Review: the role of GSDMD in sepsis

CVA16 infection causes neurological injury by engaging TLR2/MYD88/TNF-α/CXCL1 signalling pathway in hSCARB2 knock-in mice

Coxsackievirus A16 (CVA16), a major pathogen responsible for hand-foot-and-mouth disease (HFMD) in children, has frequently replaced Enterovirus A71 as the predominant causative agent in China and other Asia-Pacific regions. The lack effective drugs and vaccines against this virus exacerbates the concerns on its outbreaks. Clinical reports and laboratory studies indicate that CVA16 infection may lead to neurological injury, but the precise mechanisms remain elusive. In this study, we meticulously established a CVA16 murine disease model using 3-week-old hSCARB2 knock-in mice through intracranial inoculation. Within 4-7 days post-infection, the infected mice exhibited severe neurological symptoms featured as limb paralysis, hind limb weakness and ataxia. Furthermore, high viral loads were detected in the brain, spleen, skeletal muscle tissues, indicating a systemic infection. A robust cytokine response was observed, characterized with the elevation of TNF-α, IL-12 (p40), IL-10 and MIP-1β. Histological and immunofluorescence staining revealed extensive inflammation, marked by the concentrated infiltration of astrocytes cells, as well as severe neurological injury, which included hypertrophic and extended pseudopodia microglia, increased astrocytes with long and stretched protuberances, markedly decreased neuronal cell bodies and nerve fibers in brain. No visible pathological changes were observed in spinal cord tissues. RNA sequencing and immunofluorescence staining of brain tissue verification assays indicated that the neurological injury may engage in TLR2/MYD88/TNF-α/CXCL1 signal pathway. Over all, this work addressed the gap in the availability of CVA16 disease rodent model for vaccine development and provided novel insights into the mechanisms underlying neurological injury caused by enteroviruses and other neurotropic viruses.

Pyroptosis in sepsis-associated acute kidney injury: mechanisms and therapeutic perspectives

Sepsis-associated acute kidney injury (S-AKI) is a severe complication characterized by high morbidity and mortality, driven by multi-organ dysfunction. Recent evidence suggests that pyroptosis, a form of programmed cell death distinct from apoptosis and necrosis, plays a critical role in the pathophysiology of S-AKI. This review examines the mechanisms of pyroptosis, focusing on inflammasome activation (e.g., NLRP3), caspase-mediated processes, and the role of Gasdermin D in renal tubular damage. We also discuss the contributions of inflammatory mediators, oxidative stress, and potential therapeutic strategies targeting pyroptosis, including inflammasome inhibitors, caspase inhibitors, and anti-inflammatory therapies. Lastly, we highlight the clinical implications and challenges in translating these findings into effective treatments, underscoring the need for personalized medicine approaches in managing S-AKI.

Versatility of gasdermin D beyond pyroptosis

Gasdermin D (GSDMD) has garnered significant attention primarily for the pore-forming role of its p30 N-terminal fragment (NT-p30) generated during pyroptosis, a proinflammatory form of cell death. However, emerging evidence suggests that the formation of GSDMD-NT pores is reversible, and the activation of GSDMD does not necessarily lead to pyroptosis. Instead, this process may take part either in other forms of cell death, or in various state changes of living cells, including (i) inflammation regulation, (ii) endolysosomal pathway rewiring, (iii) granule exocytosis, (iv) type II immunity, (v) food tolerance maintenance, and (vi) temporary permeability alteration. This review explores the latest insights into the involvement of GSDMD in cell death and homeostasis maintenance, aiming to underscore the pleiotropic nature of GSDMD.

Curcumin's Protective Role in Heatstroke-Induced Acute Liver Injury: Targeting Pyroptosis and Enhancing SIRT1 Expression

Heatstroke (HS) is a severe systemic condition that significantly impacts organ function, with the liver being particularly vulnerable. Sirtuin 1 (SIRT1), a crucial deacetylase, is implicated in various diseases' pathophysiology. Curcumin, a natural polyphenol, has been shown to modulate SIRT1 activity, offering therapeutic benefits. This study explores the impact of HS on hepatic SIRT1 expression and the protective mechanisms of curcumin against HS-induced hepatic injury. Male C57BL/6 mice are divided into control and curcumin pretreatment groups, subjected to HS induction, and assessed for liver injury biomarkers, oxidative stress, and inflammatory cytokines. Results indicate that HS downregulates SIRT1, leading to liver damage and systemic inflammation. Curcumin pretreatment dose-responsively attenuates these effects, with the highest dose providing optimal protection, potentially through SIRT1 restoration. The findings suggest that curcumin's hepatoprotective role in HS may be mediated by upregulating SIRT1, highlighting its therapeutic potential in heatstroke-related liver damage.

