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 destruction of CD4 T cells in human immunodeficiency virus (HIV) infection is associated with activation of apoptotic programs, partly mediated by death receptors. The role of CD95L/CD95 in depletion of patients' CD4 T cells is well documented, but the possible contribution of the tumor necrosis factor/tumor necrosis factor receptor (TNF/TNFR) pathway has not been examined. In this study, we found that both TNFR1 and TNFR2 induced marked apoptosis in peripheral T cells from HIV-infected persons, involving both CD4 and CD8 T cells. Longitudinal follow-up of HIV(+) patients suggests an association between the in vivo evolution of CD4 T-cell numbers and variations in susceptibility to TNFR-induced apoptosis. Analysis of molecular mechanisms involved showed that it was not related to altered ex vivo expression of TNFR1-associated death domain, receptor interacting protein, or TNFR-associated factor 2. Susceptibility to TNFR-mediated apoptosis was rather related to Bcl-2 expression, because patients' T cells expressing high levels of Bcl-2 were completely protected from TNFR1- and TNFR2-induced cell death, whereas T cells expressing normal levels of Bcl-2 were not protected in patients in contrast to controls. Early recruitment of caspase-8 and caspase-3 is needed to transduce the apoptotic signals, and expression of both caspases in their active form was detected in blood T cells from HIV(+) patients, whereas it was hardly detected in controls. Moreover, ligation of TNFRs induced increased activation of both caspases in patients' T cells. Together these data demonstrate that exacerbated TNFR-mediated cell death of T cells from HIV-infected individuals is associated with both alteration of Bcl-2 expression and activation of caspase-8 and caspase-3 and may contribute to the pathogenesis of acquired immunodeficiency syndrome.
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PMID:Increased sensitivity of T lymphocytes to tumor necrosis factor receptor 1 (TNFR1)- and TNFR2-mediated apoptosis in HIV infection: relation to expression of Bcl-2 and active caspase-8 and caspase-3. 1186 Dec 82

Fas engagement rapidly induces formation of the death-inducing signaling complex (DISC) that consists of Fas, FADD and pro-caspase-8. Activated caspase-8 at the DISC directly activates downstream caspases, resulting in induction of apoptosis of the independent mitochondria. In this study, we have obtained evidence demonstrating that Fas-mediated apoptosis in AIDS-KS cells takes place in a mitochondria-dependent manner. FADD and pro-caspase-8 were detected in immunoprecipitates with anti-Fas antibody in anti-Fas mAb (CH-11)-treated Hut 78, a typical Fas-sensitive cell line. On the other hand, DISC formation by CH-11 was markedly reduced in AIDS-KS cells. In addition, CH-11-induced activation of caspase-8-like protease in AIDS-KS cells was much less pronounced compared with that in Hut 78; however, a caspase-8 inhibitor, zIETD-fmk, completely blocked the apoptosis. Further, a caspase-9 inhibitor, zLEHD-fmk, markedly inhibited Fas-mediated apoptosis in AIDS-KS cells. Several apoptotic stimuli induce mitochondria activation allowing cytochrome c release from the mitochondria. In the apoptosome, cytochrome c and Apaf-1 activate caspase-9 which subsequently leads to the activation of caspase-3. In AIDS-KS cells, CH-11 triggered cytochrome c release, an event which was inhibited by zIETD-fmk. Further, a caspase-3 inhibitor, zDEVD-fmk completely inhibited the apoptosis. Altogether, the present data provide evidence that the Fas signal in AIDS-KS cells is preferentially transduced through the mitochondria-dependent pathway, which is initiated by caspase-8 activation.
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PMID:Actinomycin D-mediated sensitization of AIDS-Kaposi's sarcoma cells to Fas-mediated apoptosis: involvement of the mitochondrion-dependent pathway. 1189 31

Human cytomegalovirus (HCMV) retinitis is the most common ocular opportunistic infection in immunocompromised patients and AIDS. It often leads to blindness if left untreated. The question as to how HCMV infection causes retinal pathogenesis and visual destruction in AIDS patients remains unresolved. To answer the question, by using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay, we detected the significant signals of apoptotic cells at the same sites in the HCMV-infected retina of AIDS patients as compared to AIDS patients without HCMV retinitis. In vitro study also revealed apoptosis induced by HCMV infection in human retinal pigment epithelium cells, mediated by activation of caspase 3 and poly(ADP-ribose) polymerase pathway. These results strongly suggest the fundamental role of HCMV-induced apoptosis in mediating cell death in infected human retina and retinal pigment epithelium cells to make severe visual impairment.
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PMID:Apoptosis of human retina and retinal pigment cells induced by human cytomegalovirus infection. 1191 9

