ABSTRACT
Osteoclasts are bone-specific multinucleated cells generated by the differentiation of monocyte/macrophage lineage precursors. Regulation of osteoclast differentiation is considered an effective therapeutic approach to the treatment of bone-lytic diseases. Periodontitis is an inflammatory disease characterized by extensive bone resorption. In this study, we investigated the effects of sodium fluoride (NaF) on osteoclastogenesis induced by Porphyromonas gingivalis, an important colonizer of the oral cavity that has been implicated in periodontitis. NaF strongly inhibited the P. gingivalis-induced alveolar bone loss. That effect was accompanied by decreased levels of cathepsin K, interleukin (IL)-1β, matrix metalloproteinase 9 (MMP9), and tartrate-resistant acid phosphatase, which were up-regulated during P. gingivalis-induced osteoclastogenesis. Consistent with the in vivo anti-osteoclastogenic effect, NaF inhibited osteoclast formation caused by the differentiation factor RANKL (receptor activator of nuclear factor κB ligand) and macrophage colony-stimulating factor (M-CSF). The RANKL-stimulated induction of the transcription factor nuclear factor of activated T cells (NFAT) c1 was also abrogated by NaF. Taken together, our data demonstrate that NaF inhibits RANKL-induced osteoclastogenesis by reducing the induction of NFATc1, ultimately leading to the suppressed expression of cathepsin K and MMP9. The in vivo effect of NaF on the inhibition of P. gingivalis-induced osteoclastogenesis strengthens the potential usefulness of NaF for treating periodontal diseases.
Subject(s)
Animals , Male , Rats , Acid Phosphatase , Alveolar Bone Loss , Microbiology , Anti-Bacterial Agents , Therapeutic Uses , Anti-Inflammatory Agents , Therapeutic Uses , Bacteroidaceae Infections , Microbiology , Bone Density Conservation Agents , Therapeutic Uses , Cathepsin K , Interleukin-1beta , Interleukin-6 , Interleukin-8 , Isoenzymes , Macrophage Colony-Stimulating Factor , Matrix Metalloproteinase 9 , Osteoclasts , Periodontitis , Microbiology , Porphyromonas gingivalis , RANK Ligand , Rats, Sprague-Dawley , Sodium Fluoride , Therapeutic Uses , Tartrate-Resistant Acid Phosphatase , Transcription Factors , X-Ray Microtomography , MethodsABSTRACT
To evaluate the achievement of medical or dental education the criterion-referenced tests must be used. In this paper we proposed a new setting method of the difficulty level of the multiple-choice questions (MCQs) used in the National Board Examinations for Medical or Dental Practice. The difficulty levels should be determined by using the idea of the “Correct Terminal” which is consisting of the minimal sets of items to answer correctly. The difficulty level, the percentage of correct answer and the phi-coefficient of a question vary depending on the arrangement of the items in the question. Therefore, it is very difficult to get the real evaluation by the criterion-referenced measurement as far as we use MCQs. We should deepen our understanding of the limit of MCQ tests rather than we might expect the limitless possibility.