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)

beta-Phenylethyl isothiocyanate (PEITC) is a promising chemoprotective compound that is routinely consumed in the diet as its glucosinolate precursor. Previous studies have shown that PEITC can inhibit phase I enzymes and induce phase II detoxification enzymes along with apoptosis in vitro. The detailed mechanisms involved in the apoptotic cascade, however, have not been elucidated. In the present study, we demonstrate that PEITC can induce apoptosis in hepatoma HepG2 cells in a concentration- and time-dependant manner as determined by TUNEL positive and SubG1 population analysis. Caspase-3-like activity and poly(ADP-ribosyl)polymerase cleavage increased during treatment with 20 microM PEITC; high concentrations, however, induced necrosis. Pre-treatment with Z-VAD-FMK and the caspase-3-specific inhibitor Ac-DEVD-CHO prevented PEITC-induced apoptosis, as determined by caspase-3-like activity and DNA fragmentation. Additional investigations also showed that at concentrations of 5-10 microM PEITC, DNA synthesis was inhibited and G2/M phase cell cycle arrest occurred, correlating with an alteration in cyclin B1 and p34(cdc2) protein levels. Furthermore, we also demonstrate a concentration- and time-dependant burst of superoxide (O2*-) in PEITC-treated cells. However, pre- and co-treatment with the free radical scavengers Trolox, ascorbate, mannitol, uric acid and the superoxide mimetic manganese (III) tetrakis (N-methyl-2-pyridyl) porphyrin failed to prevent PEITC-mediated apoptosis. Taken together, these results suggest that PEITC potently induces apoptosis and cell cycle arrest in HepG2 cells and that the generation of reactive oxygen species appears to be a secondary effect.
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PMID:beta-Phenylethyl isothiocyanate-mediated apoptosis in hepatoma HepG2 cells. 1294 35

The molecular mechanism of the cell death-promoting effect of dexamethasone (Dex) was studied during myogenesis (10 days) in L6 muscle cells by making use of several indices such as cell viability (protein synthesis, mitochondrial respiration), mortality (DNA fragmentation, chromatin condensation, structural modifications) and immunocytochemical studies [hydrogen peroxide, m-calpain (calpain 2)]. Dex initially (2 nM) stimulated protein synthesis (P < 0.001), but a further increase (20 nM) did not stimulate, whereas a higher dose (200 nM) inhibited formation of cellular proteins (P < 0.001). The latter, apparently, resulted from impaired cell viability (P < 0.001). From the day 4, structural changes featuring cell death were observed. Antioxidants [sodium ascorbate (ASC), catalase (CAT) or N-acetyl-L-cysteine (NAC)] as well as the inhibition of transcription and translation by actinomycin D abrogated Dex-induced cell death (P < 0.001). Using a fluorescent probe (DCFH-DA) we directly corroborated the working hypothesis of the mediating role of H2O2 in the reduction of cell viability by the excess of glucocorticoids. We also found that tPKC, PLCgamma, PLA2 were required to induce Dex-dependent cell death since inactivation of tPKC by H7 completely abolished the cytotoxic effect of Dex, while the blockade of PLCgamma and PLA2 by U 73122 partially abolished the effect. Cell death was triggered by Ca2+ influx necessary to activate m-calpain since it was reversed by the calcium chelator EGTA or m-calpain inhibitor ALLN but not EDTA nor ALLM. However, cell viability impaired by Ca2+ ionophore A 23187 (P < 0.001) was neither reversed by EGTA, nor EDTA, nor caspase-3 blocker--Ac DEVD CHO, nor ALLN, nor antioxidants--ASC, NAC, CAT. Specific caspase-3 inhibitor Ac DEVD CHO also did not rescue cells from Dex-induced cell death (P < 0.001), in contrast to m-calpain inhibitor--ALLN. Taken together, these findings suggest that reactive oxygen species inhibit protein synthesis and amplify m-calpain-dependent proteolysis. The events that led to the death of L6 muscle cells most likely resulted from Dex-mediated repression of antioxidative defences on the genomic level.
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PMID:Delineation of signalling pathway leading to antioxidant-dependent inhibition of dexamethasone-mediated muscle cell death. 1295 35

