Identification of Endothelial Cells and Their Progenitors

Blood vessel formation is a key feature in physiologic and pathologic processes. Once considered a homogeneous cell population that functions as a passive physical barrier between blood and tissue, endothelial cells (ECs) are now recognized to be quite "heterogeneous." While numerous attempts to enhance endothelial repair and replacement have been attempted using so called "endothelial progenitor cells" it is now clear that a better understanding of the origin, location, and activation of stem and progenitor cells of the resident vascular endothelium is required before attempting exogenous cell therapy approaches. This chapter provides an overview for performance of single-cell clonogenic studies of human umbilical cord blood circulating endothelial colony-forming cells (ECFC) that represent distinct precursors for the endothelial lineage with vessel forming potential.

Endothelial Progenitor Cells' Classification and Application in Neurological Diseases

The therapeutic effects of endothelial progenitor cells (EPCs) on ischemic stroke have been extensively studied in recent years. However, the differences in early EPCs and endothelial outgrowth cells (EOCs) are still unclear. Clarifications of their respective properties and specific functioning characteristics contribute to better applications of EPCs in ischemic diseases. In this review, we discuss cellular origin, isolation, culture, surface markers of early EPCs and EOCs and relevant applications in neurological diseases. We conclude that EOCs possess all characteristics of true endothelial progenitors and have potent advantages in EPC-based therapies for ischemic diseases. A number of preclinical and clinical applications of EPCs in neurological diseases are under study. More studies are needed to determine the specific characteristics of EPCs and the relevant mechanisms of EPCs for neurological diseases.