L-selectin regulates human neutrophil transendothelial migration

Expansion of a Novel Subset of L-Selectin+ Classical Monocytes in Kawasaki Disease

Purpose

Kawasaki disease (KD) is an acute systemic vasculitis that is associated with dysregulated immune responses. Monocytes play a central role in innate immunity. Our previous single-cell RNA sequencing of peripheral blood mononuclear cells (PBMC) revealed a new subset of monocytes in children with KD called L-Selectin+ classical monocytes (SELL+ CM). Therefore, we aimed to investigate the correlation between KD and SELL+ CM.

Patients and Methods

Peripheral blood samples were collected from 81 KD patients, 18 febrile patients and 36 healthy children before treatment. Among them, ten KD patients were followed up, and samples were obtained before and after intravenous immunoglobulin (IVIG) treatment. Analysis of SELL+ CM was performed using flow cytometry. Additionally, ROC curve analysis was conducted to assess the diagnostic value of SELL+ CM for KD.

Results

Classical monocytes (CM) expressed the highest levels of L-selectin in children with KD. The ratio of SELL+ CM in CM was significantly higher in KD patients than in febrile and healthy children. Following IVIG treatment, the ratio of SELL+ CM in CM showed a downward trend. The receiver operating characteristic (ROC) curve analysis (the area under the curve, AUC = 0.71) indicated the potential diagnostic value of SELL+ CM in KD. The correlation analysis suggested that SELL+ CM may serve as a new clinical index for patients with KD.

Conclusion

In KD, the ratio of SELL+ CM in CM significantly increases during the acute phase, which may become a potential biomarker and help facilitate KD diagnosis based on clinical features.

Adenosine Triphosphate Release From Influenza-Infected Lungs Enhances Neutrophil Activation and Promotes Disease Progression

BACKGROUND

Adenosine triphosphate (ATP) enhances neutrophil responses, but little is known about the role of ATP in influenza infections.

METHODS

We used a mouse influenza model to study if ATP release is associated with neutrophil activation and disease progression.

RESULTS

Influenza infection increased pulmonary ATP levels 5-fold and plasma ATP levels 3-fold vs healthy mice. Adding ATP at those concentrations to blood from healthy mice primed neutrophils and enhanced CD11b and CD63 expression, CD62L shedding, and reactive oxygen species production in response to formyl peptide receptor stimulation. Influenza infection also primed neutrophils in vivo, resulting in formyl peptide receptor-induced CD11b expression and CD62L shedding up to 3 times higher than that of uninfected mice. In infected mice, large numbers of neutrophils entered the lungs. These cells were significantly more activated than the peripheral neutrophils of infected mice and pulmonary neutrophils of healthy mice. Plasma ATP levels of infected mice and influenza disease progression corresponded with the numbers and activation level of their pulmonary neutrophils.

CONCLUSIONS

Findings suggest that ATP release from the lungs of infected mice promotes influenza disease progression by priming peripheral neutrophils, which become strongly activated and cause pulmonary tissue damage after their recruitment to the lungs.

Effects of peripheral blood cells on ischemic stroke: Greater immune response or systemic inflammation?

Ischemic stroke is still one of the most serious medical conditions endangering human health worldwide. Current research on the mechanism of ischemic stroke focuses on the primary etiology as well as the subsequent inflammatory response and immune modulation. Recent research has revealed that peripheral blood cells and their components are crucial to the ensuing progression of ischemic stroke. However, it remains unclear whether blood cell elements are principally in charge of systemic inflammation or immunological regulation, or if their participation is beneficial or harmful to the development of ischemic stroke. In this review, we aim to describe the changes in peripheral blood cells and their corresponding parameters in ischemic stroke. Specifically, we elaborate on the role of each peripheral component in the inflammatory response or immunological modulation as well as their interactions. It has been suggested that more specific therapies aimed at targeting peripheral blood cell components and their role in inflammation or immunity are more favorable to the treatment of ischemic stroke.

Single-cell transcriptome analysis reveals heterogeneity of neutrophils in non-small cell lung cancer

BACKGROUND

Lung cancer stands out as a highly perilous malignant tumor with severe implications for human health. There has been a growing interest in neutrophils as a result of their role in promoting cancer in recent years. Thus, the present study aimed to investigate the heterogeneity of neutrophils in non-small cell lung cancer (NSCLC).

METHODS

Single-cell RNA sequencing of tumor-associated neutrophils (TANs) and polymorphonuclear neutrophils sourced from the Gene Expression Omnibus database was analyzed. Moreover, cell-cell communication, differentiation trajectories and transcription factor analyses were performed.

RESULTS

Neutrophils were found to be closely associated with macrophages. Four major types of TANs were identified: a transitional subcluster that migrated from blood to tumor microenvironment (TAN-0), an inflammatory subcluster (TAN-1), a subpopulation that displayed a distinctive transcriptional signature (TAN-2) and a final differentiation state that promoted tumor formation (TAN-3). Meanwhile, TAN-3 displayed a marked increase in glycolytic activity. Finally, transcription factors were analyzed to uncover distinct TAN cluster-specific regulons.

