福辛普利对肾小球系膜细胞TGF-β1/Smad信号通路的干预作用

Interventional effects of fosinopril on TGF-β1/Smad signaling pathway in glomerular mesangial cells

目的观察新型血管紧张素转化酶抑制剂(ACEI)--福辛普利(fosinopril,FOS)对转化生长因子β1(TGF-β1)诱导的大鼠肾小球系膜细胞(GMC)Ⅰ型胶原(ColⅠ)蛋白分泌和Smad2、Smad7mRNA表达量的影响。方法建立体外培养的大鼠GMC,鉴定后3～10代用于实验。实验分为正常对照组、TGF-β1刺激组(加5ng/L TGF-β1和5%的胎牛血清)和FOS组(加5ng/L TGF-β1、10μmol/L FOS和5%的胎牛血清)3组,分别于6、24和48h后ELISA法测定细胞培养上清液中ColⅠ蛋白表达量,荧光定量PCR法检测Smad2、Smad7 mRNA表达量的变化。结果①正常培养的大鼠GMC均有一定量的ColⅠ蛋白表达;TGF-β1刺激组在各时间点ColⅠ蛋白分泌均高于对照组(P<0.01),FOS各组ColⅠ蛋白分泌均低于TGF-β1刺激组(P<0.05)。②正常培养的大鼠GMC可表达一定量Smad2、Smad7 mRNA,TGF-β1刺激组在各时间点Smad2、Smad7 mRNA表达量均高于对照组,FOS治疗组Smad2 mRNA表达量均低于TGF-β1刺激组;Smad7 mRNA表达量在TGF-β1刺激组和FOS治疗组间差异无统计学意义(P>0.05)。结论FOS可抑制TGF-β1诱导的GMC分泌ColⅠ增加,且能够从mRNA水平抑制TGF-β1诱导的大鼠Smad2 mRNA的表达量;FOS可能部分通过抑制TGF-β1/Smad信号通路中的Smad2的表达而发挥延缓肾小球硬化的作用。

Objective To observe the effects of fosinopril （FOS） on secretion of ColⅠ,expression of Smad2、 Smad7 mRNA in TGF-β1-induced glomerulomesangial cells （GMC） in rat model.Methods Rat glomerular mesangial cells were cultured in vitro,passages 3 - 10 cells were used in the study after identification,and the cells were divided into 3 groups： control group （Ctrl group）,TGF-β1 group,and fosinopril group.Expression of Col Ⅰ in cell culture supernatant was detected by the enzyme-linked immunosorbent assay （ELISA） at 6 h,24 h and 48 h.Changes of Smad2,Smad7 mRNA expression were evaluated by fluorescent quantitation PCR.Results Glomerular mesangial cells had Col Ⅰ protein expression.Secretion of Col Ⅰ was significantly higher in TGF-β1 group than those in Ctrl group at each time point （P〈0.01）,however the Col Ⅰ was significantly lower in fosinopril group at all time points than that in TGF-β1 groups （P〈0.05）.Glomerular mesangial cells also had Smad2,Smad7 mRNA expressions.The expressions of Smad2,Smad7 mRNA were significantly higher in TGF-β1 group than those in Ctrl group at each time point.Expression of Smad2 mRNA was significantly lower in fosinopril group than that in TGF-β1 group at all time points,while the difference in Smad7 mRNA expression between TGF-β1 group and fosinopril group showed no statistical significance （P 〉0.05）.Conclusions Fosinopril could inhibit the secretion of Col Ⅰ and expression of Smad2 mRNA in glomerular mesangial cells induced by TGF-β1,suggesting that fosinopril might delay glomerular sclerosis through inhibiting the expression of Smad2 in TGF-β1 / Smad signaling pathway.