BACKGROUNDProtease activated receptor-2 is cleaved and activated by trypsin or mast cell tryptase and may play an important role in inflammation. However, it is unknown whether PAR-2 can mediate tryptase-induced inflammatory reaction. This study was conduct to investigate whether PAR-2 could be the activated by mast cell tryptase and medicated the tryptase induced interleukin-8 expression in endothelial cells.

METHODSProtease activated receptor-2 expression was found in endothelial cell lines ECV304 cell by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. Interleukin-8 stimulated by purified human mast cell tryptase was determined by RT-PCR and enzyme linked immunosorbent assay (ELISA). Data were analysed by the S-N-K one-way ANOVA test.

RESULTSThe present study shows that mRNA and protein of protease activated receptor-2 could be expressed in ECV304 cells, and tryptase upregulated the expression levels of both interleukin-8 mRNA and protein. The increased expression of interleukin-8 was inhibited by an antiprotease activated receptor-2 monoclonal antibody, SAM11. An additional band was observed by Western blotting after the incubation of ECV304 cells with tryptase for 2 hours, which suggested that protease activated receptor-2 was activated.

CONCLUSIONProtease activated receptor-2 can mediate the mast cell tryptase stimulated expression of interleukin-8 in ECV304 cell.