WorldWideScience

Sample records for cell death induction

  1. Induction of apoptotic cell death by putrescine

    DEFF Research Database (Denmark)

    Takao, Koichi; Rickhag, Karl Mattias; Hegardt, Cecilia;

    2006-01-01

    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 for their...... growth. The induction of cell death was correlated with a dramatic increase in cellular putrescine levels. Analysis using flow cytometry revealed perturbed cell cycle kinetics, with a large accumulation of cells with sub-G1 amounts of DNA, which is a typical sign of apoptosis. Another strong indication...... polyamine homeostasis may negatively affect cell proliferation and eventually lead to cell death by apoptosis if putrescine levels become too high....

  2. Induction of cell death by chemotherapeutic methylating agents

    International Nuclear Information System (INIS)

    The mechanism of cell death induced by O6 MeG has been investigated and inhibition of homologous recombination as a strategy for sensitization of tumor cells against methylating agents SN1. 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 SN1 alkylating agent effectiveness. Evidence has been provided in NHEJ dependent inhibition of DNA-PK that not significantly sensitizes the glioblastoma cells against temozolomide

  3. Selective Induction of Cancer Cell Death by Targeted Granzyme B

    Directory of Open Access Journals (Sweden)

    Robert A. Jabulowsky

    2013-02-01

    Full Text Available The potential utility of immunotoxins for cancer therapy has convincingly been demonstrated in clinical studies. Nevertheless, the high immunogenicity of their bacterial toxin domain represents a critical limitation, and has prompted the evaluation of cell-death inducing proteins of human origin as a basis for less immunogenic immunotoxin-like molecules. In this review, we focus on the current status and future prospects of targeted fusion proteins for cancer therapy that employ granzyme B (GrB from cytotoxic lymphocytes as a cytotoxic moiety. Naturally, this serine protease plays a critical role in the immune defense by inducing apoptotic target cell death upon cleavage of intracellular substrates. Advances in understanding of the structure and function of GrB enabled the generation of chimeric fusion proteins that carry a heterologous cell binding domain for recognition of tumor-associated cell surface antigens. These hybrid molecules display high selectivity for cancer cells, with cell killing activities similar to that of corresponding recombinant toxins. Recent findings have helped to understand and circumvent intrinsic cell binding of GrB and susceptibility of the enzyme to inhibition by serpins. This now allows the rational design of optimized GrB derivatives that avoid sequestration by binding to non-target tissues, limit off-target effects, and overcome resistance mechanisms in tumor cells.

  4. RBE of neutrons for induction of cell reproductive death and chromosome aberrations in three cell lines

    International Nuclear Information System (INIS)

    The authors have compared the RBE values for induction of dicentrics and centric rings with those for cell inactivation and with the mean or effective quality factors (Q) recommended for radiation protection. The induction of cell reproductive death and chromosome aberrations has been investigated in plateau phase cultures of established lines of a rat rhabdomyosarcoma, a rat ureter carcinoma and Chinese hamster cells for single doses of 300 kV X-rays and 0.5, 4.2 and 15 MeV neutrons. The different cell lines show considerable variations in sensitivity and the RBE values obtained are presented in tabular form. The mean RBE values for the rat rhabdomyosarcoma cells are lower than those for the other two relatively resistant cell lines. Those for the Chinese hamster cells extrapolated to levels according to low doses of X-rays are in good agreement with the quoted Q values. (Auth./C.F.)

  5. Autophagy Induction Protects Against 7-Oxysterol-induced Cell Death via Lysosomal Pathway and Oxidative Stress

    OpenAIRE

    Xi-Ming Yuan; Nargis Sultana; Nabeel Siraj; Ward, Liam J.; Bijar Ghafouri; Wei Li

    2016-01-01

    7-Oxysterols are major toxic components in oxidized low-density lipoprotein and human atheroma lesions, which cause lysosomal membrane permeabilization (LMP) and cell death. Autophagy may function as a survival mechanism in this process. Here, we investigated whether 7-oxysterols mixed in an atheroma-relevant proportion induce autophagy, whether autophagy induction influences 7-oxysterol-mediated cell death, and the underlying mechanisms, by focusing on cellular lipid levels, oxidative stress...

  6. Induction of neuronal cell death by paraneoplastic Ma1 antigen.

    Science.gov (United States)

    Chen, Huai-Lu; D'Mello, Santosh R

    2010-12-01

    Paraneoplastic Ma1 (PNMA1) is a member of a family of proteins involved in an autoimmune disorder called paraneoplastic neurological syndrome. Although it is widely expressed in brain, nothing is known about the function of PNMA1 in neurons. We find that PNMA1 expression is highest in the perinatal brain, a period during which developmentally regulated neuronal death occurs. PNMA1 expression increases in cerebellar granule neurons (CGNs) induced to die by low potassium (LK) and in cortical neurons following homocysteic acid (HCA) treament. Elevated PNMA1 expression is also observed in the degenerating striatum in two separate mouse models of Huntington's disease, the R6/2 transgenic model and the 3-nitropropionic acid-induced chemical model. Suppression of endogenous PNMA1 expression inhibits LK-induced neuronal apoptosis. Ectopic expression of PNMA1 promotes apoptosis even in medium containing high potassium, a condition that normally ensures survival of CGNs. Deletion of the N-terminal half of the PNMA1 protein abrogates its apoptotic activity, whereas deletion of the C-terminal half renders the protein more toxic. Within the N-terminal half, the ability to induce neuronal death depends on the presence of a BH3-like domain. In addition to being necessary for apoptosis, the BH3-like domain is necessary for self-association of PNMA1. Apoptosis by PNMA1 expression is inhibited by overexpression of Bcl2, suggesting that PNMA1-induced neuronal death may depend on the binding of a proapoptotic member of the Bcl2 family to the BH3 domain. Taken together, our results suggest that PNMA1 is a proapoptotic protein in neurons, elevated expression of which may contribute to neurodegenerative disorders. PMID:20936693

  7. Cell death in the unicellular green alga Micrasterias upon H2O2 induction

    OpenAIRE

    Darehshouri, Anza; Affenzeller, Matthias; LÜTZ-MEINDL, URSULA

    2008-01-01

    In the present study we investigate whether the unicellular green alga Micrasterias denticulata is capable of executing programmed cell death (PCD) upon experimental induction and by which morphological, molecular and physiological hallmarks it is characterized. This is particularly interesting as unicellular fresh water green algae growing in shallow bog ponds are exposed to extreme environmental conditions and the capability to perform PCD may provide an important strategy to guarantee surv...

  8. Induction of Cancer Cell Death by Isoflavone: The Role of Multiple Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Fazlul H. Sarkar

    2011-10-01

    Full Text Available Soy isoflavones have been documented as dietary nutrients broadly classified as “natural agents” which plays important roles in reducing the incidence of hormone-related cancers in Asian countries, and have shown inhibitory effects on cancer development and progression in vitro and in vivo, suggesting the cancer preventive or therapeutic activity of soy isoflavones against cancers. Emerging experimental evidence shows that isoflavones could induce cancer cell death by regulating multiple cellular signaling pathways including Akt, NF-κB, MAPK, Wnt, androgen receptor (AR, p53 and Notch signaling, all of which have been found to be deregulated in cancer cells. Therefore, homeostatic regulation of these important cellular signaling pathways by isoflavones could be useful for the activation of cell death signaling, which could result in the induction of apoptosis of both pre-cancerous and/or cancerous cells without affecting normal cells. In this article, we have attempted to summarize the current state-of-our-knowledge regarding the induction of cancer cell death pathways by isoflavones, which is believed to be mediated through the regulation of multiple cellular signaling pathways. The knowledge gained from this article will provide a comprehensive view on the molecular mechanism(s by which soy isoflavones may exert their effects on the prevention of tumor progression and/or treatment of human malignancies, which would also aid in stimulating further in-depth mechanistic research and foster the initiation of novel clinical trials.

  9. New steroidal aromatase inhibitors: Suppression of estrogen-dependent breast cancer cell proliferation and induction of cell death

    Directory of Open Access Journals (Sweden)

    Roleira Fernanda MF

    2008-07-01

    Full Text Available Abstract Background Aromatase, the cytochrome P-450 enzyme (CYP19 responsible for estrogen biosynthesis, is an important target for the treatment of estrogen-dependent breast cancer. In fact, the use of synthetic aromatase inhibitors (AI, which induce suppression of estrogen synthesis, has shown to be an effective alternative to the classical tamoxifen for the treatment of postmenopausal patients with ER-positive breast cancer. New AIs obtained, in our laboratory, by modification of the A and D-rings of the natural substrate of aromatase, compounds 3a and 4a, showed previously to efficiently suppress aromatase activity in placental microsomes. In the present study we have investigated the effects of these compounds on cell proliferation, cell cycle progression and induction of cell death using the estrogen-dependent human breast cancer cell line stably transfected with the aromatase gene, MCF-7 aro cells. Results The new steroids inhibit hormone-dependent proliferation of MCF-7aro cells in a time and dose-dependent manner, causing cell cycle arrest in G0/G1 phase and inducing cell death with features of apoptosis and autophagic cell death. Conclusion Our in vitro studies showed that the two steroidal AIs, 3a and 4a, are potent inhibitors of breast cancer cell proliferation. Moreover, it was also shown that the antiproliferative effects of these two steroids on MCF-7aro cells are mediated by disrupting cell cycle progression, through cell cycle arrest in G0/G1 phase and induction of cell death, being the dominant mechanism autophagic cell death. Our results are important for the elucidation of the cellular effects of steroidal AIs on breast cancer.

  10. Induction of immunogenic cell death by radiation-upregulated karyopherin alpha 2 in vitro.

    Science.gov (United States)

    Song, Kyung-Hee; Jung, Seung-Youn; Kang, Seong-Mook; Kim, Mi-Hyoung; Ahn, Jiyeon; Hwang, Sang-Gu; Lee, Jun-Ho; Lim, Dae-Seog; Nam, Seon Young; Song, Jie-Young

    2016-01-01

    Accumulating evidence suggests the potential for radiation therapy to generate antitumor immune responses against tumor cells by inducing immunogenic cell death and phenotypic changes. We recently found that ionizing radiation upregulated karyopherin α2 (KPNA2) in HT-29 colorectal tumor cells using quantitative proteomic analysis. To determine whether this increased KPNA2 could function as a damage-associated molecular pattern to induce antitumor immune responses, mouse bone-marrow-derived dendritic cells (BMDCs) were treated with KPNA2. KPNA2 enhanced the surface expression of CD40, CD54, CD80, CD86, and MHC class I/II on BMDCs. DCs treated with KPNA2 exhibited increased secretion of pro-inflammatory cytokines such as IL-1β, IL-6, IL-12, IL-23, and TNF-α. Co-culture of CD4(+) T cells and KPNA2-treated DCs resulted in induction of Th1/17 cytokines (IFN-γ and IL-17) and reduction of TGF-β production. Moreover, KPNA2-treated DCs were capable of increasing granzyme B and perforin expression in cytotoxic T lymphocytes. These results demonstrated that radiation-induced dying colorectal cancer cells released considerable amounts of KPNA2 that induce the maturation and activation of DCs for synergistic antitumor effect of radiation. PMID:27107455

  11. Gene expression analysis of cell death induction by Taurolidine in different malignant cell lines

    International Nuclear Information System (INIS)

    The anti-infective agent Taurolidine (TRD) has been shown to have cell death inducing properties, but the mechanism of its action is largely unknown. The aim of this study was to identify potential common target genes modulated at the transcriptional level following TRD treatment in tumour cell lines originating from different cancer types. Five different malignant cell lines (HT29, Chang Liver, HT1080, AsPC-1 and BxPC-3) were incubated with TRD (100 μM, 250 μM and 1000 μM). Proliferation after 8 h and cell viability after 24 h were analyzed by BrdU assay and FACS analysis, respectively. Gene expression analyses were carried out using the Agilent -microarray platform to indentify genes which displayed conjoint regulation following the addition of TRD in all cell lines. Candidate genes were subjected to Ingenuity Pathways Analysis and selected genes were validated by qRT-PCR and Western Blot. TRD 250 μM caused a significant inhibition of proliferation as well as apoptotic cell death in all cell lines. Among cell death associated genes with the strongest regulation in gene expression, we identified pro-apoptotic transcription factors (EGR1, ATF3) as well as genes involved in the ER stress response (PPP1R15A), in ubiquitination (TRAF6) and mitochondrial apoptotic pathways (PMAIP1). This is the first conjoint analysis of potential target genes of TRD which was performed simultaneously in different malignant cell lines. The results indicate that TRD might be involved in different signal transduction pathways leading to apoptosis

  12. Cell death upon H(2)O(2) induction in the unicellular green alga Micrasterias.

    Science.gov (United States)

    Darehshouri, A; Affenzeller, M; Lütz-Meindl, U

    2008-11-01

    In the present study, we investigated whether the unicellular green alga Micrasterias denticulata is capable of executing programmed cell death (PCD) upon experimental induction, and which morphological, molecular and physiological hallmarks characterise this. This is particularly interesting as unicellular freshwater green algae growing in shallow bog ponds are exposed to extreme environmental conditions, and the capacity to perform PCD may be an important strategy to guarantee survival of the population. The theoretically 'immortal' alga Micrasterias is an ideal object for such investigations as it has served as a cell biological model system for many years and details on its growth properties, physiology and ultrastructure throughout the cell cycle are well known. Treatments with low concentrations of H(2)O(2) are known to induce PCD in other organisms, resulting in severe ultrastructural changes to organelles, as observed in TEM. These include deformation and part disintegration of mitochondria, abnormal dilatation of cisternal rims of dictyosomes, occurrence of multivesicular bodies, an increase in the number of ER compartments, and slight condensation of chromatin. Additionally, a statistically significant increase in caspase-3-like activity was detected, which was abrogated by a caspase-3 inhibitor. Photosynthetic activity measured by fast chlorophyll fluorescence decreased as a consequence of H(2)O(2) exposure, whereas pigment composition, except for a reduction in carotenoids, was the same as in untreated controls. TUNEL positive staining and ladder-like degradation of DNA, both frequently regarded as a hallmark of PCD in higher plants, could only be detected in dead Micrasterias cells. PMID:18950431

  13. Activation of ERK signaling and induction of colon cancer cell death by piperlongumine

    OpenAIRE

    Randhawa, H; Kibble, K; Zeng, H.; Moyer, MP; Reindl, KM

    2013-01-01

    Piperlongumine (PPLGM) is a bioactive compound isolated from long peppers that shows selective toxicity towards a variety of cancer cell types including colon cancer. The signaling pathways that lead to cancer cell death in response to PPLGM exposure have not been previously identified. Our objective was to identify the intracellular signaling mechanisms by which PPLGM leads to enhanced colon cancer cell death. We found that PPLGM inhibited the growth of colon cancer cells in time- and concen...

  14. Myt3 suppression sensitizes islet cells to high glucose-induced cell death via Bim induction.

    Science.gov (United States)

    Tennant, B R; Vanderkruk, B; Dhillon, J; Dai, D; Verchere, C B; Hoffman, B G

    2016-01-01

    Diabetes is a chronic disease that results from the body's inability to properly control circulating blood glucose levels. The loss of glucose homoeostasis can arise from a loss of β-cell mass because of immune-cell-mediated attack, as in type 1 diabetes, and/or from dysfunction of individual β-cells (in conjunction with target organ insulin resistance), as in type 2 diabetes. A better understanding of the transcriptional pathways regulating islet-cell survival is of great importance for the development of therapeutic strategies that target β-cells for diabetes. To this end, we previously identified the transcription factor Myt3 as a pro-survival factor in islets following acute suppression of Myt3 in vitro. To determine the effects of Myt3 suppression on islet-cell survival in vivo, we used an adenovirus to express an shRNA targeting Myt3 in syngeneic optimal and marginal mass islet transplants, and demonstrate that suppression of Myt3 impairs the function of marginal mass grafts. Analysis of grafts 5 weeks post-transplant revealed that grafts transduced with the shMyt3 adenovirus contained ~20% the number of transduced cells as grafts transduced with a control adenovirus. In fact, increased apoptosis and significant cell loss in the shMyt3-transduced grafts was evident after only 5 days, suggesting that Myt3 suppression sensitizes islet cells to stresses present in the early post-transplant period. Specifically, we find that Myt3 suppression sensitizes islet cells to high glucose-induced cell death via upregulation of the pro-apoptotic Bcl2 family member Bim. Taken together these data suggest that Myt3 may be an important link between glucotoxic and immune signalling pathways. PMID:27195679

  15. Activation of ERK signaling and induction of colon cancer cell death by piperlongumine.

    Science.gov (United States)

    Randhawa, H; Kibble, K; Zeng, H; Moyer, M P; Reindl, K M

    2013-09-01

    Piperlongumine (PPLGM) is a bioactive compound isolated from long peppers that shows selective toxicity towards a variety of cancer cell types including colon cancer. The signaling pathways that lead to cancer cell death in response to PPLGM exposure have not been previously identified. Our objective was to identify the intracellular signaling mechanisms by which PPLGM leads to enhanced colon cancer cell death. We found that PPLGM inhibited the growth of colon cancer cells in time- and concentration-dependent manners, but was not toxic toward normal colon mucosal cells at concentrations below 10 μM. Acute (0-60 min) and prolonged (24h) exposure of HT-29 cells to PPLGM resulted in phosphorylation of ERK. To investigate whether ERK signaling was involved in PPLGM-mediated cell death, we treated HT-29 cells with the MEK inhibitor U0126, prior to treating with PPLGM. We found that U0126 attenuated PPLGM-induced activation of ERK and partially protected against PPLGM-induced cell death. These results suggest that PPLGM works, at least in part, through the MEK/ERK pathway to result in colon cancer cell death. A more thorough understanding of the molecular mechanisms by which PPLGM induces colon cancer cell death will be useful in developing therapeutic strategies to treat colon cancer. PMID:23603476

  16. Cell death in the unicellular green alga Micrasterias upon H2O2 induction

    Science.gov (United States)

    Darehshouri, Anza; Affenzeller, Matthias; Lütz-Meindl, Ursula

    2010-01-01

    In the present study we investigate whether the unicellular green alga Micrasterias denticulata is capable of executing programmed cell death (PCD) upon experimental induction and by which morphological, molecular and physiological hallmarks it is characterized. This is particularly interesting as unicellular fresh water green algae growing in shallow bog ponds are exposed to extreme environmental conditions and the capability to perform PCD may provide an important strategy to guarantee survival of the population. The theoretically “immortal” alga Micrasterias is an ideal object for such investigations as it has served as a cell biological model system since many years and details on its growth properties, physiology and ultrastructure throughout the cell cycle are well known. Treatment with low concentrations of H2O2 known to induce PCD in other organisms resulted in severe ultrastructural changes of organelles as observed in TEM. These include deformation and partly disintegration of mitochondria, abnormal dilatation of cisternal rims of dictyosomes, the occurrence of multivesicular bodies, an increase in the number of ER compartments and slight condensation of chromatin. Additionally, a statistically significant increase in caspase-3-like activity could be detected which was abrogated by a caspase-3 inhibitor. Photosynthetic activity measured by fast chlorophyll fluorescence decreased as a consequence of H2O2 exposure whereas pigment composition, except of a reduction in carotenoids, was the same as in untreated controls. TUNEL positive staining and ladder-like degradation of DNA, both frequently regarded as PCD hallmark in higher plants could only be detected in dead Micrasterias cells. PMID:18950431

  17. Cationic polystyrene nanospheres induce autophagic cell death through the induction of endoplasmic reticulum stress

    Science.gov (United States)

    Chiu, Hui-Wen; Xia, Tian; Lee, Yu-Hsuan; Chen, Chun-Wan; Tsai, Jui-Chen; Wang, Ying-Jan

    2014-12-01

    Nanoparticles (NPs) have been used to produce a wide range of products that have applications in imaging and drug delivery in medicine. Due to their chemical stability, well-controlled sizes and surface charges, polystyrene (PS) NPs have been developed as biosensors and drug delivery carriers. However, the possible adverse biological effects and underlying mechanisms are still unclear. Recently, autophagy has been implicated in the regulation of cell death. In this study, we evaluated a library of PS NPs with different surface charges. We found that NH2-labeled polystyrene (NH2-PS) nanospheres were highly toxic with enhanced uptake in macrophage (RAW 264.7) and lung epithelial (BEAS-2B) cells. Furthermore, NH2-PS could induce autophagic cell death. NH2-PS increased autophagic flux due to reactive oxygen species (ROS) generation and endoplasmic reticulum (ER) stress caused by misfolded protein aggregation. The inhibition of ER stress decreased cytotoxicity and autophagy in the NH2-PS-treated cells. In addition, the Akt/mTOR and AMPK signaling pathways were involved in the regulation of NH2-PS-triggered autophagic cell death. These results suggest an important role of autophagy in cationic NP-induced cell death and provide mechanistic insights into the inhibition of the toxicity and safe material design.Nanoparticles (NPs) have been used to produce a wide range of products that have applications in imaging and drug delivery in medicine. Due to their chemical stability, well-controlled sizes and surface charges, polystyrene (PS) NPs have been developed as biosensors and drug delivery carriers. However, the possible adverse biological effects and underlying mechanisms are still unclear. Recently, autophagy has been implicated in the regulation of cell death. In this study, we evaluated a library of PS NPs with different surface charges. We found that NH2-labeled polystyrene (NH2-PS) nanospheres were highly toxic with enhanced uptake in macrophage (RAW 264.7) and lung

  18. Induction of cancer cell death by proton beam in tumor hypoxic region

    International Nuclear Information System (INIS)

    Proton beam has been applied to treat various tumor patients in clinical studies. However, it is still undefined whether proton radiation can inhibit the blood vessel formation and induce the cell death in vascular endothelial cells in growing organs. The aim of this study are first, to develop an optimal animal model for the observation of blood vessel development with low dose of proton beam and second, to investigate the effect of low dose proton beam on the inhibition of blood vessel formation induced by hypoxic conditions. In this study, flk1-GFP transgenic zebrafish embryos were used to directly visualize and determine the inhibition of blood vessels by low dose (1, 2, 5 Gy) of proton beam with spread out Bragg peak (SOBP). And we observed cell death by acridine orange staining at 96 hours post fertilization (hpf) stage of embryos after proton irradiation. We also compared the effects of proton beam with those of gamma-ray. An antioxidant, N-acetyl cystein (NAC) was used to investigate whether reactive oxygen species (ROS) were involved in the cell deaths induced by proton irradiation. Irradiated flk-1-GFP transgenic embryos with proton beam irradiation (35 MeV, spread out Bragg peak, SOBP) demonstrated a marked inhibition of embryonic growth and an altered fluorescent blood vessel development in the trunk region. When the cells with DNA damage in the irradiated zebrafish were stained with acridine orange, green fluorescent cell death spots were increased in trunk regions compared to non-irradiated control embryos. Proton beam also significantly increased the cell death rate in human umbilical vein endothelial cells (HUVEC), but pretreatment of N-acetyl cystein (NAC), an antioxidant, recovered the proton-induced cell death rate (p<0.01). Moreover, pretreatment of NAC abrogated the effect of proton beam on the inhibition of trunk vessel development and malformation of trunk truncation. From this study, we found that proton radiation therapy can inhibit the

  19. Non-chemotoxic induction of cancer cell death using magnetic nanowires

    KAUST Repository

    Contreras, Maria

    2015-03-01

    In this paper, we show that magnetic nanowires with weak magnetic fields and low frequencies can induce cell death via a mechanism that does not involve heat production. We incubated colon cancer cells with two concentrations (2.4 and 12 μg/mL) of nickel nanowires that were 35 nm in diameter and exposed the cells and nanowires to an alternating magnetic field (0.5 mT and 1 Hz or 1 kHz) for 10 or 30 minutes. This low-power field exerted a force on the magnetic nanowires, causing a mechanical disturbance to the cells. Transmission electron microscopy images showed that the nanostructures were internalized into the cells within 1 hour of incubation. Cell viability studies showed that the magnetic field and the nanowires separately had minor deleterious effects on the cells; however, when combined, the magnetic field and nanowires caused the cell viability values to drop by up to 39%, depending on the strength of the magnetic field and the concentration of the nanowires. Cell membrane leakage experiments indicated membrane leakage of 20%, suggesting that cell death mechanisms induced by the nanowires and magnetic field involve some cell membrane rupture. Results suggest that magnetic nanowires can kill cancer cells. The proposed process requires simple and low-cost equipment with exposure to only very weak magnetic fields for short time periods. © 2015 Contreras et al.

  20. Induction of interferon and cell death in response to cytosolic DNA in chicken macrophages.

    Science.gov (United States)

    Vitak, Nazarii; Hume, David A; Chappell, Keith J; Sester, David P; Stacey, Katryn J

    2016-06-01

    Responses to cytosolic DNA can protect against both infectious organisms and the mutagenic effect of DNA integration. Recognition of invading DNA is likely to be fundamental to eukaryotic cellular life, but has been described only in mammals. Introduction of DNA into chicken macrophages induced type I interferon mRNA via a pathway conserved with mammals, requiring the receptor cGAS and the signalling protein STING. A second pathway of cytosolic DNA recognition in mammalian macrophages, initiated by absent in melanoma 2 (AIM2), results in rapid inflammasome-mediated pyroptotic cell death. AIM2 is restricted to mammals. Nevertheless, chicken macrophages underwent lytic cell death within 15 min of DNA transfection. The mouse AIM2-mediated response requires double stranded DNA, but chicken cell death was maintained with denatured DNA. This appears to be a novel form of rapid necrotic cell death, which we propose is an ancient response rendered redundant in mammalian macrophages by the appearance of the AIM2 inflammasome. The retention of these cytosolic DNA responses through evolution, with both conserved and non-conserved mechanisms, suggests a fundamental importance in cellular defence. PMID:26828392

  1. NF-κB p65 repression by the sesquiterpene lactone, Helenalin, contributes to the induction of autophagy cell death

    Directory of Open Access Journals (Sweden)

    Lim Chuan

    2012-07-01

    Full Text Available Abstract Background Numerous studies have demonstrated that autophagy plays a vital role in maintaining cellular homeostasis. Interestingly, several anticancer agents were found to exert their anticancer effects by triggering autophagy. Emerging data suggest that autophagy represents a novel mechanism that can be exploited for therapeutic benefit. Pharmacologically active natural compounds such as those from marine, terrestrial plants and animals represent a promising resource for novel anticancer drugs. There are several prominent examples from the past proving the success of natural products and derivatives exhibiting anticancer activity. Helenalin, a sesquiterpene lactone has been demonstrated to have potent anti-inflammatory and antitumor activity. Albeit previous studies demonstrating helenalin’s multi modal action on cellular proliferative and apoptosis, the mechanisms underlying its action are largely unexplained. Methods To deduce the mechanistic action of helenalin, cancer cells were treated with the drug at various concentrations and time intervals. Using western blot, FACS analysis, overexpression and knockdown studies, cellular signaling pathways were interrogated focusing on apoptosis and autophagy markers. Results We show here that helenalin induces sub-G1 arrest, apoptosis, caspase cleavage and increases the levels of the autophagic markers. Suppression of caspase cleavage by the pan caspase inhibitor, Z-VAD-fmk, suppressed induction of LC3-B and Atg12 and reduced autophagic cell death, indicating caspase activity was essential for autophagic cell death induced by helenalin. Additionally, helenalin suppressed NF-κB p65 expression in a dose and time dependent manner. Exogenous overexpression of p65 was accompanied by reduced levels of cell death whereas siRNA mediated suppression led to augmented levels of caspase cleavage, autophagic cell death markers and increased cell death. Conclusions Taken together, these results show

  2. Induction of cancer cell death by proton beam in tumor hypoxic region

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. M.; Hur, T. R.; Lee, K. B.; Jeong, M. H.; Park, J. W. [Kyungbook National Univ., Daegu (Korea, Republic of)

    2007-04-15

    Proton beam induced apoptosis significantly in Lewis lung carcinoma cells and hepatoma HepG2 cells in a dose- and time-dependent manner, but slightly in leukemia Molt-4 cells. Relative biological effectiveness (RBE) values for death rate relative to gamma ray were ranged from 1.3 to 2.1 in LLC or HepG2 but 0.7 in Molt-4 cells at 72h after irradiation. The typical apoptosis was observed by nuclear DNA staining with DAPI. By FACS analysis after stained with PI, sub-G1 cell fraction was significantly increased but G2/M phase was not altered by proton beam irradiation measured at 24 h after irradiation. Proton beam-irradiated tumor cells induced cleavage of PARP-1 and procaspases (-3 and -9) and increased the level of p53 and p21. decreased pro-lamin B. Acitivity of caspases was significantly increased after proton beam irradiation. Furthermore, ROS were significantly increased and N-acetyl cystein (NAC) pretreatment restored the apoptotic cell death induced in proton beam-irradiated cells. In conclusion, single treatment of low energy proton beam with SOBP induced apoptosis of solid tumor cells via increased ROS, active caspase -3,-9 and p53, p2.

  3. Induction of cancer cell death by proton beam in tumor hypoxic region

    International Nuclear Information System (INIS)

    Proton beam induced apoptosis significantly in Lewis lung carcinoma cells and hepatoma HepG2 cells in a dose- and time-dependent manner, but slightly in leukemia Molt-4 cells. Relative biological effectiveness (RBE) values for death rate relative to gamma ray were ranged from 1.3 to 2.1 in LLC or HepG2 but 0.7 in Molt-4 cells at 72h after irradiation. The typical apoptosis was observed by nuclear DNA staining with DAPI. By FACS analysis after stained with PI, sub-G1 cell fraction was significantly increased but G2/M phase was not altered by proton beam irradiation measured at 24 h after irradiation. Proton beam-irradiated tumor cells induced cleavage of PARP-1 and procaspases (-3 and -9) and increased the level of p53 and p21. decreased pro-lamin B. Acitivity of caspases was significantly increased after proton beam irradiation. Furthermore, ROS were significantly increased and N-acetyl cystein (NAC) pretreatment restored the apoptotic cell death induced in proton beam-irradiated cells. In conclusion, single treatment of low energy proton beam with SOBP induced apoptosis of solid tumor cells via increased ROS, active caspase -3,-9 and p53, p2

  4. Induction of apoptosis-like cell death by coelomocyte extracts from Eisenia andrei earthworms.

    Science.gov (United States)

    Mácsik, Levente László; Somogyi, Ildikó; Opper, Balázs; Bovári-Biri, Judit; Pollák, Edit; Molnár, László; Németh, Péter; Engelmann, Péter

    2015-10-01

    Earthworm's innate immunity is maintained by cellular and humoral components. Our objective was to characterize the cytotoxicity leading to target cell death caused by earthworm coelomocytes. Coelomocyte lysates induced strong cytotoxicity in tumor cell lines. Transmission electron microscopy revealed cell membrane and intracellular damage in cells treated with coelomocyte lysates. Using TUNEL-assay, within 5 min of incubation we detected DNA fragmentation. Moreover, we found phosphatidylserine translocation in target cell-membranes. Furthermore, we detected dose-dependent Ca(2+) influx and decrease of mitochondrial membrane potential in coelomocyte lysate-treated cells. Interestingly, caspase 3/8 activation was undetectable in exposed tumor cells. One such cytotoxic molecule, lysenin identified in earthworms binds to sphingomyelin and causes target cell lysis in vertebrates. Pretreatment with our anti-lysenin monoclonal antibody rescued the majority but not all target cells from coelomocyte induced death. These data suggest that, not only lysenin but also other factors participate in the caspase-independent apoptosis induced by coelomocytes. PMID:26049811

  5. Induction of cell death in a glioblastoma line by hyperthermic therapy based on gold nanorods

    Directory of Open Access Journals (Sweden)

    Fernandez Cabada T

    2012-03-01

    Full Text Available Tamara Fernandez Cabada1,2,*, Cristina Sanchez Lopez de Pablo1,3,*, Alberto Martinez Serrano2, Francisco del Pozo Guerrero1,3, Jose Javier Serrano Olmedo1,3,*, Milagros Ramos Gomez1–3,* 1Centre for Biomedical Technology, Universidad Politecnica de Madrid, Madrid, Spain; 2Centre for Molecular Biology, "Severo Ochoa" Universidad Autonoma de Madrid, Madrid, Spain; 3Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-bbn, Zaragoza, Spain.*These authors contributed equally to this workBackground: Metallic nanorods are promising agents for a wide range of biomedical applications. In this study, we developed an optical hyperthermia method capable of inducing in vitro death of glioblastoma cells.Methods: The procedure used was based on irradiation of gold nanorods with a continuous wave laser. This kind of nanoparticle converts absorbed light into localized heat within a short period of time due to the surface plasmon resonance effect. The effectiveness of the method was determined by measuring changes in cell viability after laser irradiation of glioblastoma cells in the presence of gold nanorods.Results: Laser irradiation in the presence of gold nanorods induced a significant decrease in cell viability, while no decrease in cell viability was observed with laser irradiation or incubation with gold nanorods alone. The mechanism of cell death mediated by gold nanorods during photothermal ablation was analyzed, indicating that treatment compromised the integrity of the cell membrane instead of initiating the process of programmed cell death.Conclusion: The use of gold nanorods in hyperthermal therapies is very effective in eliminating glioblastoma cells, and therefore represents an important area of research for therapeutic development.Keywords: laser irradiation, photothermal therapy, surface plasmon resonance, cancer

  6. Daunomycin accumulation and induction of programmed cell death in rat hair follicles

    DEFF Research Database (Denmark)

    Shin, Masashi; Larsson, Lars-Inge; Hougaard, David M.;

    2009-01-01

    -positive matrix cells are detectable up to 48 h after injection and exhibit a characteristic granular morphology, which is not observed in saline-injected controls. TUNEL-staining has revealed that DM injection induces programmed cell death (PCD) in rat hair follicles. Cells undergoing PCD are detectable as late......The anthracycline antibiotic daunomycin (DM) is useful for the treatment of leukemia but has side-effects such as alopecia. Using immunocytochemistry, we show that, after a single i.v. injection, DM accumulates in the nuclei of matrix cells and in the outer root sheath of hair follicles. DM...... and in the outer root sheath. Ultrastructural immunocytochemistry has shown the presence of DM-positive cells with two different types of morphology. About half of the immunopositive cells exhibit a morphology typical of classical apoptosis (PCD type 1), whereas the other half show signs of autophagic...

  7. Synergistic chemopreventive effects of curcumin and berberine on human breast cancer cells through induction of apoptosis and autophagic cell death.

    Science.gov (United States)

    Wang, Kai; Zhang, Chao; Bao, Jiaolin; Jia, Xuejing; Liang, Yeer; Wang, Xiaotong; Chen, Meiwan; Su, Huanxing; Li, Peng; Wan, Jian-Bo; He, Chengwei

    2016-01-01

    Curcumin (CUR) and berberine (BBR) are renowned natural compounds that exhibit potent anticancer activities through distinct molecular mechanisms. However, the anticancer capacity of either CUR or BBR is limited. This prompted us to investigate the chemopreventive potential of co-treatment of CUR and BBR against breast cancers. The results showed that CUR and BBR in combination synergistically inhibited the growth of both MCF-7 and MDA-MB-231 breast cancer cells than the compounds used alone. Further study confirmed that synergistic anti-breast cancer activities of co-treatment of these two compounds was through inducing more apoptosis and autophagic cell death (ACD). The co-treatment-induced apoptosis was caspase-dependent and through activating ERK pathways. Our data also demonstrated that co-treatment of CUR and BBR strongly up-regulated phosphorylation of JNK and Beclin1, and decreased phosphorylated Bcl-2. Inhibition of JNK by SP600125 markedly decreased LC3-II and Beclin1, restored phosphorylated Bcl-2, and reduced the cytotoxicity induced by the two compounds in combination. These results strongly suggested that JNK/Bcl-2/Beclin1 pathway played a key role in the induction of ACD in breast cancer cells by co-treatment of CUR and BBR. This study provides an insight into the potential application of curcumin and berberine in combination for the chemoprevention and treatment of breast cancers. PMID:27263652

  8. Myt3 suppression sensitizes islet cells to high glucose-induced cell death via Bim induction

    OpenAIRE

    Tennant, B. R.; Vanderkruk, B; Dhillon, J; Dai, D.; Verchere, C B; Hoffman, B G

    2016-01-01

    Diabetes is a chronic disease that results from the body's inability to properly control circulating blood glucose levels. The loss of glucose homoeostasis can arise from a loss of β-cell mass because of immune-cell-mediated attack, as in type 1 diabetes, and/or from dysfunction of individual β-cells (in conjunction with target organ insulin resistance), as in type 2 diabetes. A better understanding of the transcriptional pathways regulating islet-cell survival is of great importance for the ...

  9. Suppression of mTOR pathway and induction of autophagy-dependent cell death by cabergoline.

    Science.gov (United States)

    Lin, Shao Jian; Leng, Zhi Gen; Guo, Yu Hang; Cai, Lin; Cai, Yu; Li, Ning; Shang, Han Bing; Le, Wei-Dong; Zhao, Wei Guo; Wu, Zhe Bao

    2015-11-17

    Cabergoline (CAB), the first-line drug for treatment of prolactinomas, is effective in suppressing prolactin hypersecretion, reducing tumor size, and restoring gonadal function. However, mechanisms for CAB-mediated tumor shrinkage are largely unknown. Here we report a novel cytotoxic mechanism for CAB. CAB induced formation of autophagosome in rat pituitary tumor MMQ and GH3 cells at the early stage through inhibiting mTOR pathway, resulting in higher conversion rates of LC3-I to LC3-II, GFP-LC3 aggregation, and increased autophagosome formation. Interestingly, CAB treatment augmented lysosome acidification and resulted in impaired proteolytic degradation within autolysosomes. This blocked the autophagic flux, leading to the accumulation of p62 aggregation and undigested autolysosomes. Knockdown of ATG7, ATG5, or Becn1, could significantly rescue the CAB-mediated cell death of MMQ cells (p < 0.05). CAB-induced autophagy and blockade of autophagy flux participated in antitumoral action in vivo. In conclusion, our study provides evidence that CAB concomitantly induces autophagy and inhibits the autophagic flux, leading to autophagy-dependent cell death. These findings elucidate novel mechanisms for CAB action. PMID:26513171

  10. Modelling the induction of cell death and chromosome damage by therapeutic protons

    CERN Document Server

    Carante, M P

    2015-01-01

    A two-parameter biophysical model cal led BIANCA (BIophysical ANalysis of Cell death and chromosome Aberrations), which assumes a pivotal role for DNA cluster damage and for “lethal” chromosome aberrations, was applied to calculate cell death and chromosome aberrations for normal and radio-resistant cells along a 62-MeV eye melanoma proton beam. The yield of DNA “Cluster Lesions” and the probability for a chromosome fragment of not being rejoined with any partne r were adjustable parameters. In line with other works, the beam effectiveness at inducing both biological endpoints was found to increase with increasing depth, and high levels of damage were found also beyond the dose fall-off, due to the higher biological effectiveness of low-energy protons. This implies that assuming a constant RBE along the whole SOBP, as is currently done in clinical practice, may be sub-optimal, also implying a possible underestimation of normal tissue damage. Furthermore, the calculations suggested that fo...

  11. Biological effects of radiation: The induction of malignant transformation and programmed cell death

    International Nuclear Information System (INIS)

    In the Chernobyl explosions and fire, powderized nuclear fuel was released from the reactor core, causing an unexpected fallout. X-ray analysis and scanning electron microscopy showed that the isolated single particles were essentially pure uranium. These uranium aerosols contained all of the nonvolatile fission products, including the b-emitters, 95Zr, 103Ru, 106Ru, 141Ce, and 144Ce. The hot particles are extremely effective in inducing malignant transformation in mouse fibroblast cells in vitro. The major factor responsible for this effect is focus promotion caused by a wound-mediated permanent increase in cell proliferation (mitogenesis associated with mutagenesis). Transformed foci were analysed for the activation of c-abl, c-erb-A, c-erb-B, c-fms, c-fos, c-myb, c-myc, c-Ha-ras, c-Ki-ras, c-sis, and c-raf oncogenes at the transcriptional level. The pattern of oncogene activation was found to vary from focus to focus. Long interspersed repeated DNA (L1 or LINE makes up a class of mobile genetic elements which can amplify in the cell genome by retroposition. This element is spontaneously transcriptionally activated at a critical population density and later amplified in rat chloroleukaemia cells. UV light and ionizing radiation induce this activation prematurely, and the activation is followed by programmed cell death (apoptosis) in a sequence of events identical to that seen in LIRn activation occurring spontaneously

  12. Potency of different red light sources in photodynamic induction of cell death in a squamous cell carcinoma cell line.

    Science.gov (United States)

    Novak, Ben; Peteja, Monika; Brueck, Thomas; Luebbert, Hermann

    2016-06-01

    LED illumination systems were found to be more efficacious than broad spectrum lamps in recent phase III trials on photodynamic treatment of actinic keratosis. However, a detailed comparison of the light doses emitted at the appropriate spectral range and its correlation to photodynamic effects is thus far not available for the most frequently used devices. Here, we compared the spectral emissions of three different PDT lamps with their potency of inducing cell death in ALA-loaded A431 cells, including a new system equipped with more advanced LEDs matching the photosensitizer absorption peak more precisely and emitting more homogeneous light over time. Cells were exposed to two different ALA concentrations, incubated for 1 or 3h and then illuminated by one of two different LED or a broad-spectrum system at four different light doses, whereupon viability was assessed. Maximal doses were selected in accordance to clinically applied light doses in recent phase III studies and the manufacturers' recommendations. The data gathered here clearly demonstrate that the two LED systems were significantly more effective in inducing cell death than the broad spectrum system. Most efficient was the newer LED system, in agreement with emission parameters that more accurately corresponded to the photosensitizer's absorption peak. PMID:26975298

  13. Influence the oxidant action of selenium in radiosensitivity induction and cell death in yeast Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    cells when they are challenged with ionizing radiation produced by 60Co. For this, we assessed whether selenium causes oxidative damage to cell and cell death. After that, we assessed whether differences in the oxidative damage occurs after the cells be treated with selenium and gamma irradiation. Our results showed that selenium has a radiosensitizing function playing a oxidant role in yeast cell. (author)

  14. Mechanisms and Therapeutic Implications of Cell Death Induction by Indole Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Aamir; Sakr, Wael A.; Rahman, KM Wahidur, E-mail: kmrahman@med.wayne.edu [Department of Pathology, Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI 48201 (United States)

    2011-07-19

    Indole compounds, obtained from cruciferous vegetables, are well-known for their anti-cancer properties. In particular, indole-3-carbinol (I3C) and its dimeric product, 3,3′-diindolylmethane (DIM), have been widely investigated for their effectiveness against a number of human cancers in vitro as well as in vivo. These compounds are effective inducers of apoptosis and the accumulating evidence documenting their ability to modulate multiple cellular signaling pathways is a testimony to their pleiotropic behavior. Here we attempt to update current understanding on the various mechanisms that are responsible for the apoptosis-inducing effects by these compounds. The significance of apoptosis-induction as a desirable attribute of anti-cancer agents such as indole compounds cannot be overstated. However, an equally intriguing property of these compounds is their ability to sensitize cancer cells to standard chemotherapeutic agents. Such chemosensitizing effects of indole compounds can potentially have major clinical implications because these non-toxic compounds can reduce the toxicity and drug-resistance associated with available chemotherapies. Combinational therapy is increasingly being realized to be better than single agent therapy and, through this review article, we aim to provide a rationale behind combination of natural compounds such as indoles with conventional therapeutics.

  15. Mechanisms and Therapeutic Implications of Cell Death Induction by Indole Compounds

    Directory of Open Access Journals (Sweden)

    KM Wahidur Rahman

    2011-07-01

    Full Text Available Indole compounds, obtained from cruciferous vegetables, are well-known for their anti-cancer properties. In particular, indole-3-carbinol (I3C and its dimeric product, 3,3´-diindolylmethane (DIM, have been widely investigated for their effectiveness against a number of human cancers in vitro as well as in vivo. These compounds are effective inducers of apoptosis and the accumulating evidence documenting their ability to modulate multiple cellular signaling pathways is a testimony to their pleiotropic behavior. Here we attempt to update current understanding on the various mechanisms that are responsible for the apoptosis-inducing effects by these compounds. The significance of apoptosis-induction as a desirable attribute of anti-cancer agents such as indole compounds cannot be overstated. However, an equally intriguing property of these compounds is their ability to sensitize cancer cells to standard chemotherapeutic agents. Such chemosensitizing effects of indole compounds can potentially have major clinical implications because these non-toxic compounds can reduce the toxicity and drug-resistance associated with available chemotherapies. Combinational therapy is increasingly being realized to be better than single agent therapy and, through this review article, we aim to provide a rationale behind combination of natural compounds such as indoles with conventional therapeutics.

  16. Mechanisms and Therapeutic Implications of Cell Death Induction by Indole Compounds

    International Nuclear Information System (INIS)

    Indole compounds, obtained from cruciferous vegetables, are well-known for their anti-cancer properties. In particular, indole-3-carbinol (I3C) and its dimeric product, 3,3′-diindolylmethane (DIM), have been widely investigated for their effectiveness against a number of human cancers in vitro as well as in vivo. These compounds are effective inducers of apoptosis and the accumulating evidence documenting their ability to modulate multiple cellular signaling pathways is a testimony to their pleiotropic behavior. Here we attempt to update current understanding on the various mechanisms that are responsible for the apoptosis-inducing effects by these compounds. The significance of apoptosis-induction as a desirable attribute of anti-cancer agents such as indole compounds cannot be overstated. However, an equally intriguing property of these compounds is their ability to sensitize cancer cells to standard chemotherapeutic agents. Such chemosensitizing effects of indole compounds can potentially have major clinical implications because these non-toxic compounds can reduce the toxicity and drug-resistance associated with available chemotherapies. Combinational therapy is increasingly being realized to be better than single agent therapy and, through this review article, we aim to provide a rationale behind combination of natural compounds such as indoles with conventional therapeutics

  17. T315 Decreases Acute Myeloid Leukemia Cell Viability through a Combination of Apoptosis Induction and Autophagic Cell Death

    Science.gov (United States)

    Chiu, Chang-Fang; Weng, Jing-Ru; Jadhav, Appaso; Wu, Chia-Yung; Sargeant, Aaron M.; Bai, Li-Yuan

    2016-01-01

    T315, an integrin-linked kinase (ILK) inhibitor, has been shown to suppress the proliferation of breast cancer, stomach cancer and chronic lymphocytic leukemia cells. Here we demonstrate that T315 decreases cell viability of acute myeloid leukemia (AML) cell lines (HL-60 and THP-1) and primary leukemia cells from AML patients in a dose-responsive manner. Normal human bone marrow cells are less sensitive than leukemia cells to T315. T315 down regulates protein kinase B (Akt) and p-Akt and induces caspase activation, poly-ADP-ribose polymerase (PARP) cleavage, apoptosis and autophagy through an ILK-independent manner. Interestingly, pretreatment with autophagy inhibitors rescues cells from apoptosis and concomitant PARP cleavage, which implicates a key role of autophagic cell death in T315-mediated cytotoxicity. T315 also demonstrates efficacy in vivo, suppressing the growth of THP-1 xenograft tumors in athymic nude mice when administered intraperitoneally. This study shows that autophagic cell death and apoptosis cooperatively contribute to the anticancer activity of T315 in AML cells. In conclusion, the complementary roles of apoptotic and autophagic cell death should be considered in the future assessment of the translational value of T315 in AML therapy. PMID:27537872

  18. Silencing of Hsp27 and Hsp72 in glioma cells as a tool for programmed cell death induction upon temozolomide and quercetin treatment

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowicz-Gil, Joanna, E-mail: jjgil@poczta.umcs.lublin.pl [Department of Comparative Anatomy and Anthropology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin (Poland); Langner, Ewa [Department of Medical Biology, Institute of Agricultural Medicine, Jaczewskiego 2, 20-950 Lublin (Poland); Bądziul, Dorota [Department of Comparative Anatomy and Anthropology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin (Poland); Wertel, Iwona [1st Department of Gynaecology, University School of Medicine, Staszica 16, 20-081 Lublin (Poland); Rzeski, Wojciech [Department of Medical Biology, Institute of Agricultural Medicine, Jaczewskiego 2, 20-950 Lublin (Poland); Department of Immunology and Virology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin (Poland)

    2013-12-15

    The aim of the present study was to investigate whether silencing of Hsp27 or Hsp72 expression in glioblastoma multiforme T98G and anaplastic astrocytoma MOGGCCM cells increases their sensitivity to programmed cell death induction upon temozolomide and/or quercetin treatment. Transfection with specific siRNA was performed for the Hsp gene silencing. As revealed by microscopic observation and flow cytometry, the inhibition of Hsp expression was correlated with severe apoptosis induction upon the drug treatment studied. No signs of autophagy were detected. This was correlated with a decreased mitochondrial membrane potential, increased level of cytochrome c in the cytoplasm, and activation of caspase 3 and caspase 9. All these results suggest that the apoptotic signal was mediated by an internal pathway. Additionally, in a large percentage of cells treated with temozolomide, with or without quercetin, granules within the ER system were found, which was accompanied by an increased level of caspase 12 expression. This might be correlated with ER stress. Quercetin and temozolomide also changed the shape of nuclei from circular to “croissant like” in both transfected cell lines. Our results indicate that blocking of Hsp27 and Hsp72 expression makes T98G cells and MOGGCCM cells extremely vulnerable to apoptosis induction upon temozolomide and quercetin treatment and that programmed cell death is initiated by an internal signal. - Highlights: • Hsps gene silencing induced severe apoptosis upon temozolomide–quercetin treatment • Apoptosis in transfected glioma cells was initiated by internal signal • Programmed cell death was preceded by ER stress • Temozolomide–quercetin treatment changed nuclei shape in transfected glioma cells.

  19. Silencing of Hsp27 and Hsp72 in glioma cells as a tool for programmed cell death induction upon temozolomide and quercetin treatment

    International Nuclear Information System (INIS)

    The aim of the present study was to investigate whether silencing of Hsp27 or Hsp72 expression in glioblastoma multiforme T98G and anaplastic astrocytoma MOGGCCM cells increases their sensitivity to programmed cell death induction upon temozolomide and/or quercetin treatment. Transfection with specific siRNA was performed for the Hsp gene silencing. As revealed by microscopic observation and flow cytometry, the inhibition of Hsp expression was correlated with severe apoptosis induction upon the drug treatment studied. No signs of autophagy were detected. This was correlated with a decreased mitochondrial membrane potential, increased level of cytochrome c in the cytoplasm, and activation of caspase 3 and caspase 9. All these results suggest that the apoptotic signal was mediated by an internal pathway. Additionally, in a large percentage of cells treated with temozolomide, with or without quercetin, granules within the ER system were found, which was accompanied by an increased level of caspase 12 expression. This might be correlated with ER stress. Quercetin and temozolomide also changed the shape of nuclei from circular to “croissant like” in both transfected cell lines. Our results indicate that blocking of Hsp27 and Hsp72 expression makes T98G cells and MOGGCCM cells extremely vulnerable to apoptosis induction upon temozolomide and quercetin treatment and that programmed cell death is initiated by an internal signal. - Highlights: • Hsps gene silencing induced severe apoptosis upon temozolomide–quercetin treatment • Apoptosis in transfected glioma cells was initiated by internal signal • Programmed cell death was preceded by ER stress • Temozolomide–quercetin treatment changed nuclei shape in transfected glioma cells

  20. Combined treatment with cotylenin A and phenethyl isothiocyanate induces strong antitumor activity mainly through the induction of ferroptotic cell death in human pancreatic cancer cells.

    Science.gov (United States)

    Kasukabe, Takashi; Honma, Yoshio; Okabe-Kado, Junko; Higuchi, Yusuke; Kato, Nobuo; Kumakura, Shunichi

    2016-08-01

    The treatment of pancreatic cancer, one of the most aggressive gastrointestinal tract malignancies, with current chemotherapeutic drugs has had limited success due to its chemoresistance and poor prognosis. Therefore, the development of new drugs or effective combination therapies is urgently needed. Cotylenin A (CN-A) (a plant growth regulator) is a potent inducer of differentiation in myeloid leukemia cells and exhibits potent antitumor activities in several cancer cell lines. In the present study, we demonstrated that CN-A and phenethyl isothiocyanate (PEITC), an inducer of reactive oxygen species (ROS) and a dietary anticarcinogenic compound, synergistically inhibited the proliferation of MIAPaCa-2, PANC-1 and gemcitabine-resistant PANC-1 cells. A combined treatment with CN-A and PEITC also effectively inhibited the anchorage-independent growth of these cancer cells. The combined treatment with CN-A and PEITC strongly induced cell death within 1 day at concentrations at which CN-A or PEITC alone did not affect cell viability. A combined treatment with synthetic CN-A derivatives (ISIR-005 and ISIR-042) or fusicoccin J (CN-A-related natural product) and PEITC did not have synergistic effects on cell death. The combined treatment with CN-A and PEITC synergistically induced the generation of ROS. Antioxidants (N-acetylcysteine and trolox), ferroptosis inhibitors (ferrostatin-1 and liproxstatin), and the lysosomal iron chelator deferoxamine canceled the synergistic cell death. Apoptosis inhibitors (Z-VAD-FMK and Q-VD-OPH) and the necrosis inhibitor necrostatin-1s did not inhibit synergistic cell death. Autophagy inhibitors (3-metyladenine and chloroquine) partially prevented cell death. These results show that synergistic cell death induced by the combined treatment with CN-A and PEITC is mainly due to the induction of ferroptosis. Therefore, the combination of CN-A and PEITC has potential as a novel therapeutic strategy against pancreatic cancer. PMID:27375275

  1. Effects of γ (60Co) and β (90Sr) radiations in Chinese hamster ovarian cells (CHO-K1): induction of micronuclei and cell death

    International Nuclear Information System (INIS)

    Among various types of ionising radiation, the beta emitter radionuclides are involved in many sectors of human activity, such as nuclear medicine, nuclear industries and biomedicine, with a consequent increased risk of accidental, occupational or therapeutic exposure. Despite their recognized importance, there is little information about the effect of beta particles at the cellular level when compared to other types of ionizing radiation. Thus, the objective of the present study was to evaluate the genotoxic and cytotoxic effects of 90Sr, a pure, highly energetic beta source, on CHO-K1 cells and to compare them with data obtained with 60Co. CHO-K1 cells irradiated with different doses (1.0, 2.5, 5.0, 7.5 Gy) of 60Co (0.34 Gy.min-1) and 90Sr (0.23 Gy.min-1) were processed for analysis of clonogenic death, induction of micronuclei (MN) and necrotic and apoptotic death. The survival curves obtained for both types of radiation were better fitted by the linear-quadratic model and were similar. However, the cytogenetic results showed that both the proportion of micronucleated cells and the magnitude of radioinduced lesions demonstrated by the analysis of MN distribution were significantly higher in cells irradiated with 60Co than in cells irradiated with 90Sr, whereas 90Sr was more damaging than 60Co in terms of cell death induction. Necrosis was the major type of death observed in CHO-K1 cells. The data obtained suggest that the low incidence of micronucleated cells after exposure to 90Sr may be a consequence of selective elimination of severely damaged cells from the population by the necrotic process at a higher rate than observed with 60Co exposure. The data obtained also demonstrated the need to use several parameters for a better estimate of cellular sensitivity to the action of genotoxic agents, which would be important in terms of radiobiology, oncology and therapeutics. (author)

  2. Induction of Cell Death through Alteration of Oxidants and Antioxidants in Epithelial Cells Exposed to High Energy Protons

    Science.gov (United States)

    Ramesh, Govindarajan; Wu, Honglu

    2012-01-01

    Radiation affects several cellular and molecular processes including double strand breakage, modifications of sugar moieties and bases. In outer space, protons are the primary radiation source which poses a range of potential health risks to astronauts. On the other hand, the use of proton radiation for tumor radiation therapy is increasing as it largely spares healthy tissues while killing tumor tissues. Although radiation related research has been conducted extensively, the molecular toxicology and cellular mechanisms affected by proton radiation remain poorly understood. Therefore, in the present study, we irradiated rat epithelial cells (LE) with different doses of protons and investigated their effects on cell proliferation and cell death. Our data showed an inhibition of cell proliferation in proton irradiated cells with a significant dose dependent activation and repression of reactive oxygen species (ROS) and antioxidants, glutathione and superoxide dismutase respectively as compared to control cells. In addition, apoptotic related genes such as caspase-3 and -8 activities were induced in a dose dependent manner with corresponding increased levels of DNA fragmentation in proton irradiated cells than control cells. Together, our results show that proton radiation alters oxidant and antioxidant levels in the cells to activate apoptotic pathway for cell death.

  3. Synergism between arsenite and proteasome inhibitor MG132 over cell death in myeloid leukaemic cells U937 and the induction of low levels of intracellular superoxide anion

    Energy Technology Data Exchange (ETDEWEB)

    Lombardo, Tomás [Laboratorio de Immunotoxicologia (LaITO), IDEHU-CONICET, Hospital de Clínicas, José de San Martín, Universidad de Buenos Aires (UBA), Buenos Aires (Argentina); Cavaliere, Victoria; Costantino, Susana N. [Laboratorio de Inmunología Tumoral (LIT), IDEHU-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires (Argentina); Kornblihtt, Laura [Servicio de Hematología, Hospital de Clínicas, José de San Martín (UBA), Buenos Aires (Argentina); Alvarez, Elida M. [Laboratorio de Inmunología Tumoral (LIT), IDEHU-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires (Argentina); Blanco, Guillermo A., E-mail: gblanco@ffyb.uba.ar [Laboratorio de Immunotoxicologia (LaITO), IDEHU-CONICET, Hospital de Clínicas, José de San Martín, Universidad de Buenos Aires (UBA), Buenos Aires (Argentina)

    2012-02-01

    Increased oxygen species production has often been cited as a mechanism determining synergism on cell death and growth inhibition effects of arsenic-combined drugs. However the net effect of drug combination may not be easily anticipated solely from available knowledge of drug-induced death mechanisms. We evaluated the combined effect of sodium arsenite with the proteasome inhibitor MG132, and the anti-leukaemic agent CAPE, on growth-inhibition and cell death effect in acute myeloid leukaemic cells U937 and Burkitt's lymphoma-derived Raji cells, by the Chou–Talalay method. In addition we explored the association of cytotoxic effect of drugs with changes in intracellular superoxide anion (O{sub 2}{sup −}) levels. Our results showed that combined arsenite + MG132 produced low levels of O{sub 2}{sup −} at 6 h and 24 h after exposure and were synergic on cell death induction in U937 cells over the whole dose range, although the combination was antagonistic on growth inhibition effect. Exposure to a constant non-cytotoxic dose of 80 μM hydrogen peroxide together with arsenite + MG132 changed synergism on cell death to antagonism at all effect levels while increasing O{sub 2}{sup −} levels. Arsenite + hydrogen peroxide also resulted in antagonism with increased O{sub 2}{sup −} levels in U937 cells. In Raji cells, arsenite + MG132 also produced low levels of O{sub 2}{sup −} at 6 h and 24 h but resulted in antagonism on cell death and growth inhibition. By contrast, the combination arsenite + CAPE showed high levels of O{sub 2}{sup −} production at 6 h and 24 h post exposure but resulted in antagonism over cell death and growth inhibition effects in U937 and Raji cells. We conclude that synergism between arsenite and MG132 in U937 cells is negatively associated to O{sub 2}{sup −} levels at early time points after exposure. -- Highlights: ► Arsenic combined cytotoxic and anti-proliferative effects by Chou–Talalay method. ► Cytotoxic effect

  4. Synergism between arsenite and proteasome inhibitor MG132 over cell death in myeloid leukaemic cells U937 and the induction of low levels of intracellular superoxide anion

    International Nuclear Information System (INIS)

    Increased oxygen species production has often been cited as a mechanism determining synergism on cell death and growth inhibition effects of arsenic-combined drugs. However the net effect of drug combination may not be easily anticipated solely from available knowledge of drug-induced death mechanisms. We evaluated the combined effect of sodium arsenite with the proteasome inhibitor MG132, and the anti-leukaemic agent CAPE, on growth-inhibition and cell death effect in acute myeloid leukaemic cells U937 and Burkitt's lymphoma-derived Raji cells, by the Chou–Talalay method. In addition we explored the association of cytotoxic effect of drugs with changes in intracellular superoxide anion (O2−) levels. Our results showed that combined arsenite + MG132 produced low levels of O2− at 6 h and 24 h after exposure and were synergic on cell death induction in U937 cells over the whole dose range, although the combination was antagonistic on growth inhibition effect. Exposure to a constant non-cytotoxic dose of 80 μM hydrogen peroxide together with arsenite + MG132 changed synergism on cell death to antagonism at all effect levels while increasing O2− levels. Arsenite + hydrogen peroxide also resulted in antagonism with increased O2− levels in U937 cells. In Raji cells, arsenite + MG132 also produced low levels of O2− at 6 h and 24 h but resulted in antagonism on cell death and growth inhibition. By contrast, the combination arsenite + CAPE showed high levels of O2− production at 6 h and 24 h post exposure but resulted in antagonism over cell death and growth inhibition effects in U937 and Raji cells. We conclude that synergism between arsenite and MG132 in U937 cells is negatively associated to O2− levels at early time points after exposure. -- Highlights: ► Arsenic combined cytotoxic and anti-proliferative effects by Chou–Talalay method. ► Cytotoxic effect associated with superoxide levels as assessed by flow cytometry. ► Synergism between arsenite

  5. A Combined Chemical and Magneto-Mechanical Induction of Cancer Cell Death by the Use of Functionalized Magnetic Iron Nanowires

    KAUST Repository

    Martinez Banderas, Aldo

    2016-04-01

    Cancer prevails as one of the most devastating diseases being at the top of death causes for adults despite continuous development and innovation in cancer therapy. Nanotechnology may be used to achieve therapeutic dosing, establish sustained-release drug profiles, and increase the half-life of drugs. In this context, magnetic nanowires (NWs) have shown a good biocompatibility and cellular internalization with a low cytotoxic effect. In this thesis, I induced cancer cell death by combining the chemotherapeutic effect of iron NWs functionalized with Doxorubicin (DOX) with mechanical disturbance under a low frequency alternating magnetic field. Two different agents, APTES and BSA, were separately used for coating NWs permitting further functionalization with DOX. Internalization was qualitatively and quantitatively assessed for both formulations by confocal reflection microscopy and inductively coupled plasma-mass spectrometry. From confocal reflection analysis, BSA formulations demonstrate to have a higher internalization degree and a broader distribution within the cells in comparison to APTES formulations. Both groups of functionalized NWs generated a comparable cytotoxic effect in MDA-MB-231 breast cancer cells in a DOX concentration-dependent manner, (~60% at the highest concentration tested) that was significantly different from the effect produced by the free DOX (~95% at the same concentration) and non-functionalized NWs formulations (~10% at the same NWs concentration). A synergistic cytotoxic effect is obtained when a low frequency magnetic field (1 mT, 10 Hz) is applied to cells treated with the two formulations that is again comparable (~70% at the highest concentration). Furthermore, the cytotoxic effect of both groups of coated NWs without the drug increased notoriously when the field is applied (~25% at the highest concentration tested). Here, a novel bimodal method for cancer cell destruction was developed by the conjugation of the magneto

  6. Fractionated radiotherapy is the main stimulus for the induction of cell death and of Hsp70 release of p53 mutated glioblastoma cell lines

    International Nuclear Information System (INIS)

    Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults. Despite a multimodal therapy consisting of resection followed by fractionated radiotherapy (RT) combined with the chemotherapeutic agent (CT) temozolomide (TMZ), its recurrence is almost inevitable. Since the immune system is capable of eliminating small tumor masses, a therapy should also aim to stimulate anti-tumor immune responses by induction of immunogenic cell death forms. The histone deacetylase inhibitor valproic acid (VPA) might foster this. Reflecting therapy standards, we applied in our in vitro model fractionated RT with a single dose of 2Gy and clinically relevant concentrations of CT. Not only the impact of RT and/or CT with TMZ and/or VPA on the clonogenic potential and cell cycle of the glioblastoma cell lines T98G, U251MG, and U87MG was analyzed, but also the resulting cell death forms and release of danger signals such as heat-shock protein70 (Hsp70) and high-mobility group protein B1 (HMGB1). The clonogenic assays revealed that T98G and U251MG, having mutated tumor suppressor protein p53, are more resistant to RT and CT than U87MG with wild type (WT) p53. In all glioblastoma cells lines, fractionated RT induced a G2 cell cycle arrest, but only in the case of U87MG, TMZ and/or VPA alone resulted in this cell cycle block. Further, fractionated RT significantly increased the number of apoptotic and necrotic tumor cells in all three cell lines. However, only in U87MG, the treatment with TMZ and/or VPA alone, or in combination with fractionated RT, induced significantly more cell death compared to untreated or irradiated controls. While necrotic glioblastoma cells were present after VPA, TMZ especially led to significantly increased amounts of U87MG cells in the radiosensitive G2 cell cycle phase. While CT did not impact on the release of Hsp70, fractionated RT resulted in significantly increased extracellular concentrations of Hsp70 in p53 mutated and WT glioblastoma

  7. Lanthanum Prevents Salt Stress-induced Programmed Cell Death in Rice Root Tip Cells by Controlling Early Induction Events

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In a previous study, a salt stress-induced programmed cell death (PCD) model was established in rice root tip cells. Here,by using Wuyunjing 8th rice seedlings, the effects of lanthanum on salt stress-induced PCD early events were studied. The peroxidase (APX). Imidazole (20 mmol/L), the inhibitor of nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase), could alleviate the occurrence of PCD obviously, and such alleviation could be enhanced by the addition of La3+,indicating the involvement of NADPH oxidase in the salt stress-induced PCD process. Taken together, lanthanum could prevent salt stress-induced PCD occurrence in the rice root tip cells by blocking the calcium influx under stress, which was followed by inhibiting calcium-dependent NADPH oxidase activity to prevent O2·-production and, enhancing the cytosolic antioxidative enzyme activities to scavenge the reactive oxygen species.

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

    OpenAIRE

    Diaz, Ramon; Quiles Pérez, María Teresa; Guillem Martí, Jordi; López-Cano, Manuel; Huguet, Pere; Ramon-y-Cajal, Santiago; Reventós, Jaume; Armengol Carrasco, Manuel; Arbós Vilà, Maria Antonia

    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 inc...

  9. Selenium Inhibits Metastasis of Murine Melanoma Cells through the Induction of Cell Cycle Arrest and Cell Death

    OpenAIRE

    SONG, HYUNKEUN; Hur, Indo; Park, Hyun-jin; Nam, Joohyung; PARK, GA BIN; Kong, Kyoung Hye; Hwang, Young Mi; KIM, YEONG SEOK; Cho, Dae Ho; Lee, Wang Jae; Hur, Dae Young

    2009-01-01

    Background Melanoma is the most fatal form of skin cancer due to its rapid metastasis. Recently, several studies reported that selenium can induce apoptosis in melanoma cells. However, the precise mechanism remains to be elucidated. In this study, we investigated the effect of selenium on cell proliferation in murine melanoma and on tumor growth and metastasis in C57BL/6 mice. Methods Cell proliferation was measured by MTT assay in selenium-treated melanoma cells. Cell cycle distribution was ...

