Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:A9QXG9 (bcl-2)
 7,497 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To investigate whether apoptosis is involved in the fate of oligodendrocytes in chronic multiple sclerosis lesions, the pro-apoptotic molecules fas and tumor necrosis factor receptors and the anti-apoptotic molecule bcl-2 were examined by immunohistochemistry, and DNA fragmentation was assessed by an end labeling technique. Fas and both tumor necrosis factor receptors were preferentially expressed on oligodendrocytes in multiple sclerosis lesions, this phenotype being more evident at the lesion edge. The ligand for fasL, was constitutively present at high levels on microglia. The anti-apoptotic molecule bcl-2 was selectively expressed on oligodendrocytes in silent lesions and on astrocytes in active lesions. These molecules were also detected in control material, albeit at lower levels. In chronic active lesions, a few inflammatory cells displayed fas reactivity, whereas the majority expressed bcl-2. DNA fragmentation was found in a number of infiltrating cells and some microglia, whereas, with one possible exception, oligodendrocytes showed no evidence of apoptosis. Thus, while apoptosis is involved in the elimination of infiltrating cells, it plays little or no role in oligodendrocyte depletion in multiple sclerosis, a process that may be related to a lytic pathway. In addition, microglia constitutively displayed the ligand for fas, and appeared to be the major effector cell population in the central nervous system.
 ...
PMID:Multiple sclerosis: oligodendrocytes display cell death-related molecules in situ but do not undergo apoptosis. 922 88

Common variable immunodeficiency represents the most frequently occurring primary immunodeficiency disorder and is usually detected sporadically in patients with no family history of immunodeficiency. We present the case stories of two monozygote twins, who following a period of decreasing serum immunoglobulins developed primary central nervous system lymphomas. One twin had clinical and paraclinical features mimicking multiple sclerosis. Immunohistochemical investigations on biopsy tissue showed expression of the bcl-2 and p53 gene products, and Epstein-Barr virus (EBV) encoded small RNA's (EBER) indicating latent infection were detected in lymphoma cells using in situ hybridisation techniques. The pathogenetic role of EBV in oncogenesis is discussed.
 ...
PMID:EBV-positive primary central nervous system lymphomas in monozygote twins with common variable immunodeficiency and suspected multiple sclerosis. 949 19

Multiple sclerosis (MS) is a chromatic inflammatory disease of the central nervous system. T lymphocytes play a major role in the pathogenesis of the disease. The exact mechanisms by which the inflammation is regulated in MS have not yet been defined. Studies in animal models of MS suggest that apoptosis of T cells is the main factor terminating inflammation. The process of apoptosis itself is regulated by a range of pro- and anti-apoptotic proteins. The bcl-2 gene family is an important member of these proteins. The present study investigated the expression of the anti-apoptotic protein bcl-2 in 11 chronic MS cases including five relapsing-remitting and six chronic progressive MS patients. A total of 35 lesions containing all stages of demyelinating activity were studied. The number of CD 3-positive T cells and the absolute and relative numbers of T cells expressing bcl-2 were determined by double immunocytochemistry. Bcl-2 is expressed by T lymphocytes in MS plaques. Patients with chronic progressive MS have a higher proportion of bcl-2 expressing T cells than patients with relapsing remitting disease. Highest numbers of bcl-2-positive T lymphocytes were found in remyelinating and demyelinated lesions, whereas active demyelinating lesions revealed lower numbers. These data indicate that cell-death-related proteins such as the anti-apoptotic protein bcl-2 are expressed in MS lesions and that they might have important effects on the regulation of elimination or persistence of inflammatory cells in the central nervous system.
 ...
PMID:Bcl-2 expressing T lymphocytes in multiple sclerosis lesions. 971 85

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system leading to selective destruction of myelin sheaths and/or oligodendrocytes. The immunological mechanisms responsible for myelin destruction and the primary target of the immune response have not yet been identified. Prior studies have reported a variable degree of oligodendrocyte preservation in actively demyelinating lesions. We have previously demonstrated that oligodendrocyte survival is heterogenous and varies between individual MS patients. Bcl-2 belongs to the group of apoptosis-associated proteins that protects cells from cell death. The purpose of the present study was to determine whether bcl-2 expression is associated with oligodendrocyte preservation observed in some early MS lesions. Double immunocytochemistry was performed with antibodies against bcl-2 and myelin oligodendrocyte glycoprotein (MOG) to identify bcl-2-expressing oligodendrocytes within MS lesions from 43 patients. The number of bcl-2-positive oligodendrocytes was determined depending on the lesion demyelinating activity and the disease course of the patients. The number of bcl-2-expressing oligodendrocytes increased within demyelinating lesions compared to the periplaque white matter, with highest numbers in remyelinating lesions. There was a significant association between the presence of bcl-2-positive oligodendrocytes and the presence of remyelination. The highest proportion of bcl-2-positive oligodendrocytes was observed in a subgroup of patients with relapsing-remitting disease course. The expression of apoptosis-associated proteins may contribute to oligodendrocyte preservation or loss in MS lesions.
 ...
PMID:Bcl-2-expressing oligodendrocytes in multiple sclerosis lesions. 1049 20

