title: The role of Toll-like receptor 2 and 4 in gingival tissues of chronic periodontitis subjects with type 2 diabetes.
abstract: OBJECTIVE
  Diabetes is one important risk factor of chronic periodontitis. However, the roles of toll-like receptor (TLR) 2 and TLR4, which are implicated in the inflammatory process in both chronic periodontitis and diabetes, have not been studied. This study aimed to determine whether TLR2 and TLR4 might be involved in the relationship between chronic periodontitis and diabetes by examining TLR2 and TLR4 expression in gingival tissues from subjects with chronic periodontitis without diabetes (CP) and with diabetes (CP+DM) and from periodontally healthy subjects without diabetes (PH) and with diabetes (PH+DM).
  
  
  METHODS
  Gingival tissues were collected from 23 CP subjects, 21 CP+DM subjects, 22 PH subjects and 20 PH+DM subjects. The expression of TLR2 and TLR4 in gingival tissues was determined using an immunohistochemical method. In gingival epithelium, staining patterns and intensity levels of TLR2 and TLR4 expression were studied. In connective tissues, the percentages of TLR2- and TLR4-positive cells were calculated. The intensity levels and the percentages of positive cells were statistically analyzed.
  
  
  RESULTS
  Chronic periodontitis or diabetes showed no significant effect on TLR2 expression in the oral epithelium. However, diabetes increased the expression of TLR2 in sulcular epithelium and changed the pattern of TLR2 expression in gingival epithelium. Chronic periodontitis decreased the expression of TLR4 in gingival epithelium. In connective tissue under sulcular epithelium, CP+DM subjects showed statistically significant higher percentages of TLR2- and TLR4-positive cells compared with PH and PH+DM subjects.
  
  
  CONCLUSIONS
  Our results suggest that hyperglycemia and chronic periodontitis had effects on TLR2 and TLR4 expression in gingival tissue. The differences in TLR2 and TLR4 expression could contribute to a greater inflammatory response, leading to periodontal disease initiation and progression.
authors.affiliation: Department of Oral Medicine and Periodontology, Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
authors.forename: A
authors.initials: A
authors.lastname: Promsudthi
authors.forename: S
authors.initials: S
authors.lastname: Poomsawat
authors.forename: W
authors.initials: W
authors.lastname: Limsricharoen
mesh_terms: D000328:Adult; D055113:Chronic Periodontitis / Q000150:complications / Q000276:immunology*; D003239:Connective Tissue Cells / Q000276:immunology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000276:immunology*; D018450:Disease Progression; D004846:Epithelial Attachment / Q000276:immunology; D004847:Epithelial Cells / Q000276:immunology; D005260:Female; D005881:Gingiva / Q000276:immunology*; D006801:Humans; D006943:Hyperglycemia / Q000276:immunology; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D017622:Periodontal Attachment Loss / Q000145:classification / Q000276:immunology; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000145:classification / Q000276:immunology; D051195:Toll-Like Receptor 2 / Q000032:analysis* / Q000502:physiology; D051197:Toll-Like Receptor 4 / Q000032:analysis* / Q000502:physiology
chemical_list: C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4
keywords: chronic periodontitis; diabetes; inflammation