丹酚酸B通过mTOR/Ulk1信号通路诱导胶质瘤细胞C6自噬性死亡

摘要

目的:探究丹酚酸B(Salvianolic acid B,Sal B)对胶质瘤细胞自噬的作用机制.方法:不同浓度的Sal B处理细胞,CCK8检测细胞活性,流式检测细胞凋亡情况,Western blot检测增殖、凋亡及自噬标记蛋白表达,免疫荧光检测LC3含量.结果:Sal B浓度达到100 μmol/L时能明显抑制细胞活性,因此,选择10、20、50 μmol/L三个剂量进行后续试验;Sal B能显著促进C6细胞凋亡和凋亡标记蛋白caspase-3、Bax的表达,降低Bcl-2及增殖标记蛋白Ki67的表达水平,并具有量效关系;同时,Sal B能显著促进自噬标记蛋白(Atg5、Atg7、Atg12、Beclin1)的表达,升高LC3Ⅱ/Ⅰ的比值,促进LC3荧光斑点的形成并降低p62的表达水平;此外,Sal B可明显抑制mTOR/Ulk1通路蛋白mTOR的表达,促进Ulk1的表达.结论:Sal B可通过mTOR/Ulk1信号通路诱导胶质瘤细胞自噬性死亡.%Objective:To evaluate the effects and underlying molecular mechanism of salvianolic acid B(Sal B) on autophagy in glioma cell.Methods:The C6 cells were treated with Sal B at a concentration ranging from 0 to 400 μmol/L and the cell viability were measured by CCK8 assay.Flow cytometry was performed for apoptosis,Western blot assay for protein expression and the expression of LC3 was calculated by immunofluorescence.Results:The cell viability was weakened by Sal B at a concentration of 100 μmol/L, thus,the concentration of 10,20 and 50 μmol/L were selected for further experiment.Sal B dose-dependedly induced C6 cell apoptosis and the expression of caspase-3 and Bax,notably decreased the protein level of Bcl-2 and Ki67.Meanwhile,Sal B significantly up-regulated the expression level of Atg5,Atg7,Atg12 and Beclin1,increased the ratio of LC3Ⅱ/Ⅰand the amount of LC3-labeled puncta per cell,and down-regulated the expression of p62.In addition,the protein level of mTOR was makedly decreased by Sal B and Sal B induced the expression of Ulk1.Conclusion:Sal B induces autophagic cell death in glioma cell through mTOR/Ulk1 signaling pathway.