Search

Abstract Background Ferroptosis is a type of regulated necrosis and glutathione peroxidase 4 (GPX4) has been recognized as a key enzyme that protects against ferroptosis. However, the significance of GPX4 in polymorphonuclear neutrophils (PMNs) of systemic lupus erythematosus (SLE) has not been explored. So we examined GPX4 mRNA in PMNs and analyzed its association with serological and clinical features. Methods A single center research from the Department of Rheumatology and Immunology of the Third Affiliated Hospital, Southern Medical University was conducted between December 2020 and September 2022. Real‐time transcription‐polymerase chain reaction analysis was used to determine the expression of GPX4 mRNA in PMNs from patients suffering from different rheumatoid immune diseases and healthy controls. The associations of GPX4 RNA levels in SLE patients with serological and clinical indicators were assessed by Spearman's correlation analysis. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic value of GXP4 mRNA for SLE. Results GPX4 mRNA levels were lower in SLE patients than those in healthy individuals, patients with rheumatoid arthritis and axial spondyloarthritis. GPX4 mRNA levels were negatively correlated with the number of positive autoantibodies (r = −0.3072, p = 0.0300), anti‐dsDNA antibody (r = −0.3654, p = 0.0336), antinucleosome antibody (r = −0.4052, p = 0.0263), erythrocyte sedimentation rate (r = −0.3773, p = 0.0069), C‐reactive protein (r = −0.4037, p = 0.0036), and SLE disease activity index (r = −0.3072, p = 0.0300). GPX4 mRNA levels were downregulated in patients with alopecia compared with patients without alopecia (p

The regenerative capability of the liver is remarkable, but further research is required to understand the role that neutrophils play in this process. In the present study, we reanalyzed single‐cell RNA sequencing data from a mouse partial hepatectomy (PH) model to track the transcriptional changes in hepatocytes and non‐parenchymal cells. Notably, we unraveled the regenerative capacity of hepatocytes at diverse temporal points after PH, unveiling the contributions of three distinct zones in the liver regeneration process. In addition, we observed that the depletion of neutrophils reduced the survival and liver volume after PH, confirming the important role of neutrophils in liver regeneration. CellChat analysis revealed an intricate crosstalk between neutrophils and macrophages promoting liver regeneration and, using weighted gene correlation network analysis, we identified the most significant genetic module associated with liver regeneration. Our study found that hepatocytes in the periportal zone of the liver are more active than in other zones, suggesting that the crosstalk between neutrophils and macrophages might be a potential target for liver regeneration treatment.

Abstract Despite the widespread adoption of emergency coronary reperfusion therapy, reperfusion‐induced myocardial injury remains a challenging issue in clinical practice. Following myocardial reperfusion, S100A8/A9 molecules are considered pivotal in initiating and regulating tissue inflammatory damage. Effectively reducing the S100A8/A9 level in ischemic myocardial tissue holds significant therapeutic value in salvaging damaged myocardium. In this study, HA (hemagglutinin)‐ and RAGE (receptor for advanced glycation end products)‐ comodified macrophage membrane‐coated siRNA nanoparticles (MMM/RNA NPs) with siRNA targeting S100A9 (S100A9‐siRNA) are successfully prepared. This nanocarrier system is able to target effectively the injured myocardium in an inflammatory environment while evading digestive damage by lysosomes. In vivo, migration of MMM/RNA NPs to myocardial injury lesions is confirmed in a myocardial ischemia‐reperfusion injury (MIRI) mouse model. Intravenous injection of MMM/RNA NPs significantly reduced S100A9 levels in serum and myocardial tissues, further decreasing myocardial infarction area and improving cardiac function. Targeted reduction of S100A8/A9 by genetically modified macrophage membrane‐coated nanoparticles may represent a new therapeutic intervention for MIRI.

Abstract The overactivated immune cells in the infectious lesion may lead to irreversible organ damages under severe infections. However, clinically used immunosuppressive anti‐inflammatory drugs will usually disturb immune homeostasis and conversely increase the risk of infections. Regulating the balance between anti‐inflammation and anti‐infection is thus critical in treating certain infectious diseases. Herein, considering that hydrogen peroxide (H2O2), myeloperoxidase (MPO), and neutrophils are upregulated in the inflammatory microenvironment and closely related to the severity of appendectomy patients, an inflammatory‐microenvironment‐responsive nanomedicine is designed by using poly(lactic‐co‐glycolic) acid (PLGA) nanoparticles to load chlorine E6 (Ce6), a photosensitizer, and luminal (Lum), a chemiluminescent agent. The obtained Lum/Ce6@PLGA nanoparticles, being non‐toxic within normal physiological environment, can generate cytotoxic single oxygen via bioluminescence resonance energy transfer (BRET) in the inflammatory microenvironment with upregulated H2O2 and MPO, simultaneously killing pathogens and excessive inflammatory immune cells in the lesion, without disturbing immune homeostasis. As evidenced in various clinically relevant bacterial infection models and virus‐induced pneumonia, Lum/Ce6@PLGA nanoparticles appeared to be rather effective in controlling both infection and inflammation, resulting in significantly improved animal survival. Therefore, the BRET‐based nanoparticles by simultaneously controlling infections and inflammation may be promising nano‐therapeutics for treatment of severe infectious diseases.

Abstract The development of acute respiratory distress syndrome (ARDS) in sepsis is associated with substantial morbidity and mortality. However, the molecular pathogenesis underlying sepsis‐induced ARDS remains elusive. Neutrophil heterogeneity and dysfunction contribute to uncontrolled inflammation in patients with ARDS. A specific subset of neutrophils undergoing reverse transendothelial migration (rTEM), which is characterized by an activated phenotype, is implicated in the systemic dissemination of inflammation. Using single‐cell RNA sequencing (scRNA‐seq), it identified functionally activated neutrophils exhibiting the rTEM phenotype in the lung of a sepsis mouse model using cecal ligation and puncture. The prevalence of neutrophils with the rTEM phenotype is elevated in the blood of patients with sepsis‐associated ARDS and is positively correlated with disease severity. Mechanically, scRNA‐seq and proteomic analys revealed that inflamed endothelial cell (EC) released extracellular vesicles (EVs) enriched in karyopherin subunit beta‐1 (KPNB1), promoting abluminal‐to‐luminal neutrophil rTEM. Additionally, EC‐derived EVs are elevated and positively correlated with the proportion of rTEM neutrophils in clinical sepsis. Collectively, EC‐derived EV is identified as a critical regulator of neutrophil rTEM, providing insights into the contribution of rTEM neutrophils to sepsis‐associated lung injury.

Abstract Background Severe asthma (SA) encompasses several clinical phenotypes with a heterogeneous airway microbiome. We determined the phenotypes associated with a low α‐diversity microbiome. Methods Metagenomic sequencing was performed on sputum samples from SA participants. A threshold of 2 standard deviations below the mean of α‐diversity of mild‐moderate asthma and healthy control subjects was used to define those with an abnormal abundance threshold as relative dominant species (RDS). Findings Fifty‐one out of 97 SA samples were classified as RDSs with Haemophilus influenzae RDS being most common (n = 16), followed by Actinobacillus unclassified (n = 10), Veillonella unclassified (n = 9), Haemophilus aegyptius (n = 9), Streptococcus pseudopneumoniae (n = 7), Propionibacterium acnes (n = 5), Moraxella catarrhalis (n = 5) and Tropheryma whipplei (n = 5). Haemophilus influenzae RDS had the highest duration of disease, more exacerbations in previous year and greatest number on daily oral corticosteroids. Hierarchical clustering of RDSs revealed a C2 cluster (n = 9) of highest relative abundance of exclusively Haemophilus influenzae RDSs with longer duration of disease and higher sputum neutrophil counts associated with enrichment pathways of MAPK, NF‐κB, TNF, mTOR and necroptosis, compared to the only other cluster, C1, which consisted of 7 Haemophilus influenzae RDSs out of 42. Sputum transcriptomics of C2 cluster compared to C1 RDSs revealed higher expression of neutrophil extracellular trap pathway (NETosis), IL6‐transignalling signature and neutrophil activation. Conclusion We describe a Haemophilus influenzae cluster of the highest relative abundance associated with neutrophilic inflammation and NETosis indicating a host response to the bacteria. This phenotype of severe asthma may respond to specific antibiotics.

