Effect of Pirfenidone on renal interstitial fibrosis in rats

目的 研究吡非尼酮(PFD)对大鼠肾间质纤维化的作用及其作用机制,为临床使用吡非尼酮提供理论依据.方法 24只标准雄性SD大鼠,随机分为3组:正常组(NC组)、模型组(M组)及吡非尼酮治疗组(S组).M组及S组行左侧输尿管结扎术,复制肾间质纤维化模型.S组予吡非尼酮250 mg/(kg·d)灌胃,NC组及M组大鼠予等量1％羧甲基纤维素钠溶液灌胃.分别于手术后第1、3、5、7天处死各组大鼠各2只,取梗阻侧肾脏.HE染色观察各组肾组织病理变化,实时荧光定量聚合酶链反应(qRT-PCR)检测结缔组织生长因子(CTGF)mRNA表达水平,Western blot检测转化生长因子 β(TGF-β)及α-平滑肌激动蛋白(α-SMA)的蛋白表达水平.结果 NC组未显示肾纤维化,M组显示大鼠肾间质纤维化及炎症细胞浸润.NC组TGF-β、α-SMA蛋白表达均较低,M组TGF-β、α-SMA蛋白及CTGF mRNA表达较NC组均升高,差异有统计学意义(P＜0.05),且随着梗阻时间延长,各物质表达量增高,但第7天M组及S组上述物质表达量较第5天减少,且M组与S组之间表达差异无统计学意义(P＞0.05);S组上述物质各时间点表达则较M组均减少,差异有统计学意义(P＜0.05).结论 吡非尼酮可能通过抑制大鼠肾组织TGF-β和CTGF的表达进而减少成纤维细胞转化为肌成纤维细胞,减少细胞外基质(ECM)的沉积,发挥抗肾纤维化作用.Objective To investigate the effect of Pirfenidone (PFD) on renal interstitial fibrosis in rat model of unilateral ureteral occlusion (UUO) and to reveal the anti-fibrosis mechanism of PFD.Methods Twenty-four standard male SD rats were randomly divided into three groups:normal control group (N),UUO model group (M) and Pirfenidone treated group (S).The rats of the M and S groups underwent left urethral ligation to make the renal interstitial fibrosis model.The S group was given PFD 250 mg/(kg·d) for gavage,meanwhile the N and M groups were given 1％ sodium carboxymethyl cellulose solution for gavage.Two rats were sacrificed from each group on day 1,3,5 and 7 after UUO operation,the kidney of the obstructive side was taken for further research.In each group,pathological changes were observed by HE staining,qRT-PCR was applied to detect the mRNA expression of connective tissue growth factor (CTGF),Western bolt was applied to detect the protein expressions of TGF-β and α-SMA.Results There was obvious renal interstitial fibrosis in the M group.Compared with the N group,the expressions of TGF-β and α-SMA proteins and the mRNA expression of CTGF were significantly increased in the M group(P ＜ 0.05).Compared with the M group,the expressions of above parameters in the S group were decreased significantly (P ＜ 0.05).The level of TGF-β was positively correlated with the level of α-SMA (P ＜ 0.05).Conclusions Pirfenidone has anti-fibrosis effect on rat UUO model by inhibiting renal TGF-β and CTGF expressions,which may control the fibroblast transformation and reduce the extracellular matrix deposition in the renal tissue.国家自然科学基金; 全国临床医药研究专项基金; 广东省自然科学基金; 江西省自然科学基金青年基金191-62