant cells is often accompanied by biochemical and morphological hallmarks similar to those of animal apoptosis. However, orthologs of animal caspases, cysteinyl aspartate-specific proteases that constitute the core component of animal apoptosis, have not yet been

  7. Induction of cell death by chemotherapeutic methylating agents

    International Nuclear Information System (INIS)

    Quiros Barrantes, Steve

    2012-01-01

    The mechanism of cell death induced by O 6 MeG has been investigated and inhibition of homologous recombination as a strategy for sensitization of tumor cells against methylating agents S N 1. Dependence of the cell cycle was determined toxic responses triggered by O''6 MeG and evaluated by proliferation assays if apoptotic cells have originated exclusively from the second post-treatment cycle. Dependence of O''6 MeG was found at DSB formation. The activation of the control points of the cell cycle and induction of apoptosis is generated during the second cell cycle. Additionally, a portion of the cells has been determined that triggers apoptosis in subsequent generations in the second cell cycle. Inhibition of homologous recombination has been a reasonable strategy to increase S N 1 alkylating agent effectiveness. Evidence has been provided in NHEJ dependent inhibition of DNA-PK that not significantly sensitizes the glioblastoma cells against temozolomide [es

  8. Dissection of pathways leading to antigen receptor-induced and Fas/CD95-induced apoptosis in human B cells

    NARCIS (Netherlands)

    Lens, S. M.; den Drijver, B. F.; Pötgens, A. J.; Tesselaar, K.; van Oers, M. H.; van Lier, R. A.

    1998-01-01

    To dissect intracellular pathways involved in B cell Ag receptor (BCR)-mediated and Fas-induced human B cell death, we isolated clones of the Burkitt lymphoma cell line Ramos with different apoptosis sensitivities. Selection for sensitivity to Fas-induced apoptosis also selected for clones with

  9. Nuclear orphan receptor TLX affects gene expression, proliferation and cell apoptosis in beta cells

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xiaoli; Xiong, Xiaokan; Dai, Zhe; Deng, Haohua; Sun, Li; Hu, Xuemei; Zhou, Feng; Xu, Yancheng, E-mail: oxyccc@163.com

    2015-12-04

    Nuclear orphan receptor TLX is an essential regulator of the growth of neural stem cells. However, its exact function in pancreatic islet cells is still unknown. In the present study, gene expression profiling analysis revealed that overexpression of TLX in beta cell line MIN6 causes suppression of 176 genes and upregulation of 49 genes, including a cadre of cell cycle, cell proliferation and cell death control genes, such as Btg2, Ddit3 and Gadd45a. We next examined the effects of TLX overexpression on proliferation, apoptosis and insulin secretion in MIN6 cells. Proliferation analysis using EdU assay showed that overexpression of TLX increased percentage of EdU-positive cells. Cell cycle and apoptosis analysis revealed that overexpression of TLX in MIN6 cells resulted in higher percentage of cells exiting G1 into S-phase, and a 58.8% decrease of cell apoptosis induced by 0.5 mM palmitate. Moreover, TLX overexpression did not cause impairment of insulin secretion. Together, we conclude that TLX is among factors capable of controlling beta cell proliferation and survival, which may serve as a target for the development of novel therapies for diabetes. - Highlights: • TLX overexpression in MIN6 cell causes significant expression changes of 225 genes. • TLX overexpression promotes MIN6 cell proliferation and decreases cell apoptosis. • TLX overexpression does not cause impairment of insulin secretion.

  10. Nuclear orphan receptor TLX affects gene expression, proliferation and cell apoptosis in beta cells

    International Nuclear Information System (INIS)

    Shi, Xiaoli; Xiong, Xiaokan; Dai, Zhe; Deng, Haohua; Sun, Li; Hu, Xuemei; Zhou, Feng; Xu, Yancheng

    2015-01-01

    Nuclear orphan receptor TLX is an essential regulator of the growth of neural stem cells. However, its exact function in pancreatic islet cells is still unknown. In the present study, gene expression profiling analysis revealed that overexpression of TLX in beta cell line MIN6 causes suppression of 176 genes and upregulation of 49 genes, including a cadre of cell cycle, cell proliferation and cell death control genes, such as Btg2, Ddit3 and Gadd45a. We next examined the effects of TLX overexpression on proliferation, apoptosis and insulin secretion in MIN6 cells. Proliferation analysis using EdU assay showed that overexpression of TLX increased percentage of EdU-positive cells. Cell cycle and apoptosis analysis revealed that overexpression of TLX in MIN6 cells resulted in higher percentage of cells exiting G1 into S-phase, and a 58.8% decrease of cell apoptosis induced by 0.5 mM palmitate. Moreover, TLX overexpression did not cause impairment of insulin secretion. Together, we conclude that TLX is among factors capable of controlling beta cell proliferation and survival, which may serve as a target for the development of novel therapies for diabetes. - Highlights: • TLX overexpression in MIN6 cell causes significant expression changes of 225 genes. • TLX overexpression promotes MIN6 cell proliferation and decreases cell apoptosis. • TLX overexpression does not cause impairment of insulin secretion.

  11. Patterns of cell death in the perinatal mouse forebrain.

    Science.gov (United States)

    Mosley, Morgan; Shah, Charisma; Morse, Kiriana A; Miloro, Stephen A; Holmes, Melissa M; Ahern, Todd H; Forger, Nancy G

    2017-01-01

    The importance of cell death in brain development has long been appreciated, but many basic questions remain, such as what initiates or terminates the cell death period. One obstacle has been the lack of quantitative data defining exactly when cell death occurs. We recently created a "cell death atlas," using the detection of activated caspase-3 (AC3) to quantify apoptosis in the postnatal mouse ventral forebrain and hypothalamus, and found that the highest rates of cell death were seen at the earliest postnatal ages in most regions. Here we have extended these analyses to prenatal ages and additional brain regions. We quantified cell death in 16 forebrain regions across nine perinatal ages from embryonic day (E) 17 to postnatal day (P) 11 and found that cell death peaks just after birth in most regions. We found greater cell death in several regions in offspring delivered vaginally on the day of parturition compared with those of the same postconception age but still in utero at the time of collection. We also found massive cell death in the oriens layer of the hippocampus on P1 and in regions surrounding the anterior crossing of the corpus callosum on E18 as well as the persistence of large numbers of cells in those regions in adult mice lacking the pro-death Bax gene. Together these findings suggest that birth may be an important trigger of neuronal cell death and identify transient cell groups that may undergo wholesale elimination perinatally. J. Comp. Neurol. 525:47-64, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  12. Akebia saponin PA induces autophagic and apoptotic cell death in AGS human gastric cancer cells.

    Science.gov (United States)

    Xu, Mei-Ying; Lee, Dong Hwa; Joo, Eun Ji; Son, Kun Ho; Kim, Yeong Shik

    2013-09-01

    In this study, we investigated the anticancer mechanism of akebia saponin PA (AS), a natural product isolated from Dipsacus asperoides in human gastric cancer cell lines. It was shown that AS-induced cell death is caused by autophagy and apoptosis in AGS cells. The apoptosis-inducing effect of AS was characterized by annexin V/propidium (PI) staining, increase of sub-G1 phase and caspase-3 activation, while the autophagy-inducing effect was indicated by the formation of cytoplasmic vacuoles and microtubule-associated protein 1 light chain-3 II (LC3-II) conversion. The autophagy inhibitor bafilomycin A1 (BaF1) decreased AS-induced cell death and caspase-3 activation, but caspase-3 inhibitor Ac-DEVD-CHO did not affect LC3-II accumulation or AS-induced cell viability, suggesting that AS induces autophagic cell death and autophagy contributes to caspase-3-dependent apoptosis. Furthermore, AS activated p38/c-Jun N-terminal kinase (JNK), which could be inhibited by BaF1, and caspase-3 activation was attenuated by both SB202190 and SP600125, indicating that AS-induced autophagy promotes mitogen-activated protein kinases (MAPKs)-mediated apoptosis. Taken together, these results demonstrate that AS induces autophagic and apoptotic cell death and autophagy plays the main role in akebia saponin PA-induced cell death. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. PDT-induced apoptosis in bladder carcinoma cells

    Science.gov (United States)

    Bachor, Ruediger; Reich, Ella D.; Kleinschmidt, Klaus; Repassy, Denes; Hautmann, Richard E.

    1999-02-01

    Photodynamic therapy (PDT) is a highly efficient inducer of apoptosis in EY-28 bladder carcinoma cells, resulting in extensive DNA fragmentation. Bladder carcinoma cells EY-28 (Tumorbank Heidelberg, Germany) were incubated for 1 h with 1 (mu) g AamTPPn/ml or 2 (mu) g AamTPPn/ml. After incubation cells were refed with complete medium and irradiated with 0.75 J/cm2. To identify apoptotic cells, a in situ cell death detection kit POD (Boehringer Mannheim, Germany) was used. The chromatin condensation characteristic to apoptotic cells was detected by transmission electron microscopy. Using 1 (mu) g AamTPPn/ml and 2 (mu) g AamTPPn/ml (9-Acetamido-2,7,12,17- tetra-n-Porpylporphycene), respectively, and irradiation at 0.75 J/cm2, a percentage of 36.9% and 54.7%, respectively, of apoptotic cells was detected.

  14. Cell cycle and apoptosis genes in atherosclerosis

    NARCIS (Netherlands)

    Boesten, Lianne Simone Mirjam

    2006-01-01

    The work described in this thesis was aimed at identifying the role of cell cycle and apoptosis genes in atherosclerosis. Atherosclerosis is the primary cause of cardiovascular disease, a disorder occurring in the large and medium-sized arteries of the body. Although in the beginning 90s promising

  15. Bortezomib induces autophagic death in proliferating human endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Belloni, Daniela; Veschini, Lorenzo [Myeloma Unit, Department of Oncology, IRCCS H San Raffaele, Milan (Italy); Foglieni, Chiara [Department of Cardiology, IRCCS H San Raffaele, Milan (Italy); Dell' Antonio, Giacomo [Department of Pathology, IRCCS H San Raffaele, Milan (Italy); Caligaris-Cappio, Federico [Myeloma Unit, Department of Oncology, IRCCS H San Raffaele, Milan (Italy); Universita Vita-Salute IRCCS H San Raffaele, Milan (Italy); Ferrarini, Marina [Myeloma Unit, Department of Oncology, IRCCS H San Raffaele, Milan (Italy); Ferrero, Elisabetta, E-mail: elisabetta.ferrero@hsr.it [Myeloma Unit, Department of Oncology, IRCCS H San Raffaele, Milan (Italy)

    2010-04-01

    The proteasome inhibitor Bortezomib has been approved for the treatment of relapsed/refractory multiple myeloma (MM), thanks to its ability to induce MM cell apoptosis. Moreover, Bortezomib has antiangiogenic properties. We report that endothelial cells (EC) exposed to Bortezomib undergo death to an extent that depends strictly on their activation state. Indeed, while quiescent EC are resistant to Bortezomib, the drug results maximally toxic in EC switched toward angiogenesis with FGF, and exerts a moderate effect on subconfluent HUVEC. Moreover, EC activation state deeply influences the death pathway elicited by Bortezomib: after treatment, angiogenesis-triggered EC display typical features of apoptosis. Conversely, death of subconfluent EC is preceded by ROS generation and signs typical of autophagy, including intense cytoplasmic vacuolization with evidence of autophagosomes at electron microscopy, and conversion of the cytosolic MAP LC3 I form toward the autophagosome-associated LC3 II form. Treatment with the specific autophagy inhibitor 3-MA prevents both LC3 I/LC3 II conversion and HUVEC cell death. Finally, early removal of Bortezomib is accompanied by the recovery of cell shape and viability. These findings strongly suggest that Bortezomib induces either apoptosis or autophagy in EC; interfering with the autophagic response may potentiate the antiangiogenic effect of the drug.

  16. Cigarette smoke causes caspase-independent apoptosis of bronchial epithelial cells from asthmatic donors.

    Directory of Open Access Journals (Sweden)

    Fabio Bucchieri

    Full Text Available Epidemiologic studies have demonstrated important links between air pollution and asthma. Amongst these pollutants, environmental cigarette smoke is a risk factor both for asthma pathogenesis and exacerbation. As the barrier to the inhaled environment, the bronchial epithelium is a key structure that is exposed to cigarette smoke.Since primary bronchial epithelial cells (PBECs from asthmatic donors are more susceptible to oxidant-induced apoptosis, we hypothesized that they would be susceptible to cigarette smoke-induced cell death.PBECs from normal and asthmatic donors were exposed to cigarette smoke extract (CSE; cell survival and apoptosis were assessed by fluorescence-activated cell sorting, and protective effects of antioxidants evaluated. The mechanism of cell death was evaluated using caspase inhibitors and immunofluorescent staining for apoptosis-inducing factor (AIF.Exposure of PBEC cultures to CSE resulted in a dose-dependent increase in cell death. At 20% CSE, PBECs from asthmatic donors exhibited significantly more apoptosis than cells from non-asthmatic controls. Reduced glutathione (GSH, but not ascorbic acid (AA, protected against CSE-induced apoptosis. To investigate mechanisms of CSE-induced apoptosis, caspase-3 or -9 inhibitors were tested, but these failed to prevent apoptosis; in contrast, CSE promoted nuclear translocation of AIF from the mitochondria. GSH reduced the number of nuclear-AIF positive cells whereas AA was ineffective.Our results show that PBECs from asthmatic donors are more susceptible to CSE-induced apoptosis. This response involves AIF, which has been implicated in DNA damage and ROS-mediated cell-death. Epithelial susceptibility to CSE may contribute to the impact of environmental tobacco smoke in asthma.

  17. Inhibition of apoptosis in T cells expressing human T cell leukemia virus type I Tax.

    Science.gov (United States)

    Copeland, K F; Haaksma, A G; Goudsmit, J; Krammer, P H; Heeney, J L

    1994-10-01

    This study set out to determine whether T cell dysfunction associated with HTLV-I led to increased sensitivity of infected cells to apoptosis or, owing to their potential to develop ATL, if infected cells would become resistant to this process. To test this hypothesis we utilized the monoclonal antibody anti-APO-1, which has been demonstrated to induce apoptosis in human T cells. Human T cell lines expressing HTLV-I showed reduced susceptibility to anti-APO-1-induced apoptosis despite expression of high levels of cell surface APO-1. Cell-free supernatant of the Tax-expressing cell line C8166 and heat-inactivated supernatant of the HTLV-I-producing cell line MT2 transferred increased resistance to anti-APO-1 to susceptible Jurkat T cells. Susceptible T cells transfected with an HTLV-I Tax-expressing vector or treated with soluble Tax protein became less susceptible to anti-APO-1-induced cell death. Furthermore, primary human lymphocytes treated with soluble Tax were less susceptible to apoptosis induced by anti-APO-1. The protective effect of Tax in T cell lines and primary human lymphocytes was reversed by the addition of anti-Tax antibodies. Anti-APO-1-induced apoptosis was also found to be inhibited in Jurkat cells by the induction of protein kinase C (PKC) with 12-O-tetradecanoylphorbol-13-acetate (TPA). Resistance to apoptosis conferred by HTLV-I Tax and an active PKC pathway may be factors contributing to the survival of dysregulated HTLV-I-infected T cells prone to the development of adult T cell leukemia.

  18. Stem cell death and survival in heart regeneration and repair.

    Science.gov (United States)

    Abdelwahid, Eltyeb; Kalvelyte, Audrone; Stulpinas, Aurimas; de Carvalho, Katherine Athayde Teixeira; Guarita-Souza, Luiz Cesar; Foldes, Gabor

    2016-03-01

    Cardiovascular diseases are major causes of mortality and morbidity. Cardiomyocyte apoptosis disrupts cardiac function and leads to cardiac decompensation and terminal heart failure. Delineating the regulatory signaling pathways that orchestrate cell survival in the heart has significant therapeutic implications. Cardiac tissue has limited capacity to regenerate and repair. Stem cell therapy is a successful approach for repairing and regenerating ischemic cardiac tissue; however, transplanted cells display very high death percentage, a problem that affects success of tissue regeneration. Stem cells display multipotency or pluripotency and undergo self-renewal, however these events are negatively influenced by upregulation of cell death machinery that induces the significant decrease in survival and differentiation signals upon cardiovascular injury. While efforts to identify cell types and molecular pathways that promote cardiac tissue regeneration have been productive, studies that focus on blocking the extensive cell death after transplantation are limited. The control of cell death includes multiple networks rather than one crucial pathway, which underlies the challenge of identifying the interaction between various cellular and biochemical components. This review is aimed at exploiting the molecular mechanisms by which stem cells resist death signals to develop into mature and healthy cardiac cells. Specifically, we focus on a number of factors that control death and survival of stem cells upon transplantation and ultimately affect cardiac regeneration. We also discuss potential survival enhancing strategies and how they could be meaningful in the design of targeted therapies that improve cardiac function.

  19. The Apoptosome: Heart and Soul of the Cell Death Machine

    Directory of Open Access Journals (Sweden)

    Arul M. Chinnaiyan

    1999-04-01

    Full Text Available Apoptosis is a fundamental biologic process by which metazoan cells orchestrate their own self-demise. Genetic analyses of the nematode C elegans identified three core components of the suicide apparatus which include CED-3, CED-4, and CED-9. An analogous set of core constituents exists in mammalian cells and includes caspase-9, Apaf-1, and bcl-2/xL, respectively. CED-3 and CED-4, along with their mammalian counterparts, function to kill cells, whereas CED-9 and its mammalian equivalents protect cells from death. These central components biochemically intermingle in a ternary complex recently dubbed the “apoptosome.” The C elegans protein EGL-1 and its mammalian counterparts, pro-apoptotic members of the bcl-2 family, induce cell death by disrupting apoptosome interactions. Thus, EGL-1 may represent a primordial signal integrator for the apoptosome. Various biochemical processes including oligomerization, adenosine triphosphate ATP/dATP binding, and cytochrome c interaction play a role in regulating the ternary death complex. Recent studies suggest that cell death receptors, such as CD95, may amplify their suicide signal by activating the apoptosome. These mutual associations by core components of the suicide apparatus provide a molecular framework in which diverse death signals likely interface. Understanding the apoptosome and its cellular connections will facilitate the design of novel therapeutic strategies for cancer and other disease states in which apoptosis plays a pivotal role.

  20. Expression of death receptor 4 induces caspase-independent cell death in MMS-treated yeast.

    Science.gov (United States)

    Kang, Mi-Sun; Lee, Sung-Keun; Park, Chang-Shin; Kang, Ju-Hee; Bae, Sung-Ho; Yu, Sung-Lim

    2008-11-14

    DR4, a tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor, is a key element in the extrinsic pathway of TRAIL/TRAIL receptor-related apoptosis that exerts a preferential toxic effect against tumor cells. However, TRAIL and DR4 are expressed in various normal cells, and recent studies indicate that DR4 has a number of non-apoptotic functions. In this study, we evaluated the effects of human DR4 expression in yeast to determine the function of DR4 in normal cells. The expression of DR4 in yeast caused G1 arrest, which resulted in transient growth inhibition. Moreover, treatment of DR4-expressing yeast with a DNA damaging agent, MMS, elicited drastic, and sustained cell growth inhibition accompanied with massive apoptotic cell death. Further analysis revealed that cell death in the presence of DNA damage and DR4 expression was not dependent on the yeast caspase, YCA1. Taken together, these results indicate that DR4 triggers caspase-independent programmed cell death during the response of normal cells to DNA damage.

  1. Centchroman induces redox-dependent apoptosis and cell-cycle arrest in human endometrial cancer cells.

    Science.gov (United States)

    Shyam, Hari; Singh, Neetu; Kaushik, Shweta; Sharma, Ramesh; Balapure, Anil K

    2017-04-01

    Centchroman (CC) or Ormeloxifene has been shown to induce apoptosis and cell cycle arrest in various types of cancer cells. This has, however, not been addressed for endometrial cancer cells where its (CC) mechanism of action remains unclear. This study focuses on the basis of antineoplasticity of CC by blocking the targets involved in the cell cycle, survival and apoptosis in endometrial cancer cells. Ishikawa Human Endometrial Cancer Cells were cultured under estrogen deprived medium, exposed to CC and analyzed for proliferation and apoptosis. Additionally, we also analyzed oxidative stress induced by CC. Cell viability studies confirmed the IC 50 of CC in Ishikawa cells to be 20 µM after 48 h treatment. CC arrests the cells in G0/G1 phase through cyclin D1 and cyclin E mediated pathways. Phosphatidylserine externalization, nuclear morphology changes, DNA fragmentation, PARP cleavage, and alteration of Bcl-2 family protein expression clearly suggest ongoing apoptosis in the CC treated cells. Activation of caspase 3 & 9, up-regulation of AIF and inhibition of apoptosis by z-VAD-fmk clearly explains the participation of the intrinsic pathway of programmed cell death. Further, the increase of ROS, loss of MMP, inhibition of antioxidant (MnSOD, Cu/Zn-SOD and GST) and inhibition of apoptosis with L-NAC suggests CC induced oxidative stress leading to apoptosis via mitochondria mediated pathway. Therefore, CC could be a potential therapeutic agent for the treatment of Endometrial Cancer adjunct to its utility as a contraceptive and an anti-breast cancer agent.

  2. Protein Kinase G facilitates EGFR-mediated cell death in MDA-MB-468 cells

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Nicole M.; Ceresa, Brian P., E-mail: brian.ceresa@louisville.edu

    2016-08-15

    The Epidermal Growth Factor Receptor (EGFR) is a transmembrane receptor tyrosine kinase with critical implications in cell proliferation, migration, wound healing and the regulation of apoptosis. However, the EGFR has been shown to be hyper-expressed in a number of human malignancies. The MDA-MB-468 metastatic breast cell line is one example of this. This particular cell line hyper-expresses the EGFR and undergoes EGFR-mediated apoptosis in response to EGF ligand. The goal of this study was to identify the kinases that could be potential intermediates for the EGFR-mediated induction of apoptosis intracellularly. After identifying Cyclic GMP-dependent Protein Kinase G (PKG) as a plausible intermediate, we wanted to determine the temporal relationship of these two proteins in the induction of apoptosis. We observed a dose-dependent decrease in MDA-MB-468 cell viability, which was co-incident with increased PKG activity as measured by VASPSer239 phosphorylation. In addition, we observed a dose dependent decrease in cell viability, as well as an increase in apoptosis, in response to two different PKG agonists, 8-Bromo-cGMP and 8-pCPT-cGMP. MDA-MB-468 cells with reduced PKG activity had attenuated EGFR-mediated apoptosis. These findings indicate that PKG does not induce cell death via transphosphorylation of the EGFR. Instead, PKG activity occurs following EGFR activation. Together, these data indicate PKG as an intermediary in EGFR-mediated cell death, likely via apoptotic pathway.

  3. Protein Kinase G facilitates EGFR-mediated cell death in MDA-MB-468 cells

    International Nuclear Information System (INIS)

    Jackson, Nicole M.; Ceresa, Brian P.

    2016-01-01

    The Epidermal Growth Factor Receptor (EGFR) is a transmembrane receptor tyrosine kinase with critical implications in cell proliferation, migration, wound healing and the regulation of apoptosis. However, the EGFR has been shown to be hyper-expressed in a number of human malignancies. The MDA-MB-468 metastatic breast cell line is one example of this. This particular cell line hyper-expresses the EGFR and undergoes EGFR-mediated apoptosis in response to EGF ligand. The goal of this study was to identify the kinases that could be potential intermediates for the EGFR-mediated induction of apoptosis intracellularly. After identifying Cyclic GMP-dependent Protein Kinase G (PKG) as a plausible intermediate, we wanted to determine the temporal relationship of these two proteins in the induction of apoptosis. We observed a dose-dependent decrease in MDA-MB-468 cell viability, which was co-incident with increased PKG activity as measured by VASPSer239 phosphorylation. In addition, we observed a dose dependent decrease in cell viability, as well as an increase in apoptosis, in response to two different PKG agonists, 8-Bromo-cGMP and 8-pCPT-cGMP. MDA-MB-468 cells with reduced PKG activity had attenuated EGFR-mediated apoptosis. These findings indicate that PKG does not induce cell death via transphosphorylation of the EGFR. Instead, PKG activity occurs following EGFR activation. Together, these data indicate PKG as an intermediary in EGFR-mediated cell death, likely via apoptotic pathway.

  4. Apoptotic cells can induce non-autonomous apoptosis through the TNF pathway

    Science.gov (United States)

    Pérez-Garijo, Ainhoa; Fuchs, Yaron; Steller, Hermann

    2013-01-01

    Apoptotic cells can produce signals to instruct cells in their local environment, including ones that stimulate engulfment and proliferation. We identified a novel mode of communication by which apoptotic cells induce additional apoptosis in the same tissue. Strong induction of apoptosis in one compartment of the Drosophila wing disc causes apoptosis of cells in the other compartment, indicating that dying cells can release long-range death factors. We identified Eiger, the Drosophila tumor necrosis factor (TNF) homolog, as the signal responsible for apoptosis-induced apoptosis (AiA). Eiger is produced in apoptotic cells and, through activation of the c-Jun N-terminal kinase (JNK) pathway, is able to propagate the initial apoptotic stimulus. We also show that during coordinated cell death of hair follicle cells in mice, TNF-α is expressed in apoptotic cells and is required for normal cell death. AiA provides a mechanism to explain cohort behavior of dying cells that is seen both in normal development and under pathological conditions. DOI: http://dx.doi.org/10.7554/eLife.01004.001 PMID:24066226

  5. Bifurcate effects of glucose on caspase-independent cell death during hypoxia

    International Nuclear Information System (INIS)

    Aki, Toshihiko; Nara, Akina; Funakoshi, Takeshi; Uemura, Koichi

    2010-01-01

    We investigated the effect of glucose on hypoxic death of rat cardiomyocyte-derived H9c2 cells and found that there is an optimal glucose concentration for protection against hypoxic cell death. Hypoxic cell death in the absence of glucose is accompanied by rapid ATP depletion, release of apoptosis-inducing factor from mitochondria, and nuclear chromatin condensation, all of which are inhibited by glucose in a dose-dependent manner. In contrast, excessive glucose also induces hypoxic cell death that is not accompanied by these events, suggesting a change in the mode of cell death between hypoxic cells with and without glucose supplementation.

  6. The role of heat shock protein 90 in the regulation of tumor cell apoptosis.

    Science.gov (United States)

    Kaigorodova, E V; Ryazantseva, N V; Novitskii, V V; Belkina, M V; Maroshkina, A N

    2011-02-01

    Programmed death of Jurkat tumor cells was studied under conditions of culturing with 17-AAG selective inhibitor of heat shock protein with a molecular weight of 90 kDa and etoposide. Apoptosis realization was evaluated by fluorescent microscopy with FITC-labeled annexin V and propidium iodide. Activity of caspase-3 was evaluated spectrophotometrically. Inhibition of heat shock protein with a molecular weight of 90 kDa activated the apoptotic program in Jurkat tumor cells and etoposide-induced apoptosis. The heat shock protein with a molecular weight of 90 kDa acted as apoptosis inhibitor in tumor cells.

  7. Radiation-induced cell death in embryogenic cells of coniferous plants

    International Nuclear Information System (INIS)

    Watanabe, Yoshito; Homma-Takeda, Shino; Yukawa, Masae; Nishimura, Yoshikazu; Sasamoto, Hamako; Takahagi, Masahiko

    2004-01-01

    Reproductive processes are particularly radiosensitive in plant development, which was clearly illustrated in reduction of seed formation in native coniferous plants around Chernobyl after the nuclear accident. For the purpose to investigate the effects of ionizing radiation on embryonic formation in coniferous plants, we used an embryo-derived embryogenic cell culture of a Japanese native coniferous plant, Japanese cedar (Cryplomeria japonica). The embryogenic cells were so radiosensitive that most of the cells died by X-ray irradiation of 5 Gy. This indicated that the embryogenic cells are as radiosensitive as some mammalian cells including lymphocytes. We considered that this type of radiosensitive cell death in the embryogenic cells should be responsible for reproductive damages of coniferous plants by low dose of ionizing radiation. The cell death of the embryogenic cells was characteristic of nuclear DNA fragmentation, which is typically observed in radiation-induced programmed cell death, i.e. apoptosis, in mammalian cells. On the other hand, cell death with nuclear DNA fragmentation did not develop by X-ray irradiation in vegetative cells including meristematic cells of Japanese cedar. This suggests that an apoptosis-like programmed cell death should develop cell-specifically in embryogenic cells by ionizing radiation. The abortion of embryogenic cells may work to prevent transmission of radiation-induced genetic damages to the descendants. (author)

  8. Surfactant protein D delays Fas- and TRAIL-mediated extrinsic pathway of apoptosis in T cells.

    Science.gov (United States)

    Djiadeu, Pascal; Kotra, Lakshmi P; Sweezey, Neil; Palaniyar, Nades

    2017-05-01

    Only a few extracellular soluble proteins are known to modulate apoptosis. We considered that surfactant-associated protein D (SP-D), an innate immune collectin present on many mucosal surfaces, could regulate apoptosis. Although SP-D is known to be important for immune cell homeostasis, whether SP-D affects apoptosis is unknown. In this study we aimed to determine the effects of SP-D on Jurkat T cells and human T cells dying by apoptosis. Here we show that SP-D binds to Jurkat T cells and delays the progression of Fas (CD95)-Fas ligand and TRAIL-TRAIL receptor induced, but not TNF-TNF receptor-mediated apoptosis. SP-D exerts its effects by reducing the activation of initiator caspase-8 and executioner caspase-3. SP-D also delays the surface exposure of phosphatidylserine. The effect of SP-D was ablated by the presence of caspase-8 inhibitor, but not by intrinsic pathway inhibitors. The binding ability of SP-D to dying cells decreases during the early stages of apoptosis, suggesting the release of apoptotic cell surface targets during apoptosis. SP-D also delays FasL-induced death of primary human T cells. SP-D delaying the progression of the extrinsic pathway of apoptosis could have important implications in regulating immune cell homeostasis at mucosal surfaces.

  9. Ultraviolet B irradiation of human leukaemia HL-60 cells in vitro induces apoptosis

    International Nuclear Information System (INIS)

    Martin, S.J.; Cotter, T.G.

    1991-01-01

    UV radiation is known to be a potent agent for the induction of programmed cell death (apoptosis) in human skin. However, the mechanistic aspects of UV-induced apoptosis remain ill-defined. In this study the effects of varying periods of UV-irradiation on the human leukaemia HL-60 cell line and on five other human cell lines were investigated.HL-60 cells were found to rapidly undergo apoptosis en masse after short periods of UV-irradiation whereas prolonged exposure of these cells to this form of radiation induced a more rapid form of cell death which was suggestive of necrosis, the pathological mode of cell death. UV-induced apoptosis in cell lines was characterized by morphological changes as well as DNA fragmentation into unit multiples of ∼ 200 bp, which was indicative of endogenous endonuclease activation. This DNA fragmentation pattern was not detected in cells immediately after UV-irradiation, and was therefore not the result of direct UV-induced DNA damage. UV-induced apoptosis of the HL-60 cell line was found to require extracellular calcium and to be inhibited in a dose-dependent way by zinc added to the culture medium. (author)

  10. Modulating cell-to-cell variability and sensitivity to death ligands by co-drugging

    International Nuclear Information System (INIS)

    Flusberg, Deborah A; Sorger, Peter K

    2013-01-01

    TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) holds promise as an anti-cancer therapeutic but efficiently induces apoptosis in only a subset of tumor cell lines. Moreover, even in clonal populations of responsive lines, only a fraction of cells dies in response to TRAIL and individual cells exhibit cell-to-cell variability in the timing of cell death. Fractional killing in these cell populations appears to arise not from genetic differences among cells but rather from differences in gene expression states, fluctuations in protein levels and the extent to which TRAIL-induced death or survival pathways become activated. In this study, we ask how cell-to-cell variability manifests in cell types with different sensitivities to TRAIL, as well as how it changes when cells are exposed to combinations of drugs. We show that individual cells that survive treatment with TRAIL can regenerate the sensitivity and death-time distribution of the parental population, demonstrating that fractional killing is a stable property of cell populations. We also show that cell-to-cell variability in the timing and probability of apoptosis in response to treatment can be tuned using combinations of drugs that together increase apoptotic sensitivity compared to treatment with one drug alone. In the case of TRAIL, modulation of cell-to-cell variability by co-drugging appears to involve a reduction in the threshold for mitochondrial outer membrane permeabilization. (paper)

  11. Bystander apoptosis in human cells mediated by irradiated blood plasma

    Energy Technology Data Exchange (ETDEWEB)

    Vinnikov, Volodymyr, E-mail: vlad.vinnikov@mail.ru [Grigoriev Institute for Medical Radiology of the National Academy of Medical Science of Ukraine (Ukraine); Lloyd, David; Finnon, Paul [Centre for Radiation, Chemical and Environmental Hazards of the Health Protection Agency of the United Kingdom (United Kingdom)

    2012-03-01

    Following exposure to high doses of ionizing radiation, due to an accident or during radiotherapy, bystander signalling poses a potential hazard to unirradiated cells and tissues. This process can be mediated by factors circulating in blood plasma. Thus, we assessed the ability of plasma taken from in vitro irradiated human blood to produce a direct cytotoxic effect, by inducing apoptosis in primary human peripheral blood mononuclear cells (PBM), which mainly comprised G{sub 0}-stage lymphocytes. Plasma was collected from healthy donors' blood irradiated in vitro to 0-40 Gy acute {gamma}-rays. Reporter PBM were separated from unirradiated blood with Histopaque and held in medium with the test plasma for 24 h at 37 Degree-Sign C. Additionally, plasma from in vitro irradiated and unirradiated blood was tested against PBM collected from blood given 4 Gy. Apoptosis in reporter PBM was measured by the Annexin V test using flow cytometry. Plasma collected from unirradiated and irradiated blood did not produce any apoptotic response above the control level in unirradiated reporter PBM. Surprisingly, plasma from irradiated blood caused a dose-dependent reduction of apoptosis in irradiated reporter PBM. The yields of radiation-induced cell death in irradiated reporter PBM (after subtracting the respective values in unirradiated reporter PBM) were 22.2 {+-} 1.8% in plasma-free cultures, 21.6 {+-} 1.1% in cultures treated with plasma from unirradiated blood, 20.2 {+-} 1.4% in cultures with plasma from blood given 2-4 Gy and 16.7 {+-} 3.2% in cultures with plasma from blood given 6-10 Gy. These results suggested that irradiated blood plasma did not cause a radiation-induced bystander cell-killing effect. Instead, a reduction of apoptosis in irradiated reporter cells cultured with irradiated blood plasma has implications concerning oncogenic risk from mutated cells surviving after high dose in vivo irradiation (e.g. radiotherapy) and requires further study.

  12. Bystander apoptosis in human cells mediated by irradiated blood plasma

    International Nuclear Information System (INIS)

    Vinnikov, Volodymyr; Lloyd, David; Finnon, Paul

    2012-01-01

    Following exposure to high doses of ionizing radiation, due to an accident or during radiotherapy, bystander signalling poses a potential hazard to unirradiated cells and tissues. This process can be mediated by factors circulating in blood plasma. Thus, we assessed the ability of plasma taken from in vitro irradiated human blood to produce a direct cytotoxic effect, by inducing apoptosis in primary human peripheral blood mononuclear cells (PBM), which mainly comprised G 0 -stage lymphocytes. Plasma was collected from healthy donors’ blood irradiated in vitro to 0–40 Gy acute γ-rays. Reporter PBM were separated from unirradiated blood with Histopaque and held in medium with the test plasma for 24 h at 37 °C. Additionally, plasma from in vitro irradiated and unirradiated blood was tested against PBM collected from blood given 4 Gy. Apoptosis in reporter PBM was measured by the Annexin V test using flow cytometry. Plasma collected from unirradiated and irradiated blood did not produce any apoptotic response above the control level in unirradiated reporter PBM. Surprisingly, plasma from irradiated blood caused a dose-dependent reduction of apoptosis in irradiated reporter PBM. The yields of radiation-induced cell death in irradiated reporter PBM (after subtracting the respective values in unirradiated reporter PBM) were 22.2 ± 1.8% in plasma-free cultures, 21.6 ± 1.1% in cultures treated with plasma from unirradiated blood, 20.2 ± 1.4% in cultures with plasma from blood given 2–4 Gy and 16.7 ± 3.2% in cultures with plasma from blood given 6–10 Gy. These results suggested that irradiated blood plasma did not cause a radiation-induced bystander cell-killing effect. Instead, a reduction of apoptosis in irradiated reporter cells cultured with irradiated blood plasma has implications concerning oncogenic risk from mutated cells surviving after high dose in vivo irradiation (e.g. radiotherapy) and requires further study.

  13. Cell arrest and cell death in mammalian preimplantation development: lessons from the bovine model.

    Science.gov (United States)

    Leidenfrost, Sandra; Boelhauve, Marc; Reichenbach, Myriam; Güngör, Tuna; Reichenbach, Horst-Dieter; Sinowatz, Fred; Wolf, Eckhard; Habermann, Felix A

    2011-01-01

    The causes, modes, biological role and prospective significance of cell death in preimplantation development in humans and other mammals are still poorly understood. Early bovine embryos represent a very attractive experimental model for the investigation of this fundamental and important issue. To obtain reference data on the temporal and spatial occurrence of cell death in early bovine embryogenesis, three-dimensionally preserved embryos of different ages and stages of development up to hatched blastocysts were examined in toto by confocal laser scanning microscopy. In parallel, transcript abundance profiles for selected apoptosis-related genes were analyzed by real-time reverse transcriptase-polymerase chain reaction. Our study documents that in vitro as well as in vivo, the first four cleavage cycles are prone to a high failure rate including different types of permanent cell cycle arrest and subsequent non-apoptotic blastomere death. In vitro produced and in vivo derived blastocysts showed a significant incidence of cell death in the inner cell mass (ICM), but only in part with morphological features of apoptosis. Importantly, transcripts for CASP3, CASP9, CASP8 and FAS/FASLG were not detectable or found at very low abundances. In vitro and in vivo, errors and failures of the first and the next three cleavage divisions frequently cause immediate embryo death or lead to aberrant subsequent development, and are the main source of developmental heterogeneity. A substantial occurrence of cell death in the ICM even in fast developing blastocysts strongly suggests a regular developmentally controlled elimination of cells, while the nature and mechanisms of ICM cell death are unclear. Morphological findings as well as transcript levels measured for important apoptosis-related genes are in conflict with the view that classical caspase-mediated apoptosis is the major cause of cell death in early bovine development.

