Sample records for survival cell death
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Nerve Growth Factor in Cancer Cell Death and Survival
International Nuclear Information System (INIS)
Molloy, Niamh H.; Read, Danielle E.; Gorman, Adrienne M.
2011-01-01
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 p75 NTR , a member of the death receptor superfamily. Depending on the tumor origin, pro-survival signaling can be mediated by TrkA receptors or by p75 NTR . For example, in breast cancer the aberrant expression of nerve growth factor stimulates proliferative signaling through TrkA and pro-survival signaling through p75 NTR . This latter signaling through p75 NTR promotes increased resistance to the induction of cell death by chemotherapeutic treatments. In contrast, in prostate cells the p75 NTR 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
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Nerve Growth Factor in Cancer Cell Death and Survival
Energy Technology Data Exchange (ETDEWEB)
Molloy, Niamh H.; Read, Danielle E.; Gorman, Adrienne M., E-mail: adrienne.gorman@nuigalway.ie [Apoptosis Research Centre, School of Natural Sciences, National University of Ireland, Galway (Ireland)
2011-02-01
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 p75{sup NTR}, a member of the death receptor superfamily. Depending on the tumor origin, pro-survival signaling can be mediated by TrkA receptors or by p75{sup NTR}. For example, in breast cancer the aberrant expression of nerve growth factor stimulates proliferative signaling through TrkA and pro-survival signaling through p75{sup NTR}. This latter signaling through p75{sup NTR} promotes increased resistance to the induction of cell death by chemotherapeutic treatments. In contrast, in prostate cells the p75{sup NTR} 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.
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Stem cell death and survival in heart regeneration and repair.
Abdelwahid, Eltyeb; Kalvelyte, Audrone; Stulpinas, Aurimas; de Carvalho, Katherine Athayde Teixeira; Guarita-Souza, Luiz Cesar; Foldes, Gabor
2016-03-01
Cardiovascular diseases are major causes of mortality and morbidity. Cardiomyocyte apoptosis disrupts cardiac function and leads to cardiac decompensation and terminal heart failure. Delineating the regulatory signaling pathways that orchestrate cell survival in the heart has significant therapeutic implications. Cardiac tissue has limited capacity to regenerate and repair. Stem cell therapy is a successful approach for repairing and regenerating ischemic cardiac tissue; however, transplanted cells display very high death percentage, a problem that affects success of tissue regeneration. Stem cells display multipotency or pluripotency and undergo self-renewal, however these events are negatively influenced by upregulation of cell death machinery that induces the significant decrease in survival and differentiation signals upon cardiovascular injury. While efforts to identify cell types and molecular pathways that promote cardiac tissue regeneration have been productive, studies that focus on blocking the extensive cell death after transplantation are limited. The control of cell death includes multiple networks rather than one crucial pathway, which underlies the challenge of identifying the interaction between various cellular and biochemical components. This review is aimed at exploiting the molecular mechanisms by which stem cells resist death signals to develop into mature and healthy cardiac cells. Specifically, we focus on a number of factors that control death and survival of stem cells upon transplantation and ultimately affect cardiac regeneration. We also discuss potential survival enhancing strategies and how they could be meaningful in the design of targeted therapies that improve cardiac function.
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Ras and Rheb Signaling in Survival and Cell Death
International Nuclear Information System (INIS)
Ehrkamp, Anja; Herrmann, Christian; Stoll, Raphael; Heumann, Rolf
2013-01-01
One of the most obvious hallmarks of cancer is uncontrolled proliferation of cells partly due to independence of growth factor supply. A major component of mitogenic signaling is Ras, a small GTPase. It was the first identified human protooncogene and is known since more than three decades to promote cellular proliferation and growth. Ras was shown to support growth factor-independent survival during development and to protect from chemical or mechanical lesion-induced neuronal degeneration in postmitotic neurons. In contrast, for specific patho-physiological cases and cellular systems it has been shown that Ras may also promote cell death. Proteins from the Ras association family (Rassf, especially Rassf1 and Rassf5) are tumor suppressors that are activated by Ras-GTP, triggering apoptosis via e.g., activation of mammalian sterile 20-like (MST1) kinase. In contrast to Ras, their expression is suppressed in many types of tumours, which makes Rassf proteins an exciting model for understanding the divergent effects of Ras activity. It seems likely that the outcome of Ras signaling depends on the balance between the activation of its various downstream effectors, thus determining cellular fate towards either proliferation or apoptosis. Ras homologue enriched in brain (Rheb) is a protein from the Ras superfamily that is also known to promote proliferation, growth, and regeneration through the mammalian target of rapamycin (mTor) pathway. However, recent evidences indicate that the Rheb-mTor pathway may switch its function from a pro-growth into a cell death pathway, depending on the cellular situation. In contrast to Ras signaling, for Rheb, the cellular context is likely to modulate the whole Rheb-mTor pathway towards cellular death or survival, respectively
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Ras and Rheb Signaling in Survival and Cell Death
Energy Technology Data Exchange (ETDEWEB)
Ehrkamp, Anja [Molecular Neurobiochemistry, Ruhr University of Bochum, 44780 Bochum (Germany); Herrmann, Christian [Department of Physical Chemistry1, Protein Interaction, Ruhr University of Bochum, 44780 Bochum (Germany); Stoll, Raphael [Biomolecular NMR, Ruhr University of Bochum, 44780 Bochum (Germany); Heumann, Rolf, E-mail: rolf.heumann@rub.de [Molecular Neurobiochemistry, Ruhr University of Bochum, 44780 Bochum (Germany)
2013-05-28
One of the most obvious hallmarks of cancer is uncontrolled proliferation of cells partly due to independence of growth factor supply. A major component of mitogenic signaling is Ras, a small GTPase. It was the first identified human protooncogene and is known since more than three decades to promote cellular proliferation and growth. Ras was shown to support growth factor-independent survival during development and to protect from chemical or mechanical lesion-induced neuronal degeneration in postmitotic neurons. In contrast, for specific patho-physiological cases and cellular systems it has been shown that Ras may also promote cell death. Proteins from the Ras association family (Rassf, especially Rassf1 and Rassf5) are tumor suppressors that are activated by Ras-GTP, triggering apoptosis via e.g., activation of mammalian sterile 20-like (MST1) kinase. In contrast to Ras, their expression is suppressed in many types of tumours, which makes Rassf proteins an exciting model for understanding the divergent effects of Ras activity. It seems likely that the outcome of Ras signaling depends on the balance between the activation of its various downstream effectors, thus determining cellular fate towards either proliferation or apoptosis. Ras homologue enriched in brain (Rheb) is a protein from the Ras superfamily that is also known to promote proliferation, growth, and regeneration through the mammalian target of rapamycin (mTor) pathway. However, recent evidences indicate that the Rheb-mTor pathway may switch its function from a pro-growth into a cell death pathway, depending on the cellular situation. In contrast to Ras signaling, for Rheb, the cellular context is likely to modulate the whole Rheb-mTor pathway towards cellular death or survival, respectively.
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Delayed reproductive death as a dominant phenotype in cell clones surviving X-irradiation
International Nuclear Information System (INIS)
Chang, W.P.; Little, J.B.
1992-01-01
Residual damage manifested as reduced cloning efficiency was observed in many of the cloned progeny of Chinese hamster ovary (CHO) cells and human carcinoma SQ-20B cells surviving X-irradiation. This stable phenotype, which we have termed delayed reproductive death, persisted for >50 generations of cell replication post-irradiation. Clones showing this phenotype were aneuploid, and formed colonies with a high proportion of giant cells. By somatic cell hybridization of CHO clones, the delayed reproductive death phenotype was found to be a dominant trait; the cloning efficiency of hybrid clones was persistently depressed, as compared with that of control hybrid cells. These results suggest that delayed reproductive death represents a specific cellular response that may persist in some of the progeny of mammalian cells for long periods after X-irradiation. (author)
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International Nuclear Information System (INIS)
Kilemade, Michael; Mothersill, Carmel
2003-01-01
Interest in and concern for the quality of the environment has prompted a great deal of research into methods of measuring and assessing changes in it. One problem of major interest is that of increasing amounts of mutagenic/carcinogenic chemicals generated and released into marine and freshwater ecosystems. Numerous techniques involving whole animals and cell culture for these genotoxic changes have been devised to assay specific chemicals. Little has been done to determine the effects of potential genotoxicants on aquatic organisms. The purpose of this study was to investigate if 2,4-Dichloroaniline (2,4-DCA) (CASRN: 554-00-7), induced delayed cell death (DCD) or delayed reproductive cell death a.k.a. as lethal mutations in a teleost cell line, CHSE-214. Delayed expression of cell death in the progeny of cells, which survived a toxic insult, was first shown for ionizing radiation and is one of the signs of induced genomic instability. The survival of cells initially treated with 2,4-DCA and the survival of their progeny were determined. When cells are exposed to a toxic insult, the component cells of a normal appearing survivor colony or clone were commonly thought to have proliferative capacity equivalent to that of the untreated cells. In this study, however, it was found that CHSE-214 cells surviving 2,4-DCA exposure carried heritable lethal defects, which came to light only after numerous apparently successful divisions, in the form of plating efficiencies, which were reduced below those of the untreated, control cells. DCD expression did not appear to be dose-dependent with poor cell survival occurring at the lower end of 2,4-DCA exposure and remained constant until recovering to something like 60% of the controls. A study of the CHSE-214 kinetics post-exposure showed that the apparent reduced growth rate of the cells was due to reduced numbers of reproductively viable cells in the population. Results showed that the expression of DCD occurred persistently
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Oxidative Stress, Redox Signaling, and Autophagy: Cell Death Versus Survival
Navarro-Yepes, Juliana; Burns, Michaela; Anandhan, Annadurai; Khalimonchuk, Oleh; del Razo, Luz Maria; Quintanilla-Vega, Betzabet; Pappa, Aglaia; Panayiotidis, Mihalis I.
2014-01-01
Abstract Significance: The molecular machinery regulating autophagy has started becoming elucidated, and a number of studies have undertaken the task to determine the role of autophagy in cell fate determination within the context of human disease progression. Oxidative stress and redox signaling are also largely involved in the etiology of human diseases, where both survival and cell death signaling cascades have been reported to be modulated by reactive oxygen species (ROS) and reactive nitrogen species (RNS). Recent Advances: To date, there is a good understanding of the signaling events regulating autophagy, as well as the signaling processes by which alterations in redox homeostasis are transduced to the activation/regulation of signaling cascades. However, very little is known about the molecular events linking them to the regulation of autophagy. This lack of information has hampered the understanding of the role of oxidative stress and autophagy in human disease progression. Critical Issues: In this review, we will focus on (i) the molecular mechanism by which ROS/RNS generation, redox signaling, and/or oxidative stress/damage alter autophagic flux rates; (ii) the role of autophagy as a cell death process or survival mechanism in response to oxidative stress; and (iii) alternative mechanisms by which autophagy-related signaling regulate mitochondrial function and antioxidant response. Future Directions: Our research efforts should now focus on understanding the molecular basis of events by which autophagy is fine tuned by oxidation/reduction events. This knowledge will enable us to understand the mechanisms by which oxidative stress and autophagy regulate human diseases such as cancer and neurodegenerative disorders. Antioxid. Redox Signal. 21, 66–85. PMID:24483238
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Lysosomal cysteine peptidases - Molecules signaling tumor cell death and survival.
Pišlar, Anja; Perišić Nanut, Milica; Kos, Janko
2015-12-01
Lysosomal cysteine peptidases - cysteine cathepsins - are general intracellular protein-degrading enzymes that control also a variety of specific physiological processes. They can trigger irreversible events leading to signal transduction and activation of signaling pathways, resulting in cell survival and proliferation or cell death. In cancer cells, lysosomal cysteine peptidases are involved in multiple processes during malignant progression. Their translocation from the endosomal/lysosomal pathway to nucleus, cytoplasm, plasma membrane and extracellular space enables the activation and remodeling of a variety of tumor promoting proteins. Thus, lysosomal cysteine peptidases interfere with cytokine/chemokine signaling, regulate cell adhesion and migration and endocytosis, are involved in the antitumor immune response and apoptosis, and promote cell invasion, angiogenesis and metastasis. Further, lysosomal cysteine peptidases modify growth factors and receptors involved in tyrosine kinase dependent pathways such as MAPK, Akt and JNK, thus representing key signaling tools for the activation of tumor cell growth and proliferation. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Early death, late death and repair factor in three human tumour cell lines
International Nuclear Information System (INIS)
Courdi, A.; Gioanni, J.; Mari, D.; Chauvel, P.
1997-01-01
The in vivo colony method used to generate survival curves following exposure to ionizing irradiation allows to score large clones, representing surviving cells, and small colonies, representing late reproductive death. By subtraction, early-dying cells can be estimated. In the three human tumour cell lines examined, we have observed that early cell death is a major mode of action of irradiation. The contribution of early cell death to total mortality increases as the dose increases. Moreover, repair due to dose-splitting and delayed plating in densely-inhibited cells is not observed in early-dying cells. (authors)
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Directory of Open Access Journals (Sweden)
Razmik Mirzayans
2016-05-01
Full Text Available It is widely stated that wild-type p53 either mediates the activation of cell cycle checkpoints to facilitate DNA repair and promote cell survival, or orchestrates apoptotic cell death following exposure to cancer therapeutic agents. This reigning paradigm has been challenged by numerous discoveries with different human cell types, including solid tumor-derived cell lines. Thus, activation of the p53 signaling pathway by ionizing radiation and other DNA-damaging agents hinders apoptosis and triggers growth arrest (e.g., through premature senescence in some genetic backgrounds; such growth arrested cells remain viable, secrete growth-promoting factors, and give rise to progeny with stem cell-like properties. In addition, caspase 3, which is best known for its role in the execution phase of apoptosis, has been recently reported to facilitate (rather than suppress DNA damage-induced genomic instability and carcinogenesis. This observation is consistent with an earlier report demonstrating that caspase 3 mediates secretion of the pro-survival factor prostaglandin E2, which in turn promotes enrichment of tumor repopulating cells. In this article, we review these and related discoveries and point out novel cancer therapeutic strategies. One of our objectives is to demonstrate the growing complexity of the DNA damage response beyond the conventional “repair and survive, or die” hypothesis.
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International Nuclear Information System (INIS)
Porquet, Nicolas; Huot, Jacques; Poirier, Andrée; Houle, François; Pin, Anne-Laure; Gout, Stéphanie; Tremblay, Pierre-Luc; Paquet, Éric R; Klinck, Roscoe; Auger, François A
2011-01-01
Extravasation of circulating cancer cells is a key event of metastatic dissemination that is initiated by the adhesion of cancer cells to endothelial cells. It requires interactions between adhesion receptors on endothelial cells and their counter-receptors on cancer cells. Notably, E-selectin, a major endothelial adhesion receptor, interacts with Death receptor-3 present on metastatic colon carcinoma cells. This interaction confers metastatic properties to colon cancer cells by promoting the adhesion of cancer cells to endothelial cells and triggering the activation of the pro-migratory p38 and pro-survival ERK pathways in the cancer cells. In the present study, we investigated further the mechanisms by which the E-selectin-activated pathways downstream of DR3 confer a survival advantage to colon cancer cells. Cell survival has been ascertained by using the WST-1 assay and by evaluating the activation of the PI3 kinase/NFκB survival axis. Apoptosis has been assayed by determining DNA fragmentation by Hoechst staining and by measuring cleavage of caspases-8 and -3. DR3 isoforms have been identified by PCR. For more precise quantification, targeted PCR reactions were carried out, and the amplified products were analyzed by automated chip-based microcapillary electrophoresis on an Agilent 2100 Bioanalyzer instrument. Interaction between DR3-expressing HT29 colon carcinoma cells and E-selectin induces the activation of the PI3K/Akt pathway. Moreover, p65/RelA, the anti-apoptotic subunit of NFκB, is rapidly translocated to the nucleus in response to E-selectin. This translocation is impaired by the PI3K inhibitor LY294002. Furthermore, inhibition of the PI3K/Akt pathway increases the cleavage of caspase 8 in colon cancer cells treated with E-selectin and this effect is still further increased when both ERK and PI3K pathways are concomitantly inhibited. Intriguingly, metastatic colon cancer cell lines such as HT29 and SW620 express higher levels of a splice variant of
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Directory of Open Access Journals (Sweden)
Paquet Éric R
2011-07-01
Full Text Available Abstract Background Extravasation of circulating cancer cells is a key event of metastatic dissemination that is initiated by the adhesion of cancer cells to endothelial cells. It requires interactions between adhesion receptors on endothelial cells and their counter-receptors on cancer cells. Notably, E-selectin, a major endothelial adhesion receptor, interacts with Death receptor-3 present on metastatic colon carcinoma cells. This interaction confers metastatic properties to colon cancer cells by promoting the adhesion of cancer cells to endothelial cells and triggering the activation of the pro-migratory p38 and pro-survival ERK pathways in the cancer cells. In the present study, we investigated further the mechanisms by which the E-selectin-activated pathways downstream of DR3 confer a survival advantage to colon cancer cells. Methods Cell survival has been ascertained by using the WST-1 assay and by evaluating the activation of the PI3 kinase/NFκB survival axis. Apoptosis has been assayed by determining DNA fragmentation by Hoechst staining and by measuring cleavage of caspases-8 and -3. DR3 isoforms have been identified by PCR. For more precise quantification, targeted PCR reactions were carried out, and the amplified products were analyzed by automated chip-based microcapillary electrophoresis on an Agilent 2100 Bioanalyzer instrument. Results Interaction between DR3-expressing HT29 colon carcinoma cells and E-selectin induces the activation of the PI3K/Akt pathway. Moreover, p65/RelA, the anti-apoptotic subunit of NFκB, is rapidly translocated to the nucleus in response to E-selectin. This translocation is impaired by the PI3K inhibitor LY294002. Furthermore, inhibition of the PI3K/Akt pathway increases the cleavage of caspase 8 in colon cancer cells treated with E-selectin and this effect is still further increased when both ERK and PI3K pathways are concomitantly inhibited. Intriguingly, metastatic colon cancer cell lines such as HT
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Directory of Open Access Journals (Sweden)
Wen-Hsiung Chan
2008-05-01
Full Text Available Caffeine consumption is a risk factor for osteoporosis, but the precise regulatory mechanisms are currently unknown. Here, we show that cell viability decreases in osteoblasts treated with caffeine in a dose-dependent manner. This cell death is attributed primarily to apoptosis and to a smaller extent, necrosis. Moreover, caffeine directly stimulates intracellular oxidative stress. Our data support caffeine-induced apoptosis in osteoblasts via a mitochondria-dependent pathway. The apoptotic biochemical changes were effectively prevented upon pretreatment with ROS scavengers, indicating that ROS plays a critical role as an upstream controller in the caffeine-induced apoptotic cascade. Additionally, p21-activated protein kinase 2 (PAK2 and c-Jun N-terminal kinase (JNK were activated in caffeine-treated osteoblasts. Experiments further found that PAK2 activity is required for caffeine-induced JNK activation and apoptosis. Importantly, our data also show that caffeine triggers cell death via inactivation of the survival signal, including the ERK- and Akt-mediated anti-apoptotic pathways. Finally, exposure of rats to dietary water containing 10~20 μM caffeine led to bone mineral density loss. These results demonstrate for the first time that caffeine triggers apoptosis in osteoblasts via activation of mitochondria-dependent cell death signaling and inactivation of the survival signal, and causes bone mineral density loss in vivo.
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De Nisco, Nicole J.; Kanchwala, Mohammed; Li, Peng; Fernandez, Jessie; Xing, Chao; Orth, Kim
2017-01-01
Bacterial effectors are potent manipulators of host signaling pathways. The marine bacterium Vibrio parahaemolyticus (V. para), delivers effectors into host cells through two type three secretion systems (T3SS). The ubiquitous T3SS1 is vital for V. para survival in the environment, whereas T3SS2 causes acute gastroenteritis in human hosts. Although the natural host is undefined, T3SS1 effectors attack highly conserved cellular processes and pathways to orchestrate non-apoptotic cell death. Much is known about how T3SS1 effectors function in isolation, but we wanted to understand how their concerted action globally affects host cell signaling. To assess the host response to T3SS1, we compared gene expression changes over time in primary fibroblasts infected with V. para that have a functional T3SS1 (T3SS1+) to those in cells infected with V. para lacking T3SS1 (T3SS1−). Overall, the host transcriptional response to both T3SS1+ and T3SS1− V. para was rapid, robust, and temporally dynamic. T3SS1 re-wired host gene expression by specifically altering the expression of 398 genes. Although T3SS1 effectors target host cells at the posttranslational level to cause cytotoxicity, network analysis indicated that V. para T3SS1 also precipitates a host transcriptional response that initially activates cell survival and represses cell death networks. The increased expression of several key pro-survival transcripts mediated by T3SS1 was dependent on a host signaling pathway that is silenced later in infection by the posttranslational action of T3SS1. Taken together, our analysis reveals a complex interplay between roles of T3SS1 as both a transcriptional and posttranslational manipulator of host cell signaling. PMID:28512145
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The anti-cell death FNK protein protects cells from death induced by freezing and thawing
International Nuclear Information System (INIS)
Sudo, Kentaro; Asoh, Sadamitsu; Ohsawa, Ikuroh; Ozaki, Daiya; Yamagata, Kumi; Ito, Hiromoto; Ohta, Shigeo
2005-01-01
The FNK protein, constructed from anti-apoptotic Bcl-x L 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
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Directory of Open Access Journals (Sweden)
Sebastian Horn
2017-04-01
Full Text Available Formation of the death-inducing signaling complex (DISC initiates extrinsic apoptosis. Caspase-8 and its regulator cFLIP control death signaling by binding to death-receptor-bound FADD. By elucidating the function of the caspase-8 homolog, caspase-10, we discover that caspase-10 negatively regulates caspase-8-mediated cell death. Significantly, we reveal that caspase-10 reduces DISC association and activation of caspase-8. Furthermore, we extend our co-operative/hierarchical binding model of caspase-8/cFLIP and show that caspase-10 does not compete with caspase-8 for binding to FADD. Utilizing caspase-8-knockout cells, we demonstrate that caspase-8 is required upstream of both cFLIP and caspase-10 and that DISC formation critically depends on the scaffold function of caspase-8. We establish that caspase-10 rewires DISC signaling to NF-κB activation/cell survival and demonstrate that the catalytic activity of caspase-10, and caspase-8, is redundant in gene induction. Thus, our data are consistent with a model in which both caspase-10 and cFLIP coordinately regulate CD95L-mediated signaling for death or survival.
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Plasmalogens rescue neuronal cell death through an activation of AKT and ERK survival signaling.
Directory of Open Access Journals (Sweden)
Md Shamim Hossain
Full Text Available Neuronal cells are susceptible to many stresses, which will cause the apoptosis and neurodegenerative diseases. The precise molecular mechanism behind the neuronal protection against these apoptotic stimuli is necessary for drug discovery. In the present study, we have found that plasmalogens (Pls, which are glycerophospholipids containing vinyl ether linkage at sn-1 position, can protect the neuronal cell death upon serum deprivation. Interestingly, caspse-9, but not caspase-8 and caspase-12, was cleaved upon the serum starvation in Neuro-2A cells. Pls treatments effectively reduced the activation of caspase-9. Furthermore, cellular signaling experiments showed that Pls enhanced phosphorylation of the phosphoinositide 3-kinase (PI3K-dependent serine/threonine-specific protein kinase AKT and extracellular-signal-regulated kinases ERK1/2. PI3K/AKT inhibitor LY294002 and MAPK/ERK kinase (MEK inhibitor U0126 treatments study clearly indicated that Pls-mediated cell survival was dependent on the activation of these kinases. In addition, Pls also inhibited primary mouse hippocampal neuronal cell death induced by nutrient deprivation, which was associated with the inhibition of caspase-9 and caspase-3 cleavages. It was reported that Pls content decreased in the brain of the Alzheimer's patients, which indicated that the reduction of Pls content could endanger neurons. The present findings, taken together, suggest that Pls have an anti-apoptotic action in the brain. Further studies on precise mechanisms of Pls-mediated protection against cell death may lead us to establish a novel therapeutic approach to cure neurodegenerative disorders.
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Radiation-induced cell death by chromatin loss
International Nuclear Information System (INIS)
Campbell, I.R.; Warenius, H.M.
1989-01-01
A model is proposed which relates reproductive death of cells caused by radiation to loss of chromatin at cell division. This loss of chromatin can occur through chromosomal deletions or through the formation of asymmetrical chromosomal exchanges. It is proposed that smaller doses of radiation produce fewer chromatin breaks, which are more likely to be accurately repaired, compared with larger doses. Consequently, smaller doses of radiation are less efficient in causing cell death, leading to a shoulder on the cell survival curve. Experimental evidence supports this model, and the fit between the derived formula and experimental cell survival curves is good. The derived formula approximates to the linear-quadratic equation at low doses of radiation. (author)
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XIAP is not required for human tumor cell survival in the absence of an exogenous death signal
International Nuclear Information System (INIS)
Sensintaffar, John; Scott, Fiona L; Peach, Robert; Hager, Jeffrey H
2010-01-01
The X-linked Inhibitor of Apoptosis (XIAP) has attracted much attention as a cancer drug target. It is the only member of the IAP family that can directly inhibit caspase activity in vitro, and it can regulate apoptosis and other biological processes through its C-terminal E3 ubiquitin ligase RING domain. However, there is controversy regarding XIAP's role in regulating tumor cell proliferation and survival under normal growth conditions in vitro. We utilized siRNA to systematically knock down XIAP in ten human tumor cell lines and then monitored both XIAP protein levels and cell viability over time. To examine the role of XIAP in the intrinsic versus extrinsic cell death pathways, we compared the viability of XIAP depleted cells treated either with a variety of mechanistically distinct, intrinsic pathway inducing agents, or the canonical inducer of the extrinsic pathway, TNF-related apoptosis-inducing ligand (TRAIL). XIAP knockdown had no effect on the viability of six cell lines, whereas the effect in the other four was modest and transient. XIAP knockdown only sensitized tumor cells to TRAIL and not the mitochondrial pathway inducing agents. These data indicate that XIAP has a more central role in regulating death receptor mediated apoptosis than it does the intrinsic pathway mediated cell death
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Directory of Open Access Journals (Sweden)
Masamitsu Shimazawa
2010-12-01
Full Text Available Amyotrophic lateral sclerosis (ALS is the most frequent adult-onset motor neuron disease, and recent evidence has suggested that endoplasmic reticulum (ER stress signaling is involved in the pathogenesis of ALS. Here we identified a small molecule, SUN N8075, which has a marked protective effect on ER stress-induced cell death, in an in vitro cell-based screening, and its protective mechanism was mediated by an induction of VGF nerve growth factor inducible (VGF: VGF knockdown with siRNA completely abolished the protective effect of SUN N8075 against ER-induced cell death, and overexpression of VGF inhibited ER-stress-induced cell death. VGF level was lower in the spinal cords of sporadic ALS patients than in the control patients. Furthermore, SUN N8075 slowed disease progression and prolonged survival in mutant SOD1 transgenic mouse and rat models of ALS, preventing the decrease of VGF expression in the spinal cords of ALS mice. These data suggest that VGF plays a critical role in motor neuron survival and may be a potential new therapeutic target for ALS, and SUN N8075 may become a potential therapeutic candidate for treatment of ALS.
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Prognostic Factors of Organophosphate Poisoning Between the Death and Survival Groups
Directory of Open Access Journals (Sweden)
Tzeng-Jih Lin
2007-04-01
Full Text Available In this prospective case series study, we consider the different factors between death and survival groups of organophosphate poisoning. Patients in tertiary-care medical center who had been exposed to organophosphate were included in the study. Pralidoxime (PAM was discontinued after atropine had controlled the clinical situation. We recorded the demographic data, amount of organophosphate consumption, duration of coma, duration of ventilator use, duration of hospitalization, findings of chest X-ray, white blood cell count, acetylcholinesterase concentration, plasma cholinesterase concentration, total atropine amount, duration of atropine use, total PAM amount, duration of PAM use, urine organophosphate peak concentration, duration of urine organophosphate and mortality rate. Urine was collected every 8 hours and was analyzed by gas chromatography equipped with a flame photometric detector and gas chromatography with mass spectrometer detector for organophosphate determination. The urine organophosphate peak concentration was recorded. Wilcoxon rank sum test was used to compare the factors between death and survival groups. Fisher's exact test was used to compare the different findings of chest X-ray between the death and survival groups. Evidently, the death group had a higher amount of organophosphate consumption, duration of coma, and higher white blood cell count than those in the survival group. Also, the death group had lower duration of hospitalization, and decreased concentrations of acetylcholinesterase and plasma cholinesterase. Total PAM amount use and duration of PAM use were lower. However, the duration of ventilator use, findings of chest X-ray, total atropine amount, duration of atropine, urine organophosphate peak concentration and duration of urine organophosphate were similar in both groups. The mortality rate of our 50 cases was 20%. As stated earlier, the cases of the death group had insufficient PAM therapy. The maximum
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IR-induced autophagy plays a role in survival of HeLa cells
International Nuclear Information System (INIS)
Kang, Mi Young; Jang, Eun Yeong; Ryu, Tae Ho; Chung, Dong Min; Kim, Jin Hong; Kim, Jin Kyu
2014-01-01
Cells respond to stress with repair, or are diverted into irreversible cell cycle exit (senescence) or are eliminated through programmed cell death. There are two major morphologically distinctive forms of programmed cell death, apoptosis and autophagic cell death. Apoptosis contribute to cell death, whereas autophagy can play a dual role in mediating either cell survival or death in response to various stress stimuli. Here we analysed cellular responses induced by IR. The understanding of an appropriate cellular stress response is of crucial importance in foreseeing the cell fate. Apoptotic feagures were not detected in HeLa under our experimental irradiation condition. Autophagic cell death in HeLa may play an important role in cell protection and can result in cell survival
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Gaytan, F; Morales, C; Roa, J; Tena-Sempere, M
2018-04-01
Is keratin 8/18 (K8/K18) expression linked to cell death/survival events in the human granulosa cell lineage? A close association exists between changes in K8/K18 expression and cell death/survival events along the human granulosa cell lineage lifespan. In addition to their structural and mechanical functions, K8/K18 play essential roles regulating cell death, survival and differentiation in several non-gonadal epithelial tissues. Transfection of the granulosa-like tumor KGN cells with siRNA to interfere KRT8 and KRT18 expression increases FAS-mediated apoptosis, while an inverse association between K8/K18 expression and cell death has been found in the bovine antral follicles and corpus luteum. Yet, only fragmentary and inconclusive information exists regarding K8/K18 expression in the human ovary. Expression of K8/K18 was assessed by immunohistochemistry at different stages of the granulosa cell lineage, from flattened granulosa cells in primordial follicles to fully luteinized granulosa-lutein cells in the corpus luteum (including corpus luteum of pregnancy). Immunohistochemical detection of K8/K18 was conducted in 40 archival ovarian samples from women aged 17-39 years. K8/K18 expression was analyzed at the different stages of follicle development and corpus luteum lifespan. The proportions of primordial follicles showing all K8/K18-positive, all K8/K18 negative, or a mixture of K8/K18 negative and positive granulosa cells were quantified in 18 ovaries, divided into three age groups: ≤ 25 years (N = 6), 26-30 (N = 6) and 31-36 (N = 6) years. A total number of 1793 primordial, 750 transitional and 140 primary follicles were scored. A close association was found between changes in K8/K18 expression and cell death/cell survival events in the human granulosa cell lineage. Large secondary and early antral follicles (most of them undergoing atresia) and regressing corpora lutea displayed low/absent K8/K18 expression. Conversely, early growing and some large antral
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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.
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The convergence of radiation and immunogenic cell death signaling pathways
International Nuclear Information System (INIS)
Golden, Encouse B.; Pellicciotta, Ilenia; Demaria, Sandra; Barcellos-Hoff, Mary H.; Formenti, Silvia C.
2012-01-01
Ionizing radiation (IR) triggers programmed cell death in tumor cells through a variety of highly regulated processes. Radiation-induced tumor cell death has been studied extensively in vitro and is widely attributed to multiple distinct mechanisms, including apoptosis, necrosis, mitotic catastrophe (MC), autophagy, and senescence, which may occur concurrently. When considering tumor cell death in the context of an organism, an emerging body of evidence suggests there is a reciprocal relationship in which radiation stimulates the immune system, which in turn contributes to tumor cell kill. As a result, traditional measurements of radiation-induced tumor cell death, in vitro, fail to represent the extent of clinically observed responses, including reductions in loco-regional failure rates and improvements in metastases free and overall survival. Hence, understanding the immunological responses to the type of radiation-induced cell death is critical. In this review, the mechanisms of radiation-induced tumor cell death are described, with particular focus on immunogenic cell death (ICD). Strategies combining radiotherapy with specific chemotherapies or immunotherapies capable of inducing a repertoire of cancer specific immunogens might potentiate tumor control not only by enhancing cell kill but also through the induction of a successful anti-tumor vaccination that improves patient survival.
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Energy Technology Data Exchange (ETDEWEB)
Vy Tran, An Hue; Hahm, Soo-Hyun; Han, Se Hee [Department of Advanced Technology Fusion, Konkuk University, Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of); Chung, Ji Hyung [Department of Applied Bioscience, College of Life Science, CHA University, Gyeonggi-do 463-836 (Korea, Republic of); Park, Geon Tae [Cornell University, Ithaca, NY 14850 (United States); Han, Ye Sun, E-mail: yshan@konkuk.ac.kr [College of Global Integrated Studies, Division of Interdisciplinary Studies, Konkuk University, Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)
2015-07-15
Highlights: • We determine the interaction between hMYH and hTRADD. • We examine changes in the level of hMYH–hTRADD interaction under TNF-α treatment. • hTRADD–hMYH association is involved in the nuclear translocation of NFκB. • hTRADD–hMYH complex influences the TNFR1–TRADD association. - Abstract: The tumor necrosis factor (TNF) signaling pathway is a classical immune system pathway that plays a key role in regulating cell survival and apoptosis. The TNF receptor-associated death domain (TRADD) protein is recruited to the death domain of TNF receptor 1 (TNFR1), where it interacts with TNF receptor-associated factor 2 (TRAF2) and receptor-interacting protein (RIP) for the induction of apoptosis, necrosis, nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and mitogen-activated protein (MAP) kinase activation. In this study, we found that the human MutY homolog (hMYH) interacted with human TRADD (hTRADD) via the C-terminal domain of hMYH. Moreover, under conditions promoting TNF-α-induced cell death or survival in HeLa cells, this interaction was weakened or enhanced, respectively. The interaction between hMYH and hTRADD was important for signaling pathways mediated by TNF-α. Our results also suggested that the hTRADD–hMYH association was involved in the nuclear translocation of NFκB and formation of the TNFR1–TRADD complex. Thus, this study identified a novel mechanism through which the hMYH–hTRADD interaction may affect the TNF-α signaling pathway. Implications: In HeLa cells, the hTRADD–hMYH interaction functioned in both cell survival and apoptosis pathways following TNF-α stimulation.
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Survival and death causes in differentiated thyroid carcinoma
Eustatia-Rutten, Carmen F. A.; Corssmit, Eleonora P. M.; Biermasz, Nienke R.; Pereira, Alberto M.; Romijn, Johannes A.; Smit, Johannes W.
2006-01-01
Survival studies in differentiated thyroid carcinoma (DTC) may be biased because they have been performed in heterogeneous populations. In addition, specific death causes in DTC have not been documented well in the literature. The aim of our study was to investigate survival and specific death
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De Nisco, Nicole J; Kanchwala, Mohammed; Li, Peng; Fernandez, Jessie; Xing, Chao; Orth, Kim
2017-05-16
Bacterial effectors potently manipulate host signaling pathways. The marine bacterium Vibrio parahaemolyticus ( V. para ) delivers effectors into host cells through two type 3 secretion systems (T3SSs). T3SS1 is vital for V. para survival in the environment, whereas T3SS2 causes acute gastroenteritis in human hosts. Although the natural host is undefined, T3SS1 effectors attack highly conserved cellular processes and pathways to orchestrate nonapoptotic cell death. To understand how the concerted action of T3SS1 effectors globally affects host cell signaling, we compared gene expression changes over time in primary fibroblasts infected with V. para that have a functional T3SS1 (T3SS1 + ) to those in cells infected with V. para lacking T3SS1 (T3SS1 - ). Overall, the host transcriptional response to both T3SS1 + and T3SS1 - V. para was rapid, robust, and temporally dynamic. T3SS1 rewired host gene expression by specifically altering the expression of 398 genes. Although T3SS1 effectors targeted host cells at the posttranslational level to cause cytotoxicity, V. para T3SS1 also precipitated a host transcriptional response that initially activated cell survival and repressed cell death networks. The increased expression of several key prosurvival transcripts mediated by T3SS1 depended on a host signaling pathway that is silenced posttranslationally later in infection. Together, our analysis reveals a complex interplay between the roles of T3SS1 as both a transcriptional and posttranslational manipulator of host cell signaling. Copyright © 2017, American Association for the Advancement of Science.
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Lipid raft involvement in yeast cell growth and death
Energy Technology Data Exchange (ETDEWEB)
Mollinedo, Faustino, E-mail: fmollin@usal.es [Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas - Universidad de Salamanca, Salamanca (Spain)
2012-10-10
The notion that cellular membranes contain distinct microdomains, acting as scaffolds for signal transduction processes, has gained considerable momentum. In particular, a class of such domains that is rich in sphingolipids and cholesterol, termed as lipid rafts, is thought to compartmentalize the plasma membrane, and to have important roles in survival and cell death signaling in mammalian cells. Likewise, yeast lipid rafts are membrane domains enriched in sphingolipids and ergosterol, the yeast counterpart of mammalian cholesterol. Sterol-rich membrane domains have been identified in several fungal species, including the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe as well as the pathogens Candida albicans and Cryptococcus neoformans. Yeast rafts have been mainly involved in membrane trafficking, but increasing evidence implicates rafts in a wide range of additional cellular processes. Yeast lipid rafts house biologically important proteins involved in the proper function of yeast, such as proteins that control Na{sup +}, K{sup +}, and pH homeostasis, which influence many cellular processes, including cell growth and death. Membrane raft constituents affect drug susceptibility, and drugs interacting with sterols alter raft composition and membrane integrity, leading to yeast cell death. Because of the genetic tractability of yeast, analysis of yeast rafts could be an excellent model to approach unanswered questions of mammalian raft biology, and to understand the role of lipid rafts in the regulation of cell death and survival in human cells. A better insight in raft biology might lead to envisage new raft-mediated approaches to the treatment of human diseases where regulation of cell death and survival is critical, such as cancer and neurodegenerative diseases.
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Lipid raft involvement in yeast cell growth and death
International Nuclear Information System (INIS)
Mollinedo, Faustino
2012-01-01
The notion that cellular membranes contain distinct microdomains, acting as scaffolds for signal transduction processes, has gained considerable momentum. In particular, a class of such domains that is rich in sphingolipids and cholesterol, termed as lipid rafts, is thought to compartmentalize the plasma membrane, and to have important roles in survival and cell death signaling in mammalian cells. Likewise, yeast lipid rafts are membrane domains enriched in sphingolipids and ergosterol, the yeast counterpart of mammalian cholesterol. Sterol-rich membrane domains have been identified in several fungal species, including the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe as well as the pathogens Candida albicans and Cryptococcus neoformans. Yeast rafts have been mainly involved in membrane trafficking, but increasing evidence implicates rafts in a wide range of additional cellular processes. Yeast lipid rafts house biologically important proteins involved in the proper function of yeast, such as proteins that control Na + , K + , and pH homeostasis, which influence many cellular processes, including cell growth and death. Membrane raft constituents affect drug susceptibility, and drugs interacting with sterols alter raft composition and membrane integrity, leading to yeast cell death. Because of the genetic tractability of yeast, analysis of yeast rafts could be an excellent model to approach unanswered questions of mammalian raft biology, and to understand the role of lipid rafts in the regulation of cell death and survival in human cells. A better insight in raft biology might lead to envisage new raft-mediated approaches to the treatment of human diseases where regulation of cell death and survival is critical, such as cancer and neurodegenerative diseases.
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Obligatory participation of macrophages in an angiopoietin 2-mediated cell death switch
Rao, Sujata; Lobov, Ivan B.; Vallance, Jefferson E.; Tsujikawa, Kaoru; Shiojima, Ichiro; Akunuru, Shailaja; Walsh, Kenneth; Benjamin, Laura E.; Lang, Richard A.
2007-01-01
Macrophages have a critical function in the recognition and engulfment of dead cells. In some settings, macrophages also actively signal programmed cell death. Here we show that during developmentally scheduled vascular regression, resident macrophages are an obligatory participant in a signaling switch that favors death over survival. This switch occurs when the signaling ligand angiopoietin 2 has the dual effect of suppressing survival signaling in vascular endothelial cells (VECs) and stim...
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Significance of apoptotic cell death after γ-irradiation
International Nuclear Information System (INIS)
Wu, H.G.; Kim, I.H.; Ha, S.W.; Park, C.I.
2003-01-01
Full text: The objectives of this study are to investigate the significance of apoptotic death compared to total cell death after γ-ray irradiation in human Hand N cancer cell lines and to find out correlation between apoptosis and radiation sensitivity. Materials and Method: Head and neck cancer cell lines (PCI-1, PCI-13, and SNU-1066), leukemia cell line (CCRF-CEM), and fibroblast cell line (LM217) as a normal control were used for this study. Cells were irradiated using Cs-137 animal experiment irradiator. Total cell death was measured by clonogenic assay. Annexin-V staining was used to detect the fraction of apoptotic death. The resulting data was analyzed with two parameters, apoptotic index (AI) and apoptotic fraction(AF). AI is ratio of apoptotic cells to total cells, and AF is ration of apoptotic cell death to mutant frequencytion ex(Number of apoptotic cells) / (Number of total cells counted) AF = {(AI) / (1-survival fraction)} x 100 (%) Results. Surviving fraction at 2 Gy (SF2) were 0.741, 0.544, 0.313, 0.302, and 0.100 for PCI-1, PCI-13, SNU-1066, CCRF-CEM, and LM217 cell lines, respectively. Apoptosis was detected in all cell lines. Apoptotic index reached peak value at 72 hours after irradiation in head and neck cancer cell lines, and that was at 24 hours in CCRF-CEM and LM217. Total cell death increased exponentially with increasing radiation dose from 0 Gy to 8 Gy, but the change was minimal in apoptotic index (Fig. 1.). Apoptotic fractions at 2 Gy were 46%, 48%, 46%, 24%, and 19% and at 6 Gy were 20%, 33%, 35%, 17%, and 20% for PCI-1, PCI-13, SNU-1066, CCRF-CEM, and LM217, respectively. The radioresistant cell lines showed more higher apoptotic fraction at 2 Gy (Table 1.), but there was not such correlation at 6 Gy. Conclusion: All cell lines used in this study showed apoptosis after irradiation, but time course of apoptosis was different from that of leukemia cell line and normal fibroblast cell line. Reproductive cell death was more important
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Sorafenib-induced defective autophagy promotes cell death by necroptosis
Kharaziha, Pedram; Chioureas, Dimitris; Baltatzis, George; Fonseca, Pedro; Rodriguez, Patricia; Gogvadze, Vladimir; Lennartsson, Lena; Bj?rklund, Ann-Charlotte; Zhivotovsky, Boris; Grand?r, Dan; Egevad, Lars; Nilsson, Sten; Panaretakis, Theocharis
2015-01-01
Autophagy is one of the main cytoprotective mechanisms that cancer cells deploy to withstand the cytotoxic stress and survive the lethal damage induced by anti-cancer drugs. However, under specific conditions, autophagy may, directly or indirectly, induce cell death. In our study, treatment of the Atg5-deficient DU145 prostate cancer cells, with the multi-tyrosine kinase inhibitor, sorafenib, induces mitochondrial damage, autophagy and cell death. Molecular inhibition of autophagy by silencin...
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Zhang, Y; Chen, M; Venugopal, S; Zhou, Y; Xiang, W; Li, Y-H; Lin, Q; Kini, R M; Chong, Y-S; Ge, R
2011-05-05
Isthmin (ISM) is a 60 kDa secreted-angiogenesis inhibitor that suppresses tumor growth in mouse and disrupts vessel patterning in zebrafish embryos. It selectively binds to alphavbeta5 (αvβ5) integrin on the surface of endothelial cells (ECs), but the mechanism of its antiangiogenic action remains unknown. In this work, we establish that soluble ISM suppresses in vitro angiogenesis and induces EC apoptosis by interacting with its cell surface receptor αvβ5 integrin through a novel 'RKD' motif localized within its adhesion-associated domain in MUC4 and other proteins domain. ISM induces EC apoptosis through integrin-mediated death (IMD) by direct recruitment and activation of caspase-8 without causing anoikis. On the other hand, immobilized ISM loses its antiangiogenic function and instead promotes EC adhesion, survival and migration through αvβ5 integrin by activating focal adhesion kinase (FAK). ISM unexpectedly has both a pro-survival and death-promoting effect on ECs depending on its physical state. This dual function of a single antiangiogenic protein may impact its antiangiogenic efficacy in vivo.
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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
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Kinowaki, Yuko; Kurata, Morito; Ishibashi, Sachiko; Ikeda, Masumi; Tatsuzawa, Anna; Yamamoto, Masahide; Miura, Osamu; Kitagawa, Masanobu; Yamamoto, Kouhei
2018-02-20
Regulation of oxidative stress and redox systems has important roles in carcinogenesis and cancer progression, and for this reason has attracted much attention as a new area of cancer therapeutic targets. Glutathione peroxidase 4 (GPX4), an antioxidant enzyme, has biological important functions such as signaling cell death by suppressing peroxidation of membrane phospholipids. However, few studies exist on the expression and clinical relevance of GPX4 in malignant lymphomas such as diffuse large B-cell lymphoma. In this study, we assessed the expression of GPX4 immunohistochemically. GPX4 was expressed in 35.5% (33/93) cases of diffuse large B-cell lymphoma. The GPX4-positive group had poor overall survival (P = 0.0032) and progression-free survival (P = 0.0004) compared with those of the GPX4-negative group. In a combined analysis of GPX4 and 8-hydroxydeoxyguanosine (8-OHdG), an oxidative stress marker, there was a negative correlation between GPX4 and 8-hydroxydeoxyguanosine (P = 0.0009). The GPX4-positive and 8-hydroxydeoxyguanosine-negative groups had a significantly worse prognosis than the other groups in both overall survival (P = 0.0170) and progression-free survival (P = 0.0005). These results suggest that the overexpression of GPX4 is an independent prognostic predictor in diffuse large B-cell lymphoma. Furthermore, in vitro analysis demonstrated that GPX4-overexpressing cells were resistant to reactive oxygen species-induced cell death (P = 0.0360). Conversely, GPX4-knockdown cells were sensitive to reactive oxygen species-induced cell death (P = 0.0111). From these data, we conclude that GPX4 regulates reactive oxygen species-induced cell death. Our results suggest a novel therapeutic strategy using the mechanism of ferroptosis, as well as a novel prognostic predictor of diffuse large B-cell lymphoma.
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Autophagic cell death: Loch Ness monster or endangered species?
Shen, Han-Ming; Codogno, Patrice
2011-05-01
The concept of autophagic cell death was first established based on observations of increased autophagic markers in dying cells. The major limitation of such a morphology-based definition of autophagic cell death is that it fails to establish the functional role of autophagy in the cell death process, and thus contributes to the confusion in the literature regarding the role of autophagy in cell death and cell survival. Here we propose to define autophagic cell death as a modality of non-apoptotic or necrotic programmed cell death in which autophagy serves as a cell death mechanism, upon meeting the following set of criteria: (i) cell death occurs without the involvement of apoptosis; (ii) there is an increase of autophagic flux, and not just an increase of the autophagic markers, in the dying cells; and (iii) suppression of autophagy via both pharmacological inhibitors and genetic approaches is able to rescue or prevent cell death. In light of this new definition, we will discuss some of the common problems and difficulties in the study of autophagic cell death and also revisit some well-reported cases of autophagic cell death, aiming to achieve a better understanding of whether autophagy is a real killer, an accomplice or just an innocent bystander in the course of cell death. At present, the physiological relevance of autophagic cell death is mainly observed in lower eukaryotes and invertebrates such as Dictyostelium discoideum and Drosophila melanogaster. We believe that such a clear definition of autophagic cell death will help us study and understand the physiological or pathological relevance of autophagic cell death in mammals.
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International Nuclear Information System (INIS)
Gago-Arias, Araceli; Espinoza, Ignacio; Sánchez-Nieto, Beatriz; Aguiar, Pablo; Pardo-Montero, Juan
2016-01-01
The resistance of hypoxic cells to radiation, due to the oxygen dependence of radiosensitivity, is well known and must be taken into account to accurately calculate the radiation induced cell death. A proper modelling of the response of tumours to radiation requires deriving the distribution of oxygen at a microscopic scale. This usually involves solving the reaction-diffusion equation in tumour voxels using a vascularization distribution model. Moreover, re-oxygenation arises during the course of radiotherapy, one reason being the increase of available oxygen caused by cell killing, which can turn hypoxic tumours into oxic. In this work we study the effect of cell death kinetics in tumour oxygenation modelling, analysing how it affects the timing of re-oxygenation, surviving fraction and tumour control. Two models of cell death are compared, an instantaneous cell killing, mimicking early apoptosis, and a delayed cell death scenario in which cells can die shortly after being damaged, as well as long after irradiation. For each of these scenarios, the decrease in oxygen consumption due to cell death can be computed globally (macroscopic voxel average) or locally (microscopic). A re-oxygenation model already used in the literature, the so called full re-oxygenation, is also considered. The impact of cell death kinetics and re-oxygenation on tumour responses is illustrated for two radiotherapy fractionation schemes: a conventional schedule, and a hypofractionated treatment. The results show large differences in the doses needed to achieve 50% tumour control for the investigated cell death models. Moreover, the models affect the tumour responses differently depending on the treatment schedule. This corroborates the complex nature of re-oxygenation, showing the need to take into account the kinetics of cell death in radiation response models. (paper)
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Veratridine increases the survival of retinal ganglion cells in vitro
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S.P.F. Pereira
1997-12-01
Full Text Available Neuronal cell death is an important phenomenon involving many biochemical pathways. This degenerative event has been studied to understand how the cells activate the mechanisms that lead to self-destruction. Target cells and afferent cells play a relevant role in the regulation of natural cell death. We studied the effect of veratridine (1.5, 3.0, 4.5 and 6.0 µM on the survival of neonatal rat retinal ganglion cells in vitro. Veratridine (3.0 µM, a well-known depolarizing agent that opens the Na+ channel, promoted a two-fold increase in the survival of retinal ganglion cells kept in culture for 48 h. This effect was dose-dependent and was blocked by 1.0 µM tetrodotoxin (a classical voltage-dependent Na+ channel blocker and 30.0 µM flunarizine (a Na+ and Ca2+ channel blocker. These results indicate that electrical activity is also important for the maintenance of retinal ganglion cell survival in vitro
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Modulating cell-to-cell variability and sensitivity to death ligands by co-drugging
International Nuclear Information System (INIS)
Flusberg, Deborah A; Sorger, Peter K
2013-01-01
TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) holds promise as an anti-cancer therapeutic but efficiently induces apoptosis in only a subset of tumor cell lines. Moreover, even in clonal populations of responsive lines, only a fraction of cells dies in response to TRAIL and individual cells exhibit cell-to-cell variability in the timing of cell death. Fractional killing in these cell populations appears to arise not from genetic differences among cells but rather from differences in gene expression states, fluctuations in protein levels and the extent to which TRAIL-induced death or survival pathways become activated. In this study, we ask how cell-to-cell variability manifests in cell types with different sensitivities to TRAIL, as well as how it changes when cells are exposed to combinations of drugs. We show that individual cells that survive treatment with TRAIL can regenerate the sensitivity and death-time distribution of the parental population, demonstrating that fractional killing is a stable property of cell populations. We also show that cell-to-cell variability in the timing and probability of apoptosis in response to treatment can be tuned using combinations of drugs that together increase apoptotic sensitivity compared to treatment with one drug alone. In the case of TRAIL, modulation of cell-to-cell variability by co-drugging appears to involve a reduction in the threshold for mitochondrial outer membrane permeabilization. (paper)
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Understanding cell cycle and cell death regulation provides novel weapons against human diseases.
Wiman, K G; Zhivotovsky, B
2017-05-01
Cell division, cell differentiation and cell death are the three principal physiological processes that regulate tissue homoeostasis in multicellular organisms. The growth and survival of cells as well as the integrity of the genome are regulated by a complex network of pathways, in which cell cycle checkpoints, DNA repair and programmed cell death have critical roles. Disruption of genomic integrity and impaired regulation of cell death may both lead to uncontrolled cell growth. Compromised cell death can also favour genomic instability. It is becoming increasingly clear that dysregulation of cell cycle and cell death processes plays an important role in the development of major disorders such as cancer, cardiovascular disease, infection, inflammation and neurodegenerative diseases. Research achievements in these fields have led to the development of novel approaches for treatment of various conditions associated with abnormalities in the regulation of cell cycle progression or cell death. A better understanding of how cellular life-and-death processes are regulated is essential for this development. To highlight these important advances, the Third Nobel Conference entitled 'The Cell Cycle and Cell Death in Disease' was organized at Karolinska Institutet in 2016. In this review we will summarize current understanding of cell cycle progression and cell death and discuss some of the recent advances in therapeutic applications in pathological conditions such as cancer, neurological disorders and inflammation. © 2017 The Association for the Publication of the Journal of Internal Medicine.
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Oxidative Stress and Programmed Cell Death in Yeast
International Nuclear Information System (INIS)
Farrugia, Gianluca; Balzan, Rena
2012-01-01
Yeasts, such as Saccharomyces cerevisiae, have long served as useful models for the study of oxidative stress, an event associated with cell death and severe human pathologies. This review will discuss oxidative stress in yeast, in terms of sources of reactive oxygen species (ROS), their molecular targets, and the metabolic responses elicited by cellular ROS accumulation. Responses of yeast to accumulated ROS include upregulation of antioxidants mediated by complex transcriptional changes, activation of pro-survival pathways such as mitophagy, and programmed cell death (PCD) which, apart from apoptosis, includes pathways such as autophagy and necrosis, a form of cell death long considered accidental and uncoordinated. The role of ROS in yeast aging will also be discussed.
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Attributing death to cancer: cause-specific survival estimation.
Directory of Open Access Journals (Sweden)
Mathew A
2002-10-01
Full Text Available Cancer survival estimation is an important part of assessing the overall strength of cancer care in a region. Generally, the death of a patient is taken as the end point in estimation of overall survival. When calculating the overall survival, the cause of death is not taken into account. With increasing demand for better survival of cancer patients it is important for clinicians and researchers to know about survival statistics due to disease of interest, i.e. net survival. It is also important to choose the best method for estimating net survival. Increase in the use of computer programmes has made it possible to carry out statistical analysis without guidance from a bio-statistician. This is of prime importance in third- world countries as there are a few trained bio-statisticians to guide clinicians and researchers. The present communication describes current methods used to estimate net survival such as cause-specific survival and relative survival. The limitation of estimation of cause-specific survival particularly in India and the usefulness of relative survival are discussed. The various sources for estimating cancer survival are also discussed. As survival-estimates are to be projected on to the population at large, it becomes important to measure the variation of the estimates, and thus confidence intervals are used. Rothman′s confidence interval gives the most satisfactory result for survival estimate.
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Cell Survival Signaling in Neuroblastoma
Megison, Michael L.; Gillory, Lauren A.; Beierle, Elizabeth A.
2013-01-01
Neuroblastoma is the most common extracranial solid tumor of childhood and is responsible for over 15% of pediatric cancer deaths. Neuroblastoma tumorigenesis and malignant transformation is driven by overexpression and dominance of cell survival pathways and a lack of normal cellular senescence or apoptosis. Therefore, manipulation of cell survival pathways may decrease the malignant potential of these tumors and provide avenues for the development of novel therapeutics. This review focuses on several facets of cell survival pathways including protein kinases (PI3K, AKT, ALK, and FAK), transcription factors (NF-κB, MYCN and p53), and growth factors (IGF, EGF, PDGF, and VEGF). Modulation of each of these factors decreases the growth or otherwise hinders the malignant potential of neuroblastoma, and many therapeutics targeting these pathways are already in the clinical trial phase of development. Continued research and discovery of effective modulators of these pathways will revolutionize the treatment of neuroblastoma. PMID:22934706
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Dying cells protect survivors from radiation-induced cell death in Drosophila.
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Amber Bilak
2014-03-01
Full Text Available We report a phenomenon wherein induction of cell death by a variety of means in wing imaginal discs of Drosophila larvae resulted in the activation of an anti-apoptotic microRNA, bantam. Cells in the vicinity of dying cells also become harder to kill by ionizing radiation (IR-induced apoptosis. Both ban activation and increased protection from IR required receptor tyrosine kinase Tie, which we identified in a genetic screen for modifiers of ban. tie mutants were hypersensitive to radiation, and radiation sensitivity of tie mutants was rescued by increased ban gene dosage. We propose that dying cells activate ban in surviving cells through Tie to make the latter cells harder to kill, thereby preserving tissues and ensuring organism survival. The protective effect we report differs from classical radiation bystander effect in which neighbors of irradiated cells become more prone to death. The protective effect also differs from the previously described effect of dying cells that results in proliferation of nearby cells in Drosophila larval discs. If conserved in mammals, a phenomenon in which dying cells make the rest harder to kill by IR could have implications for treatments that involve the sequential use of cytotoxic agents and radiation therapy.
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Oral squamous cell carcinoma: survival, recurrence and death
Directory of Open Access Journals (Sweden)
Antônio Camilo Souza Cruz
2014-10-01
Full Text Available This paper was based in data survey from macro and microscopic oral lesions characteristics, personal data and medical history of patients diagnosed with oral squamous cell carcinoma in the Lab of Pathological Anatomy from the Federal University of Alfenas from January 2000 to December 2010, establishing comparative parameters among clinical data, type of treatment, recurrence, survival and anatomic pathological characteristics of the lesions. Were analyzed the histopathological reports, dental and hospital records. The highest incidence was in white men, age between 50 and 60 years, married, with low education and socioeconomic levels. The beginning of treatment occurred in average 67 days after the histopathological diagnosis. The estimated survival of patients at five years was 42%. The consumption of alcohol and tobacco and the occurrence of metastasis were statistically significant for the increase of recurrence and lethality.
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Parents' Death and its Implications for Child Survival.
Atrash, Hani K
Reduction of child mortality is a global public health priority. Parents can play an important role in reducing child mortality. The inability of one or both parents to care for their children due to death, illness, divorce or separation increases the risk of death of their children. There is increasing evidence that the health, education, and socioeconomic status of mothers and fathers have significant impact on the health and survival of their children. We conducted a literature review to explore the impact of the death of parents on the survival and wellbeing of their children and the mechanisms through which this impact is mediated. Studies have generally concluded that the death of a mother significantly increased the risk of death of her children, especially during the early years; the effect continues but is significantly reduced with increasing age through the age of 15 years. The effect of the loss of a father had less impact than the effect of losing a mother although it too had negative consequences for the survival prospect of the child. A mother's health, education, socioeconomic status, fertility behavior, environmental health conditions, nutritional status and infant feeding, and the use of health services all play an important role in the level of risk of death of her children. Efforts to achieve the Millennium Development Goal No. 4 of reducing children's under-5 mortality in developing countries by two thirds by 2015 should include promoting the health and education of women.
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Cell survival and radiation induced chromosome aberrations. Pt. 2
International Nuclear Information System (INIS)
Bauchinger, M.; Schmid, E.; Braselmann, H.
1986-01-01
Human peripheral lymphocytes were irradiated in whole blood with 0.5-4.0 Gy of 220 kVp X-rays and the frequency of chromosome aberrations was determined in 1st or 2nd division metaphases discriminated by fluorescence plus giemsa staining. Using the empirical distributions of aberrations among cells, cell survival and transmission of aberrations were investigated. Considering both daughter cells, we found that 20% of fragments and 55% of dicentrics or ring chromosomes are lost during the 1st cell division; i.e. cell survival rate from 1st to 2nd generation is mainly influenced by anaphase bridging of these two-hit aberrations. Cell survival to 2nd mitosis was calculated considering this situation and compared with the survival derived from the fraction of M1 cells without unstable aberrations. The resulting shouldered survival curves showed significantly different slopes, indicating that cell reproductive death is overestimated in the latter approach. (orig.)
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Mellado-López, Maravillas; Griffeth, Richard J; Meseguer-Ripolles, Jose; Cugat, Ramón; García, Montserrat; Moreno-Manzano, Victoria
2017-01-01
Adipose-derived stem cells (ASCs) are a promising therapeutic alternative for tissue repair in various clinical applications. However, restrictive cell survival, differential tissue integration, and undirected cell differentiation after transplantation in a hostile microenvironment are complications that require refinement. Plasma rich in growth factors (PRGF) from platelet-rich plasma favors human and canine ASC survival, proliferation, and delaying human ASC senescence and autophagocytosis in comparison with serum-containing cultures. In addition, canine and human-derived ASCs efficiently differentiate into osteocytes, adipocytes, or chondrocytes in the presence of PRGF. PRGF treatment induces phosphorylation of AKT preventing ASC death induced by lethal concentrations of hydrogen peroxide. Indeed, AKT inhibition abolished the PRGF apoptosis prevention in ASC exposed to 100 μ M of hydrogen peroxide. Here, we show that canine ASCs respond to PRGF stimulus similarly to the human cells regarding cell survival and differentiation postulating the use of dogs as a suitable translational model. Overall, PRGF would be employed as a serum substitute for mesenchymal stem cell amplification to improve cell differentiation and as a preconditioning agent to prevent oxidative cell death.
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International Nuclear Information System (INIS)
Jeon, Hyejin; Zheng, Long Tai; Lee, Shinrye; Lee, Won-Ha; Park, Nammi; Park, Jae-Yong; Heo, Won Do; Lee, Myung-Shik; Suk, Kyoungho
2011-01-01
Small G protein superfamily consists of more than 150 members, and is classified into six families: the Ras, Rho, Rab, Arf, Ran, and RGK families. They regulate a wide variety of cell functions such as cell proliferation/differentiation, cytoskeletal reorganization, vesicle trafficking, nucleocytoplasmic transport and microtubule organization. The small G proteins have also been shown to regulate cell death/survival and cell shape. In this study, we compared the role of representative members of the six families of small G proteins in cell migration and cell death/survival, two cellular phenotypes that are associated with inflammation, tumorigenesis, and metastasis. Our results show that small G proteins of the six families differentially regulate cell death and cell cycle distribution. In particular, our results indicate that Rho family of small G proteins is antiapoptotic. Ras, Rho, and Ran families promoted cell migration. There was no significant correlation between the cell death- and cell migration-regulating activities of the small G proteins. Nevertheless, RalA was not only cytoprotective against multiple chemotherapeutic drugs, but also promigratory inducing stress fiber formation, which was accompanied by the activation of Akt and Erk pathways. Our study provides a framework for further systematic investigation of small G proteins in the perspectives of cell death/survival and motility in inflammation and cancer.
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International Nuclear Information System (INIS)
Koh, Sang Hyeok; Choi, Hyoung Soo; Park, Eun Sil; Kang, Hyoung Jin; Ahn, Hyo Seop; Shin, Hee Young
2005-01-01
It has been suggested that epigenetic regulation plays an important role in maintaining the stemness and lineage differentiation of hematopoietic stem cells (HSCs), 5-aza-deoxycytidine (aza-D) and Trichostatin A (TSA) being candidate additives for HSC ex vivo expansion. Although they have potent activity to maintain the stemness, they can also cause serious cell death. This study examined the effects of mesenchymal stem cells (MSCs) on the maintenance of CD34+ cells driven by aza-D and TSA in culture with the combined cytokines of thrombopoietin, flt-3 ligand, stem cell factor, interleukin-3, and interleukin-6. In cultures without MSCs, although aza-D and TSA retained the CD34 frequency 4 to 8 times more than in the cytokines alone, a large portion of cells underwent apoptotic cell death. Consequently, CD34+ cell expansion could not be achieved in any condition without MSCs. In cultures with MSCs, the total cell number was higher in aza-D or TSA than in any conditions in the cultures without MSCs. The CD34 frequency was also similar to the level in the cultures in aza-D or TSA without the MSCs. These results suggest that a co-culture of CD34+ cells with the MSCs might not simply deliver the proliferation signals but also stemness and survival signals, and overlap the action of epigenetic regulators
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Cell death in Tetrahymena thermophila: new observations on culture conditions.
Christensen, S T; Sørensen, H; Beyer, N H; Kristiansen, K; Rasmussen, L; Rasmussen, M I
2001-01-01
We previously suggested that the cell fate of the protozoan ciliate, Tetrahymena thermophila, effectively relates to a quorum-sensing mechanism where cell-released factors support cell survival and proliferation. The cells have to be present above a critical initial density in a chemically defined nutrient medium in order to release a sufficient level of these factors to allow a new colony to flourish. At a relatively high rate of metabolism and/or macromolecular synthesis and below this critical density, cells began to die abruptly within 30 min of inoculation, and this death took the form of an explosive disintegration lasting less than 50 milliseconds. The cells died at any location in the culture, and the frequency of cell death was always lower in well-filled vials than those with medium/air interface. Cell death was inhibited by the addition of Actinomycin D or through modifications of the culture conditions either by reducing the oxygen tension or by decreasing the temperature of the growth medium. In addition, plastic caps in well-filled vials release substances, which promote cell survival. The fate of low-density cultures is related to certain 'physical' conditions, in addition to the availability of oxygen within closed culture systems. Copyright 2001 Academic Press.
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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.
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The process and promotion of radiation-induced cell death
International Nuclear Information System (INIS)
Sasaki, Hiroshi
1998-01-01
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)
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Mechanisms of redox metabolism and cancer cell survival during extracellular matrix detachment.
Hawk, Mark A; Schafer, Zachary T
2018-01-16
Non-transformed cells that become detached from the extracellular matrix (ECM) undergo dysregulation of redox homeostasis and cell death. In contrast, cancer cells often acquire the ability to mitigate programmed cell death pathways and recalibrate the redox balance to survive after ECM detachment, facilitating metastatic dissemination. Accordingly, recent studies of the mechanisms by which cancer cells overcome ECM detachment-induced metabolic alterations have focused on mechanisms in redox homeostasis. The insights into these mechanisms may inform the development of therapeutics that manipulate redox homeostasis to eliminate ECM-detached cancer cells. Here, we review how ECM-detached cancer cells balance redox metabolism for survival. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.
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Activation of CHK1 in Supporting Cells Indirectly Promotes Hair Cell Survival
Directory of Open Access Journals (Sweden)
Azadeh Jadali
2017-05-01
Full Text Available The sensory hair cells of the inner ear are exquisitely sensitive to ototoxic insults. Loss of hair cells after exposure to ototoxic agents causes hearing loss. Chemotherapeutic agents such as cisplatin causes hair cell loss. Cisplatin forms DNA mono-adducts as well as intra- and inter-strand DNA crosslinks. DNA cisplatin adducts are repaired through the DNA damage response. The decision between cell survival and cell death following DNA damage rests on factors that are involved in determining damage tolerance, cell survival and apoptosis. Cisplatin damage on hair cells has been the main focus of many ototoxic studies, yet the effect of cisplatin on supporting cells has been largely ignored. In this study, the effects of DNA damage response in cochlear supporting cells were interrogated. Supporting cells play a major role in the development, maintenance and oto-protection of hair cells. Loss of supporting cells may indirectly affect hair cell survival or maintenance. Activation of the Phosphoinositide 3-Kinase (PI3K signaling was previously shown to promote hair cell survival. To test whether activating PI3K signaling promotes supporting cell survival after cisplatin damage, cochlear explants from the neural subset (NS Cre Pten conditional knockout mice were employed. Deletion of Phosphatase and Tensin Homolog (PTEN activates PI3K signaling in multiple cell types within the cochlea. Supporting cells lacking PTEN showed increased cell survival after cisplatin damage. Supporting cells lacking PTEN also showed increased phosphorylation of Checkpoint Kinase 1 (CHK1 levels after cisplatin damage. Nearest neighbor analysis showed increased numbers of supporting cells with activated PI3K signaling in close proximity to surviving hair cells in cisplatin damaged cochleae. We propose that increased PI3K signaling promotes supporting cell survival through phosphorylation of CHK1 and increased survival of supporting cells indirectly increases hair cell
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Loss of Atrx sensitizes cells to DNA damaging agents through p53-mediated death pathways.
Directory of Open Access Journals (Sweden)
Damiano Conte
Full Text Available Prevalent cell death in forebrain- and Sertoli cell-specific Atrx knockout mice suggest that Atrx is important for cell survival. However, conditional ablation in other tissues is not associated with increased death indicating that diverse cell types respond differently to the loss of this chromatin remodeling protein. Here, primary macrophages isolated from Atrx(f/f mice were infected with adenovirus expressing Cre recombinase or β-galactosidase, and assayed for cell survival under different experimental conditions. Macrophages survive without Atrx but undergo rapid apoptosis upon lipopolysaccharide (LPS activation suggesting that chromatin reorganization in response to external stimuli is compromised. Using this system we next tested the effect of different apoptotic stimuli on cell survival. We observed that survival of Atrx-null cells were similar to wild type cells in response to serum withdrawal, anti-Fas antibody, C2 ceramide or dexamethasone treatment but were more sensitive to 5-fluorouracil (5-FU. Cell survival could be rescued by re-introducing Atrx or by removal of p53 demonstrating the cell autonomous nature of the effect and its p53-dependence. Finally, we demonstrate that multiple primary cell types (myoblasts, embryonic fibroblasts and neurospheres were sensitive to 5-FU, cisplatin, and UV light treatment. Together, our results suggest that cells lacking Atrx are more sensitive to DNA damaging agents and that this may result in enhanced death during development when cells are at their proliferative peak. Moreover, it identifies potential treatment options for cancers associated with ATRX mutations, including glioblastoma and pancreatic neuroendocrine tumors.
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Directory of Open Access Journals (Sweden)
Maravillas Mellado-López
2017-01-01
Full Text Available Adipose-derived stem cells (ASCs are a promising therapeutic alternative for tissue repair in various clinical applications. However, restrictive cell survival, differential tissue integration, and undirected cell differentiation after transplantation in a hostile microenvironment are complications that require refinement. Plasma rich in growth factors (PRGF from platelet-rich plasma favors human and canine ASC survival, proliferation, and delaying human ASC senescence and autophagocytosis in comparison with serum-containing cultures. In addition, canine and human-derived ASCs efficiently differentiate into osteocytes, adipocytes, or chondrocytes in the presence of PRGF. PRGF treatment induces phosphorylation of AKT preventing ASC death induced by lethal concentrations of hydrogen peroxide. Indeed, AKT inhibition abolished the PRGF apoptosis prevention in ASC exposed to 100 μM of hydrogen peroxide. Here, we show that canine ASCs respond to PRGF stimulus similarly to the human cells regarding cell survival and differentiation postulating the use of dogs as a suitable translational model. Overall, PRGF would be employed as a serum substitute for mesenchymal stem cell amplification to improve cell differentiation and as a preconditioning agent to prevent oxidative cell death.
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Fas/Fas ligand regulation mediates cell death in human Ewing's sarcoma cells treated with melatonin
García-Santos, G; Martin, V; Rodríguez-Blanco, J; Herrera, F; Casado-Zapico, S; Sánchez-Sánchez, A M; Antolín, I; Rodríguez, C
2012-01-01
Background: Despite recent advances in cancer therapy, the 5-year survival rate for Ewing's sarcoma is still very low, and new therapeutic approaches are necessary. It was found previously that melatonin induces cell death in the Ewing's sarcoma cell line, SK-N-MC, by activating the extrinsic apoptotic pathway. Methods: Melatonin actions were analysed by metabolic viability/survival cell assays, flow cytometry, quantitative PCR for mRNA expression, western blot for protein activation/expression and electrophoretic mobility shift assay for transcription factor activation. Results: Melatonin increases the expression of Fas and its ligand Fas L, this increase being responsible for cell death induced by the indolamine. Melatonin also produces a transient increase in intracellular oxidants and activation of the redox-regulated transcription factor Nuclear factor-kappaB. Inhibition of such activation prevents cell death and Fas/Fas L upregulation. Cytotoxic effect and Fas/Fas L regulation occur in all Ewing's cell lines studied, and do not occur in the other tumour cell lines studied where melatonin does not induce cell death. Conclusion: Our data offers new insights in the study of alternative therapeutic strategies in the treatment of Ewing's sarcoma. Further attention deserves to be given to the differences in the cellular biology of sensitive tumours that could explain the cytotoxic effect of melatonin and the increase in the level of free radicals caused by this molecule, in particular cancer types. PMID:22382690
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International Nuclear Information System (INIS)
Suzuki, Keiji; Kodama, Seiji; Watanabe, Masami
2010-01-01
Ionizing radiation induces delayed destabilization of the genome in the progenies of surviving cells. This phenomenon, which is called radiation-induced genomic instability, is manifested by delayed induction of radiation effects, such as cell death, chromosome aberration, and mutation in the progeny of cells surviving radiation exposure. Previously, there was a report showing that delayed cell death was absent in Ku80-deficient Chinese hamster ovary (CHO) cells, however, the mechanism of their defect has not been determined. We found that delayed induction of DNA double strand breaks and chromosomal breaks were intact in Ku80-deficient cells surviving X-irradiation, whereas there was no sign for the production of chromosome bridges between divided daughter cells. Moreover, delayed induction of dicentric chromosomes was significantly compromised in those cells compared to the wild-type CHO cells. Reintroduction of the human Ku86 gene complimented the defective DNA repair and recovered delayed induction of dicentric chromosomes and delayed cell death, indicating that defective Ku80-dependent dicentric induction was the cause of the absence of delayed cell death. Since DNA-PKcs-defective cells showed delayed phenotypes, Ku80-dependent illegitimate rejoining is involved in delayed impairment of the integrity of the genome in radiation-survived cells.
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Energy Technology Data Exchange (ETDEWEB)
Suzuki, Keiji, E-mail: kzsuzuki@nagasaki-u.ac.jp [Course of Life Sciences and Radiation Research, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan); Kodama, Seiji [Research Institute for Advanced Science and Technology, Osaka Prefecture University, 1-2 Gakuen-machi, Sakai 599-8570 (Japan); Watanabe, Masami [Kyoto University Research Reactor Institute, Kumatori-cho Sennan-gun, Osaka 590-0494 (Japan)
2010-01-05
Ionizing radiation induces delayed destabilization of the genome in the progenies of surviving cells. This phenomenon, which is called radiation-induced genomic instability, is manifested by delayed induction of radiation effects, such as cell death, chromosome aberration, and mutation in the progeny of cells surviving radiation exposure. Previously, there was a report showing that delayed cell death was absent in Ku80-deficient Chinese hamster ovary (CHO) cells, however, the mechanism of their defect has not been determined. We found that delayed induction of DNA double strand breaks and chromosomal breaks were intact in Ku80-deficient cells surviving X-irradiation, whereas there was no sign for the production of chromosome bridges between divided daughter cells. Moreover, delayed induction of dicentric chromosomes was significantly compromised in those cells compared to the wild-type CHO cells. Reintroduction of the human Ku86 gene complimented the defective DNA repair and recovered delayed induction of dicentric chromosomes and delayed cell death, indicating that defective Ku80-dependent dicentric induction was the cause of the absence of delayed cell death. Since DNA-PKcs-defective cells showed delayed phenotypes, Ku80-dependent illegitimate rejoining is involved in delayed impairment of the integrity of the genome in radiation-survived cells.
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Survival of egg-laying controlling neuroendocrine cells during reproductive senescence of a mollusc
Janse, C.
2004-01-01
During brain aging neuronal degradation occurs. In some neurons this may result in degeneration and cell death, still other neurons may survive and maintain their basic properties. The present study deals with survival of the egg-laying controlling neuroendocrine caudodorsal cells (CDCs) during
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Tanel, André; Pallepati, Pragathi; Bettaieb, Ahmed; Morin, Patrick; Averill-Bates, Diana A
2014-05-01
Acrolein, a highly reactive α,β-unsaturated aldehyde, is a product of endogenous lipid peroxidation. It is a ubiquitous environmental pollutant that is generated mainly by smoke, overheated cooking oil and vehicle exhaust. Acrolein damages cellular proteins, which could lead to accumulation of aberrantly-folded proteins in the endoplasmic reticulum (ER). This study determines the mechanisms involved in acrolein-induced apoptosis mediated by the ER and possible links with the ER stress response in human A549 lung cells. The exposure of cells to acrolein (15-50μM) for shorter times of 15 to 30min activated several ER stress markers. These included the ER chaperone protein BiP and the three ER sensors: (i) the survival/rescue molecules protein kinase RNA (PKR)-like ER kinase (PERK) and eukaryotic initiation factor 2 alpha (eIF2α) were phosphorylated; (ii) cleavage of activating transcription factor 6 (ATF6) occurred, and (iii) inositol-requiring protein-1 alpha (IRE1α) was phosphorylated. Acrolein (25-50μM) caused apoptotic cell death mediated by the ER after 2h, which was characterised by the induction of CHOP and activation of ER proteases calpain and caspase-4. Calpain and caspase-7 were the initiating factors for caspase-4 activation in acrolein-induced apoptosis. These results increase our knowledge about cellular responses to acrolein in lung cells, which have implications for human health. Copyright © 2014 Elsevier B.V. All rights reserved.
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Sorafenib-induced defective autophagy promotes cell death by necroptosis.
Kharaziha, Pedram; Chioureas, Dimitris; Baltatzis, George; Fonseca, Pedro; Rodriguez, Patricia; Gogvadze, Vladimir; Lennartsson, Lena; Björklund, Ann-Charlotte; Zhivotovsky, Boris; Grandér, Dan; Egevad, Lars; Nilsson, Sten; Panaretakis, Theocharis
2015-11-10
Autophagy is one of the main cytoprotective mechanisms that cancer cells deploy to withstand the cytotoxic stress and survive the lethal damage induced by anti-cancer drugs. However, under specific conditions, autophagy may, directly or indirectly, induce cell death. In our study, treatment of the Atg5-deficient DU145 prostate cancer cells, with the multi-tyrosine kinase inhibitor, sorafenib, induces mitochondrial damage, autophagy and cell death. Molecular inhibition of autophagy by silencing ULK1 and Beclin1 rescues DU145 cells from cell death indicating that, in this setting, autophagy promotes cell death. Re-expression of Atg5 restores the lipidation of LC3 and rescues DU145 and MEF atg5-/- cells from sorafenib-induced cell death. Despite the lack of Atg5 expression and LC3 lipidation, DU145 cells form autophagosomes as demonstrated by transmission and immuno-electron microscopy, and the formation of LC3 positive foci. However, the lack of cellular content in the autophagosomes, the accumulation of long-lived proteins, the presence of GFP-RFP-LC3 positive foci and the accumulated p62 protein levels indicate that these autophagosomes may not be fully functional. DU145 cells treated with sorafenib undergo a caspase-independent cell death that is inhibited by the RIPK1 inhibitor, necrostatin-1. Furthermore, treatment with sorafenib induces the interaction of RIPK1 with p62, as demonstrated by immunoprecipitation and a proximity ligation assay. Silencing of p62 decreases the RIPK1 protein levels and renders necrostatin-1 ineffective in blocking sorafenib-induced cell death. In summary, the formation of Atg5-deficient autophagosomes in response to sorafenib promotes the interaction of p62 with RIPK leading to cell death by necroptosis.