The apoptosis-inducing effects of i.v. methylprednisolone were investigated as a possible method of controlling inflammation in the CNS in adoptive transfer-experimental autoimmune encephalomyelitis (AT-EAE) in Lewis rats. Two pulses of methylprednisolone were given at the peak of mild and of severe disease. T-cell apoptosis was assessed on spinal cord cross-sections by morphology and TUNEL staining. Concentrations of methylprednisolone were measured in serum, CSF and spinal cord tissue by high-pressure liquid chromatography (HPLC). In severe EAE, 10 mg/kg methylprednisolone increased T-cell apoptosis significantly and T-cell infiltration was marginally decreased. A maximal dose of 50 mg/kg methylprednisolone was superior in both respects and, in contrast to 10 mg/kg methylprednisolone, was also effective in mild EAE. A dose of 1 mg/kg methylprednisolone did not produce notable changes compared with controls treated with phosphate-buffered saline. Serum, CSF and spinal cord concentrations of methylprednisolone measured by HPLC 2 h after a single i.v. injection of 10 or 50 mg/kg methylprednisolone revealed significantly higher methylprednisolone concentrations in severe EAE compared with mild disease. With 50 mg/kg methylprednisolone, we obtained serum and CSF concentrations in the region of 10(-5) M methylprednisolone. We also studied the expression of bcl-2, a typical anti-apoptotic regulatory protein, in T cells, and found no change after methylprednisolone treatment compared with controls. Methylprednisolone did not induce apoptosis of oligodendrocytes, which would have been an unwanted side effect in CNS cells. This study provides evidence that methylprednisolone dose-dependently augments T-cell apoptosisin situ in AT-EAE. Our results may have implications for the use of glucocorticosteroids at very high doses in the treatment of inflammatory disorders of the CNS, such as multiple sclerosis, or of other target organs.
 ...
PMID:T-cell apoptosis in situ in experimental autoimmune encephalomyelitis following methylprednisolone pulse therapy. 1086 55

Polyspecific immunoglobulins (IVIg) have been shown to reduce disease activity in multiple sclerosis (MS). To investigate the mechanisms of action of IVIg, we studied the impact of IVIg on growth and death (apoptosis) of human (auto)antigen-specific T cells. We observed a substantial suppression of proliferation of specifically activated T cells, in absence of caspase activation or DNA fragmentation. Further, neither susceptibility of T cells to undergo CD95-mediated apoptosis nor expression of apoptosis-blocking bcl-2 was modulated by IVIg. We conclude that IVIg may inhibit the reactivity of antigen-specific T cells in MS through suppression of proliferation rather than modulation of apoptosis.
 ...
PMID:Polyspecific immunoglobulins (IVIg) suppress proliferation of human (auto)antigen-specific T cells without inducing apoptosis. 1124 27

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) characterized by destruction of myelin. Recent studies have indicated that axonal damage is involved in the pathogenesis of the progressive disability of this disease. To study the role of axonal damage in the pathogenesis of MS-like disease induced by myelin oligodendrocyte glycoprotein (MOG), we compared experimental autoimmune encephalomyelitis (EAE) in wild-type (WT) and transgenic mice expressing the human bcl-2 gene exclusively in neurons under the control of the neuron-specific enolase (NSE) promoter. Our study shows that, following EAE induction with pMOG 35-55, the WT mice developed significant clinical manifestations with complete hind-limb paralysis. In contrast, most of the NSE-bcl-2 mice (16/27) were completely resistant, whereas the others showed only mild clinical signs. Histological examination of CNS tissue sections showed multifocal areas of perivascular lymphohistiocytic inflammation with loss of myelin and axons in the WT mice, whereas only focal inflammation and minimal axonal damage were demonstrated in NSE-bcl-2 mice. No difference could be detected in the immune potency as indicated by delayed-type hypersensitivity (DTH) and T-cell proliferative responses to MOG. We also demonstrated that purified synaptosomes from the NSE-bcl-2 mice produce significantly lower level of reactive oxygen species (ROS) following exposure to H2O2 and nitric oxide (NO) than WT mice. In conclusion, we demonstrated that the expression of the antiapoptotic gene, bcl-2, reduces axonal damage and attenuates the severity of MOG-induced EAE. Our results emphasize the importance of developing neuroprotective therapies, in addition to immune-specific approaches, for treatment of MS.
 ...
PMID:Mice overexpressing Bcl-2 in their neurons are resistant to myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE). 1130 81