  10. CERT depletion predicts chemotherapy benefit and mediates cytotoxic and polyploid‐specific cancer cell death through autophagy induction

    DEFF Research Database (Denmark)

    Lee, Alvin J. X.; Roylance, Rebecca; Sander, Jil;

    2012-01-01

    . Live cell microscopy analysis revealed that CERT depletion induces LAMP2‐dependent death of polyploid cells following exit from mitosis in the presence of paclitaxel. We find that CERT is relatively over‐expressed in HER2+ breast cancer and CERT protein expression acts as an independent prognostic...

  11. Anti-cancer effect of bee venom toxin and melittin in ovarian cancer cells through induction of death receptors and inhibition of JAK2/STAT3 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Miran; Park, Mi Hee; Kollipara, Pushpa Saranya [College of Pharmacy and Medical Research Center, Chungbuk National University, 48, Gaeshin-dong, Heungduk-gu, Cheongju, Chungbuk, 361-763 (Korea, Republic of); An, Byeong Jun; Song, Ho Sueb [College of Oriental Medicine, Kyungwon University, San 65, Bokjeong-dong, Sujeong-gu, Seongnam, Gyeonggii 461-701 (Korea, Republic of); Han, Sang Bae [College of Pharmacy and Medical Research Center, Chungbuk National University, 48, Gaeshin-dong, Heungduk-gu, Cheongju, Chungbuk, 361-763 (Korea, Republic of); Kim, Jang Heub [Department of Obstetrics and Gynecology, College of Medicine, The Catholic University of Korea, 505, Banpo-dong, Seocho-gu, Seoul 137-040 (Korea, Republic of); Song, Min Jong, E-mail: bitsugar@catholic.ac.kr [Department of Obstetrics and Gynecology, College of Medicine, The Catholic University of Korea, 505, Banpo-dong, Seocho-gu, Seoul 137-040 (Korea, Republic of); Hong, Jin Tae, E-mail: jinthong@chungbuk.ac.kr [College of Pharmacy and Medical Research Center, Chungbuk National University, 48, Gaeshin-dong, Heungduk-gu, Cheongju, Chungbuk, 361-763 (Korea, Republic of)

    2012-01-01

    We investigated whether bee venom and melittin, a major component of bee venom, inhibit cell growth through enhancement of death receptor expressions in the human ovarian cancer cells, SKOV3 and PA-1. Bee venom (1–5 μg/ml) and melittin (0.5–2 μg/ml) inhibited the growth of SKOV3 and PA-1 ovarian cancer cells by the induction of apoptotic cell death in a dose dependent manner. Consistent with apoptotic cell death, expression of death receptor (DR) 3 and DR6 was increased in both cancer cells, but expression of DR4 was increased only in PA-1 cells. Expression of DR downstream pro-apoptotic proteins including caspase-3, 8, and Bax was concomitantly increased, but the phosphorylation of JAK2 and STAT3 and the expression of Bcl-2 were inhibited by treatment with bee venom and melittin in SKOV3 and PA-1 cells. Expression of cleaved caspase-3 was increased in SKOV3, but cleaved caspase-8 was increased in PA-1 cells. Moreover, deletion of DR3, DR4, and DR6 by small interfering RNA significantly reversed bee venom and melittin-induced cell growth inhibitory effect as well as down regulation of STAT3 by bee venom and melittin in SKOV3 and PA-1 ovarian cancer cell. These results suggest that bee venom and melittin induce apoptotic cell death in ovarian cancer cells through enhancement of DR3, DR4, and DR6 expression and inhibition of STAT3 pathway. -- Highlights: ► Some studies have showed that bee venom and/or melittin have anti-cancer effects. ► We found that bee venom and melittin inhibited cell growth in ovarian cancer cells. ► Bee venom and melittin induce apoptosis in SKOV3 and PA-1.

  12. Anti-cancer effect of bee venom toxin and melittin in ovarian cancer cells through induction of death receptors and inhibition of JAK2/STAT3 pathway

    International Nuclear Information System (INIS)

    We investigated whether bee venom and melittin, a major component of bee venom, inhibit cell growth through enhancement of death receptor expressions in the human ovarian cancer cells, SKOV3 and PA-1. Bee venom (1–5 μg/ml) and melittin (0.5–2 μg/ml) inhibited the growth of SKOV3 and PA-1 ovarian cancer cells by the induction of apoptotic cell death in a dose dependent manner. Consistent with apoptotic cell death, expression of death receptor (DR) 3 and DR6 was increased in both cancer cells, but expression of DR4 was increased only in PA-1 cells. Expression of DR downstream pro-apoptotic proteins including caspase-3, 8, and Bax was concomitantly increased, but the phosphorylation of JAK2 and STAT3 and the expression of Bcl-2 were inhibited by treatment with bee venom and melittin in SKOV3 and PA-1 cells. Expression of cleaved caspase-3 was increased in SKOV3, but cleaved caspase-8 was increased in PA-1 cells. Moreover, deletion of DR3, DR4, and DR6 by small interfering RNA significantly reversed bee venom and melittin-induced cell growth inhibitory effect as well as down regulation of STAT3 by bee venom and melittin in SKOV3 and PA-1 ovarian cancer cell. These results suggest that bee venom and melittin induce apoptotic cell death in ovarian cancer cells through enhancement of DR3, DR4, and DR6 expression and inhibition of STAT3 pathway. -- Highlights: ► Some studies have showed that bee venom and/or melittin have anti-cancer effects. ► We found that bee venom and melittin inhibited cell growth in ovarian cancer cells. ► Bee venom and melittin induce apoptosis in SKOV3 and PA-1.

  13. The heat shock protein 90 inhibitor SNX5422 has a synergistic activity with histone deacetylase inhibitors in induction of death of anaplastic thyroid carcinoma cells.

    Science.gov (United States)

    Kim, Si Hyoung; Kang, Jun Goo; Kim, Chul Sik; Ihm, Sung-Hee; Choi, Moon Gi; Yoo, Hyung Joon; Lee, Seong Jin

    2016-02-01

    The influence of the heat shock protein 90 (hsp90) inhibitor SNX5422 alone or in combination with the histone deacetylase (HDAC) inhibitors PXD101, suberoylanilide hydroxamic acid (SAHA), and trichostatin A (TSA) on survival of anaplastic thyroid carcinoma (ATC) cells was investigated. In 8505C and CAL62 cells, SNX5422 caused cell death with concomitant changes in the expression of hsp90 client proteins. After treatment of both SNX5422 and PXD101, SAHA and TSA, compared with treatment of SNX5422 alone, cell viability was diminished, whereas inhibition rate and cytotoxic activity were enhanced. All of the combination index values were lower than 1.0, suggesting the synergism between SNX5422 and PXD101, SAHA and TSA in induction of cell death. In cells treated with both SNX5422 and PXD101, SAHA and TSA, compared with cells treated with SNX5422 alone, the protein levels of Akt, phospho-4EBP1, phospho-S6 K, and survivin were diminished, while those of γH2AX, acetyl. histone H3, acetyl. histone H4, cleaved PARP, and cleaved caspase-3 were enhanced. In conclusion, these results demonstrate that SNX5422 has a cytotoxic activity in conjunction with alterations in the expression of hsp90 client proteins in ATC cells. Moreover, SNX5422 synergizes with HDAC inhibitors in induction of cytotoxicity accompanied by the suppression of PI3K/Akt/mTOR signaling and survivin, and the overexpression of DNA damage-related proteins in ATC cells. PMID:26219406

  14. Induction of multiple programmed cell death pathways by IFN-beta in human non-small-cell lung cancer cell lines.

    Science.gov (United States)

    Zhang, H; Koty, P P; Mayotte, J; Levitt, M L

    1999-02-25

    Tissue transglutaminase (tTG) and keratinocyte transglutaminase (kTG), as well as the cross-linked envelopes (CLE) that they form, have been associated with squamous differentiation and programmed cell death in epithelial cells. When interferon-beta (IFN-beta) was used to stimulate differentiation and programmed cell death in the human lung cancer cell lines NCI-H596 and NCI-H226, the cells underwent a decrease in cellular density. In NCI-H596 IFN-beta caused an increase in kTG activity and DNA fragmentation in the lower density cells, which were significantly slower growing than control cells. However, in the higher density cells, which were only slightly slower growing than control cells, IFN-beta caused an increase in tTG activity and CLE competence. Dual-parameter flow cytometry demonstrated that IFN-beta-induced squamous differentiation preceded programmed cell death. Treatment of NCI-H596 cells with monodansylcadaverine, a transglutaminase inhibitor, prevented the increase in CLE competence, but did not inhibit DNA fragmentation. These results suggest that IFN-beta can induce NCI-H596 cells to enter multiple cell death pathways and that these pathways are not only differentiation related, but may also be growth driven. PMID:10047455

  15. Investigation of selective induction of breast cancer cells to death with treatment of plasma-activated medium

    Science.gov (United States)

    Hashizume, Hiroshi; Tanaka, Hiromasa; Nakamura, Kae; Kano, Hiroyuki; Ishikawa, Kenji; Kikkawa, Fumitaka; Mizuno, Masaaki; Hori, Masaru

    2015-09-01

    The applications of plasma in medicine have much attention. We previously showed that plasma-activated medium (PAM) induced glioblastoma cells to apoptosis. However, it has not been elucidated the selectivity of PAM in detail. In this study, we investigated the selective effect of PAM on the death of human breast normal and cancer cells, MCF10A and MCF7, respectively, and observed the selective death with fluorescent microscopy. For the investigation of cell viability with PAM treatment, we prepared various PAMs according to the strengths, and treated each of cells with PAMs. Week PAM treatment only decreased the viability of MCF7 cells, while strong PAM treatment significantly affected both viabilities of MCF7 and MCF10A cells. For the fluorescent observation, we prepared the mixture of MCF7 and fluorescent-probed MCF10A cells, and seeded them. After the treatment of PAMs, the images showed that only MCF7 cells damaged in the mixture with week PAM treatment. These results suggested that a specific range existed with the selective effect in the strength of PAM. This work was partly supported by a Grant-in-Aid for Scientific Research on Innovative Areas ``Plasma Medical Innovation'' Grant No. 24108002 and 24108008 from the Ministry of Education, Culture, Sports, Science and Technology of Japan.

  16. Comparison of RBE values of high- LET α-particles for the induction of DNA-DSBs, chromosome aberrations and cell reproductive death

    International Nuclear Information System (INIS)

    Various types of radiation effects in mammalian cells have been studied with the aim to predict the radiosensitivity of tumours and normal tissues, e.g. DNA double strand breaks (DSB), chromosome aberrations and cell reproductive inactivation. However, variation in correlations with clinical results has reduced general application. An additional type of information is required for the increasing application of high-LET radiation in cancer therapy: the Relative Biological Effectiveness (RBE) for effects in tumours and normal tissues. Relevant information on RBE values might be derived from studies on cells in culture. To evaluate relationships between DNA-DSB, chromosome aberrations and the clinically most relevant effect of cell reproductive death, for ionizing radiations of different LET, dose-effect relationships were determined for the induction of these effects in cultured SW-1573 cells irradiated with gamma-rays from a Cs-137 source or with α-particles from an Am-241 source. RBE values were derived for these effects. Ionizing radiation induced foci (IRIF) of DNA repair related proteins, indicative of DSB, were assessed by counting gamma-H2AX foci. Chromosome aberration frequencies were determined by scoring fragments and translocations using premature chromosome condensation. Cell survival was measured by colony formation assay. Analysis of dose-effect relations was based on the linear-quadratic model. Our results show that, although both investigated radiation types induce similar numbers of IRIF per absorbed dose, only a small fraction of the DSB induced by the low-LET gamma-rays result in chromosome rearrangements and cell reproductive death, while this fraction is considerably enhanced for the high-LET alpha-radiation. Calculated RBE values derived for the linear components of dose-effect relations for gamma-H2AX foci, cell reproductive death, chromosome fragments and colour junctions are 1.0 ± 0.3, 14.7 ± 5.1, 15.3 ± 5.9 and 13.3 ± 6.0 respectively

  17. Comparison of RBE values of high- LET α-particles for the induction of DNA-DSBs, chromosome aberrations and cell reproductive death

    Directory of Open Access Journals (Sweden)

    Aten Jacob

    2011-06-01

    Full Text Available Abstract Background Various types of radiation effects in mammalian cells have been studied with the aim to predict the radiosensitivity of tumours and normal tissues, e.g. DNA double strand breaks (DSB, chromosome aberrations and cell reproductive inactivation. However, variation in correlations with clinical results has reduced general application. An additional type of information is required for the increasing application of high-LET radiation in cancer therapy: the Relative Biological Effectiveness (RBE for effects in tumours and normal tissues. Relevant information on RBE values might be derived from studies on cells in culture. Methods To evaluate relationships between DNA-DSB, chromosome aberrations and the clinically most relevant effect of cell reproductive death, for ionizing radiations of different LET, dose-effect relationships were determined for the induction of these effects in cultured SW-1573 cells irradiated with gamma-rays from a Cs-137 source or with α-particles from an Am-241 source. RBE values were derived for these effects. Ionizing radiation induced foci (IRIF of DNA repair related proteins, indicative of DSB, were assessed by counting gamma-H2AX foci. Chromosome aberration frequencies were determined by scoring fragments and translocations using premature chromosome condensation. Cell survival was measured by colony formation assay. Analysis of dose-effect relations was based on the linear-quadratic model. Results Our results show that, although both investigated radiation types induce similar numbers of IRIF per absorbed dose, only a small fraction of the DSB induced by the low-LET gamma-rays result in chromosome rearrangements and cell reproductive death, while this fraction is considerably enhanced for the high-LET alpha-radiation. Calculated RBE values derived for the linear components of dose-effect relations for gamma-H2AX foci, cell reproductive death, chromosome fragments and colour junctions are 1.0 ± 0.3, 14

  18. 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.

  19. Studying p53 family proteins in yeast: Induction of autophagic cell death and modulation by interactors and small molecules

    International Nuclear Information System (INIS)

    In this work, the yeast Saccharomyces cerevisiae was used to individually study human p53, p63 (full length and truncated forms) and p73. Using this cell system, the effect of these proteins on cell proliferation and death, and the influence of MDM2 and MDMX on their activities were analyzed. When expressed in yeast, wild-type p53, TAp63, ΔNp63 and TAp73 induced growth inhibition associated with S-phase cell cycle arrest. This growth inhibition was accompanied by reactive oxygen species production and autophagic cell death. Furthermore, they stimulated rapamycin-induced autophagy. On the contrary, none of the tested p53 family members induced apoptosis either per se or after apoptotic stimuli. As previously reported for p53, also TAp63, ΔNp63 and TAp73 increased actin expression levels and its depolarization, suggesting that ACT1 is also a p63 and p73 putative yeast target gene. Additionally, MDM2 and MDMX inhibited the activity of all tested p53 family members in yeast, although the effect was weaker on TAp63. Moreover, Nutlin-3a and SJ-172550 were identified as potential inhibitors of the p73 interaction with MDM2 and MDMX, respectively. Altogether, the yeast-based assays herein developed can be envisaged as a simplified cell system to study the involvement of p53 family members in autophagy, the modulation of their activities by specific interactors (MDM2 and MDMX), and the potential of new small molecules to modulate these interactions. - Highlights: • p53, p63 and p73 are individually studied in the yeast S. cerevisiae. • p53 family members induce ROS production, cell cycle arrest and autophagy in yeast. • p53 family members increase actin depolarization and expression levels in yeast. • MDM2 and MDMX inhibit the activity of p53 family members in yeast. • Yeast can be a useful tool to study the biology and drugability of p53, p63 and p73

  20. Studying p53 family proteins in yeast: Induction of autophagic cell death and modulation by interactors and small molecules

    Energy Technology Data Exchange (ETDEWEB)

    Leão, Mariana; Gomes, Sara; Bessa, Cláudia; Soares, Joana; Raimundo, Liliana [REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n. 164, 4050-313 Porto (Portugal); Monti, Paola; Fronza, Gilberto [Mutagenesis Unit, Istituto di Ricerca e Cura a Carattere Scientifico Azienda Ospedaliera Universitaria San Martino-IST-Istituto Nazionale per la Ricerca sul Cancro, 16132 Genoa (Italy); Pereira, Clara [REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n. 164, 4050-313 Porto (Portugal); Saraiva, Lucília, E-mail: lucilia.saraiva@ff.up.pt [REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n. 164, 4050-313 Porto (Portugal)

    2015-01-01

    In this work, the yeast Saccharomyces cerevisiae was used to individually study human p53, p63 (full length and truncated forms) and p73. Using this cell system, the effect of these proteins on cell proliferation and death, and the influence of MDM2 and MDMX on their activities were analyzed. When expressed in yeast, wild-type p53, TAp63, ΔNp63 and TAp73 induced growth inhibition associated with S-phase cell cycle arrest. This growth inhibition was accompanied by reactive oxygen species production and autophagic cell death. Furthermore, they stimulated rapamycin-induced autophagy. On the contrary, none of the tested p53 family members induced apoptosis either per se or after apoptotic stimuli. As previously reported for p53, also TAp63, ΔNp63 and TAp73 increased actin expression levels and its depolarization, suggesting that ACT1 is also a p63 and p73 putative yeast target gene. Additionally, MDM2 and MDMX inhibited the activity of all tested p53 family members in yeast, although the effect was weaker on TAp63. Moreover, Nutlin-3a and SJ-172550 were identified as potential inhibitors of the p73 interaction with MDM2 and MDMX, respectively. Altogether, the yeast-based assays herein developed can be envisaged as a simplified cell system to study the involvement of p53 family members in autophagy, the modulation of their activities by specific interactors (MDM2 and MDMX), and the potential of new small molecules to modulate these interactions. - Highlights: • p53, p63 and p73 are individually studied in the yeast S. cerevisiae. • p53 family members induce ROS production, cell cycle arrest and autophagy in yeast. • p53 family members increase actin depolarization and expression levels in yeast. • MDM2 and MDMX inhibit the activity of p53 family members in yeast. • Yeast can be a useful tool to study the biology and drugability of p53, p63 and p73.

  1. Differentiation inducing factor 3 mediates its anti-leukemic effect through ROS-dependent DRP1-mediated mitochondrial fission and induction of caspase-independent cell death.

    Science.gov (United States)

    Dubois, Alix; Ginet, Clemence; Furstoss, Nathan; Belaid, Amine; Hamouda, Mohamed Amine; El Manaa, Wedjene; Cluzeau, Thomas; Marchetti, Sandrine; Ricci, Jean Ehrland; Jacquel, Arnaud; Luciano, Frederic; Driowya, Mohsine; Benhida, Rachid; Auberger, Patrick; Robert, Guillaume

    2016-05-01

    Differentiation-inducing factor (DIF) defines a group of chlorinated hexaphenones that orchestrate stalk-cell differentiation in the slime mold Dictyostelium discoideum (DD). DIF-1 and 3 have also been reported to have tumor inhibiting properties; however, the mechanisms that underlie the effects of these compounds remain poorly defined. Herein, we show that DIF-3 rapidly triggers Ca2+ release and a loss of mitochondrial membrane potential (MMP) in the absence of cytochrome c and Smac release and without caspase activation. Consistently with these findings, we also detected no evidence of apoptosis in cells treated with DIF-3 but instead found that this compound induced autophagy. In addition, DIF-3 promoted mitochondrial fission in K562 and HeLa cells, as assessed by electron and confocal microscopy analysis. Importantly, DIF-3 mediated the phosphorylation and redistribution of dynamin-related protein 1 (DRP1) from the cytoplasmic to the microsomal fraction of K562 cells. Pharmacological inhibition or siRNA silencing of DRP1 not only inhibited mitochondrial fission but also protected K562 cells from DIF-3-mediated cell death. Furthermore, DIF-3 potently inhibited the growth of imatinib-sensitive and imatinib-resistant K562 cells. It also inhibited tumor formation in athymic mice engrafted with an imatinib-resistant CML cell line. Finally, DIF-3 exhibited a clear selectivity toward CD34+ leukemic cells from CML patients, compared with CD34- cells. In conclusion, we show that the potent anti-leukemic effect of DIF-3 is mediated through the induction of mitochondrial fission and caspase-independent cell death. Our findings may have important therapeutic implications, especially in the treatment of tumors that exhibit defects in apoptosis regulation. PMID:27027430

  2. Tryptophan protects hepatocytes against reactive oxygen species-dependent cell death via multiple pathways including Nrf2-dependent gene induction.

    Science.gov (United States)

    Kimura, Takuya; Watanabe, Yoshifumi

    2016-05-01

    Hepatocyte apoptosis plays a key role in the pathogenesis of immune-mediated hepatitis. However, the detailed mechanisms of apoptosis signaling are still unclear and effective therapeutic drugs for hepatitis have been explored. Here, we show that tryptophan (Trp) suppressed IFN-γ-mediated hepatic apoptosis in vitro. Trp inhibited the downstream apoptotic events of mitochondria disruption, such as cell death and caspase-3 activation, while it did not influence upstream signaling including STAT1 activation and IRF1 expression. Trp suppressed reactive oxygen species (ROS) generation at the mitochondria. IFN-γ induced ROS in mitochondria by inhibiting complex I and III, but not II. This ROS generation by IFN-γ required de novo protein synthesis. Trp showed relatively weak direct scavenging activity but antagonized IFN-γ against the suppression of complex I. In addition, Trp increased the expression of the Nrf2-dependent antioxidant genes NQO1, HO-1 and GCS in hepatocytes both in vitro and in vivo. Finally, the administration of Trp in an acetaminophen-induced ROS-dependent hepatitis model suppressed the liver injury in vivo. Thus, Trp protects hepatocytes from ROS-dependent cell injury via multiple pathways. This study suggests Trp as a therapeutic antioxidant drug for hepatitis and a regulator for Nrf2-dependent genes. PMID:26795536

  3. Induction of oxygen-dependent lethal damage by monochromatic UVB (313 nm) radiation: strand breakage, repair and cell death

    International Nuclear Information System (INIS)

    The action of UV-B (313 nm) radiation in cellular inactivation and induction and repair of DNA strand breaks were studied in a repair proficient strain and three repair deficient strains (polA, recA, uvrA) of Escherichia coli K-12. Although the induction of breaks was linear in purified T4 DNA and the polA strain, simultaneous induction and repair of breaks were observed in the uvrA, recA and repair proficient strains at doses 4 Jm-2. The final rates of induction in these strains were 1 x 10-4, 7.5 x 10-5 and 7.5 x 10-5 breaks/2.5 x 109 daltons/Jm-2, respectively. A highly efficient polA-dependent repair occurring at 00C in minimal buffer and a second slower type of repair occurring at 310C in the polA strain were detected. Oxygen dependence of cellular inactivation was observed for the polA and repair proficient strains irradiated at 313 nm thus providing biological evidence for an oxygen-dependent lesion involved in lethality in the short wavelength range of the solar u.v. The lower hypoxic break induction rates of the polA and the repair proficient strains, indicate oxygen-enhanced DNA breakage by 313 nm radiation. (author)

  4. Inhibition of class I histone deacetylases in non-small cell lung cancer by honokiol leads to suppression of cancer cell growth and induction of cell death in vitro and in vivo.

    Science.gov (United States)

    Singh, Tripti; Prasad, Ram; Katiyar, Santosh K

    2013-01-01

    Non-small-cell lung cancer (NSCLC) represents approximately 80% of all types of lung cancer. Here, we report the chemotherapeutic effect of honokiol, a phytochemical from Magnolia grandiflora, on NSCLC cells and the molecular mechanisms underlying these effects using in vitro and in vivo models. Treatment of NSCLC cells (A549, H1299, H460 and H226) with honokiol (20, 40 and 60 µM) inhibited histone deacetylase (HDAC) activity, reduced the levels of class I HDAC proteins and enhanced histone acetyltransferase activity in a dose-dependent manner. These effects of honokiol were associated with a significant reduction in the viability of NSCLC cells. Concomitant treatment of cells with a proteasome inhibitor, MG132, prevented honokiol-induced degradation of class I HDACs, suggesting that honokiol reduced the levels of HDACs in NSCLC cells through proteasomal degradation. Valproic acid, an inhibitor of HDACs, exhibited a similar pattern of reduced viability and induction of death of NSCLC cells. Treatment of A549 and H1299 cells with honokiol resulted in an increase in G 1 phase arrest, and a decrease in the levels of cyclin D1, D2 and cyclin dependent kinases. Further, administration of honokiol by oral gavage significantly inhibited the growth of subcutaneous A549 and H1299 tumor xenografts in athymic nude mice, which was associated with the induction of apoptotic cell death and marked inhibition of class I HDACs proteins and HDAC activity in the tumor xenograft tissues. Together, our study provides new insights into the role of class I HDACs in the chemotherapeutic effects of honokiol on lung cancer cells. PMID:23221619

  5. Induction of Suicidal Erythrocyte Death by Novobiocin

    Directory of Open Access Journals (Sweden)

    Adrian Lupescu

    2014-03-01

    Full Text Available Background: Novobiocin, an aminocoumarin antibiotic, interferes with heat shock protein 90 and hypoxia inducible factor dependent gene expression and thus compromises cell survival. Similar to survival of nucleated cells, erythrocyte survival could be disrupted by eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and by phospholipd scrambling of the cell membrane with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include increase of cytosolic Ca2+-activity ([Ca2+]i. The Ca2+ sensitivity of phospholipid scrambling is enhanced by ceramide. The present study explored, whether novobiocin elicits eryptosis. Methods: [Ca2+]i was estimated from Fluo3-fluorescence, ceramide abundance utilizing fluorescent antibodies, cell volume from forward scatter, phosphatidylserine-exposure from annexin V binding. Results: A 48 hours exposure to novobiocin (500 µM was followed by a significant increase of [Ca2+]i, decrease of forward scatter, increase of annexin-V-binding and enhanced ceramide formation. Removal of extracellular Ca2+ virtually abrogated the increase of annexin-V-binding following novobiocin exposure. Conclusions: Novobiocin stimulates eryptosis, an effect at least in part due to entry of extracellular Ca2+ and formation of ceramide.

  6. The Kinase Inhibitor Sorafenib Induces Cell Death through a Process Involving Induction of Endoplasmic Reticulum Stress▿ †

    OpenAIRE

    Rahmani, Mohamed; Davis, Eric Maynard; Crabtree, Timothy Ryan; Habibi, Joseph Reza; Nguyen, Tri K.; Dent, Paul; Grant, Steven

    2007-01-01

    Sorafenib is a multikinase inhibitor that induces apoptosis in human leukemia and other malignant cells. Recently, we demonstrated that sorafenib diminishes Mcl-1 protein expression by inhibiting translation through a MEK1/2-ERK1/2 signaling-independent mechanism and that this phenomenon plays a key functional role in sorafenib-mediated lethality. Here, we report that inducible expression of constitutively active MEK1 fails to protect cells from sorafenib-mediated lethality, indicating that s...

  7. Induction of apoptotic death and retardation of neuronal differentiation of human neural stem cells by sodium arsenite treatment

    OpenAIRE

    Ivanov, Vladimir N.; Hei, Tom K.

    2012-01-01

    Chronic arsenic toxicity is a global health problem that affects more than 100 million people worldwide. Long-term health effects of inorganic sodium arsenite in drinking water may result in skin, lung and liver cancer and severe neurological abnormalities. We investigated in the present study whether sodium arsenite affects signaling pathways that control cell survival, proliferation and neuronal differentiation of human neural stem cells (NSC). We demonstrated that the critical signaling pa...

  8. Induction of apoptotic death and retardation of neuronal differentiation of human neural stem cells by sodium arsenite treatment

    International Nuclear Information System (INIS)

    Chronic arsenic toxicity is a global health problem that affects more than 100 million people worldwide. Long-term health effects of inorganic sodium arsenite in drinking water may result in skin, lung and liver cancers and in severe neurological abnormalities. We investigated in the present study whether sodium arsenite affects signaling pathways that control cell survival, proliferation and neuronal differentiation of human neural stem cells (NSC). We demonstrated that the critical signaling pathway, which was suppressed by sodium arsenite in NSC, was the protective PI3K–AKT pathway. Sodium arsenite (2–4 μM) also caused down-regulation of Nanog, one of the key transcription factors that control pluripotency and self-renewal of stem cells. Mitochondrial damage and cytochrome-c release induced by sodium arsenite exposure was followed by initiation of the mitochondrial apoptotic pathway in NSC. Beside caspase-9 and caspase-3 inhibitors, suppression of JNK activity decreased levels of arsenite-induced apoptosis in NSC. Neuronal differentiation of NSC was substantially inhibited by sodium arsenite exposure. Overactivation of JNK1 and ERK1/2 and down-regulation of PI3K–AKT activity induced by sodium arsenite were critical factors that strongly affected neuronal differentiation. In conclusion, sodium arsenite exposure of human NSC induces the mitochondrial apoptotic pathway, which is substantially accelerated due to the simultaneous suppression of PI3K–AKT. Sodium arsenite also negatively affects neuronal differentiation of NSC through overactivation of MEK–ERK and suppression of PI3K–AKT. - Highlights: ► Arsenite induces the mitochondrial apoptotic pathway in human neural stem cells. ► Arsenite-induced apoptosis is strongly upregulated by suppression of PI3K–AKT. ► Arsenite-induced apoptosis is strongly down-regulated by inhibition of JNK–cJun. ► Arsenite negatively affects neuronal differentiation by inhibition of PI3K–AKT

  9. Induction of apoptotic death and retardation of neuronal differentiation of human neural stem cells by sodium arsenite treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Vladimir N., E-mail: vni3@columbia.edu [Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, NY 10032 (United States); Hei, Tom K. [Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, NY 10032 (United States)

    2013-04-01

    Chronic arsenic toxicity is a global health problem that affects more than 100 million people worldwide. Long-term health effects of inorganic sodium arsenite in drinking water may result in skin, lung and liver cancers and in severe neurological abnormalities. We investigated in the present study whether sodium arsenite affects signaling pathways that control cell survival, proliferation and neuronal differentiation of human neural stem cells (NSC). We demonstrated that the critical signaling pathway, which was suppressed by sodium arsenite in NSC, was the protective PI3K–AKT pathway. Sodium arsenite (2–4 μM) also caused down-regulation of Nanog, one of the key transcription factors that control pluripotency and self-renewal of stem cells. Mitochondrial damage and cytochrome-c release induced by sodium arsenite exposure was followed by initiation of the mitochondrial apoptotic pathway in NSC. Beside caspase-9 and caspase-3 inhibitors, suppression of JNK activity decreased levels of arsenite-induced apoptosis in NSC. Neuronal differentiation of NSC was substantially inhibited by sodium arsenite exposure. Overactivation of JNK1 and ERK1/2 and down-regulation of PI3K–AKT activity induced by sodium arsenite were critical factors that strongly affected neuronal differentiation. In conclusion, sodium arsenite exposure of human NSC induces the mitochondrial apoptotic pathway, which is substantially accelerated due to the simultaneous suppression of PI3K–AKT. Sodium arsenite also negatively affects neuronal differentiation of NSC through overactivation of MEK–ERK and suppression of PI3K–AKT. - Highlights: ► Arsenite induces the mitochondrial apoptotic pathway in human neural stem cells. ► Arsenite-induced apoptosis is strongly upregulated by suppression of PI3K–AKT. ► Arsenite-induced apoptosis is strongly down-regulated by inhibition of JNK–cJun. ► Arsenite negatively affects neuronal differentiation by inhibition of PI3K–AKT.

  10. NORE1A induction by membrane-bound CD40L (mCD40L) contributes to CD40L-induced cell death and G1 growth arrest in p21-mediated mechanism.

    Science.gov (United States)

    Elmetwali, T; Salman, A; Palmer, D H

    2016-01-01

    Membrane-bound CD40L (mCD40L) but not soluble CD40L (sCD40L) has been implicated in direct cell death induction and apoptosis in CD40-expressing carcinomas. In this study, we show that mCD40L but not sCD40L induces NORE1A/Rassf5 expression in an NFκB-dependant mechanism. NORE1A expression appeared to contribute to mCD40L-induced cell death and enhance cell transition from G1 to S phase of the cell cycle in a p21-dependent mechanism. The upregulation of p21 protein was attributed to NORE1A expression, since NORE1A inhibition resulted in p21 downregulation. p21 upregulation was concomitant with lower p53 expression in the cytoplasmic fraction with no detectable increase at the nuclear p53 level. Moreover, mCD40L-induced cell death mediated by NORE1A expression appeared to be independent of mCD40L-induced cell death mediated by sustained JNK activation since NORE1A inhibition did not affect JNK phosphorylation and vice versa. The presented data allow better understanding of the mechanism by which mCD40L induces cell death which could be exploited in the clinical development of CD40-targeted anti-cancer therapies. PMID:26986513

  11. Caspase dependence of the death of neonatal retinal ganglion cells induced by axon damage and induction of autophagy as a survival mechanism

    Directory of Open Access Journals (Sweden)

    C. Sternberg

    2010-10-01

    Full Text Available We examined the degeneration of post-mitotic ganglion cells in ex-vivo neonatal retinal explants following axon damage. Ultrastructural features of both apoptosis and autophagy were detected. Degenerating cells reacted with antibodies specific for activated caspase-3 or -9, consistent with the presence of caspase activity. Furthermore, peptidic inhibitors of caspase-9, -6 or -3 prevented cell death (100 µM Ac-LEDH-CHO, 50 µM Ac-VEID-CHO and 10 µM Z-DEVD-fmk, respectively. Interestingly, inhibition of autophagy by 7-10 mM 3-methyl-adenine increased the rate of cell death. Immunohistochemistry data, caspase activation and caspase inhibition data suggest that axotomy of neonatal retinal ganglion cells triggers the intrinsic apoptotic pathway, which, in turn, is counteracted by a pro-survival autophagic response, demonstrated by electron microscopy profiles and pharmacological autophagy inhibitor.

  12. Evaluation of the efficacy & biochemical mechanism of cell death induction by Piper longum extract selectively in in-vitro and in-vivo models of human cancer cells.

    Directory of Open Access Journals (Sweden)

    Pamela Ovadje

    Full Text Available Currently chemotherapy is limited mostly to genotoxic drugs that are associated with severe side effects due to non-selective targeting of normal tissue. Natural products play a significant role in the development of most chemotherapeutic agents, with 74.8% of all available chemotherapy being derived from natural products.To scientifically assess and validate the anticancer potential of an ethanolic extract of the fruit of the Long pepper (PLX, a plant of the piperaceae family that has been used in traditional medicine, especially Ayurveda and investigate the anticancer mechanism of action of PLX against cancer cells.Following treatment with ethanolic long pepper extract, cell viability was assessed using a water-soluble tetrazolium salt; apoptosis induction was observed following nuclear staining by Hoechst, binding of annexin V to the externalized phosphatidyl serine and phase contrast microscopy. Image-based cytometry was used to detect the effect of long pepper extract on the production of reactive oxygen species and the dissipation of the mitochondrial membrane potential following Tetramethylrhodamine or 5,5,6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine chloride staining (JC-1. Assessment of PLX in-vivo was carried out using Balb/C mice (toxicity and CD-1 nu/nu immunocompromised mice (efficacy. HPLC analysis enabled detection of some primary compounds present within our long pepper extract.Our results indicated that an ethanolic long pepper extract selectively induces caspase-independent apoptosis in cancer cells, without affecting non-cancerous cells, by targeting the mitochondria, leading to dissipation of the mitochondrial membrane potential and increase in ROS production. Release of the AIF and endonuclease G from isolated mitochondria confirms the mitochondria as a potential target of long pepper. The efficacy of PLX in in-vivo studies indicates that oral administration is able to halt the growth of colon cancer

  13. Inflammasomes as polyvalent cell death platforms.

    Science.gov (United States)

    de Vasconcelos, Nathalia M; Van Opdenbosch, Nina; Lamkanfi, Mohamed

    2016-06-01

    Inflammasomes are multi-protein platforms that are organized in the cytosol to cope with pathogens and cellular stress. The pattern recognition receptors NLRP1, NLRP3, NLRC4, AIM2 and Pyrin all assemble canonical platforms for caspase-1 activation, while caspase-11-dependent inflammasomes respond to intracellular Gram-negative pathogens. Inflammasomes are chiefly known for their roles in maturation and secretion of the inflammatory cytokines interleukin-(IL)1β and IL18, but they can also induce regulated cell death. Activation of caspases 1 and 11 in myeloid cells can trigger pyroptosis, a lytic and inflammatory cell death mode. Pyroptosis has been implicated in secretion of IL1β, IL18 and intracellular alarmins. Akin to these factors, it may have beneficial roles in controlling pathogen replication, but become detrimental in the context of chronic autoinflammatory diseases. Inflammasomes are increasingly implicated in induction of additional regulated cell death modes such as pyronecrosis and apoptosis. In this review, we overview recent advances in inflammasome-associated cell death research, illustrating the polyvalent roles of these macromolecular platforms in regulated cell death signaling. PMID:27048821

  14. Cell death proteomics database: consolidating proteomics data on cell death.

    Science.gov (United States)

    Arntzen, Magnus Ø; Bull, Vibeke H; Thiede, Bernd

    2013-05-01

    Programmed cell death is a ubiquitous process of utmost importance for the development and maintenance of multicellular organisms. More than 10 different types of programmed cell death forms have been discovered. Several proteomics analyses have been performed to gain insight in proteins involved in the different forms of programmed cell death. To consolidate these studies, we have developed the cell death proteomics (CDP) database, which comprehends data from apoptosis, autophagy, cytotoxic granule-mediated cell death, excitotoxicity, mitotic catastrophe, paraptosis, pyroptosis, and Wallerian degeneration. The CDP database is available as a web-based database to compare protein identifications and quantitative information across different experimental setups. The proteomics data of 73 publications were integrated and unified with protein annotations from UniProt-KB and gene ontology (GO). Currently, more than 6,500 records of more than 3,700 proteins are included in the CDP. Comparing apoptosis and autophagy using overrepresentation analysis of GO terms, the majority of enriched processes were found in both, but also some clear differences were perceived. Furthermore, the analysis revealed differences and similarities of the proteome between autophagosomal and overall autophagy. The CDP database represents a useful tool to consolidate data from proteome analyses of programmed cell death and is available at http://celldeathproteomics.uio.no. PMID:23537399

  15. Analysis of the influence of radiation quality on the effectiveness of small doses for induction of reproductive death and chromosome aberrations in mammalian cells

    International Nuclear Information System (INIS)

    A comparison of RBE - LET relations are made for reproductive death and chromosome aberrations in mammalian cells, as a means of providing insight into the type of mechanisms involved. An analysis of the survival curves for X-rays and gamma rays is discussed and a schematic representation is presented of differences in the dependence of the effectiveness per unit dose on LET, for which data were derived from experiments with X-rays, gamma rays, fast neutrons and heavy ions. (Auth./C.F.)

  16. The induction and repair of DNA damage and its influence on cell death in primary human fibroblasts exposed to UV-A or UV-C irradiation

    International Nuclear Information System (INIS)

    Irradiation with UV-A of normal human fibroblasts in phosphate-buffered saline induced cell death, measured as lack of colony-forming ability. After UV-A irradiation, single-strand breaks (alkali-labile bonds) could be detected in DNA; these lesions were rapidly repaired. Excision repair, monitored as unscheduled DNA synthesis, was induced strongly by irradiation with UV-C, but could not be detected after UV-A irradiation. The results indicate that lethality by UV-A wavelengths > 330 nm is caused by lesions other than single-strand breaks (alkali-labile bonds) and pyrimidine dimers. (Auth.)

  17. Chronic stress regulates NG2⁺ cell maturation and myelination in the prefrontal cortex through induction of death receptor 6.

    Science.gov (United States)

    Yang, Youjun; Zhang, Yini; Luo, Fei; Li, Baoming

    2016-03-01

    Chronic stress significantly affects neuron morphometry and function in the prefrontal cortex, a brain region controlling cognition and emotion. However, whether and how chronic stress regulates the maturation of NG2-expressing oligodendrocyte precursor cell (NG2(+) cell) and the importance of these changes remained unknown. Here, we report that exposing adult mice to chronic stress results in NG2(+) cell atrophy and myelination arrested in the medial prefrontal cortex (mPFC), and impaired mPFC-dependent functions. These alterations, are phenocopied by overexpression of death receptor 6 (DR6) in NG2(+) cell. Conversely, selectively silencing of DR6 in the NG2(+) cell can partly rescue NG2(+) cell atrophy and cognitive deficiency caused by chronic stress. We further demonstrate that myelination appears necessary for mPFC-dependent cognitive processes, as lysolecithin (LPC)-induced demyelination specifically in the mPFC is sufficient to cause these behavioral and cognitive impairments. Our results indicate that chronic stress impairs cognitive functions, at least in part, through modulation of NG2(+) cell maturation and myelination, and suggest that myelination is require for normal cognitive functions. PMID:26772637

  18. In vitro evaluation of Pandanus amaryllifolius ethanol extract for induction of cell death on non-hormone dependent human breast adenocarcinoma MDA-MB-231 cell via apoptosis

    OpenAIRE

    Chong Hueh; Yeap Swee; Rahmat Asmah; Akim Abdah; Alitheen Noorjahan; Othman Fauziah; Gwendoline-Ee Cheng

    2012-01-01

    Abstract Background Our previous study had shown that P. amaryllifolius was able to selectively inhibit cell proliferation of hormone independent breast cancer cell line MDA-MB-231. To understand the mode of killing and mechanism of action for P. amaryllifolius, the ethanol extract was evaluated for their alteration of cell cycle progression, PS externalization, DNA fragmentation and expression of anti/pro-apoptotic related protein. Results Cell cycle progression analysis, Annexin V and Tunel...

  19. Comparison of the effectiveness of different radiations for the induction of reproductive death, chromosome aberrations, morphological transformations and specific mutations in cultured mammalian cells

    International Nuclear Information System (INIS)

    Ionizing radiations can induce a variety of changes in cultured mammalian cells, many of which are initiated by damage to the chromosomes. If the primary mechanisms of damage at the molecular level are similar, it can be expected that dose-effect relationships for the different cellular responses should exhibit common characteristics. A comparison of dose-effect relationships has been made for published data on several types of cells treated with radiations of different Linear Energy Transfer (LET) and assessed with respect to two or more endpoints. Various types of cells have different sensitivities to low LET as well as to high LET radiation and cellular effects are induced at different frequencies per unit dose. Cell reproductive death and chromosome aberrations can presumably be induced as a result of damage in any one of the chromosomes. Chromosome breaks leading to deletions may occur at many sites. The probability of breaks may not be uniform along chromosomes, but this is difficult to establish. Cell transformation is more frequently (30 to 1000 times) induced by ionizing radiations than specific gene mutations and it may therefore be inferred that many, if not all, chromosomes contain one or more sites with genes which, if damaged, deleted or transposed to another site, may cause morphological malignant transformation. (Auth./C.F.)

  20. Crude aqueous extracts of Pluchea indica (L. Less. inhibit proliferation and migration of cancer cells through induction of p53-dependent cell death

    Directory of Open Access Journals (Sweden)

    Cho Jonathan J

    2012-12-01

    Full Text Available Abstract Background Pluchea indica (L. Less. (Asteraceae is a perennial shrub plant with anti-inflammatory and antioxidant medicinal properties. However, the anti-cancer properties of its aqueous extracts have not been studied. The aim of this study was to investigate the anti-proliferation, anti-migration, and pro-apoptotic properties of crude aqueous extracts of P. indica leaf and root on human malignant glioma cancer cells and human cervical cancer cells, and the underlying molecular mechanism. Methods GBM8401 human glioma cells and HeLa cervical carcinoma cells were treated with various concentrations of crude aqueous extracts of P. indica leaf and root and cancer cell proliferation and viability were measured by cell growth curves, trypan blue exclusions, and the tetrazolium reduction assay. Effects of the crude aqueous extracts on focus formation, migration, and apoptosis of cancer cells were studied as well. The molecular mechanism that contributed to the anti-cancer activities of crude aqueous extracts of P. indica root was also examined using Western blotting analysis. Results Crude aqueous extracts of P. indica leaf and root suppressed proliferation, viability, and migration of GBM8401 and HeLa cells. Treatment with crude aqueous extracts of P. indica leaf and root for 48 hours resulted in a significant 75% and 70% inhibition on proliferation and viability of GBM8401 and HeLa cancer cells, respectively. Crude aqueous extracts of P. indica root inhibited focus formation and promoted apoptosis of HeLa cells. It was found that phosphorylated-p53 and p21 were induced in GBM8401 and HeLa cells treated with crude aqueous extracts of P. indica root. Expression of phosphorylated-AKT was decreased in HeLa cells treated with crude aqueous extracts of P. indica root. Conclusion The in vitro anti-cancer effects of crude aqueous extracts of P. indica leaf and root indicate that it has sufficient potential to warrant further examination and

  1. 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)

    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

  2. Induction of chromosome aberrations in two lines of cultured cells using different types of radiation

    International Nuclear Information System (INIS)

    The induction of chromosome aberrations has been investigated in two lines of cultured cells for different types of radiation. The obtained results are compared with information on induction of cell reproductive death and malignant transformation. (Auth.)

  3. Anticancer activity of taraxerol acetate in human glioblastoma cells and a mouse xenograft model via induction of autophagy and apoptotic cell death, cell cycle arrest and inhibition of cell migration.

    Science.gov (United States)

    Hong, Jing-Fang; Song, Ying-Fang; Liu, Zheng; Zheng, Zhao-Cong; Chen, Hong-Jie; Wang, Shou-Sen

    2016-06-01

    The aim of the present study was to investigate the in vitro and in vivo anticancer and apoptotic effects of taraxerol acetate in U87 human glioblastoma cells. The effects on cell cycle phase distribution, cell cycle-associated proteins, autophagy, DNA fragmentation and cell migration were assessed. Cell viability was determined using the MTT assay, and phase contrast and fluorescence microscopy was utilized to determine the viability and apoptotic morphological features of the U87 cells. Flow cytometry using propidium iodide and Annexin V-fluorescein isothiocyanate demonstrated the effect of taraxerol acetate on the cell cycle phase distribution and apoptosis induction. Western blot analysis was performed to investigate the effect of the taraxerol acetate on cell cycle‑associated proteins and autophagy‑linked LC3B‑II proteins. The results demonstrated that taraxerol acetate induced dose‑ and time‑dependent cytotoxic effects in the U87 cells. Apoptotic induction following taraxerol acetate treatment was observed and the percentage of apoptotic cells increased from 7.3% in the control cells, to 16.1, 44.1 and 76.7% in the 10, 50 and 150 µM taraxerol acetate‑treated cells, respectively. Furthermore, taraxerol acetate treatment led to sub‑G1 cell cycle arrest with a corresponding decrease in the number of S‑phase cells. DNA fragments were observed as a result of the gel electrophoresis experiment following taraxerol acetate treatment. To investigate the inhibitory effects of taraxerol acetate on the migration of U87 cell, a wound healing assay was conducted. The number of cells that migrated to the scratched area decreased significantly following treatment with taraxerol acetate. In addition, taraxerol acetate inhibited tumor growth in a mouse xenograft model. Administration of 0.25 and 0.75 µg/g taraxerol acetate reduced the tumor weight from 1.2 g in the phosphate‑buffered saline (PBS)‑treated group (control) to 0.81 and 0.42

  4. Anticancer activity of taraxerol acetate in human glioblastoma cells and a mouse xenograft model via induction of autophagy and apoptotic cell death, cell cycle arrest and inhibition of cell migration

    Science.gov (United States)

    HONG, JING-FANG; SONG, YING-FANG; LIU, ZHENG; ZHENG, ZHAO-CONG; CHEN, HONG-JIE; WANG, SHOU-SEN

    2016-01-01

    The aim of the present study was to investigate the in vitro and in vivo anticancer and apoptotic effects of taraxerol acetate in U87 human glioblastoma cells. The effects on cell cycle phase distribution, cell cycle-associated proteins, autophagy, DNA fragmentation and cell migration were assessed. Cell viability was determined using the MTT assay, and phase contrast and fluorescence microscopy was utilized to determine the viability and apoptotic morphological features of the U87 cells. Flow cytometry using propidium iodide and Annexin V-fluorescein isothiocyanate demonstrated the effect of taraxerol acetate on the cell cycle phase distribution and apoptosis induction. Western blot analysis was performed to investigate the effect of the taraxerol acetate on cell cycle-associated proteins and autophagy-linked LC3B-II proteins. The results demonstrated that taraxerol acetate induced dose- and time-dependent cytotoxic effects in the U87 cells. Apoptotic induction following taraxerol acetate treatment was observed and the percentage of apoptotic cells increased from 7.3% in the control cells, to 16.1, 44.1 and 76.7% in the 10, 50 and 150 µM taraxerol acetate-treated cells, respectively. Furthermore, taraxerol acetate treatment led to sub-G1 cell cycle arrest with a corresponding decrease in the number of S-phase cells. DNA fragments were observed as a result of the gel electrophoresis experiment following taraxerol acetate treatment. To investigate the inhibitory effects of taraxerol acetate on the migration of U87 cell, a wound healing assay was conducted. The number of cells that migrated to the scratched area decreased significantly following treatment with taraxerol acetate. In addition, taraxerol acetate inhibited tumor growth in a mouse xenograft model. Administration of 0.25 and 0.75 µg/g taraxerol acetate reduced the tumor weight from 1.2 g in the phosphate-buffered saline (PBS)-treated group (control) to 0.81 and 0.42 g, respectively. Similarly, 0.25 and 0

  5. Modeling Stem Cell Induction Processes

    OpenAIRE

    Filipe Grácio; Joaquim Cabral; Bruce Tidor

    2012-01-01

    Technology for converting human cells to pluripotent stem cell using induction processes has the potential to revolutionize regenerative medicine. However, the production of these so called iPS cells is still quite inefficient and may be dominated by stochastic effects. In this work we build mass-action models of the core regulatory elements controlling stem cell induction and maintenance. The models include not only the network of transcription factors NANOG, OCT4, SOX2, but also important e...

  6. Glutathione in Cancer Cell Death

    International Nuclear Information System (INIS)

    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

  7. 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.

  8. Regulation of death induction and chemosensitizing action of 3-bromopyruvate in myeloid leukemia cells: energy depletion, oxidative stress, and protein kinase activity modulation.

    Science.gov (United States)

    Calviño, Eva; Estañ, María Cristina; Sánchez-Martín, Carlos; Brea, Rocío; de Blas, Elena; Boyano-Adánez, María del Carmen; Rial, Eduardo; Aller, Patricio

    2014-02-01

    3-Bromopyruvate (3-BrP) is an alkylating, energy-depleting drug that is of interest in antitumor therapies, although the mechanisms underlying its cytotoxicity are ill-defined. We show here that 3-BrP causes concentration-dependent cell death of HL60 and other human myeloid leukemia cells, inducing both apoptosis and necrosis at 20-30 μM and a pure necrotic response at 60 μM. Low concentrations of 3-BrP (10-20 μM) brought about a rapid inhibition of glycolysis, which at higher concentrations was followed by the inhibition of mitochondrial respiration. The combination of these effects causes concentration-dependent ATP depletion, although this cannot explain the lethality at intermediate 3-BrP concentrations (20-30 μM). The oxidative stress caused by exposure to 3-BrP was evident as a moderate overproduction of reactive oxygen species and a concentration-dependent depletion of glutathione, which was an important determinant of 3-BrP toxicity. In addition, 3-BrP caused glutathione-dependent stimulation of p38 mitogen-activated protein kinase (MAPK), mitogen-induced extracellular kinase (MEK)/extracellular signal-regulated kinase (ERK), and protein kinase B (Akt)/mammalian target of rapamycin/p70S6K phosphorylation or activation, as well as rapid LKB-1/AMP kinase (AMPK) activation, which was later followed by Akt-mediated inactivation. Experiments with pharmacological inhibitors revealed that p38 MAPK activation enhances 3-BrP toxicity, which is conversely restrained by ERK and Akt activity. Finally, 3-BrP was seen to cooperate with antitumor agents like arsenic trioxide and curcumin in causing cell death, a response apparently mediated by both the generation of oxidative stress induced by 3-BrP and the attenuation of Akt and ERK activation by curcumin. In summary, 3-BrP cytotoxicity is the result of several combined regulatory mechanisms that might represent important targets to improve therapeutic efficacy. PMID:24307199

  9. Cell death sensitization of leukemia cells by opioid receptor activation

    Science.gov (United States)

    Friesen, Claudia; Roscher, Mareike; Hormann, Inis; Fichtner, Iduna; Alt, Andreas; Hilger, Ralf A.; Debatin, Klaus-Michael; Miltner, Erich

    2013-01-01

    Cyclic AMP (cAMP) regulates a number of cellular processes and modulates cell death induction. cAMP levels are altered upon stimulation of specific G-protein-coupled receptors inhibiting or activating adenylyl cyclases. Opioid receptor stimulation can activate inhibitory Gi-proteins which in turn block adenylyl cyclase activity reducing cAMP. Opioids such as D,L-methadone induce cell death in leukemia cells. However, the mechanism how opioids trigger apoptosis and activate caspases in leukemia cells is not understood. In this study, we demonstrate that downregulation of cAMP induced by opioid receptor activation using the opioid D,L-methadone kills and sensitizes leukemia cells for doxorubicin treatment. Enhancing cAMP levels by blocking opioid-receptor signaling strongly reduced D,L-methadone-induced apoptosis, caspase activation and doxorubicin-sensitivity. Induction of cell death in leukemia cells by activation of opioid receptors using the opioid D,L-methadone depends on critical levels of opioid receptor expression on the cell surface. Doxorubicin increased opioid receptor expression in leukemia cells. In addition, the opioid D,L-methadone increased doxorubicin uptake and decreased doxorubicin efflux in leukemia cells, suggesting that the opioid D,L-methadone as well as doxorubicin mutually increase their cytotoxic potential. Furthermore, we found that opioid receptor activation using D,L-methadone alone or in addition to doxorubicin inhibits tumor growth significantly in vivo. These results demonstrate that opioid receptor activation via triggering the downregulation of cAMP induces apoptosis, activates caspases and sensitizes leukemia cells for doxorubicin treatment. Hence, opioid receptor activation seems to be a promising strategy to improve anticancer therapies. PMID:23633472

  10. 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...

  11. Mitochondria: pharmacological manipulation of cell death

    OpenAIRE

    Bouchier-Hayes, Lisa; Lartigue, Lydia; Newmeyer, Donald D.

    2005-01-01

    Cell death by apoptosis or necrosis is often important in the etiology and treatment of disease. Since mitochondria play important roles in cell death pathways, these organelles are potentially prime targets for therapeutic intervention. Here we discuss the mechanisms through which mitochondria participate in the cell death process and also survey some of the pharmacological approaches that target mitochondria in various ways.

  12. Nerve Growth Factor in Cancer Cell Death and Survival

    International Nuclear Information System (INIS)

    One of the major challenges for cancer therapeutics is the resistance of many tumor cells to induction of cell death due to pro-survival signaling in the cancer cells. Here we review the growing literature which shows that neurotrophins contribute to pro-survival signaling in many different types of cancer. In particular, nerve growth factor, the archetypal neurotrophin, has been shown to play a role in tumorigenesis over the past decade. Nerve growth factor mediates its effects through its two cognate receptors, TrkA, a receptor tyrosine kinase and p75NTR, a member of the death receptor superfamily. Depending on the tumor origin, pro-survival signaling can be mediated by TrkA receptors or by p75NTR. For example, in breast cancer the aberrant expression of nerve growth factor stimulates proliferative signaling through TrkA and pro-survival signaling through p75NTR. This latter signaling through p75NTR promotes increased resistance to the induction of cell death by chemotherapeutic treatments. In contrast, in prostate cells the p75NTR mediates cell death and prevents metastasis. In prostate cancer, expression of this receptor is lost, which contributes to tumor progression by allowing cells to survive, proliferate and metastasize. This review focuses on our current knowledge of neurotrophin signaling in cancer, with a particular emphasis on nerve growth factor regulation of cell death and survival in cancer

  13. Cell death in the cardiovascular system

    OpenAIRE

    Clarke, Murray; Bennett, Martin; Littlewood, Trevor

    2006-01-01

    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 norm...

  14. Actin as deathly switch? How auxin can suppress cell-death related defence.

    Directory of Open Access Journals (Sweden)

    Xiaoli Chang

    Full Text Available Plant innate immunity is composed of two layers--a basal immunity, and a specific effector-triggered immunity, which is often accompanied by hypersensitive cell death. Initiation of cell death depends on a complex network of signalling pathways. The phytohormone auxin as central regulator of plant growth and development represents an important component for the modulation of plant defence. In our previous work, we showed that cell death is heralded by detachment of actin from the membrane. Both, actin response and cell death, are triggered by the bacterial elicitor harpin in grapevine cells. In this study we investigated, whether harpin-triggered actin bundling is necessary for harpin-triggered cell death. Since actin organisation is dependent upon auxin, we used different auxins to suppress actin bundling. Extracellular alkalinisation and transcription of defence genes as the basal immunity were examined as well as cell death. Furthermore, organisation of actin was observed in response to pharmacological manipulation of reactive oxygen species and phospholipase D. We find that induction of defence genes is independent of auxin. However, auxin can suppress harpin-induced cell death and also counteract actin bundling. We integrate our findings into a model, where harpin interferes with an auxin dependent pathway that sustains dynamic cortical actin through the activity of phospholipase D. The antagonism between growth and defence is explained by mutual competition for signal molecules such as superoxide and phosphatidic acid. Perturbations of the auxin-actin pathway might be used to detect disturbed integrity of the plasma membrane and channel defence signalling towards programmed cell death.

  15. Identification of DELE, a novel DAP3-binding protein which is crucial for death receptor-mediated apoptosis induction.

    Science.gov (United States)

    Harada, Tanenobu; Iwai, Atsushi; Miyazaki, Tadaaki

    2010-10-01

    Death associated protein 3 (DAP3) is known to be a highly conserved protein, and is responsible for regulating apoptosis induced by various stimuli. To understand the molecular mechanism of how DAP3 induces apoptosis, we performed yeast two-hybrid screening, and identified a novel DAP3-binding protein termed death ligand signal enhancer (DELE). In this report, we show that DELE actually binds to DAP3 in mammalian cells. We found that the cells stably expressing DELE are susceptible to apoptosis induction by the stimulation of TNF-α and TRAIL. In addition, knockdown of DELE expression rescued the HeLa cells from apoptosis induction by these stimuli. Moreover, activation of caspase-3, caspase-8 and caspase-9 induced by stimulation of TNF-α, anti-Fas or TRAIL was significantly inhibited by the knockdown of DELE expression. These results demonstrated the biological significance of DELE for apoptosis signal mediated by death receptors. PMID:20563667

  16. Calpastatin overexpression reduces oxidative stress-induced mitochondrial impairment and cell death in human neuroblastoma SH-SY5Y cells by decreasing calpain and calcineurin activation, induction of mitochondrial fission and destruction of mitochondrial fusion.

    Science.gov (United States)

    Tangmansakulchai, Kulvadee; Abubakar, Zuroida; Kitiyanant, Narisorn; Suwanjang, Wilasinee; Leepiyasakulchai, Chaniya; Govitrapong, Piyarat; Chetsawang, Banthit

    2016-09-01

    Calpain is an intracellular Ca(2+)-dependent protease, and the activation of calpain has been implicated in neurodegenerative diseases. Calpain activity can be regulated by calpastatin, an endogenous specific calpain inhibitor. Several lines of evidence have demonstrated a potential role of calpastatin in preventing calpain-mediated pathogenesis. Additionally, several studies have revealed that calpain activation and mitochondrial damage are involved in the cell death process; however, recent evidence has not clearly indicated a neuroprotective mechanism of calpastatin against calpain-dependent mitochondrial impairment in the process of neuronal cell death. Therefore, the purpose of this study was to investigate the potential ability of calpastatin to inhibit calpain activation and mitochondrial impairment in oxidative stress-induced neuron degeneration. Calpastatin was stably overexpressed in human neuroblastoma SH-SY5Y cells. In non-calpastatin overexpressing SH-SY5Y cells, hydrogen peroxide significantly decreased cell viability, superoxide dismutase activity, mitochondrial membrane potential, ATP production and mitochondrial fusion protein (Opa1) levels in the mitochondrial fraction but increased reactive oxygen species formation, calpain and calcineurin activation, mitochondrial fission protein (Fis1 and Drp1) levels in the mitochondrial fraction and apoptotic cells. Nevertheless, these toxic effects were abolished in hydrogen peroxide-treated calpastatin-overexpressing SH-SY5Y cells. The results of the present study demonstrate the potential ability of calpastatin to diminish calpain and calcineurin activation and mitochondrial impairment in neurons that are affected by oxidative damage. PMID:27453331

  17. Morphological classification of plant cell deaths

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...

  18. The DNA damage-induced cell death response: a roadmap to kill cancer cells.

    Science.gov (United States)

    Matt, Sonja; Hofmann, Thomas G

    2016-08-01

    Upon massive DNA damage cells fail to undergo productive DNA repair and trigger the cell death response. Resistance to cell death is linked to cellular transformation and carcinogenesis as well as radio- and chemoresistance, making the underlying signaling pathways a promising target for therapeutic intervention. Diverse DNA damage-induced cell death pathways are operative in mammalian cells and finally culminate in the induction of programmed cell death via activation of apoptosis or necroptosis. These signaling routes affect nuclear, mitochondria- and plasma membrane-associated key molecules to activate the apoptotic or necroptotic response. In this review, we highlight the main signaling pathways, molecular players and mechanisms guiding the DNA damage-induced cell death response. PMID:26791483

  19. Cell death regulates muscle fiber number.

    Science.gov (United States)

    Sarkissian, Tatevik; Arya, Richa; Gyonjyan, Seda; Taylor, Barbara; White, Kristin

    2016-07-01

    Cell death can have both cell autonomous and non-autonomous roles in normal development. Previous studies have shown that the central cell death regulators grim and reaper are required for the developmentally important elimination of stem cells and neurons in the developing central nervous system (CNS). Here we show that cell death in the nervous system is also required for normal muscle development. In the absence of grim and reaper, there is an increase in the number of fibers in the ventral abdominal muscles in the Drosophila adult. This phenotype can be partially recapitulated by inhibition of cell death specifically in the CNS, indicating a non-autonomous role for neuronal death in limiting muscle fiber number. We also show that FGFs produced in the cell death defective nervous system are required for the increase in muscle fiber number. Cell death in the muscle lineage during pupal stages also plays a role in specifying fiber number. Our work suggests that FGFs from the CNS act as a survival signal for muscle founder cells. Thus, proper muscle fiber specification requires cell death in both the nervous system and in the developing muscle itself. PMID:27131625

  20. Structure-activity relationships of lipopolysaccharide (LPS) in tumor necrosis factor-alpha (TNF-alpha) production and induction of macrophage cell death in the presence of cycloheximide (CHX) in a murine macrophage-like cell line, J774.1.

    Science.gov (United States)

    Karahashi, H; Amano, F

    1998-10-01

    The structure-activity relationships of lipopolysaccharide (LPS) in tumor necrosis factor-alpha (TNF-alpha) production and induction of macrophage cell death in the presence of cycloheximide (CHX) were examined in a murine macrophage-like cell line, J774.1. TNF-alpha production is one of the characteristic phenotypes of LPS-activated macrophages, and is observed upon incubation with LPS. On the contrary, macrophage cell death, which had been found in our laboratory (Amano F., Karahashi H., J. Endotoxin Res., 3, 415423 (1996)) and was examined as the release of lactate dehydrogenase (LDH) from cells into the culture supernatant, was observed 2.5 h after the addition of LPS in the presence of CHX. However, both TNF-alpha production and macrophage cell death were similarly dependent on the structures of LPS and lipid A. At more than 10 ng/ml, wild-type LPS from E.coli and S. minnesota exhibited the highest activity, and LPS as well as diphosphoryl lipid A from S. minnesota rough mutants also exhibited activity, but E. coli LPS detoxified by alkaline treatment or monophosphoryl lipid A from S. minnesota exhibited no activity even at 100 ng/ml. These results suggest that LPS-induced macrophage cell death in the presence of CHX shows similar requirements for LPS and/or lipid A structures as for the macrophage activation at higher doses than 10 ng/ml, although the former was not observed at 1 ng/ml LPS, while the latter was. However, TNF-alpha does not seem to be involved in the induction of macrophage cell death, because a neutralizing anti-TNF-alpha antibody failed to block the macrophage cell death and because recombinant TNF-alpha had little effect on the extent of LDH release in the presence or absence of LPS and/or CHX, and also because TNF-alpha production by LPS was abolished in the presence of CHX. PMID:9821819

  1. Pneumolysin causes neuronal cell death through mitochondrial damage

    OpenAIRE

    Braun, Johann S.; Hoffmann, Olaf; Schickhaus, Miriam; Freyer, Dorette; Dagand, Emilie; Bermpohl, Daniela; Mitchell, Tim J.; Bechmann, Ingo; Weber, Joerg R.

    2007-01-01

    Bacterial toxins such as pneumolysin are key mediators of cytotoxicity in infections. Pneumolysin is a pore-forming toxin released by Streptococcus pneumoniae, the major cause of bacterial meningitis. We found that pneumolysin is the pneumococcal factor that accounts for the cell death pathways induced by live bacteria in primary neurons. The pore-forming activity of pneumolysin is essential for the induction of mitochondrial damage and apoptosis. Pneumolysin colocalized with mitochondrial me...

  2. Induction of indoleamine 2,3-dioxygenase (IDO) enzymatic activity contributes to interferon-gamma induced apoptosis and death receptor 5 expression in human non-small cell lung cancer cells.

    Science.gov (United States)

    Chung, Ting Wen; Tan, Kok-Tong; Chan, Hong-Lin; Lai, Ming-Derg; Yen, Meng-Chi; Li, Yi-Ron; Lin, Sheng Hao; Lin, Chi-Chen

    2014-01-01

    Interferon-gamma (IFN-γ) has been used to treat various malignant tumors. However, the molecular mechanisms underlying the direct anti-proliferative activity of IFN-γ are poorly understood. In the present study, we examined the in vitro antitumor activity of IFN-γ on two human non-small-cell lung carcinoma (NSCLC) cell lines, H322M and H226. Our findings indicated that IFN-γ treatment caused a time-dependent reduction in cell viability and induced apoptosis through a FADD-mediated caspase-8/tBid/mitochondria-dependent pathway in both cell lines. Notably, we also postulated that IFN-γ increased indoleamine 2,3-dioxygenase (IDO) expression and enzymatic activity in H322M and H226 cells. In addition, inhibition of IDO activity by the IDO inhibitor 1-MT or tryptophan significantly reduced IFN-γ-induced apoptosis and death receptor 5 (DR5) expression, which suggests that IDO enzymatic activity plays an important role in the anti-NSCLC cancer effect of IFN-γ. These results provide new mechanistic insights into interferon-γ antitumor activity and further support IFN-γ as a potential therapeutic adjuvant for the treatment of NCSLC. PMID:25292102

  3. Apoptosis: A Review of Programmed Cell Death

    OpenAIRE

    Elmore, Susan

    2007-01-01

    The process of programmed cell death, or apoptosis, is generally characterized by distinct morphological characteristics and energy-dependent biochemical mechanisms. Apoptosis is considered a vital component of various processes including normal cell turnover, proper development and functioning of the immune system, hormone-dependent atrophy, embryonic development and chemical-induced cell death. Inappropriate apoptosis (either too little or too much) is a factor in many human conditions incl...

  4. Programmed cell death during quinoa perisperm development

    OpenAIRE

    López-Fernández, María Paula; Maldonado, Sara

    2013-01-01

    At seed maturity, quinoa (Chenopodium quinoa Willd.) perisperm consists of uniform, non-living, thin-walled cells full of starch grains. The objective of the present study was to study quinoa perisperm development and describe the programme of cell death that affects the entire tissue. A number of parameters typically measured during programmed cell death (PCD), such as cellular morphological changes in nuclei and cytoplasm, endoreduplication, DNA fragmentation, and the participation of nucle...