CONCLUSIONS

The discovery of the dynamic characteristics of TANs in the present study is anticipated to contribute to yielding a better understanding of the tumor microenvironment and advancing the treatment of NSCLC.

GM-CSF, G-CSF or no cytokine therapy with anti-GD2 immunotherapy for high-risk neuroblastoma

Colony-stimulating factors have been shown to improve anti-disialoganglioside 2 (anti-GD2) monoclonal antibody response in high-risk neuroblastoma by enhancing antibody-dependent cell-mediated cytotoxicity (ADCC). A substantial amount of research has focused on recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) as an adjuvant to anti-GD2 monoclonal antibodies. There may be a disparity in care among patients as access to GM-CSF therapy and anti-GD2 monoclonal antibodies is not uniform. Only select countries have approved these agents for use, and even with regulatory approvals, access to these agents can be complex and cost prohibitive. This comprehensive review summarizes clinical data regarding efficacy and safety of GM-CSF, recombinant human granulocyte colony-stimulating factor (G-CSF) or no cytokine in combination with anti-GD2 monoclonal antibodies (ie, dinutuximab, dinutuximab beta or naxitamab) for immunotherapy of patients with high-risk neuroblastoma. A substantial body of clinical data support the immunotherapy combination of anti-GD2 monoclonal antibodies and GM-CSF. In contrast, clinical data supporting the use of G-CSF are limited. No formal comparison between GM-CSF, G-CSF and no cytokine has been identified. The treatment of high-risk neuroblastoma with anti-GD2 therapy plus GM-CSF is well established. Suboptimal efficacy outcomes with G-CSF raise concerns about its suitability as an alternative to GM-CSF as an adjuvant in immunotherapy for patients with high-risk neuroblastoma. While programs exist to facilitate obtaining GM-CSF and anti-GD2 monoclonal antibodies in regions where they are not commercially available, continued work is needed to ensure equitable therapeutic options are available globally.

Quantitative proteomics reveals tissue-specific, infection-induced and species-specific neutrophil protein signatures

Neutrophils are one of the first responders to infection and are a key component of the innate immune system through their ability to phagocytose and kill invading pathogens, secrete antimicrobial molecules and produce extracellular traps. Neutrophils are produced in the bone marrow, circulate within the blood and upon immune challenge migrate to the site of infection. We wanted to understand whether this transition shapes the mouse neutrophil protein landscape, how the mouse neutrophil proteome is impacted by systemic infection and perform a comparative analysis of human and mouse neutrophils. Using quantitative mass spectrometry we reveal tissue-specific, infection-induced and species-specific neutrophil protein signatures. We show a high degree of proteomic conservation between mouse bone marrow, blood and peritoneal neutrophils, but also identify key differences in the molecules that these cells express for sensing and responding to their environment. Systemic infection triggers a change in the bone marrow neutrophil population with considerable impact on the core machinery for protein synthesis and DNA replication along with environmental sensors. We also reveal profound differences in mouse and human blood neutrophils, particularly their granule contents. Our proteomics data provides a valuable resource for understanding neutrophil function and phenotypes across species and model systems.

CD_99 G1 neutrophils modulate osteogenic differentiation of mesenchymal stem cells in the pathological process of ankylosing spondylitis

OBJECTIVES

This study aimed to identify the types and heterogeneity of cells within the spinal enthesis and investigate the underlying mechanisms of osteogenesis.

METHODS

Single-cell RNA sequencing was used to identify cell populations and their gene signatures in the spinal enthesis of five patients with ankylosing spondylitis (AS) and three healthy individuals. The transcriptomes of 40 065 single cells were profiled and divided into 7 clusters: neutrophils, monocytic cells, granulomonocytic progenitor_erythroblasts, T cells, B cells, plasma cells and stromal cells. Real-time quantitative PCR, immunofluorescence, flow cytometry, osteogenesis induction, alizarin red staining, immunohistochemistry, short hairpin RNA and H&E staining were applied to validate the bioinformatics analysis.

RESULTS

Pseudo-time analysis showed two differentiation directions of stromal cells from the mesenchymal stem cell subpopulation MSC-C2 to two Cxcl12-abundant-reticular (CAR) cell subsets, Osteo-CAR and Adipo-CAR, within which three transcription factors, C-JUN, C-FOS and CAVIN1, were highly expressed in AS and regulated the osteogenesis of mesenchymal stem cells. A novel subcluster of early-stage neutrophils, CD99_G1, was elevated in AS. The proinflammatory characteristics of monocyte dendritic cell progenitor-recombinant adiponectin receptor 2 monocytic cells were explored. Interactions between Adipo-CAR cells, CD99_G1 neutrophils and other cell types were mapped by identifying ligand-receptor pairs, revealing the recruitment characteristics of CD99_G1 neutrophils by Adipo-CAR cells and the pathogenesis of osteogenesis induced in AS.

