The stringent regulation of intrahepatic metastases is essential for improving survival outcomes in patients with hepatocellular carcinoma (HCC). This study investigated the impact of gut microbiota on intrahepatic metastasis of HCC and evaluated the therapeutic potential of healthy fecal microbiota transplantation (FMT). Dysregulation of the gut microbiota, characterized by a significant reduction in the abundance of beneficial bacteria, such as Anaerotruncus colihominis and Dysosmobacter welbionis, was observed in patients with intrahepatic metastatic HCC. A human flora-associated (HFA) intrahepatic metastatic HCC mouse model was successfully established through consecutive 4 weeks of human-mouse FMT. Dysregulation of gut microbiota promoted intrahepatic metastasis in the mouse model, primarily by enhancing neutrophil-mediated inflammatory responses and lead to excessive formation of neutrophil extracellular traps (NETs). Consequently, it promoted tumor vascular growth and tissue necrosis, resulting in intrahepatic metastasis of HCC. Notably, FMT from healthy donors mitigated these pathological processes. This study elucidated the role and mechanism of dysregulated gut microbiota in promoting intrahepatic metastasis of HCC. Healthy FMT emerges as a promising novel therapeutic strategy for preventing and treating intrahepatic metastasis of HCC.

The present review describes the mechanisms of NETosis and its role in myocardial ischemia-reperfusion injury (MIRI), focusing on the release of neutrophil extracellular traps (NETs) by activated neutrophils. NETs, composed of depolymerized chromatin and granule proteins, are crucial for pathogen entrapment, infection control and immune regulation. However, NET formation, linked to neutrophil death (NETosis), exacerbates MIRI by promoting inflammation and tissue damage. To address therapeutic strategies for NETosis in MIRI, several potential clinically significant approaches were explored, including peptidylarginine deaminase 4 inhibition, DNase therapy, antioxidants, inflammation modulation, and antithrombotic treatments, which not only provide novel diagnostic biomarkers and therapeutic targets in MIRI, but are also expected to improve patient prognosis and advance the development of personalised medicine.

Iron is a crucial element for living organism in terms of oxygen transport, hematopoiesis, enzymatic activity, mitochondrial respiratory chain function and also immune system function. The human being has evolved a mechanism to regulate body iron. In some rheumatic diseases such as rheumatoid arthritis (RA), systemic lupus erythematous (SLE), systemic sclerosis (SSc), ankylosing spondylitis (AS), and gout, this balanced iron regulation is impaired. Altered iron homeostasis can contribute to disease progression through ROS production, fibrosis, inflammation, abnormal bone homeostasis, NETosis and cell senescence. In this review, we have focused on the iron metabolism in rheumatic disease and its role in disease progression.

Neutrophil extracellular traps (NETs) are network structures composed of DNA, histones, and antimicrobial proteins,released by activated neutrophils to trap and eliminate extracellular pathogens. Recent research has demonstrated a strong correlation between NETs and various diseases, including immune dysregulation, thrombosis, and malignancies. This review synthesizes current research on NETs, focusing on its biological role in oral squamous cell carcinoma (OSCC) and explores its potential in treating.

A literature review in the PubMed database was conducted to examine the impact of NETs on the homeostasis of oral microbiota and the involvement in the development of oral microbiota-related carcinogenesis.

Various microorganisms, including Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus spp., along with Candida albicans, as well as certain viruses such as Human papillomavirus (HPV), Human herpes virus 8 (HHV-8), and Herpes simplex virus-1 (HSV-1)are regulated by NETs during oral colonization and proliferation and have been identified as contributors to the pathogenesis of oral squamous cell carcinoma. NETs have been shown to play a dual role in the carcinogenic process of oral microbiota in humans. At the initial stage of tumor formation, NETs inhibit tumorigenesis by eliminating tumorigenic bacteria that infiltrated the tumor; however, following tumor establishment, various cytokines and chemokines that promote tumor progression are released by neutrophils during the NETs formation.

This article reviews the oncogenic mechanisms of NETs in the oral microbiota, with potential implications for early tumor detection and the development of microbe-targeted therapies.

Neutrophils, conventionally regarded as a homogeneous immune cell population, have emerged as a heterogeneous group of cells with distinct gene profiles and immune properties. Activated neutrophils release a spectrum of bioactive substances, including cytokines, chemokines, proteolytic enzymes, reactive oxygen species and neutrophil extracellular traps (NETs), which are composed of decondensed DNA and antimicrobial proteins. NETs have a pivotal role in innate immunity, including in preventing the ascent of uropathogenic bacteria into the kidneys, as they efficiently trap pathogenic microorganisms. However, although indispensable for defence against pathogens, NETs also pose risks of self-damage owing to their cytotoxicity, thrombogenicity and autoantigenicity. Accordingly, neutrophils and NETs have been implicated in the pathogenesis of various disorders that affect the kidneys, including acute kidney injury, vasculitis, systemic lupus erythematosus, thrombotic microangiopathy and in various aetiologies of chronic kidney disease. Pathological alterations in the glomerular vascular wall can promote the infiltration of neutrophils, which can cause tissue damage and inflammation through their interactions with kidney-resident cells, including mesangial cells and podocytes, leading to local cell death. Targeting neutrophil activation and NET formation might therefore represent a new therapeutic strategy for these conditions.

The formation of neutrophil extracellular traps (NETs) is a novel way for neutrophils to perform organismal protective functions essential for protecting the host against infections. Nevertheless, an increasing amount of data shows that uncontrolled or excessive formation of NETs in the body leads to inflammation and thrombosis. Many serious human diseases, such as sepsis, stroke, cancer, and autoimmune diseases, are associated with thrombosis, and inhibiting its formation is essential to prevent the development of many inflammatory and thrombotic diseases. With deeper research, it has been found that there is a complex interaction between NETs and platelets: platelets activate neutrophils to form NETs, while NET components enhance platelet aggregation and activation. This self-perpetuating vicious cycle between them mediates pathological processes such as inflammation, coagulation, and thrombosis. A deeper comprehension of the underlying molecular mechanisms between them promises to be a new target for thrombotic diseases. In this review, we concentrate on a summary of NET formation and its mechanisms of action. Providing a thorough summary of how neutrophils are activated by platelets to form NETs, how NETs cause platelet activation, and how this close interaction during inflammatory events affects the course of the disease, with the aim of providing fresh targets and ideas for thrombotic disease clinical prevention and therapy.

