Role of 1,25-dihydroxyvitamin D in alleviating alveolar bone loss and gingival inflammation in ligature-induced periodontitis

Objectives: The goal of this study was to assess if endogenous 1,25(OH)(2) D deficiency enhanced, whereas exogenous 1,25(OH)(2)D-3 supplementation alleviated alveolar bone loss and gingival inflammation induced by ligature-induced periodontitis. Methods: A model of ligature-induced experimental periodontitis was generated in wild-type (WT) and Cyp27b1-knockout (KO) mice on a rescue diet (RD), and un-ligated genotype-matched littermates as control, or in WT mice on a normal diet (ND) with vehicle treatment or 1,25(OH)(2)D-3 treatment, and un-ligated WT littermates as control. Alveolar bone mass and turnover, T cell infiltration and inflammatory cytokines in gingival tissues were examined. Results: In WT mice, ligature-induced alveolar bone loss occurred by inhibiting alveolar bone formation. This was characterized by reduction of osteoblast numbers, alkaline phosphatase activity and type I collagen synthesis, as well as by augmentation of osteoclastic alveolar bone resorption and gingival inflammation, including increases of osteoclast numbers, inflammatory positive cells and up-regulation of mRNA expression levels of inflammatory cytokines. Alveolar bone destruction and gingival inflammation were more severe in diet-matched Cyp27b1-KO mice than in WT littermates on RD. Supplementation of exogenous 1,25(OH)(2)D-3 alleviated alveolar bone loss and gingival inflammation in ligated WT mice on ND, but those parameters did not reach levels observed in un-ligated WT ones. Conclusions: Endogenous 1,25(OH)(2)D deficiency enhanced, whereas exogenous 1,25(OH)(2)D-3 supplementation alleviated alveolar bone loss and gingival inflammation induced by ligature-induced periodontitis.

Automated summary

This study assessed the effects of 1,25(OH)(2)D deficiency and supplementation on alveolar bone loss and gingival inflammation induced by ligature-induced periodontitis. The results showed that 1,25(OH)(2)D deficiency enhanced the severity of alveolar bone loss and gingival inflammation, while supplementation with 1,25(OH)(2)D-3 alleviated these symptoms, although not completely.