The expression and function of Erbin protein in renal interstitial fibrosis / 中华肾脏病杂志

ABSTRACT

Objective To investigate the expression of Erbin in renal interstitial fibrosis (RIF) and the effect of over-expression of Erbin on transforming growth factor β1 (TGF-(β1)-induced epithelial-mesenchymal transition (EMT) in NRK52E cells. Methods In vivo, the model of renal fibrosis was induced by 5/6 subtotal nephrectomy in rat. Scr and BUN was detected and Masson staining was used to evaluate the level of renal tissue fibrosis. The location and expression of Erbin in renal tissue were detected by immunohistochemistry and Western blotting. In vitro, after NRK52E cells were treated by TGF-β1 (10 μg/L) for 72 h, immunofluorescence and Western blotting were used to obverse the expression and distribution of E-cadherin and α-SMA. The expression of Erbin mRNA and protein were detected by RT-PCR and Western blotting respectively. NRK52E cells were transiently transfected with Prk5-myc-Erbin plasmid via lipofectamine 2000, then the expressions of Erbin, E-cadherin and α-SMA were detected by Western blotting. Results (l)Compared to sham group with Scr (33.96±7.28) μmol/L and BUN (8.11±2.55) mmol/L, rats in 5/6 nephrectomy model with Scr (140.52±61.11) μmol/L and BUN (34.23±7.66) mmol/L revealed renal dysfunction. Masson staining indicated kidney interstitial fibrosis, and the expression of Erbin was significantly increased in renal tissue(2.9 folds), especially in tubular epithelia. (2)In vitro, the expressions of Erbin and α-SMA were markedly increased (2.3 folds and 2.1 folds, P<0.05, respectively) and the expression of E-cadherin was dramatically decreased in NRK52E cells stimulated by TGF-β1, which were consistent with immunofluorescence results. TGF-β1-induced E-cadherin suppression and a-SMA induction could be efficiently blocked by over-expression of Erbin (all P <0.05). Conclusions Erbin is up-regulated in renal interstitial fibrosis, and over-expression of Erbin can partly inhibit renal EMT induced by TGF-β1, which indicates Erbin playing an protective role in renal fibrosis.