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)

Apoptosis is a highly regulated biochemical process that results in the selective death of cells. Members of the caspase family of cysteine proteases play a pivotal role in the effector phase of apoptosis. We show that, in HL-60 cells, the addition of either anisomycin, a protein synthesis inhibitor, or geranylgeraniol, an intermediate in the cholesterol biosynthetic pathway, results in a rapid and en masse induction of apoptosis. The levels of actin, p42 and p44 MAPK, JNK1, JNK2, p38, and PCNA were not substantially altered during this process. Although these treatments appear to function by diverse pathways, they both result in the processing and activation of caspase-3 (CPP32beta/Yama/Apopain). In contrast, no activation of caspase-1 (interleukin-1beta converting enzyme (ICE)) was observed. Furthermore, we obtained ambiguous results regarding the activation of caspase-2 (Ich-1) depending on the antibody used. Pretreatment of the cells with benzyloxycarbonyl-Val-Ala-Asp-(OMe)-fluoromethylketone (zVAD.fmk), a tetrapeptide inhibitor of caspases, prevented the induction of apoptosis for 24 h. Even after 72 h of treatment, some cells were still alive and progressing through the cell cycle, suggesting that blockage of caspase activity is able to protect cells. These results suggest that selective activation of some caspases is necessary to induce apoptosis in HL-60 cells.
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PMID:Selective activation of caspases during apoptotic induction in HL-60 cells. Effects Of a tetrapeptide inhibitor. 905 91

Resistance to stress-induced apoptosis was examined in cells in which the expression of hsp70 was either constitutively elevated or inducible by a tetracycline-regulated transactivator. Heat-induced apoptosis was blocked in hsp70-expressing cells, and this was associated with reduced cleavage of the common death substrate protein poly(ADP-ribose) polymerase (PARP). Heat-induced cell death was correlated with the activation of the stress-activated protein kinase SAPK/JNK (c-Jun N-terminal kinase). Activation of SAPK/JNK was strongly inhibited in cells in which hsp70 was induced to a high level, indicating that hsp70 is able to block apoptosis by inhibiting signaling events upstream of SAPK/JNK activation. In contrast, SAPK/JNK activation was not inhibited by heat shock in cells with constitutively elevated levels of hsp70. Cells that constitutively overexpress hsp70 resist apoptosis induced by ceramide, a lipid signaling molecule that is generated by apoptosis-inducing treatments and is linked to SAPK/JNK activation. Similar to heat stress, resistance to ceramide-induced apoptosis occurs in spite of strong SAPK/JNK activation. Therefore, hsp70 is also able to inhibit apoptosis at some point downstream of SAPK/JNK activation. Since PARP cleavage is prevented in both cell lines, these results suggest that hsp70 is able to prevent the effector steps of apoptotic cell death. Processing of the CED-3-related protease caspase-3 (CPP32/Yama/apopain) is inhibited in hsp70-expressing cells; however, the activity of the mature enzyme is not affected by hsp70 in vitro. Caspase processing may represent a critical heat-sensitive target leading to cell death that is inhibited by the chaperoning function of hsp70. The inhibition of SAPK/JNK signaling and apoptotic protease effector steps by hsp70 likely contributes to the resistance to stress-induced apoptosis seen in transiently induced thermotolerance.
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PMID:Role of the human heat shock protein hsp70 in protection against stress-induced apoptosis. 927 9

