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 previously demonstrated that evodimine isolated from Evodia rutaecarpa (Goshuyu in Japan) induced apoptosis in human malignant melanoma A375-S2 cells within 24 h. In this study, TUNEL assay also indicated that one cause of A375-S2 cell death induced by evodiamine was apoptosis. After treatment with evodiamine for the indicated time periods, anti-apoptotic protein SIRT1 expression was decreased; p53 expression and its phosphorylation were both enhanced, whereas transient induction of downstream p21 was not enough to promote cell cycle arrest. Inhibition of the phosphoinositide 3-OH kinase (PI3-K)/protein kinase C (PKC) survival pathway as well as subsequent inhibition of the ERK cascade might contribute to evodiamine-induced cell death. In addition, p53 activation in response to evodiamine administration was correlated with the activation of the PI3-K/PKC pro-apoptotic pathway, but did not require ERK participation. The inhibition of the PI3-K/PKC survival pathway might be responsible for SIRT1 inactivation and increased Bax/Bcl-2 expression ratio in evodiamine-induced cell death.
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PMID:Roles of SIRT1 and phosphoinositide 3-OH kinase/protein kinase C pathways in evodiamine-induced human melanoma A375-S2 cell death. 1582 41

SIRT1 is a conserved NAD-dependent deacetylase that regulates life span in accord with nutritional provision. In mammalian cells, SIRT1 also down-regulates stress-induced p53 and FoxO pathways for apoptosis, thus favoring survival under stress. The functioning of SIRT1 under normal, nonstressed conditions of cell growth is unknown. Here we have asked if SIRT1 has the capacity to influence cell viability in the absence of applied stress. For this purpose we used synthetic small interfering RNA to silence SIRT1 gene expression by RNA interference (RNAi). We show that the process of RNAi, by itself, does not affect cell growth and is not sufficient to activate a cellular stress response (indicated by lack of activation of endogenous p53). We also show that, in the absence of applied stress, SIRT1 silencing induces growth arrest and/or apoptosis in human epithelial cancer cells. In contrast, normal human epithelial cells and normal human diploid fibroblasts seem to be refractory to SIRT1 silencing. Combined gene knockout with RNAi cosilencing experiments indicate that SIRT1 and Bcl-2 may suppress separable apoptotic pathways in the same cell lineage and that the SIRT1-regulated pathway is independent of p53, Bax, and caspase-2. Alternatively, SIRT1 may suppress apoptosis downstream from these apoptotic factors. In either case, we show that FoxO4 (but not FoxO3) is required as proapoptotic mediator. We further identify caspase-3 and caspase-7 as downstream executioners of SIRT1/FoxO4-regulated apoptosis. Our work identifies SIRT1 as a novel target for selective killing of cancer versus noncancer epithelial cells.
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PMID:Cancer-specific functions of SIRT1 enable human epithelial cancer cell growth and survival. 1628 37

Silibinin, derived from the milk thistle plant, Silybum marianum, has been traditionally used as an antihepatotoxic agent for the treatment of liver disease. Our preliminary study demonstrated that silibinin has protected rat cardiac myocytes against beta-adrenergic agonist isoproterenol-induced injury through resuming mitochondrial function and regulating the expression of SIRT1 and Bcl-2 family members. In this study, we investigate whether silibinin has anti-apoptotic effect on isoproterenol-treated rat cardiac myocytes. DNA damage, detected by the TUNEL and DNA fragmentation assay, was diminished after treatment of silibinin. Results of nitrite and Western blot assays showed that the amount of NO and the expression of iNOS were decreased after treatment with silibinin, while the expression of procaspase-3 and digestion of caspase-3 substrates, the inhibitor of caspase-activated DNase (ICAD) and poly-(ADP-ribose) polymerase (PARP), were increased simultaneously. The DNA damage was reversed by down-regulation of p53 phosphorylation after treatment with silibinin. Result of flowcytometric analysis showed that the cell cycle was not affected, and the expression of cell cycle regulatory protein p21 also had no change. Consequently, silibinin protected cardiac myocytes against isoproterenol-induced DNA damage through caspase pathway and the expression of p53, but independent on regulation of cell cycle.
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PMID:Silibinin protects rat cardiac myocyte from isoproterenol-induced DNA damage independent on regulation of cell cycle. 1694 6

