Study Of Neuroprotective Mechanism Of MicroRNA181a In Parkinson's Disease

Objective:To investigate the neuroprotective mechanism of MicroRNA181a on dopaminergic neurons(DA)in primary cell model of 1-methyl-4-phcnyl-pyridinium(MPP+)induced Parkinson's disease(PD).Methods:Embryonic mouse mesencephalic primary neurons were cultured in vitro and divided into four groups:A blank control group,untreated cells.MPP+ group,On the fifth day in vitro,neurons were injured by 10 ?mol·L-1 MPP+ for 48 h.MicroRNA-NC+MPP+ group,neurons were injured by 10 ?mol·L-1 MPP' for 48 h on the fifth day and pretreated with MicroRNA-NC for 6h then changed half new medium incubating for 24 h.MicroRNA181a+MPP+ group,neurons were transfected with lentivirus containing MicroRNA 181 a for 6 h then changed half new medium incubating for 24 h before injured by MPP+ for another 48h on the fifth day.Dopaminergic neurons were identified and counted by using tyrosinehydroxlase(TH)immunostaining under microscope.Control group vs MPP group,Control group vs MicroRNA181a+MPP group,MicroRNA-NC+MPP+ group vs MicroRNA181a+MPP group respectively.Results:The DA neurons exhibited intact bodies presenting circular or triangular and a variety of dendrites and axons derived from bodies and had intact morphous and interweaved closely in control group.Treated by MPP+ we specifically found that the number of dopaminergic neurons decreased strikingly,axons and dendrites disappeared completely remaining bodies and the axons appeared abnormal varicosities,apparent string-of=beads change.The axons and dendrites almost fragmented only few cell bodies disappeared and exhibited axonal root.Compared with MPP+ group,the number of dopaminergic neurons increased and cell bodies,axons,dendrites and the death of the dopaminergic neurons became improvement.Conclusion:The results suggested that MicroRNA181a may play an important role in protecting dopaminergic neurons in MPP+ induced Parkinson's disease(PD).