miRNA-223靶向FoxO3抑制肺结核大鼠巨噬细胞凋亡研究

Mechanism of miR NA-223 inhibiting macrophage apoptosis in rat model of pulmonary tuberculosis

目的探讨miRNA-223靶向叉头框转录因子3(FoxO3)抑制肺结核大鼠巨噬细胞凋亡机制。方法将60只雌性SD大鼠随机分为正常组、模型组和给药组,每组20只。模型组和给药组大鼠尾静脉注射含结核分枝杆菌的菌液,正常组注射等体积的0.9%氯化钠注射液,给药组异烟肼药液灌胃。监测各组大鼠造模第1、15、30天的体重变化。造模第30天时处死大鼠,留取肺组织。采用RT-PCR法检测大鼠肺组织miRNA-223、FoxO3 mRNA表达水平,Western blot法检测TNF-α、巨噬细胞移动抑制因子(MIF)蛋白表达水平。结果造模第1天,3组大鼠体重比较差异无统计学意义(P>0.05)。造模第15、30天,正常组大鼠体重>给药组>模型组(均P<0.05)。3组大鼠肺组织结核分枝杆菌菌落数比较差异有统计学意义(P<0.05),且正常组<给药组<模型组(均P<0.05)。与正常组和给药组比较,模型组大鼠肺组织miRNA-223表达水平降低,FoxO3 mRNA表达水平升高(均P<0.05);而给药组与正常组大鼠肺组织miRNA-223、FoxO3 mRNA表达水平比较差异均无统计学意义(均P>0.05)。与正常组比较,模型组大鼠肺组织TNF-α、MIF蛋白表达水平均升高(均P<0.05),给药组大鼠肺组织MIF蛋白表达水平升高(P<0.05)。与模型组比较,给药组大鼠肺组织TNF-α、MIF蛋白表达水平均明显降低(均P<0.05)。结论miRNA-223或通过靶向作用于FoxO3抑制相关凋亡基因及蛋白的表达,从而抑制肺结核大鼠巨噬细胞凋亡。

Objective To investigate the mechanism of miRNA-223 inhibiting macrophage apoptosis in pulmonary tuberculosis rats.Methods Sixty female SD rats were randomly divided into control group,model group and treatment group with 20 rats in each group.The rats in the model group and treatment group were injected intravenously with Mycobacteria tuberculosis,while the normal group was injected with the same amount of 0.9%sodium chloride,and the treatment group was given isoniazid solution intragastrically.The changes in body weight were monitored on d1,d15 and d30 of modeling in each group.The rats were sacrificed on d30 of modeling and lung tissue samples was collected.The expression levels of miRNA-223 and FoxO3 mRNA in lung tissue were detected by RT-PCR,and the expression of TNF-1 and macrophage migration inhibitory factor(MIF)was detected by Western blot.Results There was no significant difference in the body weight of the three groups at d1(P>0.05).On d15 and d30 of modeling,the body weight of control group was higher than that of treatment group and model group(P<0.05),while the body weight in treatment group was higher than that of model group(P<0.05).The number of M.tuberculosis colonies in treatment group was significantly less than that in model group(P<0.05).Compared with the control group and the treatment group,the expression of miRNA-223 in the lung tissue of the model group decreased and the expression of FoxO3 mRNA increased(P<0.05).There was no significant difference in expression of miRNA 223 and FoxO3 mRNA between the treatment group and control group(P>0.05).Compared with the control group,the expression of TNF-αand MIF protein in the lung tissue of the model group was higher(P<0.05),and the expression of MIF protein in treatment group was higher(P<0.05).Compared with the model group,the expression levels of TNF-1 and MIF protein in the lung tissue of the treatment group were significantly lower(P<0.05).Conclusion MiRNA-223 can inhibit macrophage apoptosis in pulmonary tuberculosis rats by inhibiting the expression of apoptosis-related genes and proteins through targeting FoxO3.