Crosstalk of pyroptosis and cytokine in the tumor microenvironment: from mechanisms to clinical implication

In the realm of cancer research, the tumor microenvironment (TME) plays a crucial role in tumor initiation and progression, shaped by complex interactions between cancer cells and surrounding non-cancerous cells. Cytokines, as essential immunomodulatory agents, are secreted by various cellular constituents within the TME, including immune cells, cancer-associated fibroblasts, and cancer cells themselves. These cytokines facilitate intricate communication networks that significantly influence tumor initiation, progression, metastasis, and immune suppression. Pyroptosis contributes to TME remodeling by promoting the release of pro-inflammatory cytokines and sustaining chronic inflammation, impacting processes such as immune escape and angiogenesis. However, challenges remain due to the complex interplay among cytokines, pyroptosis, and the TME, along with the dual effects of pyroptosis on cancer progression and therapy-related complications like cytokine release syndrome. Unraveling these complexities could facilitate strategies that balance inflammatory responses while minimizing tissue damage during therapy. This review delves into the complex crosstalk between cytokines, pyroptosis, and the TME, elucidating their contribution to tumor progression and metastasis. By synthesizing emerging therapeutic targets and innovative technologies concerning TME, this review aims to provide novel insights that could enhance treatment outcomes for cancer patients.

SENP1 Promotes Caspase-11 Inflammasome Activation and Aggravates Inflammatory Response in Murine Acute Lung Injury Induced by Lipopolysaccharide

BACKGROUND

Infection is the leading cause of acute lung injury (ALI). Macrophages, which are pivotal innate immune cells, play a critical role in mediating inflammatory processes. Intracellular lipopolysaccharide (LPS) from invasive Gram-negative bacteria can activate the caspase-11 inflammasome, leading to the induction of pyroptosis in macrophages. This process subsequently triggers the release of inflammatory cytokines and damage-associated molecular patterns from pyroptotic macrophages, thereby exacerbating inflammatory progression in ALI. However, the precise regulatory mechanisms governing caspase-11 activation is still unclear. Sentrin-specific proteases (SENPs) have been identified as notable targets for their anti-inflammatory properties. Nevertheless, the specific role of SENPs in macrophage pyroptosis during the pathogenesis of ALI remains unknown.

METHODS

We used LPS as an endotoxin to induce ALI. We analyzed the expression and location of sentrin-specific protease 1 (SENP1), pulmonary impairment, macrophage infiltration, caspase-11 inflammasome expression and activation, caspase-11 SUMOylation, and inflammatory cytokine secretion.

RESULTS

Upregulated expression of SENP1 in lung tissue and macrophages was observed following LPS stimulation. SENP1 mediates de-SUMOylation and activation of caspase-11 inflammasome in macrophages. Moreover, pharmacological inhibition or genetic deficiency of SENP1 in macrophages significantly improved ALI-related histological damage by reducing the secretion of inflammatory cytokines and suppressing caspase-11-dependent pyroptosis.

CONCLUSIONS

Collectively, our findings highlight the involvement of SENP1 in caspase-11 activation and inflammatory progression in macrophages, thereby establishing a scientific foundation for the exploration of novel therapeutic strategies aimed at treating ALI.

