Urine microscopy and neutrophilelymphocyte ratio are early predictors of acute kidney injury in patients with urinary tract infection

Objective:Urinary tract infection(UTI)is a common cause of morbidity and hospitalisation in the population worldwide.Upper UTI is indolent and causes subclinical acute kidney injury(AKI)resulting in preventable cause of scarring of renal parenchyma.We explored urinary and serum levels of kidney injury molecule-1(KIM-1),haematological parameters and quantitative urine microscopy parameters to predict kidney injury.Methods:Neutrophilelymphocyte ratio(NLR)is obtained by dividing absolute neutrophil count with absolute lymphocyte count.Quantitative urine sediment microscopy was performed and correlated with clinical,biochemical and haematological findings to predict AKI in patients with UTI.Quantitative ELISA was performed for serum and urine levels of KIM-1.Seventy two adult patients with UTI were enrolled,45 of whom had AKI while 27 were in the non-AKI group.Results:NLR(p=0.005)and renal tubular epithelial cell-granular cast score in quantitative urine microscopy(p=0.008)are strong predictors of AKI in patients with UTI while rest of quantitative urine microscopy parameters and serum and urinary levels of KIM-1 molecule were not found to be useful in prediction of AKI.Conclusion:NLR in haemogram is a novel and useful biomarker for predicting AKI in patients with UTI.

Neutrophil peptide 1 accelerates the clearance of degenerative axons during Wallerian degeneration by activating macrophages after peripheral nerve crush injury

Macrophages play an important role in peripheral nerve regeneration,but the specific mechanism of regeneration is still unclear.Our preliminary findings indicated that neutrophil peptide 1 is an innate immune peptide closely involved in peripheral nerve regeneration.However,the mechanism by which neutrophil peptide 1 enhances nerve regeneration remains unclear.This study was designed to investigate the relationship between neutrophil peptide 1 and macrophages in vivo and in vitro in peripheral nerve crush injury.The functions of RAW 264.7 cells we re elucidated by Cell Counting Kit-8 assay,flow cytometry,migration assays,phagocytosis assays,immunohistochemistry and enzyme-linked immunosorbent assay.Axonal debris phagocytosis was observed using the CUBIC(Clear,Unobstructed Brain/Body Imaging Cocktails and Computational analysis)optical clearing technique during Wallerian degeneration.Macrophage inflammatory factor expression in different polarization states was detected using a protein chip.The results showed that neutrophil peptide 1 promoted the prolife ration,migration and phagocytosis of macrophages,and CD206 expression on the surfa ce of macrophages,indicating M2 polarization.The axonal debris clearance rate during Wallerian degeneration was enhanced after neutrophil peptide 1 intervention.Neutrophil peptide 1 also downregulated inflammatory factors interleukin-1α,-6,-12,and tumor necrosis factor-αin invo and in vitro.Thus,the results suggest that neutrophil peptide 1 activates macrophages and accelerates Wallerian degeneration,which may be one mechanism by which neutrophil peptide 1 enhances peripheral nerve regeneration.

Neutrophil extracellular traps mediate neuro-immunothrombosis

Neutrophil extracellular traps are primarily composed of DNA and histones and are released by neutrophils to promote inflammation and thrombosis when stimulated by various inflammato ry reactions.Neutrophil extracellular trap formation occurs through lytic and non-lytic pathways that can be further classified by formation mechanisms.Histones,von Willebrand factor,fibrin,and many other factors participate in the interplay between inflammation and thrombosis.Neuroimmunothrombosis summarizes the intricate interplay between inflammation and thrombosis during neural development and the pathogenesis of neurological diseases,providing cutting-edge insights into post-neurotrauma thrombotic events.The blood-brain barrier defends the brain and spinal cord against external assaults,and neutrophil extracellular trap involvement in blood-brain barrier disruption and immunothrombosis contributes substantially to secondary injuries in neurological diseases.Further research is needed to understand how neutrophil extracellular traps promote blood-brain barrier disruption and immunothrombosis,but recent studies have demonstrated that neutrophil extracellular traps play a crucial role in immunothrombosis,and identified modulators of neuro-immunothrombosis.However,these neurological diseases occur in blood vessels,and the mechanisms are unclear by which neutrophil extracellular traps penetrate the blood-brain barrier to participate in immunothrombosis in traumatic brain injury.This review discusses the role of neutrophil extracellular traps in neuro-immunothrombosis and explores potential therapeutic interventions to modulate neutrophil extracellular traps that may reduce immunothrombosis and improve traumatic brain injury outcomes.