CONCLUSIONS

Our results revealed the dynamics of cell subpopulations, gene expression and intercellular interactions during AS pathogenesis. These findings provide new insights into the cellular and molecular mechanisms of osteogenesis and will benefit the development of novel therapeutic strategies.

Monocyte-derived alveolar macrophages are key drivers of smoke-induced lung inflammation and tissue remodeling

Smoking is a leading risk factor of chronic obstructive pulmonary disease (COPD), that is characterized by chronic lung inflammation, tissue remodeling and emphysema. Although inflammation is critical to COPD pathogenesis, the cellular and molecular basis underlying smoking-induced lung inflammation and pathology remains unclear. Using murine smoke models and single-cell RNA-sequencing, we show that smoking establishes a self-amplifying inflammatory loop characterized by an influx of molecularly heterogeneous neutrophil subsets and excessive recruitment of monocyte-derived alveolar macrophages (MoAM). In contrast to tissue-resident AM, MoAM are absent in homeostasis and characterized by a pro-inflammatory gene signature. Moreover, MoAM represent 46% of AM in emphysematous mice and express markers causally linked to emphysema. We also demonstrate the presence of pro-inflammatory and tissue remodeling associated MoAM orthologs in humans that are significantly increased in emphysematous COPD patients. Inhibition of the IRAK4 kinase depletes a rare inflammatory neutrophil subset, diminishes MoAM recruitment, and alleviates inflammation in the lung of cigarette smoke-exposed mice. This study extends our understanding of the molecular signaling circuits and cellular dynamics in smoking-induced lung inflammation and pathology, highlights the functional consequence of monocyte and neutrophil recruitment, identifies MoAM as key drivers of the inflammatory process, and supports their contribution to pathological tissue remodeling.

Bioinformatics to Identify Biomarkers of Diabetic Nephropathy based on Sphingolipid Metabolism and their Molecular Mechanisms

BACKGROUND

Diabetes mellitus (DM) frequently results in Diabetic Nephropathy (DN), which has a significant negative impact on the quality of life of diabetic patients. Sphingolipid metabolism is associated with diabetes, but its relationship with DN is unclear. Therefore, screening biomarkers related to sphingolipid metabolism is crucial for treating DN.

METHODS

To identify Differentially Expressed Genes (DEGs) in the GSE142153 dataset, we conducted a differential expression analysis (DN samples versus control samples). The intersection genes were obtained by overlapping DEGs and Sphingolipid Metabolism-Related Genes (SMRGs). Furthermore, The Least Absolute Shrinkage and Selection Operator (LASSO) and Support Vector Machine Recursive Feature Elimination (SVM-RFE) algorithms were used to filter biomarkers. We further analyzed the Gene Set Enrichment analysis (GSEA) and the immunoinfiltrational analysis based on biomarkers.

RESULTS

We identified 2,186 DEGs associated with DN. Then, five SMR-DEGs were obtained. Subsequently, biomarkers associated with sphingolipid metabolism (S1PR1 and SELL) were identified by applying machine learning and expression analysis. In addition, GSEA showed that these biomarkers were correlated with cytokine cytokine receptor interaction'. Significant variations in B cells, DCs, Tems, and Th2 cells between the two groups suggested that these cells might have a role in DN.

CONCLUSION

Overall, we obtained two sphingolipid metabolism-related biomarkers (S1PR1 and SELL) associated with DN, which laid a theoretical foundation for treating DN.

Distinctive aspects of the immune status of the Kola Saami and Russians living in the Far North

OBJECTIVE

The level of immunological reactivity of the indigenous inhabitants of the Far North may depend on the extreme-discomfort factors of the climatic environment and genetic traits of the population. Therefore, the aim of this study was to identify the distinctive elements of the immune status of the Kola Saami and Russians living in the Far North (Murmansk Region).

METHODS

A complex immunological study of peripheral venous blood composition was performed and involved 67 Saami and 81 Russian inhabitants of the Far North (Murmansk Region) who were aged 21-55. Blood was collected from the cubital vein on an empty stomach in the morning. For the peripheral venous blood, we obtained a hemogram and phagocytic activity of neutrophils, determined the content of lymphocytes with CD4, CD8, CD16, and CD71 phenotypes by indirect immunoperoxidase reaction and flow cytometry using an Epics XL apparatus (Beckman Coulter, United States), obtained concentrations of IL-6, IFN-γ, IL-10, IgA, M, G, E, sCD54, and sCD62L, transferrin, and sCD71 by enzyme immunoassay using the "Evolis" enzyme immunoassay analyzer from Bio-RAD (Germany), and obtained circulating immune complexes by precipitation using 3.5%, 4.0%, and 7.5% PEG-6000. The sIgA content was determined in morning saliva, urine, and gastrointestinal tract secretions. The results were analyzed using descriptive statistics, independent sample t-criterion, and Pearson correlation coefficient.

