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)

The aim of this study was to determine whether increased apoptosis in peripheral blood lymphocytes plays a role in T cell deficiency associated with DiGeorge anomaly. T cell subsets from a patient with DiGeorge anomaly were examined for the expression of Fas, FasL, Bcl-2 and Bcl-XL at the protein level with monoclonal antibodies, using dual-colour flow cytometry, and at the mRNA level in mononuclear cells by quantitative reverse transcriptase-polymerase chain reaction. In vitro spontaneous apoptosis was examined by propidium iodide staining and DNA fragmentation, using flow cytometry and gel electrophoresis, respectively. Fas and FasL expression, both at the level of protein and of mRNA, was increased, whereas Bcl-2 expression was decreased both at the level of protein and of mRNA. However, no difference in Bcl-XL expression was observed between the patient and an age-matched control. A significant proportion of both CD4+ and CD8+ T cells from the patients underwent spontaneous apoptosis, whereas almost no spontaneous apoptosis was observed in the age-matched control. These data suggest that spontaneous apoptosis in T lymphocytes, at least in part, may be responsible for T cell deficiency in DiGeorge anomaly.
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PMID:Increased spontaneous apoptosis in T lymphocytes in DiGeorge anomaly. 969 85

Emerging data indicate that tumor necrosis factor (TNF) exerts a neuroprotective effect in response to brain injury. Here we examined the mechanism of TNF in preventing neuronal death in primary hippocampal neurons. TNF protected neurons against hypoxia- or nitric oxide-induced injury, with an increase in the anti-apoptotic proteins Bcl-2 and Bcl-x as determined by Western blot and reverse transcriptase-polymerase chain reaction analysis. Treatment of neurons with an antisense oligonucleotide to bcl-2 mRNA or that to bcl-x mRNA blocked the up-regulation of Bcl-2 or Bcl-x expression, respectively, and partially inhibited the neuroprotective effect induced by TNF. Moreover, adenovirus-mediated overexpression of Bcl-2 significantly inhibited hypoxia- or nitric oxide-induced neuronal death. To examine the possible involvement of a transcription factor, NFkappaB, in the regulation of Bcl-2 and Bcl-x expression in TNF-treated neurons, an adenoviral vector capable of expressing a mutated form of IkappaB was used to infect neurons prior to TNF treatment. Expression of the mutant NFkappaB completely inhibited NFkappaB DNA binding activity and inhibited both TNF-induced up-regulation of Bcl-2 and Bcl-x expression and neuroprotective effect. These findings indicate that induction of Bcl-2 and Bcl-x expression through NFkappaB activation is involved in the neuroprotective action of TNF against hypoxia- or nitric oxide-induced injury.
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PMID:Tumor necrosis factor induces Bcl-2 and Bcl-x expression through NFkappaB activation in primary hippocampal neurons. 1008 86

The Bcl-2 family has been shown to be vital regulators of programmed cell death in numerous systems. To investigate the role of such proteins in the regulation of apoptosis of eosinophils, the expression of Bcl-2 and homologues Bcl-xL (death antagonists), Bax, and Bcl-xS (death agonists) were examined by immunoblot, flow cytometry, and reverse transcriptase-polymerase chain reaction analysis. Potential modulation of apoptosis-associated molecules during spontaneous apoptosis and in the presence of interleukin (IL)-5 was also investigated. Peripheral blood eosinophils were found to express constitutively Bax and Bcl-x, but Bcl-2 was absent. Analysis of mRNA revealed that the bcl-xL isoform predominated, although bcl-xS was also detectable. Spontaneous apoptosis due to culturing in the absence of cytokines for 24 h did not result in modulation of any of the Bcl-2 homologues examined. Culturing eosinophils in the presence of 100 pg/ml IL-5 for 24 h significantly reduced apoptosis (P < 0.01) to 10.7 +/- 2.6% compared with 46.8 +/- 7.4% in the absence of IL-5, and induced Bcl-2 mRNA and protein expression, with no detectable change in Bax, Bcl-x, or beta-actin as a control. This investigation indicates a specific profile of apoptotic molecules in eosinophils distinct from that of neutrophils, and indicates that survival-enhancing IL-5 modulates the expression of Bcl-2 in vitro.
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PMID:Expression of Bcl-2 and its homologues in human eosinophils. Modulation by interleukin-5. 1010 Oct 4

