Effect of activated PI3-K on epithelial-mesenchymal trans-differentiation of HK cells induced by TGF-?_1 in vitro / 解放军医学杂志

ABSTRACT

Objective To investigate the effect of activated PI3-K on epithelial-mesenchymal transdifferentiation of HKCs induced by transforming growth factor?1 (TGF-?1). Methods The human kidney proximal tubular epithelial cells (HKCs) cultured on plastic plates were divided into following groups cultured with free serum medium (FSM); culture in the different concentrations of TGF-?1; cultured in the presence of recombinant human TGF-?1 and PI3-K inhibitor Wortmannin. The expression of total and phosphor-Akt (t-Akt and p-Akt) was assessed at different time points by Western blot,? smooth muscle actin(?-SMA) and E-cadherin were detected by Western blot. Results A marked increase in p-Akt was seen in HKC at 1h after being induced by TGF-?1, and its protein level was enhanced in a TGF-?1 concentration-dependent manner. Protein level of ?-SMA was increased markedly at 48 hours after the treatment of TGF-?1, but protein level of E-cadherin was decreased 48 hours after treatment of TGF-?1. Addition of PI3-K inhibitor Wortmannin (10nmol/L) largely abrogated the effect of TGF-?1. Wortmannin was showed to down-regulate ?-SMA and p-Akt expression and in response to TGF-?1 and up-regulate E-cadherin expression. Conclusion PI3-K was activated in epithelial-mesenchymal trans-differentiation of HKCs promoted by TGF-?1, and PI3-K inhibitor Wortmannin can significantly inhibit TGF-?1 induction of EMT.