Pyroptosis: host cell death and inflammation

Molecular characterization of PANoptosis-related genes associated with immune infiltration and prognosis in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic pulmonary disease with unknown pathogenesis and poor prognosis. PANoptosis, a newly identified form of inflammatory programmed cell death, has been implicated in various inflammatory lung diseases. This study aimed to identify differentially expressed PANoptosis-related genes (PRDEGs) associated with immune infiltration and prognosis in IPF, while also establishing a novel prognostic prediction model. A total of 63 PRDEGs were identified from GSE110147 dataset, with 31 exhibiting consistent expression trends in GSE213001. Enrichment analysis indicated that the majority of these PRDEGs were enriched in inflammatory and immune-related pathways. Three key PRDEGs-NLRP3, ATM, and VEGFA-were selected through univariate and multivariable Cox regression analyses. The prognostic prediction model developed from these key PRDEGs demonstrated robust predictive performance. Furthermore, the expression of most PRDEGs was positively correlated with pro-inflammatory immune cells, including macrophages, neutrophils, and CD4+ T cells. Validation of the expression levels of these key PRDEGs was conducted in fibrotic mouse lung tissue. This study suggests that PANoptosis plays a role in IPF, potentially linked to the infiltration of pro-inflammatory immune cells, and may influence disease progression through the regulation of inflammatory immune signaling pathway. A new prognostic prediction model for IPF based on PRDEGs was successfully developed.

A combined AI and cell biology approach surfaces targets and mechanistically distinct Inflammasome inhibitors

Inflammasomes are protein complexes that mediate innate immune responses whose dysregulation has been linked to a spectrum of acute and chronic human conditions, which dictates therapeutic development that is aligned with disease variability. We designed a scalable, physiologic high-content imaging assay in human PBMCs that we analyzed using a combination of machine-learning and cell biology methods. This resulted in a set of biologically interpretable readouts that can resolve a spectrum of cellular states associated with inflammasome activation and inhibition. These methods were applied to a phenotypic screen that surfaced mechanistically distinct inflammasome inhibitors from an annotated 12,000 compound library. A set of over 100 inhibitors, including an array of Raf-pathway inhibitors, were validated in downstream functional assays. This approach demonstrates how complementary machine learning-based methods can be used to generate profiles of cellular states associated with different stages of complex biological pathways and yield compound and target discovery.

Pyroptosis the Emerging Link Between Gut Microbiota and Multiple Sclerosis

This review elucidates the pivotal role of pyroptosis, triggered by gut microbiota, in the development of multiple sclerosis (MS), emphasizing its significance within the gut-brain axis. Our comprehensive analysis of recent literature reveals how dysbiosis in the gut microbiota of MS patients-characterized by reduced microbial diversity and shifts in bacterial populations-profoundly impacts immune regulation and the integrity of the central nervous system (CNS). Pyroptosis, an inflammatory form of programmed cell death, significantly exacerbates MS by promoting the release of inflammatory cytokines and causing substantial damage to CNS tissues. The gut microbiota facilitates this detrimental process through metabolites such as short-chain fatty acids and neuroactive compounds, or self-structural products like lipopolysaccharides (LPS), which modulate immune responses and influence neuronal survival. This review highlights the potential of modulating gut microbiota to regulate pyroptosis, thereby suggesting that targeting this pathway could be a promising therapeutic strategy to mitigate inflammatory responses and preserve neuronal integrity in patients with MS.

Inflammasomes: potential therapeutic targets in hematopoietic stem cell transplantation

The realm of hematopoietic stem cell transplantation (HSCT) has witnessed remarkable advancements in elevating the cure and survival rates for patients with both malignant and non-malignant hematologic diseases. Nevertheless, a considerable number of patients continue to face challenges, including transplant-related complications, infection, graft failure, and mortality. Inflammasomes, the multi-protein complexes of the innate immune system, respond to various danger signals by releasing inflammatory cytokines and even mediating cell death. While moderate activation of inflammasomes is essential for immune defense and homeostasis maintenance, excessive activation precipitates inflammatory damage. The intricate interplay between HSCT and inflammasomes arises from their pivotal roles in immune responses and inflammation. This review examines the molecular architecture and composition of various types of inflammasomes, highlighting their activation and effector mechanisms within the context of the HSCT process and its associated complications. Additionally, we summarize the therapeutic implications of targeting inflammasomes and related factors in HSCT.

Biological and pharmacological roles of pyroptosis in pulmonary inflammation and fibrosis: recent advances and future directions

Pyroptosis, an inflammatory regulated cell death (RCD) mechanism, is characterized by cellular swelling, membrane rupture, and subsequent discharge of cellular contents, exerting robust proinflammatory effects. Recent studies have significantly advanced our understanding of pyroptosis, revealing that it can be triggered through inflammasome- and caspase-independent pathways, and interacts intricately with other RCD pathways (e.g., pyroptosis, necroptosis, ferroptosis, and cuproptosis). The pathogenesis of pulmonary fibrosis (PF), including idiopathic pulmonary fibrosis (IPF) and other interstitial lung diseases, involves a multifaceted interplay of factors such as pathogen infections, environmental pollutants, genetic variations, and immune dysfunction. This chronic and progressive interstitial lung disease is characterized by persistent inflammation, extracellular matrix (ECM) accumulation, and fibrotic alveolar wall thickening, which potentially contribute to deteriorated lung function. Despite recent advances in understanding pyroptosis, the mechanisms by which it regulates PF are not entirely elucidated, and effective strategies to improve clinical outcomes remain unclear. This review strives to deliver a comprehensive overview of the biological functions and molecular mechanisms of pyroptosis, exploring its roles in the pathogenesis of PF. Furthermore, it examines potential biomarkers and therapeutic agents for anti-fibrotic treatments.

Review of research progress on different modalities of Macrophage death in Mycobacterium leprae infection

Leprosy, caused by Mycobacterium leprae (M. leprae), is a chronic infectious disease primarily affecting the skin and peripheral nerves. The interaction between M. leprae and macrophages, its primary host cell, plays a critical role in disease progression. This review explores the various forms of macrophage cell death induced by M. leprae infection, including apoptosis, autophagy, necroptosis, pyroptosis, ferroptosis and necrosis. The regulation and implications of these cell death pathways on the host immune response are discussed. Apoptosis and autophagy are highlighted as mechanisms that may limit M. leprae proliferation, while necroptosis and pyroptosis contribute to inflammation and immune response. Notably, recent studies have identified CYBB-mediated ferroptosis as essential for macrophages infected with M. leprae to polarize towards the M2 phenotype, facilitating immune evasion by the pathogen. This review underscores the complexity of macrophage cell death in leprosy, and summarize their corresponding molecular mechanisms and potential impact on the host immunity.

Iridium(III) Photosensitizers Induce Simultaneous Pyroptosis and Ferroptosis for Multi-Network Synergistic Tumor Immunotherapy

The integration of pyroptosis and ferroptosis hybrid cell death induction to augment immune activation represents a promising avenue for anti-tumor treatment, but there is a lack of research. Herein, we developed two iridium (III)-triphenylamine photosensitizers, IrC and IrF, with the capacity to disrupt redox balance and induce photo-driven cascade damage to DNA and Kelch-like ECH-associated protein 1 (KEAP1). The activation of the absent in melanoma 2 (AIM2)-related cytoplasmic nucleic acid-sensing pathway, triggered by damaged DNA, leads to the induction of gasdermin D (GSDMD)-mediated pyroptosis. Simultaneously, iron homeostasis, regulated by the KEAP1/nuclear factor erythroid 2-related factor 2 (NRF2)/heme oxygenase 1 (HO-1) pathway, serves as a pivotal bridge, facilitating not only the induction of gasdermin E (GSDME)-mediated non-canonical pyroptosis, but also ferroptosis in synergy with glutathione peroxidase 4 (GPX4) depletion. The collaborative action of pyroptosis and ferroptosis generates a synergistic effect that elicits immunogenic cell death, stimulates a robust immune response and effectively inhibits tumor growth in vivo. Our work introduces the first metal-based small molecule dual-inducers of pyroptosis and ferroptosis for potent cancer immunotherapy, and highlights the significance of iron homeostasis as a vital hub connecting synergistic effects of pyroptosis and ferroptosis.

4-Octyl itaconate blocks GSDMB-mediated pyroptosis and restricts inflammation by inactivating granzyme A

GSDMB-mediated pyroptosis facilitates a pro-inflammatory immune microenvironment and needs to be tightly regulated to avoid excessive inflammation. Here, we provide evidence that itaconate and its cell-permeable derivative 4-octyl itaconate (4-OI) can significantly inhibit GSDMB-rendered pyroptotic activity independent of Nrf2. 4-OI interferes proteolytic process of GSDMB by directly modifying Cys54, Cys148 and Ser212 on granzyme A (GrzA), a serine protease that site-specifically cleaves the inter-domain linker of GSDMB, instead of interaction with GSDMB, thereby blocking pyroptosis and exerts anti-inflammatory effects. Moreover, 4-OI alleviates inflammation by suppressing GSDMB-induced pyroptotic cell death during acute colitis models in intestinal epithelial GSDMB conditional transgenic mice. Our data expand the role of 4-OI as a crucial immunometabolic derivative that regulates innate immunity and inflammation through a newly identified posttranslational modification, and targeting of pyroptosis by 4-OI therefore holds potent therapeutic potential for primarily inflammatory and/or autoimmune diseases.

