Effects of 1,25-dihydroxyvitamin D₃ on Macrophage Cytokine Secretion Stimulated by Porphyromonas gingivalis

Abstract

Vitamin D has been known to be closely associated with periodontitis while the exact mechanisms remain to be clarified. The present study aimed to investigate the influence of 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) on porphyromonas gingivalis (Pg)-stimulated cytokine production by macrophages and the involved signaling pathways. The main observation was that 1,25(OH)₂D₃ inhibited Pg-induced IL-6 cytokine expression while improved the expression of anti-inflammatory cytokine IL-10. Further analyses showed that 1,25(OH)₂D₃ decreased the p38 MAPK and ERK1/2 phosphorylation. Inhibited phosphorylation of p38 MAPK and ERK1/2 was proved to be associated with decreased level of IL-6 expression, but not related to increased level of IL-10 expression in macrophages stimulated with Pg. These results suggest that 1,25(OH)₂D₃ may exert its anti-inflammatory effects on Pg-stimulated macrophages partly through its inhibitory effect on the p38 MAPK and ERK1/2 signaling pathway.