Astragaloside IV Inhibits Lung Injury and Fibrosis Induced by PM2.5 by Targeting RUNX1 Through miR-362-3p.

To discover the molecular mechanism of Astragaloside IV (AS IV) in PM2.5-induced lung injury and pulmonary fibrosis (PF). A lung injury rat model was induced by PM2.5 and injected intraperitoneally with AS IV. Lungs were harvested to evaluate lung tissue injury and apoptosis. Rat alveolar epithelial cells L2 were exposed to PM2.5 and treated with AS IV. After cellular transfection, cell proliferation, LDH production, and apoptosis were measured. In both models, inflammatory factors and fibrotic indices were measured by ELISA and Western blot. miR-362-3p and RUNX1 interplay was explored and confirmed. Administration of AS IV attenuated PM2.5-induced lung tissue injury, inflammation, apoptosis, and PF in rats. AS IV enhanced proliferation and reduced LDH release, apoptosis, inflammation, and PF in PM2.5-treated L2 cells. MiR-362-3p upregulation improved PM2.5-induced L2 cell injury. AS IV improved PM2.5-induced lung injury by upregulating miR-362-3p. miR-362-3p had an inhibition effect on RUNX1 expression. RUNX1 upregulation weakened the therapeutic effect of AS IV on PM2.5-induced alveolar epithelial cell injury. AS IV inhibits lung injury and PF induced by PM2.5 by targeting RUNX1 through upregulation of miR-362-3p.