title: The expression of macrophage migration inhibitory factor is correlated with receptor activator of nuclear factor kappa B ligand in induced rat periapical lesions.
abstract: BACKGROUND
  Macrophage migration inhibitory factor (MIF) has been defined as a key cytokine in regulation of innate and adaptive immunity. The purpose of this study was to investigate the immunohistochemical localization of MIF and its relationship with receptor activator of nuclear factor kappa B ligand (RANKL) protein during the development of periapical lesions in rats.
  
  
  METHODS
  Apical periodontitis was induced in Wistar rats by occlusal pulp exposure in mandibular first molar teeth. The animals were randomly killed at 0, 7, 14, 21, 28, and 35 days after pulp exposure. The jaws that contained the first molar were obtained and were prepared for histologic analysis, enzyme histochemistry, immunohistochemistry, and double immunofluorescence staining.
  
  
  RESULTS
  From day 0 to day 35, the areas of periapical bone loss increased and seemed to be stabilized on day 35. A few MIF-positive and RANKL-positive cells and osteoclasts could be observed on day 7, and all climaxed on day 14. From day 21 to day 35, the expression of MIF and RANKL protein decreased, and fewer osteoclasts could be observed.
  
  
  CONCLUSIONS
  These findings showed that MIF might be associated with the differentiation of osteoclasts in the periapical lesions. MIF contributes to the pathogenesis of the periapical lesions through the induction of RANKL protein.
authors.affiliation: State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.
authors.forename: Lingshuang
authors.initials: L
authors.lastname: Liu
authors.forename: Bin
authors.initials: B
authors.lastname: Peng
mesh_terms: D016301:Alveolar Bone Loss / Q000276:immunology; D000818:Animals; D003786:Dental Pulp Cavity / Q000276:immunology; D003789:Dental Pulp Exposure / Q000276:immunology; D004195:Disease Models, Animal; D019746:Intramolecular Oxidoreductases / Q000032:analysis*; D008263:Macrophage Migration-Inhibitory Factors / Q000032:analysis*; D008297:Male; D008336:Mandibular Diseases / Q000276:immunology; D008963:Molar / Q000276:immunology; D010010:Osteoclasts / Q000276:immunology / Q000473:pathology; D010485:Periapical Periodontitis / Q000276:immunology*; D053245:RANK Ligand / Q000032:analysis*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D019227:Tooth Apex / Q000276:immunology; D014092:Tooth Root / Q000276:immunology
chemical_list: D008263:Macrophage Migration-Inhibitory Factors; D053245:RANK Ligand; D019746:Intramolecular Oxidoreductases; C515599:Mif protein, rat
keywords: MIF; RANKL; osteoclast; periapical lesion