Abstract Objectives In cystic fibrosis (CF), an imbalanced lipid metabolism is associated with lung inflammation. Little is known about the role that specific lipid mediators (LMs) exert in CF lung inflammation, and whether their levels change during early disease progression. Therefore, we measured airway LM profiles of young CF patients, correlating these with disease‐associated parameters. Methods Levels of omega (ω)‐3/6 PUFAs and their LM derivatives were determined in bronchoalveolar lavage fluid (BALF) of children with CF ages 1–5 using a targeted high‐performance liquid chromatography–tandem mass spectrometry approach. Hierarchical clustering analysis was performed on relative LM levels. Individual relative LM levels were correlated with neutrophilic inflammation (BALF %Neu) and structural lung damage (PRAGMA‐CF %Disease). Significant correlations were included in a backward multivariate linear regression model to identify the LMs that are best related to disease progression. Results A total of 65 BALF samples were analysed for ω‐3/6 lipid content. LM profiles clustered into an arachidonic acid (AA)‐enriched and a linoleic acid (LA)‐enriched sample cluster. AA derivatives like 17‐OH‐DH‐HETE, 5‐HETE, 5,15‐diHETE, 15‐HETE, 15‐KETE, LTB4 and 6‐trans‐LTB4 positively correlated with BALF %Neu and/or PRAGMA %Dis. Contrastingly, 9‐HoTrE and the LA derivatives 9‐HoDE, 9(10)‐EpOME, 9(10)‐DiHOME, 13‐HoDE, 13‐oxoODE and 12(13)‐EpOME negatively correlated with BALF %Neu and/or PRAGMA %Dis. 6‐trans‐LTB4 was the strongest predictor for BALF %Neu. 5‐HETE and 15‐KETE contributed most to PRAGMA %Dis prediction. Conclusions Our data provide more insight into the lung lipidome of infants with CF, and show that a shift from LA derivatives to AA derivatives in BALF associates with early CF lung disease progression.

Background Venous thromboembolism is associated with endothelial cell activation that contributes to the inflammation‐dependent activation of the coagulation system. Cellular damage is associated with the release of different species of extracellular RNA (eRNA) involved in inflammation and coagulation. TLR3 (toll‐like receptor 3), which recognizes (viral) single‐stranded or double‐stranded RNAs and self‐RNA fragments, might be the receptor of these species of eRNA during venous thromboembolism. Here, we investigate how the TLR3/eRNA axis contributes to venous thromboembolism. Methods and Results Thrombus formation and size in wild‐type and TLR3 deficient (−/−) mice were monitored by ultrasonography after venous thrombosis induction using the ferric chloride and stasis models. Mice were treated with RNase I, with polyinosinic‐polycytidylic acid, a TLR3 agonist, or with RNA extracted from murine endothelial cells. Gene expression and signaling pathway activation were analyzed in HEK293T cells overexpressing TLR3 in response to eRNA or in human umbilical vein endothelial cells transfected with a small interference RNA against TLR3. Plasma clot formation on treated human umbilical vein endothelial cells was analyzed. Thrombosis exacerbated eRNA release in vivo and increased eRNA content within the thrombus. RNase I treatment reduced thrombus size compared with vehicle‐treated mice (P

Abstract Background Severe acute pancreatitis (SAP) is a potentially lethal inflammatory pancreatitis condition that is usually linked to multiple organ failure. When it comes to SAP, the lung is the main organ that is frequently involved. Many SAP patients experience respiratory failure following an acute lung injury (ALI). Clinicians provide insufficient care for compounded ALI since the underlying pathophysiology is unknown. The mortality rate of SAP patients is severely impacted by it. Objective The study aims to provide insight into immune cells, specifically their roles and modifications during SAP and ALI, through a comprehensive literature review. The emphasis is on immune cells as a therapeutic approach for treating SAP and ALI. Findings Immune cells play an important role in the complicated pathophysiology ofSAP and ALI by maintaining the right balance of pro‐ and anti‐inflammatory responses. Immunomodulatory drugs now in the market have low thepeutic efficacy because they selectively target one immune cell while ignoring immune cell interactions. Accurate management of dysregulated immune responses is necessary. A critical initial step is precisely characterizing the activity of the immune cells during SAP and ALI. Conclusion Given the increasing incidence of SAP, immunotherapy is emerging as a potential treatment option for these patients. Interactions among immune cells improve our understanding of the intricacy of concurrent ALI in SAP patients. Acquiring expertise in these domains will stimulate the development of innovative immunomodulation therapies that will improve the outlook for patients with SAP and ALI.

Abstract Cancer is a complex and dynamic disease, initiated by a multitude of intrinsic mutations and progressed with the assistance of the tissue microenvironment, encompassed by stromal cells including immune cell infiltration. The novel finding that tumors can evade anti‐cancer immune functions shaped the field of immunotherapy, which has been a revolutionary approach for the treatment of cancers. However, the development of predominantly T cell‐targeted immunotherapy approaches, such as immune checkpoint inhibition, also brought about an accumulation of evidence demonstrating other immune cell drivers of tumor progression, such as innate immune cells and notably, neutrophils. In the past decade, neutrophils have emerged to be primary mediators of multiple cancer types and even in recent years, are gaining attention for their potential use in the next generation of immunotherapies. Here, we review current immunotherapy strategies and thoroughly discuss the roles of neutrophils in cancer and novel neutrophil‐targeted methods for treating cancer.

Abstract Background Cancer is a thorny problem which cannot be conquered by mankind at present and recent researchers have put their focus on tumor microenviroment. Neutrophils, the prominent leukocytes in peripheral blood that accumulate in tumours, serves as frontline cells in response to tumour progression owing to the rapid development of micro biotechnology. Hence, targeted therapy with these neutrophils has made targeting treatment a promising field in cancer therapy. Main body We broadly summarise some studies on the phenotypes and functions of tumour‐associated neutrophils as well as the unique web‐like products of neutrophils that play a role in cancer progression—neutrophil extracellular traps—and the interactions between neutrophils and the tumour microenvironment. Moreover, several targeted neutrophils therapeutic studies have made some progress and provided potential strategies for the treatment of cancer. Conclusion This review aims to offer a holistic perspective on therapeutic interventions targeting neutrophils to further inspire more researches on cancer therapies.

Abstract For tumor treatment, the ultimate goal in tumor therapy is to eliminate the primary tumor, manage potential metastases, and trigger an antitumor immune response, resulting in the complete clearance of all malignant cells. Tumor microenvironment (TME) refers to the local biological environment of solid tumors and has increasingly become an attractive target for cancer therapy. Neutrophils within TME of gastric cancer (GC) spontaneously undergo ferroptosis, and this process releases oxidized lipids that limit T cell activity. Enhanced photodynamic therapy (PDT) mediated by di‐iodinated IR780 (Icy7) significantly increases the production of reactive oxygen species (ROS). Meanwhile, neutrophil ferroptosis can be triggered by increased ROS generation in the TME. In this study, a liposome encapsulating both ferroptosis inhibitor Liproxstatin‐1 and modified photosensitizer Icy7, denoted LLI, significantly inhibits tumor growth of GC. LLI internalizes into MFC cells to generate ROS causing immunogenic cell death (ICD). Simultaneously, liposome‐deliver Liproxstatin‐1 effectively inhibits the ferroptosis of tumor neutrophils. LLI‐based immunogenic PDT and neutrophil‐targeting immunotherapy synergistically boost the anti‐PD‐1 treatment to elicit potent TME and systemic antitumor immune response with abscopal effects. In conclusion, LLI holds great potential for GC immunotherapy.

