NLRP3 and pulmonary arterial hypertension: In the present study, by using MCT-induced PAH model rats and hypoxia-treated PASMCs, we verified that AS-IV alleviated MCT-induced pulmonary artery structural remodeling, pulmonary hypertension and right ventricular hypertrophy, and suppressed NLRP3-mediated pyroptosis and fibrosis in PAH models in vivo and in vitro.