title: Endothelial cells are essential for the self-renewal and repopulation of Notch-dependent hematopoietic stem cells.
abstract: Bone marrow endothelial cells (ECs) are essential for reconstitution of hematopoiesis, but their role in self-renewal of long-term hematopoietic stem cells (LT-HSCs) is unknown. We have developed angiogenic models to demonstrate that EC-derived angiocrine growth factors support in vitro self-renewal and in vivo repopulation of authentic LT-HSCs. In serum/cytokine-free cocultures, ECs, through direct cellular contact, stimulated incremental expansion of repopulating CD34(-)Flt3(-)cKit(+)Lineage(-)Sca1(+) LT-HSCs, which retained their self-renewal ability, as determined by single-cell and serial transplantation assays. Angiocrine expression of Notch ligands by ECs promoted proliferation and prevented exhaustion of LT-HSCs derived from wild-type, but not Notch1/Notch2-deficient, mice. In transgenic notch-reporter (TNR.Gfp) mice, regenerating TNR.Gfp(+) LT-HSCs were detected in cellular contact with sinusoidal ECs. Interference with angiocrine, but not perfusion, function of SECs impaired repopulation of TNR.Gfp(+) LT-HSCs. ECs establish an instructive vascular niche for clinical-scale expansion of LT-HSCs and a cellular platform to identify stem cell-active trophogens.
authors.affiliation: Howard Hughes Medical Institute, Department of Genetic Medicine, Weill Cornell Medical College, New York, NY 10065, USA.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Butler
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Nolan
authors.forename: Eva L
authors.initials: EL
authors.lastname: Vertes
authors.forename: Barbara
authors.initials: B
authors.lastname: Varnum-Finney
authors.forename: Hideki
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Andrea T
authors.initials: AT
authors.lastname: Hooper
authors.forename: Marco
authors.initials: M
authors.lastname: Seandel
authors.forename: Koji
authors.initials: K
authors.lastname: Shido
authors.forename: Ian A
authors.initials: IA
authors.lastname: White
authors.forename: Mariko
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Larry
authors.initials: L
authors.lastname: Witte
authors.forename: Chad
authors.initials: C
authors.lastname: May
authors.forename: Carrie
authors.initials: C
authors.lastname: Shawber
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kimura
authors.forename: Jan
authors.initials: J
authors.lastname: Kitajewski
authors.forename: Zev
authors.initials: Z
authors.lastname: Rosenwaks
authors.forename: Irwin D
authors.initials: ID
authors.lastname: Bernstein
authors.forename: Shahin
authors.initials: S
authors.lastname: Rafii
mesh_terms: D000818:Animals; D002450:Cell Communication; D019070:Cell Lineage; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D017077:Culture Media, Conditioned; D042783:Endothelial Cells / Q000166:cytology* / Q000378:metabolism*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism*; D008024:Ligands; D051379:Mice; D018345:Mice, Knockout; D051881:Receptor, Notch1 / Q000172:deficiency / Q000378:metabolism; D051883:Receptor, Notch2 / Q000172:deficiency / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D017077:Culture Media, Conditioned; D008024:Ligands; C497762:Notch1 protein, mouse; C497765:Notch2 protein, mouse; D051881:Receptor, Notch1; D051883:Receptor, Notch2