The neutrophil–osteogenic cell axis promotes bone destruction in periodontitis

The immune-stromal cell interactions play a key role in health and diseases. In periodontitis, the most prevalent infectious disease in humans, immune cells accumulate in the oral mucosa and promote bone destruction by inducing receptor activator of nuclear factor-κB ligand (RANKL) expression in osteogenic cells such as osteoblasts and periodontal ligament cells. However, the detailed mechanism underlying immune–bone cell interactions in periodontitis is not fully understood. Here, we performed single-cell RNAsequencing analysis on mouse periodontal lesions and showed that neutrophil–osteogenic cell crosstalk is involved in periodontitis-induced bone loss. The periodontal lesions displayed marked infiltration of neutrophils, and in silico analyses suggested that the neutrophils interacted with osteogenic cells through cytokine production. Among the cytokines expressed in the periodontal neutrophils, oncostatin M (OSM) potently induced RANKL expression in the primary osteoblasts, and deletion of the OSM receptor in osteogenic cells significantly ameliorated periodontitis-induced bone loss. Epigenomic data analyses identified the OSM-regulated RANKL enhancer region in osteogenic cells, and mice lacking this enhancer showed decreased periodontal bone loss while maintaining physiological bone metabolism. These findings shed light on the role of neutrophils in bone regulation during bacterial infection, highlighting the novel mechanism underlying osteoimmune crosstalk.

Cancer-educated neutrophils promote lung cancer progression via PARP-1-ALOX5-mediated MMP-9 expression

Objective:Neutrophils are one of the most predominant infiltrating leukocytes in lung cancer tissues and are associated with lung cancer progression.How neutrophils promote lung cancer progression,however,has not been established.Methods:Kaplan–Meier plotter online analysis and tissue immunohistochemistry were used to determine the relationship between neutrophils and overall survival in lung cancer patients.The effect of neutrophils on lung cancer was determined using the Transwell migration assay,a proliferation assay,and a murine tumor model.Gene knockdown was used to determine poly ADPribose polymerase(PARP)-1 function in lung cancer-educated neutrophils.Western blot analysis and gelatin zymography were used to demonstrate the correlation between PARP-1 and matrix metallopeptidase 9(MMP-9).Immunoprecipitation coupled to mass spectrometry(IP/MS)was used to identify the proteins interacting with PARP-1.Co-immunoprecipitation(Co-IP)was used to confirm that PARP-1 interacts with arachidonate 5-lipooxygenase(ALOX5).Neutrophil PARP-1 blockage by AG14361 rescued neutrophil-promoted lung cancer progression.Results:An increased number of infiltrating neutrophils was negatively associated with overall survival in lung cancer patients(P<0.001).Neutrophil activation promoted lung cancer cell invasion,migration,and proliferation in vitro,and murine lung cancer growth in vivo.Mechanistically,PARP-1 was shown to be involved in lung cancer cell-induced neutrophil activation to increase MMP-9 expression through interacting and stabilizing ALOX5 by post-translational protein modification(PARylation).Blocking PARP-1 by gene knockdown or AG14361 significantly decreased ALOX5 expression and MMP-9 production,and eliminated neutrophil-mediated lung cancer cell invasion and in vivo tumor growth.Conclusion:We identified a novel mechanism by which PARP-1 mediates lung cancer cell-induced neutrophil activation and PARylates ALOX5 to regulate MMP-9 expression,which exacerbates lung cancer progression.

Cell polarization in ischemic stroke: molecular mechanisms and advances

Ischemic stroke is a cerebrovascular disease associated with high mortality and disability rates. Since the inflammation and immune response play a central role in driving ischemic damage, it becomes essential to modulate excessive inflammatory reactions to promote cell survival and facilitate tissue repair around the injury site. Various cell types are involved in the inflammatory response, including microglia, astrocytes, and neutrophils, each exhibiting distinct phenotypic profiles upon stimulation. They display either proinflammatory or anti-inflammatory states, a phenomenon known as ‘cell polarization.’ There are two cell polarization therapy strategies. The first involves inducing cells into a neuroprotective phenotype in vitro, then reintroducing them autologously. The second approach utilizes small molecular substances to directly affect cells in vivo. In this review, we elucidate the polarization dynamics of the three reactive cell populations(microglia, astrocytes, and neutrophils) in the context of ischemic stroke, and provide a comprehensive summary of the molecular mechanisms involved in their phenotypic switching. By unraveling the complexity of cell polarization, we hope to offer insights for future research on neuroinflammation and novel therapeutic strategies for ischemic stroke.

