Extracellular Chromatin Triggers Release of Soluble CEACAM8 Upon Activation of Neutrophils

Cardiorenal protective effects of Tanhuo decoction in acute myocardial infarction via regulating multi-target inflammation and metabolic signaling pathways

Introduction

Inflammation is a key driver of adverse outcomes in acute myocardial infarction (AMI), yet current western anti-inflammatory therapies are limited by their single-target nature and side effects. Traditional Chinese medicine (TCM), such as Tanhuo Decoction (THD), offers a multi-target, low-toxicity alternative.

Methods

In a randomized controlled trial, AMI patients with high inflammatory responses received either standard Western medicine (WM) alone or combined with THD for 3 days. Clinical outcomes and inflammatory markers were assessed, and proteomic and network pharmacology analyses were performed.

Results

The THD + WM group showed significant reductions in neutrophil counts and hs-CRP levels, along with improved creatinine clearance rate (CCR), compared to WM alone. Proteomic analysis revealed downregulation of pro-inflammatory proteins (PTX3, IL-18, TNFRSF11A) and upregulation of the anti-inflammatory IL1RL2. THD also modulated lipid metabolism and insulin sensitivity pathways.

Discussions

THD enhances the anti-inflammatory and metabolic benefits of standard AMI therapy through multi-target pathway regulation. These findings support its integration into modern cardiovascular care, particularly for patients with high inflammatory and metabolic risk.

A Point-of-Care Diagnostic Platform for Detecting Host Immune Activation due to Infections: Cytocapture of Biomarkers In Situ (CyBIS)

The prompt diagnosis of internal infections is an important, but surprisingly difficult, component of healthcare. Existing clinical and laboratory tests, such as complete blood counts, are low accuracy (~70%), time consuming (>90 min), and require expensive blood analyzers. More sensitive and specific tests, such as PCR or sequencing, require access to a sample of the infected tissue, genomic data for all potential pathogens and expensive equipment. Culturing organisms introduces its own biases and is prone to false positives due to contamination. We describe a device for the rapid isolation of neutrophils and measurement of neutrophil elastase activity to provide a measure of host immune activity toward a broad range of infectious agents. CyBIS (Cytocapture of Biomarkers In Situ) is a Point-of-Care (POC) device that isolates neutrophils from a small volume of blood (75 ul) using anti-CD66b antibody-coated paramagnetic beads and analyzes elastase activity via a kinetic assay. This inexpensive and rapid (35 min) testing system provides a quantitative measure that combines neutrophil count with neutrophil elastase activity per cell to diagnose elevated host immune activity and possible infection. Neutrophil-associated elastase is elevated in emergency department patients with clinically relevant infections, including sepsis, compared to healthy control patients.

Fantastic proteins and where to find them - histones, in the nucleus and beyond

Animal genomes are packaged into chromatin, a highly dynamic macromolecular structure of DNA and histone proteins organised into nucleosomes. This accommodates packaging of lengthy genomic sequences within the physical confines of the nucleus while also enabling precise regulation of access to genetic information. However, histones existed before chromatin and have lesser-known functions beyond genome regulation. Most notably, histones are potent antimicrobial agents, and the release of chromatin to the extracellular space is a defence mechanism nearly as ancient and widespread as chromatin itself. Histone sequences have changed very little throughout evolution, suggesting the possibility that some of their 'non-canonical' functions are at play in parallel or in concert with their genome regulatory functions. In this Review, we take an evolutionary perspective of histone, nuclear chromatin and extracellular chromatin biology and describe the known extranuclear and extracellular functions of histones. We detail molecular mechanisms of chromatin release and extracellular chromatin sensing, and we discuss their roles in physiology and disease. Finally, we present evidence and give a perspective on the potential of extracellular histones to act as bioactive, cell modulatory factors.

The role of CEACAMs in neutrophil function

BACKGROUND

In addition to the long-known antibacterial actions of neutrophils, neutrophils are recognized to have a variety of other effects and are functionally diverse. Neutrophils can either stimulate or inhibit B cells and T cells, regulate NK development and activity, augment or direct the resolution of inflammation, act as myeloid-derived suppressor cells, modulate tumour growth and metastasis and trigger autoimmune diseases. CEACAMs 1, 3, 6 and 8 are expressed on human neutrophils.

METHODS

A literature review was performed on the role of CEACAMs in neutrophil function.

