title: Cellular players of hematopoietic stem cell mobilization in the bone marrow niche.
abstract: Hematopoietic stem cells (HSC) reside in perivascular regions of the bone marrow (BM) embedded within a complex regulatory unit called the niche. Cellular components of HSC niches include vascular endothelial cells, mesenchymal stromal progenitor cells and a variety of mature hematopoietic cells such as macrophages, neutrophils, and megakaryocytes-further regulated by sympathetic nerves and complement components as described in this review. Three decades ago the discovery that cytokines induce a large number of HSC to mobilize from the BM into the blood where they are easily harvested, revolutionised the field of HSC transplantation-curative for immune-deficiencies and some malignancies. However, despite now routine use of granulocyte-colony stimulating factor (G-CSF) to mobilise HSC for transplant, only in last 15 years has research on the mechanisms behind why and how HSC can be induced to move into the blood began. These studies have revealed the complexity of the niche that retains HSC in the BM. This review describes how BM niches and HSC themselves change during administration of G-CSF-or in the recovery phase of chemotherapy-to facilitate movement of HSC into the blood, and research now leading to development of novel therapeutics to further boost HSC mobilization and transplant success.
authors.affiliation: Stem Cells and Cancer Group, Blood and Bone Diseases Program, Faculty of Medicine and Biomedical Sciences, Mater Research Institute, Translational Research Institute, University of Queensland, 37 Kent Street, Woolloongabba, QLD, 4102, Australia.
authors.forename: Joshua
authors.initials: J
authors.lastname: Tay
authors.affiliation: Stem Cell Biology Group, Blood and Bone Diseases Program, Faculty of Medicine and Biomedical Sciences, Mater Research Institute, Translational Research Institute, University of Queensland, 37 Kent Street, Woolloongabba, QLD, 4102, Australia. jp.levesque@mater.uq.edu.au.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Levesque
authors.affiliation: Stem Cells and Cancer Group, Blood and Bone Diseases Program, Faculty of Medicine and Biomedical Sciences, Mater Research Institute, Translational Research Institute, University of Queensland, 37 Kent Street, Woolloongabba, QLD, 4102, Australia. Ingrid.winkler@mater.uq.edu.au.
authors.forename: Ingrid G
authors.initials: IG
authors.lastname: Winkler
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000737:chemistry / Q000187:drug effects; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods*; D006801:Humans; D055153:Stem Cell Niche / Q000187:drug effects*
chemical_list: D016179:Granulocyte Colony-Stimulating Factor
keywords: Bone marrow; Hematopoietic stem cells; Mobilization; Stem cell niche