Expression of CSF-1 receptor on TRAP-positive multinuclear cells around the erupting molars in rats.
Bone resorption overlying a developing tooth is a necessary event in the creation of an eruption pathway. The formation and function of osteoclasts, which play a major role in bone resorption, are controlled by several factors. Although CSF-1 and its mRNA are expressed in dental follicle cells required for eruption, little is known about the contribution of CSF-1 to osteoclast formation on the bony crypt around the tooth germ. The receptor protein of the CSF-1 encoded proto-oncogene c-fms was identified on multinucleated cells adjacent to the dental follicle, in conjunction with TRAP staining as a marker enzyme for osteoclasts in rat. c-Fms was highly expressed in TRAP-positive multinuclear cells at 3 days postnatal and the number of c-Fms-expressing cells was reduced thereafter. Administration of IL-1alpha, which enhances formation and function of osteoclasts, caused an increase in the number of c-Fms and TRAP-positive cells in rat. On the contrary, injection of calcitonin, which depresses osteoclast formation, caused a decrease in the number. It is obvious that the receptor of CSF-1 is expressed on the surface of osteoclasts around the tooth germ, on the dental follicle. These findings suggested that CSF-1 directly enhances the influx of osteoclasts adjacent to the erupting tooth, resulting in the formation of an eruption pathway.
Kawakami
M
M
Department of Orthodontics, Faculty of Dentistry, Osaka University, Suita, Japan. kawakami@dent.osaka-u.ac.jp
Kuroda
S
S
Yamashita
K
K
Yoshida
C A
CA
Nakagawa
K
K
Takada
K
K
D000135:Acid Phosphatase / Q000302:isolation & purification*; D000818:Animals; D015415:Biomarkers; D001862:Bone Resorption; D003795:Dental Sac / Q000378:metabolism; D015726:Giant Cells; D007527:Isoenzymes / Q000302:isolation & purification*; D008334:Mandible / Q000378:metabolism; D008963:Molar / Q000254:growth & development*; D010010:Osteoclasts / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D000071681:Tartrate-Resistant Acid Phosphatase; D014078:Tooth Eruption; D014083:Tooth Germ / Q000378:metabolism
D015415:Biomarkers; D007527:Isoenzymes; D016186:Receptor, Macrophage Colony-Stimulating Factor; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase