Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Apoptosis induced in rat hepatocytes by transforming growth factor beta1 (TGF-beta1) was accompanied by the activation of interleukin-1beta converting enzyme (ICE)-like proteases. Cell lysates were isolated at various times after TGF-beta1 treatment and analyzed for ICE and CPP32-like activity, using N-acetyl-Tyr-Val-Ala-Asp-7-amino-4-methylcoumarin (Ac-YVAD.AMC) and benzyloxycarbonyl-Asp-Glu-Val-Asp-7-amino-4-trifluoromethylcoumarin (Z-DEVD.AFC), respectively. CPP32-like but not ICE protease activity increased in a time dependent manner and preceded the onset of apoptosis. Kinetic studies in cell lysates indicated that more than one CPP32-like protease was being activated. This was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)/Western blotting of TGF-beta1-treated cells, which showed limited processing of CPP32 as shown by the appearance of the catalytically active p17 subunit. Loss of pro-Mch3alpha was also observed but the catalytically active p19 subunit was not detected. Staurosporine, which induced a much greater level of hepatocyte apoptosis, produced a concomitant increase in CPP32/Mch3alpha processing as shown by the appearance of the p17/p19 subunits and the corresponding increase in CPP32-like protease activity. Apoptosis, CPP32/Mch3alpha processing and the increase in CPP32-like protease activity induced by TGF-beta1 and staurosporine were abolished in hepatocytes pretreated with Z-Asp-Glu-Val-Asp (OMe) fluoromethylketone (Z-DEVD.FMK) or Z-Val-Ala-Asp (OMe) fluoromethylketone (Z-VAD.FMK). These peptide analogues were potent inhibitors of CPP32-like protease activity in lysates. Pretreatment of hepatocytes with cycloheximide also blocked TGF-beta1-induced apoptosis and the increase in CPP32-like activity. Unlike Z-VAD.FMK and Z-DEVD.FMK, cycloheximide did not inhibit CPP32-like protease activity in cell lysates. Thus, cycloheximide may block apoptosis by inhibiting the synthesis of a protein, which is involved in the upstream events responsible for the activation of the CPP32-like protease activity. Our studies have identified two of the CPP32-like proteases, namely CPP32 and Mch3alpha, which are activated during the execution phase of hepatocyte apoptosis.
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PMID:Processing/activation of CPP32-like proteases is involved in transforming growth factor beta1-induced apoptosis in rat hepatocytes. 918 77

In the granule exocytosis pathway of cell-mediated cytotoxicity, rapid apoptotic nuclear damage in target cells has been unequivocally linked to granzyme B activity. Direct cleavage and activation of caspase-3 and related proteases by granzyme B have been identified as a central event in apoptosis induction by cytotoxic granules. The Bcl-2 oncoprotein has been recently shown to act at the level or upstream of caspase-3 family activation to inhibit apoptosis induced by various stimuli including Fas ligation, an alternative cell-mediated lytic pathway. In this study, we have investigated whether activation of this caspase family by granzyme B, during human NK and lymphokine-activated killer cell granule-mediated apoptosis, could be influenced by Bcl-2 expression. Bcl-2-overexpressing clones were generated from parental K562 and U937 cell lines (K6 and U4 clones, respectively). Bcl-2 expression abrogated early 125I-DNA release and DNA fragmentation, these defects being compensated for by extended incubation times. Cleavage of poly(ADP-ribose) polymerase, a specific caspase-3 family substrate, was detected in parental K562 cells exposed to lymphokine-activated killer effectors but not in K6 targets, indicating that caspase-3 and related proteases function was inhibited by Bcl-2. Functional inhibition of caspase-3 family with benzyloxycarbonyl-Asp-Glu-Val-Asp(OMe) fluoromethylketone led to similar consequences on apoptotic nuclear events as for Bcl-2 expression. Thus, Bcl-2 antagonizes granzyme B-mediated apoptosis by a mechanism that interferes with caspase-3 activity. Finally, Bcl-2 expression or the Asp-Glu-Val-Asp peptide was much less efficient in preventing phosphatidylserine externalization, suggesting that despite impaired nuclear apoptosis, immediate recognition and elimination of Bcl-2-expressing cells by tissue phagocytes should remain partly unaffected.
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PMID:Bcl-2 expression in target cells leads to functional inhibition of caspase-3 protease family in human NK and lymphokine-activated killer cell granule-mediated apoptosis. 920 Apr 47