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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.
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Zinc as a paracrine effector in pancreatic islet cell death.
Kim, B J; Kim, Y H; Kim, S; Kim, J W; Koh, J Y; Oh, S H; Lee, M K; Kim, K W; Lee, M S
2000-03-01
Because of a huge amount of Zn2+ in secretory granules of pancreatic islet beta-cells, Zn2+ released in certain conditions might affect the function or survival of islet cells. We studied potential paracrine effects of endogenous Zn2+ on beta-cell death. Zn2+ induced insulinoma/islet cell death in a dose-dependent manner. Chelation of released endogenous Zn2+ by CaEDTA significantly decreased streptozotocin (STZ)-induced islet cell death in an in vitro culture system simulating in vivo circumstances but not in the conventional culture system. Zn2+ chelation in vivo by continuous CaEDTA infusion significantly decreased the incidence of diabetes after STZ administration. N-(6-methoxy-quinolyl)-para-toluene-sulfonamide staining revealed that Zn2+ was densely deposited in degenerating islet cells 24 h after STZ treatment, which was decreased by CaEDTA infusion. We show here that Zn2+ is not a passive element for insulin storage but an active participant in islet cell death in certain conditions, which in time might contribute to the development of diabetes in aged people.
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Activation-induced cell death of dendritic cells is dependent on sphingosine kinase 1
Directory of Open Access Journals (Sweden)
Anja eSchwiebs
2016-04-01
Full Text Available Sphingosine 1-phosphate (S1P is an immune modulatory lipid mediator and has been implicated in numerous pathophysiological processes. S1P is produced by sphingosine kinase 1 (Sphk1 and Sphk2. Dendritic cells (DCs are central for the direction of immune responses and crucially involved in autoimmunity and cancerogenesis. In this study we examined the function and survival of bone marrow-derived DCs under long-term inflammatory stimulation. We observed that differentiated cells undergo activation-induced cell death upon LPS stimulation with an increased metabolic activity shortly after stimulation, followed by a rapid activation of caspase 3 and subsequent augmented apoptosis. Importantly, we highlight a profound role of Sphk1 in secretion of inflammatory cytokines and survival of dendritic cells that might be mediated by a change in sphingolipid levels as well as by a change in STAT3 expression. Cell growth during differentiation of Sphk1-deficient cells treated with the functional S1P receptor antagonist FTYP was reduced. Importantly, in dendritic cells we did not observe a compensatory regulation of Sphk2 mRNA in Sphk1-deficient cells. Instead, we discovered a massive increase in Sphk1 mRNA concentration upon long-term stimulation with LPS in wild type cells that might function as an attempt to rescue from inflammation-caused cell death. Taken together, in this investigation we describe details of a crucial involvement of sphingolipids and Sphk1 in activation-induced cell death during long-term immunogenic activity of DCs that might play an important role in autoimmunity and might explain the differences in immune response observed in in vivo studies of Sphk1 modulation.
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The cell on the edge of life and death: Crosstalk between autophagy and apoptosis.
Kasprowska-Liśkiewicz, Daniela
2017-09-21
Recently, the crosstalk between autophagy and apoptosis has attracted broader attention. Basal autophagy serves to maintain cell homeostasis, while the upregulation of this process is an element of stress response that enables the cell to survive under adverse conditions. Autophagy may also determine the fate of the cell through its interactions with cell death pathways. The protein networks that control the initiation and the execution phase of these two processes are highly interconnected. Several scenarios for the crosstalk between autophagy and apoptosis exist. In most cases, the activation of autophagy represents an attempt of the cell to cope with stress, and protects the cell from apoptosis or delays its initiation. Generally, the simultaneous activation of pro-survival and pro-death pathways is prevented by the mutual inhibitory crosstalk between autophagy and apoptosis. But in some circumstances, autophagy or the proteins of the core autophagic machinery may promote cellular demise through excessive self-digestion (so-called "autophagic cell death") or by stimulating the activation of other cell death pathways. It is controversial whether cells actually die via autophagy, which is why the term "autophagic cell death" has been under intense debate lately. This review summarizes the recent findings on the multilevel crosstalk between autophagy and apoptosis in aspects of common regulators, mutual inhibition of these processes, the stimulation of apoptosis by autophagy or autophagic proteins and finally the role of autophagy as a death-execution mechanism.
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Werz, Christian; Lee, Tom V.; Lee, Peter L.; Lackey, Melinda; Bolduc, Clare; Stein, David S.; Bergmann, Andreas
2009-01-01
Summary Incorrectly specified or mis-specified cells often undergo cell death or are transformed to adopt a different cell fate during development. The underlying cause for this distinction is largely unknown. In many developmental mutants in Drosophila, large numbers of mis-specified cells die synchronously, providing a convenient model for analysis of this phenomenon. The maternal mutant bicoid is particularly useful model with which to address this issue because its mutant phenotype is a combination of both transformation of tissue (acron to telson) and cell death in the presumptive head and thorax regions. We show that a subset of these mis-specified cells die through an active gene-directed process involving transcriptional upregulation of the cell death inducer hid. Upregulation of hid also occurs in oskar mutants and other segmentation mutants. In hid bicoid double mutants, mis-specified cells in the presumptive head and thorax survive and continue to develop, but they are transformed to adopt a different cell fate. We provide evidence that the terminal torso signaling pathway protects the mis-specified telson tissue in bicoid mutants from hid-induced cell death, whereas mis-specified cells in the head and thorax die, presumably because equivalent survival signals are lacking. These data support a model whereby mis-specification can be tolerated if a survival pathway is provided, resulting in cellular transformation. PMID:16280349
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Pyridine nucleotides in regulation of cell death and survival by redox and non-redox reactions.
Novak Kujundžić, Renata; Žarković, Neven; Gall Trošelj, Koraljka
2014-01-01
Changes of the level and ratios of pyridine nucleotides determine metabolism- dependent cellular redox status and the activity of poly(ADP-ribose) polymerases (PARPs) and sirtuins, thereby influencing several processes closely related to cell survival and death. Pyridine nucleotides participate in numerous metabolic reactions whereby their net cellular level remains constant, but the ratios of NAD+/NADP+ and NADH/NADPH oscillate according to metabolic changes in response to diverse stress signals. In non-redox reactions, NAD+ is degraded and quickly, afterward, resynthesized in the NAD+ salvage pathway, unless overwhelming activation of PARP-1 consumes NAD+ to the point of no return, when the cell can no longer generate enough ATP to accommodate NAD+ resynthesis. The activity of PARP-1 is mandatory for the onset of cytoprotective autophagy on sublethal stress signals. It has become increasingly clear that redox status, largely influenced by the metabolism-dependent composition of the pyridine nucleotides pool, plays an important role in the synthesis of pro-apoptotic and anti-apoptotic sphingolipids. Awareness of the involvement of the prosurvival sphingolipid, sphingosine-1-phosphate, in transition from inflammation to malignant transformation has recently emerged. Here, the participation of pyridine nucleotides in redox and non-redox reactions, sphingolipid metabolism, and their role in cell fate decisions is reviewed.
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Cellular Glycolysis and The Differential Survival of Lung Fibroblast and Lung Carcinoma Cell Lines.
Farah, Ibrahim O
2016-04-01
Tumor growth and abnormal cell survival were shown to be associated with a number of cellular metabolic abnormalities revealed by impaired oral glucose tolerance, depressed lipoprotein lipase activity leading to hypertriglyceridemia, and changes in amino acid profile as evidenced by increased plasma free tryptophan levels in patients with breast, lung, colon, stomach, and other cancers from various origins. The above findings seem to relate to or indicate a shift to non-oxidative metabolic pathways in cancer. In contrast to normal cells, cancer cells may lose the ability to utilize aerobic respiration due to either defective mitochondria or hypoxia within the tumor microenvironments. Glucose was shown to be the major energy source in cancer cells where it utilizes aerobic /anaerobic glycolysis with the resultant lactic acid formation. The role of energetic modulations and use of glycolytic inhibitors on cancer/normal cell survival is not clearly established in the literature. We hypothesize that natural intermediates of glycolysis and the citric acid cycle will differentially and negatively impact the cancer phenotype in contrast to their no effects on the normal cell phenotype. Therefore, the purpose of this study was to evaluate six potential glycolytic modulators namely, Pyruvic acid, oxalic acid, Zn acetate, sodium citrate, fructose diphosphate (FDP) and sodium bicarbonate at μM concentrations on growing A549 (lung cancer) and MRC-5 (normal; human lung fibroblast) cell lines with the objective of determining their influence on visual impact, cell metabolic activity, cell viability and end-point cell survival. Exposed and non-exposed cells were tested with phase-contrast micro-scanning, survival/death and metabolic activity trends through MTT-assays, as well as death end-point determinations by testing re-growth on complete media and T4 cellometer counts. Results showed that oxalic acid and Zn acetate both influenced the pH of the medium and resulted in
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HAMLET (human alpha-lactalbumin made lethal to tumor cells) triggers autophagic tumor cell death.
Aits, Sonja; Gustafsson, Lotta; Hallgren, Oskar; Brest, Patrick; Gustafsson, Mattias; Trulsson, Maria; Mossberg, Ann-Kristin; Simon, Hans-Uwe; Mograbi, Baharia; Svanborg, Catharina
2009-03-01
HAMLET, a complex of partially unfolded alpha-lactalbumin and oleic acid, kills a wide range of tumor cells. Here we propose that HAMLET causes macroautophagy in tumor cells and that this contributes to their death. Cell death was accompanied by mitochondrial damage and a reduction in the level of active mTOR and HAMLET triggered extensive cytoplasmic vacuolization and the formation of double-membrane-enclosed vesicles typical of macroautophagy. In addition, HAMLET caused a change from uniform (LC3-I) to granular (LC3-II) staining in LC3-GFP-transfected cells reflecting LC3 translocation during macroautophagy, and this was blocked by the macroautophagy inhibitor 3-methyladenine. HAMLET also caused accumulation of LC3-II detected by Western blot when lysosomal degradation was inhibited suggesting that HAMLET caused an increase in autophagic flux. To determine if macroautophagy contributed to cell death, we used RNA interference against Beclin-1 and Atg5. Suppression of Beclin-1 and Atg5 improved the survival of HAMLET-treated tumor cells and inhibited the increase in granular LC3-GFP staining. The results show that HAMLET triggers macroautophagy in tumor cells and suggest that macroautophagy contributes to HAMLET-induced tumor cell death.
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International Nuclear Information System (INIS)
Damodaran, T.V.; Attia, M.K.; Abou-Donia, M.B.
2011-01-01
Organophosphorus-ester induced delayed neurotoxicity (OPIDN) is a neurodegenerative disorder characterized by ataxia progressing to paralysis with a concomitant central and peripheral, distal axonapathy. Diisopropylphosphorofluoridate (DFP) produces OPIDN in the chicken that results in mild ataxia in 7–14 days and severe paralysis as the disease progresses with a single dose. White leghorn layer hens were treated with DFP (1.7 mg/kg, sc) after prophylactic treatment with atropine (1 mg/kg, sc) in normal saline and eserine (1 mg/kg, sc) in dimethyl sulfoxide. Control groups were treated with vehicle propylene glycol (0.1 ml/kg, sc), atropine in normal saline and eserine in dimethyl sulfoxide. The hens were euthanized at different time points such as 1, 2, 5, 10 and 20 days, and the tissues from cerebrum, midbrain, cerebellum, brainstem and spinal cord were quickly dissected and frozen for mRNA (northern) studies. Northern blots were probed with BCL2, GADD45, beta actin, and 28S RNA to investigate their expression pattern. Another set of hens was treated for a series of time points and perfused with phosphate buffered saline and fixative for histological studies. Various staining protocols such as Hematoxylin and Eosin (H and E); Sevier-Munger; Cresyl echt Violet for Nissl substance; and Gallocynin stain for Nissl granules were used to assess various patterns of cell death and degenerative changes. Complex cell death mechanisms may be involved in the neuronal and axonal degeneration. These data indicate altered and differential mRNA expressions of BCL2 (anti apoptotic gene) and GADD45 (DNA damage inducible gene) in various tissues. Increased cell death and other degenerative changes noted in the susceptible regions (spinal cord and cerebellum) than the resistant region (cerebrum), may indicate complex molecular pathways via altered BCL2 and GADD45 gene expression, causing the homeostatic imbalance between cell survival and cell death mechanisms. Semi quantitative
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Blockade of maitotoxin-induced oncotic cell death reveals zeiosis
Directory of Open Access Journals (Sweden)
Schilling William P
2002-01-01
Full Text Available Abstract Background Maitotoxin (MTX initiates cell death by sequentially activating 1 Ca2+ influx via non-selective cation channels, 2 uptake of vital dyes via formation of large pores, and 3 release of lactate dehydrogenase, an indication of cell lysis. MTX also causes formation of membrane blebs, which dramatically dilate during the cytolysis phase. To determine the role of phospholipase C (PLC in the cell death cascade, U73122, a specific inhibitor of PLC, and U73343, an inactive analog, were examined on MTX-induced responses in bovine aortic endothelial cells. Results Addition of either U73122 or U73343, prior to MTX, produced a concentration-dependent inhibition of the cell death cascade (IC50 ≈ 1.9 and 0.66 μM, respectively suggesting that the effect of these agents was independent of PLC. Addition of U73343 shortly after MTX, prevented or attenuated the effects of the toxin, but addition at later times had little or no effect. Time-lapse videomicroscopy showed that U73343 dramatically altered the blebbing profile of MTX-treated cells. Specifically, U73343 blocked bleb dilation and converted the initial blebbing event into "zeiosis", a type of membrane blebbing commonly associated with apoptosis. Cells challenged with MTX and rescued by subsequent addition of U73343, showed enhanced caspase-3 activity 48 hr after the initial insult, consistent with activation of the apoptotic program. Conclusions Within minutes of MTX addition, endothelial cells die by oncosis. Rescue by addition of U73343 shortly after MTX showed that a small percentage of cells are destined to die by oncosis, but that a larger percentage survive; cells that survive the initial insult exhibit zeiosis and may ultimately die by apoptotic mechanisms.
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Exosomal lipids impact notch signaling and induce death of human pancreatic tumoral SOJ-6 cells.
Directory of Open Access Journals (Sweden)
Sadia Beloribi
Full Text Available Exosomes are of increasing interest as alternative mode of cell-to-cell communication. We previously reported that exosomes secreted by human SOJ-6 pancreatic tumor cells induce (glycoprotein ligand-independent cell death and inhibit Notch-1 pathway, this latter being particularly active during carcinogenesis and in cancer stem cells. Therefore, we asked whether exosomal lipids were key-elements for cell death and hypothesized that cholesterol-rich membrane microdomains were privileged sites of exosome interactions with tumor cells. To address these questions and based on the lipid composition of exosomes from SOJ-6 cells (Ristorcelli et al. (2008 FASEB J. 22; 3358-3369 enriched in cholesterol and sphingomyelin (lipids forming liquid-ordered phase, Lo and depleted in phospholipids (lipids forming liquid-disordered phase, Ld, we designed Synthetic Exosome-Like Nanoparticles (SELN with ratios Lo/Ld from 3.0 to 6.0 framing that of SOJ-6 cell exosomes. SELN decreased tumor cell survival, the higher the Lo/Ld ratio, the lower the cell survival. This decreased survival was due to activation of cell death with inhibition of Notch pathway. FRET analyses indicated fusions/exchanges of SELN with cell membranes. Fluorescent SELN co-localized with the ganglioside GM1 then with Rab5A, markers of lipid microdomains and of early endosomes, respectively. These interactions occurred at lipid microdomains of plasma and/or endosome membranes where the Notch-1 pathway matures. We thus demonstrated a major role for lipids in interactions between SELN and tumor cells, and in the ensued cell death. To our knowledge this is the first report on such effects of lipidic nanoparticles on tumor cell behavior. This may have implications in tumor progression.
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DEFF Research Database (Denmark)
Maddika, S; Bay, GH; Kroczak, TJ
2007-01-01
OBJECTIVES: The phosphatidylinositol 3-kinase (PI3-K)/Akt pathway is well known for the regulation of cell survival, proliferation, and some metabolic routes. MATERIALS AND METHODS: In this study, we document a novel role for the PI3-K/Akt pathway during cell death induced by apoptin, a tumour-selective....... Downstream of PI3-K, Akt is activated and translocated to the nucleus together with apoptin. Direct interaction between apoptin and Akt is documented. Co-expression of nuclear Akt significantly potentiates cell death induced by apoptin. Thus, apoptin-facilitated nuclear Akt, in contrast to when in its......, as it likely gains access to a new set of substrates in the nucleus. The implicated link between survival and cell death pathways during apoptosis opens new pharmacological opportunities to modulate apoptosis in cancer, for example through the manipulation of Akt's cellular localization....
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Nuclear DAMP complex-mediated RAGE-dependent macrophage cell death
Energy Technology Data Exchange (ETDEWEB)
Chen, Ruochan [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Department of Infectious Diseases and State Key Lab of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China); Fu, Sha; Fan, Xue-Gong [Department of Infectious Diseases and State Key Lab of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China); Lotze, Michael T.; Zeh, Herbert J. [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Tang, Daolin, E-mail: tangd2@upmc.edu [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Kang, Rui, E-mail: kangr@upmc.edu [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213 (United States)
2015-03-13
High mobility group box 1 (HMGB1), histone, and DNA are essential nuclear components involved in the regulation of chromosome structure and function. In addition to their nuclear function, these molecules act as damage-associated molecular patterns (DAMPs) alone or together when released extracellularly. The synergistic effect of these nuclear DNA-HMGB1-histone complexes as DAMP complexes (nDCs) on immune cells remains largely unexplored. Here, we demonstrate that nDCs limit survival of macrophages (e.g., RAW264.7 and peritoneal macrophages) but not cancer cells (e.g., HCT116, HepG2 and Hepa1-6). nDCs promote production of inflammatory tumor necrosis factor α (TNFα) release, triggering reactive oxygen species-dependent apoptosis and necrosis. Moreover, the receptor for advanced glycation end products (RAGE), but not toll-like receptor (TLR)-4 and TLR-2, was required for Akt-dependent TNFα release and subsequent cell death following treatment with nDCs. Genetic depletion of RAGE by RNAi, antioxidant N-Acetyl-L-cysteine, and TNFα neutralizing antibody significantly attenuated nDC-induced cell death. These findings provide evidence supporting novel signaling mechanisms linking nDCs and inflammation in macrophage cell death. - Highlights: • Nuclear DAMP complexes (nDCs) selectively induce cell death in macrophages, but not cancer cells. • TNFα-mediated oxidative stress is required for nDC-induced death. • RAGE-mediated Akt activation is required for nDC-induced TNFα release. • Blocking RAGE and TNFα inhibits nDC-induced macrophage cell death.
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Bimodal cell death induced by high radiation doses in the radioresistant sf9 insect cell line
International Nuclear Information System (INIS)
Chandna, S.
2003-01-01
Full text: This study was conducted to investigate the mode(s) of cell death induced by high radiation doses in the highly radioresistant Sf9 insect ovarian cell line. Methods: Cells were exposed to γ-radiation doses 200Gy and 500Gy, harvested at various time intervals (6h-72h) following irradiation, and subjected to cell morphology assay, DNA agarose gel electrophoresis, single cell gel electrophoresis (SCGE; comet assay) and Annexin-V labeling for the detection of membrane phosphatidylserine externalization. Cell morphology was assessed in cells entrapped and fixed in agarose gel directly from the cell suspension, thus preventing the possible loss of fragments/ apoptotic bodies. Surviving fraction of Sf9 cells was 0.01 at 200Gy and 98%) undergoing extensive DNA fragmentation at 500Gy, whereas the frequency of cells with DNA fragmentation was considerably less (∼12%) at 200Gy. Conclusions: While the mode of cell death at 200Gy seems to be different from typical apoptosis, a dose of 500Gy induced bimodal cell death, with typical apoptotic as well as the atypical cell death observed at 200Gy
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Role for protein geranylgeranylation in adult T-cell leukemia cell survival
International Nuclear Information System (INIS)
Nonaka, Mizuho; Uota, Shin; Saitoh, Yasunori; Takahashi, Mayumi; Sugimoto, Haruyo; Amet, Tohti; Arai, Ayako; Miura, Osamu; Yamamoto, Naoki; Yamaoka, Shoji
2009-01-01
Adult T-cell leukemia (ATL) is a fatal lymphoproliferative disease that develops in human T-cell leukemia virus type I (HTLV-I)-infected individuals. Despite the accumulating knowledge of the molecular biology of HTLV-I-infected cells, effective therapeutic strategies remain to be established. Recent reports showed that the hydroxyl-3-methylglutaryl (HMG)-CoA reductase inhibitor statins have anti-proliferative and apoptotic effects on certain tumor cells through inhibition of protein prenylation. Here, we report that statins hinder the survival of ATL cells and induce apoptotic cell death. Inhibition of protein geranylgeranylation is responsible for these effects, since simultaneous treatment with isoprenoid precursors, geranylgeranyl pyrophosphate or farnesyl pyrophosphate, but not a cholesterol precursor squalene, restored the viability of ATL cells. Simvastatin inhibited geranylgeranylation of small GTPases Rab5B and Rac1 in ATL cells, and a geranylgeranyl transferase inhibitor GGTI-298 reduced ATL cell viability more efficiently than a farnesyl transferase inhibitor FTI-277. These results not only unveil an important role for protein geranylgeranylation in ATL cell survival, but also implicate therapeutic potentials of statins in the treatment of ATL
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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.
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Survival and sudden cardiac death after septal ablation for hypertrophic obstructive cardiomyopathy
DEFF Research Database (Denmark)
Jensen, Morten Kvistholm; Havndrup, Ole; Hassager, Christian
2011-01-01
Reports of long-term survival and the risk of sudden cardiac death (SCD) after percutaneous transluminal septal myocardial ablation (PTSMA) in patients with hypertrophic obstructive cardiomyopathy (HOCM) are sparse.......Reports of long-term survival and the risk of sudden cardiac death (SCD) after percutaneous transluminal septal myocardial ablation (PTSMA) in patients with hypertrophic obstructive cardiomyopathy (HOCM) are sparse....
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Programmed Necrosis: A Prominent Mechanism of Cell Death following Neonatal Brain Injury
Directory of Open Access Journals (Sweden)
Raul Chavez-Valdez
2012-01-01
Full Text Available Despite the introduction of therapeutic hypothermia, neonatal hypoxic ischemic (HI brain injury remains a common cause of developmental disability. Development of rational adjuvant therapies to hypothermia requires understanding of the pathways of cell death and survival modulated by HI. The conceptualization of the apoptosis-necrosis “continuum” in neonatal brain injury predicts mechanistic interactions between cell death and hydrid forms of cell death such as programmed or regulated necrosis. Many of the components of the signaling pathway regulating programmed necrosis have been studied previously in models of neonatal HI. In some of these investigations, they participate as part of the apoptotic pathways demonstrating clear overlap of programmed death pathways. Receptor interacting protein (RIP-1 is at the crossroads between types of cellular death and survival and RIP-1 kinase activity triggers formation of the necrosome (in complex with RIP-3 leading to programmed necrosis. Neuroprotection afforded by the blockade of RIP-1 kinase following neonatal HI suggests a role for programmed necrosis in the HI injury to the developing brain. Here, we briefly review the state of the knowledge about the mechanisms behind programmed necrosis in neonatal brain injury recognizing that a significant proportion of these data derive from experiments in cultured cell and some from in vivo adult animal models. There are still more questions than answers, yet the fascinating new perspectives provided by the understanding of programmed necrosis in the developing brain may lay the foundation for new therapies for neonatal HI.
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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.
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Directory of Open Access Journals (Sweden)
Phillip Cornel J
2012-04-01
Full Text Available Abstract Background Among American men, prostate cancer is the most common, non-cutaneous malignancy that accounted for an estimated 241,000 new cases and 34,000 deaths in 2011. Previous studies have suggested that Wnt pathway inhibitory genes are silenced by CpG hypermethylation, and other studies have suggested that genistein can demethylate hypermethylated DNA. Genistein is a soy isoflavone with diverse effects on cellular proliferation, survival, and gene expression that suggest it could be a potential therapeutic agent for prostate cancer. We undertook the present study to investigate the effects of genistein on the epigenome of prostate cancer cells and to discover novel combination approaches of other compounds with genistein that might be of translational utility. Here, we have investigated the effects of genistein on several prostate cancer cell lines, including the ARCaP-E/ARCaP-M model of the epithelial to mesenchymal transition (EMT, to analyze effects on their epigenetic state. In addition, we investigated the effects of combined treatment of genistein with the histone deacetylase inhibitor vorinostat on survival in prostate cancer cells. Methods Using whole genome expression profiling and whole genome methylation profiling, we have determined the genome-wide differences in genetic and epigenetic responses to genistein in prostate cancer cells before and after undergoing the EMT. Also, cells were treated with genistein, vorinostat, and combination treatment, where cell death and cell proliferation was determined. Results Contrary to earlier reports, genistein did not have an effect on CpG methylation at 20 μM, but it did affect histone H3K9 acetylation and induced increased expression of histone acetyltransferase 1 (HAT1. In addition, genistein also had differential effects on survival and cooperated with the histone deacteylase inhibitor vorinostat to induce cell death and inhibit proliferation. Conclusion Our results suggest that
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Parents' Death and its Implications for Child Survival
Atrash, Hani K.
2011-01-01
Reduction of child mortality is a global public health priority. Parents can play an important role in reducing child mortality. The inability of one or both parents to care for their children due to death, illness, divorce or separation increases the risk of death of their children. There is increasing evidence that the health, education, and socioeconomic status of mothers and fathers have significant impact on the health and survival of their children. We conducted a literature review to e...
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Ge, Peng-Fei; Zhang, Ji-Zhou; Wang, Xiao-Fei; Meng, Fan-Kai; Li, Wen-Chen; Luan, Yong-Xin; Ling, Feng; Luo, Yi-Nan
2009-07-01
The ubiquitin-proteasome system (UPS) and lysosome-dependent macroautophagy (autophagy) are two major intracellular pathways for protein degradation. Recent studies suggest that proteasome inhibitors may reduce tumor growth and activate autophagy. Due to the dual roles of autophagy in tumor cell survival and death, the effect of autophagy on the destiny of glioma cells remains unclear. In this study, we sought to investigate whether inhibition of the proteasome can induce autophagy and the effects of autophagy on the fate of human SHG-44 glioma cells. The proteasome inhibitor MG-132 was used to induce autophagy in SHG-44 glioma cells, and the effect of autophagy on the survival of SHG-44 glioma cells was investigated using an autophagy inhibitor 3-MA. Cell viability was measured by MTT assay. Apoptosis and cell cycle were detected by flow cytometry. The expression of autophagy related proteins was determined by Western blot. MG-132 inhibited cell proliferation, induced cell death and cell cycle arrest at G(2)/M phase, and activated autophagy in SHG-44 glioma cells. The expression of autophagy-related Beclin-1 and LC3-I was significantly up-regulated and part of LC3-I was converted into LC3-II. However, when SHG-44 glioma cells were co-treated with MG-132 and 3-MA, the cells became less viable, but cell death and cell numbers at G(2)/M phase increased. Moreover, the accumulation of acidic vesicular organelles was decreased, the expression of Beclin-1 and LC3 was significantly down-regulated and the conversion of LC3-II from LC3-I was also inhibited. Inhibition of the proteasome can induce autophagy in human SHG-44 glioma cells, and inhibition of autophagy increases cell death. This discovery may shed new light on the effect of autophagy on modulating the fate of SHG-44 glioma cells.Acta Pharmacologica Sinica (2009) 30: 1046-1052; doi: 10.1038/aps.2009.71.
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Mechanisms of Sensorineural Cell Damage, Death and Survival in the Cochlea
Directory of Open Access Journals (Sweden)
Allen Frederic Ryan
2015-04-01
Full Text Available The majority of acquired hearing loss, including presbycusis, is caused by irreversible damage to the sensorineural tissues of the cochlea. This article reviews the intracellular mechanisms that contribute to sensorineural damage in the cochlea, as well as the survival signaling pathways that can provide endogenous protection and tissue rescue. These data have primarily been generated in hearing loss not directly related to age. However, there is evidence that similar mechanisms operate in presbycusis. Moreover, accumulation of damage from other causes can contribute to age-related hearing loss. Potential therapeutic interventions to balance opposing but interconnected cell damage and survival pathways, such as antioxidants, anti-apoptotics, and pro-inflammatory cytokine inhibitors, are also discussed.
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Deaths of cancer cells observed after X-Ray irradiation
International Nuclear Information System (INIS)
Kuwahara, Yoshikazu; Oikawa, Toshiyuki; Ochiai, Yasushi; Fukumoto, Motoi; Kurihara, Ai; Noma, Naoto; Shimura, Tsutomu; Fukumoto, Manabu; Ohkubo, Yasuhito
2011-01-01
Radiation induces cell death by apoptosis, autophagy (autophagic cell death, APCD), necrosis, which are respectively called type I, II, III programmed cell death, senescence, mitotic catastrophe, etc. This paper mainly describes details of authors' studies on APCD of clinically relevant radioresistant (CRR) HepG2-8960-R cells established from proliferating survivor even after repeated X-irradiation of >30 days x 2 Gy/day to the parent HepG2 cells. Autophagy forms autophagosome where many proteins are thoroughly degraded differing from proteasomal ubiquitin system, has been known essentially related to death and survival of injured cells under certain tissue conditions, and is distinguishable from other modes of cell death by morphological and cytochemical means. One of important authors' findings is as follows. APCD of CRR cells is normally seen in 20% and of the parent strain, 5%. When they are X-irradiated at 10 Gy, APCD of the latter is more (70%) than the former (40%), and no APCD is induced by 2 Gy x 5 days in the former in contrast to the latter. APCD by radiation is thus conceivably suppressed in CRR cells, suggesting that their radioresistance can be reversed by treatment to induce APCD. Autophagy is usually suppressed by mammalian target of rapamycin (mTOR), and when CRR cells are treated with rapamycin, they become radiosensitive to the comparable level to the parent HepG2. When HepG2 cells are treated with 3-methyladenine, an inhibitor of autophagy, or Beclin siRNA, they become radioresistant. For effectiveness of APCD induction and suppression on cancer therapy, results are contradictory in certain reports and autophagy should be a problem to be further elucidated from radiation biology aspect. (author)
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TP508 accelerates fracture repair by promoting cell growth over cell death
International Nuclear Information System (INIS)
Li Xinmin; Wang Hali; Touma, Edward; Qi Yuchen; Rousseau, Emma; Quigg, Richard J.; Ryaby, James T.
2007-01-01
TP508 is a synthetic 23-amino acid peptide representing a receptor-binding domain of human thrombin. We have previously shown that a single injection of TP508 accelerates fracture healing in a rat femoral fracture model. To understand how TP508 acts at the protein level during fracture healing, we compared the translational profiles between saline-control and fractured femur at six time points after TP508 treatment using the second generation of BD Clontech TM Antibody Microarray. Here, we demonstrate that TP508 accelerates fracture healing by modulating expression levels of proteins primarily involved in the functional categories of cell cycle, cellular growth and proliferation, and cell death. The majority of those proteins are physically interrelated and functionally overlapped. The action of those proteins is highlighted by a central theme of promoting cell growth via balance of cell survival over cell death signals. This appears to occur through the stimulation of several bone healing pathways including cell cycle-G1/S checkpoint regulation, apoptosis, JAK/STAT, NF-κB, PDGF, PI3K/AKT, PTEN, and ERK/MAPK
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DEFF Research Database (Denmark)
Hollmann, C Annette; Owens, Trevor; Nalbantoglu, Josephine
2006-01-01
CD40 promotes survival, proliferation, and differentiation of normal B cells but can cause activation-induced cell death in malignant B lymphocytes. CD40 ligand and anti-CD40 antibodies have been used successfully to induce apoptosis in lymphoma lines both in vitro and in xenograft tumor models. ...
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Disruptive environmental chemicals and cellular mechanisms that confer resistance to cell death.
Narayanan, Kannan Badri; Ali, Manaf; Barclay, Barry J; Cheng, Qiang Shawn; D'Abronzo, Leandro; Dornetshuber-Fleiss, Rita; Ghosh, Paramita M; Gonzalez Guzman, Michael J; Lee, Tae-Jin; Leung, Po Sing; Li, Lin; Luanpitpong, Suidjit; Ratovitski, Edward; Rojanasakul, Yon; Romano, Maria Fiammetta; Romano, Simona; Sinha, Ranjeet K; Yedjou, Clement; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Amedei, Amedeo; Brown, Dustin G; Ryan, Elizabeth P; Colacci, Annamaria; Hamid, Roslida A; Mondello, Chiara; Raju, Jayadev; Salem, Hosni K; Woodrick, Jordan; Scovassi, A Ivana; Singh, Neetu; Vaccari, Monica; Roy, Rabindra; Forte, Stefano; Memeo, Lorenzo; Kim, Seo Yun; Bisson, William H; Lowe, Leroy; Park, Hyun Ho
2015-06-01
Cell death is a process of dying within biological cells that are ceasing to function. This process is essential in regulating organism development, tissue homeostasis, and to eliminate cells in the body that are irreparably damaged. In general, dysfunction in normal cellular death is tightly linked to cancer progression. Specifically, the up-regulation of pro-survival factors, including oncogenic factors and antiapoptotic signaling pathways, and the down-regulation of pro-apoptotic factors, including tumor suppressive factors, confers resistance to cell death in tumor cells, which supports the emergence of a fully immortalized cellular phenotype. This review considers the potential relevance of ubiquitous environmental chemical exposures that have been shown to disrupt key pathways and mechanisms associated with this sort of dysfunction. Specifically, bisphenol A, chlorothalonil, dibutyl phthalate, dichlorvos, lindane, linuron, methoxychlor and oxyfluorfen are discussed as prototypical chemical disruptors; as their effects relate to resistance to cell death, as constituents within environmental mixtures and as potential contributors to environmental carcinogenesis. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Benoit, G R; Flexor, M; Besançon, F; Altucci, L; Rossin, A; Hillion, J; Balajthy, Z; Legres, L; Ségal-Bendirdjian, E; Gronemeyer, H; Lanotte, M
2001-07-01
On their own, retinoid X receptor (RXR)-selective ligands (rexinoids) are silent in retinoic acid receptor (RAR)-RXR heterodimers, and no selective rexinoid program has been described as yet in cellular systems. We report here on the rexinoid signaling capacity that triggers apoptosis of immature promyelocytic NB4 cells as a default pathway in the absence of survival factors. Rexinoid-induced apoptosis displays all features of bona fide programmed cell death and is inhibited by RXR, but not RAR antagonists. Several types of survival signals block rexinoid-induced apoptosis. RARalpha agonists switch the cellular response toward differentiation and induce the expression of antiapoptosis factors. Activation of the protein kinase A pathway in the presence of rexinoid agonists induces maturation and blocks immature cell apoptosis. Addition of nonretinoid serum factors also blocks cell death but does not induce cell differentiation. Rexinoid-induced apoptosis is linked to neither the presence nor stability of the promyelocytic leukemia-RARalpha fusion protein and operates also in non-acute promyelocytic leukemia cells. Together our results support a model according to which rexinoids activate in certain leukemia cells a default death pathway onto which several other signaling paradigms converge. This pathway is entirely distinct from that triggered by RAR agonists, which control cell maturation and postmaturation apoptosis.
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Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018
Galluzzi, L; Vitale, I; Aaronson, Sa; Abrams, Jm; Adam, D; Agostinis, P; Alnemri, Es; Altucci, L; Amelio, I; Andrews, Dw; Annicchiarico-Petruzzelli, M; Antonov, Av; Arama, E; Baehrecke, Eh; Barlev, Na
2018-01-01
Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. A...
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Tumor necrosis factor (TNF) biology and cell death.
Bertazza, Loris; Mocellin, Simone
2008-01-01
Tumor necrosis factor (TNF) was the first cytokine to be used in humans for cancer therapy. However, its role in the treatment of cancer patients is debated. Most uncertainties in this field stem from the knowledge that the pathways directly activated or indirectly affected upon TNF engagement with its receptors can ultimately lead to very different outcomes in terms of cell survival. In this article, we summarize the fundamental molecular biology aspects of this cytokine. Such a basis is a prerequisite to critically approach the sometimes conflicting preclinical and clinical findings regarding the relationship between TNF, tumor biology and anticancer therapy. Although the last decade has witnessed remarkable advances in this field, we still do not know in detail how cells choose between life and death after TNF stimulation. Understanding this mechanism will not only shed new light on the physiological significance of TNF-driven programmed cell death but also help investigators maximize the anticancer potential of this cytokine.
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Directory of Open Access Journals (Sweden)
Thomas Klein
2015-01-01
Full Text Available Endogenously formed prostacyclin (PGI2 and synthetic PGI2 analogues have recently been shown to regulate cell survival in various cell lines. To elucidate the significance of PGI2 in human breast cancer, we performed immunohistochemistry to analyze expression of prostacyclin-synthase (PGIS in 248 human breast cancer specimens obtained from surgical pathology files. We examined patients’ 10-year survival retrospectively by sending a questionnaire to their general practitioners and performed univariate analysis to determine whether PGIS expression correlated with patient survival. Lastly, the effects of PGI2 and its analogues on cell death were examined in a human breast cancer cell line (MCF-7 and a human T-cell leukemia cell line (CCRF-CEM. PGIS expression was observed in tumor cells in 48.7% of samples and was associated with a statistically significant reduction in 10-year survival (P=0.038; n=193. Transient transfection of PGIS into MCF-7 cells exposed to sulindac increased cell viability by 50% and exposure to carbaprostacyclin protected against sulindac sulfone induced apoptosis in CCRF-CEM cells. Expression of PGIS is correlated with a reduced patient survival and protects against cell death in vitro, suggesting that PGIS is a potential therapeutic target in breast cancer.
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International Nuclear Information System (INIS)
Mehnati, P.; Sasaki, Hiroshi; Morimoto, Shigeko; Yatagai, Fumio; Hanaoka, Fumio; Furusawa, Yoshiya; Kanai, Tatsuaki; Kobayashi, Yasuhiko; Wada, Seiichi
2005-01-01
The reason why relative biological effectiveness (RBE) for cell killing fell to less than unity (1.0) with very high-linear energy transfer (LET) heavy-ions ( 40 Ar: 1,640 keV/μm; 56 Fe: 780, 1,200, 2,000 keV/μm) was explored by evaluating the fraction of non-hit cell (time-lapse observation) and cells undergoing interphase death (calculation based on our previous data). Chinese hamster ovary (CHO) cells were exposed to 4 Gy (30% survival dose) of Ar (1,640 keV/μm) or Fe-ions (2,000 keV/μm). About 20% of all cells were judged to be non-hit, and about 10% cells survived radiation damage. About 70% cells died after dividing at least once (reproductive death) or without dividing (interphase death). RBE for reproductive (RBE[R]) and interphase (RBE[I]) death showed a similar LET dependence with maximum around 200 keV/μm. In this LET region, at 30% survival level, about 10% non-survivors underwent interphase death. The corresponding value for very high-LET Fe-ions (2,000 keV/μm) was not particularly high (-15%), whereas that for X-rays was less than 3%. However, reproductive death (67%) predominated over interphase death (33%) even in regard to rather severely damaged cells (1% survival level) after exposure to Fe-ions (2,000 keV/μm). These indicate that interphase death is a type of cell death characteristic for the cells exposed to high-LET radiation and is not caused by 'cellular over kill effect'. Both NHF37 (non-hit fraction at 37% survival) and inactivation cross-section for reproductive death (σ[R]) began to increase when LET exceeded 100 keV/μm. The exclusion of non-hit fraction in the calculation of surviving fraction partially prevented the fall of RBE[R] when LET exceeded 200 keV/μm. On the other hand, the mean number of lethal damage per unit dose (NLD/Gy) showed the same LET-dependent pattern as RBE[R]. These suggest that the increase in non-hit fraction and σ[R] with an increasing LET is caused by enhanced clustering of ionization and DNA damage
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Kaul, Zenia; Chakrabarti, Oishee
2018-03-25
The endosomal sorting complexes required for transport (ESCRT) proteins help in the recognition, sorting and degradation of ubiquitinated cargoes from the cell surface, long-lived proteins or aggregates, and aged organelles present in the cytosol. These proteins take part in the endo-lysosomal system of degradation. The ESCRT proteins also play an integral role in cytokinesis, viral budding and mRNA transport. Many neurodegenerative diseases are caused by toxic accumulation of cargo in the cell, which causes stress and ultimately leads to neuronal death. This accumulation of cargo occurs because of defects in the endo-lysosomal degradative pathway-loss of function of ESCRTs has been implicated in this mechanism. ESCRTs also take part in many survival processes, lack of which can culminate in neuronal cell death. While the role played by the ESCRT proteins in maintaining healthy neurons is known, their role in neurodegenerative diseases is still poorly understood. In this review, we highlight the importance of ESCRTs in maintaining healthy neurons and then suggest how perturbations in many of the survival mechanisms governed by these proteins could eventually lead to cell death; quite often these correlations are not so obviously laid out. Extensive neuronal death eventually culminates in neurodegeneration. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
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DEFF Research Database (Denmark)
Maddika, S; Ande, SR; Panigrahi, S
2007-01-01
)), and the Cip1/Waf1/Kip1-2-family (p21(Cip1/Waf1), p27(Kip1), p57(Kip2)) are shown both in the context of proliferation regulators and as contributors to the apoptotic machinery. Bcl2-family members (i.e. Bcl2, Bcl-X(L) Mcl-1(L); Bax, Bok/Mtd, Bak, and Bcl-X(S); Bad, Bid, Bim(EL), Bmf, Mcl-1(S)) are highlighted...... approaches that would involve redirecting over-active survival and proliferation pathways towards induction of apoptosis in cancer cells....
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Directory of Open Access Journals (Sweden)
Shuzi Zhang
Full Text Available BACKGROUND: Insulin-producing cell clusters (IPCCs have recently been generated in vitro from adipose tissue-derived stem cells (ASCs to circumvent islet shortage. However, it is unknown how long they can survive upon transplantation, whether they are eventually rejected by recipients, and how their long-term survival can be induced to permanently cure type 1 diabetes. IPCC graft survival is critical for their clinical application and this issue must be systematically addressed prior to their in-depth clinical trials. METHODOLOGY/PRINCIPAL FINDINGS: Here we found that IPCC grafts that differentiated from murine ASCs in vitro, unlike their freshly isolated islet counterparts, did not survive long-term in syngeneic mice, suggesting that ASC-derived IPCCs have intrinsic survival disadvantage over freshly isolated islets. Indeed, β cells retrieved from IPCC syngrafts underwent faster apoptosis than their islet counterparts. However, blocking both Fas and TNF receptor death pathways inhibited their apoptosis and restored their long-term survival in syngeneic recipients. Furthermore, blocking CD40-CD154 costimulation and Fas/TNF signaling induced long-term IPCC allograft survival in overwhelming majority of recipients. Importantly, Fas-deficient IPCC allografts exhibited certain immune privilege and enjoyed long-term survival in diabetic NOD mice in the presence of CD28/CD40 joint blockade while their islet counterparts failed to do so. CONCLUSIONS/SIGNIFICANCE: Long-term survival of ASC-derived IPCC syngeneic grafts requires blocking Fas and TNF death pathways, whereas blocking both death pathways and CD28/CD40 costimulation is needed for long-term IPCC allograft survival in diabetic NOD mice. Our studies have important clinical implications for treating type 1 diabetes via ASC-derived IPCC transplantation.
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Cell survival curves deduced from non-quantitative reactions of skin, intestinal mucosa and lung
International Nuclear Information System (INIS)
Dutreix, J.; Wambersie, A.
1975-01-01
The shape of the cell survival curve for the cell population relevant to some biological effects has been derived from the comparison of the total doses which result in the same biological effect for two irradiations delivered with N and 2N fractions in the same overall time. They show an initial slope which is interpreted as related to directly lethal, i.e. 'one-hit' or 'irreparable' events. The ratio of the initial slope and the slope at a dose D gives the contribution of the cell killing by directly lethal events relative to cell killing by accumulation of sublethal events. The bioligical effects which have been studied are: (i) dry desquamation of the skin of C 3 H mice and patients; (ii) intestinal death of BALB/c mice; and (iii) lung death of C 3 H mice. The shape of the cell survival curve has been found to be similar for skin desquamation and for intestinal death with a large contribution of lethal events, at single doses of 1000 rad. For lung death the initial tangent has a smaller slope and the shoulder is broader; this is interpreted as a relatively smaller contribution of lethal events with respect to accumulation of sublethal events. (author)
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(+)-Grandifloracin, an antiausterity agent, induces autophagic PANC-1 pancreatic cancer cell death.
Ueda, Jun-ya; Athikomkulchai, Sirivan; Miyatake, Ryuta; Saiki, Ikuo; Esumi, Hiroyasu; Awale, Suresh
2014-01-01
Human pancreatic tumors are known to be highly resistant to nutrient starvation, and this prolongs their survival in the hypovascular (austere) tumor microenvironment. Agents that retard this tolerance to nutrient starvation represent a novel antiausterity strategy in anticancer drug discovery. (+)-Grandifloracin (GF), isolated from Uvaria dac, has shown preferential toxicity to PANC-1 human pancreatic cancer cells under nutrient starvation, with a PC50 value of 14.5 μM. However, the underlying mechanism is not clear. In this study, GF was found to preferentially induce PANC-1 cell death in a nutrient-deprived medium via hyperactivation of autophagy, as evidenced by a dramatic upregulation of microtubule-associated protein 1 light chain 3. No change was observed in expression of the caspase-3 and Bcl-2 apoptosis marker proteins. GF was also found to strongly inhibit the activation of Akt, a key regulator of cancer cell survival and proliferation. Because pancreatic tumors are highly resistant to current therapies that induce apoptosis, the alternative cell death mechanism exhibited by GF provides a novel therapeutic insight into antiausterity drug candidates.
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The effects of thoughts of survival and thoughts of death on recall in the adaptive memory paradigm.
Klein, Stanley B
2014-01-01
In a recent paper Hart and Burns (2012) presented evidence that conditions that prime thoughts of one's mortality benefit recall. Drawing on the conceptual relation between thoughts of death and thoughts of survival, Hart and Burns interpret their findings as suggestive of the possibility that death-related thoughts function in manner similar to survival-related thoughts in enhancing recall. In the present study I draw on evolutionary arguments to question whether a conceptual relation between thoughts of death and thoughts of survival translates into a functional relation. I then present data showing that while death-related thoughts can promote high levels of recall, (a) the level achieved does not match that produced by survival processing and (b) survival and death cognition likely rely on different mechanisms to achieve their effects.
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Chikungunya virus–induced autophagy delays caspase-dependent cell death
Joubert, Pierre-Emmanuel; Werneke, Scott W.; de la Calle, Claire; Guivel-Benhassine, Florence; Giodini, Alessandra; Peduto, Lucie; Levine, Beth; Schwartz, Olivier; Lenschow, Deborah J.
2012-01-01
Autophagy is an important survival pathway and can participate in the host response to infection. Studying Chikungunya virus (CHIKV), the causative agent of a major epidemic in India, Southeast Asia, and southern Europe, we reveal a novel mechanism by which autophagy limits cell death and mortality after infection. We use biochemical studies and single cell multispectral assays to demonstrate that direct infection triggers both apoptosis and autophagy. CHIKV-induced autophagy is mediated by the independent induction of endoplasmic reticulum and oxidative stress pathways. These cellular responses delay apoptotic cell death by inducing the IRE1α–XBP-1 pathway in conjunction with ROS-mediated mTOR inhibition. Silencing of autophagy genes resulted in enhanced intrinsic and extrinsic apoptosis, favoring viral propagation in cultured cells. Providing in vivo evidence for the relevance of our findings, Atg16LHM mice, which display reduced levels of autophagy, exhibited increased lethality and showed a higher sensitivity to CHIKV-induced apoptosis. Based on kinetic studies and the observation that features of apoptosis and autophagy were mutually exclusive, we conclude that autophagy inhibits caspase-dependent cell death but is ultimately overwhelmed by viral replication. Our study suggests that inducers of autophagy may limit the pathogenesis of acute Chikungunya disease. PMID:22508836
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Cytoprotective effects of fisetin against hypoxia-induced cell death in PC12 cells.
Chen, Pei-Yi; Ho, Yi-Ru; Wu, Ming-Jiuan; Huang, Shun-Ping; Chen, Po-Kong; Tai, Mi-Hsueh; Ho, Chi-Tang; Yen, Jui-Hung
2015-01-01
Fisetin (3,7,3',4'-tetrahydroxyflavone), a flavonol compound of flavonoids, exhibits a broad spectrum of biological activities including anti-oxidant, anti-inflammatory, anti-cancer and neuroprotective effects. The aim of this study is to investigate the cytoprotective effect of fisetin and the underlying molecular mechanism against hypoxia-induced cell death in PC12 cells. The results of this study showed that fisetin significantly restored the cell viability of PC12 cells under both cobalt chloride (CoCl₂)- and low oxygen-induced hypoxic conditions. Treatment with fisetin successfully reduced the CoCl₂-mediated reactive oxygen species (ROS) production, which was accompanied by an increase in the cell viability of PC12 cells. Furthermore, we found that treatment of PC12 cells with fisetin markedly upregulated hypoxia-inducible factor 1α (HIF-1α), its nuclear accumulation and the hypoxia-response element (HRE)-driven transcriptional activation. The fisetin-mediated cytoprotection during CoCl₂ exposure was significantly attenuated through the administration of HIF-1α siRNA. Moreover, we demonstrated that MAPK/ERK kinase 1/2 (MEK1/2), p38 MAPK and phosphatidylinositol 3-kinase (PI3 K) inhibitors significantly blocked the increase in cell survival that was induced by fisetin treatment under hypoxic conditions. Consistently, increased phosphorylation of ERK, p38 and Akt proteins was observed in PC12 cells treated with fisetin. However, the fisetin-induced HRE-driven transcription was not affected by inhibition of these kinase signaling pathways. Current results reveal for the first time that fisetin promotes cell survival and protects against hypoxia-induced cell death through ROS scavenging and the activation of HIF1α-, MAPK/ERK-, p38 MAPK- and PI3 K/Akt-dependent signaling pathways in PC12 cells.
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MK-2206, an AKT Inhibitor, Promotes Caspase-Independent Cell Death and Inhibits Leiomyoma Growth
Sefton, Elizabeth C.; Qiang, Wenan; Serna, Vanida; Kurita, Takeshi; Wei, Jian-Jun; Chakravarti, Debabrata
2013-01-01
Uterine leiomyomas (ULs), benign tumors of the myometrium, are the number one indication for hysterectomies in the United States due to a lack of an effective alternative therapy. ULs show activation of the pro-survival AKT pathway compared with normal myometrium; however, substantial data directly linking AKT to UL cell survival are lacking. We hypothesized that AKT promotes UL cell survival and that it is a viable target for inhibiting UL growth. We used the investigational AKT inhibitor MK-2206, currently in phase II trials, on cultured primary human UL and myometrial cells, immortalized leiomyoma cells, and in leiomyoma grafts grown under the kidney capsule in mice. MK-2206 inhibited AKT and PRAS40 phosphorylation but did not regulate serum- and glucocorticoid-induced kinase and ERK1/2, demonstrating its specificity for AKT. MK-2206 reduced UL cell viability and decreased UL tumor volumes. UL cells exhibited disruption of mitochondrial structures and underwent cell death that was independent of caspases. Additionally, mammalian target of rapamycin and p70S6K phosphorylation were reduced, indicating that mammalian target of rapamycin complex 1 signaling was compromised by AKT inhibition in UL cells. MK-2206 also induced autophagy in UL cells. Pretreatment of primary UL cells with 3-methyladenine enhanced MK-2206-mediated UL cell death, whereas knockdown of ATG5 and/or ATG7 did not significantly influence UL cell viability in the presence of MK-2206. Our data provide molecular evidence for the involvement of AKT in UL cell survival and suggest that AKT inhibition by MK-2206 may be a viable option to consider for the treatment of ULs. PMID:24002033
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Cell Death in C. elegans Development.
Malin, Jennifer Zuckerman; Shaham, Shai
2015-01-01
Cell death is a common and important feature of animal development, and cell death defects underlie many human disease states. The nematode Caenorhabditis elegans has proven fertile ground for uncovering molecular and cellular processes controlling programmed cell death. A core pathway consisting of the conserved proteins EGL-1/BH3-only, CED-9/BCL2, CED-4/APAF1, and CED-3/caspase promotes most cell death in the nematode, and a conserved set of proteins ensures the engulfment and degradation of dying cells. Multiple regulatory pathways control cell death onset in C. elegans, and many reveal similarities with tumor formation pathways in mammals, supporting the idea that cell death plays key roles in malignant progression. Nonetheless, a number of observations suggest that our understanding of developmental cell death in C. elegans is incomplete. The interaction between dying and engulfing cells seems to be more complex than originally appreciated, and it appears that key aspects of cell death initiation are not fully understood. It has also become apparent that the conserved apoptotic pathway is dispensable for the demise of the C. elegans linker cell, leading to the discovery of a previously unexplored gene program promoting cell death. Here, we review studies that formed the foundation of cell death research in C. elegans and describe new observations that expand, and in some cases remodel, this edifice. We raise the possibility that, in some cells, more than one death program may be needed to ensure cell death fidelity. © 2015 Elsevier Inc. All rights reserved.
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Role and regulation of apoptotic cell death in the kidney. Y2K update.
Ortiz, A; Lorz, C; Catalan, M P; Justo, P; Egido, J
2000-08-01
Apoptosis is an active form of cell death that, in balance with mitosis, regulates cell number. Cell number abnormalities are a frequent feature of renal disease. We now review current concepts on the molecular regulation of apoptotic cell death, including the influence of survival and lethal factors from the extracellular microenvironment as well as the role of intracellular regulators of apoptosis, such as death receptors, proapoptotic and antiapoptotic bcl2-related proteins, the mitochondria and caspases. In addition the role of apoptosis in the genesis, persistence and progression and remodeling and resolution of renal injury is discussed. Information on the expression and function of apoptosis regulatory proteins in specific renal syndromes is summarized. Finally, future perspectives in research and clinical intervention are discussed.
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Nitrosothiol signaling and protein nitrosation in cell death.
Iyer, Anand Krishnan V; Rojanasakul, Yon; Azad, Neelam
2014-11-15
Nitric oxide, a reactive free radical, is an important signaling molecule that can lead to a plethora of cellular effects affecting homeostasis. A well-established mechanism by which NO manifests its effect on cellular functions is the post-translational chemical modification of cysteine thiols in substrate proteins by a process known as S-nitrosation. Studies that investigate regulation of cellular functions through NO have increasingly established S-nitrosation as the primary modulatory mechanism in their respective systems. There has been a substantial increase in the number of reports citing various candidate proteins undergoing S-nitrosation, which affects cell-death and -survival pathways in a number of tissues including heart, lung, brain and blood. With an exponentially growing list of proteins being identified as substrates for S-nitrosation, it is important to assimilate this information in different cell/tissue systems in order to gain an overall view of protein regulation of both individual proteins and a class of protein substrates. This will allow for broad mapping of proteins as a function of S-nitrosation, and help delineate their global effects on pathophysiological responses including cell death and survival. This information will not only provide a much better understanding of overall functional relevance of NO in the context of various disease states, it will also facilitate the generation of novel therapeutics to combat specific diseases that are driven by NO-mediated S-nitrosation. Copyright © 2014 Elsevier Inc. All rights reserved.
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Fang, Shenglin; Yu, Xiaonan; Ding, Haoxuan; Han, Jianan; Feng, Jie
2018-06-11
Iron overload causes many diseases, while the underlying etiologies of these diseases are unclear. Cell death processes including apoptosis, necroptosis, cyclophilin D-(CypD)-dependent necrosis and a recently described additional form of regulated cell death called ferroptosis, are dependent on iron or iron-dependent reactive oxygen species (ROS). However, whether the accumulation of intracellular iron itself induces ferroptosis or other forms of cell death is largely elusive. In present study, we study the role of intracellular iron overload itself-induced cell death mechanisms by using ferric ammonium citrate (FAC) and a membrane-permeable Ferric 8-hydroxyquinoline complex (Fe-8HQ) respectively. We show that FAC-induced intracellular iron overload causes ferroptosis. We also identify 3-phosphoinositide-dependent kinase 1 (PDK1) inhibitor GSK2334470 as a potent ferroptosis inhibitor. Whereas, Fe-8HQ-induced intracellular iron overload causes unregulated necrosis, but partially activates PARP-1 dependent parthanatos. Interestingly, we identify many phenolic compounds as potent inhibitors of Fe-8HQ-induced cell death. In conclusion, intracellular iron overload-induced cell death form might be dependent on the intracellular iron accumulation rate, newly identified cell death inhibitors in our study that target ferroptosis and unregulated oxidative cell death represent potential therapeutic strategies against iron overload related diseases. Copyright © 2018 Elsevier Inc. All rights reserved.
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Survival and mortality among users and non-users of hydroxyurea with sickle cell disease.
de Araujo, Olinda Maria Rodrigues; Ivo, Maria Lúcia; Ferreira Júnior, Marcos Antonio; Pontes, Elenir Rose Jardim Cury; Bispo, Ieda Maria Gonçalves Pacce; de Oliveira, Eveny Cristine Luna
2015-01-01
to estimate survival, mortality and cause of death among users or not of hydroxyurea with sickle cell disease. cohort study with retrospective data collection, from 1980 to 2010 of patients receiving inpatient treatment in two Brazilian public hospitals. The survival probability was determined using the Kaplan-Meier estimator, survival calculations (SPSS version 10.0), comparison between survival curves, using the log rank method. The level of significance was p=0.05. of 63 patients, 87% had sickle cell anemia, with 39 using hydroxyurea, with a mean time of use of the drug of 20.0±10.0 years and a mean dose of 17.37±5.4 to 20.94±7.2 mg/kg/day, raising the fetal hemoglobin. In the comparison between those using hydroxyurea and those not, the survival curve was greater among the users (p=0.014). A total of 10 deaths occurred, with a mean age of 28.1 years old, and with Acute Respiratory Failure as the main cause. the survival curve is greater among the users of hydroxyurea. The results indicate the importance of the nurse incorporating therapeutic advances of hydroxyurea in her care actions.
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Megasporogenesis and programmed cell death in Tillandsia (Bromeliaceae).
Papini, Alessio; Mosti, Stefano; Milocani, Eva; Tani, Gabriele; Di Falco, Pietro; Brighigna, Luigi
2011-10-01
The degeneration of three of four meiotic products is a very common process in the female gender of oogamous eukaryotes. In Tillandsia (and many other angiosperms), the surviving megaspore has a callose-free wall in chalazal position while the other three megaspores are completely embedded in callose. Therefore, nutrients and signals can reach more easily the functional megaspore from the nucellus through the chalazal pole with respect to the other megaspores. The abortion of three of four megaspores was already recognized as the result of a programmed cell death (PCD) process. We investigated the process to understand the modality of this specific type of PCD and its relationship to the asymmetric callose deposition around the tetrad. The decision on which of the four megaspores will be the supernumerary megaspores in angiosperms, and hence destined to undergo programmed cell death, appears to be linked to the callose layer deposition around the tetrad. During supernumerary megaspores degeneration, events leading to the deletion of the cells do not appear to belong to a single type of cell death. The first morphological signs are typical of autophagy, including the formation of autophagosomes. The TUNEL positivity and a change in morphology of mitochondria and chloroplasts indicate the passage to an apoptotic-like PCD phase, while the cellular remnants undergo a final process resembling at least partially (ER swelling) necrotic morphological syndromes, eventually leading to a mainly lipidic cell corpse still separated from the functional megaspore by a callose layer.
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Kang, Minyong; Jeong, Chang Wook; Ku, Ja Hyeon; Kwak, Cheol; Kim, Hyeon Hoe
2014-01-01
Statins are cholesterol reduction agents that exhibit anti-cancer activity in several human cancers. Because autophagy is a crucial survival mechanism for cancer cells under stress conditions, cooperative inhibition of autophagy acts synergistically with other anti-cancer drugs. Thus, this study investigates whether combined treatment of atorvastatin and autophagy inhibitors results in enhancing the cytotoxic effects of atorvastatin, upon human bladder cancer cells, T24 and J82, in vitro. To measure cell viability, we performed the EZ-Cytox cell viability assay. We examined apoptosis by flow cytometry using annexin-V/propidium iodide (PI and western blot using procaspase-3 and poly (ADP-ribose) polymerase (PARP) antibodies. To examine autophagy activation, we evaluated the co-localization of LC3 and LysoTracker by immunocytochemistry, as well as the expression of LC3 and p62/sequestosome-1 (SQSTM1) by western blot. In addition, we assessed the survival and proliferation of T24 and J82 cells by a clonogenic assay. We found that atorvastatin reduced the cell viability of T24 and J82 cells via apoptotic cell death and induced autophagy activation, shown by the co-localization of LC3 and LysoTracker. Moreover, pharmacologic inhibition of autophagy significantly enhanced atorvastatin-induced apoptosis in T24 and J82 cells. In sum, inhibition of autophagy potentiates atorvastatin-induced apoptotic cell death in human bladder cancer cells in vitro, providing a potential therapeutic approach to treat bladder cancer. PMID:24815071
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Setting the stage for medieval plague: Pre-black death trends in survival and mortality.
DeWitte, Sharon N
2015-11-01
The 14(th) -century Black Death was one of the most devastating epidemics in human history, killing tens of millions of people in a short period of time. It is not clear why mortality rates during the epidemic were so high. One possibility is that the affected human populations were particularly stressed in the 14(th) century, perhaps as a result of repeated famines in areas such as England. This project examines survival and mortality in two pre-Black Death time periods, 11-12(th) centuries vs 13(th) century CE, to determine if demographic conditions were deteriorating before the epidemic occurred. This study is done using a sample of individuals from several London cemeteries that have been dated, in whole or in part, either to the 11-12(th) centuries (n = 339) or 13(th) century (n = 258). Temporal trends in survivorship and mortality are assessed via Kaplan-Meier survival analysis and by modeling time period as a covariate affecting the Gompertz hazard of adult mortality. The age-at-death distributions from the two pre-Black Death time periods are significantly different, with fewer older adults in 13(th) century. The results of Kaplan-Meier survival analysis indicate reductions in survival before the Black Death, with significantly lower survival in the 13(th) century (Mantel Cox p < 0.001). Last, hazard analysis reveals increases in mortality rates before the Black Death. Together, these results suggest that health in general was declining in the 13(th) century, and this might have led to high mortality during the Black Death. This highlights the importance of considering human context to understand disease in past and living human populations. © 2015 Wiley Periodicals, Inc.
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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
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Wang, Qian; Huang, Lihong; Yue, Jianbo
2017-06-01
High intracellular levels of reactive oxygen species (ROS) cause oxidative stress that results in numerous pathologies, including cell death. Transient potential receptor melastatin-2 (TRPM2), a Ca 2+ -permeable cation channel, is mainly activated by intracellular adenosine diphosphate ribose (ADPR) in response to oxidative stress. Here we studied the role and mechanisms of TRPM2-mediated Ca 2+ influx on oxidative stress-induced cell death in cancer cells. We found that oxidative stress activated the TRPM2-Ca 2+ -CaMKII cascade to inhibit early autophagy induction, which ultimately led to cell death in TRPM2 expressing cancer cells. On the other hand, TRPM2 knockdown switched cells from cell death to autophagy for survival in response to oxidative stress. Moreover, we found that oxidative stress activated the TRPM2-CaMKII cascade to further induce intracellular ROS production, which led to mitochondria fragmentation and loss of mitochondrial membrane potential. In summary, our data demonstrated that oxidative stress activates the TRPM2-Ca 2+ -CaMKII-ROS signal loop to inhibit autophagy and induce cell death. Copyright © 2016 Elsevier B.V. All rights reserved.
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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.
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Crotamine and crotoxin interact with tumor cells and trigger cell death
International Nuclear Information System (INIS)
Soares, Marcella Araugio; Pujatti, Priscilla Brunelli; Santos, Raquel Gouvea dos; Dias, Consuelo Latorre Fortes; Chavez Olortegui, Carlos Delfin; Santos, Wagner Gouvea dos
2007-01-01
Crotoxin (Crtx) and Crotamine (Crota) are polypeptides isolated from Crotalus durissus terrificus snake venom (CV). Previous reports have been shown therapeutic effects of Crotalus durissus terrificus venom and Crtx on skin, breast and lung tumours, although, the mechanisms of this antitumoral effect are still unknown. The aim of this work was to investigate the antitumoral effect of Crtx and Crota on brain tumours cells (GH3 and RT2) in vitro and their capacity of interaction with these tumour cells membranes. Cell survival after Crtx and Crota treatment was evaluated by MTT assay in different times post-treatment and apoptosis was evaluated by DAPI staining. In order to evaluate the specific interaction of Crtx and Crota, these polypeptides were radiolabelled, using 125 I as radiotracer and binding assays were performed. The results were compared with the binding in nontumoral brain tissue. Crtx and Crota induced apoptosis on both tumour cells lineages but, Crota was more powerful than Crtx 90% and 20% cell death for RT2 cells; 80% and 20% cell death for GH3 cells, respectively). Both 125 I-Crtx and 125 I-Crota bound specifically in glioblastoma membranes. Nonetheless, CV polypeptides recognised glioblastoma cells with higher specificity than normal brain tissue. These results suggest that the Crtx and Crota interactions with the plasmatic membrane of tumour cells may be the first step of the cascade of signalling that trigger their antitumoral effect. (author)
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Cytoplasmic PELP1 and ERRgamma protect human mammary epithelial cells from Tam-induced cell death.
Girard, Brian J; Regan Anderson, Tarah M; Welch, Siya Lem; Nicely, Julie; Seewaldt, Victoria L; Ostrander, Julie H
2015-01-01
Tamoxifen (Tam) is the only FDA-approved chemoprevention agent for pre-menopausal women at high risk for developing breast cancer. While Tam reduces a woman's risk of developing estrogen receptor positive (ER+) breast cancer, the molecular mechanisms associated with risk reduction are poorly understood. Prior studies have shown that cytoplasmic proline, glutamic acid and leucine rich protein 1 (PELP1) promotes Tam resistance in breast cancer cell lines. Herein, we tested for PELP1 localization in breast epithelial cells from women at high risk for developing breast cancer and found that PELP1 was localized to the cytoplasm in 36% of samples. In vitro, immortalized HMECs expressing a nuclear localization signal (NLS) mutant of PELP1 (PELP1-cyto) were resistant to Tam-induced death. Furthermore, PELP1-cyto signaling through estrogen-related receptor gamma (ERRγ) promoted cell survival in the presence of Tam. Overexpression of ERRγ in immortalized HMECs protected cells from Tam-induced death, while knockdown of ERRγ sensitized PELP1-cyto expressing HMECs to Tam. Moreover, Tam-induced HMEC cell death was independent of apoptosis and involved accumulation of the autophagy marker LC3-II. Expression of PELP1-cyto and ERRγ reduced Tam-induced LC3-II accumulation, and knockdown of ERRγ increased LC3-II levels in response to Tam. Additionally, PELP1-cyto expression led to the upregulation of MMP-3 and MAOB, known PELP1 and ERRγ target genes, respectively. Our data indicate that cytoplasmic PELP1 induces signaling pathways that converge on ERRγ to promote cell survival in the presence of Tam. These data suggest that PELP1 localization and/or ERRγ activation could be developed as tissue biomarkers for Tam responsiveness.
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Long-term survival and causes of death after stroke
DEFF Research Database (Denmark)
Brønnum-Hansen, Henrik; Davidsen, M; Thorvaldsen, P
2001-01-01
As part of the Danish contribution to the World Health Organization (WHO) MONICA (Monitoring Trends and Determinants in Cardiovascular Disease) Project, a register of patients with stroke was established in 1982. The purpose of the present study was to analyze long-term survival and causes of death...
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Quan, Li; Ishikawa, Takaki; Michiue, Tomomi; Li, Dong-Ri; Zhao, Dong; Yoshida, Chiemi; Chen, Jian-Hua; Komatsu, Ayumi; Azuma, Yoko; Sakoda, Shigeki; Zhu, Bao-Li; Maeda, Hitoshi
2009-04-01
To investigate hematological and serum protein profiles of cadaveric heart blood with regard to the cause of death, serial forensic autopsy cases (n=308, >18 years of age, within 48 h postmortem) were examined. Red blood cells (Rbc), hemoglobin (Hb), platelets (Plt), white blood cells (Wbc), total protein (TP) and albumin (Alb) were examined in bilateral cardiac blood. Blood cell counts, collected after turning the bodies at autopsy, approximated to the clinical values. Postmortem changes were not significant for these markers. In non-head blunt injury cases, Rbc counts, Hb, TP and Alb levels in bilateral cardiac blood were lower in subacute deaths (survival time, 1-12 h) than in acute deaths (survival time hematology analyzer than by using a blood smear test, suggesting Rbc fragmentation caused by deep burns, while increases in Wbc count and decreases in Alb levels were seen for subacute deaths. For asphyxiation, Rbc count, Hb, TP and Alb levels in bilateral cardiac blood were higher than other groups, and TP and Alb levels in the right cardiac blood were higher for hanging than for strangulation. These findings suggest that analyses of blood cells and proteins are useful for investigating the cause of death.
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8-aminoadenosine enhances radiation-induced cell death in human lung carcinoma A549 cells
International Nuclear Information System (INIS)
Meike, Shunsuke; Yamamori, Tohru; Yasui, Hironobu; Eitaki, Masato; Inanami, Osamu; Matsuda, Akira
2011-01-01
The combination of a chemotherapeutic agent and radiation is widely applied to enhance cell death in solid tumor cells in cancer treatment. The purine analogue 8-aminoadenosine (8-NH 2 -Ado) is known to be a transcription inhibitor that has proved very effective in multiple myeloma cell lines and primary indolent leukemia cells. In this report, to examine whether 8-NH 2 -Ado had the ability to enhance the radiation-induced cell killing in solid tumor cells, human lung adenocarcinoma A549 cells were irradiated in the presence and absence of 8-NH 2 -Ado. 8-NH 2 -Ado significantly increased reproductive cell death and apoptosis in A549 cells exposed to X-rays. When peptide inhibitors against caspase-3, -8, and -9 were utilized to evaluate the involvement of caspases, all inhibitors suppressed the enhancement of radiation-induced apoptosis, suggesting that not only mitochondria-mediated apoptotic signal transduction pathways but also death receptor-mediated pathways were involved in this enhancement of apoptosis. In addition, in the cells exposed to the treatment combining X-irradiation and 8-NH 2 -Ado, reduction of the intracellular ATP concentration was essential for survival, and down-regulation of the expression of antiapoptotic proteins such as survivin and X-linked inhibitor of apoptosis protein (XIAP) was observed. These results indicate that 8-NH 2 -Ado has potential not only as an anti-tumor drug for leukemia and lymphoma but also as a radiosensitizing agent for solid tumors. (author)
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Energy Technology Data Exchange (ETDEWEB)
Nishioka, Yasuji (Hiroshima Univ. (Japan). School of Medicine)
1990-08-01
Radiosensitivity, thermosensitivity, drug sensitivity and their combined effects were investigated in mouse L5178Y-wild cells (LY-W) and L5178Y-sensitive cells (LY-S). The following results were obtained: LY-S were more radiosensitive than LY-W but were similar in their thermosensitivity. Thermotolerance induction was similar but the decay was faster in LY-W which had a shorter doubling time. The radiosensitizing effect of heating was similar in both cell lines. The thermal enhancement ratio was higher for a longer duration of heating at 42degC than for a shorter duration at 44degC, both of which exhibited a similar level of survival when applied alone. The eosin staining method was useful to detect heat-induced interphase death and thermal sensitizing effects of drugs. In LY-W, interphase death was the main mode of hyperthermic cell killing and was independent of the hyperthermic temperature, whereas in LY-S, the percentage of interphase death increased with the hyperthermic temperature. Procaine and bleomycin sensitized both cells to heat. Survival estimated by the eosin staining method shifted towards that obtained by colony forming method in heated LY-S after procaine. Sensitization to heat by procaine suggests that interphase death after hyperthermia is probably due to membrane damage. Comparison of the present work with previous ones, further suggests that with an increase in thermosensitivity, there is an increase in heat-induced interphase death. (author) 67 refs.
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International Nuclear Information System (INIS)
Nishioka, Yasuji
1990-01-01
Radiosensitivity, thermosensitivity, drug sensitivity and their combined effects were investigated in mouse L5178Y-wild cells (LY-W) and L5178Y-sensitive cells (LY-S). The following results were obtained: LY-S were more radiosensitive than LY-W but were similar in their thermosensitivity. Thermotolerance induction was similar but the decay was faster in LY-W which had a shorter doubling time. The radiosensitizing effect of heating was similar in both cell lines. The thermal enhancement ratio was higher for a longer duration of heating at 42degC than for a shorter duration at 44degC, both of which exhibited a similar level of survival when applied alone. The eosin staining method was useful to detect heat-induced interphase death and thermal sensitizing effects of drugs. In LY-W, interphase death was the main mode of hyperthermic cell killing and was independent of the hyperthermic temperature, whereas in LY-S, the percentage of interphase death increased with the hyperthermic temperature. Procaine and bleomycin sensitized both cells to heat. Survival estimated by the eosin staining method shifted towards that obtained by colony forming method in heated LY-S after procaine. Sensitization to heat by procaine suggests that interphase death after hyperthermia is probably due to membrane damage. Comparison of the present work with previous ones, further suggests that with an increase in thermosensitivity, there is an increase in heat-induced interphase death. (author) 67 refs
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Radiation induced reproductive death as a function of mammalian cell ploidy
International Nuclear Information System (INIS)
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 0 C, 4 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 3 HTdR and 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 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
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Energy Technology Data Exchange (ETDEWEB)
Anvekar, Rina A.; Asciolla, James J.; Missert, Derek J.; Chipuk, Jerry E., E-mail: jerry.chipuk@mssm.edu [Department of Oncological Sciences, Mount Sinai School of Medicine, New York, NY (United States); Department of Dermatology, Mount Sinai School of Medicine, New York, NY (United States); The Tisch Cancer Institute, Mount Sinai Medical Center, New York, NY (United States)
2011-10-13
The global incidence of melanoma has dramatically increased during the recent decades, yet the advancement of primary and adjuvant therapies has not kept a similar pace. The development of melanoma is often centered on cellular signaling that hyper-activates survival pathways, while inducing a concomitant blockade to cell death. Aberrations in cell death signaling not only promote tumor survival and enhanced metastatic potential, but also create resistance to anti-tumor strategies. Chemotherapeutic agents target melanoma tumor cells by inducing a form of cell death called apoptosis, which is governed by the BCL-2 family of proteins. The BCL-2 family is comprised of anti-apoptotic proteins (e.g., BCL-2, BCL-xL, and MCL-1) and pro-apoptotic proteins (e.g., BAK, BAX, and BIM), and their coordinated regulation and function are essential for optimal responses to chemotherapeutics. Here we will discuss what is currently known about the mechanisms of BCL-2 family function with a focus on the signaling pathways that maintain melanoma tumor cell survival. Importantly, we will critically evaluate the literature regarding how chemotherapeutic strategies directly impact on BCL-2 family function and offer several suggestions for future regimens to target melanoma and enhance patient survival.
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Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018
Galluzzi, Lorenzo; Vitale, Ilio; Aaronson, Stuart A.; Abrams, John M.; Adam, Dieter; Agostinis, Patrizia; Alnemri, Emad S.; Altucci, Lucia; Amelio, Ivano; Andrews, David W.; Annicchiarico-Petruzzelli, Margherita; Antonov, Alexey V.; Arama, Eli; Baehrecke, Eric H.; Barlev, Nickolai A.; Bazan, Nicolas G.; Bernassola, Francesca; Bertrand, Mathieu J. M.; Bianchi, Katiuscia; Blagosklonny, Mikhail V.; Blomgren, Klas; Borner, Christoph; Boya, Patricia; Brenner, Catherine; Campanella, Michelangelo; Candi, Eleonora; Carmona-Gutierrez, Didac; Cecconi, Francesco; Chan, Francis K.-M.; Chandel, Navdeep S.; Cheng, Emily H.; Chipuk, Jerry E.; Cidlowski, John A.; Ciechanover, Aaron; Cohen, Gerald M.; Conrad, Marcus; Cubillos-Ruiz, Juan R.; Czabotar, Peter E.; D'Angiolella, Vincenzo; Dawson, Ted M.; Dawson, Valina L.; de Laurenzi, Vincenzo; de Maria, Ruggero; Debatin, Klaus-Michael; DeBerardinis, Ralph J.; Deshmukh, Mohanish; Di Daniele, Nicola; Di Virgilio, Francesco; Dixit, Vishva M.; Dixon, Scott J.; Duckett, Colin S.; Dynlacht, Brian D.; El-Deiry, Wafik S.; Elrod, John W.; Fimia, Gian Maria; Fulda, Simone; García-Sáez, Ana J.; Garg, Abhishek D.; Garrido, Carmen; Gavathiotis, Evripidis; Golstein, Pierre; Gottlieb, Eyal; Green, Douglas R.; Greene, Lloyd A.; Gronemeyer, Hinrich; Gross, Atan; Hajnoczky, Gyorgy; Hardwick, J. Marie; Harris, Isaac S.; Hengartner, Michael O.; Hetz, Claudio; Ichijo, Hidenori; Jäättelä, Marja; Joseph, Bertrand; Jost, Philipp J.; Juin, Philippe P.; Kaiser, William J.; Karin, Michael; Kaufmann, Thomas; Kepp, Oliver; Kimchi, Adi; Kitsis, Richard N.; Klionsky, Daniel J.; Knight, Richard A.; Kumar, Sharad; Lee, Sam W.; Lemasters, John J.; Levine, Beth; Linkermann, Andreas; Lipton, Stuart A.; Lockshin, Richard A.; López-Otín, Carlos; Lowe, Scott W.; Luedde, Tom; Lugli, Enrico; MacFarlane, Marion; Madeo, Frank; Malewicz, Michal; Malorni, Walter; Manic, Gwenola; Marine, Jean-Christophe; Martin, Seamus J.; Martinou, Jean-Claude; Medema, Jan Paul; Mehlen, Patrick; Meier, Pascal; Melino, Sonia; Miao, Edward A.; Molkentin, Jeffery D.; Moll, Ute M.; Muñoz-Pinedo, Cristina; Nagata, Shigekazu; Nuñez, Gabriel; Oberst, Andrew; Oren, Moshe; Overholtzer, Michael; Pagano, Michele; Panaretakis, Theocharis; Pasparakis, Manolis; Penninger, Josef M.; Pereira, David M.; Pervaiz, Shazib; Peter, Marcus E.; Piacentini, Mauro; Pinton, Paolo; Prehn, Jochen H. M.; Puthalakath, Hamsa; Rabinovich, Gabriel A.; Rehm, Markus; Rizzuto, Rosario; Rodrigues, Cecilia M. P.; Rubinsztein, David C.; Rudel, Thomas; Ryan, Kevin M.; Sayan, Emre; Scorrano, Luca; Shao, Feng; Shi, Yufang; Silke, John; Simon, Hans-Uwe; Sistigu, Antonella; Stockwell, Brent R.; Strasser, Andreas; Szabadkai, Gyorgy; Tait, Stephen W. G.; Tang, Daolin; Tavernarakis, Nektarios; Thorburn, Andrew; Tsujimoto, Yoshihide; Turk, Boris; Vanden Berghe, Tom; Vandenabeele, Peter; Vander Heiden, Matthew G.; Villunger, Andreas; Virgin, Herbert W.; Vousden, Karen H.; Vucic, Domagoj; Wagner, Erwin F.; Walczak, Henning; Wallach, David; Wang, Ying; Wells, James A.; Wood, Will; Yuan, Junying; Zakeri, Zahra; Zhivotovsky, Boris; Zitvogel, Laurence; Melino, Gerry; Kroemer, Guido
2018-01-01
Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell
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Nonthermal-plasma-mediated animal cell death
Kim, Wanil; Woo, Kyung-Chul; Kim, Gyoo-Cheon; Kim, Kyong-Tai
2011-01-01
Animal cell death comprising necrosis and apoptosis occurred in a well-regulated manner upon specific stimuli. The physiological meanings and detailed molecular mechanisms of cell death have been continuously investigated over several decades. Necrotic cell death has typical morphological changes, such as cell swelling and cell lysis followed by DNA degradation, whereas apoptosis shows blebbing formation and regular DNA fragmentation. Cell death is usually adopted to terminate cancer cells in vivo. The current strategies against tumour are based on the induction of cell death by adopting various methods, including radiotherapy and chemotherapeutics. Among these, radiotherapy is the most frequently used treatment method, but it still has obvious limitations. Recent studies have suggested that the use of nonthermal air plasma can be a prominent method for inducing cancer cell death. Plasma-irradiated cells showed the loss of genomic integrity, mitochondrial dysfunction, plasma membrane damage, etc. Tumour elimination with plasma irradiation is an emerging concept in cancer therapy and can be accelerated by targeting certain tumour-specific proteins with gold nanoparticles. Here, some recent developments are described so that the mechanisms related to plasma-mediated cell death and its perspectives in cancer treatment can be understood.