Abstract Aims Ischaemia–reperfusion injury (IRI) following myocardial infarction remains a challenging topic in acute cardiac care and consecutively arising heart failure represents a severe long‐term consequence. The extent of neutrophil infiltration and neutrophil‐mediated cellular damage are thought to be aggravating factors enhancing primary tissue injury. Toll‐like receptor 9 was found to be involved in neutrophil activation as well as chemotaxis and may represent a target in modulating IRI, aspects we aimed to illuminate by pharmacological inhibition of the receptor. Methods and results Forty‐nine male adult Sprague–Dawley rats were used. IRI was induced by occlusion of the left coronary artery and subsequent snare removal after 30 min. Oligonucleotide (ODN) 2088, a toll‐like receptor 9 (TLR9) antagonist, control‐ODN, or DNase, were administered at the time of reperfusion and over 24 h via a mini‐osmotic pump. The hearts were harvested 24 h or 4 weeks after left coronary artery occlusion and immunohistochemical staining was performed. Echocardiography was done after 1 and 4 weeks to determine ventricular function. Inhibition of TLR9 by ODN 2088 led to left ventricular wall thinning (P = 0.003) in association with drastically enhanced neutrophil infiltration (P = 0.005) and increased markers of tissue damage. Additionally, an up‐regulation of the chemotactic receptor CXCR2 (P = 0.046) was found after TLR9 inhibition. No such effects were observed in control‐ODN or DNase‐treated animals. We did not observe changes in monocyte content or subset distribution, hinting towards neutrophils as the primary mediators of the exerted tissue injury. Conclusions Our data indicate a TLR9‐dependent, negative regulation of neutrophil infiltration. Blockage of TLR9 appears to prevent the down‐regulation of CXCR2, followed by an uncontrolled migration of neutrophils towards the area of infarction and the exertion of disproportional tissue injury resulting in potential aneurysm formation. In comparison with previous studies conducted in TLR−/− mice, we deliberately chose a transient pharmacological inhibition of TLR9 to highlight effects occurring in the first 24 h following IRI.

Abstract Occupational exposure to extreme high temperatures and the increasing global temperatures necessitates a deeper understanding of the impact of heat exposure on human health. However, the molecular mechanisms underlying the response of monocytes and neutrophils to heat exposure in occupational population remain to be fully elucidated. This study used longitudinal transcriptome to assess the impact of acute heat exposure (50°C for 30 min) in 10 subjects from a mine rescue team before acute heat exposure (baseline) and at 5 min, 30 min, 1 h, and 24 h after acute heat exposure (recovery). The time‐series analysis revealed a coordinated molecular choreography of changes involving inflammation, coagulation, extracellular matrix, and energy metabolism. Importantly, the study characterized the inflammatory signature associated with heat exposure in monocytes and neutrophils, as evidenced by the rapid activation of the inflammation‐related transcriptome following heat exposure. Additionally, we pinpointed potential regulators, such as NR4A1, FOSL1, EGR3, and ATF3. In summary, the study suggested that the initial response to heat stress in monocytes and neutrophils from mine rescue team member was primarily characterized by a pro‐inflammatory stress response, which could potentially lead to the development of inflammation and ultimately result in a systemic inflammatory response in heatstroke.

Abstract Pivotal roles of extracellular vesicles (EVs) in the pathogenesis of central nervous system (CNS) disorders including acute brain injury are increasingly acknowledged. Through the analysis of EVs packaged miRNAs in plasma samples from patients with intracerebral hemorrhage (ICH), it is discovered that the level of EVs packaged miR‐143‐3p (EVs‐miR‐143‐3p) correlates closely with perihematomal edema and neurological outcomes. Further study reveals that, upon ICH, EVs‐miR‐143‐3p is robustly secreted by astrocytes and can shuttle into brain microvascular endothelial cells (BMECs). Heightened levels of miR‐143‐3p in BMECs induce the up‐regulated expression of cell adhesion molecules (CAMs) that bind to circulating neutrophils and facilitate their transendothelial cell migration (TEM) into brain. Mechanism‐wise, miR‐143‐3p directly targets ATP6V1A, resulting in impaired lysosomal hydrolysis ability and reduced autophagic degradation of CAMs. Importantly, a VCAM‐1–targeting EVs system to selectively deliver miR‐143‐3p inhibitor to pathological BMECs is created, which shows satisfactory therapeutic effects in both ICH and traumatic brain injury (TBI) mouse models. In conclusion, the study highlights the causal role of EVs‐miR‐143‐3p in BMECs’ dysfunction in acute brain injury and demonstrates a proof of concept that engineered EVs can be devised as a potentially applicable nucleotide drug delivery system for the treatment of CNS disorders.

Abstract The intestinal microbiome has emerged as a potential contributor to the severity of sickle cell disease (SCD). We sought to determine whether SCD mice exhibit intestinal barrier dysfunction, inflammation, and dysbiosis. Using the Townes humanized sickle cell mouse model, we found a 3‐fold increase in intestinal permeability as assessed via FITC‐dextran (4 kDa) assay in SS (SCD) mice compared to AA (wild type) mice (n = 4, p

Abstract Skeletal muscle wasting, whether related to physiological ageing, muscle disuse or to an underlying chronic disease, is a key determinant to quality of life and mortality. However, cellular basis responsible for increased catabolism in myocytes often remains unclear. Although myocytes represent the vast majority of skeletal muscle cellular population, they are surrounded by numerous cells with various functions. Animal models, mostly rodents, can help to decipher the mechanisms behind this highly dynamic process, by allowing access to every muscle as well as time‐course studies. Satellite cells (SCs) play a crucial role in muscle regeneration, within a niche also composed of fibroblasts and vascular and immune cells. Their proliferation and differentiation is altered in several models of muscle wasting such as cancer, chronic kidney disease or chronic obstructive pulmonary disease (COPD). Fibro‐adipogenic progenitor cells are also responsible for functional muscle growth and repair and are associated in disease to muscle fibrosis such as in chronic kidney disease. Other cells have recently proven to have direct myogenic potential, such as pericytes. Outside their role in angiogenesis, endothelial cells and pericytes also participate to healthy muscle homoeostasis by promoting SC pool maintenance (so‐called myogenesis–angiogenesis coupling). Their role in chronic diseases muscle wasting has been less studied. Immune cells are pivotal for muscle repair after injury: Macrophages undergo a transition from the M1 to the M2 state along with the transition between the inflammatory and resolutive phase of muscle repair. T regulatory lymphocytes promote and regulate this transition and are also able to activate SC proliferation and differentiation. Neural cells such as terminal Schwann cells, motor neurons and kranocytes are notably implicated in age‐related sarcopenia. Last, newly identified cells in skeletal muscle, such as telocytes or interstitial tenocytes could play a role in tissular homoeostasis. We also put a special focus on cellular alterations occurring in COPD, a chronic and highly prevalent respiratory disease mainly linked to tobacco smoke exposure, where muscle wasting is strongly associated with increased mortality, and discuss the pros and cons of animal models versus human studies in this context. Finally, we discuss resident cells metabolism and present future promising leads for research, including the use of muscle organoids.

Abstract Neutrophil‐to‐lymphocyte ratio (NLR) has been studied as a prognostic factor for mortality in COVID‐19 patients. Our study aimed to evaluate the association between NLR at COVID‐19 diagnosis and survival during the following 90 days in hospitalized patients with solid cancer. Between May 2020 and June 2021, 120 patients were included in a retrospective cohort study. Univariable analysis showed patients with an NLR > 8.3 were associated with an increased risk of death (HR: 4.34; 95% CI: 1.74–10.84) compared to patients with NLR 8.30 independently correlated with increased mortality. In patients with solid malignancies with COVID‐19, an NLR > 8.3 is associated with an increased risk of death.

Abstract Extracellular vesicles (EVs) are membrane‐bound structures released by cells and tissues into biofluids, involved in cell‐cell communication. In humans, circulating red blood cells (RBCs), represent the most common cell‐type in the body, generating daily large numbers of microvesicles. In vitro, RBC vesiculation can be mimicked by stimulating RBCs with calcium ionophores, such as ionomycin and A23187. The fate of microvesicles released during in vivo aging of RBCs and their interactions with circulating cells is hitherto unknown. Using SEC plus DEG isolation methods, we have found that human RBCs generate microvesicles with two distinct sizes, densities and protein composition, identified by flow cytometry, and MRPS, and further validated by immune TEM. Furthermore, proteomic analysis revealed that RBC‐derived microvesicles (RBC‐MVs) are enriched in proteins with important functions in ion channel regulation, calcium homeostasis and vesicular transport, such as of sorcin, stomatin, annexin A7 and RAB proteins. Cryo‐electron microscopy identified two separate pathways of RBC‐MV‐neutrophil interaction, direct fusion with the plasma membrane and internalization, respectively. Functionally, RBC‐MVs decrease neutrophil ability to phagocytose Escherichia coli but do not affect their survival at 24 h. This work brings new insights regarding the complexity of the RBC‐MVs biogenesis, as well as their possible role in circulation.

