Search Results (759)

The link between neutrophil extracellular traps (NETs) and hepatocyte ferroptosis in liver ischemia–reperfusion injury (LIRI) is unclear. Adipose-derived mesenchymal stem cell exosomes (ADSCs-Exo) hold therapeutic potential for LIRI. This study employed miniature pigs to investigate the NETs’ role and ADSCs-Exo’s protection in LIRI. In vitro, established hepatocyte oxygen-glucose deprivation/reoxygenation (OGD/R) model and Transwell co-culture system with polymorphonuclear neutrophils (PMNs). In vivo, a laparoscopic minimally invasive LIRI model was constructed in miniature pigs, followed by ADSCs-Exo intervention. Results demonstrated that NETs exacerbate OGD/R-induced hepatocyte ferroptosis via myeloperoxidase. ADSCs-Exo inhibited NET formation via the NADPH/MAPK pathway, thereby mitigating ferroptosis, and ultimately improved liver histopathology and function. This study is the first to demonstrate in a large animal model that ADSCs-Exo alleviate LIRI by inhibiting NET formation via the NADPH/MAPK pathway, consequently attenuating hepatocyte ferroptosis. These findings provide novel insights into LIRI pathogenesis, support the translational potential of ADSCs-Exo as a cell-free therapeutic strategy, and highlight the value of the miniature pig model in liver research. Full article

Neutrophils are central executors of innate immunity. Yet murine models are inherently limited by low baseline neutrophil counts. NSG mice are among the most widely used models for xenotransplantation and studies on the humanized immune system. Although G-CSF is known to stimulate granulopoiesis, the dose- and schedule-dependent effects of intraperitoneal G-CSF administration have not been systematically characterized in this immunodeficient background. Male NSG mice received intraperitoneal G-CSF according to one of five regimens (n = 6 per group): group 0 served as the saline control, group 1 received a single dose of 250 µg/kg G-CSF administered at 48 h; group 2 received a single dose of 250 µg/kg G-CSF administered at 24 h; group 3 received three doses of 250 µg/kg administered G-CSF at 0 h, 24 h, and 48 h and group 4 received a single dose of 500 µg/kg G-CSF administered at 48 h. All animals were sacrificed at 72 h. Circulating neutrophils were then quantified by flow cytometry, bone marrow neutrophil proportions by panoptic smear analysis, and splenic neutrophil abundance by Ly6G immunofluorescence. Systemic neutrophil activation was assessed via plasma neutrophil elastase (NE) activity and cell-free DNA (cfDNA) levels. Repeated G-CSF administration (Group 3) induced an approximately 13-fold expansion of circulating neutrophils, approaching the human physiological range, with significant increases also observed in bone marrow and a trend towards increased neutrophil abundance in the spleen. A single dose of 250 µg/kg administered at 24 h (group 2), produced significant neutrophil expansion in peripheral blood and bone marrow but not in the spleen, while all other single-dose regimens failed to induce significant expansion in any compartment. NE activity and cfDNA concentrations and a selected cytokine panel remained unaltered across all groups. This systematic comparison establishes repeated intraperitoneal G-CSF administration as a reproducible strategy to achieve human-like neutrophil levels in NSG mice without inducing systemic inflammation. This provides a validated protocol with direct utility in translational models of neutrophil-dependent diseases. Full article

The interplay of the carbohydrate polysialic acid (polySia) with its interaction partners plays an important role in several physiological systems of vertebrates. The objective of this study was to develop a flexible analytical system for visualizing interaction partners of polySia using blotting and fluorescence cell staining strategies. We selected a streptavidin–biotin system due to the wide range of commercially available tools for this analytical application. After chemical polysialylation of streptavidin, the resulting bioconjugate was used to target polySia interaction partners after they had been separated via native agarose gel electrophoresis and transferred to a PVDF membrane. Furthermore, neutrophil extracellular traps (NETs) were employed to visualize polySia interaction partners within a cellular system using fluorescence-labeled biotin. The obtained results demonstrate that polysialylated streptavidin is a flexible bioconjugate that can be applied to investigate polySia interaction partners using various blotting and fluorescence imaging techniques. Full article

