Differential expression of E-cadherin and cytokeratin 19 and net proliferative rate of gingival keratinocytes in oral epithelium in periodontal health and disease

Abstract

Background: The effects of periodontal disease on the oral gingival epithelium (OGE) have not been documented fully because they may not be as dramatic as those seen on the junctional epithelium. The aim of this study was to estimate the changes occurring in the OGE with respect to its proliferation and E-cadherin and cytokeratin 19 (K19) expression during pocket formation.

Methods: Gingival samples were collected from 17 periodontally healthy subjects and 18 subjects with chronic periodontitis. K19 and E-cadherin levels were analyzed immunohistochemically. The net proliferative rate was calculated as the difference between the proliferative rate and the apoptotic rate as determined by immunohistochemical analysis of Ki-67 and p53, respectively.

Results: There was a significant increase in the net proliferative rate of the OGE during pocket formation (periodontitis group, 220.90+/-46.85; healthy group, 107.60+/-25.86; P<0.001). There was a significant reduction in E-cadherin expression (periodontitis group, 0.837+/-0.428; healthy group, 1.846+/-0.555) and a significant increase in K19 expression during pocket formation (periodontitis group, 1.45+/-0.686; healthy group, 0.533+/-0.410).

Conclusion: OGE appears to undergo significant changes in proliferation and differentiation during pocket formation that do not seem to be restricted to proteolytic destruction by the invading microorganisms.