Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10415 (Bcl-2)
33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined in vitro effects of 17beta-estradiol on H2O2-induced apoptosis in human keratinocytes. 17beta-estradiol prevented the H2O2-induced apoptosis. H2O2 decreased, whereas 17beta-estradiol increased Bcl-2 protein and mRNA levels in keratinocytes, and H2O2 plus 17beta-estradiol led to basal levels. Overexpression of Bcl-2 protected keratinocytes against H2O2-induced apoptosis, indicating the anti-apoptotic effect of Bcl-2. H2O2 suppressed, whereas 17beta-estradiol enhanced bcl-2 promoter activity, and H2O2 plus 17beta-estradiol led to basal activity. Cyclic adenosine monophosphate (cAMP) response element on bcl-2 promoter was responsible for the effects of 17beta-estradiol and H2O2. Bcl-2 expression was enhanced by membrane-impermeable bovine serum albumin-conjugated 17beta-estradiol, indicating the effects via membrane 17beta-estradiol-binding sites. H2O2 decreased, whereas 17beta-estradiol increased the amount of phosphorylated cAMP response element-binding protein and cAMP response element-dependent transcriptional activity, and H2O2 plus 17beta-estradiol led to basal levels. H-89, an inhibitor of cAMP-dependent protein kinase A, suppressed basal and 17beta-estradiol-induced cAMP response element-binding protein phosphorylation, cAMP response element-dependent transcriptional activity, Bcl-2 expression, and apoptosis resistance. The cAMP analog, dibutyryl cAMP, enhanced cAMP response element-binding protein phosphorylation, cAMP response element-dependent transcriptional activity, Bcl-2 expression, and apoptosis resistance. 17Beta-estradiol increased intracellular cAMP level and protein kinase A activity, whereas these were not altered by H2O2. Keratinocytes expressed mRNA for estrogen receptor beta and guanine nucleotide-binding protein-coupled receptor, GPR30. GPR30 anti-sense oligonucleotide did, but anti-sense estrogen receptor beta did not suppress 17beta-estradiol-induced cAMP signal, cAMP response element-binding protein phosphorylation, Bcl-2 expression, and apoptosis resistance. These results suggest that 17beta-estradiol may enhance Bcl-2 expression and prevent H2O2-induced apoptosis by phosphorylating cAMP response element-binding protein via cAMP/protein kinase A pathway in keratinocytes. These effects of 17beta-estradiol may be mediated via membrane GPR30.
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PMID:17beta-estradiol inhibits oxidative stress-induced apoptosis in keratinocytes by promoting Bcl-2 expression. 1467 2

Tumor necrosis factor (TNF) is a pleiotropic cytokine that potentiates the cytotoxic effects of chemotherapeutic drugs. Although emergence of resistance to chemotherapeutic drugs is a major problem in cancer therapy, its mechanism is incompletely understood. Recently, activation of a nuclear transcription factor NF-kappa B has been reported to be a signal for anti-apoptosis. In this report, we investigated the effect of TNF on activation of NF-kappa B, c-Jun N-terminal kinase (JNK), and apoptosis in vincristine-resistant human histiocytic lymphoma U937-VR cells. Unlike the parent clone (U937-VS), no activation of caspase-3, known to be required for apoptosism was found in vincristine-resistant cells on exposure to vincristine. These cells were also more resistant than U-937-VS cells to doxorubicin, daunomycin, and taxol. TNF-induced NF-kappa B activation, I kappa B alpha degradation, and nuclear translocation of p65 were all found to be highly suppressed in the U-937-VR cells. NF-kappa B activation by LPS, H2O2, and okadaic acid was also suppressed. However, vincristine resistance enhanced TNF-induced JNK activation. When examined for apoptosis, vincristine resistance suppressed the cytotoxic effects and caspase-3 activation by TNF. The resistant phenotype in U937-VR cells was independent of the expression of the apoptosis-suppressor, Bcl-2. Thus, overall these results indicate that vincristine resistance correlates with suppression of NF-kappa B activation, cytotoxicity, and caspase-3 activation but enhancement of JNK activation by TNF.
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PMID:Cellular resistance to vincristine suppresses NF-kappa B activation and apoptosis but enhances c-Jun-NH2-terminal protein kinase activation by tumor necrosis. 1469