Extracellular traps (ETs), comprising a DNA-protein network, are widespread and function as an innate immune defense in many species. Notably, Strongylocentrotus intermedius solely depend on innate immunity for disease resistance. This study investigated the formation and preliminary mechanism of ETs in the coelomocytes of the S. intermedius under the stimulation of bacterium Vibrio alginolyticus. These results revealed that as the concentration of V. alginolyticus increased, the formation of ETs became more significant. Flow cytometry analysis showed that the formation process of ETs was accompanied by changes in mitochondrial indicators, suggesting that mitochondria may be involved in the formation process of V. alginolyticus-induced ETs. Transcriptome analysis indicated that the ETs production by coelomocytes of the S. intermedius was related to glycolysis and ATP synthesis. A total of 2631 differentially expressed genes (DEGs) were screened in this transcriptome. We then screened 34 immune-related DEGs from 16 signaling pathways to construct the PPI network, and defined hub proteins corresponding to genes such as ATP6, ND2, G3PDH, MAPK7 and other related genes. These genes are related to mitochondrial function, glycolytic pathways, and immune pathways. Additionally, the formation of ETs led to alterations in multiple immune regulators, such as TNF, NF-κB, MAPK, PI3K-AKT, and mTOR, implying its role in cellular immunomodulation. Quantitative real-time PCR experiment revealed that the expression changes of some DEGs identified and validated in ET-formation coelomocytes matched transcriptome analysis results. This study provided insights into S. intermedius aquaculture, elucidated marine organism immune mechanisms, and advanced invertebrate innate immunity understanding.

Acute inflammation, characterized by a rapid influx of neutrophils, is a protective response that can lead to chronic inflammatory diseases when left unresolved. We previously showed that secretion of LTB4-containing exosomes via nuclear envelope-derived multivesicular bodies is required for effective neutrophil infiltration during inflammation. Here we report that the co-secretion of these exosomes with nuclear DNA facilitates the resolution of the neutrophil infiltrate in a mouse skin model of sterile inflammation. Activated neutrophils exhibit rapid and repetitive DNA secretion as they migrate directionally using a mechanism distinct from suicidal neutrophil extracellular trap release and cell death. Packaging of DNA in the lumen of nuclear envelope-multivesicular bodies is mediated by lamin B receptor and chromatin decondensation. These findings advance our understanding of neutrophil functions during inflammation and the physiological relevance of DNA secretion.

The number of metabolic dysfunction-associated steatotic liver disease (MASLD) patients is increasing rapidly. More attention has been paid to the relationship between immunity and MASLD. This study explored the roles of serum autoantibodies, immunoglobulins, and complements in MASLD. A total of 182 MASLD patients were investigated and grouped by autoantibody or NAS scores. Correlation between immunology and clinical features was assessed. In addition, metabolic dysfunction-associated steatohepatitis (MASH) models were constructed to verify the findings. Neutrophils were isolated from mice and treated with complement C3 to investigate the association between C3 and neutrophil extracellular traps (NETs). IgG, IgM, and NAS scores in the autoantibody positive group were significantly higher than those in the autoantibody negative group. Antinuclear antibodies (ANA), IgA, IgE, IgG, C3, C4, ALT, and AST were related to MASH. Meanwhile, IgA and C3 correlated with the severity of MASLD. The ROC curve showed that IgA > 2.990 g/L or C3 > 1.115 g/L predicted the presence of MASH. More importantly, IgG, activated C3, and NETs were increased in MASH. C3 stimulation directly induced NET formation in the neutrophils. Immunity systems were activated in MASH and elevated IgG activated C3 to stimulate the production of NETs, thus exacerbating MASH.

Neutrophil extracellular traps (NETs) play a crucial role in the pathophysiology of many debilitating conditions, including autoimmune diseases, inflammatory diseases, and cancer. As a result, NET-targeted therapies have been investigated in search of effective treatment strategies. Despite promising preclinical findings, clinical translation of NET inhibitors has had limited success. These preclinical studies have faced limitations such as mouse models that inaccurately reflect human disease dynamics, as well as by the complexity of NETs-including their diverse morphology and convoluted pathways to formation relative to pathology. The NET inhibitors themselves have several limitations, including off-target effects and bioavailability issues. The challenges facing NET-targeted therapies reported here may explain what is required to go from bench to bedside successfully.

Increasing evidence has shown that programmed cell death (PCD) plays a crucial role in tumorigenesis and cancer progression. The components of PCD are complex and include various mechanisms such as apoptosis, necroptosis, alkaliptosis, oxeiptosis, and anoikis, all of which are interrelated in their functions and regulatory pathways. Given the significance of these processes, it is essential to conduct a comprehensive study on PCD to elucidate its multifaceted nature. Key signaling pathways, particularly the caspase signaling pathway, the RIPK1/RIPK3/MLKL pathway, and the mTOR signaling pathway, are pivotal in regulating PCD and influencing tumor progression. In this review, we briefly describe the generation mechanisms of different PCD components and focus on the regulatory mechanisms of these three major signaling pathways within the context of global PCD. Furthermore, we discuss various tumor therapeutic compounds that target different signaling axes of these pathways, which may provide novel strategies for effective tumor therapy and help improve patient outcomes in cancer treatment.

