Interaction of dopamine and α-synuclein in SH-SY5Y cells / 中华老年医学杂志

ABSTRACT

Objective To investigate the interactive mechanism of dopamine and α-synuclein in SH-SY5Y cells,and to explore their effects on Parkinson's disease (PD).Methods The concentration of exogenous dopamine was definited by MTT method.The effect of exogenous dopamine on the expressions of α-synuclein and caspase-3 active fragments and malondialdehyde (MDA) content were detected by Western blot and commercial kit.Recombinant plasmid of wild-type α-synuclein was transfected into SH-SY5Y cells.Level changes in dopamine concentration,MDA content and expression of caspase-3 active fragment were observed.Furthermore,the effect of GBR12935,an inhibitor of dopamine transporter,on these outcomes were detected.Results Intracellular dopamine concentration was increased by 16 folds in SH-SY5Y cells which were added 300 umol/L exogenous dopamine for 24 hours as compared with blank controls (t=7.32,P＜0.01).Expressions of α-synuclein and caspase-3 active fragments and MDA content were increased in exogenous dopamine treated group as compared with blank controls (t=4.92,17.14,6.55,all P＜0.01).Intracellular dopamine concentration,MDA content and expression of caspase-3 active fragment were increased in SH-SY5Y cells transfected with recombinant plasmid of wild-type α-synuclein as compared with SH-SY5Y cells transfected with empty plasmid (F =32.97.107.80,55.54,all P＜0.01),whlie these increases could be partially inhibited by GBR12935.Conclusions Dopamine promotes the expression of α-synuclein,while over-expressed α-synuclein increases intracellular dopamine concentration,which forms a vicious cycle of cytotoxicity in SH-SY5Y cells.