Small-molecule GSDMD agonism in tumors stimulates antitumor immunity without toxicity.

Gasdermin-mediated inflammatory cell death (pyroptosis) can activate protective immunity in immunologically cold tumors. Here, we performed a high-throughput screen for compounds that could activate gasdermin D (GSDMD), which is expressed widely in tumors. We identified 6,7-dichloro-2-methylsulfonyl-3-N-tert-butylaminoquinoxaline (DMB) as a direct and selective GSDMD agonist that activates GSDMD pore formation and pyroptosis without cleaving GSDMD. In mouse tumor models, pulsed and low-level pyroptosis induced by DMB suppresses tumor growth without harming GSDMD-expressing immune cells. Protection is immune-mediated and abrogated in mice lacking lymphocytes. Vaccination with DMB-treated cancer cells protects mice from secondary tumor challenge, indicating that immunogenic cell death is induced. DMB treatment synergizes with anti-PD-1. DMB treatment does not alter circulating proinflammatory cytokine or leukocyte numbers or cause weight loss. Thus, our studies reveal a strategy that relies on a low level of tumor cell pyroptosis to induce antitumor immunity and raise the possibility of exploiting pyroptosis without causing overt toxicity.

A 360° view of the inflammasome: Mechanisms of activation, cell death, and diseases.

Inflammasomes are critical sentinels of the innate immune system that respond to threats to the host through recognition of distinct molecules, known as pathogen- or damage-associated molecular patterns (PAMPs/DAMPs), or disruptions of cellular homeostasis, referred to as homeostasis-altering molecular processes (HAMPs) or effector-triggered immunity (ETI). Several distinct proteins nucleate inflammasomes, including NLRP1, CARD8, NLRP3, NLRP6, NLRC4/NAIP, AIM2, pyrin, and caspases-4/-5/-11. This diverse array of sensors strengthens the inflammasome response through redundancy and plasticity. Here, we present an overview of these pathways, outlining the mechanisms of inflammasome formation, subcellular regulation, and pyroptosis, and discuss the wide-reaching effects of inflammasomes in human disease.

Gasdermin and MLKL necrotic cell death effectors: Signaling and diseases.

Diverse inflammatory conditions, from infections to autoimmune disease, are often associated with cellular damage and death. Apoptotic cell death has evolved to minimize its inflammatory potential. By contrast, necrotic cell death via necroptosis and pyroptosis-driven by membrane-damaging MLKL and gasdermins, respectively-can both initiate and propagate inflammatory responses. In this review, we provide insights into the function and regulation of MLKL and gasdermin necrotic effector proteins and drivers of plasma membrane rupture. We evaluate genetic evidence that MLKL- and gasdermin-driven necrosis may either provide protection against, or contribute to, disease states in a context-dependent manner. These cumulative insights using gene-targeted mice underscore the necessity for future research examining pyroptotic and necroptotic cell death in human tissue, as a basis for developing specific necrotic inhibitors with the potential to benefit a spectrum of pathological conditions.

Gasdermin D permeabilization of mitochondrial inner and outer membranes accelerates and enhances pyroptosis.

Gasdermin D (GSDMD)-activated inflammatory cell death (pyroptosis) causes mitochondrial damage, but its underlying mechanism and functional consequences are largely unknown. Here, we show that the N-terminal pore-forming GSDMD fragment (GSDMD-NT) rapidly damaged both inner and outer mitochondrial membranes (OMMs) leading to reduced mitochondrial numbers, mitophagy, ROS, loss of transmembrane potential, attenuated oxidative phosphorylation (OXPHOS), and release of mitochondrial proteins and DNA from the matrix and intermembrane space. Mitochondrial damage occurred as soon as GSDMD was cleaved prior to plasma membrane damage. Mitochondrial damage was independent of the B-cell lymphoma 2 family and depended on GSDMD-NT binding to cardiolipin. Canonical and noncanonical inflammasome activation of mitochondrial damage, pyroptosis, and inflammatory cytokine release were suppressed by genetic ablation of cardiolipin synthase (Crls1) or the scramblase (Plscr3) that transfers cardiolipin to the OMM. Phospholipid scramblase-3 (PLSCR3) deficiency in a tumor compromised pyroptosis-triggered anti-tumor immunity. Thus, mitochondrial damage plays a critical role in pyroptosis.

FADD and Caspase-8 Regulate Gut Homeostasis and Inflammation by Controlling MLKL- and GSDMD-Mediated Death of Intestinal Epithelial Cells.

