Dorso-ventral contributions in the formation of the embryonic aorta and the control of aortic hematopoiesis.
The embryonic dorsal aorta plays a pivotal role in the production of the first hematopoietic stem cells (HSCs), the founders of the adult hematopoietic system. HSC production is polarized by being restricted to the aortic floor where a specialized subset of endothelial cells (ECs) endowed with hemogenic properties undergo an endothelial-to-hematopoietic production resulting in the formation of the intra-aortic hematopoietic clusters. This production is tightly time- and space-controlled with the transcription factor Runx1 playing a key role in this process and the surrounding tissues controlling the aortic shape and fate. In this paper, we shall review (a) how hemogenic ECs differentiate from the mesoderm, (b) how the different aortic components assemble coordinately to establish the dorso-ventral polarity, and (c) how this results in the initiation of Runx1 expression in hemogenic ECs and the initiation of the hematopoietic program. These observations should elucidate the first steps in HSC commitment and help in developing techniques to manipulate adult HSCs.
CNRS, UPMC, UMR7622, Bat C, 6(ème) étage, Case 24, 9, quai Saint Bernard, 75252 Paris Cedex 05, France. Electronic address: thierry.jaffredo@upmc.fr.
Thierry
T
Jaffredo
Aveline
A
Lempereur
Charlotte
C
Richard
Karine
K
Bollerot
Rodolphe
R
Gautier
Pierre-Yves
PY
Canto
Cécile
C
Drevon
Michèle
M
Souyri
Charles
C
Durand
D000818:Animals; D001011:Aorta / Q000196:embryology*; D019070:Cell Lineage; D054338:Cell Transdifferentiation / Q000502:physiology; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism; D006066:Gonads / Q000196:embryology; D006410:Hematopoiesis / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008648:Mesoderm / Q000196:embryology; D008650:Mesonephros / Q000196:embryology; D019170:Somites / Q000196:embryology
AGM; Aorta; BMP; E; EC; Embryo; HC; HH; HSC; Hematopoiesis; Hemogenic endothelium; Runx1; Sub-aortic mesenchyme; VEGF; aorta–gonad–mesonephros; bone morphogenetic protein; embryonic; endothelial cells; hedge hog; hematopoietic cells; hematopoietic stem cells; vSMC; vascular endothelial growth factor; vascular smooth muscle cells