Terminally differentiated adult injured cardiac myocytes have been used for various animal models of heart failure. It has recently been shown that isoproterenol induces injury in rat neonatal cardiac myocytes via a beta-adrenergic pathway, suggesting that it might be one of the factors involved in myocardial cell injury in heart failure in vivo. In the study, silibinin, a plant flavanoid from milk thistle was first evaluated for its protective effect against beta-adrenergic agonist isoproterenol-induced injury in cultured rat neonatal cardiac myocytes. The viability, activation of lactate dehydrogenase (LDH), and content of maleic dialdehyde (MDA) were chosen for measuring the degree of cardiac myocytes injury. As a result, silibinin protected isoproterenol-treated rat cardiac myocytes from death and significantly decreased LDH release and MDA production. Silibinin increased superoxide dismutase activity, decreased [Ca(2+)](i), and increased mitochondrial membrane potential (DeltaPsi). Furthermore, the release of pro-apoptotic cytochrome c from mitochondria was reduced by silibinin. Silibinin increased the expression of anti-apoptotic Bcl-2 family protein Bcl-2, and up-regulation of SIRT1 inhibited the translocation of Bax from cytoplasm to mitochondria, which caused mitochondrial dysfunction and cell injury. These results demonstrate that silibinin protects against isoproterenol-induced cardiac myocytes injury through resuming mitochondrial function and regulating the expression of SIRT1 and Bcl-2 family members.
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PMID:Silibinin protects against isoproterenol-induced rat cardiac myocyte injury through mitochondrial pathway after up-regulation of SIRT1. 1717 May 12

Silibinin is a polyphenolic flavanoid derived from fruits and seeds of milk thistle (Silybum marianum). To investigate the effect and mechanism of silibinin on beta-isoproterenol-induced rat neonatal cardiac myocytes injury, the viability, the activation of lactate dehydrogenase (LDH) and the content of maleic dialdehyde (MDA) were chosen for measuring the degree of cardiac myocytes injury. Superoxide dismutase (SOD) activity, mitochondrial membrane potential (deltapsi) detected by flow cytometric analysis, and Western blotting analysis were applied to determine the related proteins. Silibinin protected isoproterenol-treated rat cardiac myocytes from death and significantly decreased LDH release and MDA production. Silibinin increased superoxide dismutase (SOD) activity, and increased mitochondrial membrane potential (deltapsi). Furthermore, the release of pro-apoptotic cytochrome c from mitochondria was reduced by silibinin. Silibinin increased the expression of anti-apoptotic Bcl-2 family protein Bcl-2, and up-regulation of SIRT1 inhibited the translocation of Bax from cytoplasm to mitochondria, which caused mitochondrial dysfunction and cell injury. Silibinin protects cardiac myocytes against isoproterenol-induced injury through resuming mitochondrial function and regulating the expression of SIRT1 and Bcl-2 family members.
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PMID:[Protective effect of silibinin against isoproterenol-induced injury to cardiac myocytes and its mechanism]. 1752 Aug 24

The RNA-binding protein HuR can stabilize and/or regulate the translation of target mRNAs, thereby affecting the cellular responses to immune, proliferative, and damaging agents. Here, we discuss emerging evidence that HuR elicits a broad anti-apoptotic function through its influence on the expression of multiple target mRNAs. HuR was previously shown to bind to the mRNA encoding the apoptosome inhibitor prothymosin a(ProT alpha) and enhanced its translation and cytoplasmic abundance. More recently, HuR was shown to increase the stability of a target mRNA encoding the pro-survival deacetylase SIRT1. The discovery that HuR likewise binds to and promotes the expression of mRNAs encoding Bcl-2 and Mcl-1, two major anti-apoptotic effectors, strongly supports HuR's role as a key upstream coordinator of a constitutive pro-survival program.
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PMID:Posttranscriptional orchestration of an anti-apoptotic program by HuR. 1753 46

Bcr-Abl-independent signaling pathways are known to be involved in imatinib resistance in some patients with chronic myelogenous leukemia (CML). In this study, to find new targets for imatinib-resistant CML displaying loss of Bcr-Abl kinase target dependence, we isolated imatinib-resistant variants, K562/R1, K562/R2, and K562/R3, which showed profound declines of Bcr-Abl levels and its tyrosine kinase activity, from K562 cells. Importantly, the imatinib resistance mechanism in these variants also included aberrant acetylation of nonhistone proteins such as p53, Ku70, and Hsp90 that was due to upregulation of histone deacetylases (HDACs) and down-regulation of histone acetyltransferase (HAT). In comparison with K562 cells, the imatinib-resistant variants showed up-regulation of HDAC1, -2, and -3 (class I HDACs) and class III SIRT1 and down-regulation of CBP/p300 and PCAF with HAT activity, and thereby p53 and cytoplasmic Ku70 were aberrantly acetylated. In addition, these were associated with down-regulation of Bax and up-regulation of Bcl-2. In contrast, the class II HDAC6 level was significantly decreased, and this was accompanied by an increase of Hsp90 acetylation in the imatinib-resistant variants, which was closely associated with loss of Bcr-Abl. These results indicate that alteration of the normal balance of HATs and HDACs leads to deregulated acetylation of Hsp90, p53, and Ku70 and thereby leads to imatinib resistance, suggesting the importance of the acetylation status of apoptosis-related nonhistone proteins in Bcr-Abl-independent imatinib resistance. We also revealed that imatinib-resistant K562 cells were more sensitive to suberoylanilide hydroxamic acid, an HDAC inhibitor, than K562 cells. These findings may have implications for HDAC as a molecular target in imatinib-resistant leukemia cells.
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PMID:Bcr-Abl-independent imatinib-resistant K562 cells show aberrant protein acetylation and increased sensitivity to histone deacetylase inhibitors. 1756 22