Inflammation is critical for controlling infections but can cause disease when unchecked. During Mycobacterium tuberculosis (Mtb) infection, neutrophil-dominated inflammation is associated with exacerbated disease. ATG5 expression by neutrophils mediates autophagy-independent control of infection but mechanistic understanding of how this regulates protective neutrophil function is lacking. Using genetic mouse models along with in vivo and in vitro infection systems, we report herein that ATG5 is required in neutrophils to suppress type I interferon-induced PAD4-mediated histone citrullination and neutrophil extracellular trap (NET) release. In addition, ATG5 suppresses type I interferon-induced CXCL2 secretion and neutrophil swarming during Mtb infection. Elevated type I IFN signalling and NET release contribute to the early susceptibility of Atg5fl/fl-LysM-Cre mice during infection. These findings identify ATG5 as a master regulator of how type I interferon influences neutrophil responses during infection, revealing a potential target for host-directed therapies.

FXII (coagulation factor XII) is best known for its roles in the contact and kallikrein-kinin pathways. FXII is converted to its active enzyme (FXIIa [activated factor XII]) by PKa (plasma kallikrein) or its unique ability to autoactivate on bacterial or other biologic surfaces. In vivo, FXIIa initiates the intrinsic coagulation pathway and promotes inflammation by reciprocal activation of prekallikrein, which cleaves HK (high-molecular-weight kininogen) to liberate bradykinin. CpaA (coagulation targeting metallo-endopeptidase of A baumannii) is a secreted metalloprotease identified in a human clinical isolate of Acinetobacter baumannii that cleaves FXII at O-linked glycosylated sites, inhibiting contact activation. While CpaA facilitates a modest in vivo fitness advantage in mice, the role of CpaA in human infection remains unclear. As such, the objectives of this study were to characterize the structural details of the interaction between CpaA, FXII, and the KKSs (kallikrein-kinin systems) and to determine the downstream consequences on thromboinflammatory responses.

The effect of purified CpaA on the coagulant activity of FXII and the generation of bradykinin was characterized. Neutrophil signaling, flow cytometry, and functional assays were performed to define how CpaA-mediated cleavage of FXII affects innate immune functions. Bacterial killing by human neutrophils was performed with wild-type and mutant A baumannii strains lacking CpaA.

We found that CpaA cleaves both FXII zymogen and FXIIa but not beta Factor XII. However, cleavage of FXIIa by CpaA does not significantly inhibit its clotting activity, demonstrating that CpaA does not inactivate FXIIa, but rather prevents activation of zymogen FXII. CpaA also cleaves HK, resulting in reduced kallikrein activation and bradykinin generation. We previously identified that zymogen FXII interacts with the urokinase receptor on neutrophils and upregulates neutrophil activation. Here, we demonstrate that CpaA cleaves neutrophil FXII, resulting in reduced Akt2 phosphorylation, chemotaxis, oxidative burst, and neutrophil extracellular trap formation. Importantly, CpaA decreases the human neutrophil killing efficiency of A baumannii in culture.

These data identify a role for FXII in responding to bacterial infection and suggest that by inhibiting the contact and KKSs and impairing neutrophil activation, CpaA may blunt the innate immune response and help prevent the elimination of A baumannii from the human host.

Neutrophil extracellular traps (NETs), web-like complex structures secreted by neutrophils, have emerged as key players in the modulation of immune responses and the immunopathogenesis of immune disorders. Initially described for their antimicrobial function, NETs now play a part in the fundamental processes of cancer biology, including cancer initiation, metastatic dissemination, and immune evasion strategies. NETs hijack anti-tumor immunity by entrapping circulating cancer cells, fostering the growth of tumors, and reorganizing the tumor microenvironment such that it is pro-malignancy. Emerging evidence emphasizes the role of NETosis coupled with non-coding RNAs-long non-coding RNAs (lncRNAs) and microRNAs (miRNAs)-as key regulators of gene expression and controllers of processes vital for cancer growth, such as immune response and programmed cell death processes like apoptosis, necroptosis, pyroptosis, and ferroptosis. Aberrantly expressed non-coding RNAs have been attributed to immune dysregulation and excessive NET production, promoting tumor growth. NETs are also associated with a myriad of pathological conditions, such as autoimmune disorders, cystic fibrosis, sepsis, and thrombotic disorders. New therapeutic approaches-such as DNase therapy and PAD4 inhibitors-target NET production and their degradation to modify immune function and the efficiency of immunotherapies. Further clarification of the intricate interactions of NETosis, lncRNAs, and miRNAs has the potential to establish new strategies for the suppression of the growth of tumors and preventing immune evasion. This review seeks to elucidate the interactions between NETosis and the regulatory networks involving non-coding RNAs that significantly contribute to the immunopathogenesis of cancer.

Excessive activation of toll-like receptor 7 and 8 (TLR7/8) plays a role in the pathogenesis of autoimmune diseases and is associated with negative outcomes from viral infections. Neutrophil activation is highly inflammatory and mediates tissue damage. We explored the effects of TLR7/8 activation in neutrophils to better understand neutrophil biology and evaluate the therapeutic utility of TLR7/8 inhibitors in indications where neutrophils contribute to disease pathogenesis. We found that TLR8, but not TLR7, is active in human neutrophils. TLR8 activation led to increased interleukin-8 (IL-8) secretion and resulted in significant changes in gene expression, as determined by RNA sequencing, with increased expression of genes encoding cytokines and other inflammatory mediators. Type I interferon (IFN) also induced gene expression changes distinct from those induced by TLR8. Additionally, neutrophil extracellular traps (NET) formation and DNA release, or NETosis, was induced by TLR8 activation in IFN-primed neutrophils. Treatment with a TLR7/8 inhibitor (CMPD2) effectively blocked IL-8 secretion and NETosis. In a Phase II clinical trial in COVID-19 pneumonia, TLR7/8 inhibition with enpatoran affected neutrophil counts. Expression of NFKBIZ was induced by TLR8 in neutrophils in vitro and found to also be reduced by enpatoran in patients with COVID-19, suggesting it may be useful as a marker for TLR8-activated neutrophils and for identifying candidate diseases and patients that may benefit from treatment with a TLR7/8 inhibitor. Overall, our findings provide new insights into TLR8 and neutrophil biology that have therapeutic implications in autoimmune diseases and immune-mediated inflammation.

