中和白细胞介素-17对特发性肺纤维化小鼠胶原和凋亡相关因子表达的影响

The effect of neutralizing interleukin-17 on the expressions of collagen andapoptosis-related factors in model mice with idiopathic pulmonary fibrosis

目的探讨中和白细胞介素-17(IL-17)对博来霉素所致特发性肺纤维化小鼠肺组织胶原和凋亡相关因子表达的影响.方法将32只雄性C57BL/6小鼠随机分为正常对照组、模型组、中和抗体组和抗体对照组.利用一次性气管内灌注博来霉素(5 U/kg)诱导特发性肺纤维化.中和抗体组和抗体对照组小鼠从造模后第3天起,每4 d尾静脉分别注射IL-17单克隆抗体和同型对照抗体,模型组和正常对照组则给予等量生理盐水.28 d后取肺组织,通过Masson染色评价各组小鼠肺纤维化程度;实时荧光定量PCR法测定肺组织胶原Ⅰ型和Ⅲ型mRNA含量;Western blot检测活化的半胱氨酸天冬氨酸蛋白酶(Cleaved-caspase)-3和Cleaved-caspase-9的表达水平.结果与模型组相比,中和抗体组肺纤维化程度显著下降(P<0.01),胶原Ⅰ型和Ⅲ型mRNA表达明显下调(P<0.01),Cleaved-caspase-3和Cleaved-caspase-9蛋白的表达显著降低(P<0.01),在模型组和抗体对照组间以上指标差异均无统计学意义.结论中和IL-17可能通过调控凋亡信号Cleaved-caspase-3和Cleaved-caspase-9蛋白的表达,改善肺纤维化.

Objective To investigate the effect of neutralizing interleukin-17(IL-17)on the expressions of collagen and apoptosis-related factors in model mice with idiopathic pulmonary fibrosis induced by bleomycin.Methods Thirty-two male C57BL/6 mice were randomly divided into normal control group,model group,neutralizing antibody group and antibody control group.The mouse model of idiopathic pulmonary fibrosis was induced by intratracheal infusion of bleomycin(BLM,5 U/kg).Mice in the neutralizing antibody group and the antibody control group were injected with IL-17 monoclonal antibody or isotype control antibody through the caudal vein every 4 days from the day 3 after BLM instillation,and the model group and the normal control group were given the same amount of normal saline.At the day 28,all mice were euthanized,the lung fibrosis degree was assessed by Masson staining.The mRNA contents of collagen typeⅠand typeⅢin lung tissues were determined by real-time fluorescent quantitative PCR,and the expression levels of Cleaved-cystein-asparate protease(Cleaved-caspase)-3 and Cleaved-caspase-9 were detected by Western blot assay.Results Compared with the model group,the degree of pulmonary fibrosis was significantly declined in the neutralizing antibody group(P<0.01),the mRNA expressions of collagen typeⅠand typeⅢwere obviously decreased(P<0.01),and the protein expressions of Cleaved-caspase-3 and Cleaved-caspase-9 were markedly reduced(P<0.01),but there were no significant differences in these data between model group and the antibody control group.Conclusion Neutralizing endogenous IL-17 may improve pulmonary fibrosis by regulating the expressions of Cleaved-caspase-3 and Cleaved-caspase-9 proteins.