title: Follicular dendritic cell-secreted protein is decreased in experimental periodontitis concurrently with the increase of interleukin-17 expression and the Rankl/Opg mRNA ratio.
abstract: OBJECTIVE
  T-helper type 17 (Th17) cells produce interleukin-17 (IL-17) and help to protect against inflammation and infection in periodontal disease. Furthermore, while follicular dendritic cell-secreted protein (FDC-SP) may be involved in the inflammation of periodontal tissue, the biological role of FDP-SP in periodontal disease is still unknown. The purpose of the present study was to clarify the expression of IL-17 and FDC-SP in experimental periodontitis in rats.
  
  
  METHODS
  Seven-week-old male Wistar rats were divided into baseline control, sham and test groups. Experimental periodontitis was induced by placing a ligature in the mesiopalatal area, and untreated rats served as a baseline control group. Morphological changes in alveolar bone were investigated 7, 14 and 28 d after treatment. Expression of the Rankl, osteoprotegerin (Opg) and Il17 genes was analyzed 5 and 7 d after the induction of experimental periodontitis.
  
  
  RESULTS
  Alveolar bone resorption progressed in the test group for 7 d, but not thereafter. At 5 d after the induction of periodontitis, the Rankl/Opg mRNA ratio and the expression of IL-17 in the test group were significantly increased compared with the respective values in the baseline control group; however, there were no significant differences between the test and control groups at 7 d. The expression of FDC-SP was significantly decreased in the test group compared with the baseline control group at 5 and 7 d after the induction of periodontitis, and this value had returned to normal levels at 14 and 28 d.
  
  
  CONCLUSIONS
  These results suggest that both IL-17 and FDC-SP could be involved in the inflammatory response, and FDC-SP in the junctional epithelium might play an important role in the Th17 cell-related immune response.
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: M
authors.initials: M
authors.lastname: Fukuda
authors.forename: A
authors.initials: A
authors.lastname: Mitani
authors.forename: T
authors.initials: T
authors.lastname: Fujimura
authors.forename: Y
authors.initials: Y
authors.lastname: Iwamura
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Kubo
authors.forename: Y
authors.initials: Y
authors.lastname: Sugita
authors.forename: H
authors.initials: H
authors.lastname: Maeda
authors.forename: T
authors.initials: T
authors.lastname: Shinomura
authors.forename: T
authors.initials: T
authors.lastname: Noguchi
mesh_terms: D016301:Alveolar Bone Loss / Q000276:immunology / Q000473:pathology; D000539:Alveolar Process / Q000276:immunology / Q000473:pathology; D000818:Animals; D020566:Dendritic Cells, Follicular / Q000276:immunology*; D018450:Disease Progression; D020381:Interleukin-17 / Q000032:analysis*; D008297:Male; D053244:Osteoprotegerin / Q000032:analysis*; D010518:Periodontitis / Q000276:immunology* / Q000473:pathology; D016133:Polymerase Chain Reaction / Q000379:methods; D011506:Proteins / Q000032:analysis*; D053245:RANK Ligand / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D058504:Th17 Cells / Q000276:immunology; D013997:Time Factors; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D020381:Interleukin-17; D053244:Osteoprotegerin; D011506:Proteins; D053245:RANK Ligand; C506032:Tnfrsf11b protein, rat
keywords: follicular dendritic cell-secreted protein; interleukin-17; junctional epithelium