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)

Radiocontrast nephropathy (RCN) is a major complication after radiographical examination with iodinated contrast media (CM). Although little is known about the mechanism of RCN, a direct toxic action on renal cells and/or decrease in renal blood flow are considered to be implicated in the pathogenesis of the disease/the condition, A large number of vasodilatory agents, including endothelin antagonists, adenosine antagonists, atrial natriuretic peptide, calcium channel blockers, dopamine, dopamine D1 receptor agonist fenoldopam, and prostaglandin E1 have been tried clinically to prevent RCN, however, most of them have failed. Although prophylactic effects of antioxidant N-acetylcysteine have recently been reported by several investigators, only hydration is a universally accepted protocol to prevent it. In our recent in vitro and in vivo study, we have elucidated that CM induced apoptosis of renal tubular cells through the reduction in Bcl-2 expression and the subsequent activation of caspase-9 and caspase-3. Moreover, we found that CM caused an increase in ceramide content in renal tubular cells, which leads to apoptosis by inhibiting the phosphorylation of Akt and cAMP responsive element binding protein (CREB) and the subsequent reduction in Bcl-2 expression. The inhibitor of ceramide synthase, fumonisin B1, reversed both the elevation of ceramide content and renal cell injury induced by CM. On the other hand, a prostacyclin analog beraprost prevented RCN in mice by the increase of endogenous cAMP and subsequent CREB phosphorylation resulted in enhancement of Bcl-2 expression. These findings suggest that ceramide synthesis inhibitor or beraprost is potentially useful for the prophylaxis of RCN.
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PMID:[Etiology of iodinated radiocontrast nephrotoxicity and its attenuation by beraprost]. 1859 70

Naja naja atra cardiotoxin 3 (CTX3) induced apoptotic death on human neuroblastoma SK-N-SH cells. The apoptosis signals of CTX3 included reactive oxygen species (ROS) generation, disruption of mitochondrial membrane potential (DeltaPsim), cytochrome c release to the cytosol and activation of caspase-9 and -3. However, CTX3-induced increase in mitochondrial permeability transition was not initiated by proteins of the Bcl-2 family. The collapse of DeltaPsim, release of cytosolic cytochrome c, production of ROS and subsequent apoptotic cell death in CTX-treated cells could not be completely abolished by either N-acetylcysteine (ROS scavenger) or cyclosporin A (an inhibitor of mitochondrial permeability transition). Co-incubation with rotenone, an inhibitor of mitochondrial electron transport chain complexes I, resulted in partial inhibition of CTX3-induced ROS generation but not the loss of DeltaPsim. Obviously, the dissipation of DeltaPsim was not an upstream event for ROS generation or vice versa. Given that CTX3 was able to induce the leakage of isolated mitochondria, our data indicate that CTX3-induced apoptotic death of SK-N-SH cells is mediated through mitochondrial alteration and ROS generation.
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PMID:Involvement of mitochondrial alteration and reactive oxygen species generation in Taiwan cobra cardiotoxin-induced apoptotic death of human neuroblastoma SK-N-SH cells. 1861 91

The role of selenium as potential cancer chemopreventive and chemotherapeutic agents has been supported by epidemiological, preclinical and clinical studies. Although cell apoptosis has been evidenced as a critical mechanism mediating the anticancer activity of selenium, the underlying molecular mechanisms remain elusive. In the present study, we showed that selenocystine (SeC), a naturally occurring selenoamino acid, induced caspase-independent apoptosis in MCF-7 breast carcinoma cells, which was accompanied by poly(ADP-ribose) polymerase (PARP) cleavage, caspase activation, DNA fragmentation, phosphatidylserine exposure and nuclear condensation. Moreover, SeC induced the loss of mitochondrial membrane potential (DeltaPsi(m)) by regulating the expression and phosphorylation of Bcl-2 family members. Loss of DeltaPsi(m) led to the mitochondrial release of cytochrome c and apoptosis-inducing factor (AIF) which subsequently translocated into the nucleus and induced chromatin condensation and DNA fragmentation. MCF-7 cells exposed to SeC shown increase in total p53 and phosphorylated p53 on serine residues of Ser15, Ser20, and Ser392 prior to mitochondrial dysfunction. Silencing and attenuating of p53 activation with RNA interference and pifithrin-alpha treatment, respectively, partially suppressed SeC-induced cell apoptosis. Furthermore, generation of reactive oxygen species and subsequent induction of DNA strand breaks were found to be upstream cellular events induced by SeC. The thiol-reducing antioxidants, N-acetylcysteine and glutathione, completely blocked the occurrence of cell apoptosis. Taken together, these results suggest that SeC, as a promising anticancer selenocompound, induces MCF-7 cell apoptosis by activating ROS-mediated mitochondrial pathway and p53 phosphorylation.
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PMID:Selenocystine induces caspase-independent apoptosis in MCF-7 human breast carcinoma cells with involvement of p53 phosphorylation and reactive oxygen species generation. 1871 51