Oxidative stress plays an important role in the induction of T lymphocyte hyporesponsiveness observed in several human pathologies including cancer, rheumatoid arthritis, leprosy, and AIDS. To investigate the molecular basis of oxidative stress-induced T cell hyporesponsiveness, we have developed an in vitro system in which T lymphocytes are rendered hyporesponsive by co-culture with oxygen radical-producing activated neutrophils. We have observed a direct correlation between the level of T cell hyporesponsiveness induced and the concentration of reactive oxygen species produced. Moreover, induction of T cell hyporesponsiveness is blocked by addition of N-acetyl cysteine, Mn(III)tetrakis(4-benzoic acid)porphyrin chloride, and catalase, confirming the critical role of oxidative stress in this system. The pattern of tyrosine-phosphorylated proteins was profoundly altered in hyporesponsive as compared with normal T cells. In hyporesponsive T cells, T cell receptor (TCR) ligation no longer induced phospholipase C-gamma1 activation and caused reduced Ca(2+) flux. In contrast, despite increased levels of ERK1/2 phosphorylation, TCR-dependent activation of mitogen-activated protein kinase ERK1/2 was unaltered in hyporesponsive T lymphocytes. A late TCR-signaling event such as caspase 3 activation was as well unaffected in hyporesponsive T lymphocytes. Our data indicate that TCR-signaling pathways are differentially affected by physiological levels of oxidative stress and would suggest that although "hyporesponsive" T cells have lost certain effector functions, they may have maintained or gained others.
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PMID:Reactive oxygen species differentially affect T cell receptor-signaling pathways. 1191 64

Human immunodeficiency virus, type 1 (HIV-1), vpr gene encodes a 14-kDa virion-associated protein, which exhibits significant effects on human cells. One important property of Vpr is its ability to induce apoptosis during infection. Apoptotic induction is likely to play a role in the pathogenesis of AIDS. However, the pathway of apoptosis is not clearly defined. In this report we investigate the mechanism of apoptosis induced by HIV-1 Vpr using a Vpr pseudotype viral infection system or adeno delivery of Vpr in primary human lymphoid cells and T-cells. With either vector, HIV-1 Vpr induced cell cycle arrest at the G(2)/M phase and apoptosis in lymphoid target cells. Furthermore, we observed that with both vectors, caspase 9, but not caspase 8, was activated following infection of human peripheral blood mononuclear cell with either Vpr-positive HIV virions or adeno-delivered Vpr. Activation of the caspase 9 pathway resulted in caspase 3 activation and apoptosis in human primary cells. These effects were coincident with the disruption of the mitochondrial transmembrane potential and induction of cytochrome c release by Vpr. The Vpr-induced signaling pathway did not induce CD95 or CD95L expression. Bcl-2 overexpressing cells succumb to Vpr-induced apoptosis. These studies illustrate that Vpr induces a mitochondria-dependent apoptotic pathway that is distinct from apoptosis driven by the Fas-FasL pathway.
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PMID:HIV-1 Vpr induces apoptosis through caspase 9 in T cells and peripheral blood mononuclear cells. 1209 93

Strict coordination of proliferation and programmed cell death (apoptosis) is essential for normal physiology. An imbalance in these two opposing processes results in various diseases including AIDS, neurodegenerative disorders, myelodysplastic syndromes, ischemiareperfusion injury, cancer, autoimmune disease, among others. Objective and quantitative noninvasive imaging of apoptosis would be a significant advance for rapid and dynamic screening as well as validation of experimental therapeutic agents. Here, we report the development of a recombinant luciferase reporter molecule that when expressed in mammalian cells has attenuated levels of reporter activity. In cells undergoing apoptosis, a caspase-3-specific cleavage of the recombinant product occurs, resulting in the restoration of luciferase activity that can be detected in living animals with bioluminescence imaging. The ability to image apoptosis noninvasively and dynamically over time provides an opportunity for high-throughput screening of proapoptotic and antiapoptotic compounds and for target validation in vivo in both cell lines and transgenic animals.
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PMID:Noninvasive real-time imaging of apoptosis. 1247 31

