Specification and function of hemogenic endothelium during embryogenesis

Abstract

Hemogenic endothelium is a specialized subset of developing vascular endothelium that acquires hematopoietic potential and can give rise to multilineage hematopoietic stem and progenitor cells during a narrow developmental window in tissues such as the extraembryonic yolk sac and embryonic aorta-gonad-mesonephros. Herein, we review current knowledge about the historical and developmental origins of hemogenic endothelium, the molecular events that govern hemogenic specification of vascular endothelial cells, the generation of multilineage hematopoietic stem and progenitor cells from hemogenic endothelium, and the potential for translational applications of knowledge gained from further study of these processes.

Keywords: Developmental hematopoiesis; Embryogenesis; Endothelial to hematopoietic transition; Hemogenic endothelium.

Fig. 1

Summary of regulation of primitive hematopoietic specification and generation of hematopoietic stem cells during embryonic development. a Schematic representation of endothelial layer of developing vascular wall (pink), listed are intra- and extraembryonic sources of vascular endothelial cells with hemogenic potential (blue box). b Schematic representation of progression of events and molecular signals governing hemogenic specification (orange boxes) and c endothelial to hematopoietic transition (green boxes), ending with generation of intra-vascular hematopoietic clusters and multi-lineage hematopoietic stem and progenitor cells (HSPC)