Bone marrow-derived osteoblast progenitor cells in circulating blood contribute to ectopic bone formation in mice

• Published in: Biochemical and biophysical research communications Vol. 354; no. 2; pp. 453 - 458
• Main Authors: Otsuru, Satoru, Tamai, Katsuto, Yamazaki, Takehiko, Yoshikawa, Hideki, Kaneda, Yasufumi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 09.03.2007
• Subjects: Adult Stem Cells - physiology; Animals; BLOOD; Blood Circulation - physiology; BONE MARROW; BONE MARROW CELLS; Bone Marrow Cells - physiology; Bone marrow transplantation; Bone morphogenetic protein; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins - physiology; Circulating osteoblast progenitor cells; COLLAGEN; Ectopic bone; EOSIN; Female; FLUORESCEIN; HEMATOXYLIN; Humans; IN VIVO; IRRADIATION; ISOTHIOCYANATES; LETHAL DOSES; Male; MICE; Mice, Inbred C57BL; Mice, Nude; Mice, Transgenic; Osteoblasts - physiology; Osteogenesis - physiology; RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS; SKELETON; Transforming Growth Factor beta - physiology; H&E; BMT; Bone marrow transplantation; DAPI; PBMNCs; TRAP; Ectopic bone; GFP; BMPs; Circulating osteoblast progenitor cells; FITC; Bone morphogenetic protein; OPCs; MOPCs
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2006.12.226

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.