Background Intracranial aneurysms (IAs) are more prevalent in women than men, and aneurysmal subarachnoid hemorrhage disproportionately affects postmenopausal women. These sex differences suggest estrogen protects against IA progression that can lead to rupture, but the underlying mechanisms are not fully understood. Although studies have demonstrated estrogen regulates inflammatory processes that contribute to IA pathogenesis, the role of neutrophils remains to be characterized. Using a murine model, we tested our hypothesis that neutrophils contribute to IA pathophysiology in an estrogen‐dependent manner. Methods and Results We compared neutrophil infiltration in C57BL/6 female mice that develop IAs to those with a normal circle of Willis. Next, we investigated the estrogen‐dependent role of neutrophils in IA formation, rupture, and symptom‐free survival using a neutrophil depletion antibody. Finally, we studied the role of neutrophil extracellular trap formation (NETosis) as an underlying mechanism of aneurysm progression. Mice that developed aneurysms had increased neutrophil infiltration compared with those with a normal circle of Willis. In estrogen‐deficient female mice, both neutrophil depletion and NETosis inhibition decreased aneurysm rupture. In estrogen‐deficient female mice treated with estrogen rescue and estrogen‐intact female mice, neither neutrophil depletion nor NETosis inhibition affected IA formation, rupture, or symptom‐free survival. Conclusions Neutrophils contribute to aneurysm rupture in an estrogen‐dependent manner. NETosis appears to be an underlying mechanism for neutrophil‐mediated IA rupture in estrogen deficiency. Targeting NETosis may lead to the development of novel therapeutics to protect against IA rupture in the setting of estrogen deficiency.

Abstract Background Racehorses commonly develop evidence of mild asthma in response to dust exposure. Diets deficient in omega‐3 polyunsaturated fatty acids (Ω‐3) might exacerbate this response. Hypothesis To compare dust exposure, bronchoalveolar lavage fluid (BALF) cytology, and plasma Ω‐3 and specialized pro‐resolving mediators (SPM) concentrations amongst racehorses fed dry hay, steamed hay, and haylage. Animals Forty‐three Thoroughbred racehorses. Methods Prospective clinical trial. Horses were randomly assigned to be fed dry hay, steamed hay, or haylage for 6 weeks. Measures of exposure to dust in the breathing zone were obtained twice. At baseline, week‐3, and week‐6, BALF cytology was examined. Plasma lipid profiles and plasma SPM concentrations were examined at baseline and week 6. Generalized linear mixed models examined the effect of forage upon dust exposure, BALF cytology, Ω‐3, and SPM concentrations. Results Respirable dust was significantly higher for horses fed hay (least‐square mean ± s.e.m. 0.081 ± 0.007 mg/m3) when compared with steamed hay (0.056 ± 0.005 mg/m3, P = .01) or haylage (0.053 ± 0.005 mg/m3, P

Abstract Extracellular trap networks (neutrophil extracellular traps [NETs]) of polymorphonuclear neutrophils are mesh‐like substances that prevent the spread of pathogens. They primarily consist of DNA skeletons, histones, granule components, and cytoplasmic proteins. NETs formation requires a certain environment and there are different pathways for NETs production. However, it is still not clear how severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) promotes NETs. NETs exert antiinflammatory effects through immune response, while they can also lead to certain adverse outcomes, such as the development of immunothrombosis. Coronavirus disease 2019 (COVID‐19) is an inflammatory reaction affecting various organs caused by SARS‐CoV‐2, especially the lungs. NETs production and disease severity are linked with unique neutrophil clusters by single‐cell RNA sequencing. NETs might exert an anti‐inflammatory role in the initial stage of lung tissue inflammation. Nevertheless, numerous studies and cases have shown that they can also result in pulmonary thrombosis. There is mounting evidence that NETs are tightly related with COVID‐19 pulmonary thrombosis, and many studies on the mechanisms are involved. The role and mechanism of NETs in the development of pulmonary thrombosis will be the main topics of this manuscript. Additionally, we address the potential targeting of NETs in COVID‐19 patients.

Abstract Introduction This study endeavored to investigate the role of DOCK8 in modulating the immune function triggered by sepsis. Methods Expression of DOCK8 in the whole blood of sepsis patients and its enrichment pathways were assayed by bioinformatics. Pearson analysis was used to predict the relationship between glycolytic signaling pathway and its relevance to neutrophil function in sepsis. A sepsis mouse model was then built by performing cecal ligation and puncture treatment on male mice. Neutrophils were isolated, and their purity was tested by flow cytometry. Neutrophils were then stimulated by lipopolysaccharide to build a sepsis cell model. Next, quantitative reverse transcription polymerase chain reaction and CCK‐8 were applied to test the expression of DOCK8 and cell viability, western blot to assay the expression of HK‐2, PKM2, and LDHA proteins, ELISA to measure the concentrations of TNF‐α, IL‐1β, and IL‐6, Transwell to detect the chemotaxis of neutrophils and flow cytometry to detect the phagocytic activity of neutrophils. Finally, in different treatment groups, we used Seahorse XF 96 to analyze the extracellular acidification rate (ECAR) of sepsis cells and used enzyme‐linked immunosorbent assay to detect the contents of pyruvic acid, lactic acid, and ATP in sepsis cells. Results DOCK8 was downregulated in sepsis blood and activated neutrophils. Aerobic glycolysis was positively correlated with sepsis. Activated neutrophils promoted the expression of inflammatory factors TNF‐α, IL‐1β, and IL‐6. Low expression of DOCK8 facilitated the proliferation, chemotaxis, and phagocytic activity of sepsis cells and promoted the expression of inflammatory factors. Bioinformatics analysis revealed that DOCK8 was enriched in the glycolytic signaling pathway. Low expression of DOCK8 induced ECAR, promoted the protein expression of HK‐2, PKM2 and LDHA, and favored the increase of pyruvate, lactate, and ATP contents. While 2‐DG treatment could restore these effects. Conclusion DOCK8 may inhibit sepsis‐induced neutrophil immune function by regulating aerobic glycolysis and causing excessive inflammation, which helps to explore potential therapeutic targets.

Abstract Lymph nodes (LNs) are frequently the first sites of metastasis. Currently, the only prognostic LN assessment is determining metastatic status. However, there is evidence suggesting that LN metastasis is facilitated by the formation of a pre‐metastatic niche induced by tumour derived extracellular vehicles (EVs). Therefore, it is important to detect and modify the LN environmental changes. Earlier work has demonstrated that neutrophil extracellular traps (NETs) can sequester and promote distant metastasis. Here, we first confirmed that LN NETs are associated with reduced patient survival. Next, we demonstrated that NETs deposition precedes LN metastasis and NETs inhibition diminishes LN metastases in animal models. Furthermore, we discovered that EVs are essential to the formation of LN NETs. Finally, we showed that lymphatic endothelial cells secrete CXCL8/2 in response to EVs inducing NETs formation and the promotion of LN metastasis. Our findings reveal the role of EV‐induced NETs in LN metastasis and provide potential immunotherapeutic vulnerabilities that may occur early in the metastatic cascade.

Abstract Ischemic stroke is a refractory disease that endangers human health and safety owing to cerebral ischemia. Brain ischemia induces a series of inflammatory reactions. Neutrophils migrate from the circulatory system to the site of cerebral ischemia and accumulate in large numbers at the site of inflammation across the blood–brain barrier. Therefore, hitchhiking on neutrophils to deliver drugs to ischemic brain sites could be an optimal strategy. Since the surface of neutrophils has a formyl peptide receptor (FPR), this work modifies a nanoplatform surface by the peptide cinnamyl‐F‐(D)L‐F‐(D)L‐F (CFLFLF), which can specifically bind to the FPR receptor. After intravenous injection, the fabricated nanoparticles effectively adhered to the surface of neutrophils in peripheral blood mediated by FPR, thereby hitchhiking with neutrophils to achieve higher accumulation at the inflammatory site of cerebral ischemia. In addition, the nanoparticle shell is composed of a polymer with reactive oxygen species (ROS)‐responsive bond breaking and is encased in ligustrazine, a natural product with neuroprotective properties. In conclusion, the strategy of hitching the delivered drugs to neutrophils in this study could improve drug enrichment in the brain, thereby providing a general delivery platform for ischemic stroke or other inflammation‐related diseases.

