Expression of p-Smad2/3 and smad7 in experimental renal tubulointerstitial fibrosis rat model

Objective To examine the expression of TGF-β1/Smads signaling pathway in renal tubulointerstitial fibrosis.Methods Male SD rats were divided into control,sham operation and tubulointerstitial fibrosis groups.They were sacrificed at day 3,7,14,28 after operation.Use masson coloration to examine the area of pathological changes.The level of TGFβ1,p-Smad2/3 and smad7 protein was examined by immunohistochemistry staining and Western blot.The level of TGF-β1 mRNA and smad7 mRNA was analyzed by RTPCR.Results Compared with sham operation group,TGF-β1 and p-Smad2/3 were significantly increased in UUO rats,while smad7 protein reduced in it.The mRNA of TGF-β1 and smad 7 increased from day 3 to day 28.Smads protein plays an important role in the synthesis and accumulation of extracellular matrix in tubulointerstitial area.The reduction of smad 7 protein may be a major cause of the interstitial fibrosis in this model.Conclusion TGF-β /Smads protein pathway perhaps is essential in the development of tubulointerstitial fibrosis.