Activin-A regulates BMP signalling in pulmonary endothelial cells without affecting BMPR-II expression.

Activin-A is elevated in PAH patients, and reportedly suppresses BMPR-II. This suggests one mechanism of action for PAH drug, sotatercept, an activin-ligand trap. However, we were unable to confirm that activin-A reduces BMPR-II in pulmonary endothelial cells. Thus, it seems unlikely that sotatercept influences BMPR-II or PAH via this mechanism.