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Query: UNIPROT:P10415 (
Bcl-2
)
33,771
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We have reported that members of the bcl-2 gene family are expressed and gonadotropin regulated in ovarian granulosa cells during follicular maturation and atresia. Because
Bcl-2
, a protein that prevents apoptosis in several cell types, is reported to function as an antioxidant or free radical scavenger, the present studies were designed to investigate if oxidative stress plays a role in granulosa cell apoptosis during follicular atresia in the immature rat ovary. In the first series of experiments, the role of oxidative stress in the induction of granulosa cell apoptosis was directly tested using a defined in vitro follicle culture system. Healthy antral follicles obtained from equine CG (eCG)-primed immature (27 day old) rats were incubated in serum-free medium for 24 h in the absence or presence of FSH (100 ng/ml; a control for inhibiting apoptosis), superoxide dismutase (SOD; 10-1000 U/ml), ascorbic acid (0.01-1 mM; a free radical scavenger), N-acetyl-L-cysteine (25-100 mM; a free radical scavenger and stimulator of endogenous glutathione peroxidase activity), or catalase (10-1000 U/ml). Granulosa cells within follicles incubated in medium alone exhibited extensive apoptosis after 24 h of incubation, and this onset of apoptosis was blocked by treatment with FSH (29 +/- 4% of controls; P < 0.001, n = 3). Moreover, apoptosis in follicles was also inhibited by treatment with SOD (44 +/- 4% of controls at 1000 U/ml; P < 0.01, n = 3), ascorbic acid (55 +/- 9% of controls at 1 mM; P < 0.05, n = 3), N-acetyl-L-cysteine (24 +/- 7% of controls at 100 mM; P < 0.001, n = 3), or catalase (35 +/- 6% of controls at 1000 U/ml; P < 0.001, n = 3). In the second series of experiments, complementary DNAs corresponding to secreted (SEC-SOD),
copper
/zinc-containing (Cu/Zn-SOD), and manganese-containing (Mn-SOD) forms of rat SOD, rat seleno-cysteine glutathione peroxidase (GSHPx), and rat catalase were isolated and used to synthesize antisense RNA probes for Northern and slot blot analysis of changes in SOD, GSHPx, and catalase gene expression during follicular maturation. In vivo priming of 25-day-old female rats for 2 days with 10 IU eCG, which promoted antral follicular growth and survival, increased levels of messenger RNA encoding SEC-SOD (216 +/- 9% of saline-treated controls, P < 0.05, n = 3) and Mn-SOD (222 +/- 14% of saline-treated controls, P < 0.05, n = 3) vs. saline-treated controls.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Inhibitors of oxidative stress mimic the ability of follicle-stimulating hormone to suppress apoptosis in cultured rat ovarian follicles. 782 37
Mutations in human Cu/Zn superoxide dismutase-1 (SOD) cause approximately 20% of cases of familial amyotrophic lateral sclerosis (FALS). We investigated the mechanism of mutant SOD-induced neuronal degeneration by expressing wild-type and mutant SODs in neuronal cells by means of infection with replication-deficient recombinant adenoviruses. Expression of two FALS-related mutant SODs (A4V and V148G) caused death of differentiated PC12 cells, superior cervical ganglion neurons, and hippocampal pyramidal neurons. Cell death included many features typical of apoptosis. Death could be prevented by
copper
(
Cu2+
) chelators,
Bcl-2
, glutathione, vitamin E, and inhibitors of caspases. Mutant SOD-expressing PC12 cells had higher rates of superoxide (O2-) production under a variety of conditions. The results support the hypothesis that mutant SOD induced-neurodegeneration is associated with disturbances of neuronal free radical homeostasis.
...