Differences in host susceptibility to viral myocarditis caused by a given strain of coxsackievirus B3 (CVB3) are known to be largely related to host genetic factors. Little is known, however, about the key genes that encode determinants (mediators) of myocarditis development or the nature of injury. To identify these genes and further understand the molecular mechanisms of the disease process, we have used a murine model and the differential display technique to fingerprint mRNAs from CVB3-infected mouse hearts. Total RNA was extracted from hearts of 4- and 10-week-old A/J(H-2(a)) mice at day 4 after CVB3 infection, and mRNAs were detected by reverse transcriptase-polymerase chain reaction and subsequently analyzed on polyacrylamide DNA sequencing gels. The differentially displayed bands were confirmed by Northern hybridization using the bands as cDNA probes. Twenty-eight upregulated or downregulated bands were selected from the sequencing gels; among these, 2 upregulated and 3 downregulated cDNA fragments were confirmed by Northern hybridization. DNA sequence analysis and GenBank searching have determined that 4 of the 5 candidate genes are homologous to genes encoding Mus musculus inducible GTPase, mouse mitochondrial hydrophobic peptide (a subunit of NADH dehydrogenase), mouse beta-globin, and Homo sapiens cAMP-regulated response element binding protein (CREB) binding protein (CBP), respectively. The remaining candidate gene matches an unpublished cDNA clone, M musculus Nip21 mRNA (GenBank accession number, AF035207), which is homologous to human Nip2, a Bcl-2 binding protein. Our data suggest preliminarily that both structural and nonstructural genes are involved in myocarditis development. For the structural gene, beta-globin, we further confirmed its downregulation at the protein level by measuring the mean cell volume of red blood cells and found it was marginally reduced in the CVB3-infected group (P<0.06), with no change in hemoglobin concentration. Cardiac myoglobin concentration was also measured and found to be decreased (P<0.005), with a parallel decrease in total soluble protein in the CVB3-infected mouse myocardium (P<0.01). We also noted that the ratio of myoglobin to total protein was not significantly changed; this may be due to the downregulation of additional genes in the host heart, a number being observed on the differential display gels. The significant downregulation of beta-globin major gene expression in the heart may be relevant to impaired cardiac function in both the early and late postinfection period. The other identified nonstructural genes are known to be involved in regulation of gene expression, signal transduction pathways, and apoptotic cell death. The altered expression of structural and nonstructural genes may play important roles in the mediation of myocarditis development and perhaps other pathological processes in the heart.
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PMID:Viral myocarditis: identification of five differentially expressed genes in coxsackievirus B3-infected mouse heart. 1018 58

Recent in vitro studies have shown that the periventricular subependymal zone (SEZ) of the rodent brain is capable of de novo generation of neurons and glia. There is less information available on neurogenesis in the adult human brain, and no study has shown the clonal generation of neurons and glia from in vitro-generated "neurospheres." Here we describe the isolation of proliferative stem/progenitor cells within neurospheres from two different regions, the SEZ and the hippocampus, from surgical biopsy specimens of adult (24-57 years) human brain. Using light and electron microscopy; immunocytochemistry for a variety of neuronal, glial, and developmental (including extracellular matrix; ECM) markers; and the reverse transcriptase polymerase chain reaction to demonstrate different gene transcripts found in neurospheres, it is shown that the adult human brain harbors a complex population of stem/progenitor cells that can generate neuronal and glial progeny under particular in vitro growth conditions. These methods also show that these neurospheres contain both neurons and glia and demonstrate regional similarities at the mRNA level, indicating common stem/progenitor cell types within two different neurogenic regions of the adult human brain. In addition to the synthesis of developmentally regulated molecules such as the ECM protein tenascin-C, a variety of other genes (e.g., Pax 6) and proteins (e.g. , Bcl-2) involved in cell survival and differentiation are expressed by adult human brain neurospheres.
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PMID:Multipotent stem/progenitor cells with similar properties arise from two neurogenic regions of adult human brain. 1032 40