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Nonthermal-plasma-mediated animal cell death
Energy Technology Data Exchange (ETDEWEB)
Kim, Wanil; Woo, Kyung-Chul; Kim, Kyong-Tai [Department of Life Science, Division of Molecular and Life Science, Pohang University of Science and Technology, San 31, Hyoja Dong, Pohang 790-784 (Korea, Republic of); Kim, Gyoo-Cheon, E-mail: ktk@postech.ac.kr [Department of Oral Anatomy and Cell Biology, School of Dentistry, Pusan National University, Yangsan 626-810 (Korea, Republic of)
2011-01-12
Animal cell death comprising necrosis and apoptosis occurred in a well-regulated manner upon specific stimuli. The physiological meanings and detailed molecular mechanisms of cell death have been continuously investigated over several decades. Necrotic cell death has typical morphological changes, such as cell swelling and cell lysis followed by DNA degradation, whereas apoptosis shows blebbing formation and regular DNA fragmentation. Cell death is usually adopted to terminate cancer cells in vivo. The current strategies against tumour are based on the induction of cell death by adopting various methods, including radiotherapy and chemotherapeutics. Among these, radiotherapy is the most frequently used treatment method, but it still has obvious limitations. Recent studies have suggested that the use of nonthermal air plasma can be a prominent method for inducing cancer cell death. Plasma-irradiated cells showed the loss of genomic integrity, mitochondrial dysfunction, plasma membrane damage, etc. Tumour elimination with plasma irradiation is an emerging concept in cancer therapy and can be accelerated by targeting certain tumour-specific proteins with gold nanoparticles. Here, some recent developments are described so that the mechanisms related to plasma-mediated cell death and its perspectives in cancer treatment can be understood. (topical review)
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Nonthermal-plasma-mediated animal cell death
International Nuclear Information System (INIS)
Kim, Wanil; Woo, Kyung-Chul; Kim, Kyong-Tai; Kim, Gyoo-Cheon
2011-01-01
Animal cell death comprising necrosis and apoptosis occurred in a well-regulated manner upon specific stimuli. The physiological meanings and detailed molecular mechanisms of cell death have been continuously investigated over several decades. Necrotic cell death has typical morphological changes, such as cell swelling and cell lysis followed by DNA degradation, whereas apoptosis shows blebbing formation and regular DNA fragmentation. Cell death is usually adopted to terminate cancer cells in vivo. The current strategies against tumour are based on the induction of cell death by adopting various methods, including radiotherapy and chemotherapeutics. Among these, radiotherapy is the most frequently used treatment method, but it still has obvious limitations. Recent studies have suggested that the use of nonthermal air plasma can be a prominent method for inducing cancer cell death. Plasma-irradiated cells showed the loss of genomic integrity, mitochondrial dysfunction, plasma membrane damage, etc. Tumour elimination with plasma irradiation is an emerging concept in cancer therapy and can be accelerated by targeting certain tumour-specific proteins with gold nanoparticles. Here, some recent developments are described so that the mechanisms related to plasma-mediated cell death and its perspectives in cancer treatment can be understood. (topical review)
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Bruno, P; Calastretti, A; Priulla, M; Asnaghi, L; Scarlatti, F; Nicolin, A; Canti, G
2007-10-01
Akt activation assists tumor cell survival and promotes resistance to chemotherapy. Here we show that constitutively active Akt (CA-Akt) cells are highly sensitized to cell death induced by nutrient and growth factor deprivation, whereas dominant-negative Akt (DN-Akt) cells have a high rate of survival. The content of autophagosomes in starved CA-Akt cells was high, while DN-Akt cells expressed autophagic vacuoles constitutively, independently of nutrition conditions. Thus Akt down-regulation and downstream events can induce autophagosomes which were not directly determinants of cell death. Biochemical analysis in Akt-mutated cells show that (i) Akt and mTOR proteins were degraded more rapidly than the housekeeping proteins, (ii) mTOR phosphorylation at position Thr(2446) was relatively high in DN-Akt and low in CA-Akt cells, induced by starvation in mock cells only, which suggests reduced autoregulation of these pathways in Akt-mutated cells, (iii) both protein synthesis and protein degradation were significantly higher in starved CA-Akt cells than in starved DN-Akt cells or mock cells. In conclusion, constitutively active Akt, unable to control synthesis and wasting of proteins, accelerates the death of starved cells.
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Involvement of yeast HSP90 isoforms in response to stress and cell death induced by acetic acid.
Directory of Open Access Journals (Sweden)
Alexandra Silva
Full Text Available Acetic acid-induced apoptosis in yeast is accompanied by an impairment of the general protein synthesis machinery, yet paradoxically also by the up-regulation of the two isoforms of the heat shock protein 90 (HSP90 chaperone family, Hsc82p and Hsp82p. Herein, we show that impairment of cap-dependent translation initiation induced by acetic acid is caused by the phosphorylation and inactivation of eIF2α by Gcn2p kinase. A microarray analysis of polysome-associated mRNAs engaged in translation in acetic acid challenged cells further revealed that HSP90 mRNAs are over-represented in this polysome fraction suggesting preferential translation of HSP90 upon acetic acid treatment. The relevance of HSP90 isoform translation during programmed cell death (PCD was unveiled using genetic and pharmacological abrogation of HSP90, which suggests opposing roles for HSP90 isoforms in cell survival and death. Hsc82p appears to promote survival and its deletion leads to necrotic cell death, while Hsp82p is a pro-death molecule involved in acetic acid-induced apoptosis. Therefore, HSP90 isoforms have distinct roles in the control of cell fate during PCD and their selective translation regulates cellular response to acetic acid stress.
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HAMLET triggers apoptosis but tumor cell death is independent of caspases, Bcl-2 and p53.
Hallgren, O; Gustafsson, L; Irjala, H; Selivanova, G; Orrenius, S; Svanborg, C
2006-02-01
HAMLET (Human alpha-lactalbumin Made Lethal to Tumor cells) triggers selective tumor cell death in vitro and limits tumor progression in vivo. Dying cells show features of apoptosis but it is not clear if the apoptotic response explains tumor cell death. This study examined the contribution of apoptosis to cell death in response to HAMLET. Apoptotic changes like caspase activation, phosphatidyl serine externalization, chromatin condensation were detected in HAMLET-treated tumor cells, but caspase inhibition or Bcl-2 over-expression did not prolong cell survival and the caspase response was Bcl-2 independent. HAMLET translocates to the nuclei and binds directly to chromatin, but the death response was unrelated to the p53 status of the tumor cells. p53 deletions or gain of function mutations did not influence the HAMLET sensitivity of tumor cells. Chromatin condensation was partly caspase dependent, but apoptosis-like marginalization of chromatin was also observed. The results show that tumor cell death in response to HAMLET is independent of caspases, p53 and Bcl-2 even though HAMLET activates an apoptotic response. The use of other cell death pathways allows HAMLET to successfully circumvent fundamental anti-apoptotic strategies that are present in many tumor cells.
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PARP-1 cleavage fragments: signatures of cell-death proteases in neurodegeneration
Directory of Open Access Journals (Sweden)
Alexander Jonathan S
2010-12-01
Full Text Available Abstract The normal function of poly (ADP-ribose polymerase-1 (PARP-1 is the routine repair of DNA damage by adding poly (ADP ribose polymers in response to a variety of cellular stresses. Recently, it has become widely appreciated that PARP-1 also participates in diverse physiological and pathological functions from cell survival to several forms of cell death and has been implicated in gene transcription, immune responses, inflammation, learning, memory, synaptic functions, angiogenesis and aging. In the CNS, PARP inhibition attenuates injury in pathologies like cerebral ischemia, trauma and excitotoxicity demonstrating a central role of PARP-1 in these pathologies. PARP-1 is also a preferred substrate for several 'suicidal' proteases and the proteolytic action of suicidal proteases (caspases, calpains, cathepsins, granzymes and matrix metalloproteinases (MMPs on PARP-1 produces several specific proteolytic cleavage fragments with different molecular weights. These PARP-1 signature fragments are recognized biomarkers for specific patterns of protease activity in unique cell death programs. This review focuses on specific suicidal proteases active towards PARP-1 to generate signature PARP-1 fragments that can identify key proteases and particular forms of cell death involved in pathophysiology. The roles played by some of the PARP-1 fragments and their associated binding partners in the control of different forms of cell death are also discussed.
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Circulating tumor cells, disease recurrence and survival in newly diagnosed breast cancer
Franken, Bas; De Groot, Marco R.; Mastboom, Walter J.B.; Vermes, I.; van der Palen, Jacobus Adrianus Maria; Tibbe, Arjan G.J.; Terstappen, Leonardus Wendelinus Mathias Marie
2012-01-01
Introduction The presence of circulating tumor cells (CTC) is an independent prognostic factor for progression-free survival and breast cancer-related death (BRD) for patients with metastatic breast cancer beginning a new line of systemic therapy. The current study was undertaken to explore whether
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Alternative Cell Death Pathways and Cell Metabolism
Directory of Open Access Journals (Sweden)
Simone Fulda
2013-01-01
Full Text Available While necroptosis has for long been viewed as an accidental mode of cell death triggered by physical or chemical damage, it has become clear over the last years that necroptosis can also represent a programmed form of cell death in mammalian cells. Key discoveries in the field of cell death research, including the identification of critical components of the necroptotic machinery, led to a revised concept of cell death signaling programs. Several regulatory check and balances are in place in order to ensure that necroptosis is tightly controlled according to environmental cues and cellular needs. This network of regulatory mechanisms includes metabolic pathways, especially those linked to mitochondrial signaling events. A better understanding of these signal transduction mechanisms will likely contribute to open new avenues to exploit our knowledge on the regulation of necroptosis signaling for therapeutic application in the treatment of human diseases.
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International Nuclear Information System (INIS)
Pan, Mu-Yun; Shen, Yuh-Chiang; Lu, Chien-Hsing; Yang, Shu-Yi; Ho, Tsing-Fen; Peng, Yu-Ta; Chang, Chia-Che
2012-01-01
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
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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
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Directory of Open Access Journals (Sweden)
Jongkyun Kang
Full Text Available The coordinated regulation of cell fate and cell survival is crucial for normal pattern formation in developing organisms. In Drosophila compound eye development, crystalline arrays of hexagonal ommatidia are established by precise assembly of diverse cell types, including the photoreceptor cells, cone cells and interommatidial (IOM pigment cells. The molecular basis for controlling the number of cone and IOM pigment cells during ommatidial pattern formation is not well understood. Here we present evidence that BarH1 and BarH2 homeobox genes are essential for eye patterning by inhibiting excess cone cell differentiation and promoting programmed death of IOM cells. Specifically, we show that loss of Bar from the undifferentiated retinal precursor cells leads to ectopic expression of Prospero and dPax2, two transcription factors essential for cone cell specification, resulting in excess cone cell differentiation. We also show that loss of Bar causes ectopic expression of the TGFβ homolog Decapentaplegic (Dpp posterior to the morphogenetic furrow in the larval eye imaginal disc. The ectopic Dpp expression is not responsible for the formation of excess cone cells in Bar loss-of-function mutant eyes. Instead, it causes reduction in IOM cell death in the pupal stage by antagonizing the function of pro-apoptotic gene reaper. Taken together, this study suggests a novel regulatory mechanism in the control of developmental cell death in which the repression of Dpp by Bar in larval eye disc is essential for IOM cell death in pupal retina.
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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.
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International Nuclear Information System (INIS)
Forrester, H.B.; Vidair, C.A.; Dewey, W.C.; Ling, C.C.
1998-01-01
Full text: Individual rat embryo fibroblasts that had been transfected with the c-myc (REC:myc) or c-Ha ras (REC:ras) oncogene were followed after irradiation using a computer video time lapse (CVTL) system in order to quantify the lethal events that resulted in loss of clonogenic survival after irradiation. By followed the cells for 2 to 3 generations before irradiation we were able to determine where they were in the cell cycle at the time of irradiation for cell cycle analysis. After irradiation, the individual cells and their progeny were followed in multiple fields for 5-6 days Then, pedigrees for individual irradiated cells were determined by noting the times of divisions fusions, and cell death. After X-irradiation, the clonogenic survival values for these two cell lines are similar. However, by using computerized video time lapse (CVTL) to follow individual cells we found that the loss of clonogenic survival was due to two different processes, cell death and a senescent-like process. The loss of clonogenic survival of x-irradiated (9.5 and 4 Gy) REC:myc cells was attributed almost entirely to the cells dying by apoptosis (∼99 and 90%). In contrast, approximately 60% of the x-irradiated (9.5 Gy) non-clonogenic REC:ras cells died by apoptosis (with a very small amount of necrosis), and the other 40% underwent a senescent-type process in which some of the cells and their progeny stopped dividing but remained as viable cells throughout 140 hours of observation. Both processes usually occurred after the cells had divided and continued to occur in the cells' progeny for up to five divisions after irradiation. The mode of cell death in the progeny of a non-clonogenic cell can be determined only by using CVTL and can not be determined by conventional clonogenic survival experiments. Also, only by following the individual cells and their progeny can the true amount of apoptosis be determined. The cumulative percentage of apoptosis scored in whole populations
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Fenske, Timothy S.; Hari, Parameswaran N.; Carreras, Jeanette; Zhang, Mei-Jie; Kamble, Rammurti T.; Bolwell, Brian J.; Cairo, Mitchell S.; Champlin, Richard E.; Chen, Yi-Bin; Freytes, César O.; Gale, Robert Peter; Hale, Gregory A.; Ilhan, Osman; Khoury, H. Jean; Lister, John; Maharaj, Dipnarine; Marks, David I.; Munker, Reinhold; Pecora, Andrew L.; Rowlings, Philip A.; Shea, Thomas C.; Stiff, Patrick; Wiernik, Peter H.; Winter, Jane N.; Rizzo, J. Douglas; van Besien, Koen; Lazarus, Hillard M.; Vose, Julie M.
2010-01-01
Incorporation of the anti-CD20 monoclonal antibody rituximab into front-line regimens for diffuse large B-cell lymphoma (DLBCL) has resulted in improved survival. Despite this progress, many patients develop refractory or recurrent DLBCL and then receive autologous hematopoietic stem cell transplantation (AuHCT). It is unclear to what extent pre-transplant exposure to rituximab affects outcomes following AuHCT. Outcomes of 994 patients receiving AuHCT for DLBCL between 1996 and 2003 were analyzed according to whether rituximab was (n=176, “+R” group) or was not (n=818, “ −R” group) administered with front-line or salvage therapy prior to AuHCT. The +R group had superior progression-free survival (50% versus 38%, p=0.008) and overall survival (57% versus 45%, p=0.006) at 3 years. Platelet and neutrophil engraftment were not affected by exposure to rituximab. Non-relapse mortality (NRM) did not differ significantly between the +R and −R groups. In multivariate analysis, the +R group had improved progression-free survival (relative risk of relapse/progression or death 0.64, p<0.001) and improved overall survival (relative risk of death of 0.74, p=0.039). We conclude that pre-transplant rituximab is associated with a lower rate of progression and improved survival following AuHCT for DLBCL, with no evidence of impaired engraftment or increased NRM. PMID:19822306
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International Nuclear Information System (INIS)
Clapp, Caitlin; Portt, Liam; Khoury, Chamel; Sheibani, Sara; Eid, Rawan; Greenwood, Matthew; Vali, Hojatollah; Mandato, Craig A.; Greenwood, Michael T.
2012-01-01
Genetically programmed cell death (PCD) mechanisms, including apoptosis, are important for the survival of metazoans since it allows, among things, the removal of damaged cells that interfere with normal function. Cell death due to PCD is observed in normal processes such as aging and in a number of pathophysiologies including hypoxia (common causes of heart attacks and strokes) and subsequent tissue reperfusion. Conversely, the loss of normal apoptotic responses is associated with the development of tumors. So far, limited success in preventing unwanted PCD has been reported with current therapeutic approaches despite the fact that inhibitors of key apoptotic inducers such as caspases have been developed. Alternative approaches have focused on mimicking anti-apoptotic processes observed in cells displaying increased resistance to apoptotic stimuli. Hormesis and pre-conditioning are commonly observed cellular strategies where sub-lethal levels of pro-apoptotic stimuli lead to increased resistance to higher or lethal levels of stress. Increased expression of anti-apoptotic sequences is a common mechanism mediating these protective effects. The relevance of the latter observation is exemplified by the observation that transgenic mice overexpressing anti-apoptotic genes show significant reductions in tissue damage following ischemia. Thus strategies aimed at increasing the levels of anti-apoptotic proteins, using gene therapy or cell penetrating recombinant proteins are being evaluated as novel therapeutics to decrease cell death following acute periods of cell death inducing stress. In spite of its functional and therapeutic importance, more is known regarding the processes involved in apoptosis than anti-apoptosis. The genetically tractable yeast Saccharomyces cerevisiae has emerged as an exceptional model to study multiple aspects of PCD including the mitochondrial mediated apoptosis observed in metazoans. To increase our knowledge of the process of anti
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Yoon, Jaemin; Ham, Hyeonmi; Sung, Jeehye; Kim, Younghwa; Choi, Youngmin; Lee, Jeom-Sig; Jeong, Heon-Sang; Lee, Junsoo
2014-01-01
BACKGROUND/OBJECTIVES The objective of this study was to evaluate the protective effect of black rice extract (BRE) on tert-butyl hydroperoxide (TBHP)-induced oxidative injury in HepG2 cells. MATERIALS/METHODS Methanolic extract from black rice was evaluated for the protective effect on TBHP-induced oxidative injury in HepG2 cells. Several biomarkers that modulate cell survival and death including reactive oxygen species (ROS), caspase-3 activity, and related cellular kinases were determined. RESULTS TBHP induced cell death and apoptosis by a rapid increase in ROS generation and caspase-3 activity. Moreover, TBHP-induced oxidative stress resulted in a transient ERK1/2 activation and a sustained increase of JNK1/2 activation. While, BRE pretreatment protects the cells against oxidative stress by reducing cell death, caspase-3 activity, and ROS generation and also by preventing ERKs deactivation and the prolonged JNKs activation. Moreover, pretreatment of BRE increased the activation of ERKs and Akt which are pro-survival signal proteins. However, this effect was blunted in the presence of ERKs and Akt inhibitors. CONCLUSIONS These results suggest that activation of ERKs and Akt pathway might be involved in the cytoprotective effect of BRE against oxidative stress. Our findings provide new insights into the cytoprotective effects and its possible mechanism of black rice against oxidative stress. PMID:24741394
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Depletion of the AP-1 repressor JDP2 induces cell death similar to apoptosis
DEFF Research Database (Denmark)
Lerdrup, Mads; Holmberg, Christian Henrik; Dietrich, Nikolaj
2005-01-01
JDP2 is a ubiquitously expressed nuclear protein that efficiently represses the activity of the transcription factor AP-1. Thus far, all studies of JDP2 function have relied on the ectopic expression of the protein. In this study, we use a different approach: depletion of JDP2 from cells. Specific...... depletion of JDP2 resulted in p53-independent cell death that resembles apoptosis and was evident at 72 h. The death mechanism was caspase dependent as the cells could be rescued by treatment with caspase inhibitor zVAD. Our studies suggest that JDP2 functions as a general survival protein, not only...
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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...
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Two modes of cell death caused by exposure to nanosecond pulsed electric field.
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Olga N Pakhomova
Full Text Available High-amplitude electric pulses of nanosecond duration, also known as nanosecond pulsed electric field (nsPEF, are a novel modality with promising applications for cell stimulation and tissue ablation. However, key mechanisms responsible for the cytotoxicity of nsPEF have not been established. We show that the principal cause of cell death induced by 60- or 300-ns pulses in U937 cells is the loss of the plasma membrane integrity ("nanoelectroporation", leading to water uptake, cell swelling, and eventual membrane rupture. Most of this early necrotic death occurs within 1-2 hr after nsPEF exposure. The uptake of water is driven by the presence of pore-impermeable solutes inside the cell, and can be counterbalanced by the presence of a pore-impermeable solute such as sucrose in the medium. Sucrose blocks swelling and prevents the early necrotic death; however the long-term cell survival (24 and 48 hr does not significantly change. Cells protected with sucrose demonstrate higher incidence of the delayed death (6-24 hr post nsPEF. These cells are more often positive for the uptake of an early apoptotic marker dye YO-PRO-1 while remaining impermeable to propidium iodide. Instead of swelling, these cells often develop apoptotic fragmentation of the cytoplasm. Caspase 3/7 activity increases already in 1 hr after nsPEF and poly-ADP ribose polymerase (PARP cleavage is detected in 2 hr. Staurosporin-treated positive control cells develop these apoptotic signs only in 3 and 4 hr, respectively. We conclude that nsPEF exposure triggers both necrotic and apoptotic pathways. The early necrotic death prevails under standard cell culture conditions, but cells rescued from the necrosis nonetheless die later on by apoptosis. The balance between the two modes of cell death can be controlled by enabling or blocking cell swelling.
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Directory of Open Access Journals (Sweden)
Derong Cui
Full Text Available Propofol exerts protective effects on neuronal cells, in part through the inhibition of programmed cell death. Autophagic cell death is a type of programmed cell death that plays elusive roles in controlling neuronal damage and metabolic homeostasis. We therefore studied whether propofol could attenuate the formation of autophagosomes, and if so, whether the inhibition of autophagic cell death mediates the neuroprotective effects observed with propofol.The cell model was established by depriving the cells of oxygen and glucose (OGD for 6 hours, and the rat model of ischemia was introduced by a transient two-vessel occlusion for 10 minutes. Transmission electron microscopy (TEM revealed that the formation of autophagosomes and autolysosomes in both neuronal PC12 cells and pyramidal rat hippocampal neurons after respective OGD and ischemia/reperfusion (I/R insults. A western blot analysis revealed that the autophagy-related proteins, such as microtubule-associated protein 1 light chain 3 (LC3-II, Beclin-1 and class III PI3K, were also increased accordingly, but cytoprotective Bcl-2 protein was decreased. The negative effects of OGD and I/R, including the formation of autophagosomes and autolysosomes, the increase in LC3-II, Beclin-1 and class III PI3K expression and the decline in Bcl-2 production were all inhibited by propofol and specific inhibitors of autophagy, such as 3-methyladenine (3-MA, LY294002 and Bafilomycin A1 (Baf,. Furthermore, in vitro OGD cultures and in vivo I/R rats showed an increase in cell survival following the administration of propofol, as assessed by an MTT assay or histochemical analyses.Our data suggest that propofol can markedly attenuate autophagic processes via the decreased expression of autophagy-related proteins in vitro and in vivo. This inhibition improves cell survival, which provides a novel explanation for the pleiotropic effects of propofol that benefit the nervous system.
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Cell death and autophagy: Cytokines, drugs, and nutritional factors
International Nuclear Information System (INIS)
Bursch, Wilfried; Karwan, Anneliese; Mayer, Miriam; Dornetshuber, Julia; Froehwein, Ulrike; Schulte-Hermann, Rolf; Fazi, Barbara; Di Sano, Federica; Piredda, Lucia; Piacentini, Mauro; Petrovski, Goran; Fesues, Laszlo; Gerner, Christopher
2008-01-01
attributed to the degree of cell damage caused by tamoxifen, either by generating ROS, increasing membrane fluidity or forming DNA-adducts. Finally, autophagy constitutes a cell's major adaptive (survival) strategy in response to metabolic challenges such as glucose or amino acid deprivation, or starvation in general. Notably, the role of autophagy appears not to be restricted to nutrient recycling in order to maintain energy supply of cells and to adapt cell(organ) size to given physiological needs. For instance, using a newly established hepatoma cell line HCC-1.2, amino acid and glucose deprivation revealed a pro-apoptotic activity, additive to TGF-β1. The pro-apoptotic action of glucose deprivation was antagonized by 2-deoxyglucose, possibly by stabilizing the mitochondrial membrane involving the action of hexokinase II. These observations suggest that signaling cascades steering autophagy appear to provide links to those regulating cell number. Taken together, our data exemplify that a given cell may flexibly respond to type and degree of (micro)environmental changes or cell death stimuli; a cell's response may shift gradually from the elimination of damaged proteins by autophagy and the recovery to autophagic or apoptotic pathways of cell death, the failure of which eventually may result in necrosis
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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.
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Delayed innocent bystander cell death following hypoxia in Caenorhabditis elegans.
Sun, C-L; Kim, E; Crowder, C M
2014-04-01
After hypoxia, cells may die immediately or have a protracted course, living or dying depending on an incompletely understood set of cell autonomous and nonautonomous factors. In stroke, for example, some neurons are thought to die from direct hypoxic injury by cell autonomous primary mechanisms, whereas other so called innocent bystander neurons die from factors released from the primarily injured cells. A major limitation in identifying these factors is the inability of current in vivo models to selectively target a set of cells for hypoxic injury so that the primarily injured cells and the innocent bystanders are clearly delineated. In order to develop such a model, we generated transgenic Caenorhabditis elegans strains where 2-3% of somatic cells were made selectively sensitive to hypoxia. This was accomplished by cell type-specific wild-type rescue in either pharyngeal myocytes or GABAergic neurons of a hypoxia resistance-producing translation factor mutation. Surprisingly, hypoxic targeting of these relatively small subsets of non-essential cells produced widespread innocent bystander cell injury, behavioral dysfunction and eventual organismal death. The hypoxic injury phenotypes of the myocyte or neuron sensitized strains were virtually identical. Using this model, we show that the C. elegans insulin receptor/FOXO transcription factor pathway improves survival when activated only after hypoxic injury and blocks innocent bystander death.
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Czech Academy of Sciences Publication Activity Database
Janečková, H.; Veselý, Pavel; Chmelík, R.
2009-01-01
Roč. 29, č. 6 (2009), s. 2339-2345 ISSN 0250-7005 Institutional research plan: CEZ:AV0Z50520514 Keywords : tumour cell * nutritional deprivation * energy deprivation * cell survival * cell death * digital holographic microscopy * dynamic phase difference Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.428, year: 2009
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Ferreira, R.; Fonseca, M. C.; Santos, T.; Sargento-Freitas, J.; Tjeng, R.; Paiva, F.; Castelo-Branco, M.; Ferreira, L. S.; Bernardino, L.
2016-04-01
Stroke is one of the leading causes of death and disability worldwide. However, current therapies only reach a small percentage of patients and may cause serious side effects. We propose the therapeutic use of retinoic acid-loaded nanoparticles (RA-NP) to safely and efficiently repair the ischaemic brain by creating a favourable pro-angiogenic environment that enhances neurogenesis and neuronal restitution. Our data showed that RA-NP enhanced endothelial cell proliferation and tubule network formation and protected against ischaemia-induced death. To evaluate the effect of RA-NP on vascular regulation of neural stem cell (NSC) survival and differentiation, endothelial cell-conditioned media (EC-CM) were collected. EC-CM from healthy RA-NP-treated cells reduced NSC death and promoted proliferation while EC-CM from ischaemic RA-NP-treated cells decreased cell death, increased proliferation and neuronal differentiation. In parallel, human endothelial progenitor cells (hEPC), which are part of the endogenous repair response to vascular injury, were collected from ischaemic stroke patients. hEPC treated with RA-NP had significantly higher proliferation, which further highlights the therapeutic potential of this formulation. To conclude, RA-NP protected endothelial cells from ischaemic death and stimulated the release of pro-survival, proliferation-stimulating factors and differentiation cues for NSC. RA-NP were shown to be up to 83-fold more efficient than free RA and to enhance hEPC proliferation. These data serve as a stepping stone to use RA-NP as vasculotrophic and neurogenic agents for vascular disorders and neurodegenerative diseases with compromised vasculature.
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Watanabe, Shinya; Nagai, Takashi
2009-06-01
To obtain the data concerning death losses due to stillbirth, neonatal death and diseases in cloned cattle derived from somatic cell nuclear transfer (SCNT) and their progeny produced by Japanese institutions, a nationwide survey was carried out in July-August, 2006. As a result, lifetime data concerning 482 SCNT cattle (97.5% of cattle produced in the country at that time) and 202 progeny of SCNT cattle were accumulated and the death loss of these cattle was analyzed. Although 1/3 of delivered SCNT calves died during the perinatal period due to stillbirth and neonatal death, incidence of death loss due to diseases in SCNT cattle surviving more than 200 days after birth seems to be the same as these in conventionally bred cattle. In contrast, progeny of SCNT cattle showed the same level in death loss as observed in conventionally bred cattle throughout their lifetime. These results suggest that robust health would be expected in SCNT cattle surviving to adulthood and their progeny.
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The critical role of ERK in death resistance and invasiveness of hypoxia-selected glioblastoma cells
International Nuclear Information System (INIS)
Kim, Jee-Youn; Kim, Yong-Jun; Lee, Sun; Park, Jae-Hoon
2009-01-01
The rapid growth of tumor parenchyma leads to chronic hypoxia that can result in the selection of cancer cells with a more aggressive behavior and death-resistant potential to survive and proliferate. Thus, identifying the key molecules and molecular mechanisms responsible for the phenotypic changes associated with chronic hypoxia has valuable implications for the development of a therapeutic modality. The aim of this study was to identify the molecular basis of the phenotypic changes triggered by chronic repeated hypoxia. Hypoxia-resistant T98G (HRT98G) cells were selected by repeated exposure to hypoxia and reoxygenation. Cell death rate was determined by the trypan blue exclusion method and protein expression levels were examined by western blot analysis. The invasive phenotype of the tumor cells was determined by the Matrigel invasion assay. Immunohistochemistry was performed to analyze the expression of proteins in the brain tumor samples. The Student T-test and Pearson Chi-Square test was used for statistical analyses. We demonstrate that chronic repeated hypoxic exposures cause T98G cells to survive low oxygen tension. As compared with parent cells, hypoxia-selected T98G cells not only express higher levels of anti-apoptotic proteins such as Bcl-2, Bcl-X L , and phosphorylated ERK, but they also have a more invasive potential in Matrigel invasion chambers. Activation or suppression of ERK pathways with a specific activator or inhibitor, respectively, indicates that ERK is a key molecule responsible for death resistance under hypoxic conditions and a more invasive phenotype. Finally, we show that the activation of ERK is more prominent in malignant glioblastomas exposed to hypoxia than in low grade astrocytic glial tumors. Our study suggests that activation of ERK plays a pivotal role in death resistance under chronic hypoxia and phenotypic changes related to the invasive phenotype of HRT98G cells compared to parent cells
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Heterogeneity reduces sensitivity of cell death for TNF-Stimuli
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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
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47. A cardiac center experience with Brugada syndrome who survived sudden cardiac death
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I. Suliman
2016-07-01
Full Text Available Brugada syndrome is a heritable arrhythmia syndrome that is characterized by an electrocardiographic pattern consisting of coved-type ST-segment elevation (2 mm followed by a negative T wave in the right precordial leads, V1 through V3 (often referred to as type 1 Brugada electrocardiographic pattern, here we describe 3 cases of Brugada who survived sudden cardiac death (SCD cardiac center experience with survived Brugada syndrome patients – case series. First Case: The Father 45 years old male, presented in 2005 after involvement in unprovoked motor vehicle accident, the patient was the driver who lost consciousness and rushed to the hospital. On arrival to our ER and putting the patient on the bed, the ER doctor observed a brief episode of VF on the monitor. The patient was taken to the catheterization Lab , his coronaries were normal. The diagnosis of Brugada was established and the patient received a defibrillator. At That Time all family members were screened and were negative. Second Case: The Son of the first patient 5 years later his 23 years old male rushed to our ER after he lost consciousness, he was passenger in the car of his friend. Third Case: The pilot A military pilot aged a male 35 years old was in very good health when he lost consciousness and brought to the hospital after resuscitation in 2005. He had full invasive cardiac evaluation, subsequently he received a defibrillator in the same admission period, till 2015 he is doing fine. Brugada syndrome is associated with high tendency for sudden cardiac death. In our three cases the first clinical presentation was survived sudden cardiac death (SCD and all three male patients survived. We did not encounter a female patient who survived sudden cardiac death.
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Bacigaluppi, Susanna; Donzelli, Elisabetta; De Cristofaro, Valentina; Bragazzi, Nicola Luigi; D'Amico, Giovanna; Scuteri, Arianna; Tredici, Giovanni
2016-09-19
Cerebral ischemia is characterized by both acute and delayed neuronal injuries. Neuro-protection is a major issue that should be properly addressed from a pharmacological point of view, and cell-based treatment approaches are of interest due to their potential pleiotropic effects. Endothelial progenitor cells have the advantage of being mobilized from the bone marrow into the circulation, but have been less studied than other stem cells, such as mesenchymal stem cells. Therefore, the comparison between human endothelial progenitor cells (hEPC) and human mesenchymal progenitor cells (hMSC) in terms of efficacy in rescuing neurons from cell death after transitory ischemia is the aim of the current study, in the effort to address further directions. In vitro model of oxygen-glucose deprivation (OGD) on a primary culture of rodent cortical neurons was set up with different durations of exposure: 1, 2 and 3hrs with assessment of neuron survival. The 2hrs OGD was chosen for the subsequent experiments. After 2hrs OGD neurons were either placed in indirect co-culture with hMSC or hEPC or cultured in hMSC or hEPC conditioned medium and cell viability was evaluated by MTT assay. At day 2 after 2hrs OGD exposure, mean neuronal survival was 47.9±24.2%. In contrast, after treatment with hEPC and hMSC indirect co-culture was 74.1±27.3%; and 69.4±18.8%, respectively. In contrast, treatment with conditioned medium did not provide any advantage in terms of survival to OGD neurons The study shows the efficacy of hEPC in indirect co-culture to rescue neurons from cell death after OGD, comparable to that of hMSC. hEPC deserve further studies given their potential interest for ischemia. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
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Tomasetti, Marco; Nocchi, Linda; Neuzil, Jiri; Goodwin, Jacob; Nguyen, Maria; Dong, Lanfeng; Manzella, Nicola; Staffolani, Sara; Milanese, Claudio; Garrone, Beatrice; Alleva, Renata; Borghi, Battista; Santarelli, Lory; Guerrieri, Roberto
2012-01-01
The redox-silent vitamin E analog α-tocopheryl succinate (α-TOS) was found to synergistically cooperate with vitamin K3 (VK3) plus ascorbic acid (AA) in the induction of cancer cell-selective apoptosis via a caspase-independent pathway. Here we investigated the molecular mechanism(s) underlying cell death induced in prostate cancer cells by α-TOS, VK3 and AA, and the potential use of targeted drug combination in the treatment of prostate cancer. The generation of ROS, cellular response to oxidative stress, and autophagy were investigated in PC3 prostate cancer cells by using drugs at sub-toxic doses. We evaluated whether PARP1-mediated apoptosis-inducing factor (AIF) release plays a role in apoptosis induced by the combination of the agents. Next, the effect of the combination of α-TOS, VK3 and AA on tumor growth was examined in nude mice. VK3 plus AA induced early ROS formation associated with induction of autophagy in response to oxidative stress, which was reduced by α-TOS, preventing the formation of autophagosomes. α-TOS induced mitochondrial destabilization leading to the release of AIF. Translocation of AIF from mitochondria to the nucleus, a result of the combinatorial treatment, was mediated by PARP1 activation. The inhibition of AIF as well as of PARP1 efficiently attenuated apoptosis triggered by the drug combination. Using a mouse model of prostate cancer, the combination of α-TOS, VK3 and AA was more efficient in tumor suppression than when the drugs were given separately, without deleterious side effects. α-TOS, a mitochondria-targeting apoptotic agent, switches at sub-apoptotic doses from autophagy-dependent survival of cancer cells to their demise by promoting the induction of apoptosis. Given the grim prognosis for cancer patients, this finding is of potential clinical relevance.
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Directory of Open Access Journals (Sweden)
Marco Tomasetti
Full Text Available BACKGROUND: The redox-silent vitamin E analog α-tocopheryl succinate (α-TOS was found to synergistically cooperate with vitamin K3 (VK3 plus ascorbic acid (AA in the induction of cancer cell-selective apoptosis via a caspase-independent pathway. Here we investigated the molecular mechanism(s underlying cell death induced in prostate cancer cells by α-TOS, VK3 and AA, and the potential use of targeted drug combination in the treatment of prostate cancer. METHODOLOGY/PRINCIPAL FINDINGS: The generation of ROS, cellular response to oxidative stress, and autophagy were investigated in PC3 prostate cancer cells by using drugs at sub-toxic doses. We evaluated whether PARP1-mediated apoptosis-inducing factor (AIF release plays a role in apoptosis induced by the combination of the agents. Next, the effect of the combination of α-TOS, VK3 and AA on tumor growth was examined in nude mice. VK3 plus AA induced early ROS formation associated with induction of autophagy in response to oxidative stress, which was reduced by α-TOS, preventing the formation of autophagosomes. α-TOS induced mitochondrial destabilization leading to the release of AIF. Translocation of AIF from mitochondria to the nucleus, a result of the combinatorial treatment, was mediated by PARP1 activation. The inhibition of AIF as well as of PARP1 efficiently attenuated apoptosis triggered by the drug combination. Using a mouse model of prostate cancer, the combination of α-TOS, VK3 and AA was more efficient in tumor suppression than when the drugs were given separately, without deleterious side effects. CONCLUSIONS/SIGNIFICANCE: α-TOS, a mitochondria-targeting apoptotic agent, switches at sub-apoptotic doses from autophagy-dependent survival of cancer cells to their demise by promoting the induction of apoptosis. Given the grim prognosis for cancer patients, this finding is of potential clinical relevance.
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Yuan, Guang-Jin; Deng, Jun-Jian; Cao, De-Dong; Shi, Lei; Chen, Xin; Lei, Jin-Ju; Xu, Xi-Ming
2017-08-14
To investigate whether autophagic cell death is involved in hyperthermic sensitization to ionizing radiation in human hepatocellular carcinoma cells, and to explore the underlying mechanism. Human hepatocellular carcinoma cells were treated with hyperthermia and ionizing radiation. MTT and clonogenic assays were performed to determine cell survival. Cell autophagy was detected using acridine orange staining and flow cytometric analysis, and the expression of autophagy-associated proteins, LC3 and p62, was determined by Western blot analysis. Intracellular reactive oxygen species (ROS) were quantified using the fluorescent probe DCFH-DA. Treatment with hyperthermia and ionizing radiation significantly decreased cell viability and surviving fraction as compared with hyperthermia or ionizing radiation alone. Cell autophagy was significantly increased after ionizing radiation combined with hyperthermia treatment, as evidenced by increased formation of acidic vesicular organelles, increased expression of LC3II and decreased expression of p62. Intracellular ROS were also increased after combined treatment with hyperthermia and ionizing radiation. Pretreatment with N-acetylcysteine, an ROS scavenger, markedly inhibited the cytotoxicity and cell autophagy induced by hyperthermia and ionizing radiation. Autophagic cell death is involved in hyperthermic sensitization of cancer cells to ionizing radiation, and its induction may be due to the increased intracellular ROS.
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DEFF Research Database (Denmark)
Gerstroem, Anna
2013-01-01
such phases. The aim of this paper is to explore how an organization’s identity is re-constructed after organizational death. Based on interviews with members of a bankrupted bank who narrate their bankruptcy experiences, the paper explores how legacy organizational identity is constructed after...... organizational death. The paper shows how members draw on their legacy organizational identity to justify their past interpretations and responses to the intensifying bankruptcy threats. Members refer to their firm belief in the bank’s solid and robust identity claim when they explain how they disregarded...
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Bone-Marrow Stem-Cell Survival in the Non-Uniformly Exposed Mammal
Energy Technology Data Exchange (ETDEWEB)
Bond, V. P.; Robinson, C. V. [Brookhaven National Laboratory, Medical Research Center, Upton, Long Island, NY (United States)
1967-07-15
For comparison of the effectiveness of non-uniform versus uniform irradiations in causing haematological death in mammals, a model of the irradiated haemopoietic system has been proposed. The essential features of this model are: (1) that different parts of the haemopoietic system have numbers of stem cells which are proportioned to the amounts of active marrow in those parts as measured by {sup 59}Fe uptake, (2) that stem cells in the different parts are subject to the, same dose-survival relationship, and (3) that survival of the animal depends on survival of a critical fraction of the total number of stem cells independent of their distribution among the parts of the total marrow mass. To apply this model one needs to know: (a) the relative {sup 59}Fe uptakes of the different parts of the haemopoietic system, (b) the doses delivered to those parts by each of the exposures to be compared, and (c) the dose-survival curve applicable to the stem cells. From these one can calculate the fraction of stem cells surviving each exposure. In a preliminary communication the applicability of the model was investigated using data obtained entirely from the literature. Additional data, particularly on bone-marrow distribution, have since been obtained and are included here. The primary object of the present paper is to test further the validity of the above 'stem-cell survival model'. Data on bilateral (essentially uniform) versus unilateral and non-uniform rotational exposures in mammals are examined with respect to the surviving fraction of stem cells at the LD{sub 50/30} day dose level. Although an adequate test is not possible at present for lack of a full set of data in any one species, a partial test indicates compatibility with data for dogs and rats. Other possible mortality determinants such as doses or exposures at entrance, midline or exit, or the gram-rads or average dose to the marrow, appear to be less useful than the critical stem-cell survival fraction.
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Directory of Open Access Journals (Sweden)
Benoît Meslin
Full Text Available Activation of proteolytic cell death pathways may circumvent drug resistance in deadly protozoan parasites such as Plasmodium falciparum and Leishmania. To this end, it is important to define the cell death pathway(s in parasites and thus characterize proteases such as metacaspases (MCA, which have been reported to induce cell death in plants and Leishmania parasites. We, therefore, investigated whether the cell death function of MCA is conserved in different protozoan parasite species such as Plasmodium falciparum and Leishmania major, focusing on the substrate specificity and functional role in cell survival as compared to Saccharomyces cerevisae. Our results show that, similarly to Leishmania, Plasmodium MCA exhibits a calcium-dependent, arginine-specific protease activity and its expression in yeast induced growth inhibition as well as an 82% increase in cell death under oxidative stress, a situation encountered by parasites during the host or when exposed to drugs such as artemisins. Furthermore, we show that MCA cell death pathways in both Plasmodium and Leishmania, involve a z-VAD-fmk inhibitable protease. Our data provide evidence that MCA from both Leishmania and Plasmodium falciparum is able to induce cell death in stress conditions, where it specifically activates a downstream enzyme as part of a cell death pathway. This enzymatic activity is also induced by the antimalarial drug chloroquine in erythrocytic stages of Plasmodium falciparum. Interestingly, we found that blocking parasite cell death influences their drug sensitivity, a result which could be used to create therapeutic strategies that by-pass drug resistance mechanisms by acting directly on the innate pathways of protozoan cell death.
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Sampaio-Barros, Percival D; Bortoluzzo, Adriana B; Marangoni, Roberta G; Rocha, Luiza F; Del Rio, Ana Paula T; Samara, Adil M; Yoshinari, Natalino H; Marques-Neto, João Francisco
2012-10-01
To analyze survival, prognostic factors, and causes of death in a large cohort of patients with systemic sclerosis (SSc). From 1991 to 2010, 947 patients with SSc were treated at 2 referral university centers in Brazil. Causes of death were considered SSc-related and non-SSc-related. Multiple logistic regression analysis was used to identify prognostic factors. Survival at 5 and 10 years was estimated using the Kaplan-Meier method. One hundred sixty-eight patients died during the followup. Among the 110 deaths considered related to SSc, there was predominance of lung (48.1%) and heart (24.5%) involvement. Most of the 58 deaths not related to SSc were caused by infection, cardiovascular or cerebrovascular disease, and cancer. Male sex, modified Rodnan skin score (mRSS) > 20, osteoarticular involvement, lung involvement, and renal crisis were the main prognostic factors associated to death. Overall survival rate was 90% for 5 years and 84% for 10 years. Patients presented worse prognosis if they had diffuse SSc (85% vs 92% at 5 yrs, respectively, and 77% vs 87% at 10 yrs, compared to limited SSc), male sex (77% vs 90% at 5 yrs and 64% vs 86% at 10 yrs, compared to female sex), and mRSS > 20 (83% vs 90% at 5 yrs and 66% vs 86% at 10 yrs, compared to mRSS < 20). Survival was worse in male patients with diffuse SSc, and lung and heart involvement represented the main causes of death in this South American series of patients with SSc.
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Energy Technology Data Exchange (ETDEWEB)
Lin, Jiong; Lin, Yao [Guangdong Provincial Key Laboratory of Stomatology, Department of Orthodontics, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, 510055 (China); Fan, Li [Department of Pharmaceutical Analysis, School of Pharmacy, The Fourth Military Medical University, Xi' an, Shaanxi, 710032 (China); Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, 510055 (China); Kuang, Wei [Department of Stomatology, Guangzhou General Hospital of Guangzhou Military Command, 111 Liuhua Road, Guangzhou, 510010 (China); Zheng, Liwei [State Key Laboratory of Oral Diseases, Sichuan University, Wuhou District, Chengdu, 610041 (China); Wu, Jiahua [Guangdong Provincial Key Laboratory of Stomatology, Department of Orthodontics, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, 510055 (China); Shang, Peng [Patient-specific Orthopedic Technology Research Center in GuangDong Research Centre for Neural Engineering, 1068 Xueyuan Boulevard, University Town of Shenzhen, Xili, Nanshan, Shenzhen, 518055 (China); Wang, Qiaofeng [Department of Pharmaceutical Chemistry, School of Pharmacy, The Fourth Military Medical University, Xi' an, Shanxi, 710032 (China); Tan, Jiali, E-mail: jasminenov@163.com [Guangdong Provincial Key Laboratory of Stomatology, Department of Orthodontics, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, 510055 (China)
2016-04-29
Oral squamous cell carcinoma (OSCC) is one of the most common types of the head and neck cancer. Chemo resistance of OSCC has been identified as a substantial therapeutic hurdle. In this study, we analyzed the role of miR-203 in the OSCC and its effects on cisplatin-induced cell death in an OSCC cell line, Tca8113. There was a significant decrease of miR-203 expression in OSCC samples, compared with the adjacent normal, non-cancerous tissue. After 3 days cisplatin treatment, the survived Tca8113 cells had a lower expression of miR-203 than that in the untreated control group. In contrast, PIK3CA showed an inverse expression in cancer and cisplatin survived Tca8113 cells. Transfection of Tca8113 cells with miR-203 mimics greatly reduced PIK3CA expression and Akt activation. Furthermore, miR-203 repressed PIK3CA expression through targeting the 3′UTR. Restoration of miR-203 not only suppressed cell proliferation, but also sensitized cells to cisplatin induced cell apoptosis. This effect was absent in cells that were simultaneously treated with PIK3CA RNAi. In summary, these findings suggest miR-203 plays an important role in cisplatin resistance in OSCC, and furthermore delivery of miR-203 analogs may serve as an adjuvant therapy for OSCC. - Highlights: • Much lower miR-203 expression in cisplatin resistant Tca8113 cells is discovered. • Delivery of miR-203 can sensitize the Tca8113 cells to cisplatin induced cell death. • MiR-203 can downregulate PIK3CA through the 3′UTR. • The effects of miR-203 on cisplatin sensitivity is mainly through PIK3CA pathway.
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Mortality risk and survival in the aftermath of the medieval Black Death.
DeWitte, Sharon N
2014-01-01
The medieval Black Death (c. 1347-1351) was one of the most devastating epidemics in human history. It killed tens of millions of Europeans, and recent analyses have shown that the disease targeted elderly adults and individuals who had been previously exposed to physiological stressors. Following the epidemic, there were improvements in standards of living, particularly in dietary quality for all socioeconomic strata. This study investigates whether the combination of the selective mortality of the Black Death and post-epidemic improvements in standards of living had detectable effects on survival and mortality in London. Samples are drawn from several pre- and post-Black Death London cemeteries. The pre-Black Death sample comes from the Guildhall Yard (n = 75) and St. Nicholas Shambles (n = 246) cemeteries, which date to the 11th-12th centuries, and from two phases within the St. Mary Spital cemetery, which date to between 1120-1300 (n = 143). The St. Mary Graces cemetery (n = 133) was in use from 1350-1538 and thus represents post-epidemic demographic conditions. By applying Kaplan-Meier analysis and the Gompertz hazard model to transition analysis age estimates, and controlling for changes in birth rates, this study examines differences in survivorship and mortality risk between the pre- and post-Black Death populations of London. The results indicate that there are significant differences in survival and mortality risk, but not birth rates, between the two time periods, which suggest improvements in health following the Black Death, despite repeated outbreaks of plague in the centuries after the Black Death.
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Mortality risk and survival in the aftermath of the medieval Black Death.
Directory of Open Access Journals (Sweden)
Sharon N DeWitte
Full Text Available The medieval Black Death (c. 1347-1351 was one of the most devastating epidemics in human history. It killed tens of millions of Europeans, and recent analyses have shown that the disease targeted elderly adults and individuals who had been previously exposed to physiological stressors. Following the epidemic, there were improvements in standards of living, particularly in dietary quality for all socioeconomic strata. This study investigates whether the combination of the selective mortality of the Black Death and post-epidemic improvements in standards of living had detectable effects on survival and mortality in London. Samples are drawn from several pre- and post-Black Death London cemeteries. The pre-Black Death sample comes from the Guildhall Yard (n = 75 and St. Nicholas Shambles (n = 246 cemeteries, which date to the 11th-12th centuries, and from two phases within the St. Mary Spital cemetery, which date to between 1120-1300 (n = 143. The St. Mary Graces cemetery (n = 133 was in use from 1350-1538 and thus represents post-epidemic demographic conditions. By applying Kaplan-Meier analysis and the Gompertz hazard model to transition analysis age estimates, and controlling for changes in birth rates, this study examines differences in survivorship and mortality risk between the pre- and post-Black Death populations of London. The results indicate that there are significant differences in survival and mortality risk, but not birth rates, between the two time periods, which suggest improvements in health following the Black Death, despite repeated outbreaks of plague in the centuries after the Black Death.
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Inhibition of Bcl-2 or IAP proteins does not provoke mutations in surviving cells
Energy Technology Data Exchange (ETDEWEB)
Shekhar, Tanmay M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Green, Maja M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Department of Anatomy & Neuroscience, The University of Melbourne, Parkville 3010 (Australia); Rayner, David M.; Miles, Mark A.; Cutts, Suzanne M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Hawkins, Christine J., E-mail: c.hawkins@latrobe.edu.au [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia)
2015-07-15
Graphical abstract: - Highlights: • Mutagenicities of anti-cancer drugs were tested using HPRT, γH2AX and comet assays. • TRAIL, doxorubicin and etoposide were more mutagenic than BH3- or Smac-mimetics. • Physiologically achievable levels of the BH3-mimetic ABT-737 were not mutagenic. • High concentrations of ABT-737 provoked mutations via an off-target mechanism. • Even very high concentrations of IAP antagonists were not mutagenic. - Abstract: Chemotherapy and radiotherapy can cause permanent damage to the genomes of surviving cells, provoking severe side effects such as second malignancies in some cancer survivors. Drugs that mimic the activity of death ligands, or antagonise pro-survival proteins of the Bcl-2 or IAP families have yielded encouraging results in animal experiments and early phase clinical trials. Because these agents directly engage apoptosis pathways, rather than damaging DNA to indirectly provoke tumour cell death, we reasoned that they may offer another important advantage over conventional therapies: minimisation or elimination of side effects such as second cancers that result from mutation of surviving normal cells. Disappointingly, however, we previously found that concentrations of death receptor agonists like TRAIL that would be present in vivo in clinical settings provoked DNA damage in surviving cells. In this study, we used cell line model systems to investigate the mutagenic capacity of drugs from two other classes of direct apoptosis-inducing agents: the BH3-mimetic ABT-737 and the IAP antagonists LCL161 and AT-406. Encouragingly, our data suggest that IAP antagonists possess negligible genotoxic activity. Doses of ABT-737 that were required to damage DNA stimulated Bax/Bak-independent signalling and exceeded concentrations detected in the plasma of animals treated with this drug. These findings provide hope that cancer patients treated by BH3-mimetics or IAP antagonists may avoid mutation-related illnesses that afflict
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Inhibition of Bcl-2 or IAP proteins does not provoke mutations in surviving cells
International Nuclear Information System (INIS)
Shekhar, Tanmay M.; Green, Maja M.; Rayner, David M.; Miles, Mark A.; Cutts, Suzanne M.; Hawkins, Christine J.
2015-01-01
Graphical abstract: - Highlights: • Mutagenicities of anti-cancer drugs were tested using HPRT, γH2AX and comet assays. • TRAIL, doxorubicin and etoposide were more mutagenic than BH3- or Smac-mimetics. • Physiologically achievable levels of the BH3-mimetic ABT-737 were not mutagenic. • High concentrations of ABT-737 provoked mutations via an off-target mechanism. • Even very high concentrations of IAP antagonists were not mutagenic. - Abstract: Chemotherapy and radiotherapy can cause permanent damage to the genomes of surviving cells, provoking severe side effects such as second malignancies in some cancer survivors. Drugs that mimic the activity of death ligands, or antagonise pro-survival proteins of the Bcl-2 or IAP families have yielded encouraging results in animal experiments and early phase clinical trials. Because these agents directly engage apoptosis pathways, rather than damaging DNA to indirectly provoke tumour cell death, we reasoned that they may offer another important advantage over conventional therapies: minimisation or elimination of side effects such as second cancers that result from mutation of surviving normal cells. Disappointingly, however, we previously found that concentrations of death receptor agonists like TRAIL that would be present in vivo in clinical settings provoked DNA damage in surviving cells. In this study, we used cell line model systems to investigate the mutagenic capacity of drugs from two other classes of direct apoptosis-inducing agents: the BH3-mimetic ABT-737 and the IAP antagonists LCL161 and AT-406. Encouragingly, our data suggest that IAP antagonists possess negligible genotoxic activity. Doses of ABT-737 that were required to damage DNA stimulated Bax/Bak-independent signalling and exceeded concentrations detected in the plasma of animals treated with this drug. These findings provide hope that cancer patients treated by BH3-mimetics or IAP antagonists may avoid mutation-related illnesses that afflict
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Directory of Open Access Journals (Sweden)
Anongnad Ngamjariyawat
Full Text Available PURPOSE: Transplantation of pancreatic islets to Type 1 diabetes patients is hampered by inflammatory reactions at the transplantation site leading to dysfunction and death of insulin producing beta-cells. Recently we have shown that co-transplantation of neural crest stem cells (NCSCs together with the islet cells improves transplantation outcome. The aim of the present investigation was to describe in vitro interactions between NCSCs and insulin producing beta-TC6 cells that may mediate protection against cytokine-induced beta-cell death. PROCEDURES: Beta-TC6 and NCSC cells were cultured either alone or together, and either with or without cell culture inserts. The cultures were then exposed to the pro-inflammatory cytokines IL-1β and IFN-γ for 48 hours followed by analysis of cell death rates (flow cytometry, nitrite production (Griess reagent, protein localization (immunofluorescence and protein phosphorylation (flow cytometry. RESULTS: We observed that beta-TC6 cells co-cultured with NCSCs were protected against cytokine-induced cell death, but not when separated by cell culture inserts. This occurred in parallel with (i augmented production of nitrite from beta-TC6 cells, indicating that increased cell survival allows a sustained production of nitric oxide; (ii NCSC-derived laminin production; (iii decreased phospho-FAK staining in beta-TC6 cell focal adhesions, and (iv decreased beta-TC6 cell phosphorylation of ERK(T202/Y204, FAK(Y397 and FAK(Y576. Furthermore, co-culture also resulted in cadherin and beta-catenin accumulations at the NCSC/beta-TC6 cell junctions. Finally, the gap junction inhibitor carbenoxolone did not affect cytokine-induced beta-cell death during co-culture with NCSCs. CONCLUSION: In summary, direct contacts, but not soluble factors, promote improved beta-TC6 viability when co-cultured with NCSCs. We hypothesize that cadherin junctions between NCSC and beta-TC6 cells promote powerful signals that maintain beta-cell
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Effects of insulin on the survival of irradiated chinese hamster lung cells
Energy Technology Data Exchange (ETDEWEB)
Lin, P S; Kwock, L; Hefter, K; Wallach, D F.H.; Brotman, R [Tufts-New England Medical Center, Boston, Mass. (USA)
1977-01-01
Insulin treatment (10/sup -7/-10/sup -9/ M) before ..gamma.. irradiation (50 to 500 rads) increases the long term survival of Chinese hamster lung cells (DON). Our data indicates that the radioprotective effect of insulin is not due to a modulation of cyclic-adenosine-3',5'-monophosphate levels within these cells. The results suggest that the radiosensitive plasma membrane component postulated to be involved in the interphase death of thymocytes and protected by insulin may have a counterpart in DON cells.
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Payne, Emily H; Ramalingam, Dhivya; Fox, Donald T; Klotman, Mary E
2018-01-15
Prior studies have found that HIV, through the Vpr protein, promotes genome reduplication (polyploidy) in infection-surviving epithelial cells within renal tissue. However, the temporal progression and molecular regulation through which Vpr promotes polyploidy have remained unclear. Here we define a sequential progression to Vpr-mediated polyploidy in human renal tubule epithelial cells (RTECs). We found that as in many cell types, Vpr first initiates G 2 cell cycle arrest in RTECs. We then identified a previously unreported cascade of Vpr-dependent events that lead to renal cell survival and polyploidy. Specifically, we found that a fraction of G 2 -arrested RTECs reenter the cell cycle. Following this cell cycle reentry, two distinct outcomes occur. Cells that enter complete mitosis undergo mitotic cell death due to extra centrosomes and aberrant division. Conversely, cells that abort mitosis undergo endoreplication to become polyploid. We further show that multiple small-molecule inhibitors of the phosphatidylinositol 3-kinase-related kinase (PIKK) family, including those that target ATR, ATM, and mTOR, indirectly prevent Vpr-mediated polyploidy by preventing G 2 arrest. In contrast, an inhibitor that targets DNA-dependent protein kinase (DNA-PK) specifically blocks the Vpr-mediated transition from G 2 arrest to polyploidy. These findings outline a temporal, molecularly regulated path to polyploidy in HIV-positive renal cells. IMPORTANCE Current cure-focused efforts in HIV research aim to elucidate the mechanisms of long-term persistence of HIV in compartments. The kidney is recognized as one such compartment, since viral DNA and mRNA persist in the renal tissues of HIV-positive patients. Further, renal disease is a long-term comorbidity in the setting of HIV. Thus, understanding the regulation and impact of HIV infection on renal cell biology will provide important insights into this unique HIV compartment. Our work identifies mechanisms that distinguish
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International Nuclear Information System (INIS)
Park, Seong H.; Choi, Won-Seok; Yoon, So-Young; Ahn, Young Soo; Oh, Young J.
2004-01-01
The nuclear factor-kappaB (NF-κB) family plays an important role in the control of the apoptotic response. Its activation has been demonstrated in both neurons and glial cells in many neurological disorders. In the present study, we specifically examined whether and to what extent NF-κB activation is involved in culture models of Parkinson's disease following exposure of MN9D dopaminergic neuronal cells to 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenyl-4-phenylpyridinium ion (MPP + ). Both analysis by immunocytochemistry and of immunoblots revealed that NF-κB-p65 was translocated into the nuclei following 6-OHDA but not MPP + -treatment. A time-dependent activation of NF-κB induced by 6-OHDA but not MPP + was also demonstrated by an electrophoretic mobility shift assay. A competition assay indicated that not only NF-κB-p65 but also -p50 is involved in 6-OHDA-induced NF-κB activity. Co-treatment with an antioxidant, N-acetyl-L-cysteine, blocked 6-OHDA-induced activation of NF-κB signaling. In the presence of an NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), 6-OHDA-induced cell death was accelerated while PDTC did not affect MPP + -induced cell death. Our data may point to a drug-specific activation of NF-κB as a survival determinant for dopaminergic neurons
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Protein kinase activity of phosphoinositide 3-kinase regulates cytokine-dependent cell survival.
Directory of Open Access Journals (Sweden)
Daniel Thomas
Full Text Available The dual specificity protein/lipid kinase, phosphoinositide 3-kinase (PI3K, promotes growth factor-mediated cell survival and is frequently deregulated in cancer. However, in contrast to canonical lipid-kinase functions, the role of PI3K protein kinase activity in regulating cell survival is unknown. We have employed a novel approach to purify and pharmacologically profile protein kinases from primary human acute myeloid leukemia (AML cells that phosphorylate serine residues in the cytoplasmic portion of cytokine receptors to promote hemopoietic cell survival. We have isolated a kinase activity that is able to directly phosphorylate Ser585 in the cytoplasmic domain of the interleukin 3 (IL-3 and granulocyte macrophage colony stimulating factor (GM-CSF receptors and shown it to be PI3K. Physiological concentrations of cytokine in the picomolar range were sufficient for activating the protein kinase activity of PI3K leading to Ser585 phosphorylation and hemopoietic cell survival but did not activate PI3K lipid kinase signaling or promote proliferation. Blockade of PI3K lipid signaling by expression of the pleckstrin homology of Akt1 had no significant impact on the ability of picomolar concentrations of cytokine to promote hemopoietic cell survival. Furthermore, inducible expression of a mutant form of PI3K that is defective in lipid kinase activity but retains protein kinase activity was able to promote Ser585 phosphorylation and hemopoietic cell survival in the absence of cytokine. Blockade of p110α by RNA interference or multiple independent PI3K inhibitors not only blocked Ser585 phosphorylation in cytokine-dependent cells and primary human AML blasts, but also resulted in a block in survival signaling and cell death. Our findings demonstrate a new role for the protein kinase activity of PI3K in phosphorylating the cytoplasmic tail of the GM-CSF and IL-3 receptors to selectively regulate cell survival highlighting the importance of targeting
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Directory of Open Access Journals (Sweden)
Leoh Lai
2009-08-01
Full Text Available Abstract Background Hormone-refractory prostate cancer (HRPC is characterized by poor response to chemotherapy and high mortality, particularly among African American men when compared to other racial/ethnic groups. It is generally accepted that docetaxel, the standard of care for chemotherapy of HRPC, primarily exerts tumor cell death by inducing mitotic catastrophe and caspase-dependent apoptosis following inhibition of microtubule depolymerization. However, there is a gap in our knowledge of mechanistic events underlying docetaxel-induced caspase-independent cell death, and the genes that antagonize this process. This knowledge is important for circumventing HRPC chemoresistance and reducing disparities in prostate cancer mortality. Results We investigated mechanistic events associated with docetaxel-induced death in HRPC cell lines using various approaches that distinguish caspase-dependent from caspase-independent cell death. Docetaxel induced both mitotic catastrophe and caspase-dependent apoptosis at various concentrations. However, caspase activity was not essential for docetaxel-induced cytotoxicity since cell death associated with lysosomal membrane permeabilization still occurred in the presence of caspase inhibitors. Partial inhibition of docetaxel-induced cytotoxicity was observed after inhibition of cathepsin B, but not inhibition of cathepsins D and L, suggesting that docetaxel induces caspase-independent, lysosomal cell death. Simultaneous inhibition of caspases and cathepsin B dramatically reduced docetaxel-induced cell death. Ectopic expression of lens epithelium-derived growth factor p75 (LEDGF/p75, a stress survival autoantigen and transcription co-activator, attenuated docetaxel-induced lysosomal destabilization and cell death. Interestingly, LEDGF/p75 overexpression did not protect cells against DTX-induced mitotic catastrophe, and against apoptosis induced by tumor necrosis factor related apoptosis inducing ligand (TRAIL
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Directory of Open Access Journals (Sweden)
Camille Duc
Full Text Available Yeast cell death can occur during wine alcoholic fermentation. It is generally considered to result from ethanol stress that impacts membrane integrity. This cell death mainly occurs when grape musts processing reduces lipid availability, resulting in weaker membrane resistance to ethanol. However the mechanisms underlying cell death in these conditions remain unclear. We examined cell death occurrence considering yeast cells ability to elicit an appropriate response to a given nutrient limitation and thus survive starvation. We show here that a set of micronutrients (oleic acid, ergosterol, pantothenic acid and nicotinic acid in low, growth-restricting concentrations trigger cell death in alcoholic fermentation when nitrogen level is high. We provide evidence that nitrogen signaling is involved in cell death and that either SCH9 deletion or Tor inhibition prevent cell death in several types of micronutrient limitation. Under such limitations, yeast cells fail to acquire any stress resistance and are unable to store glycogen. Unexpectedly, transcriptome analyses did not reveal any major changes in stress genes expression, suggesting that post-transcriptional events critical for stress response were not triggered by micronutrient starvation. Our data point to the fact that yeast cell death results from yeast inability to trigger an appropriate stress response under some conditions of nutrient limitations most likely not encountered by yeast in the wild. Our conclusions provide a novel frame for considering both cell death and the management of nutrients during alcoholic fermentation.
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DEFF Research Database (Denmark)
Groth-Pedersen, Line; Aits, Sonja; Corcelle-Termeau, Elisabeth
2012-01-01
Microtubule-disturbing drugs inhibit lysosomal trafficking and induce lysosomal membrane permeabilization followed by cathepsin-dependent cell death. To identify specific trafficking-related proteins that control cell survival and lysosomal stability, we screened a molecular motor siRNA library...... in human MCF7 breast cancer cells. SiRNAs targeting four kinesins (KIF11/Eg5, KIF20A, KIF21A, KIF25), myosin 1G (MYO1G), myosin heavy chain 1 (MYH1) and tropomyosin 2 (TPM2) were identified as effective inducers of non-apoptotic cell death. The cell death induced by KIF11, KIF21A, KIF25, MYH1 or TPM2 si......), increased dextran accumulation (KIF20A), or reduced autophagic flux (MYO1G, MYH1). Importantly, all seven siRNAs also killed human cervix cancer (HeLa) and osteosarcoma (U-2-OS) cells and sensitized cancer cells to other lysosome-destabilizing treatments, i.e. photo-oxidation, siramesine, etoposide...
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Vuppalapati, Karuna K; Bouderlique, Thibault; Newton, Phillip T; Kaminskyy, Vitaliy O; Wehtje, Henrik; Ohlsson, Claes; Zhivotovsky, Boris; Chagin, Andrei S
2015-12-01
Longitudinal bone growth takes place in epiphyseal growth plates located in the ends of long bones. The growth plate consists of chondrocytes traversing from the undifferentiated (resting zone) to the terminally differentiated (hypertrophic zone) stage. Autophagy is an intracellular catabolic process of lysosome-dependent recycling of intracellular organelles and protein complexes. Autophagy is activated during nutritionally depleted or hypoxic conditions in order to facilitate cell survival. Chondrocytes in the middle of the growth plate are hypoxic and nutritionally depleted owing to the avascular nature of the growth plate. Accordingly, autophagy may facilitate their survival. To explore the role of autophagy in chondrocyte survival and constitutional bone growth, we generated mice with cartilage-specific ablation of either Atg5 (Atg5cKO) or Atg7 (Atg7cKO) by crossing Atg5 or Atg7 floxed mice with cartilage-specific collagen type 2 promoter-driven Cre. Both Atg5cKO and Atg7cKO mice showed growth retardation associated with enhanced chondrocyte cell death and decreased cell proliferation. Similarly, inhibition of autophagy by Bafilomycin A1 (Baf) or 3-methyladenine (3MA) promoted cell death in cultured slices of human growth plate tissue. To delineate the underlying mechanisms we employed ex vivo cultures of mouse metatarsal bones and RCJ3.IC5.18 rat chondrogenic cell line. Baf or 3MA impaired metatarsal bone growth associated with processing of caspase-3 and massive cell death. Similarly, treatment of RCJ3.IC5.18 chondrogenic cells by Baf also showed massive cell death and caspase-3 cleavage. This was associated with activation of caspase-9 and cytochrome C release. Altogether, our data suggest that autophagy is important for chondrocyte survival, and inhibition of this process leads to stunted growth and caspase-dependent death of chondrocytes. © 2015 American Society for Bone and Mineral Research.
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International Nuclear Information System (INIS)
Liu Qing; He Xiaoqing; Liu Yongsheng; Du Bingbing; Wang Xiaoyan; Zhang Weisheng; Jia Pengfei; Dong Jingmei; Ma Jianxiu; Wang Xiaohu; Li Sha; Zhang Hong
2008-01-01
Oxidative damage is an important mechanism in X-ray-induced cell death. Radiolysis of water molecules is a source of reactive oxygen species (ROS) that contribute to X-ray-induced cell death. In this study, we showed by ROS detection and a cell survival assay that NADPH oxidase has a very important role in X-ray-induced cell death. Under X-ray irradiation, the upregulation of the expression of NADPH oxidase membrane subunit gp91 phox was dose-dependent. Meanwhile, the cytoplasmic subunit p47 phox was translocated to the cell membrane and localized with p22 phox and gp91 phox to form reactive NADPH oxidase. Our data suggest, for the first time, that NADPH oxidase-mediated generation of ROS is an important contributor to X-ray-induced cell death. This suggests a new target for combined gene transfer and radiotherapy.
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Delayed cell death associated with mitotic catastrophe in γ-irradiated stem-like glioma cells
International Nuclear Information System (INIS)
Firat, Elke; Gaedicke, Simone; Tsurumi, Chizuko; Esser, Norbert; Weyerbrock, Astrid; Niedermann, Gabriele
2011-01-01
Stem-like tumor cells are regarded as highly resistant to ionizing radiation (IR). Previous studies have focused on apoptosis early after irradiation, and the apoptosis resistance observed has been attributed to reduced DNA damage or enhanced DNA repair compared to non-stem tumor cells. Here, early and late radioresponse of patient-derived stem-like glioma cells (SLGCs) and differentiated cells directly derived from them were examined for cell death mode and the influence of stem cell-specific growth factors. Primary SLGCs were propagated in serum-free medium with the stem-cell mitogens epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2). Differentiation was induced by serum-containing medium without EGF and FGF. Radiation sensitivity was evaluated by assessing proliferation, clonogenic survival, apoptosis, and mitotic catastrophe. DNA damage-associated γH2AX as well as p53 and p21 expression were determined by Western blots. SLGCs failed to apoptose in the first 4 days after irradiation even at high single doses up to 10 Gy, but we observed substantial cell death later than 4 days postirradiation in 3 of 6 SLGC lines treated with 5 or 10 Gy. This delayed cell death was observed in 3 of the 4 SLGC lines with nonfunctional p53, was associated with mitotic catastrophe and occurred via apoptosis. The early apoptosis resistance of the SLGCs was associated with lower γH2AX compared to differentiated cells, but we found that the stem-cell culture cytokines EGF plus FGF-2 strongly reduce γH2AX levels. Nonetheless, in two p53-deficient SLGC lines examined γIR-induced apoptosis even correlated with EGF/FGF-induced proliferation and mitotic catastrophe. In a line containing CD133-positive and -negative stem-like cells, the CD133-positive cells proliferated faster and underwent more γIR-induced mitotic catastrophe. Our results suggest the importance of delayed apoptosis, associated mitotic catastrophe, and cellular proliferation for γIR-induced death of
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Streptococcus sanguinis induces neutrophil cell death by production of hydrogen peroxide.
Sumioka, Ryuichi; Nakata, Masanobu; Okahashi, Nobuo; Li, Yixuan; Wada, Satoshi; Yamaguchi, Masaya; Sumitomo, Tomoko; Hayashi, Mikako; Kawabata, Shigetada
2017-01-01
Streptococcus is the dominant bacterial genus in the human oral cavity and a leading cause of infective endocarditis. Streptococcus sanguinis belongs to the mitis group of streptococci and produces hydrogen peroxide (H2O2) by the action of SpxB, a pyruvate oxidase. In this study, we investigated the involvement of SpxB in survival of S. sanguinis in human blood and whether bacterial H2O2 exhibits cytotoxicity against human neutrophils. Results of a bactericidal test with human whole blood revealed that the spxB mutation in S. sanguinis is detrimental to its survival in blood. When S. sanguinis strains were exposed to isolated neutrophils, the bacterial survival rate was significantly decreased by spxB deletion. Furthermore, human neutrophils exposed to the S. sanguinis wild-type strain, in contrast to those exposed to an spxB mutant strain, underwent cell death with chromatin de-condensation and release of web-like extracellular DNA, reflecting induction of neutrophil extracellular traps (NETs). Since reactive oxygen species-mediated NET induction requires citrullination of arginine residues in histone proteins and subsequent chromatin de-condensation, we examined citrullination levels of histone in infected neutrophils. It is important to note that the citrullinated histone H3 was readily detected in neutrophils infected with the wild-type strain, as compared to infection with the spxB mutant strain. Moreover, decomposition of streptococcal H2O2 with catalase reduced NET induction. These results suggest that H2O2 produced by S. sanguinis provokes cell death of neutrophils and NET formation, thus potentially affecting bacterial survival in the bloodstream.
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Streptococcus sanguinis induces neutrophil cell death by production of hydrogen peroxide.
Directory of Open Access Journals (Sweden)
Ryuichi Sumioka
Full Text Available Streptococcus is the dominant bacterial genus in the human oral cavity and a leading cause of infective endocarditis. Streptococcus sanguinis belongs to the mitis group of streptococci and produces hydrogen peroxide (H2O2 by the action of SpxB, a pyruvate oxidase. In this study, we investigated the involvement of SpxB in survival of S. sanguinis in human blood and whether bacterial H2O2 exhibits cytotoxicity against human neutrophils. Results of a bactericidal test with human whole blood revealed that the spxB mutation in S. sanguinis is detrimental to its survival in blood. When S. sanguinis strains were exposed to isolated neutrophils, the bacterial survival rate was significantly decreased by spxB deletion. Furthermore, human neutrophils exposed to the S. sanguinis wild-type strain, in contrast to those exposed to an spxB mutant strain, underwent cell death with chromatin de-condensation and release of web-like extracellular DNA, reflecting induction of neutrophil extracellular traps (NETs. Since reactive oxygen species-mediated NET induction requires citrullination of arginine residues in histone proteins and subsequent chromatin de-condensation, we examined citrullination levels of histone in infected neutrophils. It is important to note that the citrullinated histone H3 was readily detected in neutrophils infected with the wild-type strain, as compared to infection with the spxB mutant strain. Moreover, decomposition of streptococcal H2O2 with catalase reduced NET induction. These results suggest that H2O2 produced by S. sanguinis provokes cell death of neutrophils and NET formation, thus potentially affecting bacterial survival in the bloodstream.
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Lee, Jisun; Lee, Seul; Kim, Sun-Lim; Choi, Ji Won; Seo, Jeong Yeon; Choi, Doo Jin; Park, Yong Il
2014-12-05
Despite recent advances in prostate cancer diagnostics and therapeutics, the overall survival rate still remains low. This study was aimed to assess potential anti-cancer activity of maysin, a major flavonoid of corn silk (CS, Zea mays L.), in androgen-independent human prostate cancer cells (PC-3). Maysin was isolated from CS of Kwangpyeongok, a Korean hybrid corn, via methanol extraction and preparative C18 reverse phase column chromatography. Maysin cytotoxicity was determined by either monitoring cell viability in various cancer cell lines by MTT assay or morphological changes. Apoptotic cell death was assessed by annexin V-FITC/PI double staining, depolarization of mitochondrial membrane potential (MMP), expression levels of Bcl-2 and pro-caspase-3 and by terminal transferase mediated dUTP-fluorescein nick end labeling (TUNEL) staining. Underlying mechanism in maysin-induced apoptosis of PC-3 cells was explored by evaluating its effects on Akt and ERK pathway. Maysin dose-dependently reduced the PC-3 cell viability, with an 87% reduction at 200 μg/ml. Maysin treatment significantly induced apoptotic cell death, DNA fragmentation, depolarization of MMP, and reduction in Bcl-2 and pro-caspase-3 expression levels. Maysin also significantly attenuated phosphorylation of Akt and ERK. A combined treatment with maysin and other known anti-cancer agents, including 5-FU, etoposide, cisplatin, or camptothecin, synergistically enhanced PC-3 cell death. These results suggested for the first time that maysin inhibits the PC-3 cancer cell growth via stimulation of mitochondria-dependent apoptotic cell death and may have a strong therapeutic potential for the treatment of either chemo-resistant or androgen-independent human prostate cancer. Copyright © 2014 Elsevier Inc. All rights reserved.
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p63 promotes cell survival through fatty acid synthase.
Directory of Open Access Journals (Sweden)
Venkata Sabbisetti
2009-06-01
Full Text Available There is increasing evidence that p63, and specifically DeltaNp63, plays a central role in both development and tumorigenesis by promoting epithelial cell survival. However, few studies have addressed the molecular mechanisms through which such important function is exerted. Fatty acid synthase (FASN, a key enzyme that synthesizes long-chain fatty acids and is involved in both embryogenesis and cancer, has been recently proposed as a direct target of p53 family members, including p63 and p73. Here we show that knockdown of either total or DeltaN-specific p63 isoforms in squamous cell carcinoma (SCC9 or immortalized prostate epithelial (iPrEC cells caused a decrease in cell viability by inducing apoptosis without affecting the cell cycle. p63 silencing significantly reduced both the expression and the activity of FASN. Importantly, stable overexpression of either FASN or myristoylated AKT (myr-AKT was able to partially rescue cells from cell death induced by p63 silencing. FASN induced AKT phosphorylation and a significant reduction in cell viability was observed when FASN-overexpressing SCC9 cells were treated with an AKT inhibitor after p63 knockdown, indicating that AKT plays a major role in FASN-mediated survival. Activated AKT did not cause any alteration in the FASN protein levels but induced its activity, suggesting that the rescue from apoptosis documented in the p63-silenced cells expressing myr-AKT cells may be partially mediated by FASN. Finally, we demonstrated that p63 and FASN expression are positively associated in clinical squamous cell carcinoma samples as well as in the developing prostate. Taken together, our findings demonstrate that FASN is a functionally relevant target of p63 and is required for mediating its pro-survival effects.
