目的 探讨细胞自噬在 PM2.5 诱导细胞凋亡过程中的作用机制.方法 采集 2016 年湛江市细颗粒物PM2.5,再用不同浓度PM2.5,分不同时间处理人肺腺癌( H441)细胞;用MTT比色法检测细胞增殖;PI和annexin V双染及TUNEL法检测细胞凋亡;蛋白免疫印迹法检测自噬标志物LC3Ⅱ及AKT和P-AKT蛋白表达.将H441细胞用雷帕霉素或 3-MA 预处理后,再用 PM2.5 暴露处理,锥虫蓝染色检测细胞活力.结果 与对照组相比, 100 μg/mL以上PM2.5处理24和48 h组细胞增殖明显受到抑制;随着PM2.5作用浓度的增加,细胞凋亡率明显增加,LC3Ⅱ蛋白的表达明显增多,P-AKT蛋白表达明显减少;而使用AKT抑制剂后,LC3Ⅱ蛋白增加愈明显;PM2.5暴露下,应用雷帕霉素能够降低PM2.5引起的细胞凋亡,而3-MA可促进PM2.5引起的细胞凋亡.结论 在H441细胞中,PM2.5通过抑制AKT活化而激活细胞自噬发生,而细胞自噬能够减缓PM2.5诱导的细胞凋亡.%Objective To investigate the function of autophagy in the process of PM2.5-induced apoptosis. Methods PM2.5 was obtained from Zhanjiang in 2016. Human lung adenocarcinoma cells H441 were treated with PM2.5 at different concentrations for different times. Cell proliferation was analyzed by MTT assay; Cell apoptosis was assessed by PI and Annexin V double staining and TUNEL assay. The expression of autophagy marker LC3Ⅱ, AKT and P-AKT protein was examined by Western blot ( WB). H441 cells were treated with PM2.5 following treatment with rapamycin or 3-MA. Cell viability was evaluated by trypan blue staining. Results Compared with the control group, cell proliferation was significantly inhibited by PM2.5 at concentration of 100 μg/mL or more for 24 and 48 h. With the increase of PM2.5 concentration, the cells apoptotic rate significantly increased, the protein ex-pression of LC3Ⅱwas increased as well as the P-AKT was decreased; and the protein expression of LC3Ⅱwas in-creased significantly after AKT inhibitor treatment. Moreover, rapamycin decreased PM2.5-induced cell apoptosis, and 3-MA can promote PM2.5-induced cell apoptosis. Conclusions In H441 cells, PM2.5 activates autophagy by inhibiting activation of AKT pathway, and cell autophagy can mitigate PM2.5-induced apoptosis.
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