Endothelial cells are essential for the self-renewal and repopulation of Notch-dependent hematopoietic stem cells.
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.
Butler
Jason M
JM
Howard Hughes Medical Institute, Department of Genetic Medicine, Weill Cornell Medical College, New York, NY 10065, USA.
Nolan
Daniel J
DJ
Vertes
Eva L
EL
Varnum-Finney
Barbara
B
Kobayashi
Hideki
H
Hooper
Andrea T
AT
Seandel
Marco
M
Shido
Koji
K
White
Ian A
IA
Kobayashi
Mariko
M
Witte
Larry
L
May
Chad
C
Shawber
Carrie
C
Kimura
Yuki
Y
Kitajewski
Jan
J
Rosenwaks
Zev
Z
Bernstein
Irwin D
ID
Rafii
Shahin
S
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
D017077:Culture Media, Conditioned; D008024:Ligands; C497762:Notch1 protein, mouse; C497765:Notch2 protein, mouse; D051881:Receptor, Notch1; D051883:Receptor, Notch2