  14. Cell arrest and cell death in mammalian preimplantation development: lessons from the bovine model.

    Directory of Open Access Journals (Sweden)

    Sandra Leidenfrost

    Full Text Available BACKGROUND: The causes, modes, biological role and prospective significance of cell death in preimplantation development in humans and other mammals are still poorly understood. Early bovine embryos represent a very attractive experimental model for the investigation of this fundamental and important issue. METHODS AND FINDINGS: To obtain reference data on the temporal and spatial occurrence of cell death in early bovine embryogenesis, three-dimensionally preserved embryos of different ages and stages of development up to hatched blastocysts were examined in toto by confocal laser scanning microscopy. In parallel, transcript abundance profiles for selected apoptosis-related genes were analyzed by real-time reverse transcriptase-polymerase chain reaction. Our study documents that in vitro as well as in vivo, the first four cleavage cycles are prone to a high failure rate including different types of permanent cell cycle arrest and subsequent non-apoptotic blastomere death. In vitro produced and in vivo derived blastocysts showed a significant incidence of cell death in the inner cell mass (ICM, but only in part with morphological features of apoptosis. Importantly, transcripts for CASP3, CASP9, CASP8 and FAS/FASLG were not detectable or found at very low abundances. CONCLUSIONS: In vitro and in vivo, errors and failures of the first and the next three cleavage divisions frequently cause immediate embryo death or lead to aberrant subsequent development, and are the main source of developmental heterogeneity. A substantial occurrence of cell death in the ICM even in fast developing blastocysts strongly suggests a regular developmentally controlled elimination of cells, while the nature and mechanisms of ICM cell death are unclear. Morphological findings as well as transcript levels measured for important apoptosis-related genes are in conflict with the view that classical caspase-mediated apoptosis is the major cause of cell death in early bovine

  15. Cell apoptosis, autophagy and necroptosis in osteosarcoma treatment

    Science.gov (United States)

    Li, Dongqi; Li, Huiling; Ren, Mingyan; Liao, Yedan; Yu, Shunling; Chen, Yanjin; Yang, Yihao; Zhang, Ya

    2016-01-01

    Osteosarcoma is the most common primary bone tumor in children and adolescents. Although combined therapy including surgery and multi-agent chemotherapy have resulted in great improvements in the overall survival of patients, chemoresistance remains an obstacle for the treatment of osteosarcoma. Molecular targets or effective agents that are actively involved in cell death including apoptosis, autophagy and necroptosis have been studied. We summarized how these agents (novel compounds, miRNAs, or proteins) regulate apoptotic, autophagic and necroptotic pathways; and discussed the current knowledge on the role of these new agents in chemotherapy resistance in osteosarcoma. PMID:27007056

  16. The Drosophila sterile-20 kinase slik controls cell proliferation and apoptosis during imaginal disc development.

    Directory of Open Access Journals (Sweden)

    David R Hipfner

    2003-11-01

    Full Text Available Cell proliferation and programmed cell death are closely controlled during animal development. Proliferative stimuli generally also induce apoptosis, and anti-apoptotic factors are required to allow net cell proliferation. Genetic studies in Drosophila have led to identification of a number of genes that control both processes, providing new insights into the mechanisms that coordinate cell growth, proliferation, and death during development and that fail to do so in diseases of cell proliferation. We present evidence that the Drosophila Sterile-20 kinase Slik promotes cell proliferation and controls cell survival. At normal levels, Slik provides survival cues that prevent apoptosis. Cells deprived of Slik activity can grow, divide, and differentiate, but have an intrinsic survival defect and undergo apoptosis even under conditions in which they are not competing with normal cells for survival cues. Like some oncogenes, excess Slik activity stimulates cell proliferation, but this is compensated for by increased cell death. Tumor-like tissue overgrowth results when apoptosis is prevented. We present evidence that Slik acts via Raf, but not via the canonical ERK pathway. Activation of Raf can compensate for the lack of Slik and support cell survival, but activation of ERK cannot. We suggest that Slik mediates growth and survival cues to promote cell proliferation and control cell survival during Drosophila development.

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

    Science.gov (United States)

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

    2014-07-01

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

  18. Aloin induces apoptosis in Jurkat cells.

    Science.gov (United States)

    Buenz, Eric J

    2008-03-01

    Aloe is widely used as a dietary supplement. However, there are continuing concerns over the toxicity and the purity of aloe-based products. The primary class of compounds responsible for aloe-induced toxicity are anthraquinones. One of these, aloe-emodin, has been extensively investigated for apoptosis inducing effects. Conversely, the precursor to aloe-emodin, aloin, has been subjected to only minimal investigation of any cytotoxic effects. Jurkat T cells, an established model for the study of compound toxicity, were used to evaluate the effect of aloin on cell viability. Cells were analyzed using flow cytometry and microscopy for cell size and granularity, cell membrane integrity, mitochondrial membrane potential, and cell cycle profile. Treatment with aloin resulted in a reduction in cell size, compromised membrane integrity, and loss of mitochondrial membrane potential in a dose-dependent manner. Additionally, treatment with aloin resulted in alteration of the cell cycle, specifically a block at G2/M phase. Importantly, the loss of cell membrane integrity was preceded by a loss of mitochondrial membrane potential, suggesting a mitochondrial-dependent pathway for aloin-induced apoptosis. These observations provide insight into the potential mechanisms of aloin-induced toxicity and thus, perhaps, aloe preparation-induced toxicity. Furthermore, because of the concern over the safety of aloe-based supplements, this work suggests that aloe supplements not containing aloin may be safer than aloe supplements containing aloin, and that aloin should be considered in addition to concentrations of aloe-emodin.

  19. Apoptosis in thymocytes and lymphoma cells induced by neutrons and X-rays

    International Nuclear Information System (INIS)

    Ohyama, Harumi; Koike, Sachiko; Ando, Kouichi

    1993-01-01

    Apoptosis is a distinctive mode of programmed cell death with characteristic morphological and biochemical features. The cells undergoing apoptosis display shrinkage, chromatin condensation and internucleosomal breakage of DNA. The cell death is a process through which organisms get rid of unwanted cells. Thymocytes are highly radiosensitive, and undergo typical apoptosis within a few hours after the exposure to X-ray. Also extremely radiosensitive thymic lymphoma cells have been found. The effect of 30 MeV NIRS fast neutrons on the induction of apoptosis in thymocytes and thymoma cells was examined in comparison with that of X-ray. Although apoptotic cells increased gradually with time, the apoptotic process proceeded rapidly in individual cells after the onset. By the measurement of cell size distribution, the appearance of a distinct apoptotic cell peak was observed. In the case of neutron irradiation on SCA1 thymic lymphoma cells, the method for counting apoptotic cells based on chromatin condensation was developed. The cell volume reduction of thymocytes, the dose survival curves and the induction of apoptosis in SCA1 are reported. (K.I.)

  20. HERG K+ channel-dependent apoptosis and cell cycle arrest in human glioblastoma cells.

    Directory of Open Access Journals (Sweden)

    Ingo Staudacher

    Full Text Available Glioblastoma (GB is associated with poor patient survival owing to uncontrolled tumor proliferation and resistance to apoptosis. Human ether-a-go-go-related gene K(+ channels (hERG; Kv11.1, KCNH2 are expressed in multiple cancer cells including GB and control cell proliferation and death. We hypothesized that pharmacological targeting of hERG protein would inhibit tumor growth by inducing apoptosis of GB cells. The small molecule hERG ligand doxazosin induced concentration-dependent apoptosis of human LNT-229 (EC50 = 35 µM and U87MG (EC50 = 29 µM GB cells, accompanied by cell cycle arrest in the G0/G1 phase. Apoptosis was associated with 64% reduction of hERG protein. HERG suppression via siRNA-mediated knock down mimicked pro-apoptotic effects of doxazosin. Antagonism of doxazosin binding by the non-apoptotic hERG ligand terazosin resulted in rescue of protein expression and in increased survival of GB cells. At the molecular level doxazosin-dependent apoptosis was characterized by activation of pro-apoptotic factors (phospho-erythropoietin-producing human hepatocellular carcinoma receptor tyrosine kinase A2, phospho-p38 mitogen-activated protein kinase, growth arrest and DNA damage inducible gene 153, cleaved caspases 9, 7, and 3, and by inactivation of anti-apoptotic poly-ADP-ribose-polymerase, respectively. In summary, this work identifies doxazosin as small molecule compound that promotes apoptosis and exerts anti-proliferative effects in human GB cells. Suppression of hERG protein is a crucial molecular event in GB cell apoptosis. Doxazosin and future derivatives are proposed as novel options for more effective GB treatment.

  1. Polycation-mediated integrated cell death processes

    DEFF Research Database (Denmark)

    Parhamifar, Ladan; Andersen, Helene; Wu, Linping

    2014-01-01

    standard. PEIs are highly efficient transfectants, but depending on their architecture and size they induce cytotoxicity through different modes of cell death pathways. Here, we briefly review dynamic and integrated cell death processes and pathways, and discuss considerations in cell death assay design...

  2. Cell death induced by Bothrops asper snake venom metalloproteinase on endothelial and other cell lines.

    Science.gov (United States)

    Brenes, Oscar; Muñóz, Eduardo; Roldán-Rodríguez, Raquel; Díaz, Cecilia

    2010-06-01

    Two adherent cell lines, BAEC and HeLa, and non-adherent Jurkat, were treated with snake venom metalloproteinase BaP1 to determine whether cytotoxicity, previously reported for this toxin, could be mediated by the process of anoikis. It was observed that there was no correlation between the ability of this toxin to induce loss of adherence, and the cytotoxic effect, since concentrations that do not induce loss of adherence (3-6 microg/mL), were able to trigger 50% of cytotoxicity in BAEC. In the case of HeLa, where toxicity was very low (less than 20% at maximun concentrations and times of exposure), significant detachment and no toxicity was observed at concentrations of 1.5 microg/mL, showing also no correlation between both events. We also observed differences between BAEC toxicity measured by XTT reduction and DNA fragmentation determined by flow cytometry (as an indicator of apoptosis), since concentrations that induce 100% of cytotoxicity barely showed any DNA fragmentation (12% at 24h), suggesting that if apoptosis was involved, DNA damage is still not present, although chromatin condensation, another indicator of apoptosis, is observed in 40% of the cells. Inhibition of BAEC cytotoxicity by caspase inhibitors indicate that apoptosis is playing a role in this process, but other mechanisms of cell death could be participating also. Another way to determine whether the mechanism of cell death was related to anoikis was using a non-adherent cell line, which should show substrate independence. We determined by TUNEL that at 50 microg/ml BaP1 triggered 50% of apoptosis at 96 h, an effect that was seen earlier, suggesting also that if this toxin was inducing apoptosis in a non-adherent cell line, the mechanism could not be related to loss of attachment. Cell cycle arrest in S phase was also observed in Jurkat cells, an effect that could be leading to apoptosis. In conclusion, since there was no correlation between cell detachment and cytotoxicity (and apoptosis

  3. Subamolide A Induces Mitotic Catastrophe Accompanied by Apoptosis in Human Lung Cancer Cells

    OpenAIRE

    Hung, Jen-Yu; Wen, Ching-Wen; Hsu, Ya-Ling; Lin, En-Shyh; Huang, Ming-Shyan; Chen, Chung-Yi; Kuo, Po-Lin

    2013-01-01

    This study investigated the anticancer effects of subamolide A (Sub-A), isolated from Cinnamomum subavenium, on human nonsmall cell lung cancer cell lines A549 and NCI-H460. Treatment of cancer cells with Sub-A resulted in decreased cell viability of both lung cancer cell lines. Sub-A induced lung cancer cell death by triggering mitotic catastrophe with apoptosis. It triggered oxidant stress, indicated by increased cellular reactive oxygen species (ROS) production and decreased glutathione le...

  4. Pannexin1 as mediator of inflammation and cell death.

    Science.gov (United States)

    Crespo Yanguas, Sara; Willebrords, Joost; Johnstone, Scott R; Maes, Michaël; Decrock, Elke; De Bock, Marijke; Leybaert, Luc; Cogliati, Bruno; Vinken, Mathieu

    2017-01-01

    Pannexins form channels at the plasma membrane surface that establish a pathway for communication between the cytosol of individual cells and their extracellular environment. By doing so, pannexin signaling dictates several physiological functions, but equally underlies a number of pathological processes. Indeed, pannexin channels drive inflammation by assisting in the activation of inflammasomes, the release of pro-inflammatory cytokines, and the activation and migration of leukocytes. Furthermore, these cellular pores facilitate cell death, including apoptosis, pyroptosis and autophagy. The present paper reviews the roles of pannexin channels in inflammation and cell death. In a first part, a state-of-the-art overview of pannexin channel structure, regulation and function is provided. In a second part, the mechanisms behind their involvement in inflammation and cell death are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Newly synthesized bis-benzimidazole compound 8 induces apoptosis, autophagy and reactive oxygen species generation in HeLa cells.

    Science.gov (United States)

    Chu, Naying; Yao, Guodong; Liu, Yuan; Cheng, Maosheng; Ikejima, Takashi

    2016-09-01

    Compound 8 (C8) is a newly synthesized bis-benzimidazole derivative and exerts significant anti-tumor activity in vitro. Previous studies demonstrated that C8 induced apoptosis and autophagy in human promyelocytic leukemia HL60 cells. However, cytotoxicity study on human peripheral blood mononuclear cells (hPBMC) showed that C8 exhibited less toxicity in normal cells. In this study, the molecular mechanism of C8 on human cervical carcinoma HeLa cells was investigated. The results showed that C8 inhibited the growth of HeLa cells and triggered both apoptotic and autophagic cell death. Subsequent experiment also indicated that reactive oxygen species (ROS) generation was induced in C8-treated HeLa cells. Since ROS scavenger decreased the ratio of apoptotic and autophagic cells, ROS generation contributed to C8-induced apoptosis and autophagy. Furthermore, inhibitors of apoptosis and autophagy also reduced ROS generation, respectively. Autophagy inhibition increased cell growth compared to C8-treated group and attenuated apoptotic cell death, indicating that C8-induced autophagy promoted apoptosis for cell death. However, the percentage of autophagic cells was enhanced when limiting apoptosis process. Taken together, C8 induced ROS-mediated apoptosis and autophagy in HeLa cells, autophagy promoted apoptosis but the former was antagonized by the latter. The data also gave us a new perspective on the anti-tumor effect of C8. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Resveratrol inhibits vascular smooth muscle cell proliferation and induces apoptosis.

    Science.gov (United States)

    Poussier, Bertrand; Cordova, Alfredo C; Becquemin, Jean-Pierre; Sumpio, Bauer E

    2005-12-01

    In France, despite a high intake of dietary cholesterol and saturated fat, the cardiovascular death rate is one of the lowest among developed countries. This "French paradox" has been postulated to be related to the high red wine intake in France. The aim of this study was to determine the effects of resveratrol, a major polyphenol component of red wine, on vascular smooth muscle cell (SMC) proliferation in vitro. SMCs were exposed to 10(-6) to 10(-4) M resveratrol and cell proliferation was assessed by cell counting. Cell cycle analysis was done by treating cells with propidium iodide followed by flow-activated cell sorting. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling staining. We demonstrate that resveratrol inhibited bovine aortic SMC proliferation in a dose-dependent manner. The lowest concentration of resveratrol resulting in a significant decrease in SMC proliferation compared with control was 10(-5) M. By flow cytometry, we observed a block in the G1-S phase of the SMC cycle. Resveratrol treatment also resulted in a dose-dependent apoptosis of SMCs but had no effects on SMC morphology. The results indicated that vascular SMC proliferation could be inhibited by resveratrol through a block on G1-S phase and by an increase in apoptosis. It supports the conjecture that red wine consumption may have a beneficial effect on cardiovascular mortality. Our results suggest that resveratrol inhibits, in a dose-dependent manner, smooth muscle cell proliferation, which may help to partially explain a beneficial effect of wine drinking. This inhibition is related to an early block in the cell cycle and also to a dose-dependent apoptotic effect. The present study demonstrates that resveratrol not only is an indirect marker of a healthy life style and alimentation but may also be directly responsible for the French paradox.

  7. Roles of K+ channels in regulating tumour cell proliferation and apoptosis.

    Science.gov (United States)

    Wang, Zhiguo

    2004-06-01

    K+ channels are a most diverse class of ion channels in the cytoplasmic membrane and are distributed widely in a variety of cells including cancer cells. Cell proliferation and apoptosis (programmed cell death or cell suicide) are two counterparts that share the responsibility for maintaining normal tissue homeostasis. Evidence has been accumulating from fundamental studies indicating that tumour cells possess various types of K+ channels, and that these K+ channels play important roles in regulating tumour cell proliferation and apoptosis, i.e. facilitating unlimited growth and promoting apoptotic death of tumour cells. The potential implications of K+ channels as a pharmacological target for cancer therapy and a biomarker for diagnosis of carcinogenesis are attracting increasing interest. This review aims to provide a comprehensive overview of current status of research on K+ channels/currents in tumour cells. Focus is placed on the roles of K+ channels/currents in regulating tumour cell proliferation and apoptosis. The possible mechanisms by which K+ channels affect tumour cell growth and death are discussed. Speculations are also made on the potential implications of regulation of tumour cell proliferation and apoptosis by K+ channels. Copyright 2004 Springer-Verlag

  8. Distinct protease pathways control cell shape and apoptosis in v-src-transformed quail neuroretina cells

    International Nuclear Information System (INIS)

    Neel, Benjamin D.; Aouacheria, Abdel; Nouvion, Anne-Laure; Ronot, Xavier; Gillet, Germain

    2005-01-01

    Intracellular proteases play key roles in cell differentiation, proliferation and apoptosis. In nerve cells, little is known about their relative contribution to the pathways which control cell physiology, including cell death. Neoplastic transformation of avian neuroretina cells by p60 v-src tyrosine kinase results in dramatic morphological changes and deregulation of apoptosis. To identify the proteases involved in the cellular response to p60 v-src , we evaluated the effect of specific inhibitors of caspases, calpains and the proteasome on cell shape changes and apoptosis induced by p60 v-src inactivation in quail neuroretina cells transformed by tsNY68, a thermosensitive strain of Rous sarcoma virus. We found that the ubiquitin-proteasome pathway is recruited early after p60 v-src inactivation and is critical for morphological changes, whereas caspases are essential for cell death. This study provides evidence that distinct intracellular proteases are involved in the control of the morphology and fate of v-src-transformed cells

  9. Magneto-actuated cell apoptosis by biaxial pulsed magnetic field.

    Science.gov (United States)

    Wong, De Wei; Gan, Wei Liang; Liu, Ning; Lew, Wen Siang

    2017-09-07

    We report on a highly efficient magneto-actuated cancer cell apoptosis method using a biaxial pulsed magnetic field configuration, which maximizes the induced magnetic torque. The light transmissivity dynamics show that the biaxial magnetic field configuration can actuate the magnetic nanoparticles with higher responsiveness over a wide range of frequencies as compared to uniaxial field configurations. Its efficacy was demonstrated in in vitro cell destruction experiments with a greater reduction in cell viability. Magnetic nanoparticles with high aspect ratios were also found to form a triple vortex magnetization at remanence which increases its low field susceptibility. This translates to a larger magneto-mechanical actuated force at low fields and 12% higher efficacy in cell death as compared to low aspect ratio nanoparticles.

  10. Patterns of cell death in the embryonic antenna of the grasshopper Schistocerca gregaria.

    Science.gov (United States)

    Boyan, George; Graf, Philip; Ehrhardt, Erica

    2018-03-06

    We have investigated the pattern of apoptosis in the antennal epithelium during embryonic development of the grasshopper Schistocerca gregaria. The molecular labels lachesin and annulin reveal that the antennal epithelium becomes subdivided into segment-like meristal annuli within which sensory cell clusters later differentiate. To determine whether apoptosis is involved in the development of such sensory cell clusters, we examined the expression pattern of the cell death labels acridine orange and TUNEL in the epithelium. We found stereotypic, age-dependent, wave-like patterns of cell death in the antenna. Early in embryogenesis, apoptosis is restricted to the most basal meristal annuli but subsequently spreads to encompass almost the entire antenna. Cell death then declines in more basal annuli and is only found in the tip region later in embryogenesis. Apoptosis is restricted throughout to the midregion of a given annulus and away from its border with neighboring annuli, arguing against a causal role in annular formation. Double-labeling for cell death and sensory cell differentiation reveals apoptosis occurring within bands of differentiating sensory cell clusters, matching the meristal organization of the apical antenna. Examination of the individual epithelial lineages which generate sensory cells reveals that apoptosis begins peripherally within a lineage and with age expands to encompass the differentiated sensory cell at the base. We conclude that complete lineages can undergo apoptosis and that the youngest cells in these lineages appear to die first, with the sensory neuron dying last. Lineage-based death in combination with cell death patterns in different regions of the antenna may contribute to odor-mediated behaviors in the grasshopper.

  11. Cell death in the cardiovascular system

    Science.gov (United States)

    Clarke, Murray; Bennett, Martin; Littlewood, Trevor

    2007-01-01

    Cell death is important for both development and tissue homeostasis in the adult. As such, it is tightly controlled and deregulation is associated with diverse pathologies; for example, regulated cell death is involved in vessel remodelling during development or following injury, but deregulated death is implicated in pathologies such as atherosclerosis, aneurysm formation, ischaemic and dilated cardiomyopathies and infarction. We describe the mechanisms of cell death and its role in the normal physiology and various pathologies of the cardiovascular system. PMID:16547202

  12. MicroRNA-1 promotes apoptosis of hepatocarcinoma cells by targeting apoptosis inhibitor-5 (API-5).

    Science.gov (United States)

    Li, Dong; Liu, Yu; Li, Hua; Peng, Jing-Jing; Tan, Yan; Zou, Qiang; Song, Xiao-Feng; Du, Min; Yang, Zheng-Hui; Tan, Yong; Zhou, Jin-Jun; Xu, Tao; Fu, Zeng-Qiang; Feng, Jian-Qiong; Cheng, Peng; chen, Tao; Wei, Dong; Su, Xiao-Mei; Liu, Huan-Yi; Qi, Zhong-Chun; Tang, Li-Jun; Wang, Tao; Guo, Xin; Hu, Yong-He; Zhang, Tao

    2015-01-02

    Although microRNA-1 (miR-1) is a known liver cancer suppressor, the role of miR-1 in apoptosis of hepatoma cells has remained largely unknown. Our study shows that ectopic miR-1 overexpression induced apoptosis of liver hepatocellular carcinoma (HepG2) cells. Apoptosis inhibitor 5 (API-5) was found to be a potential regulator of miR-1 induced apoptosis, using a bioinformatics approach. Furthermore, an inverse relationship between miR-1 and API-5 expression was observed in human liver cancer tissues and adjacent normal liver tissues. Negative regulation of API-5 expression by miR-1 was demonstrated to promote apoptosis of HepG2 cells. Our study provides a novel regulatory mechanism of miR-1 in the apoptosis of hepatoma cells. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  13. Foodborne cereulide causes beta-cell dysfunction and apoptosis.

    Directory of Open Access Journals (Sweden)

    Roman Vangoitsenhoven

    Full Text Available To study the effects of cereulide, a food toxin often found at low concentrations in take-away meals, on beta-cell survival and function.Cell death was quantified by Hoechst/Propidium Iodide in mouse (MIN6 and rat (INS-1E beta-cell lines, whole mouse islets and control cell lines (HepG2 and COS-1. Beta-cell function was studied by glucose-stimulated insulin secretion (GSIS. Mechanisms of toxicity were evaluated in MIN6 cells by mRNA profiling, electron microscopy and mitochondrial function tests.24 h exposure to 5 ng/ml cereulide rendered almost all MIN6, INS-1E and pancreatic islets apoptotic, whereas cell death did not increase in the control cell lines. In MIN6 cells and murine islets, GSIS capacity was lost following 24 h exposure to 0.5 ng/ml cereulide (P<0.05. Cereulide exposure induced markers of mitochondrial stress including Puma (p53 up-regulated modulator of apoptosis, P<0.05 and general pro-apoptotic signals as Chop (CCAAT/-enhancer-binding protein homologous protein. Mitochondria appeared swollen upon transmission electron microscopy, basal respiration rate was reduced by 52% (P<0.05 and reactive oxygen species increased by more than twofold (P<0.05 following 24 h exposure to 0.25 and 0.50 ng/ml cereulide, respectively.Cereulide causes apoptotic beta-cell death at low concentrations and impairs beta-cell function at even lower concentrations, with mitochondrial dysfunction underlying these defects. Thus, exposure to cereulide even at concentrations too low to cause systemic effects appears deleterious to the beta-cell.

  14. Bile duct cell apoptosis is a rare event in primary biliary cirrhosis.

    Science.gov (United States)

    Ballardini, G; Guidi, M; Susca, M; Ghetti, S; Grassi, A; Lari, F; Fusconi, M; Zauli, D; Bianchi, F B

    2001-03-01

    The frequency of apoptosis in bile duct cells of primary biliary cirrhosis is still unclear spanning from rare to 50% in the various reports. To study bile duct cell apoptosis in stage I primary biliary cirrhosis lesions. Nine stage I-II biopsies with a total number of 26 bile ducts of different sizes, selected from a larger series on the basis of the expression on serial frozen sections of HLA-DR and Fas antigens. Apoptosis was evaluated by a DNA fragmentation assay on frozen sections, according to the manufacturer's protocol and by expression of apoptosis related cytokeratin neoepitopes. Bile duct cell proliferation was assessed by MIB1 (Ki-67) expression. Apoptosis was frequently found in inflammatory cells of portal tracts and sinusoids. Apoptosis of hepatocytes was also systematically observed. Only 4 positive bile duct cells were found in 3 bile ducts from 3 biopsies. Quantitative evaluation was not attempted. Cholangiocyte proliferation was observed in the same ducts and occasionally in other biopsies. These data suggest that cholangiocyte death by apoptosis at the level of typical primary biliary cirrhosis lesions is a rare event, at least in early stages of the disease. The observed rate of proliferation was consistent with the rate of apoptosis.

  15. Programmed Cell Death in Neurospora crassa

    Directory of Open Access Journals (Sweden)

    A. Pedro Gonçalves

    2014-01-01

    Full Text Available Programmed cell death has been studied for decades in mammalian cells, but simpler organisms, including prokaryotes, plants, and fungi, also undergo regulated forms of cell death. We highlight the usefulness of the filamentous fungus Neurospora crassa as a model organism for the study of programmed cell death. In N. crassa, cell death can be triggered genetically due to hyphal fusion between individuals with different allelic specificities at het loci, in a process called “heterokaryon incompatibility.” Chemical induction of cell death can also be achieved upon exposure to death-inducing agents like staurosporine, phytosphingosine, or hydrogen peroxide. A summary of the recent advances made by our and other groups on the discovery of the mechanisms and mediators underlying the process of cell death in N. crassa is presented.

  16. Rhopalurus junceus scorpion venom induces apoptosis in the triple negative human breast cancer cell line MDA-MB-231

    OpenAIRE

    Díaz-García, Alexis; Ruiz-Fuentes, Jenny Laura; Rodríguez-Sánchez, Hermis; Fraga Castro, José A

    2017-01-01

    Rhopalurus junceus scorpion venom has demonstrated high cytotoxic activity in epithelial cancer cells. In the present study, the effect of scorpion venom on cell viability and apoptosis was evaluated in the MDA-MB-231 human breast carcinoma cell line. Cell viability was analyzed using MTT assay. The cell death event was examined trough end-point RT-PCR to identify the expression of apoptosis-related genes, fluorescent microscopy and mitochondrial membrane potential (ΔΨm) alteration. The resul...

  17. Pinpointing differences in cisplatin-induced apoptosis in adherent and non-adherent cancer cells

    DEFF Research Database (Denmark)

    Tastesen, Hanne Sørup; Holm, Jacob Bak; Poulsen, Kristian Arild

    2010-01-01

    ascites tumour cells (ELA). Loss of KCl and cell shrinkage are hallmarks in apoptosis and has been shown in EATC. However, we find no reduction in cell volume and only a minor loss of K(+) which is accompanied by net uptake of Na(+) following 18 hours cisplatin exposure in ELA. Glutathione and taurine...... have previously been demonstrated to protect cells from apoptosis. We find, however, that increase or decrease in the cellular content of glutathione and taurine has no effect on cisplatin-induced cell death in EATC and ELA. Nevertheless, knock-down of the taurine transporter TauT leads...

  18. Multiple effects of TRAIL in human carcinoma cells: Induction of apoptosis, senescence, proliferation, and cytokine production

    International Nuclear Information System (INIS)

    Levina, Vera; Marrangoni, Adele M.; DeMarco, Richard; Gorelik, Elieser; Lokshin, Anna E.

    2008-01-01

    TRAIL is a death ligand that induces apoptosis in malignant but not normal cells. Recently the ability of TRAIL to induce proliferation in apoptosis-resistant normal and malignant cells was reported. In this study, we analyzed TRAIL effects in apoptosis sensitive MCF7, OVCAR3 and H460 human tumor cell lines. TRAIL at low concentrations preferentially induced cell proliferation. At 100 ng/ml, apoptotic death was readily observed, however surviving cells acquired higher proliferative capacity. TRAIL-stimulated production of several cytokines, IL-8, RANTES, MCP-1 and bFGF, and activation of caspases 1 and 8 was essential for this effect. Antibodies to IL-8, RANTES, and bFGF blocked TRAIL-induced cell proliferation and further stimulated apoptosis. For the first time, we report that high TRAIL concentrations induced cell senescence as determined by the altered morphology and expression of several senescence markers: SA-β-gal, p21 Waf1/Cip1 , p16 INK4a , and HMGA. Caspase 9 inhibition protected TRAIL-treated cells from senescence, whereas inhibition of caspases 1 and 8 increased the yield of SLP cells. In conclusion, in cultured human carcinoma cells, TRAIL therapy results in three functional outcomes, apoptosis, proliferation and senescence. TRAIL-induced proapoptotic and prosurvival responses correlate with the strength of signaling. TRAIL-induced cytokine production is responsible for its proliferative and prosurvival effects

  19. Casticin impairs cell growth and induces cell apoptosis via cell cycle arrest in human oral cancer SCC-4 cells.

    Science.gov (United States)

    Chou, Guan-Ling; Peng, Shu-Fen; Liao, Ching-Lung; Ho, Heng-Chien; Lu, Kung-Wen; Lien, Jin-Cherng; Fan, Ming-Jen; La, Kuang-Chi; Chung, Jing-Gung

    2018-02-01

    Casticin, a polymethoxyflavone, present in natural plants, has been shown to have biological activities including anti-cancer activities. Herein, we investigated the anti-oral cancer activity of casticin on SCC-4 cells in vitro. Viable cells, cell cycle distribution, apoptotic cell death, reactive oxygen species (ROS) production, and Ca 2+ production, levels of ΔΨ m and caspase activity were measured by flow cytometric assay. Cell apoptosis associated protein expressions were examined by Western blotting and confocal laser microscopy. Results indicated that casticin induced cell morphological changes, DNA condensation and damage, decreased the total viable cells, induced G 2 /M phase arrest in SCC-4 cells. Casticin promoted ROS and Ca 2+ productions, decreases the levels of ΔΨ m , promoted caspase-3, -8, and -9 activities in SCC-4 cells. Western blotting assay demonstrated that casticin affect protein level associated with G2/M phase arrest and apoptosis. Confocal laser microscopy also confirmed that casticin increased the translocation of AIF and cytochrome c in SCC-4 cells. In conclusion, casticin decreased cell number through G 2 /M phase arrest and the induction of cell apoptosis through caspase- and mitochondria-dependent pathways in SCC-4 cells. © 2017 Wiley Periodicals, Inc.

  20. Nuclear orphan receptor TLX affects gene expression, proliferation and cell apoptosis in beta cells.

    Science.gov (United States)

    Shi, Xiaoli; Xiong, Xiaokan; Dai, Zhe; Deng, Haohua; Sun, Li; Hu, Xuemei; Zhou, Feng; Xu, Yancheng

    Nuclear orphan receptor TLX is an essential regulator of the growth of neural stem cells. However, its exact function in pancreatic islet cells is still unknown. In the present study, gene expression profiling analysis revealed that overexpression of TLX in beta cell line MIN6 causes suppression of 176 genes and upregulation of 49 genes, including a cadre of cell cycle, cell proliferation and cell death control genes, such as Btg2, Ddit3 and Gadd45a. We next examined the effects of TLX overexpression on proliferation, apoptosis and insulin secretion in MIN6 cells. Proliferation analysis using EdU assay showed that overexpression of TLX increased percentage of EdU-positive cells. Cell cycle and apoptosis analysis revealed that overexpression of TLX in MIN6 cells resulted in higher percentage of cells exiting G1 into S-phase, and a 58.8% decrease of cell apoptosis induced by 0.5 mM palmitate. Moreover, TLX overexpression did not cause impairment of insulin secretion. Together, we conclude that TLX is among factors capable of controlling beta cell proliferation and survival, which may serve as a target for the development of novel therapies for diabetes. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Apoptosis by antitumor agents and other factors in relation to cell cycle checkpoints

    International Nuclear Information System (INIS)

    Kondo, Sohei

    1995-01-01

    More than a cancer patients died in 1993 after treatment with antineoplastic derivatives of 5-fluorouracil and the antiherpes drug Sorivudine. This paper gives a short review of previous reports showing that killing of cells by 5-fluorouracil and other antitumor agents, including radiation at high doses, results from activation of apoptosis in the G2 phase. On the other hand, apoptosis of lymphocytes by radiation at low doses and treatment with other agents is known to occur in the G1 phase. The cells dying in the G1 or G2 phase could share the same final self-killing steps. For these common steps, I assume a mitotic catastrophe model, in which commitment to self-killing results from premature activation of the mitosis machinery, and propose a concept of a 'G1/G2 death circuit' for cells dying in the G1/G2 phase by short circuit to the M phase. Based on this model, reported modes of cell death, spontaneously occurring or after treatment with various agents, are classified by the phase of dying cells. The associations of incomplete apoptosis with production of chromosomal aberrations and prevention of tumorigenesis by complete apoptosis of carcinogen-treated cells are discussed. A presumptive rule for differentiation of G1 apoptosis and G2 apoptosis is proposed. (author)

  2. Oxidative Stress and Programmed Cell Death in Yeast

    International Nuclear Information System (INIS)

    Farrugia, Gianluca; Balzan, Rena

    2012-01-01

    Yeasts, such as Saccharomyces cerevisiae, have long served as useful models for the study of oxidative stress, an event associated with cell death and severe human pathologies. This review will discuss oxidative stress in yeast, in terms of sources of reactive oxygen species (ROS), their molecular targets, and the metabolic responses elicited by cellular ROS accumulation. Responses of yeast to accumulated ROS include upregulation of antioxidants mediated by complex transcriptional changes, activation of pro-survival pathways such as mitophagy, and programmed cell death (PCD) which, apart from apoptosis, includes pathways such as autophagy and necrosis, a form of cell death long considered accidental and uncoordinated. The role of ROS in yeast aging will also be discussed.

  3. Lipid peroxidation and cell death mechanisms in pulmonary epithelial cells induced by peroxynitrite and nitric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Yuan-Soon [School of Medical Technology, Taipei Medical University, Taipei (Taiwan); Liou, Hung-Bin; Lin, Yu-Ping; Guo, How-Ran; Ho, Sheng-Yow; Lee, Ching-Chang; Wang, Ying-Jan [Department of Environmental and Occupational Health, National Cheng Kung University Medical College, 138 Sheng-Li Road, Tainan (Taiwan); Lin, Jen-Kun; Pan, Min-Hsiung [Institute of Biochemistry, National Taiwan University, Medical College, Taipei (Taiwan); Jeng, Jiiang-Huei [School of Dentistry, National Taiwan University and Hospital, Medical College, Taipei (Taiwan)

    2002-08-01

    Nitric oxide (NO) is an environmental pollutant found in smog and cigarette smoke. Recently, NO has been discovered to act as a molecular messenger, mediating various physiological functions. However, when an excess of NO is present, cytotoxic and mutagenic effects can also be induced. The reaction of NO with superoxide results in the formation of peroxynitrite (ONOO{sup -}), which decomposes into the hydroxyl radical and nitrogen dioxide. Both of them are potent oxidant species that may initiate and propagate lipid peroxidation. In the present study, we examined the effects of NO and ONOO{sup -} on the induction of lipid peroxidation and cell death mechanisms in rats and in A549 pulmonary epithelial cells. The results showed that ONOO{sup -} is able to induce lipid peroxidation in pulmonary epithelial cells in a dose-dependent manner. 8-Epi-prostaglandin F{sub 2{alpha}} can serve as a good biomarker of lipid peroxidation both in vitro and in vivo. Postmitotic apoptosis was found in A549 cells exposed to NO, whereas ONOO{sup -} induced cell death more characteristic of necrosis than apoptosis. Apoptosis that occurred in cells may be related to the dysfunction of mitochondria, the release of cytochrome c into cytosol, and the activation of caspase-9. The relationship between caspase activation and the cleavage of other death substrates during postmitotic apoptosis in A549 cells needs further investigation. (orig.)

  4. α-Mangostin Induces Apoptosis and Cell Cycle Arrest in Oral Squamous Cell Carcinoma Cell

    Directory of Open Access Journals (Sweden)

    Hyun-Ho Kwak

    2016-01-01

    Full Text Available Mangosteen has long been used as a traditional medicine and is known to have antibacterial, antioxidant, and anticancer effects. Although the effects of α-mangostin, a natural compound extracted from the pericarp of mangosteen, have been investigated in many studies, there is limited data on the effects of the compound in human oral squamous cell carcinoma (OSCC. In this study, α-mangostin was assessed as a potential anticancer agent against human OSCC cells. α-Mangostin inhibited cell proliferation and induced cell death in OSCC cells in a dose- and time-dependent manner with little to no effect on normal human PDLF cells. α-Mangostin treatment clearly showed apoptotic evidences such as nuclear fragmentation and accumulation of annexin V and PI-positive cells on OSCC cells. α-Mangostin treatment also caused the collapse of mitochondrial membrane potential and the translocation of cytochrome c from the mitochondria into the cytosol. The expressions of the mitochondria-related proteins were activated by α-mangostin. Treatment with α-mangostin also induced G1 phase arrest and downregulated cell cycle-related proteins (CDK/cyclin. Hence, α-mangostin specifically induces cell death and inhibits proliferation in OSCC cells via the intrinsic apoptosis pathway and cell cycle arrest at the G1 phase, suggesting that α-mangostin may be an effective agent for the treatment of OSCC.

  5. Docosahexaenoic acid induces apoptosis in primary chronic lymphocytic leukemia cells

    Directory of Open Access Journals (Sweden)

    Romain Guièze

    2015-12-01

    Full Text Available Chronic lymphocytic leukemia is an indolent disorder with an increased infectious risk remaining one of the main causes of death. Development of therapies with higher safety profile is thus a challenging issue. Docosahexaenoic acid (DHA, 22:6 is an omega-3 fatty acid, a natural compound of normal cells, and has been shown to display antitumor potency in cancer. We evaluated the potential in vitro effect of DHA in primary CLL cells. DHA induces high level of in vitro apoptosis compared to oleic acid in a dose-dependent and time-dependent manner. Estimation of IC50 was only of 4.813 μM, which appears lower than those reported in solid cancers. DHA is highly active on CLL cells in vitro. This observation provides a rationale for further studies aiming to understand its mechanisms of action and its potent in vivo activity.

  6. Cannabidiol rather than Cannabis sativa extracts inhibit cell growth and induce apoptosis in cervical cancer cells.

    Science.gov (United States)

    Lukhele, Sindiswa T; Motadi, Lesetja R

    2016-09-01

    Cervical cancer remains a global health related issue among females of Sub-Saharan Africa, with over half a million new cases reported each year. Different therapeutic regimens have been suggested in various regions of Africa, however, over a quarter of a million women die of cervical cancer, annually. This makes it the most lethal cancer amongst black women and calls for urgent therapeutic strategies. In this study we compare the anti-proliferative effects of crude extract of Cannabis sativa and its main compound cannabidiol on different cervical cancer cell lines. To achieve our aim, phytochemical screening, MTT assay, cell growth analysis, flow cytometry, morphology analysis, Western blot, caspase 3/7 assay, and ATP measurement assay were conducted. Results obtained indicate that both cannabidiol and Cannabis sativa extracts were able to halt cell proliferation in all cell lines at varying concentrations. They further revealed that apoptosis was induced by cannabidiol as shown by increased subG0/G1 and apoptosis through annexin V. Apoptosis was confirmed by overexpression of p53, caspase 3 and bax. Apoptosis induction was further confirmed by morphological changes, an increase in Caspase 3/7 and a decrease in the ATP levels. In conclusion, these data suggest that cannabidiol rather than Cannabis sativa crude extracts prevent cell growth and induce cell death in cervical cancer cell lines.

  7. Curcumin Induces Autophagy, Apoptosis, and Cell Cycle Arrest in Human Pancreatic Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yaping Zhu

    2017-01-01

    Full Text Available Objective. Curcumin is an active extract from turmeric. The aim of this study was to identify the underlying mechanism of curcumin on PCa cells and the role of autophagy in this process. Methods. The inhibitory effect of curcumin on the growth of PANC1 and BxPC3 cell lines was detected by CCK-8 assay. Cell cycle distribution and apoptosis were tested by flow cytometry. Autophagosomes were tested by cell immunofluorescence assay. The protein expression was detected by Western blot. The correlation between LC3II/Bax and cell viability was analyzed. Results. Curcumin inhibited the cell proliferation in a dose- and time-dependent manner. Curcumin could induce cell cycle arrest at G2/M phase and apoptosis of PCa cells. The autophagosomes were detected in the dosing groups. Protein expression of Bax and LC3II was upregulated, while Bcl2 was downregulated in the high dosing groups of curcumin. There was a significant negative correlation between LC3II/Bax and cell viability. Conclusions. Autophagy could be triggered by curcumin in the treatment of PCa. Apoptosis and cell cycle arrest also participated in this process. These findings imply that curcumin is a multitargeted agent for PCa cells. In addition, autophagic cell death may predominate in the high concentration groups of curcumin.

