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)

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and its toxic metabolite 1-methyl-4-phenylpyridium ion (MPP(+)) have been shown to induce Parkinson's disease-like symptoms as well as neurotoxicity in humans and animal species. Recently, we reported that maintenance of redox balance and cellular defense against oxidative damage are primary functions of the novel antioxidant enzyme cytosolic NADP(+) -dependent isocitrate dehydrogenase (IDPc). In this study, we examined the role of IDPc in cellular defense against MPP(+) -induced oxidative injury using PC12 cells transfected with IDPc small interfering RNA (siRNA). Our results demonstrate that MPP(+) -mediated disruption of cellular redox status, oxidative damage to cells, and apoptotic cell death were significantly enhanced by knockdown of IDPc.
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PMID:Knockdown of cytosolic NADP(+) -dependent isocitrate dehydrogenase enhances MPP(+) -induced oxidative injury in PC12 cells. 2161 85

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc) and its pathogenesis is under intense investigation. Substantial evidence indicates that mitochondrial dysfunction and oxidative stress play central roles in the pathophysiology of PD, through activation of mitochondria-dependent apoptotic molecular pathways. Several mitochondrial internal regulating factors act to maintain mitochondrial function. However, the mechanism by which these internal regulating factors contribute to mitochondrial dysfunction in PD remains elusive. One of these factors, mitochondrial NADP(+)-dependent isocitrate dehydrogenase (IDH2), has been implicated in the regulation of mitochondrial redox balance and reduction of oxidative stress-induced cell injury. Here we report that IDH2 regulates mitochondrial dysfunction and cell death in MPP(+)/MPTP-induced DA neuronal cells, and in a mouse model of PD. Down-regulation of IDH2 increased DA neuron sensitivity to MPP(+); lowered IDH2 levels facilitated induction of apoptotic cell death due to elevated mitochondrial oxidative stress. Deficient IDH2 also promoted loss of DA SNpc neurons in an MPTP mouse model of PD. Interestingly, Mito-TEMPO, a mitochondrial ROS-specific scavenger, protected degeneration of SNpc DA neurons in the MPTP model of PD. These findings demonstrate that IDH2 contributes to degeneration of the DA neuron in the neurotoxin model of PD and establish IDH2 as a molecular target of potential therapeutic significance for this disabling neurological illness.
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PMID:IDH2 deficiency promotes mitochondrial dysfunction and dopaminergic neurotoxicity: implications for Parkinson's disease. 2714 42

SIRT3 have been found to be neuroprotective in many neurological diseases, but its detail mechanism is only partially understood. In this study, MPP+ was used to treat SH-SY5Y cells as the cellular model of PD to test the role of SIRT3 and the mechanism may be involved in. We focused on the changes and relationship between SIRT3 and the key mitochondrial enzymes citrate synthase (CS) and isocitrate dehydrogenase 2 (IDH2). We found MPP+ decreased SIRT3 expression. And our results showed that the enzymatic activities of CS and IDH2 were significantly reduced in MPP+ treatment cells, while protein acetylation of CS and IDH2 increased. However overexpressed-SIRT3 partially reversed at least, the decline of CS activity and the increase of CS protein acetylation. IDH2 did not showed the same changes. The study suggested that SIRT3 deacetylated and activated CS activity. Hence, we conclude that SIRT3 exhibits neuroprotection via deacetylating and increasing mitochondrial enzyme activities.
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PMID:SIRT3 deacetylated and increased citrate synthase activity in PD model. 2816 43