Possible Involvement of Leptin in Pathogenesis of Periodontal Disease

Periodontitis is a chronic inflammatory condition of the periodontal tissues, ultimately leading to their destruction. The periodontal ligament is a key structure that not only secures the teeth within the alveolus but can also act as a source of numerous mediators involved in the development of inflammation in periodontal tissues. The aim of this study was to investigate the effect of leptin on periodontal ligament cells and their secretion of selected pro-inflammatory mediators that may contribute to the pathogenesis of periodontal disease. The study was conducted on cultured periodontal ligament cells stimulated with leptin. The effect of leptin was assessed on the expression of selected cytokines implicated in the pathogenesis of periodontal disease (IL-1, IL-6, IL-8, IL-10, IL-17, IL-18, and tumour necrosis factor-alpha [TNF-α]) at the mRNA level, as well as on the protein concentrations of these cytokines in culture supernatants. Assessments were carried out after 12, 24, and 48 h of leptin stimulation. The results showed a statistically significant effect of leptin on IL-6 and IL-8 expression at both the mRNA and protein levels. For IL-1, a transient increase in mRNA expression and protein concentration was observed, persisting up to 24 h. A decrease in IL-10 mRNA expression was noted after 48 h of leptin stimulation, with no corresponding effect on IL-10 protein concentration. No significant effect of leptin was found on IL-17 or IL-18 protein concentrations in periodontal ligament cell cultures. These findings suggest that leptin may contribute to the pathogenesis of periodontitis by modulating the expression of certain pro-inflammatory cytokines in periodontal ligament cells.