Overcoming neutrophil-induced immunosuppression in postoperative cancer therapy: Combined sialic acid-modified liposomes with scaffold-based vaccines

Immunotherapy is a promising approach for preventing postoperative tumor recurrence and metastasis. However, inflammatory neutrophils, recruited to the postoperative tumor site, have been shown to exacerbate tumor regeneration and limit the efficacy of cancer vaccines. Consequently, addressing postoperative immunosuppression caused by neutrophils is crucial for improving treatment outcomes. This study presents a combined chemoimmunotherapeutic strategy that employs a biocompatible macroporous scaffold-based cancer vaccine (S-CV) and a sialic acid (SA)-modified, doxorubicin (DOX)-loaded liposomal platform (DOX@SAL). The S-CV contains whole tumor lysates as antigens and imiquimod (R837, Toll-like receptor 7 activator)-loaded PLGA nanoparticles as immune adjuvants for cancer, which enhance dendritic cell activation and cytotoxic T cell proliferation upon localized implantation. When administered intravenously, DOX@SAL specifically targets and delivers drugs to activated neutrophils in vivo, mitigating neutrophil infiltration and suppressing postoperative inflammatory responses. In vivo and vitro experiments have demonstrated that S-CV plus DOX@SAL, a combined chemo-immunotherapeutic strategy, has a remarkable potential to inhibit postoperative local tumor recurrence and distant tumor progression, with minimal systemic toxicity, providing a new concept for postoperative treatment of tumors.

Crossroads:Pathogenic role and therapeutic targets of neutrophil extracellular traps in rheumatoid arthritis

Rheumatoid arthritis(RA)is a prevalent autoimmune disease whose main features include chronic synovial inflammation,bone destruction,and joint degeneration.Neutrophils are often considered to be the first responders to inflammation and are a key presence in the inflammatory milieu of RA.Neutrophil extracellular traps(NETs),a meshwork of DNA-histone complexes and proteins released by activated neutrophils,are widely involved in the pathophysiology of autoimmune diseases,especially RA,in addition to playing a key role in the neutrophil innate immune response.NETs have been found to be an important source of citrullinated autoantigen antibodies and inflammatory factor release,which can activate RA synovial fibroblasts(FLS)and cause joint damage.This article reviews the role of NETs in the pathophysiology of RA,demonstrating the application of multiple molecules with various therapies,with a view to informing the discovery and development of novel biomarkers and therapeutic targets for RA.

Prognostic value of circulating tumor cells combined with neutrophil-lymphocyte ratio in patients with hepatocellular carcinoma

BACKGROUND Circulating tumor cell(CTC)count and neutrophil-to-lymphocyte ratio(NLR)are both closely associated with the prognosis of hepatocellular carcinoma(HCC).AIM To investigate the prognostic value of combining these two indicators in HCC.METHODS Clinical data were collected from patients with advanced HCC who received im-mune therapy combined with targeted therapy at the Department of Oncology,the Affiliated Hospital of Southwest Medical University,Sichuan,China,from 2021 to 2023.The optimal cutoff values for CTC programmed death-ligand 1(PD-L1)(+)>1 or CTC PD-L1(+)≤1 and NLR>3.89 or NLR≤3.89 were evaluated using X-Tile software.Patients were categorized into three groups based on CTC PD-L1(+)counts and NLR:CTC-NLR(0),CTC-NLR(1),and CTC-NLR(2).The relationship between CTC-NLR and clinical variables as well as survival rates was assessed.RESULTS Patients with high CTC PD-L1(+)expression or NLR at baseline had shorter median progression-free survival(m-PFS)and median overall survival(mOS)than those with low levels of CTC PD-L1(+)or NLR(P<0.001).Mean-while,patients in the CTC-NLR(2)group showed a significant decrease in mPFS and mOS.Cox regression analysis revealed that alpha-fetoprotein(AFP),CTC PD-L1(+),and CTC-NLR were independent predictors of OS.The time-dependent receiver operating characteristic curve showed that the area under the curve of CTC-NLR at 12 months(0.821)and 18 months(0.821)was superior to that of AFP and CTC PD-L1(+).CONCLUSION HCC patients with high CTC PD-L1(+)or NLR expression tend to exhibit poor prognosis,and a high baseline CTC-NLR score may indicate low survival.CTC-NLR may serve as an effective prognostic indicator for patients with advanced HCC receiving immunotherapy combined with targeted therapy.