Toxoplasmosis is a life-threatening opportunistic infection in immunocompromised patients, caused by the parasite Toxoplasma gondii. Infection is initiated through oral ingestion of Toxoplasma cysts that must survive the harsh environment of the gut to undergo excystation. Released parasites invade intestinal epithelial cells and then disseminate throughout tissues for encystation, mainly in the brain. How Toxoplasma escapes destruction mediated by gastrointestinal proteases is poorly understood. T. gondii has nine genes encoding serine protease inhibitor proteins (TgPIs). TgPI-1 is highly expressed across all Toxoplasma strains and developmental stages and contains three domains for binding to various serine proteases. Here, we explore the role of TgPI-1 in protecting Toxoplasma against serine proteases in the gut and neutrophil-derived proteases in the lamina propria. TgPI-1 localizes to the parasite plasma membrane and cyst wall. We generated ΔTgPI-1 parasites, and the mutant is more sensitive to neutrophil elastase (NE), trypsin and chymotrypsin than WT. Neutrophils exposed to Toxoplasma release neutrophil extracellular traps (NET) with strain-dependent morphologies, ranging from spiky to extended cloudy. TgPI-1 was detected on NET containing NE, and ΔTgPI-1 parasites are more susceptible to destruction by NETosis. In mice, ΔTgPI-1 parasites exhibit reduced infectivity, poor dissemination to abdominal organs, and lower cyst burden in the brain. These findings shed light on a strategy employed by Toxoplasma to counteract enzymatic antimicrobial defenses in gut tissues, highlighting potential avenues for controlling tissue dissemination of this medically significant parasite.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder primarily affecting women during the reproductive years, often complicating pregnancy outcomes with elevated levels of neutrophil extracellular traps (NETs) infiltration. However, potential impacts of NETs on placental trophoblasts in SLE and the underlying molecular mechanisms remain unclear. To address this, transcriptome sequencing was conducted on placentas collected from seven pregnant women with SLE and six healthy pregnant controls to identify SLE-specific placental features. The effects of NETs were further assessed in MRL/lpr lupus-prone mice and pristane-induced lupus (PIL) mice, focusing on pregnancy outcomes and placental pathology. In vitro, trophoblasts were stimulated with NETs derived from patients with SLE, followed by molecular analyses such as transcriptomic, cellular energy metabolism assays and liquid chromatography-tandem mass spectrometry to explore the effects and mechanisms of NETs. Results showed elevated NETs were observed in the placentas of both patients with SLE and lupus mouse models, accompanied by activation of the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome. Treatment with DNase I significantly improved pregnancy outcomes in MRL/lpr mice, while the use of peptidyl arginine deiminase 4 (PAD4)-deficient mice was beneficial on the pregnancy outcomes of PIL mice. Furthermore, SLE-derived NETs activated pyroptosis in trophoblasts by promoting glycolysis and subsequent lactylation of NLRP3. These findings highlight that NETs contribute to placental damage in SLE by inducing the lactylation of the NLRP3 inflammasome in trophoblasts, demonstrating the therapeutic potential of inhibiting NETs to improve placental function.

Rheumatoid arthritis (RA) is a chronic condition characterized by joint pain that significantly impairs patients' work and daily lives. The limited understanding of the pathological mechanisms underlying RA-related pain poses challenges for effective clinical pain management. Ganoderma lucidum spore powder (GLSP) has demonstrated therapeutic benefits in various diseases, with no reported toxicity or adverse effects.

This study investigates the role of neutrophils in the pathological mechanisms of RA-related pain using collagen-induced arthritis (CIA) mice and an ex vivo neutrophil model. A combination of techniques, including animal models, flow cytometry, behavioral testing, cell adoptive transfer, and network pharmacology analysis, was employed to evaluate the effects and targets of GLSP on pain symptoms and neutrophil activity in CIA mice.

Flow cytometric analysis revealed the accumulation and activation of neutrophils in the paws of CIA mice. Furthermore, the levels of pro-inflammatory CD95+ neutrophil subpopulations (N1 state) and ROS+ cells in the affected paws were positively correlated with the severity of mechanical allodynia and heat hyperalgesia observed in these mice. Our findings indicate that oral administration of GLSP significantly alleviates joint destruction, paw swelling, and pain hypersensitivity in CIA mice. Notably, GLSP reversed CIA-induced neutrophil accumulation, N1 polarization, and reactive oxygen species (ROS) production. Both network pharmacology target prediction and in vivo/in vitro experimental validation indicated that GLSP inhibits N1 polarization and ROS production in neutrophils by modulating the TNF-α signaling pathway, thus exerting RA-specific analgesic effects.

In summary, this study offers new insights into the pathological mechanisms of RA-related pain and demonstrates that neutrophil accumulation, N1 polarization, and ROS production contribute to RA-related pain. GLSP alleviates RA-related pain by inhibiting the pro-inflammatory phenotype of neutrophils, highlighting its potential for clinical translation in the treatment of RA.

Nucleases are critical metabolic enzymes expressed by mycoplasmas to acquire nucleic acid precursors from the host for their parasitic existence. Certain nucleases, either membrane-bound or secreted, not only contribute to the growth of mycoplasmas but also serve as key virulence factors due to their unique spatial structures and physiological activity. The pathogenesis includes, but is not limited to, degradation of host DNA and RNA, leading to disruptions of nucleic acid metabolism and the induction of host cell apoptosis; degradation of neutrophil extracellular traps (NETs), allowing escape from neutrophil-mediated killing; and upregulation of inflammatory molecules to modulate the immune response of the host. Understanding the biological functions of nucleases is essential for gaining deeper insights into the virulence and immune evasion strategies of mycoplasmas, which can inform the development of novel approaches for the prevention, diagnosis, and treatment of mycoplasma infections.