Post-acute sequelae of SARS-CoV-2 infection (PASC) extend well beyond the acute respiratory phase, with accumulating virological evidence that SARS-CoV-2 RNA, viral antigens, and proteolytic fragments may persist in cardiovascular and other extrapulmonary tissues, although the extent to which such detection represents replication-competent reservoirs versus residual viral material with uncertain pathological relevance remains under active investigation. Sudden cardiac death (SCD) and fatal pulmonary thromboembolism (PTE) have emerged as forensically and epidemiologically significant outcomes in individuals with prior infection, situated at the intersection of microbiology, public health, and forensic medicine. To synthesize current evidence on the virological mechanisms by which SARS-CoV-2 may contribute to post-acute sudden cardiac death (SCD) and pulmonary thromboembolism (PTE), the population-level epidemiology of these outcomes, and their implications for public health surveillance and forensic practice, we conducted a narrative review of PubMed (MEDLINE), Scopus, and Web of Science Core Collection. The search covered publications from January 2020 to December 2025 and focused on SARS-CoV-2 cellular tropism and tissue persistence, immune-mediated and thromboinflammatory mechanisms, excess cardiovascular and thromboembolic mortality, and autopsy-based pathological findings. After de-duplication of 1837 initially identified records (412 duplicates removed) and screening of 1425 unique records, 78 studies were retained for final synthesis based on virological, epidemiological, and forensic relevance. SARS-CoV-2 enters cardiomyocytes, pericytes, and vascular endothelial cells through ACE2-dependent mechanisms, with cathepsin L compensating for the limited cardiac expression of TMPRSS2. Viral RNA and antigen have been detected in cardiovascular and other extrapulmonary tissues months after symptom onset in selected autopsy series, although persistent detection of viral components does not necessarily indicate ongoing productive infection or direct tissue injury. Endothelial dysfunction, neutrophil extracellular trap (NET) formation, complement activation, and persistent thromboinflammation have been proposed as plausible mechanistic substrates for arrhythmogenic remodelling and thromboembolic events, although definitive causal pathways remain incompletely understood. Population-based studies document persistent excess cardiovascular mortality across multiple jurisdictions, with hazard ratios for pulmonary embolism remaining elevated months after acute infection, particularly in unvaccinated individuals. Autopsy series identify mixed pathological patterns including focal lymphocytic infiltrates, microvascular thrombosis, contraction-band necrosis, and cardiomyocyte vacuolation, although fulminant lymphocytic myocarditis fulfilling Dallas criteria remains uncommon. A microbiology-informed framework uniting tissue-based viral detection, standardized cardiac and pulmonary sampling protocols, and prospective post-mortem registries is needed to better characterize the potential contribution of SARS-CoV-2 to post-acute cardiovascular mortality and to support cause-of-death certification, public health surveillance, and medicolegal practice in the post-pandemic era. Many of the proposed mechanisms remain under active investigation, and definitive causal relationships between viral persistence and adverse cardiovascular outcomes have not yet been conclusively established. Full article

Sepsis is a systemic disorder in which infection-induced inflammation progressively disrupts vascular homeostasis and drives organ dysfunction. This review reframes septic pathophysiology as a sequential and self-amplifying process centered on endothelial failure. Early activation of innate immune pathways by pathogen- and damage-associated molecular patterns promotes cytokine release, oxidative stress, and enzymatic degradation of the endothelial glycocalyx. Loss of this protective surface layer exposes endothelial cells to unbuffered inflammatory and mechanical injury, impairing mechanotransduction, increasing leukocyte and platelet adhesion, and destabilizing vascular barrier function. Subsequent disruption of intercellular junctions promotes capillary leakage, tissue edema, and impaired oxygen diffusion, while mitochondrial dysfunction and redox imbalance reduce endothelial repair capacity. In parallel, complement activation, neutrophil extracellular trap formation, platelet–leukocyte interactions, and loss of anticoagulant signaling shift the microvasculature toward a prothrombotic and proinflammatory state. These interconnected mechanisms culminate in microvascular incoherence, characterized by heterogeneous capillary flow, regional hypoxia, impaired oxygen extraction, and progressive organ failure despite apparent restoration of systemic hemodynamics. Within this framework, biomarkers such as syndecan-1, soluble thrombomodulin, angiopoietin-2, von Willebrand factor, and plasminogen activator inhibitor-1 are best interpreted as mechanistic readouts of glycocalyx shedding, endothelial injury, permeability imbalance, and thromboinflammatory activation. Understanding sepsis as an evolving endothelial pathophysiological process provides a coherent framework for integrating inflammation, vascular leakage, hypoxia, coagulation, and organ dysfunction while identifying mechanistic biomarkers that reflect distinct stages of microvascular collapse. Full article