RESULTS

A decrease in the total number of leukocyte cells in the Saami was associated with a high incidence of leukopenia, lymphopenia, and neutropenia. Deficiency in active phagocytes and serum IgA and sIgA concentrations was revealed as well as increased contents of CD4+ and CD8+ receptor lymphocytes, membrane and free adhesion molecules, and transferrin. Leukocytosis, lymphocytosis, neutrophilia, monocytosis, and eosinophilia with increased contents of natural killer cells, IL-6, and IL-10 were recorded more frequently in the Russians. High levels of IgE and IFN-γ, which have the most pronounced cytotoxicity and are indicative of strained immune mechanisms, were characteristic of the Saami and Russians.

CONCLUSION

The distinctive aspects of the immune status of the Kola Saami is related to the deficit in the active phagocyte and serum IgA and sIgA concentrations as well as the increase in the contents of cytotoxic lymphocytes, intercellular adhesion molecules, transferrin, and IFN-γ proinflammatory cytokines. The Russian inhabitants of the Far North are characterized by an adaptive response manifested by an increase in antibody-dependent cytotoxicity, involving IL-6 and IL-10.

Intercellular adhesion molecule 1 and selectin l play crucial roles in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease that primarily affects the mucosal layer of the colon (large intestine). However, the relationship between Intercellular Adhesion Molecule-1 (ICAM1), SELL and UC is unclear. The UC datasets, GSE87466 and GSE36807, were downloaded from the gene expression omnibus database. The R package limma was utilized to identify differentially expressed genes (DEGs). Weighted gene co-expression network analysis was conducted. The construction and analysis of protein-protein interaction network, functional enrichment analysis, gene set enrichment analysis, and comparative toxicogenomics database analysis were performed. TargetScan was employed to screen miRNAs regulating central DEGs. Western blot (WB) was used to verify. A total of 2118 DEGs were identified in our study. Gene ontology analysis indicated their enrichment primarily in immune system processes, cellular responses to chemical stimuli, responses to organic substances, responses to external stimuli, and immune responses. Kyoto Encyclopedia of Genes and Genomes analysis revealed that the target cells were mainly enriched in chemokine signaling pathways and TNF signaling pathways. Gene set enrichment analysis enrichment analysis showed significant enrichment in chemokine signaling pathways and cell adhesion molecules. In the Metascape enrichment project, gene ontology terms included regulation of cell activation and positive regulation of immune response. Through the construction and analysis of a protein-protein interaction network, we identified 11 core genes (ICAM1, SELL, CD44, CD40, CCR7, CXCL8, CD19, CCL4, CD274, IL7R, IL1B). We found that the core genes (ICAM1, SELL) were highly expressed in UC samples and lowly expressed in normal samples, suggesting their potential regulatory roles in UC. These core genes were associated with lymphoproliferative disorders, inflammation and necrosis. WB results confirmed the high expression of ICAM1 and SELL in UC. ICAM1 and SELL are highly expressed in UC, and the higher the ICAM1 and SELL genes, the worse the prognosis.

Identifying New Contributors to Brain Metastasis in Lung Adenocarcinoma: A Transcriptomic Meta-Analysis

Lung tumors frequently metastasize to the brain. Brain metastasis (BM) is common in advanced cases, and a major cause of patient morbidity and mortality. The precise molecular mechanisms governing BM are still unclear, in part attributed to the rarity of BM specimens. In this work, we compile a unique transcriptomic dataset encompassing RNA-seq, microarray, and single-cell analyses from BM samples obtained from patients with lung adenocarcinoma (LUAD). By integrating this comprehensive dataset, we aimed to enhance understanding of the molecular landscape of BM, thereby facilitating the identification of novel and efficient treatment strategies. We identified 102 genes with significantly deregulated expression levels in BM tissues, and discovered transcriptional alterations affecting the key driver 'hub' genes CD69 (a type II C-lectin receptor) and GZMA (Granzyme A), indicating an important role of the immune system in the development of BM from primary LUAD. Our study demonstrated a BM-specific gene expression pattern and revealed the presence of dendritic cells and neutrophils in BM, suggesting an immunosuppressive tumor microenvironment. These findings highlight key drivers of LUAD-BM that may yield therapeutic targets to improve patient outcomes.

Glycopeptide Antibiotics Impair Neutrophil Effector Functions

INTRODUCTION

Neutrophilic granulocytes represent the first line of defense against microorganisms. Granulocytes phagocytose microorganisms and specifically synthesize oxygen radicals against them, which eventually kills the invaders.

METHODS

Neutrophilic granulocytes were isolated from peripheral blood of healthy volunteer donors. Putative interference of new-generation antibiotics with neutrophil function was tested using a collection of granulocyte-stimulating agents and Amplex™ Red-based plate assay and flow cytometry-based respiratory burst assays. In addition, phagocytosis of E. coli, IL-8 production, bactericidal activity, and CD62L expression of granulocytes were evaluated.

