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)

We tested the effects of hydroxychloroquine (HCQ), an anti-rheumatic drug, on the viability of chronic lymphocytic leukemia (CLL) cells. HCQ induced a decrease in cell viability in a dose- and time-dependent manner. The mean LC50 calculated for the cells of 20 patients was 32 +/- 7 microg/ml (range, 10-75 microg/ml). We observed a large increase in apoptotic cell number after 24 h of incubation with 50 microg/ml HCQ (55 +/- 6 vs. 23 +/- 3% in medium alone, p < 0.001). Indeed, HCQ in leukemic cells induced the features of apoptosis (cell shrinkage, decrease in mitochondrial transmembrane potential, phosphatidylserine externalization, chromatin condensation and DNA fragmentation). HCQ had marked selective cytotoxicity when compared with normal blood mononuclear cells, in which the LC50 was >100 microg/ml at 24 h. HCQ induced the proteolytic cleavage of poly(ADP(adenosine 5'-diphosphate)ribose) polymerase (PARP) and increased the activity of caspase-3. The expression of bcl-2 and bax proteins was significantly modified after incubation with the drug and HCQ activity against CLL cells occurred independently of the presence of IL-4, sCD40L and bone marrow stromal cells.
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PMID:Hydroxychloroquine-induced apoptosis of chronic lymphocytic leukemia involves activation of caspase-3 and modulation of Bcl-2/bax/ratio. 1214 91

Platelets are formed from mature megakaryocytes (MKs) and arise from the development of long and thin cytoplasmic extensions called proplatelets. After platelet release, the senescent MKs (nucleus surrounded by some cytoplasm) undergo cell death by apoptosis. To explore the precise role of apoptosis in proplatelet formation, we grew human MKs from CD34(+) cells and assessed the possible role of caspases. Proteolytic maturation of procaspase-3 and procaspase-9 was detected by immunoblots in maturing MKs as well as in proplatelet-bearing MKs and senescent MKs. Cleavage of caspase substrates such as gelsolin or poly adenosine diphosphate (ADP)-ribose polymerase (PARP) was also detected. Interestingly, activated forms of caspase-3 were detected in maturing MKs, before proplatelet formation, with a punctuate cytoplasmic distribution, whereas a diffuse staining pattern was seen in senescent and apoptotic MKs. This localized activation of caspase-3 was associated with a mitochondrial membrane permeabilization as assessed by the release of cytochrome c, suggesting an activation of the intrinsic pathway. Moreover, these MKs with localized activated caspase-3 had no detectable DNA fragmentation. In contrast, when apoptosis was induced by staurosporine, diffuse caspase activation was seen; these MKs had signs of DNA fragmentation, and no proplatelet formation occurred. The pan-caspase inhibitor z-VAD.fmk as well as more specific inhibitors of caspase-3 and caspase-9 blocked proplatelet formation, whereas an inhibitor of calpeptin had no effect. Overexpression of Bcl-2 also inhibited proplatelet formation in maturing MKs. Thus, localized caspase activation is causal to proplatelet formation. We conclude that proplatelet formation is regulated by a caspase activation limited to only some cellular compartments.
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PMID:Platelet formation is the consequence of caspase activation within megakaryocytes. 1214 86