Abstract Sleep insufficiency is associated with various disorders; the molecular basis is unknown until now. Here, 14 males and 18 females were subjected to short‐term (24 h) sleep deprivation, and donated fasting blood samples prior to (day 1) and following (days 2 and 3) short‐term sleep deprivation. We used multiple omics techniques to examine changes in volunteers’ blood samples that were subjected to integrated, biochemical, transcriptomic, proteomic, and metabolomic analyses. Sleep deprivation caused marked molecular changes (46.4% transcript genes, 59.3% proteins, and 55.6% metabolites) that incompletely reversed by day 3. The immune system in particular neutrophil‐mediated processes associated with plasma superoxidase dismutase‐1 and S100A8 gene expression was markedly affected. Sleep deprivation decreased melatonin levels and increased immune cells, inflammatory factors and c‐reactive protein. By disease enrichment analysis, sleep deprivation induced signaling pathways for schizophrenia and neurodegenerative diseases enriched. In sum, this is the first multiomics approach to show that sleep deprivation causes prominent immune changes in humans, and clearly identified potential immune biomarkers associated with sleep deprivation. This study indicated that the blood profile following sleep disruption, such as may occur among shift workers, may induce immune and central nervous system dysfunction.

Abstract Objectives This systematic review aimed to assess in vitro studies that evaluated neutrophil interactions with different roughness levels in titanium and zirconia implant surfaces. Material and Methods An electronic search for literature was conducted on PubMed, Embase, Scopus, and Web of Science and a total of 14 studies were included. Neutrophil responses were assessed based on adhesion, cell number, surface coverage, cell structure, cytokine secretion, reactive oxygen species (ROS) production, neutrophil activation, receptor expression, and neutrophil extracellular traps (NETs) release. The method of assessing the risk of bias was done using the toxicological data reliability assessment tool (TOXRTOOL). Results Ten studies have identified a significant increase in neutrophil functions, such as surface coverage, cell adhesion, ROS production, and NETs released when interacting with rough titanium surfaces. Moreover, neutrophil interaction with rough–hydrophilic surfaces seems to produce less proinflammatory cytokines and ROS when compared to naive smooth and rough titanium surfaces. Regarding membrane receptor expression, two studies have reported that the FcγIII receptor (CD16) is responsible for initial neutrophil adhesion to hydrophilic titanium surfaces. Only one study compared neutrophil interaction with titanium alloy and zirconia toughened alumina surfaces and reported no significant differences in neutrophil cell count, activation, receptor expression, and death. Conclusions There are not enough studies to conclude neutrophil interactions with titanium and zirconia surfaces. However, different topographic modifications such as roughness and hydrophilicity might influence neutrophil interactions with titanium implant surfaces.

Background Acute ischemic stroke is a neurologic emergency associated with severe disability and death. There is growing evidence that neutrophil extracellular traps (NETs) contribute to the pathogenesis of acute stroke. By mechanical removal of the occluding thrombus from the patient's vasculature, endovascular thrombectomy enables the collection of thrombus material for immunohistologic analysis. The aim of our study was to strengthen the association of NET content in ischemic thrombi with clinical outcome and guide future therapeutics. Methods We performed an immunohistologic analysis of thrombi from 101 patients with acute ischemic stroke, focusing on the association between NET content and clinical and interventional indicators. Results NETs were present in every patient with acute ischemic stroke. Their abundance in thrombi was associated with interventional markers of thrombus stability. NET‐rich thrombi were associated with unsuccessful recanalization (modified Thrombolysis in Cerebral Infarction

Background Immune cells play a vital role in the pathology of ischemic stroke. Neutrophils and polymorphonuclear myeloid‐derived suppressor cells share a similar phenotype and have attracted increasing attention in immune regulation research, yet their dynamics in ischemic stroke remain elusive. Methods and Results Mice were randomly divided into 2 groups and intraperitoneally treated with anti‐Ly6G (lymphocyte antigen 6 complex locus G) monoclonal antibody or saline. Distal middle cerebral artery occlusion and transient middle cerebral artery occlusion were applied to induce experimental stroke, and mice mortality was recorded until 28 days after stroke. Green fluorescent nissl staining was used to measure infarct volume. Cylinder and foot fault tests were used to evaluate neurological deficits. Immunofluorescence staining was conducted to confirm Ly6G neutralization and detect activated neutrophils and CD11b+Ly6G+ cells. Fluorescence‐activated cell sorting was performed to evaluate polymorphonuclear myeloid‐derived suppressor cell accumulation in brains and spleens after stroke. Anti‐Ly6G antibody successfully depleted Ly6G expression in mice cortex but did not alter cortical physiological vasculature. Prophylactic anti‐Ly6G antibody treatment ameliorated ischemic stroke outcomes in the subacute phase. Moreover, using immunofluorescence staining, we found that anti‐Ly6G antibody suppressed activated neutrophil infiltration into parenchyma and decreased neutrophil extracellular trap formation in penumbra after stroke. Additionally, prophylactic anti‐Ly6G antibody treatment reduced polymorphonuclear myeloid‐derived suppressor cell accumulation in the ischemic hemisphere. Conclusions Our study suggested a protective effect of prophylactic anti‐Ly6G antibody administration against ischemic stroke by reducing activated neutrophil infiltration and neutrophil extracellular trap formation in parenchyma and suppressing polymorphonuclear myeloid‐derived suppressor cell accumulation in the brain. This study may provide a novel therapeutic approach for ischemic stroke.

Abstract Neutrophils are essential effector cells for mediating rapid host defense and their insufficiency arising from therapy‐induced side‐effects, termed neutropenia, can lead to immunodeficiency‐associated complications. In autologous hematopoietic stem cell transplantation (HSCT), neutropenia is a complication that limits therapeutic efficacy. Here, we report the development and in vivo evaluation of an injectable, biodegradable hyaluronic acid (HA)‐based scaffold, termed HA cryogel, with myeloid responsive degradation behavior. In mouse models of immune deficiency, we show that the infiltration of functional myeloid‐lineage cells, specifically neutrophils, is essential to mediate HA cryogel degradation. Post‐HSCT neutropenia in recipient mice delayed degradation of HA cryogels by up to 3 weeks. We harnessed the neutrophil‐responsive degradation to sustain the release of granulocyte colony stimulating factor (G‐CSF) from HA cryogels. Sustained release of G‐CSF from HA cryogels enhanced post‐HSCT neutrophil recovery, comparable to pegylated G‐CSF, which, in turn, accelerated cryogel degradation. HA cryogels are a potential approach for enhancing neutrophils and concurrently assessing immune recovery in neutropenic hosts.

Abstract Several immune cell‐expressed miRNAs (miRs) are associated with altered prognostic outcome in cancer patients, suggesting that they may be potential targets for development of cancer therapies. Here, translucent zebrafish (Danio rerio) is utilized to demonstrate that genetic knockout or knockdown of one such miR, microRNA‐223 (miR223), globally or specifically in leukocytes, does indeed lead to reduced cancer progression. As a first step toward potential translation to a clinical therapy, a novel strategy is described for reprogramming neutrophils and macrophages utilizing miniature artificial protocells (PCs) to deliver anti‐miRs against the anti‐inflammatory miR223. Using genetic and live imaging approaches, it is shown that phagocytic uptake of anti‐miR223‐loaded PCs by leukocytes in zebrafish (and by human macrophages in vitro) effectively prolongs their pro‐inflammatory state by blocking the suppression of pro‐inflammatory cytokines, which, in turn, drives altered immune cell‐cancer cell interactions and ultimately leads to a reduced cancer burden by driving reduced proliferation and increased cell death of tumor cells. This PC cargo delivery strategy for reprogramming leukocytes toward beneficial phenotypes has implications also for treating other systemic or local immune‐mediated pathologies.