Leydig cells pyroptosis in testis mediates deoxynivalenol-induced male reproductive toxicity in mice

Deoxynivalenol (DON) is a toxic secondary metabolite produced by Fusarium spp. It is widely distributed among various cereals and has attracted much attention as a potential health threat to humans and domestic animals. However, the effects of DON on the reproductive systems of mammals are still ambiguous. In this study, the toxic effects of DON in the male reproduction of mice were investigated. The results showed that DON caused the shedding of sperm cells at all testis levels and the presence of inflammatory cells in the testicular interstitium. The rate of living sperm was significantly reduced, and the rate of sperm deformity was increased after DON exposure. The DON exposure resulted in decreased levels of testosterone (T) and increased levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in the serum. Measurements of oxidative stress markers showed that DON induced oxidative stress in mice testis. Meanwhile, DON triggered the assembly of NLRP3-ASC-Caspase-1 inflammatory complex and pyroptosis in both mice testis and TM3 cells, further causing the activation of GSDMD, promoting the leakage of inflammatory cytokines, including IL-1β and IL-18. Notably, the inhibition of oxidative stress was found to protect pyroptosis in TM3 cells exposed to DON. We identified a novel mechanism of reproductive damage induced by DON, demonstrating the activation of the canonical Caspase-1-dependent pyroptosis pathway and clarifying the protection of antioxidation against pyroptosis damage. Our discovery provided support for the risk assessment of DON and target exploration for clinical treatment related to pyroptosis.

Cathepsin L Promotes Pulmonary Hypertension via BMPR2/GSDME-Mediated Pyroptosis

BACKGROUND

Pulmonary hypertension (PH) is a fatal progressive disease characterized by pulmonary endothelial injury and occlusive pulmonary vascular remodeling. Lysosomal protease cathepsin L degrades essential molecules to participate in the human pathophysiological process. BMPR2 (bone morphogenetic protein type II receptor) deficiency, an important cause of PH, results from mutational inactivation or excessive lysosomal degradation and induces caspase-3-mediated cell death. Given recent evidence that pyroptosis, as a new form of programmed cell death, is induced by caspase-3-dependent GSDME (gasdermin E) cleavage, we hypothesized that cathepsin L might promote PH through BMPR2/caspase-3/GSDME axis-mediated pyroptosis.

METHODS

Cathepsin L expression was evaluated in the lungs and plasma of patients with pulmonary arterial hypertension. The role of cathepsin L in the progression of PH and vascular remodeling was assessed in vivo. Small interfering RNA, specific inhibitors, and lentiviruses were used to explore the mechanisms of cathepsin L on human pulmonary arterial endothelial cell dysfunction.

RESULTS

Cathepsin L expression is elevated in pulmonary artery endothelium from patients with idiopathic pulmonary arterial hypertension and experimental PH models. Genetic ablation of cathepsin L in PH rats relieved right ventricular systolic pressure, pulmonary vascular remodeling, and right ventricular hypertrophy, also restoring endothelial integrity. Mechanistically, cathepsin L promotes caspase-3/GSDME-mediated endothelial cell pyroptosis and represses BMPR2 signaling activity. Cathepsin L degrades BMPR2 via the lysosomal pathway, and restoring BMPR2 signaling prevents the pro-pyroptotic role of cathepsin L in PAECs and experimental PH models.

CONCLUSIONS

These results show for the first time that cathepsin L promotes the development of PH by degrading BMPR2 to induce caspase-3/GSDME-mediated endothelial pyroptosis.

Cathelicidin peptide LL-37: A multifunctional peptide involved in heart disease

Heart disease is a common human disease with high morbidity and mortality. Timely and effective prevention and treatment is an urgent clinical problem. The pathogenesis of heart disease is complex and diverse, involving hypertension, diabetes, atherosclerosis, drug toxicity, thrombosis, infection and other aspects. LL-37, an endogenous peptide, is well known for its antimicrobial properties. In recent years, LL-37 has been found to have a variety of biological functions, including its role in the regulation of atherosclerosis, thrombosis, inflammatory responses, and cardiac hypertrophy. Engineered LL-37-related peptides were developed and proved to regulate the development of disease, which revealed its potential clinical application. A comprehensive review and summary of LL-37 is presented to clarify its role in heart disease and to provide a reference and direction for future research.

Gelsevirine ameliorates sepsis-associated encephalopathy by inhibiting the STING signalling-mediated pyroptosis pathway in microglia

BACKGROUND

Sepsis-associated encephalopathy (SAE) is among the most prevalent and deadly complications associated with sepsis, but satisfactory treatments and therapeutic agents are lacking. Gelsevirine, an active ingredient derived from Gelsemium elegans Benth., has shown promising effects in animal models of anxiety, ischaemic stroke and osteoarthritis. However, its protective effect against SAE and its mechanism of action are still unknown.

PURPOSE

To elucidate the efficacy of gelsevirine against SAE and the mechanism of its protective effect through the STING signalling-mediated pyroptosis pathway.

METHODS

We constructed a mouse model of caecum ligation and puncture (CLP)-induced sepsis and explored the protective effects of gelsevirine in mice with SAE by assessing survival rates and behavioural alterations. To further explore its mechanism of action, we investigated the modulatory effects of gelsevirine on the levels of inflammatory factors, microglial activation and pyroptosis by Western blotting, immunohistochemistry staining and PCR. STING knockout mice were used to verify the protective effect of gelsevirine against SAE through the STING pathway.

RESULTS

Gelsevirine increased the survival rate of mice with SAE. The Morris water maze and open field tests revealed that gelsevirine significantly alleviated cognitive dysfunction and increased exploratory behaviour in mice with SAE. Gelsevirine inhibited the activation of microglia and decreased inflammatory factor levels in the hippocampus of mice with SAE. In mice with SAE and in vitro BV2 microglia, gelsevirine reduced levels of inflammatory factors and inhibited STING protein phosphorylation and microglial pyroptosis. However, after STING knockout, the inhibitory effect of gelsevirine on microglial pyroptosis was significantly weakened, and gelsevirine-mediated protective effects were abolished.

CONCLUSIONS

Gelsevirine increased the survival rate, ameliorated cognitive impairment, inhibited glial cell activation and reduced inflammation in the hippocampi of mice with SAE; the mechanism may be related to the inhibition of STING signalling pathway-mediated pyroptosis in microglia.

Eclipta prostrata improves alveolar development of bronchopulmonary dysplasia via suppressing the NLRP3 inflammasome in a DLD-dependent manner

OBJECTIVES

Bronchopulmonary dysplasia (BPD), the most common late morbidity in preterm infants, is characterized by impaired alveolar development caused by persistent lung inflammation. Studies have shown that NOD-, LRR- and pyrin domain-containing 3 (NLRP3) inflammasome-mediated inflammation is critically involved in the development of BPD. As a traditional Chinese medicinal herb, Eclipta prostrata (EAP) exhibits potent anti-inflammatory properties. Our study aims to investigate whether EAP could improve the lung development of BPD by suppressing the lung inflammatory response.

METHODS

The BPD rat model was established by intra-amniotic injection of lipopolysaccharide (LPS) and postnatal exposure to hyperoxia. Changes in the NLRP3 inflammasome and pyroptosis were assessed by treatment with EAP. The effect of EAP on the NLRP3 inflammasome was tested in vitro using the THP-1 cell line and primary alveolar macrophages. Proteomics analysis was used to elucidate the mechanism of action of EAP.

RESULTS

Histopathological and immunofluorescence results of lung tissues revealed that LPS and hyperoxia induced lung injury and triggered NLRP3 inflammasome activation and pyroptosis in alveolar macrophages. EAP ameliorated BPD lung injury, inhibited NLRP3 inflammasome activation and reduced gasdermin D (GSDMD) expression in alveolar macrophages. EAP downregulated the expression of NLRP3 inflammasome pathway molecules (NLRP3, caspase-1, and IL-1β) and GSDMD in LPS-stimulated THP-1 macrophages and primary alveolar macrophages. In addition, proteomics analysis identified that dihydrolipoamide dehydrogenase (DLD) interacted with EAP. Inhibition of DLD activity abolished the protective effects of EAP.

CONCLUSIONS

Our study suggested that EAP could attenuate arrest of alveolar development via inhibiting NLRP3 inflammasome in a DLD-dependent way, and could be a potential therapeutic method for BPD.

Inflammation in myelodysplastic syndrome pathogenesis

Inflammation is a key driver of the progression of preleukemic myeloid conditions, such as clonal hematopoiesis of indeterminate potential (CHIP) and clonal cytopenia of undetermined significance (CCUS), to myelodysplastic syndromes (MDS). Inflammation is a critical mediator in the complex interplay of the genetic, epigenetic, and microenvironmental factors contributing to clonal evolution. Under inflammatory conditions, somatic mutations in TET2, DNMT3A, and ASXL1, the most frequently mutated genes in CHIP and CCUS, induce a competitive advantage to hematopoietic stem and progenitor cells, which leads to their clonal expansion in the bone marrow. Chronic inflammation also drives metabolic reprogramming and immune system deregulation, further promoting the expansion of malignant clones. This review underscores the urgent need to fully elucidate the role of inflammation in MDS initiation and highlights the potential of the therapeutical targeting of inflammatory pathways as an early intervention in MDS.

