Pexidartinib Inhibits Macrophage Senescence Through Glycolysis in Periodontitis Microenvironment

OBJECTIVES: Periodontitis, a chronic inflammatory condition, is caused by complex interactions between periodontopathic bacteria and the local innate immune response. Macrophage senescence, a pivotal contributor to immune dysfunction, has been implicated in periodontitis progression. This research was conducted to clarify how macrophage senescence and glycolysis interact within the periodontal inflammatory microenvironment. Specifically, we investigated whether pexidartinib (PLX3397), known for inhibiting the colony-stimulating factor-1 receptor (CSF-1R), could mitigate macrophage senescence by modulating glycolytic activity, thereby attenuating periodontal inflammation. METHODS: We first constructed the experiential periodontitis mouse model. The alveolar bone volume was quantified using Micro-CT, while the periodontal ligament width and the distance from the cementoenamel junction (CEJ) to the alveolar bone crest (ABC) were evaluated using HE staining. The expression levels of macrophage senescence markers, glycolysis-related indicators, and CSF-1R in gingival tissues were assessed by immunofluorescence staining. For in vitro studies, Senescence was induced in RAW264.7 cells by stimulating them with Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) with or without pretreatment of PLX3397 and glycolysis modulators. Cellular senescence rates were evaluated using Senescence-associated β-Galactosidase (SA-β-Gal) staining. The presence of markers indicating senescence, CSF-1R, and glycolysis-related indicators was further analysed by RT-qPCR and Western blotting. RESULTS: The gingival tissues of mice with periodontitis showed elevated senescent macrophages, which correlated with higher CSF-1R expression and glycolytic activity. Similarly, in Pg-LPS-treated RAW264.7 macrophages, senescence markers were upregulated alongside CSF-1R and glycolysis-related indicators. Meanwhile, modulating glycolysis in vitro directly influences senescence indicators. And PLX3397 treatment reduced glycolytic activity, leading to an improvement in macrophage senescence. CONCLUSION: Our findings indicate that PLX3397 alleviates periodontal tissue inflammation by inhibiting macrophage senescence via glycolytic modulation, offering potential for immune-regulatory therapies in periodontitis management.