Phillyrin prevents sepsis-induced acute lung injury through inhibiting the NLRP3/caspase-1/GSDMD-dependent pyroptosis signaling pathway

Acute lung injury (ALI) is a severe pulmonary disorder of sepsis with high clinical incidence and mortality. Nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3)-cysteinyl aspartate specific proteinase 1-gasdermin D (GSDMD)-dependent pyroptosis of alveolar epithelial cells (AECs) has emerged as a crucial contributor to ALI during sepsis. Phillyrin (PHI), a natural lignan isolated from the traditional Chinese herbal medicine Forsythia suspensa, has been shown to have anti-inflammatory, antioxidant and antiviral properties. However, little is known about the protective role and potential mechanism of PHI in sepsis-induced ALI, and it is uncertain whether the protective effect of PHI in sepsis-induced ALI is connected to pyroptosis. This study aims to examine the preventive effects of PHI on sepsis-induced ALI via the inhibition of NLRP3/caspase-1/GSDMD-mediated pyroptosis in AECs. Our findings demonstrate that preadministration of PHI successfully reduces sepsis-induced pulmonary edema, systemic/pulmonary inflammation, and pulmonary histological damage in lung tissues, bronchoalveolar lavage fluid, and the serum of septic mice. Intriguingly, PHI preadministration suppresses sepsis-induced protein expressions of pyroptosis-specific markers, especially their active forms. In vitro assays show that PHI pretreatment also protects type II AECs (MLE-12) from lipopolysaccharide-induced pyroptosis by preventing the activation of the pyroptosis signaling pathway. The results from molecular docking and surface plasmon resonance reveal that PHI has a significant affinity for direct binding to the GSDMD protein, suggesting that GSDMD is a potential pharmacological target for PHI. In conclusion, PHI can prevent sepsis-triggered ALI by effectively suppressing the activation of the canonical pyroptosis signaling pathway and pyroptosis of AECs.

GSDMD KNOCKOUT ALLEVIATES SEPSIS-ASSOCIATED SKELETAL MUSCLE ATROPHY BY INHIBITING IL18/AMPK SIGNALING

ABSTRACT

Background: Sepsis commonly leads to skeletal muscle atrophy, characterized by substantial muscle weakness and degeneration, ultimately contributing to an adverse prognosis. Studies have shown that programmed cell death is an important factor in the progression of muscle loss in sepsis. However, the precise role and mechanism of pyroptosis in skeletal muscle atrophy are not yet fully comprehended. Therefore, we aimed to examine the role and mechanism of action of the pyroptosis effector protein GSDMD in recognized cellular and mouse models of sepsis. Methods: The levels of GSDMD and N-GSDMD in skeletal muscle were evaluated 2, 4, and 8 days after cecal ligation and puncture. Sepsis was produced in mice that lacked the Gsdmd gene (Gsdmd knockout) and in mice with the normal Gsdmd gene (wild-type) using a procedure called cecal ligation and puncture. The degree of muscular atrophy in the gastrocnemius and tibialis anterior muscles was assessed 72 h after surgery in the septic mouse model. In addition, the architecture of skeletal muscles, protein expression, and markers associated with pathways leading to muscle atrophy were examined in mice from various groups 72 h after surgery. The in vitro investigations entailed the use of siRNA to suppress Gsdmd expression in C2C12 cells, followed by stimulation of these cells with lipopolysaccharide to evaluate the impact of Gsdmd downregulation on muscle atrophy and the related signaling cascades. Results: This study has demonstrated that the GSDMD protein, known as the "executive" protein of pyroptosis, plays a crucial role in the advancement of skeletal muscle atrophy in septic mice. The expression of N-GSDMD in the skeletal muscle of septic mice was markedly higher compared with the control group. The Gsdmd knockout mice exhibited notable enhancements in survival, muscle strength, and body weight compared with the septic mice. Deletion of the Gsdmd gene reduced muscular wasting in the gastrocnemius and tibialis anterior muscles caused by sepsis. Studies conducted in living organisms ( in vivo ) and in laboratory conditions ( in vitro ) have shown that the absence of the Gsdmd gene decreases indicators of muscle loss associated with sepsis by blocking the IL18/AMPK signaling pathway. Conclusion: The results of this study demonstrate that the lack of Gsdmd has a beneficial effect on septic skeletal muscle atrophy by reducing the activation of IL18/AMPK and inhibiting the ubiquitin-proteasome system and autophagy pathways. Therefore, our research provides vital insights into the role of pyroptosis in sepsis-related skeletal muscle wasting, which could potentially lead to the development of therapeutic and interventional approaches for preventing septic skeletal muscle atrophy.

