title: The negative impact of Wnt signaling on megakaryocyte and primitive erythroid progenitors derived from human embryonic stem cells.
abstract: The Wnt gene family consists of structurally related genes encoding secreted signaling molecules that have been implicated in many developmental processes, including regulation of cell fate and patterning during embryogenesis. Previously, we found that Wnt signaling is required for primitive or yolk sac-derived-erythropoiesis using the murine embryonic stem cell (ESC) system. Here, we examine the effect of Wnt signaling on the formation of early hematopoietic progenitors derived from human ESCs. The first hematopoietic progenitor cells in the human ESC system express the pan-hematopoietic marker CD41 and the erythrocyte marker, glycophorin A or CD235. We have developed a novel serum-free, feeder-free, adherent differentiation system that can efficiently generate large numbers of CD41+CD235+ cells. We demonstrate that this cell population contains progenitors not just for primitive erythroid and megakaryocyte cells but for the myeloid lineage as well and term this population the primitive common myeloid progenitor (CMP). Treatment of mesoderm-specified cells with Wnt3a led to a loss of hematopoietic colony-forming ability while the inhibition of canonical Wnt signaling with DKK1 led to an increase in the number of primitive CMPs. Canonical Wnt signaling also inhibits the expansion and/or survival of primitive erythrocytes and megakaryocytes, but not myeloid cells, derived from this progenitor population. These findings are in contrast to the role of Wnt signaling during mouse ESC differentiation and demonstrate the importance of the human ESC system in studying species-specific differences in development.
authors.affiliation: Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Prasuna
authors.initials: P
authors.lastname: Paluru
authors.affiliation: Division of Pulmonary, Allergy & Critical Care Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Hudock
authors.affiliation: Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Cheng
authors.affiliation: Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Mills
authors.affiliation: Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Ying
authors.affiliation: Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Aline M
authors.initials: AM
authors.lastname: Galvão
authors.affiliation: Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Lin
authors.initials: L
authors.lastname: Lu
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Amita
authors.initials: A
authors.lastname: Tiyaboonchai
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Sim
authors.affiliation: Division of Hematology, Children's Hospital of Philadelphia, PA, USA.
authors.forename: Spencer K
authors.initials: SK
authors.lastname: Sullivan
authors.affiliation: Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Deborah L
authors.initials: DL
authors.lastname: French
authors.affiliation: Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA. Electronic address: gaduep@email.chop.edu.
authors.forename: Paul
authors.initials: P
authors.lastname: Gadue
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D005434:Flow Cytometry; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D008533:Megakaryocytes / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D060449:Wnt Signaling Pathway / Q000502:physiology*