β淀粉样蛋白_(1-42)促进α-突触核蛋白在Ser129位点磷酸化和聚集

Amyloid-β_(1-42) Promotes the Phosphorylation of α-synuclein and Its Aggregation at Serine 129 Site

目的:通过转染人α-突触核蛋白(α-syn)A53T突变基因的PC12细胞(A53T-PC12细胞)模型,探讨β-淀粉样蛋白1-42(Aβ1-42)对A53T-PC12细胞在Ser29位点α-syn磷酸化(Pα-syn)水平、聚集程度的影响。方法:分别予H2O2、PBS、Aβ1-42干预A53T-PC12细胞(将A53T-PC12细胞分为:PBS干预组;5μmol.L-1Aβ1-42干预组;5μmol.L-1Aβ1-42+300μmol.L-1维生素C干预组;200μmol.L-1H2O2干预组),观察细胞内活性氧自由基(ROS)水平变化。并通过双重免疫荧光染色观察A53T-PC12细胞内α-syn聚集情况,并通过Western blot半定量分析A53T-PC12细胞内Ser129位点磷酸化Pα-syn水平。结果:Aβ1-42增加细胞内ROS。免疫荧光染色提示Aβ1-42干预后促进A53T-PC12细胞内α-syn聚集;Western blot半定量分析显示Pα-syn较PBS干预组升高(P<0.001,P<0.05)。结论:Aβ1-42促进A53T-PC12细胞内α-syn在Ser129位点磷酸化和聚集。

Aim： To explore the effect of amyloid-β1-42（Aβ1-42） on the phosphorylation and aggregation of α-synuclein（α-syn） at serine 129 site in A53T-PC12 cells,which were made from the PC12 cells transfected with human A53T mutant SNCA gene.Methods： Reactive oxygen species（ROS） in A53T-PC12 cells treated by H2O2,PBS,Aβ1-42,Aβ1-42＋ vitamin C were detected,and the changes of α-syn aggregation were also detected by the double immunofluorescence dyeing,respectively.Then phosphorylated α-syn at serine 129（Pα-syn）,the aggregation of α-syn were analyzed by Western blot.Results： The amount of ROS increased in A53TPC12 cells treated respectively with H2O2and Aβ1-42,while decreased in the cells treated with Aβ1-42＋ vitamin C.Immunofluorescence showed that Aβ1-42promoted the aggregation of α-syn in A53T-PC12 cells.Compared with the PBS group,Aβ1-42 could significantly increase the relative amount of Pα-syn（P0.001） and α-syn aggregations（P0.05）.Conclusion： Aβ1-42 could enhance α-syn phosphorylation at serine129 and promote aggregation of α-syn in A53T-PC12 cells.