Predictive model for non-malignant portal vein thrombosis associated with cirrhosis based on inflammatory biomarkers

BACKGROUND Portal vein thrombosis(PVT),a complication of liver cirrhosis,is a major public health concern.PVT prediction is the most effective method for PVT diagnosis and treatment.AIM To develop and validate a nomogram and network calculator based on clinical indicators to predict PVT in patients with cirrhosis.METHODS Patients with cirrhosis hospitalized between January 2016 and December 2021 at the First Hospital of Lanzhou University were screened and 643 patients with cirrhosis who met the eligibility criteria were retrieved.Following a 1:1 propensity score matching 572 patients with cirrhosis were screened,and relevant clinical data were collected.PVT risk factors were identified using the least absolute shrinkage and selection operator(LASSO)and multivariate logistic regression analysis.Variance inflation factors and correlation matrix plots were used to analyze multicollinearity among the variables.A nomogram was constructed to predict the probability of PVT based on independent risk factors for PVT,and its predictive performance was verified using a receiver operating characteristic curve(ROC),calibration curves,and decision curve analysis(DCA).Finally,a network calculator was constructed based on the nomograms.RESULTS This study enrolled 286 cirrhosis patients with PVT and 286 without PVT.LASSO analysis revealed 13 variables as strongly associated with PVT occurrence.Multivariate logistic regression analysis revealed nine indicators as independent PVT risk factors,including etiology,ascites,gastroesophageal varices,platelet count,D-dimer,portal vein diameter,portal vein velocity,aspartate transaminase to neutrophil ratio index,and platelet-to-lymphocyte ratio.LASSO and correlation matrix plot results revealed no significant multicollinearity or correlation among the variables.A nomogram was constructed based on the screened independent risk factors.The nomogram had excellent predictive performance,with an area under the ROC curve of 0.821 and 0.829 in the training and testing groups,respectively.Calibration curves and DCA revealed its good clinical performance.Finally,the optimal cutoff value for the total nomogram score was 0.513.The sensitivity and specificity of the optimal cutoff values were 0.822 and 0.706,respectively.CONCLUSION A nomogram for predicting PVT occurrence was successfully developed and validated,and a network calculator was constructed.This can enable clinicians to rapidly and easily identify high PVT risk groups.

Machine learning based on metabolomics unveils neutrophil extracellular trap-related metabolic signatures in non-small cell lung cancer patients undergoing chemoimmunotherapy

BACKGROUND Non-small cell lung cancer(NSCLC)is the primary form of lung cancer,and the combination of chemotherapy with immunotherapy offers promising treatment options for patients suffering from this disease.However,the emergence of drug resistance significantly limits the effectiveness of these therapeutic strategies.Consequently,it is imperative to devise methods for accurately detecting and evaluating the efficacy of these treatments.AIM To identify the metabolic signatures associated with neutrophil extracellular traps(NETs)and chemoimmunotherapy efficacy in NSCLC patients.METHODS In total,159 NSCLC patients undergoing first-line chemoimmunotherapy were enrolled.We first investigated the characteristics influencing clinical efficacy.Circulating levels of NETs and cytokines were measured by commercial kits.Liquid chromatography tandem mass spectrometry quantified plasma metabolites,and differential metabolites were identified.Least absolute shrinkage and selection operator,support vector machine-recursive feature elimination,and random forest algorithms were employed.By using plasma metabolic profiles and machine learning algorithms,predictive metabolic signatures were established.RESULTS First,the levels of circulating interleukin-8,neutrophil-to-lymphocyte ratio,and NETs were closely related to poor efficacy of first-line chemoimmunotherapy.Patients were classed into a low NET group or a high NET group.A total of 54 differential plasma metabolites were identified.These metabolites were primarily involved in arachidonic acid and purine metabolism.Three key metabolites were identified as crucial variables,including 8,9-epoxyeicosatrienoic acid,L-malate,and bis(monoacylglycerol)phosphate(18:1/16:0).Using metabolomic sequencing data and machine learning methods,key metabolic signatures were screened to predict NET level as well as chemoimmunotherapy efficacy.CONCLUSION The identified metabolic signatures may effectively distinguish NET levels and predict clinical benefit from chemoimmunotherapy in NSCLC patients.