Activation of spleen tyrosine kinase (SYK) contributes to neuronal pyroptosis and cognitive impairment in diabetic mice via the NLRP3/Caspase-1/GSDMD signaling pathway

BACKGROUND/AIM

Diabetes mellitus (DM) patients are at increased risk of cognitive impairment. The precise mechanisms underlying the association between DM and cognitive impairment remain unclear. Spleen tyrosine kinase (SYK), a crucial regulator of signal transduction, has been implicated in microglial pyroptosis in experimental ischemic stroke models. The present study investigated the potential role of SYK in DM-associated cognitive impairment.

METHODS

Diabetes was induced by streptozotocin (STZ) in C57BL/6 mice, and cognitive function and cerebral injury were assessed 12 weeks later using the Morris water maze (MWM), TUNEL assay and Western blotting. In vitro, the inhibition of SYK was investigated in a mouse hippocampal neuronal cell line cultured with high glucose.

RESULTS

Compared with control mice, DM mice presented impaired spatial learning and memory. Additionally, SYK activation was linked to neuronal pyroptosis, as evidenced by increases in the number of TUNEL-positive cells and protein levels of NLRP3, ASC, procaspase-1, caspase-1, GSDMD, the GSDMD N-terminal fragment, pro-IL-1β, and IL-1β in the hippocampus of DM mice. Compared with no treatment, SYK knockdown markedly attenuated cognitive impairment and histologic and ultrastructural pathological changes in the hippocampus of DM mice. The increased expression of pyroptosis-associated proteins and the increased number of TUNEL-positive cells were also significantly reduced. In vitro, high glucose significantly activated SYK to trigger the canonical pyroptotic pathway in cultured HT22 cells. The inhibition of SYK with a small interfering RNA or specific inhibitor significantly ameliorated the neuronal pyroptosis mediated by high glucose.

CONCLUSION

Our findings demonstrate that SYK activation plays a pivotal role in promoting the cognitive impairment associated with DM. This effect is mediated by triggering neuronal pyroptosis through the canonical NLRP3/Caspase-1/GSDMD pathway. These results suggest that SYK may serve as a potential target for preventing or mitigating cognitive impairment in patients with DM.

Disturbance of mitochondrial dynamics led to spermatogenesis disorder in mice exposed to polystyrene micro- and nanoplastics

The widespread presence of polystyrene micro- and nanoplastics (PS-MPs/NPs) in the environment poses a threat to the health of the population. Animal studies have shown PS-MPs/NPs had male reproductive toxicity, while its mechanisms are unclear. To investigate that, male Balb/c mice were randomized into 3 groups: the control, 1 μm PS-MPs and 70 nm PS-NPs group, and they were given PS-MPs/NPs by intratracheal instillation for 28 days. Results revealed that PS-MPs/NPs up-regulated the expression of mitochondrial fission related factors (p-DRP1/DRP1, FIS1) and down-regulated the level of mitochondrial fusion related factors (MFN1/2, OPA1), causing over mitochondrial fission, which activating mitochondrial apoptotic pathway (BAX, Cleaved-Caspase9, Cleaved-Caspase3), resulting in cell apoptosis. Moreover, the damaged structure of mitochondria and over mitochondrial fission caused mitochondrial DNA (mtDNA) to translocate from mitochondria to cytoplasm, which activated DNA sensing pathway (cGAS-STING) and induced cell pyroptosis in testis by raising the expression of inflammation factors (NLRP3, ASC, Caspase1 p20, IL-1β). In vitro, by using the mitochondrial fission inhibitor Mdivi-1, it is found that PS-NPs-induced cell apoptosis and pyroptosis were associated with over mitochondrial fission. Taken together, we conclude that PS-MPs/NPs cause spermatogenesis disorder possibly through damaging mitochondrial structure and dynamic homeostasis, which on the one hand results in mitochondria-mediated apoptosis, and on the other hand leads to mtDNA mislocalization, activating cGAS-STING pathway and inflammation, ultimately resulting in pyroptosis. This study may provide a new reference to the potential mechanisms of male reproductive toxicity caused by PS-MPs/NPs.

Turning Neutrophil Cell Death Deadly in the Context of Hypertensive Vascular Disease

Hypertensive vascular disease (HVD) is a major health burden globally and is a comorbidity commonly associated with other metabolic diseases. Many factors are associated with HVD including obesity, diabetes, smoking, chronic kidney disease, and sterile inflammation. Increasing evidence points to neutrophils as an important component of the chronic inflammatory response in HVD. Neutrophils are abundant in the circulation and can respond rapidly upon stimulation to deploy an armament of antimicrobial effector functions. One of the outcomes of neutrophil activation is the generation of neutrophil extracellular traps (NETs), a regulated extrusion of chromatin and proteases. Although neutrophils and NETs are well described as components of the innate immune response to infection, recent evidence implicates them in HVD. Endothelial cell activation can trigger neutrophil adhesion, activation, and production of NETs promoting vascular dysfunction, vessel remodelling, and loss of resistance. The regulated release of NETs can be controlled by the pore-forming activities of distinct cell death pathways. The best characterized pathways in this context are apoptosis, pyroptosis, and necroptosis. In this review, we discuss how inflammatory cell death signalling and NET formation contribute to hypertensive disease. We also examine novel therapeutic approaches to limit NET production and their future potential as therapeutic drugs for cardiovascular disorders.

Eradication of Large Tumors by Nanoscale Drug Self-Assembly

Most patients with cancer are first diagnosed at an advanced disease stage, when tumors are already large and/or metastases are present. This circumstance has a negative impact on the prognosis and therapeutic effect of anticancer drugs. In this study, it is demonstrated that photosensitizer chlorin e6 and the photochemotherapy drug mitoxantrone self-assemble into relatively stable nanoassemblies (CM NAs) through hydrogen-bonding effect, π-π stacking, and hydrophobic interactions. Administration of CM NAs in combination with 660 nm laser irradiation shows chemotherapeutic, photothermal, and photodynamic effects, causing tumor cell apoptosis and pyroptosis and enabling noninvasive tumor ablation without compromising the surrounding normal tissue. More importantly, treatment with CM NAs increases tumor immunogenicity, leading to a strong and long-term antitumor immune response that eradicates large tumors and provides long-term protection against tumor recurrence on various tumor models.

Navigating the complexities of cell death: Insights into accidental and programmed cell death

Cell death is a critical biological phenomenon that can be categorized into accidental cell death (ACD) and programmed cell death (PCD), each exhibiting distinct signaling, mechanistic and morphological characteristics. This paper provides a comprehensive overview of seven types of ACD, including coagulative, liquefactive, caseous, fat, fibrinoid, gangrenous and secondary necrosis, discussing their pathological implications in conditions such as ischemia and inflammation. Additionally, we review eighteen forms of PCD, encompassing autophagy, apoptosis, necroptosis, pyroptosis, paraptosis, ferroptosis, anoikis, entosis, NETosis, eryptosis, parthanatos, mitoptosis, and newly recognized types such as methuosis, autosis, alkaliptosis, oxeiptosis, cuprotosis and erebosis. The implications of these cell death modalities for cellular processes, development, and disease-particularly in the context of neoplastic and neurodegenerative disorders-are also covered. Furthermore, we explore the crosstalk between various forms of PCD, emphasizing how apoptotic mechanisms can influence pathways like necroptosis and pyroptosis. Understanding this interplay is crucial for elucidating cellular responses to stress, as well as for its potential relevance in clinical applications and therapeutic strategies. Future research should focus on clarifying the molecular mechanisms that govern different forms of PCD and their interactions.

Exploring the key role of DNA methylation as an epigenetic modulator in oxidative stress related islet cell injury in patients with type 2 diabetes mellitus: a review

Type 2 diabetes mellitus (T2DM) is a multifactorial metabolic disorder characterised by impaired insulin secretion and action, often exacerbated by oxidative stress. Recent research has highlighted the intricate involvement of epigenetic mechanisms, particularly DNA methylation, in the pathogenesis of T2DM. This review aims to elucidate the role of DNA methylation as an epigenetic modifier in oxidative stress-mediated beta cell dysfunction, a key component of T2DM pathophysiology. Oxidative stress, arising from an imbalance between reactive oxygen species (ROS) production and antioxidant defence mechanisms, is a hallmark feature of T2DM. Beta cells, responsible for insulin secretion, are particularly vulnerable to oxidative damage due to their low antioxidant capacity. Emerging evidence suggests that oxidative stress can induce aberrant DNA methylation patterns in beta cells, leading to altered gene expression profiles associated with insulin secretion and cell survival. Furthermore, studies have identified specific genes involved in beta cell function and survival that undergo DNA methylation changes in response to oxidative stress in T2DM. These epigenetic modifications can perpetuate beta cell dysfunction by dysregulating key pathways essential for insulin secretion, such as the insulin signalling cascade and mitochondrial function. Understanding the interplay between DNA methylation, oxidative stress, and beta cell dysfunction holds promise for developing novel therapeutic strategies for T2DM. Targeting aberrant DNA methylation patterns may offer new avenues for restoring beta cell function and improving glycemic control in patients with T2DM. However, further research is needed to elucidate the complex mechanisms underlying epigenetic regulation in T2DM and to translate these findings into clinical interventions.