  5. Effects of {gamma} ({sup 60}Co) and {beta} ({sup 90}Sr) radiations in Chinese hamster ovarian cells (CHO-K1): induction of micronuclei and cell death; Efeitos das radiacoes {gamma} ({sup 60}Co) e {beta} ({sup 90}Sr) em celulas de ovario de hamster chines (CHO-K1): inducao de micronucleos e morte celular

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Daniella

    2003-07-01

    Among various types of ionising radiation, the beta emitter radionuclides are involved in many sectors of human activity, such as nuclear medicine, nuclear industries and biomedicine, with a consequent increased risk of accidental, occupational or therapeutic exposure. Despite their recognized importance, there is little information about the effect of beta particles at the cellular level when compared to other types of ionizing radiation. Thus, the objective of the present study was to evaluate the genotoxic and cytotoxic effects of {sup 90}Sr, a pure, highly energetic beta source, on CHO-K1 cells and to compare them with data obtained with {sup 60}Co. CHO-K1 cells irradiated with different doses (1.0, 2.5, 5.0, 7.5 Gy) of {sup 60}Co (0.34 Gy.min{sup -1}) and {sup 90}Sr (0.23 Gy.min{sup -1}) were processed for analysis of clonogenic death, induction of micronuclei (MN) and necrotic and apoptotic death. The survival curves obtained for both types of radiation were better fitted by the linear-quadratic model and were similar. However, the cytogenetic results showed that both the proportion of micronucleated cells and the magnitude of radioinduced lesions demonstrated by the analysis of MN distribution were significantly higher in cells irradiated with {sup 60}Co than in cells irradiated with {sup 90}Sr, whereas {sup 90}Sr was more damaging than {sup 60}Co in terms of cell death induction. Necrosis was the major type of death observed in CHO-K1 cells. The data obtained suggest that the low incidence of micronucleated cells after exposure to {sup 90}Sr may be a consequence of selective elimination of severely damaged cells from the population by the necrotic process at a higher rate than observed with {sup 60}Co exposure. The data obtained also demonstrated the need to use several parameters for a better estimate of cellular sensitivity to the action of genotoxic agents, which would be important in terms of radiobiology, oncology and therapeutics. (author)

  6. Lysosomal cell death at a glance

    DEFF Research Database (Denmark)

    Aits, Sonja; Jaattela, Marja

    2013-01-01

    Lysosomes serve as the cellular recycling centre and are filled with numerous hydrolases that can degrade most cellular macromolecules. Lysosomal membrane permeabilization and the consequent leakage of the lysosomal content into the cytosol leads to so-called "lysosomal cell death". This form of...... cell death is mainly carried out by the lysosomal cathepsin proteases and can have necrotic, apoptotic or apoptosis-like features depending on the extent of the leakage and the cellular context. This article summarizes our current knowledge on lysosomal cell death with an emphasis on the upstream...

  7. Plant Proteases Involved in Regulated Cell Death.

    Science.gov (United States)

    Zamyatnin, A A

    2015-12-01

    Each plant genome encodes hundreds of proteolytic enzymes. These enzymes can be divided into five distinct classes: cysteine-, serine-, aspartic-, threonine-, and metalloproteinases. Despite the differences in their structural properties and activities, members of all of these classes in plants are involved in the processes of regulated cell death - a basic feature of eukaryotic organisms. Regulated cell death in plants is an indispensable mechanism supporting plant development, survival, stress responses, and defense against pathogens. This review summarizes recent advances in studies of plant proteolytic enzymes functioning in the initiation and execution of distinct types of regulated cell death. PMID:26878575

  8. Artesunate induces necrotic cell death in schwannoma cells

    OpenAIRE

    Button, R W; Lin, F.; Ercolano, E; Vincent, J H; Hu, B.; Hanemann, C O; Luo, S

    2014-01-01

    Established as a potent anti-malaria medicine, artemisinin-based drugs have been suggested to have anti-tumour activity in some cancers. Although the mechanism is poorly understood, it has been suggested that artemisinin induces apoptotic cell death. Here, we show that the artemisinin analogue artesunate (ART) effectively induces cell death in RT4 schwannoma cells and human primary schwannoma cells. Interestingly, our data indicate for first time that the cell death induced by ART is largely ...

  9. Determination of Cell Death Induced by Lovastatin on Human Colon Cell Line HT29 Using the Comet Assay

    OpenAIRE

    Jafari, Marzieh; Rezaei, Mohsen; Kalantari, Heibatullah; Hashemitabar, Mahmoud

    2013-01-01

    Background Apoptosis or programmed cell death is an essential process for elimination of damaged cells. Also, induction of apoptosis is fundamental for treating cancer. Screening for agents that induce apoptosis in tumor cells help in the development of novel agents for cancer treatment. Numerous studies suggest that the exposure of tumor cells to statins can lead to cell death via two separate processes: apoptosis or necrosis. Severe fragmentation of DNA during apoptosis can be readily measu...

  10. Cell death in Pseudomonas aeruginosa biofilm development

    DEFF Research Database (Denmark)

    Webb, J.S.; Thompson, L.S.; James, S.;

    2003-01-01

    Bacteria growing in biofilms often develop multicellular, three-dimensional structures known as microcolonies. Complex differentiation within biofilms of Pseudomonas aeruginosa occurs, leading to the creation of voids inside microcolonies and to the dispersal of cells from within these voids....... However, key developmental processes regulating these events are poorly understood. A normal component of multicellular development is cell death. Here we report that a repeatable pattern of cell death and lysis occurs in biofilms of P. aeruginosa during the normal course of development. Cell death...... occurred with temporal and spatial organization within biofilms, inside microcolonies, when the biofilms were allowed to develop in continuous-culture flow cells. A subpopulation of viable cells was always observed in these regions. During the onset of biofilm killing and during biofilm development...

  11. Cell death in the developing vertebrate retina.

    Science.gov (United States)

    Vecino, Elena; Hernández, María; García, Mónica

    2004-01-01

    Programmed cell death occurs naturally, as a physiological process, during the embryonic development of multicellular organisms. In the retina, which belongs to the central nervous system, at least two phases of cell death have been reported to occur during development. An early phase takes place concomitant with the processes of neurogenesis, cell migration and cell differentiation. A later phase affecting mainly neurons occurs when connections are established and synapses are formed, resulting in selective elimination of inappropriate connections. This pattern of cell death in the developing retina is common among different vertebrates. However, the timing and magnitude of retinal cell death varies among species. In addition, a precise regulation of apoptosis during retinal development has been described. Factors such as neurotrophins, among many others, and electrical activity influence the survival of retinal cells during the course of development. In this paper, we present a summary of these different aspects of programmed cell death during retinal development, and examine how these differ among different species. PMID:15558487

  12. Cytokine signaling for proliferation, survival, and death in hematopoietic cells.

    Science.gov (United States)

    Miyajima, A; Ito, Y; Kinoshita, T

    1999-04-01

    The survival, proliferation, and differentiation of hematopoietic cells are regulated by cytokines. In the absence of cytokines, hematopoietic cells not only stop proliferation, but undergo apoptosis. This strict dependency of hematopoietic cells on cytokines is an important mechanism that maintains the homeostasis of blood cells. Cytokines induce various intracellular signaling pathways by activating the receptor-associated Janus kinases (Jaks), and distinct signals are responsible for cell cycle progression and cell survival. Induction of signals for cell cycle progression without suppressing apoptosis results in apoptotic cell death, indicating the essential role of anti-apoptotic signaling for cell growth. In hematopoietic cells, Ras, a cellular protooncogen product, and phosphatidylinositol 3 kinase are involved in the suppression of apoptosis. Cytokine depletion not only turns off anti-apoptotic signaling, but also actively induces cell death by activating caspases, a distinct family of cysteine proteases. Alterations in the mechanisms of cytokine signaling for cell cycle progression and anti-apoptotic function are implicated in hematological disorders. PMID:10222650

  13. Inhibition of class I histone deacetylases in non-small cell lung cancer by honokiol leads to suppression of cancer cell growth and induction of cell death in vitro and in vivo

    OpenAIRE

    Singh, Tripti; Prasad, Ram; Santosh K. Katiyar

    2013-01-01

    Non-small-cell lung cancer (NSCLC) represents approximately 80% of all types of lung cancer. Here, we report the chemotherapeutic effect of honokiol, a phytochemical from Magnolia grandiflora, on NSCLC cells and the molecular mechanisms underlying these effects using in vitro and in vivo models. Treatment of NSCLC cells (A549, H1299, H460 and H226) with honokiol (20, 40 and 60 µM) inhibited histone deacetylase (HDAC) activity, reduced the levels of class I HDAC proteins and enhanced histone a...

  14. Investigation of epothilone B-induced cell death mechanisms in human epithelial cancer cells -in consideration of combined treatment with ionizing radiation.

    Science.gov (United States)

    Baumgart, Tonja; Kriesen, Stephan; Neels, Oliver; Hildebrandt, Guido; Manda, Katrin

    2015-07-01

    Epothilone B was shown to have promising chemo- and radiosensitizing effects on cells, but the mechanisms underlying cell death remain ambiguous. The aim of the study was to examine selected cell death pathways on the basis of FaDu and A549 cells. Western blot analyses were used for investigation of specific apoptotic markers. Immunofluorescence imaging and flow cytometry were utilized for examination of cell death mechanisms. DNA-staining was used for studying influence of epothilone B on micronucleus rate. We showed that epothilone B can initiate cell death via apoptosis and mitotic catastrophe, but induction of cell death was cell type specific. PMID:25919223

  15. 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.

  16. Junctional communication of embryonic cells after induction

    Institute of Scientific and Technical Information of China (English)

    ZengMibai; JiangWansu

    1990-01-01

    Cell couplings before and after neural induction in embryos of Cynops orientalis were studied by means of single cell injection of Lucifer Yellow.Differences both in incidence and the extent of cell couplings were demonstrated.Results of cell couplings were correlated with electron microscopic observations of freeze-etching replicas.

  17. Cell death and cytokine production induced by autoimmunogenic hydrocarbon oils.

    Science.gov (United States)

    Herman, Sonja; Kny, Angelika; Schorn, Christine; Pfatschbacher, Jürgen; Niederreiter, Birgit; Herrmann, Martin; Holmdahl, Rikard; Steiner, Günter; Hoffmann, Markus H

    2012-12-01

    Hydrocarbon oils such as pristane or hexadecane induce arthritis and lupus in rodents sharing clinical and pathological features with the human diseases rheumatoid arthritis and systemic lupus erythematosus, respectively. In pristane-induced lupus in the mouse induction of apoptosis and augmentation of type-I Interferon signalling by pristane have been suggested to contribute to pathology, whereas in pristane-induced arthritis (PIA) in the rat the pathological mechanisms are still elusive. Here we show that pristane induces cell death in rat and human cells. Increased numbers of apoptotic cells were found in draining lymph nodes of pristane-injected rats and increased percentages of apoptotic and necrotic cells were observed in peripheral blood. In addition, neutrophil extracellular trap formation was triggered by pristane and hexadecane in neutrophils. Because levels of interleukin (IL)-1β were elevated in sera of pristane-injected rats, with levels mirroring the course of PIA, we examined the effect of pristane at single cell level in vitro, using rat splenocytes and the human monocytic cell line THP-1. Pristane and other hydrocarbon oils induced IL-1β secretion in THP-1 cells as well as in rat splenocytes. The potassium channel inhibitor glibenclamide partly inhibited IL-1β induction, suggesting involvement of the inflammasome. Elevated levels of IL-1α were also found in supernatants of cells treated with pristane and hexadecane. In conclusion, autoimmunogenic hydrocarbon oils induce various forms of cell death in rat and human cells. The higher serum IL-1β levels in pristane-injected animals might be caused by both inflammasome-dependent and -independent mechanisms, such as passive release from dying-cells and probably extracellular maturation of pro-IL-1β. PMID:22917079

  18. Time-Lapse Imaging of Cell Death.

    Science.gov (United States)

    Wallberg, Fredrik; Tenev, Tencho; Meier, Pascal

    2016-03-01

    The best approach to distinguish between necrosis and apoptosis is time-lapse video microscopy. This technique enables a biological process to be photographed at regular intervals over a period, which may last from a few hours to several days, and can be applied to cells in culture or in vivo. We have established two time-lapse microscopy methods based on different ways of calculating cell death: semiautomated and automated. In the semiautomated approach, cell death can be visualized by staining with combinations of Alexa Fluor 647-conjugated Annexin V and Sytox Green (SG), or Annexin V(FITC) and Propidium iodide (PI). The automated method is similar except that all cells are labeled with dyes. This allows faster quantification of data. To this end Cell Tracker Green is used to label all cells at time zero in combination with PI and Alexa Fluor 647-conjugated Annexin V. Necrotic cell death is accompanied by either simultaneous labeling with Annexin V and PI or SG (double-positive), or direct PI or SG staining. Additionally, necrotic cells display characteristic morphology, such as cytoplasmic swelling. In contrast to necrosis where membrane permeabilization is an early event, cells that die by apoptosis lose their membrane permeability relatively late. Therefore, the time between Annexin V staining and PI or SG uptake (double-positive) can be used to distinguish necrosis from apoptosis. This protocol describes the analysis of cell death by time-lapse imaging of HT1080 and L929 cells stained with these dyes, but it can be readily adapted to other cell types of interest. PMID:26933245

  19. Cell death signalling mechanisms in heart failure

    OpenAIRE

    Mughal, Wajihah; Kirshenbaum, Lorrie A.

    2011-01-01

    In 2003, cardiovascular disease was the most costly disease in Canada, and it is still on the rise. The loss of properly functioning cardiomyocytes leads to cardiac impairment, which is a consequence of heart failure. Therefore, understanding the pathways of cell death (necrosis and apoptosis) has potential implications for the development of therapeutic strategies. In addition, the role of B-cell lymphoma-2 family members is discussed and the importance of mitochondria in directing cell deat...

  20. Inducible cell death in plant immunity

    DEFF Research Database (Denmark)

    Hofius, Daniel; Tsitsigiannis, Dimitrios I; Jones, Jonathan D G;

    2006-01-01

    Programmed cell death (PCD) occurs during vegetative and reproductive plant growth, as typified by autumnal leaf senescence and the terminal differentiation of the endosperm of cereals which provide our major source of food. PCD also occurs in response to environmental stress and pathogen attack......, and these inducible PCD forms are intensively studied due their experimental tractability. In general, evidence exists for plant cell death pathways which have similarities to the apoptotic, autophagic and necrotic forms described in yeast and metazoans. Recent research aiming to understand these...... pathways and their molecular components in plants are reviewed here....

  1. Regulated cell death and adaptive stress responses.

    Science.gov (United States)

    Galluzzi, Lorenzo; Bravo-San Pedro, José Manuel; Kepp, Oliver; Kroemer, Guido

    2016-06-01

    Eukaryotic cells react to potentially dangerous perturbations of the intracellular or extracellular microenvironment by activating rapid (transcription-independent) mechanisms that attempt to restore homeostasis. If such perturbations persist, cells may still try to cope with stress by activating delayed and robust (transcription-dependent) adaptive systems, or they may actively engage in cellular suicide. This regulated form of cell death can manifest with various morphological, biochemical and immunological correlates, and constitutes an ultimate attempt of stressed cells to maintain organismal homeostasis. Here, we dissect the general organization of adaptive cellular responses to stress, their intimate connection with regulated cell death, and how the latter operates for the preservation of organismal homeostasis. PMID:27048813

  2. Alkaloids Induce Programmed Cell Death in Bloodstream Forms of Trypanosomes (Trypanosoma b. brucei)

    OpenAIRE

    Michael Wink; Vera Rosenkranz

    2008-01-01

    The potential induction of a programmed cell death (PCD) in Trypanosoma b. brucei by 55 alkaloids of the quinoline, quinolizidine, isoquinoline, indole, terpene, tropane, steroid, and piperidine type was studied by measuring DNA fragmentation and changes in mitochondrial membrane potential. For comparison, the induction of apoptosis by the same alkaloids in human leukemia cells (Jurkat APO-S) was tested. Several alkaloids of the isoquinoline, quinoline, indole and steroidal type (berberine, c...

  3. The deaths of a cell: how language and metaphor influence the science of cell death.

    Science.gov (United States)

    Reynolds, Andrew S

    2014-12-01

    Multicellular development and tissue maintenance involve the regular elimination of damaged and healthy cells. The science of this genetically regulated cell death is particularly rich in metaphors: 'programmed cell death' or 'cell suicide' is considered an 'altruistic' act on the part of a cell for the benefit of the organism as a whole. It is also considered a form of 'social control' exerted by the body/organism over its component cells. This paper analyzes the various functions of these metaphors and critical discussion about them within the scientific community. Bodies such as the Nomenclature Committee on Cell Death (NCCD) have been charged with bringing order to the language of cell death to facilitate scientific progress. While the NCCD recommends adopting more objective biochemical terminology to describe the mechanisms of cell death, the metaphors in question retain an important function by highlighting the broader context within which cell death occurs. Scientific metaphors act as conceptual 'tools' which fulfill various roles, from highlighting a phenomenon as of particular interest, situating it in a particular context, or suggesting explanatory causal mechanisms. PMID:25085023

  4. Cell death induced by ionizing radiations in human radio-resistant tumours: in-vitro and in-vivo study of mechanisms involved in its induction by different types of radiations and pharmacological modulation

    International Nuclear Information System (INIS)

    Whereas chemo-radiotherapy protocols revealed to be very efficient when taking tumours into care, the treatment of some tumours remains very limited due to their critical location or to the weak radio-sensitivity to conventional radiations. One way to work around this problem is to use high linear energy transfer radiations or hadron therapy, in combination with radio-sensitizers. This research thesis reports the assessment of radio-sensitizer effects of different molecules on human radio-resistant cell lines and more particularly the SK-Hep1 line from a hepatocellular carcinoma. In vitro studies have been performed and then in vivo studies by using fast neutron irradiation on a mice liver sample. Observations made by optic fibre confocal microscopy and transmission electronic microscopy confirmed in vitro observations: the prevailing cell death after such an irradiation is the autophagic cell death. It shows the importance of the autophagic phenomenon induced by radiations with high linear transfer energy. This could lead to new therapeutic protocols for radio-resistant cancers

  5. Activation of intracellular angiotensin AT2 receptors induces rapid cell death in human uterine leiomyosarcoma cells

    DEFF Research Database (Denmark)

    Zhao, Yi; Lützen, Ulf; Fritsch, Jürgen; Zuhayra, Maaz; Schütze, Stefan; Steckelings, Ulrike Muscha; Recarti, Chiara; Namsolleck, Pawel; Unger, Thomas; Culman, Juraj

    2015-01-01

    -peptide AT2 receptor agonist, Compound 21 (C21) penetrates the cell membrane of quiescent SK-UT-1 cells, activates intracellular AT2 receptors and induces rapid cell death; approximately 70% of cells died within 24 h. The cells, which escaped from the cell death, displayed activation of the mitochondrial...... apoptotic pathway, i. e. down-regulation of the Bcl-2 protein, induction of the Bax protein and activation of caspase-3. All quiescent SK-UT-1 cells died within 5 days after treatment with a single dose of C21. C21 was devoid of cytotoxic effects in proliferating SK-UT-1 cells and in quiescent HutSMC. Our...

  6. Different Types of Cell Death Induced by Enterotoxins

    Directory of Open Access Journals (Sweden)

    Ming-Yuan Hong

    2010-08-01

    Full Text Available The infection of bacterial organisms generally causes cell death to facilitate microbial invasion and immune escape, both of which are involved in the pathogenesis of infectious diseases. In addition to the intercellular infectious processes, pathogen-produced/secreted enterotoxins (mostly exotoxins are the major weapons that kill host cells and cause diseases by inducing different types of cell death, particularly apoptosis and necrosis. Blocking these enterotoxins with synthetic drugs and vaccines is important for treating patients with infectious diseases. Studies of enterotoxin-induced apoptotic and necrotic mechanisms have helped us to create efficient strategies to use against these well-characterized cytopathic toxins. In this article, we review the induction of the different types of cell death from various bacterial enterotoxins, such as staphylococcal enterotoxin B, staphylococcal alpha-toxin, Panton-Valentine leukocidin, alpha-hemolysin of Escherichia coli, Shiga toxins, cytotoxic necrotizing factor 1, heat-labile enterotoxins, and the cholera toxin, Vibrio cholerae. In addition, necrosis caused by pore-forming toxins, apoptotic signaling through cross-talk pathways involving mitochondrial damage, endoplasmic reticulum stress, and lysosomal injury is discussed.

  7. 甲硝唑诱导阴道毛滴虫凋亡样细胞死亡%Induction of Apoptotic-like Cell Death in Trichomonas vaginalis by Metronidazole

    Institute of Scientific and Technical Information of China (English)

    邓致刚; 黄景政; 辛致炜; 张仁利; 刘居理; 傅玉才

    2007-01-01

    目的 凋亡或程序性细胞死亡在多细胞生物体中已经被广泛研究,然而,关于单细胞寄生性原生动物细胞凋亡发生的分子机制却知之甚少.本研究旨在了解甲硝唑诱导阴道毛滴虫细胞凋亡的特征.方法 培养阴道毛滴虫并用不同浓度的甲硝唑进行处理.在不同的时间间隔进行活细胞计数.提取甲硝唑处理过的阴道毛滴虫基因组进行DNA断裂片段检测.用DNA断端末端标记(TUNEL)法测定甲硝唑处理后阴道毛滴虫核酸内切酶活性.流式细胞检测分析脂酰丝氨酸暴露情况.结果 甲硝唑可以诱导阴道毛滴虫出现凋亡样细胞死亡.这种凋亡样细胞死亡表现为细胞皱缩,磷脂酰丝氨酸暴露以及核染色体凝聚,但并未检测到寡核苷酸DNA梯带.结论 阴道毛滴虫程序性细胞死亡的调节通路不同于多细胞生物体.确定导致原生动物细胞死亡的凋亡通路也许最终可用于鉴定新的治疗靶点.%Objective Apoptosis or programmed cell death(PCD) has been studied extensively in multicellular organisms,however,very little is known about the molecular mechanisms by which apoptosis occurs in unicellular protozoan parasites.The aim of this study is to characterize the apoptosis or PCD of Trichomonas vaginalis induced by metronidazole (MTZ).Methods T. Vaginalis strain cultures were treated with various concentrations of MTZ and the number of viable cells were determined at different time intervals.The genomic DNA of MTZ treated T. Vaginalis was extracted and DNA fragmentation was analyzed.TUNEL assay was carried out to detect the endonuclease activity in T. Vaginalis after MTZ treatment.Flow cytometric analysis was used to analyse the phosphatidylserine (PS) exposure of T. Vaginalis.Results Metronidazole (MTZ) induced an apoptotic-like cell death in T. Vaginalis.This apoptotic-like cell death was demonstrated by cell shrinkage,phosphatidylserine exposure,and nuclear chromatin condensation

  8. Ganglioside GD2 in reception and transduction of cell death signal in tumor cells

    International Nuclear Information System (INIS)

    Ganglioside GD2 is expressed on plasma membranes of various types of malignant cells. One of the most promising approaches for cancer immunotherapy is the treatment with monoclonal antibodies recognizing tumor-associated markers such as ganglioside GD2. It is considered that major mechanisms of anticancer activity of anti-GD2 antibodies are complement-dependent cytotoxicity and/or antibody-mediated cellular cytotoxicity. At the same time, several studies suggested that anti-GD2 antibodies are capable of direct induction of cell death of number of tumor cell lines, but it has not been investigated in details. In this study we investigated the functional role of ganglioside GD2 in the induction of cell death of multiple tumor cell lines by using GD2-specific monoclonal antibodies. Expression of GD2 on different tumor cell lines was analyzed by flow cytometry using anti-GD2 antibodies. By using HPTLC followed by densitometric analysis we measured the amount of ganglioside GD2 in total ganglioside fractions isolated from tumor cell lines. An MTT assay was performed to assess viability of GD2-positive and -negative tumor cell lines treated with anti-GD2 mAbs. Cross-reactivity of anti-GD2 mAbs with other gangliosides or other surface molecules was investigated by ELISA and flow cytometry. Inhibition of GD2 expression was achieved by using of inhibitor for ganglioside synthesis PDMP and/or siRNA for GM2/GD2 and GD3 synthases. Anti-GD2 mAbs effectively induced non-classical cell death that combined features of both apoptosis and necrosis in GD2-positive tumor cells and did not affect GD2-negative tumors. Anti-GD2 mAbs directly induced cell death, which included alteration of mitochondrial membrane potential, induction of apoptotic volume decrease and cell membrane permeability. This cytotoxic effect was mediated exclusively by specific binding of anti-GD2 antibodies with ganglioside GD2 but not with other molecules. Moreover, the level of GD2 expression correlated with

  9. [Cell death in malignant tumors. Relevance of cell death regulation for metastasis].

    Science.gov (United States)

    Roth, W

    2015-11-01

    Defects in the regulation of cell death are important causes for both the development and therapy resistance of malignant tumors. Several distinct, molecularly defined types of cell death are known, such as apoptosis, anoikis, and necroptosis. Moreover, the specific triggering of cell death plays an important role in the prevention of metastasis. The results of recent studies have shown that various types of cell death are pivotal at different steps of the metastasis cascade, in order to prevent cellular detachment, migration, invasion, intravasation, extravasation and the establishment of micrometastasis and macrometastasis. At the subcellular level, numerous links exist between cell death regulation and metastasis, specifically regarding signaling pathways and individual proteins with dual or multiple functions. As an example, the decoy receptor 3 protein (DcR3) functions both as an anti-apoptotic protein and as a direct promotor of invasion and migration of tumor cells. In summary, the specific triggering of cell death plays a pivotal role for the prevention of metastasis. On the other hand, the stepwise process of metastasis represents a mechanism of selection resulting in established metastases with a multiresistant phenotype which corresponds to the clinical observation that many metastasized cancers are therapy resistant. In the future, innovative diagnostic tests to individually predict the resistance pattern and possibilities to overcome resistance are urgently needed. PMID:26400565

  10. Cell Death Mechanisms Induced by Cytotoxic Lymphocytes

    Institute of Scientific and Technical Information of China (English)

    Ch(a)vez-Gal(a)n L; Arenas-Del Angel MC; Zenteno E; Ch(a)vez R; Lascurain R

    2009-01-01

    One of the functions of the immune system is to recognize and destroy abnormal or infected cells to maintain homeostasis. This is accomplished by cytotoxic lymphocytes. Cytotoxicity is a highly organized multifactor process. Here, we reviewed the apoptosis pathways induced by the two main cytotoxic lymphocyte subsets, natural killer (NK) cells and CD8+T cells. In base to recent experimental evidence, we reviewed NK receptors involved in recognition of target-cell, as well as lytic molecules such as perforin, granzymes-A and -B, and granulysin. In addition, we reviewed the Fas-FasL intercellular linkage mediated pathway, and briefly the cross-linking of tumor necrosis factor (TNF) and TNF receptor pathway. We discussed three models of possible molecular interaction between lyric molecules from effector cytotoxic cells and target-cell membrane to induction of apoptosis.

  11. Immunogenic cell death by oncolytic herpes simplex virus type 1 in squamous cell carcinoma cells.

    Science.gov (United States)

    Takasu, A; Masui, A; Hamada, M; Imai, T; Iwai, S; Yura, Y

    2016-04-01

    Molecules essential for the induction of immunogenic cell death (ICD) are called damage-associated molecular patterns (DAMPs). The effects of oncolytic herpes simplex virus type 1 (HSV-1) on the production of DAMPs were examined in squamous cell carcinoma (SCC) cells. The cytopathic effects of HSV-1 RH2 were observed in mouse SCCVII cells infected at a high multiplicity of infection (MOI), and the amounts of viable cells were decreased. After being infected with RH2, ATP and high mobility group box 1 (HMGB1) were released extracellulary, while calreticulin (CRT) translocated to the cell membrane. A flow-cytometric analysis revealed an increase in the number of annexin-V and propidium iodide (PI)-stained cells; and the amount of cleaved poly (ADP-ribose) polymerase (PARP) was increased. The killing effect of RH2 was reduced by pan-caspase inhibitor z-VAD-fmk and the caspase-1 inhibitor z-YVAD-fmk, suggesting the involvement of apoptosis and pyroptosis. In C3H mice bearing synergic SCCVII tumors, the growth of tumors injected with the supernatant of RH2-infected cells was less than that of tumors injected with phosphate-buffered saline (PBS). These results indicate that oncolytic HSV-1 RH2 produces DAMPs from SCC cells to induce cell death. This may contribute to the enhancement of tumor immunity by oncolytic HSV-1. PMID:26987291

  12. Role of polyphenols in cell death control.

    Science.gov (United States)

    Giovannini, Claudio; Masella, Roberta

    2012-05-01

    Dietary consumption of fruit, vegetables, fish, and olive oil has been demonstrated to exert beneficial effects on human health. This finding may be due to the high content of antioxidant compounds including polyphenols. Current evidence strongly supports a contribution of polyphenols to the prevention of several chronic degenerative diseases such as cancer, atherosclerosis and cardiovascular diseases, central nervous system disorders, as well as aging. Apoptosis is a genetically controlled and evolutionarily conserved form of cell death of critical importance for the maintenance of tissue homeostasis in the adult organism. The malfunction of the death machinery may play a primary role in various pathologic processes, leading to proliferative or degenerative diseases. Polyphenols can interact with specific steps and/or proteins regulating the apoptotic process in different ways depending on their concentration, the cell system, the type or stage of the pathological process. Because of their ability to modulate cell death, polyphenols have been proposed as chemopreventive and therapeutic agents. This paper reviews and discusses the last 3-year findings related to the principal molecular mechanisms involved in the control of the balance between apoptosis and cell proliferation exerted by polyphenols. PMID:22584012

  13. Role of mitochondrial function in cell death and body metabolism.

    Science.gov (United States)

    Lee, Myung-Shik

    2016-01-01

    Mitochondria are the key players in apoptosis and necrosis. Mitochondrial DNA (mtDNA)-depleted r0 cells were resistant to diverse apoptosis inducers such as TNF-alpha, TNFSF10, staurosporine and p53. Apoptosis resistance was accompanied by the absence of mitochondrial potential loss or cytochrome c translocation. r0 cells were also resistant to necrosis induced by reactive oxygen species (ROS) donors due to upregulation of antioxidant enzymes such as manganese superoxide dismutase. Mitochondria also has a close relationship with autophagy that plays a critical role in the turnover of senescent organelles or dysfunctional proteins and may be included in 'cell death' category. It was demonstrated that autophagy deficiency in insulin target tissues such as skeletal muscle induces mitochondrial stress response, which leads to the induction of FGF21 as a 'mitokine' and affects the whole body metabolism. These results show that mitochondria are not simply the power plants of cells generating ATP, but are closely related to several types of cell death and autophagy. Mitochondria affect various pathophysiological events related to diverse disorders such as cancer, metabolic disorders and aging. PMID:27100503

  14. Regulation of cell death in cancer - possible implications for immunotherapy

    OpenAIRE

    Simone eFulda

    2013-01-01

    Since most anticancer therapies including immunotherapy trigger programmed cell death in cancer cells, defective cell death programs can lead to treatment resistance and tumor immune escape. Therefore, evasion of programmed cell death may provide one possible explanation as to why cancer immunotherapy has so far only shown modest clinical benefits for children with cancer. A better understanding of the molecular mechanisms that regulate sensitivity and resistance to programmed cell death is e...

  15. Regulated cell death in diagnostic histopathology.

    Science.gov (United States)

    Skenderi, Faruk; Vranic, Semir; Damjanov, Ivan

    2015-01-01

    Regulated cell death (RCD) is a controlled cellular process, essential for normal development, tissue integrity and homeostasis, and its dysregulation has been implicated in the pathogenesis of various conditions including developmental and immunological disorders, neurodegenerative diseases, and cancer. In this review, we briefly discuss the historical perspective and conceptual development of RCD, we overview recent classifications and some of the key players in RCD; finally we focus on current applications of RCD in diagnostic histopathology. PMID:26009238

  16. Resveratrol mediated cell death in cigarette smoke transformed breast epithelial cells is through induction of p21Waf1/Cip1 and inhibition of long patch base excision repair pathway

    International Nuclear Information System (INIS)

    Cigarette smoking is a key factor for the development and progression of different cancers including mammary tumor in women. Resveratrol (Res) is a promising natural chemotherapeutic agent that regulates many cellular targets including p21, a cip/kip family of cyclin kinase inhibitors involved in DNA damage-induced cell cycle arrest and blocking of DNA replication and repair. We have recently shown that cigarette smoke condensate (CSC) prepared from commercially available Indian cigarette can cause neoplastic transformation of normal breast epithelial MCF-10A cell. Here we studied the mechanism of Res mediated apoptosis in CSC transformed (MCF-10A-Tr) cells in vitro and in vivo. Res mediated apoptosis in MCF-10A-Tr cells was a p21 dependent event. It increased the p21 protein expression in MCF-10A-Tr cells and MCF-10A-Tr cells-mediated tumors in xenograft mice. Res treatment reduced the tumor size(s) and expression of anti-apoptotic proteins (e.g. PI3K, AKT, NFκB) in solid tumor. The expressions of cell cycle regulatory (Cyclins, CDC-2, CDC-6, etc.), BER associated (Pol-β, Pol-δ, Pol-ε, Pol-η, RPA, Fen-1, DNA-Ligase-I, etc.) proteins and LP-BER activity decreased in MCF-10A-Tr cells but remain significantly unaltered in isogenic p21 null MCF-10A-Tr cells after Res treatment. Interestingly, no significant changes were noted in SP-BER activity in both the cell lines after Res exposure. Finally, it was observed that increased p21 blocks the LP-BER in MCF-10A-Tr cells by increasing its interaction with PCNA via competing with Fen-1 after Res treatment. Thus, Res caused apoptosis in CSC-induced cancer cells by reduction of LP-BER activity and this phenomenon largely depends on p21. - Highlights: • Resveratrol (Res) caused reduction of MCF-10A-Tr cell growth by inducing apoptosis. • Res caused cell cycle arrest and DNA damage in p21 dependent manner. • Res mediated LP-BER reduction in MCF-10A-Tr cells was a p21 dependent phenomenon. • Res inhibits BER and PI

  17. Resveratrol mediated cell death in cigarette smoke transformed breast epithelial cells is through induction of p21Waf1/Cip1 and inhibition of long patch base excision repair pathway

    Energy Technology Data Exchange (ETDEWEB)

    Mohapatra, Purusottam; Satapathy, Shakti Ranjan; Das, Dipon; Siddharth, Sumit [Cancer Biology Division, KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024 (India); Choudhuri, Tathagata [Institute of Life Sciences, Nalco Square, Bhubaneswar, Orissa 751023 (India); Department of Biotechnology, Visva Bharati University, Santiniketan, West Bengal (India); Kundu, Chanakya Nath, E-mail: cnkundu@gmail.com [Cancer Biology Division, KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024 (India)

    2014-03-15

    Cigarette smoking is a key factor for the development and progression of different cancers including mammary tumor in women. Resveratrol (Res) is a promising natural chemotherapeutic agent that regulates many cellular targets including p21, a cip/kip family of cyclin kinase inhibitors involved in DNA damage-induced cell cycle arrest and blocking of DNA replication and repair. We have recently shown that cigarette smoke condensate (CSC) prepared from commercially available Indian cigarette can cause neoplastic transformation of normal breast epithelial MCF-10A cell. Here we studied the mechanism of Res mediated apoptosis in CSC transformed (MCF-10A-Tr) cells in vitro and in vivo. Res mediated apoptosis in MCF-10A-Tr cells was a p21 dependent event. It increased the p21 protein expression in MCF-10A-Tr cells and MCF-10A-Tr cells-mediated tumors in xenograft mice. Res treatment reduced the tumor size(s) and expression of anti-apoptotic proteins (e.g. PI3K, AKT, NFκB) in solid tumor. The expressions of cell cycle regulatory (Cyclins, CDC-2, CDC-6, etc.), BER associated (Pol-β, Pol-δ, Pol-ε, Pol-η, RPA, Fen-1, DNA-Ligase-I, etc.) proteins and LP-BER activity decreased in MCF-10A-Tr cells but remain significantly unaltered in isogenic p21 null MCF-10A-Tr cells after Res treatment. Interestingly, no significant changes were noted in SP-BER activity in both the cell lines after Res exposure. Finally, it was observed that increased p21 blocks the LP-BER in MCF-10A-Tr cells by increasing its interaction with PCNA via competing with Fen-1 after Res treatment. Thus, Res caused apoptosis in CSC-induced cancer cells by reduction of LP-BER activity and this phenomenon largely depends on p21. - Highlights: • Resveratrol (Res) caused reduction of MCF-10A-Tr cell growth by inducing apoptosis. • Res caused cell cycle arrest and DNA damage in p21 dependent manner. • Res mediated LP-BER reduction in MCF-10A-Tr cells was a p21 dependent phenomenon. • Res inhibits BER and PI

  18. Influence the oxidant action of selenium in radiosensitivity induction and cell death in yeast Saccharomyces cerevisiae; Influencia da acao oxidante do selenio na inducao da radiossensibilidade e morte celular na levedura Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Porto, Barbara Abranches de Araujo

    2012-07-01

    cells when they are challenged with ionizing radiation produced by {sup 60}Co. For this, we assessed whether selenium causes oxidative damage to cell and cell death. After that, we assessed whether differences in the oxidative damage occurs after the cells be treated with selenium and gamma irradiation. Our results showed that selenium has a radiosensitizing function playing a oxidant role in yeast cell. (author)

  19. Induction of apoptosis in frog virus 3-infected cells.

    Science.gov (United States)

    Chinchar, V G; Bryan, Locke; Wang, J; Long, Scott; Chinchar, G D

    2003-02-15

    The ability of frog virus 3 (FV3), the type species of the family Iridoviridae, to induce apoptosis was examined by monitoring DNA cleavage, chromatin condensation, and cell-surface expression of phosphotidylserine (PS) in fathead minnow (FHM) and baby hamster kidney (BHK) cells. In productively infected FHM cells, DNA fragmentation was first noted at 6-7 h postinfection and was clearly seen by 17 h postinfection, while chromatin condensation was detected at 8.5 h postinfection. As with some other viruses, FV3-induced apoptosis did not require de novo viral gene expression as both heat-inactivated and UV-inactivated virus readily triggered DNA fragmentation in FHM cells. Moreover, FV3-induced apoptosis was blocked in FHM cells by the pan-caspase inhibitor Z-VAD-FMK, suggesting that virus infection triggers programmed cell death through activation of the caspase cascade. FV3 infection also triggered apoptosis in BHK cells as monitored by TUNEL and annexin V binding assays. To determine whether FV3, similar to other large DNA viruses, encoded proteins that block or delay apoptosis, mock- and FV3-infected FHM cells were osmotically shocked and assayed for DNA fragmentation 3 hours later. DNA fragmentation was clearly seen whether or not shocked cells were previously infected with FV3, indicating that infection with FV3 did not block apoptosis induced by osmotic shock in FHM cells. The above results demonstrate that iridoviruses triggered apoptosis and that the induction of programmed cell death did not require viral gene expression. However, it remains to be determined if virion attachment to target cells is sufficient to induce cell death, or if apoptosis is triggered directly or indirectly by one or more virion-associated proteins. PMID:12642103

  20. TNF α and reactive oxygen species in necrotic cell death

    Institute of Scientific and Technical Information of China (English)

    Michael J Morgan; You-Sun Kim; Zheng-gang Liu

    2008-01-01

    Death receptors, including the TNF receptor-1 (TNF-RI), have been shown to be able to initiate caspase-independent cell death. This form of "necrotic cell death" appears to be dependent on the generation of reactive oxygen species. Recent data have indicated that superoxide generation is dependent on the activation of NADPH oxidases, which form a complex with the adaptor molecules RIP1 and TRADD. The mechanism of superoxide generation further establishes RIP1 as the central molecule in ROS production and cell death initiated by TNFa and other death receptors. A role for the sustained JNK activation in necrotic cell death is also suggested. The sensitization of virus-infected cells to TNFa indicates that necrotic cell death may represent an alternative cell death pathway for clearance of infected cells.

  1. 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.

  2. 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.

  3. Oxidative stress is involved in heat-induced cell death in Saccharomyces cerevisiae.

    OpenAIRE

    Davidson, J. F.; Whyte, B.; Bissinger, P H; Schiestl, R H

    1996-01-01

    The cause for death after lethal heat shock is not well understood. A shift from low to intermediate temperature causes the induction of heat-shock proteins in most organisms. However, except for HSP104, a convincing involvement of heat-shock proteins in the development of stress resistance has not been established in Saccharomyces cerevisiae. This paper shows that oxidative stress and antioxidant enzymes play a major role in heat-induced cell death in yeast. Mutants deleted for the antioxida...

  4. (-)-Oleocanthal rapidly and selectively induces cancer cell death via lysosomal membrane permeabilization

    Science.gov (United States)

    LeGendre, Onica; Breslin, Paul AS; Foster, David A

    2015-01-01

    (-)-Oleocanthal (OC), a phenolic compound present in extra-virgin olive oil (EVOO), has been implicated in the health benefits associated with diets rich in EVOO. We investigated the effect of OC on human cancer cell lines in culture and found that OC induced cell death in all cancer cells examined as rapidly as 30 minutes after treatment in the absence of serum. OC treatment of non-transformed cells suppressed their proliferation but did not cause cell death. OC induced both primary necrotic and apoptotic cell death via induction of lysosomal membrane permeabilization (LMP). We provide evidence that OC promotes LMP by inhibiting acid sphingomyelinase (ASM) activity, which destabilizes the interaction between proteins required for lysosomal membrane stability. The data presented here indicate that cancer cells, which tend to have fragile lysosomal membranes compared to non-cancerous cells, are susceptible to cell death induced by lysosomotropic agents. Therefore, targeting lysosomal membrane stability represents a novel approach for the induction of cancer-specific cell death. PMID:26380379

  5. BH3 Mimetics Reactivate Autophagic Cell Death in Anoxia-Resistant Malignant Glioma Cells

    Directory of Open Access Journals (Sweden)

    Holger Hetschko

    2008-08-01

    Full Text Available Here, we investigated the specific roles of Bcl-2 family members in anoxia tolerance of malignant glioma. Flow cytometry analysis of cell death in 17 glioma cell lines revealed drastic differences in their sensitivity to oxygen withdrawal (<0.1% O2. Cell death correlated with mitochondrial depolarization, cytochrome C release, and translocation of green fluorescent protein (GFP-tagged light chain 3 to autophagosomes but occurred in the absence of caspase activation or phosphatidylserine exposure. In both sensitive and tolerant glioma cell lines, anoxia caused a significant up-regulation of BH3-only genes previously implicated in mediating anoxic cell death in other cell types (BNIP3, NIX, PUMA, and Noxa. In contrast, we detected a strong correlation between anoxia resistance and high expression levels of antiapoptotic Bcl-2 family proteins Bcl-xL, Bcl-2, and Mcl-1 that function to neutralize the proapoptotic activity of BH3-only proteins. Importantly, inhibition of both Bcl-2 and Bcl-xL with the small-molecule BH3 mimetics HA14-1 and BH3I-2′ and by RNA interference reactivated anoxia-induced autophagic cell death in previously resistant glioma cells. Our data suggest that endogenous BH3-only protein induction may not be able to compensate for the high expression of antiapoptotic Bcl-2 family proteins in anoxia-resistant astrocytomas. They also support the conjecture that BH3 mimetics may represent an exciting new approach for the treatment of malignant glioma.

  6. Type I collagen gel protects murine fibrosarcoma L929 cells from TNFα-induced cell death

    International Nuclear Information System (INIS)

    Murine fibrosarcoma L929 cells have been used to test efficacy of proinflammatory cytokine TNFα. In the present study, we reported on protective effect of type I collagen gel used as L929 cell culture. L929 cell grew and proliferated well on collagen gel. However, the L929 cells exhibited cobblestone-like morphology which was much different from the spread fusiform shape when cultured on conventional cell dishes as well as the cells tended to aggregate. On conventional cell culture dishes, the cells treated with TNFα became round in shape and eventually died in a necroptotic manner. The cells cultured on collagen gel, however, were completely unaffected. TNFα treatment was reported to induce autophagy in L929 cells on the plastic dish, and therefore we investigated the effect of collagen gel on induction of autophagy. The results indicated that autophagy induced by TNFα treatment was much reduced when the cells were cultured on collagen gel. In conclusion, type I collagen gel protected L929 cell from TNFα-induced cell death. - Highlights: • Collagen gel culture changed the morphology of L929 cells. • L929 cell cultured on collagen gel were resistant to TNFα-induced cell death. • Collagen gel culture inhibited TNFα-induced autophagy in L929 cells

  7. Type I collagen gel protects murine fibrosarcoma L929 cells from TNFα-induced cell death

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hong-Ju; He, Wen-Qi; Chen, Ling; Liu, Wei-Wei; Xu, Qian; Xia, Ming-Yu; Hayashi, Toshihiko [China-Japan Research Institute of Medical and Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang 110016 (China); Fujisaki, Hitomi; Hattori, Shunji [Nippi Research Institute of Biomatrix, Toride, Ibaraki 302-0017 (Japan); Tashiro, Shin-ichi [Institute for Clinical and Biomedical Sciences, Kyoto 603-8072 (Japan); Onodera, Satoshi [Department of Clinical and Pharmaceutical Sciences, Showa Pharmaceutical University, Tokyo 194-8543 (Japan); Ikejima, Takashi, E-mail: ikejimat@vip.sina.com [China-Japan Research Institute of Medical and Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang 110016 (China)

    2015-02-20

    Murine fibrosarcoma L929 cells have been used to test efficacy of proinflammatory cytokine TNFα. In the present study, we reported on protective effect of type I collagen gel used as L929 cell culture. L929 cell grew and proliferated well on collagen gel. However, the L929 cells exhibited cobblestone-like morphology which was much different from the spread fusiform shape when cultured on conventional cell dishes as well as the cells tended to aggregate. On conventional cell culture dishes, the cells treated with TNFα became round in shape and eventually died in a necroptotic manner. The cells cultured on collagen gel, however, were completely unaffected. TNFα treatment was reported to induce autophagy in L929 cells on the plastic dish, and therefore we investigated the effect of collagen gel on induction of autophagy. The results indicated that autophagy induced by TNFα treatment was much reduced when the cells were cultured on collagen gel. In conclusion, type I collagen gel protected L929 cell from TNFα-induced cell death. - Highlights: • Collagen gel culture changed the morphology of L929 cells. • L929 cell cultured on collagen gel were resistant to TNFα-induced cell death. • Collagen gel culture inhibited TNFα-induced autophagy in L929 cells.

  8. Programmed cell death and its role in inflammation

    Institute of Scientific and Technical Information of China (English)

    Yong Yang; Ge-Ning Jiang; Peng Zhang; Jie Fan

    2015-01-01

    Cell death plays an important role in the regulation of inflammation and may be the result of inflammation. The maintenance of tissue homeostasis necessitates both the recognition and removal of invading microbial pathogens as well as the clearance of dying cells. In the past few decades, emerging knowledge on cell death and inflammation has enriched our molecular understanding of the signaling pathways that mediate various programs of cell death and multiple types of inflammatory responses. This review provides an overview of the major types of cell death related to inflammation. Modification of cell death pathways is likely to be a logical therapeutic target for inflammatory diseases.

  9. Programmed cell death in plants and caspase-like activities

    NARCIS (Netherlands)

    Gaussand, Gwénael Martial Daniel Jean-Marie

    2007-01-01

    The development of multicellular organisms involves an important balance between cell growth, cell division and cell death. In animals, programmed cell death (PCD) plays a key role by forming and deleting structures, controlling cell numbers and eliminating abnormal damaged cells. Caspases were foun

  10. Alkaloids Induce Programmed Cell Death in Bloodstream Forms of Trypanosomes (Trypanosoma b. brucei

    Directory of Open Access Journals (Sweden)

    Michael Wink

    2008-10-01

    Full Text Available The potential induction of a programmed cell death (PCD in Trypanosoma b. brucei by 55 alkaloids of the quinoline, quinolizidine, isoquinoline, indole, terpene, tropane, steroid, and piperidine type was studied by measuring DNA fragmentation and changes in mitochondrial membrane potential. For comparison, the induction of apoptosis by the same alkaloids in human leukemia cells (Jurkat APO-S was tested. Several alkaloids of the isoquinoline, quinoline, indole and steroidal type (berberine, chelerythrine, emetine, sanguinarine, quinine, ajmalicine, ergotamine, harmine, vinblastine, vincristine, colchicine, chaconine, demissidine and veratridine induced programmed cell death, whereas quinolizidine, tropane, terpene and piperidine alkaloids were mostly inactive. Effective PCD induction (EC50 below 10 µM was caused in T. brucei by chelerythrine, emetine, sanguinarine, and chaconine. The active alkaloids can be characterized by their general property to inhibit protein biosynthesis, to intercalate DNA, to disturb membrane fluidity or to inhibit microtubule formation.

  11. Inhibition of caspases prevents ototoxic and ongoing hair cell death

    Science.gov (United States)

    Matsui, Jonathan I.; Ogilvie, Judith M.; Warchol, Mark E.

    2002-01-01

    Sensory hair cells die after acoustic trauma or ototoxic insults, but the signal transduction pathways that mediate hair cell death are not known. Here we identify several important signaling events that regulate the death of vestibular hair cells. Chick utricles were cultured in media supplemented with the ototoxic antibiotic neomycin and selected pharmacological agents that influence signaling molecules in cell death pathways. Hair cells that were treated with neomycin exhibited classically defined apoptotic morphologies such as condensed nuclei and fragmented DNA. Inhibition of protein synthesis (via treatment with cycloheximide) increased hair cell survival after treatment with neomycin, suggesting that hair cell death requires de novo protein synthesis. Finally, the inhibition of caspases promoted hair cell survival after neomycin treatment. Sensory hair cells in avian vestibular organs also undergo continual cell death and replacement throughout mature life. It is unclear whether the loss of hair cells stimulates the proliferation of supporting cells or whether the production of new cells triggers the death of hair cells. We examined the effects of caspase inhibition on spontaneous hair cell death in the chick utricle. Caspase inhibitors reduced the amount of ongoing hair cell death and ongoing supporting cell proliferation in a dose-dependent manner. In isolated sensory epithelia, however, caspase inhibitors did not affect supporting cell proliferation directly. Our data indicate that ongoing hair cell death stimulates supporting cell proliferation in the mature utricle.

  12. Death-associated Protein Kinase Mediated Cell Death Modulated by Interaction with DANGER

    OpenAIRE

    Kang, Bingnan N.; Ahmad, Abdullah S.; Saleem, Sofiyan; Patterson, Randen L.; Hester, Lynda; Doré, Sylvain; Snyder, Solomon H.

    2010-01-01

    Death-associated protein kinase (DAPK) is a key player in multiple cell death signaling pathways. We report that DAPK is regulated by DANGER, a partial MAB-21-domain containing protein. DANGER binds directly to DAPK and inhibits DAPK catalytic activity. DANGER-deficient mouse embryonic fibroblasts and neurons exhibit greater DAPK activity and increased sensitivity to cell death stimuli than do wild-type control cells. In addition, DANGER-deficient mice manifest more severe brain damage after ...

  13. Blocking CD147 induces cell death in cancer cells through impairment of glycolytic energy metabolism

    International Nuclear Information System (INIS)

    CD147 is a multifunctional transmembrane protein and promotes cancer progression. We found that the anti-human CD147 mouse monoclonal antibody MEM-M6/1 strongly induces necrosis-like cell death in LoVo, HT-29, WiDr, and SW620 colon cancer cells and A2058 melanoma cells, but not in WI-38 and TIG-113 normal fibroblasts. Silencing or overexpression of CD147 in LoVo cells enhanced or decreased the MEM-M6/1 induced cell death, respectively. CD147 is known to form complex with proton-linked monocarboxylate transporters (MCTs), which is critical for lactate transport and intracellular pH (pHi) homeostasis. In LoVo cells, CD147 and MCT-1 co-localized on the cell surface, and MEM-M6/1 inhibited the association of these molecules. MEM-M6/1 inhibited lactate uptake, lactate release, and reduced pHi. Further, the induction of acidification was parallel to the decrease of the glycolytic flux and intracellular ATP levels. These effects were not found in the normal fibroblasts. As cancer cells depend on glycolysis for their energy production, CD147 inhibition might induce cell death specific to cancer cells

  14. Programmed Cell Death in Unicellular Phytoplankton.

    Science.gov (United States)

    Bidle, Kay D

    2016-07-11

    Unicellular, planktonic, prokaryotic and eukaryotic photoautotrophs (phytoplankton) have an ancient evolutionary history on Earth during which time they have played key roles in the regulation of marine food webs, biogeochemical cycles, and Earth's climate. Since they represent the basis of aquatic ecosystems, the manner in which phytoplankton die critically determines the flow and fate of photosynthetically fixed organic matter (and associated elements), ultimately constraining nutrient flow. Programmed cell death (PCD) and associated pathway genes, which are triggered by a variety of abiotic (nutrient, light, osmotic) and biotic (virus infection, allelopathy) environmental stresses, have an integral grip on cell fate, and have shaped the ecological success and evolutionary trajectory of diverse phytoplankton lineages. A combination of physiological, biochemical, and genetic techniques in model algal systems has demonstrated a conserved molecular and mechanistic framework of stress surveillance, signaling, and death activation pathways, involving collective and coordinated participation of organelles, redox enzymes, metabolites, and caspase-like proteases. This mechanistic understanding has provided insight into the integration of sensing and transduction of stress signals into cellular responses, and the mechanistic interfaces between PCD, cell stress and virus infection pathways. It has also provided insight into the evolution of PCD in unicellular photoautotrophs, the impact of PCD on the fate of natural phytoplankton assemblages and its role in aquatic biogeochemical cycles. PMID:27404255

  15. How some T cells escape tolerance induction.

    Science.gov (United States)

    Gammon, G; Sercarz, E

    1989-11-01

    A feature common to many animal models of autoimmune disease, for example, experimental allergic encephalomyelitis, experimental autoimmune myasthenia gravis and collagen-induced arthritis, is the presence of self-reactive T cells in healthy animals, which are activated to produce disease by immunization with exogenous antigen. It is unclear why these T cells are not deleted during ontogeny in the thymus and, having escaped tolerance induction, why they are not spontaneously activated by self-antigen. To investigate these questions, we have examined an experimental model in which mice are tolerant to an antigen despite the presence of antigen-reactive T cells. We find that the T cells that escape tolerance induction are specific for minor determinants on the antigen. We propose that these T cells evade tolerance induction because some minor determinants are only available in relatively low amounts after in vivo processing of the whole antigen. For the same reason, these T cells are not normally activated but can be stimulated under special circumstances to circumvent tolerance. PMID:2478888

  16. Colorectal Cancer Stem Cells and Cell Death

    International Nuclear Information System (INIS)

    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

  17. Induction of caspase-8 and death receptors by a new dammarane skeleton from the dried fruits of Forsythia koreana.

    Science.gov (United States)

    Hawas, Usama W; Gamal-Eldeen, Amira M; El-Desouky, Samy K; Kim, Young-Kyoon; Huefner, Antje; Saf, Robert

    2013-01-01

    A new naturally occurring compound based on the dammarane skeleton, i.e. cabralealactone 3-acetate-24-methyl ether, was isolated from the aqueous methanolic extract of Forsythia koreana fruits, along with eight known compounds: cabralealactone 3-acetate, ursolic acid, arctigenin, arctiin, phillyrin, rutin, caffeic acid, and rosmarinic acid. The identification of the isolated compounds was based on their spectral analysis including: HREI-MS, 1D and 2D NMR spectroscopy. The selected compounds and the aqueous methanolic extract were evaluated for their cytotoxic activity against human solid tumour cell lines. Cabralealactone 3-acetate-24-methyl ether and ursolic acid were found to be active against human breast cancer cells (MCF-7). The cytotoxicity was associated with the activation of caspase-8, the induction of the death receptors DR4 and DR5, as well as DNA fragmentation, and was thus due to apoptosis rather than necrosis. PMID:23659170

  18. Genetic regulation of programmed cell death in Drosophila

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Programmed cell death plays an important role in maintaining homeostasis during animal development, and has been conserved in animals as different as nematodes and humans. Recent studies of Drosophila have provided valuable information toward our understanding of genetic regulation of death. Different signals trigger the novel death regulators rpr, hid, and grim, that utilize the evolutionarily conserved iap and ark genes to modulate caspase function. Subsequent removal of dying cells also appears to be accomplished by conserved mechanisms. The similarity between Drosophila and human in cell death signaling pathways illustrate the promise of fruit flies as a model system to elucidate the mechanisms underlying regulation of programmed cell death.

  19. Plant programmed cell death, ethylene and flower senescence

    NARCIS (Netherlands)

    Woltering, E.J.; Jong, de A.; Hoeberichts, F.A.; Iakimova, E.T.; Kapchina, V.

    2005-01-01

    Programmed cell death (PCD) applies to cell death that is part of the normal life of multicellular organisms. PCD is found throughout the animal and plant kingdoms; it is an active process in which a cell suicide pathway is activated resulting in controlled disassembly of the cell. Most cases of PCD

  20. Cell Death Inducing Microbial Protein Phosphatase Inhibitors—Mechanisms of Action

    Directory of Open Access Journals (Sweden)

    Rune Kleppe

    2015-10-01

    Full Text Available Okadaic acid (OA and microcystin (MC as well as several other microbial toxins like nodularin and calyculinA are known as tumor promoters as well as inducers of apoptotic cell death. Their intracellular targets are the major serine/threonine protein phosphatases. This review summarizes mechanisms believed to be responsible for the death induction and tumor promotion with focus on the interdependent production of reactive oxygen species (ROS and activation of Ca2+/calmodulin kinase II (CaM-KII. New data are presented using inhibitors of specific ROS producing enzymes to curb nodularin/MC-induced liver cell (hepatocyte death. They indicate that enzymes of the arachidonic acid pathway, notably phospholipase A2, 5-lipoxygenase, and cyclooxygenases, may be required for nodularin/MC-induced (and presumably OA-induced cell death, suggesting new ways to overcome at least some aspects of OA and MC toxicity.

  1. 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.)

  2. Sensitization by wortmannin of heat- or X-ray induced cell death in cultured Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Here we found that wortmannin sensitized Chinese hamster V79 cells to hyperthermic treatment at 44.0 deg C as determined either by colony formation assay or by dye exclusion assay. Wortmannin enhanced heat-induced cell death accompanying cleavage of poly (ADP-ribose) polymerases (PARP). Additionally, the induction of heat shock protein HSP70 was suppressed and delayed in wortmannin-treated cells. Heat sensitizing effect of wortmannin was obvious at more than 5 or 10 μM of final concentrations, while radiosensitization was apparent at 5 μM. Requirement for high concentration of wortmannin, i.e., order of μM, suggests a possible role of certain protein kinases, such as DNA-PK and/or ATM among PI3-kinase family. The sensitization was minimal when wortmannin was added at the end of heat treatment. This was similar to the case of X-ray. Since heat-induced cell death and PARP cleavage preceded HSP70 induction phenomenon, the sensitization to the hyperthermic treatment was considered mainly caused by enhanced apoptotic cell death rather than secondary to suppression or delay by wortmannin of HSP70 induction. Further, in the present system radiosensitization by wortmannin was also at least partly mediated through enhancement of apoptotic cell death. (author)

  3. Analysis of cell death inducing compounds

    DEFF Research Database (Denmark)

    Spicker, Jeppe; Pedersen, Henrik Toft; Nielsen, Henrik Bjørn;

    2007-01-01

    Biomarkers for early detection of toxicity hold the promise of improving the failure rates in drug development. In the present study, gene expression levels were measured using full-genome RAE230 version 2 Affymetrix GeneChips on rat liver tissue 48 h after administration of six different compounds......), ornithine aminotransferase (OAT) and Cytochrome P450, subfamily IIC (mephenytoin 4-hydroxylase) (Cyp2C29). RT-PCR for these three genes was performed and four additional compounds were included for validation. The quantitative RT-PCR analysis confirmed the findings based on the microarray data and using the...... three genes a classification rate of 55 of 57 samples was achieved for the classification of not toxic versus toxic. The single most promising biomarker (OAT) alone resulted in a surprisingly 100% correctly classified samples. OAT has not previously been linked to toxicity and cell death in the...

  4. Calcium and cell death signaling in neurodegeneration and aging

    Directory of Open Access Journals (Sweden)

    Soraya Smaili

    2009-09-01

    Full Text Available Transient increase in cytosolic (Cac2+ and mitochondrial Ca2+ (Ca m2+ are essential elements in the control of many physiological processes. However, sustained increases in Ca c2+ and Ca m2+ may contribute to oxidative stress and cell death. Several events are related to the increase in Ca m2+, including regulation and activation of a number of Ca2+ dependent enzymes, such as phospholipases, proteases and nucleases. Mitochondria and endoplasmic reticulum (ER play pivotal roles in the maintenance of intracellular Ca2+ homeostasis and regulation of cell death. Several lines of evidence have shown that, in the presence of some apoptotic stimuli, the activation of mitochondrial processes maylead to the release of cytochrome c followed by the activation of caspases, nuclear fragmentation and apoptotic cell death. The aim of this review was to show how changes in calcium signaling can be related to the apoptotic cell death induction. Calcium homeostasis was also shown to be an important mechanism involved in neurodegenerative and aging processes.Aumentos transientes no cálcio citosólico (Ca c2+ e mitocondrial (Ca m2+ são elementos essenciais no controle de muitos processos fisiológicos. No entanto, aumentos sustentados do Ca c2+ e do Ca m2+ podem contribuir para o estresse oxidativo ea morte celular. Muitos eventos estão relacionados ao aumentono Ca c2+, incluindo a regulação e ativação de várias enzimas dependentes de Ca2+ como as fosfolipases, proteases e nucleases. A mitocôndria e o retículo endoplasmático têm um papel central na manutenção da homeostase intracellular de Ca c2+ e na regulação da morte celular. Várias evidências mostraram que, na presença de certos estímulos apoptóticos, a ativação dos processos mitocondriais pode promover a liberação de citocromo c, seguida da ativação de caspases, fragmentação nuclear e morte celular por apoptose. O objetivo desta revisão é mostrar como aumentos na sinalização de

  5. The anti-cell death FNK protein protects cells from death induced by freezing and thawing

    International Nuclear Information System (INIS)

    The FNK protein, constructed from anti-apoptotic Bcl-xL with enhanced activity, was fused with the protein transduction domain (PTD) of the HIV/Tat protein to mediate the delivery of FNK into cells. The fusion protein PTD-FNK was introduced into chondrocytes in isolated articular cartilage-bone sections, cultured neurons, and isolated bone marrow mononuclear cells to evaluate its ability to prevent cell death induced by freezing and thawing. PTD-FNK protected the cells from freeze-thaw damage in a concentration-dependent manner. Addition of PTD-FNK with conventional cryoprotectants (dimethyl sulfoxide and hydroxyethyl starch) increased surviving cell numbers around 2-fold compared with controls treated only with the cryoprotectants. Notably, PTD-FNK allowed CD34+ cells among bone marrow mononuclear cells to survive more efficiently (12-fold more than the control cells) from two successive freeze-thaw cycles. Thus, PTD-FNK prevented cell death induced by freezing and thawing, suggesting that it provides for the successful cryopreservation of biological materials

  6. Cell death triggered by alpha-emitting {sup 213}Bi-immunoconjugates in HSC45-M2 gastric cancer cells is different from apoptotic cell death

    Energy Technology Data Exchange (ETDEWEB)

    Seidl, Christof; Schroeck, Hedwig; Seidenschwang, Sabine; Beck, Roswitha; Schwaiger, Markus; Senekowitsch-Schmidtke, Reingard [Technische Universitaet Muenchen, Department of Nuclear Medicine, Munich (Germany); Schmid, Ernst [National Research Center for Environment and Health, Institute of Radiation Biology, GSF, Neuherberg (Germany); Abend, Michael [German Armed Forces, Institute of Radiobiology, Munich (Germany); Becker, Karl-Friedrich [Technische Universitaet Muenchen, Institute of Pathology, Munich (Germany); National Research Center for Environment and Health, Institute of Pathology, GSF, Neuherberg (Germany); National Research Center for Environment and Health, Institute of Molecular Immunology, GSF, Munich (Germany); Apostolidis, Christos; Nikula, Tuomo K. [European Commission, Institute for Transuranium Elements, Karlsruhe (Germany); Kremmer, Elisabeth [National Research Center for Environment and Health, Institute of Molecular Immunology, GSF, Munich (Germany)

    2005-03-01

    Radioimmunotherapy with {alpha}-particle-emitting nuclides, such as{sup 213}Bi, is a promising concept for the elimination of small tumour nodules or single disseminated tumour cells. The aim of this study was to investigate cellular damage and the mode of cell death triggered by {sup 213}Bi-immunoconjugates. Human gastric cancer cells (HSC45-M2) expressing d9-E-cadherin were incubated with different levels of activity of {sup 213}Bi-d9MAb targeting d9-E-cadherin and {sup 213}Bi-d8MAb, which does not bind to d9-E-cadherin. Micronucleated (M) cells, abnormal (A) cells and apoptotic (A) [(MAA)] cells were scored microscopically in the MAA assay following fluorescent staining of nuclei and cytoplasm. Chromosomal aberrations were analysed microscopically following Giemsa staining. The effect of z-VAD-fmk, known to inhibit apoptosis, on the prevention of cell death was investigated following treatment of HSC45-M2 cells with sorbitol as well as {sup 213}Bi-d9MAb. Activation of caspase 3 after incubation of HSC45-M2 cells with both sorbitol and {sup 213}Bi-d9MAb was analysed via Western blotting. Following incubation of HSC45-M2 human gastric cancer cells expressing d9-E-cadherin with {sup 213}Bi-d9MAb the number of cells killed increased proportional to the applied activity concentration. Microscopically visible effects of {alpha}-irradiation of HSC45-M2 cells were formation of micronuclei and severe chromosomal aberrations. Preferential induction of these lesions with specific {sup 213}Bi-d9MAb compared with unspecific {sup 213}Bi-d8MAb (not targeting d9-E-cadherin) was not observed if the number of floating, i.e. unbound {sup 213}Bi-immunoconjugates per cell exceeded 2 x 10{sup 4}, most likely due to intense crossfire. In contrast to sorbitol-induced cell death, cell death triggered by {sup 213}Bi-immunoconjugates was independent of caspase 3 activation and could not be inhibited by z-VAD-fmk, known to suppress the apoptotic pathway. {sup 213}Bi-immunoconjugates seem

  7. Cell death triggered by alpha-emitting 213Bi-immunoconjugates in HSC45-M2 gastric cancer cells is different from apoptotic cell death

    International Nuclear Information System (INIS)

    Radioimmunotherapy with α-particle-emitting nuclides, such as213Bi, is a promising concept for the elimination of small tumour nodules or single disseminated tumour cells. The aim of this study was to investigate cellular damage and the mode of cell death triggered by 213Bi-immunoconjugates. Human gastric cancer cells (HSC45-M2) expressing d9-E-cadherin were incubated with different levels of activity of 213Bi-d9MAb targeting d9-E-cadherin and 213Bi-d8MAb, which does not bind to d9-E-cadherin. Micronucleated (M) cells, abnormal (A) cells and apoptotic (A) [(MAA)] cells were scored microscopically in the MAA assay following fluorescent staining of nuclei and cytoplasm. Chromosomal aberrations were analysed microscopically following Giemsa staining. The effect of z-VAD-fmk, known to inhibit apoptosis, on the prevention of cell death was investigated following treatment of HSC45-M2 cells with sorbitol as well as 213Bi-d9MAb. Activation of caspase 3 after incubation of HSC45-M2 cells with both sorbitol and 213Bi-d9MAb was analysed via Western blotting. Following incubation of HSC45-M2 human gastric cancer cells expressing d9-E-cadherin with 213Bi-d9MAb the number of cells killed increased proportional to the applied activity concentration. Microscopically visible effects of α-irradiation of HSC45-M2 cells were formation of micronuclei and severe chromosomal aberrations. Preferential induction of these lesions with specific 213Bi-d9MAb compared with unspecific 213Bi-d8MAb (not targeting d9-E-cadherin) was not observed if the number of floating, i.e. unbound 213Bi-immunoconjugates per cell exceeded 2 x 104, most likely due to intense crossfire. In contrast to sorbitol-induced cell death, cell death triggered by 213Bi-immunoconjugates was independent of caspase 3 activation and could not be inhibited by z-VAD-fmk, known to suppress the apoptotic pathway. 213Bi-immunoconjugates seem to induce a mode of cell death different from apoptosis in HSC45-M2 cells. (orig.)