RESULTS

CEACAMs 1, 6 and 8 can be upregulated from intracellular stores, while CEACAM3, an opsonin-independent phagocytic receptor, is constitutively expressed. CEACAM1 has an intracellular ITIM motif and an ITSM motif, and CEACAM3 has an ITAM-like motif; CEACAMs 6 and 8 are glycosylphosphatidylinositol-linked. CEACAM8 can also be released in a soluble form. These CEACAMs can interact with multiple other host CEACAMs as well as other molecules on bacteria, fungi and host cells, both transmitting and receiving signals. Known CEACAM-binding pathogens bind the CFG face of the N domain which is also important in CEACAM-CEACAM binding, although the ABDE face also appears to be involved in higher-order oligomers.

CONCLUSIONS

Understanding the exact role of each individual CEACAM in human neutrophils is complicated by the fact that the neutrophil CEACAMs can interact with multiple ligands. The data demonstrates some of the many roles of CEACAMs in neutrophil function and the extensive role of the neutrophil in human biology beyond its classical role as a short-lived phagocyte.

Multi-omics landscape of childhood simple obesity: novel insights into pathogenesis and biomarkers discovery

BACKGROUND

The increasing incidence of childhood obesity annually has led to a surge in physical and mental health risks, making it a significant global public health concern. This study aimed to discover novel biomarkers of childhood simple obesity through integrative multi-omics analysis, uncovering their potential connections and providing fresh research directions for the complex pathogenesis and treatment strategies.

METHODS

Transcriptome, untargeted metabolome, and 16 S rDNA sequencing were conducted on subjects to examine transcripts, metabolites in blood, and gut microflora in stool.

RESULTS

Transcriptomic analysis identified 599 differentially expressed genes (DEGs), of which 25 were immune-related genes, and participated in immune pathways such as antimicrobial peptides, neutrophil degranulation, and interferons. The optimal random forest model based on these genes exhibited an AUC of 0.844. The metabolomic analysis examined 71 differentially expressed metabolites (DEMs), including 12 immune-related metabolites. Notably, lauric acid showed an extremely strong positive correlation with BMI and showed a good discriminative power for obesity (AUC = 0.82). DEMs were found to be significantly enriched in four metabolic pathways, namely "Aminoacyl-tRNA biosynthesis", "Valine leucine and isoleucine biosynthesis, and Glycine", "Serine and threonine metabolism", and "Biosynthesis of unsaturated fatty acids". Microbiome analysis revealed 12 differential gut microbiotas (DGMs) at the phylum and genus levels, with p_Firmicutes dominating in the obese group and g_Escherichia-Shigella in the normal group. Subsequently, a Random Forest model was developed based on the DEMs, immune-related DEGs, and metabolites with an AUC value of 0.912. The 14 indicators identified by this model could potentially serve as a set of biomarkers for obesity. The analysis of the inter-omics correlation network found 233 pairs of significant correlations. DEGs BPIFA1, BPI, and SAA1, DEMs Dimethy(tetradecyl)amine, Deoxycholic acid, Pathalic anhydride, and DL-Alanine, and DGMs g_Intestinimonas and g_Turicibacter showed strong connectivity within the network, constituting a large proportion of interactions.

CONCLUSION

This study presents the first comprehensive description of the multi-omics characteristics of childhood simple obesity, recognizing promising biomarkers. Immune-related markers offer a new perspective for researching the immunological mechanisms underlying obesity and its associated complications. The revealed interactions among these biomarkers contribute to a deeper understanding the intricate biological regulatory networks associated with obesity.

Identification of key genes as potential diagnostic biomarkers in sepsis by bioinformatics analysis

Background

Sepsis, an infection-triggered inflammatory syndrome, poses a global clinical challenge with limited therapeutic options. Our study is designed to identify potential diagnostic biomarkers of sepsis onset in critically ill patients by bioinformatics analysis.

Methods

Gene expression profiles of GSE28750 and GSE74224 were obtained from the Gene Expression Omnibus (GEO) database. These datasets were merged, normalized and de-batched. Weighted gene co-expression network analysis (WGCNA) was performed and the gene modules most associated with sepsis were identified as key modules. Functional enrichment analysis of the key module genes was then conducted. Moreover, differentially expressed gene (DEG) analysis was conducted by the "limma" R package. Protein-protein interaction (PPI) network was created using STRING and Cytoscape, and PPI hub genes were identified with the cytoHubba plugin. The PPI hub genes overlapping with the genes in key modules of WGCNA were determined to be the sepsis-related key genes. Subsequently, the key overlapping genes were validated in an external independent dataset and sepsis patients recruited in our hospital. In addition, CIBERSORT analysis evaluated immune cell infiltration and its correlation with key genes.