Aminoacetone (AA), triose phosphates, and acetone are putative endogenous sources of potentially cytotoxic and genotoxic methylglyoxal (MG), which has been reported to be augmented in the plasma of diabetic patients. In these patients, accumulation of MG derived from aminoacetone, a threonine and glycine catabolite, is inferred from the observed concomitant endothelial overexpression of circulating semicarbazide-sensitive amine oxidases. These copper-dependent enzymes catalyze the oxidation of primary amines, such as AA and methylamine, by molecular oxygen, to the corresponding aldehydes, NH4(+) ion and H2O2. We recently reported that AA aerobic oxidation to MG also takes place immediately upon addition of catalytic amounts of copper and iron ions. Taking into account that (i) MG and H2O2 are reportedly cytotoxic to insulin-producing cell lineages such as RINm5f and that (ii) the metal-catalyzed oxidation of AA is propagated by O2(*-) radical anion, we decided to investigate the possible pro-oxidant action of AA on these cells taken here as a reliable model system for pancreatic beta-cells. Indeed, we show that AA (0.10-5.0 mM) administration to RINm5f cultures induces cell death. Ferrous (50-300 microM) and Fe(3+) ion (100 microM) addition to the cell cultures had no effect, whereas Cu(2+) (5.0-100 microM) significantly increased cell death. Supplementation of the AA- and Cu(2+)-containing culture medium with antioxidants, such as catalase (5.0 microM), superoxide dismutase (SOD, 50 U/mL), and N-acetylcysteine (NAC, 5.0 mM) led to partial protection. mRNA expression of MnSOD, CuZnSOD, glutathione peroxidase, and glutathione reductase, but not of catalase, is higher in cells treated with AA (0.50-1.0 mM) plus Cu(2+) ions (10-50 microM) relative to control cultures. This may imply higher activity of antioxidant enzymes in RINm5f AA-treated cells. In addition, we have found that AA (0.50-1.0 mM) plus Cu(2+) (100 microM) (i) increase RINm5f cytosolic calcium; (ii) promote DNA fragmentation; and (iii) increase the pro-apoptotic (Bax)/antiapoptotic (Bcl-2) ratio at the level of mRNA expression. In conclusion, although both normal and pathological concentrations of AA are probably much lower than those used here, it is tempting to propose that excess AA in diabetic patients may drive oxidative damage and eventually the death of pancreatic beta-cells.
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PMID:Aminoacetone, a putative endogenous source of methylglyoxal, causes oxidative stress and death to insulin-producing RINm5f cells. 1872 31

Bcl-2/adenovirus E1B 19-kDa protein-interacting protein 3 (Bnip3) is a member of the Bcl-2 homology domain 3-only subfamily of proapoptotic Bcl-2 proteins and is associated with cell death in the myocardium. In this study, we investigated the potential mechanism(s) by which Bnip3 activity is regulated. We found that Bnip3 forms a DTT-sensitive homodimer that increased after myocardial ischemia-reperfusion (I/R). The presence of the antioxidant N-acetylcysteine reduced I/R-induced homodimerization of Bnip3. Overexpression of Bnip3 in cells revealed that most of exogenous Bnip3 exists as a DTT-sensitive homodimer that correlated with increased cell death. In contrast, endogenous Bnip3 existed mainly as a monomer under normal conditions in the heart. Screening of the Bnip3 protein sequence revealed a single conserved cysteine residue at position 64. Mutation of this cysteine to alanine (Bnip3C64A) or deletion of the NH2-terminus (amino acids 1-64) resulted in reduced cell death activity of Bnip3. Moreover, mutation of a histidine residue in the COOH-terminal transmembrane domain to alanine (Bnip3H173A) almost completely inhibited the cell death activity of Bnip3. Bnip3C64A had a reduced ability to interact with Bnip3, whereas Bnip3H173A was completely unable to interact with Bnip3, suggesting that homodimerization is important for Bnip3 function. A consequence of I/R is the production of reactive oxygen species and oxidation of proteins, which promotes the formation of disulfide bonds between proteins. Thus, these experiments suggest that Bnip3 functions as a redox sensor where increased oxidative stress induces homodimerization and activation of Bnip3 via cooperation of the NH2-terminal cysteine residue and the COOH-terminal transmembrane domain.
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PMID:Bnip3 functions as a mitochondrial sensor of oxidative stress during myocardial ischemia and reperfusion. 1879 Aug 35

