Protease-activated receptors expression in gingiva in periodontal health and disease

Abstract Objective Protease-activated receptors (PARs) are a unique class of receptors which are implicated in mediating inflammation, pain and other functions. The aim of this study was to elucidate the role of PARs in the pathogenesis of chronic periodontitis by differential expression analysis of PARs in the gingival tissues of chronic periodontitis patients compared with those of healthy control individuals. Design Gingival tissue specimens were collected from chronic periodontitis patients ( n = 20) and control individuals ( n = 20). The expression of PAR-1, -2, -3 and -4 was determined in these tissues by immunohistochemistry and differential expression between the two groups was investigated by quantitative real-time reverse transcription-polymerase chain reaction analysis. Results PAR-1, -2, -3 and -4 were expressed in all gingival tissues. A significant overexpression of PAR-3 was detected in chronic periodontitis-affected tissues compared to healthy gingival tissues. However, expression of PAR-2 was decreased in periodontal lesions. Conclusions Our study shows that PAR-1, -2, -3 and -4 are expressed in both healthy and inflamed gingival tissues. Furthermore, PAR-2 and PAR-3 may contribute to the inflammatory responses associated with chronic periodontitis.