The effect of reactive nitrogen species (RNS) against the cytotoxicity of mitomycin c (MMC) in lung epithelial cells was assessed by measuring the effect on mitochondrial membrane permeability. RNS had a differential effect against cytotoxicity of MMC depending on concentration. Viability loss in cells exposed to MMC was decreased by inhibitors of caspase-3, -8 and -9 and attenuated by antioxidants (N-acetylcysteine, dithiothreitol, ascorbate and rutin). Addition of 3-morpholinosydnonimine (SIN-1) differentially affected the MMC-induced cell death and GSH depletion concentration dependently with a maximal inhibitory effect at 150 microM. Ascorbate, superoxide dismutase and haemoglobin prevented the inhibitory effect of 150 microM SIN-1 on 10 microg/ml MMC-induced cell death. SIN-1 inhibited the MMC-induced nuclear damage, loss in mitochondrial transmembrane potential, cytosolic accumulation of cytochrome c, caspase-3 activation, increase in reactive oxygen species (ROS) formation and depletion of GSH. SIN-1 also attenuated cell death due to H(2)O(2). The cytotoxicity of MMC in the presence of oxidants or RNS producers was much less than the sum of the each effect of MMC and producer. SIN-1 may inhibit the MMC-induced viability loss in lung epithelial cells by suppressing the mitochondrial membrane permeability change and by interaction of its products with MMC.
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PMID:Differential effect of nitrogen species on changes in mitochondrial membrane permeability due to mitomycin c in lung epithelial cells. 1476 34

The cytotoxicity and apoptosis-inducing activity of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and 2-tert-butyl-4-methylphenol (BMP) and the mixture of BHA and BHT (BHA/BHT) (1:1, molar ratio) were investigated, using human promeylocytic leukemia cell lines (HL-60) and human squamous cell carcinoma cell lines (HSC-2). The 50% cytotoxic concentration (CC50) declined in the order of BHA, BHT (0.2-0.3 mM) > BHA/BHT (0.04-0.07 mM) > BMP (0.02-0.05 mM). The addition of antioxidants (N-acetyl-Lcysteine, sodium ascorbate, catalase) reduced the cytotoxicity of BHA/BHT or BMP against HSC-2 cells, but not that of BHA or BHT, whereas the addition of NADH, a quinone reductase to BMP, enhanced the cytotoxicity. These findings suggested that the cytotoxicity of BHA/BHT and BMP might be caused by reactive intermediates. BHA-induced cytotoxicity was enhanced by horseradish peroxidases, suggesting that BHA was oxidizable and produced cytotoxic BHA radicals. Internucleosomal DNA fragmentation of HL-60 cells was preferably induced by BHA/BHT and BMP, followed by BHA. The MnSOD mRNA expression in HL-60 cells assayed by reverse transcriptase-polymerase chain reaction was highly inhibited by BHA/BHT or BMP, accompanied by the change in the electrophoretic mobility of MnSOD on polyacryamide gel. These compounds activated caspase-3, 8 and 9 in HL-60 cells. Activations of caspases, particularly caspase-3, declined in the order of BHA/BHT > BHA > BMP > BHT. The most cytotoxic BMP activated caspase-3 activity to the least extent, possibly in part due to the occurrence of necrosis. The great cytotoxicity and apoptosis induction by BHA/BHT may be due to reactive intermediates derived from the interaction between BHA phenoxyl radical and BHT or BHT phenoxyl radical.
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PMID:Cytotoxicity and apoptosis induction by butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). 1498 15

