title: Expression of protease activated receptor-1 in chronic periodontitis.
abstract: BACKGROUND
  Protease activated receptor-1 (PAR1) activation by thrombin may play a role in repair and homeostasis of periodontal tissues. The main objective of this study is to investigate PAR1 expression in patients with periodontitis, before and after non-surgical periodontal treatment, and to associate its expression with the presence of inflammatory biomarkers and PAR2 expression.
  
  
  METHODS
  Gingival crevicular fluid (GCF) samples and clinical parameters, including probing depth, clinical attachment level, bleeding on probing, and gingival and plaque indices, were collected from periodontally healthy individuals and patients with moderate chronic periodontitis (CP) before and 6 weeks after periodontal non-surgical treatment. PAR1 and PAR2 messenger RNA (mRNA) at the GCF were evaluated by quantitative polymerase chain reaction (qPCR). Flow cytometry analysis identified the GCF PAR1-expressing cells. GCF inflammatory biomarkers were also determined.
  
  
  RESULTS
  Clinical parameters were significantly improved after therapy (P <0.01). The qPCR analysis showed that, before therapy, PAR1 mRNA levels in CP were similar to controls. Periodontal treatment led to increased PAR1 expression in CP (P <0.05). PAR1 expression was inversely correlated to PAR2 expression and with interleukins 6 and 8, tumor necrosis factor-α, interferon-γ, and matrix metalloproteinase-2 levels.
  
  
  CONCLUSIONS
  Periodontal treatment results in PAR1 overexpression in the GCF, and PAR1 expression is associated with decreased expression of inflammatory biomarkers and inversely correlated to PAR2 expression in the GCF. Therefore, the data suggest the importance of PAR1 mediating the known anabolic actions of thrombin in the periodontium.
authors: Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, São Paulo, Brazil.
authors: Henrique Aparecido Bueno
authors: HA
authors: da Silva
authors: Vanessa Tubero
authors: VT
authors: Euzebio Alves
authors: Luis Carlos
authors: LC
authors: Spolidório
authors: João Batista
authors: JB
authors: César Neto
authors: Rosangela Santos
authors: RS
authors: Eichler
authors: Maria Helena Catelli
authors: MH
authors: de Carvalho
authors: Marinella
authors: M
authors: Holzhausen
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D055113:Chronic Periodontitis / Q000378:metabolism* / Q000628:therapy; D003774:Dental Plaque Index; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D005883:Gingival Crevicular Fluid / Q000737:chemistry; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D007371:Interferon-gamma / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D016209:Interleukin-8 / Q000032:analysis; D007962:Leukocytes / Q000378:metabolism; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000032:analysis; D008875:Middle Aged; D017622:Periodontal Attachment Loss / Q000378:metabolism; D057747:Periodontal Debridement / Q000379:methods*; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000378:metabolism; D044463:Receptor, PAR-1 / Q000032:analysis*; D044464:Receptor, PAR-2 / Q000032:analysis; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D055815:Young Adult
chemical_list: D015415:Biomarkers; C508606:CXCL8 protein, human; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D016209:Interleukin-8; D044463:Receptor, PAR-1; D044464:Receptor, PAR-2; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2
keywords: Biological markers; chronic periodontitis; gene expression; immunity, innate; inflammation; wound healing