The emerging role of endothelial progenitor cells in pulmonary hypertension and diffuse lung diseases

The discovery that circulating bone marrow-derived cells contribute to the repair of many organs and tissues has provided new perspectives for the comprehension of the pathogenesis of lung diseases. Endothelial progenitor cells (EPCs) provide a circulating pool of cells for maintenance of the systemic and pulmonary circulation. By preserving an appropriate vascular support and/or by means of transdifferentiation, EPCs contribute to the homeostasis of the lung parenchyma. Alterations in EPCs and other extrapulmonary progenitor cells may impact on the chronic remodelling taking place in many diffuse lung diseases. In this review, we will focus on the experimental and clinical data suggesting that EPC deregulation may have a role in the pathogenesis of vascular and parenchymal lung diseases.