Triptolide inhibits the tubulointerstitial fibrosis in rats of unilateral ureteral obstruction by up-regulating Ski expression

Objective To investigate the effects of triptolide on tubulointerstitial fibrosis in rats kidneys with the unilateral ureteral obstruction (UUO) by examining the expression of collagen type Ι (Col-Ι), Ski, Smad3, TGF-β1. Methods Sixty male SD rats were divided into three groups: Sham operation group (Sham group), UUO group and triptolide (0.2 mg•kg-1•d-1) treatment group. The levels of blood urea nitrogen (BUN), serum creatinine (Scr), pathological changes were measured. Col-Ι, Ski and Smad3 expressions were assessed by immunohistochemistry. Protein and mRNA expressions of Ski, Smad3, TGF-β1 were assessed by Western blotting and real-time PCR. Results Compared with Sham group, Scr and BUN increased significantly in UUO group (P＜0.05). Interstitial fibrosis was prominent and renal interstitial injury score increased significantly in UUO group (P＜0.05). The expressions of Col-Ι and Smad3 were increased in UUO group (P＜0.05). Compared with Sham group, the protein expressions of TGF-β1 and Smad3 were increased, the Ski protein was decreased in UUO group (P＜0.05). In triptolide group, the morphological changes were notably reduced (P＜0.05). Comparison with UUO group, triptolide could increase the protein and mRNA expressions of Ski significantly, and decreased the protein and mRNA expressions of Smad3 and TGF-β1 (P＜0.05). Conclusion Triptolide can reduce the tubulointerstitial fibrosis by up-regulating Ski, and down-regulating TGF-β1 and Smad3.