microRNA-221对MPP^+诱导的帕金森病模型细胞凋亡和自噬的影响

Effect of miR-221 Expression on Apoptosis and Autophagy of Cell Modal in Patients with Parkinson's Disease Induced by MPP^+

目的:探讨microRNA-221对1-甲基-4-苯基吡啶离子(MPP+)诱导的帕金森病(PD)模型细胞凋亡和自噬的影响。方法:用不同浓度(0.5、1和2 mmol/L)MPP+诱导SH-SY5Y细胞建立PD细胞模型,采用CCK-8试剂盒检测SH-SY5Y细胞的存活率,qRT-PCR检测不同浓度MPP+诱导建立的PD细胞模型中microRNA-221的表达;将microRNA-221 mimics及mimics-NC转染至SH-SY5Y细胞,转染后细胞分为MPP+组、MPP++mimics-NC组和MPP++microRNA-221 mimics组,qRT-PCR检测转染效果,流式细胞仪分析microRNA-221对PD细胞模型凋亡的影响,Western blotting检测microRNA-221对PD细胞模型自噬蛋白标记物(LC3II、LC3I、Beclin 1)表达的影响。结果:MPP+处理后的SH-SY5Y神经母细胞瘤细胞的细胞存活率明显降低,且MPP+对SH-SY5Y细胞的毒性呈浓度依赖性,随着MPP+浓度的增加,细胞存活率明显降低(P<0.05);随着MPP+浓度升高,PD细胞模型中microRNA-221表达水平逐渐降低(P<0.05);上调PD细胞模型中microRNA-221表达,能明显降低LC3II/LC3I比值、Beclin1蛋白表达和细胞凋亡率(P<0.05)。结论:microRNA-221在PD细胞模型中表达降低,上调microRNA-221表达能明显抑制PD细胞模型的凋亡和自噬。

Objective： To investigate the effect of microRNA-221 on apoptosis and autophagy in Parkinson＇s disease（ PD） cell model induced by 1-methyl-4-phenylpyridine ions（ MPP^＋）. Methods：MPPMPP^＋at different concentrations（ 0. 5、1 and 2 mmol/L） were used to induce SH-SY5 Y cell to construct the PD cell model and the survival rate of SH-SY5 Y cell was tested by CCK-8 kit. MicroRNA-221 expression levels in PD cell model induced by MPPMPP^＋at different concentrations were detected by qRT-PCR. MicroRNA-221 mimics and mimics-NC were transfected to SH-SY5 Y cell which was divided into group MPP、MPP^＋＋ mimics-NC and MPP^＋＋ microRNA-221 mimics after transfection. The effect of transfection was detected by qRT-PCR,the effect of microRNA-221 on PD cell model apoptosis was analyzed by using cytometer while the effect of microRNA-221 on the expression of autophagy marker in PD cell model was analyzed by using Western blotting. Results： The survival rate of SH-SY5 Y neuroblastoma cell treated by MPP＋was decreased distinctly（ P〈0. 05）; MicroRNA-221 expression level in PD cell model was gradually decreased with the increase of MPP^＋concentration（ P〈0. 05）. Up-regulating microRNA-221 expression in PD cell model could significantly reduce the ratio of LC3 Ⅱ/LC3Ⅰ and the expression of Beclin1 protein and apoptosis rate（ P〈0. 05）. Conclusion：Up-regulating microRNA-221 expression can apparently suppress apoptosis and autophagy of PD cell model when microRNA-221 expression in PD cell model has been down-regulated.