SGK1超表达对人足细胞合成纤连蛋白的影响  

Effects of overexpressed SGK1 on the secretion of fibronectin in human podocytes

作　　者：张晓丽[1] 丁小强[1] 冯玉锡[2] 

机构地区：[1]复旦大学附属中山医院肾内科,上海200032 [2]华中科技大学同济医学院附属协和医院肾内科,湖北武汉430022

出　　处：《中国病理生理杂志》2007年第12期2419-2422,共4页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No30270618)

摘　　要：目的:研究高糖刺激对人足细胞血清和糖皮质激素诱导的蛋白激酶1(SGK1)和纤连蛋白(FN)表达的影响,以及SGK1超表达和灭活条件下FN的合成变化,揭示SGK1介导的信号转导途径在高糖诱导足细胞细胞外基质聚集,引发早期糖尿病肾损害过程中的作用。方法:高糖刺激人足细胞24h,Western blotting方法检测SGK1和FN蛋白水平的表达。利用构建好的SGK1激活型质粒(pIRES2-EGFP-SGK1SD)、灭活型质粒(pIRES2-EGFP-SGK1KN)和空载体(pIRES2-EGFP)分别转染人足细胞,免疫荧光方法检测足细胞合成FN的水平。结果:人足细胞中存在SGK1的表达,高糖刺激SGK1表达上调(50±4vs35±3),与此同时,FN合成亦明显增加(19±4vs12±2)。SGK1SD转染的足细胞中FN合成明显增加,相反,SGK1KN转染的足细胞中FN合成明显减少。结论:SGK1参与了高糖诱导的人足细胞FN的合成,可能在糖尿病肾病早期足细胞的受损活化过程中发挥重要作用。AIM： To investigate the effects of high concentration of glucose on the expressions of serum and glucocorticoid induced protein kinase 1 （ SGK1 ） and fibronectin in human podocytes and detect the production of fibronectin in human podocytes transfected with active and mutant forms of SGK1. METHODS： The expressions of SGK1 and fibronectin in human podocytes exposed in high glucose for 24 h were detected by using Western blotting. Human podocytes were transfected with three kinds of plasmid ： pIRES2 - EGFP - SGK1^SD （ SGK1 - active plasmid） , pIRES2 - EGFP - SGK1^KN（ SGK1 -mutant plasmid） and pIRES2 -EGFP （empty vector plasmide）. The synthesis levels of fibronectin were detected by immunofluorescence. RESULTS ： The expression of SGK1 in normal human podocytes was observed and the expression level was up - regulated in podocytes exposed to high glucose for 24 h （ 50 ± 4 vs 35 ± 3 ） , parallelly with the high expression of fibronectin （ 19 ± 4 vs 12 ± 2 ）. The secretion of fibronectin was increased obviously in SGK1 - active plasmid （SGKlSD） transfected podocytes compared with the vector transfected podocytes. Whereas, the fibronectin level was decreased significantly but not completely abolished in SGK1 - mutant plasmid （ SGK1^KN ） transfected podocytes, compared with SGK1^SD transfected podocytes. CONCLUSION： SGK1 may be involved in the synthesis of fibronectin in human podocytes induced by high glucose and play a critical role in the activation of human podocytes during early stage of diabetic nephropathy.

关 键 词：蛋白激酶类 足细胞 纤连蛋白类 转染 

分 类 号：R363[医药卫生—病理学]