Tumor necrosis factor (TNF) is thought to be one of the mediators responsible for the damage of oligodendrocytes (OLGs) in multiple sclerosis (MS). We report here the involvement of the interleukin 1beta-converting enzyme (ICE)/Caenorhabditis elegans gene ced-3 (CED-3) family in TNF-mediated cell death of OLGs. The addition of TNF-alpha to primary cultures of OLGs that express ice and cpp32 significantly decreased the number of live OLGs in 72 h. DNA fragmentation was detected in TNF-treated OLGs at 36 h with the terminal deoxynucleotidyl transferase dUTP nick end-labeling assay. Benzyloxycarbonyl-Asp-CH2OC(O)-2,6-dichlorobenzene, an inhibitor of the ICE/CED-3 family that shows p35-like inhibitory specificity, protected against the TNF-induced cell death of OLGs. Furthermore, acetyl-YVAD-CHO (a specific inhibitor of ICE-like proteases) as well as acetyl-DEVD-CHO (a specific inhibitor of CPP32-like proteases) enhanced the survival of OLGs treated with TNF-alpha, indicating that ICE- and the CPP32-mediated cell death pathways are activated in TNF-induced OLG cell death. Our results suggest that the inhibition of ICE/CED-3 proteases may be a novel approach to treat neurodegenerative diseases such as MS.
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PMID:ICE/CED-3 family executes oligodendrocyte apoptosis by tumor necrosis factor. 920 89

Transforming growth factor-beta (TGF-beta) is a potent inducer of programmed cell death in liver as well as some hepatoma cell lines. To explore the mechanism by which TGF-beta induces apoptosis, we investigated the role of caspase family proteases in the apoptotic death of a human hepatoma cell line, Hep3B. We showed that TGF-beta-induced apoptosis was blocked by expression of the cowpox virus protein CrmA, a serpin-like pseudosubstrate for some of the caspase family proteases. CrmA expression, however, did not affect TGF-beta-induced regulation of promoter activities of the cyclin A and plasminogen activator inhibitor type I genes. These results indicate that CrmA inhibits a step specific for the apoptotic effect of TGF-beta. In addition to CrmA, a tripeptide caspase-protease inhibitor, z-Val-Ala-Asp-fluoromethylketone could also suppress TGF-beta-induced apoptosis in a dose-dependent manner. In TGF-beta-treated Hep3B cells, we observed a specific degradation of the catalytic subunit of DNA-dependent protein kinase, which was previously shown to be a substrate of caspase-3 but not several other members of the caspase family. This degradation was not seen in Hep3B cells transfected with CrmA nor in Hep3B cells pretreated with the tripeptide caspase inhibitor. Our study indicates a requirement of caspase family proteases in TGF-beta-induced apoptosis.
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PMID:Involvement of caspase family proteases in transforming growth factor-beta-induced apoptosis. 921 76

Interleukin-1beta-converting enzyme (ICE) and CPP32 are cysteine proteinases, that are involved in apoptotic process in various cell systems. We investigated the effects of ICE on ultraviolet B (UVB) induced-apoptosis in SV40-transformed human keratinocytes (SVHK cells). The ICE inhibitor (Z-Val-Ala-Asp-CH2F) and CPP32 inhibitor (Z-Asp-Glu-Val-Asp-CH2F) blocked the apoptotic cell death caused by UVB irradiation. The addition of both ICE and CPP32 inhibitors to the incubation medium resulted in neither an additive nor a synergistic suppression of UVB-induced apoptosis. Reverse transcription and polymerase chain reaction (RT-PCR) analysis indicated that SVHK cells expressed ICE-alpha, and beta mRNAs. UVB irradiation increased the mRNA of both isoforms and Western blot analysis confirmed that UVB increased an active form of ICE protein, p20, that is generated by autoproteolytic cleavage of inactive 45 kDa proenzyme derived from both mRNAs. Transfection of ICE expression vector into SVHK cells resulted in apoptosis in a dose dependent manner and UVB-irradiation further augmented the ICE expression vector-induced apoptosis. These results indicate that ICE plays an important role in UVB-induced apoptosis of SVHK cells.
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PMID:Interleukin-1beta-converting enzyme and CPP32 are involved in ultraviolet B-induced apoptosis of SV40-transformed human keratinocytes. 922 51

