醛固酮通过Smad2依赖的转化生长因子-β1途径刺激大鼠系膜细胞纤连蛋白合成  

Aldosterone induces flbronectin synthesis through a Smad2-dependent TGF-β1 pathway in rat mesangial cells

作　　者：赖凌云[1] 顾勇[1] 郁胜强[1] 陈靖[1] 彭艾[1] 林善锬[1] 

机构地区：[1]复旦大学附属华山医院肾内科 复旦大学附属肾脏病研究所,上海200040

出　　处：《中华肾脏病杂志》2005年第3期153-156,共4页Chinese Journal of Nephrology

基　　金：国家自然科学基金(30270615)上海市科学委员会重大项目(03JC14084)

摘　　要：目的探讨醛固酮是否能够诱导纤连蛋白(FN)的合成,及可能的信号通路是否通过其核受体由Smad2依赖的TGF-β1途径介导。方法大鼠系膜细胞体外培养。Smad2的反义质粒由Smad2MH2功能区片段与表达绿色荧光蛋白的pEGF-C1真核质粒构建而成,运用脂质体的方法转染系膜细胞,由荧光显微镜观察细胞是否转染成功。分别用醛固酮(10-7mol/L)伴或不伴安体舒通(10-9mol/L)刺激系膜细胞,48h后收集培养上清液和各组细胞蛋白。FN、TGF-β1和Smad2的表达分别用ELISA和Western印迹的方法检测。结果醛固酮可以刺激大鼠系膜细胞TGF-β1表达升高[(134.2±13.9)%比对照组100%,P<0.05],FN合成增加[(74.2+15.0)比对照组(12.6+1.8)ng/ml,P<0.01]。先用安体舒通干预3h再加用醛固酮,则TGF-β1及FN的水平无显著变化。转染了Smad2的反义质村,醛固酮对FN的合成无显著影响,培养液中FN的浓度明显低于醛固酮刺激的未转染质粒组[(36.1±19.8)比未转染质粒组(72.3+16.6)ng/ml,P<0.05]。转染Smad2反义质粒的系膜细胞,其Smad2蛋白表达明显低于基础值[(69.1±8.6)%比基础值100%,P<0.01];而空载体pEGF-C1并不影响Smad2的表达。结论醛固酮通过核受体由Smad2依赖的TGF-β1途径诱导大鼠系膜细胞FN合成。该实验结果为临床上于预慢性肾脏病进展开辟了新的?Objective To investigate whether aldosterone promotes the synthesis of fibronectin ( FN ) in glomerular mesangial cells (GMCs) through a Smad2-dependent TGF-β1 pathway. Methods The Smad2 antisense plasmid,constructed by the DNA sequence in the Smad2 MH2 functional region and the vector pEGF-Cl,was transferred into the GMCs with Lipofectin.The transfection was followed by fluorescence microscopy.The level of FN in the GMCs incubation medium, the production of TGF-β1 and Smad2 in GMCs were detected by ELISA and Western blot, respectively.Results After the antisense plasmid transferring into the GMCs, the level of Smad2 protein was significantly lower than the baseline level [(69.1±8.6)% vs.100%, P<0.01]. The vector pEGF-Cl didn't influence the expression of Smad2. Both TGF-β1 and FN productions were both significantly increased alter exposing to 10-7mol/L aldosterone [TGF-β1:(134.2 ±13.9)% vs control 100%, P< 0.05; FN; (74.2± 15.0)ng/ml vs control ( 12.6±1.8) ng/ml, P< 0.01), but decreased in the presence of 10-9mol/L spironolactone. However,alter the cells were transferred with Smad2 antisense plasmid, aldosterone couldn' t promote the production of FN. The concentration of FN in the incubation medium was much lower than that without translection[ (36.1 ±19.8) vs (72.3±16.6) ng/ml, P < 0.05).Conclusions Aldosterone inducing FN accumulation may intertwine with TGF-β1.The Smad2 signaling pathway may participate in aldoslerone mediating fibrosis in glomerulus.

关 键 词：SMAD2 醛固酮 系膜细胞 FN TGF-β1 大鼠 转染 核受体 质粒 真核 

分 类 号：R692[医药卫生—泌尿科学] R619.6[医药卫生—外科学]