Mechanism of TSCS promote anti-Fas antibody-induced FLS apoptosis via blocking MC-tryptase-PAR-2-Rho-FLS signaling pathway

OBJECTIVE It has been supposed that mast cells have important participation in the physiopathology of RA,however,the role of mast cells in the pathogenesis of RA remains unclear.In this study,we observed the antiapoptotic effects of tryptase released by mast cell on RA synovial fibroblasts.METHODS Mast cells and fibroblasts synovial were obtained from mouse.Chemical mediator release was assessed by measuringβ-hexosa-minidase release.TSCS and bone marrow-derived mast cells were co-cultured;the toxic effects of TSCS on mast cell was measured by MTT and CCK-8 method;the releasing amount of tryptase in cell supernatants was measured by Elisa assay;the expression of FLS cell membrane receptor PAR-2 was detected by flow cytometry;the apoptosis of FLS cell was detected through flow cytometry and Western blotting;the level of activated Rho-GTP was detected by the pull-down method and Western blotting.RESULTS In this study,we observed the antiapoptotic effects of tryptase released by mast cell on RA synovial fibroblasts,and found that tryptase significantly increased the expression of PAR-2 on the surface of fibroblast-like synovial cell,significantly activated Rho kinase,significantly inhibited apoptosis of fibroblast-like synovial cell induced by CH11.The release rates ofβ-hexosaminidase and the level of tryptase from bone marrow-derived mast cells after stimulation with different antigen and co-cultured with TSCS significantly decreased compared to the control group.In the co-culture system of mast cells and fibroblast-like synovial cells,TSCS treatment significantly inhibited Rho kinase(P<0.05),significantly promoted apoptosis of fibroblast-like synovial cell induced by CH11(P<0.05).CONCLUSION These results demonstrate that tryptase may play a key role in the physiopathology of RA.TSCS can inhibit mast cells activation and promote FLS cells apoptosis.This provide theoretical and experimental basis for the study of mast cells as targets for new anti-RA drugs.