title: TNF receptor-associated factor 6 suppression inhibits inflammatory response to Porphyromonas gingivialis in human periodontal ligament cells.
abstract: OBJECTIVE
  Periodontitis is a group of inflammatory diseases caused by microorganisms. Porphyromonas gingivalis, a gram-negative bacteria, is strongly associated with the onset of periodontitis. Tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) represents an important target in the regulation of many disease processes, including immunity, inflammation, and osteoporosis. The aim of this study was to investigate the role of TRAF6 for inflammatory response in P gingivalis-infected human periodontal ligament cells (HPDLCs).
  
  
  METHODS
  HPDLCs were stimulated with 1 x 108 CFU/mL P gingivalis, or 10 ug/mL P gingivalis lipopolysaccharide (LPS), separately in the absence or presence of small interfering RNA (siRNA) for TRAF6. The expression of TRAF6 was examined by real-time polymerase chain reaction and Western blot analysis. Concentrations of IL-1B, IL-6, and IL-8 in the culture supernatants were determined by enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  In this study, we found that both P gingivalis and its LPS treatment increased the expression of TRAF6 and proinflammatory cytokine production in HPDLCs. In addition, we used siRNA for TRAF6, and the inhibition of TRAF6 expression reduced the production of proinflammatory cytokines in HPDLCs stimulated with P gingivalis and its LPS.
  
  
  CONCLUSIONS
  The results suggested that TRAF6 may be a key molecule to control proinflammatory cytokine production induced by P gingivalis and its LPS. TRAF6 suppression may inhibit inflammatory responses in HPDLCs infected by P gingivalis and its LPS.
authors: State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, Chengdu, China.
authors: Lu
authors: L
authors: Tang
authors: Xue-Dong
authors: XD
authors: Zhou
authors: Qian
authors: Q
authors: Wang
authors: Lan
authors: L
authors: Zhang
authors: Yao
authors: Y
authors: Wang
authors: Ding-Ming
authors: DM
authors: Huang
mesh_terms: D015153:Blotting, Western; D018929:Cell Culture Techniques; D004797:Enzyme-Linked Immunosorbent Assay; D020868:Gene Silencing; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D053583:Interleukin-1beta / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D016209:Interleukin-8 / Q000032:analysis; D008070:Lipopolysaccharides / Q000494:pharmacology; D010513:Periodontal Ligament / Q000166:cytology / Q000276:immunology / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000276:immunology*; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D048029:TNF Receptor-Associated Factor 6 / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D015854:Up-Regulation
chemical_list: D018836:Inflammation Mediators; D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; D008070:Lipopolysaccharides; D034741:RNA, Small Interfering; D048029:TNF Receptor-Associated Factor 6