Pathological, immunological and molecular epidemiological analysis of lumpy skin disease virus in Indian cattle during a high-mortality epidemic

Lumpy skin disease (LSD) is an economically significant, emerging viral disease of Cattle and Buffaloes. This study aimed to investigate the causes of high mortality in a recent LSD epidemic in India. We examined 1618 animals across seventy outbreaks and conducted post-mortem on 48 cattle out of 513 clinically suspected LSD cases. The morbidity, mortality and case fatality rates recorded were 31.70%, 2.97 and 9.37% respectively. Disease stages were categorized as early (20.81%), mid (42.02%), and late (37.17%) and the distribution of skin lesions was classified as mild (34.14%), moderate (39.39%), and severe (26.47%). Post-mortem findings revealed systemic infection with necrotic and ulcerative nodules on multiple internal organs. Histologically, necrotizing vasculitis and mononuclear cell infiltration with intracytoplasmic inclusions were observed in various organs. The highest viral load was found in skin nodules/scabs, trachea, tongue, and lymph nodes. The viral load was significantly higher in mid- and late-stages of skin nodules and internal organs; whereas, blood from early-stage showed high viral load. The expression of Th1-type and Th2-type cytokines varied significantly across different stages of the disease. The downregulation of the apoptotic intrinsic and upregulation of the extrinsic pathway genes, suggesting that the latter plays a role in LSDV infection. Genetic analysis revealed that the LSD virus (LSDV) isolates were derived from a Kenyan ancestral strain with unique nucleotide changes in RPO30 and P32 gene. In conclusion, the high mortality in the recent Indian LSD epidemic can be attributed to a newly identified, highly virulent strain of LSDV causing systemic infection.

T Lymphocyte-Macrophage Hybrid Membrane-Coated Biomimetic Nanoparticles Alleviate Myocarditis via Suppressing Pyroptosis by Targeting Gene Silencing

Introduction

Nanomedicine coated with cell membranes has attracted increasing attention for its enhanced targeting capability and biocompatibility. Based on previous research, we identified interferon regulatory factor 1 (IRF1)-mediated macrophage pyroptosis as a potential therapeutic target for myocarditis. Herein, we fabricated an innovative immune cell membrane-coated zeolitic imidazolate framework-8 (ZIF-8) nano-delivery platform and explored its effects on myocarditis.

Methods

ZIF-8 nanoparticles loaded with siRNA targeting IRF1 (siIRF1) were coated with a T lymphocyte-macrophage hybrid membrane (siIRF1@ZIF@HM NPs) via sonication and extrusion. The morphological and biological characteristics of the nanoparticles were evaluated using transmission electron microscopy (TEM) and dynamic light scattering (DLS). Cellular cytotoxicity was assessed by a cell counting kit-8 assay. Cellular uptake and endo-lysosomal escape in M1-differentiated macrophages were visualized via fluorescence microscopy. The targeting specificity and anti-myocarditis effects were evaluated in an experimental autoimmune myocarditis (EAM) mouse model. The anti-pyroptosis effects were assessed by Western blot analysis both in vivo and in vitro.

Results

Transcriptional sequencing identified T lymphocytes and macrophages as suitable membrane sources. The ZIF-8 nanoparticles exhibited high siRNA loading capacity and pH responsiveness, enabling an efficient release of siIRF1 from endo-lysosomes to the cytoplasm in macrophages. The hybrid membrane coating enabled specific targeting of M1 macrophages both in vivo and in vitro. Furthermore, delivery of siIRF1 effectively suppressed IRF1 expression and inhibited pyroptosis in IFN-γ-stimulated macrophages. Intravenous injection of siIRF1@ZIF@HM NPs significantly alleviated myocarditis progression without evident side effects.

Conclusion

The siIRF1 nanotherapeutic approach shows potential for attenuating myocardial inflammation and mitigating myocarditis progression. Our study highlights the promise of this customized biomimetic nano-delivery system for treating inflammatory diseases.

Salidroside promotes liver regeneration after partial hepatectomy in mice by modulating NLRP3 inflammasome-mediated pyroptosis pathway

Insufficient residual liver tissue after partial hepatectomy (PH) may lead to serious complications such as hepatic failure and small-for-size syndrome. Salidroside (SAL) is obtained from Rhodiola rosea through modernized separation and extraction and has been validated for treating various liver diseases. It's yet unknown, nevertheless, how SAL affects liver regeneration after PH. This study aimed to determine whether SAL could promote liver regeneration after PH in mice. We demonstrated that SAL could attenuate liver injury after PH and promote hepatocyte proliferation and liver mass recovery. Mechanistically, SAL inhibited the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome, attenuating pyroptosis. RNA-seq analysis indicated that SAL downregulated the transcription of NLRP3 and GSDMD genes and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the NOD-like receptor signaling pathway was significantly enriched in down-regulated signaling pathways. Notably, SAL in combination with the NLRP3 inhibitor MCC950 did not further inhibit NLRP3 inflammasome and promote liver mass recovery. In summary, our findings proved that SAL could be a potential agent for improving liver function and promoting liver regeneration after PH.

Multi-Omic Data Integration Suggests Putative Microbial Drivers of Aetiopathogenesis in Mycosis Fungoides

BACKGROUND

Mycosis fungoides (MF) represents the most prevalent entity of cutaneous T cell lymphoma (CTCL). The MF aetiopathogenesis is incompletely understood, due to significant transcriptomic heterogeneity and conflicting views on whether oncologic transformation originates in early thymocytes or mature effector memory T cells. Recently, using clinical specimens, our group showed that the skin microbiome aggravates disease course, mainly driven by an outgrowing, pathogenic S. aureus strain carrying the virulence factor spa, which was shown by others to activate the T cell signalling pathway NF-κB.

METHODS

To explore the role of the skin microbiome in MF aetiopathogenesis, we here performed RNA sequencing, multi-omic data integration of the skin microbiome and skin transcriptome using Multi-Omic Factor Analysis (MOFA), virome profiling, and T cell receptor (TCR) sequencing in 10 MF patients from our previous study group.

RESULTS

We observed that inter-patient transcriptional heterogeneity may be largely attributed to differential activation of T cell signalling pathways. Notably, the MOFA model resolved the heterogenous activation pattern of T cell signalling after denoising the transcriptome from microbial influence. The MOFA model suggested that the outgrowing S. aureus strain evoked signalling by non-canonical NF-κB and IL-1B, which in turn may have fuelled the aggravated disease course. Further, the MOFA model indicated aberrant pathways of early thymopoiesis alongside enrichment of antiviral innate immunity. In line with this, viral prevalence, particularly of Epstein-Barr virus (EBV), trended higher in both lesional skin and the blood compared to nonlesional skin. Additionally, TCRs in both MF skin lesions and the blood were significantly more likely to recognize EBV peptides involved in latent infection.

CONCLUSIONS

First, our findings suggest that S. aureus with its virulence factor spa fuels MF progression through non-canonical NF-κB and IL-1B signalling. Second, our data provide insights into the potential role of viruses in MF aetiology. Last, we propose a model of microbiome-driven MF aetiopathogenesis: Thymocytes undergo initial oncologic transformation, potentially caused by viruses. After maturation and skin infiltration, an outgrowing, pathogenic S. aureus strain evokes activation and maturation into effector memory T cells, resulting in aggressive disease. Further studies are warranted to verify and extend our data, which are based on computational analyses.

Exploring the effects of hypoxia and reoxygenation time on hepatocyte apoptosis and inflammation

Hepatic Ischemia-Reperfusion Injury (HIRI) is an unavoidable pathological process during liver surgeries such as liver transplantation and hepatic resection, which involves a complex set of molecular and cellular mechanisms. The mechanisms of HIRI may involve a variety of biological processes in which inflammation and apoptosis play a central role. Therefore, it is crucial to deeply investigate the effects of different hypoxia and reoxygenation times on the construction of an in vitro model of hepatic ischemia-reperfusion injury. The human normal liver cell line HL-7702 IRI model was constructed by hypoxia chamber, and the inflammation and apoptosis focal levels of cells were detected by enzyme-linked immunosorbent assay, western blot and quantitative reverse transcription polymerase chain reaction. When 12-hour reoxygenation time was fixed, the inflammation and apoptosis indexes of HIRI model increased with the prolongation of hypoxia time (6, 12 and 24 hours). These indices reached highest level in the model group of 24-hour fixed hypoxia and 12-hour reoxygenation. Inflammation and apoptosis indices were significantly higher in the model group of 24-hours fixed hypoxia and 12-hours reoxygenation than in the group of 6 and 24 hours of reoxygenation. Taken together, the findings from this research demonstrated that during hypoxia phase, cells exhibited a clear time-dependent response of inflammation and cell death; on the contrary, during the reoxygenation phase, the cellular damage was not monotonically incremental, but showed an inverted U-shaped dynamic pattern. The present study reveals in depth the dynamic changes of cellular responses under hypoxia and reoxygenation conditions, providing us with an important theoretical basis to guide the selection and optimization of in vitro experimental models.

