Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.61 (caspase-8)
 6,833 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

LIGHT is a member of tumor necrosis factor (TNF) superfamily, and its receptors have been identified as lymphotoxin-beta receptor (LTbetaR) and the herpesvirus entry mediator (HVEM)/ATAR/TR2, both of which lack the cytoplasmic sequence termed the "death domain." The present study has demonstrated that LIGHT inhibits TNFalpha-mediated apoptosis of human primary hepatocytes sensitized by actinomycin D (ActD), but not Fas- or TRAIL-mediated apoptosis. Furthermore, LIGHT does not prevent some cell lines such as HepG2 or HeLa from undergoing ActD/TNFalpha-induced apoptosis. This protective effect requires LIGHT pretreatment at least 3 h prior to ActD sensitization. LIGHT stimulates nuclear factor-kappaB (NF-kappaB)-dependent transcriptional activity in human hepatocytes like TNFalpha. The time course of NF-kappaB activation after LIGHT administration is similar to that of the pretreatment required for the anti-apoptotic effect of LIGHT. LIGHT inhibits caspase-3 processing on the apoptotic protease cascade in TNFalpha-mediated apoptosis but not Fas-mediated apoptosis. In addition, increased caspase-3 and caspase-8 activities in ActD/TNFalpha-treated cells are effectively blocked by LIGHT pretreatment. However, LIGHT does not change the expression of TNFRp55, TNFRp75, and Fas. These results indicate that LIGHT may act as an anti-apoptotic agent against TNFalpha-mediated liver injury by blocking the activation of both caspase-3 and caspase-8.
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PMID:LIGHT, a member of the tumor necrosis factor ligand superfamily, prevents tumor necrosis factor-alpha-mediated human primary hepatocyte apoptosis, but not Fas-mediated apoptosis. 1239 1

LIGHT is a new member of the tumor necrosis factor superfamily, which binds to lymphotoxin beta receptor, herpes virus entry mediator, or TR6. This work was carried out to elucidate the molecular mechanism of LIGHT-sensitized, interferon gamma (IFNgamma)-mediated apoptosis of MDA-MB-231 cells. It was revealed that LIGHT treatment resulted in down-regulation of anti-apoptosis Bcl-2 family member: Bcl-2, Bcl-X(L), Bag-1, and Mcl-1; up-regulation of pro-apoptosis Bcl-2 family member: Bak and Ser (112)-phosphor-Bad; down-regulation of pro-apoptosis Bcl-2 member Bax; the other pro-apoptosis member Bid remains unaltered. LIGHT treatment also resulted in activation of caspase-3, caspase-6, caspase-7, caspase-8, caspase-9, DFF45, and PARP. However, caspase activation and caspase activity, especially caspase-3 activity, is not required for LIGHT-induced apoptosis of MDA-MB-231 cells, since caspase-3 inhibitor, benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone, and a broad range caspase inhibitor, benzyloxycarbonyl-val-ala-asp-fluoromethylketone failed to block the apoptosis induced by LIGHT and IFNgamma in MDA-MB-231 cells. In summary, LIGHT-sensitized IFNgamma-mediated apoptosis of MDA-MB-231 cells is probably through down-regulation of anti-apoptosis Bcl-2 family members; it could be caspase (especially caspase-3)-independent, even though extensive caspase activation was observed.
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PMID:LIGHT sensitizes IFNgamma-mediated apoptosis of MDA-MB-231 breast cancer cells leading to down-regulation of anti-apoptosis Bcl-2 family members. 1276 29

Decoy receptor 3 (DcR3)/TR6/M68 is a soluble receptor that binds to the Fas ligand LIGHT and TL1A. Elevated levels of DcR3 expression have been found in many tumors. We report an unexpected effect of DcR3 by sensitizing Jurkat and U937 cells to apoptosis induced by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Cell death triggered by anti-Fas and tumor necrosis factor was unaffected by DcR3. DcR3 by itself did not stimulate apoptosis. The ability to augment TRAIL-initiated cell death was not observed with soluble lymphotoxin beta receptor or soluble death receptor 3, indicating that binding to LIGHT or TL1A alone is insufficient to trigger TRAIL sensitivity. Incubation with DcR3 did not increase the surface expression of TRAIL receptor, and the level of Fas-associated death domain protein and cellular FLICE-like inhibitory protein was not altered. Instead, in the presence of DcR3, TRAIL engagement resulted in an increased activation of caspase-8, an elevated cleavage of Bid, and enhanced release of Smac and cytochrome c from mitochondria to cytosol compared with TRAIL alone. This led to increased activation of caspase-9 and caspase-3. The unusual ability of DcR3 to promote TRAIL-triggered death may be used to potentiate TRAIL efficacy during treatment tumors overexpressing DcR3.
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PMID:Sensitization of cells to TRAIL-induced apoptosis by decoy receptor 3. 1547 69