ABSTRACT
Objective To observe the expression and localization of D J-1 in renal fibrosis, and to investigate the expressions of E-cadherin, vimentin and the level of β-catenin tyrosine phosphorylation in human tubular epithelial cells. Methods In vitro, the human tubular epithehal cells (HKC cell line) were cultured with 10 μg/L TGF-β1 for 72 h. The protein expressions of E-cadherin, vimentin and DJ-1 were measured by Western blot. RT-PCR was used to detect the expression of D J-1 mRNA. The intracellular distribution of DJ-1 was observed by confocal microscope. In vivo, Masson stain was used to evaluate the level of renal fibrosis. The expression and disposition of DJ-1 in renal tissue were detected by immunohistochemistry. HKC cells were transfected with pEGFP-N1-DJ-1 via lipofectamine 2000. The efficiency of transfection was detected by fluorescence microscope. The expressions of DJ-1, E-cadherin, vimentin and β-catenin tyrosine phosphorylation level in the transfected cells were detected by Western blot. Results The expressions of DJ-1 protein and DJ-1 mRNA were up-regulated in renal tubular EMT cells. Most of DJ-1 protein localized in cytoplasm, and some was in nucleus. After stimulation by TGF-β1, the expressions of DJ-1 protein both in cytoplasm and nucleus was greatly increased, especially in nucleus. In vivo, renal tissue expressed DJ-1 in tubular epithelia, but little expression in glomeruli. In renal tissue from 5/6-nephrectomized rots, DJ-1 expression was greatly increased. In the DJ-1 transfectants, the expressions of DJ-1, vimentin and β-catenin tyrosine phosphorylation level were up-regulated, but E-cadherin expression was suppressed. Conclusion The increased expression of DJ-1 may promote renal fibrosis.