Expression of Transforming Growth Factor-β_1/Smad Signaling Pathway in Rat Glomerular Mesangial Cell and Interventional Effects of Angiotensin-Converting Enzyme Inhibitor

Objective To investigate the role of transforming growth factor(TGF)-β1/Smad signaling pathway in glomerular mesangial cell(GMC),and the influence of angiotensin-converting enzyme inhibitor(ACEI)fosinopril(Fos)on the expression of phosphorylation-Smad2/3(P-Smad2/3)and collagen Ⅰ(Col Ⅰ)in this way.Methods Glomerular mesangial cells of rat in vitro were cultured,and they were divided into 3 groups:①TGF-β1 group(TGF-β1 5 ng/mL);② Fos group(TGF-β1 5 ng/mL+ Fos 1×10-4 mol/L);③control group(blank).Methyl thiazolyl tetrazolium(MTT)colorimetric method detected cellular proliferation.The change of phosphorylation-Smad2/3 expression was detected by indirect immunofluorescence.The expression of collagen Ⅰ in cell culture supernatant was detected by the enzyme-linked immunosorbent assay(ELISA).Results The optical density(OD)value of cellular proliferation was higher than that in TGF-β1 group when compared with control group(P0.05),while lower in Fos group when compared with TGF-β1 group(P0.05).Phosphorylation-Smad2/3 slightly expressed in control group,while increased obviously in TGF-β1 group compared with control group(P0.05).In Fos group,the expression of phosphorylation-Smad2/3 were decreased apparently at 12 h and 24 h than those in TGF-β1 group(P0.05).Conclusion TGF-β1 can activate the expression of phosphorylation-Smads and TGF-β1/Smad signaling pathway in glomerular mesangial cell,which will cause the increased expression of collagen Ⅰ and proliferation of glomerular mesangial cell.Fos can partially block the activation of transforming growth factor-β1/Smad signaling pathway in glomerular mesangial cell,inhibit the excretion of collagen Ⅰ and proliferation of glomerular mesangial cell.