Correlation of neutrophil to lymphocyte ratio to severity of coronary artery disease and in-hospital clinical outcomes in patients with acute coronary syndrome: A prospective observational study

Objective:To explore correlation of neutrophil-to-lymphocyte ratio(NLR)to severity of coronary artery disease(CAD)and in-hospital clinical outcomes in patients with acute coronary syndrome(ACS).Methods:In this prospective and observational study,we recruited 500 patients with ACS.For all the eligible patients,demographic details were collected,and laboratory parameters were evaluated.The CAD severity was evaluated in terms of the number of involved vessels.The NLR was calculated based on neutrophils and lymphocytes and the correlation of various risk factors and severity and outcome of CAD was performed.Results:77.2%of Patients was male,and 52%of the patients aged between 55-70 years.Based on the type of ACS,396 out of 500 patients had ST-elevation myocardial infarction.An ascending trend in the white blood cell levels and NLR value was noted as the severity of the ACS increased and the highest white blood cell levels and NLR was noted among classⅣpatients.The mean NLR value among the non-survivors were higher compared to the survivors(9.52±5.72 vs.4.76±2.36;P<0.01).Receiver operating curve showed that the cut-off NLR value was 5.76 with a sensitivity of 75.0%and a specificity of 77.3%.Conclusions:The NLR can be used as an independent prognostic marker in ACS.An elevated NLR value serves as a reliable predictor for short-term complications,notably in-hospital mortality.

Relationship of inflammatory indices with left atrial appendage thrombus or spontaneous echo contrast in patients with atrial fibrillation

BACKGROUND Inflammatory indices derived from complete blood tests have been reported to be associated with poor outcomes in patients with atrial fibrillation(AF).The data about the relationship between inflammatory indices and left atrial appendage thrombus(LAAT)or dense spontaneous echo contrast(SEC)are limited.AIM To explore the value of inflammatory indices for predicting the presence of LAAT or dense SEC in nonvalvular AF patients.METHODS A total of 406 patients with nonvalvular AF who underwent transesophageal echocardiography were included and divided into two groups based on the presence(study group)or absence(control group)of LAAT or dense SEC.Inflammatory indices,including the neutrophil-to-lymphocyte ratio(NLR),platelet–tolymphocyte ratio(PLR),and lymphocyte-to-monocyte ratio(LMR),were calculated from complete blood analysis.The associations of inflammatory indices RESULTS LAAT and dense SEC were detected in 11(2.7%)and 42(10.3%)patients,respectively.The PLR only showed an association with LAAT/dense SEC in the univariate model.Elevated NLR(odds ratio[OR]=1.48,95%confidence interval[CI]:1.11-1.98,P=0.007)and reduced LMR(OR=0.59,95%CI:0.41-0.83,P=0.003)were found to be independent risk factors for the presence of LAAT/dense SEC.The areas under the NLR and LMR curves for predicting LAAT/dense SEC were 0.73(95%CI:0.66-0.80,P<0.001)and 0.73(95%CI:0.65-0.81,P<0.001),respectively,while the cutoff values were 2.8(sensitivity:69.8%;specificity:64.0%)and 2.4(sensitivity:71.7%;specificity:60.6%),respectively.CONCLUSION Increased NLR and decreased LMR may predict LAAT/dense SEC in patients with nonvalvular AF.

The Combined Effect of Lumenato and Ceramide in the Protection of Collagen Damage Induced by Neutrophils in Normal Human Dermal Fibroblasts