Results

By WGCNA, the greenyellow module showed the highest positive correlation with sepsis (0.7, p = 2e - 19). 293 DEGs were identified in the merged datasets. The PPI network was created, and the CytoHubba was used to calculate the top 20 genes based on four algorithms (Degree, EPC, MCC, and MNC). Ultimately, LTF, LCN2, ELANE, MPO and CEACAM8 were identified as key overlapping genes as they appeared in the PPI hub genes and the key module genes of WGCNA. These sepsis-related key genes were validated in an independent external dataset (GSE131761) and sepsis patients recruited in our hospital. Additionally, the immune infiltration profiles differed significantly between sepsis and non-sepsis critical illness groups. Correlations between immune cells and these five key genes were assessed, revealing that plasma cells, macrophages M0, monocytes, T cells regulatory, eosinophils and NK cells resting were simultaneously and significantly associated with more than two key genes.

Conclusion

This study suggests a critical role of LTF, LCN2, ELANE, MPO and CEACAM8 in sepsis and may provide potential diagnostic biomarkers and therapeutic targets for the treatment of sepsis.

Immunomodulatory effects of a cell processing device to ameliorate dysregulated hyperinflammatory disease states

Cell directed therapy is an evolving therapeutic approach to treat organ dysfunction arising from hyperinflammation and cytokine storm by processing immune cells in an extracorporeal circuit. To investigate the mechanism of action of the Selective Cytopheretic Device (SCD), in vitro blood circuits were utilized to interrogate several aspects of the immunomodulatory therapy. SCD immunomodulatory activity is due to its effects on circulating neutrophils and monocytes in a low ionized calcium (iCa, Ca2+) blood circuit. Activated neutrophils adhere to the SCD fibers and degranulate with release of the constituents of their exocytotic vesicles. Adhered neutrophils in the low iCa environment display characteristics of apoptotic senescence. These neutrophils are subsequently released and returned back to circulation, demonstrating a clear potential for in vivo feedback. For monocytes, SCD treatment results in the selective adhesion of more pro-inflammatory subsets of the circulating monocyte pool, as demonstrated by both cell surface markers and cytokine secretory rates. Once bound, over time a subset of monocytes are released from the membrane with a less inflammatory functional phenotype. Similar methods to interrogate mechanism in vitro have been used to preliminarily confirm comparable findings in vivo. Therefore, the progressive amelioration of circulating leukocyte activation and immunomodulation of excessive inflammation observed in SCD clinical trials to date is likely due to this continuous autologous leukocyte processing.

Analyzing Flow Cytometry or Targeted Gene Expression Data Influences Clinical Discoveries-Profiling Blood Samples of Pancreatic Ductal Adenocarcinoma Patients

INTRODUCTION

Monitoring the therapeutic response of pancreatic ductal adenocarcinoma (PDAC) patients is crucial to determine treatment strategies. Several studies have examined the effectiveness of FOLFIRINOX as a first-line treatment in patients with locally advanced pancreatic cancer, but little attention has been paid to the immunologic alterations in peripheral blood caused by this chemotherapy regimen. Furthermore, the influence of the measurement type (e.g., flow cytometry and targeted gene expression) on the clinical discoveries is unknown. Therefore, we aimed to scrutinize the influence of using flow cytometry or targeted immune gene expression to study the immunological changes in blood samples of PDAC patients who were treated with a single-cycle FOLFIRINOX combined with lipegfilgrastim (FFX-Lipeg).

MATERIAL AND METHODS

Whole-blood samples from 44 PDAC patients were collected at two time points: before the first FOLFIRINOX cycle and 14 days after the first cycle. EDTA blood tubes were used for multiplex flow cytometry analyses to quantify 18 immune cell populations and for complete blood count tests as the standard clinical routine. The flow cytometry data were analyzed with FlowJo software. In addition, Tempus blood tubes were used to isolate RNA and measure 1230 immune-related genes using NanoString Technology®. Data quality control, normalization, and analysis were performed using nSolver™ software and the Advanced Analysis module.

