Endothelial progenitor cells in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by ongoing endothelial dysfunction and vascular remodeling. Endothelial progenitor cells (EPCs), mobilized from the bone marrow and resident locally in the lung, are thought to be important in maintaining vascular homeostasis; and there is growing interest in the potential therapeutic use of EPCs in PAH. Putative progenitor cells have also been localized to vascular lesions in the lungs of patients with PAH, raising questions about their role in vascular remodeling and disease progression. Further studies are required to determine the identity, origin, and function of progenitor cells in pulmonary vascular lesions and to establish whether the mobilization and recruitment of EPCs in the hypertensive pulmonary vascular system represent a protective process and/or involvement in the pathogenesis of PAH.