Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.64 (MPP)
 1,876 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Objective To investigate the effects of 14-3-3 protein overexpression on the 1-methyl-4-phenylpyridinium (MPP(+)) induced pheochromocytoma (PC12) cell death and the potential mechanisms. Methods pcDNA3.1(+)-14-3-3 plasmids, which could be expressed in mammalian cell, were constructed and transfected into PC12 cells with Lipofectamine 2000. The expression of 14-3-3 protein, Bcl-2 protein, and BAD protein were determined by western blot. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, microplate reader, and flow cytometric analysis were used to measure cell viability, the caspase activity, and apoptotic ratio respectively. Results (1) The expression of 14-3-3 protein increased significantly three weeks after pcDNA3.1 (+)-14-3-3 plasmids transfected into PC12 cells. (2) MPP(+) caused a decrease of cell viability in a dose-dependent manner. At 100 mu mol/L MPP(+), cell viability reduced approximately 50%. (3) The caspase activity increased along with the MPP(+) concentrations rising and reached its maximum value (0.34 mu mol/mg protein) at 100 mu mol/L MPP(+). However caspase activity decreased significantly when the MPP(+) concentration exceeded 100 mu mol/L. (4) Overexpression of 14-3-3 protein decreased the apoptosis ratio of PC12 cells treated with 100 mu mol/L MPP(+) from 26.5% to 8.6%. (5) Bcl-2 protein tended to decrease but BAD protein tended to increase after treatment of PC12 cells with 100 mu mol/L MPP(+). Overexpression of 14-3-3 protein significantly increased the cellular level of Bcl-2 protein and decreased that of BAD protein. Conclusion Overexpression of 14-3-3 protein may reduce MPP(+)-induced apoptotic cell death in PC12 cells by up-regulating the Bcl-2 expression and down-regulating the BAD expression. These results may provide a promising target for treatment of Parkinson' s disease.
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PMID:Overexpression of 14-3-3 protein protects pheochromocytoma cells against 1-methyl-4-phenylpyridinium toxicity. 1769 Jul 28

14-3-3 proteins have been confirmed to be involved in Parkinson's disease. It has been reported that an increase of 14-3-3 (theta, epsilon, and gamma) expression has neuroprotective effect in response to rotenone and MPP(+) in dopaminergic cell culture and transgenic C. elegans with alpha-synuclein overexpression. To further investigate the detail mechanism of 14-3-3 proteins in rotenone-induced dopamine neurotoxicity, we observed the expression of 14-3-3 isoforms, and the influence of 14-3-3epsilon knockdown on autophagic activity and cell function. The results showed that rotenone led to a decrease in expression of 14-3-3 protein and mRNA, and an increase in expression and aggregation of alpha-synuclein protein. Knockdown of 14-3-3epsilon expression in turn further aggravated PC12 cell damage, such as an enhancement of ROS formation, and a reduction of cell viability and ATP production. Further experiments confirmed that the autophagic activity was promoted with 14-3-3epsilon siRNA transfection, including an enhancement of autophagosome formation and the ratio of LC3-II/LC3-I. Therefore, we concluded that the regulation of 14-3-3 proteins in rotenone-induced neurotoxicity might be associated with its isoform 14-3-3epsilon's involvement in autophagy, which might be considered a mechanism in addition to the currently known function of 14-3-3 proteins in neurodegenerative disease pathogenesis.
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PMID:14-3-3 Proteins in the regulation of rotenone-induced neurotoxicity might be via its isoform 14-3-3epsilon's involvement in autophagy. 2400 77