RESULTS

Of note, we found that the two glycopeptide antibiotics dalbavancin and teicoplanin inhibited ROS production upon granulocyte activation via different signaling pathways in a dose-dependent manner. Dalbavancin also blocked the PMA-induced shedding of CD62L. In contrast, the oxazolidinone antibiotics tedizolid and linezolid had no effect on neutrophil function, while the combination of ceftazidime/avibactam dose dependently inhibited the fMLP/Cytochalasin B-induced granulocyte burst in a dose-dependent manner. Additionally, we showed that dalbavancin and teicoplanin as well as sulfametrole/trimethoprim and ceftazidime/avibactam inhibited baseline and PMA-induced IL-8 production by neutrophilic granulocytes. Moreover, dalbavancin impaired the bactericidal activity of neutrophilic granulocytes.

CONCLUSION

We here identified hitherto unknown inhibitory effects of several classes of antibiotics on the effector functions of neutrophilic granulocytes.

Single-cell RNA-seq analysis reveals BHLHE40-driven pro-tumour neutrophils with hyperactivated glycolysis in pancreatic tumour microenvironment

OBJECTIVE

Innate immunity plays important roles in pancreatic ductal adenocarcinoma (PDAC), as non-T-cell-enriched tumour. Neutrophils are major players in innate immune system. Here, we aimed to explore the heterogeneity and pro-tumour mechanisms of neutrophils in PDAC.

DESIGN

We analysed single-cell transcriptomes of peripheral blood polymorphonuclear leucocytes (PMNs) and tumour-infiltrating immune cells from five patients with PDAC, and performed immunofluorescence/immunohistochemistry staining, multi-omics analysis and in vitro experiments to validate the discoveries of bioinformatics analysis.

RESULTS

Exploration of the heterogeneity of tumour-associated neutrophils (TANs) revealed a terminally differentiated pro-tumour subpopulation (TAN-1) associated with poor prognosis, an inflammatory subpopulation (TAN-2), a population of transitional stage that have just migrated to tumour microenvironment (TAN-3) and a subpopulation preferentially expressing interferon-stimulated genes (TAN-4). Glycolysis signature was upregulated along neutrophil transition trajectory, and TAN-1 was featured with hyperactivated glycolytic activity. The glycolytic switch of TANs was validated by integrative multi-omics approach of transcriptomics, proteomics and metabolomics analysis. Activation of glycolytic activity by LDHA overexpression induced immunosuppression and pro-tumour functions in neutrophil-like differentiated HL-60 (dHL-60) cells. Mechanistic studies revealed BHLHE40, downstream to hypoxia and endoplasmic reticulum stress, was a key regulator in polarisation of neutrophils towards TAN-1 phenotype, and direct transcriptional regulation of BHLHE40 on TAN-1 marker genes was demonstrated by chromatin immunoprecipitation assay. Pro-tumour and immunosuppression functions were observed in dHL-60 cells overexpressing BHLHE40. Importantly, immunohistochemistry analysis of PDAC tissues revealed the unfavourable prognostic value of BHLHE40+ neutrophils.

CONCLUSION

The dynamic properties of TANs revealed by this study will be helpful in advancing PDAC therapy targeting innate immunity.

Crosstalk between oxidative stress and neutrophil response in early ischemic stroke: a comprehensive transcriptome analysis

Background

Ischemic stroke (IS) is the second leading cause of mortality worldwide, continuing to be a serious health concern. It is well known that oxidative stress and neutrophil response play vital roles in the pathophysiology of early IS. However, the complex interactions and critical genes associated with them have not been fully understood.

Methods

Two datasets (GSE37587 and GSE16561) from the Gene Expression Omnibus database were extracted and integrated as the discovery dataset. Subsequent GSVA and WGCNA approaches were used to investigate IS-specific oxidative stress-related genes (ISOSGS). Then, we explored IS-specific neutrophil-associated genes (ISNGS) using CIBERSORT analysis. Next, the protein-protein interaction network was established to ascertain candidate critical genes related with oxidative stress and neutrophil response. Furthermore, these candidate genes were validated using GSE58294 dataset and our clinical samples by RT-qPCR method. Finally, functional annotation, diagnostic capability evaluation and drug-gene interactions were performed by using GSEA analysis, ROC curves and DGIDB database.

Result

In our analysis of discovery dataset, 155 genes were determined as ISOSGS and 559 genes were defined as ISNGS. Afterward, 9 candidate genes were identified through the intersection of ISOSGS and ISNGS, PPI network construction, and filtration by degree algorithm. Then, six real critical genes, including STAT3, MMP9, AQP9, SELL, FPR1, and IRAK3, passed the validation using the GSE58294 dataset and our clinical samples. Further functional annotation analysis indicated these critical genes were associated with neutrophil response, especially neutrophil extracellular trap. Meanwhile, they had a good diagnostic performance. Lastly, 53 potential drugs targeting these genes were predicted by DGIDB database.

Conclusion

We identified 6 critical genes, STAT3, FPR1, AQP9, SELL, MMP9 and IRAK3, related to oxidative stress and neutrophil response in early IS, which may provide new insights into understanding the pathophysiological mechanism of IS. We hope our analysis could help develop novel diagnostic biomarkers and therapeutic strategies for IS.