  8. Apoptosis and necroptosis are induced in rainbow trout cell lines exposed to cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Krumschnabel, Gerhard, E-mail: Gerhard.Krumschnabel@i-med.ac.at [Division of Developmental Immunology, Biocenter, Medical University Innsbruck, Fritz-Preglstr. 3, Innsbruck (Austria); Ebner, Hannes L.; Hess, Michael W. [Division of Histology and Embryology, Medical University Innsbruck, Innsbruck (Austria); Villunger, Andreas [Division of Developmental Immunology, Biocenter, Medical University Innsbruck, Fritz-Preglstr. 3, Innsbruck (Austria)

    2010-08-01

    Cadmium is an important environmental toxicant that can kill cells. A number of studies have implicated apoptosis as well as necrosis and, most recently, a form of programmed necrosis termed necroptosis in the process of cadmium-mediated toxicity, but the exact mechanism remains ill-defined and may depend on the affected cell type. This study investigated which mode of cell death may be responsible for cell death induction in cadmium-exposed trout cell lines from gill and liver and if this cell death was sensitive to inhibitors of necroptosis or apoptosis, respectively. It was observed that intermediate levels of cadmium that killed approximately 50% of the cells over 96-120 h of exposure caused cell death that morphologically resembled apoptosis and was associated with an increase of apoptotic markers such as the number of cells with diminished DNA content (sub-G1 cells), condensed or fragmented nuclei, and elevation of caspase-3 activity. At the same time, however, cells also lost plasma membrane integrity, as indicated by uptake of propidium iodide, showed a decrease of ATP levels and mitochondrial membrane potential, and displayed cell swelling, signs associated with secondary necrosis, or equally possible, necroptotic cell death. Importantly, many of these alterations were at least partly inhibited by the necroptosis inhibitor necrostatin-1 and were to a lesser extent also sensitive to the pan-caspase inhibitor zVAD-fmk, indicating that multiple modes of cell death are concurrently induced in cadmium-exposed trout cells, including necroptosis and apoptosis. Cell death appeared to lack concurrent radical formation, consistent with genetically regulated necroptotic cell death, but was characterized by the rapid induction of DNA damage markers, and the early onset of disintegration of the Golgi complex. Comparative experiments evaluating copper-toxicity indicated that in comparison to cadmium much higher concentrations of this metal were required to induce cell

  9. The Arabidopsis peptide kiss of death is an inducer of programmed cell death

    OpenAIRE

    Blanvillain, Robert; Young, Bennett; Cai, Yao-min; Hecht, Valérie; Varoquaux, Fabrice; Delorme, Valérie; Lancelin, Jean-Marc; Delseny, Michel; Gallois, Patrick

    2011-01-01

    This study identifies a novel regulator of cell death in plants and shows that the 25-amino-acid peptide kiss of death regulates programmed cell death at an early step in the cell death-signalling cascade.

  10. Death of effector memory T cells characterizes AIDS.

    Science.gov (United States)

    Mireille, Laforge; Anna, Senik; Marie-Christine, Cumont; Valerie, Monceaux; Bruno, Hurtrel; Jerome, Estaquier

    2009-01-01

    The adaptive effector CD4+ T helper-mediated immune response is highly heterogeneous, based on the development of distinct subsets that are characterized by the expression of different profiles of cell surface markers. Functional impairment of T cells is characteristic of many chronic mouse and human viral infections. Excessive induction of apoptosis in infected and uninfected CD4+ T cells has been proposed as one of the pathogenic mechanisms that may impair the immune response and cause the development of acquired immune deficiency syndrome (AIDS). Thus, the death of effector/memory CD4+ T cells during both the acute and chronic phase represents one the main characteristic of such viral infection that predicts disease outcome. Improving our understanding of the molecular mechanisms leading to the death of memory CD4+ T cells should enable us to improve vaccination protocols and treatments, by combining them with antiretroviral drugs and molecules designed to decrease apoptotic phenomena.

  11. Apoptosis in chondrogenesis of human mesenchymal stem cells: effect of serum and medium supplements.

    Science.gov (United States)

    Wang, Chien-Yuan; Chen, Ling-Lan; Kuo, Pei-Yin; Chang, Jia-Ling; Wang, Yng-Jiin; Hung, Shih-Chieh

    2010-04-01

    Apoptosis is an inevitable process during development and is evident in the formation of articular cartilage and endochondral ossification of growth plate. Mesenchymal stem cells (MSCs) can serve as alternative sources for cell therapy in focal chondral lesions or diffuse osteoarthritis. But there are few, if any, studies investigating apoptosis during chondrogenesis by MSCs. The aim of this study was to find the better condition to prevent apoptosis during chondrogenesis by MSCs. Apoptosis were evaluated in MSCs induced in different chondrogenic media by the use of Annexin V, TUNEL staining, lysosomal labeling with lysotracker and immunostaining of apoptotic markers. We found apparent apoptosis was demonstrated by Annexin V, TUNEL staining and lysosomal labeling during chondrogenesis. Meanwhile, the degree of apoptosis was related to the reagents of the defined chondrogenic medium. Adding serum in medium increased apoptosis, however, TGF-beta1 inhibited apoptosis. The apoptosis was associated with the activation of caspase-3, the increase in the Bax/Bcl-2 ratio, the loss of lysosomal integrity, and the increase of PARP-cleavage. Pro-inflammatory cytokines, IL-1alpha, IL-1beta and TNFalpha did not induce any increase in apoptosis. Interestingly, the inhibition of apoptosis by serum free medium supplemented with ITS was also associated with an increase in the expression of type II collagen, and a decrease in the expression of type X collagen, Runx2, and other osteogenic genes, while TGF-beta1 increased the expression of Sox9, type II and type X collagen and decreased the expression of osteogenic genes. These data suggest apoptosis occurs during chondrogenesis by MSCs by cell death intrinsic pathway activation and this process may be modulated by culture conditions.

  12. The contribution of apoptosis and necrosis in freezing injury of sea urchin embryonic cells.

    Science.gov (United States)

    Boroda, Andrey V; Kipryushina, Yulia O; Yakovlev, Konstantin V; Odintsova, Nelly A

    2016-08-01

    Sea urchins have recently been reported to be a promising tool for investigations of oxidative stress, UV light perturbations and senescence. However, few available data describe the pathway of cell death that occurs in sea urchin embryonic cells after cryopreservation. Our study is focused on the morphological and functional alterations that occur in cells of these animals during the induction of different cell death pathways in response to cold injury. To estimate the effect of cryopreservation on sea urchin cell cultures and identify the involved cell death pathways, we analyzed cell viability (via trypan blue exclusion test, MTT assay and DAPI staining), caspase activity (via flow cytometry and spectrophotometry), the level of apoptosis (via annexin V-FITC staining), and cell ultrastructure alterations (via transmission electron microscopy). Using general caspase detection, we found that the level of caspase activity was low in unfrozen control cells, whereas the number of apoptotic cells with activated caspases rose after freezing-thawing depending on cryoprotectants used, also as the number of dead cells and cells in a late apoptosis. The data using annexin V-binding assay revealed a very high apoptosis level in all tested samples, even in unfrozen cells (about 66%). Thus, annexin V assay appears to be unsuitable for sea urchin embryonic cells. Typical necrotic cells with damaged mitochondria were not detected after freezing in sea urchin cell cultures. Our results assume that physical cell disruption but not freezing-induced apoptosis or necrosis is the predominant reason of cell death in sea urchin cultures after freezing-thawing with any cryoprotectant combination. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Oxidative Stress, Cell Death, and Other Damage to Alveolar Epithelial Cells Induced by Cigarette Smoke

    Directory of Open Access Journals (Sweden)

    Nagai A

    2003-09-01

    Full Text Available Abstract Cigarette smoking is a major risk factor in the development of various lung diseases, including pulmonary emphysema, pulmonary fibrosis, and lung cancer. The mechanisms of these diseases include alterations in alveolar epithelial cells, which are essential in the maintenance of normal alveolar architecture and function. Following cigarette smoking, alterations in alveolar epithelial cells induce an increase in epithelial permeability, a decrease in surfactant production, the inappropriate production of inflammatory cytokines and growth factors, and an increased risk of lung cancer. However, the most deleterious effect of cigarette smoke on alveolar epithelial cells is cell death, i.e., either apoptosis or necrosis depending on the magnitude of cigarette smoke exposure. Cell death induced by cigarette smoke exposure can largely be accounted for by an enhancement in oxidative stress. In fact, cigarette smoke contains and generates many reactive oxygen species that damage alveolar epithelial cells. Whether apoptosis and/or necrosis in alveolar epithelial cells is enhanced in healthy cigarette smokers is presently unclear. However, recent evidence indicates that the apoptosis of alveolar epithelial cells and alveolar endothelial cells is involved in the pathogenesis of pulmonary emphysema, an important cigarette smoke-induced lung disease characterized by the loss of alveolar structures. This review will discuss oxidative stress, cell death, and other damage to alveolar epithelial cells induced by cigarette smoke.

  14. Modulation of MAA-induced apoptosis in male germ cells: role of Sertoli cell P/Q-type calcium channels

    Directory of Open Access Journals (Sweden)

    Aguanno Salvatore

    2005-04-01

    Full Text Available Abstract Spontaneous germ cell death by apoptosis occurs during normal spermatogenesis in mammals and is thought to play a role in the physiological mechanism limiting the clonal expansion of such cell population in the male gonad. In the prepubertal rat testis, the most conspicuous dying cells are pachytene spermatocytes, which are also the primary target of the apoptosis experimentally induced by the methoxyacetic acid (MAA. Since we have recently reported that Sertoli cells, the somatic component of the seminiferous epithelium, regulate not only germ cell viability and differentiation but also their death, we have further investigated the mechanism involved in such a control. In this paper we have used the protein clusterin, produced by Sertoli cells and associated with tissue damage or injury, as indicator of germ cell apoptosis in rat seminiferous tubules treated with MAA in the presence or in the absence of omega-agatoxin, a specific inhibitor of P/Q type voltage-operated calcium channels (VOCC's. We performed both a qualitative analysis of clusterin content and germ cell apoptosis by immunofluorescence experiments and a quantitative analysis by in situ end labelling of apoptotic germ cells followed by flow cytometry. The results obtained demonstrate that Sertoli cells modulate germ cell apoptosis induced by methoxyacetic acid also throughout the P/Q-type VOCC's.

  15. Chronic Opium Treatment Can Differentially Induce Brain and Liver Cells Apoptosis in Diabetic and Non-diabetic Male and Female Rats

    OpenAIRE

    Asiabanha, Majid; Asadikaram, Gholamreza; Rahnema, Amir; Mahmoodi, Mehdi; Hasanshahi, Gholamhosein; Hashemi, Mohammad; Khaksari, Mohammad

    2011-01-01

    It has been shown that some opium derivatives promote cell death via apoptosis. This study was designed to examine the influence of opium addiction on brain and liver cells apoptosis in male and female diabetic and non-diabetic Wistar rats. This experimental study was performed on normal, opium-addicted, diabetic and diabetic opium-addicted male and female rats. Apoptosis was evaluated by TUNEL and DNA fragmentation assays. Results of this study showed that apoptosis in opium-addicted and dia...

  16. Thymoquinone causes multiple effects, including cell death, on dividing plant cells.

    Science.gov (United States)

    Hassanien, Sameh E; Ramadan, Ahmed M; Azeiz, Ahmed Z Abdel; Mohammed, Rasha A; Hassan, Sabah M; Shokry, Ahmed M; Atef, Ahmed; Kamal, Khalid B H; Rabah, Samar; Sabir, Jamal S M; Abuzinadah, Osama A; El-Domyati, Fotouh M; Martin, Gregory B; Bahieldin, Ahmed

    2013-01-01

    Thymoquinone (TQ) is a major constituent of Nigella sativa oil with reported anti-oxidative activity and anti-inflammatory activity in animal cells. It also inhibits proliferation and induces programmed cell death (apoptosis) in human skin cancer cells. The present study sought to detect the influence of TQ on dividing cells of three plant systems and on expression of Bcl2-associated athanogene-like (BAG-like) genes that might be involved during the process of cell death. BAG genes are known for the regulation of diverse physiological processes in animals, including apoptosis, tumorigenesis, stress responses, and cell division. Synthetic TQ at 0.1mg/mL greatly reduced wheat seed germination rate, whereas 0.2mg/mL completely inhibited germination. An Evans blue assay revealed moderate cell death in the meristematic zone of Glycine max roots after 1h of TQ treatment (0.2mg/mL), with severe cell death occurring in this zone after 2h of treatment. Light microscopy of TQ-treated (0.2mg/mL) onion hairy root tips for 1h revealed anti-mitotic activity and also cell death-associated changes, including nuclear membrane disruption and nuclear fragmentation. Transmission electron microscopy of TQ-treated cells (0.2mg/mL) for 1h revealed shrinkage of the plasma membrane, leakage of cell lysate, degradation of cell walls, enlargement of vacuoles and condensation of nuclei. Expression of one BAG-like gene, previously associated with cell death, was induced 20 min after TQ treatment in Glycine max root tip cells. Thus, TQ has multiple effects, including cell death, on dividing plant cells and plants may serve as a useful system to further investigate the mechanisms underlying the response of eukaryotic cells to TQ. © 2013. Published by Elsevier SAS.

  17. Tunicamycin promotes apoptosis in leukemia cells through ROS generation and downregulation of survivin expression.

    Science.gov (United States)

    Lim, Eun Jin; Heo, Jeonghoon; Kim, Young-Ho

    2015-08-01

    Tunicamycin (TN), one of the endoplasmic reticulum stress inducers, has been reported to inhibit tumor cell growth and exhibit anticarcinogenic activity. However, the mechanism by which TN initiates apoptosis remains poorly understood. In the present study, we investigated the effect of TN on the apoptotic pathway in U937 cells. We show that TN induces apoptosis in association with caspase-3 activation, generation of reactive oxygen species (ROS), and downregulation of survivin expression. P38 MAPK (mitogen-activated protein kinase) and the generation of ROS signaling pathway play crucial roles in TN-induced apoptosis in U937 cells. We hypothesized that TN-induced activation of p38 MAPK signaling pathway is responsible for cell death. To test this hypothesis, we selectively inhibited MAPK during treatment with TN. Our data demonstrated that inhibitor of p38 (SB), but not ERK (PD) or JNK (SP), partially maintained apoptosis during treatment with TN. Pre-treatment with NAC and GSH markedly prevented cell death, suggesting a role for ROS in this process. Ectopic expression of survivin in U937 cells attenuated TN-induced apoptosis by suppression of caspase-3 cleavage, mitochondrial membrane potential, and cytochrome c release in U937 cells. Taken together, our results show that TN modulates multiple components of the apoptotic response of human leukemia cells and raise the possibility of a novel therapeutic strategy for hematological malignancies.

  18. Detection of cell death in Drosophila.

    Science.gov (United States)

    McCall, Kimberly; Peterson, Jeanne S; Pritchett, Tracy L

    2009-01-01

    Drosophila is a powerful model system for the identification of cell death genes and understanding the role of cell death in development. In this chapter, we describe three methods typically used for the detection of cell death in Drosophila. The TUNEL and acridine orange methods are used to detect dead or dying cells in a variety of tissues. We focus on methods for the embryo and the ovary, but these techniques can be used on other tissues as well. The third method is the detection of genetic interactions by expressing cell death genes in the Drosophila eye.

  19. Cyclin-dependent kinases regulate apoptosis of intestinal epithelial cells

    Science.gov (United States)

    Bhattacharya, Sujoy; Ray, Ramesh M.; Johnson, Leonard R.

    2014-01-01

    Homeostasis of the gastrointestinal epithelium is dependent upon a balance between cell proliferation and apoptosis. Cyclin-dependent kinases (Cdks) are well known for their role in cell proliferation. Previous studies from our group have shown that polyamine-depletion of intestinal epithelial cells (IEC-6) decreases cyclin-dependent kinase 2 (Cdk2) activity, increases p53 and p21Cip1 protein levels, induces G1 arrest, and protects cells from camptothecin (CPT)-induced apoptosis. Although emerging evidence suggests that members of the Cdk family are involved in the regulation of apoptosis, their roles directing apoptosis of IEC-6 cells are not known. In this study, we report that inhibition of Cdk1, 2, and 9 (with the broad range Cdk inhibitor, AZD5438) in proliferating IEC-6 cells triggered DNA damage, activated p53 signaling, inhibited proliferation, and induced apoptosis. By contrast, inhibition of Cdk2 (with NU6140) increased p53 protein and activity, inhibited proliferation, but had no effect on apoptosis. Notably, AZD5438 sensitized, whereas, NU6140 rescued proliferating IEC-6 cells from CPT-induced apoptosis. However, in colon carcinoma (Caco2) cells with mutant p53, treatment with either AZD5438 or NU6140 blocked proliferation, albeit more robustly with AZD5438. Both Cdk inhibitors induced apoptosis in Caco2 cells in a p53-independent manner. In serum starved quiescent IEC-6 cells, both AZD5438 and NU6140 decreased TNF- /CPT-induced activation of p53 and, consequently, rescued cells from apoptosis, indicating that sustained Cdk activity is required for apoptosis of quiescent cells. Furthermore, AZD5438 partially reversed the protective effect of polyamine depletion whereas NU6140 had no effect. Together, these results demonstrate that Cdks possess opposing roles in the control of apoptosis in quiescent and proliferating cells. In addition, Cdk inhibitors uncouple proliferation from apoptosis in a p53-dependent manner. PMID:24242917

  20. Resistance of activated human T(h)2 cells to NO-induced apoptosis is mediated by gamma-glutamyltranspeptidase

    NARCIS (Netherlands)

    Roozendaal, R; Vellenga, E; de Jong, MA; Traanberg, KF; Postma, DS; de Monchy, JGR; Kauffman, HF

    Activation-induced death of inflammatory cells (AICD) has an important function in immune maintenance, Type 1 T-h cells are known to be more susceptible to AICD than T(h)2 cells. In the current study we examined whether NO-induced apoptosis also preferentially eliminates T(h)1 cells over Th2 cells.

  1. Zebularine inhibits the growth of A549 lung cancer cells via cell cycle arrest and apoptosis.

    Science.gov (United States)

    You, Bo Ra; Park, Woo Hyun

    2014-11-01

    Zebularine (Zeb) is a DNA methyltransferase (DNMT) inhibitor to that has an anti-tumor effect. Here, we evaluated the anti-growth effect of Zeb on A549 lung cancer cells in relation to reactive oxygen species (ROS) levels. Zeb inhibited the growth of A549 cells with an IC50 of approximately 70 µM at 72 h. Cell cycle analysis indicated that Zeb induced an S phase arrest in A549 cells. Zeb also induced A549 cell death, which was accompanied by the loss of mitochondrial membrane potential (MMP; ΔΨm ), Bcl-2 decrease, Bax increase, p53 increase and activation of caspase-3 and -8. In contrast, Zeb mildly inhibited the growth of human pulmonary fibroblast (HPF) normal cells and lead to a G1 phase arrest. Zeb did not induce apoptosis in HPF cells. In relation to ROS level, Zeb increased ROS level in A549 cells and induced glutathione (GSH) depletion. The well-known antioxidant, N-acetyl cysteine (NAC) prevented the death of Zeb-treated A549 cells. Moreover, Zeb increased the level of thioredoxin reductase 1 (TrxR1) in A549 cells. While the overexpression of TrxR1 attenuated death and ROS level in Zeb-treated A549 cells, the downregulation of TrxR1 intensified death and ROS level in these cells. In conclusion, Zeb inhibited the growth of A549 lung cancer cells via cell cycle arrest and apoptosis. The inhibition was influenced by ROS and TrxR1 levels. © 2013 Wiley Periodicals, Inc.

  2. Delayed cell death associated with mitotic catastrophe in γ-irradiated stem-like glioma cells

    International Nuclear Information System (INIS)

    Firat, Elke; Gaedicke, Simone; Tsurumi, Chizuko; Esser, Norbert; Weyerbrock, Astrid; Niedermann, Gabriele

    2011-01-01

    Stem-like tumor cells are regarded as highly resistant to ionizing radiation (IR). Previous studies have focused on apoptosis early after irradiation, and the apoptosis resistance observed has been attributed to reduced DNA damage or enhanced DNA repair compared to non-stem tumor cells. Here, early and late radioresponse of patient-derived stem-like glioma cells (SLGCs) and differentiated cells directly derived from them were examined for cell death mode and the influence of stem cell-specific growth factors. Primary SLGCs were propagated in serum-free medium with the stem-cell mitogens epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2). Differentiation was induced by serum-containing medium without EGF and FGF. Radiation sensitivity was evaluated by assessing proliferation, clonogenic survival, apoptosis, and mitotic catastrophe. DNA damage-associated γH2AX as well as p53 and p21 expression were determined by Western blots. SLGCs failed to apoptose in the first 4 days after irradiation even at high single doses up to 10 Gy, but we observed substantial cell death later than 4 days postirradiation in 3 of 6 SLGC lines treated with 5 or 10 Gy. This delayed cell death was observed in 3 of the 4 SLGC lines with nonfunctional p53, was associated with mitotic catastrophe and occurred via apoptosis. The early apoptosis resistance of the SLGCs was associated with lower γH2AX compared to differentiated cells, but we found that the stem-cell culture cytokines EGF plus FGF-2 strongly reduce γH2AX levels. Nonetheless, in two p53-deficient SLGC lines examined γIR-induced apoptosis even correlated with EGF/FGF-induced proliferation and mitotic catastrophe. In a line containing CD133-positive and -negative stem-like cells, the CD133-positive cells proliferated faster and underwent more γIR-induced mitotic catastrophe. Our results suggest the importance of delayed apoptosis, associated mitotic catastrophe, and cellular proliferation for γIR-induced death of

  3. Programmed Cell Death During Caenorhabditis elegans Development.

    Science.gov (United States)

    Conradt, Barbara; Wu, Yi-Chun; Xue, Ding

    2016-08-01

    Programmed cell death is an integral component of Caenorhabditis elegans development. Genetic and reverse genetic studies in C. elegans have led to the identification of many genes and conserved cell death pathways that are important for the specification of which cells should live or die, the activation of the suicide program, and the dismantling and removal of dying cells. Molecular, cell biological, and biochemical studies have revealed the underlying mechanisms that control these three phases of programmed cell death. In particular, the interplay of transcriptional regulatory cascades and networks involving multiple transcriptional regulators is crucial in activating the expression of the key death-inducing gene egl-1 and, in some cases, the ced-3 gene in cells destined to die. A protein interaction cascade involving EGL-1, CED-9, CED-4, and CED-3 results in the activation of the key cell death protease CED-3, which is tightly controlled by multiple positive and negative regulators. The activation of the CED-3 caspase then initiates the cell disassembly process by cleaving and activating or inactivating crucial CED-3 substrates; leading to activation of multiple cell death execution events, including nuclear DNA fragmentation, mitochondrial elimination, phosphatidylserine externalization, inactivation of survival signals, and clearance of apoptotic cells. Further studies of programmed cell death in C. elegans will continue to advance our understanding of how programmed cell death is regulated, activated, and executed in general. Copyright © 2016 by the Genetics Society of America.

  4. Retinal Cell Death Caused by Sodium Iodate Involves Multiple Caspase-Dependent and Caspase-Independent Cell-Death Pathways

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    Jasmin Balmer

    2015-07-01

    Full Text Available Herein, we have investigated retinal cell-death pathways in response to the retina toxin sodium iodate (NaIO3 both in vivo and in vitro. C57/BL6 mice were treated with a single intravenous injection of NaIO3 (35 mg/kg. Morphological changes in the retina post NaIO3 injection in comparison to untreated controls were assessed using electron microscopy. Cell death was determined by TdT-mediated dUTP-biotin nick end labeling (TUNEL staining. The activation of caspases and calpain was measured using immunohistochemistry. Additionally, cytotoxicity and apoptosis in retinal pigment epithelial (RPE cells, primary retinal cells, and the cone photoreceptor (PRC cell line 661W were assessed in vitro after NaIO3 treatment using the ApoToxGlo™ assay. The 7-AAD/Annexin-V staining was performed and necrostatin (Nec-1 was administered to the NaIO3-treated cells to confirm the results. In vivo, degenerating RPE cells displayed a rounded shape and retracted microvilli, whereas PRCs featured apoptotic nuclei. Caspase and calpain activity was significantly upregulated in retinal sections and protein samples from NaIO3-treated animals. In vitro, NaIO3 induced necrosis in RPE cells and apoptosis in PRCs. Furthermore, Nec-1 significantly decreased NaIO3-induced RPE cell death, but had no rescue effect on treated PRCs. In summary, several different cell-death pathways are activated in retinal cells as a result of NaIO3.

  5. Cell wall dynamics modulate acetic acid-induced apoptotic cell death of Saccharomyces cerevisiae

    Science.gov (United States)

    Rego, António; Duarte, Ana M.; Azevedo, Flávio; Sousa, Maria J.; Côrte-Real, Manuela; Chaves, Susana R.

    2014-01-01

    Acetic acid triggers apoptotic cell death in Saccharomyces cerevisiae, similar to mammalian apoptosis. To uncover novel regulators of this process, we analyzed whether impairing MAPK signaling affected acetic acid-induced apoptosis and found the mating-pheromone response and, especially, the cell wall integrity pathways were the major mediators, especially the latter, which we characterized further. Screening downstream effectors of this pathway, namely targets of the transcription factor Rlm1p, highlighted decreased cell wall remodeling as particularly important for acetic acid resistance. Modulation of cell surface dynamics therefore emerges as a powerful strategy to increase acetic acid resistance, with potential application in industrial fermentations using yeast, and in biomedicine to exploit the higher sensitivity of colorectal carcinoma cells to apoptosis induced by acetate produced by intestinal propionibacteria. PMID:28357256

  6. Chalcones Enhance TRAIL-Induced Apoptosis in Prostate Cancer Cells

    OpenAIRE

    Szliszka, Ewelina; Czuba, Zenon P.; Mazur, Bogdan; Sedek, Lukasz; Paradysz, Andrzej; Krol, Wojciech

    2009-01-01

    Chalcones exhibit chemopreventive and antitumor effects. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a naturally occurring anticancer agent that induces apoptosis in cancer cells and is not toxic to normal cells. We examined the cytotoxic and apoptotic effect of five chalcones in combination with TRAIL on prostate cancer cells. The cytotoxicity was evaluated by the MTT and LDH assays. The apoptosis was determined using flow cytometry with annexin V-FITC. Our study showe...

  7. Aspartame-induced apoptosis in PC12 cells

    OpenAIRE

    Horio, Yukari; Sun, Yongkun; Liu, Chuang; Saito, Takeshi; Kurasaki, Masaaki

    2014-01-01

    Aspartame is an artificial sweetner added to many low-calorie foods. The safety of aspartame remains controversial even though there are many studies on its risks. In this study, to understand the physiological effects of trace amounts of artificial sweetners on cells, the effects of aspartame on apoptosis were investigated using a PC12 cell system. In addition, the mechanism of apoptosis induced by aspartame in PC12 cells and effects on apoptotic factors such as cytochrome c, apoptosis-induc...

  8. Smac deficiency affects endoplasmic reticulum stress-induced apoptosis in human colon cancer cells

    Science.gov (United States)

    He, Qin; Shi, Jingxue; Jones, Samantha; An, Jie; Liu, Yuxin; Huang, Ying; Sheikh, M. Saeed

    2009-01-01

    Thapsigargin (TG) is a sesquiterpen lactone that inhibits the endoplasmic reticulum (ER) calcium ATPases to disrupt calcium homeostasis and consequently induces ER stress. We have previously reported that TG induces apoptosis by engaging the death receptor 5 (DR5) and the intrinsic pathways. Second mitochondrial-derived activator (Smac) is an important modulator of apoptosis that induces activation of caspases by antagonizing inhibitors of apoptosis (IAPs). In this study, we have utilized Smac-proficient and -deficient human colon cancer cells to investigate the effects of Smac deficiency during ER-stress-induced apoptosis. Our results indicate that Smac deficiency considerably affects ER stress-induced apoptosis in human colon cancer cells. For example, ER stress inducing agent TG upregulates DR5, and activates caspases 3, 9 and 8 in Smac-proficient cells. In Smac-deficient cells, although TG-induced DR5 upregulation is not affected, activation of caspases 3, 9 and 8 is affected. Smac deficiency also affects TG-induced cytochrome c release from mitochondria into cytosol suggesting the existence of a potential cross-talk between Smac and cytochrome c. Thus, our results indicate that ER stress-induced apoptosis also engages Smac for transduction of apoptotic signals in human colon cancer cells and that a potential feedback signaling between Smac and cytochrome c appears to modulate the intrinsic pathway of apoptosis. PMID:20209078

  9. MicroRNA-1185 Induces Endothelial Cell Apoptosis by Targeting UVRAG and KRIT1

    Directory of Open Access Journals (Sweden)

    Haoyuan Deng

    2017-04-01

    Full Text Available Background/Aims: Atherosclerosis is a multifactorial chronic disease and is the main cause of death and impairment in the world. Endothelial injury and apoptosis play a crucial role in the onset and development of atherosclerosis. MicroRNAs (miRNAs have been proven to be involved in the pathogenesis of atherosclerosis. However, studies of the functional role of apoptosis-related miRNAs in the endothelium during atherogenesis are limited. Methods: Cell injury and apoptosis were measured in five types of cells transfected with miR-1185 or co-transfected with miR-1185 and its inhibitor. Bioinformatics analysis and a luciferase reporter assay were used to confirm the targets of miR-1185. The effects of the targets of miR-1185 on endothelial apoptosis were determined using small-interfering RNA. Results: In this study, we first report that miR-1185 significantly promoted apoptosis in endothelial cells but not in vascular smooth muscle cells and macrophages. A mechanistic analysis showed that ultraviolet irradiation resistance-associated gene (UVRAG and krev1 interaction trapped gene 1 (KRIT1, targets of miR-1185, mediated miR-1185-induced endothelial cell apoptosis. Conclusion: The results revealed the impact of miR-1185 on endothelial apoptosis, suggesting that miR-1185 may be a potential target for the prevention and treatment of atherosclerosis.

  10. Stereospecific induction of apoptosis in tumor cells via endogenous C16-ceramide and distinct transcripts.

    Science.gov (United States)

    Blaess, M; Le, H P; Claus, R A; Kohl, M; Deigner, H-P

    2015-01-01

    Concentration and distribution of individual endogenous ceramide species is crucial for apoptosis induction in response to various stimuli. Exogenous ceramide analogs induce apoptosis and can in turn modify the composition/concentrations of endogenous ceramide species and associated signaling. In this study, we show here that the elevation of endogenous C16-ceramide levels is a common feature of several known apoptosis-inducing triggers like mmLDL, TNF-alpha, H2O2 and exogenous C6-ceramide. Vice versa apoptosis requires elevation of endogenous C16-ceramide levels in cells. Enantiomers of a synthetic ceramide analog HPL-1RS36N have been developed as probes and vary in their capacity to inducing apoptosis in macrophages and HT-29 cells. Apoptosis induction by the two synthetic ceramide analogs HPL-39N and HPL-1R36N correlates with generation of cellular C16-ceramide concentration. In contrast to the S-enantiomer HPL-1S36N, the R-enantiomer HPL-1R36N shows significant effects on the expression of distinct genes known to be involved in cell cycle, cell growth and cell death (CXCL10, CCL5 and TNF-alpha), similarly on apoptosis induction. Enantioselective effects on transcription induced by metabolically stable synthetic probes provide clues on molecular mechanisms of ceramide-induced signaling, as well as leads for future anti-cancer agents.

  11. RNA Viruses: ROS-Mediated Cell Death

    Science.gov (United States)

    Reshi, Mohammad Latif; Su, Yi-Che; Hong, Jiann-Ruey

    2014-01-01

    Reactive oxygen species (ROS) are well known for being both beneficial and deleterious. The main thrust of this review is to investigate the role of ROS in ribonucleic acid (RNA) virus pathogenesis. Much evidences has accumulated over the past decade, suggesting that patients infected with RNA viruses are under chronic oxidative stress. Changes to the body's antioxidant defense system, in relation to SOD, ascorbic acid, selenium, carotenoids, and glutathione, have been reported in various tissues of RNA-virus infected patients. This review focuses on RNA viruses and retroviruses, giving particular attention to the human influenza virus, Hepatitis c virus (HCV), human immunodeficiency virus (HIV), and the aquatic Betanodavirus. Oxidative stress via RNA virus infections can contribute to several aspects of viral disease pathogenesis including apoptosis, loss of immune function, viral replication, inflammatory response, and loss of body weight. We focus on how ROS production is correlated with host cell death. Moreover, ROS may play an important role as a signal molecule in the regulation of viral replication and organelle function, potentially providing new insights in the prevention and treatment of RNA viruses and retrovirus infections. PMID:24899897

  12. Imiquimod activates p53-dependent apoptosis in a human basal cell carcinoma cell line.

    Science.gov (United States)

    Huang, Shi-Wei; Chang, Shu-Hao; Mu, Szu-Wei; Jiang, Hsin-Yi; Wang, Sin-Ting; Kao, Jun-Kai; Huang, Jau-Ling; Wu, Chun-Ying; Chen, Yi-Ju; Shieh, Jeng-Jer

    2016-03-01

    The tumor suppressor p53 controls DNA repair, cell cycle, apoptosis, autophagy and numerous other cellular processes. Imiquimod (IMQ), a synthetic toll-like receptor (TLR) 7 ligand for the treatment of superficial basal cell carcinoma (BCC), eliminates cancer cells by activating cell-mediated immunity and directly inducing apoptosis and autophagy in cancer cells. To evaluate the role of p53 in IMQ-induced cell death in skin cancer cells. The expression, phosphorylation and subcellular localization of p53 were detected by real-time PCR, luciferase reporter assay, cycloheximide chase analysis, immunoblotting and immunocytochemistry. Using BCC/KMC1 cell line as a model, the upstream signaling of p53 activation was dissected by over-expression of TLR7/8, the addition of ROS scavenger, ATM/ATR inhibitors and pan-caspase inhibitor. The role of p53 in IMQ-induced apoptosis and autophagy was assessed by genetically silencing p53 and evaluated by a DNA content assay, immunoblotting, LC3 puncta detection and acridine orange staining. IMQ induced p53 mRNA expression and protein accumulation, increased Ser15 phosphorylation, promoted nuclear translocation and up-regulated its target genes in skin cancer cells in a TLR7/8-independent manner. In BCC/KMC1 cells, the induction of p53 by IMQ was achieved through increased ROS production to stimulate the ATM/ATR-Chk1/Chk2 axis but was not mediated by inducing DNA damage. The pharmacological inhibition of ATM/ATR significantly suppressed IMQ-induced p53 activation and apoptosis. Silencing of p53 significantly decreased the IMQ-induced caspase cascade activation and apoptosis but enhanced autophagy. Mutant p53 skin cancer cell lines were more resistant to IMQ-induced apoptosis than wildtype p53 skin cancer cell lines. IMQ induced ROS production to stimulate ATM/ATR pathways and contributed to p53-dependent apoptosis in a skin basal cell carcinoma cell line BCC/KMC1. Copyright © 2015 Japanese Society for Investigative Dermatology

  13. Induction of Programmed Cell Death in Human Alveolar Epithelial Cells Infected with Influenza Virus

    Directory of Open Access Journals (Sweden)

    Sh Shahsavandi

    2015-11-01

    Full Text Available Introduction: Avian influenza viruses are considered as a serious threat to human and animal health. An increase in expression of proinflammatory cytokines and type I IFN genes, as well as host cell death responses contribute to the pathogenesis of influenza infection. Hence, this study aimed to evaluate the growth dynamics of subacute avian influenza virus in human respiratory alveolar epithelium cells (A549. Methods: The A549 cell cultures were infected at MOIs 0.1 and 2.0 viral doses in the presence and absence of trypsin. The virus growth kinetics were elucidated by the plaque assay and the cell viability was determined by MTT at various times after the infection. The induction quality of programmed cell death as well as the signal transduction pathway of death were assessed by genomic DNA fragmentation and western blotting respectively. Results: The study findings indicated that although the H9N2 virus replication did produce a marked cytopathic effect on the alveolar cells, which led to a reduction in the cell viability, the viral titers were increased in the infected cells. The virus replication of in these cells indicated repression of host defense mechanism as well as activation of cell death. The induction of apoptosis in A549 cells was correlated with the increased virus titers as well as virus replication (p< 0.05. Conclusion: H9N2 avian influenza virus were demonstrated to induce apoptosis in human alveolar epithelial cells via the intrinsic pathway in a dose-dependent manner.

  14. Examining live cell cultures during apoptosis by digital holographic phase imaging and Raman spectroscopy

    Science.gov (United States)

    Khmaladze, Alexander

    2017-11-01

    Cellular apoptosis is a unique, organized series of events, leading to programmed cell death. In this work, we present a combined digital holography/Raman spectroscopy technique to study live cell cultures during apoptosis. Digital holographic microscopy measurements of live cell cultures yield information about cell shape and volume, changes to which are indicative of alterations in cell cycle and initiation of cell death mechanisms. Raman spectroscopic measurements provide complementary information about cells, such as protein, lipid and nucleic acid content, and the spectral signatures associated with structural changes in molecules. Our work indicates that the chemical changes in proteins, which were detected by Raman measurements, preceded morphological changes, which were seen with digital holographic microscopy.

  15. Oxaliplatin triggers necrosis as well as apoptosis in gastric cancer SGC-7901 cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Ping; Zhu, Xueping [Department of Immunology, Anhui Medical University, Hefei 230032 (China); Jin, Wei [Department of Otolaryngology, Chaohu Hospital of Anhui Medical University, Chaohu 238000 (China); Hao, Shumei; Liu, Qi [Department of Immunology, Anhui Medical University, Hefei 230032 (China); Zhang, Linjie, E-mail: zlj33@ahmu.edu.cn [Department of Immunology, Anhui Medical University, Hefei 230032 (China)

    2015-05-01

    Intrinsic apoptotic pathway is considered to be responsible for cell death induced by platinum anticancer drugs. While in this study, we found that, necrosis is an indispensable pathway besides apoptosis in oxaliplatin-treated gastric cancer SGC-7901 cells. Upon exposure to oxaliplatin, both apoptotic and necrotic features were observed. The majority of dead cells were double positive for Annexin V and propidium iodide (PI). Moreover, mitochondrial membrane potential collapsed and caspase cascades were activated. However, ultrastructural changes under transmission electron microscope, coupled with the release of cellular contents, demonstrated the rupture of the plasma membrane. Oxaliplatin administration did not stimulate reactive oxygen species (ROS) production and autophagy, but elevated the protein level of Bmf. In addition, receptor interacting protein 1 (RIP1), but not receptor interacting protein 3 (RIP3) and its downstream components participated in this death process. Necrostatin-1 (Nec-1) blocked oxaliplatin-induced cell death nearly completely, whereas z-VAD-fmk could partially suppress cell death. Oxaliplatin treatment resulted in poly(ADP-ribose) polymerase-1 (PARP-1) overactivation, as indicated by the increase of poly(ADP-ribose) (PAR), which led to NAD{sup +} and ATP depletion. PARP-1 inhibitor, olaparib, could significantly block oxaliplatin-induced cell death, thus confirming that PARP-1 activation is mainly responsible for the cytotoxicity of oxaliplatin. Phosphorylation of H2AX at Ser139 and translocalization of apoptosis-inducing factor (AIF) are critical for this death process. Taken together, these results indicate that oxaliplatin can bypass canonical cell death pathways to kill gastric cancer cells, which may be of therapeutic advantage in the treatment of gastric cancer. - Highlights: • Oxaliplatin induces apoptotic and necrotic cell death. • Nec-1 can inhibit oxaliplatin-induced cell death nearly completely. • RIP3 and its

  16. Exploiting Cell Death Pathways for Inducible Cell Elimination to Modulate Graft-versus-Host-Disease.

    Science.gov (United States)

    Falcon, Corey; Al-Obaidi, Mustafa; Di Stasi, Antonio

    2017-06-14

    Hematopoietic stem cell transplantation is a potent form of immunotherapy, potentially life-saving for many malignant hematologic diseases. However, donor lymphocytes infused with the graft while exerting a graft versus malignancy effect can also cause potentially fatal graft versus host disease (GVHD). Our group has previously validated the inducible caspase-9 suicide gene in the haploidentical stem cell transplant setting, which proved successful in reversing signs and symptoms of GVHD within hours, using a non-therapeutic dimerizing agent. Cellular death pathways such as apoptosis and necroptosis are important processes in maintaining healthy cellular homeostasis within the human body. Here, we review two of the most widely investigated cell death pathways active in T-cells (apoptosis and necroptosis), as well as the emerging strategies that can be exploited for the safety of T-cell therapies. Furthermore, such strategies could be exploited for the safety of other cellular therapeutics as well.

