title: Expression of toll-like receptors 2, 4 and 9 is increased in gingival tissue from patients with type 2 diabetes and chronic periodontitis.
abstract: OBJECTIVE
  Broad evidence indicates that diabetes both increases the risk and hastens the progression of periodontal disease. Likewise, chronic inflammation or infections seem to provoke insulin resistance and thereby contribute to the development of diabetes and its complications. Innate immune responses, which appear to be altered in individuals with diabetes, are usually mediated by the recognition of pathogens through toll-like receptors (TLRs). The constitutive expression of some TLRs has been reported in healthy human gingival tissue. Interestingly, the expression of TLRs 2 and 4 is increased with the severity of periodontal disease. Considering that the inflammatory reaction is exacerbated in individuals with diabetes and periodontitis, we suspected that the expression of some TLRs might be increased in gingival tissue in these patients.
  
  
  METHODS
  In this study, we analyzed, by immunofluorescence, the expression of TLRs 2, 3, 4 and 9 in gingival tissues from healthy individuals and from periodontal patients with or without type 2 diabetes.
  
  
  RESULTS
  We found that the expression levels of TLRs 2, 3, 4 and 9 were higher in all periodontal patients than in healthy individuals. The expression of some TLRs was increased in subjects with periodontitis and diabetes relative to subjects with periodontitis but without diabetes; this increase in expression was found particularly in TLR2 and TLR9 in the connective tissue and in TLR4 at the epithelial region.
  
  
  CONCLUSIONS
  These data suggest that the expression of these TLRs 2, 3, 4 and 9 in gingival tissue is higher in individuals with diabetes because its inflammatory reaction is exacerbated. Additionally, the expression of these TLRS is positively regulated with the severity of periodontal disease.
authors.affiliation: Laboratorio de Inmunidad en Mucosas, UBIMED FES-Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, Estado de México, México.
authors.forename: N R
authors.initials: NR
authors.lastname: Rojo-Botello
authors.forename: A L
authors.initials: AL
authors.lastname: García-Hernández
authors.forename: L
authors.initials: L
authors.lastname: Moreno-Fierros
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000276:immunology; D001786:Blood Glucose / Q000032:analysis; D016022:Case-Control Studies; D055113:Chronic Periodontitis / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D003238:Connective Tissue / Q000276:immunology; D012534:Dental Scaling; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000276:immunology* / Q000473:pathology; D004848:Epithelium / Q000276:immunology; D005260:Female; D005455:Fluorescent Antibody Technique; D005881:Gingiva / Q000276:immunology* / Q000473:pathology; D005884:Gingival Hemorrhage / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017622:Periodontal Attachment Loss / Q000276:immunology; D016745:Root Planing; D016037:Single-Blind Method; D051195:Toll-Like Receptor 2 / Q000032:analysis*; D051197:Toll-Like Receptor 4 / Q000032:analysis*; D051217:Toll-Like Receptor 9 / Q000032:analysis*
chemical_list: D001786:Blood Glucose; C495342:TLR2 protein, human; C495345:TLR4 protein, human; C495371:TLR9 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051217:Toll-Like Receptor 9