Neutrophil extracellular traps (NETs) are web-like structures released by neutrophils to trap and kill microbes. While NETs are crucial in host defense, excessive formation can lead to autoimmune diseases. Currently, no specific drugs target NETs directly; however, some medications can indirectly modulate their formation. The secretory leukocyte protease inhibitor (SLPI) is a small protein that inhibits the activity of neutrophil elastase (NE), an enzyme essential for NETs formation. By inhibiting NE activity, SLPI prevents the chromatin from decondensing, which is necessary for NETs to form; this suggests that SLPI may protect by preventing excessive NETs development. However, evidence indicates that NE can inactivate SLPI by cleaving its N-terminus. This action can create a protease/antiprotease imbalance, potentially leading to detrimental consequences for the host. In this study, we produced a recombinant variant of SLPI (SLPI-S15G-A16G: rSLPIv) using recombinant DNA technology, expressed in Escherichia coli SHuffle T7. The protein was tagged with the small metal-binding protein (SmbP) to facilitate its expression and purification through immobilized metal-affinity chromatography. Our results demonstrated that rSLPIv exhibited immunomodulatory activity at a concentration of 10 nM in neutrophils that had been prestimulated with PMA. It reduced NETs formation by 30 % and maintained this effect for up to 6 h. Confocal microscopy confirmed these findings, revealing a rSLPIv-dependent reduction in neutrophil nuclear expansion. Thus, rSLPIv shows significant suppressive activity on NETs formation at low concentrations, making it a potential candidate as an immunotherapeutic agent.

Ovarian cancer (OC) usually progresses rapidly and is associated with high mortality, while a reliable clinical factor for OC patients to predict prognosis is currently lacking. Recently, the pathogenic role of neutrophils releasing neutrophil extracellular traps (NETs) in various cancers including OC has gradually been recognized. The study objective was to determine whether NETs-related biomarkers can be used to accurately predict the prognosis and guide clinical decision-making in OC. In this study, we utilized univariate and multivariate Cox regression to identify key prognostic features and developed a model with six NETs-related lncRNAs, selected via LASSO regression. The model's predictive capability was assessed through Kaplan-Meier, ROC, and Cox analyses. To understand the model's mechanisms, we conducted GO term analysis, KEGG pathway enrichment, and GSEA. We also analyzed gene mutation status, tumor mutation load, survival rates, and model correlation. Additionally, we compared immune functions, immune checkpoint expression, and chemotherapy sensitivity between risk groups. Besides, we validated the model's predictive value using test data and tissues acquired from our institution. Finally, we performed in vitro and in vivo experiments to confirm the expression of model lncRNAs and the cellular level function of GAS5. We developed a model using six NETs-associated lncRNAs: GAS5, GBP1P1, LINC00702, LINC01933, LINC02362, and ZNF687-AS1. The model's predictive performance, evaluated via ROC curve, was compared with traditional clinicopathological features. GO process analysis highlighted molecular functions related to antigen binding and immune system biological processes. Variations were observed in transcription regulators affecting immune response, inflammation, cytotoxicity, and regulation. We also predicted IC50 values for chemotherapeutic drugs (bexarotene, bicalutamide, embelin, GDC0941, and thapsigargin) in high- and low-risk groups, finding higher IC50 values in low-risk patients. The risk model's robustness was validated using OC cells, tissues, and clinical datas.

Neutrophil extracellular traps (NETs) are web-like, bactericidal structures produced by neutrophils and are composed principally of extracellular DNA, histones, elastase, and myeloperoxidase, among other components. NET formation is an innate immune response that is beneficial for pathogen killing and clearance. However, excessive NET formation and clearance defects can lead to inflammation and induce damage to host organs. NETs are also implicated in the development of noninfectious inflammatory disorders, such as liver injury in chronic liver diseases. The liver parenchyma contains hepatocytes, liver sinusoidal endothelial cells, Kupffer cells, and hepatic stellate cells. Each of these cells possesses unique structures and functions, and their interactions with NETs result in pathophysiological changes contributing to liver injury. This review updates the findings related to the modes of action and molecular mechanisms by which NETs modulate the pathophysiology of various hepatic cells and potentiate liver injury. The article also reviews the roles of NETs in hepatic ischemia reperfusion injury, hepatocellular carcinoma pathogenesis, and cancer metastasis. Last, we examine data to determine whether NETs induce crosstalk among various hepatic cells during liver injury and to identify future research directions.

Septic arthritis, primarily caused by Staphylococcus aureus, poses a significant risk of both mortality and morbidity due to its aggressive nature. The nuc1-encoded thermonuclease NucA of S. aureus degrades extracellular DNA/RNA, allowing the pathogen to escape neutrophil extracellular traps (NETs) and maintain the infection unabated. Here we show that in the mouse model for hematogenous septic arthritis, the Δnuc1 mutant is much less pathogenic and the severity of clinical septic arthritis is markedly reduced, including decreased weight loss, lower kidney bacterial load, reduced bone erosion, and much less IL-6 production. In vitro, S. aureus genomic DNA induces a robust TNF-α response in macrophage-like RAW 264.7 cells abrogated when the DNA is degraded by NucA. Moreover, the wild type induces high levels of TNF-α, IL-10, and IL-6 in neutrophils and osteoblast-like SAOS-2 cells, respectively. NucA exacerbates septic arthritis by increasing extracellular and intracellular survival of bacteria.

Peptidylarginine deiminase 4 (PAD4) citrullinates histones, enabling the release of neutrophil extracellular traps. While neutrophil extracellular traps capture and kill pathogens, they also drive immunothrombosis, potentially worsening sepsis outcomes. However, it remains unclear whether PAD4 deficiency is beneficial or harmful in sepsis.

To evaluate the impact of PAD4 deficiency in a fecal-induced peritonitis sepsis model, with and without antibiotic treatment, and incorporating fluid resuscitation in both sexes.

Wild-type and PAD4 knockout (PAD4-/-) C57Bl/6 mice received intraperitoneal injections of fecal slurry (0.6 mg/g). Mice received buprenorphine every 8 hours and antibiotics/fluids every 12 hours. Survival studies were also conducted without antibiotics at a reduced fecal dose (0.4 mg/g). Mice were culled at 8 hours or 48 hours after infection. Organs, blood, and peritoneal cavity fluid were collected. Plasma levels of interleukin (IL)-6, IL-10, cell-free DNA, and thrombin-antithrombin were quantified, as well as bacterial loads in blood and peritoneal cavity fluid. Organ histology/immunohistochemistry was performed.