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Mind Bomb Regulates Cell Death during TNF Signaling by Suppressing RIPK1’s Cytotoxic Potential
Directory of Open Access Journals (Sweden)
Rebecca Feltham
2018-04-01
Full Text Available Summary: Tumor necrosis factor (TNF is an inflammatory cytokine that can signal cell survival or cell death. The mechanisms that switch between these distinct outcomes remain poorly defined. Here, we show that the E3 ubiquitin ligase Mind Bomb-2 (MIB2 regulates TNF-induced cell death by inactivating RIPK1 via inhibitory ubiquitylation. Although depletion of MIB2 has little effect on NF-κB activation, it sensitizes cells to RIPK1- and caspase-8-dependent cell death. We find that MIB2 represses the cytotoxic potential of RIPK1 by ubiquitylating lysine residues in the C-terminal portion of RIPK1. Our data suggest that ubiquitin conjugation of RIPK1 interferes with RIPK1 oligomerization and RIPK1-FADD association. Disruption of MIB2-mediated ubiquitylation, either by mutation of MIB2’s E3 activity or RIPK1’s ubiquitin-acceptor lysines, sensitizes cells to RIPK1-mediated cell death. Together, our findings demonstrate that Mind Bomb E3 ubiquitin ligases can function as additional checkpoint of cytokine-induced cell death, selectively protecting cells from the cytotoxic effects of TNF. : Feltham et al. show that MIB2 directly ubiquitylates RIPK1 upon TNF stimulation, suppressing the cytotoxic potential of RIPK1 and acting as a checkpoint within the TNF signaling pathway. Keywords: MIB2, RIPK1, TNF, cell death, caspase-8, IAPs, ubiquitin
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Poormoghim, Hadi; Andalib, Elham; Jalali, Arash; Ghaderi, Afshin; Ghorbannia, Ali; Mojtabavi, Nazanin
2016-07-01
The aims of the study were to determine prognostic factors for survival and causes of death in a cohort of patients with systemic sclerosis (SSc). This was a cohort study of SSc patients in single rheumatologic center from January 1998 to August 2012. They fulfilled the American College of Rheumatology classification criteria for SSc or had calcinosis Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia or sine sclerosis. Causes of death were classified as SSc related and non-SSc related. Kaplan-Meier and Cox proportional hazard regression models were used in univariate and multivariate analysis to analyse survival in subgroups and determine prognostic factors of survival. The study includes 220 patients (192 female, 28 male). Out of thirty-two (14.5 %) who died, seventeen (53.1 %) deaths were SSc related and in nine (28.1 %) non-SSc-related causes, and in six (18.8 %) of patients causes of death were not defined. Overall survival rate was 92.6 % (95 % CI 87.5-95.7 %) after 5 years and 82.3 % (95 % CI 73.4-88.4 %) after 10 years. Pulmonary involvement was a major SSc-related cause of death, occurred in seven (41.1 %) patients. Cardiovascular events were leading cause of in overall death (11) 34.3 % and 6 in non-SSc-related death. Independent risk factors for mortality were age >50 at diagnosis (HR 5.10) advance pulmonary fibrosis (HR 11.5), tendon friction rub at entry (HR 6.39), arthritis (HR 3.56). In this first Middle Eastern series of SSc registry, pulmonary and cardiac involvements were the leading cause of SSc-related death.
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Neonatal maternal separation up-regulates protein signalling for cell survival in rat hypothalamus.
Irles, Claudine; Nava-Kopp, Alicia T; Morán, Julio; Zhang, Limei
2014-05-01
We have previously reported that in response to early life stress, such as maternal hyperthyroidism and maternal separation (MS), the rat hypothalamic vasopressinergic system becomes up-regulated, showing enlarged nuclear volume and cell number, with stress hyperresponsivity and high anxiety during adulthood. The detailed signaling pathways involving cell death/survival, modified by adverse experiences in this developmental window remains unknown. Here, we report the effects of MS on cellular density and time-dependent fluctuations of the expression of pro- and anti-apoptotic factors during the development of the hypothalamus. Neonatal male rats were exposed to 3 h-daily MS from postnatal days 2 to 15 (PND 2-15). Cellular density was assessed in the hypothalamus at PND 21 using methylene blue staining, and neuronal nuclear specific protein and glial fibrillary acidic protein immunostaining at PND 36. Expression of factors related to apoptosis and cell survival in the hypothalamus was examined at PND 1, 3, 6, 9, 12, 15, 20 and 43 by Western blot. Rats subjected to MS exhibited greater cell-density and increased neuronal density in all hypothalamic regions assessed. The time course of protein expression in the postnatal brain showed: (1) decreased expression of active caspase 3; (2) increased Bcl-2/Bax ratio; (3) increased activation of ERK1/2, Akt and inactivation of Bad; PND 15 and PND 20 were the most prominent time-points. These data indicate that MS can induce hypothalamic structural reorganization by promoting survival, suppressing cell death pathways, increasing cellular density which may alter the contribution of these modified regions to homeostasis.
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Directory of Open Access Journals (Sweden)
Pierre-François Lesault
Full Text Available Transplantation of muscle precursor cells is of therapeutic interest for focal skeletal muscular diseases. However, major limitations of cell transplantation are the poor survival, expansion and migration of the injected cells. The massive and early death of transplanted myoblasts is not fully understood although several mechanisms have been suggested. Various attempts have been made to improve their survival or migration. Taking into account that muscle regeneration is associated with the presence of macrophages, which are helpful in repairing the muscle by both cleansing the debris and deliver trophic cues to myoblasts in a sequential way, we attempted in the present work to improve myoblast transplantation by coinjecting macrophages. The present data showed that in the 5 days following the transplantation, macrophages efficiently improved: i myoblast survival by limiting their massive death, ii myoblast expansion within the tissue and iii myoblast migration in the dystrophic muscle. This was confirmed by in vitro analyses showing that macrophages stimulated myoblast adhesion and migration. As a result, myoblast contribution to regenerating host myofibres was increased by macrophages one month after transplantation. Altogether, these data demonstrate that macrophages are beneficial during the early steps of myoblast transplantation into skeletal muscle, showing that coinjecting these stromal cells may be used as a helper to improve the efficiency of parenchymal cell engraftment.
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Exploration of protective strategies against oligodendrocyte cell death in Krabbe disease models
Directory of Open Access Journals (Sweden)
Gonzalo Arboleda
2015-02-01
Full Text Available Krabbe disease (KD patients accumulate psychosine (galactosylsphingosine, a cytotoxic metabolite for oligodendrocytes, inducing early demyelination. Apoptosis has been suggested that plays an important role in psychosine-induced oligodendrocytes cell death in culture and in brains of Krabbe patients and an animal model of the disease (twitcher mouse. However, the molecular mechanism that triggers the activation of the apoptotic pathway, and hence the development/progression of the disease, still is not well understood. Here we report that silencing GALC gene expression induces cell death of the human derived oligodendrocyte cell line MO3.13. The induction of cell death is associated with the activation of caspase 3 and increase in Bax expression, suggesting that mitochondria is compromise, and decrease in cell survival signaling pathways such as PI3K/AKT, MAPK/ERK and AMPK, as observed by western blot analysis, 2 days after silencing. The data suggests an important psychosine-induced deregulation in apoptotic and anti-apoptotic cellular pathways. Moreover, pre-treatment with insuline-like growth factor (IGF-1 and PPARalfa agonist (WY 14643, significantly provides protection against the psychosine-induced changes described. Our data indicates that oligodendrocytes have a marked susceptibility to endogenous accumulation of psychosine and identified potential compounds that may offer protection against psychosine-induced apoptosis in vivo.
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Cell Death and Heart Failure in Obesity: Role of Uncoupling Proteins
Directory of Open Access Journals (Sweden)
Angélica Ruiz-Ramírez
2016-01-01
Full Text Available Metabolic diseases such as obesity, metabolic syndrome, and type II diabetes are often characterized by increased reactive oxygen species (ROS generation in mitochondrial respiratory complexes, associated with fat accumulation in cardiomyocytes, skeletal muscle, and hepatocytes. Several rodents studies showed that lipid accumulation in cardiac myocytes produces lipotoxicity that causes apoptosis and leads to heart failure, a dynamic pathological process. Meanwhile, several tissues including cardiac tissue develop an adaptive mechanism against oxidative stress and lipotoxicity by overexpressing uncoupling proteins (UCPs, specific mitochondrial membrane proteins. In heart from rodent and human with obesity, UCP2 and UCP3 may protect cardiomyocytes from death and from a state progressing to heart failure by downregulating programmed cell death. UCP activation may affect cytochrome c and proapoptotic protein release from mitochondria by reducing ROS generation and apoptotic cell death. Therefore the aim of this review is to discuss recent findings regarding the role that UCPs play in cardiomyocyte survival by protecting against ROS generation and maintaining bioenergetic metabolism homeostasis to promote heart protection.
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[Methuosis: a novel type of cell death].
Cai, Hongbing; Liu, Jinkun; Fan, Qin; Li, Xin
2013-12-01
Cell death is a major physiological or pathological phenomenon in life activities. The classic forms of cell death include apoptosis, necrosis, and autophagy. Recently, a novel type of cell death has been observed and termed as methuosis, in which excessive stimuli can induce cytoplasmic uptake and accumulation of small bubbles that gradually merge into giant vacuoles, eventually leading to decreased cellular metabolic activity, cell membrane rupture and cell death. In this article, we describe the nomenclature, morphological characteristics and underlying mechanisms of methuosis, compare methuosis with autophagy, oncosis and paraptosis, and review the related researches.
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The balance between life and death of cells: Roles of Metallothioneins
DEFF Research Database (Denmark)
Penkowa, Milena; Bohr, Adam; Nielsen, Allan
2007-01-01
and death, as seen in two rather contrasting pathological conditions: Neurodegeneration and neoplasms. MT-I+II have analogous functions including: 1) Antioxidant scavenging of reactive oxygen species (ROS); 2) Cytoprotection against degeneration and apoptosis; 3) Stimulation of cell growth and repair...... including angiogenesis/revascularization, activation of stem/progenitor cells, and neuroregeneration. Thereby, MT-I+II mediate neuroprotection, CNS restoration and clinical recovery during neurodegenerative disorders. Due to the promotion of cell survival, increased MT-I+II levels have been associated......-dependent transcription factors, protein synthesis, cellular energy levels/metabolism and cell redox state. Here, the neuroprotective and regenerative functions of MT-I+II are reviewed, and the presumed link to oncogenesis is critically perused....
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Morphological classification of plant cell deaths.
van Doorn, W G; Beers, E P; Dangl, J L; Franklin-Tong, V E; Gallois, P; Hara-Nishimura, I; Jones, A M; Kawai-Yamada, M; Lam, E; Mundy, J; Mur, L A J; Petersen, M; Smertenko, A; Taliansky, M; Van Breusegem, F; Wolpert, T; Woltering, E; Zhivotovsky, B; Bozhkov, P V
2011-08-01
Programmed cell death (PCD) is an integral part of plant development and of responses to abiotic stress or pathogens. Although the morphology of plant PCD is, in some cases, well characterised and molecular mechanisms controlling plant PCD are beginning to emerge, there is still confusion about the classification of PCD in plants. Here we suggest a classification based on morphological criteria. According to this classification, the use of the term 'apoptosis' is not justified in plants, but at least two classes of PCD can be distinguished: vacuolar cell death and necrosis. During vacuolar cell death, the cell contents are removed by a combination of autophagy-like process and release of hydrolases from collapsed lytic vacuoles. Necrosis is characterised by early rupture of the plasma membrane, shrinkage of the protoplast and absence of vacuolar cell death features. Vacuolar cell death is common during tissue and organ formation and elimination, whereas necrosis is typically found under abiotic stress. Some examples of plant PCD cannot be ascribed to either major class and are therefore classified as separate modalities. These are PCD associated with the hypersensitive response to biotrophic pathogens, which can express features of both necrosis and vacuolar cell death, PCD in starchy cereal endosperm and during self-incompatibility. The present classification is not static, but will be subject to further revision, especially when specific biochemical pathways are better defined.
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DEFF Research Database (Denmark)
Straarup, EM; Schousboe, P; Hansen, HQ
1997-01-01
Autocrine factors prevent cell death in the ciliate Tetrahymena thermophila, a unicellular eukaryote, in a chemically defined medium. At certain growth conditions these factors are released at a sufficient concentration by > 500 cells ml-1 to support cell survival and proliferation. The protein...
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International Nuclear Information System (INIS)
Zhang, Kai-Xin; Firus, Jessica; Prieur, Brenda; Jia, William; Rennie, Paul S.
2011-01-01
Prostate cancer is the most frequently diagnosed non-skin cancer in adult males in North America and is the second leading cause of cancer-related mortality. For locally advanced or metastatic disease, androgen deprivation, through medical or surgical castration, is the primary treatment to induce prostate cancer cell death and extend patient survival. However, the vast majority of cancers progress to a castration-resistant/androgen-independent state where the cell death processes are no longer active. This review describes the main cell death processes, apoptosis, autophagy, necrosis and necroptosis, which may be activated in prostate cancers after androgen deprivation therapy as well as the molecular mechanisms through which the cancers progress to become castration resistant. In particular, the central role of persistent androgen receptor (AR)-mediated signaling and AR crosstalk with other critical cell signaling pathways, including (i) the PI3K/Akt pathway, (ii) receptor tyrosine kinases, (iii) the p38 MAPK pathway, and (iv) the Wnt/β-catenin pathway, as well as reactivation of AR by de novo synthesized androgen are discussed in this context. Understanding the molecular changes that subvert normal cell death mechanisms and thereby compromise the survival of prostate cancer patients continues to be a major challenge
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Energy Technology Data Exchange (ETDEWEB)
Zhang, Kai-Xin; Firus, Jessica; Prieur, Brenda [The Vancouver Prostate Centre, 2660 Oak St., Vancouver, BC V6H 3Z6 (Canada); Department of Urologic Sciences, University of British Columbia, Vancouver, BC V6H 3Z6 (Canada); Jia, William [Department of Surgery and Brain Research Centre, University of British Columbia, Vancouver, BC V6H 3Z6 (Canada); Rennie, Paul S., E-mail: prennie@interchange.ubc.ca [The Vancouver Prostate Centre, 2660 Oak St., Vancouver, BC V6H 3Z6 (Canada); Department of Urologic Sciences, University of British Columbia, Vancouver, BC V6H 3Z6 (Canada)
2011-03-24
Prostate cancer is the most frequently diagnosed non-skin cancer in adult males in North America and is the second leading cause of cancer-related mortality. For locally advanced or metastatic disease, androgen deprivation, through medical or surgical castration, is the primary treatment to induce prostate cancer cell death and extend patient survival. However, the vast majority of cancers progress to a castration-resistant/androgen-independent state where the cell death processes are no longer active. This review describes the main cell death processes, apoptosis, autophagy, necrosis and necroptosis, which may be activated in prostate cancers after androgen deprivation therapy as well as the molecular mechanisms through which the cancers progress to become castration resistant. In particular, the central role of persistent androgen receptor (AR)-mediated signaling and AR crosstalk with other critical cell signaling pathways, including (i) the PI3K/Akt pathway, (ii) receptor tyrosine kinases, (iii) the p38 MAPK pathway, and (iv) the Wnt/β-catenin pathway, as well as reactivation of AR by de novo synthesized androgen are discussed in this context. Understanding the molecular changes that subvert normal cell death mechanisms and thereby compromise the survival of prostate cancer patients continues to be a major challenge.
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Directory of Open Access Journals (Sweden)
Paul S. Rennie
2011-03-01
Full Text Available Prostate cancer is the most frequently diagnosed non-skin cancer in adult males in North America and is the second leading cause of cancer-related mortality. For locally advanced or metastatic disease, androgen deprivation, through medical or surgical castration, is the primary treatment to induce prostate cancer cell death and extend patient survival. However, the vast majority of cancers progress to a castration-resistant/androgen-independent state where the cell death processes are no longer active. This review describes the main cell death processes, apoptosis, autophagy, necrosis and necroptosis, which may be activated in prostate cancers after androgen deprivation therapy as well as the molecular mechanisms through which the cancers progress to become castration resistant. In particular, the central role of persistent androgen receptor (AR-mediated signaling and AR crosstalk with other critical cell signaling pathways, including (i the PI3K/Akt pathway, (ii receptor tyrosine kinases, (iii the p38 MAPK pathway, and (iv the Wnt/β-catenin pathway, as well as reactivation of AR by de novo synthesized androgen are discussed in this context. Understanding the molecular changes that subvert normal cell death mechanisms and thereby compromise the survival of prostate cancer patients continues to be a major challenge.
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Survival curves for irradiated cells
International Nuclear Information System (INIS)
Gibson, D.K.
1975-01-01
The subject of the lecture is the probability of survival of biological cells which have been subjected to ionising radiation. The basic mathematical theories of cell survival as a function of radiation dose are developed. A brief comparison with observed survival curves is made. (author)
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Pathophysiological mechanisms of death resistance in colorectal carcinoma.
Huang, Ching-Ying; Yu, Linda Chia-Hui
2015-11-07
Colon cancers develop adaptive mechanisms to survive under extreme conditions and display hallmarks of unlimited proliferation and resistance to cell death. The deregulation of cell death is a key factor that contributes to chemoresistance in tumors. In a physiological context, balance between cell proliferation and death, and protection against cell damage are fundamental processes for maintaining gut epithelial homeostasis. The mechanisms underlying anti-death cytoprotection and tumor resistance often bear common pathways, and although distinguishing them would be a challenge, it would also provide an opportunity to develop advanced anti-cancer therapeutics. This review will outline cell death pathways (i.e., apoptosis, necrosis, and necroptosis), and discuss cytoprotective strategies in normal intestinal epithelium and death resistance mechanisms of colon tumor. In colorectal cancers, the intracellular mechanisms of death resistance include the direct alteration of apoptotic and necroptotic machinery and the upstream events modulating death effectors such as tumor suppressor gene inactivation and pro-survival signaling pathways. The autocrine, paracrine and exogenous factors within a tumor microenvironment can also instigate resistance against apoptotic and necroptotic cell death in colon cancers through changes in receptor signaling or transporter uptake. The roles of cyclooxygenase-2/prostaglandin E2, growth factors, glucose, and bacterial lipopolysaccharides in colorectal cancer will be highlighted. Targeting anti-death pathways in the colon cancer tissue might be a promising approach outside of anti-proliferation and anti-angiogenesis strategies for developing novel drugs to treat refractory tumors.
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International Nuclear Information System (INIS)
Wang Ling; Reinach, Peter; Lu, Luo
2005-01-01
Tumor necrosis factor (TNF-α) in various cell types induces either cell death or mitogenesis through different signaling pathways. In the present study, we determined in human corneal epithelial cells how TNF-α also promotes cell survival. Human corneal epithelial (HCE) cells were cultured in DMEM/F-12 medium containing 10% FBS. TNF-α stimulation induced activation of a voltage-gated K + channel detected by measuring single channel activity using patch clamp techniques. The effect of TNF-α on downstream events included NFκB nuclear translocation and increases in DNA binding activities, but did not elicit ERK, JNK, or p38 limb signaling activation. TNF-α induced increases in p21 expression resulting in partial cell cycle attenuation in the G 1 phase. Cell cycle progression was also mapped by flow cytometer analysis. Blockade of TNF-α-induced K + channel activity effectively prevented NFκB nuclear translocation and binding to DNA, diminishing the cell-survival protective effect of TNF-α. In conclusion, TNF-α promotes survival of HCE cells through sequential stimulation of K + channel and NFκB activities. This response to TNF-α is dependent on stimulating K + channel activity because following suppression of K + channel activity TNF-α failed to activate NFκB nuclear translocation and binding to nuclear DNA
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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.
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An Optic Nerve Crush Injury Murine Model to Study Retinal Ganglion Cell Survival
Tang, Zhongshu; Zhang, Shuihua; Lee, Chunsik; Kumar, Anil; Arjunan, Pachiappan; Li, Yang; Zhang, Fan; Li, Xuri
2011-01-01
Injury to the optic nerve can lead to axonal degeneration, followed by a gradual death of retinal ganglion cells (RGCs), which results in irreversible vision loss. Examples of such diseases in human include traumatic optic neuropathy and optic nerve degeneration in glaucoma. It is characterized by typical changes in the optic nerve head, progressive optic nerve degeneration, and loss of retinal ganglion cells, if uncontrolled, leading to vision loss and blindness. The optic nerve crush (ONC) injury mouse model is an important experimental disease model for traumatic optic neuropathy, glaucoma, etc. In this model, the crush injury to the optic nerve leads to gradual retinal ganglion cells apoptosis. This disease model can be used to study the general processes and mechanisms of neuronal death and survival, which is essential for the development of therapeutic measures. In addition, pharmacological and molecular approaches can be used in this model to identify and test potential therapeutic reagents to treat different types of optic neuropathy. Here, we provide a step by step demonstration of (I) Baseline retrograde labeling of retinal ganglion cells (RGCs) at day 1, (II) Optic nerve crush injury at day 4, (III) Harvest the retinae and analyze RGC survival at day 11, and (IV) Representative result. PMID:21540827
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Radiation-induced cell death in embryogenic cells of coniferous plants
International Nuclear Information System (INIS)
Watanabe, Yoshito; Homma-Takeda, Shino; Yukawa, Masae; Nishimura, Yoshikazu; Sasamoto, Hamako; Takahagi, Masahiko
2004-01-01
Reproductive processes are particularly radiosensitive in plant development, which was clearly illustrated in reduction of seed formation in native coniferous plants around Chernobyl after the nuclear accident. For the purpose to investigate the effects of ionizing radiation on embryonic formation in coniferous plants, we used an embryo-derived embryogenic cell culture of a Japanese native coniferous plant, Japanese cedar (Cryplomeria japonica). The embryogenic cells were so radiosensitive that most of the cells died by X-ray irradiation of 5 Gy. This indicated that the embryogenic cells are as radiosensitive as some mammalian cells including lymphocytes. We considered that this type of radiosensitive cell death in the embryogenic cells should be responsible for reproductive damages of coniferous plants by low dose of ionizing radiation. The cell death of the embryogenic cells was characteristic of nuclear DNA fragmentation, which is typically observed in radiation-induced programmed cell death, i.e. apoptosis, in mammalian cells. On the other hand, cell death with nuclear DNA fragmentation did not develop by X-ray irradiation in vegetative cells including meristematic cells of Japanese cedar. This suggests that an apoptosis-like programmed cell death should develop cell-specifically in embryogenic cells by ionizing radiation. The abortion of embryogenic cells may work to prevent transmission of radiation-induced genetic damages to the descendants. (author)
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Energy Technology Data Exchange (ETDEWEB)
Lee, Su Jin; Kang, Hyung Kyung [Department of Physiology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of); Song, Dong Keun [Department of Pharmacology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of); Eum, Won Sik; Park, Jinseu [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Choi, Soo Young, E-mail: sychoi@hallym.ac.kr [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Kwon, Hyeok Yil, E-mail: hykwon@hallym.ac.kr [Department of Physiology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of)
2015-06-05
Pro-inflammatory cytokines play a crucial role in the destruction of pancreatic β-cells, thereby triggering the development of autoimmune diabetes mellitus. We recently developed a cell-permeable fusion protein, PEP-1-heme oxygenase-1 (PEP-1-HO-1) and investigated the anti-inflammatory effects in macrophage cells. In this study, we transduced PEP-1-HO-1 into INS-1 insulinoma cells and examined its protective effect against cytokine-induced cell death. PEP-1-HO-1 was successfully delivered into INS-1 cells in time- and dose-dependent manner and was maintained within the cells for at least 48 h. Pre-treatment with PEP-1-HO-1 increased the survival of INS-1 cells exposed to cytokine mixture (IL-1β, IFN-γ, and TNF-α) in a dose-dependent manner. PEP-1-HO-1 markedly decreased cytokine-induced production of reactive oxygen species (ROS), nitric oxide (NO), and malondialdehyde (MDA). These protective effects of PEP-1-HO-1 against cytokines were correlated with the changes in the levels of signaling mediators of inflammation (iNOS and COX-2) and cell apoptosis/survival (Bcl-2, Bax, caspase-3, PARP, JNK, and Akt). These results showed that the transduced PEP-1-HO-1 efficiently prevented cytokine-induced cell death of INS-1 cells by alleviating oxidative/nitrosative stresses and inflammation. Further, these results suggested that PEP-1-mediated HO-1 transduction may be a potential therapeutic strategy to prevent β-cell destruction in patients with autoimmune diabetes mellitus. - Highlights: • We showed that PEP-1-HO-1 was efficiently delivered into INS-1 cells. • Transduced PEP-1-HO-1 exerted a protective effect against cytokine-induced cell death. • Transduced PEP-1-HO-1 inhibited cytokine-induced ROS and NO accumulation. • PEP-1-HO-1 suppressed cytokine-induced expression of iNOS, COX-2, and Bax. • PEP-1-HO-1 transduction may be an efficient tool to prevent β-cell destruction.
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International Nuclear Information System (INIS)
Lee, Su Jin; Kang, Hyung Kyung; Song, Dong Keun; Eum, Won Sik; Park, Jinseu; Choi, Soo Young; Kwon, Hyeok Yil
2015-01-01
Pro-inflammatory cytokines play a crucial role in the destruction of pancreatic β-cells, thereby triggering the development of autoimmune diabetes mellitus. We recently developed a cell-permeable fusion protein, PEP-1-heme oxygenase-1 (PEP-1-HO-1) and investigated the anti-inflammatory effects in macrophage cells. In this study, we transduced PEP-1-HO-1 into INS-1 insulinoma cells and examined its protective effect against cytokine-induced cell death. PEP-1-HO-1 was successfully delivered into INS-1 cells in time- and dose-dependent manner and was maintained within the cells for at least 48 h. Pre-treatment with PEP-1-HO-1 increased the survival of INS-1 cells exposed to cytokine mixture (IL-1β, IFN-γ, and TNF-α) in a dose-dependent manner. PEP-1-HO-1 markedly decreased cytokine-induced production of reactive oxygen species (ROS), nitric oxide (NO), and malondialdehyde (MDA). These protective effects of PEP-1-HO-1 against cytokines were correlated with the changes in the levels of signaling mediators of inflammation (iNOS and COX-2) and cell apoptosis/survival (Bcl-2, Bax, caspase-3, PARP, JNK, and Akt). These results showed that the transduced PEP-1-HO-1 efficiently prevented cytokine-induced cell death of INS-1 cells by alleviating oxidative/nitrosative stresses and inflammation. Further, these results suggested that PEP-1-mediated HO-1 transduction may be a potential therapeutic strategy to prevent β-cell destruction in patients with autoimmune diabetes mellitus. - Highlights: • We showed that PEP-1-HO-1 was efficiently delivered into INS-1 cells. • Transduced PEP-1-HO-1 exerted a protective effect against cytokine-induced cell death. • Transduced PEP-1-HO-1 inhibited cytokine-induced ROS and NO accumulation. • PEP-1-HO-1 suppressed cytokine-induced expression of iNOS, COX-2, and Bax. • PEP-1-HO-1 transduction may be an efficient tool to prevent β-cell destruction
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Non-Canonical Cell Death Induced by p53
Directory of Open Access Journals (Sweden)
Atul Ranjan
2016-12-01
Full Text Available Programmed cell death is a vital biological process for multicellular organisms to maintain cellular homeostasis, which is regulated in a complex manner. Over the past several years, apart from apoptosis, which is the principal mechanism of caspase-dependent cell death, research on non-apoptotic forms of programmed cell death has gained momentum. p53 is a well characterized tumor suppressor that controls cell proliferation and apoptosis and has also been linked to non-apoptotic, non-canonical cell death mechanisms. p53 impacts these non-canonical forms of cell death through transcriptional regulation of its downstream targets, as well as direct interactions with key players involved in these mechanisms, in a cell type- or tissue context-dependent manner. In this review article, we summarize and discuss the involvement of p53 in several non-canonical modes of cell death, including caspase-independent apoptosis (CIA, ferroptosis, necroptosis, autophagic cell death, mitotic catastrophe, paraptosis, and pyroptosis, as well as its role in efferocytosis which is the process of clearing dead or dying cells.
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Song, Juhyun; Kim, Oh Yoen
2017-06-10
Insulin resistance (IR) is an important stress factor in the central nervous system, thereby aggravating neuropathogenesis and triggering cognitive decline. Melatonin, which is an antioxidant phytochemical and synthesized by the pineal gland, has multiple functions in cellular responses such as apoptosis and survival against stress. This study investigated whether melatonin modulates the signaling of neuronal cell death induced by endoplasmic reticulum (ER) stress under IR condition using SH-SY5Y neuroblastoma cells. Apoptosis cell death signaling markers (cleaved Poly [ADP-ribose] polymerase 1 (PARP), p53, and Bax) and ER stress markers (phosphorylated eIF2α (p-eIF2α), ATF4, CHOP, p-IRE1 , and spliced XBP1 (sXBP1)) were measured using reverse transcription-PCR, quantitative PCR, and western blottings. Immunofluorescence staining was also performed for p-ASK1 and p-IRE1 . The mRNA or protein expressions of cell death signaling markers and ER stress markers were increased under IR condition, but significantly attenuated by melatonin treatment. Insulin-induced activation of ASK1 ( p-ASK1 ) was also dose dependently attenuated by melatonin treatment. The regulatory effect of melatonin on neuronal cells under IR condition was associated with ASK1 signaling. In conclusion, the result suggested that melatonin may alleviate ER stress under IR condition, thereby regulating neuronal cell death signaling.
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Cascio, Vincent; Gittings, Daniel; Merloni, Kristen; Hurton, Matthew; Laprade, David; Austriaco, Nicanor
2013-02-13
Saccharomyces boulardii is a probiotic yeast routinely used to prevent and to treat gastrointestinal disorders, including the antibiotic-associated diarrhea caused by Clostridium difficile infections. However, only 1-3% of the yeast administered orally is recovered alive in the feces suggesting that this yeast is unable to survive the acidic environment of the gastrointestinal tract. We provide evidence that suggests that S. boulardii undergoes programmed cell death (PCD) in acidic environments, which is accompanied by the generation of reactive oxygen species and the appearance of caspase-like activity. To better understand the mechanism of cell death at the molecular level, we generated microarray gene expression profiles of S. boulardii cells cultured in an acidic environment. Significantly, functional annotation revealed that the up-regulated genes were significantly over-represented in cell death pathways Finally, we show that S-adenosyl-L-methionine (AdoMet), a commercially available, FDA-approved dietary supplement, enhances the viability of S. boulardii in acidic environments, most likely by preventing programmed cell death. In toto, given the observation that many of the proven health benefits of S. boulardii are dependent on cell viability, our data suggests that taking S. boulardii and AdoMet together may be a more effective treatment for gastrointestinal disorders than taking the probiotic yeast alone.
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Mitochondrial fission proteins regulate programmed cell death in yeast.
Fannjiang, Yihru; Cheng, Wen-Chih; Lee, Sarah J; Qi, Bing; Pevsner, Jonathan; McCaffery, J Michael; Hill, R Blake; Basañez, Gorka; Hardwick, J Marie
2004-11-15
The possibility that single-cell organisms undergo programmed cell death has been questioned in part because they lack several key components of the mammalian cell death machinery. However, yeast encode a homolog of human Drp1, a mitochondrial fission protein that was shown previously to promote mammalian cell death and the excessive mitochondrial fragmentation characteristic of apoptotic mammalian cells. In support of a primordial origin of programmed cell death involving mitochondria, we found that the Saccharomyces cerevisiae homolog of human Drp1, Dnm1, promotes mitochondrial fragmentation/degradation and cell death following treatment with several death stimuli. Two Dnm1-interacting factors also regulate yeast cell death. The WD40 repeat protein Mdv1/Net2 promotes cell death, consistent with its role in mitochondrial fission. In contrast to its fission function in healthy cells, Fis1 unexpectedly inhibits Dnm1-mediated mitochondrial fission and cysteine protease-dependent cell death in yeast. Furthermore, the ability of yeast Fis1 to inhibit mitochondrial fission and cell death can be functionally replaced by human Bcl-2 and Bcl-xL. Together, these findings indicate that yeast and mammalian cells have a conserved programmed death pathway regulated by a common molecular component, Drp1/Dnm1, that is inhibited by a Bcl-2-like function.
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Hayano, Azusa; Komohara, Yoshihiro; Takashima, Yasuo; Takeya, Hiroto; Homma, Jumpei; Fukai, Junya; Iwadate, Yasuo; Kajiwara, Koji; Ishizawa, Shin; Hondoh, Hiroaki; Yamanaka, Ryuya
2017-10-01
Programmed cell death ligand 1 (PD-L1)/programmed cell death 1 (PD-1) have been shown to predict response to PD-L1/PD-1-targeted therapy. We analyzed PD-L1 expression in primary central nervous system lymphomas (PCNSLs). PD-L1 protein and mRNA expression were evaluated in 64 PCNSL tissue samples. IFN-γ, IL-10, CD4, and CD8 mRNA expression was also evaluated. PD-L1 protein was detected in tumor cells in 2 (4.1%) cases and in tumor microenvironments in 25 (52%) cases. PD-L1 mRNA positively correlated with IFN-γ (p=0.0024) and CD4 (p=0.0005) mRNA expression. IFN-γ mRNA positively correlated with CD8 mRNA expression (p=0.0001). Furthermore, tumor cell PD-L1 expression correlated positively with overall survival (p=0.0177), whereas microenvironmental PD-L1 expression exhibited an insignificant negative trend with overall survival (p=0.188). PD-L1 was expressed on both tumor and/or tumor-infiltrating immune cells in PCNSL. The biological roles of this marker warrant further investigation. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.
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The Janus face of death receptor signalling during tumour immunoediting.
Directory of Open Access Journals (Sweden)
Eimear O' Reilly
2016-10-01
Full Text Available Cancer immune-surveillance is essential for the inhibition of carcinogenesis. Malignantly transformed cells can be recognised by both the innate and adaptive immune systems through different mechanisms. Immune effector cells induce extrinsic cell death in the identified tumour cells by expressing death ligand cytokines of the tumour necrosis factor ligand family. However, some tumour cells can escape immune elimination and progress. Acquisition of resistance to the death-ligand induced apoptotic pathway can be obtained through cleavage of effector-cell expressed death-ligands into a poorly active form, mutations or silencing of the death receptors or overexpression of decoy receptors and pro-survival proteins. Although the immune system is highly effective in the elimination of malignantly transformed cells, abnormal/ dysfunctional death-ligand signalling curbs its cytotoxicity. Moreover, death receptors can also transmit pro-survival and pro-migratory signals. Consequently, dysfunctional death receptor-mediated apoptosis/necroptosis signalling does not only give a passive resistance against cell death, but actively drives tumour cell motility, invasion and contributes to consequent metastasis. This dual contribution of the death ligand-death receptor signalling in both the early, elimination phase and then in the late, escape phase of the tumour immunoediting process is discussed in this review. Death receptor agonists still hold potential for cancer therapy since they can execute the tumour-eliminating immune-effector function even in the absence of activation of the immune system against the tumour. The opportunities and challenges of developing death receptor agonists into effective cancer therapeutics are also discussed.
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Stimulated human fibroblast cell survival
International Nuclear Information System (INIS)
Smith, B.P.; Gale, K.L.; Einspenner, M.; Greenstock, C.L.; Gentner, N.E.
1992-01-01
Techniques for cloning cultured mammalian cells have supported the most universally-accepted method for measuring the induction of lethality by geno-toxicants such as ionizing radiation: the 'survival of colony-forming ability (CFA)' assay. Since most cultured human cell lines exhibit plating efficiency (i.e. the percentage of cells that are capable of reproductively surviving and dividing to form visible colonies) well below 100%, such assays are in essence 'survival of plating efficiency' assays, since they are referred to the plating (or cloning) efficiency of control (i.e. unirradiated) cells. (author). 8 refs., 2 figs
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Directory of Open Access Journals (Sweden)
Clementina Sansone
Full Text Available Diatoms are an important class of unicellular algae that produce bioactive polyunsaturated aldehydes (PUAs that induce abortions or malformations in the offspring of invertebrates exposed to them during gestation. Here we compare the effects of the PUAs 2-trans,4-trans-decadienal (DD, 2-trans,4-trans-octadienal (OD and 2-trans,4-trans-heptadienal (HD on the adenocarcinoma cell lines lung A549 and colon COLO 205, and the normal lung/brunch epithelial BEAS-2B cell line. Using the viability MTT/Trypan blue assays, we show that PUAs have a toxic effect on both A549 and COLO 205 tumor cells but not BEAS-2B normal cells. DD was the strongest of the three PUAs tested, at all time-intervals considered, but HD was as strong as DD after 48 h. OD was the least active of the three PUAs. The effect of the three PUAs was somewhat stronger for A549 cells. We therefore studied the death signaling pathway activated in A549 showing that cells treated with DD activated Tumor Necrosis Factor Receptor 1 (TNFR1 and Fas Associated Death Domain (FADD leading to necroptosis via caspase-3 without activating the survival pathway Receptor-Interacting Protein (RIP. The TNFR1/FADD/caspase pathway was also observed with OD, but only after 48 h. This was the only PUA that activated RIP, consistent with the finding that OD causes less damage to the cell compared to DD and HD. In contrast, cells treated with HD activated the Fas/FADD/caspase pathway. This is the first report that PUAs activate an extrinsic apoptotic machinery in contrast to other anticancer drugs that promote an intrinsic death pathway, without affecting the viability of normal cells from the same tissue type. These findings have interesting implications also from the ecological viewpoint considering that HD is one of the most common PUAs produced by diatoms.
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Levels of p21WAF1/CIP1 do not affect radiation-induced cell death in human breast epithelial cells
International Nuclear Information System (INIS)
Kim, Harold E.; Han, Sue J.; Waid, David; Lee, Yong J.; Kim, Hyeong-Reh Choi
1997-01-01
Purpose/Objective: Loss of the wild-type p53 activity and/or overexpression of the proto-oncogene bcl-2 are frequently detected in breast cancer and suggested to be related to resistance to chemotherapy and radiation therapy. The long-term goals of this study are to identify the downstream signaling molecules for anti-proliferative and apoptotic activities of p53 and to investigate the interaction of bcl-2 with p53 in human breast epithelial cells. We previously showed that overexpression of bcl-2 downregulates radiation-induced expression of p21 WAF1/CIP1 , a p53 downstream molecule that functions to inhibit cyclin dependent kinases, and suppresses radiation-induced apoptosis in human breast epithelial cell line (MCF10A). In this study, we investigated the role of p21 WAF1/CIP1 in radiation-induced cell death in MCF10A cells. Materials and Methods: To determine whether downregulation of p21 WAF1/CIP1 is required for anti-apoptotic activity of bcl-2, and to investigate the roles of p21 WAF1/CIP1 in cell death following irradiation, we transfected p21 WAF1/CIP1 expression vector into bcl-2 overexpressing MCF10A cells. The effects of p21 WAF1/CIP1 overexpression on cell growth, radiation-induced apoptosis and clonogenic cell survival were analyzed. Results: Overexpression of p21 WAF1/CIP1 resulted in marked growth inhibition, but no effect on dose-dependent radiation-induced cell lethality as determined by clonogenic survival assay. Radiation-induced apoptosis was not detected in bcl-2 overexpressing MCF10A cells independent of levels of p21 WAF1/CIP1 expression. Conclusion: This study suggests that bcl-2 downregulation of p21 WAF1/CIP1 is independent of anti-apoptotic activity of bcl-2 and that levels of p21 WAF1/CIP1 do not affect radiation-induced cell death in human breast epithelial cells
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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.
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Emadi Baygi, Modjtaba; Soheili, Zahra Soheila; Schmitz, Ingo; Sameie, Shahram; Schulz, Wolfgang A
2010-12-01
The epithelial-mesenchymal transition (EMT) is regarded as an important step in cancer metastasis. Snail, a master regulator of EMT, has been recently proposed to act additionally as a cell survival factor and inducer of motility. We have investigated the function of Snail (SNAI1) in prostate cancer cells by downregulating its expression via short (21-mer) interfering RNA (siRNA) and measuring the consequences on EMT markers, cell viability, death, cell cycle, senescence, attachment, and invasivity. Of eight carcinoma cell lines, the prostate carcinoma cell lines LNCaP and PC-3 showed the highest and moderate expression of SNAI1 mRNA, respectively, as measured by quantitative RT-PCR. Long-term knockdown of Snail induced a severe decline in cell numbers in LNCaP and PC-3 and caspase activity was accordingly enhanced in both cell lines. In addition, suppression of Snail expression induced senescence in LNCaP cells. SNAI1-siRNA-treated cells did not tolerate detachment from the extracellular matrix, probably due to downregulation of integrin α6. Expression of E-cadherin, vimentin, and fibronectin was also affected. Invasiveness of PC-3 cells was not significantly diminished by Snail knockdown. Our data suggest that Snail acts primarily as a survival factor and inhibitor of cellular senescence in prostate cancer cell lines. We therefore propose that Snail can act as early driver of prostate cancer progression.
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Morphological classification of plant cell deaths
DEFF Research Database (Denmark)
van Doorn, W.G.; Beers, E.P.; Dangl, J.L.
2011-01-01
, which can express features of both necrosis and vacuolar cell death, PCD in starchy cereal endosperm and during self-incompatibility. The present classification is not static, but will be subject to further revision, especially when specific biochemical pathways are better defined....... the classification of PCD in plants. Here we suggest a classification based on morphological criteria. According to this classification, the use of the term 'apoptosis' is not justified in plants, but at least two classes of PCD can be distinguished: vacuolar cell death and necrosis. During vacuolar cell death...
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Drosophila Ninjurin A induces nonapoptotic cell death.
Directory of Open Access Journals (Sweden)
Sarah Broderick
Full Text Available Ninjurins are conserved transmembrane proteins that are upregulated across species in response to injury and stress. Their biological functions are not understood, in part because there have been few in vivo studies of their function. We analyzed the expression and function of one of three Drosophila Ninjurins, NijA. We found that NijA protein is redistributed to the cell surface in larval immune tissues after septic injury and is upregulated by the Toll pathway. We generated a null mutant of NijA, which displayed no detectable phenotype. In ectopic expression studies, NijA induced cell death, as evidenced by cell loss and acridine orange staining. These dying cells did not display hallmarks of apoptotic cells including TUNEL staining and inhibition by p35, indicating that NijA induced nonapoptotic cell death. In cell culture, NijA also induced cell death, which appeared to be cell autonomous. These in vivo studies identify a new role for the Ninjurin family in inducing nonapoptotic cell death.
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Directory of Open Access Journals (Sweden)
Ana Belén Herrero
2017-05-01
Full Text Available Human myeloma cell lines (HMCLs and a subset of myeloma patients with poor prognosis exhibit high levels of replication stress (RS, leading to DNA damage. In this study, we confirmed the presence of DNA double-strand breaks (DSBs in several HMCLs by measuring γH2AX and RAD51 foci and analyzed the effect of various inhibitors of the DNA damage response on MM cell survival. Inhibition of ataxia telangiectasia and Rad3-related protein (ATR, the main kinase mediating the response to RS, using the specific inhibitor VE-821 induced more cell death in HMCLs than in control lymphoblastoid cells and U266, an HMCL with a low level of DNA damage. The absence of ATR was partially compensated by ataxia telangiectasia-mutated protein (ATM, since chemical inhibition of both kinases using VE-821 and KU-55933 significantly increased the death of MM cells with DNA damage. We found that ATM and ATR are involved in DSB repair by homologous recombination (HR in MM. Inhibition of both kinases resulted in a stronger inhibition that may underlie cell death induction, since abolition of HR using two different inhibitors severely reduced survival of HMCLs that exhibit DNA damage. On the other hand, inhibition of the other route involved in DSB repair, non-homologous end joining (NHEJ, using the DNA-PK inhibitor NU7441, did not affect MM cell viability. Interestingly, we found that NHEJ inhibition did not increase cell death when HR was simultaneously inhibited with the RAD51 inhibitor B02, but it clearly increased the level of cell death when HR was inhibited with the MRE11 inhibitor mirin, which interferes with recombination before DNA resection takes place. Taken together, our results demonstrate for the first time that MM cells with ongoing DNA damage rely on an intact HR pathway, which thereby suggests therapeutic opportunities. We also show that inhibition of HR after the initial step of end resection might be more appropriate for inducing MM cell death, since it
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Live-cell visualization of gasdermin D-driven pyroptotic cell death.
Rathkey, Joseph K; Benson, Bryan L; Chirieleison, Steven M; Yang, Jie; Xiao, Tsan S; Dubyak, George R; Huang, Alex Y; Abbott, Derek W
2017-09-01
Pyroptosis is a form of cell death important in defenses against pathogens that can also result in a potent and sometimes pathological inflammatory response. During pyroptosis, GSDMD (gasdermin D), the pore-forming effector protein, is cleaved, forms oligomers, and inserts into the membranes of the cell, resulting in rapid cell death. However, the potent cell death induction caused by GSDMD has complicated our ability to understand the biology of this protein. Studies aimed at visualizing GSDMD have relied on expression of GSDMD fragments in epithelial cell lines that naturally lack GSDMD expression and also lack the proteases necessary to cleave GSDMD. In this work, we performed mutagenesis and molecular modeling to strategically place tags and fluorescent proteins within GSDMD that support native pyroptosis and facilitate live-cell imaging of pyroptotic cell death. Here, we demonstrate that these fusion proteins are cleaved by caspases-1 and -11 at Asp-276. Mutations that disrupted the predicted p30-p20 autoinhibitory interface resulted in GSDMD aggregation, supporting the oligomerizing activity of these mutations. Furthermore, we show that these novel GSDMD fusions execute inflammasome-dependent pyroptotic cell death in response to multiple stimuli and allow for visualization of the morphological changes associated with pyroptotic cell death in real time. This work therefore provides new tools that not only expand the molecular understanding of pyroptosis but also enable its direct visualization. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.
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Endoplasmic reticulum involvement in yeast cell death
International Nuclear Information System (INIS)
Nicanor Austriaco, O.
2012-01-01
Yeast cells undergo programed cell death (PCD) with characteristic markers associated with apoptosis in mammalian cells including chromatin breakage, nuclear fragmentation, reactive oxygen species generation, and metacaspase activation. Though significant research has focused on mitochondrial involvement in this phenomenon, more recent work with both Saccharomyces cerevisiae and Schizosaccharomyces pombe has also implicated the endoplasmic reticulum (ER) in yeast PCD. This minireview provides an overview of ER stress-associated cell death (ER-SAD) in yeast. It begins with a description of ER structure and function in yeast before moving to a discussion of ER-SAD in both mammalian and yeast cells. Three examples of yeast cell death associated with the ER will be highlighted here including inositol starvation, lipid toxicity, and the inhibition of N-glycosylation. It closes by suggesting ways to further examine the involvement of the ER in yeast cell death.
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Exploiting cannabinoid-induced cytotoxic autophagy to drive melanoma cell death.
Armstrong, Jane L; Hill, David S; McKee, Christopher S; Hernandez-Tiedra, Sonia; Lorente, Mar; Lopez-Valero, Israel; Eleni Anagnostou, Maria; Babatunde, Fiyinfoluwa; Corazzari, Marco; Redfern, Christopher P F; Velasco, Guillermo; Lovat, Penny E
2015-06-01
Although the global incidence of cutaneous melanoma is increasing, survival rates for patients with metastatic disease remain viability, and activation of apoptosis, whereas cotreatment with chloroquine or knockdown of Atg7, but not Beclin-1 or Ambra1, prevented THC-induced autophagy and cell death in vitro. Administration of Sativex-like (a laboratory preparation comprising equal amounts of THC and cannabidiol (CBD)) to mice bearing BRAF wild-type melanoma xenografts substantially inhibited melanoma viability, proliferation, and tumor growth paralleled by an increase in autophagy and apoptosis compared with standard single-agent temozolomide. Collectively, our findings suggest that THC activates noncanonical autophagy-mediated apoptosis of melanoma cells, suggesting that cytotoxic autophagy induction with Sativex warrants clinical evaluation for metastatic disease.
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Apoptotic intrinsic pathway proteins predict survival in canine cutaneous mast cell tumours.
Barra, C N; Macedo, B M; Cadrobbi, K G; Pulz, L H; Huete, G C; Kleeb, S R; Xavier, J G; Catão-Dias, J L; Nishiya, A T; Fukumasu, H; Strefezzi, R F
2018-03-01
Mast cell tumours (MCTs) are the most frequent canine round cell neoplasms and show variable biological behaviours with high metastatic and recurrence rates. The disease is treated surgically and wide margins are recommended. Adjuvant chemotherapy and radiotherapy used in this disease cause DNA damage in neoplastic cells, which is aimed to induce apoptotic cell death. Resisting cell death is a hallmark of cancer, which contributes to the development and progression of tumours. The aim of this study was to investigate the expression of the proteins involved in the apoptotic intrinsic pathway and to evaluate their potential use as prognostic markers for canine cutaneous MCTs. Immunohistochemistry for BAX, BCL2, APAF1, Caspase-9, and Caspase-3 was performed in 50 canine cases of MCTs. High BAX expression was associated with higher mortality rate and shorter survival. BCL2 and APAF1 expressions offered additional prognostic information to the histopathological grading systems. The present results indicate that variations in the expression of apoptotic proteins are related to malignancy of cutaneous MCTs in dogs. © 2017 John Wiley & Sons Ltd.
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Curcumin induces autophagic cell death in Spodoptera frugiperda cells.
Veeran, Sethuraman; Shu, Benshui; Cui, Gaofeng; Fu, Shengjiao; Zhong, Guohua
2017-06-01
The increasing interest in the role of autophagy (type II cell death) in the regulation of insect toxicology has propelled study of investigating autophagic cell death pathways. Turmeric, the rhizome of the herb Curcuma longa (Mañjaḷ in Tamil, India and Jiānghuáng in Chinese) have been traditionally used for the pest control either alone or combination with other botanical pesticides. However, the mechanisms by which Curcuma longa or curcumin exerts cytotoxicity in pests are not well understood. In this study, we investigated the potency of Curcuma longa (curcumin) as a natural pesticide employing Sf9 insect line. Autophagy induction effect of curcumin on Spodoptera frugiperda (Sf9) cells was investigated using various techniques including cell proliferation assay, morphology analysis with inverted phase contrast microscope and Transmission Electron Microscope (TEM) analysis. Autophagy was evaluated using the fluorescent dye monodansylcadaverine (MDC). Cell death measurement was examined using 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) within the concentrations of 5-15μg/mL. Curcumin inhibited the growth of the Sf9 cells and induced autophagic cell death in a time and dose dependent manner. Staining the cells with MDC showed the presence of autophagic vacuoles while increased in a dose and time dependent manner. At the ultrastructural level transmission electron microscopy, cells revealed massive autophagy vacuole accumulation and absence of chromatin condensation. Protein expression levels of ATG8-I and ATG8-II, well-established markers of autophagy related protein were elevated in a time dependent manner after curcumin treatment. The present study proves that curcumin induces autophagic cell death in Sf9 insect cell line and this is the first report of cytotoxic effect of curcumin in insect cells and that will be utilized as natural pesticides in future. Copyright © 2017. Published by Elsevier Inc.
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Xie, Xiaoyan; Cao, Feng; Sheikh, Ahmad Y; Li, Zongjin; Connolly, Andrew J; Pei, Xuetao; Li, Ren-Ke; Robbins, Robert C; Wu, Joseph C
2007-01-01
Cardiac stem cell therapy remains hampered by acute donor cell death posttransplantation and the lack of reliable methods for tracking cell survival in vivo. We hypothesize that cells transfected with inducible vascular endothelial growth factor 165 (VEGF(165)) can improve their survival as monitored by novel molecular imaging techniques. Mouse embryonic stem (ES) cells were transfected with an inducible, bidirectional tetracycline (Bi-Tet) promoter driving VEGF(165) and renilla luciferase (Rluc). Addition of doxycycline induced Bi-Tet expression of VEGF(165) and Rluc significantly compared to baseline (p<0.05). Expression of VEGF(165) enhanced ES cell proliferation and inhibited apoptosis as determined by Annexin-V staining. For noninvasive imaging, ES cells were transduced with a double fusion (DF) reporter gene consisting of firefly luciferase and enhanced green fluorescence protein (Fluc-eGFP). There was a robust correlation between cell number and Fluc activity (R(2)=0.99). Analysis by immunostaining, histology, and RT-PCR confirmed that expression of Bi-Tet and DF systems did not affect ES cell self-renewal or pluripotency. ES cells were differentiated into beating embryoid bodies expressing cardiac markers such as troponin, Nkx2.5, and beta-MHC. Afterward, 5 x 10(5) cells obtained from these beating embryoid bodies or saline were injected into the myocardium of SV129 mice (n=36) following ligation of the left anterior descending (LAD) artery. Bioluminescence imaging (BLI) and echocardiography showed that VEGF(165) induction led to significant improvements in both transplanted cell survival and cardiac function (p<0.05). This is the first study to demonstrate imaging of embryonic stem cell-mediated gene therapy targeting cardiovascular disease. With further validation, this platform may have broad applications for current basic research and further clinical studies.
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Methods for assessing autophagy and autophagic cell death.
Tasdemir, Ezgi; Galluzzi, Lorenzo; Maiuri, M Chiara; Criollo, Alfredo; Vitale, Ilio; Hangen, Emilie; Modjtahedi, Nazanine; Kroemer, Guido
2008-01-01
Autophagic (or type 2) cell death is characterized by the massive accumulation of autophagic vacuoles (autophagosomes) in the cytoplasm of cells that lack signs of apoptosis (type 1 cell death). Here we detail and critically assess a series of methods to promote and inhibit autophagy via pharmacological and genetic manipulations. We also review the techniques currently available to detect autophagy, including transmission electron microscopy, half-life assessments of long-lived proteins, detection of LC3 maturation/aggregation, fluorescence microscopy, and colocalization of mitochondrion- or endoplasmic reticulum-specific markers with lysosomal proteins. Massive autophagic vacuolization may cause cellular stress and represent a frustrated attempt of adaptation. In this case, cell death occurs with (or in spite of) autophagy. When cell death occurs through autophagy, on the contrary, the inhibition of the autophagic process should prevent cellular demise. Accordingly, we describe a strategy for discriminating cell death with autophagy from cell death through autophagy.
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NF-κB Protects NKT Cells from Tumor Necrosis Factor Receptor 1-induced Death.
Kumar, Amrendra; Gordy, Laura E; Bezbradica, Jelena S; Stanic, Aleksandar K; Hill, Timothy M; Boothby, Mark R; Van Kaer, Luc; Joyce, Sebastian
2017-11-15
Semi-invariant natural killer T (NKT) cells are innate-like lymphocytes with immunoregulatory properties. NKT cell survival during development requires signal processing by activated RelA/NF-κB. Nonetheless, the upstream signal(s) integrated by NF-κB in developing NKT cells remains incompletely defined. We show that the introgression of Bcl-x L -coding Bcl2l1 transgene into NF-κB signalling-deficient IκBΔN transgenic mouse rescues NKT cell development and differentiation in this mouse model. We reasoned that NF-κB activation was protecting developing NKT cells from death signals emanating either from high affinity agonist recognition by the T cell receptor (TCR) or from a death receptor, such as tumor necrosis factor receptor 1 (TNFR1) or Fas. Surprisingly, the single and combined deficiency in PKC-θ or CARMA-1-the two signal transducers at the NKT TCR proximal signalling node-only partially recapitulated the NKT cell deficiency observed in IκBΔN tg mouse. Accordingly, introgression of the Bcl2l1 transgene into PKC-θ null mouse failed to rescue NKT cell development. Instead, TNFR1-deficiency, but not the Fas-deficiency, rescued NKT cell development in IκBΔN tg mice. Consistent with this finding, treatment of thymocytes with an antagonist of the inhibitor of κB kinase -which blocks downstream NF-κB activation- sensitized NKT cells to TNF-α-induced cell death in vitro. Hence, we conclude that signal integration by NF-κB protects developing NKT cells from death signals emanating from TNFR1, but not from the NKT TCR or Fas.
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Can deaths in police cells be prevented? Experience from Norway and death rates in other countries.
Aasebø, Willy; Orskaug, Gunnar; Erikssen, Jan
2016-01-01
To describe the changes in death rates and causes of deaths in Norwegian police cells during the last 2 decades. To review reports on death rates in police cells that have been published in medical journals and elsewhere, and discuss the difficulties of comparing death rates between countries. Data on deaths in Norwegian police cells were collected retrospectively in 2002 and 2012 for two time periods: 1993-2001 (period 1) and 2003-2012 (period 2). Several databases were searched to find reports on deaths in police cells from as many countries as possible. The death rates in Norwegian police cells reduced significantly from 0.83 deaths per year per million inhabitants (DYM) in period 1 to 0.22 DYM in period 2 (p police cells reduced by about 75% over a period of approximately 10 years. This is probably mainly due to individuals with severe alcohol intoxication no longer being placed in police cells. However, there remain large methodology difficulties in comparing deaths rates between countries. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.
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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...... mechanisms that lead to lysosomal membrane permeabilization....
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Ongoing cell death and immune influences on regeneration in the vestibular sensory organs
Warchol, M. E.; Matsui, J. I.; Simkus, E. L.; Ogilive, J. M.
2001-01-01
Hair cells in the vestibular organs of birds have a relatively short life span. Mature hair cells appear to die spontaneously and are then quickly replaced by new hair cells that arise from the division of epithelial supporting cells. A similar regenerative mechanism also results in hair cell replacement after ototoxic damage. The cellular basis of hair cell turnover in the avian ear is not understood. We are investigating the signaling pathways that lead to hair cell death and the relationship between ongoing cell death and cell production. In addition, work from our lab and others has demonstrated that the avian inner ear contains a resident population of macrophages and that enhanced numbers of macrophages are recruited to sites of hair cells lesions. Those observations suggest that macrophages and their secretory products (cytokines) may be involved in hair cell regeneration. Consistent with that suggestion, we have found that treatment with the anti-inflammatory drug dexamethasone reduces regenerative cell proliferation in the avian ear, and that certain macrophage-secreted cytokines can influence the proliferation of vestibular supporting cells and the survival of statoacoustic neurons. Those results suggest a role for the immune system in the process of sensory regeneration in the inner ear.
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Non-Cell Autonomous Influence of the Astrocyte System xc − on Hypoglycaemic Neuronal Cell Death
Directory of Open Access Journals (Sweden)
Nicole A Jackman
2012-01-01
Full Text Available Despite longstanding evidence that hypoglycaemic neuronal injury is mediated by glutamate excitotoxicity, the cellular and molecular mechanisms involved remain incompletely defined. Here, we demonstrate that the excitotoxic neuronal death that follows GD (glucose deprivation is initiated by glutamate extruded from astrocytes via system xc −– – an amino acid transporter that imports L-cystine and exports L-glutamate. Specifically, we find that depriving mixed cortical cell cultures of glucose for up to 8 h injures neurons, but not astrocytes. Neuronal death is prevented by ionotropic glutamate receptor antagonism and is partially sensitive to tetanus toxin. Removal of amino acids during the deprivation period prevents – whereas addition of L-cystine restores – GD-induced neuronal death, implicating the cystine/glutamate antiporter, system xc−–. Indeed, drugs known to inhibit system xc −– ameliorate GD-induced neuronal death. Further, a dramatic reduction in neuronal death is observed in chimaeric cultures consisting of neurons derived from WT (wild-type mice plated on top of astrocytes derived from sut mice, which harbour a naturally occurring null mutation in the gene (Slc7a11 that encodes the substrate-specific light chain of system xc −– (xCT. Finally, enhancement of astrocytic system xc −– expression and function via IL-1β (interleukin-1β exposure potentiates hypoglycaemic neuronal death, the process of which is prevented by removal of L-cystine and/or addition of system xc −– inhibitors. Thus, under the conditions of GD, our studies demonstrate that astrocytes, via system xc −–, have a direct, non-cell autonomous effect on cortical neuron survival.
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Akimoto, Miho; Iizuka, Mari; Kanematsu, Rie; Yoshida, Masato; Takenaga, Keizo
2015-01-01
The extract of ginger (Zingiber officinale Roscoe) and its major pungent components, [6]-shogaol and [6]-gingerol, have been shown to have an anti-proliferative effect on several tumor cell lines. However, the anticancer activity of the ginger extract in pancreatic cancer is poorly understood. Here, we demonstrate that the ethanol-extracted materials of ginger suppressed cell cycle progression and consequently induced the death of human pancreatic cancer cell lines, including Panc-1 cells. The underlying mechanism entailed autosis, a recently characterized form of cell death, but not apoptosis or necroptosis. The extract markedly increased the LC3-II/LC3-I ratio, decreased SQSTM1/p62 protein, and enhanced vacuolization of the cytoplasm in Panc-1 cells. It activated AMPK, a positive regulator of autophagy, and inhibited mTOR, a negative autophagic regulator. The autophagy inhibitors 3-methyladenine and chloroquine partially prevented cell death. Morphologically, however, focal membrane rupture, nuclear shrinkage, focal swelling of the perinuclear space and electron dense mitochondria, which are unique morphological features of autosis, were observed. The extract enhanced reactive oxygen species (ROS) generation, and the antioxidant N-acetylcystein attenuated cell death. Our study revealed that daily intraperitoneal administration of the extract significantly prolonged survival (P = 0.0069) in a peritoneal dissemination model and suppressed tumor growth in an orthotopic model of pancreatic cancer (P < 0.01) without serious adverse effects. Although [6]-shogaol but not [6]-gingerol showed similar effects, chromatographic analyses suggested the presence of other constituent(s) as active substances. Together, these results show that ginger extract has potent anticancer activity against pancreatic cancer cells by inducing ROS-mediated autosis and warrants further investigation in order to develop an efficacious candidate drug. PMID:25961833
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Directory of Open Access Journals (Sweden)
Miho Akimoto
Full Text Available The extract of ginger (Zingiber officinale Roscoe and its major pungent components, [6]-shogaol and [6]-gingerol, have been shown to have an anti-proliferative effect on several tumor cell lines. However, the anticancer activity of the ginger extract in pancreatic cancer is poorly understood. Here, we demonstrate that the ethanol-extracted materials of ginger suppressed cell cycle progression and consequently induced the death of human pancreatic cancer cell lines, including Panc-1 cells. The underlying mechanism entailed autosis, a recently characterized form of cell death, but not apoptosis or necroptosis. The extract markedly increased the LC3-II/LC3-I ratio, decreased SQSTM1/p62 protein, and enhanced vacuolization of the cytoplasm in Panc-1 cells. It activated AMPK, a positive regulator of autophagy, and inhibited mTOR, a negative autophagic regulator. The autophagy inhibitors 3-methyladenine and chloroquine partially prevented cell death. Morphologically, however, focal membrane rupture, nuclear shrinkage, focal swelling of the perinuclear space and electron dense mitochondria, which are unique morphological features of autosis, were observed. The extract enhanced reactive oxygen species (ROS generation, and the antioxidant N-acetylcystein attenuated cell death. Our study revealed that daily intraperitoneal administration of the extract significantly prolonged survival (P = 0.0069 in a peritoneal dissemination model and suppressed tumor growth in an orthotopic model of pancreatic cancer (P < 0.01 without serious adverse effects. Although [6]-shogaol but not [6]-gingerol showed similar effects, chromatographic analyses suggested the presence of other constituent(s as active substances. Together, these results show that ginger extract has potent anticancer activity against pancreatic cancer cells by inducing ROS-mediated autosis and warrants further investigation in order to develop an efficacious candidate drug.
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BID links ferroptosis to mitochondrial cell death pathways
Directory of Open Access Journals (Sweden)
Sandra Neitemeier
2017-08-01
Full Text Available Ferroptosis has been defined as an oxidative and iron-dependent pathway of regulated cell death that is distinct from caspase-dependent apoptosis and established pathways of death receptor-mediated regulated necrosis. While emerging evidence linked features of ferroptosis induced e.g. by erastin-mediated inhibition of the Xc- system or inhibition of glutathione peroxidase 4 (Gpx4 to an increasing number of oxidative cell death paradigms in cancer cells, neurons or kidney cells, the biochemical pathways of oxidative cell death remained largely unclear. In particular, the role of mitochondrial damage in paradigms of ferroptosis needs further investigation.In the present study, we find that erastin-induced ferroptosis in neuronal cells was accompanied by BID transactivation to mitochondria, loss of mitochondrial membrane potential, enhanced mitochondrial fragmentation and reduced ATP levels. These hallmarks of mitochondrial demise are also established features of oxytosis, a paradigm of cell death induced by Xc- inhibition by millimolar concentrations of glutamate. Bid knockout using CRISPR/Cas9 approaches preserved mitochondrial integrity and function, and mediated neuroprotective effects against both, ferroptosis and oxytosis. Furthermore, the BID-inhibitor BI-6c9 inhibited erastin-induced ferroptosis, and, in turn, the ferroptosis inhibitors ferrostatin-1 and liproxstatin-1 prevented mitochondrial dysfunction and cell death in the paradigm of oxytosis. These findings show that mitochondrial transactivation of BID links ferroptosis to mitochondrial damage as the final execution step in this paradigm of oxidative cell death. Keywords: Ferroptosis, BID, Mitochondria, CRISPR, Oxytosis, Neuronal death
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Induction of cancer cell death by proton beam in tumor hypoxic region
International Nuclear Information System (INIS)
Hur, T. R.; Lee, Y. M.; Park, J. W.; Sohn, E. J.
2006-05-01
The physical properties of charged particles such as protons are uniquely suited to target the radiation dose precisely in the tumor. In proton therapy, the Bragg peak is spread out by modulating or degrading the energy of the particles to cover a well defined target volume at a given depth. Due to heterogeneity in the various tumors and end-points as well as in the physical properties of the beams considered, it is difficult to fit the various results into a clear general description of the biological effect of proton in tumor therapy. Tumor hypoxia is a main obstacle to radiotherapy, including gamma-ray. Survived tumor cells under hypoxic region are resistant to radiation and more aggressive to be metastasized. To investigate the dose of proton beam to induce cell death of various tumor cells and hypoxic tumor cells at the Bragg peak in vitro, we used 3 kinds of tumor cells, lung cancer, leukemia and hepatoma cells. Proton beam induces apoptosis in Lewis lung carcinoma cells dose dependently and, slightly in leukemia but not in hepatoma cells at all. Above 1000 gray of proton beam, 60% of cells died even the hypoxic cells in Lewis lung carcinoma cells. But the Molt-4 leukemia cells showed milder effect, 20% cell death by the above 1000 Gray of proton beam and typical resistant pattern (5-10%) of hypoxia in desferrioxamine treated cells. Hepatoma cells (HepG2) were not responsive to proton beam even in rather higher dose (4000G). However, by the gamma-irradiation, Molt-4 was more sensitive than hepatoma or lung cancer cells, but still showed hypoxic resistance. The cell death by proton beam in Lewis lung carcinoma cells was confirmed by PARP cleavage and may be mediated by increased p53. Pro-caspases were also activated and cleaved by the proton beam irradiations for lung cancer cell death. In conclusion, high dose of proton beam (above 1000 gray) may be a good therapeutic radiation even in hypoxic region at the Bragg peak, but further investigations about the
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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.
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Radionuclide blood cell survival studies
International Nuclear Information System (INIS)
Bentley, S.A.; Miller, D.T.
1986-01-01
Platelet and red cell survival studies are reviewed. The use of 51 Cr and di-isopropylfluoridate labelled with tritium or 32 P is discussed for red cell survival study and 51 Cr and 111 In-oxine are considered as platelet labels. (UK)
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The control and execution of programmed cell death
International Nuclear Information System (INIS)
Begum, R.; Pathak, N.; Hasnain, S.E.; Sah, N.K.; Athar, M.
1999-01-01
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
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The control and execution of programmed cell death
Energy Technology Data Exchange (ETDEWEB)
Begum, R.; Pathak, N.; Hasnain, S.E.; Sah, N.K. [National Inst. of Immunology, New Delhi (India). Eukaryotic Gene Expression Lab.; Taneja, T.K.; Mohan, M. [National Inst. of Immunology, New Delhi (India). Eukaryotic Gene Expression Lab.]|[Dept. of Medical Elementology and Toxicology, New Delhi (India); Athar, M. [Dept. of Medical Elementology and Toxicology, New Delhi (India)
1999-07-01
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 collectivley 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
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Mitochondrial fission proteins regulate programmed cell death in yeast
Fannjiang, Yihru; Cheng, Wen-Chih; Lee, Sarah J.; Qi, Bing; Pevsner, Jonathan; McCaffery, J. Michael; Hill, R. Blake; Basañez, Gorka; Hardwick, J. Marie
2004-01-01
The possibility that single-cell organisms undergo programmed cell death has been questioned in part because they lack several key components of the mammalian cell death machinery. However, yeast encode a homolog of human Drp1, a mitochondrial fission protein that was shown previously to promote mammalian cell death and the excessive mitochondrial fragmentation characteristic of apoptotic mammalian cells. In support of a primordial origin of programmed cell death involving mitochondria, we fo...
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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.
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Cell death induced by hydroxyapatite on L929 fibroblast cells.
Inayat-Hussain, S H; Rajab, N F; Roslie, H; Hussin, A A; Ali, A M; Annuar, B O
2004-05-01
Biomaterials intended for end-use application as bone-graft substitutes have to undergo safety evaluation. In this study, we investigated the in vitro cytotoxic effects especially to determine the mode of death of two hydroxyapatite compounds (HA2, HA3) which were synthesized locally. The methods used for cytotoxicity was the standard MTT assay whereas AO/PI staining was performed to determine the mode of cell death in HA treated L929 fibroblasts. Our results demonstrated that both HA2 and HA3 were not significantly cytotoxic as more than 75% cells after 72 hours treatment were viable. Furthermore, we found that the major mode of cell death in HA treated cells was apoptosis. In conclusion, our results demonstrated that these hydroxyapatite compounds are not cytotoxic where the mode of death was primarily via apoptosis.
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Autophagy plays an important role in Sunitinib-mediated cell death in H9c2 cardiac muscle cells
International Nuclear Information System (INIS)
Zhao Yuqin; Xue Tao; Yang Xiaochun; Zhu Hong; Ding Xiaofei; Lou Liming; Lu Wei; Yang Bo; He Qiaojun
2010-01-01
Sunitinib, which is a multitargeted tyrosine-kinase inhibitor, exhibits antiangiogenic and antitumor activity, and extends survival of patients with metastatic renal-cell carcinoma (mRCC) and gastrointestinal stromal tumors (GIST). This molecule has also been reported to be associated with cardiotoxicity at a high frequency, but the mechanism is still unknown. In the present study, we observed that Sunitinib showed high anti-proliferative effect on H9c2 cardiac muscle cells measured by PI staining and the MTT assay. But apoptotic markers (PARP cleavage, caspase 3 cleavage and chromatin condensation) were uniformly negative in H9c2 cells after Sunitinib treatment for 48 h, indicating that another cell death pathway may be involved in Sunitinib-induced cardiotoxicity. Here we found Sunitinib dramatically increased autophagic flux in H9c2 cells. Acidic vesicle fluorescence and high expression of LC3-II in H9c2 cells identified autophagy as a Sunitinib-induced process that might be associated with cytotoxicity. Furthermore, knocking down Beclin 1 by RNA-interference to block autophagy in H9c2 cells revealed that the death rate was decreased when treated with Sunitinib in comparison to control cells. These results confirmed that autophagy plays an important role in Sunitinib-mediated H9c2 cells cytotoxicity. Taken together, the data presented here strongly suggest that autophagy is associated with Sunitinib-induced cardiotoxicity, and that inhibition of autophagy constitutes a viable strategy for reducing Sunitinib-induced cardiomyocyte death thereby alleviating Sunitinib cardiotoxicity.
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The slow cell death response when screening chemotherapeutic agents.
Blois, Joseph; Smith, Adam; Josephson, Lee
2011-09-01
To examine the correlation between cell death and a common surrogate of death used in screening assays, we compared cell death responses to those obtained with the sulforhodamine B (SRB) cell protein-based "cytotoxicity" assay. With the SRB assay, the Hill equation was used to obtain an IC50 and final cell mass, or cell mass present at infinite agent concentrations, with eight adherent cell lines and four agents (32 agent/cell combinations). Cells were treated with high agent concentrations (well above the SRB IC50) and the death response determined as the time-dependent decrease in cells failing to bind both annexin V and vital fluorochromes by flow cytometry. Death kinetics were categorized as fast (5/32) (similar to the reference nonadherent Jurkat line), slow (17/32), or none (10/32), despite positive responses in the SRB assay in all cases. With slow cell death, a single exposure to a chemotherapeutic agent caused a slow, progressive increase in dead (necrotic) and dying (apoptotic) cells for at least 72 h. Cell death (defined by annexin and/or fluorochrome binding) did not correlate with the standard SRB "cytotoxicity" assay. With the slow cell death response, a single exposure to an agent caused a slow conversion from vital to apoptotic and necrotic cells over at least 72 h (the longest time point examined). Here, increasing the time of exposure to agent concentrations modestly above the SRB IC50 provides a method of maximizing cell kill. If tumors respond similarly, sustained low doses of chemotherapeutic agents, rather than a log-kill, maximum tolerated dose strategy may be an optimal strategy of maximizing tumor cell death.
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Ionizing radiation-induced cell death
International Nuclear Information System (INIS)
Szumiel, I.
1994-01-01
Selected aspects of radiation-induced cell death, connected with signal transduction pathways are reviewed. Cell death is defined as insufficiency of the cellular signal transducing system to maintain the cell's physiological functions. The insufficiency may be due to impaired signal reception and/or transduction, lack or erroneous transcription activation, and eventual cellular ''misexpression'' of the signal. The molecular basis of this insufficiency would be damage to genomic (but also other cellular) structures and closing of specific signalling pathways or opening of others (like those leading to apoptosis). I describe experimental data that suggest an important role of RAS/NFI and p53/p105 Rb proteins in cell cycle control-coupled responses to DNA damage. (Author)
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Darling, Nicola J; Balmanno, Kathryn; Cook, Simon J
2017-01-01
Disruption of protein folding in the endoplasmic reticulum (ER) causes ER stress. Activation of the unfolded protein response (UPR) acts to restore protein homeostasis or, if ER stress is severe or persistent, drive apoptosis, which is thought to proceed through the cell intrinsic, mitochondrial pathway. Indeed, cells that lack the key executioner proteins BAX and BAK are protected from ER stress-induced apoptosis. Here we show that chronic ER stress causes the progressive inhibition of the extracellular signal-regulated kinase (ERK1/2) signalling pathway. This is causally related to ER stress since reactivation of ERK1/2 can protect cells from ER stress-induced apoptosis whilst ERK1/2 pathway inhibition sensitises cells to ER stress. Furthermore, cancer cell lines harbouring constitutively active BRAFV600E are addicted to ERK1/2 signalling for protection against ER stress-induced cell death. ERK1/2 signalling normally represses the pro-death proteins BIM, BMF and PUMA and it has been proposed that ER stress induces BIM-dependent cell death. We found no evidence that ER stress increased the expression of these proteins; furthermore, BIM was not required for ER stress-induced death. Rather, ER stress caused the PERK-dependent inhibition of cap-dependent mRNA translation and the progressive loss of pro-survival proteins including BCL2, BCLXL and MCL1. Despite these observations, neither ERK1/2 activation nor loss of BAX/BAK could confer long-term clonogenic survival to cells exposed to ER stress. Thus, ER stress induces cell death by at least two biochemically and genetically distinct pathways: a classical BAX/BAK-dependent apoptotic response that can be inhibited by ERK1/2 signalling and an alternative ERK1/2- and BAX/BAK-independent cell death pathway.
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Directory of Open Access Journals (Sweden)
Nicola J Darling
Full Text Available Disruption of protein folding in the endoplasmic reticulum (ER causes ER stress. Activation of the unfolded protein response (UPR acts to restore protein homeostasis or, if ER stress is severe or persistent, drive apoptosis, which is thought to proceed through the cell intrinsic, mitochondrial pathway. Indeed, cells that lack the key executioner proteins BAX and BAK are protected from ER stress-induced apoptosis. Here we show that chronic ER stress causes the progressive inhibition of the extracellular signal-regulated kinase (ERK1/2 signalling pathway. This is causally related to ER stress since reactivation of ERK1/2 can protect cells from ER stress-induced apoptosis whilst ERK1/2 pathway inhibition sensitises cells to ER stress. Furthermore, cancer cell lines harbouring constitutively active BRAFV600E are addicted to ERK1/2 signalling for protection against ER stress-induced cell death. ERK1/2 signalling normally represses the pro-death proteins BIM, BMF and PUMA and it has been proposed that ER stress induces BIM-dependent cell death. We found no evidence that ER stress increased the expression of these proteins; furthermore, BIM was not required for ER stress-induced death. Rather, ER stress caused the PERK-dependent inhibition of cap-dependent mRNA translation and the progressive loss of pro-survival proteins including BCL2, BCLXL and MCL1. Despite these observations, neither ERK1/2 activation nor loss of BAX/BAK could confer long-term clonogenic survival to cells exposed to ER stress. Thus, ER stress induces cell death by at least two biochemically and genetically distinct pathways: a classical BAX/BAK-dependent apoptotic response that can be inhibited by ERK1/2 signalling and an alternative ERK1/2- and BAX/BAK-independent cell death pathway.
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Postirradiation DNA synthesis is inversely related to cell survival
International Nuclear Information System (INIS)
Kapiszewska, M.; Lange, C.S.
1987-01-01
Postirradiation (PI) events which might lead to cellular reproductive death or survival were studied in L5178Y-S (LY-S) cells. PI incubation at 25 0 C protects LY-S cells against the PLD fixation which takes place at 37 0 C. An optimal condition for the repair of PLD is 1h at 37 0 C followed by 4h holding at 25 0 C prior to the second half of a split dose, or 5L holding at 25 0 C without a 37 0 C incubation. Longer incubations at 37 0 C resulted in progressively decreased survivals. Postirradiation inhibition of DNA synthesis at 37 0 C was observed only during the first 30 min; thereafter, /sup 3/H-dThd incorporation was higher than in unirradiated controls. This excess synthesis effect was removed by shifting irradiated cells to 25 0 C holding. The inhibition observed at 25 0 C was reversed by shifting to 37 0 C. Thus the degree of postirradiation DNA synthesis is inversely related to PLD/SLD repair. DNA filter elution shows complete SSB repair by 3h at both temperatures (with faster kinetics at 37 0 C), and DSB repair plateaus at 80% (37 0 C) and 60% (25 0 C) after 90 min
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Par3L enhances colorectal cancer cell survival by inhibiting Lkb1/AMPK signaling pathway
International Nuclear Information System (INIS)
Li, Taiyuan; Liu, Dongning; Lei, Xiong; Jiang, Qunguang
2017-01-01
Partitioning defective 3-like protein (Par3L) is a recently identified cell polarity protein that plays an important role in mammary stem cell maintenance. Previously, we showed that high expression of Par3L is associated with poor survival in malignant colorectal cancer (CRC), but the underlying mechanism remained unknown. To this end, we established a Par3L knockout colorectal cancer cell line using the CRISPR/Cas system. Interestingly, reduced proliferation, enhanced cell death and caspase-3 activation were observed in Par3L knockout (KO) cells as compared with wildtype (WT) cells. Consistent with previous studies, we showed that Par3L interacts with a tumor suppressor protein liver kinase B1 (Lkb1). Moreover, Par3L depletion resulted in abnormal activation of Lkb1/AMPK signaling cascade. Knockdown of Lkb1 in these cells could significantly reduce AMPK activity and partially rescue cell death caused by Par3L knockdown. Furthermore, we showed that Par3L KO cells were more sensitive to chemotherapies and irradiation. Together, these results suggest that Par3L is essential for colorectal cancer cell survival by inhibiting Lkb1/AMPK signaling pathway, and is a putative therapeutic target for CRC. - Highlights: • Par3L knockout using the CRISPR/Cas system induces apoptosis in colorectal cancer cells. • Par3L interacts with Lkb1 and regulates the activity of AMPK signaling cascade. • Par3L knockout cells are more sensitive to treatment of different chemotherapy drugs and irradiation.
