Objective: To investigate the effect of curcumin on dopamine neurons in Parkinson's disease (PD) and its mechanism.
Methods: SH-SY5Y human neuroblastoma cells were treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to establish the PD cell model. The model cells were treated with curcumin and/or autophagy inhibitor 3-MA. After 48 h of drug treatment, the number of surviving dopamine neurons was detected by tyrosine hydroxylase immunofluorescence method. Western blotting was used to detect protein expression of α-Synuclein (α-Syn), transcription factor EB (TFEB) and autophagy-related proteins lysosome-associated membrane protein 2A (LAMP2A) and microtubule-associated protein 1 light chain 3-Ⅱ(LC3-Ⅱ); RT-PCR was used to detect mRNA expression of α-Syn.
Results: Compared with MPTP model group, curcumin increased the number of surviving dopamine neurons(P<0.01), decreased both protein expression and mRNA expression of α-Syn (all P<0.01), and increased protein expression of TFEB, LAMP2A and LC3-Ⅱ (all P<0.01). When curcumin and 3-MA were given concurrently, the number of surviving dopamine neurons, protein expression of TFEB, LAMP2A and LC3-Ⅱ increased (P<0.05 or P<0.01), and both protein expression and mRNA expression of α-Syn decreased (P<0.05 or P<0.01) compared with MPTP model group; but the number of surviving dopamine neurons and protein expression of LAMP2A and LC3-Ⅱ decreased compared with curcumin group (all P<0.05).
Conclusions: Curcumin exerts protective effect on dopamine neurons in PD, which may be associated with enhancing autophagy and promoting the clearance of α-Syn.
目的: 观察姜黄素对帕金森病细胞模型中多巴胺能神经元的保护作用并探讨其作用机制。
方法: 人神经母细胞瘤SH-SY5Y细胞采用1-甲基-4-苯基-四氢吡啶离子（MPTP）处理建立帕金森病细胞模型，进一步设立姜黄素干预、自噬抑制剂3-甲基腺嘌呤（3-MA）干预以及姜黄素和3-MA同时干预组。各组细胞在药物处理48 h后分别进行酪氨酸羟化酶（TH）免疫荧光染色观察多巴胺能神经元存活数；蛋白质印迹法检测α-突触核蛋白（α-Syn）、转录因子EB（TFEB）、自噬相关蛋白多克隆抗溶酶体相关膜蛋白2A（LAMP2A）和微管相关蛋白1轻链3-Ⅱ（LC3-Ⅱ）的蛋白表达；RT-PCR检测α-Syn的mRNA表达。
结果: 与模型对照组比较，姜黄素组多巴胺能神经元存活数增加（ P < 0.01），α-Syn蛋白及mRNA表达减少（均 P < 0.01），TFEB以及自噬蛋白LAMP2A和LC3-Ⅱ表达上调（均 P < 0.01）；3-MA和姜黄素同时干预组多巴胺能神经元存活数增加（ P < 0.05），α-Syn蛋白及mRNA表达减少（ P < 0.05或 P < 0.01），TFEB、LAMP2A和LC3-Ⅱ蛋白表达上调（均 P < 0.01）。与姜黄素组比较，姜黄素和3-MA同时干预组多巴胺能神经元存活数减少，LC3-Ⅱ和LAMP2A蛋白表达减少（均 P < 0.05）。
结论: 姜黄素可激活细胞自噬功能促进α-Syn自噬性清除，从而减轻MPTP所致的多巴胺能神经元损伤。