Telomerase, a specialized RNA-directed DNA polymerase that extends telomeres of eukaryotic chromosomes, is repressed in normal human somatic cells but is activated during development and upon neoplasia. Whereas activation is involved in immortalization of neoplastic cells, repression of telomerase permits consecutive shortening of telomeres in a chromosome replication-dependent fashion. This cell cycle-dependent, unidirectional catabolism of telomeres constitutes a mechanism for cells to record the extent of DNA loss and cell division number; when telomeres become critically short, the cells terminate chromosome replication and enter cellular senescence. Although neither the telomere signaling mechanisms nor the mechanisms whereby telomerase is repressed in normal cells and activated in neoplastic cells have been established, inhibition of telomerase has been shown to compromise the growth of cancer cells in culture; conversely, forced expression of the enzyme in senescent human cells extends their life span to one typical of young cells. Thus, to switch telomerase on and off has potentially important implications in anti-aging and anti-cancer therapy. There is abundant evidence that the regulation of telomerase is multifactorial in mammalian cells, involving telomerase gene expression, post-translational protein-protein interactions, and protein phosphorylation. Several proto-oncogenes and tumor suppressor genes have been implicated in the regulation of telomerase activity, both directly and indirectly; these include c-Myc, Bcl-2, p21(WAF1), Rb, p53, PKC, Akt/PKB, and protein phosphatase 2A. These findings are evidence for the complexity of telomerase control mechanisms and constitute a point of departure for piecing together an integrated picture of telomerase structure, function, and regulation in aging and tumor development-Liu, J.-P. Studies of the molecular mechanisms in the regulation of telomerase activity.
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PMID:Studies of the molecular mechanisms in the regulation of telomerase activity. 1059 57

The two anti-apoptotic proteins Bcl-2 and Bcl-x(L), and the two pro-apoptotic proteins Bax and Bcl-x(S) were measured by Western blotting in 51 neoplastic and 8 normal endometrial samples. The corresponding mRNA levels were analyzed by semiquantitative reverse transcriptase-polymerase chain reaction in a subgroup of 19 endometrial carcinomas. Neoplastic tissues had higher amounts of Bcl-2 protein than normal tissues (p < 0.051). Bcl-x(L) followed the same trend since its levels were higher in tumor than in normal samples (p < 0.048). Interestingly, Bcl-2 and Bcl-x(L) protein content showed a trend towards an inverse correlation (r = 0.27, p < 0.052). mRNA and protein levels directly correlated only with Bcl-2 (r = 0.63, p < 0.0032). Despite the fact that the amounts of Bcl-2, Bax and Bcl-x(L) proteins in the neoplastic population were not significantly differently distributed according to the clinicopathological features of the patients, the differences observed between normal and neoplastic samples suggest that these proteins may play a role in endometrial carcinoma: long-term follow-up studies will be required to confirm this hypothesis.
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PMID:Bcl-2, Bax, Bcl-x(L) and Bcl-x(S) expression in neoplastic and normal endometrium. 1070 44

