TPRC3通道对MPP+所致MN9D细胞损伤的保护作用

目的探讨经典瞬间受体电位通道蛋白(transient receptor potential-canonical channel,TRPC)家族在1-甲基-4-苯基吡啶离子(1-Methyl-4-phenylpy ridinium ion,MPP+)导致的MN9D细胞毒性损伤中的作用。方法用不同浓度(62.5、125、250、500、1000μmol/L)的MPP+处理MN9D细胞24h,500μmol/L MPP+处理MN9D细胞不同时间(3、6、12、24、36h),建立细胞损伤模型。用RT-PCR的方法检测MN9D细胞中内源性TRPC的表达情况;500μmol/L MPP+作用于MN9D细胞,以Western blot法检测MN9D细胞内源性TRPC表达的变化;构建GFP与TRPC3-GFP腺病毒载体,转染到MN9D细胞中,以四甲基偶氮唑盐比色法(methods the tetrazolium,MTT)的方法检测过表达的TRPC3对MPP+引起的MN9D细胞损伤的保护作用。结果500μmol/LMPP+处理MN9D细胞6h就可以显著降低细胞内TRPC3蛋白水平的表达,但对TRPC6的表达无影响。过表达TRPC3能够保护MN9D细胞免受MPP+的毒性损伤。结论MPP+特异性地降低MN9D细胞TRPC3蛋白水平,过表达TRPC3可以抑制MPP+引起的MN9D细胞损伤。这种现象提示TRPC3通道可能参与了帕金森病发病的分子机制。

TRPC3-mediated Inhibition of MPP~+ Neurotoxicity in MN9D Cells

Objective To study the effect of transient receptor potential-canonical channel(TRPC) on MPP⁺-induced MN9D cell damage. Methods The MN9D cell damage model was induced by treating MN9D cells with different concentrations(62.5, 125, 250, 500, 1 000 μmol/L) of MPP⁺ for 24 h and with 500 μmol/L MPP⁺ for different time course(3, 6, 12, 24, 36 hours). The mRNA expression of the members of TRPC subfamily was investigated by RT-PCR and the protein levels of TRPCs by Western blot in MN9D cells. MTT was performed to detect TRPC3-mediated inhibition of MPP⁺ neurotoxicity in MN9D cells transfected by TRPC3-GFP and GFP adenovirus. Results 500 μmol/L MPP⁺ specifically reduced the protein levels of TRPC3 in MN9D cells and overexpression of TRPC3 protected MN9D cells from MPP⁺ neurotoxicity. Conclusion Degradation of TRPC3 induced by MPP⁺ was probably involved in pathogenesis of Parkinson's disease(PD) and this study maybe provide a new target to prevent and treat PD.