title: Reduction of osteoclasts in a critical embryonic period is essential for inhibition of mouse tooth eruption.
abstract: Alveolar bone resorption by osteoclasts is essential for tooth eruption. Osteoclast-deficient Csfm(op) homozygous (op/op) mice, which lack functional macrophage colony-stimulating factor (M-CSF), suffer from osteopetrosis and completely lack tooth eruption. Although osteoclasts appear, and osteopetrosis is cured with age in op/op mice, tooth eruption is never seen. This fact suggests that there is a critical period when osteoclasts are required for tooth eruption. In this study, to detect the critical period, we administered an antagonistic antibody directed against c-Fms, a receptor for M-CSF, to inbred C57BL/6 mice for various periods. Administration of this antibody decreased tartrate-resistant acid phosphatase-positive (TRAP) osteoclasts, and incisor eruption was completely inhibited by continual administration of this antibody from embryonic day 15.5 (E15.5) until postnatal day 12.5 (D12.5). A 1-day delay of this administration abolished the inhibition of incisor eruption. The number of TRAP-positive osteoclasts was significantly reduced between E16.5 and E18.5 in the mice treated with antibody from E15.5 compared with those treated from E16.5. These results indicate that this period, during which the number of osteoclasts decreases significantly, is critical for inhibiting incisor eruption in C57BL/6 mice.
authors.affiliation: Division of Immunology. Department of Molecular and Cellular Biology, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Japan.
authors.forename: Miya
authors.initials: M
authors.lastname: Yoshino
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Yamazaki
authors.forename: Hisahiro
authors.initials: H
authors.lastname: Yoshida
authors.forename: Shumpei
authors.initials: S
authors.lastname: Niida
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Nishikawa
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ryoke
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kunisada
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Hayashi
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000539:Alveolar Process / Q000166:cytology / Q000196:embryology / Q000254:growth & development; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D005865:Gestational Age; D007180:Incisor / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D010010:Osteoclasts / Q000166:cytology* / Q000502:physiology; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000037:antagonists & inhibitors; D000071681:Tartrate-Resistant Acid Phosphatase; D014078:Tooth Eruption / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D007527:Isoenzymes; D016186:Receptor, Macrophage Colony-Stimulating Factor; D000135:Acid Phosphatase; C000605511:Acp5 protein, mouse; D000071681:Tartrate-Resistant Acid Phosphatase