  17. Exploiting Cell Death Pathways for Inducible Cell Elimination to Modulate Graft-versus-Host-Disease

    Directory of Open Access Journals (Sweden)

    Corey Falcon

    2017-06-01

    Full Text Available Hematopoietic stem cell transplantation is a potent form of immunotherapy, potentially life-saving for many malignant hematologic diseases. However, donor lymphocytes infused with the graft while exerting a graft versus malignancy effect can also cause potentially fatal graft versus host disease (GVHD. Our group has previously validated the inducible caspase-9 suicide gene in the haploidentical stem cell transplant setting, which proved successful in reversing signs and symptoms of GVHD within hours, using a non-therapeutic dimerizing agent. Cellular death pathways such as apoptosis and necroptosis are important processes in maintaining healthy cellular homeostasis within the human body. Here, we review two of the most widely investigated cell death pathways active in T-cells (apoptosis and necroptosis, as well as the emerging strategies that can be exploited for the safety of T-cell therapies. Furthermore, such strategies could be exploited for the safety of other cellular therapeutics as well.

  18. Bupivacaine-induced apoptosis independently of WDR35 expression in mouse neuroblastoma Neuro2a cells

    Science.gov (United States)

    2012-01-01

    Background Bupivacaine-induced neurotoxicity has been shown to occur through apoptosis. Recently, bupivacaine was shown to elicit reactive oxygen species (ROS) production and induce apoptosis accompanied by activation of p38 mitogen-activated protein kinase (MAPK) in a human neuroblastoma cell line. We have reported that WDR35, a WD40-repeat protein, may mediate apoptosis through caspase-3 activation. The present study was undertaken to test whether bupivacaine induces apoptosis in mouse neuroblastoma Neuro2a cells and to determine whether ROS, p38 MAPK, and WDR35 are involved. Results Our results showed that bupivacaine induced ROS generation and p38 MAPK activation in Neuro2a cells, resulting in apoptosis. Bupivacaine also increased WDR35 expression in a dose- and time-dependent manner. Hydrogen peroxide (H2O2) also increased WDR35 expression in Neuro2a cells. Antioxidant (EUK-8) and p38 MAPK inhibitor (SB202190) treatment attenuated the increase in caspase-3 activity, cell death and WDR35 expression induced by bupivacaine or H2O2. Although transfection of Neuro2a cells with WDR35 siRNA attenuated the bupivacaine- or H2O2-induced increase in expression of WDR35 mRNA and protein, in contrast to our previous studies, it did not inhibit the increase in caspase-3 activity in bupivacaine- or H2O2-treated cells. Conclusions In summary, our results indicated that bupivacaine induced apoptosis in Neuro2a cells. Bupivacaine induced ROS generation and p38 MAPK activation, resulting in an increase in WDR35 expression, in these cells. However, the increase in WDR35 expression may not be essential for the bupivacaine-induced apoptosis in Neuro2a cells. These results may suggest the existence of another mechanism of bupivacaine-induced apoptosis independent from WDR35 expression in Neuro2a cells. PMID:23227925

  19. X-linked inhibitor of apoptosis (XIAP – a critical death-resistance regulator and therapeutic target for personalized cancer therapy

    Directory of Open Access Journals (Sweden)

    Petra eObexer

    2014-07-01

    Full Text Available Defects in apoptosis regulation are one main cause of cancer development and may result from overexpression of anti-apoptotic proteins such as Inhibitor of Apoptosis Proteins (IAPs. IAPs are cell death regulators that, among other functions, bind caspases and interfere with apoptotic signaling via death receptors or intrinsic cell death pathways. All IAPs share one to three common structures, the so called baculovirus-IAP-repeat (BIR-domains that allow them to bind caspases and other proteins. X-linked inhibitor of apoptosis protein (XIAP is the most potent and best-defined anti-apoptotic IAP-family member that directly neutralizes caspase-9 via its BIR3 domain and the effector caspases-3 and -7 via its BIR2 domain. A natural inhibitor of XIAP is SMAC/Diablo which is released from mitochondria in apoptotic cells and displaces bound caspases from the BIR2/BIR3 domains of XIAP thereby reactivating cell death execution. The central apoptosis-inhibitory function of XIAP and its overexpression in many different types of advanced cancers have led to significant efforts to identify therapeutics that neutralize its anti-apoptotic effect. Most of these drugs are chemical derivatives of the N-terminal part of SMAC/Diablo. These SMAC Mimetics either specifically induce apoptosis in cancer cells or act as drug-sensitizers. Several SMAC Mimetics are currently tested by the pharmaceutical industry in Phase I and Phase II trials. In this review we will discuss recent advances in understanding the function of IAPs in normal and malignant cells and focus on approaches to specifically neutralize XIAP in cancer cells.

  20. Guidelines and recommendations on yeast cell death nomenclature

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    Didac Carmona-Gutierrez

    2018-01-01

    Full Text Available Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differential definition of terms including apoptosis, regulated necrosis, and autophagic cell death, as we refer to additional cell death routines that are relevant for the biology of (at least some species of yeast. As this area of investigation advances rapidly, changes and extensions to this set of recommendations will be implemented in the years to come. Nonetheless, we strongly encourage the authors, reviewers and editors of scientific articles to adopt these collective standards in order to establish an accurate framework for yeast cell death research and, ultimately, to accelerate the progress of this vibrant field of research.

  1. The p75NTR tumor suppressor induces cell cycle arrest facilitating caspase mediated apoptosis in prostate tumor cells

    International Nuclear Information System (INIS)

    Khwaja, Fatima; Tabassum, Arshia; Allen, Jeff; Djakiew, Daniel

    2006-01-01

    The p75 neurotrophin receptor (p75 NTR ) is a death receptor which belongs to the tumor necrosis factor receptor super-family of membrane proteins. This study shows that p75 NTR retarded cell cycle progression by induced accumulation of cells in G0/G1 and a reduction in the S phase of the cell cycle. The rescue of tumor cells from cell cycle progression by a death domain deleted (ΔDD) dominant-negative antagonist of p75 NTR showed that the death domain transduced anti-proliferative activity in a ligand-independent manner. Conversely, addition of NGF ligand rescued retardation of cell cycle progression with commensurate changes in components of the cyclin/cdk holoenzyme complex. In the absence of ligand, p75 NTR -dependent cell cycle arrest facilitated an increase in apoptotic nuclear fragmentation of the prostate cancer cells. Apoptosis of p75 NTR expressing cells occurred via the intrinsic mitochondrial pathway leading to a sequential caspase-9 and -7 cascade. Since the death domain deleted dominant-negative antagonist of p75 NTR rescued intrinsic caspase associated apoptosis in PC-3 cells, this shows p75 NTR was integral to ligand independent induction of apoptosis. Moreover, the ability of ligand to ameliorate the p75 NTR -dependent intrinsic apoptotic cascade indicates that NGF functioned as a survival factor for p75 NTR expressing prostate cancer cells

  2. Phosphorylation of XIAP by CDK1–cyclin-B1 controls mitotic cell death

    Science.gov (United States)

    Hou, Ying; Allan, Lindsey A.

    2017-01-01

    ABSTRACT Regulation of cell death is crucial for the response of cancer cells to drug treatments that cause arrest in mitosis, and is likely to be important for protection against chromosome instability in normal cells. Prolonged mitotic arrest can result in cell death by activation of caspases and the induction of apoptosis. Here, we show that X-linked inhibitor of apoptosis (XIAP) plays a key role in the control of mitotic cell death. Ablation of XIAP expression sensitises cells to prolonged mitotic arrest caused by a microtubule poison. XIAP is stable during mitotic arrest, but its function is controlled through phosphorylation by the mitotic kinase CDK1–cyclin-B1 at S40. Mutation of S40 to a phosphomimetic residue (S40D) inhibits binding to activated effector caspases and abolishes the anti-apoptotic function of XIAP, whereas a non-phosphorylatable mutant (S40A) blocks apoptosis. By performing live-cell imaging, we show that phosphorylation of XIAP reduces the threshold for the onset of cell death in mitosis. This work illustrates that mitotic cell death is a form of apoptosis linked to the progression of mitosis through control by CDK1–cyclin-B1. PMID:27927753

  3. Cytokine production and apoptosis among T cells from patients under treatment for Plasmodium falciparum malaria

    DEFF Research Database (Denmark)

    Kemp, K; Akanmori, B D; Adabayeri, V

    2002-01-01

    of inflammation, followed by their release back into the peripheral blood where they undergo apoptotic death to re-establish immunological homeostasis as inflammation subsides. However, the high proportion of pre-apoptotic cells from the time of admission suggests that apoptosis also contributes to the low...

  4. Detection of Apoptosis and Necrosis in Normal Human Lung Cells Using 1H NMR Spectroscopy

    Science.gov (United States)

    Shih, Chwen-Ming; Ko, Wun-Chang; Yang, Liang-Yo; Lin, Chien-Ju; Wu, Jui-Sheng; Lo, Tsui-Yun; Wang, Shwu-Huey; Chen, Chien-Tsu

    2005-05-01

    This study aimed to detect apoptosis and necrosis in MRC-5, a normal human lung cell line, by using noninvasive proton nuclear magnetic resonance (1H NMR). Live MRC-5 cells were processed first for 1H NMR spectroscopy; subsequently their types and the percentage of cell death were assessed on a flow cytometer. Cadmium (Cd) and mercury (Hg) induced apoptosis and necrosis in MRC-5 cells, respectively, as revealed by phosphatidylserine externalization on a flow cytometer. The spectral intensity ratio of methylene (CH2) resonance (at 1.3 ppm) to methyl (CH3) resonance (at 0.9 ppm) was directly proportional to the percentage of apoptosis and strongly and positively correlated with PI staining after Cd treatment (r2 = 0.9868, P In contrast, this ratio only increased slightly within 2-h Hg treatment, and longer Hg exposure failed to produce further increase. Following 2-h Hg exposure, the spectral intensity of choline resonance (at 3.2 ppm) was abolished, but this phenomenon was absent in Cd-induced apoptosis. These findings together demonstrate that 1H NMR is a novel tool with a quantitative potential to distinguish apoptosis from necrosis as early as the onset of cell death in normal human lung cells.

  5. Non-apoptotic cell death associated with perturbations of macropinocytosis.

    Science.gov (United States)

    Maltese, William A; Overmeyer, Jean H

    2015-01-01

    Although macropinocytosis is widely recognized as a distinct form of fluid-phase endocytosis in antigen-presenting dendritic cells, it also occurs constitutively in many other normal and transformed cell types. Recent studies have established that various genetic or pharmacological manipulations can hyperstimulate macropinocytosis or disrupt normal macropinosome trafficking pathways, leading to accumulation of greatly enlarged cytoplasmic vacuoles. In some cases, this extreme vacuolization is associated with a unique form of non-apoptotic cell death termed "methuosis," from the Greek methuo (to drink to intoxication). It remains unclear whether cell death related to dysfunctional macropinocytosis occurs in normal physiological contexts. However, the finding that some types of cancer cells are particularly vulnerable to this unusual form of cell death has raised the possibility that small molecules capable of altering macropinosome trafficking or function might be useful as therapeutic agents against cancers that are resistant to drugs that work by inducing apoptosis. Herein we review examples of cell death associated with dysfunctional macropinocytosis and summarize what is known about the underlying mechanisms.

  6. Non-apoptotic cell death associated with perturbations of macropinocytosis

    Directory of Open Access Journals (Sweden)

    William A. Maltese

    2015-02-01

    Full Text Available Although macropinocytosis is widely recognized as a distinct form of fluid-phase endocytosis in antigen-presenting dendritic cells, it also occurs constitutively in many other normal and transformed cell types. Recent studies have established that various genetic or pharmacological manipulations can hyperstimulate macropinocytosis or disrupt normal macropinosome trafficking pathways, leading to accumulation of greatly enlarged cytoplasmic vacuoles. In some cases, this extreme vacuolization is associated with a unique form of non-apoptotic cell death termed ‘methuosis’, from the Greek methuo (to drink to intoxication. It remains unclear whether cell death related to dysfunctional macropinocytosis occurs in normal physiological contexts. However, the finding that some types of cancer cells are particularly vulnerable to this unusual form of cell death has raised the possibility that small molecules capable of altering macropinosome trafficking or function might be useful as therapeutic agents against cancers that are resistant to drugs that work by inducing apoptosis. Herein we review examples of cell death associated with dysfunctional macropinocytosis and summarize what is known about the underlying mechanisms.

  7. Ulmus davidiana Nakai induces apoptosis and autophagy on non-small cell lung cancer cells.

    Science.gov (United States)

    Hong, Soon-Oh; Choi, In Keun; Jeong, Wonsik; Lee, Se Ryeon; Sung, Hwa Jung; Hong, Seong Su; Seo, Jae Hong

    2017-04-18

    Ulmus davidiana Nakai (UDN) is frequently used in the treatment of cancer in traditional oriental medicine. Although several reports indicate that UDN has inhibitory effects in some cancers, there has been no report on the inhibitory effects of UDN via both autophagy and apoptosis. Cytotoxicity induced by UDN in human non-small cell lung cancer (NSCLC) H-1299 and H-460 cell lines was evaluated using the 2, 3-Bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide inner salt (XTT) assay and trypan blue exclusion assay. Induction of apoptosis was also investigated using Hoechst staining and annexin-V binding assay and was confirmed with western blot analysis. Induction of autophagy was investigated through observation of autophagy vacuoles under inverted phase-contrast microscopy and was confirmed by observing the formation of autophagy vacuoles under a fluorescence microscope using monodansylcadaverine (MDC) staining and western blot analysis. The in vivo anti-tumorigenic effect of UDN was investigated in an athymic nude mouse xenograft model using H-1299 NSCLC cells. UDN exhibited a marked inhibitory effect on cell growth in H-1299 and H-460 human NSCLC cell lines in a dose- and time-dependent manner in vitro and in vivo. It induced not only apoptosis, but also autophagy in both H-1299 and H-460 cells in a dose-dependent manner. UDN-mediated autophagy led to the accumulation of autophagosome, resulting in apoptosis induction and cell death. From our current knowledge, we are the first to demonstrate that UDN has the potential to induce both autophagy and apoptosis in H-1299 and H-460 human NSCLC cell lines. We suggest that UDN can be considered a potential candidate for lung cancer-specific chemotherapy with efficacy as a cytotoxic agent. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  8. Aspartame-induced apoptosis in PC12 cells.

    Science.gov (United States)

    Horio, Yukari; Sun, Yongkun; Liu, Chuang; Saito, Takeshi; Kurasaki, Masaaki

    2014-01-01

    Aspartame is an artificial sweetner added to many low-calorie foods. The safety of aspartame remains controversial even though there are many studies on its risks. In this study, to understand the physiological effects of trace amounts of artificial sweetners on cells, the effects of aspartame on apoptosis were investigated using a PC12 cell system. In addition, the mechanism of apoptosis induced by aspartame in PC12 cells and effects on apoptotic factors such as cytochrome c, apoptosis-inducing factor, and caspase family proteins were studied by Western blotting and RT-PCR. Aspartame-induced apoptosis in PC12 cells in a dose-dependent manner. In addition, aspartame exposure increased the expressions of caspases 8 and 9, and cytochrome c. These results indicate that aspartame induces apoptosis mainly via mitochondrial pathway involved in apoptosis due to oxigen toxicity. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Cell shrinkage as a signal to apoptosis in NIH 3T3 fibroblasts

    DEFF Research Database (Denmark)

    Friis, Martin B; Friborg, Christel R; Schneider, Linda

    2005-01-01

    Cell shrinkage is a hallmark of the apoptotic mode of programmed cell death, but it is as yet unclear whether a reduction in cell volume is a primary activation signal of apoptosis. Here we studied the effect of an acute elevation of osmolarity (NaCl or sucrose additions, final osmolarity 687...... mosmol l(-1)) on NIH 3T3 fibroblasts to identify components involved in the signal transduction from shrinkage to apoptosis. After 1.5 h the activity of caspase-3 started to increase followed after 3 h by the appearance of many apoptotic-like bodies. The caspase-3 activity increase was greatly enhanced...

  10. [Heat shock protein 90--modulator of TNFalpha-induced apoptosis of Jurkat tumor cells].

    Science.gov (United States)

    Kaĭgorodova, E V; Riazantseva, N V; Novitskiĭ, V V; Moroshkina, A N; Belkina, M V; Iakushina, V D

    2011-01-01

    rTNFalpha-induced programmed death of Jurkat tumor cells cultured with 17-AAG, a selective inhibitor of heat shock protein (Hsp90), was studied by fluorescent microscopy with the use of FITC-labeled annexin V and propidium iodide. Caspase-3 and -8 activities were determined by spectrophotometry using a caspase- 3 and -8 colorimetric assay kit. It was shown that inhibition of Hsp90 leads to activation of Jurkat cell apoptosis while Hsp90 itself suppresses this process. 17-AAG enhances rTNFa-induced apoptosis of tumor cells.

  11. Auranofin induces apoptosis and necrosis in HeLa cells via oxidative stress and glutathione depletion.

    Science.gov (United States)

    You, Bo Ra; Shin, Hye Rim; Han, Bo Ram; Kim, Suhn Hee; Park, Woo Hyun

    2015-02-01

    Auranofin (Au), an inhibitor of thioredoxin reductase, is a known anti‑cancer drug. In the present study, the anti‑growth effect of Au on HeLa cervical cancer cells was examined in association with levels of reactive oxygen species (ROS) and glutathione (GSH). Au inhibited the growth of HeLa cells with an IC50 of ~2 µM at 24 h. This agent induced apoptosis and necrosis, accompanied by the cleavage of poly (ADP‑ribose) polymerase and loss of mitochondrial membrane potential. The pan‑caspase inhibitor, benzyloxycarbonyl‑Val‑Ala‑Asp‑fluoromethylketone, prevented apoptotic cell death and each of the assessed caspase inhibitors inhibited necrotic cell death induced by Au. With respect to the levels of ROS and GSH, Au increased intracellular O2•- in the HeLa cells and induced GSH depletion. The pan‑caspase inhibitor reduced the levels of O2•- and GSH depletion in Au‑treated HeLa cells. The antioxidant, N‑acetyl cysteine, not only attenuated apoptosis and necrosis in the Au‑treated HeLa cells, but also decreased the levels of O2•- and GSH depletion in the cells. By contrast, L‑buthionine sulfoximine, a GSH synthesis inhibitor, intensified cell death O2•- and GSH depletion in the Au‑treated HeLa cells. In conclusion, Au induced apoptosis and necrosis in HeLa cells via the induction of oxidative stress and the depletion of GSH.

  12. The Roles of ROS and Caspases in TRAIL-Induced Apoptosis and Necroptosis in Human Pancreatic Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Min Zhang

    Full Text Available Death signaling provided by tumor necrosis factor (TNF-related apoptosis-inducing ligand (TRAIL can induce death in cancer cells with little cytotoxicity to normal cells; this cell death has been thought to involve caspase-dependent apoptosis. Reactive oxygen species (ROS are also mediators that induce cell death, but their roles in TRAIL-induced apoptosis have not been elucidated fully. In the current study, we investigated ROS and caspases in human pancreatic cancer cells undergoing two different types of TRAIL-induced cell death, apoptosis and necroptosis. TRAIL treatment increased ROS in two TRAIL-sensitive pancreatic cancer cell lines, MiaPaCa-2 and BxPC-3, but ROS were involved in TRAIL-induced apoptosis only in MiaPaCa-2 cells. Unexpectedly, inhibition of ROS by either N-acetyl-L-cysteine (NAC, a peroxide inhibitor, or Tempol, a superoxide inhibitor, increased the annexin V-/propidium iodide (PI+ early necrotic population in TRAIL-treated cells. Additionally, both necrostatin-1, an inhibitor of receptor-interacting protein kinase 1 (RIP1, and siRNA-mediated knockdown of RIP3 decreased the annexin V-/PI+ early necrotic population after TRAIL treatment. Furthermore, an increase in early apoptosis was induced in TRAIL-treated cancer cells under inhibition of either caspase-2 or -9. Caspase-2 worked upstream of caspase-9, and no crosstalk was observed between ROS and caspase-2/-9 in TRAIL-treated cells. Together, these results indicate that ROS contribute to TRAIL-induced apoptosis in MiaPaCa-2 cells, and that ROS play an inhibitory role in TRAIL-induced necroptosis of MiaPaCa-2 and BxPC-3 cells, with caspase-2 and -9 playing regulatory roles in this process.

  13. Taxifolin synergizes Andrographolide-induced cell death by attenuation of autophagy and augmentation of caspase dependent and independent cell death in HeLa cells.

    Directory of Open Access Journals (Sweden)

    Mazen Alzaharna

    Full Text Available Andrographolide (Andro has emerged recently as a potential and effective anticancer agent with induction of apoptosis in some cancer cell lines while induction of G2/M arrest with weak apoptosis in others. Few studies have proved that Andro is also effective in combination therapy. The flavonoid Taxifolin (Taxi has showed anti-oxidant and antiproliferative effects against different cancer cells. Therefore, the present study investigated the cytotoxic effects of Andro alone or in combination with Taxi on HeLa cells. The combination of Andro with Taxi was synergistic at all tested concentrations and combination ratios. Andro alone induced caspase-dependent apoptosis which was enhanced by the combination with Taxi and attenuated partly by using Z-Vad-Fmk. Andro induced a protective reactive oxygen species (ROS-dependent autophagy which was attenuated by Taxi. The activation of p53 was involved in Andro-induced autophagy where the use of Taxi or pifithrin-α (PFT-α decreased it while the activation of JNK was involved in the cell death of HeLa cells but not in the induction of autophagy. The mitochondrial outer-membrane permeabilization (MOMP plays an important role in Andro-induced cell death in HeLa cells. Andro alone increased the MOMP which was further increased in the case of combination. This led to the increase in AIF and cytochrome c release from mitochondria which consequently increased caspase-dependent and independent cell death. In conclusion, Andro induced a protective autophagy in HeLa cells which was reduced by Taxi and the cell death was increased by increasing the MOMP and subsequently the caspase-dependent and independent cell death.

  14. Taxifolin synergizes Andrographolide-induced cell death by attenuation of autophagy and augmentation of caspase dependent and independent cell death in HeLa cells.

    Science.gov (United States)

    Alzaharna, Mazen; Alqouqa, Iyad; Cheung, Hon-Yeung

    2017-01-01

    Andrographolide (Andro) has emerged recently as a potential and effective anticancer agent with induction of apoptosis in some cancer cell lines while induction of G2/M arrest with weak apoptosis in others. Few studies have proved that Andro is also effective in combination therapy. The flavonoid Taxifolin (Taxi) has showed anti-oxidant and antiproliferative effects against different cancer cells. Therefore, the present study investigated the cytotoxic effects of Andro alone or in combination with Taxi on HeLa cells. The combination of Andro with Taxi was synergistic at all tested concentrations and combination ratios. Andro alone induced caspase-dependent apoptosis which was enhanced by the combination with Taxi and attenuated partly by using Z-Vad-Fmk. Andro induced a protective reactive oxygen species (ROS)-dependent autophagy which was attenuated by Taxi. The activation of p53 was involved in Andro-induced autophagy where the use of Taxi or pifithrin-α (PFT-α) decreased it while the activation of JNK was involved in the cell death of HeLa cells but not in the induction of autophagy. The mitochondrial outer-membrane permeabilization (MOMP) plays an important role in Andro-induced cell death in HeLa cells. Andro alone increased the MOMP which was further increased in the case of combination. This led to the increase in AIF and cytochrome c release from mitochondria which consequently increased caspase-dependent and independent cell death. In conclusion, Andro induced a protective autophagy in HeLa cells which was reduced by Taxi and the cell death was increased by increasing the MOMP and subsequently the caspase-dependent and independent cell death.

  15. A Mycobacterium ulcerans Toxin, Mycolactone, Causes Apoptosis in Guinea Pig Ulcers and Tissue Culture Cells

    Science.gov (United States)

    George, Kathleen M.; Pascopella, Lisa; Welty, Diane M.; Small, P. L. C.

    2000-01-01

    Mycobacterium ulcerans is the causative agent of Buruli ulcer, a tropical ulcerative skin disease. One of the most intriguing aspects of this disease is the presence of extensive tissue damage in the absence of an acute inflammatory response. We recently purified and characterized a macrolide toxin, mycolactone, from M. ulcerans. Injection of this molecule into guinea pig skin reproduced cell death and lack of acute inflammatory response similar to that seen following the injection of viable bacteria. We also showed that mycolactone causes a cytopathic effect on mouse fibroblast L929 cells that is characterized by cytoskeletal rearrangements and growth arrest within 48 h. However, these results could not account for the extensive cell death which occurs in Buruli ulcer. The results presented here demonstrate that L929 and J774 mouse macrophage cells die via apoptosis after 3 to 5 days of exposure to mycolactone. Treatment of cells with a pan-caspase inhibitor can inhibit mycolactone-induced apoptosis. We demonstrate that injection of mycolactone into guinea pig skin results in cell death via apoptosis and that the extent of apoptosis increases as the lesion progresses. These results may help to explain why tissue damage in Buruli ulcer is not accompanied by an acute inflammatory response. PMID:10639458

  16. MADD knock-down enhances doxorubicin and TRAIL induced apoptosis in breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Andrea Turner

    Full Text Available The Map kinase Activating Death Domain containing protein (MADD isoform of the IG20 gene is over-expressed in different types of cancer tissues and cell lines and it functions as a negative regulator of apoptosis. Therefore, we speculated that MADD might be over-expressed in human breast cancer tissues and that MADD knock-down might synergize with chemotherapeutic or TRAIL-induced apoptosis of breast cancer cells. Analyses of breast tissue microarrays revealed over-expression of MADD in ductal and invasive carcinomas relative to benign tissues. MADD knockdown resulted in enhanced spontaneous apoptosis in human breast cancer cell lines. Moreover, MADD knockdown followed by treatment with TRAIL or doxorubicin resulted in increased cell death compared to either treatment alone. Enhanced cell death was found to be secondary to increased caspase-8 activation. These data indicate that strategies to decrease MADD expression or function in breast cancer may be utilized to increase tumor cell sensitivity to TRAIL and doxorubicin induced apoptosis.

  17. Bee Venom Protects against Rotenone-Induced Cell Death in NSC34 Motor Neuron Cells

    Directory of Open Access Journals (Sweden)

    So Young Jung

    2015-09-01

    Full Text Available Rotenone, an inhibitor of mitochondrial complex I of the mitochondrial respiratory chain, is known to elevate mitochondrial reactive oxygen species and induce apoptosis via activation of the caspase-3 pathway. Bee venom (BV extracted from honey bees has been widely used in oriental medicine and contains melittin, apamin, adolapin, mast cell-degranulating peptide, and phospholipase A2. In this study, we tested the effects of BV on neuronal cell death by examining rotenone-induced mitochondrial dysfunction. NSC34 motor neuron cells were pretreated with 2.5 μg/mL BV and stimulated with 10 μM rotenone to induce cell toxicity. We assessed cell death by Western blotting using specific antibodies, such as phospho-ERK1/2, phospho-JNK, and cleaved capase-3 and performed an MTT assay for evaluation of cell death and mitochondria staining. Pretreatment with 2.5 μg/mL BV had a neuroprotective effect against 10 μM rotenone-induced cell death in NSC34 motor neuron cells. Pre-treatment with BV significantly enhanced cell viability and ameliorated mitochondrial impairment in rotenone-treated cellular model. Moreover, BV treatment inhibited the activation of JNK signaling and cleaved caspase-3 related to cell death and increased ERK phosphorylation involved in cell survival in rotenone-treated NSC34 motor neuron cells. Taken together, we suggest that BV treatment can be useful for protection of neurons against oxidative stress or neurotoxin-induced cell death.

  18. JNK activation is required for TNFα-induced apoptosis in human hepatocarcinoma cells.

    Science.gov (United States)

    Minero, Valerio Giacomo; Khadjavi, Amina; Costelli, Paola; Baccino, Francesco Maria; Bonelli, Gabriella

    2013-09-01

    A frequent distinctive feature of tumors, hepatocellular carcinomas included, is resistance to apoptosis induced by a variety of agents, among which the pleiotropic cytokine tumor necrosis factor-α (TNF). Compared to other cell types, hepatocytes and hepatoma-derived cell lines are poorly susceptible to TNF-induced apoptosis, which is largely ascribed to activation of the prosurvival transcription factor NF-κB and can be overcome by associating TNF to low doses of protein synthesis inhibitors or other drugs. This study analyses the molecular mechanisms by which TNF, in combination with cycloheximide (CHX), induces apoptosis in human hepatoma-derived Huh7 cells, focusing on the role played by JNK. Huh7 cell cultures were treated with TNF + CHX in the presence or in the absence of the pancaspase inhibitor zVADfmk or of the JNK inhibitor SP600125 as well as after suppression of JNK expression by RNAi. Apoptosis was assessed both by light microscopy and by flow cytometry, JNK and caspase activation by western blotting and/or enzymatic assay. TNF + CHX-induced death of Huh7 cells involved JNK activation since it was partially prevented by suppressing JNK activity or expression. Moreover, apoptosis was significantly reduced also by zVADfmk, while SP600125 and zVADfmk combined totally abrogated cell death in an additive fashion. These results demonstrate a causal role for JNK and caspases in TNF+CHX-induced apoptosis of Huh7 human hepatoma cells. Therefore, strategies aimed at enhancing both pathways should provide a profitable basis to overcome the resistance of hepatocarcinoma cells to TNF-dependent apoptosis. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Cardiac Glycoside Glucoevatromonoside Induces Cancer Type-Specific Cell Death

    Directory of Open Access Journals (Sweden)

    Naira F. Z. Schneider

    2018-03-01

    Full Text Available Cardiac glycosides (CGs are natural compounds used traditionally to treat congestive heart diseases. Recent investigations repositioned CGs as potential anticancer agents. To discover novel cytotoxic CG scaffolds, we selected the cardenolide glucoevatromonoside (GEV out of 46 CGs for its low nanomolar anti-lung cancer activity. GEV presented reduced toxicity toward non-cancerous cell types (lung MRC-5 and PBMC and high-affinity binding to the Na+/K+-ATPase α subunit, assessed by computational docking. GEV-induced cell death was caspase-independent, as investigated by a multiparametric approach, and culminates in severe morphological alterations in A549 cells, monitored by transmission electron microscopy, live cell imaging and flow cytometry. This non-canonical cell death was not preceded or accompanied by exacerbation of autophagy. In the presence of GEV, markers of autophagic flux (e.g. LC3I-II conversion were impacted, even in presence of bafilomycin A1. Cell death induction remained unaffected by calpain, cathepsin, parthanatos, or necroptosis inhibitors. Interestingly, GEV triggered caspase-dependent apoptosis in U937 acute myeloid leukemia cells, witnessing cancer-type specific cell death induction. Differential cell cycle modulation by this CG led to a G2/M arrest, cyclin B1 and p53 downregulation in A549, but not in U937 cells. We further extended the anti-cancer potential of GEV to 3D cell culture using clonogenic and spheroid formation assays and validated our findings in vivo by zebrafish xenografts. Altogether, GEV shows an interesting anticancer profile with the ability to exert cytotoxic effects via induction of different cell death modalities.

  20. Barium inhibits arsenic-mediated apoptotic cell death in human squamous cell carcinoma cells.

    Science.gov (United States)

    Yajima, Ichiro; Uemura, Noriyuki; Nizam, Saika; Khalequzzaman, Md; Thang, Nguyen D; Kumasaka, Mayuko Y; Akhand, Anwarul A; Shekhar, Hossain U; Nakajima, Tamie; Kato, Masashi

    2012-06-01

    Our fieldwork showed more than 1 μM (145.1 μg/L) barium in about 3 μM (210.7 μg/L) arsenic-polluted drinking well water (n = 72) in cancer-prone areas in Bangladesh, while the mean concentrations of nine other elements in the water were less than 3 μg/L. The types of cancer include squamous cell carcinomas (SCC). We hypothesized that barium modulates arsenic-mediated biological effects, and we examined the effect of barium (1 μM) on arsenic (3 μM)-mediated apoptotic cell death of human HSC-5 and A431 SCC cells in vitro. Arsenic promoted SCC apoptosis with increased reactive oxygen species (ROS) production and JNK1/2 and caspase-3 activation (apoptotic pathway). In contrast, arsenic also inhibited SCC apoptosis with increased NF-κB activity and X-linked inhibitor of apoptosis protein (XIAP) expression level and decreased JNK activity (antiapoptotic pathway). These results suggest that arsenic bidirectionally promotes apoptotic and antiapoptotic pathways in SCC cells. Interestingly, barium in the presence of arsenic increased NF-κB activity and XIAP expression and decreased JNK activity without affecting ROS production, resulting in the inhibition of the arsenic-mediated apoptotic pathway. Since the anticancer effect of arsenic is mainly dependent on cancer apoptosis, barium-mediated inhibition of arsenic-induced apoptosis may promote progression of SCC in patients in Bangladesh who keep drinking barium and arsenic-polluted water after the development of cancer. Thus, we newly showed that barium in the presence of arsenic might inhibit arsenic-mediated cancer apoptosis with the modulation of the balance between arsenic-mediated promotive and suppressive apoptotic pathways.

  1. Effect of Trace Elements in Alcohol Beverages on the Type of Radiation-induced Cell Death

    International Nuclear Information System (INIS)

    Sohn, Jong Gi

    2010-01-01

    Developments of radioprotective agents are important issues for minimizing the troubles and the effective treatments in radiotherapy. But few agents are useful in clinical and practical fields. It was shown that trace elements in alcohol beverages might have radioprotective effect. In this study, the types of cell death of lymphocytes according to the commercial alcohol beverage was investigated. Normal healthy volunteers ingested distilled water, beer or soju containing 8.15 mg·dl -1 ethyl ahcohol, respectively. After 2 hours, their blood were sampled with their consents. Fraction of lymphocytes was isolated by density gradient method with Histopaque-1077 (Sigma) and irradiated with dose from 0.5 to 5 Gy. After 60 hour incubation, the cells were harvested and analysed by flow cytometry. Cell viability was decreased by dose dependent manner. Cell viability of beer group was reduced about 15% compared with control group. Apoptosis in soju group was reduced about 20% compared with control group. Apoptosis of beer and control groups are similar. Necrosis of soju group significantly increased about 35% compared with control group. Early apoptosis of beer group was increased compared with control group. Early apoptosis of soju group was decreased about 25% compared with control group. Late apoptosis of beer and control group was increased by dose dependent manner. Late apoptosis of soju group was increased about 20-30% compared with control group. Late apoptosis of soju was increased and the radioprotective effect of soju was minimal because late apoptosis induced the cell necrosis. In case of soju trace elements, total cell apoptosis was decreased about 20% and early cell apoptosis was remarkably low. In this case, mitotic cells death may be dominant mechanism. Therefore, trace elements in soju may not be effective radioprotective agents

  2. Dietary antioxidants protect gut epithelial cells from oxidant-induced apoptosis

    Directory of Open Access Journals (Sweden)

    Bobrowski Paul

    2001-12-01

    Full Text Available Abstract Background The potential of ascorbic acid and two botanical decoctions, green tea and cat's claw, to limit cell death in response to oxidants were evaluated in vitro. Methods Cultured human gastric epithelial cells (AGS or murine small intestinal epithelial cells (IEC-18 were exposed to oxidants – DPPH (3 μM, H2O2 (50 μM, peroxynitrite (300 μM – followed by incubation for 24 hours, with antioxidants (10 μg/ml administered as a 1 hour pretreatment. Cell number (MTT assay and death via apoptosis or necrosis (ELISA, LDH release was determined. The direct interactions between antioxidants and DPPH (100 μM or H2O2 (50 μM were evaluated by spectroscopy. Results The decoctions did not interact with H2O2, but quenched DPPH although less effectively than vitamin C. In contrast, vitamin C was significantly less effective in protecting human gastric epithelial cells (AGS from apoptosis induced by DPPH, peroxynitrite and H2O2 (P 2O2, but green tea was more effective than cat's claw in reducing DPPH-induced apoptosis (P 2O2, and was attenuated both by cat's claw and green tea (P Conclusions These results indicate that dietary antioxidants can limit epithelial cell death in response to oxidant stress. In the case of green tea and cat's claw, the cytoprotective response exceed their inherent ability to interact with the injurious oxidant, suggestive of actions on intracellular pathways regulating cell death.

  3. Lobaplatin inhibits growth of gastric cancer cells by inducing apoptosis

    Science.gov (United States)

    Yin, Chu-Yang; Lin, Xiao-Lin; Tian, Lei; Ye, Ming; Yang, Xin-Ying; Xiao, Xiu-Ying

    2014-01-01

    AIM: To assess the anti-cancer effect of lobaplatin on human gastric cancer cells, and to explore the underlying molecular mechanisms. METHODS: The human gastric cancer cell lines MKN-28, AGS and MKN-45 were used. The cytotoxicity of lobaplatin was detected using an MTS cell proliferation assay. Flow cytometry was used to detect cell apoptosis using Annexin V-FITC Apoptosis Detection Kit. The expression of apoptosis-regulated genes was examined at the protein level using Western blot. RESULTS: Lobaplatin inhibited the proliferation of human gastric cancer cells and induced apoptosis, which may be associated with the up-regulation of Bax expression, poly(ADP-ribose) polymerase (PARP) cleavage, p53 expression and the reduction of Bcl-2 expression. CONCLUSION: The cytotoxicity of lobaplatin may be due to its ability of inducing apoptosis of gastric cancer cells, which would support the potential use of lobaplatin for the therapy of gastric cancer. PMID:25516654

  4. A critical role for ethylene in hydrogen peroxide release during programmed cell death in tomato suspension cells

    NARCIS (Netherlands)

    Jong, de A.J.; Yakimova, E.T.; Kapchina, V.M.; Woltering, E.J.

    2002-01-01

    Camptothecin, a topo isomerase-I inhibitor used in cancer therapy, induces apoptosis in animal cells. In tomato (Lycopersicon esculentum Mill.) suspension cells, camptothecin induces cell death that is accompanied by the characteristic nuclear morphological changes such as chromatin condensation and

  5. Gravisensing, apoptosis, and drug recovery in Taxus cell suspensions

    Science.gov (United States)

    Durzan, D. J.

    1999-01-01

    Haploid and diploid cell suspensions of Taxus spp. were examined for their adaptive plasticity in response to simulated microgravity, unit gravity, and hypergravity. Cell suspensions produced the taxane, paclitaxel, (TAXOL (R)), which is useful for the treatment of various cancers. Amyloplasts contributed to taxane ring biosynthesis and to drug release at the cell wall. Drug-producing cells reacted as gravisensing osmotic tensiometers. In stressed cells, amyloplasts docked and fused in clusters to sites on the plasmalemma before taxane discharge into the culture medium. In simulated microgravity and compared to all other treatments, taxane production was reduced nearly 100-fold. The percent paclitaxel of total taxanes remained 3-to 6-fold greater, and biomass doubled. When p53-independent programmed cell death was induced, taxanes were released into the culture medium as free molecules (soluble and insoluble) or bound to membranes, nuclear fragments, xylan residues, and other particulate materials. Unit gravity and especially hypergravity promoted xylogenesis and significant drug overproduction. A model relating families of >touch = (TCH), taxane early response (TER), nuclear cycling, and apoptosis-regulating genes to gravisensing, cell wall modifications, and to taxane recovery accounted for most but not all of the observations.

  6. Tempol inhibits growth of As4.1 juxtaglomerular cells via cell cycle arrest and apoptosis.

    Science.gov (United States)

    Han, Yong Hwan; Park, Woo Hyun

    2012-03-01

    A stable nitroxide 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-osyl (Tempol) is widely used as an antioxidant in vitro and in vivo. In this study, we investigated the effects of Tempol on the growth of As4.1 juxtaglomerular cells in relation to cell cycle and cell death. Tempol dose-dependently decreased the growth of As4.1 cells with an IC50 of ~1 mM at 48 h. DNA flow cytometry analysis and BrdU staining indicated that Tempol induced S phase arrest, which is accompanied by a downregulation of cyclin A. Tempol also induced apoptotic cell death, which was accompanied by the loss of mitochondrial membrane potential (MMP; ∆Ψm), an activation of caspase-3 and cleavage of poly(ADP-ribose)polymerase-1 (PARP-1). Furthermore, Tempol increased reactive oxygen species (ROS) levels, and the phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK). MEK and JNK inhibitors significantly attenuated a growth inhibition in Tempol-treated As4.1 cells. In conclusion, Tempol inhibited the growth of As4.1 cells via cell cycle arrest and apoptosis. Tempol also activated ERK and JNK signaling, which was responsible for cell growth inhibition. Our present data provide useful information for the toxicological effects of Tempol in juxtaglomerular cells in relation to cell growth inhibition and cell death.

