Identification, emergence and mobilization of circulating endothelial cells or progenitors in the embryo.
Using quail-chick parabiosis and QH1 monoclonal antibody analysis, we have identified circulating endothelial cells and/or progenitors in the embryo. These cells were already present early in ontogeny, before the third embryonic day. Under normal conditions, they integrated into most tissues but remained scarce. When experimental angiogenic responses were induced by wounding or grafts onto the chorioallantoic membrane, circulating endothelial cells were rapidly mobilized and selectively integrated sites of neoangiogenesis. Their mobilization was not dependent on the presence of the bone marrow as it was effective before its differentiation. Surprisingly, mobilization was not effective during sprouting angiogenesis following VEGF treatment of chorioallantoic membrane. Thus, embryonic circulating endothelial cells were efficiently mobilized during the establishment of an initial vascular supply to ischemic tissues following wounding or grafting, but were not involved during classical sprouting angiogenesis.
Pardanaud
Luc
L
INSERM, Unit 36, F-75005, Paris, France and Collège de France, F-75005, Paris, France. luc.pardanaud@college-de-france.fr
Eichmann
Anne
A
D000818:Animals; D001973:Bromodeoxyuridine; D002454:Cell Differentiation; D002470:Cell Survival; D002642:Chick Embryo; D003370:Coturnix; D004625:Embryo, Nonmammalian / Q000502:physiology*; D053595:Embryonic Stem Cells / Q000166:cytology / Q000502:physiology*; D042783:Endothelial Cells / Q000166:cytology / Q000502:physiology*; D019650:Hematopoietic Stem Cell Mobilization; D018919:Neovascularization, Physiologic; D033581:Stem Cell Transplantation; D014183:Transplantation, Heterologous; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology
D042461:Vascular Endothelial Growth Factor A; D001973:Bromodeoxyuridine