Role of PAR-2 in tryptase mediated IEC-6 cell injury / 中国病理生理杂志

ABSTRACT

[ ABSTRACT] AIM:To investigate the role of protease activated receptor-2 ( PAR-2 ) in the process of tryptase mediated IEC-6 cell injury.METHODS:The rat intestinal epithelial cell line IEC-6 was treated with tryptase at different concentrations (1 μg/L, 10 μg/L, 100μg/L and 1 000μg/L) in the presence or absence of PAR-2 antagonist FSLLRY-NH2 for 12 h respectively.The cell survival rate was detected by MTT assay.The protein levels of PAR-2 and cleaved-caspase 3 were determined by Western blotting.The LDH activity was also measured.RESULTS:Compared with control group, the cell survival rates were significantly decreased in 100 μg/L and 1 000 μg/L tryptase treated groups, the LDH activities were significantly increased in 10 μg/L to 1 000 μg/L tryptase treated groups, and the protein levels of PAR-2 and cleaved caspase 3 were significantly increased in 100μg/L and 1 000μg/L tryptase treated groups (P<0.05).Com-pared with 1 000 μg/L tryptase treated group, the LDH activity and cleaved caspase 3 protein level were dramatically de-creased while the survival rate was significantly increased in the presence of PAR-2 antagonist FSLLRY-NH2 (P<0.05). CONCLUSION:Tryptase induces IEC-6 cell injury in a dose-dependent manner by activating PAR-2.