Immunolocalization of osteocyte-derived molecules during bone fracture healing of mouse ribs.
We employed a well-standardized murine rib fracture model to assess the distribution, in the cortical bone, of three important osteocyte-derived molecules-dentine matrix protein 1 (DMP1), sclerostin and fibroblast growth factor 23 (FGF 23). Two days after the fracture, the periosteum thickened, and up to the seventh day post-fracture, the cortical surfaces were promoting neoformation of two tissue types depending on the distance from the fracture site: chondrogenesis was taking place near the fracture, and osteogenesis distant from it. The cortical bones supporting chondrogenesis featured several empty lacunae, while in the ones underlying newly-formed woven bone, empty lacunae were hardly seen. DMP1-immunopositive osteocytic lacunae and canaliculi were seen both close and away from the fracture. In contrast, the region close to the fracture had only few sclerostin- and FGF23-immunoreactive osteocytes, whereas the distant region revealed many osteocytes immunopositive for these markers. Mature cortical bone encompassing the native cortical bone was observed at two-, three- and four-weeks post-fracture, and the distribution of DMP1, sclerostin and FGF23 appeared to have returned to normal. In summary, early stages of fracture healing seem to be important for triggering chondrogenesis and osteogenesis that may be regulated by osteocytes via their secretory molecules.
Department of Developmental Biology of Hard Tissue Graduate School of Dental Medicine, Hokkaido University.
Zhusheng
Z
Liu
Tomomaya
T
Yamamoto
Tomoka
T
Hasegawa
Hiromi
H
Hongo
Kanako
K
Tsuboi
Erika
E
Tsuchiya
Mai
M
Haraguchi
Miki
M
Abe
Paulo Henrique Luiz de
PH
Freitas
Akira
A
Kudo
Kimimitsu
K
Oda
Minqi
M
Li
Norio
N
Amizuka
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D015415:Biomarkers; D020219:Chondrogenesis; D004195:Disease Models, Animal; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000378:metabolism; D017102:Fracture Healing / Q000502:physiology*; D006023:Glycoproteins / Q000378:metabolism; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D051379:Mice; D010011:Osteocytes / Q000378:metabolism*; D010012:Osteogenesis; D021381:Protein Transport; D012272:Ribs; D013997:Time Factors
D048868:Adaptor Proteins, Signal Transducing; D015415:Biomarkers; C513308:Dmp1 protein, mouse; D016326:Extracellular Matrix Proteins; C000717428:Fgf23 protein, mouse; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; C486030:Sost protein, mouse; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23