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Niclosamide enhances ROS-mediated cell death through c-Jun activation.
Lee, Sae-lo-oom; Son, A-Rang; Ahn, Jiyeon; Song, Jie-Young
2014-06-01
Radiotherapy is an effective treatment modality in the clinical treatment of cancers, and has been combined with chemotherapy in order to improve therapeutic efficacy. Therefore, we aimed to develop small molecules that enhance the cytotoxic effects of radiotherapy. In this study, we provide evidence that niclosamide is an effective radiosensitizer in non-small cell lung cancer cells. Using a cell-based high-throughput viability screen of 1040 compounds in combination with γ-ionizing radiation (IR), we found niclosamide, an FDA-approved antihelminthic agent, had a radiosensitizing effect on H1299 human lung cancer cells. Pretreatment with niclosamide enhanced IR- induced cell death of H1299 in a dose-dependent manner via apoptosis compared with IR or niclosamide alone. The combined treatment induced significantly more phosphorylation of p38 MAPK and c-Jun in H1299 cells than IR or niclosamide alone. Since IR induces apoptosis through generation of reactive oxygen species (ROS), hydrogen peroxide (H2O2) was employed as another ROS generator and we found that niclosamide also sensitized cells to H2O2. Niclosamide pretreatment also induced c-Jun and its phosphorylation in the presence of H2O2, thereby enhancing apoptosis. N-acetyl-L-cysteine (NAC) treatment abolished both cell death and c-Jun activation induced by the combination treatments. Knockdown of c-Jun also decreased PARP cleavage and clonogenic cell survival in niclosamide- and IR-treated H1299 cells. Our findings suggest that niclosamide could be a promising radiosensitizer in lung cancer patients through activation of the p38 MAPK-c-Jun axis. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
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Models for cell survival with low LET radiation
International Nuclear Information System (INIS)
Payne, M.G.; Garrett, W.R.
1975-01-01
A model for cell survival under low LET irradiation was developed in which the cell is considered to have N 0 -independent sensitive sites, each of which can exist in either an undamaged state (state A) or one of two damaged states. Radiation can change the sensitive sites from the undamaged state to either of two damaged states. The first damaged state (state B) can either be repaired or be promoted on the second damaged state (state C), which is irreparable. The promotion from the first damaged state to the second can occur due to any of the following: (1) further radiation damage, (2) an abortive attempt to repair the site, or (3) the arrival at a part of the cell cycle where the damage is ''fixed.'' Subject to the further assumptions that radiation damage can occur either indirectly (i.e., through radiation products) or due to direct interaction, and that repair of the first damaged state is a one-step process, expressions can be derived for P(N/sub A/, N/sub B/,t) = probability that after time t a cell will have N/sub A/ sites in state A and N/sub B/ in state B. The problem of determining P(N/sub A/, N/sub B/, t) is formulated for arbitrary time dependences of the radiation field and of all rate coefficients. A large family of cell-survival models can be described by interpreting the sensitive sites in different ways and by making different choices of rate coefficients and of the combinations of numbers of sites in different states that will lead to cell death. (U.S.)
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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...
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Miyamae, Yuka; Mochizuki, Satsuki; Shimoda, Masayuki; Ohara, Kentaro; Abe, Hitoshi; Yamashita, Shuji; Kazuno, Saiko; Ohtsuka, Takashi; Ochiai, Hiroki; Kitagawa, Yuko; Okada, Yasunori
2016-05-01
ADAM28 (disintegrin and metalloproteinase 28), which was originally reported to be lymphocyte-specific, is over-expressed by carcinoma cells and plays a key role in cell proliferation and progression in human lung and breast carcinomas. We studied ADAM28 expression in human normal tissues and examined its biological function. By using antibodies specific to ADAM28, ADAM28 was immunolocalized mainly to epithelial cells in several tissues, including epididymis, bronchus and stomach, whereas lymphocytes in lymph nodes and spleen were negligibly immunostained. RT-PCR, immunoblotting and ELISA analyses confirmed the expression in these tissues, and low or negligible expression by lymphocytes was found in the lymph node and spleen. C1q was identified as a candidate ADAM28-binding protein from a human lung cDNA library by yeast two-hybrid system, and specific binding was demonstrated by binding assays, immunoprecipitation and surface plasmon resonance. C1q treatment of normal bronchial epithelial BEAS-2B and NHBE cells, both of which showed low-level expression of ADAM28, caused apoptosis through activation of p38 and caspase-3, and cell death with autophagy through accumulation of LC3-II and autophagosomes, respectively. C1q-induced cell death was attenuated by treatment of the cells with antibodies against the C1q receptor gC1qR/p33 or cC1qR/calreticulin. Treatment of C1q with recombinant ADAM28 prior to addition to culture media reduced C1q-induced cell death, and knockdown of ADAM28 using siRNAs increased cell death. These data demonstrate that ADAM28 is expressed by epithelial cells of several normal organs, and suggest that ADAM28 plays a role in cell survival by suppression of C1q-induced cytotoxicity in bronchial epithelial cells. © 2016 Federation of European Biochemical Societies.
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A track-event theory of cell survival
Energy Technology Data Exchange (ETDEWEB)
Besserer, Juergen; Schneider, Uwe [Zuerich Univ. (Switzerland). Inst. of Physics; Radiotherapy Hirslanden, Zuerich (Switzerland)
2015-09-01
When fractionation schemes for hypofractionation and stereotactic body radiotherapy are considered, a reliable cell survival model at high dose is needed for calculating doses of similar biological effectiveness. In this work a simple model for cell survival which is valid also at high dose is developed from Poisson statistics. An event is defined by two double strand breaks (DSB) on the same or different chromosomes. An event is always lethal due to direct lethal damage or lethal binary misrepair by the formation of chromosome aberrations. Two different mechanisms can produce events: one-track events (OTE) or two-track-events (TTE). The target for an OTE is always a lethal event, the target for an TTE is one DSB. At least two TTEs on the same or different chromosomes are necessary to produce an event. Both, the OTE and the TTE are statistically independent. From the stochastic nature of cell kill which is described by the Poisson distribution the cell survival probability was derived. It was shown that a solution based on Poisson statistics exists for cell survival. It exhibits exponential cell survival at high dose and a finite gradient of cell survival at vanishing dose, which is in agreement with experimental cell studies. The model fits the experimental data nearly as well as the three-parameter formula of Hug-Kellerer and is only based on two free parameters. It is shown that the LQ formalism is an approximation of the model derived in this work. It could be also shown that the derived model predicts a fractionated cell survival experiment better than the LQ-model. It was shown that cell survival can be described with a simple analytical formula on the basis of Poisson statistics. This solution represents in the limit of large dose the typical exponential behavior and predicts cell survival after fractionated dose application better than the LQ-model.
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A track-event theory of cell survival
International Nuclear Information System (INIS)
Besserer, Juergen; Schneider, Uwe
2015-01-01
When fractionation schemes for hypofractionation and stereotactic body radiotherapy are considered, a reliable cell survival model at high dose is needed for calculating doses of similar biological effectiveness. In this work a simple model for cell survival which is valid also at high dose is developed from Poisson statistics. An event is defined by two double strand breaks (DSB) on the same or different chromosomes. An event is always lethal due to direct lethal damage or lethal binary misrepair by the formation of chromosome aberrations. Two different mechanisms can produce events: one-track events (OTE) or two-track-events (TTE). The target for an OTE is always a lethal event, the target for an TTE is one DSB. At least two TTEs on the same or different chromosomes are necessary to produce an event. Both, the OTE and the TTE are statistically independent. From the stochastic nature of cell kill which is described by the Poisson distribution the cell survival probability was derived. It was shown that a solution based on Poisson statistics exists for cell survival. It exhibits exponential cell survival at high dose and a finite gradient of cell survival at vanishing dose, which is in agreement with experimental cell studies. The model fits the experimental data nearly as well as the three-parameter formula of Hug-Kellerer and is only based on two free parameters. It is shown that the LQ formalism is an approximation of the model derived in this work. It could be also shown that the derived model predicts a fractionated cell survival experiment better than the LQ-model. It was shown that cell survival can be described with a simple analytical formula on the basis of Poisson statistics. This solution represents in the limit of large dose the typical exponential behavior and predicts cell survival after fractionated dose application better than the LQ-model.
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Mechanisms of Betulinic acid‐induced cell death
Potze, L.
2015-01-01
The scope of this thesis was to investigate the mechanisms by which BetA induces cell death in cancer cells in more detail. At the start of the studies described in this thesis several questions urgently needed an answer. Although BetA induces cell death via apoptosis, when blocking this form of
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International Nuclear Information System (INIS)
Bunagan, J.; Perey, K.; Deocaris, C.C.
1996-01-01
Biomedical studies on nuclear fallout effects show that whole-body exposure to relatively low doses of ionizing radiation (2-10 Gy) induces the hematopoietic syndrome (HS) characterized by severe anemia and immunodeficiency and death within 10-30 days. The thymocyte model applies in many cell death researches and is found to undergo a morphologically and molecularly distinct p53-based apoptosis with DNA-damaging insults, such as radiation exposure. We have shown that exogenously applied radioprotector from allium sativum (garlic), GC-2112, improves total cellular survival for various observation periods concomitantly shifting the LD 50/24 from 7 Gy (control) to 21 Gy (GC-2112). This increased survival characteristic of the radioprotected macrophage-free thymocytes, however, fails to correlate with the prevention of apoptosis-associated DNA scissions. Mechanisms to the observed radiomodification may possibly involve cysteine compounds found rich in garlic. These preliminary findings show promise in the applications of selected herbal drugs as dietary prophylaxis against clinical morbidities arising from either medical, occupational or environmental exposures to ionizing radiation. (author)
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Energy Technology Data Exchange (ETDEWEB)
Bunagan, J; Perey, K [Pamantasan ng Lungsod ng Maynila, Manila (Philippines); Deocaris, C C [Philippine Nuclear Research Inst., Diliman, Quezon City (Philippines)
1997-12-31
Biomedical studies on nuclear fallout effects show that whole-body exposure to relatively low doses of ionizing radiation (2-10 Gy) induces the hematopoietic syndrome (HS) characterized by severe anemia and immunodeficiency and death within 10-30 days. The thymocyte model applies in many cell death researches and is found to undergo a morphologically and molecularly distinct p53-based apoptosis with DNA-damaging insults, such as radiation exposure. We have shown that exogenously applied radioprotector from allium sativum (garlic), GC-2112, improves total cellular survival for various observation periods concomitantly shifting the LD{sub 50/24} from 7 Gy (control) to 21 Gy (GC-2112). This increased survival characteristic of the radioprotected macrophage-free thymocytes, however, fails to correlate with the prevention of apoptosis-associated DNA scissions. Mechanisms to the observed radiomodification may possibly involve cysteine compounds found rich in garlic. These preliminary findings show promise in the applications of selected herbal drugs as dietary prophylaxis against clinical morbidities arising from either medical, occupational or environmental exposures to ionizing radiation. (author).
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International Nuclear Information System (INIS)
Rowland, R.E.; Durbin, P.W.
1975-01-01
To determine the relationship between urinary excretion and plutonium body content, 18 persons of short life expectancy were injected with plutonium between 1945 and 1947. Seventeen of these 18 individuals have been identified; eight were found to have survived for at least eight years and four are still alive today (1975). The causes of death of 13 of these individuals have been determined from death certificates; none appear to be related to the administered plutonium. Doses to the liver and to the cells on the surface of bone have been calculated for these plutonium cases. The liver doses do not appear to be high enough to be carcinogenic, but comparison of the bone-surface doses with radium doses that have induced bone tumors indicates that six of these cases have received doses high enough to be considered carcinogenic. However, no bone tumors have yet appeared. (auth)
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BID links ferroptosis to mitochondrial cell death pathways.
Neitemeier, Sandra; Jelinek, Anja; Laino, Vincenzo; Hoffmann, Lena; Eisenbach, Ina; Eying, Roman; Ganjam, Goutham K; Dolga, Amalia M; Oppermann, Sina; Culmsee, Carsten
2017-08-01
Ferroptosis has been defined as an oxidative and iron-dependent pathway of regulated cell death that is distinct from caspase-dependent apoptosis and established pathways of death receptor-mediated regulated necrosis. While emerging evidence linked features of ferroptosis induced e.g. by erastin-mediated inhibition of the X c - system or inhibition of glutathione peroxidase 4 (Gpx4) to an increasing number of oxidative cell death paradigms in cancer cells, neurons or kidney cells, the biochemical pathways of oxidative cell death remained largely unclear. In particular, the role of mitochondrial damage in paradigms of ferroptosis needs further investigation. In the present study, we find that erastin-induced ferroptosis in neuronal cells was accompanied by BID transactivation to mitochondria, loss of mitochondrial membrane potential, enhanced mitochondrial fragmentation and reduced ATP levels. These hallmarks of mitochondrial demise are also established features of oxytosis, a paradigm of cell death induced by X c - inhibition by millimolar concentrations of glutamate. Bid knockout using CRISPR/Cas9 approaches preserved mitochondrial integrity and function, and mediated neuroprotective effects against both, ferroptosis and oxytosis. Furthermore, the BID-inhibitor BI-6c9 inhibited erastin-induced ferroptosis, and, in turn, the ferroptosis inhibitors ferrostatin-1 and liproxstatin-1 prevented mitochondrial dysfunction and cell death in the paradigm of oxytosis. These findings show that mitochondrial transactivation of BID links ferroptosis to mitochondrial damage as the final execution step in this paradigm of oxidative cell death. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Sun, Hengwen [Department of Radiation, Cancer Center of Guangdong General Hospital (Guangdong Academy of Medical Science), Guangzhou, 510080, Guangdong (China); Yang, Shana; Li, Jianhua [Department of Physiology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China); Zhang, Yajie [Department of Pathology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China); Gao, Dongsheng [Department of Oncology, Guangdong Medical College Affiliated Pengpai Memorial Hospital, Hai Feng, 516400, Gungdong (China); Zhao, Shenting, E-mail: zhaoshenting@126.com [Department of Physiology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China)
2016-03-25
Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. The aim of radiotherapy is to eradicate cancer cells with ionizing radiation. Except for the caspase-dependent mechanism, several lines of evidence demonstrated that caspase-independent mechanism is directly involved in the cell death responding to irradiation. For this reason, defining the contribution of caspase-independent molecular mechanisms represents the main goal in radiotherapy. In this study, we focused on the role of apoptosis-inducing factor (AIF), the caspase-independent molecular, in ionizing radiation induced hepatocellular carcinoma cell line (HepG2) cell death. We found that ionizing radiation has no function on AIF expression in HepG2 cells, but could induce AIF release from the mitochondria and translocate into nuclei. Inhibition of AIF could reduce ionizing radiation induced HepG2 cell death. These studies strongly support a direct relationship between AIF nuclear translocation and radiation induced cell death. What's more, AIF nuclear translocation is caspase-independent manner, but not caspase-dependent manner, in this process. These new findings add a further attractive point of investigation to better define the complex interplay between caspase-independent cell death and radiation therapy. - Highlights: • AIF nuclear translocation is involved in ionizing radiation induced hepatocellular carcinoma cell line HepG2 cell death. • AIF mediated cell death induced by ionizing radiation is caspase-independent. • Caspase-independent pathway is involved in ionzing radiation induced HepG2 cell death.
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International Nuclear Information System (INIS)
Sun, Hengwen; Yang, Shana; Li, Jianhua; Zhang, Yajie; Gao, Dongsheng; Zhao, Shenting
2016-01-01
Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. The aim of radiotherapy is to eradicate cancer cells with ionizing radiation. Except for the caspase-dependent mechanism, several lines of evidence demonstrated that caspase-independent mechanism is directly involved in the cell death responding to irradiation. For this reason, defining the contribution of caspase-independent molecular mechanisms represents the main goal in radiotherapy. In this study, we focused on the role of apoptosis-inducing factor (AIF), the caspase-independent molecular, in ionizing radiation induced hepatocellular carcinoma cell line (HepG2) cell death. We found that ionizing radiation has no function on AIF expression in HepG2 cells, but could induce AIF release from the mitochondria and translocate into nuclei. Inhibition of AIF could reduce ionizing radiation induced HepG2 cell death. These studies strongly support a direct relationship between AIF nuclear translocation and radiation induced cell death. What's more, AIF nuclear translocation is caspase-independent manner, but not caspase-dependent manner, in this process. These new findings add a further attractive point of investigation to better define the complex interplay between caspase-independent cell death and radiation therapy. - Highlights: • AIF nuclear translocation is involved in ionizing radiation induced hepatocellular carcinoma cell line HepG2 cell death. • AIF mediated cell death induced by ionizing radiation is caspase-independent. • Caspase-independent pathway is involved in ionzing radiation induced HepG2 cell death.
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Tug of War between Survival and Death: Exploring ATM Function in Cancer
Stagni, Venturina; Oropallo, Veronica; Fianco, Giulia; Antonelli, Martina; Cinà, Irene; Barilà, Daniela
2014-01-01
Ataxia-telangiectasia mutated (ATM) kinase is a one of the main guardian of genome stability and plays a central role in the DNA damage response (DDR). The deregulation of these pathways is strongly linked to cancer initiation and progression as well as to the development of therapeutic approaches. These observations, along with reports that identify ATM loss of function as an event that may promote tumor initiation and progression, point to ATM as a bona fide tumor suppressor. The identification of ATM as a positive modulator of several signalling networks that sustain tumorigenesis, including oxidative stress, hypoxia, receptor tyrosine kinase and AKT serine-threonine kinase activation, raise the question of whether ATM function in cancer may be more complex. This review aims to give a complete overview on the work of several labs that links ATM to the control of the balance between cell survival, proliferation and death in cancer. PMID:24681585
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Tug of War between Survival and Death: Exploring ATM Function in Cancer
Directory of Open Access Journals (Sweden)
Venturina Stagni
2014-03-01
Full Text Available Ataxia-telangiectasia mutated (ATM kinase is a one of the main guardian of genome stability and plays a central role in the DNA damage response (DDR. The deregulation of these pathways is strongly linked to cancer initiation and progression as well as to the development of therapeutic approaches. These observations, along with reports that identify ATM loss of function as an event that may promote tumor initiation and progression, point to ATM as a bona fide tumor suppressor. The identification of ATM as a positive modulator of several signalling networks that sustain tumorigenesis, including oxidative stress, hypoxia, receptor tyrosine kinase and AKT serine-threonine kinase activation, raise the question of whether ATM function in cancer may be more complex. This review aims to give a complete overview on the work of several labs that links ATM to the control of the balance between cell survival, proliferation and death in cancer.
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Bailey, George C; Boorjian, Stephen A; Ziegelmann, Matthew J; Westerman, Mary E; Lohse, Christine M; Leibovich, Bradley C; Cheville, John C; Thompson, R Houston
2017-04-01
To evaluate the prognostic significance of urinary collecting system invasion (UCSI) in a large series of patients with clear-cell renal cell carcinoma (RCC). Patients with clear-cell RCC treated with nephrectomy between 2001 and 2010 were reviewed from a prospectively maintained registry. One urological pathologist re-reviewed all slides. Cancer-specific survival was estimated using the Kaplan-Meier method, and associations of UCSI with death from RCC were evaluated using Cox models. Of the 859 patients with clear-cell RCC, 58 (6.8%) had UCSI. At last follow-up, 310 patients had died from RCC at a median of 1.8 years after surgery. The median follow-up for patients alive at last follow-up was 8.2 years. The estimated cancer-specific survival at 10 years after surgery for patients with UCSI was 17%, compared with 60% for patients without UCSI (P system invasion is associated with poor prognosis among patients with clear-cell RCC. If validated, consideration should be given to including UCSI in future staging systems. © 2016 The Authors BJU International © 2016 BJU International Published by John Wiley & Sons Ltd.
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Douglass, Michael; Bezak, Eva; Penfold, Scott
2015-04-21
The preliminary framework of a combined radiobiological model is developed and calibrated in the current work. The model simulates the production of individual cells forming a tumour, the spatial distribution of individual ionization events (using Geant4-DNA) and the stochastic biochemical repair of DNA double strand breaks (DSBs) leading to the prediction of survival or death of individual cells. In the current work, we expand upon a previously developed tumour generation and irradiation model to include a stochastic ionization damage clustering and DNA lesion repair model. The Geant4 code enabled the positions of each ionization event in the cells to be simulated and recorded for analysis. An algorithm was developed to cluster the ionization events in each cell into simple and complex double strand breaks. The two lesion kinetic (TLK) model was then adapted to predict DSB repair kinetics and the resultant cell survival curve. The parameters in the cell survival model were then calibrated using experimental cell survival data of V79 cells after low energy proton irradiation. A monolayer of V79 cells was simulated using the tumour generation code developed previously. The cells were then irradiated by protons with mean energies of 0.76 MeV and 1.9 MeV using a customized version of Geant4. By replicating the experimental parameters of a low energy proton irradiation experiment and calibrating the model with two sets of data, the model is now capable of predicting V79 cell survival after low energy (cell survival probability, the cell survival probability is calculated for each cell in the geometric tumour model developed in the current work. This model uses fundamental measurable microscopic quantities such as genome length rather than macroscopic radiobiological quantities such as alpha/beta ratios. This means that the model can be theoretically used under a wide range of conditions with a single set of input parameters once calibrated for a given cell line.
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Esakky, P; Hansen, D A; Drury, A M; Cusumano, A; Moley, K H
2015-01-01
Cigarette smoke exposure causes germ cell death during spermatogenesis. Our earlier studies demonstrated that cigarette smoke condensate (CSC) causes spermatocyte cell death in vivo and growth arrest of the mouse spermatocyte cell line (GC-2spd(ts)) in vitro via the aryl hydrocarbon receptor (AHR). We hypothesize here that inactivation of AHR could prevent the CSC-induced cell death in spermatocytes. We demonstrate that CSC exposure generates oxidative stress, which differentially regulates mitochondrial apoptosis in GC-2spd(ts) and wild type (WT) and AHR knockout (AHR-KO) mouse embryonic fibroblasts (MEFs). SiRNA-mediated silencing of Ahr augments the extent of CSC-mediated cellular damage while complementing the AHR-knockout condition. Pharmacological inhibition using the AHR-antagonist (CH223191) modulates the CSC-altered expression of apoptotic proteins and significantly abrogates DNA fragmentation though the cleavage of PARP appears AHR independent. Pretreatment with CH223191 at concentrations above 50 μM significantly prevents the CSC-induced activation of caspase-3/7 and externalization of phosphatidylserine in the plasma membrane. However, MAPK inhibitors alone or together with CH223191 could not prevent the membrane damage upon CSC addition and the caspase-3/7 activation and membrane damage in AHR-deficient MEF indicates the interplay of multiple cell signaling and cytoprotective ability of AHR. Thus the data obtained on one hand signifies the protective role of AHR in maintaining normal cellular homeostasis and the other, could be a potential prophylactic therapeutic target to promote cell survival and growth under cigarette smoke exposed environment by receptor antagonism via CH223191-like mechanism. Antagonist-mediated inactivation of the aryl hydrocarbon receptor blocks downstream events leading to cigarette smoke-induced cell death of a spermatocyte cell line. PMID:27551479
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Mangifera indica L. extract protects T cells from activation-induced cell death.
Hernández, Patricia; Delgado, Rene; Walczak, Henning
2006-09-01
The aqueous stem bark extract of Mangifera indica L. (Vimang) has been reported to have antioxidant properties. AIDS is characterized by up-regulation of CD95 ligand (CD95L) expression and enhancement of activation-induced cell death (AICD). Recent studies demonstrate oxidative signals combined with simultaneous calcium (Ca(2+)) influx into the cytosol are required for induction of CD95L expression. In this study we show that M. indica extract attenuated anti-CD3-induced accumulation of reactive oxygen species (ROS) and intracellular free Ca(2+) and consequently, downregulates CD95L mRNA expression and CD95-mediated AICD. In addition, TCR triggering caused an elevation in the antioxidant enzyme manganous superoxide dismutase (Mn-SOD) and the increase in c-Jun N-terminal kinase (JNK) phosphorylation, both effects being prevented by M. indica extract. We provide a number of evidences regarding how M. indica extract enhance T-cell survival by inhibiting AICD, a finding associated with a decrease in oxidative stress generated through the TCR signaling pathway in activated T cells.
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Directory of Open Access Journals (Sweden)
Joffrey ePelletier
2012-02-01
Full Text Available The hypoxia-inducible factor 1 (HIF-1, in addition to genetic and epigenetic changes, is largely responsible for alterations in cell metabolism in hypoxic tumor cells. This transcription factor not only favors cell proliferation through the metabolic shift from oxidative phosphorylation to glycolysis and lactic acid production but also stimulates nutrient supply by mediating adaptive survival mechanisms. In this study we showed that glycogen synthesis is enhanced in non-cancer and cancer cells when exposed to hypoxia, resulting in a large increase in glycogen stores. Furthermore, we demonstrated that the mRNA and protein levels of the first enzyme of glycogenesis, phosphoglucomutase1 (PGM1, were increased in hypoxia. We showed that induction of glycogen storage as well as PGM1 expression were dependent on HIF-1 and HIF-2. We established that hypoxia-induced glycogen stores are rapidly mobilized in cells that are starved of glucose. Glycogenolysis allows these hypoxia-preconditioned cells to confront and survive glucose deprivation. In contrast normoxic control cells exhibit a high rate of cell death following glucose removal. These findings point to the important role of hypoxia and HIF in inducing mechanisms of rapid adaptation and survival in response to a decrease in oxygen tension. We propose that a decrease in pO2 acts as an alarm that prepares the cells to face subsequent nutrient depletion and to survive.
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Energy Technology Data Exchange (ETDEWEB)
Pelletier, Joffrey; Bellot, Grégory [Institute of Developmental Biology and Cancer Research, CNRS-UMR 6543, Centre Antoine Lacassagne, University of Nice-Sophia Antipolis, Nice (France); Gounon, Pierre; Lacas-Gervais, Sandra [Centre Commun de Microscopie Appliquée, University of Nice-Sophia Antipolis, Nice (France); Pouysségur, Jacques; Mazure, Nathalie M., E-mail: mazure@unice.fr [Institute of Developmental Biology and Cancer Research, CNRS-UMR 6543, Centre Antoine Lacassagne, University of Nice-Sophia Antipolis, Nice (France)
2012-02-28
The hypoxia-inducible factor 1 (HIF-1), in addition to genetic and epigenetic changes, is largely responsible for alterations in cell metabolism in hypoxic tumor cells. This transcription factor not only favors cell proliferation through the metabolic shift from oxidative phosphorylation to glycolysis and lactic acid production but also stimulates nutrient supply by mediating adaptive survival mechanisms. In this study we showed that glycogen synthesis is enhanced in non-cancer and cancer cells when exposed to hypoxia, resulting in a large increase in glycogen stores. Furthermore, we demonstrated that the mRNA and protein levels of the first enzyme of glycogenesis, phosphoglucomutase1 (PGM1), were increased in hypoxia. We showed that induction of glycogen storage as well as PGM1 expression were dependent on HIF-1 and HIF-2. We established that hypoxia-induced glycogen stores are rapidly mobilized in cells that are starved of glucose. Glycogenolysis allows these “hypoxia-preconditioned” cells to confront and survive glucose deprivation. In contrast normoxic control cells exhibit a high rate of cell death following glucose removal. These findings point to the important role of hypoxia and HIF in inducing mechanisms of rapid adaptation and survival in response to a decrease in oxygen tension. We propose that a decrease in pO{sub 2} acts as an “alarm” that prepares the cells to face subsequent nutrient depletion and to survive.
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International Nuclear Information System (INIS)
Pelletier, Joffrey; Bellot, Grégory; Gounon, Pierre; Lacas-Gervais, Sandra; Pouysségur, Jacques; Mazure, Nathalie M.
2012-01-01
The hypoxia-inducible factor 1 (HIF-1), in addition to genetic and epigenetic changes, is largely responsible for alterations in cell metabolism in hypoxic tumor cells. This transcription factor not only favors cell proliferation through the metabolic shift from oxidative phosphorylation to glycolysis and lactic acid production but also stimulates nutrient supply by mediating adaptive survival mechanisms. In this study we showed that glycogen synthesis is enhanced in non-cancer and cancer cells when exposed to hypoxia, resulting in a large increase in glycogen stores. Furthermore, we demonstrated that the mRNA and protein levels of the first enzyme of glycogenesis, phosphoglucomutase1 (PGM1), were increased in hypoxia. We showed that induction of glycogen storage as well as PGM1 expression were dependent on HIF-1 and HIF-2. We established that hypoxia-induced glycogen stores are rapidly mobilized in cells that are starved of glucose. Glycogenolysis allows these “hypoxia-preconditioned” cells to confront and survive glucose deprivation. In contrast normoxic control cells exhibit a high rate of cell death following glucose removal. These findings point to the important role of hypoxia and HIF in inducing mechanisms of rapid adaptation and survival in response to a decrease in oxygen tension. We propose that a decrease in pO 2 acts as an “alarm” that prepares the cells to face subsequent nutrient depletion and to survive.
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Outcomes of chronic dialysis in Korean children with respect to survival rates and causes of death
Chang, Hye Jin; Han, Kyoung Hee; Cho, Min Hyun; Park, Young Seo; Kang, Hee Gyung; Cheong, Hae Il; Ha, Il Soo
2014-01-01
Purpose Adult Korean patients on chronic dialysis have a 9-year survival rate of 50%, with cardiovascular problems being the most significant cause of death. The 2011 annual report of the North American Pediatric Renal Trials and Collaborative Studies group reported 3-year survival rates of 93.4% and relatively poorer survival in younger patients. Methods In this study, we have reviewed data from Korean Pediatric Chronic Kidney Disease Registry from 2002 to 2010 to assess survival rates and c...
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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.
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Autophagy induced by silica nanoparticles protects RAW264.7 macrophages from cell death.
Marquardt, Clarissa; Fritsch-Decker, Susanne; Al-Rawi, Marco; Diabaté, Silvia; Weiss, Carsten
2017-03-15
Although the technological and economic benefits of engineered nanomaterials are obvious, concerns have been raised about adverse effects if such material is inhaled, ingested, applied to the skin or even released into the environment. Here we studied the cytotoxic effects of the most abundant nanomaterial, silica nanoparticles (SiO 2 -NPs), in murine RAW264.7 macrophages. SiO 2 -NPs dose-dependently induce membrane leakage and cell death without obvious involvement of reactive oxygen species. Interestingly, at low concentrations SiO 2 -NPs trigger autophagy, evidenced by morphological and biochemical hallmarks such as autophagolysosomes or increased levels of LC3-II, which serves to protect cells from cytotoxicity. Hence SiO 2 -NPs initiate an adaptive stress response which dependent on dose serve to balance survival and death and ultimately dictates the cellular fate. Copyright © 2017 Elsevier B.V. All rights reserved.
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Cigarette smoke regulates VEGFR2-mediated survival signaling in rat lungs
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Stevenson Christopher S
2010-02-01
Full Text Available Abstract Background Vascular endothelial growth factor (VEGF and VEGF receptor 2 (VEGFR2-mediated survival signaling is critical to endothelial cell survival, maintenance of the vasculature and alveolar structure and regeneration of lung tissue. Reduced VEGF and VEGFR2 expression in emphysematous lungs has been linked to increased endothelial cell death and vascular regression. Previously, we have shown that CS down-regulated the VEGFR2 and its downstream signaling in mouse lungs. However, the VEGFR2-mediated survival signaling in response to oxidants/cigarette smoke (CS is not known. We hypothesized that CS exposure leads to disruption of VEGFR2-mediated endothelial survival signaling in rat lungs. Methods Adult male Sprague-Dawley rats were exposed CS for 3 days, 8 weeks and 6 months to investigate the effect of CS on VEGFR2-mediated survival signaling by measuring the Akt/PI3-kinase/eNOS downstream signaling in rat lungs. Results and Discussion We show that CS disrupts VEGFR2/PI3-kinase association leading to decreased Akt and eNOS phosphorylation. This may further alter the phosphorylation of the pro-apoptotic protein Bad and increase the Bad/Bcl-xl association. However, this was not associated with a significant lung cell death as evidenced by active caspase-3 levels. These data suggest that although CS altered the VEGFR2-mediated survival signaling in the rat lungs, but it was not sufficient to cause lung cell death. Conclusion The rat lungs exposed to CS in acute, sub-chronic and chronic levels may be representative of smokers where survival signaling is altered but was not associated with lung cell death whereas emphysema is known to be associated with lung cell apoptosis.
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Son, S M; Byun, J; Roh, S-E; Kim, S J; Mook-Jung, I
2014-04-17
The endoplasmic reticulum (ER) is not only a home for folding and posttranslational modifications of secretory proteins but also a reservoir for intracellular Ca(2+). Perturbation of ER homeostasis contributes to the pathogenesis of various neurodegenerative diseases, such as Alzheimer's and Parkinson diseases. One key regulator that underlies cell survival and Ca(2+) homeostasis during ER stress responses is inositol-requiring enzyme 1α (IRE1α). Despite extensive studies on this ER membrane-associated protein, little is known about the molecular mechanisms by which excessive ER stress triggers cell death and Ca(2+) dysregulation via the IRE1α-dependent signaling pathway. In this study, we show that inactivation of IRE1α by RNA interference increases cytosolic Ca(2+) concentration in SH-SY5Y cells, leading to cell death. This dysregulation is caused by an accelerated ER-to-cytosolic efflux of Ca(2+) through the InsP3 receptor (InsP3R). The Ca(2+) efflux in IRE1α-deficient cells correlates with dissociation of the Ca(2+)-binding InsP3R inhibitor CIB1 and increased complex formation of CIB1 with the pro-apoptotic kinase ASK1, which otherwise remains inactivated in the IRE1α-TRAF2-ASK1 complex. The increased cytosolic concentration of Ca(2+) induces mitochondrial production of reactive oxygen species (ROS), in particular superoxide, resulting in severe mitochondrial abnormalities, such as fragmentation and depolarization of membrane potential. These Ca(2+) dysregulation-induced mitochondrial abnormalities and cell death in IRE1α-deficient cells can be blocked by depleting ROS or inhibiting Ca(2+) influx into the mitochondria. These results demonstrate the importance of IRE1α in Ca(2+) homeostasis and cell survival during ER stress and reveal a previously unknown Ca(2+)-mediated cell death signaling between the IRE1α-InsP3R pathway in the ER and the redox-dependent apoptotic pathway in the mitochondrion.
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Hoefert, Sebastian; Sade Hoefert, Claudia; Munz, Adelheid; Schmitz, Inge; Grimm, Martin; Yuan, Anna; Northoff, Hinnak; Reinert, Siegmar; Alexander, Dorothea
2016-03-01
Immune deficiency and bacterial infection have been suggested to play a role in the pathophysiology of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Zoledronate was previously found to promote THP-1 cell death. To examine this hypothesis with all commonly prescribed bisphosphonates, we tested the effect of (nitrogen-containing) ibandronate, risedronate, alendronate, pamidronate, and (non-nitrogen-containing) clodronate on macrophagic THP-1 cells. Activated THP-1 cells were exposed to .5 to 50 μM of nitrogen-containing bisphosphonates and .5 to 500 μM of clodronate. Cell adherence and survival were assessed in vitro using the xCELLigence real-time monitoring system. Results were confirmed histologically and verified with Live/Dead staining. All bisphosphonates inhibited THP-1 cell adherence and survival dose and time dependently, significant for zoledronate, alendronate, pamidronate, and clodronate in high concentrations (50 μM and 500 μM; P THP-1 cell survival compared with controls (P THP-1 cells exhibited no cytomorphologic changes at all concentrations. Commonly prescribed bisphosphonates inhibit the survival of macrophagic THP-1 cells dose-dependently without altering morphology. This may suggest a local immune dysfunction reflective of individual bisphosphonate potency leading to the pathogenesis of BRONJ. Copyright © 2016 Elsevier Inc. All rights reserved.
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Metabolic profiling of hypoxic cells revealed a catabolic signature required for cell survival.
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Christian Frezza
Full Text Available Hypoxia is one of the features of poorly vascularised areas of solid tumours but cancer cells can survive in these areas despite the low oxygen tension. The adaptation to hypoxia requires both biochemical and genetic responses that culminate in a metabolic rearrangement to counter-balance the decrease in energy supply from mitochondrial respiration. The understanding of metabolic adaptations under hypoxia could reveal novel pathways that, if targeted, would lead to specific death of hypoxic regions. In this study, we developed biochemical and metabolomic analyses to assess the effects of hypoxia on cellular metabolism of HCT116 cancer cell line. We utilized an oxygen fluorescent probe in anaerobic cuvettes to study oxygen consumption rates under hypoxic conditions without the need to re-oxygenate the cells and demonstrated that hypoxic cells can maintain active, though diminished, oxidative phosphorylation even at 1% oxygen. These results were further supported by in situ microscopy analysis of mitochondrial NADH oxidation under hypoxia. We then used metabolomic methodologies, utilizing liquid chromatography-mass spectrometry (LC-MS, to determine the metabolic profile of hypoxic cells. This approach revealed the importance of synchronized and regulated catabolism as a mechanism of adaptation to bioenergetic stress. We then confirmed the presence of autophagy under hypoxic conditions and demonstrated that the inhibition of this catabolic process dramatically reduced the ATP levels in hypoxic cells and stimulated hypoxia-induced cell death. These results suggest that under hypoxia, autophagy is required to support ATP production, in addition to glycolysis, and that the inhibition of autophagy might be used to selectively target hypoxic regions of tumours, the most notoriously resistant areas of solid tumours.
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Ayanin diacetate-induced cell death is amplified by TRAIL in human leukemia cells
International Nuclear Information System (INIS)
Marrero, María Teresa; Estévez, Sara; Negrín, Gledy; Quintana, José; López, Mariana; Pérez, Francisco J.; Triana, Jorge; León, Francisco; Estévez, Francisco
2012-01-01
Highlights: ► Ayanin diacetate as apoptotic inducer in leukemia cells. ► Cell death was prevented by caspase inhibitors and by the overexpression of Bcl-x L . ► The intrinsic and the extrinsic pathways are involved in the mechanism of action. ► Death receptors are up-regulated and TRAIL enhances apoptotic cell death. -- Abstract: Here we demonstrate that the semi-synthetic flavonoid ayanin diacetate induces cell death selectively in leukemia cells without affecting the proliferation of normal lymphocytes. Incubation of human leukemia cells with ayanin diacetate induced G 2 -M phase cell cycle arrest and apoptosis which was prevented by the non-specific caspase inhibitor z-VAD-fmk and reduced by the overexpression of Bcl-x L . Ayanin diacetate-induced cell death was found to be associated with: (i) loss of inner mitochondrial membrane potential, (ii) the release of cytochrome c, (iii) the activation of multiple caspases, (iv) cleavage of poly(ADP-ribose) polymerase and (v) the up-regulation of death receptors for TRAIL, DR4 and DR5. Moreover, the combined treatment with ayanin diacetate and TRAIL amplified cell death, compared to single treatments. These results provide a basis for further exploring the potential applications of this combination for the treatment of cancer.
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Energy Technology Data Exchange (ETDEWEB)
Song, Chang W., E-mail: songx001@umn.edu [Department of Therapeutic Radiology-Radiation Oncology, University of Minnesota Medical School, Minneapolis, Minnesota (United States); Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Lee, Yoon-Jin [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Griffin, Robert J. [Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Park, Inhwan [Department of Therapeutic Radiology-Radiation Oncology, University of Minnesota Medical School, Minneapolis, Minnesota (United States); Koonce, Nathan A. [Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Hui, Susanta [Department of Therapeutic Radiology-Radiation Oncology, University of Minnesota Medical School, Minneapolis, Minnesota (United States); Kim, Mi-Sook [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Dusenbery, Kathryn E. [Department of Therapeutic Radiology-Radiation Oncology, University of Minnesota Medical School, Minneapolis, Minnesota (United States); Sperduto, Paul W. [Minneapolis Radiation Oncology and Gamma Knife Center, University of Minnesota, Minneapolis, Minnesota (United States); Cho, L. Chinsoo [Department of Therapeutic Radiology-Radiation Oncology, University of Minnesota Medical School, Minneapolis, Minnesota (United States)
2015-09-01
Purpose: The purpose of this study was to reveal the biological mechanisms underlying stereotactic body radiation therapy (SBRT) and stereotactic radiation surgery (SRS). Methods and Materials: FSaII fibrosarcomas grown subcutaneously in the hind limbs of C3H mice were irradiated with 10 to 30 Gy of X rays in a single fraction, and the clonogenic cell survival was determined with in vivo–in vitro excision assay immediately or 2 to 5 days after irradiation. The effects of radiation on the intratumor microenvironment were studied using immunohistochemical methods. Results: After cells were irradiated with 15 or 20 Gy, cell survival in FSaII tumors declined for 2 to 3 days and began to recover thereafter in some but not all tumors. After irradiation with 30 Gy, cell survival declined continuously for 5 days. Cell survival in some tumors 5 days after 20 to 30 Gy irradiation was 2 to 3 logs less than that immediately after irradiation. Irradiation with 20 Gy markedly reduced blood perfusion, upregulated HIF-1α, and increased carbonic anhydrase-9 expression, indicating that irradiation increased tumor hypoxia. In addition, expression of VEGF also increased in the tumor tissue after 20 Gy irradiation, probably due to the increase in HIF-1α activity. Conclusions: Irradiation of FSaII tumors with 15 to 30 Gy in a single dose caused dose-dependent secondary cell death, most likely by causing vascular damage accompanied by deterioration of intratumor microenvironment. Such indirect tumor cell death may play a crucial role in the control of human tumors with SBRT and SRS.
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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.
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Effects of ethanol on pancreatic beta-cell death: interaction with glucose and fatty acids.
Dembele, Korami; Nguyen, K Hoa; Hernandez, Tiffany A; Nyomba, B L Grégoire
2009-04-01
Western lifestyle plays an important role in the prevalence of type 2 diabetes by causing insulin resistance and pancreatic beta-cell dysfunction, a prerequisite for the development of diabetes. High fat diet and alcohol are major components of the western diet. The aim of the present study was to investigate the effects of ethanol and fatty acids on beta-cell survival and metabolism. We treated the rat beta-cell line RINm5F with ethanol, a mixture of palmitic and oleic acids, or both. Reactive oxygen species (ROS) were determined by (5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate) (CM-H2DCFDA) fluorescence assay, and mitochondrial activity was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) reduction assay and by determining ATP production. Cell viability was assessed with a cell counter and trypan blue exclusion, and the mode of cell death by Hoechst33342 and propidium iodide staining. With both ethanol and fatty acid treatments, MTT reduction and ATP production decreased, whereas ROS production increased. Ethanol treatment had no effect on cell number, whereas fatty acid treatment reduced the cell number. Cell incubation with ethanol, fatty acids, or both increased the number of Hoechst 33342-positive nuclei. However, the majority of nuclei from fatty acid-treated cells were stained with propidium iodide, indicating a loss of plasma membrane integrity. We conclude that both ethanol and fatty acids generate cellular oxidative stress, and affect mitochondrial function in RINm5F beta-cells. However, ethanol causes beta-cell death by apoptosis, whereas fatty acids cause cell death predominantly by necrosis. It is not known whether these results are applicable to human beta-cells.
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Directory of Open Access Journals (Sweden)
Mazen Alzaharna
Full Text Available Andrographolide (Andro has emerged recently as a potential and effective anticancer agent with induction of apoptosis in some cancer cell lines while induction of G2/M arrest with weak apoptosis in others. Few studies have proved that Andro is also effective in combination therapy. The flavonoid Taxifolin (Taxi has showed anti-oxidant and antiproliferative effects against different cancer cells. Therefore, the present study investigated the cytotoxic effects of Andro alone or in combination with Taxi on HeLa cells. The combination of Andro with Taxi was synergistic at all tested concentrations and combination ratios. Andro alone induced caspase-dependent apoptosis which was enhanced by the combination with Taxi and attenuated partly by using Z-Vad-Fmk. Andro induced a protective reactive oxygen species (ROS-dependent autophagy which was attenuated by Taxi. The activation of p53 was involved in Andro-induced autophagy where the use of Taxi or pifithrin-α (PFT-α decreased it while the activation of JNK was involved in the cell death of HeLa cells but not in the induction of autophagy. The mitochondrial outer-membrane permeabilization (MOMP plays an important role in Andro-induced cell death in HeLa cells. Andro alone increased the MOMP which was further increased in the case of combination. This led to the increase in AIF and cytochrome c release from mitochondria which consequently increased caspase-dependent and independent cell death. In conclusion, Andro induced a protective autophagy in HeLa cells which was reduced by Taxi and the cell death was increased by increasing the MOMP and subsequently the caspase-dependent and independent cell death.
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Alzaharna, Mazen; Alqouqa, Iyad; Cheung, Hon-Yeung
2017-01-01
Andrographolide (Andro) has emerged recently as a potential and effective anticancer agent with induction of apoptosis in some cancer cell lines while induction of G2/M arrest with weak apoptosis in others. Few studies have proved that Andro is also effective in combination therapy. The flavonoid Taxifolin (Taxi) has showed anti-oxidant and antiproliferative effects against different cancer cells. Therefore, the present study investigated the cytotoxic effects of Andro alone or in combination with Taxi on HeLa cells. The combination of Andro with Taxi was synergistic at all tested concentrations and combination ratios. Andro alone induced caspase-dependent apoptosis which was enhanced by the combination with Taxi and attenuated partly by using Z-Vad-Fmk. Andro induced a protective reactive oxygen species (ROS)-dependent autophagy which was attenuated by Taxi. The activation of p53 was involved in Andro-induced autophagy where the use of Taxi or pifithrin-α (PFT-α) decreased it while the activation of JNK was involved in the cell death of HeLa cells but not in the induction of autophagy. The mitochondrial outer-membrane permeabilization (MOMP) plays an important role in Andro-induced cell death in HeLa cells. Andro alone increased the MOMP which was further increased in the case of combination. This led to the increase in AIF and cytochrome c release from mitochondria which consequently increased caspase-dependent and independent cell death. In conclusion, Andro induced a protective autophagy in HeLa cells which was reduced by Taxi and the cell death was increased by increasing the MOMP and subsequently the caspase-dependent and independent cell death. PMID:28182713
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Miro, Caterina; Ambrosio, Raffaele; De Stefano, Maria Angela; Di Girolamo, Daniela; Di Cicco, Emery; Cicatiello, Annunziata Gaetana; Mancino, Giuseppina; Porcelli, Tommaso; Raia, Maddalena; Del Vecchio, Luigi; Salvatore, Domenico; Dentice, Monica
2017-04-01
Thyroid hormones (THs) mediate pleiotropic cellular processes involved in metabolism, cellular proliferation, and differentiation. The intracellular hormonal environment can be tailored by the type 1 and 2 deiodinase enzymes D2 and D3, which catalyze TH activation and inactivation respectively. In many cellular systems, THs exert well-documented stimulatory or inhibitory effects on cell proliferation; however, the molecular mechanisms by which they control rates of cell cycle progression have not yet been entirely clarified. We previously showed that D3 depletion or TH treatment influences the proliferation and survival of basal cell carcinoma (BCC) cells. Surprisingly, we also found that BCC cells express not only sustained levels of D3 but also robust levels of D2. The aim of the present study was to dissect the contribution of D2 to TH metabolism in the BCC context, and to identify the molecular changes associated with cell proliferation and survival induced by TH and mediated by D2 and D3. We used the CRISPR/Cas9 technology to genetically deplete D2 and D3 in BCC cells and studied the consequences of depletion on cell cycle progression and on cell death. Cell cycle progression was analyzed by fluorescence activated cell sorting analysis of synchronized cells, and the apoptosis rate by annexin V incorporation. Mechanistic investigations revealed that D2 inactivation accelerates cell cycle progression thereby enhancing the proportion of S-phase cells and cyclin D1 expression. Conversely, D3 mutagenesis drastically suppressed cell proliferation and enhanced apoptosis of BCC cells. Furthermore, the basal apoptotic rate was oppositely regulated in D2- and D3-depleted cells. Our results indicate that BCC cells constitute an example in which the TH signal is finely tuned by the concerted expression of opposite-acting deiodinases. The dual regulation of D2 and D3 expression plays a critical role in cell cycle progression and cell death by influencing cyclin D1-mediated
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Mihalj, Martina; Kellermayer, Zoltán; Balogh, Peter
2013-07-01
Although a substantial number of T cells may escape depletion following in vivo mAb treatment in patients undergoing immunosuppression, their specific tissue location and phenotypic characteristics in different peripheral lymphoid tissues have not been analyzed in detail. Here we investigated the survival of CD4(+) T cells immediately following anti-Thy-1 mAb treatment in mice. We found a preferential survival of CD4(+) T cells expressing Thy-1 antigen in the Peyer's patches (PP) and also in mesenteric lymph nodes (MLN), where the relative majority of the surviving CD4(+) T cells displayed CD44(high)/CD62L(-) phenotype corresponding to effector memory T-cell features. These CD4(+) T cells also expressed CXCR5 and PD-1 (programmed cell death-1) markers characteristic for follicular Th cells (TFH). We also demonstrate that the immediate survival of these cells does not involve proliferation and is independent of IL-7. Induction of germinal center formation in spleen enhanced while the dissolution of follicular architecture by lymphotoxin-β receptor antagonist treatment slightly reduced TFH survival. Our results thus raise the possibility that the follicles within PP and MLN may create natural support niches for the preferential survival of TFH cells of the memory phenotype, thus allowing their escape during T-cell depletion.
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Plant programmed cell death, ethylene and flower senescence
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
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Denardin, Cristiane C; Martins, Leo A M; Parisi, Mariana M; Vieira, Moema Queiroz; Terra, Silvia R; Barbé-Tuana, Florencia M; Borojevic, Radovan; Vizzotto, Márcia; Emanuelli, Tatiana; Guma, Fátima Costa Rodrigues
2017-04-01
Activated hepatic stellate cells (HSC) are the major source of collagen I in liver fibrosis. Eugenia uniflora L. is a tree species that is widely distributed in South America. E. uniflora L. fruit-popularly known as pitanga-has been shown to exert beneficial properties. Autophagy contributes to the maintenance of cellular homeostasis and survival under stress situation, but it has also been suggested to be an alternative cell death pathway. Mitochondria play a pivotal role on signaling cell death. Mitophagy of damaged mitochondria is an important cell defense mechanism against organelle-mediated cell death signaling. We previously found that purple pitanga extract induced mitochondrial dysfunction, cell cycle arrest, and death by apoptosis and necrosis in GRX cells, a well-established activated HSC line. We evaluated the effects of 72-h treatment with crescent concentrations of purple pitanga extract (5 to 100 μg/mL) on triggering autophagy in GRX cells, as this is an important mechanism to cells under cytotoxic conditions. We found that all treated cells presented an increase in the mRNA expression of autophagy-related protein 7 (ATG7). Concomitantly, flow cytometry and ultrastructural analysis of treated cells revealed an increase of autophagosomes/autolysosomes that consequentially led to an increased mitophagy. As purple pitanga extract was previously found to be broadly cytotoxic to GRX cells, we postulated that autophagy contributes to this scenario, where cell death seems to be an inevitable fate. Altogether, the effectiveness on inducing activated HSC death can make purple pitanga extract a good candidate on treating liver fibrosis.
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Multiple Modes of Cell Death Discovered in a Prokaryotic (Cyanobacterial) Endosymbiont
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
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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.
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Tracking plasma cell differentiation and survival.
Roth, Katrin; Oehme, Laura; Zehentmeier, Sandra; Zhang, Yang; Niesner, Raluca; Hauser, Anja E
2014-01-01
Plasma cells play a crucial role for the humoral immune response as they represent the body's factories for antibody production. The differentiation from a B cell into a plasma cell is controlled by a complex transcriptional network and happens within secondary lymphoid organs. Based on their lifetime, two types of antibody secreting cells can be distinguished: Short-lived plasma cells are located in extrafollicular sites of secondary lymphoid organs such as lymph node medullary cords and the splenic red pulp. A fraction of plasmablasts migrate from secondary lymphoid organs to the bone marrow where they can become long-lived plasma cells. Bone marrow plasma cells reside in special microanatomical environments termed survival niches, which provide factors promoting their longevity. Reticular stromal cells producing the chemokine CXCL12, which is known to attract plasmablasts to the bone marrow but also to promote plasma cell survival, play a crucial role in the maintenance of these niches. In addition, hematopoietic cells are contributing to the niches by providing other soluble survival factors. Here, we review the current knowledge on the factors involved in plasma cell differentiation, their localization and migration. We also give an overview on what is known regarding the maintenance of long lived plasma cells in survival niches of the bone marrow. © 2013 International Society for Advancement of Cytometry.
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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.
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Radiobilogical cell survival models
International Nuclear Information System (INIS)
Zackrisson, B.
1992-01-01
A central issue in clinical radiobiological research is the prediction of responses to different radiation qualities. The choice of cell survival and dose-response model greatly influences the results. In this context the relationship between theory and model is emphasized. Generally, the interpretations of experimental data depend on the model. Cell survival models are systematized with respect to their relations to radiobiological theories of cell kill. The growing knowlegde of biological, physical, and chemical mechanisms is reflected in the formulation of new models. The present overview shows that recent modelling has been more oriented towards the stochastic fluctuations connected to radiation energy deposition. This implies that the traditional cell surivival models ought to be complemented by models of stochastic energy deposition processes and repair processes at the intracellular level. (orig.)
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International Nuclear Information System (INIS)
Bonner, James A.; Vroman, Benjamin T.; Christianson, Teresa J.H.; Karnitz, Larry M.
1998-01-01
Purpose: Ionizing radiation (IR) triggers several intracellular signaling cascades that have commonly been regarded as mitogenic, including the Raf-MEK-Erk kinase cascade. In addition to promoting proliferation, activated MEK and Erk may also prevent cell death induced by cytotoxic stimuli. Because Raf, MEK, and Erk are activated by IR in some tumor cell lines, this suggests that IR-induced activation of the kinase cascade may enhance the survival of irradiated cells. Methods and Materials: IR-induced activation of MEK and Erk was assessed in irradiated UM-SCC-6 cells, a human squamous carcinoma cell line. Activation of MEK and Erk was blocked with the pharmacological inhibitor of MEK activation, PD098059. Clonogenic survival was assessed in irradiated UM-SCC-6 cells that were pretreated with nothing or with the MEK inhibitor. Results: In UM-SCC-6 cells, IR doses as low as 2 Gy rapidly activated MEK and Erk. Pretreatment of the cells with the pharmacological inhibitor of MEK activation, PD098059, effectively blocked IR-induced activation of MEK and Erk. However, inhibition of the kinase cascade did not affect the clonogenic survival of irradiated cells in either early or delayed-plating experiments. Conclusion: Taken together, these results suggest that although MEK and Erk are rapidly activated by IR treatment, these protein kinases do not affect the clonogenic survival of irradiated UM-SCC6 cells
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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.
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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.
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Energy Technology Data Exchange (ETDEWEB)
Vadhavkar, Nikhil [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Pham, Christopher [University of Texas, Houston, TX (United States). MD Anderson Cancer Center; Georgescu, Walter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Deschamps, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Heuskin, Anne-Catherine [Univ. of Namur (Belgium). Namur Research inst. for Life Sciences (NARILIS), Research Center for the Physics of Matter and Radiation (PMR); Tang, Jonathan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Costes, Sylvain V. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.
2014-09-01
In contrast to the classic view of static DNA double-strand breaks (DSBs) being repaired at the site of damage, we hypothesize that DSBs move and merge with each other over large distances (m). As X-ray dose increases, the probability of having DSB clusters increases as does the probability of misrepair and cell death. Experimental work characterizing the X-ray dose dependence of radiation-induced foci (RIF) in nonmalignant human mammary epithelial cells (MCF10A) is used here to validate a DSB clustering model. We then use the principles of the local effect model (LEM) to predict the yield of DSBs at the submicron level. Two mechanisms for DSB clustering, namely random coalescence of DSBs versus active movement of DSBs into repair domains are compared and tested. Simulations that best predicted both RIF dose dependence and cell survival after X-ray irradiation favored the repair domain hypothesis, suggesting the nucleus is divided into an array of regularly spaced repair domains of ~;;1.55 m sides. Applying the same approach to high-linear energy transfer (LET) ion tracks, we are able to predict experimental RIF/m along tracks with an overall relative error of 12percent, for LET ranging between 30 350 keV/m and for three different ions. Finally, cell death was predicted by assuming an exponential dependence on the total number of DSBs and of all possible combinations of paired DSBs within each simulated RIF. Relative biological effectiveness (RBE) predictions for cell survival of MCF10A exposed to high-LET showed an LET dependence that matches previous experimental results for similar cell types. Overall, this work suggests that microdosimetric properties of ion tracks at the submicron level are sufficient to explain both RIF data and survival curves for any LET, similarly to the LEM assumption. Conversely, high-LET death mechanism does not have to infer linear-quadratic dose formalism as done in the LEM. In addition, the size of repair domains derived in our model
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Signal transduction events in aluminum-induced cell death in tomato suspension cells
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.
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Modrek, Aram S; Hsu, Howard C; Leichman, Cynthia G; Du, Kevin L
2015-04-24
Small cell carcinoma of the rectum is a rare neoplasm with scant literature to guide treatment. We used the Surveillance Epidemiology and End Results (SEER) database to investigate the role of radiation therapy in the treatment of this cancer. The SEER database (National Cancer Institute) was queried for locoregional cases of small cell rectal cancer. Years of diagnosis were limited to 1988-2010 (most recent available) to reduce variability in staging criteria or longitudinal changes in surgery and radiation techniques. Two month conditional survival was applied to minimize bias by excluding patients who did not survive long enough to receive cancer-directed therapy. Patient demographics between the RT and No_RT groups were compared using Pearson Chi-Square tests. Overall survival was compared between patients who received radiotherapy (RT, n = 43) and those who did not (No_RT, n = 28) using the Kaplan-Meier method. Multivariate Cox proportional hazards model was used to evaluate important covariates. Median survival was significantly longer for patients who received radiation compared to those who were not treated with radiation; 26 mo vs. 8 mo, respectively (log-rank P = 0.009). We also noted a higher 1-year overall survival rate for those who received radiation (71.1% vs. 37.8%). Unadjusted hazard ratio for death (HR) was 0.495 with the use of radiation (95% CI 0.286-0.858). Among surgery, radiotherapy, sex and age at diagnosis, radiation therapy was the only significant factor for overall survival with a multivariate HR for death of 0.393 (95% CI 0.206-0.750, P = 0.005). Using SEER data, we have identified a significant survival advantage with the use of radiation therapy in the setting of rectal small cell carcinoma. Limitations of the SEER data apply to this study, particularly the lack of information on chemotherapy usage. Our findings strongly support the use of radiation therapy for patients with locoregional small cell rectal cancer.
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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.
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Gingerol sensitizes TRAIL-induced apoptotic cell death of glioblastoma cells
International Nuclear Information System (INIS)
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 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
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Sigvaldason, Kristinn; Ingvarsson, Thoroddur; Thordardottir, Svava; Kristinsson, Jakob; Karason, Sigurbergur
2014-10-01
Injecting drug abuse is a worldwide problem with serious consequences for the individual and for society. The purpose of this study was to gather information on the most serious complications of injecting drug use from two perspectives, intensive care admissions and forensic toxicology reports. Firstly, intensive care admissions related to injecting drug abuse during a five year period were reviewed for demographics, complications and 5 year survival. Secondly, information from forensic toxicology reports regarding deaths amongst known injecting drug abusers were gathered for the same period. A total of 57 patients with a history of active injecting drug use were admitted to intensive care or approximately 1% of admissions, most often for overdose (52%) or life threatening infections (39%). Median age was 26, males were 66%. The most common substances used were prescription drugs. Hospital mortality was 16% and five year survival 65%. Average time from hospital discharge to death was 916±858 days. During the study period 38 deaths of individuals with a history of injecting drugs were identified by forensic toxicology reports or 4.1/10(5) population/year (age 15-59). Cause of death was most often overdose (53%), usually from prescription opiates but multiple drug use was common. The life expectancy of injecting drug abusers after intensive care admission is substantially decreased, with 35% death rate within five years. A widespread use of prescription drugs is of concern. Injecting drug abuse seems to be a similar health problem in magnitude in Iceland as in other Scandinavian countries.
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Epidermal cell death in frogs with chytridiomycosis
Directory of Open Access Journals (Sweden)
Laura A. Brannelly
2017-02-01
Full Text Available Background Amphibians are declining at an alarming rate, and one of the major causes of decline is the infectious disease chytridiomycosis. Parasitic fungal sporangia occur within epidermal cells causing epidermal disruption, but these changes have not been well characterised. Apoptosis (planned cell death can be a damaging response to the host but may alternatively be a mechanism of pathogen removal for some intracellular infections. Methods In this study we experimentally infected two endangered amphibian species Pseudophryne corroboree and Litoria verreauxii alpina with the causal agent of chytridiomycosis. We quantified cell death in the epidermis through two assays: terminal transferase-mediated dUTP nick end-labelling (TUNEL and caspase 3/7. Results Cell death was positively associated with infection load and morbidity of clinically infected animals. In infected amphibians, TUNEL positive cells were concentrated in epidermal layers, correlating to the localisation of infection within the skin. Caspase activity was stable and low in early infection, where pathogen loads were light but increasing. In animals that recovered from infection, caspase activity gradually returned to normal as the infection cleared. Whereas, in amphibians that did not recover, caspase activity increased dramatically when infection loads peaked. Discussion Increased cell death may be a pathology of the fungal parasite, likely contributing to loss of skin homeostatic functions, but it is also possible that apoptosis suppression may be used initially by the pathogen to help establish infection. Further research should explore the specific mechanisms of cell death and more specifically apoptosis regulation during fungal infection.
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Crystalline structure of pulverized dental calculus induces cell death in oral epithelial cells.
Ziauddin, S M; Yoshimura, A; Montenegro Raudales, J L; Ozaki, Y; Higuchi, K; Ukai, T; Kaneko, T; Miyazaki, T; Latz, E; Hara, Y
2018-06-01
Dental calculus is a mineralized deposit attached to the tooth surface. We have shown that cellular uptake of dental calculus triggers nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation, leading to the processing of the interleukin-1β precursor into its mature form in mouse and human phagocytes. The activation of the NLRP3 inflammasome also induced a lytic form of programmed cell death, pyroptosis, in these cells. However, the effects of dental calculus on other cell types in periodontal tissue have not been investigated. The aim of this study was to determine whether dental calculus can induce cell death in oral epithelial cells. HSC-2 human oral squamous carcinoma cells, HOMK107 human primary oral epithelial cells and immortalized mouse macrophages were exposed to dental calculus or 1 of its components, hydroxyapatite crystals. For inhibition assays, the cells were exposed to dental calculus in the presence or absence of cytochalasin D (endocytosis inhibitor), z-YVAD-fmk (caspase-1 inhibitor) or glyburide (NLRP3 inflammasome inhibitor). Cytotoxicity was determined by measuring lactate dehydrogenase (LDH) release and staining with propidium iodide. Tumor necrosis factor-α production was quantified by enzyme-linked immunosorbent assay. Oral epithelial barrier function was examined by permeability assay. Dental calculus induced cell death in HSC-2 cells, as judged by LDH release and propidium iodide staining. Dental calculus also induced LDH release from HOMK107 cells. Following heat treatment, dental calculus lost its capacity to induce tumor necrosis factor-α in mouse macrophages, but could induce LDH release in HSC-2 cells, indicating a major role of inorganic components in cell death. Hydroxyapatite crystals also induced cell death in both HSC-2 and HOMK107 cells, as judged by LDH release, indicating the capacity of crystal particles to induce cell death. Cell death induced by dental
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Lahlali, Thomas; Plissonnier, Marie-Laure; Romero-López, Cristina; Michelet, Maud; Ducarouge, Benjamin; Berzal-Herranz, Alfredo; Zoulim, Fabien; Mehlen, Patrick; Parent, Romain
2016-05-01
Netrin-1, a multifunctional secreted protein, is up-regulated in cancer and inflammation. Netrin-1 blocks apoptosis induced by the prototypical dependence receptors deleted in colorectal carcinoma and uncoordinated phenotype-5. Although the unfolded protein response (UPR) triggers apoptosis on exposure to stress, it first attempts to restore endoplasmic reticulum homeostasis to foster cell survival. Importantly, UPR is implicated in chronic liver conditions including hepatic oncogenesis. Netrin-1's implication in cell survival on UPR in this context is unknown. Isolation of translational complexes, determination of RNA secondary structures by selective 2'-hydroxyl acylation and primer extension/dimethyl sulfate, bicistronic constructs, as well as conventional cell biology and biochemistry approaches were used on in vitro-grown hepatocytic cells, wild-type, and netrin-1 transgenic mice. HepaRG cells constitute a bona fide model for UPR studies in vitro through adequate activation of the 3 sensors of the UPR (protein kinase RNA-like endoplasmic reticulum kinase (PERK)), inositol requiring enzyme 1α (IRE1α), and activated transcription factor 6 (ATF6). The netrin-1 messenger RNA 5'-end was shown to fold into a complex double pseudoknot and bear E-loop motifs, both of which are representative hallmarks of related internal ribosome entry site regions. Cap-independent translation of netrin 5' untranslated region-driven luciferase was observed on UPR in vitro. Unlike several structurally related oncogenic transcripts (l-myc, c-myc, c-myb), netrin-1 messenger RNA was selected for translation during UPR both in human hepatocytes and in mice livers. Depletion of netrin-1 during UPR induces apoptosis, leading to cell death through an uncoordinated phenotype-5A/C-mediated involvement of protein phosphatase 2A and death-associated protein kinase 1 in vitro and in netrin transgenic mice. UPR-resistant, internal ribosome entry site-driven netrin-1 translation leads to
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Directory of Open Access Journals (Sweden)
Wells David
2011-02-01
Full Text Available Abstract Background Fragile X syndrome (FXS, the most commonly inherited mental retardation and single gene cause of autistic spectrum disorder, occurs when the Fmr1 gene is mutated. The product of Fmr1, fragile X linked mental retardation protein (FMRP is widely expressed in HeLa cells, however the roles of FMRP within HeLa cells were not elucidated, yet. Interacting with a diverse range of mRNAs related to cellular survival regulatory signals, understanding the functions of FMRP in cellular context would provide better insights into the role of this interesting protein in FXS. Using HeLa cells treated with etoposide as a model, we tried to determine whether FMRP could play a role in cell survival. Methods Apoptotic cell death was induced by etoposide treatment on Hela cells. After we transiently modulated FMRP expression (silencing or enhancing by using molecular biotechnological methods such as small hairpin RNA virus-induced knock down and overexpression using transfection with FMRP expression vectors, cellular viability was measured using propidium iodide staining, TUNEL staining, and FACS analysis along with the level of activation of PI3K-Akt pathway by Western blot. Expression level of FMRP and apoptotic regulator BcL-xL was analyzed by Western blot, RT-PCR and immunocytochemistry. Results An increased FMRP expression was measured in etoposide-treated HeLa cells, which was induced by PI3K-Akt activation. Without FMRP expression, cellular defence mechanism via PI3K-Akt-Bcl-xL was weakened and resulted in an augmented cell death by etoposide. In addition, FMRP over-expression lead to the activation of PI3K-Akt signalling pathway as well as increased FMRP and BcL-xL expression, which culminates with the increased cell survival in etoposide-treated HeLa cells. Conclusions Taken together, these results suggest that FMRP expression is an essential part of cellular survival mechanisms through the modulation of PI3K, Akt, and Bcl-xL signal
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A Novel Role of Listeria monocytogenes Membrane Vesicles in Inhibition of Autophagy and Cell Death.
Vdovikova, Svitlana; Luhr, Morten; Szalai, Paula; Nygård Skalman, Lars; Francis, Monika K; Lundmark, Richard; Engedal, Nikolai; Johansson, Jörgen; Wai, Sun N
2017-01-01
Bacterial membrane vesicle (MV) production has been mainly studied in Gram-negative species. In this study, we show that Listeria monocytogenes , a Gram-positive pathogen that causes the food-borne illness listeriosis, produces MVs both in vitro and in vivo . We found that a major virulence factor, the pore-forming hemolysin listeriolysin O (LLO), is tightly associated with the MVs, where it resides in an oxidized, inactive state. Previous studies have shown that LLO may induce cell death and autophagy. To monitor possible effects of LLO and MVs on autophagy, we performed assays for LC3 lipidation and LDH sequestration as well as analysis by confocal microscopy of HEK293 cells expressing GFP-LC3. The results revealed that MVs alone did not affect autophagy whereas they effectively abrogated autophagy induced by pure LLO or by another pore-forming toxin from Vibrio cholerae , VCC. Moreover, Listeria monocytogenes MVs significantly decreased Torin1-stimulated macroautophagy. In addition, MVs protected against necrosis of HEK293 cells caused by the lytic action of LLO. We explored the mechanisms of LLO-induced autophagy and cell death and demonstrated that the protective effect of MVs involves an inhibition of LLO-induced pore formation resulting in inhibition of autophagy and the lytic action on eukaryotic cells. Further, we determined that these MVs help bacteria to survive inside eukaryotic cells (mouse embryonic fibroblasts). Taken together, these findings suggest that intracellular release of MVs from L. monocytogenes may represent a bacterial strategy to survive inside host cells, by its control of LLO activity and by avoidance of destruction from the autophagy system during infection.
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A Novel Role of Listeria monocytogenes Membrane Vesicles in Inhibition of Autophagy and Cell Death
Directory of Open Access Journals (Sweden)
Svitlana Vdovikova
2017-05-01
Full Text Available Bacterial membrane vesicle (MV production has been mainly studied in Gram-negative species. In this study, we show that Listeria monocytogenes, a Gram-positive pathogen that causes the food-borne illness listeriosis, produces MVs both in vitro and in vivo. We found that a major virulence factor, the pore-forming hemolysin listeriolysin O (LLO, is tightly associated with the MVs, where it resides in an oxidized, inactive state. Previous studies have shown that LLO may induce cell death and autophagy. To monitor possible effects of LLO and MVs on autophagy, we performed assays for LC3 lipidation and LDH sequestration as well as analysis by confocal microscopy of HEK293 cells expressing GFP-LC3. The results revealed that MVs alone did not affect autophagy whereas they effectively abrogated autophagy induced by pure LLO or by another pore-forming toxin from Vibrio cholerae, VCC. Moreover, Listeria monocytogenes MVs significantly decreased Torin1-stimulated macroautophagy. In addition, MVs protected against necrosis of HEK293 cells caused by the lytic action of LLO. We explored the mechanisms of LLO-induced autophagy and cell death and demonstrated that the protective effect of MVs involves an inhibition of LLO-induced pore formation resulting in inhibition of autophagy and the lytic action on eukaryotic cells. Further, we determined that these MVs help bacteria to survive inside eukaryotic cells (mouse embryonic fibroblasts. Taken together, these findings suggest that intracellular release of MVs from L. monocytogenes may represent a bacterial strategy to survive inside host cells, by its control of LLO activity and by avoidance of destruction from the autophagy system during infection.
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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.
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Rehn, Marius; Weaver, Anne; Brohi, Karim; Eshelby, Sarah; Green, Laura; Røislien, Jo; Lockey, David J
2018-04-16
Current management principles of haemorrhagic shock after trauma emphasize earlier transfusion therapy to prevent dilution of clotting factors and correct coagulopathy. London's air ambulance (LAA) was the first UK civilian pre-hospital service to routinely offer pre-hospital red blood cell (RBC) transfusion (phRTx). We investigated the effect of phRTx on mortality. Retrospective trauma database study comparing mortality before-implementation with after-implementation of phRTx in exsanguinating trauma patients. Univariate logistic regression was performed for the unadjusted association between phRTx and mortality was performed, and multiple logistic regression adjusting for potential confounders. We identified 623 subjects with suspected major haemorrhage. We excluded 84 (13.5%) patients due to missing data on survival status. Overall 187 (62.3%) patients died in the before phRTx period and 143 (59.8%) died in the after phRTx group. There was no significant improvement in overall survival after the introduction of phRTx (p = 0.554). Examination of pre-hospital mortality demonstrated 126 deaths in the pre-phRTx group (42.2%) and 66 deaths in the RBC administered group (27.6%) There was a significant reduction in pre-hospital mortality in the group who received RBC (p < 0.001). phRTx was associated with increased survival to hospital, but not overall survival. The "delay death" effect of phRTx carries an impetus to further develop in-hospital strategies to improve survival in severely bleeding patients.
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Cyclophilin B Supports Myc and Mutant p53 Dependent Survival of Glioblastoma Multiforme Cells
Choi, Jae Won; Schroeder, Mark A.; Sarkaria, Jann N.; Bram, Richard J.
2014-01-01
Glioblastoma multiforme (GBM) is an aggressive, treatment-refractory type of brain tumor for which effective therapeutic targets remain important to identify. Here we report that cyclophilin B (CypB), a prolyl isomerase residing in the endoplasmic reticulum (ER), provides an essential survival signal in GBM cells. Analysis of gene expression databases revealed that CypB is upregulated in many cases of malignant glioma. We found that suppression of CypB reduced cell proliferation and survival in human GBM cells in vitro and in vivo. We also found that treatment with small molecule inhibitors of cyclophilins, including the approved drug cyclosporine, greatly reduced the viability of GBM cells. Mechanistically, depletion or pharmacologic inhibition of CypB caused hyperactivation of the oncogenic RAS-MAPK pathway, induction of cellular senescence signals, and death resulting from loss of MYC, mutant p53, Chk1 and JAK/STAT3 signaling. Elevated reactive oxygen species, ER expansion and abnormal unfolded protein responses in CypB-depleted GBM cells indicated that CypB alleviates oxidative and ER stresses and coordinates stress adaptation responses. Enhanced cell survival and sustained expression of multiple oncogenic proteins downstream of CypB may thus contribute to the poor outcome of GBM tumors. Our findings link chaperone-mediated protein folding in the ER to mechanisms underlying oncogenic transformation, and they make CypB an attractive and immediately targetable molecule for GBM therapy. PMID:24272483
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Energy Technology Data Exchange (ETDEWEB)
Lee, B [Northwestern Memorial Hospital, Chicago, IL (United States); Georgia Institute of Technology, Atlanta, GA (Georgia); Wang, C [Georgia Institute of Technology, Atlanta, GA (Georgia)
2016-06-15
Purpose: To correlate the damage produced by particles of different types and qualities to cell survival on the basis of nanodosimetric analysis and advanced DNA structures in the cell nucleus. Methods: A Monte Carlo code was developed to simulate subnuclear DNA chromatin fibers (CFs) of 30nm utilizing a mean-free-path approach common to radiation transport. The cell nucleus was modeled as a spherical region containing 6000 chromatin-dense domains (CDs) of 400nm diameter, with additional CFs modeled in a sparser interchromatin region. The Geant4-DNA code was utilized to produce a particle track database representing various particles at different energies and dose quantities. These tracks were used to stochastically position the DNA structures based on their mean free path to interaction with CFs. Excitation and ionization events intersecting CFs were analyzed using the DBSCAN clustering algorithm for assessment of the likelihood of producing DSBs. Simulated DSBs were then assessed based on their proximity to one another for a probability of inducing cell death. Results: Variations in energy deposition to chromatin fibers match expectations based on differences in particle track structure. The quality of damage to CFs based on different particle types indicate more severe damage by high-LET radiation than low-LET radiation of identical particles. In addition, the model indicates more severe damage by protons than of alpha particles of same LET, which is consistent with differences in their track structure. Cell survival curves have been produced showing the L-Q behavior of sparsely ionizing radiation. Conclusion: Initial results indicate the feasibility of producing cell survival curves based on the Monte Carlo cell nucleus method. Accurate correlation between simulated DNA damage to cell survival on the basis of nanodosimetric analysis can provide insight into the biological responses to various radiation types. Current efforts are directed at producing cell
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Machihara, Kayo; Tanaka, Hidenori; Hayashi, Yoshihiro; Murakami, Ichiro; Namba, Takushi
2017-10-07
Hepatocellular carcinoma (HCC) is one of the most difficult cancers to treat owing to the lack of effective chemotherapeutic methods. Sorafenib, the first-line and only available treatment for HCC, extends patient overall survival by several months, with a response rate below 10%. Thus, the identification of an agent that enhances the anticancer effect of sorafenib is critical for the development of therapeutic options for HCC. Endoplasmic reticulum (ER) stress response is one of the methods of sorafenib-induced cell death. Here we report that questiomycin A suppresses expression of GRP78, a cell-protective ER chaperone protein. Analysis of the molecular mechanisms of questiomycin A revealed that this compound stimulated GRP78 protein degradation in an ER stress response-independent manner. Cotreatment with sorafenib and questiomycin A suppressed GRP78 protein expression, which is essential for the stimulation of sorafenib-induced cell death. Moreover, our in vivo study demonstrated that the coadministration of sorafenib and questiomycin A suppressed tumor formation in HCC-induced xenograft models. These results suggest that cotreatment with sorafenib and questiomycin A is a novel therapeutic strategy for HCC by enhancing sorafenib-dependent ER stress-induced cell death, and downregulation of GRP78 is a new target for the stimulation of the therapeutic effects of sorafenib in HCC. Copyright © 2017 Elsevier Inc. All rights reserved.
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IL22/IL-22R pathway induces cell survival in human glioblastoma cells.
Directory of Open Access Journals (Sweden)
Hussein Akil
Full Text Available Interleukin-22 (IL-22 is a member of the IL-10 cytokine family that binds to a heterodimeric receptor consisting of IL-22 receptor 1 (IL-22R1 and IL-10R2. IL-22R expression was initially characterized on epithelial cells, and plays an essential role in a number of inflammatory diseases. Recently, a functional receptor was detected on cancer cells such as hepatocarcinoma and lung carcinoma, but its presence was not reported in glioblastoma (GBM. Two GBM cell lines and 10 primary cell lines established from patients undergoing surgery for malignant GBM were used to investigate the expression of IL-22 and IL-22R by using quantitative RT-PCR, western blotting and confocal microscopy studies. The role of IL-22 in proliferation and survival of GBM cell lines was investigated in vitro by BrdU and ELISA cell death assays. We report herein that the two subunits of the IL-22R complex are expressed on human GBM cells. Their activation, depending on exogenous IL-22, induced antiapoptotic effect and cell proliferation. IL-22 treatment of GBM cells resulted in increased levels of phosphorylated Akt, STAT3 signaling protein and its downstream antiapoptotic protein Bcl-xL and decreased level of phosphorylated ERK1/2. In addition, IL-22R subunits were expressed in all the 10 tested primary cell lines established from GBM tumors. Our results showed that IL-22R is expressed on GBM established and primary cell lines. Depending on STAT3, ERK1/2 and PI3K/Akt pathways, IL-22 induced GBM cell survival. These data are consistent with a potential role of IL-22R in tumorigenesis of GBM. Since endogenous IL-22 was not detected in all studied GBM cells, we hypothesize that IL-22R could be activated by immune microenvironmental IL-22 producing cells.
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Is radiation-induced cell death in mouse testis apoptosis?
International Nuclear Information System (INIS)
Hasegawa, Masatoshi; Wilson, Gene; Yun Zhang; Russell, Lonnie D.; Meistrich, Marvin L.