Pathways controlling intestinal epithelial cell (IEC) death regulate gut immune homeostasis and contribute to the pathogenesis of inflammatory bowel diseases. Here, we show that caspase-8 and its adapter FADD act in IECs to regulate intestinal inflammation downstream of Z-DNA binding protein 1 (ZBP1)- and tumor necrosis factor receptor-1 (TNFR1)-mediated receptor interacting protein kinase 1 (RIPK1) and RIPK3 signaling. Mice with IEC-specific FADD or caspase-8 deficiency developed colitis dependent on mixed lineage kinase-like (MLKL)-mediated epithelial cell necroptosis. However, MLKL deficiency fully prevented ileitis caused by epithelial caspase-8 ablation, but only partially ameliorated ileitis in mice lacking FADD in IECs. Our genetic studies revealed that caspase-8 and gasdermin-D (GSDMD) were both required for the development of MLKL-independent ileitis in mice with epithelial FADD deficiency. Therefore, FADD prevents intestinal inflammation downstream of ZBP1 and TNFR1 by inhibiting both MLKL-induced necroptosis and caspase-8-GSDMD-dependent pyroptosis-like death of epithelial cells.

Inflammasome Activation Triggers Blood Clotting and Host Death through Pyroptosis.

Inflammasome activation and subsequent pyroptosis are critical defense mechanisms against microbes. However, overactivation of inflammasome leads to death of the host. Although recent studies have uncovered the mechanism of pyroptosis following inflammasome activation, how pyroptotic cell death drives pathogenesis, eventually leading to death of the host, is unknown. Here, we identified inflammasome activation as a trigger for blood clotting through pyroptosis. We have shown that canonical inflammasome activation by the conserved type III secretion system (T3SS) rod proteins from Gram-negative bacteria or noncanonical inflammasome activation by lipopolysaccharide (LPS) induced systemic blood clotting and massive thrombosis in tissues. Following inflammasome activation, pyroptotic macrophages released tissue factor (TF), an essential initiator of coagulation cascades. Genetic or pharmacological inhibition of TF abolishes inflammasome-mediated blood clotting and protects against death. Our data reveal that blood clotting is the major cause of host death following inflammasome activation and demonstrate that inflammasome bridges inflammation with thrombosis.

The Ras GTPase-activating-like protein IQGAP1 bridges Gasdermin D to the ESCRT system to promote IL-1ß release via exosomes.

IL-1ß can exit the cytosol as an exosomal cargo following inflammasome activation in intestinal epithelial cells (IECs) in a Gasdermin D (GSDMD)-dependent manner. The mechanistic connection linking inflammasome activation and the biogenesis of exosomes has so far remained largely elusive. Here, we report the Ras GTPase-activating-like protein IQGAP1 functions as an adaptor, bridging GSDMD to the endosomal sorting complexes required for transport (ESCRT) machinery to promote the biogenesis of pro-IL-1ß-containing exosomes in response to NLPR3 inflammasome activation. We identified IQGAP1 as a GSDMD-interacting protein through a non-biased proteomic analysis. Functional investigation indicated the IQGAP1-GSDMD interaction is required for LPS and ATP-induced exosome release. Further analysis revealed that IQGAP1 serves as an adaptor which bridges GSDMD and associated IL-1ß complex to Tsg101, a component of the ESCRT complex, and enables the packaging of GSDMD and IL-1ß into exosomes. Importantly, this process is dependent on an LPS-induced increase in GTP-bound CDC42, a small GTPase known to activate IQGAP1. Taken together, this study reveals IQGAP1 as a link between inflammasome activation and GSDMD-dependent, ESCRT-mediated exosomal release of IL-1ß.

The role of caspase-8 in inflammatory signalling and pyroptotic cell death.

The programmed cell death machinery exhibits surprising flexibility, capable of crosstalk and non-apoptotic roles. Much of this complexity arises from the diverse functions of caspase-8, a cysteine-aspartic acid protease typically associated with activating caspase-3 and - 7 to induce apoptosis. However, recent research has revealed that caspase-8 also plays a role in regulating the lytic gasdermin cell death machinery, contributing to pyroptosis and immune responses in contexts such as infection, autoinflammation, and T-cell signalling. In mice, loss of caspase-8 results in embryonic lethality from unrestrained necroptotic killing, while in humans caspase-8 deficiency can lead to an autoimmune lymphoproliferative syndrome, immunodeficiency, inflammatory bowel disease or, when it can't cleave its substrate RIPK1, early onset periodic fevers. This review focuses on non-canonical caspase-8 signalling that drives immune responses, including its regulation of inflammatory gene transcription, activation within inflammasome complexes, and roles in pyroptotic cell death. Ultimately, a deeper understanding of caspase-8 function will aid in determining whether, and when, targeting caspase-8 pathways could be therapeutically beneficial in human diseases.