Hepatic ischemia–reperfusion injury (HIRI) is an unavoidable clinical challenge in liver transplantation, major hepatectomy and trauma resuscitation, with no approved specific therapeutics to date. As core innate immune effector cells, neutrophils are the central driver of the sterile inflammatory cascade in HIRI. Centered on the Mac-1-Syk core regulatory axis, this review systematically elaborates the neutrophil recruitment cascade and intracellular signaling network in HIRI, focuses on the sequential formation pathways of neutrophil extracellular traps (NETs) and their multi-dimensional injury mechanisms, and dissects the inflammation–thrombosis amplification crosstalk between neutrophils and multiple hepatic non-parenchymal cells. Furthermore, this review clarifies research controversies of core therapeutic targets, analyzes key translational bottlenecks, and proposes a NETs-centered sequential multi-target combination strategy, providing a solid theoretical basis and clear translational direction for the precise targeted therapy of HIRI. Full article

Sarcoptic mange is a skin disease caused by Sarcoptes scabiei infestations, characterized by dermatitis, pruritus, and exudative responses in both humans and animals. Biologically, the life cycle of S. scabiei is confined to the host’s skin (stratum corneum), where mite-derived molecules trigger the influx of innate immune cells, including polymorphonuclear neutrophils (PMN), which play a central role in skin inflammatory responses. The antimicrobial activity of PMNs is regulated by Ca²⁺ fluxes and includes the generation of reactive oxygen species (ROS), degranulation, and the release of neutrophil extracellular traps (NETs). NETs are web-like structures composed of chromatin and enzymes that can trap and eventually kill pathogens; however, their involvement in S. scabiei infestations in bovines remains unclear. Here, we investigated interactions between bovine PMN and S. scabiei mites, as well as PMN responses to S. scabiei antigen (ScAg). Functional parameters included NET release, Ca²⁺ fluxes, ROS production and phagocytic activity, determined by fluorescence microscopy, Fluo-4 staining, luminol-derived luminescence and flow cytometry, respectively. Current data show that ScAg, but not whole mites, induces a weak NET release in exposed bovine PMN. Additionally, ScAg drives rapid and sustained Ca²⁺ fluxes and ROS production over time, without altering the phagocytic capacity of PMN. Full article

In recent years, liquid biopsy has emerged as a promising non-invasive strategy for the identification of tumor-derived biomarkers. Among circulating analytes, cell-free DNA (cfDNA), including both nuclear and mitochondrial fractions, has been extensively investigated in a variety of biological fluids for its potential applications in cancer diagnosis, disease monitoring, and prognostic stratification. Owing to its higher copy number per cell compared with nuclear DNA, mitochondrial DNA (mtDNA) is typically present at higher concentrations in body fluids and is therefore potentially detectable. Circulating cell-free mitochondrial DNA (cfmtDNA) is closely associated with pro-inflammatory signaling pathways and cellular damage responses, including apoptosis, necrosis, and neutrophil extracellular trap formation (NETosis). This review provides a comprehensive overview of the reported alterations of cfmtDNA in the most prevalent gynecological malignancies, namely ovarian and endometrial cancers, which are characterized by a chronic inflammatory microenvironment. We further critically assess the current evidence supporting cfmtDNA as a potential non-invasive biomarker in these malignancies, highlighting current limitations and future research directions. Full article