The Fas/Fas ligand (FasL) pathway is widely involved in apoptotic cell death in lymphoid and nonlymphoid cells. It has recently been postulated that many chemotherapeutic agents also induce cell death by activating the Fas/FasL pathway. In the present study we compared apoptotic pathways induced by anti-Fas or chemotherapeutic agents in the Jurkat human T-cell leukemia line. Immunoblotting showed that treatment of wild-type Jurkat cells with anti-Fas or the topoisomerase II-directed agent etoposide resulted in proteolytic cleavage of precursors for the cysteine-dependent aspartate-directed proteases caspase-3 and caspase-7 and degradation of the caspase substrates poly(ADP-ribose) polymerase (PARP) and lamin B1. Likewise, affinity labeling with N-(N(alpha)-benzyloxycarbonylglutamyl-N(epsilon)-biotinyllysyl+ ++)aspartic acid [(2,6-dimethyl-benzoyl)oxy]methyl ketone [Z-EK(bio)D-amok] labeled the same five active caspase species after each treatment, suggesting that the same downstream apoptotic pathways have been activated by anti-Fas and etoposide. Treatment with ZB4, an antibody that inhibits Fas-mediated cell death, failed to block etoposide-induced apoptosis, raising the possibility that etoposide does not initiate apoptosis through Fas/FasL interactions. To further explore the relationship between Fas- and chemotherapy-induced apoptosis, Fas-resistant Jurkat cells were treated with various chemotherapeutic agents. Multiple independently derived Fas-resistant Jurkat lines underwent apoptosis that was indistinguishable from that of the Fas-sensitive parental cells after treatment with etoposide, doxorubicin, topotecan, cisplatin, methotrexate, staurosporine, or gamma-irradiation. These results indicate that antineoplastic treatments induce apoptosis through a Fas-independent pathway even though Fas- and chemotherapy-induced pathways converge on common downstream apoptotic effector molecules.
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PMID:Comparison of apoptosis in wild-type and Fas-resistant cells: chemotherapy-induced apoptosis is not dependent on Fas/Fas ligand interactions. 924 21

Treatment of U937 cells with dolichyl phosphate led to an increase in the activity of the ICE family protease CPP32, accompanied with cleavage of pre-CPP32 to generate p17. Peptide inhibitors YVAD-cmk and Z-Asp-CH2-DCB (specific to ICE) and DEVD-CHO (specific to CPP32) blocked the dolichyl phosphate-induced apoptosis. The dolichyl phosphate-induced increase of CPP32 activity was inhibited by adenylate cyclase inhibitors, SQ 22536 and 2',5'-dideoxyadenosine. Dolichyl phosphate caused a transient increase of intracellular cAMP concentration. The results suggest that modulation of cAMP synthesis due to the stimulation of adenylate cyclase by dolichyl phosphate plays a critical role in CPP32 activation and apoptosis.
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PMID:CPP32 activation during dolichyl phosphate-induced apoptosis in U937 leukemia cells. 925 10

