New insights into deadly lung disease could pave the way to treatments

Pulmonary arterial hypertension is a deadly disease that affects the lung vasculature, leading to the stiffening and remodeling of small vessels. Currently, no disease-modifying therapies exist. Researchers recently showed that a subpopulation of cells called bone marrow (BM)–derived proangiogenic cells (PACs) directly contribute to pulmonary hypertension in mice. Specifically, BM-PACs promote the stiffening and remodeling of small vessels through signaling mediated by a protein called the serotonin 2B receptor. In mice and patients with pulmonary arterial hypertension, the presence of BM-derived PACs significantly correlated with stiffer small vessels. Moreover, treatment with a pharmacological inhibitor of the serotonin 2B receptor prevented pulmonary hypertension in mice, reducing the stiffness of small vessels in the lungs. The findings could point toward novel treatments for pulmonary arterial hypertension in humans. The study, which was partly funded by the NHLBI, was published in the journal Circulation Research.