The cytotoxic effect of the chemotherapeutic drug etoposide (VP-16) is thought to result from its ability to induce DNA damage and thereby to trigger apoptosis. Internucleosomal DNA fragmentation occurs late during apoptosis in many cell types. However, whereas human osteosarcoma cells undergo internucleosomal DNA fragmentation during staurosporine-induced apoptosis, they fail to do so in response to VP-16. Recently, we showed that these cells also do not express the poly(ADP-ribosyl)ation-regulated Ca(2+)- and Mg(2+)-dependent endonuclease DNAS1L3. The possibility that this deficiency underlies the failure of these cells to undergo internucleosomal DNA fragmentation in response to VP-16 was investigated. The proteolytic processing and consequent activation of procaspase-3, cleavage of the inhibitory subunit of DNA fragmentation factor, and the degradation of DNA into 50-kb fragments occurred similarly in osteosarcoma cells exposed to either staurosporine or VP-16. However, the additional processing of the 50-kb DNA fragments to oligonucleosomal fragments was not apparent in the VP-16-treated cells. Ectopic expression of DNAS1L3 conferred on osteosarcoma cells the ability to undergo VP-16-induced internucleosomal DNA fragmentation. Furthermore, expression of DNAS1L3 markedly potentiated the cytotoxic effect of VP-16 in these cells. Both DNAS1L3-mediated and staurosporine-induced internucleosomal DNA fragmentation were Ca(2+) dependent, but only the DNAS1L3-mediated DNA cleavage was blocked by expression of a caspase-3-resistant mutant of poly(ADP-ribose) polymerase-1. The present work results suggest a direct relation between the activity of a chemotherapeutic drug (VP-16) and a specific endonuclease (DNAS1L3). They also indicate that internucleosomal DNA fragmentation plays an active role in apoptosis and that the failure of cancer cells to undergo such DNA degradation may contribute to the development of resistance to chemotherapeutic drugs.
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PMID:The Poly(ADP-ribose) polymerase-1-regulated endonuclease DNAS1L3 is required for etoposide-induced internucleosomal DNA fragmentation and increases etoposide cytotoxicity in transfected osteosarcoma cells. 1215 52

A new photosensitizer, presently designated QLT0074, may have the potential for the treatment of immune and nonimmune conditions with photodynamic therapy (PDT). The activity of QLT0074 was tested against human peripheral blood T cells and Jurkat T lymphoma cells. At low nanomolar concentrations of QLT0074 in combination with blue light, apoptosis was rapidly induced in Jurkat and blood T cells in vitro as indicated by the expression of the apoptosis-associated mitochondrial 7A6 marker and Annexin-V labeling. Further studies performed with Jurkat T cells showed that PDT-induced apoptosis with QLT0074 was associated with caspase-3 activation and the cleavage of the caspase substrate poly(adenosine diphosphate-ribose)polymerase. Flow cytometry studies revealed that blood T cells with high expression of the interleukin-2 receptor (CD25) took up greater amounts of QLT0074 and were eliminated to a greater extent with PDT than T cells with low levels of this activation marker. This selective action of PDT was confirmed by similar reductions in the percentage of T cells that expressed other activation-related markers, including very late activation antigen-4 (CD49d), human leukocyte antigen DR (HLA-DR), intercellular adhesion molecule-1 (CD54) and Fas (CD95). For activated T cells treated with a specific dose of QLT0074 and light 24 h earlier, CD25 expression density was significantly less, whereas CD54, CD95 and HLA-DR levels were similar to those for control cells treated with light alone. This work shows that PDT with QLT0074 exerts selective, dose-related effects on T cells in vitro.
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PMID:Selective action of the photosensitizer QLT0074 on activated human T lymphocytes. 1219 21

Activation of death receptors and mitochondrial damage are well-described common apoptotic pathways. Recently, a novel pathway via endoplasmic reticulum (ER) stress has been reported. We assessed the role of tauroursodeoxycholic acid (TUDCA) in inhibition of caspase-12 activation and its effect on calcium homeostasis in an ER stress-induced model of apoptosis. The human liver-derived cell line, Huh7, was treated with thapsigargin (TG) to induce ER stress. Typical morphologic changes of ER stress preceded development of apoptotic changes, including DNA fragmentation and cleavage of poly (adenosine diphosphate-ribose) polymerase (PARP), as well as activation of caspase-3 and -7. Elevation of intracellular calcium levels without loss of mitochondrial membrane potential (MMP) was shown using Fluo-3/Fura-red labeling and flow cytometry, and confirmed by induction of Bip/GRP78, a calcium-dependent chaperon of ER lumen. These changes were accompanied by procaspase-12 processing. TUDCA abolished TG-induced markers of ER stress; reduced calcium efflux, induction of Bip/GRP78, and caspase-12 activation; and subsequently inhibited activation of effector caspases and apoptosis. In conclusion, we propose that mitochondria play a secondary role in ER-mediated apoptosis and that TUDCA prevents apoptosis by blocking a calcium-mediated apoptotic pathway as well as caspase-12 activation. This novel mechanism of TUDCA action suggests new intervention methods for ER stress-induced liver disease.
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PMID:Effect of tauroursodeoxycholic acid on endoplasmic reticulum stress-induced caspase-12 activation. 1219 51

