Effects of calcitriol on tubular epithelial myofibroblast transdifferentiation in rats with unilateral ureteral obstruction

Objective To determine the effects and potential mechanisms of calcitriol on tubular epithelial myofibroblast transdifferentiation (EMT) in young rats with unilateral ureteral obstruction (UUO), based on the expression of renal tubulointerstitial α-smooth muscle actin (α-SMA), E-cadherin (E-Cad), transforming growth factor-β1 (TGF-β1 ) and bone morphogenetic protein-7 (BMP-7) mRNA. Methods Fifty-four male Sprague-Dawley rats were randomly allocated into Sham group (group A, n=18), UUO model group (group B, n=18) and UUO treatment group (group C, n= 18). The renal tissue was biopsied at days 3, 7 and 14 for subsequent assays of α-SMA, E-Cad, TGF-β1 and BMP-7 mRNA expression by using real-time fluorescence quantitative polymerase chain reaction (RT-PCR). Results Compared with group A, significantly attenuated E-Cad and BMP-7 mRNA expression yet markedly increased α-SMA and TGF-β1 mRNA was noted in group B (all P0.01). Group C was characterized by considerably up-regulated E-Cad and BMP-7 mRNA expression yet down-regulated expression of α-SMA and TGF-β1 mRNA when compared with group B (all P0.01). Conclusion The fact that calcitriol suppresses EMT in rats with UUO may be associated with downregulation of TGF-β1 mRNA expression and up-regulated expression of BMP-7 mRNA.