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目的 观察硫辛酰胺(alpha-lipoamide,ALM)对糖尿病(diabetes Mellitus,DM)大鼠肾组织中转化生长因子β激活激酶1(TGFβ-activated-kinase1,TAK1)活性和核转录共抑制因子(ski-related novel protein N,SnoN)蛋白稳定性的影响,探讨硫辛酰胺抗肾脏纤维化的作用及其可能机制.方法 复制糖尿病(DM)大鼠模型,分为对照组NC(normalcontrol,NC)、DM组及ALM治疗组,实验6周后处死全部大鼠,测定相应生化指标,观察肾组织病理改变;免疫组化和Western blot检测TAK1、p-TAK1 (Thr184/187) (phosphoryladon-TGF β-activated-kinase1 (Thr184/187),p-TAK1(Thr184/187)、SonN、转化生长因子-β 1(trans-forminggrowth factor-β 1,TGF-β 1)、胶原Ⅳ(collagen-Ⅳ)的蛋白水平;免疫共沉淀技术(Co-immunoprecipitation,Co-IP)检测SnoN泛素化水平.结果 (1)与NC组相比,DM组24h尿蛋白(urinary protein,UP)、血糖(blood glucose,BG)、甘油三酯triglyceride (TG)、总胆固醇(total cholesterol,TC)显著增高;ALM组以上指标较DM组显著降低.(2)苏木精—伊红染色法(hematoxylin-eosin staining,HE)、Masson染色结果显示,DM组大鼠出现肾纤维化改变,ALM组肾纤维化病变明显改善.(3)与NC组相比,DM组大鼠肾组织TGF-β 1、Collagen Ⅰ、TAK1、p-TAK1 (Thr184/187)表达及SnoN泛素化水平增加,但SnoN蛋白水平降低;而与DM组相比,ALM组大鼠肾组织TGF-β1、Collagen Ⅰ、TAK1、p-TAK1 (Thr184/187)蛋白表达及SnoN泛素化水平降低,而SnoN蛋白水平有所恢复.结论 糖尿病大鼠肾组织中TAK1蛋白表达和活化水平均增加,可能通过介导SnoN磷酸化后被泛素化并降解,使TGF-β1致纤维化效应级联放大,促进DN的发生发展;而硫辛酰胺治疗后可通过减少TAK1的表达和磷酸化、降低SnoN泛素化水平,使得SnoN蛋白水平恢复而发挥抗肾脏纤维化效应.“,”Objective To investigate the effect of alpha-lipoamide (ALM) on the expression of TAK1 and the protein stability of ski-related novel protein N (SnoN) in the renal tissues of diabetic rats.Methods Rats were divided into normal control (NC) group,diabetes mellitus (DM) group and ALM group (n=8/group).The diabetic rat model was established by tail intravenous injection of streptozotocin (STZ).After 6 weeks,the rats were sacrificed and relevant biochemical parameters,pathological changes of the kidney were derected.Immunohistochemical staining and Western blotting were employed to measure the protein expression of TAK1,p-TAK1 (Thr184/187),SnoN,TGF-β1,collagen-Ⅳ;and co-immunoprecipitation was employed to detect the ubiquitination of SnoN.Results (1) Compared with NC group,24-hour urine protein,blood glucose (BG),kidney weight/body weight and triglyceride were significantly increased in the DM group.All parameters were significantly improved in ALM group.(2) Immunohistochemical results showed renal fibrosis in DM group.However,the lesions were improved in ALM group.(3) Compared with NC group,the levels of transforming growth factor β 1 (TGF-β 1),collagen Ⅰ,TAK1,p-TAK1 (Thr184/187) in the kidneys were increased in DM group,whereas the levels of SnoN was reduced.The changes were reversed after ALM intervention.Co-immunoprecipitation results revealed that the ubiquitin action of SnoN protein was increased in DM Group,and reduced in ALM group.Conclusion TAK1 protein expression and activation levels are increased in the renal tissue of diabetic rats,which probably mediates the phosphorylation of SnoN protein,enable its ubiquitin degradation,and promote the development of diabetic nephropathy (DN).This process can be inhibited after the treatment of ALM,and the fibrosis is reduced.