Pyroptosis-related lncRNAs are potential biomarkers for predicting prognoses and immune landscapes in patients with gastric adenocarcinoma

OBJECTIVES

The purpose of this study was to investigate the significance of pyroptosis-related lncRNAs (PRlncRNA) in predicting prognoses and immune landscapes of patients with gastric adenocarcinoma (STAD).

METHODS

Transcriptomic data and clinicopathological data were obtained from The Cancer Genome Atlas database. Based on correlation analysis and univariate Cox regression, prognostic PRlncRNA were identified. Subsequently, a PRlncRNA prognostic signature (PRLPS) was generated via least absolute shrinkage and selection operator (LASSO) regression, Kaplan-Meier method, receiver operating characteristic (ROC) curves, principal component analysis, and univariate and multivariate regression. Besides, the clinicopathological characteristics, tumor microenvironment (TME) scores, the immune landscapes in different risk subgroups were explored. Moreover, based on three PRlncRNA, we constructed a competing endogenous RNA (ceRNA) network. Additionally, Gene Set Enrichment Analysis (GSEA), Kyoto Encyclopedia of Genes and Genomes pathways (KEGG) and Gene Ontology (GO) analysis were performed for biological functional analysis based on the difference between high- and low- risk groups, which also used to screen out potential STAD drugs.

RESULTS

21 PRlncRNA made up the prognostic signature, which had significant value in predicting the overall survival (OS), clinicopathological features, TME, immune checkpoint genes expression, and the response to immune checkpoint inhibitors of patients with STAD. In a addition, we constructed a ceRNA network comprising 3 PRlncRNAs and 69 mRNAs. The function of PRlncRNA was related to cancer-associated pathways. Ten small molecular drugs that might improve the prognosis of patients were screened out by connectivity maps.

CONCLUSIONS

Using PRlncRNA as a prognostic indicator for STAD, we identified predictive biomarkers and immunotherapy targets while refreshing our understanding.

Immune Checkpoint-Modulating Photosensitizer That Targets BRD4 for Cancer Photoimmunotherapy

Photodynamic therapy is an efficient approach to promote cytotoxic T lymphocyte tumor infiltration to convert immunologically cold tumors into hot tumors through the induction of immunogenic cell death . However, tumors usually overexpress immune checkpoints such as PD-L1 to suppress T lymphocyte antitumor activity and evade immune surveillance. Therefore, the design of efficient photosensitizers to overcome checkpoint-mediated immune evasion is highly necessary. In this work, we report the design of BRD-PS, a BRD4-targeting photosensitizer, as a new class of immunomodulatory photosensitizer termed an immune checkpoint-modulating photosensitizer, to solve this issue. On one hand, BRD-PS induces immunogenic pyroptosis and ferroptosis to promote the activation and tumor infiltration of cytotoxic T cells. On the other hand, BRD-PS suppresses the expression of PD-L1 to avoid immune evasion. This work demonstrated the feasibility of utilizing a single photosensitizer to simultaneously induce immunogenic cell death and PD-L1 downregulation for synergistic cancer photoimmunotherapy.

Myoferlin alleviates pressure overload-induced cardiac hypertrophy and dysfunction by inhibiting NLRP3-mediated pyroptosis

Myoferlin (MYOF) is a muscle-derived secretory protein. Recent studies have found that MYOF protects against cell damage. However, the role of MYOF in cardiac hypertrophy remains unclear. Increasing evidence suggests that NLRP3 (NOD-like receptor protein 3) and the pyroptosis cascade play critical roles in the development of cardiac hypertrophy and inflammation. To investigate the role of MYOF in cardiac hypertrophy, we conducted a transverse aortic constriction (TAC) experiment in a mouse model. We found that MYOF can improve cardiac hypertrophy and cardiac function. Furthermore, our study confirmed a connection between cardiac hypertrophy and myocardial pyroptosis. Cardiac hypertrophy significantly increased the proportion of apoptotic cells and upregulated apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, and gasdermin D (GSDMD). This suggests that pharmacological or genetic inhibition of NLRP3 can effectively reduce cardiac hypertrophy. An abnormal increase in NLRP3 can reverse the cardioprotective effects of MYOF. Our findings indicate that MYOF is a potential therapeutic agent for cardiac hypertrophy.

Redundant role of PAD2 and PAD4 in the development of cardiovascular lesions in a mouse model of Kawasaki disease vasculitis

Kawasaki disease (KD) is the leading cause of acquired heart disease in children. While circulating neutrophils are increased and activated during acute KD, it is unclear whether neutrophils and neutrophil extracellular traps (NETs) contribute to the pathogenesis of KD. Peptidylarginine deiminase 4 (PAD4), an enzyme involved in protein citrullination and essential for NETs formation, is implicated in the pathogenesis of various diseases. Here, we used the Lactobacillus casei cell wall extract (LCWE)-induced mouse model of KD vasculitis to determine the contribution of PAD4 in KD vasculitis. We found that the pan-PADs inhibitor, Cl-amidine, significantly reduced LCWE-induced cardiovascular lesions, but neutrophil-specific Padi4 KO mice did not impact the development of KD vasculitis. While in vitro treatment of macrophages, which highly express Padi4, with Cl-amidine inhibited IL-1β secretion, macrophage-specific Padi4 KO mice did not reduce the lesions. Padi4-/- mice also developed KD vasculitis, AFM30a, a PAD2 inhibitor, significantly reduced KD vasculitis in Padi4-/- mice, indicating a compensatory role of PAD2 in PAD4 deficiency. We also identified several citrullinated proteins in macrophages with constitutively active NLRP3 inflammasome that were inhibited by Cl-amidine treatment, suggesting that protein citrullination participates in NLRP3 inflammasome activation. These data indicate a dispensable role for PAD4-dependent NETs formation, and a redundant role of PAD2 and PAD4 in this murine KD vasculitis. The cardioprotective effects of Cl-amidine to reduce the severity of murine KD vasculitis are not limited to PAD4 inhibition and may include decreased citrullination in the inflammasome pathway.

Dengue and SARS-CoV-2 co-circulation and overlapping infections in hospitalized patients

Since its emergence in 2019, coronavirus disease (COVID-19) has spread worldwide and consumed public health resources. However, the world still has to address the burdens of other infectious diseases that continue to thrive. Countries in the tropics and neotropics, including Brazil, are affected by annual, cyclic dengue epidemics. Little is known about the impact of subsequent infections between DENV and SARS-CoV-2. Our study was performed on 400 serum samples collected from laboratory-confirmed COVID-19 patients between January and June 2021, months historically known for DENV outbreaks in Brazil. The samples were tested by serology and molecular assays for the presence of DENV and other arboviruses. While no DENV PCR results were detected, 6% were DENV IgM-positive, and 0.25% were DENV NS1-positive according to ELISA. IgM antibodies were isolated by chromatography, and 62.5% of the samples were positive for neutralizing antibodies (FRNT80) against DENV IgM, suggesting a recent infection. We also observed increased IL-10, TNF-α, and IL-1β levels in patients with overlapping SARS-CoV-2/DENV infections. Intriguingly, diabetes was the only relevant comorbidity (p=0.046). High rates of hospitalization (94.9%) and mortality (50%) were found, with a significant increase in invasive mechanical ventilatory support (86.96%) in SARS-CoV-2/DENV- infected patients, suggesting an impact on patient clinical outcomes. When analyzing previous exposure to DENV, secondary dengue patients infected with SARS-CoV-2 more frequently presented with dyspnea and respiratory distress, longer hospital and intensive care unit (ICU) stays (4 and 20.29 days, respectively) and a higher mortality rate (60%). However, a greater proportion of patients with primary DENV infection had fever and cough than patients with secondary dengue (87.50% vs. 33.33%, p=0.027 for fever). Our data demonstrate that differentiating between the two diseases is a great concern for tropical countries and should be explored to improve patient management.

Caspase-8-and Gasdermin D (GSDMD)-Dependent PANoptosis Participate in the Seasonal Atrophy of Scented Glands in Male Muskrats

The muskrat (Ondatra zibethicus) is an animal with special economic significance whose scented glands rapidly atrophy during the non-breeding season, but the mechanism of atrophy is not clear, with significant differences in apoptotic and pyroptotic signaling pathway expression according to transcriptome sequencing. During the non-breeding season, key apoptosis-related genes such as Tnfr1 (TNF Receptor Superfamily Member 1A), TRADD (TNFRSF1A Associated via Death Domain), FADD (Fas Associated via Death Domain), Casp-8 (Cysteine-aspartic proteases-8), and Bax (Bcl-associated X protein) were upregulated in the scented glands, while Bcl2 (B-cell lymphoma-2) expression was downregulated. In the classical pyroptosis pathway, the mRNA expression levels of key genes including Nlrp3 (the Nod-like receptor family pyrin domain-containing 3), ASC (the apoptosis-associated speck-like protein), Casp-1 (Cysteine-aspartic proteases-1), Gsdmd (Gasdermin D), and IL-1β (Interleukin 1 Beta) were higher during the non-breeding season, similar to the transcription level of Ripk1 (Receptor Interacting Serine/Threonine Kinase 1) in the non-canonical pyroptosis pathway, while TAK1 (transforming growth factor kinase) expression was downregulated in this latter pathway. TUNEL assays and immunofluorescence analysis indicated increased apoptosis and GSDMD and Caspase-8 protein levels during the non-breeding season. Indeed, the protein levels of GSDMD-N, Caspase-8 p43, and Caspase-8 p18 were significantly higher during the non-breeding season, while the GSDMD levels were significantly lower compared to the secretion season. These results suggest that apoptosis and pyroptosis play regulatory roles in scented gland atrophy and that there is an interplay between them during this process.

