Gingival tissue samples from periodontitis patients demonstrate epithelial-mesenchymal transition phenotype

E-cadherin and TAC in GCF accurately discriminate periodontal health and disease

OBJECTIVE

To investigate the accuracy of gingival crevicular fluid (GCF) E-cadherin and total antioxidant capacity (TAC) to discriminate periodontal health from disease.

SUBJECTS AND METHODS

GCF samples were collected from participants with periodontal health (control), gingivitis, and periodontitis (n = 25 each group). The latter group was further subdivided according to stage (S) and grade. Periodontal parameters were recorded then levels of biomarkers were assayed using ELISA and antioxidant status by use of the Total Antioxidant Capacity Assay for E-cadherin and TAC, respectively.

RESULTS

All periodontal parameters were significantly higher in periodontally diseased groups than controls. The GCF E-cadherin significantly increased in gingivitis and periodontitis (S2 to S4) cases as compared to controls. Level of this protein in GCF samples from periodontitis S3 was significantly higher than in gingivitis and S2 groups. The GCF-TAC level was significantly higher in controls than in periodontally diseased groups. No significant differences were observed in the levels of these proteins between grade B and C periodontitis. Both molecules could discriminate periodontal health from gingivitis and periodontitis stages and differentiating periodontitis S3 from gingivitis and other periodontitis stages.

CONCLUSIONS

Levels of TAC and unbounded E-cadherin in GCF samples exhibited promising diagnostic abilities to differentiate periodontal health and disease.

Ability of gingival crevicular fluid volume, E-cadherin, and total antioxidant capacity levels for predicting outcomes of nonsurgical periodontal therapy for periodontitis patients

OBJECTIVES

To determine the potential of gingival crevicular fluid (GCF) volume, E-cadherin and total antioxidant capacity (TAC) levels to predict the outcomes of nonsurgical periodontal therapy (NSPT) for periodontitis patients.

BACKGROUND

NSPT is the gold-standard treatment for periodontal pockets < 6 mm in depth, however, successful outcomes are not always guaranteed due to several factors. Periodontitis-associated tissue destruction is evidenced by the increased level of soluble E-cadherin and reduced antioxidants in oral fluids which could be used as predictors for success/failure of NSPT.

MATERIALS AND METHODS

Patients with periodontitis (n = 24) were included in this clinical trial and full-mouth periodontal charting was recorded for each patient. GCF samples from periodontal pockets with probing pocket depth (PPD) 4-6 mm from the interproximal surfaces of anterior and premolar teeth were obtained. These sites subsequently received NSPT and were clinically re-evaluated after 1 and 3 months. Levels of GCF E-cadherin and TAC levels were assayed using ELISA.

RESULTS

All clinical periodontal parameters were significantly improved 3 months after completion of NSPT. These outcomes were associated with a significant decrease in E-cadherin levels and GCF volume, while TAC levels were significantly increased in samples obtained in follow-up appointments. Binary regression model analysis showed that PPD, GCF volume, E-cadherin, and TAC levels could significantly (p < .05) predict the outcomes of NSPT. The cut-off points for PPD, GCF volume, E-cadherin and TAC were 5 mm, 4 × 10-3, 1267.97 pg/mL and 0.09 μmol/g, respectively.

CONCLUSION

NSPT improved clinical parameters along with increased antioxidants capacity and epithelial pocket lining integrity. Discrimination of favorable/unfavorable responsiveness of periodontally diseased sites to NSPT could be possible by using GCF volume, PPD, E-cadherin and TAC level assessments.

Interleukin-22 Inhibits Apoptosis of Gingival Epithelial Cells Through TGF-β Signaling Pathway During Periodontitis

Periodontitis is a chronic inflammatory disease characterized by the destruction of tooth-supporting tissues. The gingival epithelium is the first barrier of periodontal tissue against oral pathogens and harmful substances. The structure and function of epithelial lining are essential for maintaining the integrity of the epithelial barrier. Abnormal apoptosis can lead to the decrease of functional keratinocytes and break homeostasis in gingival epithelium. Interleukin-22 is a cytokine that plays an important role in epithelial homeostasis in intestinal epithelium, inducing proliferation and inhibiting apoptosis, but its role in gingival epithelium is poorly understood. In this study, we investigated the effect of interleukin-22 on apoptosis of gingival epithelial cells during periodontitis. Interleukin-22 topical injection and Il22 gene knockout were performed in experimental periodontitis mice. Human gingival epithelial cells were co-cultured with Porphyromonas gingivalis with interleukin-22 treatment. We found that interleukin-22 inhibited apoptosis of gingival epithelial cells during periodontitis in vivo and in vitro, decreasing Bax expression and increasing Bcl-xL expression. As for the underlying mechanisms, we found that interleukin-22 reduced the expression of TGF-β receptor type II and inhibited the phosphorylation of Smad2 in gingival epithelial cells during periodontitis. Blockage of TGF-β receptors attenuated apoptosis induced by Porphyromonas gingivalis and increased Bcl-xL expression stimulated by interleukin-22. These results confirmed the inhibitory effect of interleukin-22 on apoptosis of gingival epithelial cells and revealed the involvement of TGF-β signaling pathway in gingival epithelial cell apoptosis during periodontitis.