Relationship between microRNA expression and inflammatory factors in patients with both type 2 diabetes mellitus and periodontal disease.

Objective: To investigate the expression of single-stranded microRNAs (miRNAs) in serum and gingival crevicular fluid of patients with type 2 diabetes mellitus (T2DM) complicated by periodontal disease and its correlation with inflammatory factors.

Methods: Twenty-six periodontitis patients without diabetes mellitus (periodontal group), 24 patients with T2DM (T2DM group), 22 patients with both T2DM and periodontal disease (comorbid group), and 25 healthy individuals without a history of periodontal disease (healthy group) were recruited respectively. Serum and gingival crevicular fluid specimens were collected to detect the expression levels of miRNAs and inflammatory factors including serum tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), and transforming growth factor-β (TGF-β), and their correlations were also investigated.

Results: Eleven miRNAs were detected in the gingival crevicular tissue of all subjects. The expression of miR-223 and miR-200b in serum and gingival crevicular fluid was elevated higher in the comorbid group than in the other three groups (P<0.05), and their expressions in gingival crevicular fluid contributed to the differential diagnosis of periodontal disease from diabetes mellitus comorbid with periodontal disease (P<0.05). Gingival crevicular fluid miR-223 expression was positively associated with TNF-α, clinical attachment loss (CAL), and probing pocket depth (PPD) in the periodontal group, while negatively associated with IL-10 (P<0.05), and so was gingival crevicular fluid miR-200b expression with TNF-α, CAL, and PPD (P<0.05). In the comorbid group, gingival crevicular fluid miR-223 expression showed a positive correlation with TNF-α, CAL, and PPD (P<0.05), and so did gingival crevicular fluid miR-200b expression with TNF-α, CAL, and PPD (P<0.05).

Conclusions: Our findings indicate a close link between the levels of miR-223 and miR-200b in serum and gingival crevicular fluid and susceptibility to T2DM as well as the pathogenesis of periodontal disease.