The monomer derivative of paeoniflorin inhibits macrophage pyroptosis via regulating TLR4/ NLRP3/ GSDMD signaling pathway in adjuvant arthritis rats

• Published in: International immunopharmacology 2021-12, Vol.101 (Pt A), p.108169-108169, Article 108169
• Main Authors: Xu, Li, Wang, Han, Yu, Qian-qian, Ge, Jin-ru, Zhang, Xian-zheng, Mei, Dan, Liang, Fa-qin, Cai, Xiao-yu, Zhu, Yue, Shu, Jin-ling, Tai, Yu, Wei, Wei, Zhang, Ling-ling
• Format: Article
• Language: English
• Subjects: Adjuvant arthritis; Animal models; Animals; Arthritis; Arthritis, Experimental - drug therapy; Arthritis, Experimental - immunology; Arthritis, Experimental - pathology; Arthritis, Rheumatoid - drug therapy; Arthritis, Rheumatoid - immunology; Arthritis, Rheumatoid - pathology; Bone imaging; Caspase-1; Cell morphology; Cytokines; Cytology; Enzyme-linked immunosorbent assay; Flow cytometry; Glucosides - chemistry; Glucosides - therapeutic use; Humans; IL-1β; Immunofluorescence; Inflammasomes - drug effects; Inflammasomes - immunology; Inflammasomes - metabolism; Inflammation; Interleukin 18; Kinases; Macrophage pyroptosis; Macrophages; Macrophages - drug effects; Macrophages - immunology; Macrophages - metabolism; Male; Monomer derivative of paeoniflorin; Monomers; Monoterpenes - chemistry; Monoterpenes - therapeutic use; Morphology; MyD88 protein; NLR Family, Pyrin Domain-Containing 3 Protein - metabolism; Phosphate-Binding Proteins - metabolism; Pore Forming Cytotoxic Proteins - metabolism; Pyroptosis; Pyroptosis - drug effects; Pyroptosis - immunology; Rats; Rats, Wistar; Rheumatoid arthritis; Scanning electron microscopy; Signal transduction; Signal Transduction - drug effects; Signal Transduction - immunology; Signaling; Soft tissues; TLR4 protein; TLR4/NLRP3/GSDMD signaling pathway; Toll-Like Receptor 4 - metabolism; Toll-like receptors; X ray imagery
• ISSN: 1567-5769; 1878-1705
• DOI: 10.1016/j.intimp.2021.108169

[Display omitted] •Macrophage pyroptosis was involved in the inflammatory mechanism of AA rats.•TLR4/NLRP3/GSDMD signaling pathway mediated macrophage pyroptosis in AA rats.•MDP can improve the secondary inflammation of AA rats.•MDP inhibited macrophage pyroptosis by regulating TLR4/NLRP3/GSDMD signaling pathway in AA rats. This study was aimed to investigate the effect of monomer derivative of paeoniflorin (MDP) on macrophage pyroptosis mediated by TLR4/NLRP3/GSDMD signaling pathway in adjuvant arthritis (AA) rats. Wistar rats were divided into normal group, AA model group, MDP (50 mg/kg) group and MTX (0.5 mg/kg) group. The expression of TLR4, NLRP3 and GSDMD in macrophage were detected by immunofluorescence assay. The expression of TLR4 and the ratio of macrophage pyroptosis were analyzed by flow cytometry. Cell morphology was observed by scanning electron microscopy. The cytokine levels of IL-18 and IL-1β were detected by ELISA. The expressions of proteins related to macrophage pyroptosis were detected by western blot. MDP has a therapeutic effect on rats AA by reducing the secondary inflammation and improving pathological changes. The results of X-ray imaging and ultrasound images showed that MDP could inhibit bone erosion, soft tissue swelling, and joint space narrowing. Macrophage pyroptosis was found in secondary inflammation of AA rats. The expressions of TLR4, MyD88, NLRP3, Caspase-1, ASC, and GSDMD-N in macrophage were increased, the levels of IL-18 and IL-1β were enhanced, and the morphology of pyroptosis could be observed. MDP could inhibit macrophage polarization and macrophage pyroptosis, and down-regulated the cytokine levels of IL-18 and IL-1β in AA rats. MDP could regulate the M1/M2 ratio, decreased the ratio of macrophage pyroptosis and down-regulated the expressions of TLR4, MyD88, NLRP3, Caspase-1, ASC, and GSDMD-N in vivo and in vitro. Abnormal activation of TLR4/NLRP3/GSDMD signaling pathway may be involved in macrophage pyroptosis in AA rats. The therapeutic effect of MDP on AA rats is related to the inhibition of macrophage pyroptosis by regulating the TLR4/NLRP3/GSDMD signaling pathway.