Hepatocarcinoma cells (TLT) were incubated in the presence of ascorbate and menadione, either alone or in combination. Cell death was only observed when such compounds were added simultaneously, most probably due to hydrogen peroxide (H2O2) generated by ascorbate-driven menadione redox cycling. TLT cells were particularly sensitive to such an oxidative stress due to its poor antioxidant status. DNA strand breaks were induced by this association but this process did not correspond to oligosomal DNA fragmentation (a hallmark of cell death by apoptosis). Neither caspase-3-like DEVDase activity, nor processing of procaspase-3 and cleavage of poly(ADP-ribose) polymerase (PARP) were observed in the presence of ascorbate and menadione. Cell death induced by such an association was actively dependent on protein phosphorylation since it was totally prevented by preincubating cells with sodium orthovanadate, a tyrosine phosphatase inhibitor. Finally, while H2O2, when administered as a bolus, strongly enhances a constitutive basal NF-kappaB activity in TLT cells, their incubation in the presence of ascorbate and menadione results in a total abolition of such a constitutive activity.
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PMID:Ascorbate potentiates the cytotoxicity of menadione leading to an oxidative stress that kills cancer cells by a non-apoptotic caspase-3 independent form of cell death. 1500 19

The sensitivity of human hepatoma (HepG2) and oral squamous cell carcinoma (HSC-2) cell lines against various apoptosis-inducing agents was compared. HepG2 cells were generally more resistant to an oxidant (H2O2), antioxidants (sodium ascorbate, gallic acid, epigallocatechin gallate) and anticancer drugs (doxorubicin, methotrexate, cisplatin (CDDP), etoposide, 5-fluoro-2,4(1H,3H)-pyrimidinedione (5-FU), peplomycin sulfate) as compared to HSC-2 cells. Lower concentrations of CDDP, but not other anticancer drugs, induced comparable cytostatic effects on both HSC-2 and HepG2 cells. CDDP induced internucleosomal DNA fragmentation and activation of caspases 3, 8 and 9 in HepG2 cells. On the other hand, CDDP did not induce DNA fragmentation and activated caspase 3 only marginally in HSC-2 cells. Combination treatment with CDDP (10 microM) and 5-FU (100 microM) additively activated all three caspases in HepG2 cells, but not in HSC-2 cells. The present study demonstrated the chemotherapeutic potential of combined treatment of CDDP and 5-FU against hepatoma cells and the considerable variation of drug sensitivity between cancer cell lines.
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PMID:Apoptosis-inducing activity of cisplatin (CDDP) against human hepatoma and oral squamous cell carcinoma cell lines. 1516 Oct 8

Micromolar concentrations of the flavonoid kaempferol were found to efficiently block cerebellar granule cell (CGC) death through low K+-induced apoptosis, as demonstrated by prevention of the activation of caspase-3, internucleosomal DNA fragmentation, and chromatin condensation, without a significant rise in intracellular free Ca2+ concentration. Half of the maximum protection against CGC apoptosis was attained with 8 +/- 2 microM kaempferol. Reactive oxygen species (ROS) were monitored with 2',7'-dichlorodihydrofluorescein diacetate. Quantitative analysis of intracellularly and extracellularly oriented ROS production up to 3 h from the onset of low K+-induced CGC apoptosis was carried out with acquired digital fluorescence microscopy images of CGC in culture plates using a CCD camera, and also with fluorescence measurements of resuspended CGCs. In both cases, nearly 90% of ROS production by CGCs during the early stages (up to 3 h) after induction of low-K+ apoptosis occurs at the plasma membrane. Kaempferol, at concentrations that blocked CGC apoptosis, has been found to be a particularly potent blocker of extracellularly oriented ROS production by CGCs, and to inhibit the ascorbate-dependent NADH oxidase and superoxide anion production activities of the neuronal plasma membrane redox chain.
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PMID:Kaempferol blocks oxidative stress in cerebellar granule cells and reveals a key role for reactive oxygen species production at the plasma membrane in the commitment to apoptosis. 1518 94