RESULTS

FFX-Lipeg treatment increased the number of neutrophils and monocytes, as shown by flow cytometry and complete blood count in concordance with elevated gene expression measured via targeted gene expression profiling analysis. Interestingly, flow cytometry analysis showed an increase in the number of B and T cells after treatment, while targeted gene expression analysis showed a decrease in B and T cell-specific gene expression.

CONCLUSIONS

Targeted gene expression complements flow cytometry analysis to provide a comprehensive understanding of the effects of FFX-Lipeg. Flow cytometry and targeted gene expression showed increases in neutrophils and monocytes after FFX-Lipeg. The number of lymphocytes is increased after treatment; nevertheless, their cell-specific gene expression levels are downregulated. This highlights that different techniques influence clinical discoveries. Therefore, it is important to carefully select the measurement technique used to study the effect of a treatment.

Potential biomarkers for active renal involvement in systemic lupus erythematosus patients

OBJECTIVE

This study aimed to identify the key genes related to active renal involvement in patients with systemic lupus erythematosus (SLE).

METHODS

Microarray datasets were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between SLE patients with active renal involvement and those who did not have active renal involvement were identified by R software. Hub genes were identified using protein-protein interaction networks. The relationships between the expression levels of identified hub genes and SLEDAI were subjected to linear correlation analysis. The diagnostic accuracy of the hub genes was evaluated with the area under the curve of the receiver operating characteristic curve (ROC-AUC). Transcription factors (TFs) were predicted. The expression levels of different hub genes and histopathological patterns were also examined.

RESULTS

A total of 182 DEGs were identified. Enrichment analysis indicated that DEGs were primarily enriched in neutrophil degranulation, neutrophil activation involved in immune response and neutrophil activation. The expression levels of 12 identified hub genes were verified. Ten of the 12 hub genes were positively associated with SLEDAI. The combination model of DEFA4, CTSG, RETN, CEACAM8, TOP2A, LTF, MPO, ELANE, BIRC5, and LCN2 had a certain diagnostic accuracy in detecting renal involvement with high disease activity in SLE patients. The expressions of five predicted TFs were validated by GSE65391 dataset.

CONCLUSION

This work explored the pathogenesis of renal involvement in SLE. These results may guide future experimental research and clinical transformation.

Molecular profiling of kidney compartments from serial biopsies differentiate treatment responders from non-responders in lupus nephritis

The immune pathways that define treatment response and non-response in lupus nephritis (LN) are unknown. To characterize these intra-kidney pathways, transcriptomic analysis was done on protocol kidney biopsies obtained at flare (initial biopsy (Bx1)) and after treatment (second biopsy (Bx2)) in 58 patients with LN. Glomeruli and tubulointerstitial compartments were isolated using laser microdissection. RNA was extracted and analyzed by nanostring technology with transcript expression from clinically complete responders, partial responders and non-responders compared at Bx1 and Bx2 and to the healthy controls. Top transcripts that differentiate clinically complete responders from non-responders were validated at the protein level by confocal microscopy and urine ELISA. At Bx1, cluster analysis determined that glomerular integrin, neutrophil, chemokines/cytokines and tubulointerstitial chemokines, T cell and leukocyte adhesion genes were able to differentiate non-responders from clinically complete responders. At Bx2, glomerular monocyte, extracellular matrix, and interferon, and tubulointerstitial interferon, complement, and T cell transcripts differentiated non-responders from clinically complete responders. Protein analysis identified several protein products of overexpressed glomerular and tubulointerstitial transcripts at LN flare, recapitulating top transcript findings. Urine complement component 5a and fibronectin-1 protein levels reflected complement and fibronectin expression at flare and after treatment. Thus, transcript analysis of serial LN kidney biopsies demonstrated how gene expression in the kidney changes with clinically successful and unsuccessful therapy. Hence, these insights into the molecular landscape of response and non-response may help align LN management with the pathogenesis of kidney injury.

