PI3Kγ controls IL-17A expression and attenuates alveolar bone loss in an experimental periodontitis model

Objective: In this study, we investigated the modulatory effects of PI3Kγ on IL-17A expression and the progression of experimental periodontitis in vivo. Methods: Ligature-induced periodontitis was developed around the first molar of mice. Animals were treated with anti-mouse IL-17A or IPI-549 (PI3Kγ inhibitor). In addition, PI3Kγ-deficient mice (PI3Kγ^−/−) were used in the study. Alveolar bone loss was measured and real-time PCR of Il17a and Rankl genes was performed. A bioinformatics analysis was carried out using the Gene Set Enrichment Analysis computational tool. Results: Nine days after ligature placement, alveolar bone loss scores were significantly increased, with upregulation of Il17a and Rankl genes in the gingival tissues. Treatment with anti-mouse IL-17A (100 µg/mice) significantly attenuated alveolar bone loss. Mice with ligature-induced periodontitis treated with IPI-549 (3 mg/kg) or PI3Kγ^−/− mice showed reduced alveolar bone loss and downregulation of Il17a and Rankl gene expression in the gingival tissues. Consistent with this, the bioinformatics analysis showed upregulation of IL17F, IL17A, IL17D, and STAT3 genes, as well as greater activation of IL-17 and PI3KCI pathways (upregulation of PIK3CG gene) in the gingival tissue of patients with periodontitis. Conclusion: PI3Kγ plays an important role in modulating IL-17A expression and alveolar bone loss in vivo and can be considered a promising pathway for the management of periodontal disease and the development of new therapies.