IL-17在肾间质纤维化中的作用初探

探讨白细胞介素17(IL-17)在肾间质纤维化发生发展中的作用。采用的体内实验为,以单侧输尿管梗阻(unilateral ureteric obstruction,UUO)启动纤维化病理过程。将C57BL/6小鼠分为假手术组(Sham)和单侧输尿管梗阻(unilateral ureteric obstruction,UUO)组,分别于术后第1、3、7天处死,留取手术侧肾组织。采用HE、PAS、PASM、Masson染色评价肾间质组织病理变化。以免疫组化、实时荧光定量PCR(qRT-PCR)法检测α平滑肌肌动蛋白(α-SMA)表达水平;酶联免疫吸附试验(ELISA)检测IL-17在肾组织中的表达情况。体外实验为,分离培养C57BL/6小鼠肾成纤维细胞,转化生长因子β1(TGF-β1)刺激使其转化为肌成纤维细胞,继而用蛋白免疫印迹法(western blotting)检测IL-17的刺激下α-SMA表达水平。结果显示,组织病理学检查显示随着梗阻时间延长,炎性细胞浸润明显,肾小管萎缩,间质面积增大,Ⅰ型胶原和α-SMA增多。PCR检测显示α-SMA mRNA表达增多。但ELISA结果显示肾组织中IL-17含量呈下降趋势。Western blot结果表明肌成纤维细胞在IL-17的刺激下,α-SMA蛋白水平显著下降。实验说明,单侧输尿管梗阻手术可导致相应侧肾组织发生纤维化病变,但肾组织中IL-17含量与纤维化病变并不一致,在体外实验中IL-17可下调肌成纤维细胞表达的α-SMA。

A preliminary study on the role of IL-17 in the progression of renal tubulointerstitial fibrosis

To investigate the role of IL-17 in the progression of renal tubulointerstitial fibrosis,C57BL/6 mice were randomly divided into sham-operation group and UUO(unilateral ureteral obstruction) model group.Mice were sacrificed 1,3 and 7 d after operation,and the renal tissues of the operated side(obstructed side for model group)were obtained.HE,PAS,PASM and Masson staining were used irrespectively to evaluate the pathological changes of the renal tissue.The expression level of Alpha smooth muscle actin(α-SMA) was detected by quantitative real-time PCR and immunohistochemical staining.Enzyme-linked immunosorbent assay(ELISA) was used to detect the expression level of IL-17 in the renal tissue.Renal fibroblasts of C57BL/6 mice were isolated and then cultivated with TGF-β1 in order to become myofibroblasts.Then IL-17 was added into the culture to analyse the effect of IL-17 on α-SMA expression of the myofibroblasts by Western blotting.The results showed that the histopathological staining of the renal tissue revealed that with time of ureteral obstruction inflammatory cells infiltrated,renal tubular atrophy and interstitial area increased,Alpha-SMA and typeⅠ collagen increased.The level of Alpha-SMA mRNA also increased in the renal tissue of UUO mice.While the expression level of IL-17 was gradually decreased in the renal tissue of UUO mice.Western blotting analysis demonstrated that the relative expression of α-SMA by myofibroblasts under the stimulation of IL-17 was lower than control.It is concluded that unilateral ureteral obstruction operation can lead to renal tissue fibrosis.The expression of IL-17 is not consistent with the degree of renal tubulointerstitial fibrosis.However,in vitro,IL-17 can down regulate the expression of α-SMA by myofibroblasts.