Hepatic ischemia–reperfusion injury (IRI) is an inevitable adverse event following liver surgery, leading to liver damage and potential organ failure. Despite advancements, effective interventions for hepatic IRI remain elusive, posing a significant clinical challenge. The innate immune response significantly contributes to the pathogenesis of hepatic IRI by promoting an inflammatory cytotoxic cycle. We have reported that blocking GSDMD-induced pyroptosis in innate immunity cells protected hepatic IRI from inflammatory injury. However, the search for effective pyroptosis inhibitors continues. This study aims to evaluate whether quercetin, a natural flavonoid, can inhibit GSDMD-induced pyroptosis and mitigate hepatic IRI. We established the hepatic IRI murine model and cellular pyroptosis model to evaluate the efficacy of quercetin. Quercetin effectively alleviated hepatic IRI-induced tissue necrosis and inflammation. We found that during hepatic IRI, the cleavage of GSDMD occurred in hepatic macrophages, but not in other non-parenchymal cells. Quercetin inhibited the cleavage of GSDMD in macrophages. Moreover, we found that quercetin blocked the ASC assembly to inhibit the formation of NLRP3 inflammasomes and AIM2 inflammasomes, suppressing macrophage pyroptosis. Co-immunoprecipitation experiments confirmed that quercetin inhibited the interaction between ASC and Caspase-8, which is the mechanism of ASC complex and inflammasome formation. Overexpression of Caspase-8 abolished the anti-pyroptosis effect of quercetin in NLRP3 and AIM2 inflammasome signaling. Furthermore, we found that the hepatoprotective activity of quercetin was reduced in myelocytic GSDMD-deficient mice. Our findings suggest that quercetin has beneficial effects on hepatic IRI. Quercetin could attenuate hepatic IRI and target inhibition of macrophage pyroptosis via blocking Caspase-8/ASC interaction. We recommend that quercetin might serve as a targeted approach for the prevention and personalized treatment of hepatic IRI in perioperative patients.

中文翻译：

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槲皮素是一种天然黄酮类化合物，通过抑制 Caspase-8/ASC 依赖性巨噬细胞焦亡来预防肝缺血再灌注损伤


肝缺血再灌注损伤（IRI）是肝脏手术后不可避免的不良事件，导致肝损伤和潜在的器官衰竭。尽管取得了进展，但针对肝脏 IRI 的有效干预措施仍然难以实现，这给临床带来了重大挑战。先天免疫反应通过促进炎症细胞毒性循环，显着促进肝脏 IRI 的发病机制。我们已经报道，阻断 GSDMD 诱导的先天免疫细胞焦亡可以保护肝脏 IRI 免受炎症损伤。然而，对有效的细胞焦亡抑制剂的探索仍在继续。本研究旨在评估天然类黄酮槲皮素是否可以抑制 GSDMD 诱导的细胞焦亡并减轻肝脏 IRI。我们建立了IRI小鼠肝脏模型和细胞焦亡模型来评价槲皮素的功效。槲皮素能有效减轻IRI引起的肝脏组织坏死和炎症。我们发现，在肝脏IRI过程中，GSDMD的裂解发生在肝巨噬细胞中，但不在其他非实质细胞中。槲皮素抑制巨噬细胞中 GSDMD 的裂解。此外，我们发现槲皮素阻断ASC组装，抑制NLRP3炎症小体和AIM2炎症小体的形成，抑制巨噬细胞焦亡。免疫共沉淀实验证实，槲皮素抑制ASC与Caspase-8之间的相互作用，这是ASC复合物和炎症小体形成的机制。 Caspase-8 的过表达消除了槲皮素在 NLRP3 和 AIM2 炎症小体信号传导中的抗焦亡作用。此外，我们发现在骨髓细胞 GSDMD 缺陷小鼠中槲皮素的保肝活性降低。我们的研究结果表明槲皮素对肝脏 IRI 具有有益作用。 槲皮素可以通过阻断 Caspase-8/ASC 相互作用来减弱肝脏 IRI 并靶向抑制巨噬细胞焦亡。我们建议槲皮素可以作为围手术期患者肝脏 IRI 的预防和个性化治疗的有针对性的方法。