title: CXCR4+CD45-Cells are Niche Forming for Osteoclastogenesis via the SDF-1, CXCL7, and CX3CL1 Signaling Pathways in Bone Marrow.
abstract: Bone homeostasis comprises the balance between bone-forming osteoblasts and bone-resorbing osteoclasts (OCs), with an acceleration of osteoclastic bone resorption leading to osteoporosis. OCs can be generated from bone marrow cells (BMCs) under the tightly regulated local bone environment. However, it remained difficult to identify the critical cells responsible for providing an osteoclastogenesis niche. In this study, we used a fluorescence-activated cell sorting technique to determine the cell populations important for forming an appropriate microenvironment for osteoclastogenesis and to verify the associated interactions between osteoclast precursor cells and non-OCs. We isolated and removed a small cell population specific for osteoclastogenesis (CXCR4+CD45-) from mouse BMCs and cultured the remaining cells with receptor activator of nuclear factor-kappa B ligand (RANKL) and macrophage-colony stimulating factor. The resulting cultures showed significantly less large osteoclast formation. Quantitative RT-PCR analysis revealed that these CXCR4+CD45-cells expressed low levels of RANK and RANKL, but high levels of critical chemokines including stromal cell derived factor 1 (SDF-1), chemokine (C-X-C motif) ligand 7 (CXCL7), and chemokine (C-X3-C motif) ligand 1 (CX3CL1). Furthermore, an SDF-1-specific antibody strongly suppressed OC formation in RAW264.7 cells and antibodies against SDF-1, CXCL7, and CX3CL1 suppressed OC formation in BMCs. These results suggest that isolated CXCR4+CD45-cells support an appropriate microenvironment for osteoclastogenesis with a direct effect on the cells expressing SDF-1, CXCL7, and CX3CL1 receptors. The regulation of CXCR4+CD45-cell function might therefore inform therapeutic strategies for diseases involving loss of bone homeostasis. Stem Cells 2016;34:2733-2743.
authors.affiliation: Department of Orthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.|Department of Molecular Neurobiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Yoh
authors.initials: Y
authors.lastname: Goto
authors.affiliation: Department of Molecular Neurobiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.|Department of Pathobiology, Nagoya City University Graduate School of Pharmaceutical Sciences, Nagoya, Japan.
authors.forename: Mineyoshi
authors.initials: M
authors.lastname: Aoyama
authors.affiliation: Department of Orthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.|Department of Molecular Neurobiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Sekiya
authors.affiliation: Department of Molecular Neurobiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.|Department of Perinatal and Neonatal Medicine, Aichi Medical University, Nagakute, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kakita
authors.affiliation: Department of Joint Surgery for Rheumatic Diseases, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Waguri-Nagaya
authors.affiliation: Department of Orthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Miyazawa
authors.affiliation: Department of Molecular Neurobiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Asai
authors.affiliation: Department of Orthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.
authors.forename: Shigemi
authors.initials: S
authors.lastname: Goto
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D002454:Cell Differentiation; D054428:Chemokine CX3CL1 / Q000235:genetics* / Q000378:metabolism; D054377:Chemokine CXCL12 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D019743:Chemokines, CXC / Q000235:genetics* / Q000378:metabolism; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D017493:Leukocyte Common Antigens / Q000172:deficiency / Q000235:genetics*; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D008297:Male; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010012:Osteogenesis / Q000235:genetics; D061251:Primary Cell Culture; D053245:RANK Ligand / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000235:genetics / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D013977:Tibia / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D000906:Antibodies; C514936:CXCR4 protein, mouse; D054428:Chemokine CX3CL1; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; C515539:Cx3cl1 protein, mouse; C515256:Cxcl12 protein, mouse; C446301:Cxcl7 protein, mouse; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D019718:Receptors, CXCR4; C505687:Tnfrsf11a protein, mouse; C505689:Tnfsf11 protein, mouse; D016173:Macrophage Colony-Stimulating Factor; D017493:Leukocyte Common Antigens; C516770:Ptprc protein, mouse
keywords: CXCR4+CD45− cells; Microenvironment; Osteoclastogenesis; SDF-1; SDF-1/CXCR4 axis