Oridonin, a diterpenoid isolated from Rabdosia rubescences, has been reported to have antitumor effects. In this study, the growth-inhibitory activity of oridonin for L929 cells was exerted in a time-and dose-dependent manner. After treatment with oridonin for 24 h, L929 cells underwent both apoptosis and necrosis as measured by an lactate dehydrogenase (LDH) activity-based assay. A rapid generation of reactive oxygen species (ROS) was triggered by oridonin, and subsequently up-regulation of phospho-p53 (ser 15) expression and an increased expression ratio of Bax/Bcl-2 was observed. Furthermore, there was a significant fall in mitochondrial membrane potential (MMP) and increase in caspase-3 activity after exposure to oridonin for 24 h. Surprisingly, the pan-caspase inhibitor z-VAD-fmk and caspase3 inhibitor z-DEVD-fmk rendered L929 cells more sensitive to oridonin, rather than preventing oridonin-induced cell death. Oridonin and z-VAD-fmk co-treatment not only resulted in an even higher ROS production, but also made a more significant reduction in the MMP. Pretreatment of ROS scavenger N-acetylcysteine (NAC) led to a complete inhibition of oridonin-induced cell death, intracellular ROS generation, and MMP collapse. NAC treatment also reversed the potentiation of cell death by the pan-caspase inhibitor z-VAD-fmk. Taken together, these observations showed that oridonin-induced cell death in L929 cells involved intracellular ROS generation, activation of phospho-p53 (ser 15), and up-regulation of the Bax/Bcl-2 ratio; and the augmented cell death by z-VAD-fmk was dependent on an increased ROS production.
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PMID:Caspase inhibition augmented oridonin-induced cell death in murine fibrosarcoma l929 by enhancing reactive oxygen species generation. 1881 79

Selenium, an essential trace element, showed the significant protective effects against liver and kidney damage induced by some heavy metals. However, the mechanism how selenium suppresses cadmium (Cd)-induced cytotoxicity remains unclear. In this study, we investigated the protective mechanism of selenium on Cd-induced apoptosis in LLC-PK(1) cells via reactive oxygen species (ROS) and mitochondria linked signal pathway. Studies of PI and Annexin V dual staining analysis demonstrated that 20 microM Cd-induced apoptosis as early as 18 h. A concomitant by the generation of ROS, the loss of mitochondrial membrane potential, cytochrome c (cyt c) release, activation of caspase-9, -3 and regulation of Bcl-2 and Bax were observed. N-acetylcysteine (NAC, 500 microM), a free radical scavenger, was used to determine the involvement of ROS in Cd-induced apoptosis. During the process, selenium played the same role as NAC. The anti-apoptosis exerted by selenium involved the blocking of Cd-induced ROS generation, the inhibition of Cd-induced mitochondrial membrane potential collapse, the prevention of cyt c release, subsequent inhibition of caspase activation and the changed level of Bcl-2 and Bax. Taken together, we concluded that Cd-induced apoptosis was mediated by oxidative stress and selenium produced a significant protection against Cd-induced apoptosis in LLC-PK(1) via ameliorating the mitochondrial dysfunction.
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PMID:The protection of selenium on ROS mediated-apoptosis by mitochondria dysfunction in cadmium-induced LLC-PK(1) cells. 1913 40