YgiM may act as a trigger in the sepsis caused by Klebsiella pneumoniae through the membrane-associated ceRNA network

Sepsis is one of the diseases that can cause serious mortality. In E. coli, an inner membrane protein YgiM encoded by gene ygiM can target the eukaryotic peroxisome. Peroxisome is a membrane-enclosed organelle associated with the ROS metabolism and was reported to play the key role in immune responses and inflammation during the development of sepsis. Klebsiella pneumoniae (K. pneumoniae) is one of the important pathogens causing sepsis. However, the function of gene vk055_4013 which is highly homologous to ygiM of E. coli has not been demonstrated in K. pneumoniae. In this study, we prepared ΔygiM of K. pneumoniae ATCC43816, and found that the deletion of ygiM did not affect bacterial growth and mouse mortality in the mouse infection model. Interestingly, ΔygiM not only resulted in reduced bacterial resistance to macrophages, but also attenuated pathological manifestations in mouse organs. Furthermore, based on the data of Gene Expression Omnibus, the expression profiles of micro RNAs (miRNAs) and messenger RNAs (mRNAs) in the serum of 44 sepsis patients caused by K. pneumoniae infection were analyzed, and 11 differently expressed miRNAs and 8 DEmRNAs associated with the membrane function were found. Finally, the membrane-associated competing endogenous RNAs (ceRNAs) network was constructed. In this ceRNAs network, DEmiRNAs (hsa-miR-7108-5p, hsa-miR-6780a-5p, hsa-miR-6756-5p, hsa-miR-4433b-3p, hsa-miR-3652, hsa-miR-342-3p, hsa-miR-32-5p) and their potential downstream target DEmRNAs (VNN1, CEACAM8, PGLYRP1) were verified in the cell model infected by wild type and ΔygiM of K. pneumoniae, respectively. Taken together, YgiM may trigger the sepsis caused by K. pneumoniae via membrane-associated ceRNAs. This study provided new insights into the role of YgiM in the process of K. pneumoniae induced sepsis.

Polymorphonuclear Neutrophils in Rheumatoid Arthritis and Systemic Lupus Erythematosus: More Complicated Than Anticipated

Polymorphonuclear neutrophils (PMN) are the most abundant leucocytes in the circulation in humans. They represent a heterogeneous population exerting diverse functions through several activities. Usually described as typical pro-inflammatory cells, immunomodulatory properties of PMNs have been reported. Among others, once activated and depending on the stimulus, PMNs expel neutrophil extracellular traps (NET) in the extracellular space. NETs are complexes made of DNA and granule proteins representing an innate immune mechanism fighting infections. Nevertheless, an excess of NET formation might be involved in the development of inflammatory or autoimmune responses. Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are two chronic, inflammatory, autoimmune diseases of unknown etiology and affecting mostly women. Several abnormal or non-classical functions of PMNs or PMN sub-populations have been described in SLE and RA. Particularly, NETs have been suggested to trigger pro-inflammatory responses by exposing pro-inflammatory mediators. Likewise, NETs may be the targets of autoantibodies or even might trigger the development of autoantibodies by exposing autoantigens. In the present review, we will summarize heterogeneous properties of human PMNs and we will discuss recent evidence linking PMNs and NETs to the pathogenesis of both SLE and RA.

Selecting Hub Genes and Predicting Target Genes of microRNAs in Tuberculosis via the Bioinformatics Analysis

Tuberculosis (TB) is the world's most prevalently infectious disease. Molecular mechanisms behind tuberculosis remain unknown. microRNA (miRNA) is involved in a wide variety of diseases. To validate the significant genes and miRNAs in the current sample, two messenger RNA (mRNA) expression profile datasets and three miRNA expression profile datasets were downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed (DE) genes (DEGs) and miRNAs (DE miRNAs) between healthy and TB patients were filtered out. Enrichment analysis was executed, and a protein-protein interaction (PPI) network was developed to understand the enrich pathways and hub genes of TB. Additionally, the target genes of miRNA were predicted and overlapping target genes were identified. We studied a total of 181 DEGs (135 downregulated and 46 upregulated genes) and two DE miRNAs (2 downregulated miRNAs) from two gene profile datasets and three miRNA profile datasets, respectively. 10 hub genes were defined based on high degree of connectivity. A PPI network's top module was constructed. The 23 DEGs identified have a significant relationship with miRNAs. 25 critically significant Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were discovered. The detailed study revealed that, in tuberculosis, the DE miRNA and DEGs form an interaction network. The identification of novel target genes and main pathways would aid with our understanding of miRNA's function in tuberculosis progression.