  7. 2-aryl benzimidazole conjugate induced apoptosis in human breast cancer MCF-7 cells through caspase independent pathway.

    Science.gov (United States)

    Nayak, V Lakshma; Nagesh, Narayana; Ravikumar, A; Bagul, Chandrakant; Vishnuvardhan, M V P S; Srinivasulu, Vunnam; Kamal, Ahmed

    2017-01-01

    Apoptosis is a representative form of programmed cell death, which has been assumed to be critical for cancer prevention. Thus, any agent that can induce apoptosis may be useful for cancer treatment and apoptosis induction is arguably the most potent defense against cancer promotion. In our previous studies, 2-aryl benzimidazole conjugates were synthesized and evaluated for their antiproliferative activity and one of the new molecule (2f) was considered as a potential lead. This lead molecule showed significant antiproliferative activity against human breast cancer cell line, MCF-7. The results of the present study revealed that this compound arrested the cell cycle at G2/M phase. Topoisomerase II inhibition assay and Western blot analysis suggested that this compound effectively inhibits topoisomerase II activity which leads to apoptotic cell death. Apoptosis induction in MCF-7 cells was further confirmed by loss of mitochondrial membrane potential (∆Ψm), release of cytochrome c from mitochondria, an increase in the level of apoptosis inducing factor (AIF), generation of reactive oxygen species (ROS), up regulation of proapoptotic protein Bax and down regulation of anti apoptotic protein Bcl-2. Apoptosis assay using Annexin V-FITC assay also suggested that this compound induced cell death by apoptosis. However, compound 2f induced apoptosis could not be reversed by Z-VAD-FMK (a pan-caspase inhibitor) demonstrated that the 2f induced apoptosis was caspase independent. Further, 2f treatment did not activate caspase-7 and caspase-9 activity, suggesting that this compound induced apoptosis in breast cancer cells via a caspase independent pathway. Most importantly, this compound was less toxic towards non-tumorigenic breast epithelial cells, MCF-10A. Furthermore, docking studies also support the potentiality of this molecule to bind to the DNA topoisomerase II.

  8. Terminalia Chebula provides protection against dual modes of necroptotic and apoptotic cell death upon death receptor ligation.

    Science.gov (United States)

    Lee, Yoonjung; Byun, Hee Sun; Seok, Jeong Ho; Park, Kyeong Ah; Won, Minho; Seo, Wonhyoung; Lee, So-Ra; Kang, Kidong; Sohn, Kyung-Cheol; Lee, Ill Young; Kim, Hyeong-Geug; Son, Chang Gue; Shen, Han-Ming; Hur, Gang Min

    2016-04-27

    Death receptor (DR) ligation elicits two different modes of cell death (necroptosis and apoptosis) depending on the cellular context. By screening a plant extract library from cells undergoing necroptosis or apoptosis, we identified a water extract of Terminalia chebula (WETC) as a novel and potent dual inhibitor of DR-mediated cell death. Investigation of the underlying mechanisms of its anti-necroptotic and anti-apoptotic action revealed that WETC or its constituents (e.g., gallic acid) protected against tumor necrosis factor-induced necroptosis via the suppression of TNF-induced ROS without affecting the upstream signaling events. Surprisingly, WETC also provided protection against DR-mediated apoptosis by inhibition of the caspase cascade. Furthermore, it activated the autophagy pathway via suppression of mTOR. Of the WETC constituents, punicalagin and geraniin appeared to possess the most potent anti-apoptotic and autophagy activation effect. Importantly, blockage of autophagy with pharmacological inhibitors or genetic silencing of Atg5 selectively abolished the anti-apoptotic function of WETC. These results suggest that WETC protects against dual modes of cell death upon DR ligation. Therefore, WETC might serve as a potential treatment for diseases characterized by aberrantly sensitized apoptotic or non-apoptotic signaling cascades.

  9. Granzyme B (GraB) Autonomously Crosses the Cell Membrane and Perforin Initiates Apoptosis and GraB Nuclear Localization

    OpenAIRE

    Shi, Lianfa; Mai, Sabine; Israels, Sara; Browne, Kylie; Trapani, Joseph A.; Greenberg, Arnold H.

    1997-01-01

    Granzyme B (GraB) induces apoptosis in the presence of perforin. Perforin polymerizes in the cell membrane to form a nonspecific ion pore, but it is not known where GraB acts to initiate the events that ultimately lead to apoptosis. It has been hypothesized that GraB enters the target cell through a perforin channel and then initiates apoptosis by cleaving and activating members of the ICE/Ced-3 family of cell death proteases. To determine if GraB can enter the cell, we treated YAC-1 or HeLa ...

  10. Ayanin diacetate-induced cell death is amplified by TRAIL in human leukemia cells

    International Nuclear Information System (INIS)

    Marrero, María Teresa; Estévez, Sara; Negrín, Gledy; Quintana, José; López, Mariana; Pérez, Francisco J.; Triana, Jorge; León, Francisco; Estévez, Francisco

    2012-01-01

    Highlights: ► Ayanin diacetate as apoptotic inducer in leukemia cells. ► Cell death was prevented by caspase inhibitors and by the overexpression of Bcl-x L . ► The intrinsic and the extrinsic pathways are involved in the mechanism of action. ► Death receptors are up-regulated and TRAIL enhances apoptotic cell death. -- Abstract: Here we demonstrate that the semi-synthetic flavonoid ayanin diacetate induces cell death selectively in leukemia cells without affecting the proliferation of normal lymphocytes. Incubation of human leukemia cells with ayanin diacetate induced G 2 -M phase cell cycle arrest and apoptosis which was prevented by the non-specific caspase inhibitor z-VAD-fmk and reduced by the overexpression of Bcl-x L . Ayanin diacetate-induced cell death was found to be associated with: (i) loss of inner mitochondrial membrane potential, (ii) the release of cytochrome c, (iii) the activation of multiple caspases, (iv) cleavage of poly(ADP-ribose) polymerase and (v) the up-regulation of death receptors for TRAIL, DR4 and DR5. Moreover, the combined treatment with ayanin diacetate and TRAIL amplified cell death, compared to single treatments. These results provide a basis for further exploring the potential applications of this combination for the treatment of cancer.

  11. Ayanin diacetate-induced cell death is amplified by TRAIL in human leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Marrero, Maria Teresa; Estevez, Sara; Negrin, Gledy; Quintana, Jose [Departamento de Bioquimica, Unidad Asociada al Consejo Superior de Investigaciones Cientificas, Universidad de Las Palmas de Gran Canaria, Plaza Dr. Pasteur s/n, 35016 Las Palmas de Gran Canaria (Spain); Lopez, Mariana; Perez, Francisco J.; Triana, Jorge [Departamento de Quimica, Universidad de Las Palmas de Gran Canaria, Instituto Canario de Investigacion del Cancer, 35017 Las Palmas de Gran Canaria (Spain); Leon, Francisco [Instituto de Productos Naturales y Agrobiologia, Consejo Superior de Investigaciones Cientificas, Avda. Astrofisico F. Sanchez 3, 38206 La Laguna, Tenerife (Spain); Estevez, Francisco, E-mail: festevez@dbbf.ulpgc.es [Departamento de Bioquimica, Unidad Asociada al Consejo Superior de Investigaciones Cientificas, Universidad de Las Palmas de Gran Canaria, Plaza Dr. Pasteur s/n, 35016 Las Palmas de Gran Canaria (Spain)

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer Ayanin diacetate as apoptotic inducer in leukemia cells. Black-Right-Pointing-Pointer Cell death was prevented by caspase inhibitors and by the overexpression of Bcl-x{sub L}. Black-Right-Pointing-Pointer The intrinsic and the extrinsic pathways are involved in the mechanism of action. Black-Right-Pointing-Pointer Death receptors are up-regulated and TRAIL enhances apoptotic cell death. -- Abstract: Here we demonstrate that the semi-synthetic flavonoid ayanin diacetate induces cell death selectively in leukemia cells without affecting the proliferation of normal lymphocytes. Incubation of human leukemia cells with ayanin diacetate induced G{sub 2}-M phase cell cycle arrest and apoptosis which was prevented by the non-specific caspase inhibitor z-VAD-fmk and reduced by the overexpression of Bcl-x{sub L}. Ayanin diacetate-induced cell death was found to be associated with: (i) loss of inner mitochondrial membrane potential, (ii) the release of cytochrome c, (iii) the activation of multiple caspases, (iv) cleavage of poly(ADP-ribose) polymerase and (v) the up-regulation of death receptors for TRAIL, DR4 and DR5. Moreover, the combined treatment with ayanin diacetate and TRAIL amplified cell death, compared to single treatments. These results provide a basis for further exploring the potential applications of this combination for the treatment of cancer.

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

    Science.gov (United States)

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

    2015-01-01

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

  13. Ulinastatin Reduces T Cell Apoptosis in Rats with Severe Acute ...

    African Journals Online (AJOL)

    T cell apoptosis was determined by Annexin-V/PI double-staining. Oxidative stress was evaluated by examining changes in the levels of reactive oxygen species (ROS). Total superoxide ... Key words: Ulinastatin, T cell, Apoptosis, Severe acute pancreatitis, Mitochondrion. Tropical ..... finally affect its structure and function.

  14. Apoptotic-like programed cell death in fungi: the benefits in filamentous species

    International Nuclear Information System (INIS)

    Shlezinger, Neta; Goldfinger, Nir; Sharon, Amir

    2012-01-01

    Studies conducted in the early 1990s showed for the first time that Saccharomyces cerevisiae can undergo cell death with hallmarks of animal apoptosis. These findings came as a surprise, since suicide machinery was unexpected in unicellular organisms. Today, apoptosis in yeast is well-documented. Apoptotic death of yeast cells has been described under various conditions and S. cerevisiae homologs of human apoptotic genes have been identified and characterized. These studies also revealed fundamental differences between yeast and animal apoptosis; in S. cerevisiae apoptosis is mainly associated with aging and stress adaptation, unlike animal apoptosis, which is essential for proper development. Further, many apoptosis regulatory genes are either missing, or highly divergent in S. cerevisiae. Therefore, in this review we will use the term apoptosis-like programed cell death (PCD) instead of apoptosis. Despite these significant differences, S. cerevisiae has been instrumental in promoting the study of heterologous apoptotic proteins, particularly from human. Work in fungi other than S. cerevisiae revealed differences in the manifestation of PCD in single cell (yeasts) and multicellular (filamentous) species. Such differences may reflect the higher complexity level of filamentous species, and hence the involvement of PCD in a wider range of processes and life styles. It is also expected that differences might be found in the apoptosis apparatus of yeast and filamentous species. In this review we focus on aspects of PCD that are unique or can be better studied in filamentous species. We will highlight the similarities and differences of the PCD machinery between yeast and filamentous species and show the value of using S. cerevisiae along with filamentous species to study apoptosis.

  15. Propolis Augments Apoptosis Induced by Butyrate via Targeting Cell Survival Pathways

    Science.gov (United States)

    Drago, Eric; Bordonaro, Michael; Lee, Seon; Atamna, Wafa; Lazarova, Darina L.

    2013-01-01

    Diet is one of the major lifestyle factors affecting incidence of colorectal cancer (CC), and despite accumulating evidence that numerous diet-derived compounds modulate CC incidence, definitive dietary recommendations are not available. We propose a strategy that could facilitate the design of dietary supplements with CC-preventive properties. Thus, nutrient combinations that are a source of apoptosis-inducers and inhibitors of compensatory cell proliferation pathways (e.g., AKT signaling) may produce high levels of programmed death in CC cells. Here we report the combined effect of butyrate, an apoptosis inducer that is produced through fermentation of fiber in the colon, and propolis, a honeybee product, on CC cells. We established that propolis increases the apoptosis of CC cells exposed to butyrate through suppression of cell survival pathways such as the AKT signaling. The programmed death of CC cells by combined exposure to butyrate and propolis is further augmented by inhibition of the JNK signaling pathway. Analyses on the contribution of the downstream targets of JNK signaling, c-JUN and JAK/STAT, to the apoptosis of butyrate/propolis-treated CC cells ascertained that JAK/STAT signaling has an anti-apoptotic role; whereas, the role of cJUN might be dependent upon regulatory cell factors. Thus, our studies ascertained that propolis augments apoptosis of butyrate-sensitive CC cells and re-sensitizes butyrate-resistant CC cells to apoptosis by suppressing AKT signaling and downregulating the JAK/STAT pathway. Future in vivo studies should evaluate the CC-preventive potential of a dietary supplement that produces high levels of colonic butyrate, propolis, and diet-derived JAK/STAT inhibitors. PMID:24023824

  16. Propolis augments apoptosis induced by butyrate via targeting cell survival pathways.

    Directory of Open Access Journals (Sweden)

    Eric Drago

    Full Text Available Diet is one of the major lifestyle factors affecting incidence of colorectal cancer (CC, and despite accumulating evidence that numerous diet-derived compounds modulate CC incidence, definitive dietary recommendations are not available. We propose a strategy that could facilitate the design of dietary supplements with CC-preventive properties. Thus, nutrient combinations that are a source of apoptosis-inducers and inhibitors of compensatory cell proliferation pathways (e.g., AKT signaling may produce high levels of programmed death in CC cells. Here we report the combined effect of butyrate, an apoptosis inducer that is produced through fermentation of fiber in the colon, and propolis, a honeybee product, on CC cells. We established that propolis increases the apoptosis of CC cells exposed to butyrate through suppression of cell survival pathways such as the AKT signaling. The programmed death of CC cells by combined exposure to butyrate and propolis is further augmented by inhibition of the JNK signaling pathway. Analyses on the contribution of the downstream targets of JNK signaling, c-JUN and JAK/STAT, to the apoptosis of butyrate/propolis-treated CC cells ascertained that JAK/STAT signaling has an anti-apoptotic role; whereas, the role of cJUN might be dependent upon regulatory cell factors. Thus, our studies ascertained that propolis augments apoptosis of butyrate-sensitive CC cells and re-sensitizes butyrate-resistant CC cells to apoptosis by suppressing AKT signaling and downregulating the JAK/STAT pathway. Future in vivo studies should evaluate the CC-preventive potential of a dietary supplement that produces high levels of colonic butyrate, propolis, and diet-derived JAK/STAT inhibitors.

  17. p53 modulates the AMPK inhibitor compound C induced apoptosis in human skin cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shi-Wei [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Wu, Chun-Ying [Division of Gastroenterology and Hepatology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Wang, Yen-Ting [Department of Medical Research and Education, Cheng Hsin General Hospital, Taipei, Taiwan (China); Kao, Jun-Kai [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Department of Pediatrics, Children' s Hospital, Changhua Christian Hospital, Changhua, Taiwan (China); Lin, Chi-Chen; Chang, Chia-Che; Mu, Szu-Wei; Chen, Yu-Yu [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Chiu, Husan-Wen [Institute of Biotechnology, National Cheng-Kung University, Tainan, Taiwan (China); Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan (China); Chang, Chuan-Hsun [Department of Surgical Oncology, Cheng Hsin General Hospital, Taipei, Taiwan (China); Department of Nutrition Therapy, Cheng Hsin General Hospital, Taipei, Taiwan (China); School of Nutrition and Health Sciences, Taipei Medical University, Taipei, Taiwan (China); Liang, Shu-Mei [Institute of Biotechnology, National Cheng-Kung University, Tainan, Taiwan (China); Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan (China); Chen, Yi-Ju [Department of Dermatology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Huang, Jau-Ling [Department of Bioscience Technology, Chang Jung Christian University, Tainan, Taiwan (China); Shieh, Jeng-Jer, E-mail: shiehjj@vghtc.gov.tw [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan (China)

    2013-02-15

    Compound C, a well-known inhibitor of the intracellular energy sensor AMP-activated protein kinase (AMPK), has been reported to cause apoptotic cell death in myeloma, breast cancer cells and glioma cells. In this study, we have demonstrated that compound C not only induced autophagy in all tested skin cancer cell lines but also caused more apoptosis in p53 wildtype skin cancer cells than in p53-mutant skin cancer cells. Compound C can induce upregulation, phosphorylation and nuclear translocalization of the p53 protein and upregulate expression of p53 target genes in wildtype p53-expressing skin basal cell carcinoma (BCC) cells. The changes of p53 status were dependent on DNA damage which was caused by compound C induced reactive oxygen species (ROS) generation and associated with activated ataxia-telangiectasia mutated (ATM) protein. Using the wildtype p53-expressing BCC cells versus stable p53-knockdown BCC sublines, we present evidence that p53-knockdown cancer cells were much less sensitive to compound C treatment with significant G2/M cell cycle arrest and attenuated the compound C-induced apoptosis but not autophagy. The compound C induced G2/M arrest in p53-knockdown BCC cells was associated with the sustained inactive Tyr15 phosphor-Cdc2 expression. Overall, our results established that compound C-induced apoptosis in skin cancer cells was dependent on the cell's p53 status. - Highlights: ► Compound C caused more apoptosis in p53 wildtype than p53-mutant skin cancer cells. ► Compound C can upregulate p53 expression and induce p53 activation. ► Compound C induced p53 effects were dependent on ROS induced DNA damage pathway. ► p53-knockdown attenuated compound C-induced apoptosis but not autophagy. ► Compound C-induced apoptosis in skin cancer cells was dependent on p53 status.

  18. Nano-Micelle of Moringa Oleifera Seed Oil Triggers Mitochondrial Cancer Cell Apoptosis

    Science.gov (United States)

    Abd-Rabou, Ahmed A; Zoheir, Khairy M A; Kishta, Mohamed S; Shalby, Aziza B; Ezzo, Mohamed I

    2016-01-01

    Cancer, a worldwide epidemic disease with diverse origins, involves abnormal cell growth with the potential to invade other parts of the body. Globally, it is the main cause of mortality and morbidity. To overcome the drawbacks of the commercially available chemotherapies, natural products-loaded nano-composites are recommended to improve cancer targetability and decrease the harmful impact on normal cells. This study aimed at exploring the anti-cancer impacts of Moringa oleifera seed oil in its free- (MO) and nano-formulations (MOn) through studying whether it mechanistically promotes mitochondrial apoptosis-mediating cell death. Mitochondrial-based cytotoxicity and flow cytometric-based apoptosis analyses were performed on cancer HepG2, MCF7, HCT 116, and Caco-2 cell lines against normal kidney BHK-21 cell line. The present study resulted that MOn triggered colorectal cancer Caco-2 and HCT 116 cytotoxicity via mitochondrial dysfunction more powerful than its free counterpart (MO). On the other side, MOn and MO remarkably induces HCT 116 mitochondrial apoptosis, while sparing normal BHK-21 cells with minimal cytotoxic effect. The present results concluded that nano-micelle of Moringa oleifera seed oil (MOn) can provide a novel therapeutic approach for colorectal and breast cancers via mitochondrial-mediated apoptosis, while sparing normal and even liver cancer cells a bit healthy or with minimal harmful effect. Intriguingly, MOn induced breast cancer not hepatocellular carcinoma cell death. PMID:28032498

  19. Hsp27 inhibits 6-hydroxydopamine-induced cytochrome c release and apoptosis in PC12 cells

    International Nuclear Information System (INIS)

    Gorman, Adrienne M.; Szegezdi, Eva; Quigney, Declan J.; Samali, Afshin

    2005-01-01

    Cellular stress may stimulate cell survival pathways or cell death depending on its severity. 6-Hydroxydopamine (6-OHDA) is a neurotoxin that targets dopaminergic neurons that is often used to induce neuronal cell death in models of Parkinson's disease. Here we present evidence that 6-OHDA induces apoptosis in rat PC12 cells that involves release of cytochrome c and Smac/Diablo from mitochondria, caspase-3 activation, cleavage of PARP, and nuclear condensation. 6-OHDA also induced the heat shock response, leading to increased levels of Hsp25 and Hsp70. Increased Hsp25 expression was associated with cell survival. Prior heat shock or overexpression of Hsp27 (human homologue of Hsp25) delayed cytochrome c release, caspase activation, and reduced the level of apoptosis caused by 6-OHDA. We conclude that 6-OHDA induces a variety of responses in cultured PC12 cells ranging from cell survival to apoptosis, and that induction of stress proteins such as Hsp25 may protect cells from undergoing 6-OHDA-induced apoptosis

  20. Zanthoxylum fruit extract from Japanese pepper promotes autophagic cell death in cancer cells.

    Science.gov (United States)

    Nozaki, Reo; Kono, Toru; Bochimoto, Hiroki; Watanabe, Tsuyoshi; Oketani, Kaori; Sakamaki, Yuichi; Okubo, Naoto; Nakagawa, Koji; Takeda, Hiroshi

    2016-10-25

    Zanthoxylum fruit, obtained from the Japanese pepper plant (Zanthoxylum piperitum De Candolle), and its extract (Zanthoxylum fruit extract, ZFE) have multiple physiological activities (e.g., antiviral activity). However, the potential anticancer activity of ZFE has not been fully examined. In this study, we investigated the ability of ZFE to induce autophagic cell death (ACD). ZFE caused remarkable autophagy-like cytoplasmic vacuolization, inhibited cell proliferation, and ultimately induced cell death in the human cancer cell lines DLD-1, HepG2, and Caco-2, but not in A549, MCF-7, or WiDr cells. ZFE increased the level of LC3-II protein, a marker of autophagy. Knockdown of ATG5 using siRNA inhibited ZFE-induced cytoplasmic vacuolization and cell death. Moreover, in cancer cells that could be induced to undergo cell death by ZFE, the extract increased the phosphorylation of c-Jun N-terminal kinase (JNK), and the JNK inhibitor SP600125 attenuated both vacuolization and cell death. Based on morphology and expression of marker proteins, ZFE-induced cell death was neither apoptosis nor necrosis. Normal intestinal cells were not affected by ZFE. Taken together, our findings show that ZFE induces JNK-dependent ACD, which appears to be the main mechanism underlying its anticancer activity, suggesting a promising starting point for anticancer drug development.

  1. The effect of hydroxybenzoate calcium compounds in inducing cell death in epithelial breast cancer cells

    Directory of Open Access Journals (Sweden)

    Nada M Merghani

    2015-12-01

    Full Text Available Hydroxybenzoate (HB compounds have shown their significance in inducing apoptosis in primary chronic lymphocytic leukemia (CLL and cancer cell lines, including HT-1080. The current study focuses on assessing the effects of 2-, 3- and 4-hydroxybenzoate calcium (HBCa compounds on MCF-10A, MDA-MB231 and MCF-7 epithelial breast cell lines. The HBCa-treated cells were examined using annexin V, to measure apoptosis in the three epithelial breast cell lines, after 48 h of treatment. The results indicated that 0.5 and 2.5 mmol/L of HBCa induced cell death in a dose-dependent manner. The induction of cell death in normal MCF-10A cells was found to be significantly less (p = 0.0003–0.0068, in comparison to the malignant cell lines (MDA-MB231 and MCF-7. HBCa compounds were also found to cause cell cycle arrest in the epithelial breast cells at G1/G0. Furthermore, HBCa compounds induced the upregulation of apoptotic proteins (p53, p21, Bax and caspase-3, as well as the downregulation of the anti-apoptotic protein Bcl-2, which may suggest that apoptosis is induced via the intrinsic pathway.

  2. Autophagonizer, a novel synthetic small molecule, induces autophagic cell death

    Energy Technology Data Exchange (ETDEWEB)

    Choi, In-Kwon; Cho, Yoon Sun; Jung, Hye Jin [Chemical Genomics Laboratory, Department of Biotechnology, Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Kwon, Ho Jeong, E-mail: kwonhj@yonsei.ac.kr [Chemical Genomics Laboratory, Department of Biotechnology, Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2010-03-19

    Autophagy is an apoptosis-independent mechanism of cell death that protects the cell from environmental imbalances and infection by pathogens. We identified a novel small molecule, 2-(3-Benzyl-4-oxo-3,4,5,6,7,8-hexahydro-benzo[4,5]thieno[2,3-d] pyrimidin-2-ylsulfanylmethyl)-oxazole-4-carboxylic acid (2-pyrrolidin-1-yl-ethyl)-amide (referred as autophagonizer), using high-content cell-based screening and the autophagosome marker EGFP-LC3. Autophagonizer inhibited growth and induced cell death in the human tumor cell lines MCF7, HeLa, HCT116, A549, AGS, and HT1080 via a caspase-independent pathway. Conversion of cytosolic LC3-I to autophagosome-associated LC3-II was greatly enhanced by autophagonizer treatment. Transmission electron microscopy and acridine orange staining revealed increased autophagy in the cytoplasm of autophagonizer-treated cells. In conclusion, autophagonizer is a novel autophagy inducer with unique structure, which induces autophagic cell death in the human tumor cell lines.

  3. Fumonisins and Alternaria alternata lycopersici toxins: sphinganine analog mycotoxins induce apoptosis in monkey kidney cells.

    Science.gov (United States)

    Wang, W; Jones, C; Ciacci-Zanella, J; Holt, T; Gilchrist, D G; Dickman, M B

    1996-04-16

    Fusarium moniliforme toxins (fumonisins) and Alternaria alternata lycopersici (AAL) toxins are members of a new class of sphinganine analog mycotoxins that occur widely in the food chain. These mycotoxins represent a serious threat to human and animal health, inducing both cell death and neoplastic events in mammals. The mechanisms by which this family of chemical congeners induce changes in cell homeostasis were investigated in African green monkey kidney cells (CV-1) by assessing the appearance of apoptosis, cell cycle regulation, and putative components of signal transduction pathways involved in apoptosis. Structurally, these mycotoxins resemble the sphingoid bases, sphingosine and sphinganine, that are reported to play critical roles in cell communication and signal transduction. The addition of fumonisin B1 or AAL toxin, TA, to CV-1 cells induced the stereotypical hallmarks of apoptosis, including the formation of DNA ladders, compaction of nuclear DNA, and the subsequent appearance of apoptotic bodies. Neither mycotoxin induced cell death, DNA ladders, or apoptotic bodies in CV-1 cells expressing simian virus 40 large T antigen (COS-7) at toxin concentrations that readily killed CV-1 cells. Fumonisin B1 induced cell cycle arrest in the G1 phase in CV-1 cells but not in COS-7 cells. AAL toxin TA did not arrest cell cycle progression in either cell line. The induction of apoptosis combined with the widespread presence of these compounds in food crops and animal feed identifies a previously unrecognized health risk to humans and livestock. These molecules also represent a new class of natural toxicants that can be used as model compounds to further characterize the molecular and biochemical pathways leading to apoptosis.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-15

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

  5. Dasatinib accelerates valproic acid-induced acute myeloid leukemia cell death by regulation of differentiation capacity.

    Directory of Open Access Journals (Sweden)

    Sook-Kyoung Heo

    Full Text Available Dasatinib is a compound developed for chronic myeloid leukemia as a multi-targeted kinase inhibitor against wild-type BCR-ABL and SRC family kinases. Valproic acid (VPA is an anti-epileptic drug that also acts as a class I histone deacetylase inhibitor. The aim of this research was to determine the anti-leukemic effects of dasatinib and VPA in combination and to identify their mechanism of action in acute myeloid leukemia (AML cells. Dasatinib was found to exert potent synergistic inhibitory effects on VPA-treated AML cells in association with G1 phase cell cycle arrest and apoptosis induction involving the cleavage of poly (ADP-ribose polymerase and caspase-3, -7 and -9. Dasatinib/VPA-induced cell death thus occurred via caspase-dependent apoptosis. Moreover, MEK/ERK and p38 MAPK inhibitors efficiently inhibited dasatinib/VPA-induced apoptosis. The combined effect of dasatinib and VPA on the differentiation capacity of AML cells was more powerful than the effect of each drug alone, being sufficiently strong to promote AML cell death through G1 cell cycle arrest and caspase-dependent apoptosis. MEK/ERK and p38 MAPK were found to control dasatinib/VPA-induced apoptosis as upstream regulators, and co-treatment with dasatinib and VPA to contribute to AML cell death through the regulation of differentiation capacity. Taken together, these results indicate that combined dasatinib and VPA treatment has a potential role in anti-leukemic therapy.

  6. Apoptosis of purified CD4+ T cell subsets is dominated by cytokine deprivation and absence of other cells in new onset diabetic NOD mice.

    Directory of Open Access Journals (Sweden)

    Ayelet Kaminitz

    Full Text Available BACKGROUND: Regulatory T cells (Treg play a significant role in immune homeostasis and self-tolerance. Excessive sensitivity of isolated Treg to apoptosis has been demonstrated in NOD mice and humans suffering of type 1 diabetes, suggesting a possible role in the immune dysfunction that underlies autoimmune insulitis. In this study the sensitivity to apoptosis was measured in T cells from new onset diabetic NOD females, comparing purified subsets to mixed cultures. PRINCIPAL FINDINGS: Apoptotic cells are short lived in vivo and death occurs primarily during isolation, manipulation and culture. Excessive susceptibility of CD25(+ T cells to spontaneous apoptosis is characteristic of isolated subsets, however disappears when death is measured in mixed splenocyte cultures. In variance, CD25(- T cells display balanced sensitivity to apoptosis under both conditions. The isolation procedure removes soluble factors, IL-2 playing a significant role in sustaining Treg viability. In addition, pro- and anti-apoptotic signals are transduced by cell-to-cell interactions: CD3 and CD28 protect CD25(+ T cells from apoptosis, and in parallel sensitize naïve effector cells to apoptosis. Treg viability is modulated both by other T cells and other subsets within mixed splenocyte cultures. Variations in sensitivity to apoptosis are often hindered by fast proliferation of viable cells, therefore cycling rates are mandatory to adequate interpretation of cell death assays. CONCLUSIONS: The sensitivity of purified Treg to apoptosis is dominated by cytokine deprivation and absence of cell-to-cell interactions, and deviate significantly from measurements in mixed populations. Balanced sensitivity of naïve/effector and regulatory T cells to apoptosis in NOD mice argues against the concept that differential susceptibility affects disease evolution and progression.

  7. Apoptosis and cancer stem cells : Implications for apoptosis targeted therapy

    NARCIS (Netherlands)

    Kruyt, Frank A. E.; Schuringa, Jan Jacob

    2010-01-01

    Evidence is accumulating showing that cancer stem cells or tumor-initiating cells are key drivers of tumor formation and progression. Successful therapy must therefore eliminate these cells, which is hampered by their high resistance to commonly used treatment modalities. Thus far, only a limited

  8. Effects of a novel β-lapachone derivative on Trypanosoma cruzi: Parasite death involving apoptosis, autophagy and necrosis.

    Science.gov (United States)

    Dos Anjos, Danielle Oliveira; Sobral Alves, Eliomara Sousa; Gonçalves, Vinicius Tomaz; Fontes, Sheila Suarez; Nogueira, Mateus Lima; Suarez-Fontes, Ana Márcia; Neves da Costa, João Batista; Rios-Santos, Fabricio; Vannier-Santos, Marcos André

    2016-12-01

    Natural products comprise valuable sources for new antiparasitic drugs. Here we tested the effects of a novel β-lapachone derivative on Trypanosoma cruzi parasite survival and proliferation and used microscopy and cytometry techniques to approach the mechanism(s) underlying parasite death. The selectivity index determination indicate that the compound trypanocidal activity was over ten-fold more cytotoxic to epimastigotes than to macrophages or splenocytes. Scanning electron microscopy analysis revealed that the R72 β-lapachone derivative affected the T. cruzi morphology and surface topography. General plasma membrane waving and blebbing particularly on the cytostome region were observed in the R72-treated parasites. Transmission electron microscopy observations confirmed the surface damage at the cytostome opening vicinity. We also observed ultrastructural evidence of the autophagic mechanism termed macroautophagy. Some of the autophagosomes involved large portions of the parasite cytoplasm and their fusion/confluence may lead to necrotic parasite death. The remarkably enhanced frequency of autophagy triggering was confirmed by quantitating monodansylcadaverine labeling. Some cells displayed evidence of chromatin pycnosis and nuclear fragmentation were detected. This latter phenomenon was also indicated by DAPI staining of R72-treated cells. The apoptotis induction was suggested to take place in circa one-third of the parasites assessed by annexin V labeling measured by flow cytometry. TUNEL staining corroborated the apoptosis induction. Propidium iodide labeling indicate that at least 10% of the R72-treated parasites suffered necrosis within 24 h. The present data indicate that the β-lapachone derivative R72 selectively triggers T. cruzi cell death, involving both apoptosis and autophagy-induced necrosis. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Effects of a novel β–lapachone derivative on Trypanosoma cruzi: Parasite death involving apoptosis, autophagy and necrosis

    Directory of Open Access Journals (Sweden)

    Danielle Oliveira dos Anjos

    2016-12-01

    Full Text Available Natural products comprise valuable sources for new antiparasitic drugs. Here we tested the effects of a novel β–lapachone derivative on Trypanosoma cruzi parasite survival and proliferation and used microscopy and cytometry techniques to approach the mechanism(s underlying parasite death. The selectivity index determination indicate that the compound trypanocidal activity was over ten-fold more cytotoxic to epimastigotes than to macrophages or splenocytes. Scanning electron microscopy analysis revealed that the R72 β–lapachone derivative affected the T. cruzi morphology and surface topography. General plasma membrane waving and blebbing particularly on the cytostome region were observed in the R72-treated parasites. Transmission electron microscopy observations confirmed the surface damage at the cytostome opening vicinity. We also observed ultrastructural evidence of the autophagic mechanism termed macroautophagy. Some of the autophagosomes involved large portions of the parasite cytoplasm and their fusion/confluence may lead to necrotic parasite death. The remarkably enhanced frequency of autophagy triggering was confirmed by quantitating monodansylcadaverine labeling. Some cells displayed evidence of chromatin pycnosis and nuclear fragmentation were detected. This latter phenomenon was also indicated by DAPI staining of R72-treated cells. The apoptotis induction was suggested to take place in circa one-third of the parasites assessed by annexin V labeling measured by flow cytometry. TUNEL staining corroborated the apoptosis induction. Propidium iodide labeling indicate that at least 10% of the R72-treated parasites suffered necrosis within 24 h. The present data indicate that the β–lapachone derivative R72 selectively triggers T. cruzi cell death, involving both apoptosis and autophagy-induced necrosis.

  10. HIV/SIV infection primes monocytes and dendritic cells for apoptosis.

    Directory of Open Access Journals (Sweden)

    Mireille Laforge

    2011-06-01

    Full Text Available Subversion or exacerbation of antigen-presenting cells (APC death modulates host/pathogen equilibrium. We demonstrated during in vitro differentiation of monocyte-derived macrophages and monocyte-derived dendritic cells (DCs that HIV sensitizes the cells to undergo apoptosis in response to TRAIL and FasL, respectively. In addition, we found that HIV-1 increased the levels of pro-apoptotic Bax and Bak molecules and decreased the levels of anti-apoptotic Mcl-1 and FLIP proteins. To assess the relevance of these observations in the context of an experimental model of HIV infection, we investigated the death of APC during pathogenic SIV-infection in rhesus macaques (RMs. We demonstrated increased apoptosis, during the acute phase, of both peripheral blood DCs and monocytes (CD14(+ from SIV(+RMs, associated with a dysregulation in the balance of pro- and anti-apoptotic molecules. Caspase-inhibitor and death receptors antagonists prevented apoptosis of APCs from SIV(+RMs. Furthermore, increased levels of FasL in the sera of pathogenic SIV(+RMs were detected, compared to non-pathogenic SIV infection of African green monkey. We suggest that inappropriate apoptosis of antigen-presenting cells may contribute to dysregulation of cellular immunity early in the process of HIV/SIV infection.

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

    Science.gov (United States)

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

    2018-04-01

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

  12. Establishment and characterization of GSA-1, a human cell line highly susceptible to apoptosis after free-fall

    International Nuclear Information System (INIS)

    Nomura, Jun; Himeda, Jyuni; Chen, Zheng; Sugaya, Shigeru; Takahashi, Shunji; Kita, Kazuko; Ichinose, Masaharu; Suzuki, Nobuo

    2002-01-01

    The induction of apoptosis by microgravity and/or gravity-changing stress is considered to be one of the important causes of cell death, although the molecular mechanisms of the apoptotic event remain unclarified. In this study, we established a cell line,GSA-1, from ethyl methanesulfonate-treated human RSa cells. GSA-1 cells were highly susceptible to apoptosis after a free-fall; 24.4% of these cells underwent apoptosis after free-fall, compared with only 6% of the RSa cells. The apoptosis of GSA-1 cells was augmented by ultraviolet (UV, principally 254-nm wavelength) irradiation before free-fall to a greater extents than those in RSa cells. The molecular mechanisms of apoptosis included p53 and Bax proteins; the expression of nuclear p53 and cytoplasmic Bax in GSA-1 cells increased at 4 h after free-fall irrespective of irradiation. In addition, the rate of removal of cyclobutane pyrimidine dimer (CPD) in UV-irradiated GSA-1 cells was higher in cells exposed to free-fall than in those under the l-G condition. Our results suggested that in GSA-1 cells, free-fall accelerates apoptosis, and that this process is associated with the accumulation of p53 and Bax, as well as CPD removal. Thus, GSA-1 cells should be useful for investigating the mechanism of cellular response, including the induction of apoptosis under gravity-changing stress. (author)

  13. Induction of apoptotic cell death by putrescine

    DEFF Research Database (Denmark)

    Takao, Koichi; Rickhag, Karl Mattias; Hegardt, Cecilia

    2006-01-01

    that overexpression of a metabolically stable ODC in CHO cells induced a massive cell death unless the cells were grown in the presence of the ODC inhibitor alpha-difluoromethylornithine (DFMO). Cells overexpressing wild-type (unstable) ODC, on the other hand, were not dependent on the presence of DFMO...

  14. Interferon beta induces apoptosis in nasopharyngeal carcinoma cells via the TRAIL-signaling pathway.

    Science.gov (United States)

    Makowska, Anna; Wahab, Lora; Braunschweig, Till; Kapetanakis, Nikiforos-Ioannis; Vokuhl, Christian; Denecke, Bernd; Shen, Lian; Busson, Pierre; Kontny, Udo

    2018-03-06

    The combination of neoadjuvant chemotherapy, radiochemotherapy, and maintenance therapy with interferon beta (IFNβ) has led to superior results in the treatment of children and adolescents with nasopharyngeal carcinoma (NPC). However, nothing is known about the mechanism of the antitumor activity of IFNβ in NPC. Here, we investigate the role of IFNβ on apoptosis in NPC cells. Six NPC cell lines, one patient-derived NPC xenograft (PDX) and one SV40-transformed nasoepithelial cell line were used. Induction of apoptosis by IFNβ was measured by flow cytometric analysis of subG1-DNA-content, Hoechst 33258 staining and activation of caspase-3. Dissection of death ligand signaling pathways included measuring surface expression of its components by flow cytometry, activation by death ligands and neutralization with specific antibodies and siRNA. IFNβ induced apoptosis at concentrations achievable in humans in five of six NPC cell lines and in PDX cells but not in nasoepithelial cells. Inhibition of caspases-3 and -8 abrogated this effect suggesting IFNβ promoted apoptosis through the extrinsic pathway. IFNβ induced surface expression of TRAIL and TRAIL-R2 and the addition of an anti-TRAIL-antibody or transfection with TRAIL-siRNA blocked IFNβ-induced apoptosis. No induction of TRAIL-expression was noted in the IFNβ-resistant cell line. In conclusion, IFNβ leads to apoptosis in NPC cells in an autocrine way via the induction of TRAIL expression and subsequent activation of the TRAIL-signaling pathway. The mechanism described could at least partly explain the clinical benefit of IFNβ in the treatment of NPC. Further studies in a mouse-xenograft model are warranted to substantiate this effect in vivo .

