Role of homeobox A13 in epithelial-to-mesenchymal transition induced by serum albumin overload in human renal tubular epithelial cells

Abstract

Objective To explore the role of nuclear translational factor homeobox A13(HOXA13) gene in epithelial-to-mesenchymal transition (EMT) induced by human serum albumin(HSA) overload in human renal tubular epithelial(HKC) cells. Methods HKC cells were treated with different concentrations of HSA (ranging from 0-30 g/L) for 48 h or 20 g/L HSA for different times (ranging from 0-72 h) in vitro.The protein expressions of cytokeratin (CK), Vimentin, and HOXA13 protein in HKC cells were detected by using Western blot respectively.Meanwhile, liposome-mediated DNA transfection was used to transfect the HOXA13 gene into HKC cells before HSA treatment, and the expressions of CK, Vimentin and HOXA13 protein in HKC cells were also detected by using Western blot. Results (1)The protein expression of CK decreased but Vimentin increased after HKC cells were exposed to HSA, which was in a concentration-and time-dependent manner.(2)Expression of HOXA13 was down-regulated by HSA in a dose-and time-dependent manner, and the expressions of HOXA13 protein in HKC in 5 g/L, 10 g/L, 20 g/L, 30 g/L group were 58.24%(P=0.005), 44.73%(P=0.003), 38.40%(P=0.033)and 24.83%(P=0.011)respectively as compared with 0 g/L group.Likewise, the protein expressions of HOXA13 in 24 h, 48 h, 72 h group were 52.00%(P=0.023), 46.83%(P=0.008)and 35.10%(P=0.034)respectively as compared with 0 h group.(3)There was a positive correlation between the levels of HOXA13 protein expression and CK protein expression(r=0.86, P=0.005), while the relationship between the levels of HOXA13 protein expression and Vimentin protein expression was negative(r=-0.94, P=0.002). (4)Up-regulated expression of HOXA13 in HKC cells by lipofectamine transfection alleviated the degree of EMT induced by HSA significantly.The expression of Vimentin decreased by 35.34% (P=0.005) while the expression of CK increased 360.00%-fold (P=0.005), compared with that of untransfected HKC cells. Conclusion EMT induced by HSA in HKC cells may play a role through HOXA13. Key words: Albumin overload; Renal tubular epithelial cell; Epithelial-to-mesenchymal transition; Homeobox A13