Blood endothelial cells: utility from ambiguity

Abstract

In the mid-1990s, my research group began to devise a method to establish endothelial cell cultures from human peripheral blood, with an ultimate goal of examining interindividual heterogeneity of endothelial biology. The initial work, published in the JCI in 2000, described the method enabling successful attainment of blood outgrowth endothelial cells (BOEC). Truly endothelial, BOEC are progeny of a transplantable cell that originates in bone marrow, a putative endothelial progenitor. Our subsequent experimental work focused upon practical applications of BOEC: their use for gene therapy, tissue engineering, assessment of mutant gene effect, and discovery of heterogeneity in endothelial biology.

Figure 1. Blood endothelial cell types, origins, and culture.

Circulating endothelial cells (CEC) are detached from the vessel wall endothelium as the result of injury and/or disease. Blood outgrowth endothelial cells (BOEC) have all the characteristics of mature endothelial cells. They seem to be progeny of endothelial colony–forming cells (ECFC), a marrow-derived progenitor that resides both in blood and within in situ endothelium. The other relevant cell appearing from appropriate culture of blood mononuclear cells was labeled “EPC” (intended for endothelial progenitor cells). These were later shown to be of hematopoietic stem cell (HSC) origin.