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

We have characterized the death of human aortic smooth muscle cells induced by 25-hydroxycholesterol, an oxidation product of cholesterol. Chromatin condensation characteristic of apoptosis was observed by enzymatic (TUNEL) staining of chromatin, and by electron microscopy. Fourteen percent of cells treated with 5 microg/ml of 25-hydroxycholesterol for 24 h displayed chromatin degradation as determined by positive TUNEL staining. Addition of TNF alpha (10 ng/ml) and IFN gamma (20 ng/ml) increased the proportion of TUNEL positive cells to 30%, whereas the cytokines alone were without effect. After 48 h, 40% of the cells treated with 5 microg/ml of 25-hydroxycholesterol were TUNEL positive, and 21% of the cells displayed chromatin condensation. Oligonucleosomal DNA fragmentation typical of apoptosis was demonstrated by agarose gel electrophoresis. Furthermore, activation of the ICE-like protease caspase 3 (CPP32) was observed in cells treated with 25-hydroxycholesterol. Addition of the Ca2+ entry blockers verapamil or nifedipine to the culture medium inhibited apoptosis by more than 70% and reduced cytotoxicity, while removal of Ca2+ from culture medium reduced apoptosis by 42%. Within a few minutes after addition, 25-hydroxycholesterol induced intracellular Ca2+ oscillations with a frequency of approximately 0.3-0.4 min(-1). Thus it appears that Ca2+ influx through plasma membrane channels is an important signal in oxysterol-induced apoptosis. Addition of TNF alpha and IFN gamma enhanced cytotoxicity and resulted in a higher proportion of apoptotic cells, suggesting that inflammatory cytokines can increase the cytotoxicity of lipid oxidation products.
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PMID:Ca2+ channel blockers verapamil and nifedipine inhibit apoptosis induced by 25-hydroxycholesterol in human aortic smooth muscle cells. 937 27

We show, in this study, that type I IFN induction of the cyclin-dependent kinase (cdk) inhibitor p21WAF1 in the human Burkitt lymphoma B cell-line Daudi and ensuing cell cycle arrest correlate with the terminal differentiation of these cells, and is ultimately followed by apoptosis and cell death. The expression of p21WAF1 paralleled the onset of G1 arrest and the reduction of surface IgM expression which was used as a marker of the differentiation response, and the IFN treated cells acquired a typical plasma cell-like morphology. The type II IFN IFNgamma, which does not inhibit the growth of Daudi cells, did not induce the expression of p21WAF1, nor affect the expression of surface IgM. The induction of p21WAF1 which paralleled the inhibition of the phosphorylation of the retinoblastoma protein, pRB, was preceded by the strong reduction in c-myc levels. We propose that the coupled down-regulation of c-myc and induction of p21WAF1 may be crucial to the induction of differentiation and G1 arrest in Daudi cells by type I IFN. Growth arrest and differentiation was followed by apoptosis and cell death, and was accompanied by the induction of the activity of the apoptotic ICE-family protease CPP32. G1 arrest and differentiation followed by apoptotic cell death are characteristics of terminal differentiation. Thus, our data suggest that the induction of p21WAF1 and G1 arrest mediated by type I IFN in Daudi cells is part of terminal differentiation response in these cells, highlighting a role for type I IFN as B cell terminal differentiation factors.
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PMID:Type I interferon induction of the Cdk-inhibitor p21WAF1 is accompanied by ordered G1 arrest, differentiation and apoptosis of the Daudi B-cell line. 958 86

