OBJECTIVE A novel mast cell-specific G-protein-coupled receptor(GPCR),known as mas-related GPCR-B2(MRGPRB2),plays important roles in the immune response.The opening of ion channels mediated by MRGPRB2 activation remai...OBJECTIVE A novel mast cell-specific G-protein-coupled receptor(GPCR),known as mas-related GPCR-B2(MRGPRB2),plays important roles in the immune response.The opening of ion channels mediated by MRGPRB2 activation remains unclear.METHODS AND RE⁃SULTS Calcium influx induced by activation of MRGPRB2 receptor in mouse peritoneal mast cells was related to the concentrations of calcium ions in the extracellular solution.Similarly,the volt⁃age-dependent current generated by MRGPRB2 activation was also correlated with the extracellu⁃lar calcium concentration.In addition,the in⁃creased of calcium influx or voltage-dependent current caused by activation of MrgprB2 could be blocked by U73122(PLC blocker)or 2-APB(IP3-ORAI1 blocker).Meanwhile,calcium-activated chlorine channel(TMEM16A)was involved in the generation of voltage-dependent currents in⁃duced by MRGPRB2 activation in mouse perito⁃neal mast cells.Furthermore,the degranulation of mouse peritoneal mast cells mediated by MRGPRB2 receptor could also be inhibited by U73122 or 2-APB.CONCLUSION PLC-IP3-ORAI1-TMEM16A signaling pathway was involved in MRGPRB2-mediated mast cell activation.展开更多
文摘OBJECTIVE A novel mast cell-specific G-protein-coupled receptor(GPCR),known as mas-related GPCR-B2(MRGPRB2),plays important roles in the immune response.The opening of ion channels mediated by MRGPRB2 activation remains unclear.METHODS AND RE⁃SULTS Calcium influx induced by activation of MRGPRB2 receptor in mouse peritoneal mast cells was related to the concentrations of calcium ions in the extracellular solution.Similarly,the volt⁃age-dependent current generated by MRGPRB2 activation was also correlated with the extracellu⁃lar calcium concentration.In addition,the in⁃creased of calcium influx or voltage-dependent current caused by activation of MrgprB2 could be blocked by U73122(PLC blocker)or 2-APB(IP3-ORAI1 blocker).Meanwhile,calcium-activated chlorine channel(TMEM16A)was involved in the generation of voltage-dependent currents in⁃duced by MRGPRB2 activation in mouse perito⁃neal mast cells.Furthermore,the degranulation of mouse peritoneal mast cells mediated by MRGPRB2 receptor could also be inhibited by U73122 or 2-APB.CONCLUSION PLC-IP3-ORAI1-TMEM16A signaling pathway was involved in MRGPRB2-mediated mast cell activation.