Abstract Introduction Neutrophils are crucial to antimicrobial defense, but excessive neutrophilic inflammation elicits immune pathology. Currently, no effective treatment exists to curb neutrophil activation. However, neutrophils express a variety of inhibitory receptors which may represent potential therapeutic targets to limit neutrophilic inflammation. Indeed, we previously showed that the inhibitory collagen receptor leukocyte‐associated immunoglobulin‐like receptor 1 (LAIR‐1) regulates neutrophilic airway inflammation and inhibits neutrophil extracellular trap formation. The inhibitory receptor Allergin‐1 is expressed by myeloid cells and B cells. Allergin‐1 suppresses mast cell and basophil activation, but a potential regulatory role on neutrophils remains unexplored. We aimed to demonstrate the regulation of neutrophils by Allergin‐1. Methods We examine Allergin‐1 isoform expression on human neutrophils during homeostatic (healthy donors) and chronic inflammatory (systemic lupus erythematosus patients) conditions in comparison to other circulating leukocytes by flow cytometry. To reveal a potential role for Allergin‐1 in regulating neutrophilic inflammation, we experimentally infect wild‐type (WT) and Allergin‐1‐deficient mice with a respiratory syncytial virus (RSV) and monitor disease severity and examine cellular airway infiltrate. Flow cytometry was used to confirm Allergin‐1 expression by airway‐infiltrated neutrophils in RSV infection‐induced bronchiolitis patients. Results Only the short 1 (S1) isoform, but not the long (L) or S2 isoform could be detected on blood leukocytes, with the exception of nonclassical monocytes, which exclusively express the S2 isoform. Allergin‐1 expression levels did not vary significantly between healthy individuals and patients with the systemic inflammatory disease on any interrogated cell type. Airway‐infiltrated neutrophils of pediatric RSV bronchiolitis patients were found to express Allergin‐1S1. However, Allergin‐1‐deficient mice experimentally infected with RSV did not show exacerbated disease or increased neutrophil airway infiltration compared to WT littermates. Conclusion Allergin‐1 isoform expression is unaffected by chronic inflammatory conditions. In stark contrast to fellow inhibitory receptor LAIR‐1, Allergin‐1 does not regulate neutrophilic inflammation in a mouse model of RSV bronchiolitis.

Background: Neutrophil percentage-to-albumin ratio (NPAR) was significantly correlated with diabetes-related complications. There are little data about NPAR and mortality risk in individuals with diabetes., Methods: This study included 3858 diabetes patients from the National Health and Nutrition Examination Survey (NHANES) conducted from 1988 to 2018. Using a restricted cubic spline (RCS), the relationship between the NPAR and mortality risk was shown. Multivariable Cox regression models were used to evaluate the relationship between the NPAR and diabetes-cause and all-cause death. An examination of the time-dependent receiver operating characteristic curve (ROC) was used to assess how well the NPAR predicted survival outcomes., Results: Among 3858 diabetes individuals, a total of 1198 (31.1%) died over a mean follow-up of 7.86 years; of these, 326 (8.4%) had diabetes-related deaths and 872 (22.6%) had deaths from other causes. The RCS regression analysis showed a positive linear association between the NPAR and all-cause and diabetes-cause mortality. High NPAR group had a significantly higher risk of all-cause and diabetes-cause mortality in univariate and multivariate analysis. Compared with low NPAR group, high NPAR group had a low survival rate of diabetes cases in all-cause death and diabetes-cause mortality with area under the curve of the 3-, 5-, and 10-year ROC curve being 0.725, 0.739, and 0.734 for all-cause mortality and 0.754, 0.752, and 0.745 for diabetes-cause mortality, respectively., Conclusion: In summary, we examined 3858 diabetes patients from NHANES database (1998-2018) and suggested NPAR as a biomarker for all-cause and diabetes-cause mortality prediction., (© 2024 The Author(s). Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Objective: To investigate the systemic immune-inflammation index (SII) and neutrophil-to-lymphocyte ratio (NLR) in predicting a successful methotrexate response in tubal ectopic pregnancy (TEP)., Methods: Women treated for TEP at a tertiary hospital between 2017 and 2021 were retrospectively reviewed. A total of 502 (100%) eligible patients who received methotrexate were included and divided into two groups based on whether or not they were successfully treated with methotrexate alone. Inflammatory parameters derived from the patients' hemograms at hospital admission were compared., Results: In total, 434 (86.4%) patients were successfully treated with methotrexate alone (Group 1), while 68 (13.6%) patients underwent surgery after methotrexate failure (Group 2). Median neutrophil count, NLR, platelet-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, SII, largest ectopic mass diameter, and β-human chorionic gonadotropin (β-hCG) were significantly lower, whereas median lymphocyte and platelet counts were significantly higher in Group 1. According to the receiver operating characteristic analysis performed for the discriminatory power of NLR, β-hCG, and SII for methotrexate response, the area under the curve values were 0.742, 0.730, and 0.699, respectively., Conclusion: Low NLR and SII are associated with methotrexate success and could be used to refine decision making regarding β-hCG for predicting successful response to methotrexate in patients with TEP., (© 2024 International Federation of Gynecology and Obstetrics.)

Background: Mucosal healing (MH) is an established treatment goal in inflammatory bowel disease (IBD). However, various definitions of MH exist. We aimed to identify how MH is defined in randomized controlled trials (RCTs) in ulcerative colitis (UC) and Crohn's disease (CD)., Methods: We searched MEDLINE, EMBASE, and the Cochrane library from inception to December 2023 for phase 2 and 3 RCTs of advanced therapies in IBD., Results: One hundred forty-four studies were included, 72 in UC and 72 in CD, published between 1997 and 2023. In UC, 64% (46/72) RCTs reported MH as an endpoint. 12 definitions of MH were found, from endoscopic assessment alone (35/46; 76%) to the more recent combination of histology and endoscopy (10/46; 22%). 96% (44/46) of studies used the Mayo Endoscopic Subscore. In CD, reporting of MH lagged behind UC, with only 12% (9/72) of trials specifically defining MH as an endpoint, 7 as "absence of ulceration," 2 as Simplified Endoscopic Score for CD score ≤2 or 0. Histological assessment was performed in 3 RCTs of CD. Centralized reading of endoscopy was used in 48% (35/72) of RCTs of UC and 22% (16/72) of CD. Only 1 RCT included transmural healing as an endpoint., Conclusions: A standard definition of MH in IBD is lacking. Definitions have evolved particularly in UC, which now includes the addition of histological evaluation. Transmural healing holds promise as a future target in CD. We support a greater standardization of definitions as we expect endpoints to become increasingly stringent and multimodal with computers automating the assessment., (© 2024 The Author(s). United European Gastroenterology Journal published by Wiley Periodicals LLC on behalf of United European Gastroenterology.)

Background: Patients with inflammatory bowel disease (IBD) in clinical and endoscopic remission may still experience disease relapse. Therefore, there is a need to identify outcome predictors. Recently, the role of neutrophils in predicting outcomes in ulcerative colitis (UC) has been highlighted. Furthermore, the impairment of intestinal barrier plays a key role in forecasting disease outcomes in IBD., Objective: This observational study aimed to assess the predictive role of neutrophils according to tissue localization and intestinal barrier protein expression in IBD., Methods: IBD patients in clinical remission who underwent colonoscopy between January 2020 and June 2022 at two tertiary referral centres were enrolled. Patients with Mayo Endoscopic Score ≤1 (UC) and Simple Endoscopic Score ≤6 (Crohn's disease) were included. Histological activity was assessed using validated scores. Experienced pathologists evaluated neutrophil localization in the epithelium and lamina propria and immunohistochemical expression of Claudin-2 and junctional adhesion molecule A (JAM-A)., Results: Of 60 UC and 76 CD patients, 59.7% had histological activity. 25.8% of patients developed an adverse outcome within 12 months. Neutrophils in the epithelium predicted adverse outcomes for UC (hazard ratio [HR] 5.198, p = 0.01) and CD (HR 4.377, p = 0.03) patients in endoscopic remission. Claudin-2 expression correlated with endoscopic and histological activity and predicted outcomes in UC. Similar results were found for JAM-A in CD despite this protein showing less specificity as a barrier predictor of outcome., Conclusion: This study highlights the potential role of epithelial neutrophil localization and Claudin-2 'leaky gut' expression as tools for predicting IBD outcomes and guiding further patient-tailored therapy., (© 2024 The Author(s). United European Gastroenterology Journal published by Wiley Periodicals LLC on behalf of United European Gastroenterology.)