CD95 ligand (CD95L)-induced apoptosis is a novel immunotherapeutic approach to malignant glioma. Here, we report that interferon-alpha (IFN-alpha) sensitizes LN-229 and T98G human malignant glioma cells to CD95L-induced apoptosis. In contrast to the effects of IFN-gamma and TNF-alpha which sensitize glioma cells to CD95 antibody-induced apoptosis in part by enhancing CD95 expression, IFN-alpha has no effect on CD95 expression at the cell surface of LN-229 and T98G cells. To confirm that changes in CD95 expression are not required for the effects of IFN-alpha, we show that IFN-alpha enhances CD95L-induced apoptosis even in CD95-transfected LN-308 glioma cells. These LN-308 cells have little endogenous CD95 expression but express high levels of CD95 from a stably integrated CD95 expression plasmid. The sensitizing effects of IFN-alpha appear to be independent of cell cycle effects of IFN-alpha and are unaffected by ectopic expression of the bcl-2 proto-oncogene. IFN-alpha enhances CD95L-induced activation of caspase-3, a critical mediator of CD95L-induced cell death. IFN-alpha also increases the cytotoxic effects of BCNU, teniposide and cytarabine in both cell lines, and of vincristine in LN-229 cells. Doxorubicin and 5-fluorouracil toxicity are unaffected by IFN-alpha. IFN-alpha may be a useful adjunct to novel strategies of immunochemotherapy for malignant gliomas that target CD95-mediated apoptosis.
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PMID:Interferon-alpha enhances CD95L-induced apoptosis of human malignant glioma cells. 967 Aug 53

Anti-Fas monoclonal antibody (mAb) kills Fas-expressing cells by apoptosis. Several anticancer agents also mediate apoptosis and may share common intracellular pathways leading to apoptosis with Fas. Thus, we reasoned that combination treatment of drug-resistant cells with anti-Fas mAb and drugs might overcome their resistance. We investigated whether anticancer agents enhance Fas-mediated apoptosis and cytotoxicity against renal cell carcinoma (RCC) cells. Treatment of ACHN RCC cells with anti-Fas mAb in combination with 5-fluorouracil, vinblastine, IFN-alpha, or IFN-gamma did not overcome resistance to these agents. However, combination treatment with anti-Fas mAb and Adriamycin (ADR) resulted in a synergistic cytotoxic effect. Furthermore, synergy was also obtained even when the exposure time was shortened from 24 h to 8 or 2 h. Synergy was also achieved in four other RCC cell lines and five freshly derived human RCC cells. Treatment with anti-Fas mAb in combination with epirubicin or pirarubicin also resulted in a synergistic cytotoxic effect on ACHN cells. Similar results were achieved with a combination of humanized anti-Fas mAb and ADR. Incubation of ACHN cells with ADR augmented the expression of Fas and p53, but not Bcl-2, Bax, or caspase-3. However, the activity of caspase-3 itself was apparently enhanced after treatment with ADR alone or combined treatment with anti-Fas mAb. The synergy obtained in cytotoxicity with anti-Fas mAb and ADR was also achieved in apoptosis. Exposure of ACHN cells and freshly derived RCC cells to ADR enhanced their susceptibility to lysis by peripheral blood lymphocytes and tumor-infiltrating lymphocytes. This study demonstrates that combination treatment of RCC cells with anti-Fas mAb and ADR might overcome their resistance. The sensitization required a low concentration of ADR and a short exposure time, thus supporting the potential in vivo application of a combination of ADR and anti-Fas mAb or immunotherapy in the treatment of ADR- and/or immunotherapy-resistant RCC.
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PMID:Enhancement of Fas-mediated apoptosis in renal cell carcinoma cells by adriamycin. 1085 Apr 37

In order to effectively use cynomolgus monkeys as animal models for human diseases, more than 300 anti-human monoclonal antibodies (mAbs) were studied as to their cross-reaction with various antigens from cynomolgus monkeys (Macaca fascicularis). Two hundred twenty-nine of 339 (67.55%) anti-human mAbs that react with human antigens of CD-defined molecules, chemokine receptors, and T cell receptors were cross-reactive with the monkey antigens. Using the cross-reactive antibodies and the fluorescenced beads for calibration, the procedure for the absolute count of monkey lymphocyte subsets was developed and the mean values for CD4+ and CD8+ lymphocyte subsets in peripheral blood were 718 and 573/mm3, respectively. Moreover, intracellular cytokines, IL-2, IL-4 and IFN gamma, and intracellular apoptosis-related proteins, Bcl-2, FADD and active form of caspase-3 could be detected in peripheral blood mononuclear cells as well as various tissue cells. It is therefore practicable to detail the phenotype of leukocytes, assess the production of intracellular cytokines and enumerate T-lymphocyte subsets by using the cross-reactive human antibodies with respective antigens of cynomolgus monkeys.
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PMID:Upgrading of flow cytometric analysis for absolute counts, cytokines and other antigenic molecules of cynomolgus monkeys (Macaca fascicularis) by using anti-human cross-reactive antibodies. 1088 48