  15. Ezrin dephosphorylation/downregulation contributes to ursolic acid-mediated cell death in human leukemia cells

    International Nuclear Information System (INIS)

    Li, G; Zhou, T; Liu, L; Chen, J; Zhao, Z; Peng, Y; Li, P; Gao, N

    2013-01-01

    Ezrin links the actin filaments with the cell membrane and has a functional role in the apoptotic process. It appears clear that ezrin is directly associated with Fas, leading to activation of caspase cascade and cell death. However, the exact role of ezrin in ursolic acid (UA)-induced apoptosis remains unclear. In this study, we show for the first time that UA induces apoptosis in both transformed and primary leukemia cells through dephosphorylation/downregulation of ezrin, association and polarized colocalization of Fas and ezrin, as well as formation of death-inducing signaling complex. These events are dependent on Rho-ROCK1 signaling pathway. Knockdown of ezrin enhanced cell death mediated by UA, whereas overexpression of ezrin attenuated UA-induced apoptosis. Our in vivo study also showed that UA-mediated inhibition of tumor growth of mouse leukemia xenograft model is in association with the dephosphorylation/downregulation of ezrin. Such findings suggest that the cytoskeletal protein ezrin may represent an attractive target for UA-mediated lethality in human leukemia cells

  16. Glutamate-mediated protection of crayfish glial cells from PDT-induced apoptosis

    Science.gov (United States)

    Rudkovskii, M. V.; Romanenko, N. P.; Berezhnaya, E. V.; Kovaleva, V. D.; Uzdensky, A. B.

    2011-03-01

    Photodynamic treatment that causes intense oxidative stress and kills cells is currently used in neurooncology. However, along with tumor it damages surrounding healthy neurons and glial cells. In order to study the possible role of glutamate-related signaling pathways in photodynamic injury of neurons and glia, we investigated photodynamic effect of alumophthalocyanine Photosens on isolated crayfish stretch receptor that consists of a single neuron surrounded by glial cells. The laser diode (670 nm, 0.4 W/cm2) was used for dye photoexcitation. Application of glutamate increased photodynamically induced necrosis of neurons and glial cells but significantly decreased glial apoptosis. The natural neuroglial mediator N-acetylaspartylglutamate, which releases glutamate after cleavage in the extracellular space by glutamate carboxypeptidase II, also inhibited photoinduced apoptosis. Inhibition of glutamate carboxypeptidase II, oppositely, enhanced apoptosis of glial cells. These data confirm the anti-apoptotic activity of glutamate. Application of NMDA or inhibition of NMDA receptors by MK801 did not influence photodynamic death of neurons and glial cells that indicated nonparticipation of NMDA receptors in these processes. Inhibition of metabotropic glutamate receptors by AP-3 decreased PDT-induced apoptosis. One can suggest that crayfish neurons naturally secrete NAAG, which being cleaved by GCOP produces glutamate. Glutamate prevents photoinduced apoptosis of glial cells possibly through metabotropic but not ionotropic glutamate receptors.

  17. Nonylphenol diethoxylate inhibits apoptosis induced in PC12 cells.

    Science.gov (United States)

    Liu, Chuang; Sun, Yongkun; Song, Yutong; Saito, Takeshi; Kurasaki, Masaaki

    2016-11-01

    Nonylphenol and short-chain nonylphenol ethoxylates such as NP 2 EO are present in aquatic environment as wastewater contaminants, and their toxic effects on aquatic species have been reported. Apoptosis has been shown to be induced by serum deprivation or copper treatment. To understand the toxicity of nonylphenol diethoxylate, we investigated the effects of NP 2 EO on apoptosis induced by serum deprivation and copper by using PC12 cell system. Nonylphenol diethoxylate itself showed no toxicity and recovered cell viability from apoptosis. In addition, nonylphenol diethoxylate decreased DNA fragmentation caused by apoptosis in PC12 cells. This phenomenon was confirmed after treating apoptotic PC12 cells with nonylphenol diethoxylate, whereas the cytochrome c release into the cytosol decreased as compared to that in apoptotic cells not treated with nonylphenol diethoxylates. Furthermore, Bax contents in apoptotic cells were reduced after exposure to nonylphenol diethoxylate. Thus, nonylphenol diethoxylate has the opposite effect on apoptosis in PC12 cells compared to nonylphenol, which enhances apoptosis induced by serum deprivation. The difference in structure of the two compounds is hypothesized to be responsible for this phenomenon. These results indicated that nonylphenol diethoxylate has capability to affect cell differentiation and development and has potentially harmful effect on organisms because of its unexpected impact on apoptosis. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1389-1398, 2016. © 2015 Wiley Periodicals, Inc.

  18. Synergistic interaction of Smac mimetic and IFNα to trigger apoptosis in acute myeloid leukemia cells.

    Science.gov (United States)

    Bake, Vanessa; Roesler, Stefanie; Eckhardt, Ines; Belz, Katharina; Fulda, Simone

    2014-12-28

    Therapeutic targeting of inhibitor of apoptosis (IAP) proteins by small-molecule inhibitors such as Smac mimetic is considered as a promising anticancer strategy to elicit apoptosis. Recent advances have renewed the interest in exploiting the antileukemic activity of interferon (IFN)α for the treatment of acute myeloid leukemia (AML). Here, we identify a novel synergistic interaction of the Smac mimetic BV6 and IFNα to trigger cell death in AML cells. Calculation of combination index (CI) confirms the synergism of BV6 and IFNα. In contrast to AML cells, no synergistic toxicity of BV6 and IFNα at equimolar concentrations is found against normal peripheral blood lymphocytes. BV6 and IFNα act in concert to stimulate expression of tumor necrosis factor (TNF)α and its secretion into the supernatant, thereby initiating an autocrine/paracrine TNFα/TNF receptor 1 (TNFR1) loop that drives cell death by BV6 and IFNα. Consistently, pharmacological inhibition of TNFα by the TNFα-blocking antibody Enbrel or genetic silencing of TNFR1 significantly reduces BV6/IFNα-induced cell death. In addition, BV6/IFNα-induced cell death depends on interferon regulatory factor (IRF)1, since RNA interference-imposed knockdown of IRF1 significantly rescues cell death. In conclusion, the identification of a novel synergistic antileukemic combination of Smac mimetic and IFNα has important implications for the development of innovative treatment strategies in AML. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  19. JAK/STAT autocontrol of ligand-producing cell number through apoptosis.

    Science.gov (United States)

    Borensztejn, Antoine; Boissoneau, Elisabeth; Fernandez, Guillaume; Agnès, François; Pret, Anne-Marie

    2013-01-01

    During development, specific cells are eliminated by apoptosis to ensure that the correct number of cells is integrated in a given tissue or structure. How the apoptosis machinery is activated selectively in vivo in the context of a developing tissue is still poorly understood. In the Drosophila ovary, specialised follicle cells [polar cells (PCs)] are produced in excess during early oogenesis and reduced by apoptosis to exactly two cells per follicle extremity. PCs act as an organising centre during follicle maturation as they are the only source of the JAK/STAT pathway ligand Unpaired (Upd), the morphogen activity of which instructs distinct follicle cell fates. Here we show that reduction of Upd levels leads to prolonged survival of supernumerary PCs, downregulation of the pro-apoptotic factor Hid, upregulation of the anti-apoptotic factor Diap1 and inhibition of caspase activity. Upd-mediated activation of the JAK/STAT pathway occurs in PCs themselves, as well as in adjacent terminal follicle and interfollicular stalk cells, and inhibition of JAK/STAT signalling in any one of these cell populations protects PCs from apoptosis. Thus, a Stat-dependent unidentified relay signal is necessary for inducing supernumerary PC death. Finally, blocking apoptosis of PCs leads to specification of excess adjacent border cells via excessive Upd signalling. Our results therefore show that Upd and JAK/STAT signalling induce apoptosis of supernumerary PCs to control the size of the PC organising centre and thereby produce appropriate levels of Upd. This is the first example linking this highly conserved signalling pathway with developmental apoptosis in Drosophila.

  20. Daphnoretin Induces Cell Cycle Arrest and Apoptosis in Human Osteosarcoma (HOS Cells

    Directory of Open Access Journals (Sweden)

    Jinhai He

    2012-01-01

    Full Text Available In this study antiproliferation, cell cycle arrest and apoptosis induced by daphnoretin in human osteosarcoma (HOS cells were investigated. Antiproliferative activity was measured with the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. The IC50 value of daphnoretin was 3.89 μM after 72 h treatment. Induction of apoptosis was evidenced by apoptotic body appearance and Annexin V-FITC/PI apoptosis detection kit. Flow cytometric analysis indicated daphnoretin arrested the cell cycle in the G2/M phase. Western-blot assay showed that the G2/M phase arrest was accompanied by down-regulation of cdc2, cyclin A and cyclin B1. Moreover, daphnoretin inhibited Bcl-2 expression and induced Bax expression to desintegrate the outer mitochondrial membrane and causing cytochrome c release. Mitochondrial cytochrome c release was associated with the activation of caspase-9 and caspase-3 cascade. Our results demonstrated that daphnoretin caused death of HOS cells by blocking cells successively in G2/M phases and activating the caspase-3 pathway.

  1. Radiation-induced apoptosis and cell cycle checkpoints in human colorectal tumour cell lines

    International Nuclear Information System (INIS)

    Playle, L.C.

    2001-03-01

    The p53 tumour suppressor gene is mutated in 75% of colorectal carcinomas and is critical for DNA damage-induced G1 cell cycle arrest. Data presented in this thesis demonstrate that after treatment with Ionizing Radiation (IR), colorectal tumour cell lines with mutant p53 are unable to arrest at G1 and undergo cell cycle arrest at G2. The staurosporine derivative, UCN-01, was shown to abrogate the IR-induced G2 checkpoint in colorectal tumour cell lines. Furthermore, in some cell lines, abrogation of the G2 checkpoint was associated with radiosensitisation. Data presented in this study demonstrate that 2 out of 5 cell lines with mutant p53 were sensitised to IR by UCN-01. In order to determine whether radiosensitisation correlated with lack of functional p53, transfected derivatives of an adenoma-derived cell line were studied, in which endogenous wild type p53 was disrupted by expression of a dominant negative p53 mutant protein (and with a vector control). In both these cell lines UCN-01 abrogated the G2 arrest however this was not associated with radiosensitisation, indicating that radiosensitisation is a cell type-specific phenomenon. Although 2 colorectal carcinoma cell lines, with mutant p53, were sensitised to IR by UCN-01, the mechanisms of p53-independent IR-induced apoptosis in the colon are essentially unknown. The mitogen-activated protein kinase (MAPK) pathways (that is the JNK, p38 and ERK pathways) have been implicated in apoptosis in a range of cell systems and in IR-induced apoptosis in some cell types. Data presented in this study show that, although the MAPKs can be activated by the known activator anisomycin, there is no evidence of a role for MAPKs in IR-induced apoptosis in colorectal tumour cell lines, regardless of p53 status. In summary, some colorectal tumour cell lines with mutant p53 can be sensitised to IR-induced cell death by G2 checkpoint abrogation and this may be an important treatment strategy, however mechanisms of IR-induced p53

  2. Sensitization of cancer cells to cyclophosphamide therapy by an organoselenium compound through ROS-mediated apoptosis.

    Science.gov (United States)

    Chakraborty, Pramita; Roy, Somnath Singha; Basu, Abhishek; Bhattacharya, Sudin

    2016-12-01

    Induction of apoptosis has been recognized as an excellent therapeutic approach in cancer. Selenium based compounds are well known for their antitumor and synergistic chemotherapeutic efficacy when combined with a standard antineoplastic drug. Previously, we have reported that an organoselenium compound, diphenylmethyl selenocyanate (DMSE) could effectively protect normal organs and tissues from the toxicity induced by a standard chemotherapeutic drug cyclophosphamide in a tumor bearing mouse model. In this study, as a further step, we have evaluated the effect of DMSE in sensitization of tumor cells to cyclophosphamide-induced cell death. We found that DMSE alone or in combination with cyclophosphamide could induce cell death mainly through apoptosis. Generation of reactive oxygen species (ROS) followed by down-regulation of antioxidant defense system in the tumor cells was hypothesized as the crucial cellular events occurred following DMSE treatment. In addition, DMSE in combination with cyclophosphamide also caused DNA damage in tumor cells which might be due to the consequence of oxidative stress induced by the combined therapy. Moreover, production of ROS subsequently activated p53, which in turn initiated release of mitochondrial cytochrome c via up-regulation of Bax and down-regulation of Bcl-2. Ultimately, the activation of caspase-3 played the major role to cleave PARP that finally led to apoptosis. All the above results together proposed that, DMSE sensitized tumor cells to cyclophosphamide therapy through ROS-induced p53 activation and mitochondria-mediated caspase dependent apoptosis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. SPAG6 regulates cell apoptosis through the TRAIL signal pathway in myelodysplastic syndromes.

    Science.gov (United States)

    Li, Xinxin; Yang, Bihui; Wang, Li; Chen, Liping; Luo, Xiaohua; Liu, Lin

    2017-05-01

    Myelodysplastic syndromes (MDSs) are a group of malignant clone hematopoietic stem-cell diseases, and the evolution and progression of MDS depend on the abnormal apoptosis of bone marrow cells. Our previous studies have indicated that sperm-associated antigen 6 (SPAG6), located in the uniparental disomy regions of myeloid cells, is overexpressed in patients with MDS as compared to controls, and SPAG6 can inhibit apoptosis of SKM-1. However, the concrete mechanism is still unclear. In the present study, it was found that the TNF-related apoptosis-inducing ligand (TRAIL)signal pathway was activated when the expression of SPAG6 was inhibited by SPAG6-shRNA lentivirus in SKM-1 cells. Additionally, the results of flow cytometry, Cell Counting Kit-8 assay and western blot analysis implied that the TRAIL signal pathway could be inhibited by a high expression of SPAG6. However, SPAG6 cannot influence the expression of TRAIL death receptors, except for FADD. Additionally the interaction between FADD and TRAIL death receptors also increased in SKM-1 cells infected with SPAG6-shRNA lentivirus. Thus, our study demonstrates that SPAG6 may regulate apoptosis in SKM-1 through the TRAIL signal pathway, indicating that SPAG6 could be a potential therapeutic target.

  4. Radiation-induced apoptosis in differentially modulated by PTK inhibitora in K562 cells

    International Nuclear Information System (INIS)

    Lee, Hyung Sik; Moon, Chang Woo; Hur, Won Joo; Jeong, Su Jin; Jeong Min Ho; Lee, Jeong Hyeon; Lim, Young Jin; Park, Heon Joo

    2000-01-01

    attributable to bcl-2 family. It is plausible that the relationship between cell cycle delays and cell death is essential for drug development based on molecular targeting designed to modify radiation-induced apoptosis

  5. Selective inhibition of PED protein expression sensitizes B-cell chronic lymphocytic leukaemia cells to TRAIL-induced apoptosis.

    Science.gov (United States)

    Garofalo, Michela; Romano, Giulia; Quintavalle, Cristina; Romano, Maria Fiammetta; Chiurazzi, Federico; Zanca, Ciro; Condorelli, Gerolama

    2007-03-15

    B-cell chronic lymphocytic leukaemia (B-CLL) cells fail to undergo apoptosis. The mechanism underlying this resistance to cell death is still largely unknown. Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) effectively kills tumour cells but not normal cells, and thus represents an attractive tool for the treatment of cancer. Unfortunately, lymphocytes from B-CLL patients are resistant to TRAIL-mediated apoptosis. Thus, we aimed to study the involvement of PED, a DED-family member with a broad antiapoptotic action, in this resistance. We demonstrate that B lymphocytes obtained from patients with B-CLL express high levels of PED. Treatment of B-CLL cells with specific PED antisense oligonucleotides, a protein synthesis inhibitor or HDAC inhibitors, induced a significant downregulation of PED and sensitized these cells to TRAIL-induced cell death. These findings suggest a direct involvement of PED in resistance to TRAIL-induced apoptosis in B-CLL. It also identifies this DED-family member as a potential therapeutic target for this form of leukaemia. (c) 2006 Wiley-Liss, Inc.

  6. Methuosis: nonapoptotic cell death associated with vacuolization of macropinosome and endosome compartments.

    Science.gov (United States)

    Maltese, William A; Overmeyer, Jean H

    2014-06-01

    Apoptosis is the most widely recognized form of physiological programmed cell death. During the past three decades, various nonapoptotic forms of cell death have gained increasing attention, largely because of their potential importance in pathological processes, toxicology, and cancer therapy. A recent addition to the panoply of cell death phenotypes is methuosis. The neologism is derived from the Greek methuo (to drink to intoxication) because the hallmark of this form of cell death is displacement of the cytoplasm by large fluid-filled vacuoles derived from macropinosomes. The demise of the cell resembles many forms of necrosis, insofar as there is a loss of metabolic capacity and plasma membrane integrity, without the cell shrinkage and nuclear fragmentation associated with apoptosis. Methuosis was initially defined in glioblastoma cells after ectopic expression of activated Ras, but recent reports have described small molecules that can induce the features of methuosis in a broad spectrum of cancer cells, including those that are resistant to conventional apoptosis-inducing drugs. This review summarizes the available information about the distinguishing morphological characteristics and underlying mechanisms of methuosis. We compare and contrast methuosis with other cytopathological conditions in which accumulation of clear cytoplasmic vacuoles is a prominent feature. Finally, we highlight key questions that need to be answered to determine whether methuosis truly represents a unique form of regulated cell death. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  7. DNA fragmentation and apoptosis induced by safranal in human prostate cancer cell line

    Directory of Open Access Journals (Sweden)

    Saeed Samarghandian

    2013-01-01

    Full Text Available Objectives: Apoptosis, an important mechanism that contributes to cell growth reduction, is reported to be induced by Crocus sativus (Saffron in different cancer types. However, limited effort has been made to correlate these effects to the active ingredients of saffron. The present study was designed to elucidate cytotoxic and apoptosis induction by safranal, the major coloring compound in saffron, in a human prostate cancer cell line (PC-3. Materials and Methods: PC-3 and human fetal lung fibroblast (MRC-5 cells were cultured and exposed to safranal (5, 10, 15, and 20 μg/ml. The 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay was performed to assess cytotoxicity. DNA fragmentation was assessed by gel electrophoresis. Cells were incubated with different concentrations of safranal, and cell morphologic changes and apoptosis were determined by the normal inverted microscope, Annexin V, and propidium iodide, followed by flow cytometric analysis, respectively. Results: MTT assay revealed a remarkable and concentration-dependent cytotoxic effect of safranal on PC-3 cells in comparison with non-malignant cell line. The morphologic alterations of the cells confirmed the MTT results. The IC 50 values against PC-3 cells were found to be 13.0 ΁ 0.07 and 6.4 ΁ 0.09 μg/ml at 48 and 72 h, respectively. Safranal induced an early and late apoptosis in the flow cytometry histogram of treated cells, indicating apoptosis is involved in this toxicity. DNA analysis revealed typical ladders as early as 48 and 72 h after treatment, indicative of apoptosis. Conclusions: Our preclinical study demonstrated a prostate cancer cell line to be highly sensitive to safranal-mediated growth inhibition and apoptotic cell death. Although the molecular mechanisms of safranal action are not clearly understood, it appears to have potential as a therapeutic agent.

  8. Mast Cell Function and Death in Trypanosoma cruzi Infection

    Science.gov (United States)

    Meuser-Batista, Marcelo; Corrêa, José Raimundo; Carvalho, Vinícius Frias; de Carvalho Britto, Constança Felícia De Paoli; da Cruz Moreira, Otacilio; Batista, Marcos Meuser; Soares, Maurílio José; Filho, Francisco Alves Farias; e Silva, Patrícia Machado R.; Lannes-Vieira, Joseli; Silva, Robson Coutinho; Henriques-Pons, Andrea

    2011-01-01

    Although the roles of mast cells (MCs) are essential in many inflammatory and fibrotic diseases, their role in Trypanosoma cruzi–induced cardiomyopathy is unexplored. In this study, we treated infected CBA mice with cromolyn, an MC stabilizer, and observed much greater parasitemia and interferon-γ levels, higher mortality, myocarditis, and cardiac damage. Although these data show that MCs are important in controlling acute infection, we observed MC apoptosis in the cardiac tissue and peritoneal cavity of untreated mice. In the heart, pericardial mucosal MC die, perhaps because of reduced amounts of local stem cell factor. Using RT-PCR in purified cardiac MCs, we observed that infection induced transcription of P2X7 receptor and Fas, two molecules reportedly involved in cell death and inflammatory regulation. In gld/gld mice (FasL−/−), apoptosis of cardiac, but not peritoneal, MCs was decreased. Conversely, infection of P2X7−/− mice led to reduced peritoneal, but not cardiac, MC death. These data illustrate the immunomodulatory role played by MCs in T. cruzi infection and the complexity of molecular interactions that control inflammatory pathways in different tissues and compartments. PMID:21819958

  9. 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to inhibit hepatocellular carcinoma cells

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  10. 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to inhibit hepatocellular carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-04

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

  11. A Conserved Core of Programmed Cell Death Indicator Genes Discriminates Developmentally and Environmentally Induced Programmed Cell Death in Plants.

    Science.gov (United States)

    Olvera-Carrillo, Yadira; Van Bel, Michiel; Van Hautegem, Tom; Fendrych, Matyáš; Huysmans, Marlies; Simaskova, Maria; van Durme, Matthias; Buscaill, Pierre; Rivas, Susana; Coll, Nuria S.; Coppens, Frederik; Maere, Steven; Nowack, Moritz K.

    2015-12-01

    A plethora of diverse programmed cell death (PCD) processes has been described in living organisms. In animals and plants, different forms of PCD play crucial roles in development, immunity, and responses to the environment. While the molecular control of some animal PCD forms such as apoptosis is known in great detail, we still know comparatively little about the regulation of the diverse types of plant PCD. In part, this deficiency in molecular understanding is caused by the lack of reliable reporters to detect PCD processes. Here, we addressed this issue by using a combination of bioinformatics approaches to identify commonly regulated genes during diverse plant PCD processes in Arabidopsis (Arabidopsis thaliana). Our results indicate that the transcriptional signatures of developmentally controlled cell death are largely distinct from the ones associated with environmentally induced cell death. Moreover, different cases of developmental PCD share a set of cell death-associated genes. Most of these genes are evolutionary conserved within the green plant lineage, arguing for an evolutionary conserved core machinery of developmental PCD. Based on this information, we established an array of specific promoter-reporter lines for developmental PCD in Arabidopsis. These PCD indicators represent a powerful resource that can be used in addition to established morphological and biochemical methods to detect and analyze PCD processes in vivo and in planta. © 2015 American Society of Plant Biologists. All Rights Reserved.

  12. Radiation-induced apoptosis of chicken lymphocyte B-cell line DT40

    International Nuclear Information System (INIS)

    Furusawa, Y.; Aoki, M.; Takakura, K.

    2003-01-01

    Full text: Ionizing radiation causes lesions of DNA, cell cycle arrest, induced cell death, and apoptosis in the irradiated cells. Then it is easy to expect that those events would be increased in a cell line which is defective in DNA repair system. However, induction of apoptosis by irradiation takes so complicated process when the cells are defective of DNA repair system. Indeed by many recent studies it has been clarified that DNA repair gene is also concerned with apoptotic event and some study shows the contrary data. Thus, the relationship between the genetics of apoptosis and that of DNA repair is still unclear. In this study two kinds of DNA repair proteins, Rad54 and Ku70, were focused. Proteins of Rad54 and Ku70 have important role at two type of DNA repair systems called homologous recombination repair and non-homologous end joining repair, respectively. 4 phenotypes of DT40, parent type, ku70-/-, rad54-/- and ku70-/-/rad54-/- were used to study the radiation-induced apoptosis (Previous study shows that survival fraction of 4 phenotypes of DT40 is decreased in the cell line, in which DNA repair gene is defective). From the results in this study, two things are clarifies. One is that the dependence of apoptotic index on phenotypes is so different between at low dose and at high dose irradiation. The other is that Ku70 has effective role to induce apoptosis in DT40 irradiated with high dose X-rays

  13. Proteomics informed by transcriptomics reveals Hendra virus sensitizes bat cells to TRAIL-mediated apoptosis.

    Science.gov (United States)

    Wynne, James W; Shiell, Brian J; Marsh, Glenn A; Boyd, Victoria; Harper, Jennifer A; Heesom, Kate; Monaghan, Paul; Zhou, Peng; Payne, Jean; Klein, Reuben; Todd, Shawn; Mok, Lawrence; Green, Diane; Bingham, John; Tachedjian, Mary; Baker, Michelle L; Matthews, David; Wang, Lin-Fa

    2014-01-01

    Bats are a major reservoir of emerging infectious viruses. Many of these viruses are highly pathogenic to humans however bats remain asymptomatic. The mechanism by which bats control viral replication is unknown. Here we utilize an integrated approach of proteomics informed by transcriptomics to compare the response of immortalized bat and human cells following infection with the highly pathogenic bat-borne Hendra virus (HeV). The host response between the cell lines was significantly different at both the mRNA and protein levels. Human cells demonstrated minimal response eight hours post infection, followed by a global suppression of mRNA and protein abundance. Bat cells demonstrated a robust immune response eight hours post infection, which led to the up-regulation of apoptosis pathways, mediated through the tumor necrosis factor-related apoptosis inducing ligand (TRAIL). HeV sensitized bat cells to TRAIL-mediated apoptosis, by up-regulating death receptor transcripts. At 48 and 72 hours post infection, bat cells demonstrated a significant increase in apoptotic cell death. This is the first study to comprehensively compare the response of bat and human cells to a highly pathogenic zoonotic virus. An early induction of innate immune processes followed by apoptosis of virally infected bat cells highlights the possible involvement of programmed cell death in the host response. Our study shows for the first time a side-by-side high-throughput analysis of a dangerous zoonotic virus in cell lines derived from humans and the natural bat host. This enables a way to search for divergent mechanisms at a molecular level that may influence host pathogenesis.

  14. MST1 is a novel regulator of apoptosis in pancreatic beta-cells

    Science.gov (United States)

    Ardestani, Amin; Khobragade, Vrushali; Yuan, Ting; Frogne, Thomas; Tao, Wufan; Oberholzer, Jose; Pattou, Francois; Conte, Julie Kerr; Maedler, Kathrin

    2014-01-01

    Apoptotic cell death is a hallmark of the loss of insulin producing beta-cells in all forms of diabetes mellitus. Current treatment fails to halt the decline in functional beta-cell mass. Strategies to prevent beta-cell apoptosis and dysfunction are urgently needed. Here, we identified Mammalian Sterile 20-like kinase 1 (MST1) as a critical regulator of apoptotic beta-cell death and function. MST1 was strongly activated in beta-cells under diabetogenic conditions and correlated with beta-cell apoptosis. MST1 specifically induced the mitochondrial-dependent pathway of apoptosis in beta-cells through up-regulation of the BH3-only protein Bim. MST1 directly phosphorylated PDX1 at Thr11, resulting in its ubiquitination, degradation and impaired insulin secretion. Mst1 deficiency completely restored normoglycemia, beta-cell function and survival in vitro and in vivo. We show MST1 as novel pro-apoptotic kinase and key mediator of apoptotic signaling and beta-cell dysfunction, which may serve as target for the development of novel therapies for diabetes. PMID:24633305

  15. Human retinal pigment epithelial cell-induced apoptosis in activated T cells

    DEFF Research Database (Denmark)

    Jørgensen, A; Wiencke, A K; la Cour, M

    1998-01-01

    human retinal pigment epithelial (RPE) cells can induce apoptosis in activated T cells. METHODS: Fas ligand (FasL) expression was detected by flow cytometry and immunohistochemistry. Cultured RPE cells were cocultured with T-cell lines and peripheral blood lymphocytes for 6 hours to 2 days. Induction...... of apoptosis was detected by 7-amino-actinomycin D and annexin V staining. RESULTS: Retinal pigment epithelial cells expressed FasL and induced apoptosis in activated Fas+ T cells. Blocking of Fas-FasL interaction with antibody strongly inhibited RPE-mediated T-cell apoptosis. Retinal pigment epithelial cells...... induced apoptosis in several activated T-cell populations and T-cell lines, including T-cell antigen receptor (TCR)-CD3-negative T-cell lines. In contrast, RPE cells induced little or no apoptosis in resting peripheral T cells. Major histocompatibility complex (MHC) class II monoclonal antibodies, which...

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

    Directory of Open Access Journals (Sweden)

    Pan Shiow-Lin

    2009-05-01

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

  17. In vitro and in vivo study of endothelial cells radio-induced death modulation by Sphingosine-1-Phosphate

    International Nuclear Information System (INIS)

    Bonnaud, St.

    2007-01-01

    Protecting the vasculature from radiation-induced death is a major concern in tissue radioprotection. Developing a model of endothelial cells radiosensitivity, we proved that HMEC-1 undergo 2 waves of death after exposure to 15 Gy: an early pre mitotic apoptosis dependent of ceramide generation and a delayed DNA damage-induced mitotic death. Sphingosine-1-Phosphate (S1P), a ceramide antagonist, protects HMEC-1 only from early apoptosis, but not from mitotic death. We confirmed in vivo the S1P radioprotection from ceramide-mediated radio-induced apoptosis, and that S1P radioprotection is partially mediated by S1Ps receptors. Segregation between these 2 types of death may give the opportunity to define a new class of radioprotectors for normal tissue where quiescent endothelium represent the most sensitive target, while excluding malignant tumor containing pro-proliferating angiogenic endothelial cells, sensitive to mitotic death. (author)

  18. Apoptosis in ovarian cells in postmenopausal women.

    Directory of Open Access Journals (Sweden)

    Maria Laszczyńska

    2007-06-01

    Full Text Available Apoptosis is a natural process which accompanies human ovary from the moment of birth until old age. While it is a well-known process at the reproductive age, it still needs to be thoroughly examined when referring to the postmenopausal age. The study involved 30 postmenopausal women who had their ovaries removed by laparotomy due to nonneoplastic diseases of the uterus. The women were divided into 3 groups depending on the time that had passed since the last menstruation. Group A consisted of women who had their last menstruation no more than 5 years earlier. In group B menopause occurred 5 to 10 years earlier. Group C was composed of patients who had the last menstruation over 10 years earlier. In all the patients concentrations of follitropin (FSH and estradiol (E2 in blood plasma were measured. Ovarian tissue was obtained during surgery. For morphological studies, ovaries were fixed in Bouin's solution and 4% formalin and embedded in paraffin. Morphological analysis was carried out after hematoxylin-eosin (H-E staining. For histochemical detection of apoptotic cells (in situ localization of fragment DNA, the TUNEL method was used. The expression of caspase-3 positive cells was determined immunohistochemically in paraffin-embedded specimens. Comparing to groups A and B, the ovaries in group C contained small number of corpora albicantia located in the medullary part as well as thinned blood vessels and few lymphatic vessels and nerves. In contrast to group A where the number of TUNEL-positive cells was high and caspase-3 expression was observed, no TUNEL-positive nuclei and caspase-3 expression were found in the examined ovaries of group C women.

  19. Apoptosis in HEp-2 cells infected with Ureaplasma diversum

    Directory of Open Access Journals (Sweden)

    Aline Teixeira Amorim

    2014-01-01

    Full Text Available BACKGROUND: Bacterial pathogens have many strategies for infecting and persisting in host cells. Adhesion, invasion and intracellular life are important features in the biology of mollicutes. The intracellular location ofUreaplasma diversum may trigger disturbances in the host cell. This includes activation or inhibition of pro and anti-apoptotic factors, which facilitate the development of host damage. The aim of the present study was to associate U. diversum infection in HEp-2 cells and apoptosis induction. Cells were infected for 72hs with four U. diversum clinical isolates and an ATCC strain. The U. diversuminvasion was analyzed by Confocal Laser Scanning Microscopy and gentamicin invasion assay. The apoptosis was evaluated using pro-apoptotic and anti-apoptotic gene expression, and FITC Annexin V/Dead Cell Apoptosis Kit. RESULTS: The number of internalized ureaplasma in HEp-2 cells increased significantly throughout the infection. The flow cytometry analysis with fluorochromes to detect membrane depolarization and gene expression for caspase 2, 3 and 9 increased in infected cells after 24 hours. However, after 72 hours a considerable decrease of apoptotic cells was observed. CONCLUSIONS: The data suggests that apoptosis may be initially induced by some isolates in association with HEp-2 cells, but over time, there was no evidence of apoptosis in the presence of ureaplasma and HEp-2 cells. The initial increase and then decrease in apoptosis could be related to bacterial pathogen-associated molecular pattern (PAMPS. Moreover, the isolates of U. diversum presented differences in the studied parameters for apoptosis. It was also observed that the amount of microorganisms was not proportional to the induction of apoptosis in HEp-2 cells.

  20. Apoptosis in HEp-2 cells infected with Ureaplasma diversum.

    Science.gov (United States)

    Amorim, Aline Teixeira; Marques, Lucas Miranda; Santos, Angelita Maria Oliveira Gusmão; Martins, Hellen Braga; Barbosa, Maysa Santos; Rezende, Izadora Souza; Andrade, Ewerton Ferraz; Campos, Guilherme Barreto; Lobão, Tássia Neves; Cortez, Beatriz Araujo; Monezi, Telma Alvez; Machado-Santelli, Glaucia Maria; Timenetsky, Jorge

    2014-09-04

    Bacterial pathogens have many strategies for infecting and persisting in host cells. Adhesion, invasion and intracellular life are important features in the biology of mollicutes. The intracellular location of Ureaplasma diversum may trigger disturbances in the host cell. This includes activation or inhibition of pro and anti-apoptotic factors, which facilitate the development of host damage. The aim of the present study was to associate U. diversum infection in HEp-2 cells and apoptosis induction. Cells were infected for 72hs with four U. diversum clinical isolates and an ATCC strain. The U. diversum invasion was analyzed by Confocal Laser Scanning Microscopy and gentamicin invasion assay. The apoptosis was evaluated using pro-apoptotic and anti-apoptotic gene expression, and FITC Annexin V/Dead Cell Apoptosis Kit. The number of internalized ureaplasma in HEp-2 cells increased significantly throughout the infection. The flow cytometry analysis with fluorochromes to detect membrane depolarization and gene expression for caspase 2, 3 and 9 increased in infected cells after 24 hours. However, after 72 hours a considerable decrease of apoptotic cells was observed. The data suggests that apoptosis may be initially induced by some isolates in association with HEp-2 cells, but over time, there was no evidence of apoptosis in the presence of ureaplasma and HEp-2 cells. The initial increase and then decrease in apoptosis could be related to bacterial pathogen-associated molecular pattern (PAMPS). Moreover, the isolates of U. diversum presented differences in the studied parameters for apoptosis. It was also observed that the amount of microorganisms was not proportional to the induction of apoptosis in HEp-2 cells.

  1. Alisertib Induces Cell Cycle Arrest, Apoptosis, Autophagy and Suppresses EMT in HT29 and Caco-2 Cells

    Science.gov (United States)

    Ren, Bao-Jun; Zhou, Zhi-Wei; Zhu, Da-Jian; Ju, Yong-Le; Wu, Jin-Hao; Ouyang, Man-Zhao; Chen, Xiao-Wu; Zhou, Shu-Feng

    2015-01-01

    Colorectal cancer (CRC) is one of the most common malignancies worldwide with substantial mortality and morbidity. Alisertib (ALS) is a selective Aurora kinase A (AURKA) inhibitor with unclear effect and molecular interactome on CRC. This study aimed to evaluate the molecular interactome and anticancer effect of ALS and explore the underlying mechanisms in HT29 and Caco-2 cells. ALS markedly arrested cells in G2/M phase in both cell lines, accompanied by remarkable alterations in the expression level of key cell cycle regulators. ALS induced apoptosis in HT29 and Caco-2 cells through mitochondrial and death receptor pathways. ALS also induced autophagy in HT29 and Caco-2 cells, with the suppression of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), but activation of 5′ AMP-activated protein kinase (AMPK) signaling pathways. There was a differential modulating effect of ALS on p38 MAPK signaling pathway in both cell lines. Moreover, induction or inhibition of autophagy modulated basal and ALS-induced apoptosis in both cell lines. ALS potently suppressed epithelial to mesenchymal transition (EMT) in HT29 and Caco-2 cells. Collectively, it suggests that induction of cell cycle arrest, promotion of apoptosis and autophagy, and suppression of EMT involving mitochondrial, death receptor, PI3K/Akt/mTOR, p38 MAPK, and AMPK signaling pathways contribute to the cancer cell killing effect of ALS on CRC cells. PMID:26729093

  2. Alisertib Induces Cell Cycle Arrest, Apoptosis, Autophagy and Suppresses EMT in HT29 and Caco-2 Cells

    Directory of Open Access Journals (Sweden)

    Bao-Jun Ren

    2015-12-01

    Full Text Available Colorectal cancer (CRC is one of the most common malignancies worldwide with substantial mortality and morbidity. Alisertib (ALS is a selective Aurora kinase A (AURKA inhibitor with unclear effect and molecular interactome on CRC. This study aimed to evaluate the molecular interactome and anticancer effect of ALS and explore the underlying mechanisms in HT29 and Caco-2 cells. ALS markedly arrested cells in G2/M phase in both cell lines, accompanied by remarkable alterations in the expression level of key cell cycle regulators. ALS induced apoptosis in HT29 and Caco-2 cells through mitochondrial and death receptor pathways. ALS also induced autophagy in HT29 and Caco-2 cells, with the suppression of phosphoinositide 3-kinase (PI3K/protein kinase B (Akt/mammalian target of rapamycin (mTOR, but activation of 5′ AMP-activated protein kinase (AMPK signaling pathways. There was a differential modulating effect of ALS on p38 MAPK signaling pathway in both cell lines. Moreover, induction or inhibition of autophagy modulated basal and ALS-induced apoptosis in both cell lines. ALS potently suppressed epithelial to mesenchymal transition (EMT in HT29 and Caco-2 cells. Collectively, it suggests that induction of cell cycle arrest, promotion of apoptosis and autophagy, and suppression of EMT involving mitochondrial, death receptor, PI3K/Akt/mTOR, p38 MAPK, and AMPK signaling pathways contribute to the cancer cell killing effect of ALS on CRC cells.

  3. Bimodal cell death induced by high radiation doses in the radioresistant sf9 insect cell line

    International Nuclear Information System (INIS)

    Chandna, S.

    2003-01-01

    Full text: This study was conducted to investigate the mode(s) of cell death induced by high radiation doses in the highly radioresistant Sf9 insect ovarian cell line. Methods: Cells were exposed to γ-radiation doses 200Gy and 500Gy, harvested at various time intervals (6h-72h) following irradiation, and subjected to cell morphology assay, DNA agarose gel electrophoresis, single cell gel electrophoresis (SCGE; comet assay) and Annexin-V labeling for the detection of membrane phosphatidylserine externalization. Cell morphology was assessed in cells entrapped and fixed in agarose gel directly from the cell suspension, thus preventing the possible loss of fragments/ apoptotic bodies. Surviving fraction of Sf9 cells was 0.01 at 200Gy and 98%) undergoing extensive DNA fragmentation at 500Gy, whereas the frequency of cells with DNA fragmentation was considerably less (∼12%) at 200Gy. Conclusions: While the mode of cell death at 200Gy seems to be different from typical apoptosis, a dose of 500Gy induced bimodal cell death, with typical apoptotic as well as the atypical cell death observed at 200Gy

  4. Role of passive T-cell death in chronic experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Issazadeh-Navikas, Shohreh; Abdallah, K; Chitnis, T

    2000-01-01

    The mechanisms of chronic disease and recovery from relapses in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, are unknown. Deletion of myelin-specific lymphocytes by apoptosis may play a role in termination of the inflammatory response. One pathway...... of apoptosis is the passive cell death or "cell death by neglect" pathway, which is under the control of the Bcl family of genes. To investigate the role of passive cell death pathway in EAE, we used mice with transgenic expression of the long form of the bcl-x gene (Bcl-x(L)) targeted to the T-cell lineage...... central nervous system (CNS) compared with controls. There was also a decreased number of apoptotic cells in the CNS of Bcl-x(L) transgenic mice when compared with littermates at all time points tested. This is the first report of an autoimmune disease model in Bcl-x(L) transgenic mice. Our data indicate...

