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)

Previously we showed that cardiac fibroblasts are cellular targets of estrogen and that there are significant differences in proliferative response of male and female cardiac fibroblasts under hypoxia, a condition of myocardial ischemia. Here, we tested the hypothesis that signaling pathways that control cell cycle progression and apoptosis in cardiac fibroblasts may be activated in a gender-specific manner. Cardiac fibroblasts from adult, age-matched male and female rat heart were exposed to hypoxia (2% O2) and normoxia. Western analysis of cell lysate was used to compare the level of basal and hypoxia-induced expression of signal transduction proteins, known to control cell cycle progression and cell death. Hypoxia led to significant activation of MAP (mitogen-activated protein) kinase and Jun kinase pathways, as shown by phosphorylated extracellular signal-regulated kinase (ERK1/2) and Jun kinase isotypes in male cells but this effect was modest in female cells. Male cells expressed higher levels of basal expression for transcription factors c-jun and NF-kB as well as the inhibitor of NF-kB (lk-B). Although hypoxia did not induce changes in the level of c-Jun in either cell type, it moderately increased the level of NF-kB in male cells but led to its decrease in female cells. Basal and hypoxia-induced expression of cyclin D1, c-fos, and PCNA seemed to be comparable in both male and female cells. However, hypoxia-induced activation of cyclin B1, which occurred in both cells, was stronger in female cells. Basal expression of apoptosis-associated transcription factor, p53, was comparable in both cells. However, under hypoxia, there was an increase in the p53 level only in female cells. Although female cells showed higher basal expression for survival-associated protein, Bcl-2, the level of this protein remained unchanged under hypoxia in both cells. Together, these data demonstrate differences in basal and hypoxia-induced expression of proteins with an established role in cell cycle progression and apoptosis in male and female cardiac fibroblasts. These differences may further point to gender-related differences in signal transduction pathways that control the proliferative response of those cells under hypoxia.
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PMID:Gender-related differences in basal and hypoxia-induced activation of signal transduction pathways controlling cell cycle progression and apoptosis, in cardiac fibroblasts. 1237 61

Mood disorders have traditionally been conceptualized as neurochemical disorders, but there is now evidence from a variety of sources demonstrating regional reductions in central nervous system (CNS) volume, as well as reductions in the numbers and/or sizes of glia and neurons in discrete brain areas. Although the precise cellular mechanisms underlying these morphometric changes remain to be fully elucidated, the data suggests that mood disorders are associated with impairments of structural plasticity and cellular resilience. Recent preclinical and clinical studies have shown that signaling pathways involved in regulating cell survival and cell death are long-term targets for the actions of antidepressants and mood stabilizers. Antidepressants, lithium, and valproate indirectly regulate a number of factors involved in cell survival pathways, including CREB, BDNF, Bcl-2, and MAP kinases, and may thus bring about some of their delayed long term beneficial effects via underappreciated neurotrophic effects. The future development of treatments that more directly target molecules involved in critical CNS cell survival and cell death pathways thus hold promise as novel, improved long-term treatments for mood disorders.
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PMID:Impairments of neuroplasticity and cellular resilience in severe mood disorders: implications for the development of novel therapeutics. 1239 85

Recent investigations have provided important insights into how signaling through the antigen receptors determines whether a cell survives or dies. In T cells, Grb2 and MAP kinases play essential roles in differentiating between apoptotic and survival signals. The PTEN phosphatase and Bim, a pro-apoptotic Bcl-2 family member, regulate apoptosis in both T and B cells. In B cells, antigen receptor-mediated death can be rescued by co-stimulation, in which the roles of protein kinase C and BAFF, a TNF family member, have been recently elucidated. In a recently identified mechanism of regulating inflammation, receptors such as c-mer and glycoproteins such as MFG-E8 were found to participate in the clearance of apoptotic cells.
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PMID:Apoptosis during lymphoid development. 1263 72

A series of epidemiological, experimental and preliminary clinical trials strongly suggest that mesalazine or 5-aminosalicyclic acid (5-ASA) may have antineoplastic and potentially prophylactic chemopreventive properties. It is assumed that mesalazine may have similar genetic and molecular targets as nonsteroidal anti-inflammatory drugs (NSAIDs), which is further supported by its close similarity with aspirin, differing only in its structure by the presence of an amino group at position 5 of the benzene ring. The putative chemopreventive actions include the inhibition of inflammatory cascades and/or reactions involved in cell growth and proliferation, such as cyclo-oxygenase (COX-1 and COX-2), which regulate cell proliferation through the formation of prostaglandins; lipoxygenase; nuclear factor kappaB (NFkappaB), responsible for the subsequent expression of pro-inflammatory molecules; MAP kinases and Bcl-2, as well as the activation of apoptotic processes, such as the stimulation of intestinal sphingomyelinase. The peroxisome-proliferator-activated receptor delta (PPARdelta), which also regulates gene transcription, is thought to play a role in both inflammatory and non-inflammatory driven carcinogenesis. This may be another significant target. It is hypothesized that 5-ASAs may prevent the enhancing effect of prostaglandins on PPARdelta binding to DNA by its COX inhibitory properties, decreasing proliferation of colorectal mucosal cells in non-inflammatory bowel disease patients with sporadic polyps of the large bowel.
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PMID:Review article: mechanisms of action of mesalazine in preventing colorectal carcinoma in inflammatory bowel disease. 1295 Apr 15

