黄芩素通过抑制mTOR通路激活自噬促进神经细胞过量表达的alpha-突触核蛋白清除

摘要

Objective To investigate the effects and mechanisms of Baicalein on autophage activation and the removal of abnormal alpha-synuclein aggragation in Parkinson disease.And to observe the protective effect of baicalein on mitochondrial damage induced by alpha-synuclein.Methods The overexpression of alpha-synuclein model was established in PC12 cells.Then the cells were treated by different concentrations of Baicalein.The degradation of alpha-synuclein was detected by confocal laser scanning microscopy.Finally, the cell lactate dehydrogenase release was examined by use of LDH kit.Results Baicalein can dose-dependently reduce the expression level of alpha-synuclein, activate autophagy markers LC3 and decrease the level of autophagy substrate p62.Immunofluorescence and western blotting show that Baicalein can inhibit mamamalian target of rapamycin(mTOR)to promote the formation of autophagosome.In addition, the Baicalein can decrease alpha-synuclein overexpression of nerve cell toxicity by reducing the release of cell lactate dehydrogenase.Conclusion Autophagy activation induced by mTOR signal transduction pathway can lead to the removal of abnormal aggregation alpha-synuclein in neurons.%目的 探讨黄芩素对神经细胞自噬的激活作用及其机制,以及对帕金森病病理性蛋白alpha-突触核蛋白(α-synuclein,α-syn)的清除效果.并观察黄芩素对α-syn诱导线粒体损伤的保护作用.方法 通过在PC12神经细胞中过表达α-syn建立帕金森病细胞模型.经不同浓度的黄芩素处理后,观察α-syn的降解情况,并检测细胞自噬的激活情况.检测细胞乳酸脱氢酶的释放情况,观察黄芩素对神经细胞的保护作用.结果 黄芩素处理可以剂量依赖地降低α-syn的表达水平,同时激活细胞自噬标志蛋白LC3以及降低自噬底物p62的水平.免疫荧光显示黄芩素促进了自噬小体的形成.黄芩素能够抑制哺乳动物雷帕霉素靶蛋白(mamamalian target of rapamycin,mTOR)的活性.黄芩素降低了α-syn过表达引起的神经细胞毒性,主要表现为降低了细胞乳酸脱氢酶的释放.结论 黄芩素通过抑制mTOR通路激活自噬促进神经细胞过量聚集的α-syn清除.