  8. Mitochondrial calcium uniporter silencing potentiates caspase-independent cell death in MDA-MB-231 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Curry, Merril C.; Peters, Amelia A. [School of Pharmacy, The University of Queensland, Brisbane, Queensland 4072 (Australia); Kenny, Paraic A. [Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Roberts-Thomson, Sarah J. [School of Pharmacy, The University of Queensland, Brisbane, Queensland 4072 (Australia); Monteith, Gregory R., E-mail: gregm@uq.edu.au [School of Pharmacy, The University of Queensland, Brisbane, Queensland 4072 (Australia)

    2013-05-10

    Highlights: •Some clinical breast cancers are associated with MCU overexpression. •MCU silencing did not alter cell death initiated with the Bcl-2 inhibitor ABT-263. •MCU silencing potentiated caspase-independent cell death initiated by ionomycin. •MCU silencing promoted ionomycin-mediated cell death without changes in bulk Ca{sup 2+}. -- Abstract: The mitochondrial calcium uniporter (MCU) transports free ionic Ca{sup 2+} into the mitochondrial matrix. We assessed MCU expression in clinical breast cancer samples using microarray analysis and the consequences of MCU silencing in a breast cancer cell line. Our results indicate that estrogen receptor negative and basal-like breast cancers are characterized by elevated levels of MCU. Silencing of MCU expression in the basal-like MDA-MB-231 breast cancer cell line produced no change in proliferation or cell viability. However, distinct consequences of MCU silencing were seen on cell death pathways. Caspase-dependent cell death initiated by the Bcl-2 inhibitor ABT-263 was not altered by MCU silencing; whereas caspase-independent cell death induced by the calcium ionophore ionomycin was potentiated by MCU silencing. Measurement of cytosolic Ca{sup 2+} levels showed that the promotion of ionomycin-induced cell death by MCU silencing occurs independently of changes in bulk cytosolic Ca{sup 2+} levels. This study demonstrates that MCU overexpression is a feature of some breast cancers and that MCU overexpression may offer a survival advantage against some cell death pathways. MCU inhibitors may be a strategy to increase the effectiveness of therapies that act through the induction of caspase-independent cell death pathways in estrogen receptor negative and basal-like breast cancers.

  9. Novel self-micellizing anticancer lipid nanoparticles induce cell death of colorectal cancer cells.

    Science.gov (United States)

    Sundaramoorthy, Pasupathi; Baskaran, Rengarajan; Mishra, Siddhartha Kumar; Jeong, Keun-Yeong; Oh, Seung Hyun; Kyu Yoo, Bong; Kim, Hwan Mook

    2015-11-01

    In the present study, we developed a novel drug-like self-micellizing anticancer lipid (SMAL), and investigated its anticancer activity and effects on cell death pathways in human colorectal cancer (CRC) cell lines. Three self-assembled nanoparticles were prepared, namely, SMAL102 (lauramide derivative), SMAL104 (palmitamide derivative), and SMAL108 (stearamide derivative) by a thin-film hydration technique, and were characterized for physicochemical and biological parameters. SMAL102 were nanosized (160.23 ± 8.11 nm) with uniform spherical shape, while SMAL104 and SMAL108 did not form spherical shape but formed large size nanoparticles and irregular in shape. Importantly, SMAL102 showed a cytotoxic effect towards CRC cell lines (HCT116 and HT-29), and less toxicity to a normal colon fibroblast cell line (CCD-18Co). Conversely, SMAL104 and SMAL108 did not have an anti-proliferative effect on CRC cell lines. SMAL102 nanoparticles were actively taken up by CRC cell lines, localized in the cell membrane, and exhibited remarkable cytotoxicity in a concentration-dependent manner. The normal colon cell line showed significantly less cellular uptake and non-cytotoxicity as compared with the CRC cell lines. SMAL102 nanoparticles induced caspase-3, caspase-9, and PARP cleavage in HT-29 cells, indicating the induction of apoptosis; whereas LC3B was activated in HCT116 cells, indicating autophagy-induced cell death. Collectively, these results demonstrate that SMAL102 induced cell death via activation of apoptosis and autophagy in CRC cell lines. The present study could be a pioneer for further preclinical and clinical development of such compounds. PMID:26342325

  10. Inhibition of thromboxane synthase induces lung cancer cell death via increasing the nuclear p27

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Kin Chung; Hsin, Michael K.Y.; Chan, Joey S.Y.; Yip, Johnson H.Y.; Li, Mingyue; Leung, Billy C.S. [Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Mok, Tony S.K. [Department of Clinical Oncology, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Warner, Timothy D. [The William Harvey Research Institute, Queen Mary University of London, London (United Kingdom); Underwood, Malcolm J. [Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Chen, George G., E-mail: gchen@cuhk.edu.hk [Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong)

    2009-10-15

    The role of thromboxane in lung carcinogenesis is not clearly known, though thromboxane B2 (TXB{sub 2}) level is increased and antagonists of thromboxane receptors or TXA2 can induce apoptosis of lung cancer cells. p27, an atypical tumor suppressor, is normally sequestered in the nucleus. The increased nuclear p27 may result in apoptosis of tumor cells. We hypothesize that the inhibition of thromboxane synthase (TXS) induces the death of lung cancer cells and that such inhibition is associated with the nuclear p27 level. Our experiment showed that the inhibition of TXS significantly induced the death or apoptosis in lung cancer cells. The activity of TXS was increased in lung cancer. The nuclear p27 was remarkably reduced in lung cancer tissues. The inhibition of TXS caused the cell death and apoptosis of lung cancer cells, likely via the elevation of the nuclear p27 since the TXS inhibition promoted the nuclear p27 level and the inhibition of p27 by its siRNA recovered the cell death induced by TXS inhibition. Collectively, lung cancer cells produce high levels of TXB{sub 2} but their nuclear p27 is markedly reduced. The inhibition of TXS results in the p27-related induction of cell death in lung cancer cells.

  11. Magnaporthe oryzae-Secreted Protein MSP1 Induces Cell Death and Elicits Defense Responses in Rice.

    Science.gov (United States)

    Wang, Yiming; Wu, Jingni; Kim, Sang Gon; Tsuda, Kenichi; Gupta, Ravi; Park, Sook-Young; Kim, Sun Tae; Kang, Kyu Young

    2016-04-01

    The Magnaporthe oryzae snodprot1 homolog (MSP1), secreted by M. oryzae, is a cerato-platanin family protein. msp1-knockout mutants have reduced virulence on barley leaves, indicating that MSP1 is required for the pathogenicity of rice blast fungus. To investigate the functional roles of MSP1 and its downstream signaling in rice, recombinant MSP1 was produced in Escherichia coli and was assayed for its functionality. Application of MSP1 triggered cell death and elicited defense responses in rice. MSP1 also induced H2O2 production and autophagic cell death in both suspension-cultured cells and rice leaves. One or more protein kinases triggered cell death, jasmonic acid and abscisic acid enhanced cell death, while salicylic acid suppressed it. We demonstrated that the secretion of MSP1 into the apoplast is a prerequisite for triggering cell death and activating defense-related gene expression. Furthermore, pretreatment of rice with a sublethal MSP1 concentration potentiated resistance to the pathogen. Taken together, our results showed that MSP1 induces a high degree of cell death in plants, which might be essential for its virulence. Moreover, rice can recognize MSP1, resulting in the induction of pathogen-associated molecular pattern-triggered immunity. PMID:26780420

  12. Programmed cell death: a way of life for plants.

    OpenAIRE

    Greenberg, J T

    1996-01-01

    Cell death in higher plants has been widely observed in predictable patterns throughout development and in response to pathogenic infection. Genetic, biochemical, and morphological evidence suggests that these cell deaths occur as active processes and can be defined formally as examples of programmed cell death (PCD). Intriguingly, plants have at least two types of PCD, an observation that is also true of PCD in animals [Schwartz, L. M., Smith, W.W., Jones, M. E. E. & Osborne, B. A. (1993) Pr...

  13. Mathematical Model of an Inductive Measuring Cell for Contactless Conductometry

    CERN Document Server

    Semenov, Yury S

    2013-01-01

    A research of inductive conductometric cell is presented. An equivalent circuit and a mathematical model of inductive cell are given in the article. The model takes into account sample-coil capacity (i.e. capacity formed by the coil and the sample under study) and eddy currents. It is sample-coil capacity that makes inductive cell applicable for measurement of electrical conductivity of low conductive samples (specific conductance is less than 1S/m). The model can be used to calculate impedance of inductive cell for different characteristics of sample, materials and dimensions of cell without numerical solving of partial differential equations. Results of numerical simulation were verified by experiment for several devices with inductive cell. Some features that an engineer has to hold in mind while designing a conductometer based on inductive cell are discussed. Presented model can be useful for those who study inductively coupled plasma.

  14. Inductive heating kills cells that contribute to plaque: a proof-of-concept

    Directory of Open Access Journals (Sweden)

    Angelo Gaitas

    2015-04-01

    Full Text Available Inducing cell death by heating targeted particles shows promise in cancer treatment. Here, we aim to demonstrate the feasibility of extending the use of this technique to treat and remove vascular deposits and thrombosis. We used induction heating of macrophages, which are key contributors to atherosclerosis and have demonstrated clear feasibility for heating and destroying these cells using ferromagnetic and pure iron particles. Specifically, iron particles achieved maximum temperatures of 51 ± 0.5 °C and spherical particles achieved a maximum temperature of 43.9 ± 0.2 °C (N = 6 after 30 min of inductive heating. Two days of subsequent observation demonstrated that inductive heating led to a significant reduction in cell number. Prior to induction heating, cell density was 105,000 ± 20,820 cells/ml (N = 3. This number was reduced to 6,666 ± 4,410 cells/ml for the spherical particles and 16,666 ± 9,280 cells/ml for the iron particles 24 h after inductive heating. Though cell density increased on the second day following inductive heating, the growth was minimal. Cells grew to 26,667 ± 6,670 cells/ml and 30,000 ± 15,280 cells/ml respectively. Compared to cell cultures with iron and spherical particles that were not subjected to induction heating, we observed a 97% reduction in cell count for the spherical particles and a 91% reduction for the iron particles after the first 24 h. After 48 h we observed a 95% reduction in cell growth for both spherical and iron particles. Induction heating of microparticles was thus highly effective in reducing the macrophage population and preventing their growth. These results demonstrate the feasibility of targeting cells involved in atherosclerosis and warrant further research into potential clinical applications.

  15. Senescence and programmed cell death : substance or semantics?

    NARCIS (Netherlands)

    Doorn, van W.G.; Woltering, E.J.

    2004-01-01

    The terms senescence and programmed cell death (PCD) have led to some confusion. Senescence as visibly observed in, for example, leaf yellowing and petal wilting, has often been taken to be synonymous with the programmed death of the constituent cells. PCD also obviously refers to cells, which show

  16. Autophagy in response to photodynamic therapy: cell survival vs. cell death

    Science.gov (United States)

    Oleinick, Nancy L.; Xue, Liang-yan; Chiu, Song-mao; Joseph, Sheeba

    2009-02-01

    Autophagy (or more properly, macroautophagy) is a pathway whereby damaged organelles or other cell components are encased in a double membrane, the autophagosome, which fuses with lysosomes for digestion by lysosomal hydrolases. This process can promote cell survival by removing damaged organelles, but when damage is extensive, it can also be a mechanism of cell death. Similar to the Kessel and Agostinis laboratories, we have reported the vigorous induction of autophagy by PDT; this was found in human breast cancer MCF-7 cells whether or not they were able to efficiently induce apoptosis. One way to evaluate the role of autophagy in PDT-treated cells is to silence one of the essential genes in the pathway. Kessel and Reiners silenced the Atg7 gene of murine leukemia L1210 cells using inhibitory RNA and found sensitization to PDT-induced cell death at a low dose of PDT, implying that autophagy is protective when PDT damage is modest. We have examined the role of autophagy in an epithelium-derived cancer cell by comparing parental and Atg7-silenced MCF-7 cells to varying doses of PDT with the phthalocyanine photosensitizer Pc 4. In contrast to L1210 cells, autophagy-deficient MCF-7 cells were more resistant to the lethal effects of PDT, as judged by clonogenic assays. A possible explanation for the difference in outcome for L1210 vs. MCF-7 cells is the greatly reduced ability of the latter to undergo apoptosis, a deficiency that may convert autophagy into a cell-death process even at low PDT doses. Experiments to investigate the mechanism(s) responsible are in process.

  17. α-Synuclein and neuronal cell death

    Directory of Open Access Journals (Sweden)

    Cookson Mark R

    2009-02-01

    Full Text Available Abstract α-Synuclein is a small protein that has special relevance for understanding Parkinson disease and related disorders. Not only is α-synuclein found in Lewy bodies characteristic of Parkinson disease, but also mutations in the gene for α-synuclein can cause an inherited form of Parkinson disease and expression of normal α-synuclein can increase the risk of developing Parkinson disease in sporadic, or non-familial, cases. Both sporadic and familial Parkinson disease are characterized by substantial loss of several groups of neurons, including the dopaminergic cells of the substantia nigra that are the target of most current symptomatic therapies. Therefore, it is predicted that α-synuclein, especially in its mutant forms or under conditions where its expression levels are increased, is a toxic protein in the sense that it is associated with an increased rate of neuronal cell death. This review will discuss the experimental contexts in which α-synuclein has been demonstrated to be toxic. I will also outline what is known about the mechanisms by which α-synuclein triggers neuronal damage, and identify some of the current gaps in our knowledge about this subject. Finally, the therapeutic implications of toxicity of α-synuclein will be discussed.

  18. The phytoalexin resveratrol regulates the initiation of hypersensitive cell death in Vitis cell.

    Directory of Open Access Journals (Sweden)

    Xiaoli Chang

    Full Text Available Resveratrol is a major phytoalexin produced by plants in response to various stresses and promotes disease resistance. The resistance of North American grapevine Vitis rupestris is correlated with a hypersensitive reaction (HR, while susceptible European Vitis vinifera cv. 'Pinot Noir' does not exhibit HR, but expresses basal defence. We have shown previously that in cell lines derived from the two Vitis species, the bacterial effector Harpin induced a rapid and sensitive accumulation of stilbene synthase (StSy transcripts, followed by massive cell death in V. rupestris. In the present work, we analysed the function of the phytoalexin resveratrol, the product of StSy. We found that cv. 'Pinot Noir' accumulated low resveratrol and its glycoside trans-piceid, whereas V. rupestris produced massive trans-resveratrol and the toxic oxidative δ-viniferin, indicating that the preferred metabolitism of resveratrol plays role in Vitis resistance. Cellular responses to resveratrol included rapid alkalinisation, accumulation of pathogenesis-related protein 5 (PR5 transcripts, oxidative burst, actin bundling, and cell death. Microtubule disruption and induction of StSy were triggered by Harpin, but not by resveratrol. Whereas most responses proceeded with different amplitude for the two cell lines, the accumulation of resveratrol, and the competence for resveratrol-induced oxidative burst differed in quality. The data lead to a model, where resveratrol, in addition to its classical role as antimicrobial phytoalexin, represents an important regulator for initiation of HR-related cell death.

  19. 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. PMID:25691005

  20. Sensitization of radiation-induced cell death by genistein

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Rim; Kim, In Gyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-03-15

    A number of epidemiological studies as well as biological experiments, showed that genistein, one of the isoflavone, prevents prostate cancer occurrence. In this study, we showed that genistein inhibited the cell proliferation of human promyeoltic leukemia HL-60 cells and induced G2/M phase arrest. In addition, combination of genistein treatment and {gamma}-irradiation displayed synergistic effect in apoptotic cell death of HL-60 cells. This means that the repair of genistein-induced DNA damage was hindered by {gamma}-irradiation and thus cell death was increased. In conclusion, genistein is one of the important chemicals that sensitize radiation-induced cell death.

  1. Programmed cell death and cell extrusion in rat duodenum

    DEFF Research Database (Denmark)

    Schauser, Kirsten; Larsson, Lars-Inge

    2005-01-01

    techniques detecting the events associated with PCD in order to better understand its role in the turnover of the intestinal epithelium, including modified double- and triple-staining techniques for simultaneously detecting multiple markers of PCD in individual cells. Only a partial correlation between TUNEL......The small intestinal epithelium is continously renewed through a balance between cell division and cell loss. How this balance is achieved is uncertain. Thus, it is unknown to what extent programmed cell death (PCD) contributes to intestinal epithelial cell loss. We have used a battery of...... positivity for DNA fragmentation, c-jun phosphorylation on serine-63, positivity for activated caspase-3 and apoptotic morphology was observed. Our results show that DNA fragmentation does not invariable correlate to activation of caspase-3. Moreover, many cells were found to activate caspase-3 early in the...

  2. Analysis of cell death inducing compounds.

    Science.gov (United States)

    Spicker, Jeppe S; Pedersen, Henrik Toft; Nielsen, Henrik Bjørn; Brunak, Søren

    2007-11-01

    Biomarkers for early detection of toxicity hold the promise of improving the failure rates in drug development. In the present study, gene expression levels were measured using full-genome RAE230 version 2 Affymetrix GeneChips on rat liver tissue 48 h after administration of six different compounds, three toxins (ANIT, DMN and NMF) and three non-toxins (Caeruelein, Dinitrophenol and Rosiglitazone). We identified three gene transcripts with exceptional predictive performance towards liver toxicity and/or changes in histopathology. The three genes were: glucokinase regulatory protein (GCKR), ornithine aminotransferase (OAT) and Cytochrome P450, subfamily IIC (mephenytoin 4-hydroxylase) (Cyp2C29). RT-PCR for these three genes was performed and four additional compounds were included for validation. The quantitative RT-PCR analysis confirmed the findings based on the microarray data and using the three genes a classification rate of 55 of 57 samples was achieved for the classification of not toxic versus toxic. The single most promising biomarker (OAT) alone resulted in a surprisingly 100% correctly classified samples. OAT has not previously been linked to toxicity and cell death in the literature and the novel finding represents a putative hepatotoxicity biomarker. PMID:17503021

  3. Effect of platinum nanoparticles on cell death induced by ultrasound in human lymphoma U937 cells.

    Science.gov (United States)

    Jawaid, Paras; Rehman, Mati Ur; Hassan, Mariame Ali; Zhao, Qing Li; Li, Peng; Miyamoto, Yusei; Misawa, Masaki; Ogawa, Ryohei; Shimizu, Tadamichi; Kondo, Takashi

    2016-07-01

    In this study, we report on the potential use of platinum nanoparticles (Pt-NPs), a superoxide dismutase (SOD)/catalase mimetic antioxidant, in combination with 1MHz ultrasound (US) at an intensity of 0.4W/cm(2), 10% duty factor, 100Hz PRF, for 2min. Apoptosis induction was assessed by DNA fragmentation assay, cell cycle analysis and Annexin V-FITC/PI staining. Cell killing was confirmed by cell counting and microscopic examination. The mitochondrial and Ca(2+)-dependent pathways were investigated. Caspase-8 expression and autophagy-related proteins were detected by spectrophotometry and western blot analysis, respectively. Intracellular reactive oxygen species (ROS) elevation was detected by flow cytometry, while extracellular free radical formation was assessed by electron paramagnetic resonance spin trapping spectrometry. The results showed that Pt-NPs exerted differential effects depending on their internalization. Pt-NPs functioned as potent free radical scavengers when added immediately before sonication while pre-treatment with Pt-NPs suppressed the induction of apoptosis as well as autophagy (AP), and resulted in enhanced cell killing. Dead cells displayed the features of pyknosis. The exact mode of cell death is still unclear. In conclusion, the results indicate that US-induced AP may contribute to cell survival post sonication. To our knowledge this is the first study to discuss autophagy as a pro-survival pathway in the context of US. The combination of Pt-NPs and US might be effective in cancer eradication. PMID:26964942

  4. Cell-to-Cell Transmission of HIV-1 Is Required to Trigger Pyroptotic Death of Lymphoid-Tissue-Derived CD4 T Cells

    Directory of Open Access Journals (Sweden)

    Nicole L.K. Galloway

    2015-09-01

    Full Text Available The progressive depletion of CD4 T cells underlies clinical progression to AIDS in untreated HIV-infected subjects. Most dying CD4 T cells correspond to resting nonpermissive cells residing in lymphoid tissues. Death is due to an innate immune response against the incomplete cytosolic viral DNA intermediates accumulating in these cells. The viral DNA is detected by the IFI16 sensor, leading to inflammasome assembly, caspase-1 activation, and the induction of pyroptosis, a highly inflammatory form of programmed cell death. We now show that cell-to-cell transmission of HIV is obligatorily required for activation of this death pathway. Cell-free HIV-1 virions, even when added in large quantities, fail to activate pyroptosis. These findings underscore the infected CD4 T cells as the major killing units promoting progression to AIDS and highlight a previously unappreciated role for the virological synapse in HIV pathogenesis.

  5. 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 characte

  6. Activation-Induced Cell Death in T Cells and Autoimmunity

    Institute of Scientific and Technical Information of China (English)

    JianZhang; XuemeiXu; YongLiu

    2004-01-01

    Activation-induced cell death (AICD), which results from the interaction between Fas and Fas ligand, is responsible for maintaining tolerance to self-antigen. A defect in AICD may lead to development of autoimmunity. During the last several years, much progress has been made in understanding the mechanism(s) of AICD and its potential role in the pathogenesis of autoimmune diseases. In this review, we summarize the most recent progress on the regulation of the susceptibility of T cells to AICD and its possible involvement in autoimmune diseases.

  7. Induction of apoptosis in chicken bursal B cells

    International Nuclear Information System (INIS)

    Cell death in general can be a physiological process of cell number regulation in tissue, or it can be the result of exo or endogenous injuries, such a low-dose of radiation. Chicken B cell population in the bursa of Fabricius are very susceptible to PCD. Our present studies concern the development of radiation damage of chicken defence mechanisms. In 6 experiments pathogen free chicken were irradiated by gamma rays with the total doses of 0.25, 0.5, 1.0, 2.0 and 4.0 Gy. The induction of apoptosis was checked by Flow-cyto-meter 12 h after irradiation in bursa cell suspension. There is some increase in the number of induced apoptotic cells 12 h after irradiation at the dose 0.5-.4.0 Gy. There were no significant changes in the proportion of proliferating lymphocytes (G2 M), but cellularity decreased significantly at dose 2.0 and 4.0 Gy/12 h after irradiation. (author)

  8. Application of hyperthermia in addition to ionizing irradiation fosters necrotic cell death and HMGB1 release of colorectal tumor cells

    International Nuclear Information System (INIS)

    Colorectal cancer is the second leading cause of death in developed countries. Tumor therapies should on the one hand aim to stop the proliferation of tumor cells and to kill them, and on the other hand stimulate a specific immune response against residual cancer cells. Dying cells are modulators of the immune system contributing to anti-inflammatory or pro-inflammatory responses, depending on the respective cell death form. The positive therapeutic effects of temperature-controlled hyperthermia (HT), when combined with ionizing irradiation (X-ray), were the origin to examine whether combinations of X-ray with HT can induce immune activating tumor cell death forms, also characterized by the release of the danger signal HMGB1. Human colorectal tumor cells with differing radiosensitivities were treated with combinations of HT (41.5 oC for 1 h) and X-ray (5 or 10 Gy). Necrotic cell death was prominent after X-ray and could be further increased by HT. Apoptosis remained quite low in HCT 15 and SW480 cells. X-ray and combinations with HT arrested the tumor cells in the radiosensitive G2 cell cycle phase. The amount of released HMGB1 protein was significantly enhanced after combinatorial treatments in comparison to single ones. We conclude that combining X-ray with HT may induce anti-tumor immunity as a result of the predominant induction of inflammatory necrotic tumor cells and the release of HMGB1.

  9. Application of hyperthermia in addition to ionizing irradiation fosters necrotic cell death and HMGB1 release of colorectal tumor cells

    Energy Technology Data Exchange (ETDEWEB)

    Schildkopf, Petra, E-mail: petra.schildkopf@uk-erlangen.de [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander University of Erlangen-Nuernberg (Germany); Frey, Benjamin, E-mail: benjamin.frey@uk-erlangen.de [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander University of Erlangen-Nuernberg (Germany); Mantel, Frederick, E-mail: frederick.mantel@web.de [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander University of Erlangen-Nuernberg (Germany); Ott, Oliver J., E-mail: oliver.ott@uk-erlangen.de [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander University of Erlangen-Nuernberg (Germany); Weiss, Eva-Maria, E-mail: eva-maria.weiss@uk-erlangen.de [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander University of Erlangen-Nuernberg (Germany); Sieber, Renate, E-mail: renate.sieber@uk-erlangen.de [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander University of Erlangen-Nuernberg (Germany); Janko, Christina, E-mail: christina.janko@uk-erlangen.de [Department for Internal Medicine 3, Institute for Clinical Immunology, Friedrich-Alexander University of Erlangen-Nuernberg (Germany); Sauer, Rolf, E-mail: rolf.sauer@uk-erlangen.de [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander University of Erlangen-Nuernberg (Germany); Fietkau, Rainer, E-mail: rainer.fietkau@uk-erlangen.de [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander University of Erlangen-Nuernberg (Germany); Gaipl, Udo S., E-mail: udo.gaipl@uk-erlangen.de [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander University of Erlangen-Nuernberg (Germany)

    2010-01-01

    Colorectal cancer is the second leading cause of death in developed countries. Tumor therapies should on the one hand aim to stop the proliferation of tumor cells and to kill them, and on the other hand stimulate a specific immune response against residual cancer cells. Dying cells are modulators of the immune system contributing to anti-inflammatory or pro-inflammatory responses, depending on the respective cell death form. The positive therapeutic effects of temperature-controlled hyperthermia (HT), when combined with ionizing irradiation (X-ray), were the origin to examine whether combinations of X-ray with HT can induce immune activating tumor cell death forms, also characterized by the release of the danger signal HMGB1. Human colorectal tumor cells with differing radiosensitivities were treated with combinations of HT (41.5 {sup o}C for 1 h) and X-ray (5 or 10 Gy). Necrotic cell death was prominent after X-ray and could be further increased by HT. Apoptosis remained quite low in HCT 15 and SW480 cells. X-ray and combinations with HT arrested the tumor cells in the radiosensitive G2 cell cycle phase. The amount of released HMGB1 protein was significantly enhanced after combinatorial treatments in comparison to single ones. We conclude that combining X-ray with HT may induce anti-tumor immunity as a result of the predominant induction of inflammatory necrotic tumor cells and the release of HMGB1.

  10. Evaluation of Cytotoxicity and Cell Death Induced In Vitro by Saxitoxin in Mammalian Cells.

    Science.gov (United States)

    Melegari, Silvia P; de Carvalho Pinto, Cátia R S; Moukha, Serge; Creppy, Edmond E; Matias, William G

    2015-01-01

    Since the cyanotoxin saxitoxin (STX) is a neurotoxin and induces ecological changes in aquatic environments, a potential risk to public and environmental health exists. However, data on STX-mediated cytotoxic and genotoxic effects are still scare. In order to gain a better understanding of the effects of this toxin, the cytotoxic and genotoxic potential of STX was examined in two mammalian cell lines. Neuro 2A (N2A), a neuroblastoma mouse cell line, and Vero cell line, derived from Vero green monkey kidney cells, were exposed to several concentrations of STX ranging from 0.5 to 64 nM to determine cell viability, induction of apoptosis (DNA fragmentation assay), and formation of micronuclei (MN) (cytokinesis-block micronucleus assay; CBMN) following 24 h of incubation. The half maximal effective concentration (EC50) values for STX calculated in cell viability tests were 1.01 nM for N2A and 0.82 nM for Vero cells. With increasing STX concentration there was evidence of DNA fragmentation indicating apoptosis induction in Vero cells with a 50% increase in DNA fragmentation compared to control at the highest STX concentration tested (3 nM). The results demonstrated no significant changes in the frequency of micronucleated binucleated cells in N2A and Vero cells exposed to STX, indicating the absence of genotoxicity under these test conditions. There was no apparent cellular necrosis as evidenced by a lack of formation of multinucleated cells. In conclusion, data reported herein demonstrate that STX produced death of both cell types tested through an apoptotic process. PMID:26436995

  11. Romo1 expression contributes to oxidative stress-induced death of lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jung Ar [Department of Internal Medicine, Yonsei University College of Medicine, Yonsei University Health System, Seoul 135-270 (Korea, Republic of); Chung, Jin Sil [Laboratory of Molecular Cell Biology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of); Cho, Sang-Ho [Department of Pathology, Pochon CHA University, College of Medicine, Gyeonggi-do (Korea, Republic of); Kim, Hyung Jung, E-mail: khj57@yuhs.ac.kr [Department of Internal Medicine, Yonsei University College of Medicine, Yonsei University Health System, Seoul 135-270 (Korea, Republic of); Yoo, Young Do, E-mail: ydy1130@korea.ac.kr [Laboratory of Molecular Cell Biology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of)

    2013-09-20

    Highlights: •Romo1 mediates oxidative stress-induced mitochondrial ROS production. •Romo1 induction by oxidative stress plays an important role in oxidative stress-induced apoptosis. •Romo1 overexpression correlates with epithelial cell death in patients with IPF. -- Abstract: Oxidant-mediated death of lung epithelial cells due to cigarette smoking plays an important role in pathogenesis in lung diseases such as idiopathic pulmonary fibrosis (IPF). However, the exact mechanism by which oxidants induce epithelial cell death is not fully understood. Reactive oxygen species (ROS) modulator 1 (Romo1) is localized in the mitochondria and mediates mitochondrial ROS production through complex III of the mitochondrial electron transport chain. Here, we show that Romo1 mediates mitochondrial ROS production and apoptosis induced by oxidative stress in lung epithelial cells. Hydrogen peroxide (H{sub 2}O{sub 2}) treatment increased Romo1 expression, and Romo1 knockdown suppressed the cellular ROS levels and cell death triggered by H{sub 2}O{sub 2} treatment. In immunohistochemical staining of lung tissues from patients with IPF, Romo1 was mainly localized in hyperplastic alveolar and bronchial epithelial cells. Romo1 overexpression was detected in 14 of 18 patients with IPF. TUNEL-positive alveolar epithelial cells were also detected in most patients with IPF but not in normal controls. These findings suggest that Romo1 mediates apoptosis induced by oxidative stress in lung epithelial cells.

  12. Romo1 expression contributes to oxidative stress-induced death of lung epithelial cells

    International Nuclear Information System (INIS)

    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 (H2O2) treatment increased Romo1 expression, and Romo1 knockdown suppressed the cellular ROS levels and cell death triggered by H2O2 treatment. In immunohistochemical staining of lung tissues from patients with IPF, Romo1 was mainly localized in hyperplastic alveolar and bronchial epithelial cells. Romo1 overexpression was detected in 14 of 18 patients with IPF. TUNEL-positive alveolar epithelial cells were also detected in most patients with IPF but not in normal controls. These findings suggest that Romo1 mediates apoptosis induced by oxidative stress in lung epithelial cells

  13. Cell Death Pathways in Photodynamic Therapy of Cancer

    International Nuclear Information System (INIS)

    Photodynamic therapy (PDT) is an emerging cancer therapy that uses the combination of non-toxic dyes or photosensitizers (PS) and harmless visible light to produce reactive oxygen species and destroy tumors. The PS can be localized in various organelles such as mitochondria, lysosomes, endoplasmic reticulum, Golgi apparatus and plasma membranes and this sub-cellular location governs much of the signaling that occurs after PDT. There is an acute stress response that leads to changes in calcium and lipid metabolism and causes the production of cytokines and stress response mediators. Enzymes (particularly protein kinases) are activated and transcription factors are expressed. Many of the cellular responses center on mitochondria and frequently lead to induction of apoptosis by the mitochondrial pathway involving caspase activation and release of cytochrome c. Certain specific proteins (such as Bcl-2) are damaged by PDT-induced oxidation thereby increasing apoptosis, and a build-up of oxidized proteins leads to an ER-stress response that may be increased by proteasome inhibition. Autophagy plays a role in either inhibiting or enhancing cell death after PDT

  14. Cell Death Pathways in Photodynamic Therapy of Cancer

    Directory of Open Access Journals (Sweden)

    Michael R. Hamblin

    2011-06-01

    Full Text Available Photodynamic therapy (PDT is an emerging cancer therapy that uses the combination of non-toxic dyes or photosensitizers (PS and harmless visible light to produce reactive oxygen species and destroy tumors. The PS can be localized in various organelles such as mitochondria, lysosomes, endoplasmic reticulum, Golgi apparatus and plasma membranes and this sub-cellular location governs much of the signaling that occurs after PDT. There is an acute stress response that leads to changes in calcium and lipid metabolism and causes the production of cytokines and stress response mediators. Enzymes (particularly protein kinases are activated and transcription factors are expressed. Many of the cellular responses center on mitochondria and frequently lead to induction of apoptosis by the mitochondrial pathway involving caspase activation and release of cytochrome c. Certain specific proteins (such as Bcl-2 are damaged by PDT-induced oxidation thereby increasing apoptosis, and a build-up of oxidized proteins leads to an ER-stress response that may be increased by proteasome inhibition. Autophagy plays a role in either inhibiting or enhancing cell death after PDT.

  15. Mitochondrion-mediated cell death: Dissecting yeast apoptosis for a better understanding of neurodegeneration

    Directory of Open Access Journals (Sweden)

    Ralf J Braun

    2012-11-01

    Full Text Available 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, and their induction of mitochondrion-mediated cell death pathways. Therefore, in-depth analyses of the underlying molecular pathways, including cellular mechanisms controlling the maintenance of mitochondrial function, is a prerequisite for a better understanding of neurodegenerative disorders. The yeast Saccharomyces cerevisiae is an established model for deciphering mitochondrial quality control mechanisms and the distinct mitochondrial roles during apoptosis and programmed cell death. Cell death upon expression of various human neurotoxic proteins has been characterized in yeast, revealing neurotoxic protein-specific differences. This review summarizes how mitochondria are affected in these neurotoxic yeast models, and how they are involved in the execution and prevention of cell death. I will discuss to which extent this mimics the situation in other neurotoxic model systems, and how this may contribute to a better understanding of the mitochondrial roles in the human disorders.

  16. Silencer of death domains controls cell death through tumour necrosis factor-receptor 1 and caspase-10 in acute lymphoblastic leukemia.

    Directory of Open Access Journals (Sweden)

    Adam Cisterne

    Full Text Available Resistance to apoptosis remains a significant problem in drug resistance and treatment failure in malignant disease. NO-aspirin is a novel drug that has efficacy against a number of solid tumours, and can inhibit Wnt signaling, and although we have shown Wnt signaling to be important for acute lymphoblastic leukemia (ALL cell proliferation and survival inhibition of Wnt signaling does not appear to be involved in the induction of ALL cell death. Treatment of B lineage ALL cell lines and patient ALL cells with NO-aspirin induced rapid apoptotic cell death mediated via the extrinsic death pathway. Apoptosis was dependent on caspase-10 in association with the formation of the death-inducing signaling complex (DISC incorporating pro-caspase-10 and tumor necrosis factor receptor 1 (TNF-R1. There was no measurable increase in TNF-R1 or TNF-α in response to NO-aspirin, suggesting that the process was ligand-independent. Consistent with this, expression of silencer of death domain (SODD was reduced following NO-aspirin exposure and lentiviral mediated shRNA knockdown of SODD suppressed expansion of transduced cells confirming the importance of SODD for ALL cell survival. Considering that SODD and caspase-10 are frequently over-expressed in ALL, interfering with these proteins may provide a new strategy for the treatment of this and potentially other cancers.

  17. Silencer of Death Domains Controls Cell Death through Tumour Necrosis Factor-Receptor 1 and Caspase-10 in Acute Lymphoblastic Leukemia

    Science.gov (United States)

    Khan, Naveed I.; Welschinger, Robert; Basnett, Jordan; Fung, Carina; Rizos, Helen; Bradstock, Kenneth F.; Bendall, Linda J.

    2014-01-01

    Resistance to apoptosis remains a significant problem in drug resistance and treatment failure in malignant disease. NO-aspirin is a novel drug that has efficacy against a number of solid tumours, and can inhibit Wnt signaling, and although we have shown Wnt signaling to be important for acute lymphoblastic leukemia (ALL) cell proliferation and survival inhibition of Wnt signaling does not appear to be involved in the induction of ALL cell death. Treatment of B lineage ALL cell lines and patient ALL cells with NO-aspirin induced rapid apoptotic cell death mediated via the extrinsic death pathway. Apoptosis was dependent on caspase-10 in association with the formation of the death-inducing signaling complex (DISC) incorporating pro-caspase-10 and tumor necrosis factor receptor 1 (TNF-R1). There was no measurable increase in TNF-R1 or TNF-α in response to NO-aspirin, suggesting that the process was ligand-independent. Consistent with this, expression of silencer of death domain (SODD) was reduced following NO-aspirin exposure and lentiviral mediated shRNA knockdown of SODD suppressed expansion of transduced cells confirming the importance of SODD for ALL cell survival. Considering that SODD and caspase-10 are frequently over-expressed in ALL, interfering with these proteins may provide a new strategy for the treatment of this and potentially other cancers. PMID:25061812

  18. Mechanical Stress Promotes Cisplatin-Induced Hepatocellular Carcinoma Cell Death

    Directory of Open Access Journals (Sweden)

    Laila Ziko

    2015-01-01

    Full Text Available Cisplatin (CisPt is a commonly used platinum-based chemotherapeutic agent. Its efficacy is limited due to drug resistance and multiple side effects, thereby warranting a new approach to improving the pharmacological effect of CisPt. A newly developed mathematical hypothesis suggested that mechanical loading, when coupled with a chemotherapeutic drug such as CisPt and immune cells, would boost tumor cell death. The current study investigated the aforementioned mathematical hypothesis by exposing human hepatocellular liver carcinoma (HepG2 cells to CisPt, peripheral blood mononuclear cells, and mechanical stress individually and in combination. HepG2 cells were also treated with a mixture of CisPt and carnosine with and without mechanical stress to examine one possible mechanism employed by mechanical stress to enhance CisPt effects. Carnosine is a dipeptide that reportedly sequesters platinum-based drugs away from their pharmacological target-site. Mechanical stress was achieved using an orbital shaker that produced 300 rpm with a horizontal circular motion. Our results demonstrated that mechanical stress promoted CisPt-induced death of HepG2 cells (~35% more cell death. Moreover, results showed that CisPt-induced death was compromised when CisPt was left to mix with carnosine 24 hours preceding treatment. Mechanical stress, however, ameliorated cell death (20% more cell death.

  19. Programmed Cell Death and Postharvest Deterioration of Horticultural Produce

    NARCIS (Netherlands)

    Woltering, E.J.; Iakimova, E.T.

    2010-01-01

    Programmed cell death (PCD) is a process where cells or tissues are broken down in an orderly and predictable manner, whereby nutrients are re-used by other cells, tissues or plant parts. The process of (petal) senescence shows many similarities to autophagic PCD in animal cells including a massive

  20. Induction of cellular accessibility and inaccessibility and suppression and potentiation of cell death in oat attacked by ¤Blumeria graminis¤ f.sp. ¤avenae¤

    DEFF Research Database (Denmark)

    Carver, T.L.W.; Lyngkjær, M.F.; Neyron, L.;

    1999-01-01

    First-formed (seedling) and later-formed leaves of oat cvs Selma (susceptible) and Maldwyn (adult plant resistance under complex genetic control) were subjected to a double inoculation procedure ('inducer' followed by 'challenger') with conidia of Blumeria graminis (DC.) Speer (Syn. Erysiphe...... graminis DC.). Successful penetration and haustorium formation by the inducer rendered living epidermal cells highly accessible to later challenge attack as judged by increased frequency of challenge penetration success compared to controls. Conversely, where failure of inducer attack on living epidermal...

  1. Attenuation of cisplatin-induced acute renal failure is associated with less apoptotic cell death.

    Science.gov (United States)

    Zhou, H; Miyaji, T; Kato, A; Fujigaki, Y; Sano, K; Hishida, A

    1999-12-01

    To clarify the pathophysiologic role of apoptosis in acute renal failure (ARF), we examined whether the attenuation of cisplatin-induced ARF is associated with the change in the degree of apoptotic cell death. The administration of cisplatin (CDDP) (6 mg/kg body weight) in rats induced ARF at day 5, as manifested by a significant increase in serum creatinine (Scr) and tubular damage. CDDP-induced apoptotic cell death was confirmed by electron microscopic examination, agarose gel electrophoresis, and increased cells positive for TaT-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) in the outer medulla of the kidney. Treatment with dimethylthiourea (DMTU)--a scavenger of hydroxyl radicals--or glycine abrogated CDDP-induced increases in Scr, the tubular damage score, and the number of TUNEL-positive cells. Pretreatment with uranyl acetate (UA) induced a significant expression of Bcl-2 in the kidney and ameliorated CDDP-induced increases in Scr, the tubular damage score, and TUNEL-positive cells in the outer stripe of the outer medulla. Our findings indicate (1) that the attenuation of CDDP-induced ARF was associated with less apoptotic cell death and (2) that the induction of the anti-apoptotic protein Bcl-2 attenuated apoptosis and tubular damage. Our results suggest that apoptotic cell death may play an important role in the development of cisplatin-induced ARF. PMID:10595794

  2. Transplantation Tolerance Induction: Cell Therapies and Their Mechanisms

    Science.gov (United States)

    Scalea, Joseph R.; Tomita, Yusuke; Lindholm, Christopher R.; Burlingham, William

    2016-01-01

    Cell-based therapies have been studied extensively in the context of transplantation tolerance induction. The most successful protocols have relied on transfusion of bone marrow prior to the transplantation of a renal allograft. However, it is not clear that stem cells found in bone marrow are required in order to render a transplant candidate immunologically tolerant. Accordingly, mesenchymal stem cells, regulatory myeloid cells, T regulatory cells, and other cell types are being tested as possible routes to tolerance induction, in the absence of donor-derived stem cells. Early data with each of these cell types have been encouraging. However, the induction regimen capable of achieving consistent tolerance, while avoiding unwanted sided effects, and which is scalable to the human patient, has yet to be identified. Here, we present the status of investigations of various tolerogenic cell types and the mechanistic rationale for their use in tolerance induction protocols. PMID:27014267

  3. Influence on cell death of high frequency motion of magnetic nanoparticles during magnetic hyperthermia experiments

    Science.gov (United States)

    Hallali, N.; Clerc, P.; Fourmy, D.; Gigoux, V.; Carrey, J.

    2016-07-01

    Studies with transplanted tumors in animals and clinical trials have provided the proof-of-concept of magnetic hyperthermia (MH) therapy of cancers using iron oxide nanoparticles. Interestingly, in several studies, the application of an alternating magnetic field (AMF) to tumor cells having internalized and accumulated magnetic nanoparticles (MNPs) into their lysosomes can induce cell death without detectable temperature increase. To explain these results, among other hypotheses, it was proposed that cell death could be due to the high-frequency translational motion of MNPs under the influence of the AMF gradient generated involuntarily by most inductors. Such mechanical actions of MNPs might cause cellular damages and participate in the induction of cell death under MH conditions. To test this hypothesis, we developed a setup maximizing this effect. It is composed of an anti-Helmholtz coil and two permanent magnets, which produce an AMF gradient and a superimposed static MF. We have measured the MNP heating power and treated tumor cells by a standard AMF and by an AMF gradient, on which was added or not a static magnetic field. We showed that the presence of a static magnetic field prevents MNP heating and cell death in standard MH conditions. The heating power of MNPs in an AMF gradient is weak, position-dependent, and related to the presence of a non-zero AMF. Under an AMF gradient and a static field, no MNP heating and cell death were measured. Consequently, the hypothesis that translational motions could be involved in cell death during MH experiments is ruled out by our experiments.

  4. The control and execution of programmed cell death

    International Nuclear Information System (INIS)

    Apoptosis or programmed cell death is a highly conserved genetically controlled response of metazoan cells to commit suicide. Non apoptotic programmed cell death seems to operate in single celled eukaryotes implying that evolution of PCD has preceded the evolution of multicellularity. PCD plays a crucial role in the regulation of cellular and tissue homeostasis and any aberrations in apoptosis leads to several diseases including cancer, neurodegenerative disorders and AIDS. The mechanisms by which apoptosis is controlled are varied. In some cells, members of bcl-2 family or p53 are crucial for regulating the apoptosis programme, whereas in other cells Fas ligand is more important. bcl-2 family members have a prime role in the regulation of cell death at all stages including development, whereas cell death during development is independent of p53. bcl-2 family members being localized on the outer mitochondrial membrane, control the mitochondrial homeostasis and cytochrome c redistribution and thereby regulate the cell death process. p53 promotes DNA damage mediated cell death after growth arrest and failed DNA repair. Caspases play a key role in the execution of cell death by mediating highly specific cleavages of crucial cellular proteins collectively manifesting the apoptotic phenotype. Protein inhibitors like crm A, p35 and IAPs could prevent/control apoptosis induced by a broad array of cell death stimuli by several mechanisms specially interfering in caspase activation or caspase activity. Among endonucleases, caspase activated DNase (CAD) plays a crucial role in DNA fragmentation, a biochemical hallmark of apoptosis. As regulation of cell death seems to be as complex as regulation of cell proliferation, multiple kinase mediated regulatory mechanisms might control the apoptotic process. Thus, in spite of intensive research over the past few years, the field of apoptosis still remains fertile to unravel among others, the molecular mechanisms of cytochrome c

  5. Constitutive activation of AtMEK5, a MAPK kinase, induces salicylic acid-independent cell death in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    LIU Hongxia; WANG Ying; ZHOU Tianhong; SUN Yujing; LIU Guoqin; REN Dongtao

    2004-01-01

    AtMEK5DD is an active mutant of AtMEK5, a MAP kinase kinase in Arabidopsis. Induction of AtMEK5DD expression in transgenic plants leads to activation of 44 and 48 kD MAPKs and causes a rapid cell death. To compare the cell death induced by the expression of AtMEK5DD with the HR-cell death induced by avirulence pathogen infection, we analyzed the activation of downstream MAP Kinase and induction of PR genes expression in permanent transgenic Arabidopsis plants. In-gel kinase activity assay revealed that the infection of Pseudomonas syringae DC3000 harboring Avr Rpt2 gene also lead to activation of 44 and 48 kD MAPKs. PAL, PR1 and PR5 were strongly induced in plants undergoing HR-cell death caused by the infection of P. Syringae DC3000, while only the expression of PR5 was strongly induced in transgenic plants expressing AtMEK5DD protein. NahG protein in AtMEK5DD×NahG plants cannot suppress the cell death induced by AtMEK5DD. And AtMEK5DD protein expressed AtMEK5DD×NahG plants showed no significant change in salicylic acid (SA)level.All these suggest that the cell death induced by the activation of AtMEK5 is salicylic acid-independent.

  6. Death for survival: what do we know about innate immunity and cell death in insects?

    Directory of Open Access Journals (Sweden)

    DM Cooper

    2011-09-01

    Full Text Available Insects are the most diverse and prolific animal group on Earth, and as such, important lessons can be taken from the elements that contribute to their evolutionary success. This review examines insect immunity and how insects combat infection with the pathogens they encounter: bacteria, viruses, fungi and parasites. Structural barriers, cellular and humoral responses and cell death all respond to specific immunological threats and contribute to the robust repertoire of immune strategies employed by insects. We discuss the strategies used by insects to combat pathogen infection and focus on what is currently known about cell death and its role in insect immunity.

  7. p31comet-Induced Cell Death Is Mediated by Binding and Inactivation of Mad2.

    Directory of Open Access Journals (Sweden)

    Hyun-Jin Shin

    Full Text Available Mad2, a key component of the spindle checkpoint, is closely associated with chromosomal instability and poor prognosis in cancer. p31comet is a Mad2-interacting protein that serves as a spindle checkpoint silencer at mitosis. In this study, we showed that p31comet-induced apoptosis and senescence occur via counteraction of Mad2 activity. Upon retroviral transduction of p31comet, the majority of human cancer cell lines tested lost the ability to form colonies in a low-density seeding assay. Cancer cells with p31comet overexpression underwent distinct apoptosis and/or senescence, irrespective of p53 status, confirming the cytotoxicity of p31comet. Interestingly, both cytotoxic and Mad2 binding activities were eliminated upon deletion of the C-terminal 30 amino acids of p31comet. Point mutation or deletion of the region affecting Mad2 binding additionally abolished cytotoxic activity. Consistently, wild-type Mad2 interacting with p31comet, but not its non-binding mutant, inhibited cell death, indicating that the mechanism of p31comet-induced cell death involves Mad2 inactivation. Our results clearly suggest that the regions of p31comet affecting interactions with Mad2, including the C-terminus, are essential for induction of cell death. The finding that p31comet-induced cell death is mediated by interactions with Mad2 that lead to its inactivation is potentially applicable in anticancer therapy.

  8. Cytotoxicity of obacunone and obacunone glucoside in human prostate cancer cells involves Akt-mediated programmed cell death

    International Nuclear Information System (INIS)

    Highlights: • Possible mechanism of inhibiting LNCaP cells proliferation by obacunone and obacunone glucoside is demonstrated for the first time. • Inhibition of LNCaP cells by limonoids though induction of programmed cell death, inhibition of cell signaling and inflammatory pathways. • Limonoids exhibited multi-mode inhibition of androgen expression in LNCaP cells. - Abstract: Obacunone and obacunone glucoside (OG) are naturally occurring triterpenoids commonly found in citrus and other plants of the Rutaceae family. The current study reports the mechanism of cytotoxicity of citrus-derived obacunone and OG on human androgen-dependent prostate cancer LNCaP cells. Both limonoids exhibited time- and dose-dependent inhibition of cell proliferation, with more than 60% inhibition of cell viability at 100 μM, after 24 and 48 h. Analysis of fragmentation of DNA, activity of caspase-3, and cytosolic cytochrome-c in the cells treated with limonoids provided evidence for activation of programmed cell death by limonoids. Treatment of LNCaP cells with obacunone and OG resulted in dose-dependent changes in expression of proteins responsible for the induction of programmed cell death through the intrinsic pathway and down-regulation of Akt, a key molecule in cell signaling pathways. In addition, obacunone and OG also negatively regulated an inflammation-associated transcription factor, androgen receptor, and prostate-specific antigen, and activated proteins related to the cell cycle, confirming the ability of limonoids to induce cytotoxicity through multiple pathways. The results of this study provided, for the first time, an evidence of the cytotoxicity of obacunone and OG in androgen-dependent human prostate cancer cells

  9. Rate of death of hypoxic cells in multicell spheroids

    International Nuclear Information System (INIS)

    The rate of death of hypoxic cells was measured in multicell spheroids, which are considered to model in vitro the microenvironments surrounding such cells within solid tumors. Two types of experiments were performed: (1) All of the cells in spheroids were made hypoxic (less than 100 ppM O2) and the total number of viable cells was determined by clonogenic assay at later times up to 7 days. The rate of death of cells appeared biphasic. At least 15% of the cells died within the first 6 hr. The rate of development of histological changes in the spheroids suggested that the innermost cells were most sensitive. The more peripheral layers of cells died much more slowly so that there was still about 5% survival and a significant number of histologically normal cells at 6 days. Changes in the glucose concentration in the medium (from one-third to three times normal) during exposure to hypoxia had little effect on the survival time of these outer cells. (2) The cells in the inner half of spheroids grown in 20% O2 were made hypoxic by equilibrating the growth medium with 5% O2, and the number of resistant hypoxic cells at different times later was determined after a radiation dose of 3500 rad. The number of surviving clonogenic cells after this dose of radiation decreased with a half-time for cell death of 3 hr. These results indicate that the rate of death of hypoxic cells in the central regions of spheroids is much more rapid than has been reported for monolayer cultures, although the resistance of the outer cells is similar to or greater than monolayers. Since spheroids may model the necrosis and other microenvironments near chronically hypoxic cells in tumors, the relatively rapid rate of death of hypoxic cells demonstrated here must be considered in evaluating their contribution to the size of the radiation-resistant hypoxic fraction and possible mechanisms which might contribute to the phenomenon of reoxygenation

  10. Genes and Gene Networks Involved in Sodium Fluoride-Elicited Cell Death Accompanying Endoplasmic Reticulum Stress in Oral Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Yoshiaki Tabuchi

    2014-05-01

    Full Text Available Here, to understand the molecular mechanisms underlying cell death induced by sodium fluoride (NaF, we analyzed gene expression patterns in rat oral epithelial ROE2 cells exposed to NaF using global-scale microarrays and bioinformatics tools. A relatively high concentration of NaF (2 mM induced cell death concomitant with decreases in mitochondrial membrane potential, chromatin condensation and caspase-3 activation. Using 980 probe sets, we identified 432 up-regulated and 548 down-regulated genes, that were differentially expressed by >2.5-fold in the cells treated with 2 mM of NaF and categorized them into 4 groups by K-means clustering. Ingenuity® pathway analysis revealed several gene networks from gene clusters. The gene networks Up-I and Up-II included many up-regulated genes that were mainly associated with the biological function of induction or prevention of cell death, respectively, such as Atf3, Ddit3 and Fos (for Up-I and Atf4 and Hspa5 (for Up-II. Interestingly, knockdown of Ddit3 and Hspa5 significantly increased and decreased the number of viable cells, respectively. Moreover, several endoplasmic reticulum (ER stress-related genes including, Ddit3, Atf4 and Hapa5, were observed in these gene networks. These findings will provide further insight into the molecular mechanisms of NaF-induced cell death accompanying ER stress in oral epithelial cells.

  11. Fumonisin B1 induces autophagic cell death via activation of ERN1-MAPK8/9/10 pathway in monkey kidney MARC-145 cells.

    Science.gov (United States)

    Yin, Shutao; Guo, Xiao; Li, Jinghua; Fan, Linghong; Hu, Hongbo

    2016-04-01

    Mycotoxins are secondary fungal metabolites that are capable of inducing a variety of toxic effects in animals and humans resulting from the consumption of the contaminated food. Understanding the mechanisms of the toxicities behind these mycotoxins is required to develop mechanism-based approach to counteract their toxic potential. Fumonisin B1 (FB1) is the most prevalent member of fumonisins that are a group of mycotoxins produced primarily by Fusarium verticillioides and Fusarium proliferatum. Kidney is one of the primary target organs for FB1 action. Using monkey kidney MARC-145 cells as an intro model, we found that FB1 induced caspase-independent programmed cell death accompanied with autophagy induction. Inhibition of autophagy by either chemical inhibitors or RNAi approach led to a significant reduction in cell death by FB1 exposure, indicating possible involvement of autophagy-mediated cell death in nephrotoxicity of FB1. Further mechanistic investigation revealed that activation of ERN1-MAPK8/9/10 axis played a critical role in autophagy induction and autophagy-mediated cell death by FB1 exposure. In addition, we demonstrated that disruption of sphingolipid metabolism was an apical event in FB1-induced ERN1-MAPK8/9/10-mediated autophagic cell death in MARC-145 cells. Lastly, we identified curcumin, a naturally occurring plant phenolic compound, as a possible anti-FB1 agent that can be used to protect kidney cells from FB1-induced cell death through inhibition of MAPK8/9/10 activation. PMID:25925693

  12. The intersection of cell death and inflammasome activation.

    Science.gov (United States)

    Vince, James E; Silke, John

    2016-06-01

    Inflammasomes sense cellular danger to activate the cysteine-aspartic protease caspase-1, which processes precursor interleukin-1β (IL-1β) and IL-18 into their mature bioactive fragments. In addition, activated caspase-1 or the related inflammatory caspase, caspase-11, can cleave gasdermin D to induce a lytic cell death, termed pyroptosis. The intertwining of IL-1β activation and cell death is further highlighted by research showing that the extrinsic apoptotic caspase, caspase-8, may, like caspase-1, directly process IL-1β, activate the NLRP3 inflammasome itself, or bind to inflammasome complexes to induce apoptotic cell death. Similarly, RIPK3- and MLKL-dependent necroptotic signaling can activate the NLRP3 inflammasome to drive IL-1β inflammatory responses in vivo. Here, we review the mechanisms by which cell death signaling activates inflammasomes to initiate IL-1β-driven inflammation, and highlight the clinical relevance of these findings to heritable autoinflammatory diseases. We also discuss whether the act of cell death can be separated from IL-1β secretion and evaluate studies suggesting that several cell death regulatory proteins can directly interact with, and modulate the function of, inflammasome and IL-1β containing protein complexes. PMID:27066895

  13. Cotreatment with Smac mimetics and demethylating agents induces both apoptotic and necroptotic cell death pathways in acute lymphoblastic leukemia cells.

    Science.gov (United States)

    Gerges, Steve; Rohde, Katharina; Fulda, Simone

    2016-05-28

    Treatment resistance in acute lymphoblastic leukemia (ALL) is often caused by defects in programmed cell death, e.g. by overexpression of Inhibitor of Apoptosis (IAP) proteins. Here, we report that small-molecule Smac mimetics (i.e. BV6, LCL161, birinapant) that neutralize x-linked IAP (XIAP), cellular IAP (cIAP)1 and cIAP2 cooperate with demethylating agents (i.e. 5-azacytidine (5AC) or 5-aza-2'-deoxycytidine (DAC)) to induce cell death in ALL cells. Molecular studies reveal that induction of cell death is preceded by BV6-mediated depletion of cIAP1 protein and involves tumor necrosis factor (TNF)α autocrine/paracrine signaling, since the TNFα-blocking antibody Enbrel significantly reduces BV6/5AC-induced cell death. While BV6/5AC cotreatment induces caspase-3 activation, the broad-range caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD.fmk) only partly rescues ALL cells from BV6/5AC-induced cell death. This indicates that BV6/5AC cotreatment engages non-apoptotic cell death upon caspase inhibition. Indeed, genetic silencing of key components of necroptosis such as Receptor-Interacting Protein (RIP)3 or mixed lineage kinase domain-like (MLKL) in parallel with administration of zVAD.fmk provides a significantly better protection against BV6/5AC-induced cell death compared to the use of zVAD.fmk alone. Similarly, concomitant administration of pharmacological inhibitors of necroptosis (i.e. necrostatin-1s, GSK'872, dabrafenib, NSA) together with zVAD.fmk is superior in rescuing cells from BV6/5AC-induced cell death compared to the use of zVAD.fmk alone. These findings demonstrate that in ALL cells BV6/5AC-induced cell death is mediated via both apoptotic and necroptotic pathways. Importantly, BV6/5AC cotreatment triggers necroptosis in ALL cells that are resistant to apoptosis due to caspase inhibition. This opens new perspectives to overcome apoptosis resistance with important implications for the development of new treatment strategies

  14. Plant programmed cell death and the point of no return

    NARCIS (Netherlands)

    Doorn, van W.G.

    2005-01-01

    The point of no return during programmed cell death (PCD) is defined as the step beyond which the cell is irreversibly committed to die. Some plant cells can be saved before this point by inducing the formation of functional chloroplasts. A visibly senescent tissue will then become green again and l

  15. The process and promotion of radiation-induced cell death

    International Nuclear Information System (INIS)

    Radiation-induced cell death is divided into reproductive and interphase death, whose process can be revealed by time-lapse observations. Pedigree analyses of progenies derived from a surviving progenitor cell have shown that moribund cells appear in clusters among cells which are apparently undamaged (lethal sectoring). Sister cell fusion, which likely results from chromosome bridge, is the most frequently observed cell abnormality leading to reproductive death. While interphase death does not occur unless the dose exceeds 10 Gy for low LET radiation such as X-rays, high-LET radiation is very effective at inducing interphase death (RBE: ≅3 at 230 keV/μm). Expression or fixation of potentially lethal damage (PLD) is closely associated with cell cycle events and enhanced by inducing premature chromosome condensation (PCC) at a nonpermissive temperature in tsBN2 cells with a ts-defect in RCC1 protein (a regulator of chromatin condensation) which monitors the completion of DNA replication. Furthermore, higher-order structural changes in nuclear matrix such as induced by leptomycin B, an inhibitor of CRM1 (chromosome region maintenance) protein, also play an important role in the fixation of PLD. (author)

  16. BGP-15 inhibits caspase-independent programmed cell death in acetaminophen-induced liver injury

    International Nuclear Information System (INIS)

    It has been recently shown that acute acetaminophen toxicity results in endoplasmic reticulum redox stress and an increase in cells with apoptotic phenotype in liver. Since activation of effector caspases was absent, the relevance of caspase-independent mechanisms in acetaminophen-induced programmed cell death was investigated. BGP-15, a drug with known protective actions in conditions involving redox imbalance, has been co-administered with a single sublethal dose of acetaminophen. Proapoptotic events and outcome of the injury were investigated. ER redox alterations and early ER-stress-related signaling events induced by acetaminophen, such as ER glutathione depletion, phosphorylation of eIF2α and JNK and induction of the transcription factor GADD153, were not counteracted by co-treatment with BGP-15. However, BGP-15 prevented AIF mitochondria-to-nucleus translocation and mitochondrial depolarization. BGP-15 co-treatment attenuated the rate of acetaminophen-induced cell death as assessed by apoptotic index and enzyme serum release. These results reaffirm that acute acetaminophen toxicity involves oxidative stress-induced caspase-independent cell death. In addition, pharmacological inhibition of AIF translocation may effectively protect against or at least delay acetaminophen-induced programmed cell death.

  17. Measuring Cell Death by Propidium Iodide Uptake and Flow Cytometry.

    Science.gov (United States)

    Crowley, Lisa C; Scott, Adrian P; Marfell, Brooke J; Boughaba, Jeanne A; Chojnowski, Grace; Waterhouse, Nigel J

    2016-01-01

    Propidium iodide (PI) is a small fluorescent molecule that binds to DNA but cannot passively traverse into cells that possess an intact plasma membrane. PI uptake versus exclusion can be used to discriminate dead cells, in which plasma membranes become permeable regardless of the mechanism of death, from live cells with intact membranes. PI is excited by wavelengths between 400 and 600 nm and emits light between 600 and 700 nm, and is therefore compatible with lasers and photodetectors commonly available in flow cytometers. This protocol for PI staining can be used to quantitate cell death in most modern research facilities and universities. PMID:27371595

  18. Bax-induced cell death in Candida albicans.

    Science.gov (United States)

    De Smet, Kris; Eberhardt, Ines; Reekmans, Rieka; Contreras, Roland

    2004-12-01

    Bax is a pro-apoptotic member of the Bcl-2 family of proteins involved in the regulation of genetically programmed cell death in mammalian cells. It has been shown that heterologous expression of Bax in several yeast species, such as Saccharomyces cerevisiae, Schizosaccharomyces pombe and Pichia pastoris, also induces cell death. In this study we investigated the effects of Bax expression in the pathogenic yeast Candida albicans. Cell death inducing expression of Bax required a synthetic BAX gene that was codon-optimized for expression in Candida albicans. Expression of this BAX gene resulted in growth inhibition and cell death. By fusing Bax with the yeast enhanced green fluorescent protein of Aequoria victoria, the cell death-inducing effect of Bax was increased due to reduced proteolytic degradation of Bax. Using this fusion protein we showed that, upon expression in C. albicans, Bax co-localizes with the mitochondria. Furthermore, we showed for the first time that expression of Bax in yeast causes the mitochondria, which are normally distributed throughout the cell, to cluster in the perinuclear region. PMID:15565645

  19. Modulation of cell death in age-related diseases.

    Science.gov (United States)

    Tezil, Tugsan; Basaga, Huveyda

    2014-01-01

    Aging is a stage of life of all living organisms. According to the free-radical theory, aging cells gradually become unable to maintain cellular homeostasis due to the adverse effects of reactive oxygen species (ROS). ROS can cause irreversible DNA mutations, protein and lipid damage which are increasingly accumulated in the course of time if cells could not overcome these effects by the antioxidant defence system. Accrued damaged molecules in cells may either induce cellular death or contribute to develop various pathologies. Hence, programmed cell death mechanisms, apoptosis and autophagy, play a vital role in the aging process. Although they are strictly controlled by various interconnected signalling pathways, alterations in their regulations may contribute to severe pathologies including cancer, Alzheimer's and Parkinson's diseases. In this review, we summarized our current understanding and hypotheses regarding oxidative stress and age-related dysregulation of cell death signalling pathways. PMID:24079770

  20. 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.

  1. Staurosporine induces different cell death forms in cultured rat astrocytes

    International Nuclear Information System (INIS)

    Astroglial cells are frequently involved in malignant transformation. Besides apoptosis, necroptosis, a different form of regulated cell death, seems to be related with glioblastoma genesis, proliferation, angiogenesis and invasion. In the present work we elucidated mechanisms of necroptosis in cultured astrocytes, and compared them with apoptosis, caused by staurosporine. Cultured rat cortical astrocytes were used for a cell death studies. Cell death was induced by different concentrations of staurosporine, and modified by inhibitors of apoptosis (z-vad-fmk) and necroptosis (nec-1). Different forms of a cell death were detected using flow cytometry. We showed that staurosporine, depending on concentration, induces both, apoptosis as well as necroptosis. Treatment with 10−7 M staurosporine increased apoptosis of astrocytes after the regeneration in a staurosporine free medium. When caspases were inhibited, apoptosis was attenuated, while necroptosis was slightly increased. Treatment with 10−6 M staurosporine induced necroptosis that occurred after the regeneration of astrocytes in a staurosporine free medium, as well as without regeneration period. Necroptosis was significantly attenuated by nec-1 which inhibits RIP1 kinase. On the other hand, the inhibition of caspases had no effect on necroptosis. Furthermore, staurosporine activated RIP1 kinase increased the production of reactive oxygen species, while an antioxidant BHA significantly attenuated necroptosis. Staurosporine can induce apoptosis and/or necroptosis in cultured astrocytes via different signalling pathways. Distinction between different forms of cell death is crucial in the studies of therapy-induced necroptosis

  2. Noninvasive Monitoring of Pharmacodynamics and Kinetics of a Death Receptor 5 Antibody and Its Enhanced Apoptosis Induction in Sequential Application with Doxorubicin

    Directory of Open Access Journals (Sweden)

    Thomas G Weber

    2013-08-01

    Full Text Available Induction of apoptosis plays a crucial role in the response of tumors to treatment. Thus, we investigated the pharmacodynamics and tumor saturation kinetics of a death receptor 5 antibody (anti-DR5 when combined with chemotherapeutics. For our investigations, we applied an imaging method that allows monitoring of apoptosis noninvasively in living mice. A stably transfected apoptosis reporter based on split luciferase technology facilitates to screen various chemotherapeutics and anti-DR5 on their ability to induce apoptosis in glioblastoma cells in vitro as well as in vivo. We found that doxorubicin (DOX treatment in vitro led to significant apoptosis induction within 48 hours and to a 2.3-fold increased anti-DR5 binding to the cell surface. In contrast, cisplatin and 5-fluorouracil (5-FU treatment altered anti-DR5 binding only marginally. Induction of apoptosis by treatment with anti-DR5 was dose- and time-dependent (both in vitro and in vivo. Simultaneous visualization of fluorescence-labeled anti-DR5 in tumor tissue and apoptosis revealed maximal apoptosis induction immediately after the compound had reached tumor site. Regarding combination therapy of anti-DR5 and DOX, we found that the sequential application of DOX before anti-DR5 resulted in synergistically enhanced apoptosis reporter activity. In striking contrast, anti-DR5 given before DOX did not lead to increased apoptosis induction. We suggest that DOX-induced recruitment of DR5 to the cell surface impacts the enhanced apoptotic effect that can be longitudinally monitored by apoptosis imaging. This study demonstrates that the combination of apoptosis and fluorescence imaging is an excellent method for optimizing dosing and treatment schedules in preclinical cancer models.