Molecular mechanisms of Sepsis attacking the immune system and solid organs

Remarkable progress has been achieved in sepsis treatment in recent times, the mortality rate of sepsis has experienced a gradual decline as a result of the prompt administration of antibiotics, fluid resuscitation, and the implementation of various therapies aimed at supporting multiple organ functions. However, there is still significant mortality and room for improvement. The mortality rate for septic patients, 22.5%, is still unacceptably high, accounting for 19.7% of all global deaths. Therefore, it is crucial to thoroughly comprehend the pathogenesis of sepsis in order to enhance clinical diagnosis and treatment methods. Here, we summarized classic mechanisms of sepsis progression, activation of signal pathways, mitochondrial quality control, imbalance of pro-and anti- inflammation response, diseminated intravascular coagulation (DIC), cell death, presented the latest research findings for each mechanism and identify potential therapeutic targets within each mechanism.

Inhibition of GSDMD-dependent pyroptosis decreased methamphetamine self-administration in rats

It is widely believed that the activation of the central dopamine (DA) system is crucial to the rewarding effects of methamphetamine (METH) and to the behavioral outcomes of METH use disorder. It was reported that METH exposure induced gasdermin D (GSDMD)-dependent pyroptosis in rats. The membrane pore formation caused by METH-induced pyroptosis may also contribute to the overflow of DA into the extracellular space and subsequently increase the DA levels in the brain. The present study firstly investigated whether the membrane pore information induced by GSDMD-dependent pyroptosis was associated with the increased DA levels in the ventral tegmental area (VAT) and nucleus accumbens (NAc) of rats self-administering METH and SY-SH5Y cells treated by METH. Subsequently, the effect of pore formation blockade or genetic inhibition of GSDMD on the reinforcing and motivational effect of METH was determined in rats, using the animal model of METH self-administration (SA). METH exposure significantly increased the activity of NLRP1/Cas-1/GSDMD pathway and the presence of pyroptosis, accompanied by the significantly increased DA levels in VTA and NAc. Moreover, intraperitoneal injections of disulfiram (DSF) or microinjection of rAAV-shGSDMD into VTA/NAc significantly reduced the reinforcing and motivational effect of METH, accompanied by the decreased level of DA in VTA and NAc. The results provided novel evidence that METH-induced pyroptosis could increase DA release in VTA and NAc via the NLRP1/Cas-1/GSDMD pathway. Additionally, membrane pores or GSDMD blockade could significantly reduce the reinforcing and motivational effect of METH. In conclusion, blocking GSDMD and membrane pore formation could be a promising potential target for the development of agents to treat METH use disorder.

Harnessing pyroptosis for lung cancer therapy: The impact of NLRP3 inflammasome activation

Lung cancer is still a global health challenge in terms of high incidence, morbidity, and mortality. Recent scientific studies have determined that pyroptosis, a highly inflammatory form of programmed cell death, can be identified as a potential lung cancer therapeutic target. The NLRP3 inflammasome acts as a critical mediator in this process and, upon activation, activates multiprotein complex formation as well as caspase-1 activation. This process, triggered by a release of pro-inflammatory cytokines, results in pyroptotic cell death. Also, the relationship between the NLRP3 inflammasome and lung cancer was justified by its influence on tumour growth or metastasis. The molecular pathways produce progenitive mediators and remake the tissue. Finally, targeting NLRP3 inflammasome for pyroptosis induction and inhibition of its activation appears to be a promising lung cancer treatment approach. This technique makes cancer treatment more promising and personalized. This review explores the role of NLRP3 inflammasome activation and its possibilities in lung cancer treatment.

Dual-signaling and ultrasensitive detection for PCT based on the photoelectric and electrocatalytic hydrogen evolution signals of Pt/Mo-CoFeS

Few study has been carried out on the construction of immunesensors utilized the photoelectric and catalytic signal of nanomaterial. Here, a dual-signal electrochemical immunosensor was constructed for procalcitonin (PCT) detection based on the excellent photoelectric and hydrogen evolution performance of molybdenum-doped cobalt-iron sulfur nanosheets modified by platinum nanoparticles (Pt/Mo-CoFeS). Due to the electronic structure regulation between Pt and Mo-CoFeS, Pt/Mo-CoFeS exhibits superior photoelectric and hydrogen evolution performance compared to single Mo-CoFeS, which improved the sensitivity of the electrochemical immunosensor. Furthermore, the presence of Pt improves surface area and biocompatibility, achieving more antibodies loading and signal amplification. The linear range of PCT detection are 0.002-20 ng mL-1 and 0.002-50 ng mL-1, the detection limits are 0.0015 and 0.0012 ng mL-1. In addition, this electrochemical immunosensor was applied to the PCT analysis in human serum samples with high recoveries. F-test and t-test show that there is no significant difference in the test results between the HER and photoelectric signals, the mutual verification between above two signals can effectively improve the accuracy of detection result.