Prolonged Retention of Albumin Nanoparticles Alleviates Renal Ischemia-Reperfusion Injury through Targeted Pyroptosis

Acute kidney injury (AKI) represents a prevalent and complex clinical event, characterized by irreversible damage to renal tubular epithelial cells and high intensive care unit (ICU) admission rates and mortality. The kidneys are highly susceptible to oxidative stress, inflammation, pyroptosis, and programmed cell death. Pyroptosis poses a significant risk, exacerbating the damage and inflammation of renal tubular cells. Disulfiram (DSF), an FDA-approved medication for alcohol cessation, inhibits the pyroptotic pore-forming protein Gasdermin-D (GSDMD), positioning it as a potential solution for emergency relief against an inflammatory response. However, current obstacles include poor water solubility, rapid metabolism, and off-target effects. Inspired by this discovery, bovine serum albumin (BSA), which has already entered clinical application, has been utilized to produce safe and long-lasting nanoparticles (BSA@DSF NPs), addressing the challenges posed by DSF's physicochemical properties. By targeting the GSDMD protein, the potent pro-inflammatory effects of pyroptosis were mitigated, leading to the alleviation of AKI induced by ischemia-reperfusion injury. This research offers a straightforward and efficient concept for treating AKI, potentially enhancing the transition to clinical practice.

Pyroptosis induced by natural products and their derivatives for cancer therapy

Natural products, which are compounds extracted and/or refined from plants and microbes in nature, have great potential for the discovery of therapeutic agents, especially for infectious diseases and cancer. In recent years, natural products have been reported to induce multiple cell death pathways to exhibit antitumor effects. Among them, pyroptosis is a unique programmed cell death (PCD) characterized by continuous cell membrane permeability and intracellular content leakage. According to the canonical and noncanonical pathways, the formation of gasdermin-N pores involves a variety of transcriptional targets and post-translational modifications. Thus, tailored control of PCD may facilitate dying cells with sufficient immunogenicity to activate the immune system to eliminate other tumor cells. Therefore, we summarized the currently reported natural products or their derivatives and their nano-drugs that induce pyroptosis-related signaling pathways. We reviewed six main categories of bioactive compounds extracted from natural products, including flavonoids, terpenoids, polyphenols, quinones, artemisinins, and alkaloids. Correspondingly, the underlying mechanisms of how these compounds and their derivatives engage in pyroptosis are also discussed. Moreover, the synergistic effect of natural bioactive compounds with other antitumor therapies is proposed as a novel therapeutic strategy for traditional chemotherapy, radiotherapy, chemodynamic therapy, photodynamic therapy, photothermal therapy, hyperthermal therapy, and sonodynamic therapy. Consequently, we provide insights into natural products to develop a novel antitumor therapy or qualified adjuvant agents by inducing pyroptosis, which may eventually be applied clinically.

Doxorubicin-related cardiotoxicity: review of fundamental pathways of cardiovascular system injury

Over the years, advancements in the field of oncology have made remarkable strides in enhancing the efficacy of medical care for patients with cancer. These modernizations have resulted in prolonged survival and improved the quality of life for these patients. However, this progress has also been accompanied by escalation in mortality rates associated with anthracycline chemotherapy. Anthracyclines, which are known for their potent antitumor properties, are notorious for their substantial cardiotoxic potential. Remarkably, even after 6 decades of research, a conclusive solution to protect the cardiovascular system against doxorubicin-induced damage has not yet been established. A comprehensive understanding of the pathophysiological processes driving cardiotoxicity combined with targeted research is crucial for developing innovative cardioprotective strategies. This review seeks to explain the mechanisms responsible for structural and functional alterations in doxorubicin-induced cardiomyopathy.

Deciphering interleukin-18 in diabetes and its complications: Biological features, mechanisms, and therapeutic perspectives

Interleukin-18 (IL-18), a potent and multifunctional pro-inflammatory cytokine, plays a critical role in regulating β-cell failure, β-cell death, insulin resistance, and various complications of diabetes mellitus (DM). It exerts its effects by triggering various signaling pathways, enhancing the production of pro-inflammatory cytokines and nitric oxide (NO), as well as promoting immune cells infiltration and β-cells death. Abnormal alterations in IL-18 levels have been revealed to be strongly associated with the onset and development of DM and its complications. Targeting IL-18 may present a novel and promising approach for DM therapy. An increasing number of IL-18 inhibitors, including chemical and natural inhibitors, have been developed and have been shown to protect against DM and diabetic complications. This review provides a comprehensive understanding of the production, biological functions, action mode, and activated signaling pathways of IL-18. Next, we shed light on how IL-18 contributes to the pathogenesis of DM and its associated complications with links to its roles in the modulation of β-cell failure and death, insulin resistance in various tissues, and pancreatitis. Furthermore, the therapeutic potential of targeting IL-18 for the diagnosis and treatment of DM is also highlighted. We hope that this review will help us better understand the functions of IL-18 in the pathogenesis of DM and its complications, providing novel strategies for DM diagnosis and treatment.

Gas immnuo-nanomedicines fight cancers

Certain gas molecules, including hydrogen (H2), nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S), oxygen (O2) and sulfur dioxide (SO2) exhibit significant biological functionalities that can modulate the immune response. Strategies pertaining to gas-based immune therapy have garnered considerable attention in recent years. Nevertheless, delivering various gas molecules precisely into tumors, which leads to enhanced anti-tumor immunotherapeutic effect, is still a main challenge. The advent of gas treatment modality with desirable immunotherapeutic efficiency has been made possible by the rapid development of nanotechnology, which even derives the concept of the gas immnuo-nanomedicines (GINMs). In light of the fact, we herein aim to furnish a cutting-edge review on the latest progress of GINMs. The underlying mechanisms of action for several gases utilized in cancer immunotherapy are initially outlined. Additionally, it provides a succinct overview of the current clinical landscape of gas therapy, and introduces GINMs specifically designed for cancer treatment based on immunotherapeutic principles across multiple strategies. Last but not least, we address the challenges and opportunities associated with GINMs, exploring the potential future developments and clinical applications of this innovative approach.

A Highly Charged Positive Cage Causes Simultaneous Enhancement of Type-II and O2-Independent-Type-I Photodynamic Therapy via One-/Two-Photon Stimulation and Tumor Immunotherapy via PANoptosis and Ferroptosis

To solve the oxygen dependence problem of photodynamic therapy (PDT), it is critical to explore photosensitizers that do not rely on O2 molecule to generate reactive oxygen species (ROS). Herein, a stable cationic metal-organic cage [Pd6(RuLoz 3)8](BF4)28 (MOC-88) that possesses high +28 charges is designed. The cage-confined positive microenvironment enables efficient generation of hydroxyl radicals and improved yield of the singlet oxygen under one-/two-photon excitation, showing excellent performance to concurrently enhance Type-II and O2-independent-Type-I PDT. Moreover, the effective ROS production and robust lipid peroxidation trigger a series of signaling pathways (inflammasome, cyclic guanosine monophosphate-adenosine monophosphate synthase stimulator of interferon genes, and NF-κB) to evoke PANoptosis and ferroptosis in tumor cells, enabling MOC-88 to simultaneously cause the loss of cell membrane integrity, release a series of inflammatory cytokines and damage-associated molecular patterns, stimulate the maturation and antigen presentation ability of dendritic cells, and ultimately activate T-cell-dependent adaptive immunity in vivo to inhibit tumor growth.

The human disease-associated gene ZNFX1 controls inflammation through inhibition of the NLRP3 inflammasome

Inherited deficiency of zinc finger NFX1-type containing 1 (ZNFX1), a dsRNA virus sensor, is associated with severe familial immunodeficiency, multisystem inflammatory disease, increased susceptibility to viruses, and early mortality. However, limited treatments for patients with pathological variants of ZNFX1 exist due to an incomplete understanding of the diseases resulting from ZNFX1 mutations. Here, we demonstrate that ZNFX1 specifically inhibits the activation of the NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome in response to NLRP3 activators both in vitro and in vivo. ZNFX1 retains NLRP3 in the cytoplasm and prevents its accumulation in the TGN38 + /TGN46+ vesicles in the resting state. Upon NLRP3 inflammasome activation, ZNFX1 is cleaved by caspase-1, establishing a feed-forward loop that promotes NLRP3 accumulation in the trans-Golgi network (TGN) and amplifies the activity of the downstream cascade. Expression of wild-type ZNFX1, but not of ZNFX1 with human pathogenic mutations, rescues the impairment of NLRP3 inflammasome inhibition. Our findings reveal a dual role of ZNFX1 in virus sensing and suppression of inflammation, which may become valuable for the development of treatments for ZNFX1 mutation-related diseases.