Cardiovascular disease is traditionally interpreted through macrocirculatory parameters such as cardiac output, vascular resistance, and epicardial coronary anatomy. However, clinical outcomes frequently diverge from predictions based solely on these indices, particularly in syndromes such as heart failure with preserved ejection fraction (HFpEF), cardiogenic shock, and sepsis-associated myocardial dysfunction. Increasing evidence suggests that the integrity of the microvascular–immune interface plays a central role in determining tissue perfusion and cardiovascular resilience. This review proposes a staged framework of cardiovascular decompensation centered on progressive failure of this interface. In Stage 1, chronic cardiometabolic and inflammatory stress produces a primed but compensated microvascular state characterized by endothelial activation, glycocalyx vulnerability, pericyte remodeling, platelet sensitization, and reduced lymphatic reserve. Perfusion is preserved at rest, but vasodilatory reserve and microvascular stability are reduced, narrowing the effective perfusion window under physiologic stress. In Stage 2, acute insults such as infection, ischemia, or neurohumoral activation precipitate threshold instability within the microcirculation. Perfusion becomes governed by the arterial pressure–critical closing pressure (Pa − Pcrit) relationship rather than traditional arterial–venous gradients. As this window narrows, segmental capillary derecruitment and heterogeneous flow emerge, producing loss of hemodynamic coherence in which systemic blood pressure and cardiac output may appear preserved despite impaired tissue perfusion. In Stage 3, inflammatory amplification and immunothrombotic processes consolidate microvascular dysfunction. Pericyte contraction, endothelial injury, cytokine escalation, and neutrophil extracellular trap formation promote platelet–fibrin deposition and capillary obstruction, transforming reversible conductance failure into structural microvascular impairment. This framework provides a unifying physiologic lens for diverse cardiovascular syndromes, including Type 2 myocardial infarction, HFpEF decompensation, and cardiogenic shock. It also suggests that therapeutic efficacy may depend less on macrocirculatory normalization alone and more on preserving microvascular integrity before immunothrombotic consolidation occurs. Although this model remains hypothesis-generating, it highlights the microvascular–immune interface as a central determinant of cardiovascular stability and a potential target for future precision hemodynamic and immunomodulatory strategies. Full article

Cardiovascular diseases (CVDs) are a significant health burden worldwide. One of the key pathological processes underlying CVD is thrombosis–the formation of a blood clot (thrombus) within the blood vessel. Thrombus composition typically includes fibrin, platelets, red blood cells, leukocytes, and neutrophil extracellular traps (NETs). Polyphenols, a diverse group of naturally occurring compounds abundant in plant-based foods, have shown potential cardiovascular protective properties. This review discusses and summarizes the effects of polyphenols on the endothelium, platelet function and activity, and blood coagulation, and how this may potentially contribute to attenuated thrombus formation. The available evidence discussed in this review suggests that polyphenols may confer cardiovascular benefits not only through antioxidant and anti-inflammatory actions, but also by directly modulating thrombosis-related mechanisms. Nevertheless, in vivo studies remain limited, and the lack of standardized procedures contributes to discrepancies among reported results. Moreover, differences in compound structure, absorption and bioavailability should be considered when interpreting findings and their potential application as part of preventative strategies. The evidence presented in this review suggests that polyphenols may offer benefits towards lowering thrombosis risk and reducing recurrence among patients with thrombosis, although additional studies are required to further explore their mechanistic effects. Full article