Cardiomyocyte apoptosis has been demonstrated in animal models of cardiac injury as well as in patients with congestive heart failure or acute myocardial infarction. Therefore, apoptosis has been proposed as an important process in cardiac remodeling and progression of myocardial dysfunction. However, the mechanisms underlying cardiac apoptosis are poorly understood. The present study was designed to determine whether the family of caspase proteases and stress-activated protein kinase (SAPK/JNK) are involved in cardiac apoptosis. Cultured rat neonatal cardiac myocytes were treated with staurosporine to induce apoptosis as evidenced by the morphological (including ultrastructural) characteristics of cell shrinkage, cytoplasmic and nuclear condensation, and fragmentation. Nucleosomal DNA fragmentation in myocytes was further identified by agarose gel electrophoresis (DNA ladder) as well as in situ nick end-labeling (TUNEL). Staurosporine-induced apoptosis in myocytes was a time- and concentration-(0.25-1 micro M)-dependent process. Staurosporine-induced apoptosis in myocytes was reduced by a cell-permeable, irreversible tripeptide inhibitor of caspases, ZVAD-fmk, but not by the ICE-specific inhibitor, Ac-YVAD-CHO. At 10, 50 and 100 muM of ZVAD-fmk, staurosporine-induced myocyte apoptosis was reduced by 5.8, 39.1 (P<0.01) and 53.8% (P<0.01), respectively. Staurosporine, at 0.25-1 micro M, increased caspase activity in cardiomyocytes by five- to eight-fold, peaking at 4-8 h after stimulation. Based on substrate specificity analysis, the major component of caspases activated in myocytes was consistent with caspase-3 (CPP32). Moreover, the appearance of the 17-kD subunit of active caspase-3 in staurosporine-treated myocytes was demonstrated by immunocytochemical analysis. In contrast, staurosporine induced a rapid and transient inhibition of SAPK/JNK in myocytes. The SAPK activity in myocytes was reduced by 68.3 and 58.3% (P<0.01 v basal) at 10 and 30 min after treatment with 1 micro M of staurosporine, respectively. Our results suggest that staurosporine-induced cardiac myocyte apoptosis involves activation of caspases, mainly caspase-3, but not activation of the SAPK signaling pathway.
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PMID:Staurosporine-induced apoptosis in cardiomyocytes: A potential role of caspase-3. 951 27

Mst1 is a ubiquitously expressed serine-threonine kinase, homologous to the budding yeast Ste20, whose physiological regulation and cellular function are unknown. In this paper we show that Mst1 is specifically cleaved by a caspase 3-like activity during apoptosis induced by either cross-linking CD95/Fas or by staurosporine treatment. CD95/Fas-induced cleavage of Mst1 was blocked by the cysteine protease inhibitor ZVAD-fmk, the more selective caspase inhibitor DEVD-CHO and by the viral serpin CrmA. Caspase-mediated cleavage of Mst1 removes the C-terminal regulatory domain and correlates with an increase in Mst1 activity in vivo, consistent with caspase-mediated cleavage activating Mst1. Overexpression of either wild-type Mst1 or a truncated mutant induces morphological changes characteristic of apoptosis. Furthermore, exogenously expressed Mst1 is cleaved, indicating that Mst1 can activate caspases that result in its cleavage. Kinase-dead Mst1 did not induce morphological alterations and was not cleaved upon overexpression, indicating that Mst1 must be catalytically active in order to mediate these effects. Mst1 activates MKK6, p38 MAPK, MKK7 and SAPK in co-transfection assays, suggesting that Mst1 may activate these pathways. Our findings suggest the existence of a positive feedback loop involving Mst1, and possibly the SAPK and p38 MAPK pathways, which serves to amplify the apoptotic response.
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PMID:Caspase-mediated activation and induction of apoptosis by the mammalian Ste20-like kinase Mst1. 954 36

The stress-activated protein kinase (SAPK, alternatively JNK) is activated rapidly by cell stress stimuli such as inflammatory cytokines and oxidative stress, and more slowly by the initiation of the apoptotic cell death response by events such as ligation of the Fas protein. Mitogen-activated protein kinase/Erk kinase kinase-1 (MEKK1) is an activator of SAPK, serving as a SAPK-kinase-kinase through intermediate phosphorylation of the SAPK kinase SEK1. By sequencing proteolytic cleavage products of MEKK1, we found that the proapoptotic protease caspase 3 (CPP32) cleaves MEKK1 after residue D68 both in vivo and in vitro. Cleavage of MEKK1 after D68 is blocked by viral and chemical protease inhibitors. Cleavage of MEKK1 at D68 changes the intracellular distribution of the protein from a Triton-insoluble compartment to a Triton-soluble compartment, reflected in a redistribution from a particulate to a diffuse cytoplasmic staining seen by immunofluorescence. Activation of both SAPK and MEKK1 after Fas ligation is prevented by both viral and chemical caspase 3 inhibitors, which in contrast fail to block activation of SAPK by rapidly acting cell stresses. Stress factor-induced SAPK signaling is not dependent on caspase 3 function. We propose that two mechanisms of stress signaling through MEKK1 exist. One is rapid, independent of proteases, and occurs in the particulate Triton-insoluble compartment. The other is more slowly activated and involves liberation of particulate MEKK1 by proteolytic cleavage and activation by caspase 3.
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PMID:Fas-induced proteolytic activation and intracellular redistribution of the stress-signaling kinase MEKK1. 957 28

