检测不同毒力结核分枝杆菌感染对巨噬细胞凋亡的影响及其Caspase-3和Bcl-2的表达

The Influence of the Apoptosis Rate and the Expression of Apoptosis Proteins in the Macrophages Infected by Mycobacterium tuberculosis

该文为探讨不同毒力的结核分枝杆菌感染对巨噬细胞凋亡的调控作用及其机制。实验用结核分枝杆菌国际标准强毒株H37Rv株和卡介苗BCG分别感染巨噬细胞RAW264.7株,同时设空白对照组,在感染后1,6,12,24 h,用流式细胞技术检测各组巨噬细胞的凋亡率,应用Western blot检测细胞Caspase-3和Bcl-2蛋白表达。结果发现,结核分枝杆菌感染组的凋亡率显著高于对照组,差异具有统计学意义(P<0.05);BCG感染组凋亡率高于H37Rv感染组,在感染后1,12,24 h凋亡率显著升高,差异具有统计学意义(P<0.05)。巨噬细胞感染结核分枝杆菌后其Caspase-3蛋白表达增高,结核分枝杆菌感染组的Caspase-3蛋白表达高于对照组:对照组<H37Rv感染组<BCG感染组,差异具有统计学意义(P<0.05);BCG感染组Caspase-3蛋白表达高于H37Rv感染组,在感染后1,12,24 h蛋白表达增高显著,差异具有统计学意义(P<0.05)。结核分枝杆菌感染组的Bcl-2蛋白表达低于对照组,差异具有统计学意义(P<0.05);H37Rv感染组在1,6,24 h的Bcl-2蛋白表达高于BCG感染组,差异具有统计学意义(P<0.05)。由此可见,结核分枝杆菌感染导致巨噬细胞凋亡,细胞凋亡与结核分枝杆菌的毒力强弱有关;结核分枝杆菌感染对巨噬细胞的凋亡与Caspase-3及Bcl-2的表达有关。

To explore the regulation and mechanism of apoptosis of the macrophage infected by Mycobacterium tuberculosis. Infected the macrophage RAW264.7 cell line with intemational standards with Mycobacterium tuberculosis H37Rv and BCG, at the same time, set the blank control group, after the infection at the 1, 6, 12, 24 h, flow cytometry were employed to detect the rate of the apoptosis of macrophages of each group. Then detect the Caspase-3 protein and expression levels of the gene with Westem blot. The results showed that the rate of the apoptosis of macrophage RAW264.7 cell line infected by Mycobacterium tuberculosis is significantly higher than thatof the control group, the difference was statistically significant （P〈0.05）, and the rate of apoptosis of macrophage RAW264.7 cell line infected by the BCG was higher than that of the H37Rv, after infection, at 1, 12, 24 h, the rate of the apoptosis increased significantly, and the difference was statistically significant （P〈0.05）. After being infected by Mycobacterium tuberculosis, the expression of the Caspase-3 protein in macrophages increased, and the expression of the Caspase-3 protein of the Mycobacterium tuberculosis group is higher than the control group, the control group〈H37Rv infection group〈BCG infection group. The difference was statistically significant （P〈0.05）. The expression of Caspase3 protein in BCG infection group is higher than that in H37Rv infection group, at 1, 12, 24 h, the expression of protein was significantly increased after being infected, the difference was statistically significant （P〈0.05）. The expression level of Caspase-3 gene in the Mycobacterium tuberculosis infection group was relatively higher than that in the control group, the difference was statistically significant （P〈0.05）. The expression of the Bcl-2 protein of the Mycobacterium tuberculosis infection group was significantly lower than that of the control group, the difference was statistically significant （P〈0.05）. At 1, 6, 24 h, the expression of Bcl-2 protein in the H37Rv infection group was higher than that in the BCG infection group after being infected, the difference was statistically significant （P〈0.05）. This shows the infection with Mycobacterium tuberculosis leads to the apoptosis of macrophages, the intensity of virulence of Mycobacterium tuberculosis was related to the apoptosis of cells. And the apoptosis of macrophages infected with Mycobacterium tuberculosis was related to the expression of Caspase-3 and Bcl-2.