芪贞降糖颗粒对糖尿病肾病大鼠TGF-β1/Smad信号通路的调控作用

Regulatory Effect of Qizhen Jiangtang Granule on the TGF-β1/Smad Signaling Pathway in Rats with Diabetic Nephropathy

目的观察芪贞降糖颗粒对糖尿病肾病大鼠TGF-β1/Smad信号通路的调控作用,探讨其改善糖尿病肾病的作用机制。方法采用高脂饲料喂养联合链尿佐菌素腹腔注射方法复制2型糖尿病肾病大鼠模型,选取模型复制成功的大鼠,随机分为模型组,二甲双胍组,芪贞降糖颗粒低、中、高剂量组,每组10只,另取10只正常大鼠作为正常对照组。灌胃给药8周,检测各组大鼠尿α1微球蛋白、β2微球蛋白和白蛋白含量。苏木素-伊红染色观察大鼠肾组织的损伤程度,免疫荧光染色观察大鼠肾组织转化生长因子β1(transforming growth factor beta 1,TGF-β1)和转化生长因子βⅠ型受体(transforming growth factor beta typeⅠreceptor,TGF-βRⅠ)的表达分布。RT-PCR检测肾组织TGF-β1、TGF-βRⅠ、Smad3和Smad7mRNA的表达水平,Western blot检测肾组织TGF-β1、TGF-βRⅠ、Smad3、p-Smad3、Smad7和p-Smad7的蛋白表达水平。结果与正常对照组相比,模型组大鼠尿α1微球蛋白、β2微球蛋白及白蛋白含量均明显增加(P<0.05),肾组织损伤明显,TGF-β1和TGFβ-RⅠ表达增加;TGF-β1、TGF-βRⅠ、Smad3mRNA表达水平显著增高(P<0.05),Smad7mRNA表达水平显著降低(P<0.05),TGF-β1、TGF-βRⅠ、Smad3和p-Smad3蛋白表达水平显著增加(P<0.05),Smad7和p-Smad7蛋白表达水平显著降低(P<0.05)。与模型组相比,芪贞降糖颗粒组上述指标均具有不同程度的逆转,差异具有统计学意义(P<0.05)。结论芪贞降糖颗粒能够改善糖尿病大鼠肾组织的损伤程度,其机制可能与调控TGF-β1/Smad信号通路的蛋白表达有关。

Objective To investigate the regulatory effect of Qizhen Jiangtang Granule on the TGF-β1/Smad signaling pathway in rats with diabetic nephropathy and its mechanism of action in improving diabetic nephropathy.Methods A rat model of type 2 diabetic nephropathy was established by high-fat diet combined with intraperitoneal injection of streptozotocin,and after successful modeling,the rats were randomly divided into model group,metformin group,and low-,middle-,and high-dose Qizhen Jiangtang Granule groups,with 10 rats in each group.Another 10 normal rats were enrolled as normal control group.The drugs were given by gavage for 8 weeks,and then the levels of urinaryα1 microglobulin,β2 microglobulin,and albumin.HE staining was used to observe the degree of renal tissue damage,and immunofluorescent staining was used to observe the expression of transforming growth factor beta 1(TGF-β1)and transforming growth factor beta typeⅠreceptor(TGF-βRⅠ)in renal tissue.RT-PCR was used to measure the mRNA expression of TGF-β1,TGF-βRⅠ,Smad3,and Smad7 in renal tissue,and Western blot was used to measure the protein expression of TGF-β1,TGF-βRⅠ,Smad3,p-Smad3,Smad7,and p-Smad7 in renal tissue.Results Compared with the normal control group,the model group had significant increases in the levels of urinaryα1 microglobulin,β2 microglobulin,and albumin(P<0.05),marked renal tissue damage,and increases in the expression of TGF-β1 and TGF-βRⅠ,as well as significant increases in the mRNA expression of TGF-β1,TGF-βRⅠ,and Smad3 and the protein expression of TGF-β1,TGF-βRⅠ,Smad3,and p-Smad3(P<0.05)and significant reductions in the mRNA expression of Smad7 and the protein expression of Smad7 and p-Smad7(P<0.05).Compared with the model group,the Qizhen Jiangtang Granule groups had varying degrees of reversal in the above indices(P<0.05).Conclusion To a certain degree,Qizhen Jiangtang Granule can improve the degree of renal tissue damage in rats with diabetes,possibly by regulating the protein expression of the TGF-β1/Smad signaling pathway.