Identification and Analysis of PANoptosis-Related Genes in Sepsis-Induced Lung Injury by Bioinformatics and Experimental Verification

Purpose

Sepsis-induced lung injury (SLI) is a serious complication of sepsis. PANoptosis, a novel form of inflammatory programmed cell death that is not yet to be fully investigated in SLI. Our research aims to screen and validate the signature genes of PANoptosis in SLI by bioinformatics and in vivo experiment.

Methods

SLI-related datasets were downloaded from NCBI Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) of SLI were identified and intersected with the PANoptosis gene set to obtain DEGs related to PANoptosis (SPAN_DEGs). Then, Protein-Protein Interaction (PPI) network and functional enrichment analysis were conducted based on SPAN_DEGs. SVM-REF, LASSO and RandomForest three algorithms were combined to identify the signature genes. The Nomogram and ROC curves were performed to predict diagnostic value. Immune infiltration analysis, correlation analysis and differential expression analysis were used to explore the immunological characterization, correlation and expression levels of the signature genes. Finally, H&E staining and qRT-PCR were conducted for further verification in vivo experiment.

Results

Twenty-four SPAN_DEGs were identified by intersecting 675 DEGs with the 277 PANoptosis genes. Four signature genes (CD14, GSDMD, IL1β, and FAS) were identified by three machine learning algorithms, which were highly expressed in the SLI group, and had high diagnostic value in the diagnostic model. Moreover, immune infiltration analysis showed that most immune cells and immune-related functions were higher in the SLI group than those in the control group and were closely associated with the signature genes. Finally, it was confirmed that the cecum ligation and puncture (CLP) group mice showed significant pathological damage in lung tissues, and the mRNA expression levels of CD14, IL1β, and FAS were significantly higher than the sham group.

Conclusion

CD14, FAS, and IL1β may be the signature genes in PANoptosis to drive the progression of SLI and involved in regulating immune processes.

NU6300 covalently reacts with cysteine-191 of gasdermin D to block its cleavage and palmitoylation

Gasdermin D (GSDMD) serves as a vital mediator of inflammasome-driven pyroptosis. In our study, we have identified NU6300 as a specific GSDMD inhibitor that covalently interacts with cysteine-191 of GSDMD, effectively blocking its cleavage while not affecting earlier steps such as ASC oligomerization and caspase-1 processing in AIM2- and NLRC4-mediated inflammation. On the contrary, NU6300 robustly inhibits these earlier steps in NLRP3 inflammasome, confirming a unique feedback inhibition effect in the NLRP3-GSDMD pathway upon GSDMD targeting. Our study reveals a previously undefined mechanism of GSDMD inhibitors: NU6300 impairs the palmitoylation of both full-length and N-terminal GSDMD, impeding the membrane localization and oligomerization of N-terminal GSDMD. In vivo studies further demonstrate the efficacy of NU6300 in ameliorating dextran sodium sulfate-induced colitis and improving survival in lipopolysaccharide-induced sepsis. Overall, these findings highlight the potential of NU6300 as a promising lead compound for the treatment of inflammatory diseases.

Identification of Molecular Correlations of GSDMD with Pyroptosis inAlzheimer's Disease

AIM

An analysis of bioinformatics and cell experiments was performed to verify the relationship between gasdermin D (GSDMD), an executive protein of pyroptosis, and Alzheimer's disease (AD).

