Alveolar bone regeneration of subcutaneously transplanted rat molar.
Regeneration of alveolar bone is essential for periodontal treatment. Recently, cell replacement therapy has been focused on periodontal disease, but the source of the cells that regenerate alveolar bone is still uncertain. Therefore, to clarify the source of these bone-regenerating cells, we transplanted GFP-transgenic rat molars into the subcutaneous tissues of wild-type rats. Five days after transplantation, the tooth was surrounded by connective tissue containing many blood vessels. At 10 days, bone-like tissue was formed in the connective tissue between the branches of the bifurcated root. This hard tissue expanded to almost all of this bifurcation area without osseous ankylosis after 20 days. All osteoblast-like cells in the newly formed matrix were immunopositive for GFP. In addition, these cells and the peripheral cells of the matrix showed intense immunoreactivity for BMP4, Runx2, BSP, and OPN. These results demonstrate that periodontal ligament tissue contains osteoprogenitor cells that have the ability to regenerate alveolar bone. Our model suggests that these regeneration processes might be similar to normal alveolar bone formation.
Hosoya
Akihiro
A
Department of Oral Histology, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan. hosoya@po.mdu.ac.jp
Ninomiya
Tadashi
T
Hiraga
Toru
T
Zhao
Chen
C
Yoshiba
Kunihiko
K
Yoshiba
Nagako
N
Takahashi
Masafumi
M
Okabe
Takahiro
T
Wakitani
Shigeyuki
S
Yamada
Hirohito
H
Kasahara
Etsuo
E
Ozawa
Hidehiro
H
Nakamura
Hiroaki
H
D000539:Alveolar Process / Q000166:cytology / Q000502:physiology* / Q000601:surgery; D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D003757:Dental Implantation; D007150:Immunohistochemistry; D008963:Molar / Q000637:transplantation*; D010006:Osteoblasts / Q000166:cytology; D051381:Rats; D011917:Rats, Inbred Lew; D040521:Subcutaneous Tissue; D014057:Tomography, X-Ray Computed