PMID:Mutant superoxide dismutase-1-linked familial amyotrophic lateral sclerosis: molecular mechanisms of neuronal death and protection. 934 45
Recent reports have implicated a possible role of reactive oxygen species (ROS) in the induction and mediation of apoptosis and DNA damage. Oxidative DNA base modification induced by cupric nitrilotriacetate (Cu-NTA) and the following apoptosis were observed in human promyelocytic leukemia HL-60 cells. We measured the level of ROS in the cells by using a fluorescence probe, 2',7'-dichlorofluorescein diacetate (DCFH-DA), and the amount of a modified DNA base, 8-hydroxydeoxyguanosine (8-OHdG) by HPLC-ECD. It was found that Cu-NTA exposure significantly enhanced ROS and 8-OHdG formation in the cells. Meanwhile, we observed both DNA fragmentation and morphological changes characteristic of apoptosis, which was also determined quantitatively by flow cytometry and showed dose- and time-dependent manners. Furthermore, several antioxidants such as dimethyl sulfoxide (DMSO), superoxide dismutase (SOD), and catalase were used to detect whether the apoptosis could be blocked. Only DMSO protected against this form of cell death. To elucidate molecular events in the apoptosis, expressions of
Bcl-2
protein family members, such as
Bcl-2
, Bcl-X and Bax, and heat shock protein 70 (HSP-70) were measured by western blotting using specific antibodies. The levels of Bax and Bcl-Xs remained largely unchanged, but the
Bcl-2
and Bcl-XL expression showed down-regulation. After 24 h incubation in the presence of
copper
, the levels of
Bcl-2
and Bcl-XL reduced about 33.8% and 51.1% compared with untreated cells, respectively. Furthermore, after 16 h incubation, the level of HSP-70 expression was about 3.4-fold greater than that in untreated cells, suggesting that HSP-70 is important in increasing resistance to oxidative stress induced by Cu-NTA. But overexpression of HSP-70 failed to protect HL-60 cells from apoptosis induced by Cu-NTA. We inferred that Cu-NTA may induce oxidative DNA damage through free radical injuries, which may turn on the apoptosis in HL-60 cells.
...
PMID:Cupric nitrilotriacetate induces oxidative DNA damage and apoptosis in human leukemia HL-60 cells. 974 94
If permanent focal ischemia is induced by middle cerebral artery occlusion (MCAO), neurons within the infarcted territory die by necrosis and apoptosis (or programmed cell death). We have previously shown, using a mouse strain transgenic (tg) for the nerve growth factor (NGF) gene, that tg mice have consistently smaller infarcted areas than wild-type (wt) animals, correlated with upregulated NGF synthesis and impaired apoptotic cell death. We studied, in wt and tg mice subjected to MCAO, the activities of several antioxidant enzymes and the synthesis of the proteins of the
Bcl-2
family. Our results show that the antiapoptotic
Bcl-2
protein and glutathione peroxidase are recruited after MCAO. NGF-tg mice also had an intrinsic resistance to oxidative stress because their basal
copper
zinc superoxide dismutase (SOD) and glutathione transferase activities were high. Additionally, manganese SOD activity increased in NGF-tg mice after MCAO, correlating strongly with the resistance of these mice to apoptosis.
...
PMID:Reduction of ischemic damage in NGF-transgenic mice: correlation with enhancement of antioxidant enzyme activities. 1040 7
The generation of reactive oxygen species has been implicated in the neurotoxicity of amyloid beta-peptide, the main constituent of the senile plaques that accumulates in the brain of Alzheimer's disease victims. In this study, we have compared the toxicity of amyloid beta-peptide on cultured cortical neurons from control mice and transgenic mice expressing either human copper-zinc superoxide dismutase or human
Bcl-2
, two proteins that protect cells against oxidative damage.
Copper
-zinc superoxide dismutase overexpression failed to protect cortical neurons against the toxicity of amyloid beta-peptide(25-35) [the minimal cytotoxic fragment of amyloid beta-peptide(1-42)] as assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction and an enzyme-linked immunoabsorbent assay using an antibody directed against microtubule-associated protein-2 (a specific neuronal protein), ruling out a role for superoxide anion and peroxynitrite in amyloid beta-peptide-evoked neurotoxicity. On the contrary, cortical neurons expressing human copper-zinc superoxide dismutase exhibited increased apoptotic nuclei in both untreated and amyloid beta-peptide(25-35)-exposed neurons. Transgenic neurons expressing human
Bcl-2
were partially protected against amyloid beta-peptide-induced neuronal death. This neuroprotection appears to be related to the complete inhibition of apoptosis induced by both amyloid beta-peptide(25-35) and amyloid beta-peptide(1-42). This study may be relevant for developing neuroprotective gene therapy to inhibit neuronal apoptosis in Alzheimer's disease.
...