Ceramide has been suggested as an important mediator of apoptosis. In HT-29 colorectal cancer cells increased ceramide levels, induced by exogenous N-acetylsphingosine (NAS, also known as C2-ceramide) or by 1-phenyl-2-(decanoylamino)-3-morpholino-1-propanol (PDMP), inhibited the transport and processing of cathepsin D (CD), a lysosomal protease implicated in apoptosis of tumour cells. C2-dihydroceramide (DH-C2), an inactive analogue of NAS, had no effect on CD transport and maturation. The treatment with either NAS or PDMP was revealed to be cytotoxic for HT-29 cells and led to cell death with classical features of apoptosis. Morphological signs of apoptosis and DNA fragmentation became apparent only between 24 and 48 h of incubation and poly(ADP ribose)-polymerase cleavage, a hallmark of caspase 3 activity, occurred no earlier than 8 h from incubation. Secretion of proCD was almost abolished and the formation of double-chain mature CD was reduced and delayed by NAS, whereas PDMP largely inhibited the lysosomal targeting and maturation of proCD. NAS- and PDMP-induced alteration of proCD transport and maturation were apparent already 2 h after incubation with the drugs, which is much earlier than when classical biochemical and morphological evidence of apoptosis could be detected. These data indicate that alteration of CD (and possibly of other glycoproteins) transport along the secretory pathway due to increased levels of cell-associated ceramide is an early event in cells undergoing apoptosis.
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PMID:Increase in ceramide level alters the lysosomal targeting of cathepsin D prior to onset of apoptosis in HT-29 colon cancer cells. 1222 89

Small GTP-binding Rho GTPases regulate important signaling pathways in endothelial cells, but little is known about their role in endothelial cell apoptosis. Clostridial cytotoxins specifically inactivate GTPases by glucosylation [Clostridium difficile toxin B-10463 (TcdB-10463), C. difficile toxin B-1470 (TcdB-1470)] or ADP ribosylation (C. botulinum C3 toxin). Exposure of human umbilical cord vein endothelial cells (HUVEC) to TcdB-10463, which inhibits RhoA/Rac1/Cdc42, or to C3 toxin, which inhibits RhoA, -B, -C, resulted in apoptosis, whereas inactivation of Rac1/Cdc42 with TcdB-1470 was without effect, suggesting that Rho inhibition was responsible for endothelial apoptosis. Disruption of endothelial microfilaments as well as inhibition of p160ROCK did not induce endothelial apoptosis. Exposure to TcdB-10463 resulted in activation of caspase-9 and -3 but not caspase-8 in HUVEC. Moreover, Rho inhibition reduced expression of antiapoptotic Bcl-2 and Mcl-1 and increased proapoptotic Bid but had no effect on Bax or FLIP protein levels. Caspase-3 activity and apoptosis induced by TcdB-10463 were abolished by cAMP elevation. In summary, inhibition of Rho in endothelial cells activates caspase-9- and -3-dependent apoptosis, which can be antagonized by cAMP elevation.
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PMID:Rho protein inactivation induced apoptosis of cultured human endothelial cells. 1222 60

