多巴胺对鱼藤酮诱导α-突触核蛋白聚集的促进作用

Dopamine Promotes Alpha-Synuclein Aggregation Induced by Rotenone in PC12 Cell Line

目的:探讨多巴胺能细胞内多巴胺在鱼藤酮诱导α-突触核蛋白聚集过程中的作用。方法:采用鱼藤酮(1μmol/L)处理PC12细胞,流式细胞术检测双氢罗丹明123荧光强度;Western印迹法检测胞质内α-突触核蛋白表达;免疫荧光法观察α-突触核蛋白聚集体。并采用多巴胺耗竭剂——利血平预处理3h,观察上述指标。结果:鱼藤酮处理24h后,PC12细胞内过氧化物水平显著升高,而利血平(1μmol/L和5μmol/L)预处理后,细胞内过氧化物水平较鱼藤酮组显著下降(P<0.05)。鱼藤酮处理后,α-突触核蛋白表达水平显著升高,胞质内可见α-突触核蛋白免疫阳性的聚集体形成;采用利血平预处理后,α-突触核蛋白表达水平较鱼藤酮组显著下降(P<0.05),α-突触核蛋白聚集体面积减小。结论:在鱼藤酮作用过程中,多巴胺可促进α-突触核蛋白表达上调及其聚集体的形成。

Objective：To explore the role of dopamine in α-synuclein aggregation induced by rotenone in dopaminergic cells. Methods： PC12 cells were treated with rotenone at 1 μmol/L for 24 hours, with or without pretreatment of reserpine （1 μmol/L or 5 μmol/L） for 3 hours. Intracellular reactive oxygen species were measured with the fluorescence probe of dihydrorhodamine 123 （DHR123） by flow cytometry. By Western blot, the expression of α-synuclein protein was detected. The formation of α-synuclein aggregation was observed with laser scaning confocal technique. Results： When compared with control group, rotenone caused an increase of 181% of intracellular reactive oxygen species, and up-regulated the expression of α-synuclein protein. Reserpine partially inhibited the effect of rotenone. The formation of α-synuclein immunoreactive aggregsomes was observed in rotenone group, and the area of these aggregsomes decreased in reserpine-pretreatment group.Conclusion： Dopamine promotes the formation of α-synuclein aggregation induced by rotenone.