title: Development of the hemangioblast defines the onset of hematopoiesis in human ES cell differentiation cultures.
abstract: The onset of hematopoiesis in the mouse embryo and in the embryonic stem (ES) cell differentiation model is defined by the emergence of the hemangioblast, a progenitor with both hematopoietic and vascular potential. While there is evidence for the existence of a hemangioblast in the mouse, it is unclear if this progenitor develops during the establishment of the human hematopoietic system. In this report, we have mapped hematopoietic development in human ES cell (hESC) differentiation cultures and demonstrated that a comparable hemangioblast population exists. The human hemangioblasts were identified by their capacity to generate blast colonies that display both hematopoietic and vascular potential. These colony-forming cells express the receptor tyrosine kinase KDR (VEGF receptor 2) and represent a transient population that develops in BMP-4-stimulated embryoid bodies (EBs) between 72 and 96 hours of differentiation, prior to the onset of the primitive erythroid program. Two distinct types of hemangioblasts were identified, those that give rise to primitive erythroid cells, macrophages, and endothelial cells and those that generate only the primitive erythroid population and endothelial cells. These findings demonstrate for the first time the existence of the human hemangioblast and in doing so identify the earliest stage of hematopoietic commitment.
authors.affiliation: Department of Gene and Cell Medicine, The Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York. NY 10029, USA.
authors.forename: Marion
authors.initials: M
authors.lastname: Kennedy
authors.forename: Sunita L
authors.initials: SL
authors.lastname: D'Souza
authors.forename: Macarena
authors.initials: M
authors.lastname: Lynch-Kattman
authors.forename: Staci
authors.initials: S
authors.lastname: Schwantz
authors.forename: Gordon
authors.initials: G
authors.lastname: Keller
mesh_terms: D001483:Base Sequence; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D016207:Cytokines / Q000502:physiology; D017931:DNA Primers / Q000235:genetics; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D004920:Erythropoiesis / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D006410:Hematopoiesis / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics
chemical_list: C525809:BMP4 protein, human; C525810:Bmp4 protein, mouse; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D016207:Cytokines; D017931:DNA Primers; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D040301:Vascular Endothelial Growth Factor Receptor-2