OBJECTIVETo investigate the role of integrin-linked kinase (ILK) on renal tubular epithelial-mesenchymal transition and the regulatory effect of urokinase on LIK expression in mice with obstructive nephropathy.

METHODSNormal male mice were randomly divided into sham-operated group (n=20), unilateral ureteral obstruction (UUO) group (n=28), and UUO with urokinase treatment group (uPA, n=28), and UUO was induced surgically in the latter two groups. The mice were sacrificed on days l, 3, 7 and 14 after the surgery, and renal interstitial fibrosis (RIF) was graded according to the result of Masson staining. The expression of ILK in the renal tissues of the rats was examined by immunofluorescence staining and Western blotting, and the expression of E-cadherin was detected by immunohistochemistry. RT-PCR was used to examine the mRNA expressions of ILK, E-cadherin and alpha-smooth muscle actin (alpha-SMA).

RESULTSThe expressions of ILK mRNA and protein were significantly increased in UUO group, but significantly decreased by treatment with uPA (P<0.05). The expression of alpha-SMA mRNA level was significantly increased, while E-cadherin decreased in mice with UUO on day 3 after the surgery. Treatment with uPA significantly inhibited such effects (P<0.05).

CONCLUSIONILK plays an important role in renal interstitial fibrosis by mediating epithelial-mesenchymal transition. Urokinase attenuates renal tubulointerstitial fibrosis in mice with UUO possibly by inhibiting ILK expression and preventing tubular epithelial-mesenchymal transition.