The Role of Proteinase-Activated Receptors 1 and 2 in the Regulation of Periodontal Tissue Metabolism and Disease

Table 5

Human studies on PAR₁ and PAR₂ activation associated with periodontal tissue metabolism.

	Groups	Main findings
Holzhausen et al. [30]	(i) Controls: 40 subjects; (ii) Chronic periodontitis with moderate destruction; (3 < PPD ≤ 6 mm; CAL ≤ 4 mm),; (iii) Chronic periodontitis with advanced destruction; (PPD > 6 mm; CAL > 4 mm),	(i) Chronic periodontitis patients showed higher PAR2; mRNA expression and increased levels of IL-1α, IL-6,; IL-8, TNF-α, total proteolytic activity, P. gingivalis; prevalence, and proteinase 3 mRNA expression; compared to controls.; (ii) Periodontal treatment decreased PAR2; mRNA expression.
Fagundes et al. [31]	(i) Moderate chronic periodontitis; (3 < PPD ≤ 6 mm; 3 < CAL ≤ 6 mm),	P. gingivalis presence was associated with the following: (i) higher levels of IL-1α, IL-6, and TNF-α,; (ii) higher proteolytic activity,; (iii) higher PAR2 mRNA expression.
Euzebio Alves et al. [32]	(i) Controls: 31 subjects; (ii) Moderate chronic periodontitis; (3 < PPD ≤ 6 mm; CAL ≤ 4 mm),	Chronic periodontitis patients showed overexpression of PAR2, IL-6, IL-8, TNF-α, MMP-2, MMP-8, HGF, VEGF, gingipain, and proteinase 3 and decreased levels of dentilisin, SLPI, and elafin. Periodontal treatment decreased PAR2 expression.
da Silva et al. [47]	(i) Controls: 37 subjects; (ii) Moderate chronic periodontitis; (3 < PPD ≤ 6 mm; CAL ≤ 4 mm),	Periodontal treatment resulted in PAR1 overexpression, which was inversely correlated with PAR2 expression and gingival crevicular fluid levels of IL-6, IL-8, TNF-α, IFN-γ, and MMP.

PAR: protease activated receptor; IL: interleukin; P. gingivalis: Porphyromonas gingivalis; PPD: probing pocket depth; CAL: clinical attachment level; TNF: tumor necrosis factor; P3: neutrophil serine protease 3; MMP: matrix metalloproteinase; HGF: hepatocyte growth factor; VEGF: vascular endothelial growth factor; SLPI: secretory leukocyte protease inhibitor; GCF: gingival crevicular fluid; IFN-γ: interferon gamma.