Endothelial progenitor cells and cardiovascular risk: does ageing trump all other factors?
Discovered nearly 20 years ago, endothelial progenitor cells (EPC) attract both basic and clinical researchers (1). As key regulators of vascular homeostasis in health and disease, circulating progenitor cell levels reflect endogenous regenerative potential. Upon endothelial damage, EPC are mobilized from the bone marrow and follow chemokine gradients to sites of endothelial injury where they assist in endothelial repair mainly via paracrine mechanisms. Next to the production of angiogenic growth factors, novel modes of paracrine regulation are being discovered, such as the release of endothelial cell-derived microparticles or microvesicles that contain pro-angiogenic microRNAs (2).