1996-01-01
Purpose: Radiation-induced death of spermatogonia and other germ cells in the testis has been claimed to be by an apoptotic mechanism, but these processes have been incompletely characterized. We investigated irradiated mouse testis by multiple techniques to determine whether the mode of cell death of spermatogonia can be classified as apoptosis. Materials and Methods: Adult male C57BL/6 and p53 knockout mice were irradiated with single doses of 0.5, 2.5 or 5.0 Gy. Four, 6, 8, 12, 18 or 24 hours after irradiation, testes were fixed in Bouin's solution or in 10% formalin. Slides were stained with hematoxylin and eosin or TdT-mediated dUTP-biotin nick end labeling (TUNEL). Some testes were perfusion-fixed with 5% glutaraldehyde for electron microscopy. Gel electrophoresis of DNA was also performed to identify DNA fragmentation. The number of sperm heads was counted 29 days after irradiation to evaluate the effect of radiation on the eventual survival of the differentiated spermatogonia. Results: The earliest sign of histological damage was an increase in the numbers of abnormal spermatogonia in the seminiferous tubules, particularly in stage I-VI of the seminiferous epithelial cycle. The numbers of abnormal spermatogonia began to increase at 6 hours, reached a peak 12 hours after irradiation, and then declined. The total number of spermatogonia began to decrease at 12 hours after irradiation, resulting in a 60% decline in sperm produced 29 days after 0.5 Gy. Although changes were greatest following 5.0 Gy irradiation, even 0.5 Gy induced marked changes. However, these changes were not induced in p53 knockout mice. By both light and electron microscopy, spermatogonia showed some condensation of nuclear chromatin, but margination of chromatin with clear delineation and nuclear fragmentation was rare. Many of the abnormal spermatogonia showed a positive TUNEL reaction, which was also at a maximum at 12 hours after irradiation. In addition, some TUNEL-positive and
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Gou, Xingchun; Tang, Xu; Kong, Derek Kai; He, Xinying; Gao, Xingchun; Guo, Na; Hu, Zhifang; Zhao, Zhaohua; Chen, Yanke
2016-01-01
Transarterial chemoembolization (TACE) is the standard of care for treatment of intermediate hepatocellular carcinoma (HCC), however, key molecules involved in HCC cell survival and tumor metastasis post-TACE remain unclear. CD147 is a member of the immunoglobulin superfamily that is overexpressed on the surface of HCC cells and is associated with malignant potential and poor prognosis in HCC patients. In this study, using an Earle's Balanced Salt Solution medium culture model that mimics nutrient deprivation induced by TACE, we investigated the regulation of CD147 expression on HCC cells under starvation conditions and its functional effects on HCC cell death. During early stages of starvation, the expression of CD147 was considerably upregulated in SMMC7721, HepG2 and HCC9204 hepatoma cell lines at the protein levels. Downregulation of CD147 by specific small interfering RNA (siRNA) significantly promoted starvation-induced cell death. In addition, CD147 siRNA-transfected SMMC7721 cells demonstrated significantly increased levels of both apoptosis and autophagy as compared to cells transfected with control siRNA under starvation conditions, whereas no difference was observed between the two treatment groups under normal culture conditions. Furthermore, silencing of CD147 resulted in a remarkable downregulation of phosphorylated mammalian target of rapamycin (p-mTOR) in starved SMMC7721 cells. Finally, the combined treatment of starvation and anti-CD147 monoclonal antibody exhibited a synergistic HCC cell killing effect. Our study suggests that upregulation of CD147 under starvation may reduce hepatoma cell death by modulating both apoptosis and autophagy through mTOR signaling, and that CD147 may be a novel potential molecular target to improve the efficacy of TACE.
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Directory of Open Access Journals (Sweden)
Kholoud Arafat
Full Text Available A major challenge for oncologists and pharmacologists is to develop more potent and less toxic drugs that will decrease the tumor growth and improve the survival of lung cancer patients. Salinomycin is a polyether antibiotic used to kill gram-positive bacteria including mycobacteria, protozoans such as plasmodium falciparum, and the parasites responsible for the poultry disease coccidiosis. This old agent is now a serious anti-cancer drug candidate that selectively inhibits the growth of cancer stem cells. We investigated the impact of salinomycin on survival, colony growth, migration and invasion of the differentiated human non-small cell lung cancer lines LNM35 and A549. Salinomycin caused concentration- and time-dependent reduction in viability of LNM35 and A549 cells through a caspase 3/7-associated cell death pathway. Similarly, salinomycin (2.5-5 µM for 7 days significantly decreased the growth of LNM35 and A549 colonies in soft agar. Metastasis is the main cause of death related to lung cancer. In this context, salinomycin induced a time- and concentration-dependent inhibition of cell migration and invasion. We also demonstrated for the first time that salinomycin induced a marked increase in the expression of the pro-apoptotic protein NAG-1 leading to the inhibition of lung cancer cell invasion but not cell survival. These findings identify salinomycin as a promising novel therapeutic agent for lung cancer.
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Triglyceride-induced macrophage cell death is triggered by caspase-1.
Son, Sin Jee; Rhee, Ki-Jong; Lim, Jaewon; Kim, Tae Ue; Kim, Tack-Joong; Kim, Yoon Suk
2013-01-01
Triglyceride (TG) induces macrophage cell death which contributes to the development of atherosclerosis. We confirmed that exogenous TG accumulates in human THP-1 macrophages and causes cell death. TG treated THP-1 macrophages exhibited no change in tumor necrosis factor (TNF)-α, interleukin (IL)-18, macrophage inflammatory protein (MIP)-1α, and IL-1R1 receptor mRNA expression. However, there was a marked decrease in IL-1β mRNA expression but an increase in IL-1β protein secretion. Decreased expression of IL-1β mRNA and increased secretion of IL-1β protein was not the direct cause of cell death. Until now, TG was assumed to induce necrotic cell death in macrophages. Since caspase-1 is known to be involved in activation and secretion of IL-1β protein and pyroptotic cell death, next we determined whether caspase-1 is associated with TG-induced macrophage cell death. We found an increase in caspase-1 activity in TG-treated THP-1 macrophages and inhibition of caspase-1 activity using a specific inhibitor partially rescued cell death. These results suggest activation of the pyroptotic pathway by TG. This is the first report implicating the activation of caspase-1 and the triggering of the pyroptosis pathway in TG-induced macrophage cell death.
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Mechanical Stress Promotes Cisplatin-Induced Hepatocellular Carcinoma Cell Death
Riad, Sandra; Bougherara, Habiba
2015-01-01
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). PMID:25685789
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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.
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International Nuclear Information System (INIS)
Seidl, Christof; Schroeck, Hedwig; Seidenschwang, Sabine; Beck, Roswitha; Schwaiger, Markus; Senekowitsch-Schmidtke, Reingard; Schmid, Ernst; Abend, Michael; Becker, Karl-Friedrich; Apostolidis, Christos; Nikula, Tuomo K.; Kremmer, Elisabeth
2005-01-01
Radioimmunotherapy with α-particle-emitting nuclides, such as 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 213 Bi-immunoconjugates. Human gastric cancer cells (HSC45-M2) expressing d9-E-cadherin were incubated with different levels of activity of 213 Bi-d9MAb targeting d9-E-cadherin and 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 213 Bi-d9MAb. Activation of caspase 3 after incubation of HSC45-M2 cells with both sorbitol and 213 Bi-d9MAb was analysed via Western blotting. Following incubation of HSC45-M2 human gastric cancer cells expressing d9-E-cadherin with 213 Bi-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 213 Bi-d9MAb compared with unspecific 213 Bi-d8MAb (not targeting d9-E-cadherin) was not observed if the number of floating, i.e. unbound 213 Bi-immunoconjugates per cell exceeded 2 x 10 4 , most likely due to intense crossfire. In contrast to sorbitol-induced cell death, cell death triggered by 213 Bi-immunoconjugates was independent of caspase 3 activation and could not be inhibited by z-VAD-fmk, known to suppress the apoptotic pathway. 213 Bi-immunoconjugates seem to induce a mode of cell death different from apoptosis in HSC45-M2 cells
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Guidelines and recommendations on yeast cell death nomenclature
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Didac Carmona-Gutierrez
2018-01-01
Full Text Available Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differential definition of terms including apoptosis, regulated necrosis, and autophagic cell death, as we refer to additional cell death routines that are relevant for the biology of (at least some species of yeast. As this area of investigation advances rapidly, changes and extensions to this set of recommendations will be implemented in the years to come. Nonetheless, we strongly encourage the authors, reviewers and editors of scientific articles to adopt these collective standards in order to establish an accurate framework for yeast cell death research and, ultimately, to accelerate the progress of this vibrant field of research.
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Guidelines and recommendations on yeast cell death nomenclature
Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andrés; Austriaco, Nicanor; Ayscough, Kathryn; Balzan, Rena; Bar-Nun, Shoshana; Barrientos, Antonio; Belenky, Peter; Blondel, Marc; Braun, Ralf J.; Breitenbach, Michael; Burhans, William C.; Büttner, Sabrina; Cavalieri, Duccio; Chang, Michael; Cooper, Katrina F.; Côrte-Real, Manuela; Costa, Vítor; Cullin, Christophe; Dawes, Ian; Dengjel, Jörn; Dickman, Martin B.; Eisenberg, Tobias; Fahrenkrog, Birthe; Fasel, Nicolas; Fröhlich, Kai-Uwe; Gargouri, Ali; Giannattasio, Sergio; Goffrini, Paola; Gourlay, Campbell W.; Grant, Chris M.; Greenwood, Michael T.; Guaragnella, Nicoletta; Heger, Thomas; Heinisch, Jürgen; Herker, Eva; Herrmann, Johannes M.; Hofer, Sebastian; Jiménez-Ruiz, Antonio; Jungwirth, Helmut; Kainz, Katharina; Kontoyiannis, Dimitrios P.; Ludovico, Paula; Manon, Stéphen; Martegani, Enzo; Mazzoni, Cristina; Megeney, Lynn A.; Meisinger, Chris; Nielsen, Jens; Nyström, Thomas; Osiewacz, Heinz D.; Outeiro, Tiago F.; Park, Hay-Oak; Pendl, Tobias; Petranovic, Dina; Picot, Stephane; Polčic, Peter; Powers, Ted; Ramsdale, Mark; Rinnerthaler, Mark; Rockenfeller, Patrick; Ruckenstuhl, Christoph; Schaffrath, Raffael; Segovia, Maria; Severin, Fedor F.; Sharon, Amir; Sigrist, Stephan J.; Sommer-Ruck, Cornelia; Sousa, Maria João; Thevelein, Johan M.; Thevissen, Karin; Titorenko, Vladimir; Toledano, Michel B.; Tuite, Mick; Vögtle, F.-Nora; Westermann, Benedikt; Winderickx, Joris; Wissing, Silke; Wölfl, Stefan; Zhang, Zhaojie J.; Zhao, Richard Y.; Zhou, Bing; Galluzzi, Lorenzo; Kroemer, Guido; Madeo, Frank
2018-01-01
Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differential definition of terms including apoptosis, regulated necrosis, and autophagic cell death, as we refer to additional cell death routines that are relevant for the biology of (at least some species of) yeast. As this area of investigation advances rapidly, changes and extensions to this set of recommendations will be implemented in the years to come. Nonetheless, we strongly encourage the authors, reviewers and editors of scientific articles to adopt these collective standards in order to establish an accurate framework for yeast cell death research and, ultimately, to accelerate the progress of this vibrant field of research. PMID:29354647
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Regulatory dendritic cell infusion prolongs kidney allograft survival in non-human primates
Ezzelarab, M.; Zahorchak, A.F.; Lu, L.; Morelli, A.E.; Chalasani, G.; Demetris, A.J.; Lakkis, F.G.; Wijkstrom, M.; Murase, N.; Humar, A.; Shapiro, R.; Cooper, D.K.C.; Thomson, A.W.
2013-01-01
We examined the influence of regulatory dendritic cells (DCreg), generated from cytokine-mobilized donor blood monocytes in vitamin D3 and IL-10, on renal allograft survival in a clinically-relevant rhesus macaque model. DCreg expressed low MHC class II and costimulatory molecules, but comparatively high levels of programmed death ligand-1 (B7-H1), and were resistant to pro-inflammatory cytokine-induced maturation. They were infused intravenously (3.5–10×106/kg), together with the B7-CD28 cos...
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Important prognostic factors for the long-term survival of lung cancer subjects in Taiwan
International Nuclear Information System (INIS)
Chiang, Tai-An; Chen, Ping-Ho; Wu, Pei-Fen; Wang, Tsu-Nai; Chang, Po-Ya; Ko, Albert Min-Shan; Huang, Ming-Shyan; Ko, Ying-Chin
2008-01-01
This study used a large-scale cancer database in determination of prognostic factors for the survival of lung cancer subjects in Taiwan. Total of 24,910 subjects diagnosed with lung cancer was analysed. Survival estimates by Kaplan-Meier methods. Cox proportional-hazards model estimated the death risk (hazard ratio (HR)) for various prognostic factors. The prognostic indicators associated with a higher risk of lung cancer deaths are male gender (males versus females; HR = 1.07, 95% confidence intervals (CI): 1.03–1.11), males diagnosed in later periods (shown in 1991–1994 versus 1987–1990; HR = 1.13), older age at diagnosis, large cell carcinoma (LCC)/small cell carcinoma (SCC), and supportive care therapy over chemotherapy. The overall 5-year survival rate for lung cancer death was significantly poorer for males (21.3%) than females (23.6%). Subjects with squamous cell carcinoma (SQCC) and treatment by surgical resection alone had better prognosis. We find surgical resections to markedly increase 5-year survival rate from LCC, decreased risk of death from LCC, and no improved survival from SCC. Gender and clinical characteristics (i.e. diagnostic period, diagnostic age, histological type and treatment modality) play important roles in determining lung cancer survival
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Transglutaminase induction by various cell death and apoptosis pathways.
Fesus, L; Madi, A; Balajthy, Z; Nemes, Z; Szondy, Z
1996-10-31
Clarification of the molecular details of forms of natural cell death, including apoptosis, has become one of the most challenging issues of contemporary biomedical sciences. One of the effector elements of various cell death pathways is the covalent cross-linking of cellular proteins by transglutaminases. This review will discuss the accumulating data related to the induction and regulation of these enzymes, particularly of tissue type transglutaminase, in the molecular program of cell death. A wide range of signalling pathways can lead to the parallel induction of apoptosis and transglutaminase, providing a handle for better understanding the exact molecular interactions responsible for the mechanism of regulated cell death.
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Directory of Open Access Journals (Sweden)
Maria Teresa Gentile
Full Text Available Glioblastoma multiforme is a highly aggressive brain tumor whose prognosis is very poor. Due to early invasion of brain parenchyma, its complete surgical removal is nearly impossible, and even after aggressive combined treatment (association of surgery and chemo- and radio-therapy five-year survival is only about 10%. Natural products are sources of novel compounds endowed with therapeutic properties in many human diseases, including cancer. Here, we report that the water extract of Ruta graveolens L., commonly known as rue, induces death in different glioblastoma cell lines (U87MG, C6 and U138 widely used to test novel drugs in preclinical studies. Ruta graveolens' effect was mediated by ERK1/2 and AKT activation, and the inhibition of these pathways, via PD98058 and wortmannin, reverted its antiproliferative activity. Rue extract also affects survival of neural precursor cells (A1 obtained from embryonic mouse CNS. As in the case of glioma cells, rue stimulates the activation of ERK1/2 and AKT in A1 cells, whereas their blockade by pharmacological inhibitors prevents cell death. Interestingly, upon induction of differentiation and cell cycle exit, A1 cells become resistant to rue's noxious effects but not to those of temozolomide and cisplatin, two alkylating agents widely used in glioblastoma therapy. Finally, rutin, a major component of the Ruta graveolens water extract, failed to cause cell death, suggesting that rutin by itself is not responsible for the observed effects. In conclusion, we report that rue extracts induce glioma cell death, discriminating between proliferating/undifferentiated and non-proliferating/differentiated neurons. Thus, it can be a promising tool to isolate novel drugs and also to discover targets for therapeutic intervention.
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Lung cells support osteosarcoma cell migration and survival.
Yu, Shibing; Fourman, Mitchell Stephen; Mahjoub, Adel; Mandell, Jonathan Brendan; Crasto, Jared Anthony; Greco, Nicholas Giuseppe; Weiss, Kurt Richard
2017-01-25
Osteosarcoma (OS) is the most common primary bone tumor, with a propensity to metastasize to the lungs. Five-year survival for metastatic OS is below 30%, and has not improved for several decades despite the introduction of multi-agent chemotherapy. Understanding OS cell migration to the lungs requires an evaluation of the lung microenvironment. Here we utilized an in vitro lung cell and OS cell co-culture model to explore the interactions between OS and lung cells, hypothesizing that lung cells would promote OS cell migration and survival. The impact of a novel anti-OS chemotherapy on OS migration and survival in the lung microenvironment was also examined. Three human OS cell lines (SJSA-1, Saos-2, U-2) and two human lung cell lines (HULEC-5a, MRC-5) were cultured according to American Type Culture Collection recommendations. Human lung cell lines were cultured in growth medium for 72 h to create conditioned media. OS proliferation was evaluated in lung co-culture and conditioned media microenvironment, with a murine fibroblast cell line (NIH-3 T3) in fresh growth medium as controls. Migration and invasion were measured using a real-time cell analysis system. Real-time PCR was utilized to probe for Aldehyde Dehydrogenase (ALDH1) expression. Osteosarcoma cells were also transduced with a lentivirus encoding for GFP to permit morphologic analysis with fluorescence microscopy. The anti-OS efficacy of Disulfiram, an ALDH-inhibitor previously shown to inhibit OS cell proliferation and metastasis in vitro, was evaluated in each microenvironment. Lung-cell conditioned medium promoted osteosarcoma cell migration, with a significantly higher attractive effect on all three osteosarcoma cell lines compared to basic growth medium, 10% serum containing medium, and NIH-3 T3 conditioned medium (p cell conditioned medium induced cell morphologic changes, as demonstrated with GFP-labeled cells. OS cells cultured in lung cell conditioned medium had increased alkaline
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International Nuclear Information System (INIS)
Zhou, Yan; Li, Yuan; Ni, Hong-Min; Ding, Wen-Xing; Zhong, Hua
2016-01-01
Non-small cell lung cancer (NSCLC) is one of the most common malignancies in the world. Icotinib and Gefitinib are two epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) that have been used to treat NSCLC. While it is well known that mutations of EGFR can affect the sensitivity of NSCLC to the EGFR-TKI, other mechanisms may also be adopted by lung cancer cells to develop resistance to EGFR-TKI treatment. Cancer cells can use multiple adaptive mechanisms such as activation of autophagy and Nrf2 to protect against various stresses and chemotherapeutic drugs. Whether autophagy or Nrf2 activation contributes to the resistance of NSCLC to EGFR-TKI treatment in wild-type EGFR NSCLC cells remains elusive. In the present study, we confirmed that Icotinib and Gefitinib induced apoptosis in EGFR mutant HCC827 but not in EGFR wild-type A549 NSCLC cells. Icotinib and Gefitinib did not induce autophagic flux or inhibit mTOR in A549 cells. Moreover, suppression of autophagy by chloroquine, a lysosomal inhibitor, did not affect Icotinib- or Gefitinib-induced cell death in A549 cells. In contrast, Brusatol, an Nrf2 inhibitor, significantly suppressed the cell survival of A549 cells. However, Brusatol did not further sensitize A549 cells to EGFR TKI-induced cell death. Results from this study suggest that inhibition of Nrf2 can decrease cell vitality of EGFR wild-type A549 cells independent of autophagy. - Highlights: • Cancer cells use adaptive mechanisms against chemotherapy. • Autophagy is not essential for the drug resistance of lung cancer A549 cells. • Inhibition of Nrf2 decreases cell survival of lung cancer A549 cells.
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Energy Technology Data Exchange (ETDEWEB)
Zhou, Yan [Department of Pulmonary, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030 (China); Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160 (United States); Li, Yuan; Ni, Hong-Min; Ding, Wen-Xing [Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160 (United States); Zhong, Hua, E-mail: eddiedong8@hotmail.com [Department of Pulmonary, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030 (China)
2016-11-01
Non-small cell lung cancer (NSCLC) is one of the most common malignancies in the world. Icotinib and Gefitinib are two epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) that have been used to treat NSCLC. While it is well known that mutations of EGFR can affect the sensitivity of NSCLC to the EGFR-TKI, other mechanisms may also be adopted by lung cancer cells to develop resistance to EGFR-TKI treatment. Cancer cells can use multiple adaptive mechanisms such as activation of autophagy and Nrf2 to protect against various stresses and chemotherapeutic drugs. Whether autophagy or Nrf2 activation contributes to the resistance of NSCLC to EGFR-TKI treatment in wild-type EGFR NSCLC cells remains elusive. In the present study, we confirmed that Icotinib and Gefitinib induced apoptosis in EGFR mutant HCC827 but not in EGFR wild-type A549 NSCLC cells. Icotinib and Gefitinib did not induce autophagic flux or inhibit mTOR in A549 cells. Moreover, suppression of autophagy by chloroquine, a lysosomal inhibitor, did not affect Icotinib- or Gefitinib-induced cell death in A549 cells. In contrast, Brusatol, an Nrf2 inhibitor, significantly suppressed the cell survival of A549 cells. However, Brusatol did not further sensitize A549 cells to EGFR TKI-induced cell death. Results from this study suggest that inhibition of Nrf2 can decrease cell vitality of EGFR wild-type A549 cells independent of autophagy. - Highlights: • Cancer cells use adaptive mechanisms against chemotherapy. • Autophagy is not essential for the drug resistance of lung cancer A549 cells. • Inhibition of Nrf2 decreases cell survival of lung cancer A549 cells.
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UV-Induced Cell Death in Plants
Nawkar, Ganesh M.; Maibam, Punyakishore; Park, Jung Hoon; Sahi, Vaidurya Pratap; Lee, Sang Yeol; Kang, Chang Ho
2013-01-01
Plants are photosynthetic organisms that depend on sunlight for energy. Plants respond to light through different photoreceptors and show photomorphogenic development. Apart from Photosynthetically Active Radiation (PAR; 400–700 nm), plants are exposed to UV light, which is comprised of UV-C (below 280 nm), UV-B (280–320 nm) and UV-A (320–390 nm). The atmospheric ozone layer protects UV-C radiation from reaching earth while the UVR8 protein acts as a receptor for UV-B radiation. Low levels of UV-B exposure initiate signaling through UVR8 and induce secondary metabolite genes involved in protection against UV while higher dosages are very detrimental to plants. It has also been reported that genes involved in MAPK cascade help the plant in providing tolerance against UV radiation. The important targets of UV radiation in plant cells are DNA, lipids and proteins and also vital processes such as photosynthesis. Recent studies showed that, in response to UV radiation, mitochondria and chloroplasts produce a reactive oxygen species (ROS). Arabidopsis metacaspase-8 (AtMC8) is induced in response to oxidative stress caused by ROS, which acts downstream of the radical induced cell death (AtRCD1) gene making plants vulnerable to cell death. The studies on salicylic and jasmonic acid signaling mutants revealed that SA and JA regulate the ROS level and antagonize ROS mediated cell death. Recently, molecular studies have revealed genes involved in response to UV exposure, with respect to programmed cell death (PCD). PMID:23344059
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van Gennip, Isis E.; Pasman, H. Roeline W.; Kaspers, Pam J.; Oosterveld-Vlug, Mariska G.; Willems, Dick L.; Deeg, Dorly J. H.; Onwuteaka-Philipsen, Bregje D.
2013-01-01
Death with dignity has been identified as important both to patients and their surviving family. While research results have been published on what patients themselves believe may affect the dignity of their deaths, little is known about what family caregivers consider to be a dignified death. (1)
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International Nuclear Information System (INIS)
Thomson, A.E.R.; Vaughan-Smith, S.; Peel, W.E.
1982-01-01
The analysis was based on observations of survival decrease as a function of dose (range 0-5 Gy (= 500 rad)) and time after irradiation in vitro. Since lymphocyte survival is also sensitive to culture conditions the effects of radiation were examined daily up to 3 days only, while survival of control cells remained ca. 90 per cent. The time-dependent changes were resolved as the death rates (first-order governed) of lethally-hit cells (apparent survivors), so rendering these distinguishable from the morphologically identical, true (ultimate) survivors. For 12 blood donors the estimated dose permitting 37 per cent ultimate survival (D 37 value) averaged 0.72 +- 0.18 (SD) Gy for the more radiosensitive lymphocyte fraction and 2.50 +- 0.67 Gy for the less radiosensitive, each fraction proving homogeneously radiosensitive and the latter identifying substantially in kind with T-type (E-rosetting lymphocytes). The half-life of lethally-hit members of either fraction varied widely among the donors (ranges, 25-104 hours and 11-40 hours, respectively). Survival curves reconstructed by summating the numerical estimates of the six parameters according to the theoretical model closely matched those observed experimentally (ranged in multiple correlation coefficient, 0.9709-0.9994) for all donors). This signified the absence of any additional, totally radioresistant cell fraction. (author)
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Expression of death receptor 4 induces caspase-independent cell death in MMS-treated yeast.
Kang, Mi-Sun; Lee, Sung-Keun; Park, Chang-Shin; Kang, Ju-Hee; Bae, Sung-Ho; Yu, Sung-Lim
2008-11-14
DR4, a tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor, is a key element in the extrinsic pathway of TRAIL/TRAIL receptor-related apoptosis that exerts a preferential toxic effect against tumor cells. However, TRAIL and DR4 are expressed in various normal cells, and recent studies indicate that DR4 has a number of non-apoptotic functions. In this study, we evaluated the effects of human DR4 expression in yeast to determine the function of DR4 in normal cells. The expression of DR4 in yeast caused G1 arrest, which resulted in transient growth inhibition. Moreover, treatment of DR4-expressing yeast with a DNA damaging agent, MMS, elicited drastic, and sustained cell growth inhibition accompanied with massive apoptotic cell death. Further analysis revealed that cell death in the presence of DNA damage and DR4 expression was not dependent on the yeast caspase, YCA1. Taken together, these results indicate that DR4 triggers caspase-independent programmed cell death during the response of normal cells to DNA damage.
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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...
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Mitochondrial apoptotic pathways induced by Drosophila programmed cell death regulators
International Nuclear Information System (INIS)
Claveria, Cristina; Torres, Miguel
2003-01-01
Multicellular organisms eliminate unwanted or damaged cells by cell death, a process essential to the maintenance of tissue homeostasis. Cell death is a tightly regulated event, whose alteration by excess or defect is involved in the pathogenesis of many diseases such as cancer, autoimmune syndromes, and neurodegenerative processes. Studies in model organisms, especially in the nematode Caenorhabditis elegans, have been crucial in identifying the key molecules implicated in the regulation and execution of programmed cell death. In contrast, the study of cell death in Drosophila melanogaster, often an excellent model organism, has identified regulators and mechanisms not obviously conserved in other metazoans. Recent molecular and cellular analyses suggest, however, that the mechanisms of action of the main programmed cell death regulators in Drosophila include a canonical mitochondrial pathway
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Sickle cell trait and sudden death--bringing it home.
Mitchell, Bruce L.
2007-01-01
Sickle cell trait continues to be the leading cause of sudden death for young African Americans in military basic training and civilian organized sports. The syndrome may have caused the death of up to 10 college football players since 1974 and, as recently as 2000, was suspected as the cause of death of three U.S. Army recruits. The penal military-style boot camps in the United States and the recent death of two teenagers with sickle cell trait merits renewed vigor in the education of athletic instructors, the military and the public about conditions associated with sudden death in individuals with sickle cell trait. Images Figure 1 Figure 2 PMID:17393956
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Sharma, Aditya K.; Arora, Divya; Singh, Lalit K.; Gangwal, Aakriti; Sajid, Andaleeb; Molle, Virginie; Singh, Yogendra; Nandicoori, Vinay Kumar
2016-01-01
Protein phosphatases play vital roles in phosphorylation-mediated cellular signaling. Although there are 11 serine/threonine protein kinases in Mycobacterium tuberculosis, only one serine/threonine phosphatase, PstP, has been identified. Although PstP has been biochemically characterized and multiple in vitro substrates have been identified, its physiological role has not yet been elucidated. In this study, we have investigated the impact of PstP on cell growth and survival of the pathogen in the host. Overexpression of PstP led to elongated cells and partially compromised survival. We find that depletion of PstP is detrimental to cell survival, eventually leading to cell death. PstP depletion results in elongated multiseptate cells, suggesting a role for PstP in regulating cell division events. Complementation experiments performed with PstP deletion mutants revealed marginally compromised survival, suggesting that all of the domains, including the extracellular domain, are necessary for complete rescue. On the other hand, the catalytic activity of PstP is absolutely essential for the in vitro growth. Mice infection experiments establish a definitive role for PstP in pathogen survival within the host. Depletion of PstP from established infections causes pathogen clearance, indicating that the continued presence of PstP is necessary for pathogen survival. Taken together, our data suggest an important role for PstP in establishing and maintaining infection, possibly via the modulation of cell division events. PMID:27758870
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Yin, Shengyong; Miao, Xudong; Zhang, Xueming; Chen, Xinhua; Wen, Hao
2018-02-01
Nanosecond pulsed electric field (nsPEF) is a novel non-thermal tumor ablation technique. However, how nsPEF affect cell physiology at different environmental temperature is still kept unknown. But this issue is of critical clinical practice relevance. This work aim to investigate how nsPEF treated cancer cells react to different environmental temperatures (0, 4, 25, and 37°C). Their cell viability, apoptosis, mitochondrial membrane potential, and reactive oxygen species (ROS) were examined. Lower temperature resulted in higher apoptosis rate, decreased mitochondria membrane potential, and increased ROS levels. Sucrose and N-acetylcysteine (NAC) pre-incubation inhibit ROS generation and increase cell survival, protecting nsPEF-treated cells from low temperature-caused cell death. This work provides an experimental basis for hypothermia and fluid transfusion during nsPEF ablation with anesthesia. © 2017 Wiley Periodicals, Inc.
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Propolis augments apoptosis induced by butyrate via targeting cell survival pathways.
Directory of Open Access Journals (Sweden)
Eric Drago
Full Text Available Diet is one of the major lifestyle factors affecting incidence of colorectal cancer (CC, and despite accumulating evidence that numerous diet-derived compounds modulate CC incidence, definitive dietary recommendations are not available. We propose a strategy that could facilitate the design of dietary supplements with CC-preventive properties. Thus, nutrient combinations that are a source of apoptosis-inducers and inhibitors of compensatory cell proliferation pathways (e.g., AKT signaling may produce high levels of programmed death in CC cells. Here we report the combined effect of butyrate, an apoptosis inducer that is produced through fermentation of fiber in the colon, and propolis, a honeybee product, on CC cells. We established that propolis increases the apoptosis of CC cells exposed to butyrate through suppression of cell survival pathways such as the AKT signaling. The programmed death of CC cells by combined exposure to butyrate and propolis is further augmented by inhibition of the JNK signaling pathway. Analyses on the contribution of the downstream targets of JNK signaling, c-JUN and JAK/STAT, to the apoptosis of butyrate/propolis-treated CC cells ascertained that JAK/STAT signaling has an anti-apoptotic role; whereas, the role of cJUN might be dependent upon regulatory cell factors. Thus, our studies ascertained that propolis augments apoptosis of butyrate-sensitive CC cells and re-sensitizes butyrate-resistant CC cells to apoptosis by suppressing AKT signaling and downregulating the JAK/STAT pathway. Future in vivo studies should evaluate the CC-preventive potential of a dietary supplement that produces high levels of colonic butyrate, propolis, and diet-derived JAK/STAT inhibitors.
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Olariu, Ana; Cleaver, Kathryn M; Shore, Lauren E; Brewer, Michelle D; Cameron, Heather A
2005-01-01
Granule cells born in the adult dentate gyrus undergo a 4-week developmental period characterized by high susceptibility to cell death. Two forms of hippocampus-dependent learning have been shown to rescue many of the new neurons during this critical period. Here, we show that a natural form of associative learning, social transmission of food preference (STFP), can either increase or decrease the survival of young granule cells in adult rats. Increased numbers of pyknotic as well as phospho-Akt-expressing BrdU-labeled cells were seen 1 day after STFP training, indicating that training rapidly induces both cell death and active suppression of cell death in different subsets. A single day of training for STFP increased the survival of 8-day-old BrdU-labeled cells when examined 1 week later. In contrast, 2 days of training decreased the survival of BrdU-labeled cells and the density of immature neurons, identified with crmp-4. This change from increased to decreased survival could not be accounted for by the ages of the cells. Instead, we propose that training may initially increase young granule cell survival, then, if continued, cause them to die. This complex regulation of cell death could potentially serve to maintain granule cells that are actively involved in memory consolidation, while rapidly using and discarding young granule cells whose training is complete to make space for new naïve neurons. Published 2005 Wiley-Liss, Inc.
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Bifurcate effects of glucose on caspase-independent cell death during hypoxia
International Nuclear Information System (INIS)
Aki, Toshihiko; Nara, Akina; Funakoshi, Takeshi; Uemura, Koichi
2010-01-01
We investigated the effect of glucose on hypoxic death of rat cardiomyocyte-derived H9c2 cells and found that there is an optimal glucose concentration for protection against hypoxic cell death. Hypoxic cell death in the absence of glucose is accompanied by rapid ATP depletion, release of apoptosis-inducing factor from mitochondria, and nuclear chromatin condensation, all of which are inhibited by glucose in a dose-dependent manner. In contrast, excessive glucose also induces hypoxic cell death that is not accompanied by these events, suggesting a change in the mode of cell death between hypoxic cells with and without glucose supplementation.
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Overexpression of Drosophila frataxin triggers cell death in an iron-dependent manner.
Edenharter, Oliver; Clement, Janik; Schneuwly, Stephan; Navarro, Juan A
2017-12-01
Friedreich ataxia (FRDA) is the most important autosomal recessive ataxia in the Caucasian population. FRDA patients display severe neurological and cardiac symptoms that reflect a strong cellular and axonal degeneration. FRDA is caused by a loss of function of the mitochondrial protein frataxin which impairs the biosynthesis of iron-sulfur clusters and in turn the catalytic activity of several enzymes in the Krebs cycle and the respiratory chain leading to a diminished energy production. Although FRDA is due to frataxin depletion, overexpression might also be very helpful to better understand cellular functions of frataxin. In this work, we have increased frataxin expression in neurons to elucidate specific roles that frataxin might play in these tissues. Using molecular, biochemical, histological and behavioral methods, we report that frataxin overexpression is sufficient to increase oxidative phosphorylation, modify mitochondrial morphology, alter iron homeostasis and trigger oxidative stress-dependent cell death. Interestingly, genetic manipulation of mitochondrial iron metabolism by silencing mitoferrin successfully improves cell survival under oxidative-attack conditions, although enhancing antioxidant defenses or mitochondrial fusion failed to ameliorate frataxin overexpression phenotypes. This result suggests that cell degeneration is directly related to enhanced incorporation of iron into the mitochondria. Drosophila frataxin overexpression might also provide an alternative approach to identify processes that are important in FRDA such as changes in mitochondrial morphology and oxidative stress induced cell death.
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Directory of Open Access Journals (Sweden)
Marina Mihaela
2012-07-01
Full Text Available Abstract MEK Partner 1 (MP1 or MAPKSP1 is a scaffold protein that has been reported to function in multiple signaling pathways, including the ERK, PAK and mTORC pathways. Several of these pathways influence the biology of breast cancer, but MP1’s functional significance in breast cancer cells has not been investigated. In this report, we demonstrate a requirement for MP1 expression in estrogen receptor (ER positive breast cancer cells. MP1 is widely expressed in both ER-positive and negative breast cancer cell lines, and in non-tumorigenic mammary epithelial cell lines. However, inhibition of its expression using siRNA duplexes resulted in detachment and apoptosis of several ER-positive breast cancer cell lines, but not ER-negative breast cancer cells or non-tumorigenic mammary epithelial cells. Inhibition of MP1 expression in ER-positive MCF-7 cells did not affect ERK activity, but resulted in reduced Akt1 activity and reduced ER expression and activity. Inhibition of ER expression did not result in cell death, suggesting that decreased ER expression is not the cause of cell death. In contrast, pharmacological inhibition of PI3K signaling did induce cell death in MCF-7 cells, and expression of a constitutively active form of Akt1 partially rescued the cell death observed when the MP1 gene was silenced in these cells. Together, these results suggest that MP1 is required for pro-survival signaling from the PI3K/Akt pathway in ER-positive breast cancer cells.
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Cyclophilin B supports Myc and mutant p53-dependent survival of glioblastoma multiforme cells.
Choi, Jae Won; Schroeder, Mark A; Sarkaria, Jann N; Bram, Richard J
2014-01-15
Glioblastoma multiforme is an aggressive, treatment-refractory type of brain tumor for which effective therapeutic targets remain important to identify. Here, we report that cyclophilin B (CypB), a prolyl isomerase residing in the endoplasmic reticulum (ER), provides an essential survival signal in glioblastoma multiforme cells. Analysis of gene expression databases revealed that CypB is upregulated in many cases of malignant glioma. We found that suppression of CypB reduced cell proliferation and survival in human glioblastoma multiforme cells in vitro and in vivo. We also found that treatment with small molecule inhibitors of cyclophilins, including the approved drug cyclosporine, greatly reduced the viability of glioblastoma multiforme cells. Mechanistically, depletion or pharmacologic inhibition of CypB caused hyperactivation of the oncogenic RAS-mitogen-activated protein kinase pathway, induction of cellular senescence signals, and death resulting from loss of MYC, mutant p53, Chk1, and Janus-activated kinase/STAT3 signaling. Elevated reactive oxygen species, ER expansion, and abnormal unfolded protein responses in CypB-depleted glioblastoma multiforme cells indicated that CypB alleviates oxidative and ER stresses and coordinates stress adaptation responses. Enhanced cell survival and sustained expression of multiple oncogenic proteins downstream of CypB may thus contribute to the poor outcome of glioblastoma multiforme tumors. Our findings link chaperone-mediated protein folding in the ER to mechanisms underlying oncogenic transformation, and they make CypB an attractive and immediately targetable molecule for glioblastoma multiforme therapy.
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C/EBPβ LIP augments cell death by inducing osteoglycin.
Wassermann-Dozorets, Rina; Rubinstein, Menachem
2017-04-06
Many types of tumor cell are devoid of the extracellular matrix proteoglycan osteoglycin (Ogn), but its role in tumor biology is poorly studied. Here we show that RNAi of Ogn attenuates stress-triggered cell death, whereas its overexpression increases cell death. We found that the transcription factor C/EBPβ regulates the expression of Ogn. C/EBPβ is expressed as a full-length, active form (LAP) and as a truncated, dominant-negative form (LIP), and the LIP/LAP ratio is positively correlated with the extent of cell death under stress. For example, we reported that drug-resistant tumor cells lack LIP altogether, and its supplementation abolished their resistance to chemotherapy and to endoplasmic reticulum (ER) stress. Here we further show that elevated LIP/LAP ratio robustly increased Ogn expression and cell death under stress by modulating the mitogen-activated protein kinase/activator protein 1 pathway (MAPK/AP-1). Our findings suggest that LIP deficiency renders tumor cell resistant to ER stress by preventing the induction of Ogn.
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Repair models of cell survival and corresponding computer program for survival curve fitting
International Nuclear Information System (INIS)
Shen Xun; Hu Yiwei
1992-01-01
Some basic concepts and formulations of two repair models of survival, the incomplete repair (IR) model and the lethal-potentially lethal (LPL) model, are introduced. An IBM-PC computer program for survival curve fitting with these models was developed and applied to fit the survivals of human melanoma cells HX118 irradiated at different dose rates. Comparison was made between the repair models and two non-repair models, the multitar get-single hit model and the linear-quadratic model, in the fitting and analysis of the survival-dose curves. It was shown that either IR model or LPL model can fit a set of survival curves of different dose rates with same parameters and provide information on the repair capacity of cells. These two mathematical models could be very useful in quantitative study on the radiosensitivity and repair capacity of cells
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Directory of Open Access Journals (Sweden)
Jerry W. Marlin
2009-03-01
Full Text Available p21-Activated kinase 2 (PAK-2 seems to be a regulatory switch between cell survival and cell death signaling. We have shown previously that activation of full-length PAK-2 by Rac or Cdc42 stimulates cell survival, whereas caspase activation of PAK-2 to the proapoptotic PAK-2p34 fragment is involved in the cell death response. In this study, we present a role of elevated activity of full-length PAK-2 in anchorage-independent growth and resistance to anticancer drug–induced apoptosis of cancer cells. Hs578T human breast cancer cells that have low levels of PAK-2 activity were more sensitive to anticancer drug–induced apoptosis and showed higher levels of caspase activation of PAK-2 than MDA-MB435 and MCF-7 human breast cancer cells that have high levels of PAK-2 activity. To examine the role of elevated PAK-2 activity in breast cancer, we have introduced a conditionally active PAK-2 into Hs578T human breast cells. Conditional activation of PAK-2 causes loss of contact inhibition and anchorage-independent growth of Hs578T cells. Furthermore, conditional activation of PAK-2 suppresses activation of caspase 3, caspase activation of PAK-2, and apoptosis of Hs578T cells in response to the anticancer drug cisplatin. Our data suggest a novel mechanism by which full-length PAK-2 activity controls the apoptotic response by regulating levels of activated caspase 3 and thereby its own cleavage to the proapoptotic PAK-2p34 fragment. As a result, elevated PAK-2 activity interrupts the apoptotic response and thereby causes anchorage-independent survival and growth and resistance to anticancer drug–induced apoptosis.
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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
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Friemel, Juliane; Foraita, Ronja; Günther, Kathrin; Heibeck, Mathias; Günther, Frauke; Pflueger, Maren; Pohlabeln, Hermann; Behrens, Thomas; Bullerdiek, Jörn; Nimzyk, Rolf; Ahrens, Wolfgang
2016-03-11
The survival time of patients with head and neck squamous cell carcinoma (HNSCC) is related to health behavior, such as tobacco smoking and alcohol consumption. Poor oral health (OH), dental care (DC) and the frequent use of mouthwash have been shown to represent independent risk factors for head and neck cancerogenesis, but their impact on the survival of HNSCC patients has not been systematically investigated. Two hundred seventy-six incident HNSCC cases recruited for the ARCAGE study were followed through a period of 6-10 years. Interview-based information on wearing of dentures, gum bleeding, teeth brushing, use of floss and dentist visits were grouped into weighted composite scores, i.e. oral health (OH) and dental care (DH). Use of mouthwash was assessed as frequency per day. Also obtained were other types of health behavior, such as smoking, alcohol drinking and diet, appreciated as both confounding and study variables. Endpoints were progression-free survival, overall survival and tumor-specific survival. Prognostic values were estimated using Kaplan-Meier analysis and Cox proportional hazards regression models. A good dental care score, summarizing annual dental visits, daily teeth cleaning and use of floss was associated with longer overall survival time (p = .001). The results of the Cox regression models similarly suggested a higher risk of tumor progression and shortened overall survival in patients with poor dental care, but the results lost their statistical significance after other types of health behavior had been controlled for. Frequent use of mouthwash (≥ 2 times/day) significantly increased the risk of tumor-specific death (HR = 2.26; CI = 1.19-4.32). Alcohol consumption and tobacco smoking were dose-dependently associated with tumor progression and shorter overall survival. Frequent mouthwash use of ≥ 2 times/day seems to elevate the risk of tumor-specific death in HNSCC patients. Good dental care scores are associated with longer overall
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Watanabe, Shinya
2013-09-01
To increase public understanding on cloned cattle derived from somatic cell nuclear transfer (SCNT), the present review describes the effect of calf death loss on an SCNT cattle herd. The incidence of death loss in SCNT cattle surviving more than 200 days reached the same level as that in conventionally bred cattle. This process could be considered as removal of SCNT cattle with congenital defects caused by calf death loss. As a result of comparative studies of SCNT cattle and conventionally bred cattle, the substantial equivalences in animal health status, milk and meat productive performance have been confirmed. Both sexes of SCNT cattle surviving to adulthood were fertile and their reproductive performance, including efficiency of progeny production, was the same as that in conventionally bred cattle. The presence of substantial equivalence between their progeny and conventionally bred cattle also existed. Despite these scientific findings, the commercial use of food products derived from SCNT cattle and their progeny has not been allowed by governments for reasons including the lack of public acceptance of these products and the low efficiency of animal SCNT. To overcome this situation, communication of the low risk of SCNT technology and research to improve SCNT efficiency are required. © 2013 Japanese Society of Animal Science.
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Park, Woo Hyun
2017-08-01
Oxidative stress induces apoptosis in endothelial cells (ECs). Reactive oxygen species (ROS) promote cell death by regulating the activity of various mitogen-activated protein kinases (MAPKs) in ECs. The present study investigated the effects of MAPK inhibitors on cell survival and glutathione (GSH) levels upon H 2 O 2 treatment in calf pulmonary artery ECs (CPAECs). H 2 O 2 treatment inhibited the growth and induced the death of CPAECs, as well as causing GSH depletion and the loss of mitochondrial membrane potential (MMP). While treatment with the MEK or JNK inhibitor impaired the growth of H 2 O 2 -treated CPAECs, treatment with the p38 inhibitor attenuated this inhibition of growth. Additionally, JNK inhibitor treatment increased the proportion of sub-G 1 phase cells in H 2 O 2 -treated CPAECs and further decreased the MMP. However, treatment with a p38 inhibitor reversed the effects of H 2 O 2 treatment on cell growth and the MMP. Similarly, JNK inhibitor treatment further increased, whereas p38 inhibitor treatment decreased, the proportion of GSH-depleted cells in H 2 O 2 -treated CPAECs. Each of the MAPK inhibitors affected cell survival, and ROS or GSH levels differently in H 2 O 2 -untreated, control CPAECs. The data suggest that the exposure of CPAECs to H 2 O 2 caused the cell growth inhibition and cell death through GSH depletion. Furthermore, JNK inhibitor treatment further enhanced, whereas p38 inhibitors attenuated, these effects. Thus, the results of the present study suggest a specific protective role for the p38 inhibitor, and not the JNK inhibitor, against H 2 O 2 -induced cell growth inhibition and cell death.
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Sigma-2 ligands and PARP inhibitors synergistically trigger cell death in breast cancer cells
International Nuclear Information System (INIS)
McDonald, Elizabeth S.; Mankoff, Julia; Makvandi, Mehran; Chu, Wenhua; Chu, Yunxiang; Mach, Robert H.; Zeng, Chenbo
2017-01-01
The sigma-2 receptor is overexpressed in proliferating cells compared to quiescent cells and has been used as a target for imaging solid tumors by positron emission tomography. Recent work has suggested that the sigma-2 receptor may also be an effective therapeutic target for cancer therapy. Poly (ADP-ribose) polymerase (PARP) is a family of enzymes involved in DNA damage response. In this study, we looked for potential synergy of cytotoxicity between PARP inhibitors and sigma-2 receptor ligands in breast cancer cell lines. We showed that the PARP inhibitor, YUN3-6, sensitized mouse breast cancer cell line, EMT6, to sigma-2 receptor ligand (SV119, WC-26, and RHM-138) induced cell death determined by cell viability assay and colony forming assay. The PARP inhibitor, olaparib, sensitized tumor cells to a different sigma-2 receptor ligand SW43-induced apoptosis and cell death in human triple negative cell line, MDA-MB-231. Olaparib inhibited PARP activity and cell proliferation, and arrested cells in G2/M phase of the cell cycle in MDA-MB-231 cells. Subsequently cells became sensitized to SW43 induced cell death. In conclusion, the combination of sigma-2 receptor ligands and PARP inhibitors appears to hold promise for synergistically triggering cell death in certain types of breast cancer cells and merits further investigation. - Highlights: • PARPi, YUN3-6 and olaparib, and σ2 ligands, SV119 and SW43, were evaluated. • Mouse and human breast cancer cells, EMT6 and MDA-MB-231 respectively, were used. • YUN3-6 and SV119 synergistically triggered cell death in EMT6 cells. • Olaparib and SW43 additively triggered cell death in MDA-MB-231 cells. • Olaparib arrested cells in G2/M in MDA-MB-231 cells.
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Sensitization of vascular smooth muscle cell to TNF-α-mediated death in the presence of palmitate
International Nuclear Information System (INIS)
Rho, Mun-Chual; Ah Lee, Kyeong; Mi Kim, Sun; Sik Lee, Chang; Jeong Jang, Min; Kook Kim, Young; Sun Lee, Hyun; Hyun Choi, Yung; Yong Rhim, Byung; Kim, Koanhoi
2007-01-01
Saturated free fatty acids (FFAs), including palmitate, can activate the intrinsic death pathway in cells. However, the relationship between FFAs and receptor-mediated death pathway is still unknown. In this study, we have investigated whether FFAs are able to trigger receptor-mediated death. In addition, to clarify the mechanisms responsible for the activation, we examined the biochemical changes in dying vascular smooth muscle cell (VSMC) and the effects of various molecules to the receptor-mediated VSMC death. Tumor necrosis factor (TNF)-α-mediated VSMC death occurred in the presence of sub-cytotoxic concentration of palmitate as determined by assessing viability and DNA degradation, while the cytokine did not influence VSMC viability in the presence of oleate. The VSMC death was inhibited by the gene transfer of a dominant-negative Fas-associated death domain-containing protein and the baculovirus p35, but not by the bcl-xL or the c-Jun N-terminal kinase (JNK) binding domain of JNK-interacting protein-1, in tests utilizing recombinant adenoviruses. The VSMC death was also inhibited by a neutralizing anti-TNF receptor 1 antibody, the caspase inhibitor z-VAD, and the cathepsin B inhibitor CA074, a finding indicative of the role of both caspases and cathepsin B in this process. Consistent with this finding, caspase-3 activation and an increase in cytosolic cathepsin B activity were detected in the dying VSMC. Palmitate inhibited an increase of TNF-α-mediated nuclear factor kappa B (NF-κB) activity, the survival pathway activated by the cytokine, by hindering the translocation of the NF-κB subunit of p65 from the cytosol into the nucleus. The gene transfer of inhibitor of NF-κB predisposed VSMC to palmitate-induced cell death. To the best of our knowledge, this study is the first report to demonstrate the activation of TNF-α-mediated cell death in the presence of palmitate. The current study proposes that FFAs would take part in deleterious vascular
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Characterization of a serine protease-mediated cell death program activated in human leukemia cells
International Nuclear Information System (INIS)
O'Connell, A.R.; Holohan, C.; Torriglia, A.; Lee, B.F.; Stenson-Cox, C.
2006-01-01
Tightly controlled proteolysis is a defining feature of apoptosis and caspases are critical in this regard. Significant roles for non-caspase proteases in cell death have been highlighted. Staurosporine causes a rapid induction of apoptosis in virtually all mammalian cell types. Numerous studies demonstrate that staurosporine can activate cell death under caspase-inhibiting circumstances. The aim of this study was to investigate the proteolytic mechanisms responsible for cell death under these conditions. To that end, we show that inhibitors of serine proteases can delay cell death in one such system. Furthermore, through profiling of proteolytic activation, we demonstrate, for the first time, that staurosporine activates a chymotrypsin-like serine protease-dependent cell death in HL-60 cells independently, but in parallel with the caspase controlled systems. Features of the serine protease-mediated system include cell shrinkage and apoptotic morphology, regulation of caspase-3, altered nuclear morphology, generation of an endonuclease and DNA degradation. We also demonstrate a staurosporine-induced activation of a putative 16 kDa chymotrypsin-like protein during apoptosis
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How Kidney Cell Death Induces Renal Necroinflammation.
Mulay, Shrikant R; Kumar, Santhosh V; Lech, Maciej; Desai, Jyaysi; Anders, Hans-Joachim
2016-05-01
The nephrons of the kidney are independent functional units harboring cells of a low turnover during homeostasis. As such, physiological renal cell death is a rather rare event and dead cells are flushed away rapidly with the urinary flow. Renal cell necrosis occurs in acute kidney injuries such as thrombotic microangiopathies, necrotizing glomerulonephritis, or tubular necrosis. All of these are associated with intense intrarenal inflammation, which contributes to further renal cell loss, an autoamplifying process referred to as necroinflammation. But how does renal cell necrosis trigger inflammation? Here, we discuss the role of danger-associated molecular patterns (DAMPs), mitochondrial (mito)-DAMPs, and alarmins, as well as their respective pattern recognition receptors. The capacity of DAMPs and alarmins to trigger cytokine and chemokine release initiates the recruitment of leukocytes into the kidney that further amplify necroinflammation. Infiltrating neutrophils often undergo neutrophil extracellular trap formation associated with neutrophil death or necroptosis, which implies a release of histones, which act not only as DAMPs but also elicit direct cytotoxic effects on renal cells, namely endothelial cells. Proinflammatory macrophages and eventually cytotoxic T cells further drive kidney cell death and inflammation. Dissecting the molecular mechanisms of necroinflammation may help to identify the best therapeutic targets to limit nephron loss in kidney injury. Copyright © 2016 Elsevier Inc. All rights reserved.
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Partner resources and incidence and survival in two major causes of death
Directory of Open Access Journals (Sweden)
Jenny Torssander
2018-04-01
Full Text Available Because people tend to marry social equals – and possibly also because partners affect each other’s health – the social position of one partner is associated with the other partner’s health and mortality. Although this link is fairly well established, the underlying mechanisms are not fully identified. Analyzing disease incidence and survival separately may help us to assess when in the course of the disease a partner’s resources are of most significance. This article addresses the importance of partner’s education, income, employment status, and health for incidence and survival in two major causes of death: cancer and cardiovascular diseases (CVD. Based on a sample of Finnish middle-aged and older couples (around 200,000 individuals we show that a partner’s education is more often connected to incidence than to survival, in particular for CVD. Once ill, any direct effect of partner’s education seems to decline: The survival chances after being hospitalized for cancer or CVD are rather associated with partner’s employment status and/or income level when other individual and partner factors are adjusted for. In addition, a partner’s history of poor health predicted higher CVD incidence and, for women, lower cancer survival. The findings suggest that various partner’s characteristics may have different implications for disease and survival, respectively. A wider focus on social determinants of health at the household level, including partner’s social resources, is needed. Keywords: Marital/cohabiting partners, Education, Income, CVD, Cancer, Survival, Finland
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Jasmonic acid signaling modulates ozone-induced hypersensitive cell death.
Rao, M V; Lee, H; Creelman, R A; Mullet, J E; Davis, K R
2000-09-01
Recent studies suggest that cross-talk between salicylic acid (SA)-, jasmonic acid (JA)-, and ethylene-dependent signaling pathways regulates plant responses to both abiotic and biotic stress factors. Earlier studies demonstrated that ozone (O(3)) exposure activates a hypersensitive response (HR)-like cell death pathway in the Arabidopsis ecotype Cvi-0. We now have confirmed the role of SA and JA signaling in influencing O(3)-induced cell death. Expression of salicylate hydroxylase (NahG) in Cvi-0 reduced O(3)-induced cell death. Methyl jasmonate (Me-JA) pretreatment of Cvi-0 decreased O(3)-induced H(2)O(2) content and SA concentrations and completely abolished O(3)-induced cell death. Cvi-0 synthesized as much JA as did Col-0 in response to O(3) exposure but exhibited much less sensitivity to exogenous Me-JA. Analyses of the responses to O(3) of the JA-signaling mutants jar1 and fad3/7/8 also demonstrated an antagonistic relationship between JA- and SA-signaling pathways in controlling the magnitude of O(3)-induced HR-like cell death.
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Gordillo, Gayle M; Biswas, Ayan; Khanna, Savita; Spieldenner, James M; Pan, Xueliang; Sen, Chandan K
2016-05-06
Endothelial cell tumors are the most common soft tissue tumors in infants. Tumor-forming endothelial (EOMA) cells are able to escape cell death fate despite excessive nuclear oxidant burden. Our previous work recognized perinuclear Nox-4 as a key contributor to EOMA growth. The objective of this work was to characterize the mechanisms by which EOMA cells evade oxidant toxicity and thrive. In EOMA cells, compared with in the cytosol, the nuclear GSSG/GSH ratio was 5-fold higher. Compared to the ratio observed in healthy murine aortic endothelial (MAE) cells, GSSG/GSH was over twice as high in EOMA cells. Multidrug resistance-associated protein-1 (MRP-1), an active GSSG efflux mechanism, showed 2-fold increased activity in EOMA compared with MAE cells. Hyperactive YB-1 and Ape/Ref-1 were responsible for high MRP-1 expression in EOMA. Proximity ligand assay demonstrated MRP-1 and YB-1 binding. Such binding enabled the nuclear targeting of MRP-1 in EOMA in a leptomycin-B-sensitive manner. MRP-1 inhibition as well as knockdown trapped nuclear GSSG, causing cell death of EOMA. Disulfide loading of cells by inhibition of GSSG reductase (bischoloronitrosourea) or thioredoxin reductase (auranofin) was effective in causing EOMA death as well. In sum, EOMA cells survive a heavy oxidant burden by rapid efflux of GSSG, which is lethal if trapped within the cell. A hyperactive MRP-1 system for GSSG efflux acts as a critical survival factor for these cells, making it a potential target for EOMA therapeutics. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.
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Gordillo, Gayle M.; Biswas, Ayan; Khanna, Savita; Spieldenner, James M.; Pan, Xueliang; Sen, Chandan K.
2016-01-01
Endothelial cell tumors are the most common soft tissue tumors in infants. Tumor-forming endothelial (EOMA) cells are able to escape cell death fate despite excessive nuclear oxidant burden. Our previous work recognized perinuclear Nox-4 as a key contributor to EOMA growth. The objective of this work was to characterize the mechanisms by which EOMA cells evade oxidant toxicity and thrive. In EOMA cells, compared with in the cytosol, the nuclear GSSG/GSH ratio was 5-fold higher. Compared to the ratio observed in healthy murine aortic endothelial (MAE) cells, GSSG/GSH was over twice as high in EOMA cells. Multidrug resistance-associated protein-1 (MRP-1), an active GSSG efflux mechanism, showed 2-fold increased activity in EOMA compared with MAE cells. Hyperactive YB-1 and Ape/Ref-1 were responsible for high MRP-1 expression in EOMA. Proximity ligand assay demonstrated MRP-1 and YB-1 binding. Such binding enabled the nuclear targeting of MRP-1 in EOMA in a leptomycin-B-sensitive manner. MRP-1 inhibition as well as knockdown trapped nuclear GSSG, causing cell death of EOMA. Disulfide loading of cells by inhibition of GSSG reductase (bischoloronitrosourea) or thioredoxin reductase (auranofin) was effective in causing EOMA death as well. In sum, EOMA cells survive a heavy oxidant burden by rapid efflux of GSSG, which is lethal if trapped within the cell. A hyperactive MRP-1 system for GSSG efflux acts as a critical survival factor for these cells, making it a potential target for EOMA therapeutics. PMID:26961872
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Bim and Mcl-1 exert key roles in regulating JAK2V617F cell survival
International Nuclear Information System (INIS)
Rubert, Joëlle; Qian, Zhiyan; Andraos, Rita; Guthy, Daniel A; Radimerski, Thomas
2011-01-01
The JAK2 V617F mutation plays a major role in the pathogenesis of myeloproliferative neoplasms and is found in the vast majority of patients suffering from polycythemia vera and in roughly every second patient suffering from essential thrombocythemia or from primary myelofibrosis. The V617F mutation is thought to provide hematopoietic stem cells and myeloid progenitors with a survival and proliferation advantage. It has previously been shown that activated JAK2 promotes cell survival by upregulating the anti-apoptotic STAT5 target gene Bcl-xL. In this study, we have investigated the role of additional apoptotic players, the pro-apoptotic protein Bim as well as the anti-apoptotic protein Mcl-1. Pharmacological inhibition of JAK2/STAT5 signaling in JAK2 V617F mutant SET-2 and MB-02 cells was used to study effects on signaling, cell proliferation and apoptosis by Western blot analysis, WST-1 proliferation assays and flow cytometry. Cells were transfected with siRNA oligos to deplete candidate pro- and anti-apoptotic proteins. Co-immunoprecipitation assays were performed to assess the impact of JAK2 inhibition on complexes of pro- and anti-apoptotic proteins. Treatment of JAK2 V617F mutant cell lines with a JAK2 inhibitor was found to trigger Bim activation. Furthermore, Bim depletion by RNAi suppressed JAK2 inhibitor-induced cell death. Bim activation following JAK2 inhibition led to enhanced sequestration of Mcl-1, besides Bcl-xL. Importantly, Mcl-1 depletion by RNAi was sufficient to compromise JAK2 V617F mutant cell viability and sensitized the cells to JAK2 inhibition. We conclude that Bim and Mcl-1 have key opposing roles in regulating JAK2 V617F cell survival and propose that inactivation of aberrant JAK2 signaling leads to changes in Bim complexes that trigger cell death. Thus, further preclinical evaluation of combinations of JAK2 inhibitors with Bcl-2 family antagonists that also tackle Mcl-1, besides Bcl-xL, is warranted to assess the therapeutic potential
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Gechev, Tsanko S.; Minkov, Ivan N.; Hille, Jacques
2005-01-01
Hydrogen peroxide is a major regulator of plant programmed cell death (PCD) but little is known about the downstream genes from the H2O2-signaling network that mediate the cell death. To address this question, a novel system for studying H2O2-induced programmed cell death in Arabidopsis thaliana was
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Programmed cell death for defense against anomaly and tumor formation
International Nuclear Information System (INIS)
Kondo, Sohei; Norimura, Toshiyuki; Nomura, Taisei
1995-01-01
Cell death after exposure to low-level radiation is often considered evidence that radiation is poisonous, however small the dose. Evidence has been accumulating to support the notion that cell death after low-level exposure to radiation results from activation of suicidal genes open-quote programmed cell death close-quote or open-quote apoptosis close-quote - for the health of the whole body. This paper gives experimental evidence that embryos of fruit flies and mouse fetuses have potent defense mechanisms against teratogenic or tumorigenic injury caused by radiation and carcinogens, which function through programmed cell death
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Cardiac Glycoside Glucoevatromonoside Induces Cancer Type-Specific Cell Death
Directory of Open Access Journals (Sweden)
Naira F. Z. Schneider
2018-03-01
Full Text Available Cardiac glycosides (CGs are natural compounds used traditionally to treat congestive heart diseases. Recent investigations repositioned CGs as potential anticancer agents. To discover novel cytotoxic CG scaffolds, we selected the cardenolide glucoevatromonoside (GEV out of 46 CGs for its low nanomolar anti-lung cancer activity. GEV presented reduced toxicity toward non-cancerous cell types (lung MRC-5 and PBMC and high-affinity binding to the Na+/K+-ATPase α subunit, assessed by computational docking. GEV-induced cell death was caspase-independent, as investigated by a multiparametric approach, and culminates in severe morphological alterations in A549 cells, monitored by transmission electron microscopy, live cell imaging and flow cytometry. This non-canonical cell death was not preceded or accompanied by exacerbation of autophagy. In the presence of GEV, markers of autophagic flux (e.g. LC3I-II conversion were impacted, even in presence of bafilomycin A1. Cell death induction remained unaffected by calpain, cathepsin, parthanatos, or necroptosis inhibitors. Interestingly, GEV triggered caspase-dependent apoptosis in U937 acute myeloid leukemia cells, witnessing cancer-type specific cell death induction. Differential cell cycle modulation by this CG led to a G2/M arrest, cyclin B1 and p53 downregulation in A549, but not in U937 cells. We further extended the anti-cancer potential of GEV to 3D cell culture using clonogenic and spheroid formation assays and validated our findings in vivo by zebrafish xenografts. Altogether, GEV shows an interesting anticancer profile with the ability to exert cytotoxic effects via induction of different cell death modalities.
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Luquin, Natasha; Mitrofanis, John
2008-01-01
We have explored the survival of dopaminergic cells of the substantia nigra pars compacta (SNc) in 6 hydroxydopamine (6OHDA)-lesioned rats with prior cortical removal. There were approximately 35% more dopaminergic cells in the ventral sector of SNc (vSNc) of 6OHDA-lesioned rats that had prior cortical removal compared to those that did not. By contrast, there were no differences in dopaminergic cell number between these experimental groups in the ventral tegmental area (VTA) and the dorsal sector of SNc (dSNc). Hence, prior cortical removal in 6OHDA-lesioned rats neuroprotected vSNc--but not VTA or dSNc--dopaminergic cells from death.
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Autophagic components contribute to hypersensitive cell death in Arabidopsis
DEFF Research Database (Denmark)
Hofius, Daniel; Schultz-Larsen, Torsten; Joensen, Jan
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...... expression. Here, we examined receptor-mediated HR PCD responses in autophagy-deficient Arabidopsis knockout mutants (atg), and show that infection-induced lesions are contained in atg mutants. We also provide evidence that HR cell death initiated via Toll/Interleukin-1 (TIR)-type immune receptors through...... the defense regulator EDS1 is suppressed in atg mutants. Furthermore, we demonstrate that PCD triggered by coiled-coil (CC)-type immune receptors via NDR1 is either autophagy-independent or engages autophagic components with cathepsins and other unidentified cell death mediators. Thus, autophagic cell death...
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Mechanisms of Ionizing Radiation-Induced Cell Death in Primary Lung Cells
2013-03-05
lose their capacity to replicate after a certain number 10 of passages. This finite number was termed the “ Hayflick limit ” and cells...Upstream and downstream of mTOR. Genes & development 18:1926-45 78. Hayflick L. 1965. The Limited in Vitro Lifetime of Human Diploid Cell Strains...can lead to death. During the course of radiotherapy, the use of IR for the treatment of thoracic cancers is limited by IR-induced cell death to the
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Non-apoptotic cell death associated with perturbations of macropinocytosis.
Maltese, William A; Overmeyer, Jean H
2015-01-01
Although macropinocytosis is widely recognized as a distinct form of fluid-phase endocytosis in antigen-presenting dendritic cells, it also occurs constitutively in many other normal and transformed cell types. Recent studies have established that various genetic or pharmacological manipulations can hyperstimulate macropinocytosis or disrupt normal macropinosome trafficking pathways, leading to accumulation of greatly enlarged cytoplasmic vacuoles. In some cases, this extreme vacuolization is associated with a unique form of non-apoptotic cell death termed "methuosis," from the Greek methuo (to drink to intoxication). It remains unclear whether cell death related to dysfunctional macropinocytosis occurs in normal physiological contexts. However, the finding that some types of cancer cells are particularly vulnerable to this unusual form of cell death has raised the possibility that small molecules capable of altering macropinosome trafficking or function might be useful as therapeutic agents against cancers that are resistant to drugs that work by inducing apoptosis. Herein we review examples of cell death associated with dysfunctional macropinocytosis and summarize what is known about the underlying mechanisms.
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Non-apoptotic cell death associated with perturbations of macropinocytosis
Directory of Open Access Journals (Sweden)
William A. Maltese
2015-02-01
Full Text Available Although macropinocytosis is widely recognized as a distinct form of fluid-phase endocytosis in antigen-presenting dendritic cells, it also occurs constitutively in many other normal and transformed cell types. Recent studies have established that various genetic or pharmacological manipulations can hyperstimulate macropinocytosis or disrupt normal macropinosome trafficking pathways, leading to accumulation of greatly enlarged cytoplasmic vacuoles. In some cases, this extreme vacuolization is associated with a unique form of non-apoptotic cell death termed ‘methuosis’, from the Greek methuo (to drink to intoxication. It remains unclear whether cell death related to dysfunctional macropinocytosis occurs in normal physiological contexts. However, the finding that some types of cancer cells are particularly vulnerable to this unusual form of cell death has raised the possibility that small molecules capable of altering macropinosome trafficking or function might be useful as therapeutic agents against cancers that are resistant to drugs that work by inducing apoptosis. Herein we review examples of cell death associated with dysfunctional macropinocytosis and summarize what is known about the underlying mechanisms.
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Cylindromatosis mediates neuronal cell death in vitro and in vivo.
Ganjam, Goutham K; Terpolilli, Nicole Angela; Diemert, Sebastian; Eisenbach, Ina; Hoffmann, Lena; Reuther, Christina; Herden, Christiane; Roth, Joachim; Plesnila, Nikolaus; Culmsee, Carsten
2018-01-19
The tumor-suppressor cylindromatosis (CYLD) is a deubiquitinating enzyme and key regulator of cell proliferation and inflammation. A genome-wide siRNA screen linked CYLD to receptor interacting protein-1 (RIP1) kinase-mediated necroptosis; however, the exact mechanisms of CYLD-mediated cell death remain unknown. Therefore, we investigated the precise role of CYLD in models of neuronal cell death in vitro and evaluated whether CYLD deletion affects brain injury in vivo. In vitro, downregulation of CYLD increased RIP1 ubiquitination, prevented RIP1/RIP3 complex formation, and protected neuronal cells from oxidative death. Similar protective effects were achieved by siRNA silencing of RIP1 or RIP3 or by pharmacological inhibition of RIP1 with necrostatin-1. In vivo, CYLD knockout mice were protected from trauma-induced brain damage compared to wild-type littermate controls. These findings unravel the mechanisms of CYLD-mediated cell death signaling in damaged neurons in vitro and suggest a cell death-mediating role of CYLD in vivo.
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Modification of bacterial cell survival by postirradiation hypoxia
Energy Technology Data Exchange (ETDEWEB)
Vexler, F B; Eidus, L Kh
1986-01-27
It is shown that postirradiation hypoxia affects the survival of E.coli. Hypoxic conditions immediately after a single-dose irradiation diminish cell survival in nutrient medium. Increasing time intervals between irradiation and hypoxia decrease the efficiency of the latter, while 1 h after irradiation hypoxia does not modify the survival of irradiated cells. These findings reveal that the mechanisms of action of postirradiation hypoxia on eu- and prokaryotic cells are similar.
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Directory of Open Access Journals (Sweden)
Agnieszka Kobylińska
2017-09-01
Full Text Available Melatonin was discovered in plants more than two decades ago and, especially in the last decade, it has captured the interests of plant biologists. Beyond its possible participation in photoperiod processes and its role as a direct free radical scavenger as well as an indirect antioxidant, melatonin is also involved in plant defense strategies/reactions. However, the mechanisms that this indoleamine activates to improve plant stress tolerance still require identification and clarification. In the present report, the ability of exogenous melatonin to protect Nicotiana tabacum L. line Bright Yellow 2 (BY-2 suspension cells against the toxic exposure to lead was examined. Studies related to cell proliferation and viability, DNA fragmentation, possible translocation of cytochrome c from mitochondria to cytosol, cell morphology after fluorescence staining and also the in situ accumulation of superoxide radicals measured via the nitro blue tetrazolium reducing test, were conducted. This work establishes a novel finding by correcting the inhibition of release of mitochondrial ctytocrome c in to the cytoplasm with the high accumulation of superoxide radicals. The results show that pretreatment with 200 nm of melatonin protected tobacco cells from DNA damage caused by lead. Melatonin, as an efficacious antioxidant, limited superoxide radical accumulation as well as cytochrome c release thereby, it likely prevents the activation of the cascade of processes leading to cell death. Fluorescence staining with acridine orange and ethidium bromide documented that lead-stressed cells additionally treated with melatonin displayed intact nuclei. The results revealed that melatonin at proper dosage could significantly increase BY-2 cell proliferation and protected them against death. It was proved that melatonin could function as an effective priming agent to promote survival of tobacco cells under harmful lead-induced stress conditions.
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Kobylińska, Agnieszka; Reiter, Russel J.; Posmyk, Malgorzata M.
2017-01-01
Melatonin was discovered in plants more than two decades ago and, especially in the last decade, it has captured the interests of plant biologists. Beyond its possible participation in photoperiod processes and its role as a direct free radical scavenger as well as an indirect antioxidant, melatonin is also involved in plant defense strategies/reactions. However, the mechanisms that this indoleamine activates to improve plant stress tolerance still require identification and clarification. In the present report, the ability of exogenous melatonin to protect Nicotiana tabacum L. line Bright Yellow 2 (BY-2) suspension cells against the toxic exposure to lead was examined. Studies related to cell proliferation and viability, DNA fragmentation, possible translocation of cytochrome c from mitochondria to cytosol, cell morphology after fluorescence staining and also the in situ accumulation of superoxide radicals measured via the nitro blue tetrazolium reducing test, were conducted. This work establishes a novel finding by correcting the inhibition of release of mitochondrial ctytocrome c in to the cytoplasm with the high accumulation of superoxide radicals. The results show that pretreatment with 200 nm of melatonin protected tobacco cells from DNA damage caused by lead. Melatonin, as an efficacious antioxidant, limited superoxide radical accumulation as well as cytochrome c release thereby, it likely prevents the activation of the cascade of processes leading to cell death. Fluorescence staining with acridine orange and ethidium bromide documented that lead-stressed cells additionally treated with melatonin displayed intact nuclei. The results revealed that melatonin at proper dosage could significantly increase BY-2 cell proliferation and protected them against death. It was proved that melatonin could function as an effective priming agent to promote survival of tobacco cells under harmful lead-induced stress conditions. PMID:28959267
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Dual role of proapoptotic BAD in insulin secretion and beta cell survival.
Danial, Nika N; Walensky, Loren D; Zhang, Chen-Yu; Choi, Cheol Soo; Fisher, Jill K; Molina, Anthony J A; Datta, Sandeep Robert; Pitter, Kenneth L; Bird, Gregory H; Wikstrom, Jakob D; Deeney, Jude T; Robertson, Kirsten; Morash, Joel; Kulkarni, Ameya; Neschen, Susanne; Kim, Sheene; Greenberg, Michael E; Corkey, Barbara E; Shirihai, Orian S; Shulman, Gerald I; Lowell, Bradford B; Korsmeyer, Stanley J
2008-02-01
The proapoptotic BCL-2 family member BAD resides in a glucokinase-containing complex that regulates glucose-driven mitochondrial respiration. Here, we present genetic evidence of a physiologic role for BAD in glucose-stimulated insulin secretion by beta cells. This novel function of BAD is specifically dependent upon the phosphorylation of its BH3 sequence, previously defined as an essential death domain. We highlight the pharmacologic relevance of phosphorylated BAD BH3 by using cell-permeable, hydrocarbon-stapled BAD BH3 helices that target glucokinase, restore glucose-driven mitochondrial respiration and correct the insulin secretory response in Bad-deficient islets. Our studies uncover an alternative target and function for the BAD BH3 domain and emphasize the therapeutic potential of phosphorylated BAD BH3 mimetics in selectively restoring beta cell function. Furthermore, we show that BAD regulates the physiologic adaptation of beta cell mass during high-fat feeding. Our findings provide genetic proof of the bifunctional activities of BAD in both beta cell survival and insulin secretion.
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Acrolein-induced cell death in PC12 cells: role of mitochondria-mediated oxidative stress.
Luo, Jian; Robinson, J Paul; Shi, Riyi
2005-12-01
Oxidative stress has been implicated in acrolein cytotoxicity in various cell types, including mammalian spinal cord tissue. In this study we report that acrolein also decreases PC12 cell viability in a reactive oxygen species (ROS)-dependent manner. Specifically, acrolein-induced cell death, mainly necrosis, is accompanied by the accumulation of cellular ROS. Elevating ROS scavengers can alleviate acrolein-induced cell death. Furthermore, we show that exposure to acrolein leads to mitochondrial dysfunction, denoted by the loss of mitochondrial transmembrane potential, reduction of cellular oxygen consumption, and decrease of ATP level. This raises the possibility that the cellular accumulation of ROS could result from the increased production of ROS in the mitochondria of PC12 cells as a result of exposure to acrolein. The acrolein-induced significant decrease of ATP production in mitochondria may also explain why necrosis, not apoptosis, is the dominant type of cell death. In conclusion, our data suggest that one possible mechanism of acrolein-induced cell death could be through mitochondria as its initial target. The subsequent increase of ROS then inflicts cell death and further worsens mitochondria function. Such mechanism may play an important role in CNS trauma and neurodegenerative diseases.
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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.
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Directory of Open Access Journals (Sweden)
Cinzia Fabrizi
2014-01-01
Full Text Available Autophagy is an evolutionary conserved mechanism that allows for the degradation of long-lived proteins and entire organelles which are driven to lysosomes for digestion. Different kinds of stressful conditions such as starvation are able to induce autophagy. Lithium and rapamycin are potent autophagy inducers with different molecular targets. Lithium stimulates autophagy by decreasing the intracellular myo-inositol-1,4,5-triphosphate levels, while rapamycin acts through the inhibition of the mammalian target of rapamycin (mTOR. The correlation between autophagy and cell death is still a matter of debate especially in transformed cells. In fact, the execution of autophagy can protect cells from death by promptly removing damaged organelles such as mitochondria. Nevertheless, an excessive use of the autophagic machinery can drive cells to death via a sort of self-cannibalism. Our data show that lithium (used within its therapeutic window stimulates the overgrowth of the rat Pheochromocytoma cell line PC12. Besides, lithium and rapamycin protect PC12 cells from toxic compounds such as thapsigargin and trimethyltin. Taken together these data indicate that pharmacological activation of autophagy allows for the survival of Pheochromocytoma cells in stressful conditions such as high-density cultures and exposure to toxins.
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Vacuolar processing enzyme: an executor of plant cell death.
Hara-Nishimura, Ikuko; Hatsugai, Noriyuki; Nakaune, Satoru; Kuroyanagi, Miwa; Nishimura, Mikio
2005-08-01
Apoptotic cell death in animals is regulated by cysteine proteinases called caspases. Recently, vacuolar processing enzyme (VPE) was identified as a plant caspase. VPE deficiency prevents cell death during hypersensitive response and cell death of limited cell layers at the early stage of embryogenesis. Because plants do not have macrophages, dying cells must degrade their materials by themselves. VPE plays an essential role in the regulation of the lytic system of plants during the processes of defense and development. VPE is localized in the vacuoles, unlike animal caspases, which are localized in the cytosol. Thus, plants might have evolved a regulated cellular suicide strategy that, unlike animal apoptosis, is mediated by VPE and the vacuoles.
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Sphingosine kinase-2 maintains viral latency and survival for KSHV-infected endothelial cells.
Directory of Open Access Journals (Sweden)
Lu Dai
Full Text Available Phosphorylation of sphingosine by sphingosine kinases (SphK1 and SphK2 generates sphingosine-1-phosphate (S1P, a bioactive sphingolipid which promotes cancer cell survival and tumor progression in vivo. We have recently reported that targeting SphK2 induces apoptosis for human primary effusion lymphoma (PEL cell lines infected by the Kaposi's sarcoma-associated herpesvirus (KSHV, and this occurs in part through inhibition of canonical NF-κB activation. In contrast, pharmacologic inhibition of SphK2 has minimal impact for uninfected B-cell lines or circulating human B cells from healthy donors. Therefore, we designed additional studies employing primary human endothelial cells to explore mechanisms responsible for the selective death observed for KSHV-infected cells during SphK2 targeting. Using RNA interference and a clinically relevant pharmacologic approach, we have found that targeting SphK2 induces apoptosis selectively for KSHV-infected endothelial cells through induction of viral lytic gene expression. Moreover, this effect occurs through repression of KSHV-microRNAs regulating viral latency and signal transduction, including miR-K12-1 which targets IκBα to facilitate activation of NF-κB, and ectopic expression of miR-K12-1 restores NF-κB activation and viability for KSHV-infected endothelial cells during SphK2 inhibition. These data illuminate a novel survival mechanism and potential therapeutic target for KSHV-infected endothelial cells: SphK2-associated maintenance of viral latency.
