Zebrafish GSDMEb Cleavage-Gated Pyroptosis Drives Septic Acute Kidney Injury In Vivo

Abstract

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.

Caspase 3/GSDME-dependent pyroptosis contributes to chemotherapy drug-induced nephrotoxicity

“…In vivo, the Gsdme-derived inhibitor, Ac-DMLD-CMK, alleviated deterioration of kidney function, attenuated renal tubular epithelial cell injury, reduced inflammatory cytokine secretion, and inhibited caspase 3-GSDME signaling induced by cisplatin. Similarly, a previous study reported that GSDMEb knockout-or GSDMEb-derived inhibitor Ac-FEID-CMK-treated zebrafish exhibited reduced proximal renal tubule structure injury compared to the control, indicating that GSDMEb plays an essential role in proximal tubular cell pyroptosismediated AKI in zebrafish 46 . In fact, in addition to the kidney, GSDME also plays an important role in other organs and diseases, however, most of the current studies on GSDME focus on tumors 14 .…”

The Role and Mechanism of Pyroptosis and Potential Therapeutic Targets in Sepsis: A Review

“…the caspy2-GSDMEb signaling pathway was essential in LPSinduced fatal renal tubular injury caused by septic shock, and the specific GSDMEB inhibitor Ac-FEID-CMK could reduce the incidence of septic AKI and zebrafish mortality (55). These results highlight potential therapeutic targets of septic AKI.…”

Pyroptosis: A New Frontier in Kidney Diseases

“…It is likely that the contrast agents damage the membrane of epithelial cells, entering into the cells to activate caspase-4/5/11, to cleave GSDMD, and to initiate pyroptosis [ 61 ]. An up-to-date study found that pyroptosis mediated by the caspase-11/GSDMD signaling pathway not only affected the release of cytokines but also determined the severity of AKI following septic shock [ 62 ]. These results suggest a close correlation between the pathogenesis of AKI and the caspase-4/5/11-mediated atypical pathway in pyroptosis.…”