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)

Mitochondrial uncoupling protein-4 (UCP4) enhances neuronal cell survival in MPP(+)-induced toxicity by suppressing oxidative stress and preserving intracellular ATP and mitochondrial membrane potential. UCP4 expression is increased by MPP(+), but its regulation is unknown. Using serial human UCP4 promoter-luciferase reporter gene constructs, we identified and characterized several cis-acting elements that can regulate UCP4 expression. Core promoter activity exists within 100 bp upstream of the transcription initiation site (TIS=+1). Both CAAT box (-33/-27) and Sp1 (-62/-49) elements are crucial and act synergistically in its transcription. We identified a NF-kappaB putative binding site at -507/-495. Mutation of this site significantly decreased UCP4 promoter activity. Activation of NF-kappaB by TNFalpha or cycloheximide increased, whereas its inhibition by 4-hydroxy-2-nonenal or transfection of pIkappaBalphaM suppressed, UCP4 promoter activity. NF-kappaB inhibition significantly suppressed the MPP(+)-induced increase in UCP4 expression. MPP(+) increased specific binding of NF-kappaB protein complexes to this site in electrophoretic mobility shift assay. Both UCP4 knockdown and NF-kappaB inhibition exacerbated MPP(+)-induced cell death. We present the first direct evidence that UCP4 is regulated by NF-kappaB, mediated via a functional NF-kappaB site in its promoter region, and that UCP4 has a significant role in NF-kappaB prosurvival signaling, mediating its protection against MPP(+) toxicity.
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PMID:Transcriptional regulation of UCP4 by NF-kappaB and its role in mediating protection against MPP+ toxicity. 2038 26

Monoamine oxidase B (MAO B) inhibitors, which inhibit dopamine decomposition by antagonizing MAO B activity, are approved and widely used for clinical treatment of Parkinson's disease (PD). Nonetheless, the mechanism of the abnormally increased MAO B activity in PD is still unclear. Previous research showed transcription factor specificity protein 1 (SP1) directly regulates MAO B activity by binding the SP1 binding sequence in MAO B promoter. In our study, we first observed that the SP1 protein level and SP1 binding activity in the MAO B promoter were increased in 1-methyl-4-phenylpyridinium (MPP+ ) neurotoxin-induced SH-SY5Y cells. Inhibition of SP1 by pretreatment with SP1 inhibitor mithramycin A (MMA) attenuated the abnormal increase in SP1 binding activity and the MAO B protein level to basal levels. Then, we investigated the neuroprotective effects of SP1 inhibition. In SH-SY5Y cell models of PD, preincubation with MMA or knockdown by SP1-specific small interfering RNA showed potent protection against MPP+ -induced apoptosis via SP1. In a male C57BL/6 mouse model of PD, MAO B activity and MPP+ concentrations in mouse brain following injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were increased, whereas the elevated MAO B activity was decreased after pre-injection of MMA. Moreover, MMA ameliorated MPTP-induced loss of dopaminergic neurons in the substantia nigra pars compacta and mouse behavioral impairments. Altogether, our study suggests that SP1 is a principal factor regulating increases in MAO B activity, and SP1 inhibition produces neuroprotective effects in PD models through decreases in MAO B activity, which may be a new neuroprotective therapeutic strategy for PD treatment.
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PMID:Inhibition of transcription factor SP1 produces neuroprotective effects through decreasing MAO B activity in MPTP/MPP+ Parkinson's disease models. 3000 36