Enhancement of Cell Adhesion by Anaplasma phagocytophilum Nucleolin-Interacting Protein AFAP

Anaplasma phagocytophilum, the aetiologic agent of human granulocytic anaplasmosis (HGA), is an obligate intracellular Gram-negative bacterium. During infection, A. phagocytophilum enhances the adhesion of neutrophils to the infected endothelial cells. However, the bacterial factors contributing to this phenomenon remain unknown. In this study, we characterized a type IV secretion system substrate of A. phagocytophilum, AFAP (an actin filament-associated Anaplasma phagocytophilum protein) and found that it dynamically changed its pattern and subcellular location in cells and enhanced cell adhesion. Tandem affinity purification combined with mass spectrometry identified host nucleolin as an AFAP-interacting protein. Further study showed the disruption of nucleolin by RNA interference, and the treatment of a nucleolin-binding DNA aptamer AS1411 attenuated AFAP-mediated cell adhesion, indicating that AFAP enhanced cell adhesion in a nucleolin-dependent manner. The characterization of cell adhesion-enhancing AFAP and the identification of host nucleolin as its interaction partner may help understand the mechanism underlying A. phagocytophilum-promoting cell adhesion, facilitating the elucidation of HGA pathogenesis.

Neutrophil phenotypes in bronchial airways differentiate single from dual responding allergic asthmatics

INTRODUCTION

Allergic asthmatics with both an early (EAR) and a late allergic reaction (LAR) following allergen exposure are termed 'dual responders' (DR), while 'single responders' (SR) only have an EAR. Mechanisms that differentiate DR from SR are largely unknown, particularly regarding the role and phenotypes of neutrophils. Therefore, we aimed to study neutrophils in DR and SR asthmatics.

METHODS

Thirty-four allergic asthmatics underwent an inhaled allergen challenge, samples were collected before and up to 24 h post-challenge. Cell differentials were counted from bronchial lavage, alveolar lavage and blood; and tissue neutrophils were quantified in immune-stained bronchial biopsies. Lavage neutrophil nuclei lobe segmentation was used to classify active (1-4 lobes) from suppressive neutrophils (≥5 lobes). Levels of transmigration markers: soluble (s)CD62L and interleukin-1Ra, and activity markers: neutrophil elastase (NE), DNA-histone complex and dsDNA were measured in lavage fluid and plasma.

RESULTS

Compared with SR at baseline, DR had more neutrophils in their bronchial airways at baseline, both in the lavage (p = .0031) and biopsies (p = .026) and elevated bronchial neutrophils correlated with less antitransmigratory IL-1Ra levels (r = -0.64). DR airways had less suppressive neutrophils and more 3-lobed (active) neutrophils (p = .029) that correlated with more bronchial lavage histone (p = .020) and more plasma NE (p = .0016). Post-challenge, DR released neutrophil extracellular trap factors in the blood earlier and had less pro-transmigratory sCD62L during the late phase (p = .0076) than in SR.

CONCLUSION

DR have a more active airway neutrophil phenotype at baseline and a distinct neutrophil response to allergen challenge that may contribute to the development of an LAR. Therefore, neutrophil activity should be considered during targeted diagnosis and bio-therapeutic development for DR.

Uncovering the gene regulatory network of type 2 diabetes through multi-omic data integration

BACKGROUND

Type 2 diabetes (T2D) onset is a complex, organized biological process with multilevel regulation, and its physiopathological mechanisms are yet to be elucidated. This study aims to find out the key drivers and pathways involved in the pathogenesis of T2D through multi-omics analysis.

METHODS

The datasets used in the experiments comprise three groups: (1) genomic (2) transcriptomic, and (3) epigenomic categories. Then, a series of bioinformatics technologies including Marker set enrichment analysis (MSEA), weighted key driver analysis (wKDA) was performed to identify key drivers. The hub genes were further verified by the Receiver Operator Characteristic (ROC) Curve analysis, proteomic analysis, and Real-time quantitative polymerase chain reaction (RT-qPCR). The multi-omics network was applied to the Pharmomics pipeline in Mergeomics to identify drug candidates for T2D treatment. Then, we used the drug-gene interaction network to conduct network pharmacological analysis. Besides, molecular docking was performed using AutoDock/Vina, a computational docking program.

RESULTS

Module-gene interaction network was constructed using MSEA, which revealed a significant enrichment of immune-related activities and glucose metabolism. Top 10 key drivers (PSMB9, COL1A1, COL4A1, HLA-DQB1, COL3A1, IRF7, COL5A1, CD74, HLA-DQA1, and HLA-DRB1) were selected by wKDA analysis. Among these, COL5A1, IRF7, CD74, and HLA-DRB1 were verified to have the capability to diagnose T2D, and expression levels of PSMB9 and CD74 had significantly higher in T2D patients. We further predict the co-expression network and transcription factor (TF) binding specificity of the key driver. Besides, based on module interaction networks and key driver networks, 17 compounds are considered to possess T2D-control potential, such as sunitinib.