  3. Mechanism of heavy ion radiation-induced cancer cell death

    International Nuclear Information System (INIS)

    We previously reported that the carbon beam triggers apoptosis in radio-resistant cancer cell lines via extracellular signal-regulated kinase (ERK)- and mitochondrial Bcl-2 family protein-dependant mechanism. Here, we further examined the further apoptosis-inducing mechanism of carbon beam in two glioma cell lines (T98G, U251). ERK1/2 knockdown experiments revealed that ERK regulates this apoptosis-inducing machinery upstream of mitochondria. Furthermore, we also found that both T98G cell and U251 cell stably expressing dominant-negative ERK2 suppress cell death induced by carbon beam irradiation. We also found proapoptotic PUMA and antiapoptotic Bcl-2 dynamically chang their expression levels corresponding to ERK activation after CB irradiation in U251 cell, and knockdown of PUMA decreased CB-induced U251 cell death. These data suggest that kinase action of ERK is essential for CB-induced glioma cell death, and proapoptotic PUMA and antiapoptotic Bcl-2 might be downstream targets of ERK in CB-induced glioma cell death mechanism. (author)

  4. Early cell death detection with digital holographic microscopy.

    Directory of Open Access Journals (Sweden)

    Nicolas Pavillon

    Full Text Available BACKGROUND: Digital holography provides a non-invasive measurement of the quantitative phase shifts induced by cells in culture, which can be related to cell volume changes. It has been shown previously that regulation of cell volume, in particular as it relates to ionic homeostasis, is crucially involved in the activation/inactivation of the cell death processes. We thus present here an application of digital holographic microscopy (DHM dedicated to early and label-free detection of cell death. METHODS AND FINDINGS: We provide quantitative measurements of phase signal obtained on mouse cortical neurons, and caused by early neuronal cell volume regulation triggered by excitotoxic concentrations of L-glutamate. We show that the efficiency of this early regulation of cell volume detected by DHM, is correlated with the occurrence of subsequent neuronal death assessed with the widely accepted trypan blue method for detection of cell viability. CONCLUSIONS: The determination of the phase signal by DHM provides a simple and rapid optical method for the early detection of cell death.

  5. Programmed cell death in plants: A chloroplastic connection

    OpenAIRE

    Ambastha, Vivek; Tripathy, Baishnab C; Tiwari, Budhi Sagar

    2015-01-01

    Programmed cell death (PCD) is an integral cellular program by which targeted cells culminate to demise under certain developmental and pathological conditions. It is essential for controlling cell number, removing unwanted diseased or damaged cells and maintaining the cellular homeostasis. The details of PCD process has been very well elucidated and characterized in animals but similar understanding of the process in plants has not been achieved rather the field is still in its infancy that ...

  6. Photothermal reshaping of gold nanorods prevents further cell death

    International Nuclear Information System (INIS)

    The combined use of phosphatidylcholine passivated gold nanorods (PC-NRs) and pulsed near-infrared (near-IR) irradiation resulted in cell death. Pulsed near-IR laser irradiation also induced reshaping of PC-NRs into spherical nanoparticles. Since reshaped particles showed no absorption in the near-IR region, successive laser irradiation did not affect cells. Photo-reshaping of PC-NRs is expected to be advantageous in preventing unwanted cell damage following destruction of target cells

  7. Diagnosis of Cell Death by Means of Infrared Spectroscopy

    OpenAIRE

    Zelig, Udi; Kapelushnik, Joseph; Moreh, Raymond; Mordechai, Shaul; Nathan, Ilana

    2009-01-01

    Fourier transform infrared (FTIR) spectroscopy has been established as a fast spectroscopic method for biochemical analysis of cells and tissues. In this research we aimed to investigate FTIR's utility for identifying and characterizing different modes of cell death, using leukemic cell lines as a model system. CCRF-CEM and U937 leukemia cells were treated with arabinoside and doxorubicin apoptosis inducers, as well as with potassium cyanide, saponin, freezing-thawing, and H2O2 necrosis induc...

  8. Porcine circovirus-2 capsid protein induces cell death in PK15 cells

    International Nuclear Information System (INIS)

    Studies have shown that Porcine circovirus (PCV)-2 induces apoptosis in PK15 cells. Here we report that cell death is induced in PCV2b-infected PK15 cells that express Capsid (Cap) protein and this effect is enhanced in interferon gamma (IFN-γ)-treated cells. We further show that transient PCV2a and 2b-Cap protein expression induces cell death in PK15 cells at rate similar to PCV2 infection, regardless of Cap protein localization. These data suggest that Cap protein may have the capacity to trigger different signaling pathways involved in cell death. Although further investigation is needed to gain deeper insights into the nature of the pathways involved in Cap-induced cell death, this study provides evidence that PCV2-induced cell death in kidney epithelial PK15 cells can be mapped to the Cap protein and establishes the need for future research regarding the role of Cap-induced cell death in PCV2 pathogenesis. - Highlights: • IFN-γ enhances PCV2 replication that leads to cell death in PK15 cells. • IFN-γ enhances nuclear localization of the PCV2 Capsid protein. • Transient PCV2a and 2b-Capsid protein expression induces cell death. • Cell death is not dictated by specific Capsid protein sub-localization

  9. Porcine circovirus-2 capsid protein induces cell death in PK15 cells

    Energy Technology Data Exchange (ETDEWEB)

    Walia, Rupali; Dardari, Rkia, E-mail: rdardari@ucalgary.ca; Chaiyakul, Mark; Czub, Markus

    2014-11-15

    Studies have shown that Porcine circovirus (PCV)-2 induces apoptosis in PK15 cells. Here we report that cell death is induced in PCV2b-infected PK15 cells that express Capsid (Cap) protein and this effect is enhanced in interferon gamma (IFN-γ)-treated cells. We further show that transient PCV2a and 2b-Cap protein expression induces cell death in PK15 cells at rate similar to PCV2 infection, regardless of Cap protein localization. These data suggest that Cap protein may have the capacity to trigger different signaling pathways involved in cell death. Although further investigation is needed to gain deeper insights into the nature of the pathways involved in Cap-induced cell death, this study provides evidence that PCV2-induced cell death in kidney epithelial PK15 cells can be mapped to the Cap protein and establishes the need for future research regarding the role of Cap-induced cell death in PCV2 pathogenesis. - Highlights: • IFN-γ enhances PCV2 replication that leads to cell death in PK15 cells. • IFN-γ enhances nuclear localization of the PCV2 Capsid protein. • Transient PCV2a and 2b-Capsid protein expression induces cell death. • Cell death is not dictated by specific Capsid protein sub-localization.

  10. Mitochondrial regulation of cell death: a phylogenetically conserved control

    Directory of Open Access Journals (Sweden)

    Lorenzo Galluzzi

    2016-02-01

    Full Text Available Mitochondria are fundamental for eukaryotic cells as they participate in critical catabolic and anabolic pathways. Moreover, mitochondria play a key role in the signal transduction cascades that precipitate many (but not all regulated variants of cellular demise. In this short review, we discuss the differential implication of mitochondria in the major forms of regulated cell death.

  11. Induction of apoptosis in human cancer cells by targeting mitochondria with gold nanoparticles.

    Science.gov (United States)

    Mkandawire, M M; Lakatos, M; Springer, A; Clemens, A; Appelhans, D; Krause-Buchholz, U; Pompe, W; Rödel, G; Mkandawire, M

    2015-06-28

    A major challenge in designing cancer therapies is the induction of cancer cell apoptosis, although activation of intrinsic apoptotic pathways by targeting gold nanoparticles to mitochondria is promising. We report an in vitro procedure targeting mitochondria with conjugated gold nanoparticles and investigating effects on apoptosis induction in the human breast cancer cell line Jimt-1. Gold nanoparticles were conjugated to a variant of turbo green fluorescent protein (mitoTGFP) harbouring an amino-terminal mitochondrial localization signal. Au nanoparticle conjugates were further complexed with cationic maltotriose-modified poly(propylene imine) third generation dendrimers. Fluorescence and transmission electron microscopy revealed that Au nanoparticle conjugates were directed to mitochondria upon transfection, causing partial rupture of the outer mitochondrial membrane, triggering cell death. The ability to target Au nanoparticles into mitochondria of breast cancer cells and induce apoptosis reveals an alternative application of Au nanoparticles in photothermal therapy of cancer. PMID:26022234

  12. 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.

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

    International Nuclear Information System (INIS)

    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

  14. Modeling cell-death patterning during biofilm formation

    International Nuclear Information System (INIS)

    Self-organization by bacterial cells often leads to the formation of a highly complex spatially-structured biofilm. In such a bacterial biofilm, cells adhere to each other and are embedded in a self-produced extracellular matrix (ECM). Bacillus substilis bacteria utilize localized cell-death patterns which focuses mechanical forces to form wrinkled sheet-like structures in three dimensions. A most intriguing feature underlying this biofilm formation is that vertical buckling and ridge location is biased to occur in region of high cell-death. Here we present a spatially extended model to investigate the role of the bacterial secreted ECM during the biofilm formation and the self-organization of cell-death. Using this reaction-diffusion model we show that the interaction between the cell's motion and the ECM concentration gives rise to a self-trapping instability, leading to variety of cell-death patterns. The resultant spot patterns generated by our model are shown to be in semi-quantitative agreement with recent experimental observation. (paper)

  15. Lapatinib induces autophagic cell death and differentiation in acute myeloblastic leukemia

    Directory of Open Access Journals (Sweden)

    Chen YJ

    2016-07-01

    Full Text Available Yu-Jen Chen,1–4 Li-Wen Fang,5 Wen-Chi Su,6,7 Wen-Yi Hsu,1 Kai-Chien Yang,1 Huey-Lan Huang8 1Department of Medical Research, 2Department of Radiation Oncology, Mackay Memorial Hospital, 3Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, 4Institute of Pharmacology, Taipei Medical University, Taipei, 5Department of Nutrition, I-Shou University, Kaohsiung, 6Research Center for Emerging Viruses, China Medical University Hospital, 7Graduate Institute of Clinical Medical Science, China Medical University, Taichung, 8Department of Bioscience Technology, College of Health Science, Chang Jung Christian University, Tainan, Taiwan, Republic of China Abstract: Lapatinib is an oral-form dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR or ErbB/Her superfamily members with anticancer activity. In this study, we examined the effects and mechanism of action of lapatinib on several human leukemia cells lines, including acute myeloid leukemia (AML, chronic myeloid leukemia (CML, and acute lymphoblastic leukemia (ALL cells. We found that lapatinib inhibited the growth of human AML U937, HL-60, NB4, CML KU812, MEG-01, and ALL Jurkat T cells. Among these leukemia cell lines, lapatinib induced apoptosis in HL-60, NB4, and Jurkat cells, but induced nonapoptotic cell death in U937, K562, and MEG-01 cells. Moreover, lapatinib treatment caused autophagic cell death as shown by positive acridine orange staining, the massive formation of vacuoles as seen by electronic microscopy, and the upregulation of LC3-II, ATG5, and ATG7 in AML U937 cells. Furthermore, autophagy inhibitor 3-methyladenine and knockdown of ATG5, ATG7, and Beclin-1 using short hairpin RNA (shRNA partially rescued lapatinib-induced cell death. In addition, the induction of phagocytosis and ROS production as well as the upregulation of surface markers CD14 and CD68 was detected in lapatinib-treated U937 cells, suggesting the induction of

  16. Cell death and autophagy: Cytokines, drugs, and nutritional factors

    International Nuclear Information System (INIS)

    Cells may use multiple pathways to commit suicide. In certain contexts, dying cells generate large amounts of autophagic vacuoles and clear large proportions of their cytoplasm, before they finally die, as exemplified by the treatment of human mammary carcinoma cells with the anti-estrogen tamoxifen (TAM, ≤1 μM). Protein analysis during autophagic cell death revealed distinct proteins of the nuclear fraction including GST-π and some proteasomal subunit constituents to be affected during autophagic cell death. Depending on the functional status of caspase-3, MCF-7 cells may switch between autophagic and apoptotic features of cell death [Fazi, B., Bursch, W., Fimia, G.M., Nardacci R., Piacentini, M., Di Sano, F., Piredda, L., 2008. Fenretinide induces autophagic cell death in caspase-defective breast cancer cells. Autophagy 4(4), 435-441]. Furthermore, the self-destruction of MCF-7 cells was found to be completed by phagocytosis of cell residues [Petrovski, G., Zahuczky, G., Katona, K., Vereb, G., Martinet, W., Nemes, Z., Bursch, W., Fesues, L., 2007. Clearance of dying autophagic cells of different origin by professional and non-professional phagocytes. Cell Death Diff. 14 (6), 1117-1128]. Autophagy also constitutes a cell's strategy of defense upon cell damage by eliminating damaged bulk proteins/organelles. This biological condition may be exemplified by the treatment of MCF-7 cells with a necrogenic TAM-dose (10 μM), resulting in the lysis of almost all cells within 24 h. However, a transient (1 h) challenge of MCF-7 cells with the same dose allowed the recovery of cells involving autophagy. Enrichment of chaperones in the insoluble cytoplasmic protein fraction indicated the formation of aggresomes, a potential trigger for autophagy. In a further experimental model HL60 cells were treated with TAM, causing dose-dependent distinct responses: 1-5 μM TAM, autophagy predominant; 7-9 μM, apoptosis predominant; 15 μM, necrosis. These phenomena might be

  17. Signal transduction events in aluminum-induced cell death in tomato suspension cells

    NARCIS (Netherlands)

    Iakimova, E.T.; Kapchina-Toteva, V.M.; Woltering, E.J.

    2007-01-01

    In this study, some of the signal transduction events involved in AlCl3-induced cell death in tomato (Lycopersicon esculentum Mill.) suspension cells were elucidated. Cells treated with 100 ¿M AlCl3 showed typical features of programmed cell death (PCD) such as nuclear and cytoplasmic condensation.

  18. Induction of Functional Hair-Cell-Like Cells from Mouse Cochlear Multipotent Cells

    OpenAIRE

    Quanwen Liu; Yi Shen; Jiarong Chen; Jie Ding; Zihua Tang; Cui Zhang; Jianling Chen; Liang Li; Ping Chen; Jinfu Wang

    2016-01-01

    In this paper, we developed a two-step-induction method of generating functional hair cells from inner ear multipotent cells. Multipotent cells from the inner ear were established and induced initially into progenitor cells committed to the inner ear cell lineage on the poly-L-lysine substratum. Subsequently, the committed progenitor cells were cultured on the mitotically inactivated chicken utricle stromal cells and induced into hair-cell-like cells containing characteristic stereocilia bund...

  19. Programmed Cell Death During Female Gametophyte Development

    Energy Technology Data Exchange (ETDEWEB)

    Drews, Gary, N.

    2004-09-15

    Endosperm is a storage tissue in the angiosperm seed that is important both biologically and agriculturally. Endosperm is biologically important because it provides nutrients to the embryo during seed development and agriculturally important because it is a significant source of food, feed, and industrial raw materials. Approximately two-thirds of human calories are derived from endosperm, either directly or indirectly through animal feed. Furthermore, endosperm is used as a raw material for numerous industrial products including ethanol. A major event in endosperm development is the transition between the syncytial phase, during which the endosperm nuclei undergo many rounds of mitosis without cytokinesis, and the cellularized phase, during which cell walls form around the endosperm nuclei. Understanding how the syncytial-cellular transition is regulated is agriculturally important because it influences seed size, seed sink strength, and grain weight. However, the molecular processes controlling this transition are not understood. This project led to the identification of the AGL62 gene that regulates the syncytial-cellular transition during endosperm development. AGL62 is expressed during the syncytial phase and suppresses endosperm cellularization during this period. AGL62 most likely does so by suppressing the expression of genes required for cellularization. At the end of the syncytial phase, the FIS PcG complex suppresses AGL62 expression, which allows expression of the cellularization genes and triggers the initiation of the cellularized phase. Endosperm arises following fertilization of the central cell within the female gametophyte. This project also led to the identification of the AGL80 gene that is required for development of the central cell into the endosperm. Within the ovule and seed, AGL80 is expressed exclusively in the central cell and uncellularized endosperm. AGL80 is required for expression of several central cell-expressed genes, including

  20. Quantum algorithm for programmed cell death of Caenorhabditis elegans

    International Nuclear Information System (INIS)

    During the development of Caenorhabditis elegans, through cell divisions, a total of exactly 1090 cells are generated, 131 of which undergo programmed cell death (PCD) to result in an adult organism comprising 959 cells. Of those 131, exactly 113 undergo PCD during embryogenesis, subdivided across the cell lineages in the following fashion: 98 for AB lineage; 14 for MS lineage; and 1 for C lineage. Is there a law underlying these numbers, and if there is, what could it be? Here we wish to show that the count of the cells undergoing PCD complies with the cipher laws related to the algorithms of Shor and of Grover

  1. Necroptosis: an alternative cell death program defending against cancer.

    Science.gov (United States)

    Chen, Dongshi; Yu, Jian; Zhang, Lin

    2016-04-01

    One of the hallmarks of cancer is resistance to programmed cell death, which maintains the survival of cells en route to oncogenic transformation and underlies therapeutic resistance. Recent studies demonstrate that programmed cell death is not confined to caspase-dependent apoptosis, but includes necroptosis, a form of necrotic death governed by Receptor-Interacting Protein 1 (RIP1), RIP3, and Mixed Lineage Kinase Domain-Like (MLKL) protein. Necroptosis serves as a critical cell-killing mechanism in response to severe stress and blocked apoptosis, and can be induced by inflammatory cytokines or chemotherapeutic drugs. Genetic or epigenetic alterations of necroptosis regulators such as RIP3 and cylindromatosis (CYLD), are frequently found in human tumors. Unlike apoptosis, necroptosis elicits a more robust immune response that may function as a defensive mechanism by eliminating tumor-causing mutations and viruses. Furthermore, several classes of anticancer agents currently under clinical development, such as SMAC and BH3 mimetics, can promote necroptosis in addition to apoptosis. A more complete understanding of the interplay among necroptosis, apoptosis, and other cell death modalities is critical for developing new therapeutic strategies to enhance killing of tumor cells. PMID:26968619

  2. Role of mitochondria on muscle cell death and meat tenderization.

    Science.gov (United States)

    Sierra, Verónica; Oliván, Mamen

    2013-05-01

    The possibility that mitochondria are involved in cellular dysfunction is particularly high in situations associated with increases in free radical activity, like hypoxia or ischemia; therefore its potential role in the muscle post-mortem metabolism is reviewed. In the dying muscle, different routes of cell death catabolism (apoptosis, autophagy) may occur having great influence on the process of conversion of muscle into meat. Mitochondria are the first and also one of the main organelles affected by post-mortem changes; therefore they are decisive in the subsequent cellular responses influencing the pathway to cell demise and thus, the final meat quality. Depending on the cell death programme followed by muscle cells after exsanguination, diverse proteases would be activated to a different extent, which is also reviewed in order to understand how they affect meat tenderization. This review also summarizes recent patents relating cell death processes and meat tenderness. Further research is encouraged as there is still a need of knowledge on cell death post-mortem processes to increase our understanding of the conversion of muscle into meat. PMID:23432120

  3. Hydrogen Peroxide Produced by Oral Streptococci Induces Macrophage Cell Death

    OpenAIRE

    Okahashi, Nobuo; Nakata, Masanobu; Sumitomo, Tomoko; Terao, Yutaka; Kawabata, Shigetada

    2013-01-01

    Hydrogen peroxide (H2O2) produced by members of the mitis group of oral streptococci plays important roles in microbial communities such as oral biofilms. Although the cytotoxicity of H2O2 has been widely recognized, the effects of H2O2 produced by oral streptococci on host defense systems remain unknown. In the present study, we investigated the effect of H2O2 produced by Streptococcus oralis on human macrophage cell death. Infection by S. oralis was found to stimulate cell death of a THP-1 ...

  4. Sensory hair cell death and regeneration in fishes

    Directory of Open Access Journals (Sweden)

    Gopinath Rajadinakaran

    2015-04-01

    Full Text Available Sensory hair cells are specialized mechanotransductive receptors required for hearing and vestibular function. Loss of hair cells in humans and other mammals is permanent and causes reduced hearing and balance. In the early 1980’s, it was shown that hair cells continue to be added to the inner ear sensory epithelia in cartilaginous and bony fishes. Soon thereafter, hair cell regeneration was documented in the chick cochlea following acoustic trauma. Since then, research using chick and other avian models has led to great insights into hair cell death and regeneration. However, with the rise of the zebrafish as a model organism for studying disease and developmental processes, there has been an increased interest in studying sensory hair cell death and regeneration in its lateral line and inner ears. Advances derived from studies in zebrafish and other fish species include understanding the effect of ototoxins on hair cells and finding otoprotectants to mitigate ototoxin damage, the role of cellular proliferation versus direct transdifferentiation during hair cell regeneration, and elucidating cellular pathways involved in the regeneration process. This review will summarize research on hair cell death and regeneration using fish models, indicate the potential strengths and weaknesses of these models, and discuss several emerging areas of future studies.

  5. Cadmium induces neuronal cell death through reactive oxygen species activated by GADD153

    Directory of Open Access Journals (Sweden)

    Kim Seungwoo

    2013-01-01

    Full Text Available Abstract Background Cadmium(Cd, a heavy metal, which has a potent harmful effects, is a highly stress-inducible material that is robustly expressed following disruption of homeostasis in the endoplasmic reticulum (ER (so-called ER stress. The mechanism Cd induced cell death of neuroblastoma cells complex, involving cellular signaling pathways as yet incompletely defined but, in part, involving the generation of reactive oxygen species (ROS. Several studies have correlated GADD153 expression with cell death, but a mechanistic link between GADD153 and apoptosis has never been demonstrated. Results SH-SY5Y cells were treated Cd led to increase in intracellular ROS levels. ROS generation is not consistent with intracellular [Ca2+]. The exposure of neuroblastoma cells to Cd led to increase in intracellular GADD153 and Bak levels in a doses and time dependent manner. The induction of these genes by Cd was attenuated by NAC. Cd-induced apoptosis is decreased in GADD153 knockdown cells compared with normal cells. The effect of GADD153 on the binding of C/EBP to the Bak promoters were analyzed ChIP assay. Basal constitutive GADD153 recruitment to the –3,398/–3,380 region of the Bak promoter is observed in SH-SY5Y cells. Conclusions The exposure of SH-SY5Y cells to Cd led to increase in intracellular ROS levels in a doses and time dependent manner. The generation of ROS result in the induction of GADD153 is causative of cadmium-induced apoptosis. GADD153 regulates Bak expression by its binding to promoter region (between −3,398 and −3,380. Therefore, we conclude that GADD153 sensitizes cells to ROS through mechanisms that involve up-regulation of BAK and enhanced oxidant injury.

  6. High Cell Surface Death Receptor Expression Determines Type I Versus Type II Signaling*

    Science.gov (United States)

    Meng, Xue Wei; Peterson, Kevin L.; Dai, Haiming; Schneider, Paula; Lee, Sun-Hee; Zhang, Jin-San; Koenig, Alexander; Bronk, Steve; Billadeau, Daniel D.; Gores, Gregory J.; Kaufmann, Scott H.

    2011-01-01

    Previous studies have suggested that there are two signaling pathways leading from ligation of the Fas receptor to induction of apoptosis. Type I signaling involves Fas ligand-induced recruitment of large amounts of FADD (FAS-associated death domain protein) and procaspase 8, leading to direct activation of caspase 3, whereas type II signaling involves Bid-mediated mitochondrial perturbation to amplify a more modest death receptor-initiated signal. The biochemical basis for this dichotomy has previously been unclear. Here we show that type I cells have a longer half-life for Fas message and express higher amounts of cell surface Fas, explaining the increased recruitment of FADD and subsequent signaling. Moreover, we demonstrate that cells with type II Fas signaling (Jurkat or HCT-15) can signal through a type I pathway upon forced receptor overexpression and that shRNA-mediated Fas down-regulation converts cells with type I signaling (A498) to type II signaling. Importantly, the same cells can exhibit type I signaling for Fas and type II signaling for TRAIL (TNF-α-related apoptosis-inducing ligand), indicating that the choice of signaling pathway is related to the specific receptor, not some other cellular feature. Additional experiments revealed that up-regulation of cell surface death receptor 5 levels by treatment with 7-ethyl-10-hydroxy-camptothecin converted TRAIL signaling in HCT116 cells from type II to type I. Collectively, these results suggest that the type I/type II dichotomy reflects differences in cell surface death receptor expression. PMID:21865165

  7. Hydrogen peroxide produced by oral Streptococci induces macrophage cell death.

    Directory of Open Access Journals (Sweden)

    Nobuo Okahashi

    Full Text Available Hydrogen peroxide (H2O2 produced by members of the mitis group of oral streptococci plays important roles in microbial communities such as oral biofilms. Although the cytotoxicity of H2O2 has been widely recognized, the effects of H2O2 produced by oral streptococci on host defense systems remain unknown. In the present study, we investigated the effect of H2O2 produced by Streptococcus oralis on human macrophage cell death. Infection by S. oralis was found to stimulate cell death of a THP-1 human macrophage cell line at multiplicities of infection greater than 100. Catalase, an enzyme that catalyzes the decomposition of H2O2, inhibited the cytotoxic effect of S. oralis. S. oralis deletion mutants lacking the spxB gene, which encodes pyruvate oxidase, and are therefore deficient in H2O2 production, showed reduced cytotoxicity toward THP-1 macrophages. Furthermore, H2O2 alone was capable of inducing cell death. The cytotoxic effect seemed to be independent of inflammatory responses, because H2O2 was not a potent stimulator of tumor necrosis factor-α production in macrophages. These results indicate that streptococcal H2O2 plays a role as a cytotoxin, and is implicated in the cell death of infected human macrophages.

  8. CSR1 induces cell death through inactivation of CPSF3.

    Science.gov (United States)

    Zhu, Z-H; Yu, Y P; Shi, Y-K; Nelson, J B; Luo, J-H

    2009-01-01

    CSR1 (cellular stress response 1), a newly characterized tumor-suppressor gene, undergoes hypermethylation in over 30% of prostate cancers. Re-expression of CSR1 inhibits cell growth and induces cell death, but the mechanism by which CSR1 suppresses tumor growth is not clear. In this study, we screened a prostate cDNA library using a yeast two-hybrid system and found that the cleavage and polyadenylation-specific factor 3 (CPSF3), an essential component for converting heteronuclear RNA to mRNA, binds with high affinity to the CSR1 C terminus. Further analyses determined that the binding motifs for CPSF3 are located between amino acids 440 and 543. The interaction between CSR1 and CPSF3 induced CPSF3 translocation from the nucleus to the cytoplasm, resulting in inhibition of polyadenylation both in vitro and in vivo. Downregulation of CPSF3 using small interfering RNA induced cell death in a manner similar to CSR1 expression. A CSR1 mutant unable to bind to CPSF3 did not alter CPSF3 subcellular distribution, did not inhibit its polyadenylation activity and did not induce cell death. In summary, CSR1 appears to induce cell death through a novel mechanism by hijacking a critical RNA processing enzyme. PMID:18806823

  9. Real-time monitoring of cisplatin-induced cell death.

    Directory of Open Access Journals (Sweden)

    Hamed Alborzinia

    Full Text Available Since the discovery of cisplatin more than 40 years ago and its clinical introduction in the 1970s an enormous amount of research has gone into elucidating the mechanism of action of cisplatin on tumor cells. With a novel cell biosensor chip system allowing continuous monitoring of respiration, glycolysis, and impedance we followed cisplatin treatment of different cancer cell lines in real-time. Our measurements reveal a first effect on respiration, in all cisplatin treated cell lines, followed with a significant delay by interference with glycolysis in HT-29, HCT-116, HepG2, and MCF-7 cells but not in the cisplatin-resistant cell line MDA-MB-231. Most strikingly, cell death started in all cisplatin-sensitive cell lines within 8 to 11 h of treatment, indicating a clear time frame from exposure, first response to cisplatin lesions, to cell fate decision. The time points of most significant changes were selected for more detailed analysis of cisplatin response in the breast cancer cell line MCF-7. Phosphorylation of selected signal transduction mediators connected with cellular proliferation, as well as changes in gene expression, were analyzed in samples obtained directly from sensor chips at the time points when changes in glycolysis and impedance occurred. Our online cell biosensor measurements reveal for the first time the time scale of metabolic response until onset of cell death under cisplatin treatment, which is in good agreement with models of p53-mediated cell fate decision.

  10. Melatonin Prevents Chemical-Induced Haemopoietic Cell Death

    Directory of Open Access Journals (Sweden)

    Sara Salucci

    2014-04-01

    Full Text Available Melatonin (MEL, a methoxyindole synthesized by the pineal gland, is a powerful antioxidant in tissues as well as within cells, with a fundamental role in ameliorating homeostasis in a number of specific pathologies. It acts both as a direct radical scavenger and by stimulating production/activity of intracellular antioxidant enzymes. In this work, some chemical triggers, with different mechanisms of action, have been chosen to induce cell death in U937 hematopoietic cell line. Cells were pre-treated with 100 µM MEL and then exposed to hydrogen peroxide or staurosporine. Morphological analyses, TUNEL reaction and Orange/PI double staining have been used to recognize ultrastructural apoptotic patterns and to evaluate DNA behavior. Chemical damage and potential MEL anti-apoptotic effects were quantified by means of Tali® Image-Based Cytometer, able to monitor cell viability and apoptotic events. After trigger exposure, chromatin condensation, micronuclei formation and DNA fragmentation have been observed, all suggesting apoptotic cell death. These events underwent a statistically significant decrease in samples pre-treated with MEL. After caspase inhibition and subsequent assessment of cell viability, we demonstrated that apoptosis occurs, at least in part, through the mitochondrial pathway and that MEL interacts at this level to rescue U937 cells from death.

  11. The antineoplastic agent α-bisabolol promotes cell death by inducing pores in mitochondria and lysosomes.

    Science.gov (United States)

    Rigo, Antonella; Vinante, Fabrizio

    2016-08-01

    The sesquiterpene α-bisabolol (α-BSB) has been shown to be an effective cytotoxic agent for a variety of human cancer cells in culture and animal models. However, much of its intracellular action remains elusive. We evaluated the cytotoxic action of α-BSB against CML-T1, Jurkat and HeLa cell lines, as preclinical models for myeloid, lymphoid and epithelial neoplasias. The approach included single cell analysis (flow cytometry, immunocytology) combined with cytotoxicity and proliferation assays to characterize organelle damage, autophagy, cytostatic effect, and apoptosis. The study focuses on the relevant steps in the cytotoxic cascade triggered by α-BSB: (1) the lipid rafts through which α-BSB enters the cells, (2) the opening of pores in the mitochondria and lysosomes, (3) the activation of both caspase-dependent and caspase-independent cell death pathways, (4) the induction of autophagy and (5) apoptosis. The effectiveness of α-BSB as an agent against tumor cells is grounded on its capability to act on different layers of cell regulation to elicit different concurrent death signals, thereby neutralizing a variety of aberrant survival mechanisms leading to treatment resistance in neoplastic cell. PMID:27278818

  12. Unc93b Induces Apoptotic Cell Death and Is Cleaved by Host and Enteroviral Proteases.

    Directory of Open Access Journals (Sweden)

    Katharine G Harris

    Full Text Available Unc93b is an endoplasmic reticulum (ER-resident transmembrane protein that serves to bind and traffic toll-like receptors (TLRs from the ER to their appropriate subcellular locations for ligand sensing. Because of its role in TLR trafficking, Unc93b is necessary for an effective innate immune response to coxsackievirus B3 (CVB, a positive-sense single stranded RNA virus belonging to the enterovirus family. Here, we show that Unc93b is cleaved by a CVB-encoded cysteine protease (3Cpro during viral replication. Further, we define a role for Unc93b in the induction of apoptotic cell death and show that expression of wild-type Unc93b, but not a mutant incapable of binding TLRs or exiting the ER (H412R, induces apoptosis. Furthermore, we show that cellular caspases activated during apoptosis directly cleave Unc93b. Interestingly, we show that the 3Cpro- and caspase-mediated cleavage of Unc93b both occur within ten amino acids in the distal N-terminus of Unc93b. Mechanistically, neither caspase-mediated nor 3Cpro-mediated cleavage of Unc93b altered its trafficking function, inhibited its role in facilitating TLR3 or TLR8 signaling, or altered its apoptosis-inducing effects. Taken together, our studies show that Unc93b is targeted by both viral- and host cell-specific proteases and identify a function of Unc93b in the induction of apoptotic cell death.

  13. Autophagic components contribute to hypersensitive cell death in Arabidopsis

    DEFF Research Database (Denmark)

    Hofius, Daniel; Schultz-Larsen, Torsten; Joensen, Jan; Tsitsigiannis, Dimitrios I; Petersen, Nikolaj H T; Mattsson, Ole; Jørgensen, Lise Bolt; Jones, Jonathan D G; Mundy, John; Petersen, Morten

    2009-01-01

    Autophagy has been implicated as a prosurvival mechanism to restrict programmed cell death (PCD) associated with the pathogen-triggered hypersensitive response (HR) during plant innate immunity. This model is based on the observation that HR lesions spread in plants with reduced autophagy gene...

  14. Mitochondrial and Cell Death Mechanisms in Neurodegenerative Diseases

    Directory of Open Access Journals (Sweden)

    Lee J. Martin

    2010-03-01

    Full Text Available Alzheimer’s disease (AD, Parkinson’s disease (PD and amyotrophic lateral sclerosis (ALS are the most common human adult-onset neurodegenerative diseases. They are characterized by prominent age-related neurodegeneration in selectively vulnerable neural systems. Some forms of AD, PD, and ALS are inherited, and genes causing these diseases have been identified. Nevertheless, the mechanisms of the neuronal cell death are unresolved. Morphological, biochemical, genetic, as well as cell and animal model studies reveal that mitochondria could have roles in this neurodegeneration. The functions and properties of mitochondria might render subsets of selectively vulnerable neurons intrinsically susceptible to cellular aging and stress and overlying genetic variations, triggering neurodegeneration according to a cell death matrix theory. In AD, alterations in enzymes involved in oxidative phosphorylation, oxidative damage, and mitochondrial binding of Aβ and amyloid precursor protein have been reported. In PD, mutations in putative mitochondrial proteins have been identified and mitochondrial DNA mutations have been found in neurons in the substantia nigra. In ALS, changes occur in mitochondrial respiratory chain enzymes and mitochondrial cell death proteins. Transgenic mouse models of human neurodegenerative disease are beginning to reveal possible principles governing the biology of selective neuronal vulnerability that implicate mitochondria and the mitochondrial permeability transition pore. This review summarizes how mitochondrial pathobiology might contribute to neuronal death in AD, PD, and ALS and could serve as a target for drug therapy.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Metal-accelerated oxidation in plant cell death

    Energy Technology Data Exchange (ETDEWEB)

    Czuba, M. (National Research Council, Ottawa, Ontario (Canada))

    1993-05-01

    Cadmium and mercury toxicity is further enhanced by external oxidizing conditions O[sub 3] or inherent plant processes. Lepidium sativum L, Lycopersicon esculentum Mill., or Phaseolus vulgaris L, were grown inpeat-lite to maturity under continuous cadmium exposure followed by one oxidant (O[sub 3]-6 hr. 30 pphm) exposure, with or without foliar calcium pretreatments. In comparison, Daucus carota, L and other species grown in a 71-V suspension, with or without 2,4-D were exposed continuously to low levels of methylmercury during exponential growth and analyzed in aggregates of distinct populations. Proteins were extracted and analyzed. Mechanisms of toxicity and eventual cell death are Ca-mediated and involve chloroplast, stomatal-water relations and changes in oxidant-anti-oxidant components in cells. Whether the metal-accelerated oxidative damage proceeds to cell death, depends on the species and its differential biotransformation system and cell association component.

  17. Plant caspase-like proteases in plant programmed cell death

    OpenAIRE

    Xu, Qixian; Zhang, Lingrui

    2009-01-01

    Programmed cell death (PCD) is a genetically-controlled disassembly of the cell. In animal systems, the central core execution switch for apoptotic PCD is the activation of caspases (Cysteine-containing Aspartate-specific proteases). Accumulating evidence in recent years suggests the existence of caspase-like activity in plants and its functional involvement in various types of plant PCD, although no functional homologs of animal caspases were identified in plant genome. In this mini-review, ...

  18. Mitochondrial and Cell Death Mechanisms in Neurodegenerative Diseases

    OpenAIRE

    Martin, Lee J.

    2010-01-01

    Alzheimer’s disease (AD), Parkinson’s disease (PD) and amyotrophic lateral sclerosis (ALS) are the most common human adult-onset neurodegenerative diseases. They are characterized by prominent age-related neurodegeneration in selectively vulnerable neural systems. Some forms of AD, PD, and ALS are inherited, and genes causing these diseases have been identified. Nevertheless, the mechanisms of the neuronal cell death are unresolved. Morphological, biochemical, genetic, as well as cell and ani...

  19. Heterogeneity reduces sensitivity of cell death for TNF-Stimuli

    Directory of Open Access Journals (Sweden)

    Schliemann Monica

    2011-12-01

    Full Text Available Abstract Background Apoptosis is a form of programmed cell death essential for the maintenance of homeostasis and the removal of potentially damaged cells in multicellular organisms. By binding its cognate membrane receptor, TNF receptor type 1 (TNF-R1, the proinflammatory cytokine Tumor Necrosis Factor (TNF activates pro-apoptotic signaling via caspase activation, but at the same time also stimulates nuclear factor κB (NF-κB-mediated survival pathways. Differential dose-response relationships of these two major TNF signaling pathways have been described experimentally and using mathematical modeling. However, the quantitative analysis of the complex interplay between pro- and anti-apoptotic signaling pathways is an open question as it is challenging for several reasons: the overall signaling network is complex, various time scales are present, and cells respond quantitatively and qualitatively in a heterogeneous manner. Results This study analyzes the complex interplay of the crosstalk of TNF-R1 induced pro- and anti-apoptotic signaling pathways based on an experimentally validated mathematical model. The mathematical model describes the temporal responses on both the single cell level as well as the level of a heterogeneous cell population, as observed in the respective quantitative experiments using TNF-R1 stimuli of different strengths and durations. Global sensitivity of the heterogeneous population was quantified by measuring the average gradient of time of death versus each population parameter. This global sensitivity analysis uncovers the concentrations of Caspase-8 and Caspase-3, and their respective inhibitors BAR and XIAP, as key elements for deciding the cell's fate. A simulated knockout of the NF-κB-mediated anti-apoptotic signaling reveals the importance of this pathway for delaying the time of death, reducing the death rate in the case of pulse stimulation and significantly increasing cell-to-cell variability. Conclusions Cell

  20. How Heme Oxygenase-1 Prevents Heme-Induced Cell Death

    OpenAIRE

    Lilibeth Lanceta; Mattingly, Jacob M.; Chi Li; Eaton, John W.

    2015-01-01

    Earlier observations indicate that free heme is selectively toxic to cells lacking heme oxygenase-1 (HO-1) but how this enzyme prevents heme toxicity remains unexplained. Here, using A549 (human lung cancer) and immortalized human bronchial epithelial cells incubated with exogenous heme, we find knock-down of HO-1 using siRNA does promote the accumulation of cell-associated heme and heme-induced cell death. However, it appears that the toxic effects of heme are exerted by "loose" (probably in...

  1. Networked T cell death following macrophage infection by Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Stephen H-F Macdonald

    Full Text Available BACKGROUND: Depletion of T cells following infection by Mycobacterium tuberculosis (Mtb impairs disease resolution, and interferes with clinical test performance that relies on cell-mediated immunity. A number of mechanisms contribute to this T cell suppression, such as activation-induced death and trafficking of T cells out of the peripheral circulation and into the diseased lungs. The extent to which Mtb infection of human macrophages affects T cell viability however, is not well characterised. METHODOLOGY/PRINCIPAL FINDINGS: We found that lymphopenia (<1.5 × 10(9 cells/l was prevalent among culture-positive tuberculosis patients, and lymphocyte counts significantly improved post-therapy. We previously reported that Mtb-infected human macrophages resulted in death of infected and uninfected bystander macrophages. In the current study, we sought to examine the influence of infected human alveolar macrophages on T cells. We infected primary human alveolar macrophages (the primary host cell for Mtb or PMA-differentiated THP-1 cells with Mtb H37Ra, then prepared cell-free supernatants. The supernatants of Mtb-infected macrophages caused dose-dependent, caspase-dependent, T cell apoptosis. This toxic effect of infected macrophage secreted factors did not require TNF-α or Fas. The supernatant cytotoxic signal(s were heat-labile and greater than 50 kDa in molecular size. Although ESAT-6 was toxic to T cells, other Mtb-secreted factors tested did not influence T cell viability; nor did macrophage-free Mtb bacilli or broth from Mtb cultures. Furthermore, supernatants from Mycobacterium bovis Bacille de Calmette et Guerin (BCG- infected macrophages also elicited T cell death suggesting that ESAT-6 itself, although cytotoxic, was not the principal mediator of T cell death in our system. CONCLUSIONS: Mtb-Infected macrophages secrete heat-labile factors that are toxic to T cells, and may contribute to the immunosuppression seen in tuberculosis as well as

  2. Radiation induced reproductive death as a function of mammalian cell ploidy

    Energy Technology Data Exchange (ETDEWEB)

    Philbrick, D.A.

    1976-09-01

    Mammalian cells containing different multiples of the diploid chromosome set were created through drug induction and cell fusion. In all cell strains used the chromosome number was determined from metaphase spreads, as well as from DNA content and cell size. The survival of cells as a function of radiation dose was determined for cell lines with differing chromosome complements at 37/sup 0/C, 4/sup 0/C, in hypertonic media, while frozen, and with increasing levels of incorporated IUdR. Survival of frozen diploid and hypotetraploid Chinese hamster cells was determined following varying numbers of decays of incorporated /sup 3/HTdR and /sup 125/IUdR. The percent of reproductively viable cells following irradiation is a function of the cell ploidy, i.e., the number of haploid sets of chromosomes contained in the cell genome. At 37/sup 0/C and in hypertonic media, the Chinese hamster cells of progressively higher ploidies are increasingly sensitive to irradiation. As the number of chromosomes per unit cell volume increases the radiosensitivity increases. Both trends suggest interaction between chromosomes as an important cause of cell death.

  3. Cell killing and mutation induction on Chinese hamster cells by photoradiations

    International Nuclear Information System (INIS)

    The subject matter of this investigation concerns the killing and mutagenic effects induced by far-UV radiation and broad spectra of black, white and gold lights. Applying radiation directly on CHO (Chinese hamster ovary) cells, far-UV is more effective than black light, and black light is more effective than white light in inducing proliferative death and in inducing resistance to 6-thioguanine (6TG), ouabain and diptheria toxin (DT). Cells in the G1/early S boundary are the most sensitive to far-UV or unfiltered fluorescent lights. When synchronous cells are irradiated with moderate doses of far-UV or unfiltered broad spectra of black light, mutations to 6-TG and ouabain resistance are slightly higher in early S period than in the remaining parts of the cell cycle. Mutation induction of 6-TG, ouabain or DT resistance is increased in the split-dose samples of the asynchronous and synchronous CHO cells. CHO cells predominantly express an error-prone repair mechanism after photoirradiation

  4. Cell death in the injured brain: roles of metallothioneins

    DEFF Research Database (Denmark)

    Pedersen, Mie Ø; Larsen, Agnete; Stoltenberg, Meredin; Penkowa, Milena

    2009-01-01

    In traumatic brain injury (TBI), the primary, irreversible damage associated with the moment of impact consists of cells dying from necrosis. This contributes to fuelling a chronic central nervous system (CNS) inflammation with increased formation of proinflammatory cytokines, enzymes and reactive...... provides an overview of the TBI pathophysiology leading to cell death and neurological impairment. We also discuss endogenously expressed neuroprotectants and drug candidates, which at this stage may still hold the potential for treating brain injured patients....... oxygen species (ROS). ROS promote oxidative stress, which leads to neurodegeneration and ultimately results in programmed cell death (secondary injury). Since this delayed, secondary tissue loss occurs days to months following the primary injury it provides a therapeutic window where potential...

  5. Cell death is involved in sexual dimorphism during preimplantation development.

    Science.gov (United States)

    Oliveira, C S; Saraiva, N Z; Lima, M R de; Oliveira, L Z; Serapião, R V; Garcia, J M; Borges, C A V; Camargo, L S A

    2016-02-01

    In bovine preimplantation development, female embryos progress at lower rates and originate smaller blastocysts than male counterparts. Although sex-specific gene expression patterns are reported, when and how sex dimorphism is established is not clear. Differences among female and male early development can be useful for human assisted reproductive medicine, when X-linked disorders risk is detected, and for genetic breeding programs, especially in dairy cattle, which requires female animals for milk production. The aim of this study was to characterize the development of female and male embryos, attempting to identify sex effects during preimplantation development and the role of cell death in this process. Using sex-sorted semen from three different bulls for fertilization, we compared kinetics of bovine sex-specific embryos in six time points, and cell death was assessed in viable embryos. For kinetics analysis, we detected an increased population of female embryos arrested at 48 and 120h.p.i., suggesting this time points as delicate stages of development for female embryos that should be considered for testing improvement strategies for assisted reproductive technologies. Assessing viable embryos quality, we found 144h.p.i. is the first time point when viable embryos are phenotypically distinct: cell number is decreased, and apoptosis and cell fragmentation are increased in female embryos at this stage. These new results lead us to propose that sex dimorphism in viable embryos is established during morula-blastocyst transition, and cell death is involved in this process. PMID:26752320

  6. Investigating cell death mechanisms in Amyotrophic lateral sclerosis using transcriptomics

    Directory of Open Access Journals (Sweden)

    Paul Roy Heath

    2013-12-01

    Full Text Available Amyotrophic lateral sclerosis is a motor neuron disease characterised by degeneration and loss of upper and lower motor neurons from the motor cortex, brainstem and spinal cord although evidence is suggesting that there is further involvement of other cell types in the surrounding tissue. Transcriptomic analysis by gene expression profiling using microarray technology has enabled the determination of patterns of cell death in the degenerating tissues. This work has examined gene expression at the level of the tissue and individual cell types in both sporadic and familial forms of the disease. In addition, further studies have examined the differential vulnerability of neuronal cells in different regions of the central nervous system. Model systems have also provided further information to help unravel the mechanisms that lead to death of the motor neurons in disease and also provided novel insights. In this review we shall describe the methods that have been used in these investigations and describe how they have contributed to our knowledge of the cell death mechanisms in ALS.

  7. Inhibition of HAS2 induction enhances the radiosensitivity of cancer cells via persistent DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yan Nan; Shin, Hyun-Jin; Joo, Hyun-Yoo; Park, Eun-Ran; Kim, Su-Hyeon; Hwang, Sang-Gu [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Park, Sang Jun; Kim, Chun-Ho [Laboratory of Tissue Engineering, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Lee, Kee-Ho, E-mail: khlee@kirams.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)

    2014-01-17

    Highlights: •HAS2 may be a promising target for the radiosensitization of human cancer. •HAS2 is elevated (up to ∼10-fold) in irradiated radioresistant and -sensitive cancer cells. •HAS2 knockdown sensitizes cancer cells to radiation. •HAS2 knockdown potentiates irradiation-induced DNA damage and apoptotic death. •Thus, the irradiation-induced up-regulation of HAS2 contributes to the radioresistance of cancer cells. -- Abstract: Hyaluronan synthase 2 (HAS2), a synthetic enzyme for hyaluronan, regulates various aspects of cancer progression, including migration, invasion and angiogenesis. However, the possible association of HAS2 with the response of cancer cells to anticancer radiotherapy, has not yet been elucidated. Here, we show that HAS2 knockdown potentiates irradiation-induced DNA damage and apoptosis in cancer cells. Upon exposure to radiation, all of the tested human cancer cell lines exhibited marked (up to 10-fold) up-regulation of HAS2 within 24 h. Inhibition of HAS2 induction significantly reduced the survival of irradiated radioresistant and -sensitive cells. Interestingly, HAS2 depletion rendered the cells to sustain irradiation-induced DNA damage, thereby leading to an increase of apoptotic death. These findings indicate that HAS2 knockdown sensitizes cancer cells to radiation via persistent DNA damage, further suggesting that the irradiation-induced up-regulation of HAS2 contributes to the radioresistance of cancer cells. Thus, HAS2 could potentially be targeted for therapeutic interventions aimed at radiosensitizing cancer cells.

  8. Staurosporine induces necroptotic cell death under caspase-compromised conditions in U937 cells.

    Directory of Open Access Journals (Sweden)

    Zsuzsanna A Dunai

    Full Text Available For a long time necrosis was thought to be an uncontrolled process but evidences recently have revealed that necrosis can also occur in a regulated manner. Necroptosis, a type of programmed necrosis is defined as a death receptor-initiated process under caspase-compromised conditions. The process requires the kinase activity of receptor-interacting protein kinase 1 and 3 (RIPK1 and RIPK3 and mixed lineage kinase domain-like protein (MLKL, as a substrate of RIPK3. The further downstream events remain elusive. We applied known inhibitors to characterize the contributing enzymes in necroptosis and their effect on cell viability and different cellular functions were detected mainly by flow cytometry. Here we report that staurosporine, the classical inducer of intrinsic apoptotic pathway can induce necroptosis under caspase-compromised conditions in U937 cell line. This process could be hampered at least partially by the RIPK1 inhibitor necrotstin-1 and by the heat shock protein 90 kDa inhibitor geldanamycin. Moreover both the staurosporine-triggered and the classical death ligand-induced necroptotic pathway can be effectively arrested by a lysosomal enzyme inhibitor CA-074-OMe and the recently discovered MLKL inhibitor necrosulfonamide. We also confirmed that the enzymatic role of poly(ADP-ribosepolymerase (PARP is dispensable in necroptosis but it contributes to membrane disruption in secondary necrosis. In conclusion, we identified a novel way of necroptosis induction that can facilitate our understanding of the molecular mechanisms of necroptosis. Our results shed light on alternative application of staurosporine, as a possible anticancer therapeutic agent. Furthermore, we showed that the CA-074-OMe has a target in the signaling pathway leading to necroptosis. Finally, we could differentiate necroptotic and secondary necrotic processes based on participation of PARP enzyme.

  9. Programmed cell death and clearance of cell corpses in Caenorhabditis elegans.

    Science.gov (United States)

    Wang, Xiaochen; Yang, Chonglin

    2016-06-01

    Programmed cell death is critical to the development of diverse animal species from C. elegans to humans. In C. elegans, the cell death program has three genetically distinguishable phases. During the cell suicide phase, the core cell death machinery is activated through a protein interaction cascade. This activates the caspase CED-3, which promotes numerous pro-apoptotic activities including DNA degradation and exposure of the phosphatidylserine "eat me" signal on the cell corpse surface. Specification of the cell death fate involves transcriptional activation of the cell death initiator EGL-1 or the caspase CED-3 by coordinated actions of specific transcription factors in distinct cell types. In the cell corpse clearance stage, recognition of cell corpses by phagocytes triggers several signaling pathways to induce phagocytosis of apoptotic cell corpses. Cell corpse-enclosing phagosomes ultimately fuse with lysosomes for digestion of phagosomal contents. This article summarizes our current knowledge about programmed cell death and clearance of cell corpses in C. elegans. PMID:27048817

  10. Influence of chlorine dioxide on cell death and cell cycle of human gingival fibroblasts

    OpenAIRE

    Nishikiori, Ryo; Nomura, Yuji; Sawajiri, Masahiko; Masuki, Kohei; Hirata, Isao; Okazaki, Masayuki

    2008-01-01

    Objectives: The effects of chlorine dioxide (ClO2), sodium hypochlorite (NaOCl), and hydrogen peroxide (H2O2) on cell death and the cell cycle of human gingival fibroblast (HGF) cells were examined. Methods: The inhibition of HGF cell growth was evaluated using a Cell Counting Kit-8. The cell cycle was assessed with propidium iodide-stained cells (distribution of cells in G0/G1, S, G2/M phases) using flow cytometry. The patterns of cell death (necrosis and apoptosis) were analyzed using f...

  11. Programmed cell death 1 ligand 1 expression in osteosarcoma

    OpenAIRE

    Shen, Jacson K.; Cote, Gregory M.; Choy, Edwin; Yang, Pei; Harmon, David; Schwab, Joseph; Nielsen, G. Petur; Chebib, Ivan; Ferrone, Soldano; Wang, Xinhui; Wang, Yangyang; Mankin, Henry; Francis J. Hornicek; Duan, Zhenfeng

    2014-01-01

    Programmed cell death 1 ligand 1 (PD-L1, B7H1) is a cell-surface protein that suppresses the cytotoxic CD8+ T cell-mediated immune response. PD-L1 expression and its clinical relevance in sarcomas are not well understood. Therefore, we sought to measure RNA expression levels for PD-L1 in 38 clinically annotated osteosarcoma tumor samples, and aimed to determine if PD-L1 expression correlates with clinical features and tumor-infiltrating T-lymphocytes (TILs). Quantitative real-time RT-PCR for ...

  12. Benzyl isothiocyanate alters the gene expression with cell cycle regulation and cell death in human brain glioblastoma GBM 8401 cells.

    Science.gov (United States)

    Tang, Nou-Ying; Chueh, Fu-Shin; Yu, Chien-Chih; Liao, Ching-Lung; Lin, Jen-Jyh; Hsia, Te-Chun; Wu, King-Chuen; Liu, Hsin-Chung; Lu, Kung-Wen; Chung, Jing-Gung

    2016-04-01

    Glioblastoma multiforme (GBM) is a highly malignant devastating brain tumor in adults. Benzyl isothiocyanate (BITC) is one of the isothiocyanates that have been shown to induce human cancer cell apoptosis and cell cycle arrest. Herein, the effect of BITC on cell viability and apoptotic cell death and the genetic levels of human brain glioblastoma GBM 8401 cells in vitro were investigated. We found that BITC induced cell morphological changes, decreased cell viability and the induction of cell apoptosis in GBM 8401 cells was time-dependent. cDNA microarray was used to examine the effects of BITC on GBM 8401 cells and we found that numerous genes associated with cell death and cell cycle regulation in GBM 8401 cells were altered after BITC treatment. The results show that expression of 317 genes was upregulated, and two genes were associated with DNA damage, the DNA-damage-inducible transcript 3 (DDIT3) was increased 3.66-fold and the growth arrest and DNA-damage-inducible α (GADD45A) was increased 2.34-fold. We also found that expression of 182 genes was downregulated and two genes were associated with receptor for cell responses to stimuli, the EGF containing fibulin-like extracellular matrix protein 1 (EFEMP1) was inhibited 2.01-fold and the TNF receptor-associated protein 1 (TRAP1) was inhibited 2.08-fold. BITC inhibited seven mitochondria ribosomal genes, the mitochondrial ribosomal protein; tumor protein D52 (MRPS28) was inhibited 2.06-fold, the mitochondria ribosomal protein S2 (MRPS2) decreased 2.07-fold, the mitochondria ribosomal protein L23 (MRPL23) decreased 2.08-fold, the mitochondria ribosomal protein S2 (MRPS2) decreased 2.07-fold, the mitochondria ribosomal protein S12 (MRPS12) decreased 2.08-fold, the mitochondria ribosomal protein L12 (MRPL12) decreased 2.25-fold and the mitochondria ribosomal protein S34 (MRPS34) was decreased 2.30-fold in GBM 8401 cells. These changes of gene expression can provide the effects of BITC on the

  13. In vitro apoptotic cell death during erythroid differentiation.

    Science.gov (United States)

    Zamai, L; Burattini, S; Luchetti, F; Canonico, B; Ferri, P; Melloni, E; Gonelli, A; Guidotti, L; Papa, S; Falcieri, E

    2004-03-01

    Erythropoiesis occurs in bone marrow and it has been shown that during in vivo erythroid differentiation some immature erythroblasts undergo apoptosis. In this regard, it is known that immature erythroblasts are FasL- and TRAIL-sensitive and can be killed by cells expressing these ligand molecules. In the present study, we have investigated the cell death phenomenon that occurs during a common unilineage model of erythroid development. Purified CD34+ human haemopoietic progenitors were cultured in vitro in the presence of SCF, IL-3 and erythropoietin. Their differentiation stages and apoptosis were followed by multiple technical approaches. Flow cytometric evaluation of surface and intracellular molecules revealed that glycophorin A appeared at day 3-4 of incubation and about 75% of viable cells co-expressed high density glycophorin A (Gly(bright)) and adult haemoglobin at day 14 of culture, indicating that this system reasonably recapitulates in vivo normal erythropoiesis. Interestingly, when mature (Gly(bright)) erythroid cells reached their higher percentages (day 14) almost half of cultured cells were apoptotic. Morphological studies indicated that the majority of dead cells contained cytoplasmic granular material typical of basophilic stage, and DNA analysis by flow cytometry and TUNEL reaction revealed nuclear fragmentation. These observations indicate that in vitro unilineage erythroid differentiation, as in vivo, is associated with apoptotic cell death of cells with characteristics of basophilic erythroblasts. We suggest that the interactions between different death receptors on immature basophilic erythroblasts with their ligands on more mature erythroblasts may contribute to induce apoptosis in vitro. PMID:15004520

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

    Science.gov (United States)

    Jung, So Young; Lee, Kang-Woo; Choi, Sun-Mi; Yang, Eun Jin

    2015-09-01

    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. PMID:26402700

  15. 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.

  16. Cell-nonautonomous regulation of C. elegans germ cell death by kri-1.

    Science.gov (United States)

    Ito, Shu; Greiss, Sebastian; Gartner, Anton; Derry, W Brent

    2010-02-23

    Programmed cell death (or apoptosis) is an evolutionarily conserved, genetically controlled suicide mechanism for cells that, when deregulated, can lead to developmental defects, cancers, and degenerative diseases. In C. elegans, DNA damage induces germ cell death by signaling through cep-1/p53, ultimately leading to the activation of CED-3/caspase. It has been hypothesized that the major regulatory events controlling cell death occur by cell-autonomous mechanisms, that is, within the dying cell. In support of this, genetic studies in C. elegans have shown that the core apoptosis pathway genes ced-4/APAF-1 and ced-3/caspase are required in cells fated to die. However, it is not known whether the upstream signals that activate apoptosis function in a cell-autonomous manner. Here we show that kri-1, an ortholog of KRIT1/CCM1, which is mutated in the human neurovascular disease cerebral cavernous malformation, is required to activate DNA damage-dependent cell death independently of cep-1/p53. Interestingly, we find that kri-1 regulates cell death in a cell-nonautonomous manner, revealing a novel regulatory role for nondying cells in eliciting cell death in response to DNA damage. PMID:20137949

  17. Induction and identification of rabbit peripheral blood derived dendritic cells

    Science.gov (United States)

    Zhou, Jing; Yang, FuYuan; Chen, WenLi

    2012-03-01

    Purpose: To study a method of the induction of dendritic cells (DCs) from rabbit peripheral blood. Methods: Peripheral blood cells were removed from rabbit, filtered through nylon mesh. Peripheral blood mononuclear cells (PBMC) were isolated from the blood cells by Ficoll-Hypaque centrifugation (density of 1.077g/cm3).To obtain DCs, PBMC were cultured in RPMI1640 medium containing 10% fetal calf serum, 50U/mL penicillin and streptomycin, referred to subsequently as complete medium, at 37°C in 5% CO2 atmosphere for 4 hours. Nonadherent cells were aspirated, adherent cells were continued incubated in complete medium, supplemented with granulocyte/macrophage colony-stimulating factor (GM-CSF, 50ng/ml),and interleukin 4 (IL-4, 50ng/ml) for 9 days. Fluorescein labeled antibodies(anti-CD14, anti-HLA-DR, anti-CD86) were used to sign cells cultured for 3,6,9 days respectively, Then flow cytometry was performed. Results: Ratio of anti-HLA-DR and anti-CD86 labeled cells increased with induction time extension, in contrast with anti-CD14. Conclusion: Dendritic cells can be effectively induced by the method of this experiment, cell maturation status increased with induction time extension.

  18. Triggering cell death by nanographene oxide mediated hyperthermia

    International Nuclear Information System (INIS)

    Graphene oxide (GO) has been proposed as an hyperthermia agent for anticancer therapies due to its near-infrared (NIR) optical absorption ability which, with its small two-dimensional size, could have a unique performance when compared to that of any other nanoparticle. Nevertheless, attention should be given to the hyperthermia route and the kind of GO–cell interactions induced in the process. The hyperthermia laser irradiation parameters, such as exposure time and laser power, were investigated to control the temperature rise and consequent damage in the GOs containing cell culture medium. The type of cell damage produced was evaluated as a function of these parameters. The results showed that cell culture temperature (after irradiating cells with internalized GO) increases preferentially with laser power rather than with exposure time. Moreover, when laser power is increased, necrosis is the preferential cell death leading to an increase of cytokine release to the medium. (paper)

  19. Cell death induced by gamma irradiation of developing skeletal muscle

    International Nuclear Information System (INIS)

    Newborn Sprague-Dawley rats were exposed to a single dose of 2 Gy gamma rays and killed from 6 h to 5 d later. Increased numbers of dying cells, characterised by their extreme chromatin condensation and often nuclear fragmentation were seen in skeletal muscle 6 h after irradiation. Dying cells decreased to nearly normal values 48 h later. In situ labelling of nuclear DNA fragmentation identified individual cells bearing fragmented DNA. The effects of gamma rays were suppressed following cycloheximide i.p. at a dose of 1 μg/g body weight given at the time of irradiation. Taken together, the present morphological and pharmacological results suggest that gamma ray induced cell death in skeletal muscle is apoptotic, and that the process is associated with protein synthesis. Finally, proliferating cell nuclear antigen-immunoreactive cells, which were abundant in control rats, decreased in number 48 h after irradiation. However, a marked increase significantly above normal age values was observed at the 5th day, thus suggesting that regeneration occurs following irradiation-induced cell death in developing muscle. (author)

  20. Regulating the reapers: activating metacaspases for programmed cell death.

    Science.gov (United States)

    Lam, Eric; Zhang, Yi

    2012-08-01

    Research during the past two decades has revealed that specialized cysteine proteases act as conserved initiators or executioners for programmed cell death (PCD) in eukaryotes. Caspases were first identified as common regulators of PCD in metazoans, whereas the role of metacaspases (MCs) as regulators of cellular suicide in plants has only been shown genetically in the past several years. Together with recent biochemical and molecular characterizations of some of the representative MCs from different model systems, multiple mechanisms that can mediate the post-translational regulation of these proteases are beginning to emerge. Further elucidation of these regulatory pathways and definition of the downstream degradomes targeted by MCs should lead to a better understanding of cell death control in plants, protozoans, and fungi. PMID:22658651

  1. Molecular mechanisms of cell death in intervertebral disc degeneration (Review).

    Science.gov (United States)

    Zhang, Fan; Zhao, Xueling; Shen, Hongxing; Zhang, Caiguo

    2016-06-01

    Intervertebral discs (IVDs) are complex structures that consist of three parts, namely, nucleus pulposus, annulus fibrosus and cartilage endplates. With aging, IVDs gradually degenerate as a consequence of many factors, such as microenvironment changes and cell death. Human clinical trial and animal model studies have documented that cell death, particularly apoptosis and autophagy, significantly contribute to IVD degeneration. The mechanisms underlying this phenomenon include the activation of apoptotic pathways and the regulation of autophagy in response to nutrient deprivation and multiple stresses. In this review, we briefly summarize recent progress in understanding the function and regulation of apoptosis and autophagy signaling pathways. In particular, we focus on studies that reveal the functional mechanisms of these pathways in IVD degeneration. PMID:27121482

  2. Sphingolipid signalling: molecular basis and role in TNF-alpha-induced cell death.

    Science.gov (United States)

    Malagarie-Cazenave, Sophie; Andrieu-Abadie, Nathalie; Ségui, Bruno; Gouazé, Valérie; Tardy, Claudine; Cuvillier, Olivier; Levade, Thierry

    2002-12-01

    Various lipidic molecules serve as second messengers for transducing signals from the cell surface to the cell interior and trigger specific cellular responses. Sphingolipids represent a complex group of lipids that have recently emerged as new transducers in eukaryotic cells. Several sphingolipid molecules are able to modulate cell growth, differentiation and death. This review summarises current knowledge of the signalling functions of sphingolipids, especially in the regulation of tumour necrosis factor [alpha] (TNF-[alpha])-mediated cytotoxic effects. TNF-[alpha] is a multifaceted cytokine that controls a wide range of immune responses in mammals, including induction of programmed cell death (also called apoptosis). On the basis of recent observations, a working model is proposed for the molecular mechanisms underlying regulation of sphingolipid generation following TNF-[alpha] receptor 1 activation. The implications of these findings for the development of future pharmacological strategies to prevent the cytotoxic TNF-[alpha] response and subsequent cellular dysfunctions (as seen in various human diseases) are discussed. PMID:14987386

  3. Induction of myeloid-derived suppressor cells by tumor exosomes

    OpenAIRE

    Xiang, Xiaoyu; Poliakov, Anton; Liu, Cunren; Liu, Yuelong; Deng, Zhong-Bin; wang, Jianhua; Cheng, Ziqiang; Shah, Spandan V.; Wang, Gui-Jun; Zhang, Liming; Grizzle, William E.; Mobley, Jim; Zhang, Huang-Ge

    2009-01-01

    Myeloid-derived suppressor cells (MDSCs) promote tumor progression. The mechanisms of MDSC development during tumor growth remain unknown. Tumor exosomes (T-exosomes) have been implicated to play a role in immune regulation, however the role of exosomes in the induction of MDSCs is unclear. Our previous work demonstrated that exosomes isolated from tumor cells are taken up by bone marrow myeloid cells. Here, we extend those findings showing that exosomes isolated from T-exosomes switch the di...