Bioinformatics Analysis for Identifying Pertinent Pathways and Genes in Sepsis

Purpose

Sepsis becomes the main death reason in hospitals with rising incidence, causing a growing economic and medical burden. However, the genes related to the pathogenesis and prognosis of sepsis are still unclear, which is a problem that needs to be solved urgently.

Materials and Methods

Gene expression profiles of GSE69528 were obtained from the National Center for Biotechnology Information. Limma software package got employed to search for differentially expressed genes (DEGs). Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) were used for enrichment analysis. Protein-protein interaction (PPI) network was built by the Search Tool for the Retrieval of Interacting Genes (STRING) database.

Results

We screened 101 DEGs, containing 81 upregulated DEGs and 20 downregulated DEGs. GO analysis demonstrated that the upregulated DEGs were chiefly concentrated in negative regulation of response to interferon-gamma and regulation of granulocyte differentiation. KEGG analysis revealed that the pathways of upregulated DEGs were concentrated in prion diseases, complement and coagulation cascades, and Staphylococcus aureus infection. The PPI network constructed by upregulated DEGs contained 67 nodes (proteins) and 110 edges (interactions). Analysis of bioinformatics results showed that CEACAM8, MPO, and RETN were hub genes of sepsis.

Conclusion

Our analysis reveals a series of signal pathways and key genes related to the mechanism of sepsis, which are promising biotargets and biomarkers of sepsis.

Polymorphonuclear myeloid-derived suppressor cells link inflammation and damage response after trauma

Elimination of the posttraumatic inflammatory response and recovery of homeostasis are crucial for the positive prognosis of trauma patients. Myeloid-derived suppressor cells (MDSCs) are known to play a regulatory role in the posttraumatic immune response in mice, but their induction source and involved potential mechanism are poorly understood. Here, we report that polymorphonuclear MDSCs (PMN-MDSCs) are activated after trauma and are closely associated with the progression of the posttraumatic inflammatory response. In humans, lectin-type oxidized LDL receptor 1 (LOX1) was used to specifically characterize LOX1⁺ PMN-MDSCs. Trauma patients showed high intracellular reactive oxygen species (ROS) production, as well as activation of LOX1⁺ PMN-MDSCs. These MDSCs contribute to the anti-inflammatory immune response by regulating the Treg/Th17 and Th2/Th1 balances after trauma, increasing the levels of anti-inflammatory factors, and decreasing the levels of proinflammatory factors. The number of LOX1⁺ PMN-MDSCs was positively correlated with the positive clinical prognosis of trauma patients with infection. Activation of LOX1⁺ PMN-MDSCs is mediated by NF-κB signal, and TGF-β1 may be as an important inducer for LOX1⁺ PMN-MDSCs in the posttraumatic cytokine environment. In a pseudofracture trauma mouse model, we also observed the activation of PMN-MDSCs, accompanying high levels of intracellular ROS production, NF-κB phosphorylation, and changes in the inflammatory environment, in particularly by regulating the Treg/Th17 and Th2/Th1 balance. And more significantly, posttraumatic inflammation was alleviated in mice after transferring trauma-derived PMN-MDSCs, but aggravated after injecting with Gr1 agonistic antibody. These findings provide evidence for the specific role of PMN-MDSCs in the regulation of posttraumatic inflammation.

Neutrophil Pathways of Inflammation Characterize the Blood Transcriptomic Signature of Patients with Psoriasis and Cardiovascular Disease

BACKGROUND

Patients with psoriasis have an increased risk of atherosclerotic cardiovascular disease (CVD). The molecular mechanisms behind this connection are not fully understood, but the involvement of neutrophils have drawn attention as a shared inflammatory factor.

METHODS

RNA sequencing using the Illumina platform was performed on blood from 38 patients with moderate to severe psoriasis; approximately half had prior CVD. The neutrophil to lymphocyte ratio (NLR) was obtained from blood samples. Subclinical atherosclerosis was assessed by ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography and ultrasound imaging. Transcriptomic analysis for differential expression and functional enrichment were performed, followed by correlation analyses of differentially expressed genes (DEGs), NLR and subclinical measurers of CVD.

RESULTS

291 genes were differentially expressed between patients with psoriasis with and without CVD. These included 208 upregulated and 83 downregulated DEGs. Neutrophil degranulation was identified as the most significant process related to the upregulated DEGs. Genes for the neutrophil-associated markers MPO, MMP9, LCN2, CEACAM1, CEACAM6 and CEACAM8 were identified as being of special interest and their mRNA levels correlated with NLR, high-sensitive C-reactive protein and markers of subclinical CVD.

