依帕司他对单侧输尿管梗阻大鼠肾间质纤维化的干预作用及其机制

目的:观察依帕司他(EPS)对单侧输尿管梗阻(UUO)大鼠间质纤维化的保护作用及其机制。方法:实验设假手术组(Sham)组、UUO、UUO+EPS(50 mg/kg)及UUO+EPS(100 mg/kg)剂量组,每组n=8。左侧输尿管结扎制备UUO大鼠模型。造模后连续灌胃给药3周,sham和UUO组给予等体积的羟甲基纤维素钠。HE和Masson染色观察肾组织病理变化及胶原沉积情况。免疫组化法观察肾组织醛糖还原酶(AR)表达情况,分别采用real-time PCR和(或) Western blot检测肾脏I型胶原(collagen I)、III型胶原(collagen III)、α-平滑肌肌动蛋白(α-SMA)、成纤维细胞特异蛋白-1(FSP-1)、纤连蛋白(FN)、E-钙粘蛋白(E-cadherin)、转化生成因子-β1(TGF-β1)和AR mRNA及蛋白表达。结果:与Sham组相比,UUO组大鼠小管上皮细胞萎缩、空泡样变性,肾间质成纤维细胞及肌成纤维细胞大量增殖并伴大量炎症细胞浸润,胶原沉积明显增加,collagen I、collagen III、TGF-β1和AR mRNA及蛋白表达水平明显升高(P<0.01),同时EMT标志性蛋白α-SMA、FSP-1、FN mRNA及蛋白表达水平明显升高(P<0.01),而E-cadherin mRNA及蛋白表达水平明显降低。与UUO组相比,经EPS治疗3周后,肾间质纤维化程度明显减轻,胶原沉积明显减少,collagen I、collagen III、TGF-β1和AR mRNA及蛋白表达水平明显降低(P<0.01或P<0.05),另外α-SMA、FSP-1、FN mRNA及蛋白表达水平明显降低(P<0.01或P<0.05),而E-cadherin mRNA及蛋白表达水平明显升高(P<0.01或P<0.05),而且100 mg/kg剂量组上述指标的改变均好于低剂量组(P<0.05,P<0.01)。结论:依帕司他对肾间质纤维化具有一定的改善作用,其机制可能与其抑制TGF-β1介导的AR表达、进而抑制大鼠肾小管上皮细胞EMT有关。

Interventional effect of epalrestat on renal interstitial fibrosis in unilateral ureteral obstruction rats and its mechanism

Objective:To observe the protective effects of epalrestat (EPS) on interstitial fibrosis in unilateral ureteral obstruction (UUO) rats and its mechanism.Methods: Rats were randomly divided into four groups: sham group, UUO group, UUO + epalrestat (50 or 100 mg/kg), 8 rats in each group.Rats in UUO and UUO + epalrestat group were obstructed left ureter.In the sham group, rats had their left ureters exposed and manipulated without ligation.Animals for epalrestat treatment received daily drug via gavage for 3 weeks, the rats of sham and UUO groups received equal amount of sodium carboxymethyl cellulose with the same regimen.Renal tissues pathological changes and collagen deposition were observed by HE and Masson's staining.The aldose reductase(AR) expression in renal tissues was measured by immunohistochemisty.The expression levels of collagen I, collagen III, alpha-smooth muscle actin (α-SMA), fibroblast-specific protein1 (FSP-1), fibronectin (FN), epithelial cadherin (E-cadherin), transforming growth factor-β1 (TGF-β1) and AR from kidney tissues were measured by real-time RT-PCR or Western blot.Results: Compared with the sham group, the renal tissues of the UUO group showed significant fibrosis, including renal tubular epithelial cell atrophy and vacuolated degeneration, collagen deposition, fibroblasts and myofibroblasts proliferation and inflammatory cell infiltration, and concomitantly with the expressions of collagen I, collagen III, TGF-β1, AR, α-SMA, FSP-1 and FN were remarkably up-regulated, but E-cadherin was significantly reduced in UUO group.Compared with the UUO group, after 3 weeks epalrestat administration, the level of renal interstitial fibrosis was obviously ameliorated and the expressions of collagen I, collagen III, TGF-β1, AR, α-SMA, FSP-1 and FN were remarkably down-regulated, but E-cadherin was significantly increased in rats of epalrestat groups.Conclusion: These results suggest that epalrestat attenuates renal interstitial fibrosis possibly through inhibition of EMT via inhibiting TGF-β1 and AR expression.