The regulation of pyroptosis by post-translational modifications: molecular mechanisms and therapeutic targets

Pyroptosis, a type of programmed cell death mediated by gasdermin family proteins, releases a large amount of immune stimulatory substances, which further contribute to inflammation and elicit an adaptive immune response against tumours and pathogens. And it occurs through multiple pathways that involve the activation of specific caspases and the cleavage of gasdermins. Post-translational modifications (PTMs) could influence the chemical properties of the modified residues and neighbouring regions, ultimately affecting the activity, stability, and functions of proteins to regulate pyroptosis. Many studies have been conducted to explore the influence of PTMs on the regulation of pyroptosis. In this review, we provide a comprehensive summary of different types of PTMs that influence pyroptosis, along with their corresponding modifying enzymes. Moreover, it elaborates on the specific contributions of different PTMs to pyroptosis and delves into how the regulation of these modifications can be leveraged for therapeutic interventions in cancer and inflammatory diseases.

Advancements in Engineering Tetrahedral Framework Nucleic Acids for Biomedical Innovations

Tetrahedral framework nucleic acids (tFNAs) are renowned for their controllable self-assembly, exceptional programmability, and excellent biocompatibility, which have led to their widespread application in the biomedical field. Beyond these features, tFNAs demonstrate unique chemical and biological properties including high cellular uptake efficiency, structural bio-stability, and tissue permeability, which are derived from their distinctive 3D structure. To date, an extensive range of tFNA-based nanostructures are intelligently designed and developed for various biomedical applications such as drug delivery, gene therapy, biosensing, and tissue engineering, among other emerging fields. In addition to their role in drug delivery systems, tFNAs also possess intrinsic properties that render them highly effective as therapeutic agents in the treatment of complex diseases, including arthritis, neurodegenerative disorders, and cardiovascular diseases. This dual functionality significantly enhances the utility of tFNAs in biomedical research, presenting valuable opportunities for the development of next-generation medical technologies across diverse therapeutic and diagnostic platforms. Consequently, this review comprehensively introduces the latest advancements of tFNAs in the biomedical field, with a focus on their benefits and applications as drug delivery nanoplatforms, and their inherent capabilities as therapeutic agents. Furthermore, the current limitations, challenges, and future perspectives of tFNAs are explored.

Embryo-Derived Cathepsin B Promotes Implantation and Decidualization by Activating Pyroptosis

Embryo implantation and decidualization are crucial for a successful pregnancy. How the inflammatory response is regulated during these processes is undefined. Pyroptosis is an inflammatory form of cell death mediated by gasdermin D (GSDMD). Through in vivo, cultured epithelial cells and organoids, it is shown that pyroptosis occurs in epithelial cells at the implantation site. Compared with those on day 4 of pseudopregnancy and delayed implantation, pyroptosis-related protein levels are significantly increased on day 4 of pregnancy and activated implantation, suggesting that blastocysts are involved in regulating pyroptosis. Blastocyst-derived cathepsin B (CTSB) is stimulated by preimplantation estradiol-17β and induces pyroptosis in epithelial cells. Pyroptosis-induced IL-18 secretion from epithelial cells activates a disintegrin and metalloprotease 12 (ADAM12) to process the epiregulin precursor into mature epiregulin. Epiregulin (EREG) enhances in vitro decidualization in mice. Pyroptosis-related proteins are detected in the mid-secretory human endometrium and are elevated in the recurrent implantation failure endometrium. Lipopolysaccharide treatment in pregnant mice causes implantation failure and increases pyroptosis-related protein levels. Therefore, the data suggest that modest pyroptosis is beneficial for embryo implantation and decidualization. Excessive pyroptosis can be harmful and lead to pregnancy failure.

Neutrophil pyroptosis regulates corneal wound healing and post-injury neovascularisation

RATIONALE

The cornea is a unique structure that maintains its clarity by remaining avascular. Corneal injuries can lead to neovascularisation (CNV) and fibrosis and are the third most common cause of blindness worldwide.

OBJECTIVE

Corneal injuries induce an immune cell infiltration to initiate reparative processes. However, inflammation caused by sustained immune cell infiltration is known to be detrimental and can delay the healing process. This study was designed to understand the potential role of neutrophil and epithelial cell crosstalk in post-injury CNV.

METHODS AND RESULTS

Western blotting and immunostaining assays demonstrated that neutrophils infiltrated corneas and underwent pyroptosis following acute alkali injury. In vivo studies showed that genetic ablation of Gasdermin D (GsdmD), a key effector of pyroptosis, enhanced corneal re-epithelialisation and suppressed post-injury CNV. In vitro co-culture experiments revealed that interleukin-1β (IL-1β) was released from pyroptotic neutrophils which suppressed migration of murine corneal epithelial cells. Real-time RT-PCR and immunostaining assays identified two factors, Wnt5a and soluble fms-like tyrosine kinase-1 (sflt-1), highly expressed in newly healed epithelial cells. sflt-1 is known to promote corneal avascularity. Bone marrow transplantation, antibody mediated neutrophil depletion, and pharmacological inhibition of pyroptosis promoted corneal wound healing and inhibited CNV in an in vivo murine corneal injury model.

CONCLUSION

Taken together, our study reveals the importance of neutrophil/epithelium crosstalk and neutrophil pyroptosis in response to corneal injuries. Inhibition of neutrophil pyroptosis may serve as a potential treatment to promote corneal healing without CNV.

KEY POINTS

Neutrophil pyroptosis delays re-epithelialization after corneal injury Compromised re-epithelialization promotes corneal neovascularization after injury Inhibition of post-injury pyroptosis could be an effective therapy to promote corneal wound healing.

(Pro)renin receptor aggravates myocardial pyroptosis in diabetic cardiomyopathy through AMPK-NLRP3 pathway

Introduction

As one of the most common complications of diabetes, diabetic cardiomyopathy (DCM) is the main cause of heart failure in patients with diabetes. However, the lack of effective treatments for DCM remains a clinical challenge. (Pro) renin receptor (PRR) is a member of renin angiotensin aldosterone system (RAAS). Here, we aim to determine whether PRR is involved in myocardial pyroptosis in diabetic cardiomyopathy.

Methods

We established diabetic rats model by intraperitoneal injection of streptozotocin (STZ). PRR overexpression adenovirus or PRR knockdown adenovirus was injected into the tail vein. Western blot, histopathology and immunohistochemistry staining, ELISA and Echocardiography were used to detect cardiac function changes and myocardial injury levels of DCM rats. Primary cardiomyocytes were stimulated with high glucose and PRR overexpression or PRR knockdown was achieved by adenovirus transfection, we also used the inhibitor of AMPK to decrease the activity of AMPK. Western blot, Real-time PCR, Immunofluorescence and ELISA were used to detect the level of PRR and pyroptosis in cardiomyocyte.

Results

We found that high glucose increased the expression of PRR in heart. After overexpression of PRR, the expression of the pyroptosis related proteins such as Caspase-1, IL-1β, IL-18, and NLRP3 was significantly increased, the phosphorylation level of AMPK was significantly decreased, and the fibrosis level was significantly increased, thus aggravating the cardiac function injury of DCM. On the contrary, PRR knockdown can alleviate the level of myocardial pyroptosis in DCM and improve cardiac function. The related mechanism was that PRR could inhibit AMPK phosphorylation and promote the activation of NLRP3 inflammasome.

Discussion

PRR aggravated pyroptosis of cardiomyocyte, increased the dysfunction of cardiomyocyte, and may be related to the decrease of AMPK phosphorylation and the overactivation of NLRP3. This may provide new ideas and targets for the treatment of DCM.

Deficiency of NLRP3 protects cerebral pericytes and attenuates Alzheimer's pathology in tau-transgenic mice

Introduction

Activation of NLRP3-containing inflammasome, which is responsible for IL-1β maturation, has been shown to contribute to Alzheimer's disease (AD)-associated pathogenesis in both APP- and tau-transgenic mice. However, effects of NLRP3 on pericytes and subsequent cerebrovascular pathology in AD remain unknown.

Methods

NLRP3-deficient and wild-type AD animal models were generated by crossing human P301S tau-transgenic mice and Nlrp3 knockout mice. AD-associated neuroinflammation, tauopathy, vasculature and pericyte coverage in the brain were investigated using immunohistological and molecular biological methods. To investigate how NLRP3 regulates pericyte activation and survival, pericytes from the brains of Nlrp3 knockout and wild-type mice were cultured, treated with IL-1β and H2O2 at different concentrations and analyzed by confocal microscopy and flow cytometry after staining with fluorescently labelled phalloidin, annexin-V and PDGFRβ antibody.

Results

Deficiency of NLRP3 (1) reduced Iba-1, GFAP and AT8 antibody-immunoreactive phosphorylated tau-positive cells, without significantly altering transcription of inflammatory genes, (2) preserved cerebral vasculature and pericyte coverage and up-regulated Osteopontin gene transcription, and (3) improved cognitive function in tau-transgenic mice. In cell culture, NLRP3 deficiency prevented pericyte apoptosis. Treatment with IL-1β or H2O2 increased the expression of PDGFRβ in NLRP3-deficient pericytes, but decreased it in NLRP3 wild-type pericytes in a dose-dependent manner.