A major component of Alzheimer's disease plaque amyloid beta protein (betaAP) showed the cytolytic activity to rat pheochromocytoma PC 12 cells. Nuclear morphological study revealed that betaAP-induced cytolytic activity is due to necrotic cell death, rather than apoptotic cell death. To examine the molecular machinery of betaAP-induced necrotic cell death in detail, I investigated the direct involvement of caspase. When nerve growth factor-treated and -untreated PC12 cells were incubated with the synthesized tetrapeptide inhibitors of caspase, YVAD-CHO (Ac-Tyr-Val-Ala-Asp-CHO) or DEVD-CHO (Ac-Asp-Glu-Val-Asp-CHO), betaAP-induced necrotic cell death was prevented. In addition, the interleukin-1beta converting enzyme (ICE) subfamily activation preceded CPP32 subfamily activation during betaAP-induced necrotic cell death. On the basis of these findings, I suggest that betaAP induces necrotic cell death mediated by the ICE cascade and that the ICE cascade may possibly be involved in Alzheimer's disease.
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PMID:Amyloid beta-protein induces necrotic cell death mediated by ICE cascade in PC12 cells. 926 Sep 21

Members of the CED-3/interleukin-1beta-converting enzyme (ICE) protease (caspase) family are synthesized as proforms, which are proteolytically cleaved and activated during apoptosis. We report here that caspase-2 (ICH-1/NEDD-2), a member of the ICE family, is activated during apoptosis by another ICE member, a caspase-3 (CPP32)-like protease(s). When cells are induced to undergo apoptosis, endogenous caspase-2 is first cleaved into three fragments of 32-33 kDa and 14 kDa, which are then further processed into 18- and 12-kDa active subunits. Up to 50 microM N-acetyl-Asp-Glu-Val-Asp-aldehyde (DEVD-CHO), a caspase-3-preferred peptide inhibitor, inhibits caspase-2 activation and DNA fragmentation in vivo, but does not prevent loss of mitochondrial function, while higher concentrations of DEVD-CHO (>50 microM) inhibit both. In comparison, although the activity of caspase-3 is very sensitive to the inhibition of DEVD-CHO (<50 nM), inhibition of caspase-3 activation as marked by processing of the proform requires more than 100 microM DEVD-CHO. Our results suggest that the first cleavage of caspase-2 is accomplished by a caspase-3-like activity, and other ICE-like proteases less sensitive to DEVD-CHO may be responsible for activation of caspase-3 and loss of mitochondrial function.
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PMID:Activation of caspase-2 in apoptosis. 926 Nov 2

The human leukemia cell line, HL60 is very sensitive to various apoptotic stimuli and p53-null. The death-related cysteine proteases of the caspases family play a central role in the execution phase of apoptosis, and we recently reported the importance of serine protease activation in camptothecin-induced apoptotic endonuclease activation in HL60 cells. In the present study, we investigated the role of caspases (ICE/CED-3-related cysteine proteases) and serine proteases in cell death induced by the topoisomerase I inhibitor, camptothecin, in HL60 cells and in a cell-free system. We found that CPP32 is activated during camptothecin-induced apoptosis, and that N-benzyloxycarbony-Val-Ala-Asp (O-methyl) -fluoromethyketone (Z-VAD-fmk), a cell permeable caspase inhibitor blocks all features of apoptosis: morphological changes, cleavage of caspase 3 (CPP32/Yama/Apopain) and poly(ADP-ribose) polymerase, lamin B degradation and DNA fragmentation. However, Z-VAD-fmk and two other ICE/CED-3 inhibitors, YVAD-CHO and DEVD-CHO, were inactive in a cell-free system reconstituted from nuclei of untreated HL60 cells and cytosol from camptothecin-treated cells, suggesting that caspases are not required for endonuclease activation or lamin B cleavage in the cell-free system. By contrast, the serine protease inhibitors, 3,4-dichloroisocoumarin (DCI) and L-1-chloro-3-(4-tosylamido)-4-phenyl-2-butanone tosyl-L-phenylalanine chloromethyl ketone (TPCK), abolished the apoptosis-associated biochemical changes induced by camptothecin both in whole cells and in a cell-free system. DCI also inhibited CPP32 cleavage. Taken together, these results suggest that in HL60 cells, both CPP32 and serine proteases are activated in camptothecin-induced apoptosis.
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PMID:Camptothecin-induced apoptosis in p53-null human leukemia HL60 cells and their isolated nuclei: effects of the protease inhibitors Z-VAD-fmk and dichloroisocoumarin suggest an involvement of both caspases and serine proteases. 926 76


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