R-Ras and insulin-like growth factor-1 (IGF-1) synergistically inhibit apoptosis of BaF3 cells upon interleukin-3 deprivation. To characterize the mechanism of this synergistic inhibition, we examined the effect of R-Ras and IGF-1 on several apoptosis-related proteins. Extracellular signal-regulated kinase (ERK) was activated by IGF-1, but not by R-Ras. In contrast, Akt was activated strongly by R-Ras, but weakly by IGF-1. It was also found that R-Ras and IGF-1 cooperatively induced Bcl-xL expression and inhibited caspase-3 activation.
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PMID:Synergistic action of R-Ras and IGF-1 on Bcl-xL expression and caspase-3 inhibition in BaF3 cells: R-Ras and IGF-1 control distinct anti-apoptotic kinase pathways. 980 82

A novel anticancer drug, cytotrienin A, isolated from Streptomyces sp., induces apoptosis (or programmed cell death) in human promyelocytic leukemia HL-60 cells within 4 h. To elucidate the mechanism of this process, we performed an in-gel kinase assay using myelin basic protein (MBP) as a substrate and found the activation of kinase with an apparent molecular mass of 36 kDa (p36 MBP kinase). The dose of cytotrienin A required to activate p36 MBP kinase was consistent with that required to induce apoptotic DNA fragmentation in HL-60 cells. This p36 MBP kinase was activated with kinetics distinct from the activation of JNK (c-Jun N-terminal kinase)/stress-activated protein kinase and p38 MAPK (mitogen-activated protein kinase). Importantly, the p36 MBP kinase was immunologically different from MAPK superfamily molecules such as ERK1, JNK isoforms, and p38 MAPK. In addition, the p36 MBP kinase activation and apoptotic DNA fragmentation were inhibited by antioxidants such as N-acetylcysteine and reduced-form glutathione. The p36 MBP kinase activation was also observed during hydrogen peroxide (H2O2) and okadaic acid-induced apoptosis. Although a specific inhibitor of caspase-3-like proteases (Ac-DEVD-CHO) or a specific inhibitor of caspase-1-like proteases (Ac-YVAD-CHO) did not block the cytotrienin A-, H2O2-, or okadaic acid-induced apoptosis, a broad specificity inhibitor of caspases (Z-Asp-CH2-DCB) strongly inhibited the apoptosis of HL-60 cells. Surprisingly, Z-Asp-CH2-DCB inhibited the activation of p36 MBP kinase induced by cytotrienin A or H2O2, but did not inhibit the activation of JNK/stress-activated protein kinase and p38 MAPK. Taken together, these results indicate that p36 MBP kinase activation is downstream of the activation of Z-Asp-CH2-DCB-sensitive caspases, and reactive oxygen species could be included in the apoptotic events. Moreover, according to the Western blotting using the antibodies against MST1/Krs2 or MST2/Krs1, it is suggested that the p36 MBP kinase is an active proteolytic product of MST1/Krs2 and MST2/Krs1, which are originally cloned by virtue of its homology to the budding yeast Ste20 kinase. Thus, the p36 MBP kinase might be a common component of the diverse signaling pathways leading to apoptosis, and controlling this p36 MBP kinase pathway might be a novel strategy for cancer chemotherapy.
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PMID:Caspase-mediated activation of a 36-kDa myelin basic protein kinase during anticancer drug-induced apoptosis. 980 95

TL1 is a recently discovered novel member of the tumor necrosis factor (TNF) cytokine family. TL1 is abundantly expressed in endothelial cells, but its function is not known. The present study was undertaken to explore whether TL1 induces apoptosis in endothelial cells and, if so, to explore its mechanism of action. Cultured bovine pulmonary artery endothelial cells (BPAEC) exposed to TL1 showed morphological (including ultrastructural) and biochemical features characteristic of apoptosis. TL1-induced apoptosis in BPAEC was a time- and concentration-dependent process (EC50 = 72 ng/ml). The effect of TL1 was not inhibited by soluble TNF receptors 1 or 2. TL1 up-regulated Fas expression in BPAEC at 8 and 24 h after treatment, and significantly activated stress-activated protein kinase (SAPK) and p38 mitogen-activated protein kinase (p38 MAPK). The peak activities of SAPK and p38 MAPK in TL1-treated BPAEC were increased by 9- and 4-fold, respectively. TL1-induced apoptosis in the BPAEC was reduced by expression of a dominant-interfering mutant of c-Jun (62.8%, p < 0.05) or by a specific p38 inhibitor, SB203580 (1-10 microM) dose-dependently. TL1 also activated caspases in BPAEC, and TL1-induced apoptosis in BPAEC was significantly attenuated by the caspase inhibitor, ZVAD-fluromethyl-ketone. The major component activated by TL1 in BPAEC was caspase-3, which was based on substrate specificity and immunocytochemical analysis. These findings suggest that TL1 may act as an autocrine factor to induce apoptosis in endothelial cells via activation of multiple signaling pathways, including stress protein kinases as well as certain caspases.
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PMID:TL1, a novel tumor necrosis factor-like cytokine, induces apoptosis in endothelial cells. Involvement of activation of stress protein kinases (stress-activated protein kinase and p38 mitogen-activated protein kinase) and caspase-3-like protease. 988 May 23