In the present study, using a rat pheochromocytoma (PC12) cell line, the effect of catalpol on H2O2-induced apoptosis was studied. The apoptosis in H2O2-induced PC12 cells was accompanied by down-regulation of Bcl-2, up-regulation of Bax, the release of mitochondrial cytochrome c to cytosol and sequential activation of caspase-1 and caspase-3 then leading to cleavage of poly-ADP-ribose polymerase (PARP). Catalpol not only suppressed the down-regulation of Bcl-2, up-regulation of Bax and the release of mitochondrial cytochrome c to cytosol, but also attenuated caspase-3 activation, PARP cleavage, and eventually protected against H2O2-induced apoptosis. Taken together, these results suggest that treatment of PC12 cells with catalpol can block H2O2-induced apoptosis by the regulation of Bcl-2 family members, as well as suppression of cytochrome c release and caspase cascade activation.
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PMID:Catalpol inhibits apoptosis in hydrogen peroxide-induced PC12 cells by preventing cytochrome c release and inactivating of caspase cascade. 1503 29

Ethyl 5-amino-6,7,8,9-tetrahydro-2-methyl-4-phenylbenzol[1,8] naphthyridine-3-carboxylate (ITH4012) is a novel tacrine derivative that can reduce cell death induced by various compounds with different mechanisms of action, such as thapsigargin (reticular stress), H2O2 (free radicals), and veratridine (calcium overload), in bovine chromaffin cell. Cell viability, quantified as lactic dehydrogenase release, was significantly reduced by ITH4012 at concentrations ranging from 0.01 to 3 microM. In the human neuroblastoma cell line SH-SY5Y, ITH4012 also reduced amyloid beta25-35-induced apoptosis, determined by flow cytometry. ITH4012 caused a slight elevation in the cytosolic concentration of Ca2+ in fura 2-loaded bovine chromaffin cells, which could be related to the induction of protein synthesis relevant for cell survival. Blockade of protein synthesis by cycloheximide or blockade of Bcl-2's active site with HA14-1 (ethyl 2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate) reversed the cytoprotective action of ITH4012. Furthermore, exposure of bovine chromaffin cells for 24 or 48 h to neuroprotective concentrations of this compound enhanced, nearly 3-fold, the expression of the antiapoptotic protein Bcl-2. In conclusion, ITH4012 is a tacrine derivative that maintains acetylcholinesterase-inhibiting activity (IC50=0.8 microM) but has the additional property of acting as a calcium promotor, a property leading to neuroprotection through the induction of antiapoptotic proteins.
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PMID:ITH4012 (ethyl 5-amino-6,7,8,9-tetrahydro-2-methyl-4-phenylbenzol[1,8]naphthyridine-3-carboxylate), a novel acetylcholinesterase inhibitor with "calcium promotor" and neuroprotective properties. 1511 41

Hydrogen peroxide (H(2)O(2)) is generated endogenously during execution of both intrinsic as well as extrinsic apoptotic programs suggesting that it may function as a secondary messenger in apoptotic pathways. In the present study, we investigated the role of endogenously generated H(2)O(2) by using two cell lines-HL-60 cells and its subclone, H(2)O(2) resistant HP100 cells overexpressing catalase (CAT). With the exception of CAT, we found no differences in the expression of other primary antioxidant enzymes (Cu/Zn-superoxide dismutase, Mn-superoxide dismutase, and glutathione peroxidase) or apoptosis-related proteins (Bcl-2 and Bax) in HP100 cells as compared with the parental HL-60 cells. Production of H(2)O(2) was readily detectable as early as 1 h after melphalan (Mel) exposure of HL-60 cells but not HP-100 cells. Biomarkers of apoptosis, such as release of cytochrome c, disruption of mitochondrial transmembrane potential, caspase-3 activation, and chromatin condensation, became apparent much later, 3 h and onward after Mel treatment of HL-60 cells. The emergence of essentially all biomarkers of apoptosis was dramatically delayed in HP100 cells as compared with HL-60 cells. A relatively minor phospholipid species, phosphatidylserine (PS), was markedly oxidized 3 h after Mel treatment in HL-60 cells (but not in HP100 cells) where it was significantly inhibited by exogenously added CAT. The two most abundant classes of membrane phospholipids, phosphatidylcholine and phosphatidyletanolamine, did not undergo any significant oxidation. PS oxidation took place 3 h after exposure of HL-60 cells to Mel and paralleled the appearance of cytochrome c in the cytosol. Neither cytochrome c release nor PS oxidation occurred in Mel-treated HP100 cells, indicating that both endogenous H(2)O(2) and cytochrome c were essential for selective PS oxidation detected in HL-60 cells. Mel-induced PS oxidation was also associated with externalization of PS on the surface of HL-60 cells. Given that 3-amino-1,2,4-triazole, a CAT inhibitor, suppressed the resistance of HP100 cells to apoptosis, production of reactive oxygen species, PS oxidation, and PS externalization induced by Mel, the results from the present study suggest that H(2)O(2) is critical for triggering the Mel-induced apoptotic program as well as PS oxidation and externalization.
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PMID:Endogenously generated hydrogen peroxide is required for execution of melphalan-induced apoptosis as well as oxidation and externalization of phosphatidylserine. 1514 26

