Interaction between p-AMPK and RIPK3 reveals a mechanism by which AdipoAI suppresses necroptosis to attenuate periodontitis.

Necroptosis is implicated in the pathogenesis of various inflammatory diseases, including periodontitis. This study aimed to investigate the molecular mechanisms underlying necroptosis in gingival fibroblasts (GFs) and to evaluate the therapeutic potential of AdipoAI, a novel adiponectin receptor agonist, administered locally, along with its regulatory effect on necroptosis. Analysis of single-cell RNA sequencing data using the AUCell scoring system demonstrated significant activation of necroptosis in human periodontal tissues, with GFs identified as the primary cellular target. Integrated approaches, including molecular docking, co-immunoprecipitation, and immunofluorescence, revealed a physical association between phosphorylated AMP-activated protein kinase (p-AMPK) and Receptor-Interacting Protein Kinase 3 (RIPK3). Additionally, we established a mouse model of experimental periodontitis and an LPS/AZD'5582/z-VAD-fmk (LAZ)-induced necroptosis model in hGFs. Techniques including Western blotting, flow cytometry, and transmission electron microscopy were employed to evaluate the effects of AdipoAI administration. Local administration of AdipoAI significantly alleviated gingival inflammation and alveolar bone resorption in mice. In hGFs, AdipoAI effectively suppressed the activation of p-RIPK3 and phosphorylated Mixed Lineage Kinase Domain-Like protein (p-MLKL) and reduced the production of inflammatory factors. Mechanistic investigations revealed that AdipoAI binds to Adiponectin Receptor 1 (AdipoR1) - adiponectin receptor interacting protein (APPL1) to activate the AMPK signaling pathway, facilitating the association between p-AMPK and RIPK3, thereby inhibiting RIPK3/MLKL-mediated necroptosis. This study is the first to unveil a mechanism by which AdipoAI suppresses GF necroptosis through p-AMPK-mediated RIPK3 regulation, offering new strategic insights and experimental evidence for targeted periodontitis therapy.