Effects Of Lentivirus-mediated SiRNA Suppressing PGC-1?Gene On Mitochondria Of MPTP-induced C57BL Mice

?Background?Parkinson's disease(PD)is a common neurodegenerative disease with pathological features of dopaminergic neurons degeneration and loss,formation and accumulation of the Lewy bodies(LB)in the midbrain region.There exists an increasingly high incidence among elderly people in recent decades.Mitochondrial dysfunction was treated as one of the key processes in the pathogenesis of PD for its significant connections with aging and DA neurons survival.Human peroxisome proliferator-activated receptor ? coactivator 1?(PGC-1?),encoded by the gene PPARGC1 A,is a strong multifunctional transcription factor.By interacting with multiple transcription factors,it could widely regulate the mitochondrial biogenesis and oxidative stress.Evidences showed that PGC-1? could also play beneficial roles on central nervous system,especially on neurodegenerative diseases which were pathologically closely associated with mitochondrial defect,including PD.Previously we had verified the positive effect of PGC-1? on the MPP+ induced SH-SY5 Y cells model when the mitochondrial lesion,oxidative stress injuries and the loss of DA neurons were aggravated after the interference of PGC-1? gene.However the potential neuroprotective mechanism involving the employment of PGC-1? in PD model in vivo has not been fully explored.?Objective?Our study aimed at identifying the efficiency of PGC-1?-si RNA-GV118 in down-regulating the expression of PGC-1? gene,and probing the further pathogenic consequences of such down-expression on the MPTP-induced PD mice model,in the aspects of neurons loss and mitochondrial dysfunction.?Methods?1.To establish the mice model for PD,adult male C57BL/6 mice were received five-days intraperitoneal injections of MPTP(30 mg/kg)two weeks after stereotaxicallydelivery of PGC-1?-si RNA-GV118(2.5 ul,5×108 /ul)into the region of right striatum.2.Motor assessments were carried out by behavior observation and the Rotarod Test.The efficiency of PGC-1?-si RNA-GV118 in substantia nigra(SN)was validated by Western blot and quantitative RT-q PCR analysis.Immunohistochemistry,as well as WB of the tyrosine hydroxylase(TH)antibody were employed to access the loss of DA neurons.Mitochondrial damage and oxidative stress injury were observed by electron microscopy and examined by ELISA assay for detecting SOD levels respectively.?Results?1.The expressing level of PGC-1? m RNA and protein were significantly reduced after PGC-1?-si RNA-GV118 intervention.2.MPTP treated C57BL/6 mice showed meaningful impairments of motor coordination,deletion of DA neurons,slightly destruction of mitochondrial ultrastructure,along with declining SOD activity.3.Compared with the lentivirus-vector control group,PGC-1? interference brought more significant damage of motor ability and DA neurons in MPTP–induced mice.Meanwhile,the ultrastucture of mitochondria was seriously destroyed and the activity of SOD was coordinately decreased.?Conclusions?1.Employment of PGC-1?-si RNA-GV118 stereotaxically injection in striatum was proved to be fully capable of effectively interfered the expression of PGC-1? in SN.2.MPTP-induced C57BL/6 male mice displayed both impaired behavior performance and DA neurons deficiency,could be regarded as a tenable PD animal model3.Interference of PGC-1? could exacerbate the toxicity of MPTP,leading to the mitochondria dysfunction and vulnerable antioxidant ability.Thus,the strong ability of PGC-1? in mitochondrial regulation could probably be regarded as a promising target of mitochondrial-protection strategy for PD patients.