This study was designed to evaluate the synergistic cytotoxicity of herb prescription, Palgin, in adriamycin-treated cancer cells. The combination of Palgin and adriamycin synergistically augmented the cytotoxicity of Chang and HL-60 cells, but not in Hep3B and Alexander cells. The cytotoxicity of two drugs was revealed as apoptosis characterized by nuclear fragmentation. The apoptotic cell death was accompanied by the activation of caspase-3 as well as cleavage of poly(ADP) ribose polymerase (PARP) in Chang cells. Interestingly, a synergistic increase in apoptosis by the combination of two drugs was accompanied by the enhancement of Fas and Fas ligand (FasL) expression in Chang cells. Taken together, the combination of Palgin and adriamycin significantly augmented the apoptotic cytotoxicity of Fas-positive cells, such as Chang and HL-60 cells, via activation of caspase signaling pathway. This notion will provide a new trial to treat cancer patients in clinical fields as a complementary treatment of Western and Oriental medicine.
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PMID:Palgin sensitizes the adriamycin-induced apoptosis via the enhancement of Fas/Fas ligand expression. 1223

BACKGROUND: The frequently occurring 185delAG mutation occurs in the amino-terminal zinc RING domain of the breast and ovarian cancer susceptibility gene, BRCA1. We sought to determine differential cell viability and apoptotic response of human ovarian surface epithelial cells with and without the 185delAG mutation. RESULTS: BRCA1wt and BRCA1+ cells were treated with staurosporine. Cell proliferation assays showed BRCA1wt cells grew to a greater extent compared to BRCA1+ cells. Trypan blue exclusion assays confirmed this observation. Western immunoblot analysis revealed that caspase 3 levels were higher after staurosporine treatment in BRCA1+ cells than in wild type cells, while full length DNA Fragmentation Factor 45 levels were lower in BRCA1+ cells. While there was no significant difference in levels of excision repair cross complementing protein1 (ERCC1) with BRCA1 status, BRCA1+ cells demonstrated cleavage of polyribose ADP polymerase (PARP) before wild type cells. CONCLUSIONS: Disruption of the BRCA1 RING domain caused altered cell viability and caspase-dependent apoptotic response after chemotoxic stress.
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PMID:BRCA1 Zinc RING Finger Domain Disruption Alters Caspase Response in Ovarian Surface Epithelial Cells. 1223 76

Previous studies have shown that the liver is the first organ to display signs of injury during hemorrhagic shock. We examined the mechanism by which pyruvate can prevent liver damage during hemorrhagic shock in swine anesthetized with halothane. Thirty minutes after the induction of a 240-min controlled arterial hemorrhage targeted at 40 mmHg, hypertonic sodium pyruvate (0.5 g. kg(-1). h(-1)) was infused to achieve an arterial concentration of 5 mM. The volume and osmolality effects of pyruvate were matched with 10% saline (HTS) and 0.9% saline (NS). Although the peak hemorrhage volume increased significantly in both the pyruvate and HTS group, only the pyruvate treatment was effective in delaying cardiovascular decompensation. In addition, pyruvate effectively maintained the NADH/NAD redox state, as evidenced by increased microdialysate pyruvate levels and a significantly lower lactate-to-pyruvate ratio. Pyruvate also prevented the loss of intracellular antioxidants (GSH) and a reduction in the GSH-to-GSSG ratio. These beneficial effects on the redox environment decreased hepatic cellular death by apoptosis. Pyruvate significantly increased the ratio of Bcl-Xl (antiapoptotic molecule)/Bax (proapoptotic molecule), prevented the release of cytochrome c from mitochondria, and decreased the fragmentation of caspase 3 and poly(ADP ribose) polymerase (DNA repair enzyme). These beneficial findings indicate that pyruvate infused 30 min after the onset of severe hemorrhagic shock is effective in maintaining the redox environment, preventing the loss of the key antioxidant GSH, and decreasing early apoptosis indicators.
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PMID:Pyruvate improves redox status and decreases indicators of hepatic apoptosis during hemorrhagic shock in swine. 1223 18


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