Endothelial progenitor cells (EPCs) in therapy

Abstract

Stem progenitor cells serve as a functional reserve and may differentiate into mature cells with a different phenotype. Partially differentiated endothelial progenitor cells (EPCs) are characterized by the expression of surface molecules such as endoglin (CD105), vWF, PECAM-1/CD31, VE-cadherin, CD146, CD62E, CD51/61, CD106, CD41a, CD41b, CD34 and AC133, growth factor receptors (e.g. Flt-1, KDR and Tie-1) and others. They may also express the functional capabilities of endothelial cells in the course of their differentiation (e.g. incorporation of modified LDL). Animal studies have confirmed the proangiogenic activity of labelled human (bone marrow, umbilical cord and peripheral blood) as well as animal EPCs in the experimental models of myocardial, peripheral and cerebral ischaemia. The goal of these studies has been to improve the vascularisation and functional activity of the target organs.
The first clinical studies in peripheral and coronary artery disease revealed the clinical efficacy of human bone marrow-derived mononuclear fraction in diminishing the adverse effects of peripheral and myocardial ischaemia. No significant side-effects of the EPC application were observed, but further studies are required to confirm the long-term safety and efficacy of this method as well as to assess its possible hazards.