Objective: Olfactory neuroblastoma is a rare sinonasal malignancy with comparatively positive prognosis and survival, but with a range of biological behaviors that can be difficult to prognosticate with current means of risk stratification. Neutrophil-to-lymphocyte ratio (NLR) has been found across a diverse range of malignancies to be associated with poorer outcomes. This paper aims to elucidate the relationship of NLR with olfactory neuroblastoma to assess its prognostic value in this setting., Study Design: Retrospective chart review., Setting: A single tertiary care academic hospital., Methods: The study cohort included all patients treated for initial presentation of olfactory neuroblastoma from 2004 to 2020. NLR was calculated from preoperative labs, and each patient was evaluated for Kadish staging, Hyams grade, intraoperative positive margin, use of adjuvant therapy, posttreatment recurrence, and death. All statistical analysis was conducted using R and relationship between NLR and variables was assessed via binomial logistic regression., Results: Forty-four patients were included, 24 were male. Average age 52.8, average length of follow-up was 9.6 years. Patients were grouped by low (Kadish A/B) and advanced (Kadish C/D) stage, n = 23 and n = 21, respectively, and low (Hyams I/II) and high (Hyams III/IV) risk, n = 15 and n = 11, respectively. Advanced Kadish stage was associated with elevated NLR, odds ratio 5.69 [2.30, 20.7], P = .001. No other variables were associated with elevated NLR including Hyams grade, margin status, recurrence, and mortality., Conclusion: Higher Kadish grade is associated with elevated NLR which may provide novel prognostic value to current risk-stratifying systems., (© 2024 The Author(s). Otolaryngology–Head and Neck Surgery published by Wiley Periodicals LLC on behalf of American Academy of Otolaryngology–Head and Neck Surgery Foundation.)

Background: Severe asthma (SA) encompasses several clinical phenotypes with a heterogeneous airway microbiome. We determined the phenotypes associated with a low α-diversity microbiome., Methods: Metagenomic sequencing was performed on sputum samples from SA participants. A threshold of 2 standard deviations below the mean of α-diversity of mild-moderate asthma and healthy control subjects was used to define those with an abnormal abundance threshold as relative dominant species (RDS)., Findings: Fifty-one out of 97 SA samples were classified as RDSs with Haemophilus influenzae RDS being most common (n = 16), followed by Actinobacillus unclassified (n = 10), Veillonella unclassified (n = 9), Haemophilus aegyptius (n = 9), Streptococcus pseudopneumoniae (n = 7), Propionibacterium acnes (n = 5), Moraxella catarrhalis (n = 5) and Tropheryma whipplei (n = 5). Haemophilus influenzae RDS had the highest duration of disease, more exacerbations in previous year and greatest number on daily oral corticosteroids. Hierarchical clustering of RDSs revealed a C2 cluster (n = 9) of highest relative abundance of exclusively Haemophilus influenzae RDSs with longer duration of disease and higher sputum neutrophil counts associated with enrichment pathways of MAPK, NF-κB, TNF, mTOR and necroptosis, compared to the only other cluster, C1, which consisted of 7 Haemophilus influenzae RDSs out of 42. Sputum transcriptomics of C2 cluster compared to C1 RDSs revealed higher expression of neutrophil extracellular trap pathway (NETosis), IL6-transignalling signature and neutrophil activation., Conclusion: We describe a Haemophilus influenzae cluster of the highest relative abundance associated with neutrophilic inflammation and NETosis indicating a host response to the bacteria. This phenotype of severe asthma may respond to specific antibiotics., (© 2024 The Author(s). Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.)

Abstract Background Re‐designing services and processes to meet growing demands in chemotherapy services is necessary with increasing treatments. There is little evidence guiding the timing and thresholds to be attained of pre‐chemotherapy blood assessments, namely neutrophils. Methods A survey was developed and distributed to health professionals in the United Kingdom (UK) to examine current practice in timing and threshold values of neutrophils and platelets before treatment administration. This was followed by a retrospective cohort study, using data from electronic patient record systems; including patients initiating treatment between January 2013 and December 2018, to determine a safe timeframe for blood assessments; comparing neutrophil, platelet, creatinine and bilirubin levels at different time points. Results The survey captured 25% of hospitals in the UK and variations were apparent in both the timing of assessments and thresholds needed, particularly for neutrophils. 616 (6.5%) of 4007 patients included had neutrophil levels measured twice within 7 days of treatment (with the first level taken beyond 3 days and the second test being within 3 days of treatment‐ the UK standard). Of the patients that attained an acceptable neutrophil level at their first test, five of the 616 (0.8%) became ineligible for administration from the test 2 level. 23% of patients improved their grade and became eligible for treatment. Little difference was observed for platelets. Conclusions We have demonstrated that extending the timeframe for blood tests can be safe, however, this practice may cause unnecessary delays for patients if only an early test is relied on for eligibility.

Abstract Objective Previous studies have shown that increased neutrophils, as a manifestation of oxidative stress, may be involved in the progression of kidney disease. To our knowledge, little is known about the relationship between neutrophils and renal impairment in rheumatoid arthritis (RA). Therefore, we aim to investigate whether neutrophil is associated with renal impairment in RA patients. Methods We retrospectively investigated the renal function of 602 RA patients in the First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine by estimated glomerular filtration rate (eGFR) from September 2018 and September 2019. The exposure variable was neutrophils, and the main outcome was eGFR. General data (gender, age, duration, hypertension, diabetes, hobbies, and medication history), whole blood markers, lipid indexes, and inflammatory indexes were collected as much as possible. We used multivariable logistic regression analysis to evaluate the association between neutrophils and renal impairment in RA participants. Results A total of 89 cases (14.8%) had renal impairment with eGFR 3.53 (OR = 1.757, 95% CI: 1.104–2.799, p = .018), hemoglobin less than 120 g/L (OR = 2.413, 95% CI: 1.418–4.118, p = .001), and UA > 360 μmol/L (OR = 6.052, 95% CI: 3.708–9.878, p

Thromboinflammation has become a topic of key interest in cardiovascular disease and the prevention of diabetes complications because of the interplay between thrombosis and inflammation in diabetes. Specifically, the significant risk of vascular thrombotic disease in diabetes highlights the need for new and better therapeutic targets to help manage and prevent vascular thrombo‐occlusive disease in this condition. Similarly, the prominent role of inflammation in diabetes has sparked interest in anti‐inflammatory agents to better prevent and control vascular disease. Investigations on the effects of anticoagulation and antiplatelet interventions in patients with diabetes and cardiovascular disease show a potential role for these agents in decreasing morbidity and mortality. Neutrophils and platelets are key players in inflammation and wound‐healing response, respectively. The interaction between neutrophils and platelets is thought to be an important driver of thromboinflammation. Therefore, this review describes the mechanisms involved in platelet–neutrophil interactions that contribute to the development or exacerbation of thromboinflammation in the context of diabetes and its associated comorbidities. The effects observed by the antithrombotic/antidiabetic treatments and physical activity/dietary interventions on attenuating thromboinflammation are discussed. These data suggest that mechanisms involved in platelet–neutrophil interaction, platelet activation/aggregation, and the recruitment of neutrophils have a promising potential to become therapeutic targets to decrease thromboinflammation in patients with diabetes.