  5. Induction of ROS Overload by Alantolactone Prompts Oxidative DNA Damage and Apoptosis in Colorectal Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yushuang Ding

    2016-04-01

    Full Text Available Cancer cells typically display higher than normal levels of reactive oxygen species (ROS, which may promote cancer development and progression but may also render the cancer cells more vulnerable to further ROS insult. Indeed, many of the current anticancer therapeutics kill cancer cells via induction of oxidative stress, though they target both cancer and normal cells. Recently, alantolactone (ATL, a natural sesquiterpene lactone, has been shown to induce apoptosis by increasing ROS levels specifically in cancer cells; however, the molecular mechanisms linking ROS overproduction to apoptosis remain unclear. Here we show that the ATL-induced ROS overload in human SW480 and SW1116 colorectal cancer cells was followed by a prominent accumulation of cellular oxidized guanine (8-oxoG and immediate increase in the number of DNA strand breaks, indicating that increased ROS resulted in extensive oxidative DNA damage. Consequently, the G1/S-CDK suppresser CDKN1B (p21 and pro-apoptotic proteins Bax and activated caspase-3 were upregulated, while anti-apoptotic Bcl-2 was downregulated, which were followed by cell cycle arrest at G1 and marked apoptosis in ATL-treated cancer but not non-cancer cells. These results suggest that the ATL-induced ROS overload triggers cell death through induction of massive oxidative DNA damage and subsequent activation of the intrinsic apoptosis pathway.

  6. 17-AAG and Apoptosis, Autophagy, and Mitophagy in Canine Osteosarcoma Cell Lines.

    Science.gov (United States)

    Massimini, M; Palmieri, C; De Maria, R; Romanucci, M; Malatesta, D; De Martinis, M; Maniscalco, L; Ciccarelli, A; Ginaldi, L; Buracco, P; Bongiovanni, L; Della Salda, L

    2017-05-01

    Canine osteosarcoma is highly resistant to current chemotherapy; thus, clarifying the mechanisms of tumor cell resistance to treatments is an urgent need. We tested the geldanamycin derivative 17-AAG (17-allylamino-17-demethoxygeldanamycin) prototype of Hsp90 (heat shock protein 90) inhibitors in 2 canine osteosarcoma cell lines, D22 and D17, derived from primary and metastatic tumors, respectively. With the aim to understand the interplay between cell death, autophagy, and mitophagy, in light of the dual effect of autophagy in regulating cancer cell viability and death, D22 and D17 cells were treated with different concentrations of 17-AAG (0.5 μM, 1 μM) for 24 and 48 hours. 17-AAG-induced apoptosis, necrosis, autophagy, and mitophagy were assessed by transmission electron microscopy, flow cytometry, and immunofluorescence. A simultaneous increase in apoptosis, autophagy, and mitophagy was observed only in the D22 cell line, while D17 cells showed low levels of apoptotic cell death. These results reveal differential cell response to drug-induced stress depending on tumor cell type. Therefore, pharmacological treatments based on proapoptotic chemotherapy in association with autophagy regulators would benefit from a predictive in vitro screening of the target cell type.

  7. Apoptosis and radiosensitivity induced by N-acety1 phytosphingosine, in human cancer cell line

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. H.; Kim, K. S.; Han, Y. S.; Jeon, S. J.; Song, J. Y.; Jung, I. S.; Hong, S. H.; Yun, Y. S. [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Park, J. S. [Doosan Biotech, Yongin (Korea, Republic of)

    2004-07-01

    Ceramide is a key lipid molecule in signal transduction with a role in various regulatory pathways including differentiation, proliferation and especially apoptosis. Ionizing radiation-induced apoptosis is associated with accumulation of ceramide, and the sphingomyelinase deficiency results in radioresistance. We investigated the exogenous treatment of N-acetyl-phytosphingosine (NAPS), an analogue of N-acetyl-sphingosine (C{sub 2}-Ceramide), and C{sub 2}-ceramide exert apoptotic effect on human T cell lymphoma Jurkat cells and breast cancer cell line MDA-MB-231. NAPS and C{sub 2}-Ceramide has cytotoxic effect in time- and dose-dependent manner, and increased caspase-3, 8 activity. However, NAPS induced apoptosis more effectively, and increased caspase activity induced by NAPS is more higher than C{sub 2}-ceramide. Moreover, NAPS decreased clonogenicity of irradiated cells and increased radiation-induced apoptosis significantly. Increased cell death by irradiation in the presence of NAPS is owing to the increase of caspase activity. These data suggest that NAPS might be used for lead as a new type of radiosensitizing agent increasing radiation-induced apoptosis.

  8. Apoptosis and radiosensitivity induced by N-acety1 phytosphingosine, in human cancer cell line

    International Nuclear Information System (INIS)

    Kim, Y. H.; Kim, K. S.; Han, Y. S.; Jeon, S. J.; Song, J. Y.; Jung, I. S.; Hong, S. H.; Yun, Y. S.; Park, J. S.

    2004-01-01

    Ceramide is a key lipid molecule in signal transduction with a role in various regulatory pathways including differentiation, proliferation and especially apoptosis. Ionizing radiation-induced apoptosis is associated with accumulation of ceramide, and the sphingomyelinase deficiency results in radioresistance. We investigated the exogenous treatment of N-acetyl-phytosphingosine (NAPS), an analogue of N-acetyl-sphingosine (C 2 -Ceramide), and C 2 -ceramide exert apoptotic effect on human T cell lymphoma Jurkat cells and breast cancer cell line MDA-MB-231. NAPS and C 2 -Ceramide has cytotoxic effect in time- and dose-dependent manner, and increased caspase-3, 8 activity. However, NAPS induced apoptosis more effectively, and increased caspase activity induced by NAPS is more higher than C 2 -ceramide. Moreover, NAPS decreased clonogenicity of irradiated cells and increased radiation-induced apoptosis significantly. Increased cell death by irradiation in the presence of NAPS is owing to the increase of caspase activity. These data suggest that NAPS might be used for lead as a new type of radiosensitizing agent increasing radiation-induced apoptosis

  9. Combination of ascorbate/epigallocatechin-3-gallate/gemcitabine synergistically induces cell cycle deregulation and apoptosis in mesothelioma cells

    Energy Technology Data Exchange (ETDEWEB)

    Martinotti, Simona [Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale “Amedeo Avogadro”, viale T. Michel 11, 15121 Alessandria (Italy); Ranzato, Elia, E-mail: ranzato@unipmn.it [Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale “Amedeo Avogadro”, viale T. Michel 11, 15121 Alessandria (Italy); Parodi, Monica [IRCCS A.O.U. S. Martino-IST, Istituto Nazionale per la Ricerca sul Cancro, 16132 Genova (Italy); DI.ME.S., Università degli Studi di Genova, Via L. Alberti 2, 16132 Genova (Italy); Vitale, Massimo [IRCCS A.O.U. S. Martino-IST, Istituto Nazionale per la Ricerca sul Cancro, 16132 Genova (Italy); Burlando, Bruno [Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale “Amedeo Avogadro”, viale T. Michel 11, 15121 Alessandria (Italy)

    2014-01-01

    Malignant mesothelioma (MMe) is a poor-prognosis tumor in need of innovative therapies. In a previous in vivo study, we showed synergistic anti-MMe properties of the ascorbate/epigallocatechin-3-gallate/gemcitabine combination. We have now focused on the mechanism of action, showing the induction of apoptosis and cell cycle arrest through measurements of caspase 3, intracellular Ca{sup 2+}, annexin V, and DNA content. StellArray™ PCR technology and Western immunoblotting revealed DAPK2-dependent apoptosis, upregulation of cell cycle promoters, downregulation of cell cycle checkpoints and repression of NFκB expression. The complex of data indicates that the mixture is synergistic in inducing cell cycle deregulation and non-inflammatory apoptosis, suggesting its possible use in MMe treatment. - Highlights: • Ascorbate/epigallocathechin-gallate/gemcitabine has been tested on mesothelioma cells • A synergistic mechanism has been shown for cell cycle arrest and apoptosis • PCR-array analysis has revealed the de-regulation of apoptosis and cell cycle genes • Maximum upregulation has been found for the Death-Associated Protein Kinase-2 gene • Data suggest that the mixture could be used as a clinical treatment.

  10. Smac Mimetic Bypasses Apoptosis Resistance in FADD- or Caspase-8-Deficient Cells by Priming for Tumor Necrosis Factor α-Induced Necroptosis

    Directory of Open Access Journals (Sweden)

    Bram Laukens

    2011-10-01

    Full Text Available Searching for new strategies to bypass apoptosis resistance, we investigated the potential of the Smac mimetic BV6 in Jurkat leukemia cells deficient in key molecules of the death receptor pathway. Here, we demonstrate for the first time that Smac mimetic primes apoptosis-resistant, FADD- or caspase-8-deficient leukemia cells for TNFα-induced necroptosis in a synergistic manner. In contrast to TNFα, Smac mimetic significantly enhances CD95-induced apoptosis in wild-type but not in FADD-deficient cells. Interestingly, Smac mimetic- and TNFα-mediated cell death occurs without characteristic features of apoptosis (i.e., caspase activation, DNA fragmentation in FADD-deficient cells. By comparison, Smac mimetic and TNFα trigger activation of caspase-8, -9, and -3 and DNA fragmentation in wild-type cells. Consistently, the caspase inhibitor zVAD.fmk fails to block Smac mimetic- and TNFα-triggered cell death in FADD- or caspase-8-deficient cells, while it confers protection in wild-type cells. By comparison, necrostatin-1, an RIP1 kinase inhibitor, abolishes Smac mimetic- and TNFα-induced cell death in FADD- or caspase-8-deficient. Thus, Smac mimetic enhances TNFα-induced cell death in leukemia cells via two distinct pathways in a context-dependent manner: it primes apoptosis-resistant cells lacking FADD or caspase-8 to TNFα-induced, RIP1-dependent and caspase-independent necroptosis, whereas it sensitizes apoptosis-proficient cells to TNFα-mediated, caspase-dependent apoptosis. These findings have important implications for the therapeutic exploitation of necroptosis as an alternative cell death program to overcome apoptosis resistance.

  11. Smac Mimetic Bypasses Apoptosis Resistance in FADD- or Caspase-8-Deficient Cells by Priming for Tumor Necrosis Factor α-Induced Necroptosis12

    Science.gov (United States)

    Laukens, Bram; Jennewein, Claudia; Schenk, Barbara; Vanlangenakker, Nele; Schier, Alexander; Cristofanon, Silvia; Zobel, Kerry; Deshayes, Kurt; Vucic, Domagoj; Jeremias, Irmela; Bertrand, Mathieu JM; Vandenabeele, Peter; Fulda, Simone

    2011-01-01

    Searching for new strategies to bypass apoptosis resistance, we investigated the potential of the Smac mimetic BV6 in Jurkat leukemia cells deficient in key molecules of the death receptor pathway. Here, we demonstrate for the first time that Smac mimetic primes apoptosis-resistant, FADD- or caspase-8-deficient leukemia cells for TNFα-induced necroptosis in a synergistic manner. In contrast to TNFα, Smac mimetic significantly enhances CD95-induced apoptosis in wild-type but not in FADD-deficient cells. Interestingly, Smac mimetic- and TNFα-mediated cell death occurs without characteristic features of apoptosis (i.e., caspase activation, DNA fragmentation) in FADD-deficient cells. By comparison, Smac mimetic and TNFα trigger activation of caspase-8, -9, and -3 and DNA fragmentation in wild-type cells. Consistently, the caspase inhibitor zVAD.fmk fails to block Smac mimetic- and TNFα-triggered cell death in FADD- or caspase-8-deficient cells, while it confers protection in wild-type cells. By comparison, necrostatin-1, an RIP1 kinase inhibitor, abolishes Smac mimetic- and TNFα-induced cell death in FADD- or caspase-8-deficient. Thus, Smac mimetic enhances TNFα-induced cell death in leukemia cells via two distinct pathways in a context-dependent manner: it primes apoptosis-resistant cells lacking FADD or caspase-8 to TNFα-induced, RIP1-dependent and caspase-independent necroptosis, whereas it sensitizes apoptosis-proficient cells to TNFα-mediated, caspase-dependent apoptosis. These findings have important implications for the therapeutic exploitation of necroptosis as an alternative cell death program to overcome apoptosis resistance. PMID:22028622

  12. Smac mimetic bypasses apoptosis resistance in FADD- or caspase-8-deficient cells by priming for tumor necrosis factor α-induced necroptosis.

    Science.gov (United States)

    Laukens, Bram; Jennewein, Claudia; Schenk, Barbara; Vanlangenakker, Nele; Schier, Alexander; Cristofanon, Silvia; Zobel, Kerry; Deshayes, Kurt; Vucic, Domagoj; Jeremias, Irmela; Bertrand, Mathieu J M; Vandenabeele, Peter; Fulda, Simone

    2011-10-01

    Searching for new strategies to bypass apoptosis resistance, we investigated the potential of the Smac mimetic BV6 in Jurkat leukemia cells deficient in key molecules of the death receptor pathway. Here, we demonstrate for the first time that Smac mimetic primes apoptosis-resistant, FADD- or caspase-8-deficient leukemia cells for TNFα-induced necroptosis in a synergistic manner. In contrast to TNFα, Smac mimetic significantly enhances CD95-induced apoptosis in wild-type but not in FADD-deficient cells. Interestingly, Smac mimetic- and TNFα-mediated cell death occurs without characteristic features of apoptosis (i.e., caspase activation, DNA fragmentation) in FADD-deficient cells. By comparison, Smac mimetic and TNFα trigger activation of caspase-8, -9, and -3 and DNA fragmentation in wild-type cells. Consistently, the caspase inhibitor zVAD.fmk fails to block Smac mimetic- and TNFα-triggered cell death in FADD- or caspase-8-deficient cells, while it confers protection in wild-type cells. By comparison, necrostatin-1, an RIP1 kinase inhibitor, abolishes Smac mimetic- and TNFα-induced cell death in FADD- or caspase-8-deficient. Thus, Smac mimetic enhances TNFα-induced cell death in leukemia cells via two distinct pathways in a context-dependent manner: it primes apoptosis-resistant cells lacking FADD or caspase-8 to TNFα-induced, RIP1-dependent and caspase-independent necroptosis, whereas it sensitizes apoptosis-proficient cells to TNFα-mediated, caspase-dependent apoptosis. These findings have important implications for the therapeutic exploitation of necroptosis as an alternative cell death program to overcome apoptosis resistance.

  13. The Life and Death of a Plant Cell.

    Science.gov (United States)

    Kabbage, Mehdi; Kessens, Ryan; Bartholomay, Lyric C; Williams, Brett

    2017-04-28

    Like all eukaryotic organisms, plants possess an innate program for controlled cellular demise termed programmed cell death (PCD). Despite the functional conservation of PCD across broad evolutionary distances, an understanding of the molecular machinery underpinning this fundamental program in plants remains largely elusive. As in mammalian PCD, the regulation of plant PCD is critical to development, homeostasis, and proper responses to stress. Evidence is emerging that autophagy is key to the regulation of PCD in plants and that it can dictate the outcomes of PCD execution under various scenarios. Here, we provide a broad and comparative overview of PCD processes in plants, with an emphasis on stress-induced PCD. We also discuss the implications of the paradox that is functional conservation of apoptotic hallmarks in plants in the absence of core mammalian apoptosis regulators, what that means, and whether an equivalent form of death occurs in plants.

  14. Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018

    NARCIS (Netherlands)

    Galluzzi, Lorenzo; Vitale, Ilio; Aaronson, Stuart A.; Abrams, John M.; Adam, Dieter; Agostinis, Patrizia; Alnemri, Emad S.; Altucci, Lucia; Amelio, Ivano; Andrews, David W.; Annicchiarico-Petruzzelli, Margherita; Antonov, Alexey V.; Arama, Eli; Baehrecke, Eric H.; Barlev, Nickolai A.; Bazan, Nicolas G.; Bernassola, Francesca; Bertrand, Mathieu J. M.; Bianchi, Katiuscia; Blagosklonny, Mikhail V.; Blomgren, Klas; Borner, Christoph; Boya, Patricia; Brenner, Catherine; Campanella, Michelangelo; Candi, Eleonora; Carmona-Gutierrez, Didac; Cecconi, Francesco; Chan, Francis K.-M.; Chandel, Navdeep S.; Cheng, Emily H.; Chipuk, Jerry E.; Cidlowski, John A.; Ciechanover, Aaron; Cohen, Gerald M.; Conrad, Marcus; Cubillos-Ruiz, Juan R.; Czabotar, Peter E.; D'Angiolella, Vincenzo; Dawson, Ted M.; Dawson, Valina L.; de Laurenzi, Vincenzo; de Maria, Ruggero; Debatin, Klaus-Michael; DeBerardinis, Ralph J.; Deshmukh, Mohanish; Di Daniele, Nicola; Di Virgilio, Francesco; Dixit, Vishva M.; Dixon, Scott J.; Duckett, Colin S.; Dynlacht, Brian D.; El-Deiry, Wafik S.; Elrod, John W.; Fimia, Gian Maria; Fulda, Simone; García-Sáez, Ana J.; Garg, Abhishek D.; Garrido, Carmen; Gavathiotis, Evripidis; Golstein, Pierre; Gottlieb, Eyal; Green, Douglas R.; Greene, Lloyd A.; Gronemeyer, Hinrich; Gross, Atan; Hajnoczky, Gyorgy; Hardwick, J. Marie; Harris, Isaac S.; Hengartner, Michael O.; Hetz, Claudio; Ichijo, Hidenori; Jäättelä, Marja; Joseph, Bertrand; Jost, Philipp J.; Juin, Philippe P.; Kaiser, William J.; Karin, Michael; Kaufmann, Thomas; Kepp, Oliver; Kimchi, Adi; Kitsis, Richard N.; Klionsky, Daniel J.; Knight, Richard A.; Kumar, Sharad; Lee, Sam W.; Lemasters, John J.; Levine, Beth; Linkermann, Andreas; Lipton, Stuart A.; Lockshin, Richard A.; López-Otín, Carlos; Lowe, Scott W.; Luedde, Tom; Lugli, Enrico; MacFarlane, Marion; Madeo, Frank; Malewicz, Michal; Malorni, Walter; Manic, Gwenola; Marine, Jean-Christophe; Martin, Seamus J.; Martinou, Jean-Claude; Medema, Jan Paul; Mehlen, Patrick; Meier, Pascal; Melino, Sonia; Miao, Edward A.; Molkentin, Jeffery D.; Moll, Ute M.; Muñoz-Pinedo, Cristina; Nagata, Shigekazu; Nuñez, Gabriel; Oberst, Andrew; Oren, Moshe; Overholtzer, Michael; Pagano, Michele; Panaretakis, Theocharis; Pasparakis, Manolis; Penninger, Josef M.; Pereira, David M.; Pervaiz, Shazib; Peter, Marcus E.; Piacentini, Mauro; Pinton, Paolo; Prehn, Jochen H. M.; Puthalakath, Hamsa; Rabinovich, Gabriel A.; Rehm, Markus; Rizzuto, Rosario; Rodrigues, Cecilia M. P.; Rubinsztein, David C.; Rudel, Thomas; Ryan, Kevin M.; Sayan, Emre; Scorrano, Luca; Shao, Feng; Shi, Yufang; Silke, John; Simon, Hans-Uwe; Sistigu, Antonella; Stockwell, Brent R.; Strasser, Andreas; Szabadkai, Gyorgy; Tait, Stephen W. G.; Tang, Daolin; Tavernarakis, Nektarios; Thorburn, Andrew; Tsujimoto, Yoshihide; Turk, Boris; Vanden Berghe, Tom; Vandenabeele, Peter; Vander Heiden, Matthew G.; Villunger, Andreas; Virgin, Herbert W.; Vousden, Karen H.; Vucic, Domagoj; Wagner, Erwin F.; Walczak, Henning; Wallach, David; Wang, Ying; Wells, James A.; Wood, Will; Yuan, Junying; Zakeri, Zahra; Zhivotovsky, Boris; Zitvogel, Laurence; Melino, Gerry; Kroemer, Guido

    2018-01-01

    Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell

  15. Bufalin Induces Reactive Oxygen Species Dependent Bax Translocation and Apoptosis in ASTC-a-1 Cells

    Directory of Open Access Journals (Sweden)

    Lei Sun

    2011-01-01

    Full Text Available Bufalin has been shown to induce cancer cell death through apoptotic pathways. However, the molecular mechanisms are not well understood. In this study, we used the confocal fluorescence microscopy (CFM to monitor the spatio-temporal dynamics of reactive oxygen species (ROS production, Bax translocation and caspase-3 activation during bufalin-induced apoptosis in living human lung adenocarcinoma (ASTC-a-1 cells. Bufalin induced ROS production and apoptotic cell death, demonstrated by Hoechst 33258 staining as well as flow cytometry analysis. Bax redistributed from cytosol to mitochondria from 12 to 48 h after bufalin treatment in living cells expressed with green fluorescent protein Bax. Treatment with the antioxidant N-acetyl-cysteine (NAC, a ROS scavenger, inhibited ROS generation and Bax translocation and led to a significant protection against bufalin-induced apoptosis. Our results also revealed that bufalin induced a prominent increase of caspase-3 activation blocked potently by NAC. Taken together, bufalin induced ROS-mediated Bax translocation, mitochondrial permeability transition and caspase-3 activation, implying that bufalin induced apoptosis via ROS-dependent mitochondrial death pathway in ASTC-a-1 cells.

  16. JNK1 Deficient Insulin-Producing Cells Are Protected against Interleukin-1 beta-Induced Apoptosis Associated with Abrogated Myc Expression

    DEFF Research Database (Denmark)

    Prause, Michala; Mayer, Christopher Michael; Brorsson, Caroline

    2016-01-01

    -induced INS-1 cell apoptosis associated with decreased 46 kDa isoform JNK protein phosphorylation and attenuated Myc expression. Transient knockdown of Myc also prevented IL-1β-induced apoptosis as well as caspase 3 cleavage. JNK2 shRNA potentiated IL-1β-induced apoptosis and caspase 3 cleavage, whereas JNK3...... shRNA did not affect IL-1β-induced β-cell death compared to nonsense shRNA expressing INS-1 cells. In conclusion, JNK1 mediates INS-1 cell death associated with increased Myc expression. These findings underline the importance of differentiated targeting of JNK subtypes in the development...

  17. Programmed cell death in periodontitis: recent advances and future perspectives.

    Science.gov (United States)

    Song, B; Zhou, T; Yang, W L; Liu, J; Shao, L Q

    2017-07-01

    Periodontitis is a highly prevalent infectious disease, characterized by destruction of the periodontium, and is the main cause of tooth loss. Periodontitis is initiated by periodontal pathogens, while other risk factors including smoking, stress, and systemic diseases aggravate its progression. Periodontitis affects many people worldwide, but the molecular mechanisms by which pathogens and risk factors destroy the periodontium are unclear. Programmed cell death (PCD), different from necrosis, is an active cell death mediated by a cascade of gene expression events and can be mainly classified into apoptosis, autophagy, necroptosis, and pyroptosis. Although PCD is involved in many inflammatory diseases, its correlation with periodontitis is unclear. After reviewing the relevant published articles, we found that apoptosis has indeed been reported to play a role in periodontitis. However, the role of autophagy in periodontitis needs further verification. Additionally, implication of necroptosis or pyroptosis in periodontitis remains unknown. Therefore, we recommend future studies, which will unravel the pivotal role of PCD in periodontitis, allowing us to prevent, diagnose, and treat the disease, as well as predict its outcomes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Regulatory mechanism of radiation-induced cancer cell death by the change of cell cycle

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Soo Jin; Jeong, Min Ho; Jang, Ji Yeon [College of Medicine, Donga Univ., Pusan (Korea, Republic of)

    2003-09-01

    In our previous study, we have shown the main cell death pattern induced by irradiation or protein tyrosine kinase (PTK) inhibitors in K562 human myelogenous leukemic cell line. Death of the cells treated with irradiation alone was characterized by mitotic catastrophe and typical radiation-induced apoptosis was accelerated by herbimycin A (HMA). Both types of cell death were inhibited by genistein. In this study, we investigated the effects of HMA and genistein on cell cycle regulation and its correlation with the alterations of radiation-induced cell death. K562 cells in exponential growth phase were used for this study. The cells were irradiated with 10 Gy using 6 MeV Linac (200-300 cGy/min). Immediately after irradiation, cells were treated with 250 nM of HMA or 25{mu}M of genistein. The distributions of cell cycle, the expressions of cell cycle-related protein, the activities of cyclin-dependent kinase, and the yield of senescence and differentiation were analyzed. X-irradiated cells were arrested in the G2 phase of the cell cycle but unlike the p53-positive cells, they were not able to sustain the cell cycle arrest. An accumulation of cells in G2 phase of first cell-cycle post-treatment and an increase of cyclin B1 were correlated with spontaneous, premature, chromosome condensation and mitotic catastrophe. HMA induced rapid G2 checkpoint abrogation and concomitant p53-independent G1 accumulation HMA-induced cell cycle modifications correlated with the increase of cdc2 kinase activity, the decrease of the expressions of cyclins E and A and of CDK2 kinase activity, and the enhancement of radiation-induced apoptosis. Genistein maintained cells that were arrested in the G2-phase, decreased the expressions of cyclin B1 and cdc25C and cdc2 kinase activity, increased the expression of p16, and sustained senescence and megakaryocytic differentiation. The effects of HMA and genistein on the radiation-induced cell death of K562 cells were closely related to the cell

  19. Lozenge directly activates argos and klumpfuss to regulate programmed cell death.

    Science.gov (United States)

    Wildonger, Jill; Sosinsky, Alona; Honig, Barry; Mann, Richard S

    2005-05-01

    We show that reducing the activity of the Drosophila Runx protein Lozenge (Lz) during pupal development causes a decrease in cell death in the eye. We identified Lz-binding sites in introns of argos (aos) and klumpfuss (klu) and demonstrate that these genes are directly activated targets of Lz. Loss of either aos or klu reduces cell death, suggesting that Lz promotes apoptosis at least in part by regulating aos and klu. These results provide novel insights into the control of programmed cell death (PCD) by Lz during Drosophila eye development.

  20. Apoptosis after irradiation of the rat cortical and hippocampal cells in culture

    International Nuclear Information System (INIS)

    Coffigny, H.; Lane, M.C.

    1997-01-01

    During the development of the central nervous system many neurons are generated but over 50% die by natural apoptosis; this phenomenon occurred in neurons without or with wrong connections with their target cells. Children exposed in utero to Hiroshima or Nagasaki bombing presented microcephaly due to cell deaths and mental retardation. In animals, the number of apoptotic cells in the developing central nervous system increased as a function of the dose received. In vitro, we have shown that 1 Gy irradiation induced 50 % decrease of cortical and hippocampal cell survival. Nervous cells when seeded in a plate were round without processes. Neuritis outgrowth increased with culture time and physical contacts were established between cells. Our purpose is to test the importance of these contacts in the radio-induced apoptosis. (authors)

  1. Chalcones Enhance TRAIL-Induced Apoptosis in Prostate Cancer Cells

    Directory of Open Access Journals (Sweden)

    Ewelina Szliszka

    2009-12-01

    Full Text Available Chalcones exhibit chemopreventive and antitumor effects. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL is a naturally occurring anticancer agent that induces apoptosis in cancer cells and is not toxic to normal cells. We examined the cytotoxic and apoptotic effect of five chalcones in combination with TRAIL on prostate cancer cells. The cytotoxicity was evaluated by the MTT and LDH assays. The apoptosis was determined using flow cytometry with annexin V-FITC. Our study showed that all five tested chalcones: chalcone, licochalcone-A, isobavachalcone, xanthohumol, butein markedly augmented TRAIL-mediated apoptosis and cytotoxicity in prostate cancer cells and confirmed the significant role of chalcones in chemoprevention of prostate cancer.

  2. Chalcones Enhance TRAIL-Induced Apoptosis in Prostate Cancer Cells

    Science.gov (United States)

    Szliszka, Ewelina; Czuba, Zenon P; Mazur, Bogdan; Sedek, Lukasz; Paradysz, Andrzej; Krol, Wojciech

    2009-01-01

    Chalcones exhibit chemopreventive and antitumor effects. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a naturally occurring anticancer agent that induces apoptosis in cancer cells and is not toxic to normal cells. We examined the cytotoxic and apoptotic effect of five chalcones in combination with TRAIL on prostate cancer cells. The cytotoxicity was evaluated by the MTT and LDH assays. The apoptosis was determined using flow cytometry with annexin V-FITC. Our study showed that all five tested chalcones: chalcone, licochalcone-A, isobavachalcone, xanthohumol, butein markedly augmented TRAIL-mediated apoptosis and cytotoxicity in prostate cancer cells and confirmed the significant role of chalcones in chemoprevention of prostate cancer. PMID:20161998

  3. Apoptosis-Inducing Effect of Three Medicinal Plants on Oral Cancer Cells KB and ORL-48

    Directory of Open Access Journals (Sweden)

    Mohd Zabidi Majid

    2014-01-01

    Full Text Available Brucea javanica, Azadirachta indica, and Typhonium flagelliforme are medicinal plants commonly used to treat conditions associated with tumour formation. This study aimed to determine the antiproliferative activity of these plants extracts on KB and ORL-48 oral cancer cell lines and to suggest their mode of cell death. The concentration producing 50% cell inhibition (IC50 was determined and the activity was examined under an inverted microscope. Immunohistochemistry fluorescent staining method (TUNEL was performed to indicate the mechanism of cell death and the fragmented DNA band pattern produced was obtained for verification. Compared to Azadirachta sp. and Typhonium sp., the antiproliferative activity of Brucea sp. extract was the most potent on both KB and ORL-48 cells with IC50 of 24.37 ± 1.75 and 6.67 ± 1.15 µg/mL, respectively. Signs of cell attrition were observed 24 hr after treatment. Green fluorescent spots indicating cell death by apoptosis were observed in images of both cells following treatment with all the three extracts. DNA fragments harvested from Brucea-treated cells produced bands in a ladder pattern suggesting the apoptotic effect of the extract. It is thus concluded that Brucea sp. extract exhibited cytotoxic activity on ORL-48 cells and their action mechanism is via apoptosis.

  4. Glycolaldehyde induces endoplasmic reticulum stress and apoptosis in Schwann cells

    Directory of Open Access Journals (Sweden)

    Keisuke Sato

    2015-01-01

    Full Text Available Schwann cell injury is caused by diabetic neuropathy. The apoptosis of Schwann cells plays a pivotal role in diabetic nerve dysfunction. Glycolaldehyde is a precursor of advanced glycation end products that contribute to the pathogenesis of diabetic neuropathy. In this study, we examined whether glycolaldehyde induces endoplasmic reticulum (ER stress and apoptosis in rat Schwann cells. Schwann cells treated with 500 μM glycolaldehyde showed morphological changes characteristic of apoptosis. Glycolaldehyde activated apoptotic signals, such as caspase-3 and caspase-8. Furthermore, it induced ER stress response involving RNA-dependent protein kinase-like ER kinase (PERK, inositol-requiring ER-to-nucleus signal kinase 1α (IRE1α, and eukaryotic initiation factor 2α (eIF2α. In addition, glycolaldehyde activated CCAAT/enhancer-binding homologous protein (CHOP, an ER stress response factor crucial to executing apoptosis. Knockdown of nuclear factor E2-related factor 2 (Nrf2, which is involved in the promotion of cell survival following ER stress, enhanced glycolaldehyde-induced cytotoxicity, indicating that Nrf2 plays a protective role in the cytotoxicity caused by glycolaldehyde. Taken together, these findings indicate that glycolaldehyde is capable of inducing apoptosis and ER stress in Schwann cells. The ER stress induced by glycolaldehyde may trigger the glycolaldehyde-induced apoptosis in Schwann cells. This study demonstrated for the first time that glycolaldehyde induced ER stress.

  5. Renal cell apoptosis in human lupus nephritis: a histological study

    DEFF Research Database (Denmark)

    Faurschou, M; Penkowa, Milena; Andersen, C B

    2009-01-01

    Nuclear autoantigens from apoptotic cells are believed to drive the immunological response in systemic lupus erythematosus (SLE). Conflicting data exist as to the possible renal origin of apoptotic cells in SLE patients with nephritis. We assessed the level of renal cell apoptosis in kidney...... for tubulointerstitial mononuclear cell infiltration than patients without apoptotic tubular cells in their biopsies (P = 0.01). Furthermore, the level of tubular cell apoptosis displayed a statistically significant, positive correlation with the activity index score for mononuclear cell infiltration (r(s) = 0.472, P...... = 0.004) but not with scores for other activity or chronicity index components. These observations indicate that the degree of tubular cell apoptosis correlates with the severity of tubulointerstitial inflammation in SLE-associated nephritis. However, our findings do not suggest that apoptotic renal...

  6. Knockdown of WISP1 inhibit proliferation and induce apoptosis in ALL Jurkat cells.

    Science.gov (United States)

    Zhang, Xiaomin; Chen, Xi; Liu, Juan; Dong, Xiushuai; Jin, Yinglan; Tian, Yaoyao; Xue, Yanming; Chen, Liyan; Chang, Yuying; Liu, Yao; Wang, Jinghua

    2015-01-01

    WISP1, a Wnt-induced secreted protein, has been found to have anticancer activity. ALL is a leading cause of death. Here we investigate the WISP1 effects on ALL Jurkat cells. Cell viability was assessed by CCK-8. Cell cycle and apoptosis were detected by flow cytometry. Mitochondrial membrane potential (MMP) was monitored using TMRM. Generation of reactive oxygen species (ROS) was quantified using DCFH-DA. Western blot was used to detect the expression of cell proliferation and apoptosis related genes. The results showed that knockdown of WISP1 significantly inhibited proliferation of Jurkat cells. Parallelly, cell cycle distribution was increased at G1 phase and apoptotic rate was induced after WISP1 knockdown. Furthermore, knockdown of WISP1 induced apoptosis of Jurkat cells was also associated with loss of MMP and generation of ROS. Western blot results showed that the protein expression p-AKT, PCNA, CDK1, P-ERK, CDK2, VEGF, VEGFR2 and Bcl2 were decreased, while the expression of Bax was up-regulated. In conclusion, WISP1 plays an important role in proliferation and apoptosis of Jurkat cells in mitochondria dependent pathway, the specific mechanisms need further study.

  7. Differential effect of baicalein on ionizing radiation induced cell death in normal lymphocytes and lymphoma cells

    International Nuclear Information System (INIS)

    Patwardhan, R.S.; Sharma, Deepak; Checker, Rahul; Santosh Kumar, S.

    2013-01-01

    Baicalein (5,6,7-trihydroxy-2-phenyl-4H-1-benzopyran-4-one), a naturally occurring flavone, present in Indian and Chinese medicinal plants has been reported to possess potent antioxidant activity. Previous reports from our laboratory have elucidated the radical scavenging and radioprotective potential of this compound in cell free system. To investigate potential of baicalein as a radioprotector, we have studied its effect on normal lymphocytes and lymphoma cells (EL-4 cells) in presence of radiation. Baicalein protected murine splenic lymphocytes against radiation (4Gy) induced apoptosis as assessed by propidium iodide staining. It inhibited background cell death in lymphocytes whereas, baicalein induced concentration dependent cell death in EL-4 cells and did not protect against radiation induced apoptosis. Interestingly, baicalein scavenged radiation derived ROS (reactive oxygen species) in both the cell types suggesting that, it is not exhibiting differential antioxidant action. Despite scavenging radiation derived ROS, which are principal mediators of radiation induced cell death, baicalein induced cell death in EL-4 cells. To investigate the reason for this differential behavior, we investigated the effect of baicalein on pro-survival molecules viz. ERK and NF-kB. Baicalein induced phosphorylation of ERK in normal lymphocytes in a time dependent manner, but, it did not alter pERK levels in EL-4 cells. Baicalein treatment per se induced degradation of IkBα and increased nuclear accumulation of NF-kB in normal lymphocytes. Whereas, baicalein pre-treatment reduced basal NF-kB levels in EL-4 cells and it also suppressed TNF-α induced nuclear accumulation of NF-kB. This study suggests that, differential regulation of pro-survival transcription factor NF-kB may be playing a role in differential effect of baicalein in normal lymphocytes and lymphoma cells. (author)

  8. Development of RI-based real-time display technology of apoptotic cell death

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Hyun; Jagn, Beom Su; Hayu, Tyas Utami

    2012-01-15

    Apoptosis, or the programmed cell death, is the generally normal death of a cell in living organisms. Inappropriate apoptosis (either too little or too much) is a factor in many human disease including neurodegenerative diseases, autoimmune disorders and many types of cancer. Therefore, it is one of the most challenging and widely studied topics currently. Development of RI-based real-time display technology of apoptosis can be provided invaluable analysis data for diagnosis and treatment of various diseases. In this study, bifunctional chelator (BFC) for Tc-99m tricarbonyl was synthesized for ML-10 derivative radiolabeling. The formation of complexation of apoptotic cells was developed by combining the ML-10 moiety with the BFC for {sup 99m}Tc-tricarbonyl precursor. The results of this project will be utilized for the development of RI-Biomics Center-based Total Analysis System (TAS) through the optimization of equipment in the RI-Biomics Center.

  9. Oxidative stress-induced apoptosis in granulosa cells involves JNK, p53 and Puma.

    Science.gov (United States)

    Yang, Hongyan; Xie, Yan; Yang, Dongyu; Ren, Decheng

    2017-04-11

    Reactive oxygen species (ROS) play important roles in follicular development and survival. Granulosa cell death is associated with increased ROS, but the mechanism of granulosa cell death induced by ROS is not clear. In order to define the molecular link between ROS and granulosa cell death, COV434, human granulosa tumor cells, were treated with H2O2. Compared to control cells, H2O2 induced granulosa cell death in a dose- and time-dependent manner. H2O2 induced an increase in Bax, Bak and Puma, and a decrease in anti-apoptotic molecules such as Bcl-2, Bcl-xL and Mcl-1. Both knockdown of Puma and overexpression of Bcl-xL could inhibit H2O2-induced granulosa cell death. These results suggest that suppression of Puma and overexpression of anti-apoptotic Bcl-2 family members could improve granulosa cell survival. To explore the mechanisms responsible for these findings, ROS in granulosa cells treatment with H2O2 were measured. The results showed that ROS was increased in a H2O2 dose- and time-dependent manner at the earlier time point. In addition, H2O2 induced an increase in Nrf2 and phosphorylation of JNK and p53. SP600125, an inhibitor of JNK, inhibits H2O2-induced phosphorylation of JNK and p53, and granulosa cell death. Antioxidant N-acetylcysteine (NAC) dose-dependently prevents H2O2-induced granulosa cell death. Furthermore, NAC also prevents phosphorylation of JNK and p53 induced by H2O2. Taken together, these data suggest that H2O2 regulates cell death in granulosa cells via the ROS-JNK-p53 pathway. These findings provide an improved understanding of the mechanisms underlying granulosa cell apoptosis, which could potentially be useful for future clinical applications.

  10. DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Clement G. Yedjou

    2015-12-01

    Full Text Available In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO32] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60 cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO32 for 24 h. Live cells and necrotic death cells were measured by the propidium idiode (PI assay using the cellometer vision. Cell apoptosis was measured by the flow cytometry and DNA laddering. Cell cycle analysis was evaluated by the flow cytometry. The result of the PI demonstrated a significant (p < 0.05 increase of necrotic cell death in Pb(NO32-treated cells, indicative of membrane rupture by Pb(NO32 compared to the control. Data generated from the comet assay indicated a concentration-dependent increase in DNA damage, showing a significant increase (p < 0.05 in comet tail-length and percentages of DNA cleavage. Data generated from the flow cytometry assessment indicated that Pb(NO32 exposure significantly (p < 0.05 increased the proportion of caspase-3 positive cells (apoptotic cells compared to the control. The flow cytometry assessment also indicated Pb(NO32 exposure caused cell cycle arrest at the G0/G1 checkpoint. The result of DNA laddering assay showed presence of DNA smear in the agarose gel with little presence of DNA fragments in the treated cells compared to the control. In summary, Pb(NO32 inhibits HL-60 cells proliferation by not only inducing DNA damage and cell cycle arrest at the G0/G1 checkpoint but also triggering the apoptosis through caspase-3 activation and nucleosomal DNA fragmentation accompanied by secondary necrosis. We believe that our study provides a new insight into the mechanisms of Pb(NO32 exposure and its associated adverse

  11. Apoptosis in chronic myeloid leukaemia: normal responses by progenitor cells to growth factor deprivation, X-irradiation and glucocorticoids

    Energy Technology Data Exchange (ETDEWEB)

    Amos, T.A.S.; Lewis, J.L.; Grand, F.H.; Gooding, R.P.; Goldman, J.M.; Gordon, M.Y. [Royal Postgraduate Medical School, London (United Kingdom)

    1995-10-01

    Inhibition of apoptosis (genetically programmed active cell death) by p210 BCR-ABL expression is a mechanism that might contribute to clonal expansion in chronic myeloid leukaemia (CML). Since cell death following exposure to ionizing radiation and many chemotherapeutic agents can occur by the apoptotic pathway, inhibition of apoptosis would be expected to confer a relative resistance to these treatments. Similarly, cells deprived of growth factors in vitro die by apoptosis, and inhibition of apoptosis would therefore be expected to allow cells to survive better in growth factor-deprived conditions. We found that the survival of normal and CML myeloid progenitors was the same after in vitro incubation in deprived conditions and after treatment with X-irradiation or glucocorticoids. We also found that mature cells in colonies produced by CML progenitors (CFU-GM) did not survive better than those produced by normal progenitor cells. Flow cytometric analysis of propidium iodide-stained cells provided a direct indication that the degree of apoptosis may correspond to the degree of deprivation. These results suggest that inhibition of apoptosis may not be the primary mechanism whereby BCR-ABL influences the expansion of the malignant clone in CML. (Author).

