MTOR and pulmonary arterial hypertension: However, berberine substantially decreased pulmonary vascular remodeling in mice with hypoxia-induced PAH by inhibiting Akt/mammalian target of rapamycin (mTOR)/HIF-1α and transforming growth factor β (TGF-β) pathways, and activating bone morphogenetic protein type 2 (BMPR-2) receptor (Chen et al., 2019; Liu et al., 2019).