Apoptosis was induced in human glioma cell lines by exposure to 100 nM calphostin C, a specific inhibitor of protein kinase C. Calphostin C-induced apoptosis was associated with synchronous down-regulation of Bcl-2 and Bcl-xL as well as activation of caspase-3 but not caspase-1. The exposure to calphostin C led to activation of stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK) and p38 kinase and concurrent inhibition of extracellular signal-regulated kinase (ERK). Upstream of ERK, Shc was shown to be activated, but its downstream Raf1 and ERK were inhibited. The pretreatment with acetyl-Tyr-Val-Ala-Asp-aldehyde, a relatively selective inhibitor of caspase-3, or benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (z-VAD.fmk), a broad spectrum caspase inhibitor, similarly inhibited calphostin C-induced activation of SAPK/JNK and p38 kinase as well as apoptotic nuclear damages (chromatin condensation and DNA fragmentation) and cell shrinkage, suggesting that caspase-3 functions upstream of SAPK/JNK and p38 kinase, but did not block calphostin C-induced surface blebbing and cell death. On the other hand, the inhibition of SAPK/JNK by transfection of dominant negative SAPK/JNK and that of p38 kinase by SB203580 induced similar effects on the calphostin C-induced apoptotic phenotypes and cell death as did z-VAD.fmk and acetyl-Tyr-Val-Ala-Asp-aldehyde, but the calphostin C-induced PARP cleavage was not changed, suggesting that SAPK/JNK and p38 kinase are involved in the DNA fragmentation pathway downstream of caspase-3. The present findings suggest, therefore, that the activation of SAPK/JNK and p38 kinase is dispensable for calphostin C-mediated and z-VAD.fmk-resistant cell death.
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PMID:Activation of stress-activated protein kinase/c-Jun NH2-terminal kinase and p38 kinase in calphostin C-induced apoptosis requires caspase-3-like proteases but is dispensable for cell death. 1002 38

The antineoplastic agent paclitaxel (TaxolTM), a microtubule stabilizing agent, is known to arrest cells at the G2/M phase of the cell cycle and induce apoptosis. We and others have recently demonstrated that paclitaxel also activates the c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) signal transduction pathway in various human cell types, however, no clear role has been established for JNK/SAPK in paclitaxel-induced apoptosis. To further examine the role of JNK/SAPK signaling cascades in apoptosis resulting from microtubular dysfunction induced by paclitaxel, we have coexpressed dominant negative (dn) mutants of signaling proteins of the JNK/SAPK pathway (Ras, ASK1, Rac, JNKK, and JNK) in human ovarian cancer cells with a selectable marker to analyze the apoptotic characteristics of cells expressing dn vectors following exposure to paclitaxel. Expression of these dn signaling proteins had no effect on Bcl-2 phosphorylation, yet inhibited apoptotic changes induced by paclitaxel up to 16 h after treatment. Coexpression of these dn signaling proteins had no protective effect after 48 h of paclitaxel treatment. Our data indicate that: (i) activated JNK/SAPK acts upstream of membrane changes and caspase-3 activation in paclitaxel-initiated apoptotic pathways, independently of cell cycle stage, (ii) activated JNK/SAPK is not responsible for paclitaxel-induced phosphorylation of Bcl-2, and (iii) apoptosis resulting from microtubule damage may comprise multiple mechanisms, including a JNK/SAPK-dependent early phase and a JNK/SAPK-independent late phase.
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PMID:Microtubule dysfunction induced by paclitaxel initiates apoptosis through both c-Jun N-terminal kinase (JNK)-dependent and -independent pathways in ovarian cancer cells. 1007 25


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