  12. Apoptosis in chronic myeloid leukaemia: normal responses by progenitor cells to growth factor deprivation, X-irradiation and glucocorticoids

    International Nuclear Information System (INIS)

    Amos, T.A.S.; Lewis, J.L.; Grand, F.H.; Gooding, R.P.; Goldman, J.M.; Gordon, M.Y.

    1995-01-01

    Inhibition of apoptosis (genetically programmed active cell death) by p210 BCR-ABL expression is a mechanism that might contribute to clonal expansion in chronic myeloid leukaemia (CML). Since cell death following exposure to ionizing radiation and many chemotherapeutic agents can occur by the apoptotic pathway, inhibition of apoptosis would be expected to confer a relative resistance to these treatments. Similarly, cells deprived of growth factors in vitro die by apoptosis, and inhibition of apoptosis would therefore be expected to allow cells to survive better in growth factor-deprived conditions. We found that the survival of normal and CML myeloid progenitors was the same after in vitro incubation in deprived conditions and after treatment with X-irradiation or glucocorticoids. We also found that mature cells in colonies produced by CML progenitors (CFU-GM) did not survive better than those produced by normal progenitor cells. Flow cytometric analysis of propidium iodide-stained cells provided a direct indication that the degree of apoptosis may correspond to the degree of deprivation. These results suggest that inhibition of apoptosis may not be the primary mechanism whereby BCR-ABL influences the expansion of the malignant clone in CML. (Author)

  13. Immunoregulatory mechanisms in Chagas disease: modulation of apoptosis in T-cell mediated immune responses.

    Science.gov (United States)

    Chaves, Ana Thereza; de Assis Silva Gomes Estanislau, Juliana; Fiuza, Jacqueline Araújo; Carvalho, Andréa Teixeira; Ferreira, Karine Silvestre; Fares, Rafaelle Christine Gomes; Guimarães, Pedro Henrique Gazzinelli; de Souza Fagundes, Elaine Maria; Morato, Maria José; Fujiwara, Ricardo Toshio; da Costa Rocha, Manoel Otávio; Correa-Oliveira, Rodrigo

    2016-04-30

    after in vitro stimulation. Interestingly, the in vitro TcAg stimulation increased considerably the expression of cell death TNF/TNFR superfamily and Caspase family receptors genes in CARD patients. Taken together, our results suggest that apoptosis may be an important mechanism for the control of morbidity in T. cruzi infection by modulating the expression of apoptosis genes, the cytokine environment and/or killing of effector cells.

  14. Growth-Inhibitory and Apoptosis-Inducing Effects of Punica granatum L. var. spinosa (Apple Punice) on Fibrosarcoma Cell Lines

    OpenAIRE

    Sineh Sepehr, Koushan; Baradaran, Behzad; Mazandarani, Masoumeh; Yousefi, Bahman; Abdollahpour Alitappeh, Meghdad; Khori, Vahid

    2014-01-01

    Purpose: Punica granatum L. var. granatum (Pomegranate), an herbaceous plant found in Iran, The aim of this study was to investigate the cytotoxic effects, induction of apoptosis, and the mechanism of cell death of ethanol extract from Punica granatum L. var. spinosa on the mouse fibrosarcoma cell line, WEHI-164.

  15. Cigarette smoke-induced blockade of the mitochondrial respiratory chain switches lung epithelial cell apoptosis into necrosis

    NARCIS (Netherlands)

    van der Toorn, Marco; Slebos, Dirk-Jan; de Bruin, Harold G.; Leuvenink, Henri G.; Bakker, Stephan J. L.; Gans, Rijk O. B.; Koeter, Gerard H.; van Oosterhout, Antoon J. M.; Kauffman, Henk F.

    Increased lung cell apoptosis and necrosis occur in patients with chronic obstructive pulmonary disease ( COPD). Mitochondria are crucially involved in the regulation of these cell death processes. Cigarette smoke is the main risk factor for development of COPD. We hypothesized that cigarette smoke

  16. Apoptosis and necrosis in vaccinia virus-infected HeLa G and BSC-40 cells.

    Science.gov (United States)

    Liskova, Jana; Knitlova, Jarmila; Honner, Richard; Melkova, Zora

    2011-09-01

    In most cells, vaccinia virus (VACV) infection is considered to cause a lytic cell death, an equivalent of necrosis. However, upon infection of the epithelial cell lines HeLa G and BSC-40 with VACV strain Western Reserve (WR), we have previously observed an increased activation of and activity attributable to caspases, a typical sign of apoptosis. In this paper, we have further analyzed the type of cell death in VACV-infected cells HeLa G and BSC-40. In a cell-based flow cytometric assay, we showed a specific activation of caspase-2 and 4 in HeLa G and BSC-40 cells infected with VACV, strain WR, while we did not find any effects of inhibitors of calpain and cathepsin D and E. The actual activity of the two caspases, but also of caspase-3, was then confirmed in lysates of infected HeLa G, but not in BSC-40 cells. Accordingly, poly(ADP)-ribose polymerase (PARP) cleavage was found increased only in infected HeLa G cells. Consequently, we have determined morphological features of apoptosis and/or activity of the executioner caspase-3 in infected HeLa G cells in situ, while only a background apoptosis was observed in infected BSC-40 cells. Finally, vaccination strains Dryvax and Praha were found to induce apoptosis in both HeLa G and BSC-40 cells, as characterized morphologically and by PARP cleavage. These findings may be important for understanding the differences in VACV-host interactions and post-vaccination complications in different individuals. Copyright © 2011 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2005-12-01

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

  18. Beryllium-stimulated apoptosis in macrophage cell lines.

    Science.gov (United States)

    Sawyer, R T; Fadok, V A; Kittle, L A; Maier, L A; Newman, L S

    2000-08-21

    In vitro stimulation of bronchoalveolar lavage cells from patients with chronic beryllium disease (CBD) induces the production of TNF-alpha. We tested the hypothesis that beryllium (Be)-stimulated TNF-alpha might induce apoptosis in mouse and human macrophage cell lines. These cell lines were selected because they produce a range of Be-stimulated TNF-alpha. The mouse macrophage cell line H36.12j produces high levels of Be-stimulated TNF-alpha. The mouse macrophage cell line P388D.1 produces low, constitutive, levels of TNF-alpha and does not up-regulate Be-stimulated TNF-alpha production. The DEOHS-1 human CBD macrophage cell line does not produce constitutive or Be-stimulated TNF-alpha. Apoptosis was determined by microscopic observation of propidium iodide stained fragmented nuclei in unstimulated and BeSO(4)-stimulated macrophage cell lines. BeSO(4) induced apoptosis in all macrophage cell lines tested. Beryllium-stimulated apoptosis was dose-responsive and maximal after 24 h of exposure to 100 microM BeSO(4). In contrast, unstimulated and Al(2)(SO(4))(3)-stimulated macrophage cell lines did not undergo apoptosis. The general caspase inhibitor BD-fmk inhibited Be-stimulated macrophage cell line apoptosis at concentrations above 50 microM. Our data show that Be-stimulated macrophage cell line apoptosis was caspase-dependent and not solely dependent on Be-stimulated TNF-alpha levels. We speculate that the release of Be-antigen from apoptotic macrophages may serve to re-introduce Be material back into the lung microenvironment, make it available for uptake by new macrophages, and thereby amplify Be-stimulated cytokine production, promoting ongoing inflammation and granuloma maintenance in CBD.

  19. Growth-Inhibitory and Apoptosis-Inducing Effects of Punica granatum L. var. spinosa (Apple Punice) on Fibrosarcoma Cell Lines.

    Science.gov (United States)

    Sineh Sepehr, Koushan; Baradaran, Behzad; Mazandarani, Masoumeh; Yousefi, Bahman; Abdollahpour Alitappeh, Meghdad; Khori, Vahid

    2014-12-01

    Punica granatum L. var. granatum (Pomegranate), an herbaceous plant found in Iran, The aim of this study was to investigate the cytotoxic effects, induction of apoptosis, and the mechanism of cell death of ethanol extract from Punica granatum L. var. spinosa on the mouse fibrosarcoma cell line, WEHI-164. Various parts of the herbs were extracted from fruit using ethanol as the solvent, and the cytotoxicity and cell viability of the ethanolic extract were determined by the MTT assay. To determine whether necrosis or apoptosis is the predominant cause of cell death, cell death detection was performed using the ELISA method. The induction of apoptosis was confirmed using the terminal deoxynucleotidyl transferase- (TdT-) mediated dUTP nick end labeling (TUNEL) assay. Moreover, a sensitive immunoblotting technique was used to examine the production of Caspase-3 and Bcl2 proteins. Our findings suggested that the ethalonic extract of Punica granatum L. var. spinosa altered cell morphology, decreased cell viability, suppressed cell proliferation and induced cell death in a time- and dose-dependent manner in WEHI-164 cells (IC50 = 229.024μg/ml), when compared to a chemotherapeutic anticancer drug, Toxol (Vesper Pharmaceuticals), with increased nucleosome production from apoptotic cells. Induction of apoptosis by the plant extract was proved by the decrease of pro-Caspase-3 and Bcl2 proteins and quantitatively confirmed by Immunoblotting analysis. The results obtained from the present study have demonstrated the growth-inhibitory effect of Ethanol Extracts from Punica granatum L. var. spinosa, and clearly showed that apoptosis was the major mechanism of in-vitro cell death induced by the extract.

  20. Programmed cell death and hybrid incompatibility.

    Science.gov (United States)

    Frank, S A; Barr, C M

    2003-01-01

    We propose a new theory to explain developmental aberrations in plant hybrids. In our theory, hybrid incompatibilities arise from imbalances in the mechanisms that cause male sterility in hermaphroditic plants. Mitochondria often cause male sterility by killing the tapetal tissue that nurtures pollen mother cells. Recent evidence suggests that mitochondria destroy the tapetum by triggering standard pathways of programmed cell death. Some nuclear genotypes repress mitochondrial male sterility and restore pollen fertility. Normal regulation of tapetal development therefore arises from a delicate balance between the disruptive effects of mitochondria and the defensive countermeasures of the nuclear genes. In hybrids, incompatibilities between male-sterile mitochondria and nuclear restorers may frequently upset the regulatory control of programmed cell death, causing tapetal abnormalities and male sterility. We propose that hybrid misregulation of programmed cell death may also spill over into other tissues, explaining various developmental aberrations observed in hybrids.

  1. Strain Difference in Photoreceptor Cell Death After Retinal Detachment in Mice

    Science.gov (United States)

    Matsumoto, Hidetaka; Kataoka, Keiko; Tsoka, Pavlina; Connor, Kip M.; Miller, Joan W.; Vavvas, Demetrios G.

    2014-01-01

    Purpose. To evaluate the potential for mouse genetic background to effect photoreceptor cell death in response to experimental retinal detachment (RD). Methods. Retinal detachment was induced in three inbred mouse strains (C57BL/6, BALB/c, and B6129SF2) by subretinal injection of sodium hyaluronate. A time course of photoreceptor cell death was assessed by TUNEL assay. Total photoreceptor cell death was analyzed through comparing the outer nuclear layer (ONL)/inner nuclear layer (INL) ratio 7 days post RD. Western blot analysis or quantitative real-time PCR (qPCR) were performed to assess cell death signaling, expression of endogenous neurotrophin, and levels of apoptosis inhibitors 24 hours after RD. Inflammatory cytokine secretion and inflammatory cell infiltration were quantified by ELISA and immunostaining, respectively. Results. The peak of photoreceptor cell death after RD was at 24 hours in all strains. Photoreceptor cell death as well as monocyte chemoattractant protein 1 and interleukin 6 secretion at 24 hours after RD was the highest in BALB/c, followed in order of magnitude by C57BL/6 and B6129SF2. Conversely, nerve growth factor expression and ONL/INL ratio were the lowest in BALB/c. Apoptosis signaling was higher in C57BL/6, whereas necroptosis signaling was higher in C57BL/6 and BALB/c. Autophagic signaling was higher in BALB/c. X-linked inhibitor of apoptosis (XIAP) and survivin protein levels were lower in C57BL/6 and BALB/c, respectively. Macrophage/microglia infiltration was higher in C57BL/6 and BALB/c at 24 hours after RD. Conclusions. Photoreceptor cell death after RD was significantly different among the three strains, suggesting the presence of genetic factors that affect photoreceptor cell death after RD. PMID:24854853

  2. Mevalonate cascade regulation of airway mesenchymal cell autophagy and apoptosis: a dual role for p53.

    Directory of Open Access Journals (Sweden)

    Saeid Ghavami

    2011-01-01

    Full Text Available Statins inhibit the proximal steps of cholesterol biosynthesis, and are linked to health benefits in various conditions, including cancer and lung disease. We have previously investigated apoptotic pathways triggered by statins in airway mesenchymal cells, and identified reduced prenylation of small GTPases as a primary effector mechanism leading to p53-mediated cell death. Here, we extend our studies of statin-induced cell death by assessing endpoints of both apoptosis and autophagy, and investigating their interplay and coincident regulation. Using primary cultured human airway smooth muscle (HASM and human airway fibroblasts (HAF, autophagy, and autophagosome formation and flux were assessed by transmission electron microscopy, cytochemistry (lysosome number and co-localization with LC3 and immunoblotting (LC3 lipidation and Atg12-5 complex formation. Chemical inhibition of autophagy increased simvastatin-induced caspase activation and cell death. Similarly, Atg5 silencing with shRNA, thus preventing Atg5-12 complex formation, increased pro-apoptotic effects of simvastatin. Simvastatin concomitantly increased p53-dependent expression of p53 up-regulated modulator of apoptosis (PUMA, NOXA, and damage-regulated autophagy modulator (DRAM. Notably both mevalonate cascade inhibition-induced autophagy and apoptosis were p53 dependent: simvastatin increased nuclear p53 accumulation, and both cyclic pifithrin-α and p53 shRNAi partially inhibited NOXA, PUMA expression and caspase-3/7 cleavage (apoptosis and DRAM expression, Atg5-12 complex formation, LC3 lipidation, and autophagosome formation (autophagy. Furthermore, the autophagy response is induced rapidly, significantly delaying apoptosis, suggesting the existence of a temporally coordinated p53 regulation network. These findings are relevant for the development of statin-based therapeutic approaches in obstructive airway disease.

  3. Crotamine and crotoxin interact with tumor cells and trigger cell death

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Marcella Araugio; Pujatti, Priscilla Brunelli; Santos, Raquel Gouvea dos [Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN-MG, Belo Horizonte, MG (Brazil)]. E-mails: maso@cdtn.br; santosr@cdtn.br; Dias, Consuelo Latorre Fortes [Fundacao Ezequiel Dias FUNED, Belo Horizonte, MG (Brazil); Chavez Olortegui, Carlos Delfin [Universidade Federal de Minas Gerais UFMG, Belo Horizonte, MG (Brazil). Inst. de Ciencias Biologicas; Santos, Wagner Gouvea dos [Medical College of Virginia, Richmond, VA (United States). Neurosurgery Dept.

    2007-07-01

    Crotoxin (Crtx) and Crotamine (Crota) are polypeptides isolated from Crotalus durissus terrificus snake venom (CV). Previous reports have been shown therapeutic effects of Crotalus durissus terrificus venom and Crtx on skin, breast and lung tumours, although, the mechanisms of this antitumoral effect are still unknown. The aim of this work was to investigate the antitumoral effect of Crtx and Crota on brain tumours cells (GH3 and RT2) in vitro and their capacity of interaction with these tumour cells membranes. Cell survival after Crtx and Crota treatment was evaluated by MTT assay in different times post-treatment and apoptosis was evaluated by DAPI staining. In order to evaluate the specific interaction of Crtx and Crota, these polypeptides were radiolabelled, using {sup 125}I as radiotracer and binding assays were performed. The results were compared with the binding in nontumoral brain tissue. Crtx and Crota induced apoptosis on both tumour cells lineages but, Crota was more powerful than Crtx 90% and 20% cell death for RT2 cells; 80% and 20% cell death for GH3 cells, respectively). Both {sup 125}I-Crtx and {sup 125}I-Crota bound specifically in glioblastoma membranes. Nonetheless, CV polypeptides recognised glioblastoma cells with higher specificity than normal brain tissue. These results suggest that the Crtx and Crota interactions with the plasmatic membrane of tumour cells may be the first step of the cascade of signalling that trigger their antitumoral effect. (author)

  4. Crotamine and crotoxin interact with tumor cells and trigger cell death

    International Nuclear Information System (INIS)

    Soares, Marcella Araugio; Pujatti, Priscilla Brunelli; Santos, Raquel Gouvea dos; Dias, Consuelo Latorre Fortes; Chavez Olortegui, Carlos Delfin; Santos, Wagner Gouvea dos

    2007-01-01

    Crotoxin (Crtx) and Crotamine (Crota) are polypeptides isolated from Crotalus durissus terrificus snake venom (CV). Previous reports have been shown therapeutic effects of Crotalus durissus terrificus venom and Crtx on skin, breast and lung tumours, although, the mechanisms of this antitumoral effect are still unknown. The aim of this work was to investigate the antitumoral effect of Crtx and Crota on brain tumours cells (GH3 and RT2) in vitro and their capacity of interaction with these tumour cells membranes. Cell survival after Crtx and Crota treatment was evaluated by MTT assay in different times post-treatment and apoptosis was evaluated by DAPI staining. In order to evaluate the specific interaction of Crtx and Crota, these polypeptides were radiolabelled, using 125 I as radiotracer and binding assays were performed. The results were compared with the binding in nontumoral brain tissue. Crtx and Crota induced apoptosis on both tumour cells lineages but, Crota was more powerful than Crtx 90% and 20% cell death for RT2 cells; 80% and 20% cell death for GH3 cells, respectively). Both 125 I-Crtx and 125 I-Crota bound specifically in glioblastoma membranes. Nonetheless, CV polypeptides recognised glioblastoma cells with higher specificity than normal brain tissue. These results suggest that the Crtx and Crota interactions with the plasmatic membrane of tumour cells may be the first step of the cascade of signalling that trigger their antitumoral effect. (author)

  5. Modulation of Apoptosis Pathways by Oxidative Stress and Autophagy in β Cells

    Directory of Open Access Journals (Sweden)

    Maorong Wang

    2012-01-01

    Full Text Available Human islets isolated for transplantation are exposed to multiple stresses including oxidative stress and hypoxia resulting in significant loss of functional β cell mass. In this study we examined the modulation of apoptosis pathway genes in islets exposed to hydrogen peroxide, peroxynitrite, hypoxia, and cytokines. We observed parallel induction of pro- and antiapoptotic pathways and identified several novel genes including BFAR, CARD8, BNIP3, and CIDE-A. As BNIP3 is an inducer of autophagy, we examined this pathway in MIN6 cells, a mouse beta cell line and in human islets. Culture of MIN6 cells under low serum conditions increased the levels of several proteins in autophagy pathway, including ATG4, Beclin 1, LAMP-2, and UVRAG. Amino acid deprivation led to induction of autophagy in human islets. Preconditioning of islets with inducers of autophagy protected them from hypoxia-induced apoptosis. However, induction of autophagy during hypoxia exacerbated apoptotic cell death. ER stress led to induction of autophagy and apoptosis in β cells. Overexpression of MnSOD, an enzyme that scavenges free radicals, resulted in protection of MIN6 cells from cytokine-induced apoptosis. Ceramide, a mediator of cytokine-induced injury, reduced the active phosphorylated form of Akt and downregulated the promoter activity of the antiapoptotic gene bcl-2. Furthermore, cytokine-stimulated JNK pathway downregulated the bcl-2 promoter activity which was reversed by preincubation with SP600125, a JNK inhibitor. Our findings suggest that β cell apoptosis by multiple stresses in islets isolated for transplantation is the result of orchestrated gene expression in apoptosis pathway.

  6. Withaferin A-induced apoptosis in human breast cancer cells is mediated by reactive oxygen species.

    Directory of Open Access Journals (Sweden)

    Eun-Ryeong Hahm

    Full Text Available Withaferin A (WA, a promising anticancer constituent of Ayurvedic medicinal plant Withania somnifera, inhibits growth of MDA-MB-231 and MCF-7 human breast cancer cells in culture and MDA-MB-231 xenografts in vivo in association with apoptosis induction, but the mechanism of cell death is not fully understood. We now demonstrate, for the first time, that WA-induced apoptosis is mediated by reactive oxygen species (ROS production due to inhibition of mitochondrial respiration. WA treatment caused ROS production in MDA-MB-231 and MCF-7 cells, but not in a normal human mammary epithelial cell line (HMEC. The HMEC was also resistant to WA-induced apoptosis. WA-mediated ROS production as well as apoptotic histone-associated DNA fragment release into the cytosol was significantly attenuated by ectopic expression of Cu,Zn-superoxide dismutase in both MDA-MB-231 and MCF-7 cells. ROS production resulting from WA exposure was accompanied by inhibition of oxidative phosphorylation and inhibition of complex III activity. Mitochondrial DNA-deficient Rho-0 variants of MDA-MB-231 and MCF-7 cells were resistant to WA-induced ROS production, collapse of mitochondrial membrane potential, and apoptosis compared with respective wild-type cells. WA treatment resulted in activation of Bax and Bak in MDA-MB-231 and MCF-7 cells, and SV40 immortalized embryonic fibroblasts derived from Bax and Bak double knockout mouse were significantly more resistant to WA-induced apoptosis compared with fibroblasts derived from wild-type mouse. In conclusion, the present study provides novel insight into the molecular circuitry of WA-induced apoptosis involving ROS production and activation of Bax/Bak.

  7. Ras and Rheb Signaling in Survival and Cell Death

    Energy Technology Data Exchange (ETDEWEB)

    Ehrkamp, Anja [Molecular Neurobiochemistry, Ruhr University of Bochum, 44780 Bochum (Germany); Herrmann, Christian [Department of Physical Chemistry1, Protein Interaction, Ruhr University of Bochum, 44780 Bochum (Germany); Stoll, Raphael [Biomolecular NMR, Ruhr University of Bochum, 44780 Bochum (Germany); Heumann, Rolf, E-mail: rolf.heumann@rub.de [Molecular Neurobiochemistry, Ruhr University of Bochum, 44780 Bochum (Germany)

    2013-05-28

    One of the most obvious hallmarks of cancer is uncontrolled proliferation of cells partly due to independence of growth factor supply. A major component of mitogenic signaling is Ras, a small GTPase. It was the first identified human protooncogene and is known since more than three decades to promote cellular proliferation and growth. Ras was shown to support growth factor-independent survival during development and to protect from chemical or mechanical lesion-induced neuronal degeneration in postmitotic neurons. In contrast, for specific patho-physiological cases and cellular systems it has been shown that Ras may also promote cell death. Proteins from the Ras association family (Rassf, especially Rassf1 and Rassf5) are tumor suppressors that are activated by Ras-GTP, triggering apoptosis via e.g., activation of mammalian sterile 20-like (MST1) kinase. In contrast to Ras, their expression is suppressed in many types of tumours, which makes Rassf proteins an exciting model for understanding the divergent effects of Ras activity. It seems likely that the outcome of Ras signaling depends on the balance between the activation of its various downstream effectors, thus determining cellular fate towards either proliferation or apoptosis. Ras homologue enriched in brain (Rheb) is a protein from the Ras superfamily that is also known to promote proliferation, growth, and regeneration through the mammalian target of rapamycin (mTor) pathway. However, recent evidences indicate that the Rheb-mTor pathway may switch its function from a pro-growth into a cell death pathway, depending on the cellular situation. In contrast to Ras signaling, for Rheb, the cellular context is likely to modulate the whole Rheb-mTor pathway towards cellular death or survival, respectively.

  8. Ras and Rheb Signaling in Survival and Cell Death

    International Nuclear Information System (INIS)

    Ehrkamp, Anja; Herrmann, Christian; Stoll, Raphael; Heumann, Rolf

    2013-01-01

    One of the most obvious hallmarks of cancer is uncontrolled proliferation of cells partly due to independence of growth factor supply. A major component of mitogenic signaling is Ras, a small GTPase. It was the first identified human protooncogene and is known since more than three decades to promote cellular proliferation and growth. Ras was shown to support growth factor-independent survival during development and to protect from chemical or mechanical lesion-induced neuronal degeneration in postmitotic neurons. In contrast, for specific patho-physiological cases and cellular systems it has been shown that Ras may also promote cell death. Proteins from the Ras association family (Rassf, especially Rassf1 and Rassf5) are tumor suppressors that are activated by Ras-GTP, triggering apoptosis via e.g., activation of mammalian sterile 20-like (MST1) kinase. In contrast to Ras, their expression is suppressed in many types of tumours, which makes Rassf proteins an exciting model for understanding the divergent effects of Ras activity. It seems likely that the outcome of Ras signaling depends on the balance between the activation of its various downstream effectors, thus determining cellular fate towards either proliferation or apoptosis. Ras homologue enriched in brain (Rheb) is a protein from the Ras superfamily that is also known to promote proliferation, growth, and regeneration through the mammalian target of rapamycin (mTor) pathway. However, recent evidences indicate that the Rheb-mTor pathway may switch its function from a pro-growth into a cell death pathway, depending on the cellular situation. In contrast to Ras signaling, for Rheb, the cellular context is likely to modulate the whole Rheb-mTor pathway towards cellular death or survival, respectively

  9. Anthraquinone G503 Induces Apoptosis in Gastric Cancer Cells through the Mitochondrial Pathway

    Science.gov (United States)

    Li, Shuai; Duan, Junting; Ye, Fang; Li, Hanxiang; She, Zhigang; Gao, Guoquan; Yang, Xia

    2014-01-01

    G503 is an anthraquinone compound isolated from the secondary metabolites of a mangrove endophytic fungus from the South China Sea. The present study elucidates the anti-tumor activity and the underlying mechanism of G503. Cell viability assay performed in nine cancer cell lines and two normal cell lines demonstrated that the gastric cancer cell line SGC7901 is the most G503-sensitive cancer cells. G503 induced SGC7901 cell death via apoptosis. G503 exposure activated caspases-3, -8 and -9. Pretreatment with the pan-caspase inhibitor Z-VAD-FMK and caspase-9 inhibitor Z-LEHD-FMK, but not caspase-8 inbibitor Z-IETD-FMK, attenuated the effect of G503. These results suggested that the intrinsic mitochondrial apoptosis pathway, rather than the extrinsic pathway, was involved in G503-induced apoptosis. Furthermore, G503 increased the ratio of Bax to Bcl-2 in the mitochondria and decreased the ratio in the cytosol. G503 treatment resulted in mitochondrial depolarization, cytochrome c release and the subsequent cleavage of caspase -9 and -3. Moreover, it is reported that the endoplasmic reticulum apoptosis pathway may also be activated by G503 by inducing capase-4 cleavage. In consideration of the lower 50% inhibitory concentration for gastric cancer cells, G503 may serve as a promising candidate for gastric cancer chemotherapy. PMID:25268882

  10. Herpes Simplex Virus Type 1 Renders Infected Cells Resistant to Cytotoxic T-Lymphocyte-Induced Apoptosis

    OpenAIRE

    Jerome, Keith R.; Tait, Jonathan F.; Koelle, David M.; Corey, Lawrence

    1998-01-01

    Many viruses interfere with apoptosis of infected cells, presumably preventing cellular apoptosis as a direct response to viral infection. Since cytotoxic T lymphocytes (CTL) induce apoptosis of infected cells as part of the “lethal hit,” inhibition of apoptosis could represent an effective immune evasion strategy. We report here herpes simplex virus type 1 (HSV-1) interference with CTL-induced apoptosis of infected cells and show that HSV-1 inhibits the nuclear manifestations of apoptosis bu...

  11. Suppression of survivin expression in glioblastoma cells by the Ras inhibitor farnesylthiosalicylic acid promotes caspase-dependent apoptosis.

    Science.gov (United States)

    Blum, Roy; Jacob-Hirsch, Jasmine; Rechavi, Gideon; Kloog, Yoel

    2006-09-01

    The Ras inhibitor farnesylthiosalicylic acid (FTS) has been shown to induce apoptosis in glioblastoma multiforme, but its mechanism of action was unknown. We show that FTS or dominant-negative Ras, by deregulating extracellular signal-regulated kinase and Akt signaling, decreases survivin gene transcripts in U87 glioblastoma multiforme, leading to disappearance of survivin protein and cell death. FTS affected both Ras-controlled regulators of survivin transcription and Ras-regulated survival signals. Thus, Ras inhibition by FTS resulted in release of the survivin "brake" on apoptosis and in activation of the mitochondrial apoptotic pathway: dephosphorylation of Bad, activation of Bax, release of cytochrome c, and caspase activation. FTS-induced apoptosis of U87 cells was strongly attenuated by forced expression of survivin or by caspase inhibitors. These results show that resistance to apoptosis in glioblastoma multiforme can be abolished by a single Ras inhibitor, which targets both survivin, a critical inhibitor of apoptosis, and the intrinsic mitochondrial apoptotic machinery.

  12. Immunohistochemical detection of the apoptosis-related proteins FADD, FLICE, and FLIP in Langerhans cell histiocytosis

    DEFF Research Database (Denmark)

    Bank, Micha I; Gudbrand, Charlotte; Lundegaard, Pia Rengtved

    2005-01-01

    FLICE, and FLIP. The clinical outcome of the disease could not be correlated to the expression of the investigated proteins. This study shows a high expression of the apoptosis-related proteins FADD, active FLICE, and FLIP in pLCs. The authors previously showed that pLCs express Fas and Fas ligand......Langerhans cell histiocytosis (LCH) is characterized by an accumulation of dendritic Langerhans cells in granulomatous lesions in various organs. The etiology of LCH remains enigmatic. Fas/APO-1/CD95 belongs to the "death receptor" family of apoptosis regulators and has been implicated...... in the downregulation of immune responses. The authors examined the expression of three proteins that are engaged in the Fas signaling cascade-FADD/Fas-associated death domain-containing protein, FLICE/FADD-like interleukin-1beta-converting enzyme (both pro-apoptotic), and FLIP/FLICE-inhibitory protein (anti...

  13. Hydrogen sulfide is expressed in the human and the rat cultured nucleus pulposus cells and suppresses apoptosis induced by hypoxia.

    Directory of Open Access Journals (Sweden)

    Haolin Sun

    Full Text Available Apoptosis plays pivotal role in the pathogenesis of degenerative disc diseases, which is the primary contributor to low back pain. Although the role of hydrogen sulfide (H2S in cell apoptosis is well appreciated, the effects and mechanism that H2S regulates the program death of intervertebral disc cell are not yet elucidated. In this study, we utilized the nucleus pulposus (NP from patients with lumbar disc herniation to investigate the relationship between endogenous H2S and NP cells apoptosis in human. Furthermore, we analyzed primary rat NP cells to study the effects of exogenous H2S on hypoxia induced cell apoptosis. Human NP samples were obtained from patients with lumbar disc herniation and were divided into uncontained and contained herniation groups. Using immunohistochemistry staining and sulphur-sensitive electrode, we detected the expression of cystathionine-β-synthase (CBS and cystathionine γ-lyase (CSE, as well as the production of endogenous H2S in human NP. Tunel staining showed increased apoptosis in NP from herniated disc; and there was significant correlation between H2S generation and apoptosis in human NP. CoCl2 was then used to induce hypoxia in cultured primary rat NP cells. Annexin V staining indicated that exogenous NaHS attenuated hypoxia induced apoptosis in rat NP cells. Furthermore, hypoxia significantly increased the levels of multiple apoptosis associated proteins (Fas, Cytochromes C, Caspase 9 and cleaved-Caspase-3 in cells, which were eliminated by NaHS. Our study demonstrates the presence of endogenous H2S in human intervertebral disc; and the endogenous H2S generation rate is associated with NP apoptosis in herniated disc. In vitro study showes exogenous H2S donor attenuates hypoxia induced apoptosis in primary rat NP cells. Thus, our work provides insights that H2S may have beneficial effects in treating degenerative disc diseases.

  14. Ordering of ceramide formation and caspase-9 activation in CD95L-induced Jurkat leukemia T cell apoptosis.

    Science.gov (United States)

    Lafont, Elodie; Dupont, Romain; Andrieu-Abadie, Nathalie; Okazaki, Toshiro; Schulze-Osthoff, Klaus; Levade, Thierry; Benoist, Hervé; Ségui, Bruno

    2012-04-01

    Ceramide, a biologically active sphingolipid in cell death signaling, accumulates upon CD95L treatment, concomitantly to apoptosis induction in Jurkat leukemia T cells. Herein, we show that ceramide did not increase in caspase-8 and -10-doubly deficient Jurkat cells in response to CD95L, indicating that apical caspases are essential for CD95L-triggered ceramide formation. Jurkat cells are typically defined as type 2 cells, which require the activation of the mitochondrial pathway for efficient apoptosis induction in response to CD95L. Caspase-9-deficient Jurkat cells significantly resisted CD95L-induced apoptosis, despite ceramide accumulation. Knock-down of sphingomyelin synthase 1, which metabolizes ceramide to sphingomyelin, enhanced (i) CD95L-triggered ceramide production, (ii) cytochrome c release from the mitochondria and (iii) caspase-9 activation. Exogenous ceramide-induced caspase-3 activation and apoptosis were impaired in caspase-9-deficient Jurkat cells. Conversely, caspase-9 re-expression in caspase-9-deficient Jurkat cells restored caspase-3 activation and apoptosis upon exogenous ceramide treatment. Collectively, our data provide genetic evidence that CD95L-triggered endogenous ceramide increase in Jurkat leukemia T cells (i) is not a mere consequence of cell death and occurs mainly in a caspase-9-independent manner, (ii) is likely involved in the pro-apoptotic mitochondrial pathway leading to caspase-9 activation. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Bioactive compounds from crocodile (Crocodylus siamensis) white blood cells induced apoptotic cell death in hela cells.

    Science.gov (United States)

    Patathananone, Supawadee; Thammasirirak, Sompong; Daduang, Jureerut; Chung, Jing Gung; Temsiripong, Yosapong; Daduang, Sakda

    2016-08-01

    Crocodile (Crocodylus siamensis) white blood cell extracts (WBCex) were examined for anticancer activity in HeLa cell lines using the MTT assay. The percentage viability of HeLa cells significantly deceased after treatment with WBCex in a dose- and time-dependent manner. The IC50 dose was suggested to be approximately 225 μg/mL protein. Apoptotic cell death occurred in a time-dependent manner based on investigation by flow cytometry using annexin V-FITC and PI staining. DAPI nucleic acid staining indicated increased chromatin condensation. Caspase-3, -8 and -9 activities also increased, suggesting the induction of the caspase-dependent apoptotic pathway. Furthermore, the mitochondrial membrane potential (ΔΨm ) of HeLa cells was lost as a result of increasing levels of Bax and reduced levels of Bcl-2, Bcl-XL, Bcl-Xs, and XIAP. The decreased ΔΨm led to the release of cytochrome c and the activation of caspase-9 and -3. Apoptosis-inducing factor translocated into the nuclei, and endonuclease G (Endo G) was released from the mitochondria. These results suggest that anticancer agents in WBCex can induce apoptosis in HeLa cells via both caspase-dependent and -independent pathways. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 986-997, 2016. © 2015 Wiley Periodicals, Inc.

  16. Cisplatin induced apoptosis of ovarian cancer A2780s cells by activation of ERK/p53/PUMA signals.

    Science.gov (United States)

    Song, Hao; Wei, Mei; Liu, Wenfen; Shen, Shulin; Li, Jiaqun; Wang, Liming

    2018-01-01

    Cisplatin (CDDP) is one of the most effective anticancer agents widely used in the treatment of solid tumors, including ovarian cancer. It is generally considered as a cytotoxic drug which kills cancer cells by causing DNA damage, and subsequently inducing apoptosis in cancer cells. However, the underlying mechanisms leading to cell apoptosis remain obscure. In this study, the signaling pathways involved in CDDP-induced apoptosis were examined using CDDP-sensitive ovarian cancer A2780s cells. A2780s cells were treated with CDDP (1.5-3 μg/ml) for 6h, 12h and 24h. Using siRNA targeting P53 and PUMA, and a selective MEK inhibitor, PD98059 to examine the relation between ERK1/2 activation, p53 and PUMA expression after exposure to CDDP, and the effect on CDDP-induced apoptosis. The results shown that treatment of A2780s cells with CDDP (3 μg/ml) for 6-24h induced apoptosis, resulting in the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and accumulation of p53 and PUMA (p53 upregulated modulator of apoptosis) protein. Knockdown of P53 or PUMA by siRNA transfection blocked CDDP-induced apoptosis. Inhibition of ERK1/2 using PD98059, a selective MEK inhibitor, blocked the apoptotic cell death but prevented CDDP-induced accumulation of p53 and PUMA. Knockdown of P53 by siRNA transfection also blocked CDDP-induced accumulation of PUMA. We therefore concluded that CDDP activated ERK1/2 and induced-p53-dependent PUMA upregulation, resulting in triggering apoptosis in A2780s cells. Our study clearly demonstrates that the ERK1/2/p53/PUMA axis is related to CDDP-induced cell death in A2780s cells.

  17. Romo1 expression contributes to oxidative stress-induced death of lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jung Ar [Department of Internal Medicine, Yonsei University College of Medicine, Yonsei University Health System, Seoul 135-270 (Korea, Republic of); Chung, Jin Sil [Laboratory of Molecular Cell Biology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of); Cho, Sang-Ho [Department of Pathology, Pochon CHA University, College of Medicine, Gyeonggi-do (Korea, Republic of); Kim, Hyung Jung, E-mail: khj57@yuhs.ac.kr [Department of Internal Medicine, Yonsei University College of Medicine, Yonsei University Health System, Seoul 135-270 (Korea, Republic of); Yoo, Young Do, E-mail: ydy1130@korea.ac.kr [Laboratory of Molecular Cell Biology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of)

    2013-09-20

    Highlights: •Romo1 mediates oxidative stress-induced mitochondrial ROS production. •Romo1 induction by oxidative stress plays an important role in oxidative stress-induced apoptosis. •Romo1 overexpression correlates with epithelial cell death in patients with IPF. -- Abstract: Oxidant-mediated death of lung epithelial cells due to cigarette smoking plays an important role in pathogenesis in lung diseases such as idiopathic pulmonary fibrosis (IPF). However, the exact mechanism by which oxidants induce epithelial cell death is not fully understood. Reactive oxygen species (ROS) modulator 1 (Romo1) is localized in the mitochondria and mediates mitochondrial ROS production through complex III of the mitochondrial electron transport chain. Here, we show that Romo1 mediates mitochondrial ROS production and apoptosis induced by oxidative stress in lung epithelial cells. Hydrogen peroxide (H{sub 2}O{sub 2}) treatment increased Romo1 expression, and Romo1 knockdown suppressed the cellular ROS levels and cell death triggered by H{sub 2}O{sub 2} treatment. In immunohistochemical staining of lung tissues from patients with IPF, Romo1 was mainly localized in hyperplastic alveolar and bronchial epithelial cells. Romo1 overexpression was detected in 14 of 18 patients with IPF. TUNEL-positive alveolar epithelial cells were also detected in most patients with IPF but not in normal controls. These findings suggest that Romo1 mediates apoptosis induced by oxidative stress in lung e