Immunohistochemical observations of cellular differentiation and proliferation in endochondral bone formation from grafted periosteum: expression and localization of BMP-2 and -4 in the grafted periosteum.
OBJECTIVE
To clarify the involvement of bone morphogenetic proteins (BMPs) in the proliferation and differentiation of osteo/chondrogenic cells during the process of bone formation from grafted periosteum.


METHODS
Tibial periosteum of young Japanese white rabbits was grafted into suprahyoid muscles and removed after 7, 9, 14 or 21 days. BMP-2, -4, proliferative cell nucleus antigen (PCNA) immunoreaction and Alcian blue staining in grafted periosteum was then sought microscopically.


RESULTS
PCNA positive cells in the grafted periosteum expressed BMP-2 at 7 days. These cells differentiated into chondroblasts that expressed BMP-2 and Alcian blue at 9 days. After 14 days, cartilage formation was seen, and BMP-2 and -4 expressions were observed in mature and hypertrophic chondrocytes. Endochondral ossification was observed at 21 days and osteoblasts showed both BMP-2 and -4 expression.


CONCLUSIONS
Both BMP-2 and -4 appear to play regulatory roles in the process of endochondral ossification from grafted periosteum, due to their involvement in the proliferation and differentiation into chondrogenic and osteogenic cells.
Ueno
Takaaki
T
Department of Oral and Maxillofacial Reconstructive Surgery, Okayama University, Graduate School of Medicine and Dentistry, Okayama, Japan. ueno@md.okayama-u.ac.jp
Kagawa
Toshimasa
T
Kanou
Miwa
M
Fujii
Takashi
T
Fukunaga
Joji
J
Mizukawa
Nobuyoshi
N
Sugahara
Toshio
T
Yamamoto
Toshio
T
D000423:Alcian Blue; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000032:analysis*; D002356:Cartilage / Q000473:pathology; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D019902:Chondrocytes / Q000473:pathology; D020219:Chondrogenesis / Q000502:physiology; D004396:Coloring Agents; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D018482:Muscle, Skeletal / Q000601:surgery; D010006:Osteoblasts / Q000473:pathology; D010012:Osteogenesis / Q000502:physiology*; D010521:Periosteum / Q000473:pathology / Q000637:transplantation*; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D011817:Rabbits; D013977:Tibia / Q000473:pathology; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000032:analysis*
D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D004396:Coloring Agents; D018809:Proliferating Cell Nuclear Antigen; D016212:Transforming Growth Factor beta; D000423:Alcian Blue