title: CSF-1 regulation of osteoclastogenesis for tooth eruption.
abstract: The dental follicle regulates the alveolar bone resorption needed for tooth eruption. In the rat first mandibular molar, a decrease in the expression of osteoprotegerin (OPG) in the dental follicle at day 3 enables the osteoclastogenesis needed for eruption to occur. Because colony-stimulating factor-1 (CSF-1) is maximally expressed in the dental follicle at day 3, it was hypothesized that CSF-1 down-regulates OPG gene expression in the dental follicle in vivo. To test this, we compared the expression of OPG in osteopetrotic toothless (tl/tl) rats deficient in CSF-1 with expression in their normal littermates for given ages. OPG gene expression was found to be higher in the dental follicle of the tl/tl mutants than in normals. Transfecting short interfering RNA specific for CSF-1 mRNA into dental follicle cells resulted in an up-regulation of OPG expression. Thus, these studies support our hypothesis that the down-regulation of OPG needed for tooth eruption is mediated by CSF-1.
authors.affiliation: Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA. gwise@vetmed.lsu.edu
authors.forename: G E
authors.initials: GE
authors.lastname: Wise
authors.forename: S
authors.initials: S
authors.lastname: Yao
authors.forename: P R
authors.initials: PR
authors.lastname: Odgren
authors.forename: F
authors.initials: F
authors.lastname: Pan
mesh_terms: D000818:Animals; D003795:Dental Sac / Q000378:metabolism*; D015536:Down-Regulation; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D007124:Immunoenzyme Techniques; D016173:Macrophage Colony-Stimulating Factor / Q000502:physiology*; D010010:Osteoclasts / Q000502:physiology*; D053244:Osteoprotegerin; D034741:RNA, Small Interfering / Q000502:physiology; D051381:Rats; D011922:Rats, Mutant Strains; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis* / Q000235:genetics; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014078:Tooth Eruption / Q000502:physiology*; D014162:Transfection
chemical_list: D006023:Glycoproteins; D053244:Osteoprotegerin; D034741:RNA, Small Interfering; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C506032:Tnfrsf11b protein, rat; D016173:Macrophage Colony-Stimulating Factor