Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The scrapie prion protein, PrP(Sc), as well as its peptide fragment, PrP106-126, are toxic on neuronal cells, resulting in cell death by an apoptotic, rather than necrotic mechanism. The apoptotic process of neuronal cells induced by prion protein supports diagnosis and offers potential targets for therapeutic intervention of the prion diseases. Among the cerebrospinal fluid (CSF) proteins, which may serve as markers of neuronal cell death associated with prion diseases, the 14-3-3 protein(s) turned out to be the most promising one. A new sensitive assay allows the detection of even small changes in the normally low levels of these proteins. In vitro, the toxic effects displayed by PrP(Sc) and its peptide fragment can be blocked by antagonists of N-methyl-D-aspartate (NMDA) receptor channels, like Memantine. Also Flupirtine, a non-opiod analgesic drug, which is already in clinical use, was found to display in vitro a strong cytoprotective effect on neurons treated with PrP(Sc) or PrP106-126. This drug acts like a NMDA receptor antagonists, but does not bind to the receptor. Clinical trials on prion diseases with Flupirtine are in progress. Flupirtine was found to enhance the intracellular levels of the antiapoptotic protein Bcl-2 and the antioxidative agent glutathione (GSH). Due to its favourable pharmacokinetic profile, Flupirtine is considered to be a promising drug to prevent neuronal death in Creutzfeldt-Jakob disease (CJD) and other neurodegenerative disorders occurring with age, e.g. Alzheimer's disease.
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PMID:Novel approaches in diagnosis and therapy of Creutzfeldt-Jakob disease. 1099 19

Examination of the expression of proteins linked with signaling pathways commanding cell death and cell survival has been carried out to increase understanding on the mechanisms leading to cell death in the cerebellum in Creutzfeldt-Jakob disease (CJD). Expression of Fas, Fas ligand (Fas-L), ERK, MEK, Bcl-2, Bax, N-myc, c-myc, pro-caspase-2 and active caspase-3 was examined by immunohistochemistry in the cerebellum of six patients with sporadic CJD, three patients with olivopontocerebellar atrophy (OPCA) and six age-matched controls. No modifications in the expression of these proteins were observed in granule cells in CJD and OPCA when compared with controls, except in a few cells in the molecular and granular layers in CJD that displayed dense homogeneous active caspase-3 immunostaining. This suggests selective activation of caspase-3 in association with increased cellular vulnerability in CJD. No modifications in pro-caspase-2 and c-myc immunoreactivity were observed in Purkinje cells in diseased brains when compared with controls. However, increased diffuse Fas, Fas-L, MEK, ERK and Bax expression, and enhanced granular active caspase-3 immunoreactivity was found in the cytoplasm of Purkinje cells in CJD. Increase in Bcl-2 and N-myc occurred in Purkinje cells in CJD and OPCA. These results indicate that enhanced Fas, Fas-L, MERK, ERK, Bax and granular active caspase-3 expression is not lethal to Purkinje cells in CJD, whereas increased Bcl-2 and N-myc does not preclude per se cell death or death survival in CJD and OPCA. These findings point to the likelihood that expression of these cell death proteins in neurodegeneration has functional roles differing from those related with apoptosis.
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PMID:Cell death signaling in the cerebellum in Creutzfeldt-Jakob disease. 1158 44

Apoptotic neuronal cell death is a hallmark of prion diseases. The apoptotic process in neuronal cells is thought to be caused by the scrapie prion protein, PrPSc, and can be experimentally induced by its peptide fragment, PrP106-126. This process is a target for potential drugs to combat prion disease or to ameliorate its symptoms. Flupirtine (Katadolon), a pyridine derivative that is in clinical use as a nonopioid analgesic, has a potent cytoprotective effect, at concentrations above 1 microg/mL, on neuronal cells treated with PrP(Sc) or PrP106-126. This drug acts as an N-methyl-D-aspartate (NMDA) antagonist, but does not bind to NMDA receptors. Flupirtine normalizes the level of intracellular glutathione and increases the expression of the antiapoptotic Bcl-2 protein in neuronal cells exposed to prion protein. In view of its favorable pharmacokinetic profile, flupirtine is the first drug to be considered as a potential treatment for Creutzfeldt-Jakob disease, the human form of prion diseases. Clinical trials are underway.
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PMID:Neuroprotective effect of flupirtine in prion disease. 1253 84

Prion diseases are characterized by accumulation of misfolded prion protein (PrP(Sc)), and neuronal death by apoptosis. Here we show that nanomolar concentrations of purified PrP(Sc) from mouse scrapie brain induce apoptosis of N2A neuroblastoma cells. PrP(Sc) toxicity was associated with an increase of intracellular calcium released from endoplasmic reticulum (ER) and up-regulation of several ER chaperones. Caspase-12 activation was detected in cells treated with PrP(Sc), and cellular death was inhibited by overexpression of a catalytic mutant of caspase-12 or an ER-targeted Bcl-2 chimeric protein. Scrapie-infected N2A cells were more susceptible to ER-stress and to PrP(Sc) toxicity than non-infected cells. In scrapie-infected mice a correlation between caspase-12 activation and neuronal loss was observed in histological and biochemical analyses of different brain areas. The extent of prion replication was closely correlated with the up-regulation of ER-stress chaperone proteins. Similar results were observed in humans affected with sporadic and variant Creutzfeldt-Jakob disease, implicating for the first time the caspase-12 dependent pathway in a neurodegenerative disease in vivo, and thus offering novel potential targets for the treatment of prion disorders.
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PMID:Caspase-12 and endoplasmic reticulum stress mediate neurotoxicity of pathological prion protein. 1453 16

The 14-3-3 proteins are a family of highly homologous and ubiquitously expressed isoforms that are involved in a wide variety of physiological processes. 14-3-3 have showed actively molecular interaction with PrP and positive 14-3-3 is frequently observed in the cerebrospinal fluid (CSF) samples of the patients with sporadic Creutzfeldt-Jakob disease (CJD). However, the alterations of 14-3-3 in the brain tissues of patients with prion diseases remain little addressed. To address the possible change of brain 14-3-3 during prion infection, we firstly tested the levels of 14-3-3 in the brain tissues of scrapie agent 263 K infected hamsters. Obviously decreased 14-3-3 were observed in the samples of the infected animals, showing time-dependent reduction in the incubation period, while the amounts of S-nitrosylated 14-3-3 were increased in the brains collected at the late stage. A low level of 14-3-3 was also observed in the scrapie infectious cell line SMB-S15, accompanied with up-regulated Bax and down-regulated Bcl-2. Moreover, we found that treatment of PrP106-126 on the cultured cells decreased the cellular 14-3-3 and caused translocations of cellular Bax to the membrane fractions. Knockdown of cellular 14-3-3 sensitized the cultured cells to the challenge of PrP106-126. These data illustrate that significant down-regulation of brain 14-3-3 levels during prion infection may not only be a scenario of the terminal consequence of interacting with abnormal PrP(Sc) but may also participate in the pathogenesis of neuronal damage.
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PMID:Infection of prions and treatment of PrP106-126 alter the endogenous status of protein 14-3-3 and trigger the mitochondrial apoptosis possibly via activating Bax pathway. 2413 6