Background: Acute lung injury (ALI) is a major contributor to mortality in neonatal sepsis, yet the mechanisms underlying early lung damage remain incompletely understood. Although extracellular traps (ETs) have been implicated in inflammatory injury, the cellular origin and regulatory pathways of ET formation in neonatal sepsis remain unclear. This study aimed to determine the source of ETs and to investigate the role of hypoxia-inducible factor-1α (HIF-1α) in regulating macrophage extracellular traps (METs) formation and lung injury. Methods: Neonatal sepsis was induced in mice by intraperitoneal injection of cecal slurry. METs formation was assessed by immunofluorescence staining, Western blotting, and extracellular DNA quantification. Selective depletion of macrophages or neutrophils was performed to determine the cellular source of ETs. In vitro experiments were conducted using macrophages stimulated with lipopolysaccharide or phorbol 12-myristate 13-acetate. RNA sequencing analysis and pharmacological inhibition were used to examine the roles of HIF-1α, glycolysis, and enolase 2 (ENO2) in METs formation, lung injury, and survival outcomes. Results: We identify macrophages as a predominant source of ETs in the lung and demonstrate that METs contribute to lung injury in neonatal sepsis. Depletion of macrophages or pharmacological inhibition of METs formation markedly attenuated lung injury and improved survival in neonatal sepsis mice. Mechanistically, we suggest that HIF-1α promotes METs formation by driving glycolysis in macrophages. Furthermore, this process appears to involve the upregulation of key glycolytic enzymes, including ENO2, potentially facilitating METs release. In turn, METs are implicated in enhancing macrophage inflammatory activation, which could exacerbate lung injury. Importantly, pharmacological targeting of HIF-1α pathways reduces METs formation, attenuates lung inflammation, and improves survival outcomes. Conclusions: These findings suggest a role for HIF-1α in regulating METs formation and support that targeting this pathway could represent a potential therapeutic strategy for neonatal sepsis-associated acute lung injury. Full article

Neutrophil extracellular traps (NETs) contribute to innate immunity in sepsis, but their diagnostic value in neonates is unclear. We evaluated whether circulating NET-associated biomarkers discriminate septic from non-infected neonates. In this prospective observational study 96 neonates (≥34 weeks gestational age) with clinical suspicion of infection were enrolled (36 sepsis, 60 controls). Serum cell-free DNA (cfDNA), myeloperoxidase–DNA complexes (MPO-DNA), neutrophil elastase–DNA complexes (NE-DNA), and citrullinated histone H3 (H3cit) were measured alongside CRP and IL-6 at days 1, 3, and 5. Diagnostic performance was assessed by receiver operating characteristic (ROC) analysis with bootstrap confidence intervals. CRP (AUC 0.75, 95% CI 0.66–0.85) and IL-6 (AUC 0.73, 95% CI 0.61–0.83) showed the best diagnostic performance. cfDNA demonstrated moderate discrimination (AUC 0.72, 95% CI 0.60–0.84) but was only transiently elevated at day 1. MPO-DNA (AUC 0.47), NE-DNA (AUC 0.44), and H3cit (AUC 0.47) performed no better than chance. Within the sepsis group, MPO-DNA and NE-DNA at day 3 strongly correlated with the immature-to-total neutrophil ratio (ρ = 0.76 and 0.72), suggesting these markers reflect neutrophil degranulation rather than NET formation. NET-associated biomarkers do not improve diagnostic accuracy for neonatal sepsis beyond CRP and IL-6. These findings support the concept that neonatal innate immune responses differ fundamentally from adult patterns. Full article

Venous thromboembolism (VTE) is a clinically significant complication in patients with breast cancer (BC) and may disrupt treatment continuity while contributing to adverse outcomes. Although BC is generally regarded as a relatively low-risk malignancy for VTE compared with several other cancer types, its high incidence and the increasing use of multimodal therapies have resulted in a growing clinical burden of breast cancer-associated VTE. This review summarizes the epidemiological features, risk factors, biological mechanisms, and advances in the prevention and management of breast cancer-associated VTE. Current evidence indicates that patients with cancer have an approximately 4- to 7-fold higher risk of VTE than the general population, with the risk in BC being particularly pronounced during the first 3–6 months after diagnosis. Older age, metabolic comorbidities, advanced disease, and exposure to multiple anticancer therapies have all been associated with an increased risk of VTE. Mechanistically, tissue factor, procoagulant extracellular vesicles, neutrophil extracellular traps, and inflammatory signaling pathways may contribute to breast cancer-associated VTE by promoting coagulation activation and endothelial dysfunction, while also linking thrombosis to immune evasion and Smetastatic progression. Improved identification of high-risk patients, optimization of dynamic risk assessment, and the implementation of individualized prophylactic and anticoagulant strategies may help improve outcomes in patients with BC. Full article

