Neutrophil Extracellular Traps Induce Pyroptosis of Gingival Fibroblasts in Peri‐Implantitis

OBJECTIVES: This study aimed to verify the release of neutrophil extracellular traps (NETs) in peri-implantitis and explore whether NETs induce pyroptosis and inflammatory responses in human gingival fibroblasts (HGFs). MATERIALS AND METHODS: Peri-implant soft tissue samples were collected from healthy individuals and patients with peri-implantitis. NETs and the expression of pyroptosis-related factors including NLRP3, Caspase1, GSDMD, and IL-1β were detected. In vitro, NETs induced from differentiated HL60 (dHL60) cells and human neutrophils were used to stimulate HGFs. Transcriptome sequencing analysis and functional enrichment analysis were performed to analyze the influence of NETs on programmed cell death and inflammatory-related signaling pathways in HGFs. Further investigations were conducted to explore the changes in cell viability, cell membrane permeability, and the expression levels of inflammatory factors and pyroptosis-related markers in HGFs treated with NETs in the presence or absence of DNase I. RESULTS: Compared to healthy samples, the release of NETs was significantly elevated in soft tissues with peri-implantitis, accompanied by increased expression of NLRP3, Caspase1, GSDMD, and IL-1β. Functional enrichment analyses revealed that NETs activated signaling pathways related to pyroptosis and inflammatory responses of HGFs. Meanwhile, the results of the in vitro study revealed that NETs reduced cell viability, increased cell membrane permeability, and upregulated expression of inflammatory cytokines and pyroptosis markers in HGFs, which were partially reversed by DNase I treatment. CONCLUSION: NETs may exacerbate the pathological progression of peri-implantitis by inducing pyroptosis and inflammatory responses in HGFs. Targeting NETs may offer a potential therapeutic strategy to mitigate the inflammation in peri-implantitis.