Chemical modulation of gasdermin D activity: Therapeutic implications and consequences.

The gasdermin family of proteins are central effectors of the inflammatory, lytic cell death modality known as pyroptosis. Characterized in 2015, the most well-studied member gasdermin D can be proteolyzed, typically by caspases, to generate an active pore-forming N-terminal domain. At least well-studied three pharmacological inhibitors (necrosulfonamide, disulfiram, dimethyl fumarate) since 2018 have been shown to affect gasdermin D activity either through modulation of processing or interference with pore formation. A multitude of murine in vivo studies have since followed. Here, we discuss the current state of research surrounding these three inhibitors, caveats to their use, and a set of guiding principles that researchers should consider when pursuing further studies of gasdermin D inhibition.

Pyroptosis-induced inflammation and tissue damage.

Pyroptosis is a programmed necrotic cell death executed by gasdermins, a family of pore-forming proteins. The cleavage of gasdermins by specific proteases enables their pore-forming activity. The activation of the prototype member of the gasdermin family, gasdermin D (GSDMD), is linked to innate immune monitoring by inflammasomes. Additional gasdermins such as GSDMA, GSDMB, GSDMC, and GSDME are activated by inflammasome-independent mechanisms. Pyroptosis is emerging as a key host defense strategy against pathogens. However, excessive pyroptosis causes cytokine storm and detrimental inflammation leading to tissue damage and organ dysfunction. Consequently, dysregulated pyroptotic responses contribute to the pathogenesis of various diseases, including sepsis, atherosclerosis, acute respiratory distress syndrome, and neurodegenerative disorders. This review will discuss the inflammatory consequences of pyroptosis and the mechanisms of pyroptosis-induced tissue damage and disease pathogenesis.

SARS-CoV-2 nucleocapsid suppresses host pyroptosis by blocking Gasdermin D cleavage.

SARS-CoV-2 is an emerging coronavirus that causes dysfunctions in multiple human cells and tissues. Studies have looked at the entry of SARS-CoV-2 into host cells mediated by the viral spike protein and human receptor ACE2. However, less is known about the cellular immune responses triggered by SARS-CoV-2 viral proteins. Here, we show that the nucleocapsid of SARS-CoV-2 inhibits host pyroptosis by blocking Gasdermin D (GSDMD) cleavage. SARS-CoV-2-infected monocytes show enhanced cellular interleukin-1ß (IL-1ß) expression, but reduced IL-1ß secretion. While SARS-CoV-2 infection promotes activation of the NLRP3 inflammasome and caspase-1, GSDMD cleavage and pyroptosis are inhibited in infected human monocytes. SARS-CoV-2 nucleocapsid protein associates with GSDMD in cells and inhibits GSDMD cleavage in vitro and in vivo. The nucleocapsid binds the GSDMD linker region and hinders GSDMD processing by caspase-1. These insights into how SARS-CoV-2 antagonizes cellular inflammatory responses may open new avenues for treating COVID-19 in the future.

Atg16l2 augments Nlrc4 inflammasome activation by facilitating NAIPs-NLRC4 association.

As cytoplasmic protein complexes that are pivotal for innate immunity, inflammasomes act primarily through the detection of pathogen- or danger-associated molecular patterns. Nucleotide oligomerisation domain-like receptor family and caspase activation recruitment domain-containing protein 4 (NLRC4) inflammasomes identify and eliminate intracellular pathogens, a process contingent on the ligand-recognition capabilities of neuronal apoptosis inhibitory proteins (NAIPs). Upon detection of specific molecules indicative of intracellular infection, NAIPs discern distinct pathogenic components and subsequently transmit signals to NLRC4, thus initiating their activation and triggering an inflammatory response. However, the mechanisms underlying NLRC4 inflammasome remain unclear. In this study, we elucidated the critical role of ATG16L2 in activating the NLRC4 inflammasome. ATG16L2-deficient macrophages exhibited reduced NLRC4 inflammasome activation, characterised by decreased oligomerisation of apoptosis-associated speck-like protein containing a CARD and attenuated cleavage of Pro-caspase-1, Pro-IL-1ß and gasdermin D. Co-immunoprecipitation assays revealed an interaction between ATG16L2 and NAIPs. Furthermore, ATG16L2 enhanced the association between NAIPs and NLRC4 by binding to NAIPs. For ATG16L2-knockout mice infected with Salmonella typhimurium, pathogen clearance and survival rates markedly decreased. Collectively, our findings suggest that ATG16L2 is a significant modulator of the innate immune system, influencing the activity of the NLRC4 inflammasome and the host's defensive response to intracellular pathogens.

