Calycosin represses AIM2 inflammasome-mediated inflammation and pyroptosis to attenuate monosodium urate-induced gouty arthritis through NF-κB and p62-Keap1 pathways.

Gouty arthritis is an inflammatory disease induced by monosodium urate (MSU), and is closely related to the activation of inflammasomes. Calycosin plays an anti-inflammatory role in arthritis. This study explored the mechanism of Calycosin in MSU-induced gouty arthritis. MSU-induced gouty arthritis mouse models with or without treatment of Calycosin were established, and physiological and pathological indicators were determined. Similarly, peripheral blood mononuclear cells (PBMCs) and THP-1 macrophages were used in vitro. Lactate dehydrogenase (LDH) was tested. The degree of centrifugal infiltration was detected by immunofluorescence. ELISA and quantitative reverse-transcription polymerase chain reaction were conducted to determine the levels of inflammatory factors. Immunohistochemistry, immunofluorescence, and flow cytometry were utilized to detect the content of caspase-1. Protein expressions of NF-κB-, p62-Keap1 pathway-, and pyroptosis-related factors were examined by western blot. In MSU-induced mouse models, calycosin increased mechanical hyperalgesia but decreased the swelling index of the mouse knee joint in a time-dependent manner. MSU treatment increased inflammatory cells and LysM-eGFP neutrophils recruitment in vivo, and promoted the LDH content in vitro, and meanwhile, calycosin reversed the aforementioned effects of MSU. In addition, calycosin repressed the release of inflammatory factors, promoted p62 level and diminished the levels of AIM2, caspase-1, ASC, IL-1β, Keap1, Cleaved GSDMD, and Cleaved caspase-1 and phosphorylation of p65 and IκBα in MSU-induced mouse or cell models. Furthermore, AIM2 silencing also inhibited MSU-induced inflammation and pyroptosis. Collectively, calycosin may inhibit AIM2 inflammasomes-mediated inflammation and pyroptosis through NF-κB and p62-Keap1 pathways, ultimately playing a protective role in gouty arthritis.