Many types of mammalian cells produce ROS in response to many different stimuli to modulate a number of cellular functions, including apoptosis. However, the correlation between ROS and apoptosis remains controversial, and the mechanisms whereby ROS-induced signals are propagated to critical downstream targets remain largely undefined. Here, we demonstrate that hydrogen peroxide (H2O2) upregulates the expression of Bfl-1, an antiapoptotic member of the Bcl-2 family, and that this is responsible for the antiapoptotic activity of ROS. When Jurkat, human leukemic T cells, were pretreated with 100 microM H2O2 and then treated with anti-Fas antibody, apoptosis was impaired without change of cell surface Fas expression. An investigation of the expression patterns of Bcl-2 family genes revealed that H2O2 treatment induced Bfl-1 gene expression, but left other genes unchanged, and this Bfl-1 expression and H2O2 -induced antiapoptotic effect was inhibited by antioxidants or NF-kappaB inhibitor. In addition, an electromobility shift assay revealed that the p65/p50 subunits of NF-kappaB activated by H2O2 bound to a bfl-1 promoter. Neither the induction of Bfl-1 nor the antiapoptotic effect of H2O2 was detected in Bfl-1-knockdown Jurkat cell line containing Bfl-1 antisense (Bfl-1AS). These data indicate that oxidative stress induces the expression of Bfl-1 via NF-kappaB activation, and this early-response gene protects cells from Fas-mediated apoptosis. This may be a cellular survival mechanism of cells exposed to phagocytes-derived ROS.
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PMID:Oxidative stress attenuates Fas-mediated apoptosis in Jurkat T cell line through Bfl-1 induction. 1559 13

Flavonoids from the leaves of Diospyros kaki L (FLDK-P70) are main therapeutic components of NaoXingQing, which is a novel and patented Traditional Chinese Medicine drug used for the treatment of syndrome of apoplexy for years in China. The present study investigated the effects of FLDK-P70 on hydrogen peroxide (H2O2)-induced apoptosis-like damage of NG108-15 cells. Pretreatment of cells with FLDK-P70 alleviated H2O2-induced cell injury and apoptosis by upregulating Bcl-2 expression and improving redox imbalance as indicated by the alleviation of the decline in the intracellular endogenous antioxidants: glutathione and glutathione peroxidase as well as catalase, with the decrease of the leak of lactate dehydrogenase and the reduction of the accumulation of malondialdehyde. These results indicate that FLDK-P70 may be potentially used in the prevention and treatment of ischemia/reperfusion injury and other neurodegenerative disease. Upregulating bcl-2 and improving cellular redox state by FLDK-P70 may play critical roles in attenuating oxidative injury.
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PMID:Flavonoids from the leaves of Diospyros kaki reduce hydrogen peroxide-induced injury of NG108-15 cells. 1570 80

3-nitropropionic acid (3-NPA), a complex II inhibitor of the electron transport chain, causes Huntington disease-like symptoms after administration into animals. However, primary mechanisms of cell death are not clearly understood. This study tested the hypothesis that 3-NPA leads to the generation of reactive oxygen species (ROS), mitochondrial DNA damage, and loss of mitochondrial function. Amplex red and horseradish peroxidase were used to accurately measure the amount of H2O2, and showed that PC12 cells treated with 3-NPA (4 mM) lead to the production of hydrogen peroxide (1 nmol/10(6) cells/h). This amount of 3-NPA also leads to a rapid decline of ATP levels. There was time- and dose-dependent mitochondrial DNA damage following 3-NPA treatment. Overexpression of the proto-oncogene bcl-2 protects cells from apoptosis induced by various stimuli. Overexpression of Bcl-2 leads to almost threefold higher levels of ATP and also decreased the 3-NPA-mediated induction of hydrogen peroxide by over 50%. Bcl-2-overexpressing PC12 cells were also protected from mitochondrial DNA damage. These data show that ROS production followed by mitochondrial DNA damage is the primary event in 3-NPA toxicity, and Bcl-2 protects PC12 cells from 3-NPA toxicity by preventing mitochondrial DNA damage.
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PMID:3-nitropropionic acid-induced hydrogen peroxide, mitochondrial DNA damage, and cell death are attenuated by Bcl-2 overexpression in PC12 cells. 1571 Feb 38

