A common precursor for hematopoietic and endothelial cells

TLDR

Embryoid bodies derived from embryonic stem cells contain a precursor that, upon VEGF stimulation, forms blast colonies in semi‑solid medium. When transferred to liquid culture with cytokines, these blast colonies differentiate into both hematopoietic and stromal cells. The blast‑colony forming cell is a transient hemangioblast that generates hematopoietic and endothelial lineages, evidenced by endothelial marker expression, mixed‑lineage differentiation, and rapid loss during embryoid body development.

Abstract

ABSTRACT Embryonic stem cell-derived embryoid bodies contain a unique precursor population which, in response to vascular endothelial growth factor, gives rise to blast colonies in semi-solid medium. Upon transfer to liquid culture with appropriate cytokines, these blast colonies generate both hematopoietic and adherent, stromal-type cells. Cells within the adherent population display characteristics of endothelial lineage including the expression of CD31, flk-1, flt-1, tie-2, the capacity to take up acetylated LDL and the presence of cytoplasmic Weibel-Palade bodies. Mixing studies demonstrated that the hematopoietic and endothelial precursors within the blast colonies develop from the same cell, the blast colony-forming cell. Kinetic analysis showed that the blast colony-forming cell represents a transient cell population that develops early and is lost quickly during embryoid body development. These findings provide strong evidence that the blast colony-forming cell represents the long-hypothesized hemangioblast, the common precursor of the hematopoietic and endothelial lineages.