CONCLUSIONS

We identified signature genes, biomolecular processes, and pathways using multi-omics networks. Moreover, our computational network analysis revealed potential novel strategies for pharmacologic interventions of T2D.

Macromolecules Absorbed from Influenza Infection-Based Sera Modulate the Cellular Uptake of Polymeric Nanoparticles

Optimizing the biological identity of nanoparticles (NPs) for efficient tumor uptake remains challenging. The controlled formation of a protein corona on NPs through protein absorption from biofluids could favor a biological identity that enables tumor accumulation. To increase the diversity of proteins absorbed by NPs, sera derived from Influenza A virus (IAV)-infected mice were used to pre-coat NPs formed using a hyperbranched polyester polymer (HBPE-NPs). HBPE-NPs, encapsulating a tracking dye or cancer drug, were treated with sera from days 3-6 of IAV infection (VS3-6), and uptake of HBPE-NPs by breast cancer cells was examined. Cancer cells demonstrated better uptake of HBPE-NPs pre-treated with VS3-6 over polyethylene glycol (PEG)-HBPE-NPs, a standard NP surface modification. The uptake of VS5 pre-treated HBPE-NPs by monocytic cells (THP-1) was decreased over PEG-HBPE-NPs. VS5-treated HBPE-NPs delivered a cancer drug more efficiently and displayed better in vivo distribution over controls, remaining stable even after interacting with endothelial cells. Using a proteomics approach, proteins absorbed from sera-treated HBPE-NPs were identified, such as thrombospondin-1 (TSP-1), that could bind multiple cancer cell receptors. Our findings indicate that serum collected during an immune response to infection is a rich source of macromolecules that are absorbed by NPs and modulate their biological identity, achieving rationally designed uptake by targeted cell types.

Single-cell RNA sequencing reveals cellular and molecular reprograming landscape of gliomas and lung cancer brain metastases

BACKGROUND

Brain malignancies encompass gliomas and brain metastases originating from extracranial tumours including lung cancer. Approximately 50% of patients with lung adenocarcinoma (LUAD) will eventually develop brain metastases. However, the specific characteristics of gliomas and lung-to-brain metastases (LC) are largely unknown.

METHODS

We applied single-cell RNA sequencing to profile immune and nonimmune cells in 4 glioma and 10 LC samples.

RESULTS

Our analysis revealed that tumour microenvironment (TME) cells are present in heterogeneous subpopulations. LC reprogramed cells into immune suppressed state, including microglia, macrophages, endothelial cells, and CD8+ T cells, with unique cell proportions and gene signatures. Particularly, we identified that a subset of macrophages was associated with poor prognosis. ROS (reactive oxygen species)-producing neutrophils was found to participant in angiogenesis. Furthermore, endothelial cells participated in active communication with fibroblasts. Metastatic epithelial cells exhibited high heterogeneity in chromosomal instability (CIN) and cell population.

CONCLUSIONS

Our findings provide a comprehensive understanding of the heterogenicity of the tumor microenvironment and tumour cells and it will be crucial for successful immunotherapy development for brain metastasis of lung cancer.

SELL and GUCY1A1 Gene Polymorphisms in Patients with Unstable Angina

Acute ischaemia is mostly caused by the rupture of an unstable atherosclerotic plaque in a coronary artery, resulting in platelet accumulation and thrombus formation, which closes the lumen of the coronary vessel. Many different factors can cause atherosclerotic plaques to occlude the lumen of a coronary artery, including factors that increase vascular inflammation and blood platelet aggregation, as well as genetic factors. L-selectin is an adhesion molecule encoded by the human SELL gene, playing an important role in leukocyte adhesion to the endothelium and the development of inflammation. Guanylate cyclase 1 soluble subunit alpha 1 (GUCY1A1) is a gene that affects vasoreactivity and platelet function, thereby influencing thrombotic processes and the risk of developing thrombotic lesions in the coronary vessels. In SELL and GUCY1A1 genes, several polymorphisms have been detected, which may affect gene expression. The aim of our study was to assess the association between the SELL rs2205849 and rs2229569 and GUCY1A1 rs7692387 polymorphisms with the risk of acute coronary syndromes in the form of unstable angina pectoris, and the association between these polymorphisms and selected clinical parameters affecting the risk of developing ischemic heart disease. The study included 232 patients with unstable angina. The diagnosis of unstable angina was achieved by a typical clinical presentation and confirmation of significant coronary artery lumen stenosis (>70%) during coronary angiography. There were no statistically significant differences in GUCY1A1 rs7692387 and SELL rs2205849 and rs2229569 polymorphism distribution between the total study and the control groups. However, when only analysing patients over 55 years of age, we found a decreased frequency of the GUCY1A1 rs7692387AA genotype (AA vs. GA + GG, OR: 0.07; 95% CI: 0.01−0.78) and an increased frequency of the SELL rs2205849 CC genotype (CC vs. TC + TT p = 0.022) and SELL rs2229569 AA genotype (AA vs. GA + GG p = 0.022) in patients with unstable angina. Our results suggest that the SELL rs2205849 and rs2229569 and GUCY1A1 rs7692387 polymorphisms are not risk factors for unstable angina in the Polish population. The GUCY1A1 rs7692387 polymorphism may increase the risk of unstable angina in patients younger than 55 years, while the SELL polymorphisms rs2205849 and rs2229569 may increase the risk of unstable angina in patients older than 55 years in the Polish population.