Female PAD4-/- mice had worsened survival compared with female wild-type mice. Male mice exhibited worse survival than females in both strains. Antibiotics eliminated survival differences between strains and sexes. Septic PAD4-/- mice had reduced IL-10 in the early phase of sepsis, increased lung myeloperoxidase, and exacerbated lung injury compared with septic wild-type mice.

PAD4 deficiency in female mice worsened survival in the fecal-induced peritonitis sepsis model. In both strains, male mice exhibited worse survival compared with their female counterparts. PAD4 deficiency is associated with reduced IL-10, increased neutrophil infiltration, and exacerbated lung injury. Antibiotics eliminated survival differences between strains and sexes.

Neutrophils play a critical role in immune response, using mechanisms as degranulation, phagocytosis, and the release of extracellular DNA together with microbicidal proteins, the so-called neutrophil extracellular traps (NETs), to combat pathogens. Multiple mechanisms might be involved in neutrophil's response to stimuli, but the biochemical characterization of each different pathway is still lacking. In this study, we used superoxide measurements, live-imaging microscopy and high-resolution proteomics to provide a thorough biochemical characterization of the neutrophil's response following activation by two well-known stimuli, namely phorbol-12-myristate-13-acetate (PMA), and ionomycin, a calcium ionophore. Our results demonstrated that although both stimuli induce extracellular DNA release, signals and mediators released by activated cells before this final event were distinct. Thus, PMA-treated neutrophils induce superoxide production, and degranulation of proteins from all granules, especially those derived from secretory vesicles and tertiary granules. On the other hand, ionomycin-treated neutrophils do not stimulate superoxide generation, but induce extensive protein citrullination (also known as arginine deimination), particularly modifying proteins related to actin cytoskeleton organization, nucleus stability, and the NADPH oxidase complex. Interestingly, many of the citrullinated proteins detected in this work were also found to act as autoantigens in autoimmune diseases such as rheumatoid arthritis. These striking differences show neutrophils' response to PMA and ionomycin are two distinct biochemical processes that point towards neutrophils diversification and plasticity responding to the environment. It also provides implications for understanding neutrophil-driven microbial response and potential roles in autoimmune diseases.

Macrophages are crucial to innate immunity, eliminating pathogens and damaged tissues through phagocytosis and modulating immune responses. Recently, macrophage extracellular traps (METs) have been identified as chromatin-based structures composed of DNA and various immune-related proteins. While METs play a defensive role in trapping and neutralizing pathogens, they are also implicated in disease pathology, contributing to chronic inflammation, tissue damage, and immune dysregulation. The precise mechanisms regulating MET formation are still under investigation, but emerging evidence indicates the involvement of various regulatory factors. Dysregulated MET activity has been associated with various diseases, including autoimmune disorders, cancer, and neurological conditions. A deeper understanding of MET mechanisms and their pathological impact may offer novel therapeutic strategies. Given the limited number of reviews and articles on METs, this review provides valuable insights into MET formation, regulatory pathways, and their role in disease progression.

Macrophages can respond to infection or cellular stress by forming inflammasomes or by releasing extracellular traps (ETs) of DNA through METosis. While ETs have been extensively studied in neutrophils, there are fewer studies on METosis. We show that extracellular calcium and LPS enable human monocyte-derived macrophages (hMDM) to release extracellular DNA decorated with myeloperoxidase (MPO) and citrullinated histone, alongside ASC aggregation and IL-1ß maturation, indicating NLRP3 inflammasome activation. Compared with m-CSF differentiated macrophages only gm-CSF differentiated macrophages expressed macrophage elastase (MMP12) and METs released by the latter had significantly more bactericidal activity toward E. coli. Mechanistically, phospholipase C and peptidyl arginine deiminase-2 inhibition attenuate MET release. Interestingly, NLRP3 inflammasome blockade by MCC950 had a significant effect on MET release. Finally, MET release was completely blocked by plasma membrane stabilization by punicalagin. Altogether, we demonstrate that extracellular calcium-activated hMDM extrude DNA, containing citrullinated histones, MPO, MMP12, and ASC specks and released METs kill bacteria independent of hMDM phagocytotic activity. We believe that calcium-activated hMDM adds a physiologically relevant condition to calcium ionophore induced cell death that may be important in autoimmunity.

To summarize the current knowledge of the neutrophil extracellular traps (NETs) and its critical role in various oral diseases.

We reviewed the recent research on NETs through PubMed and Web of Science. An analysis of recent research results was summarized from three aspects: NETs induction and formation, functions of NETs, and NETs in oral diseases.

The relationship between neutrophils and NETs is critical to the body's defense against microbial invasion. NETs can effectively combat pathogens with an anti-inflammatory effect and meanwhile it can contribute to inflammation. Moreover, it can synergize with other immune cells to respond to stimuli, such as pathogens, host-derived mediators, and drugs. It was revealed that NETs play different roles to influence various oral diseases like periodontitis, endodontic infection, oral mucosal diseases, maxillofacial tumors, and many other oral diseases.

The balance between the protective and potentially harmful effects of NETs is a key factor in determining the outcome of infections and inflammatory responses. The role of NETs in oral diseases needs to be further studied to enable better understanding of its role in the different oral diseases.