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Tervonen, Hanna E; Roder, David; Morrell, Stephen; You, Hui; Currow, David C
2017-06-01
Death Certificate Only (DCO) cancer cases are commonly excluded from survival analyses due to unknown survival time. This study examines whether socio-demographic factors are associated with DCO diagnosis, and the potential effects of excluding DCO cases on socio-demographic cancer survival disparities in NSW, Australia. NSW Cancer Registry data for cases diagnosed in 2000-2008 were used in this study. Logistic regression was used to estimate the odds of DCO registration by socio-demographic sub-group (socio-economic disadvantage, residential remoteness, country of birth, age at diagnosis). Cox proportional hazard regression was used to estimate the probability of death from cancer by socio-demographic subgroup when DCO cases were included and excluded from analyses. DCO cases consisted of 1.5% (n=4336) of all cases (n=299,651). DCO diagnosis was associated with living in socio-economically disadvantaged areas (most disadvantaged compared with least disadvantaged quintile: odds ratio OR 1.25, 95%CI 1.12-1.40), living in inner regional (OR 1.16, 95%CI 1.08-1.25) or remote areas (OR 1.48, 95%CI 1.01-2.19), having an unknown country of birth (OR 1.63, 95%CI 1.47-1.81) and older age. Including or excluding DCO cases had no significant impact on hazard ratios for cancer death by socio-economic disadvantage quintile or remoteness category, and only a minor impact on hazard ratios by age. Socio-demographic factors were associated with DCO diagnosis in NSW. However, socio-demographic cancer survival disparities remained unchanged or varied only slightly irrespective of including/excluding DCO cases. Further research could examine the upper limits of DCO proportions that significantly alter estimated cancer survival differentials if DCOs are excluded. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.
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Control of neural stem cell survival by electroactive polymer substrates.
Directory of Open Access Journals (Sweden)
Vanessa Lundin
Full Text Available Stem cell function is regulated by intrinsic as well as microenvironmental factors, including chemical and mechanical signals. Conducting polymer-based cell culture substrates provide a powerful tool to control both chemical and physical stimuli sensed by stem cells. Here we show that polypyrrole (PPy, a commonly used conducting polymer, can be tailored to modulate survival and maintenance of rat fetal neural stem cells (NSCs. NSCs cultured on PPy substrates containing different counter ions, dodecylbenzenesulfonate (DBS, tosylate (TsO, perchlorate (ClO(4 and chloride (Cl, showed a distinct correlation between PPy counter ion and cell viability. Specifically, NSC viability was high on PPy(DBS but low on PPy containing TsO, ClO(4 and Cl. On PPy(DBS, NSC proliferation and differentiation was comparable to standard NSC culture on tissue culture polystyrene. Electrical reduction of PPy(DBS created a switch for neural stem cell viability, with widespread cell death upon polymer reduction. Coating the PPy(DBS films with a gel layer composed of a basement membrane matrix efficiently prevented loss of cell viability upon polymer reduction. Here we have defined conditions for the biocompatibility of PPy substrates with NSC culture, critical for the development of devices based on conducting polymers interfacing with NSCs.
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Induction of apoptotic cell death by putrescine
DEFF Research Database (Denmark)
Takao, Koichi; Rickhag, Karl Mattias; Hegardt, Cecilia
2006-01-01
that overexpression of a metabolically stable ODC in CHO cells induced a massive cell death unless the cells were grown in the presence of the ODC inhibitor alpha-difluoromethylornithine (DFMO). Cells overexpressing wild-type (unstable) ODC, on the other hand, were not dependent on the presence of DFMO...... 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...... of apoptosis was the finding that one of the key enzymes in the apoptotic process, caspase-3, was induced when DFMO was omitted from the growth medium. Furthermore, inhibition of the caspase activity significantly reduced the recruitment of cells to the sub-G1 fraction. In conclusion, deregulation of polyamine...
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Cell Death Conversion under Hypoxic Condition in Tumor Development and Therapy
Directory of Open Access Journals (Sweden)
Yu Qiu
2015-10-01
Full Text Available Hypoxia, which is common during tumor progression, plays important roles in tumor biology. Failure in cell death in response to hypoxia contributes to progression and metastasis of tumors. On the one hand, the metabolic and oxidative stress following hypoxia could lead to cell death by triggering signal cascades, like LKB1/AMPK, PI3K/AKT/mTOR, and altering the levels of effective components, such as the Bcl-2 family, Atg and p62. On the other hand, hypoxia-induced autophagy can serve as a mechanism to turn over nutrients, so as to mitigate the adverse condition and then avoid cell death potentially. Due to the effective role of hypoxia, this review focuses on the crosstalk in cell death under hypoxia in tumor progression. Additionally, the illumination of cell death in hypoxia could shed light on the clinical applications of cell death targeted therapy.
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LENUS (Irish Health Repository)
Creagh, Emma M
2009-01-01
Members of the caspase family of cysteine proteases coordinate cell death through restricted proteolysis of diverse protein substrates and play a conserved role in apoptosis from nematodes to man. However, while numerous substrates for the mammalian cell death-associated caspases have now been described, few caspase substrates have been identified in other organisms. Here, we have utilized a proteomics-based approach to identify proteins that are cleaved by caspases during apoptosis in Drosophila D-Mel2 cells, a subline of the Schneider S2 cell line. This approach identified multiple novel substrates for the fly caspases and revealed that bicaudal\\/betaNAC is a conserved substrate for Drosophila and mammalian caspases. RNAi-mediated silencing of bicaudal expression in Drosophila D-Mel2 cells resulted in a block to proliferation, followed by spontaneous apoptosis. Similarly, silencing of expression of the mammalian bicaudal homologue, betaNAC, in HeLa, HEK293T, MCF-7 and MRC5 cells also resulted in spontaneous apoptosis. These data suggest that bicaudal\\/betaNAC is essential for cell survival and is a conserved target of caspases from flies to man.
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Weld, R; Heinemann, J; Eady, C
2001-03-01
The transient nature of T-DNA expression was studied with a gfp reporter gene transferred to Nicotiana plumbaginifolia suspension cells from Agrobacterium tumefaciens. Individual GFP-expressing protoplasts were isolated after 4 days' co-cultivation. The protoplasts were cultured without selection and 4 weeks later the surviving proto-calluses were again screened for GFP expression. Of the proto-calluses initially expressing GFP, 50% had lost detectable GFP activity during the first 4 weeks of culture. Multiple T-DNA copies of the gfp gene were detected in 10 of 17 proto-calluses lacking visible GFP activity. The remaining 7 cell lines contained no gfp sequences. Our results confirm that transiently expressed T-DNAs can be lost during growth of somatic cells and demonstrate that transiently expressing cells frequently integrate multiple T-DNAs that become silenced. In cells competent for DNA uptake, cell death and gene silencing were more important barriers to the recovery of stably expressing transformants than lack of T-DNA integration.
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Directory of Open Access Journals (Sweden)
Sachiko Hirai
Full Text Available Up-regulated sirtuin 1 (SIRT1, an NAD+-dependent class III histone deacetylase, deacetylates p53 and inhibits its transcriptional activity, leading to cell survival. SIRT1 overexpression has been reported to predict poor survival in some malignancies, including gastric cancer. However, the antitumor effect of SIRT1 inhibition remains elusive in gastric cancer. Here, we investigated the antitumor mechanisms of a sirtuin inhibitor, tenovin-6, in seven human gastric cancer cell lines (four cell lines with wild-type TP53, two with mutant-type TP53, and one with null TP53. Interestingly, tenovin-6 induced apoptosis in all cell lines, not only those with wild-type TP53, but also mutant-type and null versions, accompanied by up-regulation of death receptor 5 (DR5. In the KatoIII cell line (TP53-null, DR5 silencing markedly attenuated tenovin-6-induced apoptosis, suggesting that the pivotal mechanism behind its antitumor effects is based on activation of the death receptor signal pathway. Although endoplasmic reticulum stress caused by sirtuin inhibitors was reported to induce DR5 up-regulation in other cancer cell lines, we could not find marked activation of its related molecules, such as ATF6, PERK, and CHOP, in gastric cancer cells treated with tenovin-6. Tenovin-6 in combination with docetaxel or SN-38 exerted a slight to moderate synergistic cytotoxicity against gastric cancer cells. In conclusion, tenovin-6 has potent antitumor activity against human gastric cancer cells via DR5 up-regulation. Our results should be helpful for the future clinical development of sirtuin inhibitors.
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Effects of epigallocatechin gallate on ultra-violet-induced cell death in PC12 cells
International Nuclear Information System (INIS)
Takahashi, Hideo; Seki, Sakiko; Sakamoto, Naotaka; Nakagawa, Shigeki
2002-01-01
We examined the effects of catechin on ultra-violet-induced cell death in PC12 cells. PC12 cells were irradiated by ultra-violet C (254 nm) (UVC). We found that the lactate dehydrogenase (LDH) activities in culture media and lipid peroxide in PC12 cells, which indicate cell death and cell membrane damage, respectively, were increased by UVC irradiation in a time-dependent manner. Cell death was gradually stimulated for 9 hours of cultivation after a UVC irradiation period of 10 or 30 min. Epigallocatechin gallate (EGCG), which is one of the main catechins found in green tea, suppressed the increase in LDH activity in culture medium and also inhibited the formation of lipid peroxide. IκB, a member of the cell death signaling system, was phosphorylated at 1 hour after 10 min of UVC irradiation. Stimulation of phosphorylation of IκB by UVC was suppressed by the addition of EGCG. We concluded that EGCG protects the PC12 cell from cell damage caused by UVC irradiation. (author)
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DEFF Research Database (Denmark)
Sucheston-Campbell, Lara E; Cannioto, Rikki; Clay, Alyssa I
2017-01-01
BACKGROUND: The precise mechanism by which the immune system is adversely affected in cancer patients remains poorly understood, but the accumulation of immune suppressive/pro-tumorigenic myeloid-derived suppressor cells (MDSCs) is thought to be one prominent mechanism contributing to immunologic...... tolerance of malignant cells in epithelial ovarian cancer (EOC). To this end, we hypothesized genetic variation in MDSC pathway genes would be associated with survival after EOC diagnoses. METHODS: We measured the hazard of death due to EOC within 10 years of diagnosis, overall and by invasive subtype...
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Mechanisms underlying 3-bromopyruvate-induced cell death in colon cancer.
Sun, Yiming; Liu, Zhe; Zou, Xue; Lan, Yadong; Sun, Xiaojin; Wang, Xiu; Zhao, Surong; Jiang, Chenchen; Liu, Hao
2015-08-01
3-Bromopyruvate (3BP) is an energy-depleting drug that inhibits Hexokinase II activity by alkylation during glycolysis, thereby suppressing the production of ATP and inducing cell death. As such, 3BP can potentially serve as an anti-tumorigenic agent. Our previous research showed that 3BP can induce apoptosis via AKT /protein Kinase B signaling in breast cancer cells. Here we found that 3BP can also induce colon cancer cell death by necroptosis and apoptosis at the same time and concentration in the SW480 and HT29 cell lines; in the latter, autophagy was also found to be a mechanism of cell death. In HT29 cells, combined treatment with 3BP and the autophagy inhibitor 3-methyladenine (3-MA) exacerbated cell death, while viability in 3BP-treated cells was enhanced by concomitant treatment with the caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp fluoromethylketone (z-VAD-fmk) and the necroptosis inhibitor necrostatin (Nec)-1. Moreover, 3BP inhibited tumor growth in a SW480 xenograft mouse model. These results indicate that 3BP can suppress tumor growth and induce cell death by multiple mechanisms at the same time and concentration in different types of colon cancer cell by depleting cellular energy stores.
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Programmed cell death during quinoa perisperm development.
López-Fernández, María Paula; Maldonado, Sara
2013-08-01
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 nucleases and caspase-like proteases in nucleus dismantling, were evaluated; morphological changes in cytoplasm included subcellular aspects related to starch accumulation. This study proved that, following fertilization, the perisperm of quinoa simultaneously accumulates storage reserves and degenerates, both processes mediated by a programme of developmentally controlled cell death. The novel findings regarding perisperm development provide a starting point for further research in the Amaranthaceae genera, such as comparing seeds with and without perisperm, and specifying phylogeny and evolution within this taxon. Wherever possible and appropriate, differences between quinoa perisperm and grass starchy endosperm--a morphologically and functionally similar, although genetically different tissue--were highlighted and discussed.
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Maitotoxin-induced liver cell death involving loss of cell ATP following influx of calcium
International Nuclear Information System (INIS)
Kutty, R.K.; Singh, Y.; Santostasi, G.; Krishna, G.
1989-01-01
Maitotoxin, one of the most potent marine toxins known, produced cell death in cultures of rat hepatocytes with a TD50 of 80 pM at 24 hr. The cell death, as indicated by a dose- and time-dependent leakage of lactate dehydrogenase (LDH), was also associated with the leakage of [14C]adenine nucleotides from hepatocytes prelabeled with [14C]-adenine. The toxic effect of maitotoxin was completely abolished by the omission of calcium from the culture medium. The cell death induced by maitotoxin increased with increasing concentrations of calcium in the medium. Treatment of hepatocytes with low concentrations of the toxin (less than 0.5 ng/ml) resulted in increases in 45Ca influx into the cells. At higher concentrations of maitotoxin (greater than 1ng/ml), the initial increase in 45Ca influx was followed by the release of the 45Ca from the cells into the medium. Since the 45Ca release paralleled the LDH leakage, the release of calcium was due to cell death. The 45Ca influx, [14C]adenine nucleotide leakage, and LDH leakage were effectively inhibited by verapamil, a calcium channel blocker. Maitotoxin also induced a time- and dose-dependent loss of ATP from hepatocytes, which preceded the [14C]adenine nucleotide and LDH leakage. Thus, it appears that the cell death resulting from maitotoxin treatment is caused by the elevated intracellular calcium, which in turn inhibits mitochondrial oxidative phosphorylation causing depletion of cell ATP. Loss of cell ATP may be the causative event in the maitotoxin-induced cell death
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Dotiwala, Farokh; Sen Santara, Sumit; Binker-Cosen, Andres Ariel; Li, Bo; Chandrasekaran, Sriram; Lieberman, Judy
2017-11-16
Human cytotoxic lymphocytes kill intracellular microbes. The cytotoxic granule granzyme proteases released by cytotoxic lymphocytes trigger oxidative bacterial death by disrupting electron transport, generating superoxide anion and inactivating bacterial oxidative defenses. However, they also cause non-oxidative cell death because anaerobic bacteria are also killed. Here, we use differential proteomics to identify granzyme B substrates in three unrelated bacteria: Escherichia coli, Listeria monocytogenes, and Mycobacteria tuberculosis. Granzyme B cleaves a highly conserved set of proteins in all three bacteria, which function in vital biosynthetic and metabolic pathways that are critical for bacterial survival under diverse environmental conditions. Key proteins required for protein synthesis, folding, and degradation are also substrates, including multiple aminoacyl tRNA synthetases, ribosomal proteins, protein chaperones, and the Clp system. Because killer cells use a multipronged strategy to target vital pathways, bacteria may not easily become resistant to killer cell attack. Copyright © 2017 Elsevier Inc. All rights reserved.
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Baldassarro, Vito A; Marchesini, Alessandra; Giardino, Luciana; Calzà, Laura
2017-07-01
Poly (ADP-ribose) polymerase (PARP) family members are ubiquitously expressed and play a key role in cellular processes, including DNA repair and cell death/survival balance. Accordingly, PARP inhibition is an emerging pharmacological strategy for cancer and neurodegenerative diseases. Consistent evidences support the critical involvement of PARP family members in cell differentiation and phenotype maturation. In this study we used an oligodendrocyte precursor cells (OPCs) enriched system derived from fetal and adult brain to investigate the role of PARP in OPCs proliferation, survival, and differentiation. The PARP inhibitors PJ34, TIQ-A and Olaparib were used as pharmacological tools. The main results of the study are: (i) PARP mRNA expression and PARP activity are much higher in fetal than in adult-derived OPCs; (ii) the culture treatment with PARP inhibitors is cytotoxic for OPCs derived from fetal, but not from adult, brain; (iii) PARP inhibition reduces cell number, according to the inhibitory potency of the compounds; (iv) PARP inhibition effect on fetal OPCs is a slow process; (v) PARP inhibition impairs OPCs maturation into myelinating OL in fetal, but not in adult cultures, according to the inhibitory potency of the compounds. These results have implications for PARP-inhibition therapies for diseases and lesions of the central nervous system, in particular for neonatal hypoxic/ischemic encephalopathy. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
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Regulatory dendritic cell infusion prolongs kidney allograft survival in nonhuman primates.
Ezzelarab, M B; Zahorchak, A F; Lu, L; Morelli, A E; Chalasani, G; Demetris, A J; Lakkis, F G; Wijkstrom, M; Murase, N; Humar, A; Shapiro, R; Cooper, D K C; Thomson, A W
2013-08-01
We examined the influence of regulatory dendritic cells (DCreg), generated from cytokine-mobilized donor blood monocytes in vitamin D3 and IL-10, on renal allograft survival in a clinically relevant rhesus macaque model. DCreg expressed low MHC class II and costimulatory molecules, but comparatively high levels of programmed death ligand-1 (B7-H1), and were resistant to pro-inflammatory cytokine-induced maturation. They were infused intravenously (3.5-10 × 10(6) /kg), together with the B7-CD28 costimulation blocking agent CTLA4Ig, 7 days before renal transplantation. CTLA4Ig was given for up to 8 weeks and rapamycin, started on Day -2, was maintained with tapering of blood levels until full withdrawal at 6 months. Median graft survival time was 39.5 days in control monkeys (no DC infusion; n = 6) and 113.5 days (p DCreg-treated animals (n = 6). No adverse events were associated with DCreg infusion, and there was no evidence of induction of host sensitization based on circulating donor-specific alloantibody levels. Immunologic monitoring also revealed regulation of donor-reactive memory CD95(+) T cells and reduced memory/regulatory T cell ratios in DCreg-treated monkeys compared with controls. Termination allograft histology showed moderate combined T cell- and Ab-mediated rejection in both groups. These findings justify further preclinical evaluation of DCreg therapy and their therapeutic potential in organ transplantation. © Copyright 2013 The American Society of Transplantation and the American Society of Transplant Surgeons.
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The extrinsic cell death pathway and the élan mortel.
Wallach, D; Kang, T-B; Kovalenko, A
2008-10-01
Early in the exploration of the chemical nature of life, it was widely believed that the molecules of living organisms, by their very nature, differ from those of inorganic material molecules and possess a vital force ('élan vital'). Similarly, early scientific thinking on the subject of cell death and its induction by cytotoxic cells of the immune system was pervaded by a sense that the molecules mediating these functions possess intrinsic deadly activity and are dedicated exclusively to death-related tasks. This impression was also reflected in the initial notions of the mode of action of intracellular proteins that signal for death. It is now gradually becoming clear, however, that proteins participating in death induction also have functions unrelated to death. Nevertheless, as exemplified by studies of the function of caspase-8 (an enzyme that signals both for activation of the extrinsic cell-death pathway and for non-death-related effects), analysis of the mechanistic basis for such heterogeneity might allow identification of distinct structural determinants in the proteins participating in death induction that do bear death specificity.
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International Nuclear Information System (INIS)
Zhang, X.; Li, L.; Zhang, L.; Borowitz, J.L.; Isom, G.E.
2009-01-01
Cyanide is a potent inhibitor of mitochondrial oxidative metabolism and produces mitochondria-mediated death of dopaminergic neurons and sublethal intoxications that are associated with a Parkinson-like syndrome. Cyanide toxicity is enhanced when mitochondrial uncoupling is stimulated following up-regulation of uncoupling protein-2 (UCP-2). In this study, the role of a pro-survival protein, Bcl-2, in cyanide-mediated cell death was determined in a rat dopaminergic immortalized mesencephalic cell line (N27 cells). Following pharmacological up-regulation of UCP-2 by treatment with Wy14,643, cyanide reduced cellular Bcl-2 expression by increasing proteasomal degradation of the protein. The increased turnover of Bcl-2 was mediated by an increase of oxidative stress following UCP-2 up-regulation. The oxidative stress involved depletion of mitochondrial glutathione (mtGSH) and increased H 2 O 2 generation. Repletion of mtGSH by loading cells with glutathione ethyl ester reduced H 2 O 2 generation and in turn blocked the cyanide-induced decrease of Bcl-2. To determine if UCP-2 mediated the response, RNAi knock down was conducted. The RNAi decreased cyanide-induced depletion of mtGSH, reduced H 2 O 2 accumulation, and inhibited down-regulation of Bcl-2, thus blocking cell death. To confirm the role of Bcl-2 down-regulation in the cell death, it was shown that over-expression of Bcl-2 by cDNA transfection attenuated the enhancement of cyanide toxicity after UCP-2 up-regulation. It was concluded that UCP-2 up-regulation sensitizes cells to cyanide by increasing cellular oxidative stress, leading to an increase of Bcl-2 degradation. Then the reduced Bcl-2 levels sensitize the cells to cyanide-mediated cell death.
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Mlejnek, Petr
2013-10-01
N(6)-benzyladenine (BA) and N(6)-benzyladenosine ([9R]BA) induce massive production of reactive oxygen species (ROS) that is eventually followed by a loss of cell viability in tobacco BY-2 cells (Mlejnek et al. Plant Cell Environ 26:1723-1735, 2003, Plant Sci 168:389-395, 2005). Results presented in this work suggest that the main sources of ROS are likely mitochondria and that the maintenance of the mitochondrial transmembrane potential is crucial for ROS production in cytokinin-treaded BY-2 cells. Therefore, the possible involvement of alternative oxidase (AOX) in cell death process induced by BA and [9R]BA was studied. About three- to fourfold increase in mRNA levels of AOX1 was observed a few hours after the BA and [9R]BA addition into the growth medium. The elevated expression of AOX1 mRNA could be prevented by adding adenine and adenosine which simultaneously reduced the cytotoxic effects of BA and [9R]BA, respectively. N(6)-benzyladenine 7-β-D-glucoside ([7G]BA) which is a common non-toxic metabolite of BA and [9R]BA did not affect the AOX1 mRNA expression. Although AOX1 seemed to be involved in protection of BY-2 cells against the abiotic stress induced by BA and [9R]BA, the results do not support the idea that it protects cells from death exclusively by scavenging of reactive oxygen species. Indeed, N-propyl gallate, an inhibitor of AOX, decreased cell survival despite it concomitantly decreased the ROS production. This finding is in contrast to the effect of salicylhydroxamic acid, another well-known inhibitor of AOX, which also increased the number of dying cells while it increased the ROS production.
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DEFF Research Database (Denmark)
Andersson, Hedvig Bille; Pedersen, Frants; Engstrøm, Thomas
2018-01-01
Aims: We aimed to study survival and causes of death in patients with ST-elevation acute coronary syndrome (STE-ACS) with and without obstructive coronary artery disease (CAD). Methods and results: We included 4793 consecutive patients with STE-ACS triaged for acute coronary angiography at a larg...... than patients with obstructive CAD. Causes of death were less often cardiovascular. This suggests that STE-ACS patients without obstructive CAD warrant medical attention and close follow-up.......Aims: We aimed to study survival and causes of death in patients with ST-elevation acute coronary syndrome (STE-ACS) with and without obstructive coronary artery disease (CAD). Methods and results: We included 4793 consecutive patients with STE-ACS triaged for acute coronary angiography at a large...
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Yadav, Saveg; Kujur, Praveen Kumar; Pandey, Shrish Kumar; Goel, Yugal; Maurya, Babu Nandan; Verma, Ashish; Kumar, Ajay; Singh, Rana Pratap; Singh, Sukh Mahendra
2018-01-15
Evidences demonstrate that metabolic inhibitor 3-bromopyruvate (3-BP) exerts a potent antitumor action against a wide range of malignancies. However, the effect of 3-BP on progression of the tumors of thymic origin remains unexplored. Although, constituents of tumor microenvironment (TME) plays a pivotal role in regulation of tumor progression, it remains unclear if 3-BP can alter the composition of the crucial tumor growth regulatory components of the external surrounding of tumor cells. Thus, the present investigation attempts to understand the effect of 3-BP administration to a host bearing a progressively growing tumor of thymic origin on tumor growth regulatory soluble, cellular and biophysical components of tumor milieu vis-à-vis understanding its association with tumor progression, accompanying cell cycle events and mode of cell death. Further, the expression of cell survival regulatory molecules and hemodynamic characteristics of the tumor milieu were analysed to decipher mechanisms underlying the antitumor action of 3-BP. Administration of 3-BP to tumor-bearing hosts retarded tumor progression accompanied by induction of tumor cell death, cell cycle arrest, declined metabolism, inhibited mitochondrial membrane potential, elevated release of cytochrome c and altered hemodynamics. Moreover, 3-BP reconstituted the external milieu, in concurrence with deregulated glucose and pH homeostasis and increased tumor infiltration by NK cells, macrophages, and T lymphocytes. Further, 3-BP administration altered the expression of key regulatory molecules involved in glucose uptake, intracellular pH and tumor cell survival. The outcomes of this study will help in optimizing the therapeutic application of 3-BP by targeting crucial tumor growth regulatory components of tumor milieu. Copyright © 2017 Elsevier Inc. All rights reserved.
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Starenki, Dmytro
2013-01-01
Context: Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor mainly caused by mutations in the RET proto-oncogene. For MTC therapy, the U.S. Food and Drug Administration recently approved vandetanib and cabozantinib, multikinase inhibitors targeting RET and other tyrosine kinase receptors of vascular endothelial growth factor, epidermal growth factor, or hepatocyte growth factor. Nevertheless, not all patients with the progressive MTC respond to these drugs, requiring the development of additional therapeutic modalities that have distinct activity. Objective: We aimed to evaluate mitochondria-targeted carboxy-proxyl (Mito-CP), a mitochondria-targeted redox-sensitive agent, for its tumor-suppressive efficacy against MTC. Design: In vitro cultures of 2 human MTC cell lines, TT and MZ-CRC-1, and TT xenografts in mice were treated with Mito-CP in comparison with vandetanib. The effects on cell survival/death, RET expression, mitochondrial integrity, and oxidative stress were determined. Results: Contrary to vandetanib, Mito-CP induced RET downregulation and strong cytotoxic effects in both cell lines in vitro, including caspase-dependent apoptosis. These effects were accompanied by mitochondrial membrane depolarization, decreased oxygen consumption, and increased oxidative stress in cells. Intriguingly, Mito-CP–induced cell death, but not RET downregulation, was partially inhibited by the reactive oxygen species scavenger, N-acetyl-cysteine, indicating that Mito-CP mediates tumor-suppressive effects via redox-dependent as well as redox-independent mechanisms. Orally administered Mito-CP effectively suppressed TT xenografts in mice, with an efficacy comparable to vandetanib and relatively low toxicity to animals. Conclusion: Our results suggest that Mito-CP can effectively suppress MTC cell growth/survival via a mechanism distinct from vandetanib effects. Mitochondrial targeting may be a potential strategy for MTC therapy. PMID:23509102
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DNA strand breaks, repair, and survival in x-irradiated mammalian cells
International Nuclear Information System (INIS)
Dugle, D.L.; Gillespie, C.J.; Chapman, J.D.
1976-01-01
The yields of unrepairable single- and double-strand breaks in the DNA of x-irradiated Chinese hamster cells were measured by low-speed neutral and alkaline sucrose density gradient sedimentation in order to investigate the relation between these lesions and reproductive death. After maximal single-strand rejoining, at all doses, the number of residual single-strand breaks was twice the number of residual double-strand breaks. Both double-strand and unrepairable single-strand breaks were proportional to the square of absorbed dose, in the range 10-50 krad. No rejoining of double-strand breaks was observed. These observations suggest that, in mammalian cells, most double-strand breaks are not repairable, while all single-strand breaks are repaired except those that are sufficiently close on complementary strands to constitute double-strand breaks. Comparison with cell survival measurements at much lower doses suggests that loss of reproductive capacity corresponds to induction of approximately one double-strand break
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Directory of Open Access Journals (Sweden)
Ying Liu
2017-11-01
Full Text Available Background/Aims: Osteosarcoma (OS is the most common primary malignant tumor of bone tissue. Although treatment effectiveness has improved, the OS survival rate has fluctuated in recent years. Andrographolide (AG has been reported to have antitumor activity against a variety of tumors. Our aim was to investigate the effects and potential mechanisms of AG in human osteosarcoma. Methods: Cell viability and morphological changes were assessed by MTT and live/dead assays. Apoptosis was detected using Annexin V-FITC/PI double staining, DAPI, and caspase-3 assays. Autophagy was detected with mRFP-GFP-LC3 adenovirus transfection and western blot. Cell migration and invasion were detected by wound healing assay and Transwell® experiments. Results: AG dose-dependently reduced the viability of osteosarcoma cells. No increase in apoptosis was detected in AG-treated human OS MG-63 and U-2OS cells, and the pan-caspase inhibitor z-VAD did not attenuate AG-induced cell death. However, AG induced autophagy by suppressing PI3K/Akt/mTOR and enhancing JNK signaling pathways. 3-MA and Beclin-1 siRNA could reverse the cytotoxic effects of AG. In addition, AG inhibited the invasion and metastasis of OS, and this effect could be reversed with Beclin-1 siRNA. Conclusion: AG inhibits viability and induces autophagic death in OS cells. AG-induced autophagy inhibits the invasion and metastasis of OS.
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Hauptmann, Peter; Lehle, Ludwig
2008-07-04
N-glycosylation in the endoplasmic reticulum is an essential protein modification and highly conserved in evolution from yeast to humans. The key step of this pathway is the transfer of the lipid-linked core oligosaccharide to the nascent polypeptide chain, catalyzed by the oligosaccharyltransferase complex. Temperature-sensitive oligosaccharyltransferase mutants of Saccharomyces cerevisiae at the restrictive temperature, such as wbp1-1, as well as wild-type cells in the presence of the N-glycosylation inhibitor tunicamycin display typical apoptotic phenotypes like nuclear condensation, DNA fragmentation, phosphatidylserine translocation, caspase-like activity, and reactive oxygen species accumulation. Since deletion of the yeast metacaspase YCA1 did not abrogate this death pathway, we postulated a different proteolytic process to be responsible. Here, we show that Kex1 protease is involved in the programmed cell death caused by defective N-glycosylation. Its disruption decreases caspase-like activity, production of reactive oxygen species, and fragmentation of mitochondria and, conversely, improves growth and survival of cells. Moreover, we demonstrate that Kex1 contributes also to the active cell death program induced by acetic acid stress or during chronological aging, suggesting that Kex1 plays a more general role in cellular suicide of yeast.
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Rajput, Ashwani; Teggart, Carol A.; Brattain, Lisa E.; Weber, Hannah R.; Chowdhury, Aparajita; Brattain, Michael G.
2011-01-01
Background Understanding drivers for metastasis in human cancer is important for potential development of therapies to treat metastases. The role of loss of TGFβ tumor suppressor activities in the metastatic process is essentially unknown. Methodology/Principal Findings Utilizing in vitro and in vivo techniques, we have shown that loss of TGFβ tumor suppressor signaling is necessary to allow the last step of the metastatic process - colonization of the metastatic site. This work demonstrates for the first time that TGFβ receptor reconstitution leads to decreased metastatic colonization. Moreover, we have identified a novel TGFβ/PKA tumor suppressor pathway that acts directly on a known cell survival mechanism that responds to stress with the survivin/XIAP dependent inhibition of caspases that effect apoptosis. The linkage between the TGFβ/PKA transduceome signaling and control of metastasis through induction of cell death was shown by TGFβ receptor restoration with reactivation of the TGFβ/PKA pathway in receptor deficient metastatic colon cancer cells leading to control of aberrant cell survival. Conclusion/Significance This work impacts our understanding of the possible mechanisms that are critical to the growth and maintenance of metastases as well as understanding of a novel TGFβ function as a metastatic suppressor. These results raise the possibility that regeneration of attenuated TGFβ signaling would be an effective target in the treatment of metastasis. Our work indicates the clinical potential for developing anti-metastasis therapy based on inhibition of this very important aberrant cell survival mechanism by the multifaceted TGFβ/PKA transduceome induced pathway. Development of effective treatments for metastatic disease is a pressing need since metastases are the major cause of death in solid tumors. PMID:21559296
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Directory of Open Access Journals (Sweden)
Sanjib Chowdhury
2011-05-01
Full Text Available Understanding drivers for metastasis in human cancer is important for potential development of therapies to treat metastases. The role of loss of TGFβ tumor suppressor activities in the metastatic process is essentially unknown.Utilizing in vitro and in vivo techniques, we have shown that loss of TGFβ tumor suppressor signaling is necessary to allow the last step of the metastatic process - colonization of the metastatic site. This work demonstrates for the first time that TGFβ receptor reconstitution leads to decreased metastatic colonization. Moreover, we have identified a novel TGFβ/PKA tumor suppressor pathway that acts directly on a known cell survival mechanism that responds to stress with the survivin/XIAP dependent inhibition of caspases that effect apoptosis. The linkage between the TGFβ/PKA transduceome signaling and control of metastasis through induction of cell death was shown by TGFβ receptor restoration with reactivation of the TGFβ/PKA pathway in receptor deficient metastatic colon cancer cells leading to control of aberrant cell survival.This work impacts our understanding of the possible mechanisms that are critical to the growth and maintenance of metastases as well as understanding of a novel TGFβ function as a metastatic suppressor. These results raise the possibility that regeneration of attenuated TGFβ signaling would be an effective target in the treatment of metastasis. Our work indicates the clinical potential for developing anti-metastasis therapy based on inhibition of this very important aberrant cell survival mechanism by the multifaceted TGFβ/PKA transduceome induced pathway. Development of effective treatments for metastatic disease is a pressing need since metastases are the major cause of death in solid tumors.
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JTC801 Induces pH-dependent Death Specifically in Cancer Cells and Slows Growth of Tumors in Mice.
Song, Xinxin; Zhu, Shan; Xie, Yangchun; Liu, Jiao; Sun, Lingyi; Zeng, Dexing; Wang, Pengcheng; Ma, Xiaochao; Kroemer, Guido; Bartlett, David L; Billiar, Timothy R; Lotze, Michael T; Zeh, Herbert J; Kang, Rui; Tang, Daolin
2018-04-01
Maintenance of acid-base homeostasis is required for normal physiology, metabolism, and development. It is not clear how cell death is activated in response to changes in pH. We performed a screen to identify agents that induce cell death in a pH-dependent manner (we call this alkaliptosis) in pancreatic ductal adenocarcinoma cancer (PDAC) cells and tested their effects in mice. We screened a library of 254 compounds that interact with G-protein-coupled receptors (GPCRs) to identify those with cytotoxic activity against a human PDAC cell line (PANC1). We evaluated the ability of JTC801, which binds the opiod receptor and has analgesic effects, to stimulate cell death in human PDAC cell lines (PANC1, MiaPaCa2, CFPAC1, PANC2.03, BxPc3, and CAPAN2), mouse pancreatic cancer-associated stellate cell lines, primary human pancreatic ductal epithelial cells, and 60 cancer cell lines (the NCI-60 panel). Genes encoding proteins in cell death and GPCR signaling pathways, as well as those that regulate nuclear factor-κB (NF-κB) activity, were knocked out, knocked down, or expressed from transgenes in cancer cell lines. JTC801 was administered by gavage to mice with xenograft tumors, C57BL/6 mice with orthographic pancreatic tumors grown from Pdx1-Cre;KRas G12D/+ ;Tp53 R172H/+ (KPC) cells, mice with metastases following tail-vein injection of KPC cells, and Pdx-1-Cre;Kras G12D/+ mice crossed with Hmgb1 flox/flox mice (KCH mice). Pancreata were collected from mice and analyzed for tumor growth and by histology and immunohistochemistry. We compared gene and protein expression levels between human pancreatic cancer tissues and patient survival times using online R2 genomic or immunohistochemistry analyses. Exposure of human PDAC cell lines (PANC1 and MiaPaCa2) to JTC801 did not induce molecular markers of apoptosis (cleavage of caspase 3 or poly [ADP ribose] polymerase [PARP]), necroptosis (interaction between receptor-interacting serine-threonine kinase 3 [RIPK3] and mixed
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Directory of Open Access Journals (Sweden)
Thomas Lahlali
2016-05-01
Full Text Available Background & Aims: Netrin-1, a multifunctional secreted protein, is up-regulated in cancer and inflammation. Netrin-1 blocks apoptosis induced by the prototypical dependence receptors deleted in colorectal carcinoma and uncoordinated phenotype-5. Although the unfolded protein response (UPR triggers apoptosis on exposure to stress, it first attempts to restore endoplasmic reticulum homeostasis to foster cell survival. Importantly, UPR is implicated in chronic liver conditions including hepatic oncogenesis. Netrin-1's implication in cell survival on UPR in this context is unknown. Methods: Isolation of translational complexes, determination of RNA secondary structures by selective 2â-hydroxyl acylation and primer extension/dimethyl sulfate, bicistronic constructs, as well as conventional cell biology and biochemistry approaches were used on in vitroâgrown hepatocytic cells, wild-type, and netrin-1 transgenic mice. Results: HepaRG cells constitute a bona fide model for UPR studies in vitro through adequate activation of the 3 sensors of the UPR (protein kinase RNAâlike endoplasmic reticulum kinase (PERK, inositol requiring enzyme 1α (IRE1α, and activated transcription factor 6 (ATF6. The netrin-1 messenger RNA 5'-end was shown to fold into a complex double pseudoknot and bear E-loop motifs, both of which are representative hallmarks of related internal ribosome entry site regions. Cap-independent translation of netrin 5' untranslated regionâdriven luciferase was observed on UPR in vitro. Unlike several structurally related oncogenic transcripts (l-myc, c-myc, c-myb, netrin-1 messenger RNA was selected for translation during UPR both in human hepatocytes and in mice livers. Depletion of netrin-1 during UPR induces apoptosis, leading to cell death through an uncoordinated phenotype-5A/Câmediated involvement of protein phosphatase 2A and death-associated protein kinase 1 in vitro and in netrin
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A High-Throughput Small Molecule Screen for C. elegans Linker Cell Death Inhibitors.
Directory of Open Access Journals (Sweden)
Andrew R Schwendeman
Full Text Available Programmed cell death is a ubiquitous process in metazoan development. Apoptosis, one cell death form, has been studied extensively. However, mutations inactivating key mammalian apoptosis regulators do not block most developmental cell culling, suggesting that other cell death pathways are likely important. Recent work in the nematode Caenorhabditis elegans identified a non-apoptotic cell death form mediating the demise of the male-specific linker cell. This cell death process (LCD, linker cell-type death is morphologically conserved, and its molecular effectors also mediate axon degeneration in mammals and Drosophila. To develop reagents to manipulate LCD, we established a simple high-throughput screening protocol for interrogating the effects of small molecules on C. elegans linker cell death in vivo. From 23,797 compounds assayed, 11 reproducibly block linker cell death onset. Of these, five induce animal lethality, and six promote a reversible developmental delay. These results provide proof-of principle validation of our screening protocol, demonstrate that developmental progression is required for linker cell death, and suggest that larger scale screens may identify LCD-specific small-molecule regulators that target the LCD execution machinery.
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Siavashi, Vahid; Asadian, Simin; Taheri-Asl, Masoud; Keshavarz, Samaneh; Zamani-Ahmadmahmudi, Mohamad; Nassiri, Seyed Mahdi
2017-10-01
Microvascular dysfunction plays a key role in the pathology of sepsis, leading to multi-organ failure, and death. Circulating endothelial progenitor cells (cEPCs) are critically involved in the maintenance of the vascular homeostasis in both physiological and pathological contexts. In this study, concentration of cEPCs in preterm infants with sepsis was determined to recognize whether the EPC mobilization would affect the clinical outcome of infantile sepsis. One hundred and thirty-three preterm infants (81 with sepsis and 52 without sepsis) were enrolled in this study. The release of EPCs in circulation was first quantified. Thereafter, these cells were cultivated and biological features of these cells such as, proliferation and colony forming efficiency were analyzed. The levels of chemoattractant cytokines were also measured in infants. In mouse models of sepsis, effects of VEGF and SDF-1 as well as anti-VEGF and anti-SDF-1 were evaluated in order to shed light upon the role which the EPC mobilization plays in the overall survival of septic animals. Circulating EPCs were significantly higher in preterm infants with sepsis than in the non-sepsis group. Serum levels of VEGF, SDF-1, and Angiopoietin-2 were also higher in preterm infants with sepsis than in control non-sepsis. In the animal experiments, injection of VEGF and SDF-1 prompted the mobilization of EPCs, leading to an improvement in survival whereas injection of anti-VEGF and anti-SDF-1 was associated with significant deterioration of survival. Overall, our results demonstrated the beneficial effects of EPC release in preterm infants with sepsis, with increased mobilization of these cells was associated with improved survival. J. Cell. Biochem. 118: 3299-3307, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
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Sensory hair cell death and regeneration in fishes
Directory of Open Access Journals (Sweden)
Jerry D. Monroe
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.
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Mechanisms of Virus-Induced Neural Cell Death
National Research Council Canada - National Science Library
Tyler, Kenneth
2002-01-01
Virtually all known neurotropic viruses are capable of killing infected cells by inducing a specific pattern of cell death known as apoptosis, yet the mechanism by which this occurs and its relevance...
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Circulating cell death products predict clinical outcome of colorectal cancer patients
International Nuclear Information System (INIS)
Koelink, Pim J; Lamers, Cornelis BHW; Hommes, Daan W; Verspaget, Hein W
2009-01-01
Tumor cell death generates products that can be measured in the circulation of cancer patients. CK18-Asp396 (M30 antigen) is a caspase-degraded product of cytokeratin 18 (CK18), produced by apoptotic epithelial cells, and is elevated in breast and lung cancer patients. We determined the CK18-Asp396 and total CK18 levels in plasma of 49 colorectal cancer patients, before and after surgical resection of the tumor, by ELISA. Correlations with patient and tumor characteristics were determined by Kruskal-Wallis H and Mann-Whitney U tests. Disease-free survival was determined using Kaplan-Meier methodology with Log Rank tests, and univariate and multivariate Cox proportional hazard analysis. Plasma CK18-Asp396 and total CK18 levels in colorectal cancer patients were related to disease stage and tumor diameter, and were predictive of disease-free survival, independent of disease-stage, with hazard ratios (HR) of patients with high levels (> median) compared to those with low levels (≤ median) of 3.58 (95% CI: 1.17–11.02) and 3.58 (95% CI: 0.97–7.71), respectively. The CK18-Asp396/CK18 ratio, which decreased with tumor progression, was also predictive of disease-free survival, with a low ratio (≤ median) associated with worse disease-free survival: HR 2.78 (95% CI: 1.06–7.19). Remarkably, the plasma CK18-Asp396 and total CK18 levels after surgical removal of the tumor were also predictive of disease-free survival, with patients with high levels having a HR of 3.78 (95% CI: 0.77–18.50) and 4.12 (95% CI: 0.84–20.34), respectively, indicating that these parameters can be used also to monitor patients after surgery. CK18-Asp396 and total CK18 levels in the circulation of colorectal cancer patients are predictive of tumor progression and prognosis and might be helpful for treatment selection and monitoring of these patients
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Targeting Cellular Calcium Homeostasis to Prevent Cytokine-Mediated Beta Cell Death.
Clark, Amy L; Kanekura, Kohsuke; Lavagnino, Zeno; Spears, Larry D; Abreu, Damien; Mahadevan, Jana; Yagi, Takuya; Semenkovich, Clay F; Piston, David W; Urano, Fumihiko
2017-07-17
Pro-inflammatory cytokines are important mediators of islet inflammation, leading to beta cell death in type 1 diabetes. Although alterations in both endoplasmic reticulum (ER) and cytosolic free calcium levels are known to play a role in cytokine-mediated beta cell death, there are currently no treatments targeting cellular calcium homeostasis to combat type 1 diabetes. Here we show that modulation of cellular calcium homeostasis can mitigate cytokine- and ER stress-mediated beta cell death. The calcium modulating compounds, dantrolene and sitagliptin, both prevent cytokine and ER stress-induced activation of the pro-apoptotic calcium-dependent enzyme, calpain, and partly suppress beta cell death in INS1E cells and human primary islets. These agents are also able to restore cytokine-mediated suppression of functional ER calcium release. In addition, sitagliptin preserves function of the ER calcium pump, sarco-endoplasmic reticulum Ca 2+ -ATPase (SERCA), and decreases levels of the pro-apoptotic protein thioredoxin-interacting protein (TXNIP). Supporting the role of TXNIP in cytokine-mediated cell death, knock down of TXNIP in INS1-E cells prevents cytokine-mediated beta cell death. Our findings demonstrate that modulation of dynamic cellular calcium homeostasis and TXNIP suppression present viable pharmacologic targets to prevent cytokine-mediated beta cell loss in diabetes.
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Blockade of the ERK pathway markedly sensitizes tumor cells to HDAC inhibitor-induced cell death
International Nuclear Information System (INIS)
Ozaki, Kei-ichi; Minoda, Ai; Kishikawa, Futaba; Kohno, Michiaki
2006-01-01
Constitutive activation of the extracellular signal-regulated kinase (ERK) pathway is associated with the neoplastic phenotype of a large number of human tumor cells. Although specific blockade of the ERK pathway by treating such tumor cells with potent mitogen-activated protein kinase/ERK kinase (MEK) inhibitors completely suppresses their proliferation, it by itself shows only a modest effect on the induction of apoptotic cell death. However, these MEK inhibitors markedly enhance the efficacy of histone deacetylase (HDAC) inhibitors to induce apoptotic cell death: such an enhanced cell death is observed only in tumor cells in which the ERK pathway is constitutively activated. Co-administration of MEK inhibitor markedly sensitizes tumor cells to HDAC inhibitor-induced generation of reactive oxygen species, which appears to mediate the enhanced cell death induced by the combination of these agents. These results suggest that the combination of MEK inhibitors and HDAC inhibitors provides an efficient chemotherapeutic strategy for the treatment of tumor cells in which the ERK pathway is constitutively activated
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van Gennip, I.E.; Pasman, H.R.W.; Kaspers, P.J.; Oosterveld-Vlug, M.G.; Willems, D.L.; Deeg, D.J.H.; Onwuteaka-Philipsen, B.D.
2013-01-01
Background: Death with dignity has been identified as important both to patients and their surviving family. While research results have been published on what patients themselves believe may affect the dignity of their deaths, little is known about what family caregivers consider to be a dignified
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Cell death by pyroptosis drives CD4 T-cell depletion in HIV-1 infection
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.
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International Nuclear Information System (INIS)
Liu Xiangde; Nelson, Amy; Wang Xingqi; Kanaji, Nobuhiro; Kim, Miok; Sato, Tadashi; Nakanishi, Masanori; Li Yingji; Sun Jianhong; Michalski, Joel; Patil, Amol; Basma, Hesham; Rennard, Stephen I.
2009-01-01
MicroRNA plays an important role in cell differentiation, proliferation and cell death. The current study found that miRNA-146a was up-regulated in human bronchial epithelial cells (HBECs) in response to stimulation by TGF-ss1 plus cytomix (a mixture of IL-1ss, IFN-γ and TNF-α). TGF-ss1 plus cytomix (TCM) induced apoptosis in HBECs (3.4 ± 0.6% of control vs 83.1 ± 4.0% of TCM treated cells, p < 0.01), and this was significantly blocked by the miRNA-146a mimic (8.8 ± 1.5%, p < 0.01). In contrast, a miRNA-146a inhibitor had only a modest effect on cell survival but appeared to augment the induction of epithelial-mesenchymal transition (EMT) in response to the cytokines. The MicroRNA-146a mimic appears to modulate HBEC survival through a mechanism of up-regulating Bcl-XL and STAT3 phosphorylation, and by this mechanism it could contribute to tissue repair and remodeling.
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Lehnerdt, G F; Franz, P; Bankfalvi, A; Grehl, S; Kelava, A; Nückel, H; Lang, S; Schmid, K W; Siffert, W; Bachmann, H S
2009-06-01
Expression of the antiapoptotic and antiproliferative protein B-cell lymphoma 2 (Bcl-2) has been repeatedly shown to be associated with better locoregional control and patients' survival in oropharyngeal squamous cell carcinoma (OSCC). A regulatory (-938C>A) single-nucleotide polymorphism (SNP) in the inhibitory P2 BCL2 gene promoter generates significantly different BCL2 promoter activities and has been associated with outcome in different malignancies. The aim of the present study was to analyze the possible influence of the (-938C>A) SNP on survival of patients suffering from OSCC. One hundred and thirty-three patients with primary OSCC were retrospectively investigated. Bcl-2 expression of tumor cells was demonstrated by means of immunohistochemistry. Both the Bcl-2 expression and the (-938C>A) genotypes were correlated with the patients' survival. The (-938C>A) SNP was significantly related to Bcl-2 expression (P = 0.008). Kaplan-Meier curves revealed a significant association of the -938 SNP with relapse-free (P = 0.0283) and overall survival (P = 0.0247). Multiple Cox regression identified the BCL2 (-938CC) genotype as an independent prognostic factor for relapse [hazard ratio (HR) 1.898, P = 0.021] as well as for death in OSCC patients (HR 1.897, P = 0.013). The (-938C>A) SNP represents a potential novel prognostic marker in patients with OSCC that could help to identify a group of patients at high risk for relapse and death.
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Directory of Open Access Journals (Sweden)
Day Wanda V
2005-04-01
Full Text Available Abstract Background Androgens and androgen receptors (AR regulate normal prostate development and growth. They also are involved in pathological development of prostatic diseases, including benign prostatic hyperplasia (BPH and prostate cancer (PCa. Antiandrogen therapy for PCa, in conjunction with chemical or surgical castration, offers initial positive responses and leads to massive prostate cell death. However, cancer cells later appear as androgen-independent PCa. To investigate the role of AR in prostate cell proliferation and survival, we introduced a vector-based small interfering RNA (siRNA. This siRNA targeted 5'-untranslated region of AR mRNA for extended suppression of AR expression in androgen-sensitive human prostate LNCaP cells. Results The siRNA design successfully suppressed endogenous AR expression, as revealed by western blotting and immunofluorescence staining in LNCaP cells. LNCaP cells did not proliferate in the absence of AR and underwent apoptosis, based on elevated phospho-Histone H2B expression and higher number of apoptotic body as compared to control cells. Conclusion We demonstrated that AR is vital for prostate cell proliferation and survival in this androgen-sensitive prostate cell line. These results further strengthen the hypothesis that AR can be a therapeutic target for treating androgen-sensitive stages of PCa. Unlike antiandorgens, however, siRNA targeting AR provides a direct inactivation of AR function through the suppression of AR protein expression.
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Energy Technology Data Exchange (ETDEWEB)
Kim, In Gyu, E-mail: igkim@kaeri.re.kr [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Department of Radiation Biotechnology and Applied Radioisotope, University of Science and Technology (UST), 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Kim, Seo Yoen [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Biomedical Translational Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Kim, Hyun A; Kim, Jeong Yul [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Lee, Jae Ha; Choi, Soo Im [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Department of Radiation Biotechnology and Applied Radioisotope, University of Science and Technology (UST), 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Han, Jeong Ran; Kim, Kug Chan [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Cho, Eun Wie [Biomedical Translational Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of)
2014-01-03
Highlights: •DKK1 was expressed differently among non-small-cell lung cancer cell lines. •DKK1 negatively regulated ROMO1 gene expression. •Disturbance of DKK1 level induced the imbalance of cellular ROS. •DKK1/ROMO1-induced ROS imbalance is involved in cell survival in NSCLC. -- Abstract: Dickkopf1 (DKK1), a secreted protein involved in embryonic development, is a potent inhibitor of the Wnt signaling pathway and has been postulated to be a tumor suppressor or tumor promoter depending on the tumor type. In this study, we showed that DKK1 was expressed differently among non-small-cell lung cancer cell lines. The DKK1 expression level was much higher in A549 cells than in H460 cells. We revealed that blockage of DKK1 expression by silencing RNA in A549 cells caused up-regulation of intracellular reactive oxygen species (ROS) modulator (ROMO1) protein, followed by partial cell death, cell growth inhibition, and loss of epithelial–mesenchymal transition property caused by ROS, and it also increased γ-radiation sensitivity. DKK1 overexpression in H460 significantly inhibited cell survival with the decrease of ROMO1 level, which induced the decrease of cellular ROS. Thereafter, exogenous N-acetylcysteine, an antioxidant, or hydrogen peroxide, a pro-oxidant, partially rescued cells from death and growth inhibition. In each cell line, both overexpression and blockage of DKK1 not only elevated p-RB activation, which led to cell growth arrest, but also inactivated AKT/NF-kB, which increased radiation sensitivity and inhibited cell growth. This study is the first to demonstrate that strict modulation of DKK1 expression in different cell types partially maintains cell survival via tight regulation of the ROS-producing ROMO1 and radiation resistance.
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International Nuclear Information System (INIS)
Kim, In Gyu; Kim, Seo Yoen; Kim, Hyun A; Kim, Jeong Yul; Lee, Jae Ha; Choi, Soo Im; Han, Jeong Ran; Kim, Kug Chan; Cho, Eun Wie
2014-01-01
Highlights: •DKK1 was expressed differently among non-small-cell lung cancer cell lines. •DKK1 negatively regulated ROMO1 gene expression. •Disturbance of DKK1 level induced the imbalance of cellular ROS. •DKK1/ROMO1-induced ROS imbalance is involved in cell survival in NSCLC. -- Abstract: Dickkopf1 (DKK1), a secreted protein involved in embryonic development, is a potent inhibitor of the Wnt signaling pathway and has been postulated to be a tumor suppressor or tumor promoter depending on the tumor type. In this study, we showed that DKK1 was expressed differently among non-small-cell lung cancer cell lines. The DKK1 expression level was much higher in A549 cells than in H460 cells. We revealed that blockage of DKK1 expression by silencing RNA in A549 cells caused up-regulation of intracellular reactive oxygen species (ROS) modulator (ROMO1) protein, followed by partial cell death, cell growth inhibition, and loss of epithelial–mesenchymal transition property caused by ROS, and it also increased γ-radiation sensitivity. DKK1 overexpression in H460 significantly inhibited cell survival with the decrease of ROMO1 level, which induced the decrease of cellular ROS. Thereafter, exogenous N-acetylcysteine, an antioxidant, or hydrogen peroxide, a pro-oxidant, partially rescued cells from death and growth inhibition. In each cell line, both overexpression and blockage of DKK1 not only elevated p-RB activation, which led to cell growth arrest, but also inactivated AKT/NF-kB, which increased radiation sensitivity and inhibited cell growth. This study is the first to demonstrate that strict modulation of DKK1 expression in different cell types partially maintains cell survival via tight regulation of the ROS-producing ROMO1 and radiation resistance
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Radiation-induced cellular reproductive death and chromosome aberrations
International Nuclear Information System (INIS)
Bedford, J.S.; Mitchell, J.B.; Griggs, H.G.; Bender, M.A.
1978-01-01
If a major mode of cell killing by ionizing radiation is the death of cells containing visible chromosomal aberrations, as for example from anaphase-bridge formation at mitosis, then cells bearing such aberrations should be selectively eliminated from the population, resulting in an increased survival potential for the population remaining at each succeeding cell generation. Using synchronized V79B Chinese hamster cells, we measured the aberration frequency and the colony-forming ability of mitotic cells at each of the first three generations following irradiation in G1. Cells were resynchronized by mechanial harvest at each succeeding mitosis after irradiation in order to avoid mixing of generations in the cell population at later sampling times. As anticipated, the chromosome aberration frequencies decreased markedly from the first to the second and from the second to the third mitosis. The surviving fraction, however, was virtually the same for plating assays carried out immediately after irradiation, at the first, or at the second mitosis. The surviving fraction was significantly higher for cells reaching the third postirradiation mitosis. Survival and aberration frequencies were assayed again at approximately the fourteenth postirradiation division, by which time the irradiated and control populations were not significantly different
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Transient Receptor Potential Vanilloid 1 Expression Mediates Capsaicin-Induced Cell Death
Directory of Open Access Journals (Sweden)
Ricardo Ramírez-Barrantes
2018-06-01
Full Text Available The transient receptor potential (TRP ion channel family consists of a broad variety of non-selective cation channels that integrate environmental physicochemical signals for dynamic homeostatic control. Involved in a variety of cellular physiological processes, TRP channels are fundamental to the control of the cell life cycle. TRP channels from the vanilloid (TRPV family have been directly implicated in cell death. TRPV1 is activated by pain-inducing stimuli, including inflammatory endovanilloids and pungent exovanilloids, such as capsaicin (CAP. TRPV1 activation by high doses of CAP (>10 μM leads to necrosis, but also exhibits apoptotic characteristics. However, CAP dose–response studies are lacking in order to determine whether CAP-induced cell death occurs preferentially via necrosis or apoptosis. In addition, it is not known whether cytosolic Ca2+ and mitochondrial dysfunction participates in CAP-induced TRPV1-mediated cell death. By using TRPV1-transfected HeLa cells, we investigated the underlying mechanisms involved in CAP-induced TRPV1-mediated cell death, the dependence of CAP dose, and the participation of mitochondrial dysfunction and cytosolic Ca2+ increase. Together, our results contribute to elucidate the pathophysiological steps that follow after TRPV1 stimulation with CAP. Low concentrations of CAP (1 μM induce cell death by a mechanism involving a TRPV1-mediated rapid and transient intracellular Ca2+ increase that stimulates plasma membrane depolarization, thereby compromising plasma membrane integrity and ultimately leading to cell death. Meanwhile, higher doses of CAP induce cell death via a TRPV1-independent mechanism, involving a slow and persistent intracellular Ca2+ increase that induces mitochondrial dysfunction, plasma membrane depolarization, plasma membrane loss of integrity, and ultimately, cell death.
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Maltese, William A.; Overmeyer, Jean H.
2014-01-01
Apoptosis is the most widely recognized form of physiological programmed cell death. During the past three decades, various nonapoptotic forms of cell death have gained increasing attention, largely because of their potential importance in pathological processes, toxicology, and cancer therapy. A recent addition to the panoply of cell death phenotypes is methuosis. The neologism is derived from the Greek methuo (to drink to intoxication) because the hallmark of this form of cell death is disp...
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Therapeutic approaches to preventing cell death in Huntington disease.
Kaplan, Anna; Stockwell, Brent R
2012-12-01
Neurodegenerative diseases affect the lives of millions of patients and their families. Due to the complexity of these diseases and our limited understanding of their pathogenesis, the design of therapeutic agents that can effectively treat these diseases has been challenging. Huntington disease (HD) is one of several neurological disorders with few therapeutic options. HD, like numerous other neurodegenerative diseases, involves extensive neuronal cell loss. One potential strategy to combat HD and other neurodegenerative disorders is to intervene in the execution of neuronal cell death. Inhibiting neuronal cell death pathways may slow the development of neurodegeneration. However, discovering small molecule inhibitors of neuronal cell death remains a significant challenge. Here, we review candidate therapeutic targets controlling cell death mechanisms that have been the focus of research in HD, as well as an emerging strategy that has been applied to developing small molecule inhibitors-fragment-based drug discovery (FBDD). FBDD has been successfully used in both industry and academia to identify selective and potent small molecule inhibitors, with a focus on challenging proteins that are not amenable to traditional high-throughput screening approaches. FBDD has been used to generate potent leads, pre-clinical candidates, and has led to the development of an FDA approved drug. This approach can be valuable for identifying modulators of cell-death-regulating proteins; such compounds may prove to be the key to halting the progression of HD and other neurodegenerative disorders. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Hegedűs, Csaba; Lakatos, Petra; Kiss-Szikszai, Attila; Patonay, Tamás; Gergely, Szabolcs; Gregus, Andrea; Bai, Péter; Haskó, György; Szabó, Éva; Virág, László
2013-06-01
Screening of a small in-house library of 1863 compounds identified 29 compounds that protected Jurkat cells from hydrogen peroxide-induced cytotoxicity. From the cytoprotective compounds eleven proved to possess antioxidant activity (ABTS radical scavenger effect) and two were found to inhibit poly(ADP-ribosyl)ation (PARylation), a cytotoxic pathway operating in severely injured cells. Four cytoprotective dibenzoylmethane (DBM) derivatives were investigated in more detail as they did not scavenge hydrogen peroxide nor did they inhibit PARylation. These compounds protected cells from necrotic cell death while caspase activation, a parameter of apoptotic cell death was not affected. Hydrogen peroxide activated extracellular signal regulated kinase (ERK1/2) and p38 MAP kinases but not c-Jun N-terminal kinase (JNK). The cytoprotective DBMs suppressed the activation of Erk1/2 but not that of p38. Cytoprotection was confirmed in another cell type (A549 lung epithelial cells), indicating that the cytoprotective effect is not cell type specific. In conclusion we identified DBM analogs as a novel class of cytoprotective compounds inhibiting ERK1/2 kinase and protecting from necrotic cell death by a mechanism independent of poly(ADP-ribose) polymerase inhibition. Copyright © 2013 Elsevier Ltd. All rights reserved.
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International Nuclear Information System (INIS)
Takatsuji, Toshihiro; Yoshikawa, Isao; Sasaki, Masao S.
1999-01-01
The frequency of chromosome aberrations per traversal of a nucleus by a charged particle at the low dose limit increases proportionally to the square of the linear energy transfer (LET), peaks at about 100 keV/μm and then decreases with further increase of LET. This has long been interpreted as an excessive energy deposition over the necessary energy required to produce a biologically effective event. Here, we present an alternative interpretation. Cell traversed by a charged particle has certain probability to receive lethal damage leading to direct death. Such events may increase with an increase of LET and the number of charged particles traversing the cell. Assuming that the lethal damage is distributed according to a Poisson distribution, the probability that a cell has no such damage is expressed by e -cLx , where c is a constant, L is LET, and x is the number of charged particles traversing the cell. From these assumptions, the frequency of chromosome aberration in surviving cells can be described by Y=αSD+βS 2 D 2 with the empirical relation Y=αD+βD 2 in the low LET region, where S=e -cL , α is a value proportional to LET, β is a constant, and D is the absorbed dose. This model readily explains the empirically established relationship between LET and relative biological effectiveness (RBE). The model can also be applied to clonogenic survival. If cells can survive and they have neither unstable chromosome aberrations nor other lethal damage, the LET-RBE relationship for clonogenic survival forms a humped curve. The relationship between LET and inactivation cross-section becomes proportional to the square of LET in the low LET region when the frequency of a directly lethal events is sufficiently smaller than unity, and the inactivation cross-section saturates to the cell nucleus cross-sectional area with an increase in LET in the high LET region. (author)
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Active ras triggers death in glioblastoma cells through hyperstimulation of macropinocytosis.
Overmeyer, Jean H; Kaul, Aparna; Johnson, Erin E; Maltese, William A
2008-06-01
Expression of activated Ras in glioblastoma cells induces accumulation of large phase-lucent cytoplasmic vacuoles, followed by cell death. This was previously described as autophagic cell death. However, unlike autophagosomes, the Ras-induced vacuoles are not bounded by a double membrane and do not sequester organelles or cytoplasm. Moreover, they are not acidic and do not contain the autophagosomal membrane protein LC3-II. Here we show that the vacuoles are enlarged macropinosomes. They rapidly incorporate extracellular fluid-phase tracers but do not sequester transferrin or the endosomal protein EEA1. Ultimately, the cells expressing activated Ras detach from the substratum and rupture, coincident with the displacement of cytoplasm with huge macropinosome-derived vacuoles. These changes are accompanied by caspase activation, but the broad-spectrum caspase inhibitor carbobenzoxy-Val-Ala-Asp-fluoromethylketone does not prevent cell death. Moreover, the majority of degenerating cells do not exhibit chromatin condensation typical of apoptosis. These observations provide evidence for a necrosis-like form of cell death initiated by dysregulation of macropinocytosis, which we have dubbed "methuosis." An activated form of the Rac1 GTPase induces a similar form of cell death, suggesting that Ras acts through Rac-dependent signaling pathways to hyperstimulate macropinocytosis in glioblastoma. Further study of these signaling pathways may lead to the identification of other chemical and physiologic triggers for this unusual form of cell death.
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Reddien, Peter W; Andersen, Erik C; Huang, Michael C; Horvitz, H Robert
2007-04-01
The genes egl-1, ced-9, ced-4, and ced-3 play major roles in programmed cell death in Caenorhabditis elegans. To identify genes that have more subtle activities, we sought mutations that confer strong cell-death defects in a genetically sensitized mutant background. Specifically, we screened for mutations that enhance the cell-death defects caused by a partial loss-of-function allele of the ced-3 caspase gene. We identified mutations in two genes not previously known to affect cell death, dpl-1 and mcd-1 (modifier of cell death). dpl-1 encodes the C. elegans homolog of DP, the human E2F-heterodimerization partner. By testing genes known to interact with dpl-1, we identified roles in cell death for four additional genes: efl-1 E2F, lin-35 Rb, lin-37 Mip40, and lin-52 dLin52. mcd-1 encodes a novel protein that contains one zinc finger and that is synthetically required with lin-35 Rb for animal viability. dpl-1 and mcd-1 act with efl-1 E2F and lin-35 Rb to promote programmed cell death and do so by regulating the killing process rather than by affecting the decision between survival and death. We propose that the DPL-1 DP, MCD-1 zinc finger, EFL-1 E2F, LIN-35 Rb, LIN-37 Mip40, and LIN-52 dLin52 proteins act together in transcriptional regulation to promote programmed cell death.
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Mukai, J; Hachiya, T; Shoji-Hoshino, S; Kimura, M T; Nadano, D; Suvanto, P; Hanaoka, T; Li, Y; Irie, S; Greene, L A; Sato, T A
2000-06-09
The low affinity neurotrophin receptor p75NTR can mediate cell survival as well as cell death of neural cells by NGF and other neurotrophins. To elucidate p75NTR-mediated signal transduction, we screened p75NTR-associated proteins by a yeast two-hybrid system. We identified one positive clone and named NADE (p75NTR-associated cell death executor). Mouse NADE has marked homology to the human HGR74 protein. NADE specifically binds to the cell-death domain of p75NTR. Co-expression of NADE and p75NTR induced caspase-2 and caspase-3 activities and the fragmentation of nuclear DNA in 293T cells. However, in the absence of p75NTR, NADE failed to induce apoptosis, suggesting that NADE expression is necessary but insufficient for p75NTR-mediated apoptosis. Furthermore, p75NTR/NADE-induced cell death was dependent on NGF but not BDNF, NT-3, or NT-4/5, and the recruitment of NADE to p75NTR (intracellular domain) was dose-dependent. We obtained similar results from PC12 cells, nnr5 cells, and oligodendrocytes. Taken together, NADE is the first signaling adaptor molecule identified in the involvement of p75NTR-mediated apoptosis induced by NGF, and it may play an important role in the pathogenesis of neurogenetic diseases.
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Dörrie, J; Schuh, W; Keil, A; Bongards, E; Greil, J; Fey, G H; Zunino, S J
1999-10-01
The regulatory effects of IFNgamma on CD95 expression and CD95-mediated cell death were investigated in three high-risk pro-B acute lymphoblastic leukemia (ALL) lines that carry the chromosomal translocation t(4;11)(q21;q23). These leukemias are characteristically refractory to conventional chemotherapeutic treatments operating through the induction of apoptosis. However, the mechanisms leading to increased cell survival and resistance to cell death in these leukemias are largely unknown. Interferon-gamma (IFNgamma), a potent inhibitor of hematopoiesis, acts in part by upregulating CD95 and sensitizing cells to CD95-induced apoptosis. The t(4;11) lines SEM, RS4;11, and MV4;11 expressed low levels of CD95, but were completely resistant to CD95-mediated death. Addition of IFNgamma markedly upregulated CD95 expression in SEM (8-9-fold), RS4;11 (2-3-fold), and MV4;11 (2-3-fold) lines. However, after treatment with IFNgamma, only an 11% increase in sensitivity to CD95-mediated cell death was observed in SEM cells, whereas RS4;11 and MV4;11 cells remained resistant. Cycloheximide, but not actinomycin D or brefeldin A, increased CD95-specific cell death only in IFNgamma-treated RS4;11 cells by approximately 12%. Abundant levels of Bcl-2 and Bcl-XL, known to inhibit CD95-signaling in some cells, were present suggesting a possible role for both molecules in the resistance to CD95-mediated cell death. Resistance of the leukemic blasts to CD95-mediated cell death and the failure of IFNgamma to substantially sensitize the CD95-signaling pathway may contribute to the highly malignant phenotype of pro-B ALL with translocation t(4;11).
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Long-term treatment of anterior pituitary cells with nitric oxide induces programmed cell death.
Velardez, Miguel Omar; Poliandri, Ariel Hernán; Cabilla, Jimena Paula; Bodo, Cristian Carlos Armando; Machiavelli, Leticia Inés; Duvilanski, Beatriz Haydeé
2004-04-01
Nitric oxide (NO) plays a complex role in modulating programmed cell death. It can either protect the cell from apoptotic death or mediate apoptosis, depending on its concentration and the cell type and/or status. In this study, we demonstrate that long-term exposition to NO induces cell death of anterior pituitary cells from Wistar female rats. DETA NONOate (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate, 1 mm], a NO donor that releases NO for an extended period of time, decreased cellular viability and prolactin release from primary cultures of anterior pituitary cells. Morphological studies showed an increase in the number of cells with chromatin condensation and nuclear fragmentation at 24 and 48 h after DETA/NO exposure. DNA internucleosomal fragmentation was also observed at the same time. Reversibility of the NO effect on cellular viability and prolactin release was observed only when the cells were incubated with DETA/NO for less than 6 h. Most apoptotic cells were immunopositive for prolactin, suggesting a high susceptibility of lactotrophs to the effect of NO. The cytotoxic effect of NO is dependent of caspase-9 and caspase-3, but seems to be independent of oxidative stress or nitrosative stress. Our results show that the exposition of anterior pituitary cells to NO for long periods induces programmed cell death of anterior pituitary cells.
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Koh, Eun-Jeong; Kim, Kui-Jin; Choi, Jia; Kang, Do-Hyung; Lee, Boo-Yong
2018-04-23
Spirulina maxima is a blue-green micro alga that contains abundant amounts of proteins (60-70%), vitamins, chlorophyll a, and C-phycocyanin (C-PC). It has been shown to reduce oxidative stress, and prevent diabetes and non-alcoholic fatty liver disease. However, it is unclear whether Spirulina maxima 70% ethanol extract (SM70EE), chlorophyll a, and C-PC prevent Aβ 1-42 -induced neurotoxicity in PC12 cells. The aim of this study was to investigate whether SM70EE, chlorophyll a, and C-PC prevent Aβ 1-42 -induced cell death. SM70EE, chlorophyll a, and C-PC suppressed the Aβ 1-42 -induced increase in poly-ADP ribose polymerase-1 (PARP-1) cleavage and reduced Aβ 1-42 -induced decreases in glutathione and its associated factors. The level of brain-derived neurotrophic factor (BDNF), which plays a critical role in neuronal survival and neuroprotection, was increased by SM70EE, chlorophyll a, and C-PC in Aβ 1-42 -treated cells. SM70EE treatment decreased oxidative stress and cell death in response to Aβ 1-42 treatment, while simultaneously suppressing PARP cleavage and increasing the levels of glutathione (GSH) and its associated factors. Moreover, SM70EE lowered the levels of APP and BACE1, two major factors involved in APP processing, and increased BDNF expression during Aβ 1-42 -induced neurotoxicity in PC12 cells. We suggest that SM70EE prevents cell death caused by Aβ 1-42 -induced neurotoxicity via the activation of BDNF signaling. Copyright © 2018 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Han Seol
2011-07-01
Full Text Available Abstract Background At the beginning of neurogenesis, massive brain cell death occurs and more than 50% of cells are eliminated by apoptosis along with neuronal differentiation. However, few studies were conducted so far regarding the regulation of neural progenitor cells (NPCs death during development. Because of the physiological role of cell death during development, aberration of normal apoptotic cell death is detrimental to normal organogenesis. Apoptosis occurs in not only neuron but also in NPCs and neuroblast. When growth and survival signals such as EGF or LIF are removed, apoptosis is activated as well as the induction of differentiation. To investigate the regulation of cell death during developmental stage, it is essential to investigate the regulation of apoptosis of NPCs. Methods Neural progenitor cells were cultured from E14 embryonic brains of Sprague-Dawley rats. For in vivo VPA animal model, pregnant rats were treated with VPA (400 mg/kg S.C. diluted with normal saline at E12. To analyze the cell death, we performed PI staining and PARP and caspase-3 cleavage assay. Expression level of proteins was investigated by Western blot and immunocytochemical assays. The level of mRNA expression was investigated by RT-PCR. Interaction of Bcl-XL gene promoter and NF-κB p65 was investigated by ChIP assay. Results In this study, FACS analysis, PI staining and PARP and caspase-3 cleavage assay showed that VPA protects cultured NPCs from cell death after growth factor withdrawal both in basal and staurosporine- or hydrogen peroxide-stimulated conditions. The protective effect of prenatally injected VPA was also observed in E16 embryonic brain. Treatment of VPA decreased the level of IκBα and increased the nuclear translocation of NF-κB, which subsequently enhanced expression of anti-apoptotic protein Bcl-XL. Conclusion To the best of our knowledge, this is the first report to indicate the reduced death of NPCs by VPA at developmentally
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Murine Th9 cells promote the survival of myeloid dendritic cells in cancer immunotherapy.
Park, Jungsun; Li, Haiyan; Zhang, Mingjun; Lu, Yong; Hong, Bangxing; Zheng, Yuhuan; He, Jin; Yang, Jing; Qian, Jianfei; Yi, Qing
2014-08-01
Dendritic cells (DCs) are professional antigen-presenting cells to initiate immune responses, and DC survival time is important for affecting the strength of T-cell responses. Interleukin (IL)-9-producing T-helper (Th)-9 cells play an important role in anti-tumor immunity. However, it is unclear how Th9 cells communicate with DCs. In this study, we investigated whether murine Th9 cells affected the survival of myeloid DCs. DCs derived from bone marrow of C57BL/6 mice were cocultured with Th9 cells from OT-II mice using transwell, and the survival of DCs was examined. DCs cocultured with Th9 cells had longer survival and fewer apoptotic cells than DCs cultured alone in vitro. In melanoma B16-OVA tumor-bearing mice, DCs conditioned by Th9 cells lived longer and induced stronger anti-tumor response than control DCs did in vivo. Mechanistic studies revealed that IL-3 but not IL-9 secreted by Th9 cells was responsible for the prolonged survival of DCs. IL-3 upregulated the expression of anti-apoptotic protein Bcl-xL and activated p38, ERK and STAT5 signaling pathways in DCs. Taken together, our data provide the first evidence that Th9 cells can promote the survival of DCs through IL-3, and will be helpful for designing Th9 cell immunotherapy and more effective DC vaccine for human cancers.
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PAI-1-dependent endothelial cell death determines severity of radiation-induced intestinal injury.
Directory of Open Access Journals (Sweden)
Rym Abderrahmani
Full Text Available Normal tissue toxicity still remains a dose-limiting factor in clinical radiation therapy. Recently, plasminogen activator inhibitor type 1 (SERPINE1/PAI-1 was reported as an essential mediator of late radiation-induced intestinal injury. However, it is not clear whether PAI-1 plays a role in acute radiation-induced intestinal damage and we hypothesized that PAI-1 may play a role in the endothelium radiosensitivity. In vivo, in a model of radiation enteropathy in PAI-1 -/- mice, apoptosis of radiosensitive compartments, epithelial and microvascular endothelium was quantified. In vitro, the role of PAI-1 in the radiation-induced endothelial cells (ECs death was investigated. The level of apoptotic ECs is lower in PAI-1 -/- compared with Wt mice after irradiation. This is associated with a conserved microvascular density and consequently with a better mucosal integrity in PAI-1 -/- mice. In vitro, irradiation rapidly stimulates PAI-1 expression in ECs and radiation sensitivity is increased in ECs that stably overexpress PAI-1, whereas PAI-1 knockdown increases EC survival after irradiation. Moreover, ECs prepared from PAI-1 -/- mice are more resistant to radiation-induced cell death than Wt ECs and this is associated with activation of the Akt pathway. This study demonstrates that PAI-1 plays a key role in radiation-induced EC death in the intestine and suggests that this contributes strongly to the progression of radiation-induced intestinal injury.
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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.
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International Nuclear Information System (INIS)
Elisova, I.V.; Feoktistova, I.P.
1983-01-01
The culture of Chinese hamster cells (clone 431) has been used to study cysteamine action on mutagenous effect of X-rays, determined by the induction of resistance of gene mutations to 6-thioguanine and chromosomal abberations, as well as on the reproductive form of death of irradiated cells. Dose--- effect curves are obtained under conditions of irradiation with and without protector. The factor of dose alteration is 2.0 for chromosomal aberrations and cell survival, and 2.8 for gene mutations. It is sUpposed that cysteamine affects the general mechanisms, which take part in the realis zation of injuries that bring about gene mutations, chromosomal aberrations and cell lethality
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Directory of Open Access Journals (Sweden)
Bailong Li
2013-12-01
Full Text Available Background: Exposure of high dose ionizing radiation is lethal. Signal pathways involved in radiation biology reaction still remain illdefined. Lipopolysaccharides (LPS, the ligands of Toll-like receptor 4(TLR4, could elicit strong immune responses. Glycogen synthase kinase-3β(GSK-3β promotes the production of inflammatory molecules and cell migration. Inhibition of GSK-3β provides protection against inflammation in animal models. The aim of the study was to investigate role of GSK-3β in LPS shock and ionizing radiation. Methods: WT or IL-6-/-mice or cells were pretreated with SB216763, a GSK-3β inhibitor, and survival of the mice was determined. Cell viability was assayed by Cell Counting Kit. Apoptosis was assayed by Annexin V-PI double staining. Serum concentrations of IL-6 and TNF-α were determined by ELISA. Results: SB216763 attenuated LPS induced mice or cell death but aggravated radiation induced mice or cell death. SB216763 reduced IL-6, but not TNF-α levels in vivo. IL-6-/- mice were more resistant to LPS-induced death but less resistant to radiation-induced death than wild type mice. Conclusions: Inhibition of GSK-3β conferred resistance to LPS shock but fostered death induced by ionizing radiation. Inhibition of GSK-3β was effective by reducing IL-6.
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Regulatory dendritic cell infusion prolongs kidney allograft survival in non-human primates
Ezzelarab, M.; Zahorchak, A.F.; Lu, L.; Morelli, A.E.; Chalasani, G.; Demetris, A.J.; Lakkis, F.G.; Wijkstrom, M.; Murase, N.; Humar, A.; Shapiro, R.; Cooper, D.K.C.; Thomson, A.W.
