Activation of receptor-interacting protein 3-mediated necroptosis accelerates periodontitis in mice

Objective: To investigate the involvement and role of receptor-interacting protein 3 (RIP3)-mediated necroptosis in periodontitis.Methods: A periodontitis murine model was established by oral infection with Porphyromonas gingivalis, and activation of necroptosis pathway was identified by immunohistochemistry. Adeno-associated virus was used to knock down Rip3 and the effect of Rip3 knockdown on periodontal inflammation was examined by Micro-CT, qRT-PCR and histological staining. In vitro, P. gingivalis-LPS was used to infect fibroblast cell line L929 and siRNA was used to knock down Rip3. Necroptosis pathway signalling and inflammation in cells were detected by cell viability and death assay, Western Blot, qRT-PCR and immunofluorescence analysis.Results: Phosphorylation of RIP3 and mixed lineage kinase domain-like protein (MLKL) was increased in the periodontal ligament of mice infected with P. gingivalis. RIP3 knockdown reduced osteoclastogenesis and inflammatory cytokines in the periodontal area, and alleviated alveolar bone loss in vivo. In vitro, P. gingivalis-LPS-induced RIP3-mediated necroptosis in L929 cells, and knockdown of RIP3 by siRNA decreased the expression of inflammatory cytokines.Conclusion: RIP3-mediated necroptosis is activated in periodontitis and blocking necroptosis alleviates disease progression, indicating that RIP3 may be a potential target for periodontitis treatment.