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)

The involvement of p53, Bax, cytochrome C and CPP-32 (caspase-3) in the molecular mechanism ofTGF-beta1-induced apoptosis in HC11 mouse mammary epithelial cells (MEC) was examined. Laser scanning cytometry (LSC) was applied for the quantitative analysis of expression and distribution of examined apoptosis-related proteins in the cytoplasmic (Cf) and nuclear (Nf) area. Maximal pixel of fluorescence (MP) parameter corresponding to aggregation of molecules in the cell was also measured. Confocal and immunoelectron microscopy were used as a complementary methods. Apoptosis induced by TGF-beta1 (2 ng/ml) was associated with the increase of Bax MP observed within 60 min. after cytokine administration, indicating aggregation of Bax in the cell. Immunoelectron microscopy revealed Bax aggregation on mitochondrial membranes, rough endoplasmic reticulum, Golgi apparatus, cytoskeleton, nuclear envelope and inside of nucleus. The accumulation of Bax in the nucleus was confirmed by compartmental Bax analysis, showing the increase of cell number with elevated Bax Nf in 2 hr after TGF-beta1 administration to the culture. The redistribution of Bax within the cell was dependent on its activation occurring by the cleavage at N-terminal epitope and exposure of BH3 domain. Bax aggregation on organelles was completely abolished by prolactin or IGF-I. TGF-beta1 increased p53 MP, evidently after 4 hr of cell culture exposure to this cytokine. p53 was accumulated first of all in the nucleus, which was shown by significant increase of p53 Nf/Cf ratio and increase of p53-related nuclear fluorescence on confocal images. TGF-beta1 decreased cytochrome C MP, which corresponded to its release from mitochondria and dissipation in the cytosol. It was accompanied by the increase of CPP-32 MP and concentration of 89 kDa product of PARP degradation in the nucleus. In conclusion, TGF-beta1 triggers apoptosis in MEC through mitochondrial pathway involving: activation and translocation of Bax to mitochondrial membranes, release of cytochrome C from mitochondria, activation of CPP-32 and degradation of its substrate - PARP in the nucleus. Activation and subcellular redistribution of Bax is inhibited by lactogenic hormones: prolactin and IGF-I.
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PMID:Molecular mechanism of TGF-beta1-induced apoptosis in HC11 mouse mammary epithelial cells (MEC). 1193 68

Several tumor suppressor genes have been shown to regulate cellular susceptibility to proliferation or apoptotic cell death. An essential first step in studies with the long-range goal of determining the effect of a tumor suppressor gene on cellular susceptibility to apoptosis is careful characterization of the cell's response to an apoptotic stimulus. The goals of this study were to characterize the apoptotic response of a tuberous sclerosis complex-2 (Tsc2) tumor suppressor gene-null cell line, to establish valid biochemical events that can be used as apoptosis markers, and to determine how these events correlate with apoptosis-specific morphologic changes. For characterization of apoptosis, we treated Tsc2-null renal epithelial tumor cells (ERC-18) with okadaic acid (OKA, 0.1-0.25 microM), and measured the biochemical and morphologic events during the apoptotic response. Electron microscopic and immunocytochemical evaluation showed an early loss of microvilli and a loss of vinculin and talin staining from focal adhesions within 1 hour. During the first 2 hours of treatment with 0.25 microM OKA, ERC-18 cells rounded and approximately 50% detached from the culture vessel with minimal membrane bleb formation. Phosphatidylserine externalization, chromatin margination and fragmentation, cytochrome C release, and caspase-3 and -7 cleavage were evident at 6 hours. Maximal membrane bleb formation occurred between 6 and 10 hours. Cells progressed to secondary oncotic necrosis between 10 and 24 hours of OKA treatment. Almost all cells had an oncotic phenotype after 24 hours, and 17.5% lost cell membrane integrity. A small subpopulation (< or = 5%) of OKA-treated cells underwent primary oncotic necrosis within 6 hours. Interestingly, the caspase-3 and -7 inhibitor Z-DEVD-FMK did not inhibit or delay OKA-induced apoptosis in these cells. Our results suggest a complex apoptotic model involving 2 or more potentially parallel death pathways. Although caspase-3 and -7 cleavage occurs during apoptosis in this model, this cleavage may not independently regulate cell death in ERC-18 cells. Therefore, measurement of apoptosis in this model requires analysis of both biochemical and morphologic events.
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PMID:Biochemical and morphological events during okadaic acid-induced apoptosis of Tsc2-null ERC-18 cell line. 1195 Jan 67