  4. Protein kinase CK2 inhibition induces cell death via early impact on mitochondrial function*

    Science.gov (United States)

    Qaiser, Fatima; Trembley, Janeen H.; Kren, Betsy T.; Wu, Jing-Jiang; Naveed, A. Khaliq; Ahmed, Khalil

    2014-01-01

    CK2 (official acronym for casein kinase 2 or II) is a potent suppressor of apoptosis in response to diverse apoptotic stimuli —thus its molecular downregulation or activity inhibition results in potent induction of cell death. CK2 downregulation is known to impact mitochondrial apoptotic circuitry but the underlying mechanism(s) remain unclear. Utilizing prostate cancer cell lines subjected to CK2-specific inhibitors which cause loss of cell viability, we have found that CK2 inhibition in cells causes rapid early decrease in mitochondrial membrane potential (Δψm). Cells treated with the CK2 inhibitors TBB (4,5,6,7-tetrabromobenzotriazole) or TBCA (tetrabromocinnamic acid) demonstrate changes in Δψm which become apparent within 2 h, i.e., significantly prior to evidence of activation of other mitochondrial apoptotic signals whose temporal expression ensues subsequent to loss of Δψm. Further, we have demonstrated the presence of CK2 in purified mitochondria and it appears that the effect on Δψm evoked by inhibition of CK2 may involve mitochondrial localized CK2. Results also suggest that alterations in Ca2+ signaling may be involved in the CK2 mediated regulation of Δψm and mitochondrial permeability. Thus, we propose that a key mechanism of CK2 impact on mitochondrial apoptotic circuitry and cell death involves early loss of Δψm which may be a primary trigger for apoptotic signaling and cell death resulting from CK2 inhibition. PMID:25043911

  5. A Novel Cell Death Gene Acts to Repair Patterning Defects in Drosophila melanogaster

    OpenAIRE

    Tanaka, Kentaro M.; Takahashi, Aya; Fuse, Naoyuki; Takano-Shimizu-Kouno, Toshiyuki

    2014-01-01

    Cell death is a mechanism utilized by organisms to eliminate excess cells during development. Here, we describe a novel regulator of caspase-independent cell death, Mabiki (Mabi), that is involved in the repair of the head patterning defects caused by extra copies of bicoid in Drosophila melanogaster. Mabiki functions together with caspase-dependent cell death mechanisms to provide robustness during development.

  6. Methylglyoxal (MGO) inhibits proliferation and induces cell death of human glioblastoma multiforme T98G and U87MG cells.

    Science.gov (United States)

    Paul-Samojedny, Monika; Łasut, Barbara; Pudełko, Adam; Fila-Daniłow, Anna; Kowalczyk, Małgorzata; Suchanek-Raif, Renata; Zieliński, Michał; Borkowska, Paulina; Kowalski, Jan

    2016-05-01

    Glioblastoma multiforme (GBM) is the most malignant and invasive human brain tumor and it is characterized by a poor prognosis and short survival time. Current treatment strategies for GBM using surgery, chemotherapy and/or radiotherapy are ineffective. Thus new therapeutic strategies to target GBM are urgently needed. The effect of methylglyoxal (MGO) on the cell cycle, cell death and proliferation of human GBM cells was investigated. The T98G and U87MG cell lines were cultured in modified EMEM supplemented with 10% fetal bovine serum and maintained at 37°C in a humidified atmosphere of 5% CO2 in air. Cells were exposed to methylglyoxal (0.025mM) per 72h. The influence of MGO on T98G and U87MG cell cycle, proliferation and apoptosis was evaluated as well. Cell cycle phase distribution, proliferation, apoptosis were analyzed by flow cytometry. MGO causes changes in cell cycle and induces accumulation of G1/G0-phase cells and reduced fraction of cells in S and G2/M phases. We have also observed inhibition of cell proliferation and induction of apoptosis in cancer cells. We have also revealed that MGO induces senescence of U87MG but not T98G cells, but further studies are necessary in order to clarify and check mechanism of action of methylglyoxal and it Is a positive phenomenon for the treatment of GBM. PMID:27133062

  7. 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.

  8. Cell Death Characterization In Tumor Constructs Using Irreversible Electroporation

    OpenAIRE

    Prokop, Katherine Jane

    2013-01-01

    Cell Death Characterization in Tumor Constructs Using Irreversible Electroporation Katherine Jane Prokop ABSTRACT Pancreatic and prostate cancer are both prevalent cancers in the United States with pancreatic being one of the most aggressive of all cancers and prostate cancer being one of the most common, ranking as the number one cancer in men. Treatment of both cancers can be quite challenging as the anatomy of the pancreas and prostate, as well as the development and diagnos...

  9. Population based model of human embryonic stem cell (hESC differentiation during endoderm induction.

    Directory of Open Access Journals (Sweden)

    Keith Task

    Full Text Available The mechanisms by which human embryonic stem cells (hESC differentiate to endodermal lineage have not been extensively studied. Mathematical models can aid in the identification of mechanistic information. In this work we use a population-based modeling approach to understand the mechanism of endoderm induction in hESC, performed experimentally with exposure to Activin A and Activin A supplemented with growth factors (basic fibroblast growth factor (FGF2 and bone morphogenetic protein 4 (BMP4. The differentiating cell population is analyzed daily for cellular growth, cell death, and expression of the endoderm proteins Sox17 and CXCR4. The stochastic model starts with a population of undifferentiated cells, wherefrom it evolves in time by assigning each cell a propensity to proliferate, die and differentiate using certain user defined rules. Twelve alternate mechanisms which might describe the observed dynamics were simulated, and an ensemble parameter estimation was performed on each mechanism. A comparison of the quality of agreement of experimental data with simulations for several competing mechanisms led to the identification of one which adequately describes the observed dynamics under both induction conditions. The results indicate that hESC commitment to endoderm occurs through an intermediate mesendoderm germ layer which further differentiates into mesoderm and endoderm, and that during induction proliferation of the endoderm germ layer is promoted. Furthermore, our model suggests that CXCR4 is expressed in mesendoderm and endoderm, but is not expressed in mesoderm. Comparison between the two induction conditions indicates that supplementing FGF2 and BMP4 to Activin A enhances the kinetics of differentiation than Activin A alone. This mechanistic information can aid in the derivation of functional, mature cells from their progenitors. While applied to initial endoderm commitment of hESC, the model is general enough to be applicable

  10. Targeted cancer cell death induced by biofunctionalized magnetic nanowires

    KAUST Repository

    Contreras, Maria F.

    2014-02-01

    Magnetic micro and nanomaterials are increasingly interesting for biomedical applications since they possess many advantageous properties: they can become biocompatible, they can be functionalized to target specific cells and they can be remotely manipulated by magnetic fields. The goal of this study is to use antibody-functionalized nickel nanowires (Ab-NWs) as an alternative method in cancer therapy overcoming the limitations of current treatments that lack specificity and are highly cytotoxic. Ab-NWs have been incubated with cancer cells and a 12% drop on cell viability was observed for a treatment of only 10 minutes and an alternating magnetic field of low intensity and low frequency. It is believed that the Ab-NWs vibrate transmitting a mechanical force to the targeted cells inducing cell death. © 2014 IEEE.

  11. 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. PMID:24296078

  12. Using microfluidics to study programmed cell death: A new approach

    DEFF Research Database (Denmark)

    Mark, Christina; Zor, Kinga; Heiskanen, Arto; Svensson, Birte; Emnéus, Jenny; Dufva, Martin; Finnie, Christine

    This project focuses on applying microfluidic tissue culture for electrochemical or optical measurements during programmed cell death (PCD) in barley aleurone layer to increase understanding of the underlying mechanisms of PCD in plants. Microfluidic tissue culture enables in vitro experiments to...... approach in vivo conditions. Microfluidics also allow implementation of a wide range of electrochemical or optical assays for online, real-time, parallel analysis of important parameters such as redox activity, O2 and H2O2 concentration, extracellular pH, cell viability and enzyme activity1,2. Currently...

  13. CSR1 induces cell death through inactivation of CPSF3

    OpenAIRE

    Zhu, Z-H; Yu, YP; Shi, Y-K; Nelson, JB; Luo, J-H

    2008-01-01

    CSR1 (cellular stress response 1), a newly characterized tumor-suppressor gene, undergoes hypermethylation in over 30% of prostate cancers. Re-expression of CSR1 inhibits cell growth and induces cell death, but the mechanism by which CSR1 suppresses tumor growth is not clear. In this study, we screened a prostate cDNA library using a yeast two-hybrid system and found that the cleavage and polyadenylation-specific factor 3 (CPSF3), an essential component for converting heteronuclear RNA to mRN...

  14. Sudden death of a patient with pulmonary Langerhans cell histiocytosis.

    Science.gov (United States)

    Nakhla, Hassan; Jumbelic, Mary I

    2005-06-01

    We report a case of sudden death due to bilateral pneumothorax in a previously healthy 16-year-old adolescent white girl. She presented with sudden onset of shortness of breath followed by loss of consciousness. Postmortem chest radiograph showed bilateral pneumothoraces. Autopsy confirmed the bilateral pneumothorax and additionally showed emphysematous changes and bullae throughout the lung tissue. Microscopic sections of the lungs showed Langerhans cell histiocytosis. To the best of our knowledge, this is the first reported case of fatal presentation of pulmonary Langerhans cell histiocytosis. PMID:15913433

  15. Heat shock genes – integrating cell survival and death

    Indian Academy of Sciences (India)

    Richa Arya; Moushami Mallik; Subhash C Lakhotia

    2007-04-01

    Heat shock induced gene expression and other cellular responses help limit the damage caused by stress and thus facilitate cellular recovery. Cellular damage also triggers apoptotic cell death through several pathways. This paper briefly reviews interactions of the major heat shock proteins with components of the apoptotic pathways. Hsp90, which acts as a chaperone for unstable signal transducers to keep them poised for activation, interacts with RIP and Akt and promotes NF-B mediated inhibition of apoptosis; in addition it also blocks some steps in the apoptotic pathways. Hsp70 is mostly anti-apoptotic and acts at several levels like inhibition of translocation of Bax into mitochondria, release of cytochrome c from mitochondria, formation of apoptosome and inhibition of activation of initiator caspases. Hsp70 also modulates JNK, NF-B and Akt signaling pathways in the apoptotic cascade. In contrast, Hsp60 has both anti- and pro-apoptotic roles. Cytosolic Hsp60 prevents translocation of the pro-apoptotic protein Bax into mitochondria and thus promotes cell survival but it also promotes maturation of procaspase-3, essential for caspase mediated cell death. Our recent in vivo studies show that RNAi for the Hsp60D in Drosophila melanogaster prevents induced apoptosis. Hsp27 exerts its anti-apoptotic influence by inhibiting cytochrome c and TNF-mediated cell death. crystallin suppresses caspase-8 and cytochrome c mediated activation of caspase-3. Studies in our laboratory also reveal that absence or reduced levels of the developmentally active as well as stress induced non-coding hsr transcripts, which are known to sequester diverse hnRNPs and related nuclear RNA-binding proteins, block induced apoptosis in Drosophila. Modulation of the apoptotic pathways by Hsps reflects their roles as ``weak links” between various ``hubs” in cellular networks. On the other hand, non-coding RNAs, by virtue of their potential to bind with multiple proteins, can act as ``hubs” in

  16. Role of activation-induced cell death in pathogenesis of patients with chronic hepatitis B

    Institute of Scientific and Technical Information of China (English)

    Chun-Sheng Hou; Gui-Qiang Wang; Shu-Lan Lu; Bei Yue; Ming-Rong Li; Xiao-Yan Wang; Jian-Wu Yu

    2003-01-01

    AIM: To study and compare the difference of activationinduced cell death (AICD) in peripheral blood T-lymphocytes (PBL-Ts) from patients with chronic hepatitis B (CHB) and the normal people in vitro, and to explore the role of AICD in chronic hepatitis B virus (HBV) infection and the pathogenesis of CHB.METHODS: Twenty-five patients and fourteen healthy people were selected for isolation of PBL-Ts. During cultivation, antiCD3 mAb, PMA and ionomycin were used for AICD of PBL-Ts.AICD ratio of PBL-Ts was detected with TdT-mediated dUTP nick end labeling and assessed by flow cytometry.RESULTS: When induced with anti-CD3, PMA and ionomycin in vitro, AICD ratio of PBL-Ts from CHB patients was significantly higher than that from healthy control (17.24±1.21VS. 6.63±1.00, P<0.01) and that from CHB patients without induction (17.24±1.21 VS. 9.88±1.36, P<0.0L). There was a similar AICD ratio of PBL-Ts between induction group and without induction group, but no difference was found before and after induction in healthy control. The density of INF-γ in culture media of induction groups of CHB was lower than that of other groups (P<0.01). There was no difference between these groups in density of IL-10 (P>0.05).CONCLUSION: When induced during cultivation in vitro,PBL-Ts from CHB have AICD very commonly. This phenomenon has a potentially important relation with pathogenesis of CHB and chronicity of HBV infection.

  17. EFFECTS OF ETHANOL AND HYDROGEN PEROXIDE ON MOUSE LIMB BUD MESENCHYME DIFFERENTIATION AND CELL DEATH

    Science.gov (United States)

    Many of the morphological defects associated with embryonic alcohol exposure are a result of cell death. During limb development, ethanol administration produces cell death in the limb and digital defects, including postaxial ectrodactyly. Because an accumulation of reactive oxyg...

  18. Induction of Neurorestoration From Endogenous Stem Cells.

    Science.gov (United States)

    Yu, Ji Hea; Seo, Jung-Hwa; Lee, Ji Yong; Lee, Min-Young; Cho, Sung-Rae

    2016-01-01

    Neural stem cells (NSCs) persist in the subventricular zone lining the ventricles of the adult brain. The resident stem/progenitor cells can be stimulated in vivo by neurotrophic factors, hematopoietic growth factors, magnetic stimulation, and/or physical exercise. In both animals and humans, the differentiation and survival of neurons arising from the subventricular zone may also be regulated by the trophic factors. Since stem/progenitor cells present in the adult brain and the production of new neurons occurs at specific sites, there is a possibility for the treatment of incurable neurological diseases. It might be feasible to induce neurogenesis, which would be particularly efficacious in the treatment of striatal neurodegenerative conditions such as Huntington's disease, as well as cerebrovascular diseases such as ischemic stroke and cerebral palsy, conditions that are widely seen in the clinics. Understanding of the molecular control of endogenous NSC activation and progenitor cell mobilization will likely provide many new opportunities as therapeutic strategies. In this review, we focus on endogenous stem/progenitor cell activation that occurs in response to exogenous factors including neurotrophic factors, hematopoietic growth factors, magnetic stimulation, and an enriched environment. Taken together, these findings suggest the possibility that functional brain repair through induced neurorestoration from endogenous stem cells may soon be a clinical reality. PMID:26787093

  19. Induction of apoptosis in oral epithelial cells by Candida albicans.

    Science.gov (United States)

    Villar, C Cunha; Chukwuedum Aniemeke, J; Zhao, X-R; Huynh-Ba, G

    2012-12-01

    During infection, interactions between Candida albicans and oral epithelial cells result in oral epithelial cell death. This is clinically manifested by the development of oral mucosal ulcerations generally associated with discomfort. In vitro studies have shown that C. albicans induces early apoptotic alterations in oral epithelial cells; however, these studies have also shown that treatment of infected cells with caspase inhibitors does not prevent their death. The reasons for these contradictory results are unknown and it is still not clear if C. albicans stimulates oral epithelial signaling pathways that promote apoptotic cell death. Activation of specific death pathways in response to microbial organisms plays an essential role in modulating the pathogenesis of a variety of infectious diseases. The aim of this study was to (i) characterize C. albicans-induced apoptotic morphological alterations in oral epithelial cells, and (ii) investigate the activation of apoptotic signaling pathways and expression of apoptotic genes during infection. Candida albicans induced early apoptotic changes in over 50% of oral epithelial cells. However, only 15% of those showed mid-late apoptotic alterations. At the molecular level, C. albicans caused a loss of the mitochondrial transmembrane potential and translocation of mitochondrial cytochrome c. Caspase-3/9 activities increased only during the first hours of infection. Moreover, poly[ADP ribose] polymerase 1 was cleaved into apoptotic and necrotic-like fragments. Finally, five anti-apoptotic genes were significantly upregulated and two pro-apoptotic genes were downregulated during infection. Altogether, these findings indicate that epithelial apoptotic pathways are activated in response to C. albicans, but fail to progress and promote apoptotic cell death. PMID:23134609

  20. Gingerol sensitizes TRAIL-induced apoptotic cell death of glioblastoma cells

    OpenAIRE

    Lee, Dae-Hee; Kim, Dong-Wook; Jung, Chang-Hwa; Lee, Yong J.; Park, Daeho

    2014-01-01

    Glioblastoma multiforme (GBM) is the most lethal and aggressive astrocytoma of primary brain tumors in adults. Although there are many clinical trials to induce the cell death of glioblastoma cells, most glioblastoma cells have been reported to be resistant to TRAIL-induced apoptosis. Here, we showed that gingerol as a major component of ginger can induce TRAIL-mediated apoptosis of glioblastoma. Gingerol increased death receptor (DR) 5 levels in a p53-dependent manner. Furthermore, gingerol ...

  1. Induction

    DEFF Research Database (Denmark)

    Sprogøe, Jonas; Elkjaer, Bente

    2010-01-01

    The purpose of this paper is to explore how induction of newcomers can be understood as both organizational renewal and the maintenance of status quo, and to develop ways of describing this in terms of learning.......The purpose of this paper is to explore how induction of newcomers can be understood as both organizational renewal and the maintenance of status quo, and to develop ways of describing this in terms of learning....

  2. Inactivation, DNA double strand break induction and their rejoining in bacterial cells irradiated with heavy ions

    Science.gov (United States)

    Schaefer, M.; Zimmermann, H.; Schmitz, C.

    1994-01-01

    Besides inactivation one of the major interests in our experiments is to study the primary damage in the DNA double strand breaks (DSB) after heavy ion irradiation. These damages lead not only to cell death but also under repair activities to mutations. In further experiments we have investigated the inactivation with two different strains of Deinococcus radiodurans (R1, Rec 30) and the induction of DSB as well as the rejoining of DSB in stationary cells of E. coli (strain B/r) irradiated with radiations of different quality. In the latter case irradiations were done so that the cell survival was roughly at the same level. We measured the DSB using the pulse field gelelectrophoresis which allows to separate between intact (circular) and damaged (linear) DNA. The irradiated cells were transferred to NB medium and incubated for different times to allow rejoining.

  3. Expression of TNF-related apoptosis-inducing ligand (TRAIL in keratinocytes mediates apoptotic cell death in allogenic T cells

    Directory of Open Access Journals (Sweden)

    Kiefer Paul

    2009-11-01

    Full Text Available Abstract The objective of the present study was to evaluate the aptitude of TRAIL gene expression for inducing apoptosis in co-cultivated T-cells. This should allow preparing a strategy for the development of a durable, allogenic skin substitute based on the induction of an immune-privileged transplant. In order to counteract the significant potential of rejection in transplanted allogenic keratinocytes, we created a murine keratinocyte cell line which expressed TRAIL through stable gene transfer. The exogenic protein was localized on the cellular surface and was not found in soluble condition as sTRAIL. Contact to TRAIL expressing cells in co-culture induced cell death in sensitive Jurkat-cells, which was further intensified by lymphocyte activation. This cytotoxic effect is due to the induction of apoptosis. We therefore assume that the de-novo expression of TRAIL in keratinocytes can trigger apoptosis in activated lymphocytes and thus prevent the rejection of keratinocytes in allogenic, immune-privileged transplants.

  4. MicroRNA-351 Regulates Two-Types of Cell Death, Necrosis and Apoptosis, Induced by 5-fluoro-2'-deoxyuridine

    Science.gov (United States)

    Omi, Takuya; Yamamoto, Akihiro; Satake, Akito; Hiramoto, Akiko; Masutani, Mitsuko; Tanuma, Sei-ichi; Wataya, Yusuke; Kim, Hye-Sook

    2016-01-01

    Cell-death can be necrosis and apoptosis. We are investigating the mechanisms regulating the cell death that occurs on treatment of mouse cancer cell-line FM3A with antitumor 5-fluoro-2'-deoxyuridine (FUdR): necrosis occurs for the original clone F28-7, and apoptosis for its variant F28-7-A. Here we report that a microRNA (miR-351) regulates the cell death pattern. The miR-351 is expressed strongly in F28-7-A but only weakly in F28-7. Induction of a higher expression of miR-351 in F28-7 by transfecting an miRNA mimic into F28-7 resulted in a change of the death mode; necrosis to apoptosis. Furthermore, transfection of an miR-351 inhibitor into F28-7-A resulted in the morphology change, apoptosis to necrosis, in this death-by-FUdR. Possible mechanism involving lamin B1 in this miR-351’s regulatory action is discussed. PMID:27071035

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

    Energy Technology Data Exchange (ETDEWEB)

    Aki, Toshihiko, E-mail: aki.legm@tmd.ac.jp [Section of Forensic Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519 (Japan); Nara, Akina; Funakoshi, Takeshi; Uemura, Koichi [Section of Forensic Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519 (Japan)

    2010-06-04

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

    International Nuclear Information System (INIS)

    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.

  7. Targeting Protective Autophagy Exacerbates UV-Triggered Apoptotic Cell Death

    Directory of Open Access Journals (Sweden)

    Shih-Hwa Chiou

    2012-01-01

    Full Text Available Autophagy is activated by various stresses, including DNA damage, and previous studies of DNA damage-induced autophagy have focused on the response to chemotherapeutic drugs, ionizing radiation, and reactive oxygen species. In this study, we investigated the biological significance of autophagic response to ultraviolet (UV irradiation in A549 and H1299 cells. Our results indicated that UV induces on-rate autophagic flux in these cells. Autophagy inhibition resulting from the knockdown of beclin-1 and Atg5 reduced cell viability and enhanced apoptosis. Moreover, we found that ATR phosphorylation was accompanied by microtubule-associated protein 1 light chain 3B II (LC3B-II expression during the early phases following UV irradiation, which is a well-established inducer of ATR. Knocking down ATR further attenuated the reduction in LC3B-II at early stages in response to UV treatment. Despite the potential role of ATR in autophagic response, reduced ATR expression does not affect autophagy induction during late phases (24 and 48 h after UV treatment. The result is consistent with the reduced ATR phosphorylation at the same time points and suggests that autophagic response at this stage is activated via a distinct pathway. In conclusion, this study demonstrated that autophagy acts as a cytoprotective mechanism against UV-induced apoptosis and that autophagy induction accompanied with apoptosis at late stages is independent of ATR activation.

  8. Synergistic growth inhibition of cancer cells harboring the RET/PTC1 oncogene by staurosporine and rotenone involves enhanced cell death

    Indian Academy of Sciences (India)

    António Pedro Gonçalves; Arnaldo Videira; Valdemar Máximo; Paula Soares

    2011-09-01

    TPC-1 is a highly proliferative thyroid papillary carcinoma-derived cell line. These cells express the RET/PTC1 fusion protein, whose isoforms are characterized in this work. The bacterial alkaloid staurosporine and the plant extract rotenone are death-inducing drugs that have an inhibitory synergistic effect on the growth of TPC-1 cells. We show that this synergism is accompanied by an enhancement of the induction of cell death. Staurosporine alone induces cell cycle arrest in G1, whereas rotenone induces arrest in G2/M. We suggest that this additive pressure may drive cells to die, resulting in the synergistic interaction of the drug combination. These data emphasize the potential use of the staurosporine plus rotenone combination as an anticancer tool.

  9. Cell culture: Progenitor cells from human brain after death

    Science.gov (United States)

    Palmer, Theo D.; Schwartz, Philip H.; Taupin, Philippe; Kaspar, Brian; Stein, Stuart A.; Gage, Fred H.

    2001-05-01

    Culturing neural progenitor cells from the adult rodent brain has become routine and is also possible from human fetal tissue, but expansion of these cells from postnatal and adult human tissue, although preferred for ethical reasons, has encountered problems. Here we describe the isolation and successful propagation of neural progenitor cells from human postmortem tissues and surgical specimens. Although the relative therapeutic merits of adult and fetal progenitor cells still need to be assessed, our results may extend the application of these progenitor cells in the treatment of neurodegenerative diseases.

  10. Mycobacterium tuberculosis infection induces non-apoptotic cell death of human dendritic cells

    LENUS (Irish Health Repository)

    Ryan, Ruth CM

    2011-10-24

    Abstract Background Dendritic cells (DCs) connect innate and adaptive immunity, and are necessary for an efficient CD4+ and CD8+ T cell response after infection with Mycobacterium tuberculosis (Mtb). We previously described the macrophage cell death response to Mtb infection. To investigate the effect of Mtb infection on human DC viability, we infected these phagocytes with different strains of Mtb and assessed viability, as well as DNA fragmentation and caspase activity. In parallel studies, we assessed the impact of infection on DC maturation, cytokine production and bacillary survival. Results Infection of DCs with live Mtb (H37Ra or H37Rv) led to cell death. This cell death proceeded in a caspase-independent manner, and without nuclear fragmentation. In fact, substrate assays demonstrated that Mtb H37Ra-induced cell death progressed without the activation of the executioner caspases, 3\\/7. Although the death pathway was triggered after infection, the DCs successfully underwent maturation and produced a host-protective cytokine profile. Finally, dying infected DCs were permissive for Mtb H37Ra growth. Conclusions Human DCs undergo cell death after infection with live Mtb, in a manner that does not involve executioner caspases, and results in no mycobactericidal effect. Nonetheless, the DC maturation and cytokine profile observed suggests that the infected cells can still contribute to TB immunity.

  11. p-Cresol mediates autophagic cell death in renal proximal tubular cells.

    Science.gov (United States)

    Lin, Hsin-Hung; Huang, Chiu-Ching; Lin, Tze-Yi; Lin, Ching-Yuang

    2015-04-01

    Higher serum level of p-cresol (PC) in chronic kidney disease (CKD) patients has been linked with CKD progression. The toxic effect of PC on diverse cells has been reported by prior studies, except for renal tubular cells. Both autophagy and apoptosis contribute to renal tubular cell death, yet evidence of its response to PC is limited and their crosstalk is still unclear. Autophagy is an important cellular process involved in toxin-induced cell death. Renal tubular cell death in tubular injury is thought to be one of the key events causing the progression of CKD. Thus, we treated rat (NRK-52E) and human (HRPTEC) renal proximal tubular cells (RPTC) with PC and found the cell proliferation was significantly decreased. Cell apoptosis was significantly increased and accompanied with the activation of autophagy as evidenced by increases in LC3-II, beclin 1 and Atg 4. We also found an increase of p62 by c-Jun activation. p62 accumulation could mediate the activation of caspase 8-dependent cell apoptosis. Conversely, knockdown of p62 by siRNA of p62 had the opposite effect by arresting LC3-II accumulation and promoting increasing cell viability. We conclude that PC triggered autophagic RPTC death via JNK-mediated p62 accumulation and then activated caspase 8-dependent cell death pathway. PC can be considered as one of the key events causing progression of CKD, which might affect drug disposition in CKD cases. PMID:25668154

  12. Methyl Vitamin B12 but not methylfolate rescues a motor neuron-like cell line from homocysteine-mediated cell death

    International Nuclear Information System (INIS)

    Homocysteine is an excitatory amino acid implicated in multiple diseases including amyotrophic lateral sclerosis (ALS). Information on the toxicity of homocysteine in motor neurons is limited and few studies have examined how this toxicity can be modulated. In NSC-34D cells (a hybrid cell line derived from motor neuron-neuroblastoma), homocysteine induces apoptotic cell death in the millimolar range with a TC50 (toxic concentration at which 50% of maximal cell death is achieved) of 2.2 mM, confirmed by activation of caspase 3/7. Induction of apoptosis was independent of short-term reactive oxygen species (ROS) generation. Methyl Vitamin B12 (MeCbl) and methyl tetrahydrofolate (MTHF), used clinically to treat elevated homocysteine levels, were tested for their ability to reverse homocysteine-mediated motor neuron cell death. MeCbl in the micromolar range was able to provide neuroprotection (2 h pretreatment prior to homocysteine) and neurorescue (simultaneous exposure with homocysteine) against millimolar homocysteine with an IC50 (concentration at which 50% of maximal cell death is inhibited) of 0.6 μM and 0.4 μM, respectively. In contrast, MTHF (up to 10 μM) had no effect on homocysteine-mediated cell death. MeCbl inhibited caspase 3/7 activation by homocysteine in a time- and dose-dependent manner, whereas MTHF had no effect. We conclude that MeCbl is effective against homocysteine-induced cell death in motor neurons in a ROS-independent manner, via a reduction in caspase activation and apoptosis. MeCbl decreases Hcy induced motor neuron death in vitro in a hybrid cell line derived from motor neuron-neuroblastoma and may play a role in the treatment of late stage ALS where HCy levels are increased in animal models of ALS.

  13. 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

  14. CytoregR inhibits growth and proliferation of human adenocarcinoma cells via induction of apoptosis

    Directory of Open Access Journals (Sweden)

    Hassanhi M

    2006-01-01

    Full Text Available Abstract Background Cancer is one of the devastating neovascular diseases that incapacitate so many people the world over. Recent reports from the National Cancer Institute indicate some significant gain therapy and cancer management as seen in the increase in the 5-year survival rate over the past two decades. Although near-perfect cure rate have been reported in the early-stage disease, these data reveal high recurrence rate and serious side effects including second malignancies and fatalities. Most of the currently used anticancer agents are only effective against proliferating cancer cells. Thus attention has been focused on potential anti-cancer agents capable of killing cancer cells independent of the cell cycle state, to ensure effective elimination of most cancer cells. The objective of this study was to test the chemosensitivity and potential mechanism of action of a novel cancer drug, CytoregR, in a panel of human cancer cells. Methods the study was performed using a series of bioassays including Trypan blue exclusion, MTS Growth inhibition, LDH-cytotoxicity, TUNEL-Terminal DNA fragmentation Apoptosis Assay, and the Caspase protease CPP32 activity assays. Results CytoregR induced significant dose- and time-dependent inhibition of growth in all the cells; with significant differences in chemosensitivity (P < 0.05 between the target cells becoming more apparent at 48 hr exposure. CytoregR showed no significant effect on normal cells relative to the tumor cells. Growth inhibition in all the cells was due to induction of apoptosis at lower concentrations of cytoregR (> 1:300. CytoregR-induced caspase protease-3 (CPP32 activation significantly and positively correlated with apoptosis induction and growth inhibition; thus implicating CPP32 as the principal death pathway in cytoregR-induced apoptosis. Conclusion CytoregR exerted a dose-and time-dependent growth inhibitory effect in all the target cells through induction of apoptosis via the

  15. Gossypol Induced Cell Death in DU 145 Prostate Cancer Cells

    OpenAIRE

    Kennelly, Susan

    2010-01-01

    Cancer Biology Tumourigenesis is a multistep process which includes the transformation of healthy cells into extremely malignant cells, caused by the disruption of normal tissue homeostasis. Hanahan and Weinberg propose that there are a common set of 'acquired capabilities' that most if not all cancers posses's in order to survive and proliferate despite changes in their normal cell physiology during cancer development (Hanahan and Weinberg, 2000). These "Hallmarks of Cancer", according to...

  16. Anhydrobiosis and programmed cell death in plants: Commonalities and Differences

    Directory of Open Access Journals (Sweden)

    Samer Singh

    2015-05-01

    Full Text Available Anhydrobiosis is an adaptive strategy of certain organisms or specialised propagules to survive in the absence of water while programmed cell death (PCD is a finely tuned cellular process of the selective elimination of targeted cell during developmental programme and perturbed biotic and abiotic conditions. Particularly during water stress both the strategies serve single purpose i.e., survival indicating PCD may also function as an adaptive process under certain conditions. During stress conditions PCD cause targeted cells death in order to keep the homeostatic balance required for the organism survival, whereas anhydrobiosis suspends cellular metabolic functions mimicking a state similar to death until reestablishment of the favourable conditions. Anhydrobiosis is commonly observed among organisms that have ability to revive their metabolism on rehydration after removal of all or almost all cellular water without damage. This feature is widely represented in terrestrial cyanobacteria and bryophytes where it is very common in both vegetative and reproductive stages of life-cycle. In the course of evolution, with the development of advanced vascular system in higher plants, anhydrobiosis was gradually lost from the vegetative phase of life-cycle. Though it is retained in resurrection plants that primarily belong to thallophytes and a small group of vascular angiosperm, it can be mostly found restricted in orthodox seeds of higher plants. On the contrary, PCD is a common process in all eukaryotes from unicellular to multicellular organisms including higher plants and mammals. In this review we discuss physiological and biochemical commonalities and differences between anhydrobiosis and PCD.

  17. Mitochondrial dynamics and cell death in heart failure.

    Science.gov (United States)

    Marín-García, José; Akhmedov, Alexander T

    2016-03-01

    The highly regulated processes of mitochondrial fusion (joining), fission (division) and trafficking, collectively called mitochondrial dynamics, determine cell-type specific morphology, intracellular distribution and activity of these critical organelles. Mitochondria are critical for cardiac function, while their structural and functional abnormalities contribute to several common cardiovascular diseases, including heart failure (HF). The tightly balanced mitochondrial fusion and fission determine number, morphology and activity of these multifunctional organelles. Although the intracellular architecture of mature cardiomyocytes greatly restricts mitochondrial dynamics, this process occurs in the adult human heart. Fusion and fission modulate multiple mitochondrial functions, ranging from energy and reactive oxygen species production to Ca(2+) homeostasis and cell death, allowing the heart to respond properly to body demands. Tightly controlled balance between fusion and fission is of utmost importance in the high energy-demanding cardiomyocytes. A shift toward fission leads to mitochondrial fragmentation, while a shift toward fusion results in the formation of enlarged mitochondria and in the fusion of damaged mitochondria with healthy organelles. Mfn1, Mfn2 and OPA1 constitute the core machinery promoting mitochondrial fusion, whereas Drp1, Fis1, Mff and MiD49/51 are the core components of fission machinery. Growing evidence suggests that fusion/fission factors in adult cardiomyocytes play essential noncanonical roles in cardiac development, Ca(2+) signaling, mitochondrial quality control and cell death. Impairment of this complex circuit causes cardiomyocyte dysfunction and death contributing to heart injury culminating in HF. Pharmacological targeting of components of this intricate network may be a novel therapeutic modality for HF treatment. PMID:26872674

  18. Ras and Rheb Signaling in Survival and Cell Death

    International Nuclear Information System (INIS)

    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

  19. Multiple Modes of Cell Death Discovered in a Prokaryotic (Cyanobacterial Endosymbiont.

    Directory of Open Access Journals (Sweden)

    Weiwen Zheng

    Full Text Available Programmed cell death (PCD is a genetically-based cell death mechanism with vital roles in eukaryotes. Although there is limited consensus on similar death mode programs in prokaryotes, emerging evidence suggest that PCD events are operative. Here we present cell death events in a cyanobacterium living endophytically in the fern Azolla microphylla, suggestive of PCD. This symbiosis is characterized by some unique traits such as a synchronized development, a vertical transfer of the cyanobacterium between plant generations, and a highly eroding cyanobacterial genome. A combination of methods was used to identify cell death modes in the cyanobacterium. Light- and electron microscopy analyses showed that the proportion of cells undergoing cell death peaked at 53.6% (average 20% of the total cell population, depending on the cell type and host developmental stage. Biochemical markers used for early and late programmed cell death events related to apoptosis (Annexin V-EGFP and TUNEL staining assays, together with visualization of cytoskeleton alterations (FITC-phalloidin staining, showed that all cyanobacterial cell categories were affected by cell death. Transmission electron microscopy revealed four modes of cell death: apoptotic-like, autophagic-like, necrotic-like and autolytic-like. Abiotic stresses further enhanced cell death in a dose and time dependent manner. The data also suggest that dynamic changes in the peptidoglycan cell wall layer and in the cytoskeleton distribution patterns may act as markers for the various cell death modes. The presence of a metacaspase homolog (domain p20 further suggests that the death modes are genetically programmed. It is therefore concluded that multiple, likely genetically programmed, cell death modes exist in cyanobacteria, a finding that may be connected with the evolution of cell death in the plant kingdom.

  20. Multiple Modes of Cell Death Discovered in a Prokaryotic (Cyanobacterial) Endosymbiont.

    Science.gov (United States)

    Zheng, Weiwen; Rasmussen, Ulla; Zheng, Siping; Bao, Xiaodong; Chen, Bin; Gao, Yuan; Guan, Xiong; Larsson, John; Bergman, Birgitta

    2013-01-01

    Programmed cell death (PCD) is a genetically-based cell death mechanism with vital roles in eukaryotes. Although there is limited consensus on similar death mode programs in prokaryotes, emerging evidence suggest that PCD events are operative. Here we present cell death events in a cyanobacterium living endophytically in the fern Azolla microphylla, suggestive of PCD. This symbiosis is characterized by some unique traits such as a synchronized development, a vertical transfer of the cyanobacterium between plant generations, and a highly eroding cyanobacterial genome. A combination of methods was used to identify cell death modes in the cyanobacterium. Light- and electron microscopy analyses showed that the proportion of cells undergoing cell death peaked at 53.6% (average 20%) of the total cell population, depending on the cell type and host developmental stage. Biochemical markers used for early and late programmed cell death events related to apoptosis (Annexin V-EGFP and TUNEL staining assays), together with visualization of cytoskeleton alterations (FITC-phalloidin staining), showed that all cyanobacterial cell categories were affected by cell death. Transmission electron microscopy revealed four modes of cell death: apoptotic-like, autophagic-like, necrotic-like and autolytic-like. Abiotic stresses further enhanced cell death in a dose and time dependent manner. The data also suggest that dynamic changes in the peptidoglycan cell wall layer and in the cytoskeleton distribution patterns may act as markers for the various cell death modes. The presence of a metacaspase homolog (domain p20) further suggests that the death modes are genetically programmed. It is therefore concluded that multiple, likely genetically programmed, cell death modes exist in cyanobacteria, a finding that may be connected with the evolution of cell death in the plant kingdom. PMID:23822984

  1. Multiple Modes of Cell Death Discovered in a Prokaryotic (Cyanobacterial) Endosymbiont

    Science.gov (United States)

    Zheng, Weiwen; Rasmussen, Ulla; Zheng, Siping; Bao, Xiaodong; Chen, Bin; Gao, Yuan; Guan, Xiong; Larsson, John; Bergman, Birgitta

    2013-01-01

    Programmed cell death (PCD) is a genetically-based cell death mechanism with vital roles in eukaryotes. Although there is limited consensus on similar death mode programs in prokaryotes, emerging evidence suggest that PCD events are operative. Here we present cell death events in a cyanobacterium living endophytically in the fern Azolla microphylla, suggestive of PCD. This symbiosis is characterized by some unique traits such as a synchronized development, a vertical transfer of the cyanobacterium between plant generations, and a highly eroding cyanobacterial genome. A combination of methods was used to identify cell death modes in the cyanobacterium. Light- and electron microscopy analyses showed that the proportion of cells undergoing cell death peaked at 53.6% (average 20%) of the total cell population, depending on the cell type and host developmental stage. Biochemical markers used for early and late programmed cell death events related to apoptosis (Annexin V-EGFP and TUNEL staining assays), together with visualization of cytoskeleton alterations (FITC-phalloidin staining), showed that all cyanobacterial cell categories were affected by cell death. Transmission electron microscopy revealed four modes of cell death: apoptotic-like, autophagic-like, necrotic-like and autolytic-like. Abiotic stresses further enhanced cell death in a dose and time dependent manner. The data also suggest that dynamic changes in the peptidoglycan cell wall layer and in the cytoskeleton distribution patterns may act as markers for the various cell death modes. The presence of a metacaspase homolog (domain p20) further suggests that the death modes are genetically programmed. It is therefore concluded that multiple, likely genetically programmed, cell death modes exist in cyanobacteria, a finding that may be connected with the evolution of cell death in the plant kingdom. PMID:23822984

  2. 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

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

    International Nuclear Information System (INIS)

    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

  4. Possible involvement of protein kinase C in apoptotic cell death of macrophages infected with Actinobacillus actinomycetemcomitans.

    Science.gov (United States)

    Nonaka, K; Ishisaki, A; Muro, M; Kato, S; Oido, M; Nakashima, K; Kowashi, Y; Nishihara, T

    1998-02-15

    We have previously reported the evidence for apoptosis in the mouse macrophage cell line J774.1 by the periodontopathic bacterium Actinobacillus actinomycetemcomitans. In this study, we examined the role of protein kinases in the induction of apoptosis in A. actinomycetemcomitans-infected J774.1 cells by the MTT assay, fluorescence microscopy and flow cytometric analysis. After J774.1 cells were precultured with protein kinase C (PKC) activator, phorbol 12-myristate 13-acetate (PMA), J774.1 cells infected with A. actinomycetemcomitans showed the increased percentage of apoptotic cells. On the contrary, protein kinase A (PKA) activators, such as forskolin and dibutyryl cAMP, do not mimic the effect of PMA. PKC inhibitors, such as staurosporine, calphostin C, chelerythrine chloride, and H7 were found to suppress apoptotic cell death in J774.1 cells infected with A. actinomycetemcomitans. However, HA1004, known as PKA inhibitor, had no effect on apoptosis in infected macrophages. The results presented here suggest that the signals through PKC may play crucial roles in the modulation of apoptosis in macrophages infected with A. actinomycetemcomitans. PMID:9503618

  5. Sulbutiamine counteracts trophic factor deprivation induced apoptotic cell death in transformed retinal ganglion cells.

    Science.gov (United States)

    Kang, Kui Dong; Majid, Aman Shah Abdul; Kim, Kyung-A; Kang, Kyungsu; Ahn, Hong Ryul; Nho, Chu Won; Jung, Sang Hoon

    2010-11-01

    Sulbutiamine is a highly lipid soluble synthetic analogue of vitamin B(1) and is used clinically for the treatment of asthenia. The aim of our study was to demonstrate whether sulbutiamine is able to attenuate trophic factor deprivation induced cell death to transformed retinal ganglion cells (RGC-5). Cells were subjected to serum deprivation for defined periods and sulbutiamine at different concentrations was added to the cultures. Various procedures (e.g. cell viability assays, apoptosis assay, reactive oxygen species analysis, Western blot analysis, flow cytometric analysis, glutathione (GSH) and glutathione-S-transferase (GST) measurement) were used to demonstrate the effect of sulbutiamine. Sulbutiamine dose-dependently attenuated apoptotic cell death induced by serum deprivation and stimulated GSH and GST activity. Moreover, sulbutiamine decreased the expression of cleaved caspase-3 and AIF. This study demonstrates for the first time that sulbutiamine is able to attenuate trophic factor deprivation induced apoptotic cell death in neuronal cells in culture. PMID:20809085

  6. DIETARY PHYTOCHEMICALS INDUCE p53- AND CASPASE-INDEPENDENT CELL DEATH IN HUMAN NEUROBLASTOMA CELLS

    OpenAIRE

    Sukumari-Ramesh, Sangeetha; Bentley, J Nicole; Laird, Melissa D.; Singh, Nagendra; Vender, John R.; Dhandapani, Krishnan M.

    2011-01-01

    Neuroblastoma (NB) is the most prevalent pediatric solid tumor and a leading cause of cancer-related death in children. In the present study, a novel cytotoxic role for the dietary compounds, curcumin, andrographolide, wedelolactone, dibenzoylmethane, and tanshinone IIA was identified in human S-type NB cells, SK-N-AS and SK-N-BE(2). Mechanistically, cell death appeared apoptotic by flow cytometry; however, these effects proceeded independently from both caspase-3 and p53 activation, as asses...

  7. Bimodal cell death induced by high radiation doses in the radioresistant sf9 insect cell line

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    Flusberg, Deborah A.; Sorger, Peter K.

    2013-06-01

    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.

  9. The mystery of underground death: cell death in roots during ontogeny and in response to environmental factors.

    Science.gov (United States)

    Bagniewska-Zadworna, A; Arasimowicz-Jelonek, M

    2016-03-01

    Programmed cell death (PCD) is an essential part of the ontogeny of roots and their tolerance/resistance mechanisms, allowing adaptation and growth under adverse conditions. It occurs not only at the cellular and subcellular level, but also at the levels of tissues, organs and even whole plants. This process involves a wide spectrum of mechanisms, from signalling and the expression of specific genes to the degradation of cellular structures. The major goals of this review were to broaden current knowledge about PCD processes in roots, and to identify mechanisms associated with both developmental and stress-associated cell death in roots. Vacuolar cell death, when cell contents are removed by a combination of an autophagy-associated process and the release of hydrolases from a collapsed vacuole, is responsible for programming self-destruction. Regardless of the conditions and factors inducing PCD, its subcellular events usually include the accumulation of autophagosome-like structures, and the formation of massive lytic compartments. In some cases these are followed by the nuclear changes of chromatin condensation and DNA fragmentation. Tonoplast disruption and vacuole implosion occur very rapidly, are irreversible and constitute a definitive step toward cell death in roots. Active cell elimination plays an important role in various biological processes in the life history of plants, leading to controlled cellular death during adaptation to changing environmental conditions, and organ remodelling throughout development and senescence. PMID:26332667

  10. Attenuation of oxidative neuronal cell death by coffee phenolic phytochemicals

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Eun Sun; Jang, Young Jin [Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Hwang, Mun Kyung; Kang, Nam Joo [Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Department of Bioscience and Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of); Lee, Ki Won [Department of Bioscience and Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)], E-mail: kiwon@konkuk.ac.kr; Lee, Hyong Joo [Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of)], E-mail: leehyjo@snu.ac.kr

    2009-02-10

    Neurodegenerative disorders such as Alzheimer's disease (AD) are strongly associated with oxidative stress, which is induced by reactive oxygen species (ROS) including hydrogen peroxide (H{sub 2}O{sub 2}). Recent studies suggest that moderate coffee consumption may reduce the risk of neurodegenerative diseases such as AD, but the molecular mechanisms underlying this effect remain to be clarified. In this study, we investigated the protective effects of chlorogenic acid (5-O-caffeoylquinic acid; CGA), a major phenolic phytochemical found in instant decaffeinated coffee (IDC), and IDC against oxidative PC12 neuronal cell death. IDC (1 and 5 {mu}g/ml) or CGA (1 and 5 {mu}M) attenuated H{sub 2}O{sub 2}-induced PC12 cell death. H{sub 2}O{sub 2}-induced nuclear condensation and DNA fragmentation were strongly inhibited by pretreatment with IDC or CGA. Pretreatment with IDC or CGA also inhibited the H{sub 2}O{sub 2}-induced cleavage of poly(ADP-ribose) polymerase (PARP), and downregulation of Bcl-X{sub L} and caspase-3. The accumulation of intracellular ROS in H{sub 2}O{sub 2}-treated PC12 cells was dose-dependently diminished by IDC or CGA. The activation of c-Jun N-terminal protein kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) by H{sub 2}O{sub 2} in PC12 cells was also inhibited by IDC or CGA. Collectively, these results indicate that IDC and CGA protect PC12 cells from H{sub 2}O{sub 2}-induced apoptosis by blocking the accumulation of intracellular ROS and the activation of MAPKs.

  11. Attenuation of oxidative neuronal cell death by coffee phenolic phytochemicals

    International Nuclear Information System (INIS)

    Neurodegenerative disorders such as Alzheimer's disease (AD) are strongly associated with oxidative stress, which is induced by reactive oxygen species (ROS) including hydrogen peroxide (H2O2). Recent studies suggest that moderate coffee consumption may reduce the risk of neurodegenerative diseases such as AD, but the molecular mechanisms underlying this effect remain to be clarified. In this study, we investigated the protective effects of chlorogenic acid (5-O-caffeoylquinic acid; CGA), a major phenolic phytochemical found in instant decaffeinated coffee (IDC), and IDC against oxidative PC12 neuronal cell death. IDC (1 and 5 μg/ml) or CGA (1 and 5 μM) attenuated H2O2-induced PC12 cell death. H2O2-induced nuclear condensation and DNA fragmentation were strongly inhibited by pretreatment with IDC or CGA. Pretreatment with IDC or CGA also inhibited the H2O2-induced cleavage of poly(ADP-ribose) polymerase (PARP), and downregulation of Bcl-XL and caspase-3. The accumulation of intracellular ROS in H2O2-treated PC12 cells was dose-dependently diminished by IDC or CGA. The activation of c-Jun N-terminal protein kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) by H2O2 in PC12 cells was also inhibited by IDC or CGA. Collectively, these results indicate that IDC and CGA protect PC12 cells from H2O2-induced apoptosis by blocking the accumulation of intracellular ROS and the activation of MAPKs

  12. Cell Death Pathways and Phthalocyanine as an Efficient Agent for Photodynamic Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Ivan Mfouo-Tynga

    2015-05-01

    Full Text Available The mechanisms of cell death can be predetermined (programmed or not and categorized into apoptotic, autophagic and necrotic pathways. The process of Hayflick limits completes the execution of death-related mechanisms. Reactive oxygen species (ROS are associated with oxidative stress and subsequent cytodamage by oxidizing and degrading cell components. ROS are also involved in immune responses, where they stabilize and activate both hypoxia-inducible factors and phagocytic effectors. ROS production and presence enhance cytodamage and photodynamic-induced cell death. Photodynamic cancer therapy (PDT uses non-toxic chemotherapeutic agents, photosensitizer (PS, to initiate a light-dependent and ROS-related cell death. Phthalocyanines (PCs are third generation and stable PSs with improved photochemical abilities. They are effective inducers of cell death in various neoplastic models. The metallated PCs localize in critical cellular organelles and are better inducers of cell death than other previous generation PSs as they favor mainly apoptotic cell death events.

  13. Radiation induction of multiaberrant cells in Allium cepa L

    International Nuclear Information System (INIS)

    'Rogue' cells determined by human geneticists as the cells with many chromosome aberrations. The main enigma of this phenomenon is its levels are unexpected higher in many studies. Frequently, these cells emergence in human are linked with radiation or viruses. 'Rogue' cells supposed to be very important in mutagenesis, oncogenesis and even in evolution process. We use plant assay (Allium cepa L.) to analyze the induction of cells with many chromosome aberration of different types. Cytogenetic damage of gamma-irradiation as frequency of multiaberrant cells in the root tip cells of Allium was determined. The empiric numbers of cells with many aberrations were compared with those expected in theoretical distributions (Poisson, geometric and Pascal). The frequency of multiaberrant cells in root tip cells was increased up to 83,33 ± 10,76 % under gamma-irradiation in various doses. Gamma-irradiation induced more multiaberrant cells in A. cepa meristems than expected in theoretical distributions. We supposed dependency of chromosome aberrations origin in the same cell after irradiation. The data obtained elucidate that under gamma-irradiation accumulation of aberrations in aberrant cells are not random, the appearance of one aberration in cell induced the appearance of others in the same cell. (author)

  14. Cell-to-cell variability in cell death: can systems biology help us make sense of it all?

    OpenAIRE

    Xia, X; Owen, M. S.; Lee, R E C; Gaudet, S

    2014-01-01

    One of the most common observations in cell death assays is that not all cells die at the same time, or at the same treatment dose. Here, using the perspective of the systems biology of apoptosis and the context of cancer treatment, we discuss possible sources of this cell-to-cell variability as well as its implications for quantitative measurements and computational models of cell death. Many different factors, both within and outside of the apoptosis signaling networks, have been correlated...

  15. Vitamin E, γ-tocotrienol, Protects Against Buthionine Sulfoximine-Induced Cell Death by Scavenging Free Radicals in SH-SY5Y Neuroblastoma Cells.

    Science.gov (United States)

    Tan, Jen-Kit; Then, Sue-Mian; Mazlan, Musalmah; Jamal, Rahman; Ngah, Wan Zurinah Wan

    2016-04-01

    The induction of reactive oxygen species (ROS) to selectively kill cancer cells is an important feature of radiotherapy and various chemotherapies. Depletion of glutathione can induce apoptosis in cancer cells or sensitize them to anticancer treatments intended to modulate ROS levels. In contrast, antioxidants protect cancer cells from oxidative stress-induced cell death by scavenging ROS. The role of exogenous antioxidants in cancer cells under oxidative insults remains controversial and unclear. This study aimed to identify protective pathways modulated by γ-tocotrienol (γT3), an isomer of vitamin E, in human neuroblastoma SH-SY5Y cells under oxidative stress. Using buthionine sulfoximine (BSO) as an inhibitor of glutathione synthesis, we found that BSO treatment reduced the viability of SH-SY5Y cells. BSO induced cell death by increasing apoptosis, decreased the level of reduced glutathione (GSH), and increased ROS levels in SH-SY5Y cells. Addition of γT3 increased the viability of BSO-treated cells, suppressed apoptosis, and decreased the ROS level induced by BSO, while the GSH level was unaffected. These results suggest that decreasing GSH levels by BSO increased ROS levels, leading to apoptosis in SH-SY5Y cells. γT3 attenuated the BSO-induced cell death by scavenging free radicals. PMID:27008382

  16. Mitophagy switches cell death from apoptosis to necrosis in NSCLC cells treated with oncolytic measles virus.

    Science.gov (United States)

    Xia, Mao; Meng, Gang; Jiang, Aiqin; Chen, Aiping; Dahlhaus, Meike; Gonzalez, Patrick; Beltinger, Christian; Wei, Jiwu

    2014-06-15

    Although apoptotic phenomena have been observed in malignant cells infected by measles virus vaccine strain Edmonston B (MV-Edm), the precise oncolytic mechanisms are poorly defined. In this study we found that MV-Edm induced autophagy and sequestosome 1-mediated mitophagy leading to decreased cytochrome c release, which blocked the pro-apoptotic cascade in non-small cell lung cancer cells (NSCLCs). The decrease of apoptosis by mitophagy favored viral replication. Persistent viral replication sustained by autophagy ultimately resulted in necrotic cell death due to ATP depletion. Importantly, when autophagy was impaired in NSCLCs MV-Edm-induced cell death was significantly abrogated despite of increased apoptosis. Taken together, our results define a novel oncolytic mechanism by which mitophagy switches cell death from apoptosis to more efficient necrosis in NSCLCs following MV-Edm infection. This provides a foundation for future improvement of oncolytic virotherapy or antiviral therapy. PMID:25004098

  17. Apoptotic cell death and its relationship to gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Ferda Bir; Nese Calli-Demirkan; A Cevik Tufan; Metin Akbulut; N Lale Satiroglu-Tufan

    2007-01-01

    .05].CONCLUSION: Existence of apoptotic cells on the basis of TUNEL positivity is shown in intestinal metaplasias co-localizing to both diffuse and intestinal type gastric cancers in this study. Our results also suggested bax expression dependent induction of apoptosis especially in intestinal metaplasia areas adjacent to tumors. These findings strongly support the involvement of apoptotic mechanisms in the process of gastric carcinogenesis especially in the transition from intestinal metaplasia to gastric cancer. It may be suggested that induction of apoptosis in intestinal metaplasia areas adjacent to tumors may involve different mechanisms than induction by chronic inflammation.

  18. Primary observations of the existence of Fas-like cytoplasmic death factor in plant cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The main activity of Fas is to trigger cytoplasm death program in animal cells. In G2 pea, vacuole plays a pivotal role in inducing cell death in the cytoplasm of longday (LD) grown apical meristem cells. Expression patterns of the Fas in G2 pea cells revealed that the Fas is mainly localized in the vacuole of cells undergoing programmed cell death (PCD). The Fas expression is corresponding to the initiation of menadione-induced PCD in tobacco protoplasts.The results suggest the existence of the Fas-like mediated cytoplasmic death pathway in plant cells.``

  19. Regulation of cell survival and death during Flavivirus infections

    Institute of Scientific and Technical Information of China (English)

    Sounak; Ghosh; Roy; Beata; Sadigh; Emmanuel; Datan; Richard; A; Lockshin; Zahra; Zakeri

    2014-01-01

    Flaviviruses, ss(+) RNA viruses, include many of mankind’s most important pathogens. Their pathogenicity derives from their ability to infect many types of cells including neurons, to replicate, and eventually to kill the cells. Flaviviruses can activate tumor necrosis factor α and both intrinsic(Bax-mediated) and extrinsic pathways to apoptosis. Thus they can use many approaches for activating these pathways. Infection can lead to necrosis if viral load is extremely high or to other types of cell death if routes to apoptosis are blocked. Dengue and Japanese Encephalitis Virus can also activate autophagy. In this case the autophagy temporarily spares the infected cell, allowing a longer period of reproduction for the virus, and the autophagy further protects the cell against other stresses such as those caused by reactive oxygen species. Several of the viral proteins have been shown to induce apoptosis or autophagy on their own, independent of the presence of other viral proteins. Given the versatility of these viruses to adapt to and manipulate the metabolism, and thus to control the survival of, the infected cells, we need to understand much better how the specific viral proteins affect the pathways to apoptosis and autophagy. Only in this manner will we be able to minimize the pathology that they cause.

  20. Role of p53 in Cell Death and Human Cancers

    International Nuclear Information System (INIS)

    p53 is a nuclear transcription factor with a pro-apoptotic function. Since over 50% of human cancers carry loss of function mutations in p53 gene, p53 has been considered to be one of the classical type tumor suppressors. Mutant p53 acts as the dominant-negative inhibitor toward wild-type p53. Indeed, mutant p53 has an oncogenic potential. In some cases, malignant cancer cells bearing p53 mutations display a chemo-resistant phenotype. In response to a variety of cellular stresses such as DNA damage, p53 is induced to accumulate in cell nucleus to exert its pro-apoptotic function. Activated p53 promotes cell cycle arrest to allow DNA repair and/or apoptosis to prevent the propagation of cells with serious DNA damage through the transactivation of its target genes implicated in the induction of cell cycle arrest and/or apoptosis. Thus, the DNA-binding activity of p53 is tightly linked to its tumor suppressive function. In the present review article, we describe the regulatory mechanisms of p53 and also p53-mediated therapeutic strategies to cure malignant cancers

  1. THAP5 is a DNA-binding transcriptional repressor that is regulated in melanoma cells during DNA damage-induced cell death

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishnan, Meenakshi P.; Cilenti, Lucia; Ambivero, Camilla [Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL (United States); Goto, Yamafumi [Department of Dermatology, Shinshu University School of Medicine, Matsumoto (Japan); Takata, Minoru [Department of Dermatology, Okayama University Graduate School of Medical Dentistry and Pharmaceutical Sciences, Okayama (Japan); Turkson, James; Li, Xiaoman Shawn [Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL (United States); Zervos, Antonis S., E-mail: azervos@mail.ucf.edu [Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL (United States)

    2011-01-07

    Research highlights: {yields} THAP5 is a DNA-binding protein and a transcriptional repressor. {yields} THAP5 is induced in melanoma cells upon exposure to UV or treatment with cisplatin. {yields} THAP5 induction correlates with the degree of apoptosis in melanoma cell population. {yields} THAP5 is a pro-apoptotic protein involved in melanoma cell death. -- Abstract: THAP5 was originally isolated as a specific interactor and substrate of the mitochondrial pro-apoptotic Omi/HtrA2 protease. It is a human zinc finger protein characterized by a restricted pattern of expression and the lack of orthologs in mouse and rat. The biological function of THAP5 is unknown but our previous studies suggest it could regulate G2/M transition in kidney cells and could be involved in human cardiomyocyte cell death associated with coronary artery disease (CAD). In this report, we expanded our studies on the properties and function of THAP5 in human melanoma cells. THAP5 was expressed in primary human melanocytes as well as in all melanoma cell lines that were tested. THAP5 protein level was significantly induced by UV irradiation or cisplatin treatment, conditions known to cause DNA damage. The induction of THAP5 correlated with a significant increase in apoptotic cell death. In addition, we show that THAP5 is a nuclear protein that could recognize and bind a specific DNA motif. THAP5 could also repress the transcription of a reporter gene in a heterologous system. Our work suggests that THAP5 is a DNA-binding protein and a transcriptional repressor. Furthermore, THAP5 has a pro-apoptotic function and it was induced in melanoma cells under conditions that promoted cell death.

  2. THAP5 is a DNA-binding transcriptional repressor that is regulated in melanoma cells during DNA damage-induced cell death

    International Nuclear Information System (INIS)

    Research highlights: → THAP5 is a DNA-binding protein and a transcriptional repressor. → THAP5 is induced in melanoma cells upon exposure to UV or treatment with cisplatin. → THAP5 induction correlates with the degree of apoptosis in melanoma cell population. → THAP5 is a pro-apoptotic protein involved in melanoma cell death. -- Abstract: THAP5 was originally isolated as a specific interactor and substrate of the mitochondrial pro-apoptotic Omi/HtrA2 protease. It is a human zinc finger protein characterized by a restricted pattern of expression and the lack of orthologs in mouse and rat. The biological function of THAP5 is unknown but our previous studies suggest it could regulate G2/M transition in kidney cells and could be involved in human cardiomyocyte cell death associated with coronary artery disease (CAD). In this report, we expanded our studies on the properties and function of THAP5 in human melanoma cells. THAP5 was expressed in primary human melanocytes as well as in all melanoma cell lines that were tested. THAP5 protein level was significantly induced by UV irradiation or cisplatin treatment, conditions known to cause DNA damage. The induction of THAP5 correlated with a significant increase in apoptotic cell death. In addition, we show that THAP5 is a nuclear protein that could recognize and bind a specific DNA motif. THAP5 could also repress the transcription of a reporter gene in a heterologous system. Our work suggests that THAP5 is a DNA-binding protein and a transcriptional repressor. Furthermore, THAP5 has a pro-apoptotic function and it was induced in melanoma cells under conditions that promoted cell death.

  3. Bcl-2 Knockdown Accelerates T Cell Receptor-Triggered Activation-Induced Cell Death in Jurkat T Cells

    OpenAIRE

    Lee, Yun-Jung; Won, Tae Joon; Hyung, Kyeong Eun; Lee, Mi Ji; Moon, Young-hye; Lee, Ik Hee; Go, Byung Sung; Hwang, Kwang Woo

    2014-01-01

    Cell death and survival are tightly controlled through the highly coordinated activation/inhibition of diverse signal transduction pathways to insure normal development and physiology. Imbalance between cell death and survival often leads to autoimmune diseases and cancer. Death receptors sense extracellular signals to induce caspase-mediated apoptosis. Acting upstream of CED-3 family proteases, such as caspase-3, Bcl-2 prevents apoptosis. Using short hairpin RNAs (shRNAs), we suppressed Bcl-...

  4. Nanosecond pulsed electric fields induce poly(ADP-ribose) formation and non-apoptotic cell death in HeLa S3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Morotomi-Yano, Keiko; Akiyama, Hidenori [Institute of Pulsed Power Science, Kumamoto University, Kumamoto 860-8555 (Japan); Yano, Ken-ichi, E-mail: yanoken@kumamoto-u.ac.jp [Priority Organization for Innovation and Excellence, Kumamoto University, Kumamoto 860-8555 (Japan)

    2013-08-30

    Highlights: •Nanosecond pulsed electric field (nsPEF) is a new and unique means for life sciences. •Apoptosis was induced by nsPEF exposure in Jurkat cells. •No signs of apoptosis were detected in HeLa S3 cells exposed to nsPEFs. •Formation of poly(ADP-ribose) was induced in nsPEF-exposed HeLa S3 cells. •Two distinct modes of cell death were activated by nsPEF in a cell-dependent manner. -- Abstract: Nanosecond pulsed electric fields (nsPEFs) have recently gained attention as effective cancer therapy owing to their potency for cell death induction. Previous studies have shown that apoptosis is a predominant mode of nsPEF-induced cell death in several cell lines, such as Jurkat cells. In this study, we analyzed molecular mechanisms for cell death induced by nsPEFs. When nsPEFs were applied to Jurkat cells, apoptosis was readily induced. Next, we used HeLa S3 cells and analyzed apoptotic events. Contrary to our expectation, nsPEF-exposed HeLa S3 cells exhibited no molecular signs of apoptosis execution. Instead, nsPEFs induced the formation of poly(ADP-ribose) (PAR), a hallmark of necrosis. PAR formation occurred concurrently with a decrease in cell viability, supporting implications of nsPEF-induced PAR formation for cell death. Necrotic PAR formation is known to be catalyzed by poly(ADP-ribose) polymerase-1 (PARP-1), and PARP-1 in apoptotic cells is inactivated by caspase-mediated proteolysis. Consistently, we observed intact and cleaved forms of PARP-1 in nsPEF-exposed and UV-irradiated cells, respectively. Taken together, nsPEFs induce two distinct modes of cell death in a cell type-specific manner, and HeLa S3 cells show PAR-associated non-apoptotic cell death in response to nsPEFs.

  5. Programmed cell death of Ulmus pumila L. seeds during aging

    Institute of Scientific and Technical Information of China (English)

    Yulan ZHANG; Ming ZHANG; Fang LI; Xiaofeng WANG

    2008-01-01

    The programmed cell death (PCD) character-istics of Ulmus pumila L. seeds were investigated. The seeds were treated at a high temperature of 37℃ and 100% relative humidity for six days. DAPI (4'6-diami-dino-2-phenylindole) staining revealed that the aging treatment induced condensation and margination of chro-matin, as well as the formation of apoptotic bodies. DNA electrophoresis results of U. pumila seeds on an agarose gel showed a characteristic "ladder" pattern. Levels of electrolyte leakage of seed cells showed that membranes retained their integral form during almost the entire aging time. There was an immediate increase in the production rate of superoxide anion (O2-) and in the amount of hydrogen peroxide (H2O2), which remained at a μmol level. All of these common characteristics indicate that seed aging can be classified as PCD.

  6. Uropathogenic Escherichia coli Epigenetically Manipulate Host Cell Death Pathways.

    Science.gov (United States)

    Zhang, Zhengguo; Wang, Ming; Eisel, Florian; Tchatalbachev, Svetlin; Chakraborty, Trinad; Meinhardt, Andreas; Bhushan, Sudhanshu

    2016-04-01

    Urinary tract infections caused by uropathogenic Escherichia coli (UPEC) pathovars belong to the most frequent infections in human. It is well established that UPEC can subvert innate immune responses, but the role of UPEC in interfering with host cell death pathways is not known. Here, we show that UPEC abrogates activation of the host cell prosurvival protein kinase B signaling pathway, which results in the activation of mammalian forkhead box O (FOXO) transcription factors. Although FOXOs were localized in the nucleus and showed increased DNA-binding activity, no change in the expression levels of FOXO target genes were observed. UPEC can suppress BIM expression induced by LY249002, which results in attenuation of caspase 3 activation and blockage of apoptosis. Mechanistically, BIM expression appears to be epigenetically silenced by a decrease in histone 4 acetylation at the BIM promoter site. Taken together, these results suggest that UPEC can epigenetically silence BIM expression, a molecular switch that prevents apoptosis. PMID:26621912

  7. Morphologic categorization of cell death induced by mild hyperthermia and comparison with death induced by ionizing radiation and cytotoxic drugs

    International Nuclear Information System (INIS)

    This paper presents a summary of the morphological categorization of cell death, results of two in vivo studies on the cell death induced by mild hyperthermia in rat small intestine and mouse mastocytoma, and a comparison of the cell death induced by hyperthermia, radiation and cytotoxic drugs. Two distinct forms of cell death, apoptosis and necrosis, can be recognized on morphologic grounds. Apoptosis appears to be a process of active cellular self-destruction to which a biologically meaningful role can usually be attributed, whereas necrosis is a passive degenerative phenomenon that results from irreversible cellular injury. Light and transmission electron microscopic studies showed that lower body hyperthermia (43 degrees C for 30 min) induced only apoptosis of intestinal epithelial cells, and of lymphocytes, plasma cells, and eosinophils. In the mastocytoma, hyperthermia (43 degrees C for 15 min) produced widespread tumor necrosis and also enhanced apoptosis of tumor cells. Ionizing radiation and cytotoxic drugs are also known to induce apoptosis in a variety of tissues. It is attractive to speculate that DNA damage by each agent is the common event which triggers the same process of active cellular self-destruction that characteristically effects selective cell deletion in normal tissue homeostasis

  8. Cell Death Atlas of the Postnatal Mouse Ventral Forebrain and Hypothalamus: Effects of Age and Sex

    Science.gov (United States)

    Ahern, Todd H.; Krug, Stefanie; Carr, Audrey V.; Murray, Elaine K.; Fitzpatrick, Emmett; Bengston, Lynn; McCutcheon, Jill; De Vries, Geert J.; Forger, Nancy G.

