The continuous generation of blood cells throughout life relies on the existence of hematopoietic stem cells (HSC) generated during embryogenesis. Given the importance of HSC transplantation in cell-based therapeutic approaches, considerable efforts have been made toward understanding the developmental origins of embryonic HSC. Adult-type HSC are first generated in the aorta-gonad-mesonephros (AGM) region between days 27 and 40 of human embryonic development. It is relatively well accepted that the HSC emerge in the AGM through a hemogenic endothelium, but the direct precursor of this cell type remains to be clearly identified. The current picture of human hematopoietic development is largely extrapolated from animal models (mouse and zebrafish), as comparable studies on the human embryo are not possible. Human pluripotent stem cells (hPSCs) offer unprecedented opportunity to complement this knowledge, assuming that differentiation in the culture dish can recapitulate the dynamic and complexity of hematopoietic development in vivo. Here we summarize the recent advances made to understand the origins of hematopoietic stem cells in the early embryo and we discuss in detail latest protocols to obtain HSC from hPSCs.
Clinical Laboratory Scientist17%
Medical Laboratory Technician17%