The chemopreventive properties of the isothiocyanates have been attributed to their ability to inhibit phase I enzymes that activate procarcinogens, induce phase II protective enzymes and trigger apoptosis in transformed cells. In this study we provide evidence for a new mechanism of chemoprevention, wherein sublethal doses of phenethyl isothiocyanate (PEITC) sensitize cells to Fas-mediated apoptosis. The phenomenon was observed in the Fas-resistant T24 bladder carcinoma cell line and in Jurkat T cells overexpressing the anti-apoptotic protein Bcl-2. Caspase-3-like activity was increased up to 20-fold of that observed with either PEITC or anti-Fas antibody alone. While PEITC activated ERK, JNK and p38, inhibitors of these MAP kinases did not block apoptosis. PEITC transiently depleted cellular glutathione, providing a putative mechanism for sensitizing the cells to apoptosis. However, lowering glutathione with buthionine sulfoximine did not mimic the effect of PEITC. Instead, we propose that PEITC promotes apoptosis by directly modifying intracellular thiol proteins. The ability of PEITC to sensitize cells to receptor-mediated apoptosis provides an additional mechanism to explain its chemopreventive properties.
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PMID:The chemopreventive agent phenethyl isothiocyanate sensitizes cells to Fas-mediated apoptosis. 1472 92

Activation of the apoptosis program by an increased production of beta-amyloid peptides (Abeta) has been implicated in the neuronal cell death of Alzheimer's disease (AD). Bcl-2 is a well-demonstrated anti-apoptotic protein, however, the mechanisms of anti-apoptotic action of Bcl-2 in Abeta-induced neuronal cell death are not fully understood. In the present study, we therefore have investigated the possibility that overexpression of Bcl-2 may prevent Abeta-induced cell death through inhibition of pro-apoptotic activation of p38 MAP kinase and the transcription factor NF-kappaB in nerve growth factor (NGF)-induced differentiated PC12 cells. Treatment of Abeta into differentiated PC12 cells transfected with plasmid alone resulted in increase of cell death determined by measurement of cytotoxicity and apoptosis in a dose dependent manner. Consistent with the increase of cell death, treatment of Abeta resulted in increase of p38 MAP kinase and NF-kappaB activation. However, overexpression of Bcl-2 reduced Abeta-induced apoptosis, and suppressed the activation of p38 MAP kinase and NF-kappaB. In addition, a p38 MAP kinase specific inhibitor SB 203580 attenuated Abeta-induced apoptosis. This inhibitory effect was correlated well with the inhibition of p38 MAP kniase and NF-kappaB activation. Moreover, inhibition of NF-kappaB activation by sodium salicylates reduced Abeta-induced apoptosis and activation of p38 MAP kinase, and up regulated Bcl-2 expression. These results suggest that Bcl-2 overexpression protects against Abeta-induced cell death of differentiated PC12, and its protective effect may be related to the reduction of Abeta-induced activation of p38 MAP kinase and NF-kappaB.
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PMID:Protective role of Bcl-2 on beta-amyloid-induced cell death of differentiated PC12 cells: reduction of NF-kappaB and p38 MAP kinase activation. 1509 5

