title: Maintenance of quiescent hematopoietic stem cells in the osteoblastic niche.
abstract: Hematopoietic stem cells (HSCs) are responsible for blood cell production throughout an individual's lifetime. Interaction of HSCs with their specific microenvironments, known as stem cell niches, is critical for maintaining stem cell properties, including self-renewal capacity and the ability to differentiate into multiple lineages. During postnatal life, the bone marrow (BM) supports both self-renewal and differentiation of HSCs in specialized microenvironmental niches. In the adult BM, HSCs are located in the trabecular endosteum (osteoblastic niche) or sinusoidal perivascular (vascular niche) areas. Here we show that osteoblastic cells (OBs) are a critical component for sustaining slow-cycling or quiescent HSCs. Interaction of HSCs with OBs through signaling and cell adhesion molecules maintains the balance in HSCs between cell division/proliferation and quiescence. In particular, the quiescent state is thought to be an essential mechanism to protect HSCs from stress and to sustain long-term hematopoiesis.
authors.affiliation: Department of Cell Differentiation, The Sakaguchi Laboratory of Developmental Biology, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582, Japan. farai@sc.itc.keio.ac.jp
authors.forename: Fumio
authors.initials: F
authors.lastname: Arai
authors.forename: Toshio
authors.initials: T
authors.lastname: Suda
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology*; D002448:Cell Adhesion; D002454:Cell Differentiation; D049109:Cell Proliferation; D002469:Cell Separation; D005434:Flow Cytometry; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D008954:Models, Biological; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D018384:Oxidative Stress; D013234:Stem Cells / Q000166:cytology; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D048051:p38 Mitogen-Activated Protein Kinases