Genistein ameliorates parathyroid hormone-induced epithelial-to-mesenchymal transition and inhibits expression of connective tissue growth factor in human renal proximal tubular cells

INTRODUCTION Genistein, a soybean and soy-based product, has been reported to inhibit the growth of a wide range of cancer cells, but there is no evidence concerning its treatment of chronic kidney disease. The aim was to investigate whether genistein has potential to inhibit parathyroid hormone (PTH)-induced renal interstitial fibrosis. MATERIAL AND METHODS Using human renal tubular epithelial HK-2 cells, α-smooth muscle actin (α-SMA) was assessed by using immunofluorescence detection. α-Smooth muscle actin, E-cadherin and connective tissue growth factor (CTGF) were measured by Western blot analysis. The promoter activity of the CTGF gene was examined by the luciferase reporter assay. RESULTS When cells were treated with PTH (0.1 nM) for 48 h, α-SMA protein expression was induced significantly, the protein expression of E-cadherin decreased substantially, and the promoter activity of the CTGF gene as well as its mRNA and protein expression levels increased (p < 0.01). Interestingly, genistein effectively inhibited PTH-induced α-SMA expression, restored E-cadherin expression, decreased mRNA and protein expression of CTGF, and suppressed the promoter activity of CTGF in a dose-dependent manner. CONCLUSIONS Genistein has the ability to block the biomarker for renal transdifferentiation and epithelial-to-mesenchymal transition, α-SMA, following PTH treatment and inhibit CTGF expression in human renal tubular epithelial cells; these might be important modes of actions that contribute to genistein anti-fibrogenic effects and may have great implications for its potential in clinical treatment of renal interstitial fibrosis.