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目的:探讨miRNA-181a对l-甲基-4-苯基吡啶离子(1-methyl-4-phenyl-pyridinium,MPP+)诱导的帕金森病(Parkinson’s disease,PD)多巴胺能神经元损伤的影响及其相关机制。方法 :采用胎龄12.5 d的C57BL/6小鼠胚胎中脑进行多巴胺能神经元原代培养,依据不同处理方法分为4组:(1)空白对照(Control)组;(2)PD模型(MPP+)组;(3)阴性对照(miRNA-NC+MPP+)组;(4)miRNA-181a+MPP+组。酪氨酸羟化酶(tyrosine hydroxlase,TH)可以选择性标记多巴胺能神经元,因此采用荧光显微镜对各组TH染色阳性神经元数目、初级突触分枝及最长突触长度进行观察,分析各组之间的差异。结果:Control组多巴胺能神经元细胞体积较大,呈圆形或三角形,胞体发出1个、2个或多个长的分枝以及轴突发出的次级突起,胞体和轴突表面光滑,形态完整,神经元分枝之间相互交织呈网络,联系密切。miRNA-NC+MPP+组经MPP+作用后多巴胺能神经元的数量减少,绝大多数表现为胞体存在,分枝数目及最长突触长度明显减少,网状交织稀少,表面不光滑,有的呈串珠样肿胀或轴突中断、丢失,仅存胞体,少数也表现为胞体空虚、丢失,仅存突起。miRNA-181a+MPP+组较miRNA-NC+MPP+组多巴胺能神经元数目有所增加,胞体形态较好,分枝数目与最长突触长度较miRNA-NC+MPP+组有所改善,且表面较光滑,神经元死亡程度较低。结论:miRNA-181a对MPP+所致多巴胺能神经元损伤起到神经保护作用。
OBJECTIVE: To investigate the effect of miRNA-181a on dopaminergic neuron damage induced by 1-methyl-4-phenyl-pyridinium (MPP +) in Parkinson’s disease (PD) Its related mechanism. Methods: C57BL / 6 mouse embryonic midbrain at a gestational age of 12.5 days was used for primary culture of dopaminergic neurons. According to different treatment methods, the cells were divided into 4 groups: (1) control group; (2) PD model MPP +) group, (3) negative control group (miRNA-NC + MPP +) group, and (4) miRNA-181a + MPP + group. Tyrosine hydroxylase (tyrosine hydroxlase, TH) can be selectively labeled dopaminergic neurons, so the number of TH-stained neurons, primary synaptic branches and the longest synaptic length were observed by fluorescence microscopy Differences between groups. Results: The dopaminergic neurons in Control group were larger in size, round or triangular in shape, with one, two or more long branches of the cell body and secondary projections of axons. The surface of cell body and axon were smooth, Shape complete, interwoven neuronal branches were networked, closely linked. The number of dopaminergic neurons in the miRNA-NC + MPP + group decreased after MPP + treatment, most of them showed the existence of cell bodies, the number of branches and the longest synapse length were significantly reduced, the network was sparsely interwoven, the surface was not smooth, and some were Beaded swelling or axon interruption, loss, only the presence of cells, a small number of cells also showed empty, lost, remaining only protruding. Compared with miRNA-NC + MPP + group, the number of dopaminergic neurons increased in miRNA-181a + MPP + group, the morphology of the cell body was better, the number of branches and the longest synapse length were better than the group of miRNA-NC + MPP + Smooth, neuronal death less. Conclusion: miRNA-181a plays a neuroprotective role in MPP + -induced dopaminergic neuron injury.