Evaluation of DNA methylation of inflammatory genes following treatment of chronic periodontitis: A pilot case–control study

ObjectiveTo evaluate the influence of periodontal therapy on DNA methylation in patients with chronic periodontitis as compared to healthy individuals.Material and MethodsTwenty patients were enrolled into two groups: (i) 10 diagnosed as clinically healthy; and (ii) 10 diagnosed with chronic periodontitis. Clinical measures were recorded and gingival biopsies were harvested at baseline (both patient groups) and at 2 and 8 weeks post‐baseline for diseased individuals. Molecular DNA methylation analysis was performed by pyrosequencing for the putative inflammation‐associated genes LINE‐1, COX‐2, IFN‐γ and TNF‐α. Random‐intercept linear regression models were applied to evaluate methylation levels across groups at baseline and the methylation changes over time in the diseased and normal tissues.ResultsPeriodontal therapy did not influence gene expression methylation of TNF‐α, IFN‐γ and LINE‐1 levels at normal and periodontitis sites over time. However, it significantly reduced COX‐2 methylation levels comparable to healthy individuals at both 2 and 8 weeks post‐treatment (p < .05).ConclusionsPeriodontal therapy resets the DNA methylation status of inflammatory gene for COX‐2 in patients with periodontal disease. DNA methylation levels of TNF‐α, IFN‐γ and LINE‐1 were sustained in periodontitis sites despite therapy. Future studies should consider an expanded panel of inflammatory genes over time. (ClinicalTrials.gov NCT02835898).Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138219/1/jcpe12783.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138219/2/jcpe12783_am.pd