    2016-01-01

    Naturally occurring cell death is essential to the development of the mammalian nervous system. Although the importance of developmental cell death has been appreciated for decades, there is no comprehensive account of cell death across brain areas in the mouse. Moreover, several regional sex differences in cell death have been described for the ventral forebrain and hypothalamus, but it is not known how widespread the phenomenon is. We used immunohistochemical detection of activated caspase-3 to identify dying cells in the brains of male and female mice from postnatal day (P) 1 to P11. Cell death density, total number of dying cells, and regional volume were determined in 16 regions of the hypothalamus and ventral forebrain (the anterior hypothalamus, arcuate nucleus, anteroventral periventricular nucleus, medial preoptic nucleus, paraventricular nucleus, suprachiasmatic nucleus, and ventromedial nucleus of the hypothalamus; the basolateral, central, and medial amygdala; the lateral and principal nuclei of the bed nuclei of the stria terminalis; the caudate-putamen; the globus pallidus; the lateral septum; and the islands of Calleja). All regions showed a significant effect of age on cell death. The timing of peak cell death varied between P1 to P7, and the average rate of cell death varied tenfold among regions. Several significant sex differences in cell death and/or regional volume were detected. These data address large gaps in the developmental literature and suggest interesting region-specific differences in the prevalence and timing of cell death in the hypothalamus and ventral forebrain. PMID:23296992

  9. DNA damage-induced cell death: lessons from the central nervous system

    Institute of Scientific and Technical Information of China (English)

    Helena Lobo Borges; Rafael Linden; Jean YJ Wang

    2008-01-01

    DNA damage can, but does not always, induce cell death. While several pathways linking DNA damage signals to mitochondria-dependent and -independent death machineries have been elucidated, the connectivity of these pathways is subject to regulation by multiple other factors that are not well understood. We have proposed two conceptual models to explain the delayed and variable cell death response to DNA damage: integrative surveillance versus autonomous pathways. In this review, we discuss how these two models may explain the in vivo regulation of cell death induced by ionizing radiation (IR) in the developing central nervous system, where the death response is regulated by radiation dose, cell cycle status and neuronal development.

  10. Cancer Cell Growth Inhibitory Effect of Bee Venom via Increase of Death Receptor 3 Expression and Inactivation of NF-kappa B in NSCLC Cells

    Directory of Open Access Journals (Sweden)

    Kyung Eun Choi

    2014-07-01

    Full Text Available Our previous findings have demonstrated that bee venom (BV has anti-cancer activity in several cancer cells. However, the effects of BV on lung cancer cell growth have not been reported. Cell viability was determined with trypan blue uptake, soft agar formation as well as DAPI and TUNEL assay. Cell death related protein expression was determined with Western blotting. An EMSA was used for nuclear factor kappaB (NF-κB activity assay. BV (1–5 μg/mL inhibited growth of lung cancer cells by induction of apoptosis in a dose dependent manner in lung cancer cell lines A549 and NCI-H460. Consistent with apoptotic cell death, expression of DR3 and DR6 was significantly increased. However, deletion of DRs by small interfering RNA significantly reversed BV induced cell growth inhibitory effects. Expression of pro-apoptotic proteins (caspase-3 and Bax was concomitantly increased, but the NF-κB activity and expression of Bcl-2 were inhibited. A combination treatment of tumor necrosis factor (TNF-like weak inducer of apoptosis, TNF-related apoptosis-inducing ligand, docetaxel and cisplatin, with BV synergistically inhibited both A549 and NCI-H460 lung cancer cell growth with further down regulation of NF-κB activity. These results show that BV induces apoptotic cell death in lung cancer cells through the enhancement of DR3 expression and inhibition of NF-κB pathway.

  11. 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

  12. AB158. Atorvastatin induces autophagic cell death in prostate cancer cells in vitro

    Science.gov (United States)

    He, Zhenhua; Wang, Zhiping

    2016-01-01

    Objective Although it is well known that apoptosis contributes to cancer cell death, the role of autophagy in cancer cell death has remained in dispute. Atorvastatin has been suggested to exhibit anti-cancer effects. The present study aimed to examine atorvastatin-induced autophagy-associated cell death and the autophagy-associated gene expression profile in the PC3 prostate carcinoma cell line. Methods The atorvastatin-induced process of autophagy in PC3 cells was determined via evaluation of the cellular expression levels of autophagosomal marker light-chain-3 (LC3)-II, using immunoblotting and counting of green fluorescent protein (GFP)-LC3-transfected autophagiccells. Apoptosis was examined by terminal deoxynucleotidyl transferase dUTP nick end labeling assay and an MTT assay was used to evaluate cell viability. Total RNA of PC3 cells was isolated for characterization of the gene expression profile following atorvastatin treatment. Results Atorvastatin treatment of PC3 cells for 24 h increased the expression of GFP-LC3-II by >25% and expression continued for >72 h, while apoptosis was not significantly induced within this time period. Four genes associated with the autophagy machinery were also significantly upregulated. Conclusions In the presence of atorvastatin, autophagy may be unable to abrogate cell damage and may therefore contribute to cellular dysfunction, leading to autophagic/type II programmed cell death. In response to atorvastatin treatment, the expression of genes involved in autophagic mediating pathways may have a role in tumor suppression.

  13. Increasing RpoS expression causes cell death in Borrelia burgdorferi.

    Directory of Open Access Journals (Sweden)

    Linxu Chen

    Full Text Available RpoS, one of the two alternative σ factors in Borrelia burgdorferi, is tightly controlled by multiple regulators and, in turn, determines expression of many critical virulence factors. Here we show that increasing RpoS expression causes cell death. The immediate effect of increasing RpoS expression was to promote bacterial division and as a consequence result in a rapid increase in cell number before causing bacterial death. No DNA fragmentation or degradation was observed during this induced cell death. Cryo-electron microscopy showed induced cells first formed blebs, which were eventually released from dying cells. Apparently blebbing initiated cell disintegration leading to cell death. These findings led us to hypothesize that increasing RpoS expression triggers intracellular programs and/or pathways that cause spirochete death. The potential biological significance of induced cell death may help B. burgdorferi regulate its population to maintain its life cycle in nature.

  14. Iodixanol induces apoptotic and antiproliferative effects but no necrotic cell death in renal proximal tubular cells in vitro

    International Nuclear Information System (INIS)

    Purpose: To evaluate the cytotoxic effects of the iso-osmolar contrast medium iodixanol on renal tubular cell cultures. Materials and Methods: LLC-PK1 cells were incubated with iodixanol and isotonic NaCl (18.75 - 75 mg I/ml, 1 - 24 hours). Cell death was assessed by the trypan blue exclusion test. To assess apoptosis, mononucleosomes and oligonucleosomes of cell lysates were determined. Measurement of BrdU (5-bromo-2'-deoxyuridine) incorporation into the DNA was used for the quantification of cell proliferation. Results: Iodixanol did not induce any significant increase in the number of necrotic cells (8 % and 9 % at 37.5 and 75 mg I/ml vs. 8 % for control, p > 0.05). In contrast, iodixanol significantly increased the number of oligonucleosomes indicating induction of apoptosis (125 ± 4 % of control, p < 0.05). Iodixanol induced a significant, dose- and time-dependent inhibition of BrdU incorporation indicating the inhibition of cell proliferation (92 ± 2 % and 79 ± 2 % of control at 18.75 and 37.5 mg I/ml, p < 0.001). (orig.)

  15. Iodixanol induces apoptotic and antiproliferative effects but no necrotic cell death in renal proximal tubular cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, M.C.; Scheer, M.; Heckmann, M.; Kuefner, M.A.; Uder, M. [Universitaetsklinikum Erlangen (Germany). Radiologisches Inst.

    2009-04-15

    Purpose: To evaluate the cytotoxic effects of the iso-osmolar contrast medium iodixanol on renal tubular cell cultures. Materials and Methods: LLC-PK1 cells were incubated with iodixanol and isotonic NaCl (18.75 - 75 mg I/ml, 1 - 24 hours). Cell death was assessed by the trypan blue exclusion test. To assess apoptosis, mononucleosomes and oligonucleosomes of cell lysates were determined. Measurement of BrdU (5-bromo-2'-deoxyuridine) incorporation into the DNA was used for the quantification of cell proliferation. Results: Iodixanol did not induce any significant increase in the number of necrotic cells (8 % and 9 % at 37.5 and 75 mg I/ml vs. 8 % for control, p > 0.05). In contrast, iodixanol significantly increased the number of oligonucleosomes indicating induction of apoptosis (125 {+-} 4 % of control, p < 0.05). Iodixanol induced a significant, dose- and time-dependent inhibition of BrdU incorporation indicating the inhibition of cell proliferation (92 {+-} 2 % and 79 {+-} 2 % of control at 18.75 and 37.5 mg I/ml, p < 0.001). (orig.)

  16. Statins, Bcl-2 and Apoptosis: Cell Death or Cell Protection?

    OpenAIRE

    Wood, W. Gibson; Igbavboa, Urule; Muller, Walter E.; Gunter P. Eckert

    2013-01-01

    Statins have proven their effectiveness in the treatment of cardiovascular disease. This class of drugs has also attracted attention as a potential treatment for dissimilar diseases such as certain types of cancers and neurodegenerative diseases. What appears to be a contradiction is that in the case of cancer, it has been suggested that statins increase apoptosis and alter levels of Bcl-2 family members (e.g., reduce Bcl-2 and increase Bax) whereas, studies mainly using non-cancerous cells r...

  17. Sphingosine-1-phosphate in cell growth and cell death.

    Science.gov (United States)

    Spiegel, S; Cuvillier, O; Edsall, L C; Kohama, T; Menzeleev, R; Olah, Z; Olivera, A; Pirianov, G; Thomas, D M; Tu, Z; Van Brocklyn, J R; Wang, F

    1998-06-19

    Recent evidence suggests that branching pathways of sphingolipid metabolism may mediate either apoptotic or mitogenic responses depending on the cell type and the nature of the stimulus. While ceramide has been shown to be an important regulatory component of apoptosis induced by tumor necrosis factor alpha and Fas ligand, sphingosine-1-phosphate (SPP), a further metabolite of ceramide, has been implicated as a second messenger in cellular proliferation and survival induced by platelet-derived growth factor, nerve growth factor, and serum. SPP protects cells from apoptosis resulting from elevations of ceramide. Inflammatory cytokines stimulate sphingomyelinase, but not ceramidase, leading to accumulation of ceramide, whereas growth signals also leading to accumulation of ceramide, whereas growth signals also stimulate ceramidase and sphingosine kinase leading to increased SPP levels. We propose that the dynamic balance between levels of sphingolipid metabolites, ceramide, and SPP, and consequent regulation of different family members of mitogen-activated protein kinases (JNK versus ERK), is an important factor that determines whether a cell survives or dies. PMID:9668339

  18. 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. PMID:27417660

  19. Ficus carica latex prevents invasion through induction of let-7d expression in GBM cell lines.

    Science.gov (United States)

    Tezcan, Gulcin; Tunca, Berrin; Bekar, Ahmet; Yalcin, Murat; Sahin, Saliha; Budak, Ferah; Cecener, Gulsah; Egeli, Unal; Demir, Cevdet; Guvenc, Gokcen; Yilmaz, Gozde; Erkan, Leman Gizem; Malyer, Hulusi; Taskapilioglu, Mevlut Ozgur; Evrensel, Turkkan; Bilir, Ayhan

    2015-03-01

    Glioblastoma multiforme (GBM) is one of the deadliest human malignancies. A cure for GBM remains elusive, and the overall survival time is less than 1 year. Thus, the development of more efficient therapeutic approaches for the treatment of these patients is required. Induction of tumor cell death by certain phytochemicals derived from medicinal herbs and dietary plants has become a new frontier for cancer therapy research. Although the cancer suppressive effect of Ficus carica (fig) latex (FCL) has been determined in a few cancer types, the effect of this latex on GBM tumors has not been investigated. Therefore, in the current study, the anti-proliferative activity of FCL and the effect of the FCL-temozolomide (TMZ) combination were tested in the T98G, U-138 MG, and U-87 MG GBM cell lines using the WST-1 assay. The mechanism of cell death was analyzed using Annexin-V/FITC and TUNEL assays, and the effect of FCL on invasion was tested using the chick chorioallantoic membrane assay. To determine the effect of FCL on GBM progression, the expression levels of 40 GBM associated miRNAs were analyzed in T98G cells using RT-qPCR. According to the obtained data, FCL causes cell death in GBM cells with different responses to TMZ, and this effect is synergistically increased in combination with TMZ. In addition, the current study is the first to demonstrate the effect of FCL on modulation of let-7d expression, which may be an important underlying mechanism of the anti-invasive effect of this extract. PMID:25212824

  20. A novel cell death gene acts to repair patterning defects in Drosophila melanogaster.

    Science.gov (United States)

    Tanaka, Kentaro M; Takahashi, Aya; Fuse, Naoyuki; Takano-Shimizu-Kouno, Toshiyuki

    2014-06-01

    Cell death is a mechanism utilized by organisms to eliminate excess cells during development. Here, we describe a novel regulator of caspase-independent cell death, Mabiki (Mabi), that is involved in the repair of the head patterning defects caused by extra copies of bicoid in Drosophila melanogaster. Mabiki functions together with caspase-dependent cell death mechanisms to provide robustness during development. PMID:24671768

  1. Fenugreek extract as an inducer of cellular death via autophagy in human T lymphoma Jurkat cells

    Directory of Open Access Journals (Sweden)

    Al-Daghri Nasser M

    2012-10-01

    Full Text Available Abstract Background Drugs used both in classical chemotherapy and the more recent targeted therapy do not have cancer cell specificity and, hence, cause severe systemic side effects. Tumors also develop resistance to such drugs due to heterogeneity of cell types and clonal selection. Several traditional dietary ingredients from plants, on the other hand, have been shown to act on multiple targets/pathways, and may overcome drug resistance. The dietary agents are safe and readily available. However, application of plant components for cancer treatment/prevention requires better understanding of anticancer functions and elucidation of their mechanisms of action. The current study focuses on the anticancer properties of fenugreek, a herb with proven anti-diabetic, antitumor and immune-stimulating functions. Method Jurkat cells were incubated with 30 to 1500 μg/mL concentrations of 50% ethanolic extract of dry fenugreek seeds and were followed for changes in viability (trypan blue assay, morphology (microscopic examination and autophagic marker LC3 transcript level (RT-PCR. Results Incubation of Jurkat cells with fenugreek extract at concentrations ranging from 30 to 1500 μg/mL for up to 3 days resulted in cell death in a dose- and time-dependent manner. Jurkat cell death was preceded by the appearance of multiple large vacuoles, which coincided with transcriptional up-regulation of LC3. GC-MS analysis of fenugreek extract indicated the presence of several compounds with anticancer properties, including gingerol (4.82%, cedrene (2.91%, zingerone (16.5%, vanillin (1.52% and eugenol (1.25%. Conclusions Distinct morphological changes involving appearance of large vacuoles, membrane disintegration and increased expression of LC3 transcripts indicated that fenugreek extract induced autophagy and autophagy-associated death of Jurkat cells. In addition to the already known apoptotic activation, induction of autophagy may be an additional mechanism

  2. Cell death, clearance and immunity in the skeletal muscle.

    Science.gov (United States)

    Sciorati, C; Rigamonti, E; Manfredi, A A; Rovere-Querini, P

    2016-06-01

    accumulation and promoting autoimmunity itself. There is strong promise for novel treatments based on new knowledge of cell death, clearance and immunity in the muscle. PMID:26868912

  3. The calcimimetic R-568 induces apoptotic cell death in prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Cheng Guangming

    2009-07-01

    Full Text Available Abstract Background Increased serum level of parathyroid hormone (PTH was found in metastatic prostate cancers. Calcimimetic R-568 was reported to reduce PTH expression, to suppress cell proliferation and to induce apoptosis in parathyroid cells. In this study, we investigated the effect of R-568 on cellular survival of prostate cancer cells. Methods Prostate cancer cell lines LNCaP and PC-3 were used in this study. Cellular survival was determined with MTT, trypan blue exclusion and fluorescent Live/Death assays. Western blot assay was utilized to assess apoptotic events induced by R-568 treatment. JC-1 staining was used to evaluate mitochondrial membrane potential. Results In cultured prostate cancer LNCaP and PC-3 cells, R-568 treatment significantly reduced cellular survival in a dose- and time-dependent manner. R-568-induced cell death was an apoptotic event, as evidenced by caspase-3 processing and PARP cleavage, as well as JC-1 color change in mitochondria. Knocking down calcium sensing receptor (CaSR significantly reduced R-568-induced cytotoxicity. Enforced expression of Bcl-xL gene abolished R-568-induced cell death, while loss of Bcl-xL expression led to increased cell death in R-568-treated LNCaP cells,. Conclusion Taken together, our data demonstrated that calcimimetic R-568 triggers an intrinsic mitochondria-related apoptotic pathway, which is dependent on the CaSR and is modulated by Bcl-xL anti-apoptotic pathway.

  4. Baicalein induces programmed cell death in Candida albicans.

    Science.gov (United States)

    Dai, Bao-Di; Cao, Ying-Ying; Huang, Shan; Xu, Yong-Gang; Gao, Ping-Hui; Wang, Yan; Jiang, Yuan-Ying

    2009-08-01

    Recent evidence has revealed the occurrence of an apoptotic phenotype in Candida albicans that is inducible with environmental stresses such as acetic acid, hydrogen peroxide, and amphotericin B. In the present study, we found that the Chinese herbal medicine Baicalein (BE), which was one of the skullcapflavones, can induce apoptosis in C. albicans. The apoptotic effects of BE were detected by flow cytometry using Annexin V-FITC and DAPI, and it was confirmed by transmission electron microscopy analysis. After exposure to 4 microg/ml BE for 12 h, about 10% of C. albicans cells were apoptotic. Both the increasing intracellular levels of reactive oxygen species (ROS) and upregulation of some redox-related genes (CAP1, SOD2, TRR1) were observed. Furthermore, we compared the survivals of CAP1 deleted, wild-type, and overexpressed strains and found that Cap1p attenuated BE-initiated cell death, which was coherent with a higher mRNA level of the CAP1 gene. In addition, the mitochondrial membrane potential of C. albicans cells changed significantly ( palbicans cells, and the apoptosis was associated with the breakdown of mitochondrial membrane potential. PMID:19734718

  5. Markov mean properties for cell death-related protein classification.

    Science.gov (United States)

    Fernandez-Lozano, Carlos; Gestal, Marcos; González-Díaz, Humberto; Dorado, Julián; Pazos, Alejandro; Munteanu, Cristian R

    2014-05-21

    The cell death (CD) is a dynamic biological function involved in physiological and pathological processes. Due to the complexity of CD, there is a demand for fast theoretical methods that can help to find new CD molecular targets. The current work presents the first classification model to predict CD-related proteins based on Markov Mean Properties. These protein descriptors have been calculated with the MInD-Prot tool using the topological information of the amino acid contact networks of the 2423 protein chains, five atom physicochemical properties and the protein 3D regions. The Machine Learning algorithms from Weka were used to find the best classification model for CD-related protein chains using all 20 attributes. The most accurate algorithm to solve this problem was K*. After several feature subset methods, the best model found is based on only 11 variables and is characterized by the Area Under the Receiver Operating Characteristic Curve (AUROC) of 0.992 and the true positive rate (TP Rate) of 88.2% (validation set). 7409 protein chains labeled with "unknown function" in the PDB Databank were analyzed with the best model in order to predict the CD-related biological activity. Thus, several proteins have been predicted to have CD-related function in Homo sapiens: 3DRX-involved in virus-host interaction biological process, protein homooligomerization; 4DWF-involved in cell differentiation, chromatin modification, DNA damage response, protein stabilization; 1IUR-involved in ATP binding, chaperone binding; 1J7D-involved in DNA double-strand break processing, histone ubiquitination, nucleotide-binding oligomerization; 1UTU-linked with DNA repair, regulation of transcription; 3EEC-participating to the cellular membrane organization, egress of virus within host cell, class mediator resulting in cell cycle arrest, negative regulation of ubiquitin-protein ligase activity involved in mitotic cell cycle and apoptotic process. Other proteins from bacteria predicted as

  6. Induction of embryonic stem cells to hematopoietic cells in vitro

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to get hematopoietic cells from embryonic stem (ES) cells and to study development mechanisms of hematopoietic cells, the method of inducing embryonic stem cells to hematopoietic cells was explored by differenciating mouse ES cells and human embryonic cells in three stages. The differentiated cells were identified by flow cytometry, immunohistochemistry and Wright's staining. The results showed that embryoid bodies (EBs) could form when ES cells were cultured in the medium with 2-mercaptoethanol (2-ME). However, cytokines, such as stem cell factor (SCF), thrombopoietin (TPO), interleukin-3 (IL-3), interleukin-6 (IL-6), erythropoietin (EPO) and granular colony stimulating factor (G-CSF), were not helpful for forming EBs. SCF, TPO and embryonic cell conditional medium were useful for the differentiation of mouse EBs to hematopoietic progenitors. Eighty-six percent of these cells were CD34+ after 6-d culture. Hematopoietic progenitors differentiated to B lymphocytes when they were cocultured with primary bone marrow stroma cells in the DMEM medium with SCF and IL-6. 14 d later, most of the cells were CD34-CD38+. Wright's staining and immunohistochemistry showed that 80% of these cells were plasma-like morphologically and immunoglubolin positive. The study of hematopoietic cells from human embryonic cells showed that human embryonic cell differentiation was very similar to that of mouse ES cells. They could form EBs in the first stage and the CD34 positive cells account for about 48.5% in the second stage.

  7. The Protective Effects of Insulin and Natural Honey against Hippocampal Cell Death in Streptozotocin-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Iraj Jafari Anarkooli

    2014-01-01

    Full Text Available We investigated the effects of insulin and honey as antioxidants to prevent the hippocampal cell death in streptozotocin-induced diabetic rats. We selected sixty Wister rats (5 groups of 12 animals each, including the control group (C, and four diabetic groups (control (D and 3 groups treated with insulin (I, honey (H, and insulin plus honey (I + H. Diabetes was induced by streptozotocin injection (IP, 60 mg/kg. Six weeks after the induction of diabetes, the group I received insulin (3-4 U/kg/day, SC, group H received honey (5 mg/kg/day, IP, and group I + H received a combination of the above at the same dose. Groups C and D received normal saline. Two weeks after treatment, rats were sacrificed and the hippocampus was extracted. Neuronal cell death in the hippocampal region was examined using trypan blue assay, “H & E” staining, and TUNEL assay. Cell viability assessment showed significantly lower number of living cells in group D than in group C. Besides, the mean number of living cells was significantly higher in group I, H, and I + H compared to group D. Therefore, it can be concluded that the treatment of the diabetic rats with insulin, honey, and a combination of insulin and honey can prevent neuronal cell death in different hippocampal areas of the studied samples.

  8. 213Bi-anti-EGFR radioimmunoconjugates and X-ray irradiation trigger different cell death pathways in squamous cell carcinoma cells

    International Nuclear Information System (INIS)

    Introduction: Treatment of patients with squamous cell carcinoma of head and neck is hampered by resistance of tumor cells to irradiation. Additional therapies enhancing the effect of X-ray irradiation may be beneficial. Antibodies targeting EGFR have been shown to improve the efficacy of radiation therapy. Therefore, we analyzed cytotoxicity of 213Bi-anti-EGFR immunoconjugates in combination with X-ray irradiation. Methods: The monoclonal anti-EGFR antibody matuzumab was coupled to CHX-A”-DTPA forming stable complexes with 213Bi. Cytotoxicity of X-ray radiation, of treatment with 213Bi-anti-EGFR monoclonal antibodies (MAb) or of a combined treatment regimen was assayed using cell proliferation and colony formation assays in UD-SCC5 cells. Key proteins of cell-cycle arrest and cell death were examined by Western blot analysis. Cell cycle analysis was performed by flow cytometry. DNA double-strand breaks were detected via γH2AX and quantified using Definiens™ software. Results: Irradiation with X-rays or treatment with 213Bi-anti-EGFR-MAb resulted in median lethal dose (LD50) values of 12 Gy or 130 kBq/mL, respectively. Treatment with 37 kBq/mL of 213Bi-anti-EGFR-MAb or 2 Gy of X-rays had only little effect on colony formation of UD-SCC5 cells. In contrast, a combined treatment regimen (37 kBq/mL plus 2 Gy) significantly decreased colony formation and enhanced the formation of DNA double-strand breaks. As revealed by flow cytometry, radiation treatments caused accumulation of cells in the G0/G1 phase. Both treatment with 213Bi-anti-EGFR immunoconjugates and application of the combined treatment regimen triggered activation of genes of signaling pathways involved in cell-cycle arrest and induction of apoptosis like p21/Waf, GADD45, Puma and Bax, which were only marginally modulated by X-ray irradiation of cells. Conclusions: 213Bi-anti-EGFR-MAb enhances cytotoxicity of X-ray irradiation in UD-SCC5 cells most probably due to effective induction of DNA double

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

    International Nuclear Information System (INIS)

    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

  10. 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.

  11. Melatonina: modulador de morte celular Melatonin: cell death modulator

    Directory of Open Access Journals (Sweden)

    Cecília da Silva Ferreira

    2010-01-01

    Full Text Available A apoptose ou morte programada é um fenômeno biológico essencial para o desenvolvimento e manutenção de uma população celular. Neste processo, as células senescentes ou indesejáveis são eliminadas após ativação de um programa de morte celular, que envolve a participação de moléculas pró-apoptóticas (Fas, FasL, Bax, Caspases 2, 3, 6, 7, 8 e 9. A ativação destas moléculas provoca típicas alterações morfológicas como a retração celular, perda de aderência à matriz extracelular e às células vizinhas, condensação da cromatina, fragmentação do DNA e formação de corpos apoptóticos. Moléculas antiapoptóticas (Bcl2, FLIP bloqueiam o surgimento e a evolução destas alterações celulares e evitam a morte celular. É o equilíbrio entre moléculas pró e antiapoptóticas que assegura a homeostase tecidual. O descontrole da apoptose pode contribuir para o aparecimento de diversas doenças neoplásicas, autoimunes e neurodegenerativas. Diversos agentes indutores e inibidores de apoptose são reconhecidos como armas potenciais no combate a doenças relacionadas a distúrbios de proliferação e morte celular, dentre eles, destacam-se os hormônios. A melatonina tem sido relatada com importante ação antiápoptótica em diversos tecidos, modulando a expressão de agentes, reduzindo a entrada de cálcio na célula, bem como atenuando a produção de espécies reativas de oxigênio e de proteínas pró-apoptóticas, tal como, diminuição da Bax. O conhecimento de novos agentes capazes de atuar nas vias da apoptose é de grande valia para o desenvolvimento de futuras terapias no tratamento de diversas doenças. Assim, o objetivo dessa revisão é elucidar os principais aspectos da morte celular pela apoptose e o papel da melatonina neste processo.Apoptosis or programmed death is a biological phenomenon, which is essential for the development and maintenance of a cell population. In this process, senescent or damaged

  12. Fine-mapping of an Arabidopsis cell death mutation locus

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An Arabidopsis cell death mutation locus was mapped to chromosome 2 between IGS1 and mi421. The YAC clone ends, CIC9A3R, CIC11C7L, CIC2G5R and RFLP marker CDs3 within this interval, were used to probe TAMU BAC library and 31 BAC clones were obtained. A BAC contig encompassing the mutation locus, which consists of T6P5, T7M23, T12A21, T8L6 and T18A18, was identified by Southern hybridization with the BAC ends as probes. 11 CAPS and 12 STS markers were developed in this region. These results will facilitate map-based cloning of the genes and sequencing of the genomic DNA in this region.

  13. Programmed cell death in developing human fetal CNS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The spatial and temporal distributions of programmed cell death (PCD) in developing central nervous system (CNS) of human fetuses ranging from 12 to 39 weeks of gestation were investigated using techniques of flow cytometry and terminal transferase-mediated nick end labeling (TUNEL). The results showed that PCD did occur in every representative brain region of all fetuses examined in different stages. It was found that there were two peaks of PCD appearing at the 12th and 39th weeks respectively, which suggested that the first peak of apoptosis may be involved in the selective elimination of neurons overproduced during the early development and the second may play an important role in establishing the correct neuronal circuitry.

  14. Galantamine and carbon monoxide protect brain microvascular endothelial cells by heme oxygenase-1 induction

    International Nuclear Information System (INIS)

    Galantamine, a reversible inhibitor of acetylcholine esterase (AChE), is a novel drug treatment for mild to moderate Alzheimer's disease and vascular dementia. Interestingly, it has been suggested that galantamine treatment is associated with more clinical benefit in patients with mild-to-moderate Alzheimer disease compared to other AChE inhibitors. We hypothesized that the protective effects of galantamine would involve induction of the protective gene, heme oxygenase-1 (HO-1), in addition to enhancement of the cholinergic system. Brain microvascular endothelial cells (mvECs) were isolated from spontaneous hypertensive rats. Galantamine significantly reduced H2O2-induced cell death of mvECs in association with HO-1 induction. These protective effects were completely reversed by nuclear factor-κB (NF-κB) inhibition or HO inhibition. Furthermore, galantamine failed to induce HO-1 in mvECs which lack inducible nitric oxide synthase (iNOS), supplementation of a nitric oxide (NO) donor or iNOS gene transfection on iNOS-deficient mvECs resulted in HO-1 induction with galantamine. These data suggest that the protective effects of galantamine require NF-κB activation and iNOS expression, in addition to HO-1. Likewise, carbon monoxide (CO), one of the byproducts of HO, up-regulated HO-1 and protected mvECs from oxidative stress in a similar manner. Our data demonstrate that galantamine mediates cytoprotective effects on mvECs through induction HO-1. This pharmacological action of galantamine may, at least in part, account for the superior clinical efficacy of galantamine in vascular dementia and Alzheimer disease

  15. Inhibition of telomerase causes vulnerability to endoplasmic reticulum stress-induced neuronal cell death.

    Science.gov (United States)

    Hosoi, Toru; Nakatsu, Kanako; Shimamoto, Akira; Tahara, Hidetoshi; Ozawa, Koichiro

    2016-08-26

    Endoplasmic reticulum (ER) stress is implicated in several diseases, such as cancer and neurodegenerative diseases. In the present study, we investigated the possible involvement of telomerase in ER stress-induced cell death. ER stress-induced cell death was ameliorated in telomerase reverse transcriptase (TERT) over-expressing MCF7 cells (MCF7-TERT cell). Telomerase specific inhibitor, BIBR1532, reversed the inhibitory effect of TERT on ER stress-induced cell death in MCF7-TERT cells. These findings suggest that BIBR1532 may specifically inhibit telomerase activity, thereby inducing cell death in ER stress-exposed cells. TERT was expressed in the SH-SY5Y neuroblastoma cell line. To analyze the possible involvement of telomerase in ER stress-induced neuronal cell death, we treated SH-SY5Y neuroblastoma cells with BIBR1532 and analyzed ER stress-induced cell death. We found that BIBR1532 significantly enhanced the ER stress-induced neuronal cell death. These findings suggest that inhibition of telomerase activity may enhance vulnerability to neuronal cell death caused by ER stress. PMID:27443785

  16. Hepatic Stellate Cells Regulate Immune Response via Induction of Myeloid Suppressor Cells

    OpenAIRE

    Chou, Hong-Shiue; Hsieh, Ching-Chuan; Yang, Horng-Ren; Wang, Lianfu; Arakawa, Yusuke; Brown, Kathleen; Wu, Qingyu; Lin, Feng; Peters, Marion; Fung, John J.; Lu, Lina; Qian, Shiguang

    2011-01-01

    Although organ transplants have been applied for decades, outcomes of somatic cell transplants remain disappointing, presumably due to lack of appropriate supporting stromal cells. Thus, cotransplantation with liver stromal cells, hepatic stellate cells (HSC), achieves long-term survival of islet allografts in mice via induction of effector T cell apoptosis and generation of regulatory T (Treg) cells. In this study, we provide evidence both in vitro and in vivo that HSC can promote generation...

  17. Characterization of Salmonella-Induced Cell Death in Human Macrophage-Like THP-1 Cells

    OpenAIRE

    Valle, Eulalia; Guiney, Donald G.

    2005-01-01

    Salmonella strains are facultative intracellular pathogens that produce marked cytopathology during infection of host cells. Different forms of cytopathic effects have been associated with the virulence systems encoded by the two Salmonella pathogenicity islands (SPI-1 and SPI-2) and the spv locus. We used Salmonella enterica serovar Dublin to investigate the induction of cytopathology during infection of the human macrophage-like cell line THP-1. Analysis of host cells by flow cytometry usin...

  18. XBP1 mitigates aminoglycoside-induced endoplasmic reticulum stress and neuronal cell death.

    Science.gov (United States)

    Oishi, N; Duscha, S; Boukari, H; Meyer, M; Xie, J; Wei, G; Schrepfer, T; Roschitzki, B; Boettger, E C; Schacht, J

    2015-01-01

    Here we study links between aminoglycoside-induced mistranslation, protein misfolding and neuropathy. We demonstrate that aminoglycosides induce misreading in mammalian cells and assess endoplasmic reticulum (ER) stress and unfolded protein response (UPR) pathways. Genome-wide transcriptome and proteome analyses revealed upregulation of genes related to protein folding and degradation. Quantitative PCR confirmed induction of UPR markers including C/EBP homologous protein, glucose-regulated protein 94, binding immunoglobulin protein and X-box binding protein-1 (XBP1) mRNA splicing, which is crucial for UPR activation. We studied the effect of a compromised UPR on aminoglycoside ototoxicity in haploinsufficient XBP1 (XBP1(+/-)) mice. Intra-tympanic aminoglycoside treatment caused high-frequency hearing loss in XBP1(+/-) mice but not in wild-type littermates. Densities of spiral ganglion cells and synaptic ribbons were decreased in gentamicin-treated XBP1(+/-) mice, while sensory cells were preserved. Co-injection of the chemical chaperone tauroursodeoxycholic acid attenuated hearing loss. These results suggest that aminoglycoside-induced ER stress and cell death in spiral ganglion neurons is mitigated by XBP1, masking aminoglycoside neurotoxicity at the organismal level. PMID:25973683

  19. 5-Hydroxy-7-Methoxyflavone Triggers Mitochondrial-Associated Cell Death via Reactive Oxygen Species Signaling in Human Colon Carcinoma Cells

    Science.gov (United States)

    Paul, Souren; Jakhar, Rekha; Han, Jaehong; Kang, Sun Chul

    2016-01-01

    Plant-derived compounds are an important source of clinically useful anti-cancer agents. Chrysin, a biologically active flavone found in many plants, has limited usage for cancer chemotherapeutics due to its poor oral bioavailability. 5-Hydroxy-7-methoxyflavone (HMF), an active natural chrysin derivative found in various plant sources, is known to modulate several biological activities. However, the mechanism underlying HMF-induced apoptotic cell death in human colorectal carcinoma cells in vitro is still unknown. Herein, HMF was shown to be capable of inducing cytotoxicity in HCT-116 cells and induced cell death in a dose-dependent manner. Treatment of HCT-116 cells with HMF caused DNA damage and triggered mitochondrial membrane perturbation accompanied by Cyt c release, down-regulation of Bcl-2, activation of BID and Bax, and caspase-3-mediated apoptosis. These results show that ROS generation by HMF was the crucial mediator behind ER stress induction, resulting in intracellular Ca2+ release, JNK phosphorylation, and activation of the mitochondrial apoptosis pathway. Furthermore, time course study also reveals that HMF treatment leads to increase in mitochondrial and cytosolic ROS generation and decrease in antioxidant enzymes expression. Temporal upregulation of IRE1-α expression and JNK phosphorylation was noticed after HMF treatment. These results were further confirmed by pre-treatment with the ROS scavenger N-acetyl-l-cysteine (NAC), which completely reversed the effects of HMF treatment by preventing lipid peroxidation, followed by abolishment of JNK phosphorylation and attenuation of apoptogenic marker proteins. These results emphasize that ROS generation by HMF treatment regulates the mitochondrial-mediated apoptotic signaling pathway in HCT-116 cells, demonstrating HMF as a promising pro-oxidant therapeutic candidate for targeting colorectal cancer. PMID:27116119

  20. Temporal rhythm of petal programmed cell death in Ipomoea purpurea.

    Science.gov (United States)

    Gui, M-Y; Ni, X-L; Wang, H-B; Liu, W-Z

    2016-09-01

    Flowers are the main sexual reproductive organs in plants. The shapes, colours and scents of corolla of plant flowers are involved in attracting insect pollinators and increasing reproductive success. The process of corolla senescence was investigated in Ipomoea purpurea (Convolvulaceae) in this study. In the research methods of plant anatomy, cytology, cell chemistry and molecular biology were used. The results showed that at the flowering stage cells already began to show distortion, chromatin condensation, mitochondrial membrane degradation and tonoplast dissolution and rupture. At this stage genomic DNA underwent massive but gradual random degradation. However, judging from the shape and structure, aging characteristics did not appear until the early flower senescence stage. The senescence process was slow, and it was completed at the late stage of flower senescence with a withering corolla. We may safely arrive at the conclusion that corolla senescence of I. purpurea was mediated by programmed cell death (PCD) that occurred at the flowering stage. The corolla senescence exhibited an obvious temporal rhythm, which demonstrated a high degree of coordination with pollination and fertilization. PMID:27259176

  1. Global survey of cell death mechanisms reveals metabolic regulation of ferroptosis.

    Science.gov (United States)

    Shimada, Kenichi; Skouta, Rachid; Kaplan, Anna; Yang, Wan Seok; Hayano, Miki; Dixon, Scott J; Brown, Lewis M; Valenzuela, Carlos A; Wolpaw, Adam J; Stockwell, Brent R

    2016-07-01

    Apoptosis is one type of programmed cell death. Increasingly, non-apoptotic cell death is recognized as being genetically controlled, or 'regulated'. However, the full extent and diversity of alternative cell death mechanisms remain uncharted. Here we surveyed the landscape of pharmacologically accessible cell death mechanisms. In an examination of 56 caspase-independent lethal compounds, modulatory profiling showed that 10 compounds induced three different types of regulated non-apoptotic cell death. Optimization of one of those ten resulted in the discovery of FIN56, a specific inducer of ferroptosis. Ferroptosis has been found to occur when the lipid-repair enzyme GPX4 is inhibited. FIN56 promoted degradation of GPX4. FIN56 also bound to and activated squalene synthase, an enzyme involved in isoprenoid biosynthesis, independent of GPX4 degradation. These discoveries show that dysregulation of lipid metabolism is associated with ferroptosis. This systematic approach is a means to discover and characterize novel cell death phenotypes. PMID:27159577

  2. Neuroprotection by GH against excitotoxic-induced cell death in retinal ganglion cells.

    Science.gov (United States)

    Martínez-Moreno, Carlos G; Ávila-Mendoza, José; Wu, Yilun; Arellanes-Licea, Elvira Del Carmen; Louie, Marcela; Luna, Maricela; Arámburo, Carlos; Harvey, Steve

    2016-08-01

    Retinal growth hormone (GH) has been shown to promote cell survival in retinal ganglion cells (RGCs) during developmental waves of apoptosis during chicken embryonic development. The possibility that it might also against excitotoxicity-induced cell death was therefore examined in the present study, which utilized quail-derived QNR/D cells as an in vitro RGC model. QNR/D cell death was induced by glutamate in the presence of BSO (buthionine sulfoxamide) (an enhancer of oxidative stress), but this was significantly reduced (PGH (rcGH). Similarly, QNR/D cells that had been prior transfected with a GH plasmid to overexpress secreted and non-secreted GH. This treatment reduced the number of TUNEL-labeled cells and blocked their release of lactate dehydrogenase (LDH). In a further experiment with dissected neuroretinal explants from ED (embryonic day) 10 embryos, rcGH treatment of the explants also reduced (PGH-overexpressing QNR/D cells. As rcGH treatment and GH-overexpression cells also increased the content of IGF-1 and IGF-1 mRNA this neuroprotective action of GH is likely to be mediated, at least partially, through an IGF-1 mechanism. This possibility is supported by the fact that the siRNA knockdown of GH or IGF-1 significantly reduced QNR/D cell viability, as did the immunoneutralization of IGF-1. GH is therefore neuroprotective against excitotoxicity-induced RGC cell death by anti-apoptotic actions involving IGF-1 stimulation. PMID:27129619

  3. 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.

  4. Gingerol sensitizes TRAIL-induced apoptotic cell death of glioblastoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dae-Hee, E-mail: leedneo@gmail.com [Departments of Surgery and Pharmacology and Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Kim, Dong-Wook [Department of Microbiology, Immunology, and Cancer Biology, University of VA (United States); Jung, Chang-Hwa [Division of Metabolism and Functionality Research, Korea Food Research Institute (Korea, Republic of); Lee, Yong J. [Departments of Surgery and Pharmacology and Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Park, Daeho, E-mail: daehopark@gist.ac.kr [School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

    2014-09-15

    Glioblastoma multiforme (GBM) is the most lethal and aggressive astrocytoma of primary brain tumors in adults. Although there are many clinical trials to induce the cell death of glioblastoma cells, most glioblastoma cells have been reported to be resistant to TRAIL-induced apoptosis. Here, we showed that gingerol as a major component of ginger can induce TRAIL-mediated apoptosis of glioblastoma. Gingerol increased death receptor (DR) 5 levels in a p53-dependent manner. Furthermore, gingerol decreased the expression level of anti-apoptotic proteins (survivin, c-FLIP, Bcl-2, and XIAP) and increased pro-apoptotic protein, Bax and truncate Bid, by generating reactive oxygen species (ROS). We also found that the sensitizing effects of gingerol in TRAIL-induced cell death were blocked by scavenging ROS or overexpressing anti-apoptotic protein (Bcl-2). Therefore, we showed the functions of gingerol as a sensitizing agent to induce cell death of TRAIL-resistant glioblastoma cells. This study gives rise to the possibility of applying gingerol as an anti-tumor agent that can be used for the purpose of combination treatment with TRAIL in TRAIL-resistant glioblastoma tumor therapy. - Highlights: • Most GBM cells have been reported to be resistant to TRAIL-induced apoptosis. • Gingerol enhances the expression level of anti-apoptotic proteins by ROS. • Gingerol enhances TRAIL-induced apoptosis through actions on the ROS–Bcl2 pathway.

  5. Gingerol sensitizes TRAIL-induced apoptotic cell death of glioblastoma cells

    International Nuclear Information System (INIS)

    Glioblastoma multiforme (GBM) is the most lethal and aggressive astrocytoma of primary brain tumors in adults. Although there are many clinical trials to induce the cell death of glioblastoma cells, most glioblastoma cells have been reported to be resistant to TRAIL-induced apoptosis. Here, we showed that gingerol as a major component of ginger can induce TRAIL-mediated apoptosis of glioblastoma. Gingerol increased death receptor (DR) 5 levels in a p53-dependent manner. Furthermore, gingerol decreased the expression level of anti-apoptotic proteins (survivin, c-FLIP, Bcl-2, and XIAP) and increased pro-apoptotic protein, Bax and truncate Bid, by generating reactive oxygen species (ROS). We also found that the sensitizing effects of gingerol in TRAIL-induced cell death were blocked by scavenging ROS or overexpressing anti-apoptotic protein (Bcl-2). Therefore, we showed the functions of gingerol as a sensitizing agent to induce cell death of TRAIL-resistant glioblastoma cells. This study gives rise to the possibility of applying gingerol as an anti-tumor agent that can be used for the purpose of combination treatment with TRAIL in TRAIL-resistant glioblastoma tumor therapy. - Highlights: • Most GBM cells have been reported to be resistant to TRAIL-induced apoptosis. • Gingerol enhances the expression level of anti-apoptotic proteins by ROS. • Gingerol enhances TRAIL-induced apoptosis through actions on the ROS–Bcl2 pathway

  6. Cell death by pyroptosis drives CD4 T-cell depletion in HIV-1 infection

    Science.gov (United States)

    Doitsh, Gilad; Galloway, Nicole L. K.; Geng, Xin; Yang, Zhiyuan; Monroe, Kathryn M.; Zepeda, Orlando; Hunt, Peter W.; Hatano, Hiroyu; Sowinski, Stefanie; Muñoz-Arias, Isa; Greene, Warner C.

    2014-01-01

    The pathway causing CD4 T-cell death in HIV-infected hosts remains poorly understood although apoptosis has been proposed as a key mechanism. We now show that caspase-3-mediated apoptosis accounts for the death of only a small fraction of CD4 T cells corresponding to those that are both activated and productively infected. The remaining over 95% of quiescent lymphoid CD4 T cells die by caspase-1-mediated pyroptosis triggered by abortive viral infection. Pyroptosis corresponds to an intensely inflammatory form of programmed cell death in which cytoplasmic contents and pro-inflammatory cytokines, including IL-1β, are released. This death pathway thus links the two signature events in HIV infection--CD4 T-cell depletion and chronic inflammation--and creates a pathogenic vicious cycle in which dying CD4 T cells release inflammatory signals that attract more cells to die. This cycle can be broken by caspase 1 inhibitors shown to be safe in humans, raising the possibility of a new class of `anti-AIDS' therapeutics targeting the host rather than the virus.

  7. Cell Death-Associated Molecular-Pattern Molecules: Inflammatory Signaling and Control

    OpenAIRE

    Beatriz Sangiuliano; Nancy Marcela Pérez; Moreira, Dayson F; Belizário, José E.

    2014-01-01

    Apoptosis, necroptosis, and pyroptosis are different cellular death programs characterized in organs and tissues as consequence of microbes infection, cell stress, injury, and chemotherapeutics exposure. Dying and death cells release a variety of self-proteins and bioactive chemicals originated from cytosol, nucleus, endoplasmic reticulum, and mitochondria. These endogenous factors are named cell death-associated molecular-pattern (CDAMP), damage-associated molecular-pattern (DAMP) molecules,...

  8. Genetic Variation in Cell Death Genes and Risk of Non-Hodgkin Lymphoma

    OpenAIRE

    Johanna M. Schuetz; Denise Daley; Jinko Graham; Berry, Brian R.; Gallagher, Richard P.; Connors, Joseph M; Gascoyne, Randy D.; Spinelli, John J.; Angela R Brooks-Wilson

    2012-01-01

    BACKGROUND: Non-Hodgkin lymphomas are a heterogeneous group of solid tumours that constitute the 5(th) highest cause of cancer mortality in the United States and Canada. Poor control of cell death in lymphocytes can lead to autoimmune disease or cancer, making genes involved in programmed cell death of lymphocytes logical candidate genes for lymphoma susceptibility. MATERIALS AND METHODS: We tested for genetic association with NHL and NHL subtypes, of SNPs in lymphocyte cell death genes using...

  9. Differential effect of baicalein on ionizing radiation induced cell death in normal lymphocytes and lymphoma cells

    International Nuclear Information System (INIS)

    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)

  10. Inhibition of apoptic cell death induced by Pseudomonas syringae pv. Tabaci and mycotoxin fumonisin B1

    NARCIS (Netherlands)

    Iakimova, E.T.; Batchvorova, R.; Kapchina, V.; Popov, T.; Atanassov, A.; Woltering, E.J.

    2004-01-01

    The impact of programmed cell death (PCD) inhibitors on lesion formation and biochemical events in transgenic (ttr line) and non-transgenic (Nevrokop 1164) tobacco infected with Pseudomonas syringae pv. tabaci was tested. Programmed cell death in tomato cell culture was induced by Fumonisin B1 (FUM)

  11. Non-canonical kinase signaling by the death ligand TRAIL in cancer cells : discord in the death receptor family

    NARCIS (Netherlands)

    Azijli, K.; Weyhenmeyer, B.; Peters, G. J.; de Jong, S.; Kruyt, F. A. E.

    2013-01-01

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-based therapy is currently evaluated in clinical studies as a tumor cell selective pro-apoptotic approach. However, besides activating canonical caspase-dependent apoptosis by binding to TRAIL-specific death receptors, the TRAIL ligand

  12. 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

    2016-01-01

    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. PMID:27117478

  13. Ultraviolet-induced cell death is independent of DNA replication in rat kangeroo cells

    Energy Technology Data Exchange (ETDEWEB)

    Miyaji, E.N.; Menck, C.F.M. [Sao Paulo Univ., SP (Brazil). Inst. de Biociencias

    1995-05-01

    Rat kangaroo (Potorous tridactylus) cells have an efficient repair system for photoreactivation of lethal lesions induced by 254 nm UV. However, this ability is lost with increasing time after UV, being completely ineffective after 24 h. Critical events leading to UV-induced cell death must occur within this period of time. DNA synthesis was inhibited by the DNA polymerase inhibitor aphidicolin and the loss of the capability to photorepair lethal lesions was maintained for replicating cells. Similar data were obtained in synchronized cells UV irradiated immediately before S phase. Under the same conditions, the ability to remove cyclobutane pyrimidine dimers by photoreactivation in these cells remained unchanged 24 h after irradiation. These data indicate that the critical events responsible for UV-induced cell death occur in the absence of DNA replication. (author).

  14. Ultraviolet-induced cell death is independent of DNA replication in rat kangeroo cells

    International Nuclear Information System (INIS)

    Rat kangaroo (Potorous tridactylus) cells have an efficient repair system for photoreactivation of lethal lesions induced by 254 nm UV. However, this ability is lost with increasing time after UV, being completely ineffective after 24 h. Critical events leading to UV-induced cell death must occur within this period of time. DNA synthesis was inhibited by the DNA polymerase inhibitor aphidicolin and the loss of the capability to photorepair lethal lesions was maintained for replicating cells. Similar data were obtained in synchronized cells UV irradiated immediately before S phase. Under the same conditions, the ability to remove cyclobutane pyrimidine dimers by photoreactivation in these cells remained unchanged 24 h after irradiation. These data indicate that the critical events responsible for UV-induced cell death occur in the absence of DNA replication. (author)

  15. Cyclic dinucleotides modulate human T-cell response through monocyte cell death.

    Science.gov (United States)

    Tosolini, Marie; Pont, Frédéric; Verhoeyen, Els; Fournié, Jean-Jacques

    2015-12-01

    Cyclic dinucleotides, a class of microbial messengers, have been recently identified in bacteria, but their activity in humans remains largely unknown. Here, we have studied the function of cyclic dinucleotides in humans. We found that c-di-AMP and cGAMP, two adenosine-based cyclic dinucleotides, activated T lymphocytes in an unusual manner through monocyte cell death. c-di-AMP and cGAMP induced the selective apoptosis of human monocytes, and T lymphocytes were activated by the direct contact with these dying monocytes. The ensuing T-cell response comprised cell-cycle exit, phenotypic maturation into effector memory cells and proliferation arrest, but not cell death. This quiescence was transient since T cells remained fully responsive to further restimulation. Together, our results depict a novel activation pattern for human T lymphocytes: a transient quiescence induced by c-di-AMP- or cGAMP-primed apoptotic monocytes. PMID:26460927

  16. AtPDCD5 Plays a Role in Programmed Cell Death after UV-B Exposure in Arabidopsis1[OPEN

    Science.gov (United States)

    Falcone Ferreyra, María Lorena; D’Andrea, Lucio; AbdElgawad, Hamada

    2016-01-01

    DNA damage responses have evolved to sense and react to DNA damage; the induction of DNA repair mechanisms can lead to genomic restoration or, if the damaged DNA cannot be adequately repaired, to the execution of a cell death program. In this work, we investigated the role of an Arabidopsis (Arabidopsis thaliana) protein, AtPDCD5, which is highly similar to the human PDCD5 protein; it is induced by ultraviolet (UV)-B radiation and participates in programmed cell death in the UV-B DNA damage response. Transgenic plants expressing AtPDCD5 fused to GREEN FLUORESCENT PROTEIN indicate that AtPDCD5 is localized both in the nucleus and the cytosol. By use of pdcd5 mutants, we here demonstrate that these plants have an altered antioxidant metabolism and accumulate higher levels of DNA damage after UV-B exposure, similar to levels in ham1ham2 RNA interference transgenic lines with decreased expression of acetyltransferases from the MYST family. By coimmunoprecipitation and pull-down assays, we provide evidence that AtPDCD5 interacts with HAM proteins, suggesting that both proteins participate in the same pathway of DNA damage responses. Plants overexpressing AtPDCD5 show less DNA damage but more cell death in root tips upon UV-B exposure. Finally, we here show that AtPDCD5 also participates in age-induced programmed cell death. Together, the data presented here demonstrate that AtPDCD5 plays an important role during DNA damage responses induced by UV-B radiation in Arabidopsis and also participates in programmed cell death programs. PMID:26884483

  17. Selective induction of oxidative stress in cancer cells via synergistic combinations of agents targeting redox homeostasis.

    Science.gov (United States)

    Akladios, Fady N; Andrew, Scott D; Parkinson, Christopher J

    2015-07-01

    Cancer cell resistance to chemotherapy is still a heavy burden that impairs the response of many cancer patients to conventional chemotherapy. Using drug combinations is one therapeutic approach to overcome the developing resistance to any one drug. Oxidative stress is now a generally regarded hallmark of cancer that can be one approach to selectively target cancer cells while sparing normal cells. With the aim of increasing oxidative stress in cancer cells to a lethal set point, we have generated and combined several series of redox active compounds that act at different points of the cellular oxidative cascade. The premise of such combinations is to deplete of endogenous antioxidant defence proteins (e.g., Glutathione) while concomitantly increasing the generation of ROS via metal redox recycling and Fenton chemistry which eventually leads to the disruption of cellular redox homeostasis and induction of cell death. Through this approach, we have identified highly synergistic combinations of two distinctive classes of compounds (Azines and Copper(II) complexes of 2-pyridyl ketone thiosemicarbazones) which are capable of eliminating cancer cells without concomitant increase in toxicity toward normal cells. In one of our most potent combinations, a combination index (CI) value of 0.056 was observed, representing a 17 fold enhancement in activity beyond additive effects. Such new combination regimen of redox active compounds can be one step closer to potentially safer low dose chemotherapy. PMID:26022081

  18. Induction of apoptosis on human hepatocarcinoma cell lines by an alkyl resorcinol isolated from Lithraea molleoides

    Institute of Scientific and Technical Information of China (English)

    Luciana Barbini; Paula Lopez; Julieta Ruffa; Virginia Martino; Graciela Ferraro; Rodolfo Campos; Lucia Cavallaro

    2006-01-01

    AIM: To study the mechanism of cytotoxicity of a new active 5-alkyl resorcinol [1, 3-dihydroxy-5- (tridec-4', 7'-dienyl) benzene] isolated from Lithraea molleoides leaves on liver tumor cells.METHODS: Human hepatocarcinoma cell lines (HepG2and Hep3B) in culture were treated with inhibitory concentrations, 50% of the compound, for 24 h. The induction of apoptosis was detected in treated cells by analysis of DNA fragmentation, DNA content, and acridine orange and propidium iodide staining.RESULTS: After 24 h of 5-alkyl resorcinol treatment,both cell lines showed: (1) the typical morphological alterations of apoptosis; (2) DNA fragmentation, detected by laddering and appearance of a subG0 population by flow cytometry; and (3) condensed and fragmented nuclei by acridine orange-propidium iodide staining.CONCLUSION: Based on the results, this compound exerts its cytotoxic effect in both hepatocellular cell lines through apoptotic cell death. For Hep3B, cells with mutated p53 and Fas, apoptosis would proceed by p53-or Fas-independent pathways.

  19. Role of phosphoinositide 3-kinase in the autophagic death of serum-deprived PC12 cells.

    Science.gov (United States)

    Guillon-Munos, A; van Bemmelen, M X P; Clarke, P G H

    2005-10-01

    The death of serum-deprived undifferentiated PC12 cells shows both autophagic and apoptotic features. Since it is still controversial whether the autophagy is instrumental in the cell death or a mere epiphenomenon, we tested the effects of inhibiting the autophagy by a variety of phosphoinositide 3-kinase inhibitors, and provided evidence that the autophagy, or a related trafficking event, is indeed instrumental in the cell death. Furthermore, by comparing the effects of PI3-K inhibition and caspase-inhibition on autophagic and apoptotic cellular events, we showed that in this case the autophagic and apoptotic mechanisms mediate cell death by parallel pathways and do not act in series. PMID:16151638

  20. CTLA-4 promotes Foxp3 induction and regulatory T cell accumulation in the intestinal lamina propria

    OpenAIRE

    Barnes, M. J.; Griseri, T; Johnson, A M F; Young, W; Powrie, F; Izcue, A

    2012-01-01

    Thymic induction of CD4+Foxp3+ regulatory T (Treg) cells relies on CD28 costimulation and high-affinity T-cell receptor (TCR) signals, whereas Foxp3 (forkhead box P3) induction on activated peripheral CD4+ T cells is inhibited by these signals. Accordingly, the inhibitory molecule CTLA-4 (cytotoxic T-lymphocyte antigen 4) promoted, but was not essential for CD4+ T-cell Foxp3 induction in vitro. We show that CTLA-4-deficient cells are equivalent to wild-type cells in the thymic induction of Fo...

  1. Caspase dependent programmed cell death in developing embryos: a potential target for therapeutic intervention against pathogenic nematodes.

    Directory of Open Access Journals (Sweden)

    Alok Das Mohapatra

    2011-09-01

    Full Text Available BACKGROUND: Successful embryogenesis is a critical rate limiting step for the survival and transmission of parasitic worms as well as pathology mediated by them. Hence, blockage of this important process through therapeutic induction of apoptosis in their embryonic stages offers promise for developing effective anti-parasitic measures against these extra cellular parasites. However, unlike in the case of protozoan parasites, induction of apoptosis as a therapeutic approach is yet to be explored against metazoan helminth parasites. METHODOLOGY/PRINCIPAL FINDINGS: For the first time, here we developed and evaluated flow cytometry based assays to assess several conserved features of apoptosis in developing embryos of a pathogenic filarial nematode Setaria digitata, in-vitro as well as ex-vivo. We validated programmed cell death in developing embryos by using immuno-fluorescence microscopy and scoring expression profile of nematode specific proteins related to apoptosis [e.g. CED-3, CED-4 and CED-9]. Mechanistically, apoptotic death of embryonic stages was found to be a caspase dependent phenomenon mediated primarily through induction of intracellular ROS. The apoptogenicity of some pharmacological compounds viz. DEC, Chloroquine, Primaquine and Curcumin were also evaluated. Curcumin was found to be the most effective pharmacological agent followed by Primaquine while Chloroquine displayed minimal effect and DEC had no demonstrable effect. Further, demonstration of induction of apoptosis in embryonic stages by lipid peroxidation products [molecules commonly associated with inflammatory responses in filarial disease] and demonstration of in-situ apoptosis of developing embryos in adult parasites in a natural bovine model of filariasis have offered a framework to understand anti-fecundity host immunity operational against parasitic helminths. CONCLUSIONS/SIGNIFICANCE: Our observations have revealed for the first time, that induction of apoptosis in

  2. Activation-induced and damage-induced cell death in aging human T cells.

    Science.gov (United States)

    Sikora, Ewa

    2015-11-01

    In multicellular organisms the proper system functionality is ensured by the balance between cell division, differentiation, senescence and death. This balance is changed during aging. Immunosenescence plays a crucial role in aging and leads to the shrinkage of T cell repertoire and the propensity to apoptosis. The elimination of expanded T cells at the end of immune response is crucial to maintain homeostasis and avoid any uncontrolled inflammation. Resting mature T lymphocytes, when activated via their antigen-specific receptor (TCR) and CD28 co-receptor, start to proliferate and then undergo the so called activation induced cell death (AICD), which mechanistically is triggered by the death receptor and leads to apoptosis. T lymphocytes, like other cells, are also exposed to damage, which can trigger the so called damage-induced cell death (DICD). It was hypothesized that oxidative stress and chronic antigenic load increasing with age reduced lymphocyte susceptibility to DICD and enhanced a proinflamatory status leading to increased AICD. However, data collected so far are inconsistent and does not support this assumption. Systematic and comprehensive studies are still needed for conclusive elucidation of the role of AICD and DICD in human immunosenescence, including the role of autophagy and necroptosis in the processes. PMID:25843236

  3. Immunosuppressive T-cell antibody induction for heart transplant recipients

    DEFF Research Database (Denmark)

    Penninga, Luit; Møller, Christian H; Gustafsson, Finn;

    2013-01-01

    Heart transplantation has become a valuable and well-accepted treatment option for end-stage heart failure. Rejection of the transplanted heart by the recipient's body is a risk to the success of the procedure, and life-long immunosuppression is necessary to avoid this. Clear evidence is required...... to identify the best, safest and most effective immunosuppressive treatment strategy for heart transplant recipients. To date, there is no consensus on the use of immunosuppressive antibodies against T-cells for induction after heart transplantation....

  4. Pathways to ischemic neuronal cell death: are sex differences relevant?

    Directory of Open Access Journals (Sweden)

    McCullough Louise D

    2008-06-01

    Full Text Available Abstract We have known for some time that the epidemiology of human stroke is sexually dimorphic until late in life, well beyond the years of reproductive senescence and menopause. Now, a new concept is emerging: the mechanisms and outcome of cerebral ischemic injury are influenced strongly by biological sex as well as the availability of sex steroids to the brain. The principal mammalian estrogen (17 β estradiol or E2 is neuroprotective in many types of brain injury and has been the major focus of investigation over the past several decades. However, it is becoming increasingly clear that although hormones are a major contributor to sex-specific outcomes, they do not fully account for sex-specific responses to cerebral ischemia. The purpose of this review is to highlight recent studies in cell culture and animal models that suggest that genetic sex determines experimental stroke outcome and that divergent cell death pathways are activated after an ischemic insult. These sex differences need to be identified if we are to develop efficacious neuroprotective agents for use in stroke patients.

  5. Thiosemicarbazone p-Substituted Acetophenone Derivatives Promote the Loss of Mitochondrial Δψ, GSH Depletion, and Death in K562 Cells.

    Science.gov (United States)

    Pessoto, Felipe S; Yokomizo, Cesar H; Prieto, Tatiana; Fernandes, Cleverton S; Silva, Alan P; Kaiser, Carlos R; Basso, Ernani A; Nantes, Iseli L

    2015-01-01

    A series of thiosemicarbazone (TSC) p-substituted acetophenone derivatives were synthesized and chemically characterized. The p-substituents appended to the phenyl group of the TSC structures were hydrogen, fluor, chlorine, methyl, and nitro, producing compounds named TSC-H, TSC-F, TSC-Cl, TSC-Me, and TSC-NO2, respectively. The TSC compounds were evaluated for their capacity to induce mitochondrial permeability, to deplete mitochondrial thiol content, and to promote cell death in the K562 cell lineage using flow cytometry and fluorescence microscopy. TSC-H, TSC-F, and TSC-Cl exhibited a bell-shaped dose-response curve for the induction of apoptosis in K562 cells due to the change from apoptosis to necrosis as the principal mechanism of cell death at the highest tested doses. TSC-Me and TSC-NO2 exhibited a typical dose-response profile, with a half maximal effective concentration of approximately 10 µM for cell death. Cell death was also evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which revealed lower toxicity of these compounds for peripheral blood mononuclear cells than for K562 cells. The possible mechanisms leading to cell death are discussed based on the observed effects of the new TSC compounds on the cellular thiol content and on mitochondrial bioenergetics. PMID:26075034

  6. Thiosemicarbazone p-Substituted Acetophenone Derivatives Promote the Loss of Mitochondrial Δψ, GSH Depletion, and Death in K562 Cells

    Directory of Open Access Journals (Sweden)

    Felipe S. Pessoto

    2015-01-01

    Full Text Available A series of thiosemicarbazone (TSC p-substituted acetophenone derivatives were synthesized and chemically characterized. The p-substituents appended to the phenyl group of the TSC structures were hydrogen, fluor, chlorine, methyl, and nitro, producing compounds named TSC-H, TSC-F, TSC-Cl, TSC-Me, and TSC-NO2, respectively. The TSC compounds were evaluated for their capacity to induce mitochondrial permeability, to deplete mitochondrial thiol content, and to promote cell death in the K562 cell lineage using flow cytometry and fluorescence microscopy. TSC-H, TSC-F, and TSC-Cl exhibited a bell-shaped dose-response curve for the induction of apoptosis in K562 cells due to the change from apoptosis to necrosis as the principal mechanism of cell death at the highest tested doses. TSC-Me and TSC-NO2 exhibited a typical dose-response profile, with a half maximal effective concentration of approximately 10 µM for cell death. Cell death was also evaluated using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay, which revealed lower toxicity of these compounds for peripheral blood mononuclear cells than for K562 cells. The possible mechanisms leading to cell death are discussed based on the observed effects of the new TSC compounds on the cellular thiol content and on mitochondrial bioenergetics.

  7. Activation of Cyclin-Dependent Kinase 5 Is a Consequence of Cell Death

    Directory of Open Access Journals (Sweden)

    Yixia Ye

    2009-01-01

    Full Text Available Cyclin-dependent kinase 5 (Cdk5 is similar to other Cdks but is activated during cell differentiation and cell death rather than cell division. Since activation of Cdk5 has been reported in many situations leading to cell death, we attempted to determine if it was required for any form of cell death. We found that Cdk5 is activated during apoptotic deaths and that the activation can be detected even when the cells continue to secondary necrosis. This activation can occur in the absence of Bim, calpain, or neutral cathepsins. The kinase is typically activated by p25, derived from p35 by calpain-mediated cleavage, but inhibition of calpain does not affect cell death or the activation of Cdk5. Likewise, RNAi-forced suppression of the synthesis of Cdk5 does not affect the incidence or kinetics of cell death. We conclude that Cdk5 is activated as a consequence of metabolic changes that are common to many forms of cell death. Thus its activation suggests processes during cell death that will be interesting or important to understand, but activation of Cdk5 is not necessary for cells to die.

