Effect Of SiRNA Targeting PGC-1α On Mitochondrial Signal Transduction In Dopaminergic Neurons

BackgroundParkinson’s disease(PD) is a common neurodegenerative disorder in the elderly nervous system, and the etiology and pathogenesis of PD is complex and still not fully understood. Recent years, researches has suggested the mitochondrial dysfunction attracted more and more attention. Peroxisome proliferator-activated receptorr γcoactivator-1α(PGC-1α) is a master regulators of mitochondrial biogenesis and functions, but its effect on mitochondrial signal transduction is unclear. This study intends to investigate the effects of down-expressed of PGC-1α gene on mitochondria signal transduction in dopaminergic neurons by RNA interference.ObjectiveIn this study, the adenovirus vector-based si RNA targeting PGC-1α gene and green fluorescent protein was transfected into SH-SY5 Y cell, then assessed the impact of down-expressed of PGC-1α gene on mitochondrial signal transduction in Parkinson’s disease.MethodsSH-SY5 Y cells treated with MPP+(1000umol/L) were used as the PD cell model in vitro, then the adenovirus vector-based si RNA targeting PGC-1α gene was transfected into SH-SY5 Y cell. The groups in experiment are: PBS group、MPP+ group、Ad+PBS group、Ad+MPP+ group、si RNA-PGC-1α+PBS group、si RNA-PGC-1α+MPP+ group.The cytochrome c content changes in cytoplasm and mitochondrial were tested by ELISA. The nuclear translocation of PGC-1α was observed by fluorescence microscope.Real-time PCR and Western blot analysis were used to detected PGC-1α, NRF-1, ERRαand NRF-2 m RNA and protein expression, then assessed the impact of down-expressed of PGC-1α on NRF-1, NRF-2 and ERRα.ResultThe mitochondrial cytochrome c was deceased by MPP+ treatment, further silence PGC-1α gene lead to more cytochrome c transferred to cytoplasm compared with the empty viral infection. Immunofluorescence revealed that PGC-1α is mainly located in the nucleus, whereas it can transferred to the cytoplasm by MPP+ treatment,especially when MPP+ was 1000umol/L. When SH-SY5 Y cells were treated with MPP+, the expression of PGC-1α, NRF-1, ERRα and NRF-2 protein were decreased compared with negative control group(P<0.05). In addition, when slience the PGC-1αgene, the expression of protein and m RNA of above factors were significantly decreased compared with the empty viral infection.Conclutions1. Si RNA interference targeting PGC-1α gene may cause mitochondrial dysfunction in SH-SY5 Y cell, and induce the decrease of mitochondrial cytochrome c.2. When slience the PGC-1α gene, along with the low expression of PGC-1α protein,the expression of ERRα, NRF-1 and NRF-2 protein were also descend, which indicate that PGC-1α gene may modulate mitochondrial function by up-regulated ERRα,NRF-1 and NRF-2.