PMID:Transgenic murine cortical neurons expressing human Bcl-2 exhibit increased resistance to amyloid beta-peptide neurotoxicity. 1042 99
It has been proposed that mutations in
copper
/zinc-superoxide dismutase (SOD1), the only proven cause of amyotrophic lateral sclerosis (ALS), induce the disease by a toxic property that promotes apoptosis. Consistent with this, we have demonstrated that overexpression of
Bcl-2
, a protein that inhibits apoptosis, attenuates neurodegeneration produced by the familial ALS-linked SOD1 mutant G93A (mSOD1). Herein, we assessed the status of key members of the
Bcl-2
family in the spinal cord of transgenic mSOD1 mice at different stages of the disease. In asymptomatic transgenic mSOD1 mice, expression of
Bcl-2
, Bcl-XL, Bad, and Bax does not differ from that in nontransgenic mice. In contrast, in symptomatic mice, expression of
Bcl-2
and Bcl-XL, which inhibit apoptosis, is reduced, whereas expression of Bad and Bax, which stimulate apoptosis, is increased. These alterations are specific to affected brain regions and are caused by the mutant and not by the normal SOD1 enzyme. Relevant to the neuroprotective effects of
Bcl-2
in transgenic mSOD1 mice, overexpression of
Bcl-2
increases the formation of
Bcl-2
:Bax heterodimers, which abolish the Bax proapoptotic property. This study demonstrates significant alterations in the expression of key members of the
Bcl-2
family associated with mSOD1 deleterious effects. That these changes contribute to the neurodegenerative process in this model of ALS is supported by our observations in double transgenic mSOD1/
Bcl-2
mice in which the pernicious increase of Bax is tempered by an increase in formation of
Bcl-2
:Bax heterodimers. Based on these findings, it may be concluded that
Bcl-2
family members appear as invaluable targets for the development of new neuroprotective therapies in ALS.
...
PMID:Bax and Bcl-2 interaction in a transgenic mouse model of familial amyotrophic lateral sclerosis. 1058 6
Nuclear factor kappaB (NF-kappaB) is a transcription factor involved in the expression of a wide range of genes, most of which code for proteins that play a role in immunity and inflammation. Pyrrolidine dithiocarbamate (PDTC) is a well-known inhibitor of NF-kappaB. Although its mechanism of action is conferred by its antioxidant property, other mechanisms by which PDTC can act as a prooxidant, metal chelator, and free thiol group modulator have recently been suggested. Here we report that PDTC caused a dual effect on cell viability in neuronal rat pheochromocytoma (PC12) cells, depending on its concentration. Increase of intracellular zinc and
copper
ion levels selectively potentiated the cytotoxic PDTC effect in a dose-dependent manner, and thiol reagents, such as glutathione and N-acetylcysteine, as well as divalent metal-chelating reagents, such as EDTA and bathocuproline disulfonic acid, blocked its cell death effect. The differential effect of PDTC on cell viability correlates well with the inhibition of NF-kappaB activities. In addition, PDTC differentially activated microtubule-associated protein (MAP) kinases, such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), but not p38, depending on its dose, and the coaddition of glutathione (GSH), other antioxidants, and metal ions also modulated their activities. Furthermore, stable
Bcl-2
expression blocked the PDTC-induced cell death. These results suggest that the thiol groups and free zinc and
copper
ion levels are important for the novel biphasic PDTC effect on cell viability, which is associated with the differential activation of NF-kappaB and MAP kinases.
...
PMID:Novel biphasic effect of pyrrolidine dithiocarbamate on neuronal cell viability is mediated by the differential regulation of intracellular zinc and copper ion levels, NF-kappaB, and MAP kinases. 1065 92
Nitric oxide (NO) challenge to human neuroblastoma cells (SH-SY5Y) ultimately results in apoptosis. Tumor suppressor protein p53 and cell cycle inhibitor p21 accumulate as an early sign of S-nitrosoglutathione-mediated toxicity. Cytochrome c release from mitochondria and caspase 3 activation also occurred. Cells transfected with either wild type (WT) or mutant (G93A) Cu, Zn-superoxide dismutase (Cu,Zn-SOD) produced comparable amounts of nitrite/nitrate but showed different degree of apoptosis. G93A cells were the most affected and WT cells the most protected; however, Cu, Zn-SOD content of these two cell lines was 2-fold the SH-SY5Y cells under both resting and treated conditions. We linked decreased susceptibility of the WT cells to higher and more stable
Bcl-2
and decreased reactive oxygen species. Conversely, we linked G93A susceptibility to increased reactive oxygen species production since simultaneous administration of S-nitrosoglutathione and
copper
chelators protects from apoptosis. Furthermore, G93A cells showed a significant decrease of
Bcl-2
expression and, as target of NO-derived radicals, showed lower cytochrome c oxidase activity. These results demonstrate that resistance to NO-mediated apoptosis is strictly related to the level and integrity of Cu,Zn-SOD and that the balance between reactive nitrogen and reactive oxygen species regulates neuroblastoma apoptosis.