Introduction: Collagen is the primary structural protein fibroblasts produce in the skin’s extracellular matrix. Infiltration of neutrophils into the epidermis and dermis by exposure to UV causes collagen damage and contributes to photoaging. Methods: To study the combined effect of Lumenato and ceramide in preventing collagen-1 damage induced by phagocytes, we used co-cultures of normal human dermal fibroblasts (fibroblasts) and activated human neutrophils. The present study aimed to determine the protective effect of the combination of Lumenato and ceramide on fibroblast collagen-1 damage induced by neutrophils. Results: Lumenato (in the range of 6.5 - 208 μg/ml) or ceramide (in the range of 0.1 - 50 μM) inhibited the production of superoxides and MPO by TNFα-stimulated neutrophils, as well as the production of NO by LPS-stimulated macrophages in a dose-dependent manner. The combinations of Lumenato and ceramide, in low concentrations, caused synergistic prevention of fibroblasts’ collagen-1 damage induced by TNFα-activated neutrophils, detected by fluorescence immunostaining and WB analysis. MPO activity in the supernatants of the co-cultures was also synergistically inhibited. Adding Lumenato or ceramide singly or in combinations in these low concentrations to the fibroblast cultures did not affect the expression of collagen-1. The combinations of Lumenato or ceramide in these concentrations also caused a synergistic inhibition of NO production by activated macrophages. Conclusions: The results suggest that combining low concentrations of Lumenato and ceramide results in synergistic protection against fibroblasts’ collagen-1 damage induced by neutrophils, thus indicating their possible potential for enhanced skin health.

Correlation between Neutrophil Percentage-to-albumin Ratio and Coronary Heart Disease Complicated with Diabetes Mellitus

[Objectives]This study was conducted to explore the relationship between neutrophil percentage-to-albumin ratio(NPAR)and coronary heart disease complicated with diabetes.[Methods]A total of 603 patients with coronary heart disease who underwent coronary angiography in Pingquan County Hospital from January,2023 to December,2023 and met the inclusion criteria were included as the research object.All the patients were divided into a coronary heart disease complicated with diabetes group(CAD+T2DM group)(n=298 cases)and a control group(CAD group)(n=305 cases),according to patients medical history,heart color ultrasound and biochemical test results.The clinical data,biochemical test results and coronary artery imaging data of patients were recorded,and the Gensini score was calculated.The neutrophil percentage(NEUT%)and albumin count were determined to calculate NPAR.[Results]The NPAR value of the coronary heart disease complicated with diabetes mellitus group was(1.6±0.42),which was significantly higher than that of the control group(1.47±0.49),and the difference was statistically significant(P<0.05).The area under the ROC curve was 0.619(95%CI:0.591-0.675,P<0.05),and the prediction of coronary heart disease complicated with diabetes using NPAR showed a Youden index of 0.31,a sensitivity of 60.4%,a specificity of 40.3%,and a best cut-off score of 1.4506.[Conclusions]The neutrophil percentage-to-albumin ratio(NPAR)is closely related to coronary heart disease complicated with diabetes mellitus,and NPAR has clinical application value in the diagnosis of coronary heart disease complicated with diabetes mellitus.

Predictive Value of the Neutrophil to Lymphocyte Ratio (NLR) to Predict the Development of Preeclampsia and Pregnancy Induced Hypertension at 1st Trimester

Introduction: Hypertensive disorder in pregnancy affects 4 to 6 percent of all pregnancies and carries risks for the both baby and the mother. Only a few groups of women who are at high-risk pregnancies are received prophylaxis Aspirin, more than 15 percent of women develop pre-eclampsia with a single minor risk factor. Methods: This descriptive cross-sectional study was conducted to compare the 1st trimester NLR value of normotensive, pregnancy induced hypertensive and pre-eclamptic pregnant women. The study was conducted with a sample of 416, antenatal patients who were admitted to ward 25, at Colombo North Teaching Hospital Ragama. Data was collected as separated three groups. NLR value was calculated separately and ANOVA test was used to analyze the 3 categorical data. Post HOC test was done to assess the multiple comparison. Results: The prevalence rates of pregnancy induced hypertension and pre-eclampsia among the pregnant women were 8.6% and 5.7%. The mean NLR values of normotensive group was 2.708, pregnancy induced hypertensive group was 2.650 and pre eclamptic group was 3.789. There was a significant difference in NLR value between pre eclamptic group and other two groups with P value of Conclusion: The 1st trimester NLR value of pre eclamptic patients significantly increased compared to normotensive women.

Neutrophil elastase:From mechanisms to therapeutic potential

Neutrophil elastase(NE),a major protease in the primary granules of neutrophils,is involved in microbicidal activity.NE is an important factor promoting inflammation,has bactericidal effects,and shortens the inflammatory process.NE also regulates tumor growth by promoting metastasis and tumor microenvironment remodeling.However,NE plays a role in killing tumors under certain conditions and promotes other diseases such as pulmonary ventilation dysfunction.Additionally,it plays a complex role in various physiological processes and mediates several diseases.Sivelestat,a specific NE inhibitor,has strong potential for clinical application,particularly in the treatment of coronavirus disease 2019(COVID-19).This review discusses the pathophysiological processes associated with NE and the potential clinical applications of sivelestat.

