title: Increased hematopoietic stem cell mobilization in aged mice.
abstract: 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.
authors.affiliation: Division of Experimental Hematology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229, USA.
authors.forename: Zhenlan
authors.initials: Z
authors.lastname: Xing
authors.forename: Marnie A
authors.initials: MA
authors.lastname: Ryan
authors.forename: Deidre
authors.initials: D
authors.lastname: Daria
authors.forename: Kalpana J
authors.initials: KJ
authors.lastname: Nattamai
authors.forename: Gary
authors.initials: G
authors.lastname: Van Zant
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Zheng
authors.forename: Hartmut
authors.initials: H
authors.lastname: Geiger
mesh_terms: 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
chemical_list: D016179:Granulocyte Colony-Stimulating Factor; D020764:cdc42 GTP-Binding Protein; D020741:rho GTP-Binding Proteins