To define the molecular pathways involved in radiation-induced apoptosis and the role of the mitochondria, 32D cl 3 hematopoietic cells and subclones overexpressing either the human manganese superoxide dismutase (SOD2) transgene (1F2 and 2C6) or BCL2L1 (also known as Bcl-xl) transgene (32D-Bcl-xl) were compared for their response to radiation at the subcellular level, comparing nuclear to mitochondrial localized pathways. All cell lines showed complete detectable DNA repair by 30 min after irradiation, and clearly delayed migration of BAX and active stress-activated protein (SAP) kinases MAPK1 (also known as p38) and MAPK8 (also known as JNK1) to the mitochondria at 3 h. Radioresistant clonal lines 1F2, 2C6 and 32D-Bcl-xl showed significant decreases in mitochondrial membrane permeability, cytochrome C release, caspase 3 and poly(adenosine diphosphate-ribose) polymerase (PARP) activation at 6-12 h, and in apoptosis at 24 h. Since the nuclear-to-cytoplasm events preceding the release of cytochrome C were similar in all cell lines, and increased expression of either the SOD2 or the BCL2L1 transgene provided radiation protection, we conclude that events at the level of the mitochondria are critically involved in radiation-induced apoptosis.
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PMID:Manganese superoxide dismutase (SOD2) inhibits radiation-induced apoptosis by stabilization of the mitochondrial membrane. 1196 23

Annexins are widely expressed Ca(2+)-dependent phospholipid-binding proteins with poorly understood physiological roles. Proposed functions include Ca(2+) channel activity and vesicle trafficking, but neither have been proven in vivo. Here we used targeted gene disruption to generate B-lymphocytes lacking annexin 5 (Anx5) expression and show that this results in reduced susceptibility to a range of apoptotic stimuli. By comparison B-lymphocytes lacking annexin 2 (Anx2) showed no such resistance, providing evidence that this effect is specific to loss of Anx5. The defect in the ANX5(-/-) cells occurs early in the apoptotic program before nuclear condensation, caspase 3 activation, and cell shrinkage, but downstream of an initial Ca(2+) influx. Only UVA/B irradiation induced similar levels of apoptosis in wild-type and ANX5(-/-) cells. Unexpectedly, ANX5(-/-) cells permeabilized in vitro also failed to release mitochondrial cytochrome C, suggesting a possible mechanism for their resistance to apoptosis. These findings demonstrate a role for Anx5 in determining the susceptibility of B-lymphocytes to apoptosis.
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PMID:DT40 cells lacking the Ca2+-binding protein annexin 5 are resistant to Ca2+-dependent apoptosis. 1206 Jul 52

The effect of xymedone, a non-glucoside analog of pyridine nucleosides, on the apoptosis of human CD4+ T cells of the Jurkat line was studied by laser flow cytometry method. Xymedone decreased the membrane expression of phosphatidylserine and suppressed the increase in permeability of the cytoplasmic membrane, thus inhibiting the onset of a degradation stage of the apoptotic cascade. Possible mechanisms of the antiapoptogenic effect of xymedone within the framework of a (cytochrome C/caspase 3)-dependent signal pathway of the apoptosis are discussed.
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PMID:[Xymedon decreases phosphatidylserine membrane expression induced by proapoptogenic deficit of serum growth factors in Jurkat T-cells]. 1222 95

We have shown that a combination of fish oil (high in n-3 fatty acids) with the butyrate-producing fiber pectin, upregulates apoptosis in colon cells exposed to the carcinogen azoxymethane, protecting against colon tumor development. We now hypothesize that n-3 fatty acids prime the colonocytes such that butyrate can initiate apoptosis. To test this, 30 Sprague-Dawley rats were provided with diets differing in the fatty acid composition (corn oil, fish oil or a purified fatty acid ethyl ester diet). Intact colon crypts were exposed ex vivo to butyrate, and analyzed for reactive oxygen species (ROS), mitochondrial membrane potential (MMP), translocation of cytochrome C to the cytosol, and caspase-3 activity (early events in apoptosis). The fatty acid composition of the three major mitochondrial phospholipids was also determined, and an unsaturation index calculated. The unsaturation index in cardiolipin was correlated with ROS levels (R = 0.99; P = 0.02). When colon crypts from fish oil and FAEE-fed rats were exposed to butyrate, MMP decreased (P = 0.041); and translocation of cytochrome C to the cytosol (P = 0.037) and caspase-3 activation increased (P = 0.032). The data suggest that fish oil may prime the colonocytes for butyrate-induced apoptosis by enhancing the unsaturation of mitochondrial phospholipids, especially cardiolipin, resulting in an increase in ROS and initiating apoptotic cascade.
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PMID:Fish oil increases mitochondrial phospholipid unsaturation, upregulating reactive oxygen species and apoptosis in rat colonocytes. 1241 41