Clinical course, outcome, radiological features, severity, and histopathology are heterogenous in multiple sclerosis (MS). Since MS is considered to be a polygenic disease, the genetic background may at least partly be responsible for this variability. Some MS cases are histopathologically characterized by a dramatic oligodendrocyte loss that is in part caused by apoptosis. A dysregulated apoptotic elimination of self-reactive T cells may also contribute to disease susceptibility. To analyze genetic differences in the apoptosis regulating factors bcl-2, bax, bcl-x and p53 we investigated polymorphisms of these genes in 105 patients with a relapsing remitting disease course and 99 controls by PCR-SSCP and direct sequencing. We identified so far unpublished sequence alterations in the promotor region of the bxl-x gene, in exon 7 of the p53 gene, and in exon 1 of the bax gene. No differences were observed between MS patients and controls. Additional known polymorphisms were found in intron 3 of the bax gene and in exon 6 of the p53 gene. No significant differences in the frequency of gene sequence variations were found between MS patients and controls. The apoptosis genes studied here therefore appear less likely to be important effector genes in MS.
 ...
PMID:Investigation of bax, bcl-2, bcl-x and p53 gene polymorphisms in multiple sclerosis. 1216 Oct 31

The elimination of T cells by apoptosis is considered to be one of the regulatory factors in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. To address further the role of apoptotic T cell death in EAE, we investigated myelin oligodendrocyte glycoprotein (MOG)-induced EAE in transgenic mice overexpressing the anti-apoptotic gene, bcl-2, in T cells. During the acute phase of EAE, no significant difference was observed in the clinical course, pathology and T cell response to MOG between bcl-2 transgenic mice and wild-type littermates. While the recovery from the first attack of EAE was not impaired in the bcl-2 transgenic mice, a more severe disease was observed during the chronic phase of the disease even though T and B cell responses to MOG were comparable to those of wild-type littermates. A flow cytometric analysis by Annexin V showed a significant decrease of apoptotic T cells in the central nervous system (CNS) of the bcl-2 transgenic mice with EAE compared with controls during the chronic as well as the acute phase of disease. These results suggest that while T cell apoptosis in the CNS may play a regulatory role in EAE, the spontaneous recovery from acute EAE cannot solely be explained by T cell apoptosis.
 ...
PMID:The suppression of T cell apoptosis influences the severity of disease during the chronic phase but not the recovery from the acute phase of experimental autoimmune encephalomyelitis in mice. 1245 43

Peroxisomal proliferator-activated receptors (PPARs) belong to a nuclear receptor superfamily of ligand-activated transcription factors. The PPAR-gamma isoform is expressed in human T lymphocytes, and oral administration of PPAR-gamma agonists ameliorates the clinical course and histopathological features in experimental autoimmune encephalomyelitis, an animal model for multiple sclerosis, suggesting a potential role for PPAR-gamma agonists in the treatment of autoimmune diseases. To assess a potential therapeutic role of PPAR-gamma agonists in multiple sclerosis, we compared the immunomodulatory effects of the thiazolidinedione (TZD) drugs pioglitazone (PIO) and ciglitazone and the non-TZD PPAR-gamma agonist GW347845 on human T leukemia cells (Jurkat cells) and phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMCs) derived from 21 multiple sclerosis patients and 12 healthy donors. PIO, ciglitazone, and GW347845 suppressed PHA-induced T cell proliferation by 40-50% and secretion of interferon-gamma and tumor necrosis factor alpha, by 30-50%. Inhibition of proliferation was increased to approximately 80% and that of proinflammatory cytokine secretion, to 80-90% when PBMCs were first preincubated with PPAR-gamma agonists and re-exposed at the time of PHA stimulation, indicating a sensitizing effect of PPAR-gamma agonists. Inhibition of proliferation was also observed in the tetanus toxoid-specific T cell line KHS.TT2, albeit to a lesser extent. The antiproliferative effects of PIO and GW347845 were accompanied by a decrease of cell viability. Electron microscopy and Western blot analysis revealed DNA condensation and down-regulation of bcl-2, suggesting the induction of apoptosis in activated T lymphocytes. In summary, the data support the potential use of PPAR-gamma agonists as immunomodulatory, therapeutic agents for autoimmune diseases.
 ...
PMID:Anti-inflammatory and antiproliferative actions of PPAR-gamma agonists on T lymphocytes derived from MS patients. 1465 13


1 2 Next >>