Increased hematopoietic stem cell mobilization in aged mice.
Hematopoietic stem and progenitor cells (HSPCs) are located in the bone marrow in close association with a highly organized 3-dimensional structure formed by stroma cells, referred to as the niche. Mobilization of HSPCs from bone marrow to peripheral blood in response to granulocyte colony-stimulating factor (G-CSF) requires de-adhesion of HSPCs from the niche. The influence of aging of HSPCs on cell-stroma interactions has not been determined in detail. Using a mouse model of G-CSF-induced mobilization, we demonstrated that the ability to mobilize hematopoietic stem cells is approximately 5-fold greater in aged mice. Competitive mobilization experiments confirmed that enhanced mobilization ability was intrinsic to the stem cell. Enhanced mobilization efficiency of primitive hematopoietic cells from aged mice correlated with reduced adhesion of hematopoietic progenitor cells to stroma and with elevated levels of GTP-bound Cdc42. These results might indicate that stroma-stem cell interactions are dynamic over a lifetime and result in physiologically relevant changes in the biology of primitive hematopoietic cells with age.
Xing
Zhenlan
Z
Division of Experimental Hematology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229, USA.
Ryan
Marnie A
MA
Daria
Deidre
D
Nattamai
Kalpana J
KJ
Van Zant
Gary
G
Wang
Lei
L
Zheng
Yi
Y
Geiger
Hartmut
H
D000375:Aging; D000818:Animals; D002448:Cell Adhesion; D002465:Cell Movement; D016179:Granulocyte Colony-Stimulating Factor / Q000378:metabolism; D019650:Hematopoietic Stem Cell Mobilization; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D013234:Stem Cells / Q000166:cytology; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000378:metabolism
D016179:Granulocyte Colony-Stimulating Factor; D020764:cdc42 GTP-Binding Protein; D020741:rho GTP-Binding Proteins