白藜芦醇对高脂饮食诱导肾损伤小鼠肾组织单核细胞趋化蛋白1及转化生长因子β1表达的影响

Effects of resveratrol on the expression of MCP-1 and TGF-β1 in mice with high-fat diet-induced renal injury

目的观察白藜芦醇(resveratrol,Res)对高脂饮食诱导肾损伤小鼠肾组织单核细胞趋化蛋白1(monocyte chemotactic protein-1,MCP-1)及转化生长因子β1(transforming growth factor-β1,TGF-β1)表达的影响,并探讨其肾脏保护机制。方法 24只健康雄性C57BL/6小鼠随机分为3组,每组7只:正常对照(normal control,NC)组、高脂饮食(high-fat diet,HFD)组和高脂饮食+白藜芦醇干预(high-fat diet with resveratrol intervention,HFD+Res)组。HFD+Res组小鼠每日予以白藜芦醇[35 mg/(kg·d)]灌胃,NC和HFD组予以同等剂量的羧甲基纤维素钠灌胃。12周时,常规生化检测血清总胆固醇(total cholesterol,TC)、三酰甘油(triglyceride,TG)、低密度脂蛋白(low density lipoprotein,LDL)、血清肌酐(serum creatinine,Scr)及尿素氮(blood urea nitrogen,BUN)水平,采用HE染色法观察肾组织病理学改变,免疫组织化学法、蛋白印迹法检测肾组织中MCP-1和TGF-β1的表达水平。结果正常对照组、高脂饮食组和高脂饮食+白藜芦醇干预组3组间在TC(F=48.688,P<0.001),TG(F=15.361,P=0.001),LDL(F=50.401,P<0.001),Scr(F=27.143,P<0.001)及BUN(F=23.369,P<0.001)的差异具有统计学意义。与NC组及HFD+Res组相比,HFD组小鼠的TC、TG、LDL、Scr、BUN水平显著增高(与NC组比较:P<0.001;P=0.002;P<0.001;P<0.001;P<0.001;与HFD+Res组比较:P=0.022;P=0.027;P<0.001;P=0.001;P=0.001)。HE染色显示,HFD组肾小球系膜细胞和基质稍增多,肾小管上皮细胞胞质增多,HFD+Res组病理损伤减轻。免疫组化结果显示,HFD组MCP-1及TGF-β1表达高于NC组(P=0.004;P<0.001)及HFD+Res组(P=0.023;P=0.007),蛋白印迹结果同样显示:HFD组MCP-1及TGF-β1表达高于NC组(P=0.013;P=0.002)及HFD+Res组(P=0.044;P=0.039)。结论 MCP-1和TGF-β1可能参与了高脂肾损伤发病及进展,白藜芦醇可能通过下调其表达起到肾脏保护作用。

Objective To investigate the effect of resveratrol （Res） on the expression of monocyte chemo- tactic protein-1 （MCP-1） and transforming growth factor-β1 （TGF-β1） in mice with high-fat diet-induced renal injury, and to explore the mechanism of renal protection. Methods A total of 24 healthy C57BL/6 male mice were randomly divided into 3 groups （n=7 each）： normal control （NC） group, high-fat diet （HFD） group, and high-fat diet with Res intervention （HFD＋Res） group. Mice in HFD＋Res group were treated with resveratrol [35 mg/（kg·d）] by lavage everyday, and mice in NC and HFD groups were treated with the same volume of carboxymethylcellulose by lavage. After 12 weeks, serum total cholesterol （TC）, triglyceride （TG）, low density lipoprotein （LDL）, creatinine （Scr）, blood urea nitrogen （BUN）, HE staining for histopathological changes, immunohistochemistry and western blotting for the expressions of MCP-1 and TGF-β1 were assayed. Results There were statistically differences in TC （F=48.688, P〈0.001）, TG （F=15.361, P=-0.001）, LDL （F= 50.401, P〈0.001）, Scr （F=27.143, P〈0.001） and BUN （F=23.369, P〈0.001） between NC, HFD and HFD＋ Res groups. TC, TG, LDL, Scr and BUN increased significantly in HFD group as compared with those in NC group （P〈0.001 for TC; P=0.002 for TG; P〈0.001 for LDL; P〈0.001 for Scr; P〈0.001 for BUN） and with those in HFD＋Res group （P=0.022 for TC; P=0.027 for TG; P〈0.001 for LDL; P=0.001 for Scr; P=0.001 for BUN）. HE staining revealed evident histopathological lesions including slight increase of mesangial cells and matrix and proliferation of renal tubular epithelial cells in HFD group. In contrast, less pathological changes were found in HFD＋Res group. Immunohistochemistry demonstrated that MCP-1 and TGF-β1 expressions were higher in HFD group than in NC group （P=0.004 for MCP-1; P〈0.001 for TGF-β1） and HFD＋Res group （P=-0.023 for MCP-1; P=-0.007 for TGF-β1）. Western blotting also demonstrated the higher expressions of MCP-1 and TGF-β1 in HFD group than in NC group （P=0.013 for MCP-1; P=0.002 for TGF-β1） and HFD＋Res group （P=0.044 for MCP-1;P=0.039 for TGF-β1）. Conclusion MCP-1 and TGF-β1 may be involved in the pathogenesis and progression of HFD-induced renal injury. Res can ameliorate the renal injury in mice by decreasing the expressions of MCP-1 and TGF-β1.