RESUMO
Objective To detect the expression of heat shock protein 47(HSP47) in renal proximal epithelial cell lines (HK-2) and to investigate the role of HSP47 in the progress of transforming growth factor β1 (TGF-β1) induced epithelial-mesenchymal transdifferentiation (EMT) in HK-2 cells.Methods HK-2 cells were exposed to TGF-β1 (0,2.5,5,10 μg/L) for different time (0,12,24,48 h).The expression of HSP47 was examined by Western blotting.Then HK-2 cells were exposed to 10 μg/L TGF-β1,the expressions of vimentin,zona occludens-1 (ZO-1) were examined by Western blotting and real-time PCR.Furthermore,the expressions of p-Smad3 and Smad3 were examined by Western blotting.HK-2 cells were transfected with HSP47 siRNA and siRNA negative control before exposing to TGF-β1.Then the expressions of vimentin,ZO-1 were detected by Western blotting and real-time PCR,meanwhile Western blotting for HSP47,p-Smad3 and Smad3.Results Stimulating HK-2 with TGF-β1 resulted in a significant increased expression of HSP47 in time-and concentration-dependent manner (P ＜ 0.05).Meanwhile,TGF-β1 up-regulated the protein and mRNA expression of vimentin (P ＜ 0.05),and down-regulated the protein and mRNA expression of ZO-1 (P ＜ 0.05),all in time-dependent manner.Stimulating HK-2 with TGF-β1 resulted in phosphorylation of Smad3,which was peaked at 30 min,slightly decreased at 1 h,and then increased again between 24 and 48 h (P ＜ 0.05).Compared to the TGF-β1 group,inhibition of HSP4.7 expression in HK-2up-regulated the protein and mRNA expression of ZO-1,down-regulated the protein and mRNA expression of vimentin (P ＜ 0.05) and down-regulated the ratio of p-Smad3/Smad3.HSP47 siRNA negative control had no significant effect on the expressions of ZO-1,vimentin and p-Smad3/Smad3 (P ＞ 0.05).Conclusion HSP47 can promote the EMT of renal tubular epithelial cell which is possibly via the TGF-β1-Smad3 pathway.