Role of the protease-activated receptor 2 in multi-walled carbon nanotube-induced macrophage polarization ex vivo and airway fibrosis in murine allergic lung disease in vivo

MWCNT exposure exacerbates Th2-driven M2 macrophage polarization in a PAR2-dependent manner, leading to increased fibroblast activation and collagen deposition. Myeloid PAR2 is a critical driver of fibrotic remodeling in allergic lung disease, representing a potential therapeutic target for mitigating fibrosis in environmentally exacerbated asthma.