SARS-CoV-2 and oncolytic EV-D68-encoded proteases differentially regulate pyroptosis.

Pyroptosis, a pro-inflammatory programmed cell death, has been implicated in the pathogenesis of coronavirus disease 2019 and other viral diseases. Gasdermin family proteins (GSDMs), including GSDMD and GSDME, are key regulators of pyroptotic cell death. However, the mechanisms by which virus infection modulates pyroptosis remain unclear. Here, we employed a mCherry-GSDMD fluorescent reporter assay to screen for viral proteins that impede the localization and function of GSDMD in living cells. Our data indicated that the main protease NSP5 of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) blocked GSDMD-mediated pyroptosis via cleaving residues Q29 and Q193 of GSDMD. While another SARS-CoV-2 protease, NSP3, cleaved GSDME at residue G370 but activated GSDME-mediated pyroptosis. Interestingly, respiratory enterovirus EV-D68-encoded proteases 3C and 2A also exhibit similar differential regulation on the functions of GSDMs by inactivating GSDMD but initiating GSDME-mediated pyroptosis. EV-D68 infection exerted oncolytic effects on human cancer cells by inducing pyroptotic cell death. Our findings provide insights into how respiratory viruses manipulate host cell pyroptosis and suggest potential targets for antiviral therapy as well as cancer treatment.IMPORTANCEPyroptosis plays a crucial role in the pathogenesis of coronavirus disease 2019, and comprehending its function may facilitate the development of novel therapeutic strategies. This study aims to explore how viral-encoded proteases modulate pyroptosis. We investigated the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and respiratory enterovirus D68 (EV-D68) proteases on host cell pyroptosis. We found that SARS-CoV-2-encoded proteases NSP5 and NSP3 inactivate gasdermin D (GSDMD) but initiate gasdermin E (GSDME)-mediated pyroptosis, respectively. We also discovered that another respiratory virus EV-D68 encodes two distinct proteases 2A and 3C that selectively trigger GSDME-mediated pyroptosis while suppressing the function of GSDMD. Based on these findings, we further noted that EV-D68 infection triggers pyroptosis and produces oncolytic effects in human carcinoma cells. Our study provides new insights into the molecular mechanisms underlying virus-modulated pyroptosis and identifies potential targets for the development of antiviral and cancer therapeutics.

The Yersinia Type III Secretion System as a Tool for Studying Cytosolic Innate Immune Surveillance.

Microbial pathogens have evolved complex mechanisms to interface with host cells in order to evade host defenses and replicate. However, mammalian innate immune receptors detect the presence of molecules unique to the microbial world or sense the activity of virulence factors, activating antimicrobial and inflammatory pathways. We focus on how studies of the major virulence factor of one group of microbial pathogens, the type III secretion system (T3SS) of human pathogenic Yersinia, have shed light on these important innate immune responses. Yersinia are largely extracellular pathogens, yet they insert T3SS cargo into target host cells that modulate the activity of cytosolic innate immune receptors. This review covers both the host pathways that detect the Yersinia T3SS and the effector proteins used by Yersinia to manipulate innate immune signaling.

Serum GSDMD for Early Diagnosis of Bloodstream Infection and Differentiating Bacterial from Fungal Infections.

