Role of PAR-2 in tryptase mediated IEC-6 cell injury

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,100 μg / L and 1 000 μg / L) in the presence or absence of PAR-2 antagonist FSLLRYNH2 for 12 h respectively. The cell survival rate was detected by MTT assay. The protein levels of PAR-2 and cleavedcaspase 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-2and cleaved caspase 3 were significantly increased in 100 μg / L and 1 000 μg / L tryptase treated groups( P 0. 05). Compared with 1 000 μg / L tryptase treated group,the LDH activity and cleaved caspase 3 protein level were dramatically decreased 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.