Abstract

The protease-activated receptor 1 (PAR1) is a critical component of cellular signaling, mediating both procoagulant and cytoprotective effects, notably those of Activated Protein C (APC). This study investigates the regulatory role of APC and a specific PAR1 agonist peptide on the proinflammatory activation of RBL-2H3 cells, a widely utilized mast cell line model for studying allergic and inflammatory responses. RBL-2H3 cells, upon activation, release potent inflammatory mediators, making them an ideal system to explore anti-inflammatory mechanisms. Using established cell culture and biochemical assays, we examined the impact of APC and the PAR1 agonist on key markers of mast cell activation, including degranulation and the release of pro-inflammatory cytokines. Our findings demonstrate that both APC and the PAR1 agonist peptide significantly attenuate the proinflammatory response in RBL-2H3 cells, suggesting a common PAR1-mediated signaling pathway that suppresses mast cell activity. This regulatory mechanism highlights a novel therapeutic potential for PAR1-targeting agents in the management of allergic diseases and chronic inflammatory conditions.