PDGF-dependent β-catenin activation is associated with abnormal pulmonary artery smooth muscle cell proliferation in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterized by excessive pulmonary arterial smooth muscle cells (PASMCs) growth, partially in response to PDGF-BB but whether this is dependent on β-catenin (βC) activation is unclear. Compared to healthy cells, PAH PASMCs demonstrate higher levels of proliferation both at baseline and with PDGF-BB that correlate with GSK3β dependent βC activation. We show that βC knockdown but not Wnt5a stimulation reduces PDGF-BB dependent growth and normalizes PAH PASMCs proliferation. These findings support that cross-talk between PDGF and Wnt signaling modulates PASMC proliferation and suggest that βC targeted therapies could treat abnormal vascular remodeling in PAH.