We have previously described a soluble 6000-Da peptide produced by an HIV-1-infected human macrophage cell line, clone 43(HIV), which induces apoptosis in T and B cells. We have identified this factor as the novel cDNA clone FL14676485 that encodes for the human hypothetical protein, FLJ21908. The FL14676485 cDNA clone was isolated from a 43(HIV) lambda ZAP Escherichia coli expression library and screened with a panel of rabbit and mouse anti-apoptotic Abs. We transfected the FL14676485 clone into Bosc cells and non-HIV-1-infected 43 cells. Western blot analysis of lysates from the FL14676485-transfected 43 cells and Bosc cells using anti-proapoptotic factor Abs revealed a protein with a molecular mass of 66 kDa corresponding to the size of the full-length gene product of the FL14676485 clone, while Western blot of the supernatant demonstrated a doublet of 46-kDa and 6000-Da peptide that corresponds to our previously described proapoptotic factor. Primary HIV-1(BaL)-infected monocytes also produce the FLJ21908 protein. Supernatants from these transfected cells induced apoptosis in PBMC, CD4(+), and CD8(+) T and B cells similar to the activity of our previously described proapoptotic factor. PCR analysis of 43 cells and 43(HIV) cells revealed a base pair fragment of 420 bp corresponding to the FL14676485 gene product in 43(HIV) cells, but not in 43 cells. The FLJ21908 protein induces apoptosis through activation of caspase-9 and caspase-3. We have further demonstrated that the FLJ21908 protein has apoptotic activity in the SH-SY5Y neuronal cell line and can be detected in brain and lymph tissue from HIV-1-infected patients who have AIDS dementia. The FLJ21908 protein may contribute to the apoptosis and dementia observed in AIDS patients.
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PMID:Induction of apoptosis by HIV-1-infected monocytic cells. 1642 27

The paradigm of HIV-1 infection includes the diminution of CD4(+) T cells, loss of immune function, and eventual progression to AIDS. However, the mechanisms that drive host T cell depletion remain elusive. One HIV protein thought to participate in this destructive cascade is the Vpr gene product. Accordingly, we review the biology of the HIV-1 viral protein R (Vpr) an apoptogenic HIV-1 accessory protein that is packaged into the virus particle. In this review we focus specifically on Vpr's ability to induce host cell apoptosis. Recent evidence suggests that Vpr implements a unique mechanism to drive host cell apoptosis, by directly depolarizing the mitochondria membrane potential. Vpr's attack on the mitochondria results in release of cytochrome c resulting in activation of the caspase 9 pathway culminating in the activation of caspase 3 and the downstream events of apoptosis. Vpr may interact with the adenine nucleotide translocator (ANT) to prompt this cascade. The role of Vpr-induced apoptosis in HIV pathogenesis is considered.
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PMID:Mechanism of HIV-1 viral protein R-induced apoptosis. 1272 93

Inappropriate imbalances between proteases and protease inhibitors are known to occur under cerebral ischemia and neurodegenerative processes, and could be contributors to various diseases that are characterized by excessive (ischemia, AIDS) or inadequate (cancer, autoimmunity) cell death. For instance, calpain is activated in various necrotic and apoptotic conditions, whereas caspase-3 is only activated in neuronal apoptosis. Caspases and calpains are cysteine proteases that require proteolytic cleavage for activation. The substrates cleaved by caspases include cytoskeletal and associated proteins, kinases, members of the Bcl-2 family of apoptosis-related proteins, presenilins, and DNA-modulating enzymes. Calpain substrates include cytoskeletal and associated proteins, kinases and phosphatases, membrane receptors and transporters, and steroid receptors. This article provides a review of the properties of caspases and calpains, their roles in cell death pathways following cerebral ischemia, and the substrates upon which they act. Because calpain inhibitors and caspase inhibitors appear to protect brain tissue by distinct mechanisms in cerebral ischemia, the possible therapeutic interactions between these drugs in a well-defined rodent model of global ischemia are briefly discussed and documented.
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PMID:Ischemic neuronal death in the rat hippocampus: the calpain-calpastatin-caspase hypothesis. 1282 32

TNF-alpha is a pro-inflammatory cytokine that plays a key role in disorders due to HIV-1 infection and replication such as Kaposi sarcoma, wasting, aphthous ulcerations and progression to AIDS. The controversial drug thalidomide is anti-inflammatory, anti-angiogenic and a selective inhibitor of TNF-alpha that is being studied as a treatment for HIV-1-related disorders, immune disorders and cancer. The cellular and molecular mechanism of thalidomide is unclear despite renewed clinical interest in the drug. Previous data from this laboratory indicate that thalidomide decreases cell growth and cell-cell interactions of human T leukemic cells. The specific aim of the present study is to determine whether thalidomide administration induces cell death via apoptosis. Low dose thalidomide treatment of human T leukemic cells exhibited rapid increases in caspase-3 activity, annexin V-FITC binding and DNA disintegration that is characteristic of apoptosis. These data indicate that low doses of thalidomide signal human T leukemic cells to die by apoptosis, which is a possible method of altering inflammatory cells and inflammatory activities.
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PMID:Exposure to the anti-TNF-alpha drug thalidomide induces apoptotic cell death in human T leukemic cells. 1468 94


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