Neutrophils possess a very short lifespan, dying by apoptosis. HL-60 cells undergo apoptosis after neutrophil differentiation with dimethyl sulfoxide (DMSO). We have found that the onset of apoptosis in neutrophil-differentiating HL-60 cells correlates with the achievement of an apoptosis-related gene expression pattern similar to that of peripheral blood mature neutrophils. Using reverse transcriptase-polymerase chain reaction, cloning, and sequencing techniques, we have found that HL-60 cells express bak, bik, bax, bad, bcl-2, bcl-xL, bcl-w, bfl-1, fas, and caspases 1-4 and 7-10. After DMSO treatment, bak, bcl-w, bfl-1, fas, and caspases 1 and 9 were up-regulated, whereas bik, bcl-2, and caspases 2, 3, and 10 were down-regulated at different degrees, achieving mRNA expression levels that correlated with those detected in peripheral blood neutrophils. Caspase-2 mRNA and protein expression was drastically reduced after HL-60 cell differentiation, being absent in both HL-60-differentiated neutrophils and mature neutrophils, whereas caspase-3 and -10 mRNA and protein expression were diminished upon HL-60 cell differentiation until achieving the respective levels found in mature neutrophils. Bak and bfl-1 mRNA levels were largely increased during DMSO-induced differentiation of HL-60 cells, and these genes were the bcl-2 family members that were expressed most abundantly in mature neutrophils. Bcl-2 overexpression or caspase inhibition prevented differentiation-induced apoptosis in HL-60 cells, but not their differentiation capability. Neutrophil spontaneous apoptosis was also blocked by the caspase inhibitor z-Asp-2,6-dichlorobenzoyloxymethylketone. Peripheral blood neutrophils expressed bak, bad, bcl-w, bfl-1, fas, and caspases 1, 3, 4, and 7-10, but hardly expressed bcl-2, bcl-xL, bik, bax, and caspase-2. These results suggest that the above gene expression changes in neutrophil-differentiating HL-60 cells may play a role in the acquisition of the neutrophil apoptotic features.
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PMID:Expression of genes involved in initiation, regulation, and execution of apoptosis in human neutrophils and during neutrophil differentiation of HL-60 cells. 1081 Oct 13

The present study investigates the molecular apoptotic pathway in germ cells following acute ischemia of the rat testis. Rats were subjected to ischemia-inducing torsion and testes were harvested after reperfusion. Apoptotic cells were identified with an antibody to single-stranded DNA. Seminiferous tubule RNA was examined by RNase protection assay or by reverse transcriptase-polymerase chain reaction (RT-PCR) for the presence and regulation of apoptotic molecules. Proteins from seminiferous tubules were used for Western blot analysis of cytochrome c. Germ cell apoptosis was maximal at 24 h after repair of torsion. Germ cells in stages II-III of the seminiferous epithelium cycle were the predominant early responders. The RNase protection assays revealed that Bcl-X(L) was the prominent mRNA species. Caspases 1, 2, 3, and Bax mRNA were consistently upregulated; however, the time of upregulation after torsion was variable. The Bcl-X(L) and Bcl-X(S) mRNAs were less consistently upregulated and there was no evidence for upregulation of Fas or Bcl-2. Fas ligand (FasL) was not detected by RNase protection assay, but RT-PCR revealed a significant increase in FasL expression 4 h after the repair of torsion. Western blot analysis for cytochrome c release demonstrated a significant increase 4 h after the repair of torsion. Results suggest that germ cell apoptosis following ischemia/reperfusion of the rat testis is initiated through the mitochondria-associated molecule Bax as well as Fas-FasL interactions.
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PMID:Molecular pathway of germ cell apoptosis following ischemia/reperfusion of the rat testis. 1105 53

Treatment of haematopoietic BA/F3 cells with the thymidylate synthase inhibitor 5-fluoro-2'-deoxyuridine (FUdR) activated apoptosis through a mechanism that required continuous protein synthesis and was inhibited by Bcl-2 over-expression. Analysis of p53 levels in cells treated with FUdR indicated a marked accumulation of this protein. Accumulation of p53 was also observed in cells over-expressing Bcl-2. In BA/F3 cells transfected with a cDNA coding for the human papilloma virus protein E6, p53 accumulation after FUdR treatment was inhibited markedly. However, apoptosis was induced in both control and E6 cells to a similar extent. The role of the CD95/CD95 ligand (CD95L) system in FUdR-induced apoptosis was also assessed. As determined by reverse transcriptase PCR, BA/F3 expressed a low constitutive level of CD95L mRNA, which decreased following FUdR treatment. Moreover, blocking CD95-CD95L interactions with antagonistic CD95 monoclonal antibody did not prevent drug-induced apoptosis. Furthermore, analysis of caspase involvement showed important differences in apoptosis induced by CD95-triggering or FUdR treatment. In summary, these results suggest that apoptosis induced by thymineless stress in haematopoietic BA/F3 cells occurs by a mechanism that does not require accumulation of p53 and which is independent of CD95-CD95L interactions.
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PMID:Apoptosis of haematopoietic cells upon thymidylate synthase inhibition is independent of p53 accumulation and CD95-CD95 ligand interaction. 1111 3


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