Regulation of transforming growth factor-beta receptor expression by hypoxia in vitro and in vivo

Rationale: Pulmonary arterial hypertension (PAH) is characterized by pulmonary arterial remodelling, leading to a progressive increase in pulmonary arterial pressure and right heart failure. Mutations in activin A receptor type II-like 1 (ALK1), a TGF-beta type 1 receptor previously reported to cause type 2 hereditary hemorrhagic telangiectasia (HHT), have been detected in HHT families with clinical and histological features of PAH. A major component of the pulmonary vascular remodelling process that leads to PAH is pulmonary arterial smooth muscle cell (PASMC) proliferation, which may result from an increased s…