SIRT3, one of seven mammalian sirtuins, is a NAD-dependent deacetylase. SIRT3 localizes to mitochondria where it deacetylates and thus activates acetyl-CoA synthetase 2 (AceCS2), indicating a role for SIRT3 in metabolism. Here we provide evidence that SIRT3 also impacts upon apoptosis and cell growth control. Using RNAi under basal (non-stress) conditions we show that SIRT3 is required for apoptosis induced by selective silencing of Bcl-2 in HCT116 human epithelial cancer cells. Identical treatment of ARPE19 epithelial non-cancer cells induces G(1) growth arrest which also proved to be SIRT3-dependent. Previously we have identified SIRT1 and JNK2 as constitutive suppressors of apoptosis in HCT116 cells. We now demonstrate that SIRT3 functions in JNK2-regulated apoptosis but is dispensable for SIRT1-regulated apoptosis. SIRT3 is also dispensable for stress-induced apoptosis. Thus the pro-apoptotic functioning of SIRT3 is selectively coupled with defined pathways regulating cell survival under basal conditions.
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PMID:SIRT3 is pro-apoptotic and participates in distinct basal apoptotic pathways. 1795 39

The aim of the present study was to investigate the mechanism of hyperoside protecting ECV-304 cells against tertbutyl hydroperoxide (TBHP)-induced injury. ECV-304 cell viability was measured by MTT assay. Cellular morphologic changes were observed using phase contrast microscopy. The genotoxic effects of TBHP and the protective ability of hyperoside were assessed by the Comet test. Lipid peroxidation was measured by HPLC method. The cellular redox status was determined from GSH/GSSG ratios. Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. Western blot analysis was used to evaluate the levels of cytochrome c, p53, SIRT1, Bax and Bcl-2 expression. The results showed that 128 mumol/l hyperoside could effectively protect TBHP-treated ECV-304 cells from death, increase superoxide dismutase activity and significantly decrease malondialdehyde production. Hyperoside was effective in protecting against the induction of oxidized DNA bases and redox state alterations induced by TBHP. Furthermore, the release of proapoptotic cytochrome c from mitochondria was reduced by hyperoside, which increased the expression of antiapoptotic SIRT1 and inhibited the translocation of Bax from cytoplasm to mitochondria. Taken together, these results indicate that hyperoside is effective in protecting against the oxidative damage induced by TBHP. The mechanism of hyperoside protecting against ECV-304 cell apoptosis by TBHP is related with resuming mitochondrial function and regulating the expression of SIRT1 and Bcl-2 family members.
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PMID:The mechanism of hyperoside protection of ECV-304 cells against tert-butyl hydroperoxide-induced injury. 1855 16

Many natural polyphenolic compounds have been shown to attenuate reactive oxygen/nitrogen species (ROS/RNS) formation and protect against ischemia/reperfusion injury both in vitro and in vivo. 2,3,5,4'-tetrahydroxystilbene-2-O-beta-D-glucoside (TSG), an active component of the rhizome extract from Polygonum multiflorum, exhibits antioxidative and anti-inflammatory effects. Here, we used an in vitro ischemic model of oxygen-glucose deprivation followed by reperfusion (OGD-R) and an in vivo ischemic model of middle cerebral artery occlusion (MCAO) to investigate the neuroprotective effects of TSG on ischemia/reperfusion brain injury and the related mechanisms. We demonstrated that OGD-R-induced neuronal injury, intracellular ROS generation, and mitochondrial membrane potential dissipation were reversed by TSG. The elevation of H2O2-induced [Ca2+]i was also attenuated by TSG. Inhibition of the c-Jun N-terminal kinase (JNK) and Bcl-2 family-related apoptotic signaling pathway was involved in the neuroprotection afforded by TSG. Meanwhile, TSG inhibited iNOS mRNA expression induced by OGD-R, which may be mediated by the activation of SIRT1 and inhibition of NF-kappaB activation. In vivo studies further demonstrated that TSG significantly reduced the brain infarct volume and the number of positive cells by TUNEL staining in the cerebral cortex compared to the MCAO group. Our study indicates that TSG protects against cerebral ischemia/reperfusion injury through multifunctional cytoprotective pathways.
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PMID:Protection by tetrahydroxystilbene glucoside against cerebral ischemia: involvement of JNK, SIRT1, and NF-kappaB pathways and inhibition of intracellular ROS/RNS generation. 1927 42


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