This study investigated the immune role of serous cells from the bivalve Ruditapes philippinarum. Histochemical and immunohistochemical assays revealed that the serous cells contained large cytoplasmic vacuoles rich in heparinoid molecules. Heparin and histamine were detected within vacuoles, with distinct spatial distributions, and histoenzymatic assays for serine proteases revealed both tryptase and chymase activity. These findings, together with membrane immunolabelling for c-kit, suggest similarities with vertebrate mast cells. After in vivo bacterial inoculation, serous cells first accumulated at the injury site within 12 h, and 15 h after in vitro treatment, a significant increase in the percentage of serous cells was observed in bacteria-treated samples, supporting targeted responses of proliferation and differentiation following bacterial challenge. Serous cells also underwent marked degranulation following bacterial stimulation, and aggregates of granulocytes, hyalinocytes and serous cells appeared within 1 h of treatment. Extracellular trap formation (ETosis), which is rich in degranulated serous cells and trapped dying bacteria, was observed after 15 h. Serous cells showed nuclear envelope loss and chromatin fragmentation. The extracellular nets were primarily composed of fragmented chromatin and amyloid fibrils forming a scaffold of woven fibres, to which the adhesion of heparin, histamine, and serine proteases occurred after their release into the extracellular environment. To our knowledge, this is the first study that highlights the important role of serous cells in the immune response of bivalves and provides new perspectives for future investigations into the modulation of the inflammatory process.

Since their discovery in 2004, neutrophil extracellular traps (NETs) have been at the center of multidisciplinary attention. Although a key tool in neutrophil-mediated immunity, these filamentous, enzyme-enriched DNA-histone complexes can be detrimental to tissues and have been identified as an underlying factor in a range of pathological conditions. Building on more than 20 years of research into NETs, this review places thrombosis, the pathological formation of blood clots, in the spotlight. From this point of view, we discuss the structure and formation of NETs, as well as the interaction of their components with the hemostatic system, dissecting the pathways through which NETs exert their marked effect on formation and the dissolution of thrombi. We pay distinct attention to the latest developments in the research of a key player in NET formation, peptidyl-arginine-deiminase (PAD) enzymes: their types, sources, and potential cross-play with the hemostatic machinery. Besides these molecular details, we elaborate on the link between pathological thrombosis, NETs, and widespread conditions that represent a debilitating public health burden worldwide, such as sepsis and neoplasms. Finally, future implications on the treatment of thrombosis-related conditions will be discussed.

Sepsis is a common critical condition that can lead to multiple organ injury. Sepsis-induced acute respiratory distress syndrome (ARDS) is frequently an important cause of poor prognosis and is associated with high mortality rates, despite existing therapeutic interventions. Neutrophil infiltration and extracellular traps (NET) are implicated in acute lung injury (ALI) and ARDS following sepsis. As circulating neutrophils infiltrate infected tissues, they come into direct contact with vascular endothelial cells (ECs). Although the ability of NETs to induce endothelial damage is well established, the specific role of direct EC-neutrophil interactions in NET formation and lung injury during sepsis is not fully understood.

In this study, NET formation was assessed when neutrophils were co-culture with ECs or separated from them and stimulated with phorbol 12-myristate 13-acetate (PMA), lipopolysaccharide (LPS), lipoteichoic acid (LTA), or septic plasma.

We found that adhesion of neutrophils on ECs is critical in NET formation in response to LPS, LTA, or septic plasma in vitro. Blocking the macrophage-1 antigen (Mac-1) impeded NET formation, while inhibiting P-selectin glycoprotein ligand-1 (PSGL-1) or leukocyte function-associated antigen-1 (LFA-1) did not. This adhesion-dependent NET formation was reliant on the influx of extracellular calcium and peptidylarginine deiminase 4 (PAD4)-mediated citrullination of histone H3. However, Mac-1 blockade did not alter calcium influx. In a murine model of LPS-induced sepsis, Mac-1 blockade reduced NET release, lowered inflammatory cytokine levels, mitigated endothelial damage, and attenuated lung injury.

Our findings offer insights into the critical role of EC-neutrophil direct contact in NET formation during sepsis and propose Mac-1 as a potential therapeutic target.

Giardia duodenalis is a globally distributed zoonotic parasite primarily transmitted through the fecal-oral route, infecting various vertebrates, and the infection of which is prevalent in goats. Immune cells play a crucial role in pathogens invasion, and neutrophil extracellular traps (NETs) released by neutrophils serve as a non-specific defense mechanism against pathogens including parasites. In this study, we investigated the characteristics, components, and molecular mechanisms of goat NETs upon stimulation with G. duodenalis trophozoites. This study demonstrates that G. duodenalis trigger dose-dependent NETs formation in goat neutrophils, composed of DNA, citrullinated histone H3 (CitH3), and neutrophil elastase (NE). Reactive oxygen species (ROS) accumulation synchronizes with NETosis during G. duodenalis infection. Inhibitor experiments confirmed that G. duodenalis-induced NETs and ROS production depend on TLR2/4 signaling and require NADPH oxidase (NOX), ERK1/2, and p38 MAPK activation. This work identifies TLR2/4, NOX, ERK1/2, and p38 MAPK pathways as key regulators of NETs/ROS coordination during G. duodenalis infection, providing the first evidence of G. duodenalis-triggered NETs in goats. The findings highlight NETs as critical components of anti-G. duodenalis immunity and suggest potential for NETs-targeted therapeutic strategies.

Atherosclerosis is a chronic inflammatory condition that is typified by the deposition of lipids and the subsequent inflammation of medium and large arteries. Neutrophil extracellular traps (NETs) are fibrous meshworks of DNA, histones, and granzymes expelled by activated neutrophils in response to a variety of pathogenic conditions. In addition to their role in pathogen eradication, NETs have been demonstrated to play a pivotal role in the development of atherosclerosis. This article presents a review of the bidirectional interactions in which atherosclerosis-related risk factors stimulate the formation of NETs, which in turn support disease progression. This article emphasizes the involvement of NETs in the various stages of atherogenesis and development, influencing multiple factors such as the vascular endothelium, platelets, the inflammatory milieu, and lipid metabolism. The findings of this study offer new insights and avenues for further investigation into the processes underlying the formation and regulation of the vascular inflammatory microenvironment in atherosclerosis. Finally, potential targeted therapeutic strategies for NETs are discussed to facilitate their progression to clinical practice (Graphical Abstract).