Recent data have implicated nuclear factor-kappaB (NF-kappaB) and Bcl-2 in the regulation of apoptotic and necrotic cell death in various cells. However, mechanisms of their effects on cell death of renal epithelial cells are not clear. First, we investigated the effect of specific inhibition of NF-kappaB and overexpression of Bcl-2 on necrotic cell death induced by hydrogen peroxide or cisplatin in renal collecting duct cells. M-1 cells, which were derived from outer cortical collecting duct, were stably transfected with the non-phosphorylatable mutant of inhibitory-kappaBalpha (I-kappaBalpha) and Bcl-2. Overexpression of I-kappaBalpha and Bcl-2 did not affect cisplatin-induced necrotic cell death, but overexpression of I-kappaBalpha significantly decreased H2O2-induced cell death. Regarding apoptotic cell death induced by cisplatin, serum deprivation and contact inhibition was increased by overexpression of I-kappaBalpha, whereas overexpression of bcl-2 inhibited the apoptotic cell death. I-kappaBalpha overexpression increased Bax expression and decreased cIAP-1 and -2 expression compared to vector-transfected cells, but did not alter SAPK/JNK activity in the presence or absence of cisplatin. NF-kappaB activity was significantly higher in bcl-2-overexpressing cells than in control cells. These data show that activation of NF-kappaB mediates H2O2-induced necrotic injury, but inhibits apoptotic cell death in renal collecting duct cells, and that Bcl-2 selectively protects apoptotic cell death in M-1 cells.
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PMID:Roles of NF-kappaB and bcl-2 in two differential modes of cell death of mouse cortical collecting duct cells. 1574 59

We reported recently that (-)epigallocatechin gallate and quercetin inhibited H2O2-induced apoptosis through modulation of the expression of apoptosis-related Bcl-2 and Bax in endothelial cells. This study attempted to identify possible regulatory sites and mechanisms of antiapoptotic flavonoids, focusing on ROS-mediated signaling in HUVEC. The effects of apigenin on the signaling pathway downstream were compared. Submillimolar H2O2 caused >30% cell killing with intracellular oxidant generation. H2O2-induced oxidant generation markedly decreased total intracellular glutathione (GSH) levels. Micromolar (-)epigallocatechin gallate and quercetin partially eliminated the dichlorodihydrofluorescein (DCF) and phospho-p53 staining, suggesting that these flavonoids inhibited the accumulation of intracellular oxidants and nuclear transactivation of p53 in H2O2-exposed cells. In contrast, cells treated with apigenin remained DCF and phospho-p53 staining positive in response to H2O2. (-)Epigallocatechin gallate significantly raised the total GSH level that had been depleted by H2O2. Caspase-3 activity was enhanced by H2O2, and this increase was inhibited by (-)epigallocatechin gallate and quercetin. Additionally, the upregulation of caspase-3 activation was reversed by these flavonoids at > or =10 micromol/L; these inhibitory effects were dose dependent. Western blot data revealed that H2O2 upregulated phosphorylation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), which was rapidly reversed by quercetin within 30 min; H2O2 activation of c-Jun was downregulated. (-)Epigallocatechin gallate inhibited H2O2-induced phosphorylation of JNK and p38 MAPK after 60 min. These results reveal that quercetin blocks JNK- and p38 MAPK-related signaling triggered by the oxidant and may regulate expression of apoptotic downstream genes, preventing apoptosis and promoting cell survival. (-)Epigallocatechin gallate may function as an antiapoptotic agent through other antiapoptotic pathways.
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PMID:(-)Epigallocatechin gallate and quercetin enhance survival signaling in response to oxidant-induced human endothelial apoptosis. 1579 22


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