Mapping disease-specific vascular cell populations responsible for obliterative arterial remodeling during development of pulmonary arterial hypertension.

Background: Pulmonary arterial hypertension (PAH) is a lethal pulmonary vascular disease characterized by arteriolar pruning and occlusive vascular remodeling leading to increased pulmonary vascular resistance and eventually right heart failure. While endothelial cell (EC) injury and apoptosis are known triggers for this disease, the mechanisms by which they lead to complex arterial remodeling remain obscure.

Aims: We employed multiplexed single-cell RNA sequencing at multiple timepoints during the onset and progression of disease in a model of severe PAH to identify mechanisms involved in the development of occlusive arterial lesions.

Cellular senescence in the pathogenesis of pulmonary arterial hypertension: the good, the bad and the uncertain.

Senescence refers to a cellular state marked by irreversible cell cycle arrest and the secretion of pro-inflammatory and tissue-remodeling factors. The senescence associated secretory phenotype (SASP) impacts the tissue microenvironment and provides cues for the immune system to eliminate senescent cells (SCs). Cellular senescence has a dual nature; it can be beneficial during embryonic development, tissue repair, and tumor suppression, but it can also be detrimental in the context of chronic stress, persistent tissue injury, together with an impairment in SC clearance.