Neutrophil extracellular traps (NETs), intricate reticular structures released by activated neutrophils, play a pivotal regulatory role in the pathogenesis of malignant tumors. Lung cancer is one of the most prevalent malignancies globally, with persistently high incidence and mortality rates. Recent studies have revealed that NETs dynamically modulate the tumor microenvironment through unique pathological mechanisms, exhibiting complex immunoregulatory characteristics during the progression of lung cancer, and this discovery has increasingly become a focal point in tumor immunology research. This paper provides a comprehensive review of the latest advancements in NETs research related to lung cancer, offering an in-depth analysis of their impact on lung cancer progression, their potential diagnostic value, and the current state of research on targeting NETs for lung cancer prevention and treatment. The aim is to propose novel strategies to enhance therapeutic outcomes and improve the prognosis for lung cancer patients.
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Histones are nuclear proteins that play a key role in chromatin assembly and regulation of gene expression by their ability to bind to DNA. Histones can also be released from cells owing to necrosis or extracellular trap release from neutrophils (NETs) and other immune cells. The presence of histones in the extracellular environment has implications for many pathologies, including diabetes mellitus, owing to the cytotoxic nature of these proteins, and their ability to promote inflammation. NETs also contain myeloperoxidase, a defensive enzyme that produces hypochlorous acid (HOCl), to kill pathogens, but also readily damages host proteins. In this study, we examined the reactivity of histones with and without HOCl modification, with a pancreatic β-cell model. Exposure of β-cells to histones resulted in a loss of metabolic activity and cell death by a combination of apoptosis and necrosis. This toxicity was increased on pretreatment of the β-cells with tumour necrosis factor α and interleukin 1β. Histones upregulated endoplasmic reticulum (ER) stress genes, including the pro-apoptotic transcription factor CHOP. There was also evidence for alterations to the cellular redox environment and upregulation of antioxidant gene expression. However, downregulation of insulin-associated genes and insulin was observed. Interestingly, modification of the histones with HOCl reduced their toxicity and altered the patterns of gene expression observed, and a further decrease in the expression of insulin-associated genes was observed. These findings could be relevant to the development of Type 2 diabetes, where low-grade inflammation favours NET release, resulting in elevated histones in the circulation.

Tumor-associated neutrophils (TANs) play crucial roles in tumor progression, immune response modulation, and the therapeutic outcomes. Despite significant advancements in TAN research, a comprehensive bibliometric analysis that objectively presents the current status and trends in this field is lacking. This study aims to fill this gap by visually analyzing global trends in TANs research using bibliometric and knowledge mapping techniques.

We retrieved articles and reviews related to TANs from the Web of Science core collection database, spanning the period from 2012 to2024. The data was analyzed using bibliometric tools such as Excel 365, CiteSpace, VOSviewer, and Bibliometrix (R-Tool of R-Studio) to identify key trends, influential countries and institutions, collaborative networks. and citation patterns.

A total of 6l5 publications were included in the bibliometric analysis, showing a significant upward trend in TANs research over the last two decades. The United States and China emerged as the leading contributors with the highest number of publications and citations. The journal with the most publications in this field is Frontiers in Immunology, Prominent authors such as Fridlender ZG was identified as the key contributor, with his works frequently cited. The analysis highlighted major research themes. including the role of TANs in tumor microenvironment modulation, their dual functions in tumor promotion and suppression, and the exploration of TANs-targeted therapies, Emerging research hotspots include studies on TANs plasticity and their interactions with other immune cells.

This study is the first to employ bibliometric methods to visualize trends and frontiers in TANs research. The findings provide valuable insights into the evolution of the field, highlighting critical areas for future investigation and potential collaborative opportunities. This comprehensive analysis serves as a crucial resource for researchers and practitioners aiming to advance TAN research and its application in cancer therapy.

During sterile inflammation, tissue damage induces excessive activation and infiltration of neutrophils into tissues, where they critically contribute to organ dysfunction. Tight regulation of neutrophil migration and their effector functions is crucial to prevent overshooting immune responses. Neutrophils utilize more glutamine, the most abundant free α-amino acid in the human blood, than other leukocytes. However, under inflammatory conditions, the body's requirements exceed its ability to produce sufficient amounts of glutamine. This study investigates the impact of glutamine on neutrophil recruitment and their key effector functions. Glutamine treatment effectively reduced neutrophil activation by modulating β2-integrin activity and chemotaxis in vitro. In a murine in vivo model of sterile inflammation induced by renal ischemia-reperfusion injury, glutamine administration significantly attenuated neutrophil recruitment into injured kidneys. Transcriptomic analysis revealed, glutamine induces transcriptomic reprograming in murine neutrophils, thus improving mitochondrial functionality and glutathione metabolism. Further, glutamine influenced key neutrophil effector functions, leading to decreased production of reactive oxygen species and formation of neutrophil extracellular traps. Mechanistically, we used a transglutaminase 2 inhibitor to identify transglutaminase 2 as a downstream mediator of glutamine effects on neutrophils. In conclusion, our findings suggest that glutamine diminishes activation and recruitment of neutrophils and thus identify glutamine as a potent means to curb overshooting neutrophil responses during sterile inflammation.

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by the occurrence of thrombotic or obstetrical events in patients with persistent antiphospholipid antibodies (aPL). Thrombotic events, the primary pathological hallmarks and clinical manifestations, are among the leading causes of mortality in APS. Our understanding of the mechanism underlying APS-related thrombosis has significantly advanced in recent years. The presence of aPL, particularly anti-β2-glycoprotein I (anti-β2GPI) antibodies, is a major driver of thrombosis. The proposed pathophysiological mechanisms of aPL-mediated pro-thrombotic events can be broadly categorized into three types: disruption of anticoagulant reactions and fibrinolysis, interference with coagulation cascade cells, and complement activation. A triggering 'second hit' is typically necessary to initiate thrombosis. The development of animal models of APS has further refined our understanding of the role of aPL in thrombosis. In this review, we focused on the role of β2GPI-dependent aPL in thrombosis of thrombotic APS.