Neutrophil-derived interleukin-17A participates in neuroinflammation induced by traumatic brain injury

After brain injury, infiltration and abnormal activation of neutrophils damages brain tissue and worsens inflammation, but the mediators that connect activated neutrophils with neuroinflammation have not yet been fully clarified. To identify regulators of neutrophil-mediated neuroinflammation after traumatic brain injury, a mouse model of traumatic brain injury was established by controlled cortical impact. At 7 days post-injury(sub-acute phase), genome-wide transcriptomic data showed that interleukin 17 A-associated signaling pathways were markedly upregulated, suggesting that interleukin 17 A may be involved in neuroinflammation. Double immunofluorescence staining showed that interleukin 17 A was largely secreted by neutrophils rather than by glial cells and neurons. Furthermore, nuclear factor-kappaB and Stat3, both of which are important effectors in interleukin 17 A-mediated proinflammatory responses, were significantly activated. Collectively, our findings suggest that neutrophil-derived interleukin 17 A participates in neutrophil-mediated neuroinflammation during the subacute phase of traumatic brain injury. Therefore, interleukin 17 A may be a promising therapeutic target for traumatic brain injury.

Intersections between innate immune response and gastric cancer development

Worldwide,gastric cancer(GC)is the fifth most commonly diagnosed malignancy.It has a reduced prevalence but has maintained its poor prognosis being the fourth leading cause of deaths related to cancer.The highest mortality rates occur in Asian and Latin American countries,where cases are usually diagnosed at advanced stages.Overall,GC is viewed as the consequence of a multifactorial process,involving the virulence of the Helicobacter pylori(H.pylori)strains,as well as some environmental factors,dietary habits,and host intrinsic factors.The tumor microenvironment in GC appears to be chronically inflamed which promotes tumor progression and reduces the therapeutic opportunities.It has been suggested that inflammation assessment needs to be measured qualitatively and quantitatively,considering cell-infiltration types,availability of receptors to detect damage and pathogens,and presence or absence of aggressive H.pylori strains.Gastrointestinal epithelial cells express several Toll-like receptors and determine the first defensive line against pathogens,and have been also described as mediators of tumorigenesis.However,other molecules,such as cytokines related to inflammation and innate immunity,including immune checkpoint molecules,interferon-gamma pathway and NETosis have been associated with an increased risk of GC.Therefore,this review will explore innate immune activation in the context of premalignant lesions of the gastric epithelium and established gastric tumors.

Neutrophils as key regulators of tumor immunity that restrict immune checkpoint blockade in liver cancer

Objective:Liver cancer is a deadly malignancy associated with high mortality and morbidity.Less than 20%of patients with advanced liver cancer respond to a single anti-PD-1 treatment.The high heterogeneity of neutrophils in the tumor immune microenvironment in liver cancer may contribute to resistance to immune checkpoint blockade(ICB).However,the underlying mechanism remains largely unknown.Methods:We established an orthotopic liver cancer model by using transposable elements to integrate the oncogenes Myc and KrasG12Dinto the genome in liver cells from conditional Trp53 null/null mice(pTMK/Trp53^(-/-)).Flow cytometry and immunohistochemistry were used to assess the changes in immune cells in the tumor microenvironment.An ex vivo coculture assay was performed to test the inhibitory effects of tumor-associated neutrophils(TANs)on CD8^(+)T cells.The roles of neutrophils,T cells,and NK cells were validated through antibody-mediated depletion.The efficacy of the combination of neutrophil depletion and ICB was evaluated.Results:Orthotropic pTMK/Trp53^(-/-)mouse liver tumors displayed a moderate response to anti-Ly6G treatment but not PD-1 blockade.Depletion of neutrophils increased the infiltration of CD8^(+)T cells and decreased the number of exhausted T cells in the tumor microenvironment.Furthermore,depletion of either CD8^(+)T or NK cells abrogated the antitumor efficacy of anti-Ly6G treatment.Moreover,the combination of anti-Ly6G with anti-PD-L1 enhanced the infiltration of cytotoxic CD8^(+)T cells and thereafter resulted in a significantly greater decrease in tumor burden.Conclusions:Our data suggest that TANs may contribute to the resistance of liver cancer to ICB,and combining TAN depletion with T cell immunotherapy synergistically increases antitumor efficacy.