2014-01-01
We examined the influence of regulatory dendritic cells (DCreg), generated from cytokine-mobilized donor blood monocytes in vitamin D3 and IL-10, on renal allograft survival in a clinically-relevant rhesus macaque model. DCreg expressed low MHC class II and costimulatory molecules, but comparatively high levels of programmed death ligand-1 (B7-H1), and were resistant to pro-inflammatory cytokine-induced maturation. They were infused intravenously (3.5–10×106/kg), together with the B7-CD28 costimulation blocking agent CTLA4Ig, 7 days before renal transplantation. CTLA4Ig was given for up to 8 weeks and rapamycin, started on day −2, was maintained with tapering of blood levels until full withdrawal at 6 months. Median graft survival time was 39.5 days in control monkeys (no DC infusion; n=6) and 113.5 days (pDCreg-treated animals (n=6). No adverse events were associated with DCreg infusion, and there was no evidence of induction of host sensitization based on circulating donor-specific alloantibody levels. Immunologic monitoring also revealed regulation of donor-reactive memory CD95+ T cells and reduced memory/regulatory T cell ratios in DCreg-treated monkeys compared with controls. Termination allograft histology showed moderate combined T cell- and Ab-mediated rejection in both groups. These findings justify further pre-clinical evaluation of DCreg therapy and their therapeutic potential in organ transplantation. PMID:23758811
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Lee, Sook-Jeong; Koh, Jae-Young
2010-10-26
Zinc dyshomeostasis has been recognized as an important mechanism for cell death in acute brain injury. An increase in the level of free or histochemically reactive zinc in astrocytes and neurons is considered one of the major causes of death of these cells in ischemia and trauma. Although zinc dyshomeostasis can lead to cell death via diverse routes, the major pathway appears to involve oxidative stress.Recently, we found that a rise of zinc in autophagic vacuoles, including autolysosomes, is a prerequisite for lysosomal membrane permeabilization and cell death in cultured brain cells exposed to oxidative stress conditions. The source of zinc in this process is likely redox-sensitive zinc-binding proteins such as metallothioneins, which release zinc under oxidative conditions. Of the metallothioneins, metallothionein-3 is especially enriched in the central nervous system, but its physiologic role in this tissue is not well established. Like other metallothioneins, metallothionein-3 may function as metal detoxicant, but is also known to inhibit neurite outgrowth and, sometimes, promote neuronal death, likely by serving as a source of toxic zinc release. In addition, metallothionein-3 regulates lysosomal functions. In the absence of metallothionein-3, there are changes in lysosome-associated membrane protein-1 and -2, and reductions in certain lysosomal enzymes that result in decreased autophagic flux. This may have dual effects on cell survival. In acute oxidative injury, zinc dyshomeostasis and lysosomal membrane permeabilization are diminished in metallothionein-3 null cells, resulting in less cell death. But over the longer term, diminished lysosomal function may lead to the accumulation of abnormal proteins and cause cytotoxicity.The roles of zinc and metallothionein-3 in autophagy and/or lysosomal function have just begun to be investigated. In light of evidence that autophagy and lysosomes may play significant roles in the pathogenesis of various neurological
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Directory of Open Access Journals (Sweden)
Lee Sook-Jeong
2010-10-01
Full Text Available Abstract Zinc dyshomeostasis has been recognized as an important mechanism for cell death in acute brain injury. An increase in the level of free or histochemically reactive zinc in astrocytes and neurons is considered one of the major causes of death of these cells in ischemia and trauma. Although zinc dyshomeostasis can lead to cell death via diverse routes, the major pathway appears to involve oxidative stress. Recently, we found that a rise of zinc in autophagic vacuoles, including autolysosomes, is a prerequisite for lysosomal membrane permeabilization and cell death in cultured brain cells exposed to oxidative stress conditions. The source of zinc in this process is likely redox-sensitive zinc-binding proteins such as metallothioneins, which release zinc under oxidative conditions. Of the metallothioneins, metallothionein-3 is especially enriched in the central nervous system, but its physiologic role in this tissue is not well established. Like other metallothioneins, metallothionein-3 may function as metal detoxicant, but is also known to inhibit neurite outgrowth and, sometimes, promote neuronal death, likely by serving as a source of toxic zinc release. In addition, metallothionein-3 regulates lysosomal functions. In the absence of metallothionein-3, there are changes in lysosome-associated membrane protein-1 and -2, and reductions in certain lysosomal enzymes that result in decreased autophagic flux. This may have dual effects on cell survival. In acute oxidative injury, zinc dyshomeostasis and lysosomal membrane permeabilization are diminished in metallothionein-3 null cells, resulting in less cell death. But over the longer term, diminished lysosomal function may lead to the accumulation of abnormal proteins and cause cytotoxicity. The roles of zinc and metallothionein-3 in autophagy and/or lysosomal function have just begun to be investigated. In light of evidence that autophagy and lysosomes may play significant roles in the
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Sodium nitroprusside induces autophagic cell death in glutathione-depleted osteoblasts.
Son, Min Jeong; Lee, Seong-Beom; Byun, Yu Jeong; Lee, Hwa Ok; Kim, Ho-Shik; Kwon, Oh-Joo; Jeong, Seong-Whan
2010-01-01
Previous studies reported that high levels of nitric oxide (NO) induce apoptotic cell death in osteoblasts. We examined molecular mechanisms of cytotoxic injury induced by sodium nitroprusside (SNP), a NO donor, in both glutathione (GSH)-depleted and control U2-OS osteoblasts. Cell viability was reduced by much lower effective concentrations of SNP in GSH-depleted cells compared to normal cells. The data suggest that the level of intracellular GSH is critical in SNP-induced cell death processes of osteoblasts. The level of oxidative stress due to SNP treatments doubled in GSH-depleted cells when measured with fluorochrome H2DCFDA. Pretreatment with the NO scavenger PTIO preserved the viability of cells treated with SNP. Viability of cells treated with SNP was recovered by pretreatment with Wortmannin, an autophagy inhibitor, but not by pretreatment with zVAD-fmk, a pan-specific caspase inhibitor. Large increases of LC3-II were shown by immunoblot analysis of the SNP-treated cells, and the increase was blocked by pretreatment with PTIO or Wortmannin; this implies that under GSH-depleted conditions SNP induces different molecular signaling that lead to autophagic cell death. The ultrastructural morphology of SNP-treated cells in transmission electron microscopy showed numerous autophagic vacuoles. These data suggest NO produces oxidative stress and cellular damage that culminate in autophagic cell death of GSH-depleted osteoblasts. Copyright 2010 Wiley Periodicals, Inc.
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Harini, Lakshminarasimhan; Karthikeyan, Bose; Srivastava, Sweta; Suresh, Srinag Bangalore; Ross, Cecil; Gnanakumar, Georgepeter; Rajagopal, Srinivasan; Sundar, Krishnan; Kathiresan, Thandavarayan
2017-02-01
Breast cancer accounts for the first highest mortality rate in India and second in world. Though current treatment strategies are effectively killing cancer cells, they also end in causing severe side effects and drug resistance. Curcumin is a nutraceutical with multipotent activity but its insolubility in water limits its therapeutic potential as an anti-cancer drug. The hydrophilicity of curcumin could be increased by nanoformulation or changing its functional groups. In this study, curcumin is loaded on mesoporous silica nanoparticle and its anti-cancer activity is elucidated with MCF-7 cell death. Structural characteristics of Mobil Composition of Matter - 41(MCM-41) as determined by high-resolution transmission electron microscopy (HR-TEM) shows that MCM-41 size ranges from 100 to 200 nm diameters with pore size 2-10 nm for drug adsorption. The authors found 80-90% of curcumin is loaded on MCM-41 and curcumin is released efficiently at pH 3.0. The 50 µM curcumin-loaded MCM-41 induced 50% mortality of MCF-7 cells. Altogether, their results suggested that increased curcumin loading and sustained release from MCM-41 effectively decreased cell survival of MCF-7 cells in vitro.
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Directory of Open Access Journals (Sweden)
Susana Scott
Full Text Available The death of a mother is a tragedy in itself but it can also have devastating effects for the survival of her children. We aim to explore the impact of a mother's death on child survival in rural Gambia, West Africa.We used 25 years of prospective surveillance data from the Farafenni Health and Demographic surveillance system (FHDSS. Mortality rates per 1,000 child-years up to ten years of age were estimated and Kaplan-Meier survival curves plotted by maternal vital status. Cox proportional hazard models were used to examine factors associated with child survival.Between 1st April 1989 and 31st December 2014, a total of 2, 221 (7.8% deaths occurred during 152,906 child-years of follow up. Overall mortality rate was 14.53 per 1,000 child-years (95% CI: 13.93-15.14. Amongst those whose mother died, the rate was 25.89 (95% CI: 17.99-37.25 compared to 14.44 (95% CI: 13.84-15.06 per 1,000 child-years for those whose mother did not die. Children were 4.66 (95% CI: 3.15-6.89 times more likely to die if their mother died compared to those with a surviving mother. Infants whose mothers died during delivery or shortly after were up to 7 times more likely to die within the first month of life compared to those whose mothers survived. Maternal vital status was significantly associated with the risk of dying within the first 2 years of life (p-value <0.05, while this was no longer observed for children over 2 years of age (P = 0.872. Other factors associated with an increased risk of dying were living in more rural areas, and birth spacing and year of birth.Mother's survival is strongly associated with child survival. Our findings highlight the importance of the continuum of care for both the mother and child not only throughout pregnancy, and childbirth but beyond 6 weeks post-partum.
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Hallgren, Oskar; Aits, Sonja; Brest, Patrick; Gustafsson, Lotta; Mossberg, Ann-Kristin; Wullt, Björn; Svanborg, Catharina
2008-01-01
HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a molecular complex derived from human milk that kills tumor cells by a process resembling programmed cell death. The complex consists of partially unfolded alpha-lactalbumin and oleic acid, and both the protein and the fatty acid are required for cell death. HAMLET has broad antitumor activity in vitro, and its therapeutic effect has been confirmed in vivo in a human glioblastoma rat xenograft model, in patients with skin papillomas and in patients with bladder cancer. The mechanisms of tumor cell death remain unclear, however. Immediately after the encounter with tumor cells, HAMLET invades the cells and causes mitochondrial membrane depolarization, cytochrome c release, phosphatidyl serine exposure, and a low caspase response. A fraction of the cells undergoes morphological changes characteristic of apoptosis, but caspase inhibition does not rescue the cells and Bcl-2 overexpression or altered p53 status does not influence the sensitivity of tumor cells to HAMLET. HAMLET also creates a state of unfolded protein overload and activates 20S proteasomes, which contributes to cell death. In parallel, HAMLET translocates to tumor cell nuclei, where high-affinity interactions with histones cause chromatin disruption, loss of transcription, and nuclear condensation. The dying cells also show morphological changes compatible with macroautophagy, and recent studies indicate that macroautophagy is involved in the cell death response to HAMLET. The results suggest that HAMLET, like a hydra with many heads, may interact with several crucial cellular organelles, thereby activating several forms of cell death, in parallel. This complexity might underlie the rapid death response of tumor cells and the broad antitumor activity of HAMLET.
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Gupta, Subash C.; Kim, Ji Hye; Prasad, Sahdeo
2010-01-01
Almost 25 centuries ago, Hippocrates, the father of medicine, proclaimed “Let food be thy medicine and medicine be thy food.” Exploring the association between diet and health continues today. For example, we now know that as many as 35% of all cancers can be prevented by dietary changes. Carcinogenesis is a multistep process involving the transformation, survival, proliferation, invasion, angiogenesis, and metastasis of the tumor and may take up to 30 years. The pathways associated with this process have been linked to chronic inflammation, a major mediator of tumor progression. The human body consists of about 13 trillion cells, almost all of which are turned over within 100 days, indicating that 70,000 cells undergo apoptosis every minute. Thus, apoptosis/cell death is a normal physiological process, and it is rare that a lack of apoptosis kills the patient. Almost 90% of all deaths due to cancer are linked to metastasis of the tumor. How our diet can prevent cancer is the focus of this review. Specifically, we will discuss how nutraceuticals, such as allicin, apigenin, berberine, butein, caffeic acid, capsaicin, catechin gallate, celastrol, curcumin, epigallocatechin gallate, fisetin, flavopiridol, gambogic acid, genistein, plumbagin, quercetin, resveratrol, sanguinarine, silibinin, sulforaphane, taxol, γ-tocotrienol, and zerumbone, derived from spices, legumes, fruits, nuts, and vegetables, can modulate inflammatory pathways and thus affect the survival, proliferation, invasion, angiogenesis, and metastasis of the tumor. Various cell signaling pathways that are modulated by these agents will also be discussed. PMID:20737283
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Up-regulation of Kir2.1 by ER stress facilitates cell death of brain capillary endothelial cells
International Nuclear Information System (INIS)
Kito, Hiroaki; Yamazaki, Daiju; Ohya, Susumu; Yamamura, Hisao; Asai, Kiyofumi; Imaizumi, Yuji
2011-01-01
Highlights: → We found that application of endoplasmic reticulum (ER) stress with tunicamycin to brain capillary endothelial cells (BCECs) induced cell death. → The ER stress facilitated the expression of inward rectifier K + channel (K ir 2.1) and induced sustained membrane hyperpolarization. → The membrane hyperpolarization induced sustained Ca 2+ entry through voltage-independent nonspecific cation channels and consequently facilitated cell death. → The K ir 2.1 up-regulation by ER stress is, at least in part, responsible for cell death of BCECs under pathological conditions. -- Abstract: Brain capillary endothelial cells (BCECs) form blood brain barrier (BBB) to maintain brain homeostasis. Cell turnover of BCECs by the balance of cell proliferation and cell death is critical for maintaining the integrity of BBB. Here we found that stimuli with tunicamycin, endoplasmic reticulum (ER) stress inducer, up-regulated inward rectifier K + channel (K ir 2.1) and facilitated cell death in t-BBEC117, a cell line derived from bovine BCECs. The activation of K ir channels contributed to the establishment of deeply negative resting membrane potential in t-BBEC117. The deep resting membrane potential increased the resting intracellular Ca 2+ concentration due to Ca 2+ influx through non-selective cation channels and thereby partly but significantly regulated cell death in t-BBEC117. The present results suggest that the up-regulation of K ir 2.1 is, at least in part, responsible for cell death/cell turnover of BCECs induced by a variety of cellular stresses, particularly ER stress, under pathological conditions.
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Mitra, Sumonto; Srivastava, Ankit; Khandelwal, Shashi
2013-12-06
The widespread use of tributyltin (TBT) as biocides in antifouling paints and agricultural chemicals has led to environmental and marine pollution. Human exposure occurs mainly through TBT contaminated seafood and drinking water. It is a well known endocrine disruptor in mammals, but its molecular mechanism in testicular damage is largely unexplored. This study was therefore, designed to ascertain effects of tributyltin chloride (TBTC) on sertoli-germ cell co-culture in ex-vivo and in the testicular tissue in-vivo conditions. An initial Ca(2+) rise followed by ROS generation and glutathione depletion resulted in oxidative damage and cell death. We observed p38 and JNK phosphorylation, stress proteins (Nrf2, MT and GST) induction and mitochondrial depolarization leading to caspase-3 activation. Prevention of TBTC reduced cell survival and cell death by Ca(2+) inhibitors and free radical scavengers specify definitive role of Ca(2+) and ROS. Sertoli cells were found to be more severely affected which in turn can hamper germ cells functionality. TBTC exposure in-vivo resulted in increased tin content in the testis with enhanced Evans blue leakage into the testicular tissue indicating blood-testis barrier disruption. Tesmin levels were significantly diminished and histopathological studies revealed marked tissue damage. Our data collectively indicates the toxic manifestations of TBTC on the male reproductive system and the mechanisms involved. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
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International Nuclear Information System (INIS)
Oorschot, B. van; Assenbrunner, B.; Beckmann, G.; Flentje, M.; Schuler, M.
2014-01-01
Survival and prognostic variables in patients with advanced or metastatic non-small cell lung cancer (NSCLC) requiring thoracic palliative radiotherapy using a moderately hypofractionated regime (13-15 x 3 Gy) were evaluated. From March 2006 to April 2012, 120 patients with a physician estimated prognosis of 6-12 months were treated with this regime using CT-based 3D conformal radiotherapy. We collected data on patient characteristics, comorbidities, toxicity, and treatment parameters. Radiotherapy was completed as prescribed in 114 patients (95.0 %, premature termination 5.0 %). Acute grade 3 toxicity was seen in 6.4 % of patients. The median survival of all patients was 5.8 months. Nonmetastatic patients survived significantly longer than patients with metastatic disease (median 11.7 months vs 4.7 months, p = 0.0001) and 18.6 % of nonmetastatic patients survived longer than 2 years. In 12.7 % radiotherapy started less than 30 days before death and 14.2 % of patients received radiotherapy within 14 days before death. In the multivariate analysis, good general condition, nonmetastatic disease, and a stable or improved general condition at the end of radiotherapy were significant. The treatment parameters, age, and comorbidities were not statistically significant. Our data confirm considerable effectiveness of 13 x 3 Gy with conformal radiotherapy for patients with locally confined NSCLC not fit for radical treatment and raise doubt for this regimen in metastatic patients and ECOG ≥ 2 when burden, acute toxicity, and resources are considered. (orig.) [de
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BID links ferroptosis to mitochondrial cell death pathways
Neitemeier, Sandra; Jelinek, Anja; Laino, Vincenzo; Hoffmann, Lena; Eisenbach, Ina; Eying, Roman; Ganjam, Goutham K; Dolga, Amalia M; Oppermann, Sina; Culmsee, Carsten
2017-01-01
Ferroptosis has been defined as an oxidative and iron-dependent pathway of regulated cell death that is distinct from caspase-dependent apoptosis and established pathways of death receptor-mediated regulated necrosis. While emerging evidence linked features of ferroptosis induced e.g. by
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THE PROGRAMED CELL DEATH REGULATORS OF ISOLATED MODEL SYSTEMS
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D. V. Vatlitsov
2016-06-01
Full Text Available The technology evolution creates the prerequisites for the emergence of new informational concept and approaches to the formation of a fundamentally new principles of biological objects understanding. The aim was to study the activators of the programmed cell death in an isolated system model. Cell culture aging parameters were performed on flow cytometer. It had formed the theory that the changes in the concentrations of metal ions and increase their extracellular concentration had formed a negative gradient into the cells.regulation of cell death. It was shown that the metals ions concentrations.
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Directory of Open Access Journals (Sweden)
Kai-Wen Hsu
2018-02-01
Full Text Available Breast cancer is the most common malignancy in women and the second leading cause of cancer death in women. Triple negative breast cancer (TNBC subtype is a breast cancer subset without ER (estrogen receptor, PR (progesterone receptor and HER2 (human epidermal growth factor receptor 2 expression, limiting treatment options and presenting a poorer survival rate. Thus, we investigated whether histone deacetylation inhibitor (HDACi could be used as potential anti-cancer therapy on breast cancer cells. In this study, we found TNBC and HER2-enriched breast cancers are extremely sensitive to Panobinostat, Belinostat of HDACi via experiments of cell viability assay, apoptotic marker identification and flow cytometry measurement. On the other hand, we developed a bioluminescence-based live cell non-invasive apoptosis detection sensor (NIADS detection system to evaluate the quantitative and kinetic analyses of apoptotic cell death by HDAC treatment on breast cancer cells. In addition, the use of HDACi may also contribute a synergic anti-cancer effect with co-treatment of chemotherapeutic agent such as doxorubicin on TNBC cells (MDA-MB-231, but not in breast normal epithelia cells (MCF-10A, providing therapeutic benefits against breast tumor in the clinic.
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International Nuclear Information System (INIS)
Deep, Gagan; Kumar, Rahul; Jain, Anil K.; Agarwal, Chapla; Agarwal, Rajesh
2014-01-01
Highlights: • Silibinin inhibits fibronectin-induce motile morphology in PC3 cells. • Silibinin inhibits fibronectin-induced migration and invasion in PC3 cells. • Silibinin targets fibronectin-induced integrins and downstream signaling molecule. - Abstract: Prostate cancer (PCA) is the 2nd leading cause of cancer-related deaths among men in the United States. Preventing or inhibiting metastasis-related events through non-toxic agents could be a useful approach for lowering high mortality among PCA patients. We have earlier reported that natural flavonoid silibinin possesses strong anti-metastatic efficacy against PCA however, mechanism/s of its action still remains largely unknown. One of the major events during metastasis is the replacement of cell–cell interaction with integrins-based cell–matrix interaction that controls motility, invasiveness and survival of cancer cells. Accordingly, here we examined silibinin effect on advanced human PCA PC3 cells’ interaction with extracellular matrix component fibronectin. Silibinin (50–200 μM) treatment significantly decreased the fibronectin (5 μg/ml)-induced motile morphology via targeting actin cytoskeleton organization in PC3 cells. Silibinin also decreased the fibronectin-induced cell proliferation and motility but significantly increased cell death in PC3 cells. Silibinin also inhibited the PC3 cells invasiveness in Transwell invasion assays with fibronectin or cancer associated fibroblasts (CAFs) serving as chemoattractant. Importantly, PC3-luc cells cultured on fibronectin showed rapid dissemination and localized in lungs following tail vein injection in athymic male nude mice; however, in silibinin-treated PC3-luc cells, dissemination and lung localization was largely compromised. Molecular analyses revealed that silibinin treatment modulated the fibronectin-induced expression of integrins (α5, αV, β1 and β3), actin-remodeling (FAK, Src, GTPases, ARP2 and cortactin), apoptosis (cPARP and
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Energy Technology Data Exchange (ETDEWEB)
Deep, Gagan [Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO (United States); University of Colorado Cancer Center, University of Colorado Denver, Aurora, CO (United States); Kumar, Rahul; Jain, Anil K. [Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO (United States); Agarwal, Chapla [Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO (United States); University of Colorado Cancer Center, University of Colorado Denver, Aurora, CO (United States); Agarwal, Rajesh, E-mail: Rajesh.agarwal@ucdenver.edu [Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO (United States); University of Colorado Cancer Center, University of Colorado Denver, Aurora, CO (United States)
2014-10-15
Highlights: • Silibinin inhibits fibronectin-induce motile morphology in PC3 cells. • Silibinin inhibits fibronectin-induced migration and invasion in PC3 cells. • Silibinin targets fibronectin-induced integrins and downstream signaling molecule. - Abstract: Prostate cancer (PCA) is the 2nd leading cause of cancer-related deaths among men in the United States. Preventing or inhibiting metastasis-related events through non-toxic agents could be a useful approach for lowering high mortality among PCA patients. We have earlier reported that natural flavonoid silibinin possesses strong anti-metastatic efficacy against PCA however, mechanism/s of its action still remains largely unknown. One of the major events during metastasis is the replacement of cell–cell interaction with integrins-based cell–matrix interaction that controls motility, invasiveness and survival of cancer cells. Accordingly, here we examined silibinin effect on advanced human PCA PC3 cells’ interaction with extracellular matrix component fibronectin. Silibinin (50–200 μM) treatment significantly decreased the fibronectin (5 μg/ml)-induced motile morphology via targeting actin cytoskeleton organization in PC3 cells. Silibinin also decreased the fibronectin-induced cell proliferation and motility but significantly increased cell death in PC3 cells. Silibinin also inhibited the PC3 cells invasiveness in Transwell invasion assays with fibronectin or cancer associated fibroblasts (CAFs) serving as chemoattractant. Importantly, PC3-luc cells cultured on fibronectin showed rapid dissemination and localized in lungs following tail vein injection in athymic male nude mice; however, in silibinin-treated PC3-luc cells, dissemination and lung localization was largely compromised. Molecular analyses revealed that silibinin treatment modulated the fibronectin-induced expression of integrins (α5, αV, β1 and β3), actin-remodeling (FAK, Src, GTPases, ARP2 and cortactin), apoptosis (cPARP and
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HOIP Deficiency Causes Embryonic Lethality by Aberrant TNFR1-Mediated Endothelial Cell Death
Directory of Open Access Journals (Sweden)
Nieves Peltzer
2014-10-01
Full Text Available Summary: Linear ubiquitination is crucial for innate and adaptive immunity. The linear ubiquitin chain assembly complex (LUBAC, consisting of HOIL-1, HOIP, and SHARPIN, is the only known ubiquitin ligase that generates linear ubiquitin linkages. HOIP is the catalytically active LUBAC component. Here, we show that both constitutive and Tie2-Cre-driven HOIP deletion lead to aberrant endothelial cell death, resulting in defective vascularization and embryonic lethality at midgestation. Ablation of tumor necrosis factor receptor 1 (TNFR1 prevents cell death, vascularization defects, and death at midgestation. HOIP-deficient cells are more sensitive to death induction by both tumor necrosis factor (TNF and lymphotoxin-α (LT-α, and aberrant complex-II formation is responsible for sensitization to TNFR1-mediated cell death in the absence of HOIP. Finally, we show that HOIP’s catalytic activity is necessary for preventing TNF-induced cell death. Hence, LUBAC and its linear-ubiquitin-forming activity are required for maintaining vascular integrity during embryogenesis by preventing TNFR1-mediated endothelial cell death. : HOIP is the main catalytic subunit of the linear ubiquitin chain assembly complex (LUBAC, a crucial regulator of TNF and other immune signaling pathways. Peltzer et al. find that HOIP deficiency results in embryonic lethality at midgestation due to endothelial cell death mediated by TNFR1. Aberrant formation of a TNF-mediated cell-death-inducing complex in HOIP-deficient (but not -proficient cells underlies the phenotype, with the catalytic activity of HOIP required for the control of cell death in response to TNF.
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Scarlatti, F; Maffei, R; Beau, I; Codogno, P; Ghidoni, R
2008-08-01
Resveratrol, a polyphenol found in grapes and other fruit and vegetables, is a powerful chemopreventive and chemotherapeutic molecule potentially of interest for the treatment of breast cancer. The human breast cancer cell line MCF-7, which is devoid of caspase-3 activity, is refractory to apoptotic cell death after incubation with resveratrol. Here we show that resveratrol arrests cell proliferation, triggers death and decreases the number of colonies of cells that are sensitive to caspase-3-dependent apoptosis (MCF-7 casp-3) and also those that are unresponsive to it (MCF-7vc). We demonstrate that resveratrol (i) acts via multiple pathways to trigger cell death, (ii) induces caspase-dependent and caspase-independent cell death in MCF-7 casp-3 cells, (iii) induces only caspase-independent cell death in MCF-7vc cells and (iv) stimulates macroautophagy. Using BECN1 and hVPS34 (human vacuolar protein sorting 34) small interfering RNAs, we demonstrate that resveratrol activates Beclin 1-independent autophagy in both cell lines, whereas cell death via this uncommon form of autophagy occurs only in MCF-7vc cells. We also show that this variant form of autophagic cell death is blocked by the expression of caspase-3, but not by its enzymatic activity. In conclusion, this study reveals that non-canonical autophagy induced by resveratrol can act as a caspase-independent cell death mechanism in breast cancer cells.
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Del Bello, Barbara; Toscano, Marzia; Moretti, Daniele; Maellaro, Emilia
2013-01-01
The interplay between a non-lethal autophagic response and apoptotic cell death is still a matter of debate in cancer cell biology. In the present study performed on human melanoma cells, we investigate the role of basal or stimulated autophagy in cisplatin-induced cytotoxicity, as well as the contribution of cisplatin-induced activation of caspases 3/7 and conventional calpains. The results show that, while down-regulating Beclin-1, Atg14 and LC3-II, cisplatin treatment inhibits the basal autophagic response, impairing a physiological pro-survival response. Consistently, exogenously stimulated autophagy, obtained with trehalose or calpains inhibitors (MDL-28170 and calpeptin), protects from cisplatin-induced apoptosis, and such a protection is reverted by inhibiting autophagy with 3-methyladenine or ATG5 silencing. In addition, during trehalose-stimulated autophagy, the cisplatin-induced activation of calpains is abrogated, suggesting the existence of a feedback loop between the autophagic process and calpains. On the whole, our results demonstrate that in human melanoma cells autophagy may function as a beneficial stress response, hindered by cisplatin-induced death mechanisms. In a therapeutic perspective, these findings suggest that the efficacy of cisplatin-based polychemotherapies for melanoma could be potentiated by inhibitors of autophagy.
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Quality of life assessment as a predictor of survival in non-small cell lung cancer
Directory of Open Access Journals (Sweden)
Staren Edgar D
2011-08-01
Full Text Available Abstract Background There are conflicting and inconsistent results in the literature on the prognostic role of quality of life (QoL in cancer. We investigated whether QoL at admission could predict survival in lung cancer patients. Methods The study population consisted of 1194 non-small cell lung cancer patients treated at our institution between Jan 2001 and Dec 2008. QoL was evaluated using EORTC-QLQ-C30 prior to initiation of treatment. Patient survival was defined as the time interval between the date of first patient visit and the date of death from any cause/date of last contact. Univariate and multivariate Cox regression evaluated the prognostic significance of QoL. Results Mean age at presentation was 58.3 years. There were 605 newly diagnosed and 589 previously treated patients; 601 males and 593 females. Stage of disease at diagnosis was I, 100; II, 63; III, 348; IV, 656; and 27 indeterminate. Upon multivariate analyses, global QoL as well as physical function predicted patient survival in the entire study population. Every 10-point increase in physical function was associated with a 10% increase in survival (95% CI = 6% to 14%, p Conclusions Baseline global QoL and physical function provide useful prognostic information in non-small cell lung cancer patients.
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Ganglioside GD2 in reception and transduction of cell death signal in tumor cells
International Nuclear Information System (INIS)
Doronin, Igor I; Vishnyakova, Polina A; Kholodenko, Irina V; Ponomarev, Eugene D; Ryazantsev, Dmitry Y; Molotkovskaya, Irina M; Kholodenko, Roman V
2014-01-01
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
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Targeting of nucleotide-binding proteins by HAMLET--a conserved tumor cell death mechanism.
Ho, J C S; Nadeem, A; Rydström, A; Puthia, M; Svanborg, C
2016-02-18
HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) kills tumor cells broadly suggesting that conserved survival pathways are perturbed. We now identify nucleotide-binding proteins as HAMLET binding partners, accounting for about 35% of all HAMLET targets in a protein microarray comprising 8000 human proteins. Target kinases were present in all branches of the Kinome tree, including 26 tyrosine kinases, 10 tyrosine kinase-like kinases, 13 homologs of yeast sterile kinases, 4 casein kinase 1 kinases, 15 containing PKA, PKG, PKC family kinases, 15 calcium/calmodulin-dependent protein kinase kinases and 13 kinases from CDK, MAPK, GSK3, CLK families. HAMLET acted as a broad kinase inhibitor in vitro, as defined in a screen of 347 wild-type, 93 mutant, 19 atypical and 17 lipid kinases. Inhibition of phosphorylation was also detected in extracts from HAMLET-treated lung carcinoma cells. In addition, HAMLET recognized 24 Ras family proteins and bound to Ras, RasL11B and Rap1B on the cytoplasmic face of the plasma membrane. Direct cellular interactions between HAMLET and activated Ras family members including Braf were confirmed by co-immunoprecipitation. As a consequence, oncogenic Ras and Braf activity was inhibited and HAMLET and Braf inhibitors synergistically increased tumor cell death in response to HAMLET. Unlike most small molecule kinase inhibitors, HAMLET showed selectivity for tumor cells in vitro and in vivo. The results identify nucleotide-binding proteins as HAMLET targets and suggest that dysregulation of the ATPase/kinase/GTPase machinery contributes to cell death, following the initial, selective recognition of HAMLET by tumor cells. The findings thus provide a molecular basis for the conserved tumoricidal effect of HAMLET, through dysregulation of kinases and oncogenic GTPases, to which tumor cells are addicted.
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Akebia saponin PA induces autophagic and apoptotic cell death in AGS human gastric cancer cells.
Xu, Mei-Ying; Lee, Dong Hwa; Joo, Eun Ji; Son, Kun Ho; Kim, Yeong Shik
2013-09-01
In this study, we investigated the anticancer mechanism of akebia saponin PA (AS), a natural product isolated from Dipsacus asperoides in human gastric cancer cell lines. It was shown that AS-induced cell death is caused by autophagy and apoptosis in AGS cells. The apoptosis-inducing effect of AS was characterized by annexin V/propidium (PI) staining, increase of sub-G1 phase and caspase-3 activation, while the autophagy-inducing effect was indicated by the formation of cytoplasmic vacuoles and microtubule-associated protein 1 light chain-3 II (LC3-II) conversion. The autophagy inhibitor bafilomycin A1 (BaF1) decreased AS-induced cell death and caspase-3 activation, but caspase-3 inhibitor Ac-DEVD-CHO did not affect LC3-II accumulation or AS-induced cell viability, suggesting that AS induces autophagic cell death and autophagy contributes to caspase-3-dependent apoptosis. Furthermore, AS activated p38/c-Jun N-terminal kinase (JNK), which could be inhibited by BaF1, and caspase-3 activation was attenuated by both SB202190 and SP600125, indicating that AS-induced autophagy promotes mitogen-activated protein kinases (MAPKs)-mediated apoptosis. Taken together, these results demonstrate that AS induces autophagic and apoptotic cell death and autophagy plays the main role in akebia saponin PA-induced cell death. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Zhang, Shufang; Jiang, Yang Zi; Zhang, Wei; Chen, Longkun; Tong, Tong; Liu, Wanlu; Mu, Qin; Liu, Hua; Ji, Junfeng; Ouyang, Hong Wei
2013-01-01
Immunological response hampers the investigation of human embryonic stem cells (hESCs) or their derivates for tissue regeneration in vivo. Immunosuppression is often used after surgery, but exhibits side effects of significant weight loss and allows only short-term observation. The purpose of this study was to investigate whether neonatal desensitization supports relative long-term survival of hESC-derived mesenchymal stem cells (hESC-MSCs) and promotes cartilage regeneration. hESC-MSCs were injected on the day of birth in rats. Six weeks after neonatal injection, a full-thickness cylindrical cartilage defect was created and transplanted with a hESC-MSC-seeded collagen bilayer scaffold (group d+s+c) or a collagen bilayer scaffold (group d+s). Rats without neonatal injection were transplanted with the hESC-MSC-seeded collagen bilayer scaffold to serve as controls (group s+c). Cartilage regeneration was evaluated by histological analysis, immunohistochemical staining, and biomechanical test. The role of hESC-MSCs in cartilage regeneration was analyzed by CD4 immunostaining, cell death detection, and visualization of human cells in regenerated tissues. hESC-MSCs expressed CD105, CD73, CD90, CD29, and CD44, but not CD45 and CD34, and possessed trilineage differentiation potential. Group d+s+c exhibited greater International Cartilage Repair Society (ICRS) scores than group d+s or group s+c. Abundant collagen type II and improved mechanical properties were detected in group d+s+c. There were less CD4+ inflammatory cell infiltration and cell death at week 1, and hESC-MSCs were found to survive as long as 8 weeks after transplantation in group d+s+c. Our study suggests that neonatal desensitization before transplantation may be an efficient way to develop a powerful tool for preclinical study of human cell-based therapies in animal models. PMID:22788986
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Directory of Open Access Journals (Sweden)
Hourinaz Behesti
2013-01-01
BMI1 is a potent inducer of neural stem cell self-renewal and neural progenitor cell proliferation during development and in adult tissue homeostasis. It is overexpressed in numerous human cancers – including medulloblastomas, in which its functional role is unclear. We generated transgenic mouse lines with targeted overexpression of Bmi1 in the cerebellar granule cell lineage, a cell type that has been shown to act as a cell of origin for medulloblastomas. Overexpression of Bmi1 in granule cell progenitors (GCPs led to a decrease in cerebellar size due to decreased GCP proliferation and repression of the expression of cyclin genes, whereas Bmi1 overexpression in postmitotic granule cells improved cell survival in response to stress by altering the expression of genes in the mitochondrial cell death pathway and of Myc and Lef-1. Although no medulloblastomas developed in ageing cohorts of transgenic mice, crosses with Trp53−/− mice resulted in a low incidence of medulloblastoma formation. Furthermore, analysis of a large collection of primary human medulloblastomas revealed that tumours with a BMI1high TP53low molecular profile are significantly enriched in Group 4 human medulloblastomas. Our data suggest that different levels and timing of Bmi1 overexpression yield distinct cellular outcomes within the same cellular lineage. Importantly, Bmi1 overexpression at the GCP stage does not induce tumour formation, suggesting that BMI1 overexpression in GCP-derived human medulloblastomas probably occurs during later stages of oncogenesis and might serve to enhance tumour cell survival.
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Zebrafish hair cell mechanics and physiology through the lens of noise-induced hair cell death
Coffin, Allison B.; Xu, Jie; Uribe, Phillip M.
2018-05-01
Hair cells are exquisitely sensitive to auditory stimuli, but also to damage from a variety of sources including noise trauma and ototoxic drugs. Mammals cannot regenerate cochlear hair cells, while non-mammalian vertebrates exhibit robust regenerative capacity. Our research group uses the lateral line system of larval zebrafish to explore the mechanisms underlying hair cell damage, identify protective therapies, and determine molecular drivers of innate regeneration. The lateral line system contains externally located sensory organs called neuromasts, each composed of ˜8-20 hair cells. Lateral line hair cells are homologous to vertebrate inner ear hair cells and share similar susceptibility to ototoxic damage. In the last decade, the lateral line has emerged as a powerful model system for understanding hair cell death mechanisms and for identifying novel protective compounds. Here we demonstrate that the lateral line is a tractable model for noise-induced hair cell death. We have developed a novel noise damage system capable of inducing over 50% loss of lateral line hair cells, with hair cell death occurring in a dose- and time-dependent manner. Cell death is greatest 72 hours post-exposure. However, early signs of hair cell damage, including changes in membrane integrity and reduced mechanotransduction, are apparent within hours of noise exposure. These features, early signs of damage followed by delayed hair cell death, are consistent with mammalian data, suggesting that noise acts similarly on zebrafish and mammalian hair cells. In our future work we will use our new model system to investigate noise damage events in real time, and to develop protective therapies for future translational research.
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Directory of Open Access Journals (Sweden)
Hossein Zhaleh
2016-11-01
Full Text Available Mouse bone marrow mesenchymal stem cells (mBMSCs soup is promising tool for the treatment of neurodegenerative diseases. mBMSCs soup is easily obtained and is capable of transplantation without rejection. We investigated the effects of mBMSC soup on staurosporine-induced cell death in PC12 and U87 cells lines. The percentage of cell viability, cell death, NO concentration, total neurite length (TNL and fraction of cell differentiation (f% were assessed. Viability assay showed that mBM soup (24 and 48h in time dependent were increased cell viability (p<0.05 and also cell death assay showed that cell death in time dependent were decreased, respectively (p<0.05. TNL and fraction of cell differentiation significantly were increased compared with treatment1 (p<0.05. Our data showed that mBM Soup protects cells, increases cell viability, suppresses cell death and improvement the neurite elongation. We concluded that Mouse bone marrow mesenchymal stem cell soup plays an important protective role in staurosporine-induced cell death in PC12 and U87 cell lines.
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Kim, Sang Eun; Park, Hye-Jin; Jeong, Hye Kyoung; Kim, Mi-Jung; Kim, Minyeong; Bae, Ok-Nam; Baek, Seung-Hoon
2015-07-31
Pancreatic ductal adenocarcinomas are an extremely aggressive and devastating type of cancer with high mortality. Given the dense stroma and poor vascularization, accessibility to nutrients is limited in the tumor microenvironment. Here, we aimed to elucidate the role of autophagy in promoting the survival of human pancreatic cancer PANC-1 cells exposed to nutrient-deprived media (NDM) lacking glucose, amino acids, and serum. NDM inhibited Akt activity and phosphorylation of p70 S6K, and induced AMPK activation and mitochondrial depolarization. NDM also time-dependently increased LC3-II accumulation, number of GFP-LC3 puncta, and colocalization between GFP-LC3 and lysosomes. These results suggested that autophagy was progressively activated through Akt- and AMPK-mTOR pathway in nutrient-deficient PANC-1 cells. Autophagy inhibitors (chloroquine and wortmannin) or silencing of Atg5 augmented PANC-1 cell death in NDM. In cells exposed to NDM, chloroquine and wortmannin induced apoptosis and Z-VAD-fmk inhibited cytotoxicity of these inhibitors. These data demonstrate that autophagy is anti-apoptotic and sustains the survival of PANC-1 cells following extreme nutrient deprivation. Autophagy modulation may be a viable therapeutic option for cancer cells located in the core of solid tumors with a nutrient-deficient microenvironment. Copyright © 2015 Elsevier Inc. All rights reserved.
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Yakimova, E.T.; Kapchina-Toteva, V.M.; Laarhoven, L.J.J.; Harren, F.J.M.; Woltering, E.J.
2006-01-01
Cadmium-induced cell death was studied in suspension-cultured tomato (Lycopersicon esculentum Mill.) cells (line MsK8) treated with CdSO4. Within 24 h, cadmium treatment induced cell death in a concentration-dependent manner. Cell cultures showed recovery after 23 days which indicates the existence
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International Nuclear Information System (INIS)
Murakami, Daniella
2003-01-01
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 90 Sr, a pure, highly energetic beta source, on CHO-K1 cells and to compare them with data obtained with 60 Co. CHO-K1 cells irradiated with different doses (1.0, 2.5, 5.0, 7.5 Gy) of 60 Co (0.34 Gy.min -1 ) and 90 Sr (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 60 Co than in cells irradiated with 90 Sr, whereas 90 Sr was more damaging than 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 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 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)
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Okahashi, Nobuo; Okinaga, Toshinori; Sakurai, Atsuo; Terao, Yutaka; Nakata, Masanobu; Nakashima, Keisuke; Shintani, Seikou; Kawabata, Shigetada; Ooshima, Takashi; Nishihara, Tatsuji
2011-10-01
Streptococcus sanguinis, a normal inhabitant of the human oral cavity, is a common streptococcal species implicated in infective endocarditis. Herein, we investigated the effects of infection with S. sanguinis on foam cell formation and cell death of macrophages. Infection with S. sanguinis stimulated foam cell formation of THP-1, a human macrophage cell line. At a multiplicity of infection >100, S. sanguinis-induced cell death of the macrophages. Viable bacterial infection was required to trigger cell death because heat-inactivated S. sanguinis did not induce cell death. The production of cytokines interleukin-1β and tumor necrosis factor-α from macrophages was also stimulated during bacterial infection. Inhibition of the production of reactive oxygen species (ROS) resulted in reduced cell death, suggesting an association of ROS with cell death. Furthermore, S. sanguinis-induced cell death appeared to be independent of activation of inflammasomes, because cleavage of procaspase-1 was not evident in infected macrophages. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.
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International Nuclear Information System (INIS)
Kim, Sung Hun; Yoo, Chong Il; Kim, Hui Taek; Park, Ji Yeon; Kwon, Chae Hwa; Keun Kim, Yong
2006-01-01
The present study was undertaken to determine the role of the mitogen-activated protein kinase (MAPK) subfamilies in cell death induced by PPARγ agonists in osteoblastic cells. Ciglitazone and troglitazone, PPARγ agonists, resulted in a concentration- and time-dependent cell death, which was largely attributed to apoptosis. But a PPARα agonist ciprofibrate did not affect the cell death. Ciglitazone caused reactive oxygen species (ROS) generation and ciglitazone-induced cell death was prevented by antioxidants, suggesting an important role of ROS generation in the ciglitazone-induced cell death. ROS generation and cell death induced by ciglitazone were inhibited by the PPARγ antagonist GW9662. Ciglitazone treatment caused activation of extracellular signal-regulated kinase (ERK) and p38. Activation of ERK was dependent on epidermal growth factor receptor (EGFR) and that of p38 was independent. Ciglitazone-induced cell death was significantly prevented by PD98059, an inhibitor of ERK upstream kinase MEK1/2, and SB203580, a p38 inhibitor. Ciglitazone treatment increased Bax expression and caused a loss of mitochondrial membrane potential, and its effect was prevented by N-acetylcysteine, PD98059, and SB203580. Ciglitazone induced caspase activation, which was prevented by PD98059 and SB203580. The general caspase inhibitor z-DEVD-FMK and the specific inhibitor of caspases-3 DEVD-CHO exerted the protective effect against the ciglitazone-induced cell death. The EGFR inhibitors AG1478 and suramin protected against the ciglitazone-induced cell death. Taken together, these findings suggest that the MAPK signaling pathways play an active role in mediating the ciglitazone-induced cell death of osteoblasts and function upstream of a mitochondria-dependent mechanism. These data may provide a novel insight into potential therapeutic strategies for treatment of osteoporosis
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Guidelines and recommendations on yeast cell death nomenclature
Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andres; Austriaco, Nicanor; Sigrist, Stephan J.
2018-01-01
Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of mor...
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Wei, Shenhai; Tian, Jintao; Song, Xiaoping; Wu, Bingqun; Liu, Limin
2018-01-01
To investigate the probability of death (POD) from any causes by time after diagnosis of non-small cell lung cancer (NSCLC) and the factors associated with survival for NSCLC patients. A total of 202,914 patients with NSCLC from 2004 to 2013 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The overall survival (OS) and lung cancer-specific survival (LCSS) were calculated and POD from any causes at different time periods after diagnosis was explored. The predictive factors for OS, LCSS and survival from non-lung cancer deaths were investigated using multivariate analysis with Cox proportional hazards regression and competing risk regression analysis. The 5- and 10-year OS were 20.4% and 11.5%, accordingly that for LCSS were 25.5% and 18.4%, respectively. Lung cancer contributed 88.3% (n = 128,402) of the deaths. The POD from lung cancer decreased with time after diagnosis. In multivariate analysis, advanced age and advanced stage of NSCLC were associated with decreased OS and LCSS. Comparing to no surgery, any kind of resection conferred lower risk of death from lung cancer and higher risk of dying from non-lung cancer conditions except lobectomy or bilobectomy, which was associated with lower risk of death from both lung cancer and non-lung cancer conditions. Most of the patients with NSCLC died from lung cancer. Rational surveillance and treatment policies should be made for them. Early stage and lobectomy or bilobectomy were associated with improved OS and LCSS. It is reasonable to focus on early detection and optimal surgical treatment for NSCLC.
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Award nomination for study of cell death in radiation sickness
Energy Technology Data Exchange (ETDEWEB)
Ivanitskiy, G
1985-01-01
The author discusses the importance of the work entitled Formulation of Theoretical Bases of the Phenomenon of Cell Death and Their Use in Explaining the Pathogenesis of Radiation Sickness, which has been nominated for the 1985 USSR State Prize. The author notes that the study of the nature and mechanisms of cell death from ionizing radiation consumed the efforts of researchers of various specialties for more than 20 years. The author observes that study of the molecular basis of the high radiosensitivity of lymphocytes became the key to understanding the general biological phenomenon of cell death.
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International Nuclear Information System (INIS)
Sergeant, Gregory; Eijsden, Rudy van; Roskams, Tania; Van Duppen, Victor; Topal, Baki
2012-01-01
Most cancer deaths are caused by metastases, resulting from circulating tumor cells (CTC) that detach from the primary cancer and survive in distant organs. The aim of the present study was to develop a CTC gene signature and to assess its prognostic relevance after surgery for pancreatic ductal adenocarcinoma (PDAC). Negative depletion fluorescence activated cell sorting (FACS) was developed and validated with spiking experiments using cancer cell lines in whole human blood samples. This FACS-based method was used to enrich for CTC from the blood of 10 patients who underwent surgery for PDAC. Total RNA was isolated from 4 subgroup samples, i.e. CTC, haematological cells (G), original tumour (T), and non-tumoural pancreatic control tissue (P). After RNA quality control, samples of 6 patients were eligible for further analysis. Whole genome microarray analysis was performed after double linear amplification of RNA. ‘Ingenuity Pathway Analysis’ software and AmiGO were used for functional data analyses. A CTC gene signature was developed and validated with the nCounter system on expression data of 78 primary PDAC using Cox regression analysis for disease-free (DFS) and overall survival (OS). Using stringent statistical analysis, we retained 8,152 genes to compare expression profiles of CTC vs. other subgroups, and found 1,059 genes to be differentially expressed. The pathway with the highest expression ratio in CTC was p38 mitogen-activated protein kinase (p38 MAPK) signaling, known to be involved in cancer cell migration. In the p38 MAPK pathway, TGF-β1, cPLA2, and MAX were significantly upregulated. In addition, 9 other genes associated with both p38 MAPK signaling and cell motility were overexpressed in CTC. High co-expression of TGF-β1 and our cell motility panel (≥ 4 out of 9 genes for DFS and ≥ 6 out of 9 genes for OS) in primary PDAC was identified as an independent predictor of DFS (p=0.041, HR (95% CI) = 1.885 (1.025 – 3.559)) and OS (p=0.047, HR
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Kohr, Mark J; Evangelista, Alicia M; Ferlito, Marcella; Steenbergen, Charles; Murphy, Elizabeth
2014-04-01
Oxidative stress and membrane damage following myocardial ischemia/reperfusion injury are important contributors to cardiomyocyte death and the loss of myocardial function. Our previous study identified cysteine 144 (C144) of tripartite motif-containing protein 72 (TRIM72) as a potential site for S-nitrosylation (SNO). TRIM72 is a cardioprotective membrane repair protein that can be both activated and targeted for degradation by different oxidative modifications. Consistent with the potential regulation of TRIM72 by various oxidative modifications, we found that SNO levels increased at C144 of TRIM72 with ischemic preconditioning. Therefore, to investigate the role of C144 in the regulation of TRIM72 function, we mutated C144 of TRIM72 to a serine residue (TRIM72(C144S)), and expressed either TRIM72(WT) or TRIM72(C144S) in HEK-293 cells, which lack endogenous TRIM72, in order to examine the effect of this mutation on the functional stability of TRIM72 and on cell survival. We hypothesized that SNO of TRIM72 stabilizes the protein, thus allowing for membrane repair and enhanced cell survival. Upon treatment with hydrogen peroxide (H2O2), we found that TRIM72(WT) levels were decreased, but not TRIM72(C144S) and this correlated with increased H2O2-induced cell death in TRIM72(WT) cells. Additionally, we found that treatment with the cardioprotective S-nitrosylating agent S-nitrosoglutathione (GSNO), was able to preserve TRIM72(WT) protein levels and enhance TRIM72(WT)-mediated cell survival, but had no effect on TRIM72(C144S) levels. Consistent with our hypothesis, GSNO was also found to increase SNO levels and inhibit H2O2-induced irreversible oxidation for TRIM72(WT) without affecting TRIM72(C144S). In further support of our hypothesis, GSNO blocked the ischemia/reperfusion-induced decrease in TRIM72 levels and reduced infarct size in a Langendorff-perfused heart model. The results of these studies have important implications for cardioprotection and suggest that
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Quantification of cell death in developing cerebellum by a 14C tracer method
International Nuclear Information System (INIS)
Griffin, W.S.; Woodward, D.J.; Chanda, R.
1978-01-01
To study the question of whether or not cell death contributes significantly to normal or stressed postnatal brain development in a way which is biochemically quantifiable, we carried out an experiment to assess the amount of cell death in developing cerebellum. By measuring the loss of DNA content and the loss of 14 C from labelled thymidine previously incorporated into the DNA fraction (DNAF) in X-irradiated neonatal animals, shown by histological methods to have cell death to the degree of degranulating the external granular layer (EGL), we showed that when cells die both label and DNA content are greatly decreased in the cerebellum. Experiments on both normal and malnourished animals showed that cell death does not contribute significantly to cerebellar development in either malnutrition-stressed or normal animals. Here, we present a biochemical tool for assessing cell death and evidence that cell death does not contribute significantly to cerebellar development
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The mechanism of radiation-induced interphase death of lymphoid cells: A new hypothesis
International Nuclear Information System (INIS)
Eidus, L.K.; Korystov, Yu.N.; Dobrovinskaja, O.R.; Shaposhnikova, V.V.
1990-01-01
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
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Topoisomerase IIbeta is required for proper retinal development and survival of postmitotic cells
Directory of Open Access Journals (Sweden)
Ying Li
2014-01-01
Topoisomerase IIbeta (Top2b is an enzyme that modulates DNA supercoiling by catalyzing the passage of DNA duplexes through one another. It is ubiquitously expressed in postmitotic cells and known to function during the development of neuromuscular junctions in the diaphragm and the proper formation of laminar structure in the cerebral cortex. However, due to the perinatal death phenotype of the traditional constitutive and brain-specific Top2b knockout mice, the precise in vivo function of Top2b, especially during postnatal neural development, remains to be determined. Using both the constitutive and retina-specific knockout mouse models, we showed that Top2b deficiency resulted in delayed neuronal differentiation, degeneration of the plexiform layers and outer segment of photoreceptors, as well as dramatic reduction in cell number in the retina. Genome-wide transcriptome analysis by RNA sequencing revealed that genes involved in neuronal survival and neural system development were preferentially affected in Top2b-deficient retinas. Collectively, our findings have indicated an important function of Top2b in proper development and the maintenance/survival of postmitotic neurons in the retina.
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The statistical treatment of cell survival data
International Nuclear Information System (INIS)
Boag, J.W.
1975-01-01
The paper considers the sources of experimental error in cell survival experiments and discusses in simple terms how these combine to influence the accuracy of single points and the parameters of complete survival curves. Cell sampling and medium-dilution errors are discussed at length and one way of minimizing the former is examined. The Monte-Carlo method of estimating the distribution of derived parameters in small samples is recommended and illustrated. (author)
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Iakimova, E.T.; Kapchina-Toteva, V.M.; Laarhoven, L.J.; Harren, F.; Woltering, E.J.
2006-01-01
Cadmium-induced cell death was studied in suspension-cultured tomato (Lycopersicon esculentum Mill.) cells (line MsK8) treated with CdSO4. Within 24 h, cadmium treatment induced cell death in a concentration-dependent manner. Cell cultures showed recovery after 2¿3 days which indicates the existence
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Non-canonical programmed cell death mechanisms triggered by natural compounds.
Diederich, Marc; Cerella, Claudia
2016-10-01
Natural compounds are the fundament of pharmacological treatments and more than 50% of all anticancer drugs are of natural origins or at least derived from scaffolds present in Nature. Over the last 25 years, molecular mechanisms triggered by natural anticancer compounds were investigated. Emerging research showed that molecules of natural origins are useful for both preventive and therapeutic purposes by targeting essential hallmarks and enabling characteristics described by Hanahan and Weinberg. Moreover, natural compounds were able to change the differentiation status of selected cell types. One of the earliest response of cells treated by pharmacologically active compounds is the change of its morphology leading to ultra-structural perturbations: changes in membrane composition, cytoskeleton integrity, alterations of the endoplasmic reticulum, mitochondria and of the nucleus lead to formation of morphological alterations that are a characteristic of both compound and cancer type preceding cell death. Apoptosis and autophagy were traditionally considered as the most prominent cell death or cell death-related mechanisms. By now multiple other cell death modalities were described and most likely involved in response to chemotherapeutic treatment. It can be hypothesized that especially necrosis-related phenotypes triggered by various treatments or evolving from apoptotic or autophagic mechanisms, provide a more efficient therapeutic outcome depending on cancer type and genetic phenotype of the patient. In fact, the recent discovery of multiple regulated forms of necrosis and the initial elucidation of the corresponding cell signaling pathways appear nowadays as important tools to clarify the immunogenic potential of non-canonical forms of cell death induction. Copyright © 2016 Elsevier Ltd. All rights reserved.
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NETs: The missing link between cell death and systemic autoimmune diseases?
Directory of Open Access Journals (Sweden)
Felipe eAndrade
2013-01-01
Full Text Available For almost 20 years, apoptosis and secondary necrosis have been considered the major source of autoantigens and endogenous adjuvants in the pathogenic model of systemic autoimmune diseases. This focus is justified in part because initial evidence in systemic lupus erythematosus (SLE guided investigators toward the study of apoptosis, but also because other forms of cell death were unknown. To date, it is known that many other forms of cell death occur, and that they vary in their capacity to stimulate as well as inhibit the immune system. Among these, NETosis (an antimicrobial form of death in neutrophils in which nuclear material is extruded from the cell forming extracellular traps, is gaining major interest as a process that may trigger some of the immune features found in SLE, granulomatosis with polyangiitis (formerly Wegener’s granulomatosis and Felty’s syndrome. Although there have been volumes of very compelling studies published on the role of cell death in autoimmunity, no unifying theory has been adopted nor have any successful therapeutics been developed based on this important pathway. The recent inclusion of NETosis into the pathogenic model of autoimmune diseases certainly adds novel insights into this paradigm, but also reveals a previously unappreciated level of complexity and raises many new questions. This review discusses the role of cell death in systemic autoimmune diseases with a focus on apoptosis and NETosis, highlights the current short comings in our understanding of the vast complexity of cell death, and considers the potential shift in the cell death paradigm in autoimmunity. Understanding this complexity is critical in order to develop tools to clearly define the death pathways that are active in systemic autoimmune diseases, identify drivers of disease propagation, and develop novel therapeutics.
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Spontaneous and radiation induced cell death in HeLa S3 human carcinoma
International Nuclear Information System (INIS)
Zaric, B.; Milosavljevic, B.; Radojcic, M.
2001-01-01
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 HeLaS 3 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 HeLaS 3 population was necrosis and the radiation dose which caused 50% of cell death after 72 h (termed ND 50 ) was between 30-40 Gy. (author)
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The Interaction of CD154 with the α5β1 Integrin Inhibits Fas-Induced T Cell Death.
Bachsais, Meriem; Naddaf, Nadim; Yacoub, Daniel; Salti, Suzanne; Alaaeddine, Nada; Aoudjit, Fawzi; Hassan, Ghada S; Mourad, Walid
2016-01-01
CD154, a critical regulator of the immune response, is usually associated with chronic inflammatory, autoimmune diseases as well as malignant disorders. In addition to its classical receptor CD40, CD154 is capable of binding other receptors, members of the integrin family, the αIIbβ3, αMβ2 and α5β1. Given the role attributed to integrins and particularly the β1 integrins in inhibiting apoptotic events in normal as well as malignant T cells, we were highly interested in investigating the role of the CD154/α5β1 interaction in promoting survival of malignant T cells contributing as such to tumor development and/or propagation. To support our hypothesis, we first show that soluble CD154 binds to the T-cell acute lymphoblastic leukemia cell line, Jurkat E6.1 in a α5β1-dependent manner. Binding of soluble CD154 to α5β1 integrin of Jurkat cells leads to the activation of key survival proteins, including the p38 and ERK1/2 mitogen-activated protein kinases (MAPKs), phosphoinositide 3 kinase (PI-3K), and Akt. Interestingly, soluble CD154 significantly inhibits Fas-mediated apoptosis in T cell leukemia-lymphoma cell lines, Jurkat E6.1 and HUT78 cells, an important hallmark of T cell survival during malignancy progression. These anti-apoptotic effects were mainly mediated by the activation of the PI-3K/Akt pathway but also involved the p38 and the ERK1/2 MAPKs cascades. Our data also demonstrated that the CD154-triggered inhibition of the Fas-mediated cell death response was dependent on a suppression of caspase-8 cleavage, but independent of de novo protein synthesis or alterations in Fas expression on cell surface. Together, our results highlight the impact of the CD154/α5β1 interaction in T cell function/survival and identify novel targets for the treatment of malignant disorders, particularly of T cell origin.
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The Interaction of CD154 with the α5β1 Integrin Inhibits Fas-Induced T Cell Death.
Directory of Open Access Journals (Sweden)
Meriem Bachsais
Full Text Available CD154, a critical regulator of the immune response, is usually associated with chronic inflammatory, autoimmune diseases as well as malignant disorders. In addition to its classical receptor CD40, CD154 is capable of binding other receptors, members of the integrin family, the αIIbβ3, αMβ2 and α5β1. Given the role attributed to integrins and particularly the β1 integrins in inhibiting apoptotic events in normal as well as malignant T cells, we were highly interested in investigating the role of the CD154/α5β1 interaction in promoting survival of malignant T cells contributing as such to tumor development and/or propagation. To support our hypothesis, we first show that soluble CD154 binds to the T-cell acute lymphoblastic leukemia cell line, Jurkat E6.1 in a α5β1-dependent manner. Binding of soluble CD154 to α5β1 integrin of Jurkat cells leads to the activation of key survival proteins, including the p38 and ERK1/2 mitogen-activated protein kinases (MAPKs, phosphoinositide 3 kinase (PI-3K, and Akt. Interestingly, soluble CD154 significantly inhibits Fas-mediated apoptosis in T cell leukemia-lymphoma cell lines, Jurkat E6.1 and HUT78 cells, an important hallmark of T cell survival during malignancy progression. These anti-apoptotic effects were mainly mediated by the activation of the PI-3K/Akt pathway but also involved the p38 and the ERK1/2 MAPKs cascades. Our data also demonstrated that the CD154-triggered inhibition of the Fas-mediated cell death response was dependent on a suppression of caspase-8 cleavage, but independent of de novo protein synthesis or alterations in Fas expression on cell surface. Together, our results highlight the impact of the CD154/α5β1 interaction in T cell function/survival and identify novel targets for the treatment of malignant disorders, particularly of T cell origin.
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International Nuclear Information System (INIS)
Duchesne, G.M.; Peacock, J.H.
1987-01-01
The radiation sensitivity of two small-cell lung carcinoma cell lines growing as multicellular spheroids in static culture was determined using clonogenic cell survival and growth delay as endpoints. Growth delay determination suggested that clonogenic cell kill was less than was obtained by direct assay of cell survival. Recovery from potentially lethal damage was assayed in one line (HC12) but was not demonstrable, and clonogenic cell survival decreased with time in treated spheroids with diameters greater than 300 μm which contained a hypoxic cell population. Microscopic examination of the treated spheroids showed the emergence of an abnormal giant-cell population, and the progressive clonogenic cell loss that occurred after treatment was thought to be due to oxygen and nutrient deprivation of the remaining viable cells by this doomed cell population. Correction of the growth delay measurements for changes in cell size and clonogenic cell population allowed correlation of the growth delay and cell survival data. (author)
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Attenuated Mycobacterium tuberculosis SO2 vaccine candidate is unable to induce cell death.
Directory of Open Access Journals (Sweden)
Adriana Aporta
Full Text Available It has been proposed that Mycobacterium tuberculosis virulent strains inhibit apoptosis and trigger cell death by necrosis of host macrophages to evade innate immunity, while non-virulent strains induce typical apoptosis activating a protective host response. As part of the characterization of a novel tuberculosis vaccine candidate, the M. tuberculosis phoP mutant SO2, we sought to evaluate its potential to induce host cell death. The parental M. tuberculosis MT103 strain and the current vaccine against tuberculosis Bacillus Calmette-Guérin (BCG were used as comparators in mouse models in vitro and in vivo. Our data reveal that attenuated SO2 was unable to induce apoptotic events neither in mouse macrophages in vitro nor during lung infection in vivo. In contrast, virulent MT103 triggers typical apoptotic events with phosphatidylserine exposure, caspase-3 activation and nuclear condensation and fragmentation. BCG strain behaved like SO2 and did not induce apoptosis. A clonogenic survival assay confirmed that viability of BCG- or SO2-infected macrophages was unaffected. Our results discard apoptosis as the protective mechanism induced by SO2 vaccine and provide evidence for positive correlation between classical apoptosis induction and virulent strains, suggesting apoptosis as a possible virulence determinant during M. tuberculosis infection.
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International Nuclear Information System (INIS)
Latonen, Leena; Jaervinen, Paeivi M.; Laiho, Marikki
2008-01-01
Members of the cysteine-rich protein (CRP) family are actin cytoskeleton-interacting LIM-domain proteins known to act in muscle cell differentiation. We have earlier found that CRP1, a founding member of this family, is transcriptionally induced by UV radiation in human diploid fibroblasts [M. Gentile, L. Latonen, M. Laiho, Cell cycle arrest and apoptosis provoked by UV radiation-induced DNA damage are transcriptionally highly divergent responses, Nucleic Acids Res. 31 (2003) 4779-4790]. Here we show that CRP1 is induced by growth-inhibitory signals, such as increased cellular density, and cytotoxic stress induced by UV radiation or staurosporine. We found that high levels of CRP1 correlate with differentiation-associated morphology towards the myofibroblast lineage and that expression of ectopic CRP1 suppresses cell proliferation. Following UV- and staurosporine-induced stresses, expression of CRP1 provides a survival advantage evidenced by decreased cellular death and increased cellular metabolic activity and attachment. Our studies identify that CRP1 is a novel stress response factor, and provide evidence for its growth-inhibitory and cytoprotective functions
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A shift to organismal stress resistance in programmed cell death mutants.
Directory of Open Access Journals (Sweden)
Meredith E Judy
Full Text Available Animals have many ways of protecting themselves against stress; for example, they can induce animal-wide, stress-protective pathways and they can kill damaged cells via apoptosis. We have discovered an unexpected regulatory relationship between these two types of stress responses. We find that C. elegans mutations blocking the normal course of programmed cell death and clearance confer animal-wide resistance to a specific set of environmental stressors; namely, ER, heat and osmotic stress. Remarkably, this pattern of stress resistance is induced by mutations that affect cell death in different ways, including ced-3 (cell death defective mutations, which block programmed cell death, ced-1 and ced-2 mutations, which prevent the engulfment of dying cells, and progranulin (pgrn-1 mutations, which accelerate the clearance of apoptotic cells. Stress resistance conferred by ced and pgrn-1 mutations is not additive and these mutants share altered patterns of gene expression, suggesting that they may act within the same pathway to achieve stress resistance. Together, our findings demonstrate that programmed cell death effectors influence the degree to which C. elegans tolerates environmental stress. While the mechanism is not entirely clear, it is intriguing that animals lacking the ability to efficiently and correctly remove dying cells should switch to a more global animal-wide system of stress resistance.
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International Nuclear Information System (INIS)
Bhavsar, Shefalee K.; Merches, Katja; Bobbala, Diwakar; Lang, Florian
2012-01-01
Highlights: ► Akt/SGK dependent phosphorylation of GSK3α,β regulates T lymphocytes. ► T cells from mice expressing Akt/SGK insensitive GSK3α,β (gsk3 KI ) release less IL-2. ► CD4 + cells from gsk3 KI mice express less CD62L. ► CD8 + cells from gsk3 KI mice are relatively resistant to activation induced cell death. ► Perforin expression is enhanced in gsk3 KI T cells. -- Abstract: Survival and function of T-lymphocytes critically depends on phosphoinositide (PI) 3 kinase. PI3 kinase signaling includes the PKB/Akt and SGK dependent phosphorylation and thus inhibition of glycogen synthase kinase GSK3α,β. Lithium, a known unspecific GSK3 inhibitor protects against experimental autoimmune encephalomyelitis. The present study explored, whether Akt/SGK-dependent regulation of GSK3 activity is a determinant of T cell survival and function. Experiments were performed in mutant mice in which Akt/SGK-dependent GSK3α,β inhibition was disrupted by replacement of the serine residue in the respective SGK/Akt-phosphorylation consensus sequence by alanine (gsk3 KI ). T cells from gsk3 KI mice were compared to T cells from corresponding wild type mice (gsk3 WT ). As a result, in gsk3 KI CD4 + cells surface CD62L (L-selectin) was significantly less abundant than in gsk3 WT CD4 + cells. Upon activation in vitro T cells from gsk3 KI mice reacted with enhanced perforin production and reduced activation induced cell death. Cytokine production was rather reduced in gsk3 KI T cells, suggesting that GSK3 induces effector function in CD8 + T cells. In conclusion, PKB/Akt and SGK sensitive phosphorylation of GSK3α,β is a potent regulator of perforin expression and activation induced cell death in T lymphocytes.
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Petrova, E S; Otellin, V A
2003-09-01
Morphological study of allotransplants of rat embryonic neocortex 14-18 months after transplantation into the neocortex, lateral cerebral ventricle, and sciatic nerve of adult animals revealed death of nerve and glial cells in the delayed postoperation period independently on the site of transplantation. After heterotopic transplantation the count of degenerated neurons was 2 times higher that after homotopic transplantation. In heterotopic transplants a considerable number of grafted neurons underwent reversible and irreversible degenerative changes accompanied by their premature aging. Neuronal death is probably determined by insufficiency of trophic influence from afferent structures and target tissues. We hypothesized that antiapoptotic preparations can be used for prevention of transplanted cell death. It was also found that degeneration of neurons was associated with impaired vascularization of transplants and pronounced immune reaction of the recipient in late posttransplantation period. Transplantation of embryonic brain structures can serve as a model system in studies concerning involutive and pathological processes in the central nervous system and in the search for factors improving survival of neurons.
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International Nuclear Information System (INIS)
Lee, Myoung Woo; Kim, Dae Seong; Kim, Hye Ryung; Kim, Hye Jin; Yang, Jin Mo; Ryu, Somi; Noh, Yoo Hun; Lee, Soo Hyun; Son, Meong Hi; Jung, Hye Lim; Yoo, Keon Hee; Koo, Hong Hoe; Sung, Ki Woong
2012-01-01
Highlights: ► Greater than 30 μM ciglitazone induces cell death in glioma cells. ► Cell death by ciglitazone is independent of PPARγ in glioma cells. ► CGZ induces cell death by the loss of MMP via decreased Akt. -- Abstract: Peroxisome proliferator-activated receptor γ (PPARγ) regulates multiple signaling pathways, and its agonists induce apoptosis in various cancer cells. However, their role in cell death is unclear. In this study, the relationship between ciglitazone (CGZ) and PPARγ in CGZ-induced cell death was examined. At concentrations of greater than 30 μM, CGZ, a synthetic PPARγ agonist, activated caspase-3 and induced apoptosis in T98G cells. Treatment of T98G cells with less than 30 μM CGZ effectively induced cell death after pretreatment with 30 μM of the PPARγ antagonist GW9662, although GW9662 alone did not induce cell death. This cell death was also observed when cells were co-treated with CGZ and GW9662, but was not observed when cells were treated with CGZ prior to GW9662. In cells in which PPARγ was down-regulated cells by siRNA, lower concentrations of CGZ (<30 μM) were sufficient to induce cell death, although higher concentrations of CGZ (⩾30 μM) were required to induce cell death in control T98G cells, indicating that CGZ effectively induces cell death in T98G cells independently of PPARγ. Treatment with GW9662 followed by CGZ resulted in a down-regulation of Akt activity and the loss of mitochondrial membrane potential (MMP), which was accompanied by a decrease in Bcl-2 expression and an increase in Bid cleavage. These data suggest that CGZ is capable of inducing apoptotic cell death independently of PPARγ in glioma cells, by down-regulating Akt activity and inducing MMP collapse.
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NanOx, a new model to predict cell survival in the context of particle therapy
Cunha, M.; Monini, C.; Testa, E.; Beuve, M.
2017-02-01
Particle therapy is increasingly attractive for the treatment of tumors and the number of facilities offering it is rising worldwide. Due to the well-known enhanced effectiveness of ions, it is of utmost importance to plan treatments with great care to ensure tumor killing and healthy tissues sparing. Hence, the accurate quantification of the relative biological effectiveness (RBE) of ions, used in the calculation of the biological dose, is critical. Nevertheless, the RBE is a complex function of many parameters and its determination requires modeling. The approaches currently used have allowed particle therapy to thrive, but still show some shortcomings. We present herein a short description of a new theoretical framework, NanOx, to calculate cell survival in the context of particle therapy. It gathers principles from existing approaches, while addressing some of their weaknesses. NanOx is a multiscale model that takes the stochastic nature of radiation at nanometric and micrometric scales fully into account, integrating also the chemical aspects of radiation-matter interaction. The latter are included in the model by means of a chemical specific energy, determined from the production of reactive chemical species induced by irradiation. Such a production represents the accumulation of oxidative stress and sublethal damage in the cell, potentially generating non-local lethal events in NanOx. The complementary local lethal events occur in a very localized region and can, alone, lead to cell death. Both these classes of events contribute to cell death. The comparison between experimental data and model predictions for the V79 cell line show a good agreement. In particular, the dependence of the typical shoulders of cell survival curves on linear energy transfer are well described, but also the effectiveness of different ions, including the overkill effect. These results required the adjustment of a number of parameters compatible with the application of the model in
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Loor, Gabriel; Kondapalli, Jyothisri; Schriewer, Jacqueline M; Chandel, Navdeep S; Vanden Hoek, Terry L; Schumacker, Paul T
2010-12-15
Low levels of reactive oxygen species (ROS) can function as redox-active signaling messengers, whereas high levels of ROS induce cellular damage. Menadione generates ROS through redox cycling, and high concentrations trigger cell death. Previous work suggests that menadione triggers cytochrome c release from mitochondria, whereas other studies implicate the activation of the mitochondrial permeability transition pore as the mediator of cell death. We investigated menadione-induced cell death in genetically modified cells lacking specific death-associated proteins. In cardiomyocytes, oxidant stress was assessed using the redox sensor RoGFP, expressed in the cytosol or the mitochondrial matrix. Menadione elicited rapid oxidation in both compartments, whereas it decreased mitochondrial potential and triggered cytochrome c redistribution to the cytosol. Cell death was attenuated by N-acetylcysteine and exogenous glutathione or by overexpression of cytosolic or mitochondria-targeted catalase. By contrast, no protection was observed in cells overexpressing Cu,Zn-SOD or Mn-SOD. Overexpression of antiapoptotic Bcl-X(L) protected against staurosporine-induced cell death, but it failed to confer protection against menadione. Genetic deletion of Bax and Bak, cytochrome c, cyclophilin D, or caspase-9 conferred no protection against menadione-induced cell death. However, cells lacking PARP-1 showed a significant decrease in menadione-induced cell death. Thus, menadione induces cell death through the generation of oxidant stress in multiple subcellular compartments, yet cytochrome c, Bax/Bak, caspase-9, and cyclophilin D are dispensable for cell death in this model. These studies suggest that multiple redundant cell death pathways are activated by menadione, but that PARP plays an essential role in mediating each of them. Copyright © 2010 Elsevier Inc. All rights reserved.
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Bisland, Stuart K.; Modi, Nayan; Wilson, Brian C.
2004-10-01
The ability to customize photodynamic therapy (PDT) parameters with regards to timing and dosing of administered drug and light can be beneficial in determining target specificity and mode of cell death. Sustained, low level PDT or metronomic PDT (mPDT) may afford enhanced apoptotic cell death. This is of particular importance when considering PDT for the treatment of brain tumors as unlike apoptosis, necrotic cell death often leads to inflammation with increased intracranial pressure. The ability, therefore, to 'fine tune' PDT in favour of apoptosis is paramount. We have studied both acute (one time treatment) PDT (aPDT) and mPDT delivery strategies in combination with nicotinamide (NA) in an attempt to maximize the number of tumor cells dieing by apoptosis. Using several different glioma cell lines (9L, U87-MG and CNS-1) we now confirm that NA provides a dose-dependent (0.1-0.5 mM) increase in apoptotic cells following d-aminolevulinic acid-mediated aPDT or mPDT. Furthermore, using the 9L cell line stably transfected with the luciferase gene, NA was shown to delay the depletion of bioluminscence signal in aPDT and mPDT treated cells, inferring that adenosine triphosphate levels are maintained for longer following NA treatment. NA has previously been reported as promoting neuronal and vascular cell survival in normal brain following a number of neurological insults in which reactive oxygen species are implicated including, stroke, Alzheimer's disease and toxin-induced lesions. It is likely that the effects of NA reflect its capacity as an antioxidant as well as its ability to inhibit poly (adenosine diphosphate-ribose) polymerase-mediated depletion of ATP. Our results indicate that NA may prove therapeutically advantageous when used in combination with PDT treatment of brain tumors.
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Gürsel, Demirkan B; Banu, Matei A; Berry, Nicholas; Marongiu, Roberta; Burkhardt, Jan-Karl; Kobylarz, Keith; Kaplitt, Michael G; Rafii, Shahin; Boockvar, John A
2015-01-01
Malignant gliomas represent one of the most aggressive forms of cancer, displaying high mortality rates and limited treatment options. Specific subpopulations of cells residing in the tumor niche with stem-like characteristics have been postulated to initiate and maintain neoplasticity while resisting conventional therapies. The study presented here aims to define the role of glycogen synthase kinase 3 beta (GSK3b) in patient-derived glioblastoma (GBM) stem-like cell (GSC) proliferation, apoptosis and invasion. To evaluate the potential role of GSK3b in GBM, protein profiles from 68 GBM patients and 20 normal brain samples were analyzed for EGFR-mediated PI3kinase/Akt and GSK3b signaling molecules including protein phosphatase 2A (PP2A). To better understand the function of GSK3b in GBM, GSCs were isolated from GBM patient samples. Blocking GSK3b phosphorylation at Serine 9 attenuated cell proliferation while concomitantly stimulating apoptosis through activation of Caspase-3 in patient-derived GSCs. Increasing GSK3b protein content resulted in the inhibition of cell proliferation, colony formation and stimulated programmed cell death. Depleting GSK3b in GSCs down regulated PP2A. Furthermore, knocking down PP2A or blocking its activity by okadaic acid inactivated GSK3b by increasing GSK3b phosphorylation at Serine 9. Our data suggests that GSK3b may function as a regulator of apoptosis and tumorigenesis in GSCs. Therapeutic approaches targeting GSK3b in glioblastoma stem-like cells may be a useful addition to our current therapeutic armamentarium.
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McDermott, David F; Drake, Charles G; Sznol, Mario; Choueiri, Toni K; Powderly, John D; Smith, David C; Brahmer, Julie R; Carvajal, Richard D; Hammers, Hans J; Puzanov, Igor; Hodi, F Stephen; Kluger, Harriet M; Topalian, Suzanne L; Pardoll, Drew M; Wigginton, Jon M; Kollia, Georgia D; Gupta, Ashok; McDonald, Dan; Sankar, Vindira; Sosman, Jeffrey A; Atkins, Michael B
2015-06-20
Blockade of the programmed death-1 inhibitory cell-surface molecule on immune cells using the fully human immunoglobulin G4 antibody nivolumab mediates tumor regression in a portion of patients with advanced treatment-refractory solid tumors. We report clinical activity, survival, and long-term safety in patients with advanced renal cell carcinoma (RCC) treated with nivolumab in a phase I study with expansion cohorts. A total of 34 patients with previously treated advanced RCC, enrolled between 2008 and 2012, received intravenous nivolumab (1 or 10 mg/kg) in an outpatient setting once every two weeks for up to 96 weeks and were observed for survival and duration of response after treatment discontinuation. Ten patients (29%) achieved objective responses (according to RECIST [version 1.0]), with median response duration of 12.9 months; nine additional patients (27%) demonstrated stable disease lasting > 24 weeks. Three of five patients who stopped treatment while in response continued to respond for ≥ 45 weeks. Median overall survival in all patients (71% with two to five prior systemic therapies) was 22.4 months; 1-, 2-, and 3-year survival rates were 71%, 48%, and 44%, respectively. Grade 3 to 4 treatment-related adverse events occurred in 18% of patients; all were reversible. Patients with advanced treatment-refractory RCC treated with nivolumab demonstrated durable responses that in some responders persisted after drug discontinuation. Overall survival is encouraging, and toxicities were generally manageable. Ongoing randomized clinical trials will further assess the impact of nivolumab on overall survival in patients with advanced RCC. © 2015 by American Society of Clinical Oncology.
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International Nuclear Information System (INIS)
Niwinska, Anna; Tacikowska, Malgorzata; Murawska, Magdalena
2010-01-01
Purpose: The aim of the study is to evaluate disease-free survival, survival from the detection of brain metastases, overall survival, and cause of death in patients with occult brain metastases (Group I) vs. patients with symptomatic brain metastases (Group II). Methods and Materials: In 80 HER2-positive breast cancer patients, treated with trastuzumab and cytostatic agents for metastatic disease, magnetic resonance imaging screening of the brain was performed, and in 29 patients (36%) occult brain metastasis was detected (Group I). Whole-brain radiotherapy was delivered to Group I. This first group was compared with 52 patients who had symptomatic brain metastases (Group II) and was treated the same way, at the same clinic, during the same time period. Results: Median disease-free survival was 17 months in Group I and 19.9 months in Group II (p = 0.58). The median time interval between the dissemination of the disease and the detection of occult or symptomatic brain metastases was 9 and 15 months, respectively (p = 0.11). When the brain metastases were detected, the median survival was 9 and 8.78 months, respectively (p = 0.80). The median overall survival was 53 and 51 months, respectively (p = 0.94). In the group with occult brain metastases (Group I) 16% of patients died because of progression within the brain. In the group with symptomatic brain metastases (Group II) the rate of cerebral death was 48% (p = 0.009). Conclusions: Whole-brain radiotherapy of occult brain metastases in HER2-positive breast cancer patients with visceral dissemination produces a three-fold decrease in cerebral deaths but does not prolong survival.