State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, China.
J Immunol. 2020 Apr 1;204(7):1929-1942. doi: 10.4049/jimmunol.1901456. Epub 2020 Feb 28.
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.
细菌 LPS 是导致败血症的主要内毒素之一；其感应途径诱导的细胞焦亡在先天免疫中起着重要作用。然而，过度的细胞焦亡可能会导致免疫性疾病，甚至通过未知机制导致多器官衰竭和死亡。鉴于败血症患者急性肾损伤 (AKI) 的发展会导致显著的发病率和死亡率，细胞焦亡在调节败血症性 AKI 中的机制尚不清楚。在这项研究中，我们建立了一个斑马鱼crisprant 体内分析模型，揭示了 caspy2 和 gasdermin Eb（GSDMEb）都有助于致命 LPS 诱导的败血症性休克。同时，体外分析表明 caspy2 激活可以特异性切割 GSDMEb 以释放其 N 端来介导细胞焦亡，其在哺乳动物中充当 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，揭示了 caspy2-GSDMEb 信号级联对于增强致命 LPS 诱导的败血症性休克期间肾小管损伤是必不可少的，而给予斑马鱼特异性 GSDMEb 衍生肽抑制剂 Ac-FEID-CMK 可以减轻体内死亡率和败血症性 AKI。此外，我们证实 caspase-11 或 GSDMD 缺陷均减少炎症细胞因子和肾功能障碍酶的释放，并延长败血症性休克小鼠模型的存活时间。总之，这些发现证明了斑马鱼细胞焦亡的进化执行者，并揭示了肾小管细胞的细胞焦亡是败血症性 AKI 的主要原因，并且为潜在的抗脓毒症治疗策略提供了理想的体内筛选模型。