A new human myeloma cell line, OPM-6, was established from the peripheral blood of a patient with advanced IgG-kappa plasma cell leukemia. Cytogenetic and phenotypic analysis confirmed that the cells were derived from the patient's leukemic cells. Insulin-like growth factor-1 (IGF-1) acts as an autocrine growth factor in these cells. In addition, OPM-6 cells were particularly sensitive to dexamethasone (DEX), when endogenous IGF-1 was blocked. Under these conditions, >95% of the DEX-treated cells died within 36 h. Therefore, OPM-6 represents a potentially powerful tool for the analysis of the molecular mechanisms of DEX-induced apoptosis, because it is possible to easily analyze the direct effects of DEX using this system. Using this culture system of OPM-6, we demonstrated that the treatment with DEX plus a monoclonal antibody to the human IGF-1 receptor (alphaIGF-1R) leads to the down-regulation of the gene expression of Bcl-xL, an antiapoptotic gene, and the activation of CPP32 during this apoptotic process. IFN-alpha as well as IL-6 prevented DEX plus alphaIGF-1R-induced apoptosis, and this prevention was blocked by the mitogen-activated protein kinase kinase inhibitor, PD098059, or the phosphatidylinositol 3-kinase inhibitor, wortmannin. Therefore, both IL-6 and IFN-alpha blocked DEX plus alphaIGF-1R-induced apoptosis through activation of the mitogen-activated protein kinase and phosphatidylinositol 3-kinase pathways.
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PMID:Cytokines prevent dexamethasone-induced apoptosis via the activation of mitogen-activated protein kinase and phosphatidylinositol 3-kinase pathways in a new multiple myeloma cell line. 1094 40

Interferon-alpha (IFN-alpha) displays antitumor action by inducing direct cytotoxicity against tumor cells in addition to generation of cytotoxic cells. The IFN-alpha-induced direct cytotoxicity is at least partly due to induction of apoptosis. In the present study, we examined signaling pathways implicated in IFN-alpha-induced apoptosis in Daudi cells. Release of cytochrome c from mitochondria to cytosol was found after 12 h incubation with IFN-alpha, followed by a decline in mitochondrial membrane potential (Delta psi(m)) and procaspase-3 activation at 24 and 36 h, respectively. Cleavage of endogenous Bax-alpha (21 kDa), generating an 18-kDa fragment (p18 Bax-alpha), was found at 36 h. Although the endogenous p21 Bax-alpha was located in both cytosol and mitochondrial membranes, the p18 Bax-alpha resided only on mitochondrial membranes. IFN-alpha-induced apoptosis occurred 48 h after stimulation, with a further increase in proportion up to 72 h. Pretreatment with pancaspase inhibitor Z-VAD-fmk substantially inhibited the IFN-alpha-mediated Bax-alpha cleavage and apoptosis, but not the decline in Delta psi(m), suggesting the possibility that caspase-3 activation is implicated in the Bax-alpha cleavage, probably leading to amplification of the apoptotic processes. Our results suggest that modulation of endogenous p21 Bax-alpha is implicated in IFN-alpha-induced apoptosis.
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PMID:Cytochrome c release, mitochondrial membrane depolarization, caspase-3 activation, and Bax-alpha cleavage during IFN-alpha-induced apoptosis in Daudi B lymphoma cells. 1115 79