BACKGROUND: The role of Gasdermin D (GSDMD) in bloodstream infection (BSI) diagnosis is unknown. METHODS: Serum GSDMD levels were measured in BSI patients. Endothelial cells and PBMCs were isolated, infected with bacteria/fungi, and intracellular/extracellular GSDMD concentrations were measured. An animal model was established to investigate the association between serum GSDMD levels and BSI incidence/progression. RESULTS: ROC curve analysis indicated that GSDMD could be a potential early diagnostic biomarker for BSI (AUC = 0.9885). Combining GSDMD with procalcitonin (PCT) improved the differential diagnosis of Gram-positive and Gram-negative bacteria (AUC = 0.6699, 66.15% specificity), and early diagnosis of Gram-positive bacteria (98.46% sensitivity), while PCT was not significantly elevated. The combined GSDMD and G-test had higher sensitivity (AUC = 0.7174) for differential diagnosis of bacterial and fungal infections, and early detection of fungal infections (98.44% sensitivity). In vitro and in vivo experiments confirmed that GSDMD levels increased significantly within 2 hours, peaked at 16 hours, and exhibited a time-dependent upward trend. CONCLUSIONS: Serum GSDMD, alone or combined with other biomarkers, has potential for early diagnosis and differential diagnosis of BSI caused by various pathogens. This finding offers a new strategy for early detection and treatment of BSI.

EEBR induces Caspase-1-dependent pyroptosis through the NF-κB/NLRP3 signalling cascade in non-small cell lung cancer.

Lung cancer is a leading cause of cancer-related deaths worldwide. Recent studies have identified pyroptosis, a type of programmed cell death, as a critical process in the development and progression of lung cancer. In this study, we investigated the effect of EEBR, a new compound synthesized by our team, on pyroptosis in non-small cell lung cancer cells (NSCLC) and the underlying molecular mechanisms. Our results demonstrated that EEBR significantly reduced the proliferation and metastasis of NSCLC cells in vitro. Moreover, EEBR-induced pyroptosis in NSCLC cells, as evidenced by cell membrane rupture, the release of cytokines such as interleukin-18 and interleukin-1 beta and the promotion of Gasdermin D cleavage in a Caspase-1-dependent manner. Furthermore, EEBR promoted the nuclear translocation of NF-κB and upregulated the protein level of NLRP3. Subsequent studies revealed that EEBR-induced pyroptosis was suppressed by the inhibition of NF-κB. Finally, EEBR effectively suppressed the growth of lung cancer xenograft tumours by promoting NSCLC pyroptosis in animal models. Taken together, our findings suggest that EEBR induces Caspase-1-dependent pyroptosis through the NF-κB/NLRP3 signalling cascade in NSCLC, highlighting its potential as a candidate drug for NSCLC treatment.

Protein engineering reveals that gasdermin A preferentially targets mitochondrial membranes over the plasma membrane during pyroptosis.

When activated, gasdermin family members are thought to be pore-forming proteins that cause lytic cell death. Despite this, numerous studies have suggested that the threshold for lytic cell death is dependent on which gasdermin family member is activated. Determination of the propensity of various gasdermin family members to cause pyroptosis has been handicapped by the fact that for many of them, the mechanisms and timing of their activation are uncertain. In this article, we exploit the recently discovered exosite-mediated recognition of gasdermin D (GSDMD) by the inflammatory caspases to develop a system that activates gasdermin family members in an efficient and equivalent manner. We leverage this system to show that upon activation, GSDMD and gasdermin A (GSDMA) exhibit differential subcellular localization, differential plasma membrane permeabilization, and differential lytic cell death. While GSDMD localizes rapidly to both the plasma membrane and organelle membranes, GSDMA preferentially localizes to the mitochondria with delayed and diminished accumulation at the plasma membrane. As a consequence of this differential kinetics of subcellular localization, N-terminal GSDMA results in early mitochondrial dysfunction relative to plasma membrane permeabilization. This study thus challenges the assumption that gasdermin family members effect cell death through identical mechanisms and establishes that their activation in their respective tissues of expression likely results in different immunological outcomes.

Caspase-11 signaling promotes damage to hippocampal CA3 to enhance cognitive dysfunction in infection.