Difficult-to-treat systemic lupus erythematosus (D2T-SLE) remains a major unmet challenge in contemporary lupus care, yet it continues to be defined predominantly by clinical non-response rather than underlying biology. Current biomarkers largely quantify inflammatory burden, immune complex activity, or organ damage and do not reliably capture persistent activation of pathogenic pathways under therapy. Emerging multi-omics, single-cell, and longitudinal studies suggest that, in a subset of patients, apparent treatment failure may reflect incomplete attenuation of dominant immune circuits rather than uniformly elevated inflammation. We propose molecular refractoriness in systemic lupus erythematosus (SLE) as sustained, pathway-level immune activity despite apparently adequate, mechanism-directed therapy. We outline the major immune programs implicated in this process—including interferon-enriched, B-cell/plasmablast-associated, neutrophil extracellular trap (NET)-related, cytotoxic T-cell, and cytokine-associated states—and discuss their relevance for biomarker development and precision trial design. Importantly, we emphasize that interferon gene signatures (IGS) should be interpreted as context-dependent and non-specific markers of interferon responsiveness, reflecting combined activity of type I, II, and III interferons, and functioning primarily as predictive rather than mechanistic biomarkers. We further highlight critical limitations of a purely endotype-based model, including the need to distinguish true molecular refractoriness from damage-dominant and pseudo-refractory states, as well as the emerging role of immune-reset strategies such as cluster of differentiation 19 (CD19)-directed chimeric antigen receptor T-cell (CAR-T) therapy, which may overcome refractoriness independently of specific pathway dominance. These observations suggest that difficult-to-treat SLE encompasses biologically heterogeneous states that may not be fully captured by pathway-resolved stratification alone. Reframing D2T-SLE as a biologically heterogeneous state of incomplete immune attenuation may help bridge the gap between clinical treatment failure and mechanism-informed precision medicine in systemic lupus erythematosus. Full article

Chronic obstructive pulmonary disease (COPD) and pulmonary tuberculosis (TB) are major causes of morbidity and mortality worldwide. Epidemiologic studies indicate an increased risk of tuberculosis in patients with COPD; however, the shared molecular mechanisms underlying the pathogenesis of these two diseases remain insufficiently understood. Objective. Based on a comparative bioinformatics analysis of peripheral blood transcriptomic profiles in patients with COPD and pulmonary tuberculosis, to identify common systemic immune mechanisms associated with the pathogenesis of both diseases. Gene expression data from the NCBI GEO public database were analyzed. GSE34608 included blood samples from 8 patients with tuberculosis and 18 healthy controls. The GSE76705 dataset contained peripheral-blood samples from 364 former smokers (225 with COPD and 139 without). Functional enrichment (GO Biological Process and KEGG) was run in ShinyGO; protein–protein interaction networks were built in STRING, and the top-15 hub genes were ranked by the MCC algorithm in CytoHubba. In tuberculosis, 892 up-regulated and 1448 down-regulated genes were identified; in COPD, 520 up-regulated and 1329 down-regulated. Common upregulated DEGs are involved in toll-like receptor signaling pathways, NOD-like receptor signaling pathways, neutrophil extracellular trap (NET) formation, phagosomes, and tuberculosis. Downregulated genes in each of the diseases were associated with processes of transcriptional regulation and RNA metabolism, which may indicate common transcriptional abnormalities in COPD and tuberculosis. COPD and tuberculosis share common pathogenic mechanisms, including the activation of innate immune signaling pathways (TLR, NOD), neutrophilic inflammation, the formation of neutrophil extracellular traps (NETosis), and phagocyte dysfunction. The identified common genes and signaling pathways may serve as a basis for the development of biomarkers and therapeutic targets; however, they require further validation in independent cohorts. Full article