title: Bone marrow-derived osteoblast progenitor cells in circulating blood contribute to ectopic bone formation in mice.
abstract: Recent studies have suggested the existence of osteoblastic cells in the circulation, but the origin and role of these cells in vivo are not clear. Here, we examined how these cells contribute to osteogenesis in a bone morphogenetic protein (BMP)-induced model of ectopic bone formation. Following lethal dose-irradiation and subsequent green fluorescent protein-transgenic bone marrow cell-transplantation (GFP-BMT) in mice, a BMP-2-containing collagen pellet was implanted into muscle. Three weeks later, a significant number of GFP-positive osteoblastic cells were present in the newly generated ectopic bone. Moreover, peripheral blood mononuclear cells (PBMNCs) from the BMP-2-implanted mouse were then shown to include osteoblast progenitor cells (OPCs) in culture. Passive transfer of the PBMNCs isolated from the BMP-2-implanted GFP-mouse to the BMP-2-implanted nude mouse led to GFP-positive osteoblast accumulation in the ectopic bone. These data provide new insight into the mechanism of ectopic bone formation involving bone marrow-derived OPCs in circulating blood.
authors.affiliation: Division of Gene Therapy Science, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Otsuru
authors.forename: Katsuto
authors.initials: K
authors.lastname: Tamai
authors.forename: Takehiko
authors.initials: T
authors.lastname: Yamazaki
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Kaneda
mesh_terms: D053687:Adult Stem Cells / Q000502:physiology*; D000818:Animals; D001775:Blood Circulation / Q000502:physiology*; D001854:Bone Marrow Cells / Q000502:physiology*; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D008822:Mice, Transgenic; D010006:Osteoblasts / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology*; D016212:Transforming Growth Factor beta / Q000502:physiology
chemical_list: C525718:BMP2 protein, human; C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D016212:Transforming Growth Factor beta