Selectin-Mediated Signaling-Shedding Light on the Regulation of Integrin Activity in Neutrophils

As a consequence of tissue injury or infection, neutrophils are recruited in a stepwise recruitment process from the bloodstream into the surrounding tissue. Selectins are a family of adhesion molecules comprised of L-, E-, and P-selectin. Differences in expression patterns, protein structure, and ligand binding characteristics mediate distinct functions of each selectin. Interactions of selectins and their counter-receptors mediate the first contact of neutrophils with the endothelium, as well as subsequent neutrophil rolling along the endothelial surface. For efficient neutrophil recruitment, activation of β₂-integrins on the cell surface is essential. Integrin activation can be elicited via selectin- as well as chemokine-mediated inside-out signaling resulting in integrin conformational changes and clustering. Dysregulation of selectin-induced integrin activation on neutrophils is involved in the development of severe pathological disease conditions including leukocyte adhesion deficiency (LAD) syndromes in humans. Here, we review molecular mechanisms involved in selectin-mediated signaling pathways in neutrophils and their impact on integrin activation, neutrophil recruitment, and inflammatory diseases.

Dysregulation of Biomarkers of Hemostatic Activation and Inflammatory Processes are Associated with Adverse Outcomes in Pulmonary Embolism

Introduction

The pathophysiology of pulmonary embolism (PE) represents complex, multifactorial processes involving blood cells, vascular endothelium, and the activation of inflammatory pathways. Platelet (P), endothelial (E), and leukocyte (L)-selectin molecules may play an important role in PE pathophysiology. We aimed to profile the biomarkers of inflammation, including selectins in PE patients, and compare them to healthy individuals.

Materials and methods

100 acute PE patients and 50 controls were included in this case control study. ELISA methods were used to quantify levels of selectins, inflammatory, and hemostatic biomarkers.

Results

In PE patients, levels of selectin molecules as compared to controls convey increased P-selectin levels (95 ng/mL vs 40 ng/mL, p < .0001) and decreased L-selectin levels (1468 ng/mL vs 1934 ng/mL, p < .0001). Significant correlations were found between selectins and Plasminogen Activating Inhibitor-1 (PAI-1), Tumor Necrosis Factor-a (TNFa), and D-dimer. Fold change between selectins and controls is compared to other biomarkers, illustrating degrees of change comparable to TNFa, alpha-2-antiplasmin, and microparticles. L-selectin levels are inversely associated with all-cause-mortality in PE patients, (p = .040).

Conclusion

These studies suggest that various thrombo-inflammatory biomarkers are elevated in PE patients. Furthermore, L-selectin levels are inversely associated with mortality outcomes.

Rho signaling inhibition mitigates lung injury via targeting neutrophil recruitment and selectin-AKT signaling

Neutrophils, the early responders of the immune system, eliminate intruders, but their over-activation can also instigate tissue damage leading to various autoimmune and inflammatory disease conditions. As approaches causing neutropenia are associated with immunodeficiency, targeting aberrant neutrophil infiltration offers an attractive strategy in neutrophil-centered diseases including acute lung injury. Rho GTPase family proteins Rho, Rac and Cdc42 play important role as regulators of chemotaxis in diverse systems. Rho inhibitors protected against lung injuries, while genetic Rho-deficiency exhibited neutrophil hyperactivity and exacerbated lung injury. These differential outcomes might be due to distinct effects on different cell types or activation/ inhibition of specific signaling pathways responsible for neutrophil polarity, migration and functions. In this study, we explored neutrophil centric effects of Rho signaling mitigation. Consistent with previous reports, Rho signaling inhibitor Y-27632 provided protection against acute lung injury, but without regulating LPS mediated systemic increase of neutrophils in the circulation. Interestingly, the adoptive transfer approach identified a specific defect in neutrophil migration capacity after Rho signaling mitigation. These defects were associated with loss of polarity and altered actin dynamics identified using time-lapse in vitro studies. Further analysis revealed a rescue of stimulation-dependent L-selectin shedding on neutrophils with Rho signaling inhibitor. Surprisingly, functional blocking of L-selectin (CD62L) led to defective recruitment of neutrophils into inflamed lungs. Further, single-cell level analyses identified MAPK signaling as downstream mechanism of Rho signaling and L-selectin mediated effects. p-AKT levels were diminished in detergent resistance membrane-associated signalosome upon Rho signaling inhibition and blockade of selectin. Moreover, inhibition of AKT signaling as well as selectin blocking led to defects in neutrophil polarity. Together, this study identified Rho-dependent distinct L-selectin and AKT signaling mediated regulation of neutrophil recruitment to inflamed lung tissue.