METHODS

The training set GSE33000 was utilized to identify differentially expressed genes (DEGs) in both the AD group and control group, as well as in the GSDMD protein high/low expression group. Subsequently, the weighted gene co-expression network analysis (WGCNA) and the least absolute shrinkage and selection operator (LASSO) regression analysis were conducted, followed by the selection of the key genes for the subsequent Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The association between GSDMD and AD was assessed and confirmed in the training set GSE33000, as well as in the validation sets GSE5281 and GSE48350. Immunofluorescence (IF) was employed to detect the myelin basic protein (MBP), a distinctive protein found in the rat oligodendrocytes (OLN-93 cells). A range of concentrations (1-15 μmol/L) of β-amyloid 1-42 (Aβ1-42) were exposed to the cells, and the subsequent observations were made regarding cell morphology. Additionally, the assessments were conducted to evaluate the cell viability, the lactate dehydrogenase (LDH) release, the cell membrane permeability, and the GSDMD protein expression.

RESULTS

A total of 7,492 DEGs were screened using GSE33000. Subsequently, WGCNA analysis identified 19 genes that exhibited the strongest correlation with clinical traits in AD. Additionally, LASSO regression analysis identified 13 key genes, including GSDMD, AFF1, and ATOH8. Furthermore, the investigation revealed that the key genes were associated with cellular inflammation based on GO and KEGG analyses. Moreover, the area under the curve (AUC) values for the key genes in the training and validation sets were determined to be 0.95 and 0.70, respectively. Significantly, GSDMD demonstrated elevated levels of expression in AD across both datasets. The positivity of MBP expression in cells exceeded 95%. As the concentration of Aβ1-42 action gradually escalated, the detrimental effects on cells progressively intensified, resulting in a gradual decline in cell survival rate, accompanied by an increase in lactate dehydrogenase release, cell membrane permeability, and GSDMD protein expression.

CONCLUSION

The association between GSDMD and AD has been observed, and it has been found that Aβ1-42 can induce a significant upregulation of GSDMD in OLN-93 cells. This suggests that Aβ1-42 has the potential to induce cellular pyroptosis and can serve as a valuable cellular pyroptosis model for the study of AD.

Redox regulation of the NLRP3-mediated inflammation and pyroptosis

The review considers modern data on the mechanisms of activation and redox regulation of the NLRP3 inflammasome and gasdermins, as well as the role of selenium in these processes. Activation of the inflammasome and pyroptosis represent an evolutionarily conserved mechanism of the defense against pathogens, described for various types of cells and tissues (macrophages and monocytes, microglial cells and astrocytes, podocytes and parenchymal cells of the kidneys, periodontal tissues, osteoclasts and osteoblasts, as well as cells of the digestive and urogenital systems, etc.). Depending on the characteristics of redox regulation, the participants of NLRP3 inflammation and pyroptosis can be subdivided into 2 groups. Members of the first group block the mitochondrial electron transport chain, promote the formation of reactive oxygen species and the development of oxidative stress. This group includes granzymes, the mitochondrial antiviral signaling protein MAVS, and others. The second group includes thioredoxin interacting protein (TXNIP), erythroid-derived nuclear factor-2 (NRF2), Kelch-like ECH-associated protein 1 (Keap1), ninjurin (Ninj1), scramblase (TMEM16), inflammasome regulatory protein kinase NLRP3 (NEK7), caspase-1, gasdermins GSDM B, D and others. They have redox-sensitive domains and/or cysteine residues subjected to redox regulation, glutathionylation/deglutathionylation or other types of regulation. Suppression of oxidative stress and redox regulation of participants in NLRP3 inflammation and pyroptosis depends on the activity of the antioxidant enzymes glutathione peroxidase (GPX) and thioredoxin reductase (TRXR), containing a selenocysteine residue Sec in the active site. The expression of GPX and TRXR is regulated by NRF2 and depends on the concentration of selenium in the blood. Selenium deficiency causes ineffective translation of the Sec UGA codon, translation termination, and, consequently, synthesis of inactive selenoproteins, which can cause various types of programmed cell death: apoptosis of nerve cells and sperm, necroptosis of erythrocyte precursors, pyroptosis of infected myeloid cells, ferroptosis of T- and B-lymphocytes, kidney and pancreatic cells. In addition, suboptimal selenium concentrations in the blood (0.86 μM or 68 μg/l or less) have a significant impact on expression of more than two hundred and fifty genes as compared to the optimal selenium concentration (1.43 μM or 113 μg/l). Based on the above, we propose to consider blood selenium concentrations as an important parameter of redox homeostasis in the cell. Suboptimal blood selenium concentrations (or selenium deficiency states) should be used for assessment of the risk of developing inflammatory processes.