Abstract Background Inflammation and the immune system significantly impact the development, progression, and treatment response of hepatocellular carcinoma (HCC). This retrospective study investigated the neutrophil‐to‐lymphocyte ratio (NLR) as a prognostic biomarker in Western patients with HCC in the setting of chronic viral hepatitis. Methods Patients diagnosed with HCC from 2005 to 2016 were selected from a tertiary care institution. NLR was calculated within 30 days prior to treatment and dichotomized at the median. Kaplan–Meier overall survival (OS) curves and Cox hazard proportional models were utilized. Tumor and liver reserve parameters were included in multivariable analyses (MVA). Results A total of 581 patients met inclusion criteria (median age 61.0 yr; 78.3% male; 66.3% Caucasian) with median OS = 34.9 mo. 371 patients (63.9%) had viral hepatitis, of which 350 had hepatitis C (94.3%). The low‐NLR group (

Abstract Porphyromonas gingivalis (P. gingivalis) is a gram‐negative bacterium and an important etiologic agent of periodontitis. P. gingivalis releases outer membrane vesicles containing lipopolysaccharides (LPS), which can penetrate periodontal tissues. Once in the periodontal tissues and in contact with immune cells, it may participate in the destructive innate host response associated with the disease. The exact mechanism of P. gingivalis LPS in the disease process is not clear, but it is known to affect a variety of immune responses. Objectives To investigate how LPS from P. gingivalis affect neutrophil extracellular trap (NET) formation, cell death and production of cytokines from human neutrophils and peripheral mononuclear blood mononuclear cells (PBMCs). Materials and methods Isolated neutrophils and PBMCs were cultured with LPS from P. gingivalis or Escherichia coli (E. coli) (control). The NET formation was measured using Sytox green stain. Cell death of neutrophils and PBMCs was analyzed using flow cytometry or Sytox green stain. Cytokine production was measured using enzyme‐linked immunosorbent assay (ELISA) kit or Bio‐Plex assay. Results Exposure to LPS from P. gingivalis and E. coli caused significantly lower cell death in neutrophils. NETs were formed after exposure to the two different LPS. In PBMCs, exposure to P. gingivalis and E. coli LPS caused increased levels of IL‐1β and IL‐6 compared to unstimulated controls. Increased cell death in PBMCs after exposure to LPS from E. coli in comparison to LPS from P. gingivalis and unstimulated controls was also observed. Conclusions LPS from P. gingivalis has the ability to affect both human neutrophils and PBMCs with regard to cytokine production, cell death and production of NETs. LPS from P. gingivalis could be involved in the pathogenesis of periodontitis, and our results may contribute information regarding possible markers for diagnosis and targets for treatment of periodontal disease.

Abstract Background Infection with SARS‐CoV‐2 leads to COVID‐19, the course of which is highly variable and depends on numerous patient‐specific risk factors. Patients with tumor diseases are considered to be more susceptible to severe COVID‐19; however, they also represent a heterogeneous group of individuals with variable risk. Identifying specific risk factors for a severe course of COVID‐19 in patients with cancer is of great importance. Methods Patients diagnosed with solid tumors or hematological malignancies and PCR‐confirmed SARS‐CoV‐2 infection were included into the multicentric ADHOK (Arbeitsgemeinschaft der Hämatologen und Onkologen im Krankenhaus e.V.) coronavirus tumor registry. Detailed information about the patients’ cancer disease, treatment, and laboratory parameters prior to infection, was collected retrospectively. The outcome of the SARS‐CoV‐2 infection was graded according to the WHO. Results A total of 195 patients (68% with solid neoplasms and 32% with hematological malignancies) were included in the registry. Overall, the course of the SARS‐CoV‐2 infection varied greatly, as 69% of all patients were either asymptomatic or encountered a mild to moderate course, while 23% of the cohort died from COVID‐19. In multivariable analysis, preinfection laboratory parameters (determined at least 10 days and a median of 21 days before the first documentation of SARS‐CoV‐2 infection) significantly correlated with severe course of the disease. Out of these, the absolute neutrophil count prior to infection showed the strongest association with COVID‐19‐related death. Conclusion The course of COVID‐19 in patients with tumor diseases is highly variable. Preinfection laboratory parameters may aid to identify patients at risk for severe COVID‐19 at an early stage prior to infection with the virus. German Clinical Trials Register identification: DRKS00023012.

Abstract Inflammation plays a crucial role in triggering regeneration, while inadequate or chronic inflammation hinders the regenerative process, resulting in refractory wounds. Inspired by the ideal regeneration mode in lower vertebrates and the human oral mucosa, realigning dysregulated inflammation to a heightened and acute response provides a promising option for refractory wound therapy. Neutrophils play important roles in inflammation initiation and resolution. Here, a hybrid biomaterial is used to stimulate transiently heightened inflammatory responses by precise tempospatial regulation of neutrophil recruitment and apoptosis. The hybrid biomaterial (Gel@fMLP/SiO2‐FasL) is constructed by loading of formyl‐met‐leu‐phe (fMLP) and FasL‐conjugated silica nanoparticles (SiO2‐FasL) into a pH‐responsive hydrogel matrix. This composition enables burst release of fMLP to rapidly recruit neutrophils for heightened inflammation initiation. After neutrophils act to produce acids, the pH‐responsive hydrogel degrades to expose SiO2‐FasL, which induces activated neutrophils apoptosis via FasL‐Fas signaling triggering timely inflammation resolution. Apoptotic neutrophils are subsequently cleared by macrophages, and this efferocytosis activates key signalings to promote macrophage anti‐inflammatory phenotypic transformation to drive regeneration. Ultimately, Gel@fMLP/SiO2‐FasL successfully promotes tissue regeneration by manipulating inflammation in critical‐sized calvarial bone defects and diabetic cutaneous wound models. This work provides a new strategy for refractory wound therapy via inducing transiently heightened inflammatory responses.

Abstract Introduction The skin immune system is tightly regulated to prevent inappropriate inflammation in response to harmless environmental substances. This regulation is actively maintained by mechanisms including cytokines and cell surface receptors and its loss results in inflammatory disease. In the case of psoriasis, inappropriate immune activation leads to IL‐17‐driven chronic inflammation, but molecular mechanisms underlying this loss of regulation are not well understood. Immunoglobulin family member CD200 and its receptor, CD200R1, are important regulators of inflammation. Therefore, we determined if this pathway is dysregulated in psoriasis, and how this affects immune cell activity. Methods Human skin biopsies were examined by quantitative polymerase chain reaction, flow cytometry, and immunohistochemistry. The role of CD200R1 in regulating psoriasis‐like skin inflammation was examined using CD200R1 blocking antibodies in mouse psoriasis models. CD200R1 blocking antibodies were also used in an in vivo neutrophil recruitment assay and in vitro assays to examine macrophage, innate lymphoid cell, γδ T cell, and neutrophil activity. Results We reveal that CD200 and signaling via CD200R1 are reduced in non‐lesional psoriasis skin. In mouse models of psoriasis CD200R1 was shown to limit psoriasis‐like inflammation by enhancing acanthosis, CCL20 production and neutrophil recruitment, but surprisingly, macrophage function and IL‐17 production were not affected, and neutrophil reactive oxygen species production was reduced. Conclusion Collectively, these data show that CD200R1 affects neutrophil function and limits inflammatory responses in healthy skin by restricting neutrophil recruitment. However, the CD200 pathway is reduced in psoriasis, resulting in a loss of immune control, and increased neutrophil recruitment in mouse models. In conclusion, we highlight CD200R1:CD200 as a pathway that might be targeted to dampen inflammation in patients with psoriasis.

Abstract Background Bone marrow mesenchymal stem cells (BM‐MSCs), as multipotent cells with self‐renewal and plastic‐adherent properties, have immunomodulatory effects on immune cells, including neutrophils. These cells are in close proximity in bone marrow (BM) sinusoids with non‐multiplicative immature neutrophils. BM‐MSCs exert their immunomodulatory effects on adjacent cells both directly (cell‐to‐cell contact) and indirectly (secretion of soluble factors). Objectives The aim of this study was to evaluate the effect of equine bone marrow mesenchymal stem cells (BM‐MSCs) on the expression of some pro‐ and anti‐apoptotic genes (p53, survivin and Bcl2) in neutrophils co‐cultured with BM‐MSCs. Methods For this purpose, peripheral blood neutrophils were isolated and separately co‐cultured for 12 hr with both BM‐MSCs and the BM‐MSCs΄ supernatant. Four groups were included: neutrophils with only culture media (as control), neutrophils co‐cultured with BM‐MScs, neutrophils cultured with BM‐MSCs’ supernatant and neutrophils cultured with lipopolysaccharide (LPS, as positive control). Then, the expression of mentioned genes (p53, survivin and Bcl2) was evaluated by quantitative polymerase chain reaction (qPCR). Results Compared with control neutrophils, in neutrophils co‐cultured with both BM‐MSCs and BM‐MSCs’ supernatant, the mRNA expression levels of p53, as pro‐apoptotic gene, and survivin and Bcl2, as anti‐apoptotic genes, were remarkably increased and decreased (p