title: Increased nucleic Acid receptor expression in chronic periodontitis.
abstract: BACKGROUND
  Nucleic acid sensing has emerged as one of the important components of the immune system triggering inflammation. The aim of this study is to determine the expression of bacterial DNA sensors, including Toll-like receptor 9 (TLR-9), DNA-dependent activator of interferon-regulatory factors (DAI), and absent in melanoma 2 (AIM2) in chronic periodontitis (CP versus healthy) (H) tissues.
  
  
  METHODS
  Thirty-five CP and 27 H gingival biopsies were included. Real-time quantitative polymerase chain reaction was performed to determine mRNA levels of AIM2, DAI, and TLRs (TLR-1 through TLR-9). The difference in gene expression for each sensor between CP and H tissues was calculated using analysis of covariance. The Spearman test was used to determine correlations among innate receptors. The expression of TLR-9, AIM2, and DAI in gingival tissues was further confirmed using immunohistochemistry.
  
  
  RESULTS
  The present results reveal statistically significant upregulation of TLR-9 (P <0.006), DAI (P <0.001), and TLR-8 (P <0.01) in CP tissues compared to H sites. Although mRNA expression was not changed significantly between groups for other receptors, the present results reveal significant correlations between receptors (P <0.05), suggesting that cooperation between multiple components of the host immune system may influence the overall response. Immunohistochemistry further confirmed expression of TLR-9, AIM2, and DAI in gingival tissues.
  
  
  CONCLUSIONS
  This study highlights a possible role for nucleic acid receptors in periodontal inflammation. Future investigations will determine whether cytoplasmic receptors and their ligands can be targeted to improve clinical outcomes in periodontitis.
authors: Department of Periodontics, School of Dentistry, Virginia Commonwealth University, Richmond, VA.
authors: S Esra
authors: SE
authors: Sahingur
authors: Xia-Juan
authors: XJ
authors: Xia
authors: Stephanie C
authors: SC
authors: Voth
authors: W Andrew
authors: WA
authors: Yeudall
authors: John C
authors: JC
authors: Gunsolley
mesh_terms: D000328:Adult; D000368:Aged; D055113:Chronic Periodontitis / Q000276:immunology*; D004268:DNA-Binding Proteins / Q000032:analysis*; D005260:Female; D005881:Gingiva / Q000276:immunology; D006801:Humans; D008297:Male; D008545:Melanoma / Q000276:immunology; D008875:Middle Aged; D009687:Nuclear Proteins / Q000032:analysis*; D010519:Periodontium / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis; D016601:RNA-Binding Proteins; D060888:Real-Time Polymerase Chain Reaction; D051194:Toll-Like Receptor 1 / Q000032:analysis; D051195:Toll-Like Receptor 2 / Q000032:analysis; D051196:Toll-Like Receptor 3 / Q000032:analysis; D051197:Toll-Like Receptor 4 / Q000032:analysis; D051198:Toll-Like Receptor 5 / Q000032:analysis; D051216:Toll-Like Receptor 6 / Q000032:analysis; D051199:Toll-Like Receptor 7 / Q000032:analysis; D051200:Toll-Like Receptor 8 / Q000032:analysis; D051217:Toll-Like Receptor 9 / Q000032:analysis; D051193:Toll-Like Receptors / Q000032:analysis*; D015854:Up-Regulation; D055815:Young Adult
chemical_list: C410167:AIM2 protein, human; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C495344:TLR3 protein, human; C495345:TLR4 protein, human; C495346:TLR5 protein, human; C495368:TLR6 protein, human; C495348:TLR7 protein, human; C495349:TLR8 protein, human; C495371:TLR9 protein, human; D051194:Toll-Like Receptor 1; D051195:Toll-Like Receptor 2; D051196:Toll-Like Receptor 3; D051197:Toll-Like Receptor 4; D051198:Toll-Like Receptor 5; D051216:Toll-Like Receptor 6; D051199:Toll-Like Receptor 7; D051200:Toll-Like Receptor 8; D051217:Toll-Like Receptor 9; D051193:Toll-Like Receptors; C485731:ZBP1 protein, human