The role of FOXM1 in acetylcysteine improving diabetic periodontitis

Abstract

Diabetic periodontitis (DP) stems from hyperglycemia-driven oxidative stress amplification and chronic inflammation, leading to periodontal tissue breakdown. Misregulated forkhead box protein M1 (FOXM1) play key roles in this process, exacerbating both inflammation and oxidative stress. In light of N-Acetylcysteine (NAC)’s potent anti-oxidative capacity and anti-inflammatory potential, understanding how it modulates these central pathways to alleviate DP holds high scientific and clinical importance. An animal model of diabetic mice periodontitis was established, and the model mice were injected with FOXM 1 adenovirus to enrich FOXM 1, and the periodontal pathological histology of each group was evaluated by HE staining. Western blotting and RT-PCR evaluated the expression levels of factors involved in bone destruction. ELISA evaluated the amount of inflammatory factors in mice serum. FOXM 1 over-expression and NAC were treated in murine macrophages, and the intracellular reactive oxygen species(ROS) levels in macrophages were measured using a DCFH-DA probe. Receptor activator of NF-κB ligand (RANKL) and lipopolysaccharide (LPS) were used to establish the macrophage osteoclast differentiation model and test the expression level of osteoclast differentiation factors after giving NAC. Hydrogen peroxide was used to establish a peroxidation environment, the plasmid silenced C-JUN, and the DNA binding activity of activating protein-1(AP1) was detected by EMSA. The effect of peroxidation on the osteoclast differentiation level was determined by WB. Mice with DP model had epithelial damage and inflammatory infiltration in periodontal tissues, and in the FOXM1 enriched group, the periodontal epithelial damage was repaired and inflammation was alleviated. FOXM1 enrichment resulted in DP model lower expression of RANKL (P < 0.01), macrophage colony-stimulating factor (M-CSF) (P < 0.01) and elevated expression of osteoprotegerin (OPG) (P < 0.001). Serum levels of pro-inflammatory factors interleukin (IL)-1β, tumor necrosis factor (TNF-α), and inducible nitric oxide synthase (iNOS) were elevated in DP mice (P < 0.001), and anti-inflammatory factor IL-10 was reduced(P < 0.001),, and FOXM1 enrichment significantly reversed inflammatory factor levels (P < 0.01). Overexpression of FOXM1 reduced ROS content in macrophages (P < 0.001), and NAC was performed to further reduce ROS content (P < 0.01). Silencing of FOXM1 elevated the expression of osteoclast-specific genes NFATc1, TRAP and OSCAR (P < 0.01), and the addition of NAC on top of silencing of FOXM1 markedly suppressed the expression level of osteoclast-specific genes (P < 0.01). ROS increased the transcriptional activity of AP1 (P < 0.001), which promoted osteoclast-specific gene expression (P < 0.001), and osteoclast-specific gene expression was decreased after silencing C-JUN (P < 0.01). FOXM1 relieve diabetic periodontitis inflammation and promote bone formation, regulates ROS production and ROS increases the transcriptional activity of AP1 and affects the osteoclastic differentiation of macrophages, which plays a positive role in bone protection in diabetic periodontitis.