Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P42574 (caspase-3)
 45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Death induced by doxorubicin (dox) in neuroblastoma (NB) cells was originally thought to occur via the Fas pathway, however since studies suggest that caspase-8 expression is silenced in most high stage NB tumors, it is more probable that dox-induced death occurs via a different mechanism. Caspase-8 silenced N-type invasive NB cell lines LAN-1 and IMR-32 were investigated for their sensitivity to dox, and compared to S-type noninvasive SH-EP NB cells expressing caspase-8. All cell lines had similar sensitivities to dox, independently of caspase-8 expression. Dox induced caspase-3, -7, -8 and -9 and Bid cleavage in S-type cells and death was blocked by caspase inhibitors but not by oxygen radical scavenger BHA. In contrast, dox-induced death in N-type cells was caspase-independent and was inhibited by BHA. Dox induced a drop in mitochondrial membrane permeability in all cell lines. Dox-induced death in S-type cells gave rise to apoptotic nuclei, whereas in N-type cells nuclei were non-apoptotic in morphology. Transfection of SH-EP cells with a dominant negative FADD mutant inhibited TRAIL-induced death, but had no effect on dox-induced apoptosis. These results suggest that S-type cells undergo apoptosis after dox treatment independently of death receptors, whereas N-type cells are killed by a caspase-independent mechanism.
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PMID:Doxorubicin-induced death in neuroblastoma does not involve death receptors in S-type cells and is caspase-independent in N-type cells. 1220 25

Small GTP-binding Rho GTPases regulate important signaling pathways in endothelial cells, but little is known about their role in endothelial cell apoptosis. Clostridial cytotoxins specifically inactivate GTPases by glucosylation [Clostridium difficile toxin B-10463 (TcdB-10463), C. difficile toxin B-1470 (TcdB-1470)] or ADP ribosylation (C. botulinum C3 toxin). Exposure of human umbilical cord vein endothelial cells (HUVEC) to TcdB-10463, which inhibits RhoA/Rac1/Cdc42, or to C3 toxin, which inhibits RhoA, -B, -C, resulted in apoptosis, whereas inactivation of Rac1/Cdc42 with TcdB-1470 was without effect, suggesting that Rho inhibition was responsible for endothelial apoptosis. Disruption of endothelial microfilaments as well as inhibition of p160ROCK did not induce endothelial apoptosis. Exposure to TcdB-10463 resulted in activation of caspase-9 and -3 but not caspase-8 in HUVEC. Moreover, Rho inhibition reduced expression of antiapoptotic Bcl-2 and Mcl-1 and increased proapoptotic Bid but had no effect on Bax or FLIP protein levels. Caspase-3 activity and apoptosis induced by TcdB-10463 were abolished by cAMP elevation. In summary, inhibition of Rho in endothelial cells activates caspase-9- and -3-dependent apoptosis, which can be antagonized by cAMP elevation.
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PMID:Rho protein inactivation induced apoptosis of cultured human endothelial cells. 1222 60

Caspase-11 is an essential mediator of septic shock response and caspase-11-deficient mice are resistant to LPS-induced shock. Here we report that LPS-induced caspase-11 regulates lymphocyte apoptosis by activating both caspase-3 and caspase-7. The activation of caspase-11 preceded that of caspase-1 and caspases-3/-7, and in the absence of caspase-11, the activation of caspases-3/-7 was significantly reduced. The early activation of caspases-3/-7 by caspase-11 was not affected by blocking of caspase-1 activity and IL-1beta release, implying that caspase-11 activates caspases-3/-7 independently of caspase-1 activation. Furthermore, we show that caspase-11-mediated apoptosis under septic condition is Bid-independent. Our work suggests that the human homologue of caspase-11 may be an effective therapeutic target for treatment of septic shock.
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PMID:Distinct downstream pathways of caspase-11 in regulating apoptosis and cytokine maturation during septic shock response. 1223

Apoptosis of vascular smooth muscle cells (VSMCs) is an integral part of cardiovascular diseases including atherosclerosis, hypertension and restenosis. Here we studied the fate of VSMCs in response to intracellular superoxide stimulation. Diethyldithiocarbamic acid (DDC) was used to inhibit copper-zinc superoxide dismutase thereby increasing intracellular superoxide levels. The results show that DDC at a dose from 25-100 micro M is able to induce VSMC apoptosis. Superoxide was found to be responsible for DDC-induced apoptosis. In the apoptotic process mitochondrial membrane potential was decreased and caspase-3, -8 and -9 were activated. Surprisingly, neither cytochrome c release nor Bid cleavage could be observed. These data suggest a role for intracellular superoxide in the regulation of VSMCs apoptosis.
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PMID:Intracellular superoxide induces apoptosis in VSMCs: role of mitochondrial membrane potential, cytochrome C and caspases. 1237 Apr 93