Gasdermin D-Mediated Pyroptosis in Diabetic Cardiomyopathy: Molecular Mechanisms and Pharmacological Implications

Diabetic cardiomyopathy (DCM) is a pathophysiological condition triggered by diabetes mellitus (DM), which can lead to heart failure (HF). One of the most important cellular processes associated with DCM is the death of cardiomyocytes. Gasdermin D (GSDMD) plays a key role in mediating pyroptosis, a type of programmed cell death closely associated with inflammasome activation. Recent studies have revealed that pyroptosis is induced during hyperglycemia, which is crucial to the development of DCM. Although the effects of pyroptosis on DCM have been discussed, the relationship between DCM and GSDMD is not fully clarified. Recent studies gave us the impetus for clarifying the meaning of GSDMD in DCM. The purpose of this review is to summarize new and emerging insights, mainly discussing the structures of GSDMD and the mechanism of pore formation, activation pathways, molecular mechanisms of GSDMD-mediated pyroptosis, and the therapeutic potential of GSDMD in DCM. The implications of this review will pave the way for a new therapeutic target in DCM.

The role of neutrophil extracellular traps in sepsis and sepsis-related acute lung injury

Neutrophils release neutrophil extracellular traps (NETs) to trap pathogenic microorganisms. NETs are involved in the inflammatory response and bacterial killing and clearance. However, their excessive activation can lead to an inflammatory storm in the body, which may damage tissues and cause organ dysfunction. Organ dysfunction is the main pathophysiological cause of sepsis and also a cause of the high mortality rate in sepsis. Acute lung injury caused by sepsis accounts for the highest proportion of organ damage in sepsis. NET formation can lead to the development of sepsis because by promoting the release of interleukin-1 beta, interleukin-8, and tumor necrosis factor-alpha, thereby accelerating acute lung injury. In this review, we describe the critical role of NETs in sepsis-associated acute lung injury and review the current knowledge and novel therapeutic approaches.

CONSTRUCTION OF SEPSIS DIAGNOSTIC MODELS AND IDENTIFICATION OF MACROPHAGE SUBPOPULATIONS BASED ON PYROPTOSIS-RELATED GENES

ABSTRACT

Background: Numerous studies have shown that pyroptosis is associated with sepsis progression, which can lead to dysregulated host immune responses and organ dysfunction. Therefore, investigating the potential prognostic and diagnostic values of pyroptosis in patients with sepsis is essential. Methods: We conducted a study using bulk and single-cell RNA sequencing (scRNA-seq) from the Gene Expression Omnibus database to examine the role of pyroptosis in sepsis. Univariate logistic analysis, least absolute shrinkage, and selection operator regression analysis were used to identify pyroptosis-related genes (PRGs), construct a diagnostic risk score model, and evaluate the selected genes' diagnostic value. Consensus clustering analysis was used to identify the PRG-related sepsis subtypes with varying prognoses. Functional and immune infiltration analyses were used to explain the subtypes' distinct prognoses, and scRNA-seq data were used to differentiate immune-infiltrating cells and macrophage subsets and study cell-cell communication. Results: A risk model was established based on 10 key PRGs ( NAIP , ELANE , GSDMB , DHX9 , NLRP3 , CASP8 , GSDMD , CASP4 , APIP , and DPP9 ), of which four ( ELANE , DHX9 , GSDMD , and CASP4 ) were associated with prognosis. Two subtypes with different prognoses were identified based on the key PRG expressions. Functional enrichment analysis revealed diminished nucleotide oligomerization domain-like receptor pathway activity and enhanced neutrophil extracellular trap formation in the subtype with a poor prognosis. Immune infiltration analysis suggested a different immune status between the two sepsis subtypes, with the subtype with a poor prognosis exhibiting stronger immunosuppression. The single-cell analysis identified a macrophage subpopulation characterized by gasdermin D (GSDMD) expression that may be involved in pyroptosis regulation, which was associated with the prognosis of sepsis. Conclusion: We developed and validated a risk score for sepsis identification based on 10 PRGs, four of which also have potential value in the prognosis of sepsis. We identified a subset of gasdermin D macrophages associated with poor prognosis, providing new insights into the role of pyroptosis in sepsis.