There is increasing evidence that IL-18 is a key pro-inflammatory cytokine and an important mediator of Th1 immune response. The main source of IL-18 is macrophage-like cells. In the present study we have investigated IL-18 protein expression in primary human macrophages in response to influenza A and Sendai virus infections. Macrophages constitutively expressed proIL-18 but produced biologically active IL-18 only after virus infection. The IL-18 release was due to virus infection-induced proteolytic processing of 24-kDa proIL-18 into its mature 18-kDa form. ProIL-18 processing required active caspase-1 enzyme and the release of mature IL-18 was blocked with a caspase-1-specific inhibitor. Caspase-3 inhibitor also reduced IL-18 production in response to virus infection. Inactive proforms of caspase-1 and caspase-3 were basally expressed in macrophages, and virus infection induced the cleavage of procaspases into their mature forms. Besides increasing the expression of caspase proteins, virus infection enhanced caspase mRNA expression in macrophages. The enhancement of caspase gene expression was abrogated by anti-IFN-alpha antibody. Furthermore, IFN-alpha and IFN-gamma could induce caspase gene expression. These results imply that interferons are involved in virus-induced caspase activation that leads to proIL-18 processing and subsequent release of mature IL-18.
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PMID:Virus infection induces proteolytic processing of IL-18 in human macrophages via caspase-1 and caspase-3 activation. 1124 Dec 76

The caspase family of proteases is speculated to have a crucial role in apoptosis. The effect of treatment with adriamycin (ADR), cisplatin (CDDP), 5-fluorouracil (5-FU), vinblastine (VLB), IFN-alpha, or IFN-gamma on the activation of caspase-3, -6, -8, and -9 in renal cell carcinoma (RCC) cells was investigated, to clarify the mechanisms of chemo- and immunotherapeutic agent-mediated apoptosis. Caspase activity was determined by a quantitative colorimetric assay. Apoptosis was monitored by acridine-orange staining assay. Treatment of ACHN cells with CDDP, VLB, IFN-alpha, or IFN-gamma did not activate caspase-3, but its activity was increased 7.2-fold (p = 0.0001) with ADR and 2.8-fold (p = 0.0385) with 5-FU in comparison with control. Furthermore, when the ADR treatment time was shortened from 24 to 8 or 2 h, the same caspase-3 activation occurred. Activation of caspase-3 was also observed in six freshly isolated human RCC cells after the treatment with ADR. Of the six freshly derived RCC cells treated with 5-FU, caspase-3 activity was increased 3.1-fold (p = 0.0051) and 2.4-fold (p = 0.0346) in two of them, respectively. Epirubicin and pirarubicin, compounds closely related to ADR, also respectively enhanced 4.2-fold (p = 0.0052) and 2.8-fold (p = 0.0147) caspase-3 activity in ACHN cells. The activation of caspase-3 observed with a colorimetric assay was confirmed with immunocytochemical analysis using the anti-active caspase-3 mAb, which specifically recognizes the active form of caspase-3. Furthermore, both active caspase-3 and apoptosis triggered by either ADR or 5-FU were inhibited significantly by the general caspase inhibitor Z-VAD-FMK, or a specific caspase-3 inhibitor DMQD-CHO. These findings provide a mechanistic explanation for anthracyclines and 5-FU induced-apoptosis.
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PMID:Activation of caspase-3 in renal cell carcinoma cells by anthracyclines or 5-fluorouracil. 1140 17

Interferon alpha (IFN-alpha) is the mainstay in the treatment of chronic hepatitis C virus (HCV) infection. Interleukin-16 (IL-16) attracts CD4+ cells to sites of inflammation and plays a role in the interaction of dendritic cells, T cells and B cells. In this study, we show that IFN-alpha itself induces IL-16 secretion by peripheral blood lymphocytes (PBL) and enhances IL-16 secretion by anti-CD3 stimulated PBL. Pro-IL-16 is cleaved into its active form by caspase-3. IFN-alpha increases caspase-3 mRNA levels in activated T cells (ATC), as shown by Northern blot analysis, whereas IL-16 mRNA levels are not affected by IFN-alpha. IL-16 secretion into culture supernatants correlates tightly with intracellular caspase-3 activity in ATC. In our experiments addition of specific caspase inhibitors did not reduce the proportion of ATC undergoing Fas-mediated cell death, but completely blocked IFN-alpha-induced IL-16 secretion into culture supernatants. In conclusion, our results suggest that IFN-alpha activates caspase-3, thereby increasing secretion of IL-16, whereas IFN-alpha-enhanced Fas-mediated cell death in ATC is not caspase-dependent.
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PMID:Activation of caspase-3 by interferon alpha causes interleukin-16 secretion but fails to modulate activation induced cell death. 1156 29


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