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Updated: Mar 15, 2026

Directed Differentiation of Primitive and Definitive Hematopoietic Progenitors from Human Pluripotent Stem Cells
Published on: November 1, 2017
Origin of the hematopoietic system in the human embryo
Emmanuelle Julien1, Reine El Omar1, Manuela Tavian1
1Inserm UMR-S949, Etablissement Français du Sang-ALCA, University of Strasbourg, France.
Abstract:
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, but an elusive blood-forming potential is present earlier in the underlying splanchnopleura. 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. This review is intended to summarize the recent advances made to understand the origins of hematopoietic stem cells in the early human embryo. In addition, we discuss in detail the discovery of the angiotensin-converting enzyme (ACE) as a novel marker of human HSC and of prehematopoietic precursors inside the embryo.
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