Effect of cyclopamine on aristolochic acid-induced phenotypic transforma-tion and Hedgehog pathway in renal epithelial cells / 中国病理生理杂志

ABSTRACT

AIM:To investigate the effect of cyclopamine on Hedgehog (HH) signaling, phenotypic transfor-mation and matrix accumulation induced by aristolochic acid (AA) in renal tubular epithelial cell NRK-52E.METHODS:NRK-52E cells were randomly divided into control group (treated with solvent only), AA group (treated with AA at con-centrations of 1, 5, 10 mg/L) and cyclopamine group (treated with AA at concentration of 10 mg/L plus cyclopamine at concentrations of 1, 5, 10μmol/L).After cultured for 24 h, the mRNA expression of Ptch1, Smo,α-SMA, E-cadherin, ZO-1, BMP-7, type I collagen and type III collagen was quantified by real-time PCR.The protein levels of Shh and TGF-β1 were detected by ELISA .Immunofluorescence staining was used to evaluate the expression of Ptch 1, Smo,α-SMA, E-cadherin and type III collagen in the NRK-52E cells.RESULTS: AA increased the expression of TGF-β1, α-SMA and type III collagen, decreased the expression of E-cadherin and ZO-1 protein, and down-regulated the expression of Ptch1, Shh and Smo mRNA in the NRK-52E cells, indicating that AA activated HH signaling , and phenotypic transformation and matrix accumulation occurred in AA-treated NRK-52E cells.Treatment with cyclopamine inhibited HH signaling by decrea-sing Smo expression and increasing Ptch 1 expression.Moreover, cyclopamine also down-regulated the expression of TGF-β1,α-SMA, type I collagen and III collagen , and up-regulated the expression of BMP-7, ZO-1 and E-cadherin.CON-CLUSIONAA induces phenotypic transformation and matrix accumulation in renal tubular epithelial cells , which can be inhibited by cyclopamine treatment .The possible mechanism is that cyclopamine suppresses the activation of HH signaling , resulting in the reduction of epithelial-to-mesenchymal transition and matrix deposition .