Chronic high doses of morphine inhibit the growth of various human cancer cell lines. However, the mechanisms by which such high-dose morphine inhibits cell proliferation and induces cell death are not fully understood. Here we show that c-Jun N-terminal kinase (JNK) plays a pivotal role in high-dose morphine-induced apoptosis of SH-SY5Y cells in a mitochondria-dependent manner. Activation of JNK by morphine led to reactive oxygen species (ROS) generation via the mitochondrial permeability transition pore, because the mPTP inhibitor cyclosporin A significantly inhibited ROS generation. ROS in turn exerted feedback regulation on JNK activation, as shown by the observations that cyclosporin A and the antioxidant N-acetylcysteine significantly inhibited the phosphorylation of JNK induced by morphine. ROS-amplified JNK induced cytochrome c release and caspase-9/3 activation through enhancement of expression of the proapoptotic protein Bim and reduction of expression of the antiapoptotic protein Bcl-2. All of these effects of morphine could be suppressed by the JNK inhibitor SP600125 and N-acetylcysteine. The key role of the JNK pathway in morphine-induced apoptosis was further confirmed by the observation that decreased levels of JNK in cells transfected with specific small interfering RNA resulted in resistance to the proapoptotic effect of morphine. Thus, the present study clearly shows that morphine-induced apoptosis in SH-SY5Y cells involves JNK-dependent activation of the mitochondrial death pathway, and that ROS signaling exerts positive feedback regulation of JNK activity.
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PMID:Chronic high-dose morphine treatment promotes SH-SY5Y cell apoptosis via c-Jun N-terminal kinase-mediated activation of mitochondria-dependent pathway. 1929 71

Emodin was isolated from Rheum palmatum L. and exhibits an anticancer effect on human cancer cell lines, however, the molecular mechanisms of emodin-mediated apoptosis in human tongue cancer cells have not been fully investigated. In this study, treatment of human tongue cancer SCC-4 cells with various concentrations of emodin led to G2/M arrest through promoted p21 and Chk2 expression but inhibited cyclin B1 and cdc2; it also induced apoptosis through the pronounced release of cytochrome c from mitochondria and activations of caspase-9 and caspase-3. These events were accompanied by the generation of reactive oxygen species (ROS), disruption of mitochondrial membrane potential (delta psi(m)) and a decrease in the ratio of mitochondrial Bcl-2 and Bax content; emodin also promoted the levels of GADD153 and GRP78. The free radical scavenger N-acetylcysteine and caspase inhibitors markedly blocked emodin-induced apoptosis. Taken together, these findings suggest that emodin mediated oxidative injury (DNA damage) based on ROS production and ER stress based on the levels of GADD153 and GRP78 that acts as an early and upstream change in the cell death cascade to caspase- and mitochondria-dependent signaling pathways, triggers mitochondrial dysfunction from Bcl-2 and Bax modulation, mitochondrial cytochrome c release and caspase activation, consequently leading to apoptosis in SCC-4 cells.
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PMID:Emodin induces apoptosis of human tongue squamous cancer SCC-4 cells through reactive oxygen species and mitochondria-dependent pathways. 1933 Nov 69

Oxidative stress and endoplasmic reticulum (ER) stress have been implicated in cardiovascular diseases although the interplay between the two is not clear. This study was designed to examine the influence of oxidative stress through glutathione depletion on myocardial ER stress and contractile function in the absence or presence of the heavy metal scavenger antioxidant metallothionein (MT). FVB and MT overexpression transgenic mice received the GSH synthase inhibitor buthionine sulfoximine (BSO, 30 mM) in drinking water for 2 weeks. Oxidative stress, ER stress, apoptosis, cardiac function and ultrastructure were assessed using GSH/GSSG assay, reactive oxygen species (ROS), immunoblotting, caspase-3 activity, Langendorff perfused heart function (LVDP and +/-dP/dt), and transmission electron microscopy. BSO led to a robust decrease in the GSH/GSSG ratio and increased ROS production, consolidating oxidative stress. Cardiac function and ultrastructure were compromised following BSO treatment, the effect of which was obliterated by MT. BSO promoted overt ER stress as evidenced by upregulated BiP, calregulin, phospho-IRE1 alpha and phospho-eIF2 alpha without affecting total IRE1 alpha and eIF2 alpha. BSO treatment led to apoptosis manifested as elevated expression of CHOP/GADD153, caspase-12 and Bax as well as caspase-3 activity, reduced Bcl-2 expression and JNK phosphorylation, all of which was ablated by MT. Moreover, both antioxidant N-acetylcysteine and the ER stress inhibitor tauroursodeoxycholic acid reversed the oxidative stress inducer menadione-elicited depression in cardiomyocyte contractile function. Taken together, these data suggested that ER stress occurs likely downstream of oxidative stress en route to cardiac dysfunction.
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PMID:Metallothionein alleviates oxidative stress-induced endoplasmic reticulum stress and myocardial dysfunction. 1934 29


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