Discussion

Inhibition of NLRP3 can promote pericyte survival, improve cerebrovascular function, and attenuate AD pathology in the brain of tau-transgenic mice. Our study supports NLRP3 as a novel therapeutic target for Alzheimer's patients.

Beyond Inflammation: Role of Pyroptosis Pathway Activation by Gram-Negative Bacteria and Their Outer Membrane Vesicles (OMVs) in the Interaction with the Host Cell

Pyroptosis is a gasdermin-mediated pro-inflammatory programmed cell death that, during microbial infections, aims to restrict the spreading of bacteria. Nevertheless, excessive pyroptosis activation leads to inflammation levels that are detrimental to the host. Pathogen-associated molecular patterns (PAMPs) present in bacteria and outer membrane vesicles (OMVs) can trigger pyroptosis pathways in different cell types with different outcomes. Moreover, some pathogens have evolved virulence factors that directly interfere with pyroptosis pathways, like Yersinia pestis YopM and Shigella flexneri IpaH7.8. Other virulence factors, such as those of Neisseria meningitidis, Neisseria gonorrhoeae, Salmonella enterica, and Helicobacter pylori affect pyroptosis pathways indirectly with important differences between pathogenic and commensal species of the same family. These pathogens deserve special attention because of the increasing antimicrobial resistance of S. flexneri and N. gonorrhoeae, the high prevalence of S. enterica and H. pylori, and the life-threatening diseases caused by N. meningitidis and Y. pestis. While inflammation due to macrophage pyroptosis has been extensively addressed, the effects of activation of pyroptosis pathways on modulation of cell cytoskeleton and cell-cell junctions in epithelia and endothelia and on the bacterial crossing of epithelial and endothelial barriers have only been partly investigated. Another important point is the diverse consequences of pyroptosis pathways on calcium influx, like activation of calcium-dependent enzymes and mitochondria dysregulation. This review will discuss the pyroptotic pathways activated by Gram-negative bacteria and their OMVs, analyzing the differences between pathogens and commensal bacteria. Particular attention will also be paid to the experimental models adopted and the main results obtained in the different models. Finally, strategies adopted by pathogens to modulate these pathways will be discussed with a perspective on the use of pyroptosis inhibitors as adjuvants in the treatment of infections.

Potential Roles of IP3 Receptors and Calcium in Programmed Cell Death and Implications in Cardiovascular Diseases

Inositol 1,4,5-trisphosphate receptors (IP3Rs) play a crucial role in maintaining intracellular/cytosolic calcium ion (Ca2+i) homeostasis. The release of Ca2+ from IP3Rs serves as a second messenger and a modulatory factor influencing various intracellular and interorganelle communications during both physiological and pathological processes. Accumulating evidence from in vitro, in vivo, and clinical studies supports the notion that the overactivation of IP3Rs is linked to the pathogenesis of various cardiac conditions. The overactivation of IP3Rs results in the dysregulation of Ca2+ concentration ([Ca2+]) within cytosolic, mitochondrial, and nucleoplasmic cellular compartments. In cardiovascular pathologies, two isoforms of IP3Rs, i.e., IP3R1 and IP3R2, have been identified. Notably, IP3R1 plays a pivotal role in cardiac ischemia and diabetes-induced arrhythmias, while IP3R2 is implicated in sepsis-induced cardiomyopathy and cardiac hypertrophy. Furthermore, IP3Rs have been reported to be involved in various programmed cell death (PCD) pathways, such as apoptosis, pyroptosis, and ferroptosis underscoring their multifaceted roles in cardiac pathophysiology. Based on these findings, it is evident that exploring potential therapeutic avenues becomes crucial. Both genetic ablation and pharmacological intervention using IP3R antagonists have emerged as promising strategies against IP3R-related pathologies suggesting their potential therapeutic potency. This review summarizes the roles of IP3Rs in cardiac physiology and pathology and establishes a foundational understanding with a particular focus on their involvement in the various PCD pathways within the context of cardiovascular diseases.

Genetic removal of Nlrp3 protects against sporadic and R345W Efemp1-induced basal laminar deposit formation

Chronic, unresolved inflammation has long been speculated to serve as an initiating and propagating factor in numerous neurodegenerative diseases, including a leading cause of irreversible blindness in the elderly, age-related macular degeneration (AMD). Intracellular multiprotein complexes called inflammasomes in combination with activated caspases facilitate production of pro-inflammatory cytokines such as interleukin 1 beta. Specifically, the nucleotide-binding oligomerization (NOD)-like receptor protein 3 (NLRP3) has received heightened attention due to the wide range of stimuli to which it can respond and its potential involvement in AMD. In this study, we directly tested the role of Nlrp3 and its downstream effector, caspase 1 (Casp1) in mediating early AMD-like pathology (i.e., basal laminar deposits [BLamDs]) in wild-type (WT) mice and the Malattia Leventinese/Doyne honeycomb retinal dystrophy (ML/DHRD) mouse model (p.R345W mutation in Efemp1). Compared to aged-matched controls, R345W+/+ knockin mice demonstrated increased Muller cell gliosis, subretinal Iba-1+ microglial cells, higher Nlrp3 immunoreactivity in the retina, as well as significant transcriptional upregulation of complement component 3, Nlrp3, pro-Il1b, pro-caspase-1, and tissue inhibitor of matrix metalloproteinase 3 in the retinal pigmented epithelium (RPE)/choroid. These findings were accompanied by an age-related increase in BLamD formation in the R345W+/+ mice. Genetic elimination of either Nlrp3 or Casp1 significantly reduced both the size and coverage of BLamDs in the R345W+/+ background, highlighting an important and underappreciated pathway that could affect ML/DHRD onset and progression. Moreover, Nlrp3 knockout reduced spontaneous, idiopathic BLamDs in WT mice, suggesting translatability of our findings not only to rare inherited retinal dystrophies, but also potentially to AMD itself.

Caspase-8 in inflammatory diseases: a potential therapeutic target

Caspase-8, a renowned cysteine-aspartic protease within its enzyme family, initially garnered attention for its regulatory role in extrinsic apoptosis. With advancing research, a growing body of evidence has substantiated its involvement in other cell death processes, such as pyroptosis and necroptosis, as well as its modulatory effects on inflammasomes and proinflammatory cytokines. PANoptosis, an emerging concept of cell death, encompasses pyroptosis, apoptosis, and necroptosis, providing insight into the often overlapping cellular mortality observed during disease progression. The activation or deficiency of caspase-8 enzymatic activity is closely linked to PANoptosis, positioning caspase-8 as a key regulator of cell survival or death across various physiological and pathological processes. Aberrant expression of caspase-8 is closely associated with the development and progression of a range of inflammatory diseases, including immune system disorders, neurodegenerative diseases (NDDs), sepsis, and cancer. This paper delves into the regulatory role and impact of caspase-8 in these conditions, aiming to elucidate potential therapeutic strategies for the future intervention.

Targeting the smooth muscle cell Keap1-Nrf2-GSDMD-pyroptosis axis by cryptotanshinone prevents abdominal aortic aneurysm formation

Rationale: Abdominal aortic aneurysm (AAA) is an inflammatory, fatal aortic disease that currently lacks any effective drugs. Cryptotanshinone (CTS) is a prominent and inexpensive bioactive substance derived from Salvia miltiorrhiza Bunge, a well-known medicinal herb for treating cardiovascular diseases through its potent anti-inflammatory properties. Nevertheless, the therapeutic effect of CTS on AAA formation remains unknown. Methods: To investigate the therapeutic effect of CTS in AAA, variety of experimental approaches were employed, majorly including AAA mouse model establishment, real-time polymerase chain reaction (PCR), RNA sequencing, western blot, co-immunoprecipitation, scanning/transmission electron microscopy (SEM/TEM), enzyme-linked immunosorbent assay (ELISA), seahorse analysis, immunohistochemistry, and confocal imaging. Results: In this study, we demonstrated that CTS suppressed the formation of AAA in apolipoprotein E knock-out (ApoE-/-) mice infused with Ang II. A combination of network pharmacology and whole transcriptome sequencing analysis indicated that activation of the Keap1-Nrf2 pathway and regulation of programmed cell death in vascular smooth muscle cells (VSMCs) are closely linked to the anti-AAA effect of CTS. Mechanistically, CTS promoted the transcription of Nrf2 target genes, particularly Hmox-1, which prevented the activation of NLRP3 and GSDMD-initiated pyroptosis in VSMCs, thereby mitigating VSMC inflammation and maintaining the VSMC contractile phenotype. Subsequently, by utilizing molecular docking, together with the cellular thermal shift assay (CETSA) and isothermal titration calorimetry (ITC), a particular binding site was established between CTS and Keap1 at Arg415. To confirm the binding site, site-directed mutagenesis was performed, which intriguingly showed that the Arg415 mutation eliminated the binding between CTS and the Keap1-Nrf2 protein and abrogated the antioxidant and anti-pyroptosis effects of CTS. Furthermore, VSMC-specific Nrf2 knockdown in mice dramatically reversed the protective action of CTS in AAA and the inhibitory effect of CTS on VSMC pyroptosis. Conclusion: Naturally derived CTS exhibits promising efficacy as a treatment drug for AAA through its targeting of the Keap1-Nrf2-GSDMD-pyroptosis axis in VSMCs.