Polycystic ovarian syndrome is seen in 5% of fertile aged women. However, there is no satisfactory PCOS model in experimental animals. To induce polycystic ovary phenotype in immature female rats, Wistar rats 21 days of age were injected daily with testosterone propionate 1 mg/100 g body weight dissolved in propylene glycol or propylene glycol for up to 35 days. Seven days of injection with testosterone (T) resulted in the appearance of large cystic follicles and a dramatic accumulation of multi-layer preantral follicles. At 42 days of age puberty in control animals was evident by the appearance of corpora lutea. In contrast in T treated animals no corpora lutea formation was seen even at the age of 56 days. Progesterone in the control animals was elevated at the age of 42 days in contrast with the T treated animals in which progesterone remained low (20% of control). While during 14 days of T injection most of the follicles did not have progressive apoptosis, at 21-35 days of injection (42-56 days of age) the vast majority of follicles became apoptotic. Progressive degeneration of oocytes was evident in T treated animals reaching 70-85% of total oocytes at 21-35 days of T injection compared to 30-40% in control animals. Western blot analysis of ovarian homogenates revealed gradual decrease in Bcl-2 content, evident at 28 and 35 days of T injection compared to control animals. Interestingly, the fasting glucose/insulin ratio was dramatically reduced in T treated animals following 14 days of testosterone treatment compared to controls. Our data suggest that T injection to immature female rats can induce polycystic ovaries, block ovulation and attenuate progesterone production. Moreover, normal/low glucose and high insulin blood levels in the testosterone treated rats raises the possibility that elevated androgens can lead to insulin resistance in this experimental PCOS model.
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PMID:Induction of polycystic ovary by testosterone in immature female rats: Modulation of apoptosis and attenuation of glucose/insulin ratio. 1525 67

In previous studies we demonstrated that IGF-I induces proliferation of pituitary lactotrophs. In addition to its mitotrophic actions, IGF-I is known to prevent apoptosis induced by diverse stimuli in several cell types. In this study, we investigated the action of IGF-I on pituitary cell survival and the intracellular signaling transduction pathway implicated in this effect. Treatment of cultured male rat pituitary cells with IGF-I (10(-7) M) for 24 h prevented pituitary cell death induced by serum deprivation. The protective effect of IGF-I was blocked by phosphoinositide 3-kinase (PI3-kinase) inhibitor, LY294002, but was unaffected by PD98059, which inhibits MAP/ERK kinase (MEK1). IGF-I activation of PI3-kinase induced the phosphorylation and activation of the serine/threonine kinase Akt. Moreover, IGF-I increased the phosphorylation of the pro-apoptotic factor Bad and the levels of the anti-apoptotic protein Bcl-2 through the PI3-kinase pathway in primary pituitary cells.
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PMID:IGF-I inhibits apoptosis through the activation of the phosphatidylinositol 3-kinase/Akt pathway in pituitary cells. 1529 50

The proto-oncogene, bcl-2, has various functions besides its role in protecting cells from apoptosis. One of the functions is to regulate expression of other genes. Previous studies have demonstrated that Bcl-2 regulates activities of several important transcription factors including NF-kappaB and p53, and also their downstream genes. In our recent studies, we reported that Bcl-2 substantially downregulates expression of the endogenous alphaB-crystallin gene through modulating the transcriptional activity of lens epithelium-derived growth factor (LEDGF). In the present communication, we report that human Bcl-2 can positively regulate expression of the proto-oncogenes c-jun and c-fos. Moreover, it enhances the DNA binding activity and transactivity of the activating protein-1 (AP-1). Furthermore, we present evidence to show that Bcl-2 can also activate both ERK1 and ERK2 MAP kinases. Inhibition of the activities of these kinases or the upstream activating kinases by pharmacological inhibitors or dominant-negative mutants abolishes the Bcl-2-mediated regulation of AP-1, LEDGF and their downstream genes. Together, our results demonstrate that through activation of the ERK kinase signaling pathway, Bcl-2 regulates the transcriptional activities of multiple transcription factors, and hence modulates the expression of their downstream genes. Thus, our results provide a mechanism to explain how Bcl-2 may regulate expression of other genes.
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PMID:Human Bcl-2 activates ERK signaling pathway to regulate activating protein-1, lens epithelium-derived growth factor and downstream genes. 1532 76

The exposure of cells to TGF-beta1 can trigger a variety of cellular responses including the inhibition of cell growth, migration, differentiation and apoptosis. TGF-beta1-regulated apoptosis is cell type and context-dependent, indeed TGF-beta1 provides signals for both cell survival or apoptosis. The molecular mechanisms underlying the role of TGF-beta1 in apoptosis remains unclear. The proteins that primarily mediate the intracellular signaling of TGF-beta1 are the members of the Smad family. Nevertheless, TGF-beta1 signaling can also cooperate with the death receptor apoptotic pathway (Fas, TNF), with the intracellular modulators of apoptosis JNK and p38 MAP kinases, Akt, NF-kappaB, and with the mitochondrial apoptotic pathway mediated by members of the Bcl-2 family. Moreover, the involvement of TGF-beta1 in the production of oxidative stress and in preventing the inflammatory processes required for the clearance of apoptotic bodies is further evidence of its integration into apoptotic pathways. The interaction and balance between different stimuli provides the basis for the pro- or anti-apoptotic output of TGF-beta1 signaling in a given cell.
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PMID:Dual role for TGF-beta1 in apoptosis. 1573 30


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