...
PMID:Cu,Zn-superoxide dismutase-dependent apoptosis induced by nitric oxide in neuronal cells. 1067 49
Apoptosis may play an important role in atherogenesis. Oxidized low-density lipoprotein (oxLDL) promotes apoptosis in the arterial wall in addition to several other proatherogenic effects. Tocopherol supplements have been suggested to protect against coronary heart disease (CHD) in epidemiological studies. The effects of oxLDL and alpha- and gamma-tocopherol on apoptotic signaling pathways are poorly understood. Thus, the goal of the study was to investigate these pathways in the presence of
copper
-oxidized LDL and tocopherols in human coronary smooth muscle cells (SMC). We showed that oxLDL-mediated apoptosis, assessed by DNA fragmentation, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, and caspase activation stimulated several transcription factors and proapoptotic dynamic movements of the
Bcl-2
family proteins through the mitogen-activated protein kinase (MAPK) and Jun kinase pathways. alpha-Tocopherol and gamma-tocopherol significantly reduced these molecular events and cell death effectors caspase-3 and -8. Under our experimental conditions, alpha-tocopherol was significantly more effective than gamma-tocopherol, and oxLDL-mediated apoptosis increased c-Jun, cyclic AMP-responsive element-binding, Ets-like element kinase-dependent 7, and activating transcription factor-2 proteins as well as nuclear activity of the activated protein-1 complex in human coronary SMC. Moreover, our results demonstrate that tocopherols may exert their antiatherogenic effects at least in part via reduction of the MAPK and JunK cascade together with a protective profile of apoptotic genes of the
Bcl-2
family. These data are consistent with the beneficial effects of tocopherols on atherogenesis seen in experimental studies and on CHD in epidemiological surveys.
...
PMID:Modulation by alpha- and gamma-tocopherol and oxidized low-density lipoprotein of apoptotic signaling in human coronary smooth muscle cells. 1075 58
Hyperoxic lung injury is commonly encountered in patients who require treatment with high concentrations of inspired oxygen. To determine whether interleukin (IL)-6 is protective in oxygen toxicity, we compared the effects of 100% O(2) in transgenic mice that overexpress IL-6 in the lung and transgene (-) controls. IL-6 markedly enhanced survival, with 100% of transgene (-) animals dying within 72 to 96 h, 100% of transgene (+) animals living for more than 8 d and more than 90% of transgene (+) animals living longer than 12 d. This protection was associated with markedly diminished alveolar-capillary protein leak, endothelial and epithelial membrane injury, and lung lipid peroxidation. Hyperoxia also caused cell death with DNA fragmentation in the lungs of transgene (-) animals and IL-6 markedly diminished this cytopathic response. The protective effects of IL-6 were not associated with significant alterations in the activities of
copper
/ zinc superoxide dismutase (SOD) or manganese SOD. They were, however, associated with the enhanced accumulation of the cell-death inhibitor
Bcl-2
, but not the cell-death stimulator BAX, and with the heightened accumulation of the cell-death regulator tissue inhibitor of metalloproteinase-1 (TIMP-1). These studies demonstrate that IL-6 markedly diminishes hyperoxic lung injury and that this protection is associated with a marked diminution in hyperoxia-induced cell death and DNA fragmentation. They also demonstrate that this protection is not associated with significant alterations in SOD activity, but is associated with the induction of
Bcl-2
and TIMP-1.
...
PMID:Interleukin-6-induced protection in hyperoxic acute lung injury. 1078 24
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