血管紧张素Ⅱ在肺纤维化进展中的作用机制研究

Study on the action mechanism of angiotensin Ⅱ in the progression of pulmonary fibrosis in rats

目的探究血管紧张素Ⅱ(AngⅡ)在肺纤维化进展中的作用机制。方法随机将30只清洁级雄性大鼠分为3组,每组10只,分别为空白对照组、模型组、AngⅡ组。空白对照组经气管滴入0.9%氯化钠溶液200 ml,模型组气管滴入博来霉素5 mg/kg,AngⅡ组气管滴入博来霉素同时皮下埋入AngⅡ微量泵,以25μg·kg-1·h-1的速度持续泵入AngⅡ,用药4周后取肺组织进行NOX4、NALP3免疫荧光染色,采用免疫印迹法检测相关蛋白的表达水平。结果荧光免疫染色可见,与空白对照组相比,模型组大鼠肺组织中NOX4蛋白强度明显增加,AngⅡ组大鼠的肺纤维化程度较模型组进一步加重,NOX4强度明显增加,免疫印迹试验结果显示,NOX4蛋白表达为AngⅡ组(0.76±0.14)>模型组(0.58±0.19)>空白对照组(0.18±0.07),组间差异有统计学意义(P<0.05);荧光免疫染色可见,与空白对照组相比,模型组大鼠肺组织中NALP3染色细胞明显增多,强度增加,AngⅡ组大鼠的肺纤维化程度较模型组进一步加重,NALP3强度明显增加,免疫印迹试验结果显示,NALP3蛋白表达为AngⅡ组(0.50±0.04)>模型组(0.25±0.03)>空白对照组(0.11±0.01),组间差异统计学意义(P<0.05)。结论 AngⅡ能够激活NOX4、NALP3信号通路,从而加重大鼠肺纤维化进程。

Objective To investigate the action mechanism of angiotensin Ⅱ(Ang Ⅱ) in the progression of pulmonary fibrosis in rats.Methods Thirty male rats were randomly divided into three groups: blank control group,model group and Ang Ⅱ group,with 10 rats in each group. The rats blank control group were given 0.9% sodium chloride solution 200 ml dropping into trachea,and the rats in model group were given boonomycin 5 mg/kg dropping into trachea,and the rats in Ang Ⅱ group were given boonomycin 5 mg/kg dropping into trachea,at the same time, Ang Ⅱ micro pump was subcutaneously buried,with 25μg·kg-1·h-1 continuing pumping.After 4-week, the lung tissues of rats were taken to detect the levels of NOX4,NALP3 by immunofluorescence staining,and the expression levels of related protein were detected by immunoblotting assay.Results As compared with that in blank control group,the intensity of NOX4 protein in lung tissue in model group was significantly increased,as compared with that in model group,and the pulmonary fibrosis degree in Ang Ⅱ group was further aggratated,and the intensity of NOX4 was significantly increased further. The immunoblotting assay results showed that the expression levels of NOX4 protein were 0.76±0.14 in Ang Ⅱ group,which were significantly higher than those(0.58±0.19) in model group,which in model group were significantly higher than those(0.18±0.07) in blank control group(P<0.05).The fluorescence immunostaining results showed that as compared with those in blank control group,the expression levels of NOX4 protein in lung tissues in model group were significantly increased,and the pulmonary fibrosis degree in Ang Ⅱ group was further aggratated.Moreover the expression levels of NALP3 protein were 0.50±0.04 in Ang Ⅱ group,which were significantly higher than those(0.25±0.03) in model group,which in model group were significantly higher than those(0.11±0.01) in blank control group(P<0.05).Conclusion Ang Ⅱ can activate NOX4 and NALP3 signaling pathway,so as to aggravate the process of pulmonary fibrosis in rats.