Role of protease activated receptor-2 expression in renal interstitial fibrosis model in mice

The role of protease activated receptor-2 (PAR-2) in the renal tubulointerstitial lesion induced by unilateral ureteral obstruction (UUO) was explored. Mice were sacrificed on the day 1, 3, 5, 7, 10, 14 and 21 after UUO. The expression of PAR-2 mRNA and protein and alpha-smooth muscle actin (alpha-SMA) protein in tubulointerstitium was detected by RT-PCR and immunohistochemistry at each time point, respectively. The results showed that the PAR-2 expression in renal tubulointerstitium was increased progressively starting from 24 h to the day 14 post-ligation, and it was significantly associated with the relative volume of interstitium and the positive area of alpha-SMA. PAR-2 was mainly expressed in renal tubule epithelial cells, especially in proximal tubular cells. It also located in renal capillary ansa, interstitial infiltrate cells and fibroblasts. It was concluded that PAR-2 was active in interstitial and tubular cells in the early phase of fibrotic process and played an important role in mediating the tubulointerstitial lesion after UUO.