Neutrophil Extracellular Traps Induce Pyroptosis Of Fibroblasts In Peri-Implantitis

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). Peri-implant soft tissue samples were collected from healthy individuals and patients with peri-implantitis. NETs and the expression of pyroptosis-related factors were detected. NETs induced from HL60 cells were used to stimulate HGFs in vitro. 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. Compared with that in healthy specimens, the release of NETs in peri-implant soft tissues was significantly increased in specimens with peri-implantitis, accompanied by higher mRNA and protein expression of Caspase1 and NLPR3 compared with healthy specimens. GO, KEGG, and GSEA analyses revealed that NETs activated signaling pathways related to pyroptosis and inflammatory responses of HGFs. Meanwhile, NETs decreased cell viability, increased cell membrane permeability, and elevated the expression of inflammatory factors and pyroptosis-related markers in HGFs, which were partially rescued by DNase I. NETs may exacerbate the pathological progression of peri-implantitis by inducing pyroptosis and inflammatory responses in HGFs, which serve as therapeutic targets in peri-implantitis to mitigate bone resorption.