Expression Patterns of E-Cadherin and N-Cadherin Proteins in the Periodontal Pocket Epithelium of Chronic Periodontitis

STATEMENT OF THE PROBLEM: E-cadherin and N-cadherin are two types of cell adhesion molecules that are involved in organ development, wound healing, and pathological conditions through the process of epithelial-mesenchymal transition (EMT). However, their role has not yet been fully elucidated in the pathogenesis of periodontal diseases. PURPOSE: To determine the expression level of proteins associated with the EMT process (E-cadherin and N-cadherin) in chronic periodontitis. MATERIALS AND METHOD: In this cross-sectional study, 37 samples (19 cases with healthy gingival tissue and 18 cases with severe chronic periodontitis) that referred to the Periodontology Department of Zahedan Dental School, Zahedan, Iran, in 2018 were included. The samples were immunohistochemically stained with E-cadherin and N-cadherin monoclonal antibodies. Afterward, the percentage of stained cells and the staining intensity of the cells were evaluated. Finally, the obtained data were analyzed using by IBM© SPSS© Statistics version 21 using Mann-Whitney statistical test. RESULTS: In this study, 89.5% of the healthy gingival tissue samples and 61.1% of samples with chronic periodontitis showed E-cadherin expression in more than 50% of cells. This difference between the two groups was not significant (p= 0.13); however, the E-cadherin staining intensity of the healthy gingival tissue was strong while that of the samples with chronic periodontitis was moderate (p= 0.002). The N-cadherin expression was negative in 68.4% of healthy gingival cases, while 50% of the cases with chronic periodontitis showed a high expression of N-cadherin. This difference was statistically significant (p= 0.04). Moreover, the N-cadherin staining intensity also had a significant difference between the two groups (p= 0.004). CONCLUSION: Based on the results of the present study, the increased expression of N-cadherin and reduction of staining intensity of E-cadherin was found in chronic periodontitis compared to healthy gingival tissues. Therefore, EMT process may be involved in the pathogenesis of severe chronic periodontitis.