WNT4及其抑制因子SFRP1在糖尿病肾病大鼠肾组织中的表达

摘要

目的 观察WNT4/β-catenin信号通路及其抑制因子分泌型卷曲相关蛋白1(SFRPl)在糖尿病肾病(DN)大鼠肾组织中的表达变化,探讨其在肾 脏纤维化发生发展中的可能作用.方法 将大鼠随机分为正常对照(NC)组和 DN组,8只/组.尾静脉注射STZ 55 mg/kg复制IDDM模型.HE、PAS及 Masson染色观察肾组织形态学结构和纤维化病变;免疫组织化学法观察WNT4和β-catenin蛋白在肾组织的表达部位;Western blot检测WNT4、SFRP1、 β-catenin、p-GSK-3β、GSK-3β、Collagen I、α-SMA和 E-cadherin 蛋白在肾组织中的表达;Real-time PCR检测 WNT4及SFRPl mRNA在肾组织中 的表达.结果 与NC组相比,DN组大鼠肾组织纤维化病变明显;WNT4蛋白和mRNA表达显著增多(P＜0.05) ;β-catenin、p-GSK-3β、α-SMA和 Collagen I蛋白的表达显著增多(P＜0.05) ;E-cadherin 蛋白表达显著减少(P＜0.05);SFRP1蛋白和mRNA表达显著下降(P＜0.05).结论 在DN发病中 ,WNT4/β-catenin信号通路异常活化;SFRP1表达减少可能抑制该通路,促进了 DN肾纤维化的发生发展.%Objective To observe the change of expression of WNT4/β-catenin signaling pathway and its inhibitory factor secreted frizzled-related protein 1 (SFRP1) in renal tissue in diabetic nephropathy(DN) rats, and to explore its possible role in the development of renal fibrosis. Methods Rats were randomly divided into normal control(NC) group and DN group, and equipped with 8 in each group. The IDDM model was prepared by tail vein injection of STZ 55 mg/kg. Hemotoxyin and eosin、Periodic Acid-Schiff and Masson stain were used to observe the morphological structure and fibrotic lesions in renal tissue;Immunohistochemical analysis was used to observe the protein expression of WNT4 and β-catenin in renal tissue;Western blot was used to detect the protein expression changes of WNT4, SFRP1, β-catenin, p-GSK-3β, GSK-3β, Collagenl, a-SMA, E-cadherin in renal tissue in each group;The mRNA expression of WNT4 and SFRPl in renal tissues of rat was detected by realtime PCR. Results Compared with NC group, renal tissue fibrosis was obvious in DN group. Compared with NC group, the protein and mRNA expressions of WNT4 significantly increased (P＜0.05), the protein expressions of β-catenin, p-GSK-3β, α-SMA and collagen I significantly increased (P < 0.05), the protein expressions of Ecadherin significantly decreased (P＜0. 05), the protein and mRNA expression of SFRPl significantly decreased (P＜0.05). Conclusions In the case of DN, the signal pathway of WNT4/β-catenin is abnormal activation. The expression of SFRPl is decreased, and that may inhibit this pathway and promote the development of renal fibrosis in DN.