CSF-1 regulation of osteoclastogenesis for tooth eruption.
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.
Wise
G E
GE
Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA. gwise@vetmed.lsu.edu
Yao
S
S
Odgren
P R
PR
Pan
F
F
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
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