The effect of ascorbate on cell death was examined in Jurkat cells (human T-cell leukemia) by incubation with dehydroascorbate (DHA), which is rapidly taken up by cells and efficiently reduced to ascorbate. Apoptosis was evaluated by caspase-3 activity in cell extracts and flow cytometry of annexin V-labeled cells. In parallel, necrosis was estimated by the release of lactate dehydrogenase. Minor effects on cell death were observed when Jurkat cells were incubated with either DHA alone (100-1,000 microM) or a single dose of 10 microM H(2)O(2). However, pre-incubation with DHA followed by exposure to H(2)O(2) clearly stimulated both apoptosis and necrosis. In complete contrast, pre-incubation of cells with DHA significantly inhibited apoptosis, but did not affect necrosis, induced by the topoisomerase I inhibitor camptothecin. Our results indicate that intracellular ascorbate can modulate cell death in a manner which depends upon the nature of the apoptotic stimulus, which in turn has critical implications regarding the mechanism and potential application of ascorbate in cancer therapy.
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PMID:Ascorbate modulation of H(2)O(2) and camptothecin-induced cell death in Jurkat cells. 1519 88

Free radical scavenging and antioxidant activities of a standardized extract of Hypericum perforatum (SHP) were examined for inhibition of lipid peroxidation, for hydroxyl radical scavenging activity and interaction with 1,1-diphenyl-2-picrylhydrazyl stable free radical (DPPH). Concentrations between 1 and 50 microg/ml of SHP effectively inhibited lipid peroxidation of rat brain cortex mitochondria induced by Fe2+/ascorbate or NADPH system. The results showed that SHP scavenged DPPH radical in a dose-dependent manner and also presented inhibitory effects on the activity of xanthine oxidase. In contrast, hydroxyl radical scavenging occurs at high doses. The protective effect of the standardized extract against H2O2-induced oxidative damage on the pheochromocytoma cell line PC 12 was investigated by measuring cell viability via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH) assays, caspase-3-enzyme activity and accumulation of reactive oxygen species [2',7'-dichlorofluorescin (DCF) assay]. Following 8-h cell exposure to H2O2 (300 microM), a marked reduction in cell survival was observed, which was significantly prevented by SHP (pre-incubated for 24 h) at 1-100 microg/ml. In a separate experiment, different concentrations of the standardized extract (0.1-100 microg/ml) also attenuated the increase in caspase-3 activity and suppressed the H2O2 -induced reactive oxygen species generation. Taken together, these results suggest that SHP shows relevant antioxidant activity both in vitro and in a cell system, by means of inhibiting free radical generation and lipid peroxidation.
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PMID:Antioxidant properties and protective effects of a standardized extract of Hypericum perforatum on hydrogen peroxide-induced oxidative damage in PC12 cells. 1521 14

Reactive oxygen species play a central role in myocardial ischemic injury and are a target for therapeutic intervention. Vitamin C is an essential antioxidant yet difficult to deliver in pharmacologic concentration to the myocardium. We found that adult rat cardiomyocytes accumulate vitamin C by transporting dehydroascorbic acid (DHA), the oxidized form of vitamin C, but do not transport ascorbic acid. Loading cells with vitamin C by DHA treatment resulted in resistance to hypoxia- and hypoxia/reoxygenation-induced cell death associated with the quenching of reactive oxygen species. When rats were injected with DHA before coronary occlusion, the ascorbic acid content in the heart was six to eight times higher than in untreated controls and myocardial infarction was reduced by 62%. DHA also provided significant protection when administered intravenously 2 h after coronary occlusion. In cardiomyocytes subjected to hypoxia/reoxygenation, DHA treatment resulted in decreased apoptosis associated with inhibition of Bax expression, caspase-3 activation, and cytochrome c translocation into the cytoplasm. DHA treatment also inhibited Jak2, STAT1, and STAT5 phosphorylation, and increased STAT3 phosphorylation, in hypoxic cardiomyocytes and ischemic myocardial tissue. Our findings suggest that DHA may be useful as a cardioprotectant in ischemic heart disease.
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PMID:Vitamin C inhibits hypoxia-induced damage and apoptotic signaling pathways in cardiomyocytes and ischemic hearts. 1545 81


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