Effect of valsartan on expression of TGF-?/Smads signaling pathway in human kidney proximal tubular epithelial cell / 中国药理学通报

ABSTRACT

Aim To observe the effect of valsartan on expression of Smads of HKCs stimulated by TGF-?1.Methods HKCs were divided into three groupscontrol group,TGF-?1 group and valsartan group.Total protein was firstly abstracted at 30 min after stimulation to detect p-Smad2/3 protein by Western blot.Total RNA and protein were abstracted at 48 hours after stimulation.The expressions of Smad2/3,Smad7 were measured by Western blot.Smad2mRNA and Smad7mRNA were measured by RT-PCR.Meanwhile, The protein synthesis of Col Ⅰ in the supernatants of the HKCs was detected by Western blot.MTT assay was used to investigate the effect of valsartan on proliferation of HKCs stimulated by 5 ?g?L-1 TGF-?1 at different time and different drug concentration.Results Western blot analysis indicated that TGF-?1 stimulation could increase the expression of Smad2/3 and activate phosphorylation of Smad2/3 at 48 hour.At the same time,Smad7 decreased.Valsartan could reduce the level of Smad2/3 and p-Smad2/3 but it did not have any effect on the expression of Smad7 protein.RT-PCR analysis also showed that the expression of Smad2mRNA or Smad7mRNA was higher after TGF-?1 stimulation than control group,while valsartan could down-regulate the expression of Smad2mRNA.There was no difference of the expression of Smad7mRNA between the TGF-?1 stimulation group and valsartan treatment group.Valsartan could also greatly ameliorate the secretion of Col Ⅰ in the supernatants of the HKCs stimulated by TGF-?1 detected by Western blot.Compared with control group,TGF-?1 supressed the proliferation of HKCs,While 1,10 and 100 ?mol?L-1 valsartan ameliorated it and the effect was dependent of dose.Conclusion Valsartan has some renal protective effects on renal interstitial fibrosis,partly through inhibiting TGF-?/Smads signaling pathway.