title: The role of bone marrow-derived cells during the bone healing process in the GFP mouse bone marrow transplantation model.
abstract: Bone healing is a complex and multistep process in which the origin of the cells participating in bone repair is still unknown. The involvement of bone marrow-derived cells in tissue repair has been the subject of recent studies. In the present study, bone marrow-derived cells in bone healing were traced using the GFP bone marrow transplantation model. Bone marrow cells from C57BL/6-Tg (CAG-EGFP) were transplanted into C57BL/6 J wild mice. After transplantation, bone injury was created using a 1.0-mm drill. Bone healing was histologically assessed at 3, 7, 14, and 28 postoperative days. Immunohistochemistry for GFP; double-fluorescent immunohistochemistry for GFP-F4/80, GFP-CD34, and GFP-osteocalcin; and double-staining for GFP and tartrate-resistant acid phosphatase were performed. Bone marrow transplantation successfully replaced the hematopoietic cells into GFP-positive donor cells. Immunohistochemical analyses revealed that osteoblasts or osteocytes in the repair stage were GFP-negative, whereas osteoclasts in the repair and remodeling stages and hematopoietic cells were GFP-positive. The results indicated that bone marrow-derived cells might not differentiate into osteoblasts. The role of bone marrow-derived cells might be limited to adjustment of the microenvironment by differentiating into inflammatory cells, osteoclasts, or endothelial cells in immature blood vessels.
authors.affiliation: Department of Oral Pathology and Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8525, Japan. tsuji@md.okayama-u.ac.jp
authors.forename: Hidetsugu
authors.initials: H
authors.lastname: Tsujigiwa
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Hirata
authors.forename: Naoki
authors.initials: N
authors.lastname: Katase
authors.forename: Rosario Rivera
authors.initials: RR
authors.lastname: Buery
authors.forename: Ryo
authors.initials: R
authors.lastname: Tamamura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ito
authors.forename: Shin
authors.initials: S
authors.lastname: Takagi
authors.forename: Seiji
authors.initials: S
authors.lastname: Iida
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nagatsuka
mesh_terms: D000818:Animals; D016026:Bone Marrow Transplantation; D001842:Bone and Bones / Q000293:injuries* / Q000601:surgery*; D002454:Cell Differentiation; D005260:Female; D049452:Green Fluorescent Proteins; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D023421:Models, Animal; D010006:Osteoblasts / Q000166:cytology; D010011:Osteocytes / Q000166:cytology; D014945:Wound Healing / Q000502:physiology*
chemical_list: D049452:Green Fluorescent Proteins