Imexon is a new antitumor agent with high activity in multiple myeloma. This drug induces apoptosis, oxidative stress and mitochondrial alterations. However, it was unknown whether imexon activates an intrinsic apoptotic pathway that is associated with activation of caspase-9 or an extrinsic pathway that is induced by receptor-mediated signals such as Fas ligand characterized by caspase-8 activation. In addition, we wanted to investigate the effect of imexon on Bcl-2 family proteins. In RPMI8226 myeloma cells, imexon activated caspase-9 and -3 in a time- and concentration-dependent manner. In contrast, cleavage of procaspase-8 was observed late and only after exposure to very high concentrations of imexon. Confocal microscopy confirmed that caspase-3 is also activated after treatment with imexon. High imexon concentrations activated caspase-3 and -9 at 12 h, while caspase-8 activation occurred only at 48 h. Imexon cytotoxicity was unchanged in three RPMI8226 cell lines with different levels (low, medium and high) of FAS expression. Similarly, the levels of Bcl-2, Bax and Bcl-xL were unchanged in imexon-treated cells. However, Bcl-xL was translocated to the mitochondria. These data suggest that imexon-induced oxidation activates the intrinsic or mitochondrial pathway of apoptosis, involving cytochrome release and activation of caspase-9 and -3.
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PMID:Imexon activates an intrinsic apoptosis pathway in RPMI8226 myeloma cells. 1243 37

Apoptotic death is a physiological process with regulatory mechanisms that are under the control of different molecules such as caspases. These are classified as initiators, such as caspases-8 and -9, and effectors, such as caspases-3 and -7. The participation of caspase-2 in the effector phase of apoptosis has been commonly observed in many cell types; however, it is able to act as an initiator caspase, depending on the apoptotic stimulus. Cerebellar granule cells (CGCs) undergo apoptosis when they are transferred from high potassium (K25) to low potassium (K5); this process seems to be mediated by caspase-3 activation. Staurosporine (STS), a full strength inhibitor of kinase proteins, also induces apoptosis in these cells. To characterize the caspase cascade induced by two stimuli in the same cell type we studied the activation of different caspases in CGCs treated with STS or K5. We found that both K5 and STS induce the activation of caspase-3. This result was confirmed by the proteolytic cleavage of poly (ADP-ribose) polymerase (PARP), an endogenous caspase-3 substrate. Caspase-2 was activated preferentially by STS, which showed a temporal course suggesting that this caspase was induced before caspase-3. The initiator caspase-9 was also activated by both K5 and STS, as well as cytochrome-c release. The results obtained in this study suggest that STS and K5 induced different activation caspase pathways for apoptotic cell death of CGCs.
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PMID:Caspase activation pathways induced by staurosporine and low potassium: role of caspase-2. 1252 27

We studied the effect of over-expression of Bcl-xl on cell death of the monocytic cell line U937. Over-expression of Bcl-xl inhibits apoptotic changes induced by Etoposide including cytochrome-c release, caspase-3 activation and DNA fragmentation. However, Etoposide treatment resulted in cell death in U937 cells over-expressing Bcl-xl, which had a necrotic-like phenotype with no evidence of caspase-3 activation. On the other hand, Bcl-xl over-expression did not prevent U937 cell apoptotic cell death in response to the specific proteasome inhibitor Lactacystin. There was no significant change in the level of Bcl-xl or evidence of its cleavage. These results suggest that Bcl-xl over-expression does not confer protection against cell death in U937 cells and that Lactacystin utilizes an apoptotic pathway not susceptible to Bcl-xl inhibition.
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PMID:Differential effect of Bcl-xl over-expression on cell death of the monocytic leukemia cell line U937. 1255 12

There is substantial evidence that cytokines induce apoptosis of vascular smooth muscle cells (VSMCs) in atherosclerosis. Its regulation, however, is not completely defined. The aim of this study is to investigate whether proteasome activity is related with apoptosis in VSMCs by tumor necrosis factor-alpha (TNF-alpha). Rat aorta smooth muscle cells were treated with TNF-alpha and proteasome inhibitor MG132 and then cell death was determined by morphology, viability, and DNA fragmentation. MG132 or TNF-alpha alone did not induce cell death. In contrast, co-treatment of TNF-alpha and proteasome inhibitor induced death and DNA degradation in VSMCs, suggesting proteasome inhibitor enhanced death activity of TNF-alpha. The death was not blocked by ascorbic acid but by nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine. Both caspase-3 and -8 were activated during the death by the proteasome inhibitor and TNF-alpha. The death was effectively blocked by the caspase-3 inhibitor z-DEVD-fmk, suggesting a role of caspase-3 in the death. Nonetheless, there were no significant alterations in the level of Bcl-2, Bcl-X(L), Bax and Bak by the proteasome inhibitor, nor any evidence of cytochrome (cyt) c release into cytosol from dying cells, suggesting that cyt c is not involved. These results suggest that proteasome inhibition potentiates TNF-mediated death in VSMCs in a cyt c-independent pathway. The present study proposes a new mechanism by which VSMCs undergo death by cytokines.
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PMID:Enhancement of TNF-alpha-mediated cell death in vascular smooth muscle cells through cytochrome c-independent pathway by the proteasome inhibitor. 1256 Jan 2


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