BACKGROUND: Cognitive dysfunction caused by infection frequently emerges as a complication in sepsis survivor patients. However, a comprehensive understanding of its pathogenesis remains elusive. METHODS: In our in vivo experiments, an animal model of endotoxemia was employed, utilizing the Novel Object Recognition Test and Morris Water Maze Test to assess cognitive function. Various techniques, including immunofluorescent staining, Western blotting, blood‒brain barrier permeability assessment, Limulus Amebocyte Lysate (LAL) assay, and Proximity-ligation assay, were employed to identify brain pathological injury and neuroinflammation. To discern the role of Caspase-11 (Casp11) in hematopoietic or non-hematopoietic cells in endotoxemia-induced cognitive decline, bone marrow chimeras were generated through bone marrow transplantation (BMT) using wild-type (WT) and Casp11-deficient mice. In vitro studies involved treating BV2 cells with E. coli-derived outer membrane vesicles to mimic in vivo conditions. RESULTS: Our findings indicate that the deficiency of Casp11-GSDMD signaling pathways reverses infection-induced cognitive dysfunction. Moreover, cognitive dysfunction can be ameliorated by blocking the IL-1 effect. Mechanistically, the absence of Casp11 signaling significantly mitigated blood‒brain barrier leakage, microglial activation, and synaptic damage in the hippocampal CA3 region, ultimately leading to improved cognitive function. CONCLUSION: This study unveils the crucial contribution of Casp11 and GSDMD to cognitive impairments and spatial memory loss in a murine sepsis model. Targeting Casp11 signaling emerges as a promising strategy for preventing or treating cognitive dysfunction in patients with severe infections.

GSDMD-mediated NETosis promotes the development of acute respiratory distress syndrome.

Gasdermin D (GSDMD) is a classical molecule involved in pyroptosis. It has been reported to be cleaved into N-terminal fragments to form pores in the neutrophil membrane and promote the release of neutrophil extracellular traps (NETs). However, it remains unclear if GSDMD is involved in neutrophil regulation and NET release during ARDS. The role of neutrophil GSDMD in the development of ARDS was investigated in a murine model of ARDS induced by lipopolysaccharide (LPS) using the neutrophil specific GSDMD-deficient mice. The neutrophil GSDMD cleavage and its relationship with NETosis were also explored in ARDS patients. The cleavage of GSDMD in neutrophils from ARDS patients and mice was upregulated. Inhibition of GSDMD by genetic knockout or inhibitors resulted in reduced production of NET both in vivo and in vitro, and attenuation of LPS-induced lung injury. Moreover, in vitro experiments showed that the inhibition of GSDMD attenuated endothelial injury co-cultured with neutrophils from ARDS patients, while extrinsic NETs reversed the protective effect of GSDMD inhibition. Collectively, our data suggest that the neutrophil GSDMD cleavage is crucial in NET release during ARDS. The NET release maintained by cleaved GSDMD in neutrophils may be a key event in the development of ARDS.

GSDMD/Drp1 signaling pathway mediates hippocampal synaptic damage and neural oscillation abnormalities in a mouse model of sepsis-associated encephalopathy.

BACKGROUND: Gasdermin D (GSDMD)-mediated pyroptotic cell death is implicated in the pathogenesis of cognitive deficits in sepsis-associated encephalopathy (SAE), yet the underlying mechanisms remain largely unclear. Dynamin-related protein 1 (Drp1) facilitates mitochondrial fission and ensures quality control to maintain cellular homeostasis during infection. This study aimed to investigate the potential role of the GSDMD/Drp1 signaling pathway in cognitive impairments in a mouse model of SAE. METHODS: C57BL/6 male mice were subjected to cecal ligation and puncture (CLP) to establish an animal model of SAE. In the interventional study, mice were treated with the GSDMD inhibitor necrosulfonamide (NSA) or the Drp1 inhibitor mitochondrial division inhibitor-1 (Mdivi-1). Surviving mice underwent behavioral tests, and hippocampal tissues were harvested for histological analysis and biochemical assays at corresponding time points. Haematoxylin-eosin staining and TUNEL assays were used to evaluate neuronal damage. Golgi staining was used to detect synaptic dendritic spine density. Additionally, transmission electron microscopy was performed to assess mitochondrial and synaptic morphology in the hippocampus. Local field potential recordings were conducted to detect network oscillations in the hippocampus. RESULTS: CLP induced the activation of GSDMD, an upregulation of Drp1, leading to associated mitochondrial impairment, neuroinflammation, as well as neuronal and synaptic damage. Consequently, these effects resulted in a reduction in neural oscillations in the hippocampus and significant learning and memory deficits in the mice. Notably, treatment with NSA or Mdivi-1 effectively prevented these GSDMD-mediated abnormalities. CONCLUSIONS: Our data indicate that the GSDMD/Drp1 signaling pathway is involved in cognitive deficits in a mouse model of SAE. Inhibiting GSDMD or Drp1 emerges as a potential therapeutic strategy to alleviate the observed synaptic damages and network oscillations abnormalities in the hippocampus of SAE mice.