  8. Insulin receptor substrate-1 prevents autophagy-dependent cell death caused by oxidative stress in mouse NIH/3T3 cells

    Directory of Open Access Journals (Sweden)

    Chan Shih-Hung

    2012-07-01

    Full Text Available Abstract Background Insulin receptor substrate (IRS-1 is associated with tumorigenesis; its levels are elevated in several human cancers. IRS-1 protein binds to several oncogene proteins. Oxidative stress and reactive oxygen species (ROS are involved in the initiation and progression of cancers. Cancer cells produce greater levels of ROS than normal cells do because of increased metabolic stresses. However, excessive production of ROS kills cancer cells. Autophagy usually serves as a survival mechanism in response to stress conditions, but excessive induction of autophagy results in cell death. In addition to inducing necrosis and apoptosis, ROS induces autophagic cell death. ROS inactivates IRS-1 mediated signaling and reduces intracellular IRS-1 concentrations. Thus, there is a complex relationship between IRS-1, ROS, autophagy, and cancer. It is not fully understood how cancer cells grow rapidly and survive in the presence of high ROS levels. Methods and results In this study, we established mouse NIH/3T3 cells that overexpressed IRS-1, so mimicking cancers with increased IRS-1 expression levels; we found that the IRS-1 overexpressing cells grow more rapidly than control cells do. Treatment of cells with glucose oxidase (GO provided a continuous source of ROS; low dosages of GO promoted cell growth, while high doses induced cell death. Evidence for GO induced autophagy includes increased levels of isoform B-II microtubule-associated protein 1 light chain 3 (LC3, aggregation of green fluorescence protein-tagged LC3, and increased numbers of autophagic vacuoles in cells. Overexpression of IRS-1 resulted in inhibition of basal autophagy, and reduced oxidative stress-induced autophagy and cell death. ROS decreased the mammalian target of rapamycin (mTOR/p70 ribosomal protein S6 kinase signaling, while overexpression of IRS-1 attenuated this inhibition. Knockdown of autophagy-related gene 5 inhibited basal autophagy and diminished oxidative stress

  9. Inhibition of mTOR-dependent autophagy sensitizes leukemic cells to cytarabine-induced apoptotic death.

    Directory of Open Access Journals (Sweden)

    Mihajlo Bosnjak

    Full Text Available The present study investigated the role of autophagy, a cellular self-digestion process, in the cytotoxicity of antileukemic drug cytarabine towards human leukemic cell lines (REH, HL-60, MOLT-4 and peripheral blood mononuclear cells from leukemic patients. The induction of autophagy was confirmed by acridine orange staining of intracellular acidic vesicles, electron microscopy visualization of autophagic vacuoles, as well as by the increase in autophagic proteolysis and autophagic flux, demonstrated by immunoblot analysis of p62 downregulation and LC3-I conversion to autophagosome-associated LC3-II in the presence of proteolysis inhibitors, respectively. Moreover, the expression of autophagy-related genes Atg4, Atg5 and Atg7 was stimulated by cytarabine in REH cells. Cytarabine reduced the phosphorylation of the major negative regulator of autophagy, mammalian target of rapamycin (mTOR, and its downstream target p70S6 kinase in REH cells, which was associated with downregulation of mTOR activator Akt and activation of extracellular signal- regulated kinase. Cytarabine had no effect on the activation of mTOR inhibitor AMP-activated protein kinase. Leucine, an mTOR activator, reduced both cytarabine-induced autophagy and cytotoxicity. Accordingly, pharmacological downregulation of autophagy with bafilomycin A1 and chloroquine, or RNA interference-mediated knockdown of LC3β or p62, markedly increased oxidative stress, mitochondrial depolarization, caspase activation and subsequent DNA fragmentation and apoptotic death in cytarabine-treated REH cells. Cytarabine also induced mTOR-dependent cytoprotective autophagy in HL-60 and MOLT-4 leukemic cell lines, as well as primary leukemic cells, but not normal leukocytes. These data suggest that the therapeutic efficiency of cytarabine in leukemic patients could be increased by the inhibition of the mTOR-dependent autophagic response.

  10. THAP5 is a DNA binding transcriptional repressor that is regulated in melanoma cells during DNA damage-induced cell death

    Science.gov (United States)

    Balakrishnan, Meenakshi P.; Cilenti, Lucia; Ambivero, Camilla; Goto, Yamafumi; Takata, Minoru; Turkson, James; Li, Xiaoman Shawn; Zervos, Antonis S.

    2011-01-01

    THAP5 was originally isolated as a specific interactor and substrate of the mitochondrial pro-apoptotic Omi/HtrA2 protease. It is a human zinc finger protein characterized by a restricted pattern of expression and the lack of orthologs in mouse and rat. The biological function of THAP5 is unknown but our previous studies suggest it could regulate G2/M transition in kidney cells and could be involved in human cardiomyocyte cell death associated with coronary artery disease (CAD). In this report, we expanded our studies on the properties and function of THAP5 in human melanoma cells. THAP5 was expressed in primary human melanocytes as well as in all melanoma cell lines that were tested. THAP5 protein level was significantly induced by UV irradiation or cisplatin treatment, conditions known to cause DNA damage. The induction of THAP5 correlated with a significant increase in apoptotic cell death. In addition, we show that THAP5 is a nuclear protein that could recognize and bind a specific DNA motif. THAP5 could also repress the transcription of a reporter gene in a heterologous system. Our work suggests that THAP5 is a DNA binding protein and a transcriptional repressor. Furthermore, THAP5 has a pro-apoptotic function and it was induced in melanoma cells under conditions that promoted cell death. PMID:21110952

  11. Effect of advanced glycation end-products on cell proliferation and cell death.

    Science.gov (United States)

    Peterszegi, G; Molinari, J; Ravelojaona, V; Robert, L

    2006-09-01

    The effect of advanced glycation end products (AGE-s) was studied on the proliferation and cell death of human skin fibroblasts in culture. Several AGE-products were prepared from proteins, a peptide and amino acids, using Glucose or Fructose, with or without Fe2+. The AGE preparations increased cell death at the 7th day, after only 72 hours of incubation. Some of these glycation products modified also proliferation. This effect of AGE-s was even maintained without these products in fresh medium for a second period of incubation up to 10 days from the start of the experiment. In order to explore the role of AGE-receptors, especially of AGE-receptor and of growth factor receptors (fibroblast and epidermal growth factors receptors), antibodies to these receptors were added to cell cultures and their effect on both cell death and proliferation were determined as for the AGE-s. These anti-receptor antibodies imitated to some extent the results obtained with AGE-s, producing increase of cell death and proliferation, followed above a certain concentration of antibodies by a decrease and a new increase or plateau. This might correspond to the internalization of the receptors followed by a re-expression on the cell membrane. The role of receptor-mediated Reactive Oxygen Species-production was also explored using scavengers: N-acetyl-cysteine (NAC), L-Carnosine, superoxide dismutase (SOD) and Catalase. Several of these scavengers decreased cell death, suggesting that Reactive Oxygen Species-production is partially involved in the observed phenomena. PMID:16919894

  12. Coniferyl aldehyde attenuates radiation enteropathy by inhibiting cell death and promoting endothelial cell function.

    Directory of Open Access Journals (Sweden)

    Ye-Ji Jeong

    Full Text Available Radiation enteropathy is a common complication in cancer patients. The aim of this study was to investigate whether radiation-induced intestinal injury could be alleviated by coniferyl aldehyde (CA, an HSF1-inducing agent that increases cellular HSP70 expression. We systemically administered CA to mice with radiation enteropathy following abdominal irradiation (IR to demonstrate the protective effects of CA against radiation-induced gastrointestinal injury. CA clearly alleviated acute radiation-induced intestinal damage, as reflected by the histopathological data and it also attenuated sub-acute enteritis. CA prevented intestinal crypt cell death and protected the microvasculature in the lamina propria during the acute and sub-acute phases of damage. CA induced HSF1 and HSP70 expression in both intestinal epithelial cells and endothelial cells in vitro. Additionally, CA protected against not only the apoptotic cell death of both endothelial and epithelial cells but also the loss of endothelial cell function following IR, indicating that CA has beneficial effects on the intestine. Our results provide novel insight into the effects of CA and suggest its role as a therapeutic candidate for radiation-induced enteropathy due to its ability to promote rapid re-proliferation of the intestinal epithelium by the synergic effects of the inhibition of cell death and the promotion of endothelial cell function.

  13. Cell proliferation and cell death are disturbed during prenatal and postnatal brain development after uranium exposure.

    Science.gov (United States)

    Legrand, M; Elie, C; Stefani, J; N Florès; Culeux, C; Delissen, O; Ibanez, C; Lestaevel, P; Eriksson, P; Dinocourt, C

    2016-01-01

    The developing brain is more susceptible to neurotoxic compounds than adult brain. It is also well known that disturbances during brain development cause neurological disorders in adulthood. The brain is known to be a target organ of uranium (U) exposure and previous studies have noted that internal U contamination of adult rats induces behavioral disorders as well as affects neurochemistry and neurophysiological properties. In this study, we investigated whether depleted uranium (DU) exposure affects neurogenesis during prenatal and postnatal brain development. We examined the structural morphology of the brain, cell death and finally cell proliferation in animals exposed to DU during gestation and lactation compared to control animals. Our results showed that DU decreases cell death in the cortical neuroepithelium of gestational day (GD) 13 embryos exposed at 40mg/L and 120mg/L and of GD18 fetuses exposed at 120mg/L without modification of the number of apoptotic cells. Cell proliferation analysis showed an increase of BrdU labeling in the dentate neuroepithelium of fetuses from GD18 at 120mg/L. Postnatally, cell death is increased in the dentate gyrus of postnatal day (PND) 0 and PND5 exposed pups at 120mg/L and is associated with an increase of apoptotic cell number only at PND5. Finally, a decrease in dividing cells is observed in the dentate gyrus of PND21 rats developmentally exposed to 120mg/L DU, but not at PND0 and PND5. These results show that DU exposure during brain development causes opposite effects on cell proliferation and cell death processes between prenatal and postnatal development mainly at the highest dose. Although these modifications do not have a major impact in brain morphology, they could affect the next steps of neurogenesis and thus might disrupt the fine organization of the neuronal network. PMID:26506049

  14. Effects of gamma-radiation on cell growth, cycle arrest, death, and superoxide dismutase expression by DU 145 human prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Vucic V.

    2006-01-01

    Full Text Available Gamma-irradiation (gamma-IR is extensively used in the treatment of hormone-resistant prostate carcinoma. The objective of the present study was to investigate the effects of 60Co gamma-IR on the growth, cell cycle arrest and cell death of the human prostate cancer cell line DU 145. The viability of DU 145 cells was measured by the Trypan blue exclusion assay and the 3(4,5-dimethylthiazol-2-yl-2,5,diphenyltetrazolium bromide test. Bromodeoxyuridine incorporation was used for the determination of cell proliferation. Cell cycle arrest and cell death were analyzed by flow cytometry. Superoxide dismutase (SOD, specifically CuZnSOD and MnSOD protein expression, after 10 Gy gamma-IR, was determined by Western immunoblotting analysis. gamma-IR treatment had a significant (P < 0.001 antiproliferative and cytotoxic effect on DU 145 cells. Both effects were time and dose dependent. Also, the dose of gamma-IR which inhibited DNA synthesis and cell proliferation by 50% was 9.7 Gy. Furthermore, gamma-IR induced cell cycle arrest in the G2/M phase and the percentage of cells in the G2/M phase was increased from 15% (control to 49% (IR cells, with a nonsignificant induction of apoptosis. Treatment with 10 Gy gamma-IR for 24, 48, and 72 h stimulated CuZnSOD and MnSOD protein expression in a time-dependent manner, approximately by 3- to 3.5-fold. These data suggest that CuZnSOD and MnSOD enzymes may play an important role in the gamma-IR-induced changes in DU 145 cell growth, cell cycle arrest and cell death.

  15. Role of dendritic cells in the induction of regulatory T cells

    Directory of Open Access Journals (Sweden)

    Kushwah Rahul

    2011-05-01

    Full Text Available Abstract Dendritic cells (DCs play a key role in initiating immune responses and maintaining immune tolerance. In addition to playing a role in thymic selection, DCs play an active role in tolerance under steady state conditions through several mechanisms which are dependent on IL-10, TGF-β, retinoic acid, indoleamine-2,3,-dioxygenase along with vitamin D. Several of these mechanisms are employed by DCs in induction of regulatory T cells which are comprised of Tr1 regulatory T cells, natural and inducible foxp3+ regulatory T cells, Th3 regulatory T cells and double negative regulatory T cells. It appears that certain DC subsets are highly specialized in inducing regulatory T cell differentiation and in some tissues the local microenvironment plays a role in driving DCs towards a tolerogenic response. In this review we discuss the recent advances in our understanding of the mechanisms underlying DC driven regulatory T cell induction.

  16. Radioadaptive Response for Reproductive Cell Death Demonstrated in In Vivo Tissue Model of Caenorhabditis elegans.

    Science.gov (United States)

    Tang, Huangqi; Chen, Liangwen; Liu, Jialu; Shi, Jue; Li, Qingqing; Wang, Ting; Wu, Lijun; Zhan, Furu; Bian, Po

    2016-04-01

    Reproductive cell death (RCD) occurs after one or more cell divisions resulting from an insult such as radiation exposure or other treatments with carcinogens or mutagens. The radioadaptive response for RCD is usually investigated by in vitro or in vivo clonogenic assay. To date, this has not been demonstrated in the vulval tissue in Caenorhabditis elegans ( C. elegans ), which is a well established in vivo model for radiation-induced RCD. In this study to determine whether radioadaptive response occurs in the vulval tissue model of C. elegans , early larval worms were gamma irradiated with lower adaptive doses, followed by higher challenge doses. The ratio of protruding vulva was used to assess the RCD of vulval cells. The results of this study showed that the radioadaptive response for RCD in this vulval tissue model could be well induced by dose combinations of 5 + 75 Gy and 5 + 100 Gy at the time point of 14-16 h in worm development. In addition, the time course analysis indicated that radioresistance in vulval cells developed within 1.75 h after an adaptive dose and persisted for only a short period of time (2-4 h). DNA damage checkpoint and non-homologous end joining were involved in the radioadaptive response, exhibiting induction of protruding vulva in worms deficient in these two pathways similar to their controls. Interestingly, the DNA damage checkpoint was not active in the somatic vulval cells, and it was therefore suggested that the DNA damage checkpoint might mediate the radioadaptive response in a cell nonautonomous manner. Here, we show evidence of the occurrence of a radioadaptive response for RCD in the vulval tissue model of C. elegans . This finding provides a potential opportunity to gain further insight into the underlying mechanisms of the radioadaptive response for RCD, in view of the abundant genetic resources of C. elegans . PMID:27023260

  17. Macrophage Activation Redirects Yersinia-Infected Host Cell Death from Apoptosis to Caspase-1-Dependent Pyroptosis

    OpenAIRE

    Bergsbaken, Tessa; Cookson, Brad T.

    2007-01-01

    Infection of macrophages by Yersinia species results in YopJ-dependent apoptosis, and naïve macrophages are highly susceptible to this form of cell death. Previous studies have demonstrated that macrophages activated with lipopolysaccharide (LPS) prior to infection are resistant to YopJ-dependent cell death; we found this simultaneously renders macrophages susceptible to killing by YopJ− Yersinia pseudotuberculosis (Yptb). YopJ− Yptb-induced macrophage death was dependent on caspase-1 activat...

  18. Mitochondria and Mitophagy: The Yin and Yang of Cell Death Control

    OpenAIRE

    Kubli, Dieter A.; Gustafsson, Åsa B.

    2012-01-01

    Mitochondria are primarily responsible for providing the contracting cardiac myocyte with a continuous supply of ATP. However, mitochondria can rapidly change into death-promoting organelles. In response to changes in the intracellular environment, mitochondria become producers of excessive reactive oxygen species and release pro-death proteins, resulting in disrupted ATP synthesis and activation of cell death pathways. Interestingly, cells have developed a defense mechanism against aberrant ...

  19. Triptolide induces apoptotic cell death of human cholangiocarcinoma cells through inhibition of myeloid cell leukemia-1

    International Nuclear Information System (INIS)

    Cholangiocarcinoma (CCA), a devastating neoplasm, is highly resistant to current chemotherapies. CCA cells frequently overexpress the antiapoptotic protein myeloid cell leukemia-1(Mcl-1), which is responsible for its extraordinary ability to evade cell death. Triptolide, a bioactive ingredient extracted from Chinese medicinal plant, has been shown to inhibit cell proliferation and induce apoptosis in several cancers. CCK-8 assay was performed to detect cell survival rate in vitro. DAPI staining and Flow cytometry were used to analyze apoptosis. Western blot was performed to determine the expression levels of caspase-3, caspase-7, caspase-9, PARP, and Mcl-1. Quantitative real-time PCR and immunofluorescence were used to detect the expression levels of Mcl-1. The nude mice xenograft model was used to evaluate the antitumor effect of triptolide in vivo. Triptolide reduced cell viability in cholangiocarcinoma cell lines in a dose- and time-dependent manner, with IC50 values of 12.6 ± 0.6 nM, 20.5 ± 4.2 nM, and 18.5 ± 0.7 nM at 48 h for HuCCT1, QBC939, and FRH0201 respectively. Triptolide induced apoptosis in CCA cell lines in part through mitochondrial pathway. Using quantitative real-time PCR, western blot and immunofluorescence, we have shown that triptolide downregulates Mcl-1 mRNA and protein levels. Furthermore, triptolide inhibited the CCA growth in vivo. Triptolide has profound antitumor effect on CCA, probably by inducing apoptosis through inhibition of Mcl-1. Triptolide would be a promising therapeutic agent for CCA

  20. Transformation-associated changes in sphingolipid metabolism sensitize cells to lysosomal cell death induced by inhibitors of acid sphingomyelinase

    DEFF Research Database (Denmark)

    Petersen, Nikolaj H T; Olsen, Ole D; Groth-Pedersen, Line;

    2013-01-01

    Lysosomal membrane permeabilization and subsequent cell death may prove useful in cancer treatment, provided that cancer cell lysosomes can be specifically targeted. Here, we identify acid sphingomyelinase (ASM) inhibition as a selective means to destabilize cancer cell lysosomes. Lysosome...

  1. Human cytochrome c enters murine J774 cells and causes G1 and G2/M cell cycle arrest and induction of apoptosis

    International Nuclear Information System (INIS)

    Cytochrome c is well known as a carrier of electrons during respiration. Current evidence indicates that cytochrome c also functions as a major component of apoptosomes to induce apoptosis in eukaryotic cells as well as an antioxidant. More recently, a prokaryotic cytochrome c, cytochrome c 551 from Pseudomonas aeruginosa, has been shown to enter in mammalian cells such as the murine macrophage-like J774 cells and causes inhibition of cell cycle progression. Much less is known about such functions by mammalian cytochromes c, particularly the human cytochrome c. We now report that similar to P. aeruginosa cytochrome c 551, the purified human cytochrome c protein can enter J774 cells and induce cell cycle arrest at the G1 to S phase, as well as at the G2/M phase at higher concentrations. Unlike P. aeruginosa cytochrome c 551 which had no effect on the induction of apoptosis, human cytochrome c induces significant apoptosis and cell death in J774 cells, presumably through inhibition of the cell cycle at the G2/M phase. When incubated with human breast cancer MCF-7 and normal mammary epithelial cell line MCF-10A1 cells, human cytochrome c entered in both types of cells but induced cell death only in the normal MCF-10A1 cells. The ability of human cytochrome c to enter J774 cells was greatly reduced at 4 deg. C, suggesting energy requirement in the entry process

  2. Modulation of Programmed Cell Death in a Model System of Xylogenic Zinnia (Zinnia Elegans) Cell Culture

    NARCIS (Netherlands)

    Yakimova, E.T.; Woltering, E.J.

    2009-01-01

    Programmed cell death is an integral part of the latest stage of differentiation of the tracheary elements of plant xylem vascular system. In this study, by applying a pharmacological approach with specific peptide inhibitors, we have elucidated the involvement of plant caspase-like proteases in cel

  3. 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

  4. Transcranial amelioration of inflammation and cell death after brain injury

    Science.gov (United States)

    Roth, Theodore L.; Nayak, Debasis; Atanasijevic, Tatjana; Koretsky, Alan P.; Latour, Lawrence L.; McGavern, Dorian B.

    2014-01-01

    Traumatic brain injury (TBI) is increasingly appreciated to be highly prevalent and deleterious to neurological function. At present, no effective treatment options are available, and little is known about the complex cellular response to TBI during its acute phase. To gain insights into TBI pathogenesis, we developed a novel murine closed-skull brain injury model that mirrors some pathological features associated with mild TBI in humans and used long-term intravital microscopy to study the dynamics of the injury response from its inception. Here we demonstrate that acute brain injury induces vascular damage, meningeal cell death, and the generation of reactive oxygen species (ROS) that ultimately breach the glial limitans and promote spread of the injury into the parenchyma. In response, the brain elicits a neuroprotective, purinergic-receptor-dependent inflammatory response characterized by meningeal neutrophil swarming and microglial reconstitution of the damaged glial limitans. We also show that the skull bone is permeable to small-molecular-weight compounds, and use this delivery route to modulate inflammation and therapeutically ameliorate brain injury through transcranial administration of the ROS scavenger, glutathione. Our results shed light on the acute cellular response to TBI and provide a means to locally deliver therapeutic compounds to the site of injury.

  5. Prodigiosin activates endoplasmic reticulum stress cell death pathway in human breast carcinoma cell lines

    International Nuclear Information System (INIS)

    Prodigiosin is a bacterial tripyrrole pigment with potent cytotoxicity against diverse human cancer cell lines. Endoplasmic reticulum (ER) stress is initiated by accumulation of unfolded or misfolded proteins in the ER lumen and may induce cell death when irremediable. In this study, the role of ER stress in prodigiosin-induced cytotoxicity was elucidated for the first time. Comparable to the ER stress inducer thapsigargin, prodigiosin up-regulated signature ER stress markers GRP78 and CHOP in addition to activating the IRE1, PERK and ATF6 branches of the unfolded protein response (UPR) in multiple human breast carcinoma cell lines, confirming prodigiosin as an ER stress inducer. Prodigiosin transcriptionally up-regulated CHOP, as evidenced by its promoting effect on the CHOP promoter activity. Of note, knockdown of CHOP effectively lowered prodigiosin's capacity to evoke PARP cleavage, reduce cell viability and suppress colony formation, highlighting an essential role of CHOP in prodigiosin-induced cytotoxic ER stress response. In addition, prodigiosin down-regulated BCL2 in a CHOP-dependent manner. Importantly, restoration of BCL2 expression blocked prodigiosin-induced PARP cleavage and greatly enhanced the survival of prodigiosin-treated cells, suggesting that CHOP-dependent BCL2 suppression mediates prodigiosin-elicited cell death. Moreover, pharmacological inhibition of JNK by SP600125 or dominant-negative blockade of PERK-mediated eIF2α phosphorylation impaired prodigiosin-induced CHOP up-regulation and PARP cleavage. Collectively, these results identified ER stress-mediated cell death as a mode-of-action of prodigiosin's tumoricidal effect. Mechanistically, prodigiosin engages the IRE1–JNK and PERK–eIF2α branches of the UPR signaling to up-regulate CHOP, which in turn mediates BCL2 suppression to induce cell death. Highlights: ► Prodigiosin is a bacterial tripyrrole pigment with potent anticancer effect. ► Prodigiosin is herein identified as an

  6. Prodigiosin activates endoplasmic reticulum stress cell death pathway in human breast carcinoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Mu-Yun [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Shen, Yuh-Chiang [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); National Research Institute of Chinese Medicine, Taipei, Taiwan (China); Lu, Chien-Hsing [Department of Obstetrics and Gynecology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan (China); Yang, Shu-Yi [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Ho, Tsing-Fen [Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan (China); Peng, Yu-Ta [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Chang, Chia-Che, E-mail: chia_che@dragon.nchu.edu.tw [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan (China)

    2012-12-15

    Prodigiosin is a bacterial tripyrrole pigment with potent cytotoxicity against diverse human cancer cell lines. Endoplasmic reticulum (ER) stress is initiated by accumulation of unfolded or misfolded proteins in the ER lumen and may induce cell death when irremediable. In this study, the role of ER stress in prodigiosin-induced cytotoxicity was elucidated for the first time. Comparable to the ER stress inducer thapsigargin, prodigiosin up-regulated signature ER stress markers GRP78 and CHOP in addition to activating the IRE1, PERK and ATF6 branches of the unfolded protein response (UPR) in multiple human breast carcinoma cell lines, confirming prodigiosin as an ER stress inducer. Prodigiosin transcriptionally up-regulated CHOP, as evidenced by its promoting effect on the CHOP promoter activity. Of note, knockdown of CHOP effectively lowered prodigiosin's capacity to evoke PARP cleavage, reduce cell viability and suppress colony formation, highlighting an essential role of CHOP in prodigiosin-induced cytotoxic ER stress response. In addition, prodigiosin down-regulated BCL2 in a CHOP-dependent manner. Importantly, restoration of BCL2 expression blocked prodigiosin-induced PARP cleavage and greatly enhanced the survival of prodigiosin-treated cells, suggesting that CHOP-dependent BCL2 suppression mediates prodigiosin-elicited cell death. Moreover, pharmacological inhibition of JNK by SP600125 or dominant-negative blockade of PERK-mediated eIF2α phosphorylation impaired prodigiosin-induced CHOP up-regulation and PARP cleavage. Collectively, these results identified ER stress-mediated cell death as a mode-of-action of prodigiosin's tumoricidal effect. Mechanistically, prodigiosin engages the IRE1–JNK and PERK–eIF2α branches of the UPR signaling to up-regulate CHOP, which in turn mediates BCL2 suppression to induce cell death. Highlights: ► Prodigiosin is a bacterial tripyrrole pigment with potent anticancer effect. ► Prodigiosin is herein identified

  7. 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

  8. Radiation induced cell death in cervical squamous cell carcinoma. An immunohistochemical and ultrastructural study

    International Nuclear Information System (INIS)

    To study the process of cell death in cervical squamous cell carcinoma (SCC) after radiation, an ultrastructural and immunohistochemical study was performed. Paraffin-embedded tissue blocks of biopsy samples pre- and post-radiation stage III SCC (n=15) were collected. Irradiation caused varying ultrastructural changes including nuclear and cytoplasmic disorganization suggesting cell necrosis. Immunohistochemically, the pre-radiation specimens showed no positive reaction for tumor necrosis factor-alpha (TNF-α), tumor necrosis factor-receptor (TNF-γ) or Fas. C-fos, p53 and bcl-2 showed positive reactions in only a few non-irradiated specimens. All of the irradiated specimens showed a positive reaction for TNF-α, and variable positive reactions were observed for TNF-γ, Fas, p53, c-fos and bcl-2. These results suggest that TNF-α, TNF-γ, and c-fos are responsible for radiation induced cell death in cervical SCC. (author)

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

    AIM: To investigate the roles of Bax and p53 proteins in photosensitivity of human colon cancer cells by using lysosome-localizing photosensitizer, ATX-S10Na (Ⅱ).METHODS: 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.RESULTS: 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-XL,were decreased in Bax- and p53-independent manner.CONCLUSION: Our results indicate that early apoptosis and cell death of human colon cancer cells induced by photodynamic therapy with lysosome-localizingphotosensitizer ATX-S10Na (Ⅱ) are mediated by p53-Bax network and Iow levels of Bcl-2 and Bcl-XL proteins.Our results might help in formulating new therapeutic approaches in photedynamic therapy.

  10. Cloning and analysis of a defender against apoptotic cell death (DAD1) homologue from tomato

    NARCIS (Netherlands)

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

    2001-01-01

    A cDNA clone homologous to the human defender against apoptotic cell death (DAD1) gene, which is believed to be a conserved inhibitor of programmed cell death, was isolated from tomato (Lycopersicon esculentum cv. Prisca). The 351 basepairs open reading frame predicted a 116 amino acid protein seque

  11. Triptolide induces lysosomal-mediated programmed cell death in MCF-7 breast cancer cells

    Directory of Open Access Journals (Sweden)

    Owa C

    2013-09-01

    Full Text Available Chie Owa, Michael E Messina Jr, Reginald HalabyDepartment of Biology, Montclair State University, Montclair, NJ, USABackground: Breast cancer is a major cause of death; in fact, it is the most common type, in order of the number of global deaths, of cancer in women worldwide. This research seeks to investigate how triptolide, an extract from the Chinese herb Tripterygium wilfordii Hook F, induces apoptosis in MCF-7 human breast cancer cells. Accumulating evidence suggests a role for lysosomal proteases in the activation of apoptosis. However, there is also some controversy regarding the direct participation of lysosomal proteases in activation of key apoptosis-related caspases and release of mitochondrial cytochrome c. In the present study, we demonstrate that triptolide induces an atypical, lysosomal-mediated apoptotic cell death in MCF-7 cells because they lack caspase-3.Methods: MCF-7 cell death was characterized via cellular morphology, chromatin condensation, 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide colorimetric cell growth inhibition assay and the expression levels of proapoptotic proteins. Acridine orange and LysoTracker® staining were performed to visualize lysosomes. Lysosomal enzymatic activity was monitored using an acid phosphatase assay and western blotting of cathepsin B protein levels in the cytosolic fraction, which showed increased enzymatic activity in drug-treated cells.Results: These experiments suggest that triptolide-treated MCF-7 cells undergo atypical apoptosis and that, during the early stages, lysosomal enzymes leak into the cytosol, indicating lysosomal membrane permeability.Conclusion: Our results suggest that further studies are warranted to investigate triptolide's potential as an anticancer therapeutic agent.Keywords: triptolide, MCF-7 breast cancer cells, apoptosis, lysosomes, lysosomal membrane permeabilization (LMP

  12. Akt inhibitor MK-2206 promotes anti-tumor activity and cell death by modulation of AIF and Ezrin in colorectal cancer

    International Nuclear Information System (INIS)

    There is extensive evidence for the role of aberrant cell survival signaling mechanisms in cancer progression and metastasis. Akt is a major component of cell survival-signaling mechanisms in several types of cancer. It has been shown that activated Akt stabilizes XIAP by S87 phosphorylation leading to survivin/XIAP complex formation, caspase inhibition and cytoprotection of cancer cells. We have reported that TGFβ/PKA/PP2A-mediated tumor suppressor signaling regulates Akt phosphorylation in association with the dissociation of survivin/XIAP complexes leading to inhibition of stress-dependent induction of cell survival. IGF1R-dependent colon cancer cells (GEO and CBS) were used for the study. Effects on cell proliferation and cell death were determined in the presence of MK-2206. Xenograft studies were performed to determine the effect of MK-2206 on tumor volume. The effect on various cell death markers such as XIAP, survivin, AIF, Ezrin, pEzrin was determined by western blot analysis. Graph pad 5.0 was used for statistical analysis. P < 0.05 was considered significant. We characterized the mechanisms by which a novel Akt kinase inhibitor MK-2206 induced cell death in IGF1R-dependent colorectal cancer (CRC) cells with upregulated PI3K/Akt signaling in response to IGF1R activation. MK-2206 treatment generated a significant reduction in tumor growth in vivo and promoted cell death through two mechanisms. This is the first report demonstrating that Akt inactivation by MK-2206 leads to induction of and mitochondria-to-nuclear localization of the Apoptosis Inducing Factor (AIF), which is involved in caspase-independent cell death. We also observed that exposure to MK-2206 dephosphorylated Ezrin at the T567 site leading to the disruption of Akt-pEzrin-XIAP cell survival signaling. Ezrin phosphorylation at this site has been associated with malignant progression in solid tumors. The identification of these 2 novel mechanisms leading to induction of cell death indicates

  13. Programmed cell death features in apple suspension cells under low oxygen culture

    Institute of Scientific and Technical Information of China (English)

    XU Chang-jie(徐昌杰); CHEN Kun-song(陈昆松); FERGUSON Ian B.

    2004-01-01

    Suspension-cultured apple fruit cells (Malus pumila Mill. cv. Braeburn) were exposed to a low oxygen atmosphere to test whether programmed cell death (PCD) has a role in cell dysfunction and death under hypoxic conditions. Protoplasts were prepared at various times after low oxygen conditions were established, and viability tested by triple staining with fluorescein diacetate (FDA), propidium iodide (PI) and Hoechst33342 (HO342). DNA breakdown and phosphatidylserine exposure on the plasma membrane were observed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and annexin V binding. About 30% of protoplasts from cells after 48 h under low oxygen showed an increased accumulation of HO342, indicating increased membrane permeability. Positive TUNEL and annexin V results were also only obtained with protoplasts from cells under low oxygen. The results suggest that apple cell death under low oxygen is at least partially PCD mediated, and may explain tissue breakdown under controlled atmosphere (low oxygen) conditions in apple fruit.

  14. Cell death effects of resin-based dental material compounds and mercurials in human gingival fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Reichl, Franz-Xaver [Walther-Straub-Institute of Pharmacology and Toxicology, Munich (Germany); Ludwig-Maximilians-University, Department of Operative Dentistry and Periodontology, Munich (Germany); Esters, Magali; Simon, Sabine; Seiss, Mario [Walther-Straub-Institute of Pharmacology and Toxicology, Munich (Germany); Kehe, Kai [Bundeswehr Institute of Pharmacology and Toxicology, Munich (Germany); Kleinsasser, Norbert [University of Regensburg, Head and Neck Surgery, Department of Otolaryngology, Regensburg (Germany); Folwaczny, Matthias; Glas, Juergen; Hickel, Reinhard [Ludwig-Maximilians-University, Department of Operative Dentistry and Periodontology, Munich (Germany)

    2006-06-15

    In order to test the hypothesis that released dental restorative materials can reach toxic levels in human oral tissues, the cytotoxicities of the resin-based dental (co)monomers hydroxyethylmethacrylate (HEMA), triethyleneglycoldimethacrylate (TEGDMA), urethanedimethacrylate (UDMA), and bisglycidylmethacrylate (BisGMA) compared with methyl mercury chloride (MeHgCl) and the amalgam component mercuric chloride (HgCl{sub 2}) were investigated on human gingival fibroblasts (HGF) using two different test systems: (1) the modified XTT-test and (2) the modified H 33342 staining assay. The HGF were exposed to various concentrations of the test-substances in all test systems for 24 h. All tested (co)monomers and mercury compounds significantly (P<0.05) decreased the formazan formation in the XTT-test. EC{sub 50} values in the XTT assay were obtained as half-maximum-effect concentrations from fitted curves. Following EC{sub 50} values were found (mean [mmol/l]; s.e.m. in parentheses; n=12; * significantly different to HEMA): HEMA 11.530 (0.600); TEGDMA* 3.460 (0.200); UDMA* 0.106 (0.005); BisGMA* 0.087 (0.001); HgCl{sub 2}* 0.013 (0.001); MeHgCl* 0.005 (0.001). Following relative toxicities were found: HEMA 1; TEGDMA 3; UDMA 109; BisGMA 133; HgCl{sub 2} 887; MeHgCl 2306. A significant (P<0.05) increase of the toxicity of (co)monomers and mercurials was found in the XTT-test in the following order: HEMA < TEGDMA < UDMA < BisGMA < HgCl{sub 2} < MeHgCl. TEGDMA and MeHgCl induced mainly apoptotic cell death. HEMA, UDMA, BisGMA, and HgCl{sub 2} induced mainly necrotic cell death. The results of this study indicate that resin composite components have a lower toxicity than mercury from amalgam in HGF. HEMA, BisGMA, UDMA, and HgCl{sub 2} induced mainly necrosis, but it is rather unlikely that eluted substances (solely) can reach concentrations, which might induce necrotic cell death in the human physiological situation, indicating that other (additional) factors may be involved in

  15. Mycobacterial secretion systems ESX-1 and ESX-5 play distinct roles in host cell death and inflammasome activation

    KAUST Repository

    Abdallah, Abdallah

    2011-09-28

    During infection of humans and animals, pathogenic mycobacteria manipulate the host cell causing severe diseases such as tuberculosis and leprosy. To understand the basis of mycobacterial pathogenicity, it is crucial to identify the molecular virulence mechanisms. In this study, we address the contribution of ESX-1 and ESX-5 - two homologous type VII secretion systems of mycobacteria that secrete distinct sets of immune modulators - during the macrophage infection cycle. Using wild-type, ESX-1- and ESX-5-deficient mycobacterial strains, we demonstrate that these secretion systems differentially affect subcellular localization and macrophage cell responses. We show that in contrast to ESX-1, the effector proteins secreted by ESX-5 are not required for the translocation of Mycobacterium tuberculosis or Mycobacterium marinum to the cytosol of host cells. However, the M. marinum ESX-5 mutant does not induce inflammasome activation and IL-1b activation. The ESX-5 system also induces a caspase-independent cell death after translocation has taken place. Importantly, by means of inhibitory agents and small interfering RNA experiments, we reveal that cathepsin B is involved in both the induction of cell death and inflammasome activation upon infection with wild-type mycobacteria. These results reveal distinct roles for two different type VII secretion systems during infection and shed light on how virulent mycobacteria manipulate the host cell in various ways to replicate and spread. Copyright © 2011 by The American Association of Immunologists, Inc.

  16. Mycobacterial secretion systems ESX-1 and ESX-5 play distinct roles in host cell death and inflammasome activation.

    Science.gov (United States)

    Abdallah, Abdallah M; Bestebroer, Jovanka; Savage, Nigel D L; de Punder, Karin; van Zon, Maaike; Wilson, Louis; Korbee, Cees J; van der Sar, Astrid M; Ottenhoff, Tom H M; van der Wel, Nicole N; Bitter, Wilbert; Peters, Peter J

    2011-11-01

    During infection of humans and animals, pathogenic mycobacteria manipulate the host cell causing severe diseases such as tuberculosis and leprosy. To understand the basis of mycobacterial pathogenicity, it is crucial to identify the molecular virulence mechanisms. In this study, we address the contribution of ESX-1 and ESX-5--two homologous type VII secretion systems of mycobacteria that secrete distinct sets of immune modulators--during the macrophage infection cycle. Using wild-type, ESX-1- and ESX-5-deficient mycobacterial strains, we demonstrate that these secretion systems differentially affect subcellular localization and macrophage cell responses. We show that in contrast to ESX-1, the effector proteins secreted by ESX-5 are not required for the translocation of Mycobacterium tuberculosis or Mycobacterium marinum to the cytosol of host cells. However, the M. marinum ESX-5 mutant does not induce inflammasome activation and IL-1β activation. The ESX-5 system also induces a caspase-independent cell death after translocation has taken place. Importantly, by means of inhibitory agents and small interfering RNA experiments, we reveal that cathepsin B is involved in both the induction of cell death and inflammasome activation upon infection with wild-type mycobacteria. These results reveal distinct roles for two different type VII secretion systems during infection and shed light on how virulent mycobacteria manipulate the host cell in various ways to replicate and spread. PMID:21957139

  17. Crotamine and crotoxin interact with tumor cells and trigger cell death

    International Nuclear Information System (INIS)

    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 125I 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 125I-Crtx and 125I-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)

  18. Sesamol protects human embryonic kidney cells from radiation induced cell death: a potential radioprotective agent

    International Nuclear Information System (INIS)

    Radioprotectors are agents which reduce the radiation effects on cell when applied prior to exposure of radiation. In our earlier studies, we have demonstrated that sesamol protected DNA (plasmid and calf thymus) and V79 cells from radiation induced cell death and the effect was higher (DMF=2) in comparison to melatonin (DMF=1.3). This prompted us to study, sesamol mediated radioprotection in detail to understand the mechanism of action. We have chosen human embryonic kidney (HEK) cells to understand the mechanism of radioprotection. The HEK cells were treated with sesamol before exposure of g rays (60Co teletherapy, Bhabhatron II) in the radiation dose range 0-7 Gy for clonogenic survival. Toxicity, antioxidant enzyme activity other biochemical assays were performed. Flow cytometric analysis (FACS Calibre, BD, USA) was used to determine the apoptotic population and mitochondrial membrane potential (Rh 123, JC-1). ROS was determined using DCFHDA. Cell cycle analysis, caspase 3 activity and cytochrome C were also measured. Results suggested that sesamol protected HEK cells from cell death. The dose modifying factor for sesamol was 1.3, whereas the alpha protection factor was 2. Sesamol inhibited radiation induced cell cycle arrest in G2/M phase; ROS generation and depolarization of mitochondrial membrane potential and caspase-3 activity. Sesamol inhibited damage of critical cellular components (protein, lipids, membrane and amino acid) and maintained the redox status of cells. The results will be helpful in understanding the mechanistic aspects and development of sesamol based radioprotector. (author)

  19. Activation of SK2 channels preserves ER Ca(2+) homeostasis and protects against ER stress-induced cell death.

    Science.gov (United States)

    Richter, M; Vidovic, N; Honrath, B; Mahavadi, P; Dodel, R; Dolga, A M; Culmsee, C

    2016-05-01

    Alteration of endoplasmic reticulum (ER) Ca(2+) homeostasis leads to excessive cytosolic Ca(2+) accumulation and delayed neuronal cell death in acute and chronic neurodegenerative disorders. While our recent studies established a protective role for SK channels against excessive intracellular Ca(2+) accumulation, their functional role in the ER has not been elucidated yet. We show here that SK2 channels are present in ER membranes of neuronal HT-22 cells, and that positive pharmacological modulation of SK2 channels with CyPPA protects against cell death induced by the ER stressors brefeldin A and tunicamycin. Calcium imaging of HT-22 neurons revealed that elevated cytosolic Ca(2+) levels and decreased ER Ca(2+) load during sustained ER stress could be largely prevented by SK2 channel activation. Interestingly, SK2 channel activation reduced the amount of the unfolded protein response transcription factor ATF4, but further enhanced the induction of CHOP. Using siRNA approaches we confirmed a detrimental role for ATF4 in ER stress, whereas CHOP regulation was dispensable for both, brefeldin A toxicity and CyPPA-mediated protection. Cell death induced by blocking Ca(2+) influx into the ER with the SERCA inhibitor thapsigargin was not prevented by CyPPA. Blocking the K(+) efflux via K(+)/H(+) exchangers with quinine inhibited CyPPA-mediated neuroprotection, suggesting an essential role of proton uptake and K(+) release in the SK channel-mediated neuroprotection. Our data demonstrate that ER SK2 channel activation preserves ER Ca(2+) uptake and retention which determines cell survival in conditions where sustained ER stress contributes to progressive neuronal death. PMID:26586570

  20. Breast cancer cells with acquired antiestrogen resistance are sensitized to cisplatin-induced cell death

    DEFF Research Database (Denmark)

    Yde, Christina Westmose; Gyrd-Hansen, Mads; Lykkesfeldt, Anne E; Issinger, Olaf-Georg; Stenvang, Jan

    2007-01-01

    future breast cancer treatment. In this study, we have investigated the effect of the chemotherapeutic compound cisplatin using a panel of antiestrogen-resistant breast cancer cell lines established from the human breast cancer cell line MCF-7. We show that the antiestrogen-resistant cells are...... parental MCF-7 cells. Our data show that Bcl-2 can protect antiestrogen-resistant breast cancer cells from cisplatin-induced cell death, indicating that the reduced expression of Bcl-2 in the antiestrogen-resistant cells plays a role in sensitizing the cells to cisplatin treatment.......Antiestrogens are currently used for treating breast cancer patients who have estrogen receptor-positive tumors. However, patients with advanced disease will eventually develop resistance to the drugs. Therefore, compounds effective on antiestrogen-resistant tumors will be of great importance for...

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

    OpenAIRE

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

    2009-01-01

    It has long been observed that cancer cells rely more on glycolysis to generate ATP and actively use certain glycolytic metabolic intermediates for biosynthesis. Hexokinase II (HKII) is a key glycolytic enzyme that plays a role in the regulation of the mitochondria-initiated apoptotic cell death. As a potent inhibitor of hexokinase, 3-bromopyruvate (3-BrPA) is known to inhibit cancer cell energy metabolism and trigger cell death, supposedly through depletion of cellular ATP. The current study...

  2. Spontaneous and radiation induced cell death in HeLa S3 human carcinoma

    International Nuclear Information System (INIS)

    Radiation biologists have classified radiation-induced cell death based on cell proliferative capacity to either mitotic or interphase death. Cytologists have revealed two morphologically and biochemically diverse forms of cell death, apoptosis and necrosis. While the knowledge of the former is already well exploited by radiologists, cell susceptibility to apoptosis and necrosis is still under investigation. We studied characteristics of spontaneous cell death, and dose dependence and time course of radiation-induced cell death of human uterine cervix epitheloid carcinoma HeLaS3 in culture. Cells were irradiated with 2-40 Gy of γ-rays. The effect on growth, viability, morphology and genomic DNA structure were followed 24-72 h after irradiation. Cell viability was evaluated by trypan-blue exclusion assay and cell morphology by in situ DNA staining with propidium iodide. Cell genomic DNA fragmentation pattern was determined by electrophoresis on 2% agarose gels. At all cell densities 25-35% cells were PI positive and their DNA was fragmented to a high molecular size (≥20 kbp), but the internucleosomal ladder was not observed. A significant decrease in viability to 33% was observed 72 h post 40 Gy irradiation. It corresponded to 55% of PI positive cells. A smear of smaller DNA fragments (0.1-1 kbp), 24 h after 10-20 Gy irradiation was considered as proof that the dominant form of radiation-induced cell death was necrosis. It was concluded that the dominant form of radiation-induced cell death in HeLaS3 population was necrosis and the radiation dose which caused 50% of cell death after 72 h (termed ND50) was between 30-40 Gy. (author)

  3. The mechanism of radiation-induced interphase death of lymphoid cells: A new hypothesis

    International Nuclear Information System (INIS)

    The interphase death of irradiated rat thymocytes depends on their concentration during postirradiation incubation. The kinetics of pycnosis and cell death determined with the trypan blue exclusion test in the samples with the highest cell concentration (1-2 x 10(7) cells/ml) is consistent with the data available in the literature, whereas the samples with the lowest concentration (2 x 10(5) cells/ml) undergo almost no pycnosis and death after irradiation with doses up to 50 Gy. On the basis of these results, we suggest a new mechanism of interphase death involving an interaction between irradiated thymocytes and the fraction of thymus cells possessing cytocidal activity. The observed correlation between the cytocidal activity and interphase death of thymocytes from animals of different ages favors our mechanism. It was found that the inhibitors which prevent the conjugation of killer cells and their targets do not influence interphase death, while the substances which block the secretion of cytotoxic factors or their action on the target membrane do protect from interphase death. Thus we suggest that the irradiation activates the killer cells to secrete some cytotoxic factors which induce pycnosis and interphase death of thymocytes

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

    International Nuclear Information System (INIS)

    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

  5. ShaPINg cell fate upon DNA damage:role of Pin1 isomerase in DNA damage-induced cell death and repair

    Directory of Open Access Journals (Sweden)

    Thomas G Hofmann

    2014-06-01

    Full Text Available The peptidyl-prolyl cis/trans isomerase Pin1 acts as a molecular timer in proline-directed Ser/Thr kinase signaling and shapes cellular responses based on recognition of phosphorylation marks and implementing conformational changes in its substrates. Accordingly, Pin1 has been linked to numerous phosphorylation-controlled signaling pathways and cellular processes such as cell cycle progression, proliferation and differentiation. In addition, Pin1 plays a pivotal role in DNA damage-triggered cell fate decisions. Whereas moderate DNA damage is balanced by DNA repair, cells confronted with massive genotoxic stress are eliminated by the induction of programmed cell death or cellular senescence. In this review we summarize and discuss the current knowledge on how Pin1 specifies cell fate through regulating key players of the apoptotic and the repair branch of the DNA damage response.

  6. Vacuolar processing enzyme is essential for mycotoxin-induced cell death in Arabidopsis thaliana.

    Science.gov (United States)

    Kuroyanagi, Miwa; Yamada, Kenji; Hatsugai, Noriyuki; Kondo, Maki; Nishimura, Mikio; Hara-Nishimura, Ikuko

    2005-09-23

    Some compatible pathogens secrete toxins to induce host cell death and promote their growth. The toxin-induced cell death is a pathogen strategy for infection. To clarify the executioner of the toxin-induced cell death, we examined a fungal toxin (fumonisin B1 (FB1))-induced cell death of Arabidopsis plants. FB1-induced cell death was accompanied with disruption of vacuolar membrane followed by lesion formation. The features of FB1-induced cell death were completely abolished in the Arabidopsis vacuolar processing enzyme (VPE)-null mutant, which lacks all four VPE genes of the genome. Interestingly, an inhibitor of caspase-1 abolished FB1-induced lesion formation, as did a VPE inhibitor. The VPE-null mutant had no detectable activities of caspase-1 or VPE in the FB1-treated leaves, although wild-type leaves had the caspase-1 and VPE activities, both of which were inhibited by a caspase-1 inhibitor. gammaVPE is the most essential among the four VPE homologues for FB1-induced cell death in Arabidopsis leaves. Recombinant gammaVPE recognized a VPE substrate with Km = 30.3 microm and a caspase-1 substrate with Km = 44.2 microm, which is comparable with the values for mammalian caspase-1. The gammaVPE precursor was self-catalytically converted into the mature form exhibiting caspase-1 activity. These in vivo and in vitro analyses demonstrate that gammaVPE is the proteinase that exhibits a caspase-1 activity. We show that VPE exhibiting a caspase-1 activity is a key molecule in toxin-induced cell death. Our findings suggest that a susceptible response of toxin-induced cell death is caused by the VPE-mediated vacuolar mechanism similar to a resistance response of hypersensitive cell death (Hatsugai, N., Kuroyanagi, M., Yamada, K., Meshi, T., Tsuda, S., Kondo, M., Nishimura, M., and Hara-Nishimura, I. (2004) Science 305, 855-858). PMID:16043487

  7. Cell death induced by the application of alternating magnetic fields to nanoparticle-loaded dendritic cells

    Science.gov (United States)

    Marcos-Campos, I.; Asín, L.; Torres, T. E.; Marquina, C.; Tres, A.; Ibarra, M. R.; Goya, G. F.

    2011-05-01

    In this work, the capability of primary, monocyte-derived dendritic cells (DCs) to uptake iron oxide magnetic nanoparticles (MNPs) is assessed and a strategy to induce selective cell death in these MNP-loaded DCs using external alternating magnetic fields (AMFs) is reported. No significant decrease in the cell viability of MNP-loaded DCs, compared to the control samples, was observed after five days of culture. The number of MNPs incorporated into the cytoplasm was measured by magnetometry, which confirmed that 1-5 pg of the particles were uploaded per cell. The intracellular distribution of these MNPs, assessed by transmission electron microscopy, was found to be primarily inside the endosomic structures. These cells were then subjected to an AMF for 30 min and the viability of the blank DCs (i.e. without MNPs), which were used as control samples, remained essentially unaffected. However, a remarkable decrease of viability from approximately 90% to 2-5% of DCs previously loaded with MNPs was observed after the same 30 min exposure to an AMF. The same results were obtained using MNPs having either positive (NH2 + ) or negative (COOH - ) surface functional groups. In spite of the massive cell death induced by application of AMF to MNP-loaded DCs, the number of incorporated magnetic particles did not raise the temperature of the cell culture. Clear morphological changes at the cell structure after magnetic field application were observed using scanning electron microscopy. Therefore, local damage produced by the MNPs could be the main mechanism for the selective cell death of MNP-loaded DCs under an AMF. Based on the ability of these cells to evade the reticuloendothelial system, these complexes combined with an AMF should be considered as a potentially powerful tool for tumour therapy.

  8. Cell death induced by the application of alternating magnetic fields to nanoparticle-loaded dendritic cells

    International Nuclear Information System (INIS)

    In this work, the capability of primary, monocyte-derived dendritic cells (DCs) to uptake iron oxide magnetic nanoparticles (MNPs) is assessed and a strategy to induce selective cell death in these MNP-loaded DCs using external alternating magnetic fields (AMFs) is reported. No significant decrease in the cell viability of MNP-loaded DCs, compared to the control samples, was observed after five days of culture. The number of MNPs incorporated into the cytoplasm was measured by magnetometry, which confirmed that 1-5 pg of the particles were uploaded per cell. The intracellular distribution of these MNPs, assessed by transmission electron microscopy, was found to be primarily inside the endosomic structures. These cells were then subjected to an AMF for 30 min and the viability of the blank DCs (i.e. without MNPs), which were used as control samples, remained essentially unaffected. However, a remarkable decrease of viability from approximately 90% to 2-5% of DCs previously loaded with MNPs was observed after the same 30 min exposure to an AMF. The same results were obtained using MNPs having either positive (NH2+) or negative (COOH-) surface functional groups. In spite of the massive cell death induced by application of AMF to MNP-loaded DCs, the number of incorporated magnetic particles did not raise the temperature of the cell culture. Clear morphological changes at the cell structure after magnetic field application were observed using scanning electron microscopy. Therefore, local damage produced by the MNPs could be the main mechanism for the selective cell death of MNP-loaded DCs under an AMF. Based on the ability of these cells to evade the reticuloendothelial system, these complexes combined with an AMF should be considered as a potentially powerful tool for tumour therapy.

  9. Cell death induced by the application of alternating magnetic fields to nanoparticle-loaded dendritic cells

    Energy Technology Data Exchange (ETDEWEB)

    Marcos-Campos, I; AsIn, L; Torres, T E; Tres, A; Ibarra, M R; Goya, G F [Instituto de Nanociencia de Aragon (INA), Mariano Esquillor s/n, CP 50018, Zaragoza (Spain); Marquina, C, E-mail: goya@unizar.es [Condensed Matter Department, Sciences Faculty, University of Zaragoza, 50009 (Spain)

    2011-05-20

    In this work, the capability of primary, monocyte-derived dendritic cells (DCs) to uptake iron oxide magnetic nanoparticles (MNPs) is assessed and a strategy to induce selective cell death in these MNP-loaded DCs using external alternating magnetic fields (AMFs) is reported. No significant decrease in the cell viability of MNP-loaded DCs, compared to the control samples, was observed after five days of culture. The number of MNPs incorporated into the cytoplasm was measured by magnetometry, which confirmed that 1-5 pg of the particles were uploaded per cell. The intracellular distribution of these MNPs, assessed by transmission electron microscopy, was found to be primarily inside the endosomic structures. These cells were then subjected to an AMF for 30 min and the viability of the blank DCs (i.e. without MNPs), which were used as control samples, remained essentially unaffected. However, a remarkable decrease of viability from approximately 90% to 2-5% of DCs previously loaded with MNPs was observed after the same 30 min exposure to an AMF. The same results were obtained using MNPs having either positive (NH{sub 2}{sup +}) or negative (COOH{sup -}) surface functional groups. In spite of the massive cell death induced by application of AMF to MNP-loaded DCs, the number of incorporated magnetic particles did not raise the temperature of the cell culture. Clear morphological changes at the cell structure after magnetic field application were observed using scanning electron microscopy. Therefore, local damage produced by the MNPs could be the main mechanism for the selective cell death of MNP-loaded DCs under an AMF. Based on the ability of these cells to evade the reticuloendothelial system, these complexes combined with an AMF should be considered as a potentially powerful tool for tumour therapy.

  10. Ezrin dephosphorylation/downregulation contributes to ursolic acid-mediated cell death in human leukemia cells

    International Nuclear Information System (INIS)

    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

  11. Programmed cell death features in apple suspension cells under low oxygen culture

    Institute of Scientific and Technical Information of China (English)

    徐昌杰; 陈昆松; FERGUSONIanB

    2004-01-01

    Suspension-cultured apple fruit cells (Malus pumila Mill. cv. Braeburn) were exposed to a low oxygen atmosphere to test whether programmed cell death (PCD) has a role in cell dysfunction and death under hypoxic conditions. Protoplasts were prepared at various times after low oxygen conditions were established, and viability tested by triple staining with fluorescein diacetate (FDA), propidium iodide (PI) and Hoechst33342 (HO342). DNA breakdown and phosphatidylserine exposure on the plasma membrane were observed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and annexin V binding. About 30% of protoplasts from cells after 48 h under low oxygen showed an increased accumulation of HO342, indicating increased membrane permeability. Positive TUNEL and annexin V results were also only obtained with protoplasts from cells under low oxygen. The results suggest that apple celi death under low oxygen is at least partially PCD mediated, and may explain tissue breakdown under controlled atmosphere (low oxygen) conditions in apple fruit.

  12. Dig1 protects against cell death provoked by glyphosate-based herbicides in human liver cell lines

    Directory of Open Access Journals (Sweden)

    Travert Carine

    2010-10-01

    Full Text Available Abstract Background Worldwide used pesticides containing different adjuvants like Roundup formulations, which are glyphosate-based herbicides, can provoke some in vivo toxicity and in human cells. These pesticides are commonly found in the environment, surface waters and as food residues of Roundup tolerant genetically modified plants. In order to know their effects on cells from liver, a major detoxification organ, we have studied their mechanism of action and possible protection by precise medicinal plant extracts called Dig1. Methods The cytotoxicity pathways of four formulations of glyphosate-based herbicides were studied using human hepatic cell lines HepG2 and Hep3B, known models to study xenobiotic effects. We monitored mitochondrial succinate dehydrogenase activity and caspases 3/7 for cell mortality and protection by Dig1, as well as cytochromes P450 1A1, 1A2, 3A4 and 2C9 and glutathione-S-transferase to approach the mechanism of actions. Results All the four Roundup formulations provoke liver cell death, with adjuvants having stronger effects than glyphosate alone. Hep3B are 3-5 times more sensitive over 48 h. Caspases 3/7 are greatly activated in HepG2 by Roundup at non-cytotoxic levels, and some apoptosis induction by Roundup is possible together with necrosis. CYP3A4 is specifically enhanced by Roundup at doses 400 times less than used in agriculture (2%. CYP1A2 is increased to a lesser extent together with glutathione-S-transferase (GST down-regulation. Dig 1, non cytotoxic and not inducing caspases by itself, is able to prevent Roundup-induced cell death in a time-dependant manner with an important efficiency of up to 89%, within 48 h. In addition, we evidenced that it prevents Caspases 3/7 activation and CYP3A4 enhancement, and not GST reduction, but in turn it slightly inhibited CYP2C9 when added before Roundup. Conclusion Roundup is able to provoke intracellular disruption in hepatic cell lines at different levels, but a

  13. Ochratoxin A: induction of (oxidative) DNA damage, cytotoxicity and apoptosis in mammalian cell lines and primary cells

    International Nuclear Information System (INIS)

    Ochratoxin A (OTA) is a nephrotoxic/-carcinogenic mycotoxin, produced by several Aspergillus- and Penicillium-strains. Humans are exposed to OTA via food contamination, a causal relationship of OTA to human endemic Balkan nephropathy is still under debate. Since DNA-adducts of OTA or its metabolites could not be identified unambiguously, its carcinogenic effectiveness might be related to secondary effects, such as oxidative cell damage or cell proliferation. In this study, OTA mediated induction of (oxidative) DNA damage, cytotoxicity (necrosis, growth inhibition, apoptosis) and modulation of glutathione were investigated in cell lines (V79, CV-1) and primary rat kidney cells. After 24 h incubation, viability of V79 cells was strongly decreased by OTA concentrations >2.5 μmol/L, whereas CV-1 cells were clearly less sensitive. Strong growth inhibition occurred in both cell lines (IC50 ∼2 μmol/L). Apoptosis, detected with an immunochemical test and with flow cytometry, was induced by >1 μmol/L OTA. Oxidative DNA damage, detected by comet assay after additional treatment with repair enzymes, was induced in all cell systems already at five-fold lower concentrations. Glutathione in CV-1 cells was depleted after 1 h incubation (>100 μmol/L). In contrast, an increase was measured after 24 h incubation (>0.5 μmol/L). In conclusion, OTA induces oxidative DNA damage at low, not yet cytotoxic concentrations. Oxidative DNA damage might initiate cell transformation eventually in connection with proliferative response following cytotoxic cell death. Both events might represent pivotal factors in the chain of cellular events leading into nephro-carcinogenicity of OTA

  14. Induction of premature senescence by single and fractionated irradiation in human cancer cell line and xenografted mice model

    International Nuclear Information System (INIS)

    Radiation therapy (RT) is one of the best therapeutic strategies for cancer treatment. The cellular responses to ionizing radiation (IR) are varied ranging from cellular senescence to apoptotic cell death. To increase the efficacy of IR treatment is a major issue of radiation biology. From the point of view, the induction of premature senescence using the therapeutic dose of IR could be a promising treatment for tumors. The aim of this study is whether the premature senescence could contribute to cancer treatment by irradiation

  15. Autophagic Cell Death and Apoptosis Jointly Mediate Cisatracurium Besylate-Induced Cell Injury

    Directory of Open Access Journals (Sweden)

    Haixia Zhuang

    2016-04-01

    Full Text Available Cisatracurium besylate is an ideal non-depolarizing muscle relaxant which is widely used in clinical application. However, some studies have suggested that cisatracurium besylate can affect cell proliferation. Moreover, its specific mechanism of action remains unclear. Here, we found that the number of GFP-LC3 (green fluoresent protein-light chain 3 positive autophagosomes and the rate of mitochondria fracture both increased significantly in drug-treated GFP-LC3 and MitoDsRed stable HeLa cells. Moreover, cisatracurium promoted the co-localization of LC3 and mitochondria and induced formation of autolysosomes. Levels of mitochondrial proteins decreased, which were reversed by the lysosome inhibitor Bafinomycin A1. Similar results with evidence of dose-dependent effects were found in both HeLa and Human Umbilical Vein Endothelial Cells (HUVECs. Cisatracurium lowered HUVEC viability to 0.16 (OD490 at 100 µM and to 0.05 (OD490 after 48 h in vitro; it increased the cell death rate to 56% at 100 µM and to 60% after 24 h in a concentration- and time-dependent manner (p < 0.01. Cell proliferation decreased significantly by four fold in Atg5 WT (wildtype MEF (mouse embryonic fibroblast (p < 0.01 but was unaffected in Atg5 KO (Knockout MEF, even upon treatment with a high dose of cisatracurium. Cisatracurium induced significant increase in cell death of wild-type MEFs even in the presence of the apoptosis inhibitor zVAD. Thus, we conclude that activation of both the autophagic cell death and cell apoptosis pathways contributes to cisatracurium-mediated cell injury.

  16. Histone deacetylase inhibitor upregulates peroxisomal fatty acid oxidation and inhibits apoptotic cell death in abcd1-deficient glial cells.

    Directory of Open Access Journals (Sweden)

    Jaspreet Singh

    Full Text Available In X-ALD, mutation/deletion of ALD gene (ABCD1 and the resultant very long chain fatty acid (VLCFA derangement has dramatically opposing effects in astrocytes and oligodendrocytes. While loss of Abcd1 in astrocytes produces a robust inflammatory response, the oligodendrocytes undergo cell death leading to demyelination in X-linked adrenoleukodystrophy (X-ALD. The mechanisms of these distinct pathways in the two cell types are not well understood. Here, we investigated the effects of Abcd1-knockdown and the subsequent alteration in VLCFA metabolism in human U87 astrocytes and rat B12 oligodendrocytes. Loss of Abcd1 inhibited peroxisomal β-oxidation activity and increased expression of VLCFA synthesizing enzymes, elongase of very long chain fatty acids (ELOVLs (1 and 3 in both cell types. However, higher induction of ELOVL's in Abcd1-deficient B12 oligodendrocytes than astrocytes suggests that ELOVL pathway may play a prominent role in oligodendrocytes in X-ALD. While astrocytes are able to maintain the cellular homeostasis of anti-apoptotic proteins, Abcd1-deletion in B12 oligodendrocytes downregulated the anti-apototic (Bcl-2 and Bcl-xL and cell survival (phospho-Erk1/2 proteins, and upregulated the pro-apoptotic proteins (Bad, Bim, Bax and Bid leading to cell loss. These observations provide insights into different cellular signaling mechanisms in response to Abcd1-deletion in two different cell types of CNS. The apoptotic responses were accompanied by activation of caspase-3 and caspase-9 suggesting the involvement of mitochondrial-caspase-9-dependent mechanism in Abcd1-deficient oligodendrocytes. Treatment with histone deacetylase (HDAC inhibitor suberoylanilide hydroxamic acid (SAHA corrected the VLCFA derangement both in vitro and in vivo, and inhibited the oligodendrocytes loss. These observations provide a proof-of principle that HDAC inhibitor SAHA may have a therapeutic potential for X-ALD.

  17. Developmental cell death programs license cytotoxic cells to eliminate histocompatible partners.

    Science.gov (United States)

    Corey, Daniel M; Rosental, Benyamin; Kowarsky, Mark; Sinha, Rahul; Ishizuka, Katherine J; Palmeri, Karla J; Quake, Stephen R; Voskoboynik, Ayelet; Weissman, Irving L

    2016-06-01

    In a primitive chordate model of natural chimerism, one chimeric partner is often eliminated in a process of allogeneic resorption. Here, we identify the cellular framework underlying loss of tolerance to one partner within a natural Botryllus schlosseri chimera. We show that the principal cell type mediating chimeric partner elimination is a cytotoxic morula cell (MC). Proinflammatory, developmental cell death programs render MCs cytotoxic and, in collaboration with activated phagocytes, eliminate chimeric partners during the "takeover" phase of blastogenic development. Among these genes, the proinflammatory cytokine IL-17 enhances cytotoxicity in allorecognition assays. Cellular transfer of FACS-purified MCs from allogeneic donors into recipients shows that the resorption response can be adoptively acquired. Transfer of 1 × 10(5) allogeneic MCs eliminated 33 of 78 (42%) recipient primary buds and 20 of 76 (20.5%) adult parental adult organisms (zooids) by 14 d whereas transfer of allogeneic cell populations lacking MCs had only minimal effects on recipient colonies. Furthermore, reactivity of transferred cells coincided with the onset of developmental-regulated cell death programs and disproportionately affected developing tissues within a chimera. Among chimeric partner "losers," severe developmental defects were observed in asexually propagating tissues, reflecting a pathologic switch in gene expression in developmental programs. These studies provide evidence that elimination of one partner in a chimera is an immune cell-based rejection that operates within histocompatible pairs and that maximal allogeneic responses involve the coordination of both phagocytic programs and the "arming" of cytotoxic cells. PMID:27217570

  18. Killing of Cancer Cells by the Photoactivatable Protein Kinase C Inhibitor, Calphostin C, Involves Induction of Endoplasmic Reticulum Stress

    Directory of Open Access Journals (Sweden)

    Aparna Kaul

    2009-09-01

    Full Text Available Calphostin C (cal-C is a photoactivatable inhibitor that binds to the regulatory domain of protein kinase C (PKC and to other proteins that contain diacylglycerol/phorbol ester binding sites. Cal-C is cytotoxic against many types of cancer cells, yet the basis for this activity remains poorly understood. Here, we show that one of the earliest effects of cal-C is an impairment of glycoprotein export from the endoplasmic reticulum (ER, accompanied by formation of ER-derived vacuoles. Vacuolization of the ER is correlated with induction of an ER stress response that includes activation of c-Jun N-terminal kinase and protein kinase R-like ER kinase, as well as increased expression of CCAAT/enhancer binding protein homologous transcription factor (CHOP; GADD153. These effects of cal-C are not mimicked by staurosporine, an inhibitor of PKC catalytic activity, indicating that ER stress is due to interaction of cal-C with targets other than PKC. In conjunction with the induction of ER stress, breast carcinoma cells undergo caspase-dependent cell death with early activation of caspases 9 and 7 and cleavage of poly(ADP-ribosepolymerase. Reduction of CHOP expression by short hairpin RNA decreases the sensitivity of the cells to cal-C, suggesting that induction of apoptosis by cal-C is related, at least in part, to ER stress triggered by disruption of ER morphology and transport function. Antineoplastic drugs that work by inducting ER stress have shown promise in preclinical and clinical trials. Thus, the present findings raise the possibility that cal-C may be useful for photodynamic therapy based on induction of ER stress in some forms of cancer.

  19. Inhibition of thymus cell proliferation: possibilities of elociting natural cell death with the organ and its contribution to the induced interphase death

    International Nuclear Information System (INIS)

    Parallelism was noted between the suppression of proliferation and the amount of cells dying in mouse thymus after the effects inducing cell destruction. However, inhibition of DNA synthesis under the effect of nontoxic doses of arabinoside cytosine increased insignificantly the number of dying cells