Apoptosis is an important phenomenon in cytotoxicity induced by anticancer drugs. Here, we review the current status of the molecular mechanisms of anticancer drug-induced apoptosis in order to assess the contribution of molecular-level analysis to cancer chemotherapy. It is apparent that the molecular mechanisms by which anticancer drugs induce apoptosis are mediated by death receptor-dependent and -independent pathways, which are related to the release of cytochrome c through voltage-dependent anion channels in the mitochondrial inner membrane. The release of cytochrome c is the central gate in turning on/off apoptosis, and is regulated by the interaction of proapoptotic proteins, including Bid, Bax and Bak, and antiapoptotic proteins including Bcl-2 and Bcl-X(L), and a specific class of inhibitors of apoptosis proteins (IAPs) including Akt, survivin, and heat-shock proteins. The caspase cascade is activated by the release of cytochrome c, which is initiated by the formation of apoptosomes consisting of procaspase-9, Apaf-1 and cytochrome c in the presence of dATP, and results in the activation of caspase-9 and caspase-3, thereby leading to apoptosis. Drug sensitivity can be enhanced by the introduction of proapoptotic genes and the inhibition of antiapoptotic proteins. The latter process is mediated by antisense oligonucleotides and is associated with apoptosis. The signal transduction pathways that are triggered by the central gate in mitochondria play a critical role in anticancer drug-induced apoptosis. The modulation of signal transduction pathways targeting the proteins involved in these signal transduction pathways using antisense IAPs, and growth factor antibodies may be a good strategy for enhancing therapeutic efficacy of anticancer drugs in cancer chemotherapy.
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PMID:Current status of the molecular mechanisms of anticancer drug-induced apoptosis. The contribution of molecular-level analysis to cancer chemotherapy. 1243 91

Cells respond to poliovirus infection by switching on the apoptotic program, implementation of which is usually suppressed by viral antiapoptotic functions. We show here that poliovirus infection of HeLa cells or derivatives of MCF-7 cells was accompanied by the efflux of cytochrome c from mitochondria. This efflux occurred during both abortive infection (e.g., interrupted by guanidine-HCl and ending with apoptosis) and productive infection (leading to cytopathic effect). The former type of infection, but not the latter, was accompanied by truncation of the proapoptotic protein Bid. The virus-triggered cytochrome c efflux was suppressed by overexpression of Bcl-2. Both abortive and productive infections also resulted in a decreased level of procaspase-9, as revealed by Western blotting. In the former case, this decrease was accompanied by the accumulation of a protein with the electrophoretic mobility of active caspase-9. In contrast, in the productively infected cells, the latter protein was absent but caspase-9-related polypeptides with altered mobility could be detected. Both caspase-9 and caspase-3 were shown to be essential for the development of such hallmarks of virus-induced apoptosis as chromatin condensation, DNA degradation, and nuclear fragmentation. These and some other results suggest the following scenario. Poliovirus infection activates the apoptotic pathway, involving mitochondrial damage, cytochrome c efflux, and consecutive activation of caspase-9 and caspase-3. The apoptotic signal appears to be amplified by a loop which includes secondary processing of Bid. The implementation of the apoptotic program in productively infected cells may be suppressed, however, by the viral antiapoptotic functions, which act at a step(s) downstream of the cytochrome c efflux. The suppression appears to be caused, at least in part, by aberrant processing and degradation of procaspase-9.
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PMID:The major apoptotic pathway activated and suppressed by poliovirus. 1247 9

The in vivo response to radiotherapy is not well understood but appears to involve the p53 tumor suppressor protein. We investigated the expression of apoptosis-inducing p53 target genes during gamma-irradiation-induced cell death in p53(+/+) or p53(-/-) mouse tissues using in situ hybridization. Our results reveal striking tissue specificity with distinct regulation of target p53-induced genes in different cells and tissue compartments, as well as variations in dependence on p53 for basal expression. p53-dependent induction of Puma occurred in the splenic white pulp, whereas Noxa and Bid were induced in the red pulp. These patterns correlated with activation of caspase-3 in both compartments. All apoptotic targets of p53 studied here (DR5, Bid, Puma, Noxa) were induced in the jejunum and ileum, which appeared to be the tissues most sensitive to irradiation. We also observed unexpected differences in p53 target gene activation between the transverse and descending colon. Finally, in the liver where irradiation did not lead to caspase-3 activation, we primarily observed p21(WAF1) induction as the major p53-dependent target gene response. Our findings indicate that the selectivity of p53 in transactivation following DNA damage in vivo results in unique tissue and cell type specificity, which may correlate with growth arrest or variable sensitivity to gamma-irradiation.
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PMID:Tissue-specific induction of p53 targets in vivo. 1249 75

