Key Points GSDMEb is an evolutionary pyroptosis executor downstream of caspy2 in zebrafish. Caspy2–GSDMEb signaling activation drives proximal renal tubular damage. GSDMEb cleavage-mediated pyroptosis enhances septic AKI in vivo. The bacteria LPS is one of the leading endotoxins responsible for sepsis; its sensing pathway–induced pyroptosis plays an important role in innate immunity. However, excessive pyroptosis might cause immunological diseases, even multiple organ failure and death by undefined mechanisms. Given that the development of acute kidney injury (AKI) in patients with sepsis causes significant morbidity and mortality, the mechanism of pyroptosis in regulating septic AKI remains unknown. In this study, we establish a zebrafish crispant in vivo analysis model and reveal that both caspy2 and gasdermin Eb (GSDMEb) contribute to lethal LPS-induced septic shock. Meanwhile, the in vitro analysis reveals that caspy2 activation can specifically cleave GSDMEb to release its N terminus to mediate pyroptosis, which functions as GSDMD in mammals. Interestingly, we establish an in vivo propidium iodide–staining method and reveal that the caspy2–GSDMEb signaling cascade is essential for enhancing renal tubular damage during lethal LPS-induced septic shock, whereas administration of the zebrafish-specific GSDMEb-derived peptide inhibitor Ac-FEID-CMK can attenuate mortality and septic AKI in vivo. Moreover, we confirm that either caspase-11 or GSDMD deficiency decreases both inflammatory cytokines and kidney dysfunction enzyme release and prolongs survival in a murine model of septic shock. Taken together, these findings demonstrate an evolutionary executor for pyroptosis in zebrafish and reveal that the pyroptosis of renal tubular cells is a major cause of septic AKI, and also provide an ideal in vivo screening model for potential antisepsis therapeutic strategies.

中文翻译：

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斑马鱼 GSDMEb 卵裂门控细胞焦亡在体内导致败血性急性肾损伤

关键点 GSDMEb 是斑马鱼 caspy2 下游的进化焦亡执行者。Caspy2-GSDMEb 信号激活驱动近端肾小管损伤。GSDMEb 裂解介导的细胞焦亡增强了体内脓毒症 AKI。细菌 LPS 是导致败血症的主要内毒素之一。其传感途径诱导的细胞焦亡在先天免疫中起重要作用。然而，过度的细胞焦亡可能会导致免疫疾病，甚至多器官功能衰竭和不明机制的死亡。鉴于脓毒症患者急性肾损伤 (AKI) 的发展会导致显着的发病率和死亡率，细胞焦亡调节脓毒症 AKI 的机制仍然未知。在这项研究中，我们建立了斑马鱼脆片体内分析模型，并揭示了 caspy2 和 gasdermin Eb (GSDMEb) 都有助于致命的 LPS 诱导的感染性休克。同时，体外分析表明 caspy2 激活可以特异性裂解 GSDMEb 以释放其 N 末端以介导细胞焦亡，其在哺乳动物中起到 GSDMD 的作用。有趣的是，我们建立了一种体内碘化丙啶染色方法，并揭示了 caspy2-GSDMEb 信号级联对于在致死性 LPS 诱导的感染性休克期间增强肾小管损伤至关重要，而施用斑马鱼特异性 GSDMEb 衍生肽抑制剂 Ac- FEID-CMK 可以降低体内死亡率和脓毒性 AKI。而且，我们证实，caspase-11 或 GS​​DMD 缺乏会降低炎性细胞因子和肾功能障碍酶的释放，并延长脓毒性休克小鼠模型的存活时间。综上所述，这些发现证明了斑马鱼焦亡的进化执行者，并揭示肾小管细胞焦亡是脓毒症 AKI 的主要原因，也为潜在的防腐治疗策略提供了理想的体内筛选模型。