Apoptosis is a highly regulated form of cell death distinguished by the activation of a family of cysteine-aspartate proteases (caspases) that cleave various proteins resulting in morphological and biochemical changes characteristic of this form of cell death. Abundant evidence supports a role for mitochondria in regulating apoptosis. Specifically, it seems that a number of death triggers target these organelles and stimulate, by an unknown mechanism, the release of several proteins, including cytochrome c. Once released into the cytosol, cytochrome c binds to its adaptor molecule, apoptotic protease activating factor-1, which oligomerizes and then activates pro-caspase-9. Caspase-9 can signal downstream and activate pro-caspase-3 and -7. The release of cytochrome c can be influenced by different Bcl-2 family member proteins, including Bax, Bid, Bcl-2, and Bcl-X(L). Bax and Bid potentiate cytochrome c release, whereas Bcl-2 and Bcl-X(L) antagonize this event. Although toxicologists have traditionally associated cell death with necrosis, emerging evidence suggests that different types of environmental contaminants exert their toxicity, at least in part, by triggering apoptosis. The mechanism responsible for eliciting the pro-apoptotic effect of a given chemical is often unknown, although in many instances mitochondria appear to be key participants. Here, we provide an overview of our current understanding of the role of apoptosis in toxicant-induced cell death, using dioxin, organotin compounds, dithiocarbamates, as well as the chemotherapeutic agent etoposide, as specific examples.
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PMID:Role of mitochondria in toxic cell death. 1250 58

The proinflammatory cytokine IL-4 is secreted in large amounts during allergic inflammatory response in asthma and plays a pivotal role in the airway inflammation. IL-4 has been shown to up-regulate 15-lipoxygenase and produce 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE) in A549 cells via the Janus kinase/STAT6 pathway under coactivation of CREB binding protein/p300. IL-4 has also been shown to up-regulate peroxisome proliferator-activated receptor gamma (PPARgamma) nuclear receptors in macrophages and A549 cells. In this study we demonstrate that 15(S)-HETE binds to PPARgamma nuclear receptors and induces apoptosis in A549 cells. Moreover, pretreatment of cells with nordihydroguaiaretic acid, a 15-lipoxygenase inhibitor, prevented PPARgamma activation and apoptosis. The latter was accomplished by the interaction of the 15(S)-HETE/PPARgamma complex with the adapter protein Fas-associating protein with death domain and caspase-8, as shown by transfection of Fas-associating protein with death domain dominant negative vector and cleavage of caspase 8 to active subunits p41/42 and p18. Whereas IL-4 and PPARgamma ligands failed to induce cleavage of Bid and release of cytochrome c from mitochondria, they caused translocation of the proapoptotic protein Bax from cytoplasm to mitochondria with a concomitant decrease in the Bcl-x(L) level. We therefore believe that in unstimulated cells Bcl-x(L) and Bax form a heterodimer, in which Bcl-x(L) dominates and prevents the induction of apoptosis, whereas in IL-4-stimulated cells the 15(S)-HETE/PPARgamma complex down-regulates Bcl-x(L), and the resulting overweight of Bax commits the cell to apoptosis via caspase-3. However, this pathway does not rule out the direct caspase-8-mediated activation of caspase-3. In conclusion, IL-4-induced apoptosis may contribute to severe loss of alveolar structures and infiltration of eosinophils, mononuclear phagocytes, etc., into the lung tissue of chronic asthma patients.
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PMID:IL-4 induces apoptosis in A549 lung adenocarcinoma cells: evidence for the pivotal role of 15-hydroxyeicosatetraenoic acid binding to activated peroxisome proliferator-activated receptor gamma transcription factor. 1251 54

Photoreceptor apoptosis and resultant visual deficits occur in humans and animals with inherited and disease-, injury-, and chemical-induced retinal degeneration. A clinically relevant mouse model of progressive rod photoreceptor-selective apoptosis was produced by low-level developmental lead exposure and studied in combination with transgenic mice overexpressing Bcl-x(L) only in the photoreceptors. A multiparametric analysis of rod apoptosis and mitochondrial structure-function was performed. Mitochondrial cristae topography and connectivity, matrix volume, and contact sites were examined by using 3D electron tomography. Lead-induced rod-selective apoptosis was accompanied by rod Ca(2+) overload, rhodopsin loss, translocation of Bax from the cytosol to the mitochondria, decreased rod mitochondrial respiration and membrane potential, mitochondrial cytochrome c release, caspase-3 activation, and an increase in the number of mitochondrial contact sites. These effects occurred without mitochondrial matrix swelling, outer membrane rupture, caspase-8 activation, or Bid cleavage. Bcl-x(L) overexpression completely blocked all apoptotic events, except Ca(2+) overload, and maintained normal rod mitochondrial function throughout adulthood. This study presents images of mitochondrial contact sites in an in vivo apoptosis model and shows that Bcl-x(L) overexpression blocks increased contact sites and apoptosis. These findings extend our in vitro retinal studies with Pb(2+) and Ca(2+) and suggest that developmental lead exposure produced rod-selective apoptosis without mitochondrial swelling by translocating cytosolic Bax to the mitochondria, which likely sensitized the Pb(2+) and Ca(2+) overloaded rod mitochondria to release cytochrome c. These results have relevance for therapies in a wide variety of progressive retinal and neuronal degenerations where Ca(2+) overload, lead exposure, andor mitochondrial dysfunction occur.
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PMID:Bcl-xL overexpression blocks bax-mediated mitochondrial contact site formation and apoptosis in rod photoreceptors of lead-exposed mice. 1254 Aug 25


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