CONCLUSIONS

Patients with psoriasis and CVD had an increased expression of genes related to neutrophil degranulation in their blood transcriptome compared with patients with psoriasis without CVD. NLR may be a potential biomarker of subclinical CVD in psoriasis.

Neutrophil Extracellular Traps Activate Proinflammatory Functions of Human Neutrophils

Neutrophil extracellular traps (NETs) consist of decondensed nuclear chromatin that is associated with proteins and are released by neutrophils during an inflammatory response. Released NETs are able to capture pathogens, prevent their dissemination and potentially kill them via antimicrobial peptides and proteins that are associated with the decondensed chromatin. In addition to their antimicrobial functions, NETs have also been shown to exert immunomodulatory effects by activation and differentiation of macrophages, dendritic cells and T cells. However, the effect of NETs on neutrophil functions is poorly understood. Here we report the first comprehensive study regarding the effects of NETs on human primary neutrophils in vitro. NETs were isolated from cultures of PMA-exposed neutrophils. Exposure of neutrophils to isolated NETs resulted in the activation of several neutrophil functions in a concentration-dependent manner. NETs induced exocytosis of granules, the production of reactive oxygen species (ROS) by the NADPH oxidase NOX2, NOX2-dependent NET formation, increased the phagocytosis and killing of microbial pathogens. Furthermore, NETs induced the secretion of the proinflammatory chemokine IL-8 and the B-cell-activating cytokine BAFF. We could show that the NET-induced activation of neutrophils occurs by pathways that involve the phosphorylation of Akt, ERK1/2 and p38. Taken together our results provide further insights into the proinflammatory role of NETs by activating neutrophil effector function and further supports the view that NETs can amplify inflammatory events. On the one hand the amplified functions enhance the antimicrobial defense. On the other hand, NET-amplified neutrophil functions can be involved in the pathophysiology of NET-associated diseases. In addition, NETs can connect the innate and adaptive immune system by inducing the secretion of the B-cell-activating cytokine BAFF.

Increased Concentrations of Circulating Soluble MHC Class I-Related Chain A (sMICA) and sMICB and Modulation of Plasma Membrane MICA Expression: Potential Mechanisms and Correlation With Natural Killer Cell Activity in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a severe autoimmune disease of unknown etiology. The major histocompatibility complex (MHC) class I-related chain A (MICA) and B (MICB) are stress-inducible cell surface molecules. MICA and MICB label malfunctioning cells for their recognition by cytotoxic lymphocytes such as natural killer (NK) cells. Alterations in this recognition have been found in SLE. MICA/MICB can be shed from the cell surface, subsequently acting either as a soluble decoy receptor (sMICA/sMICB) or in CD4⁺ T-cell expansion. Conversely, NK cells are frequently defective in SLE and lower NK cell numbers have been reported in patients with active SLE. However, these cells are also thought to exert regulatory functions and to prevent autoimmunity. We therefore investigated whether, and how, plasma membrane and soluble MICA/B are modulated in SLE and whether they influence NK cell activity, in order to better understand how MICA/B may participate in disease development. We report significantly elevated concentrations of circulating sMICA/B in SLE patients compared with healthy individuals or a control patient group. In SLE patients, sMICA concentrations were significantly higher in patients positive for anti-SSB and anti-RNP autoantibodies. In order to study the mechanism and the potential source of sMICA, we analyzed circulating sMICA concentration in Behcet patients before and after interferon (IFN)-α therapy: no modulation was observed, suggesting that IFN-α is not intrinsically crucial for sMICA release in vivo. We also show that monocytes and neutrophils stimulated in vitro with cytokines or extracellular chromatin up-regulate plasma membrane MICA expression, without releasing sMICA. Importantly, in peripheral blood mononuclear cells from healthy individuals stimulated in vitro by cell-free chromatin, NK cells up-regulate CD69 and CD107 in a monocyte-dependent manner and at least partly via MICA-NKG2D interaction, whereas NK cells were exhausted in SLE patients. In conclusion, sMICA concentrations are elevated in SLE patients, whereas plasma membrane MICA is up-regulated in response to some lupus stimuli and triggers NK cell activation. Those results suggest the requirement for a tight control in vivo and highlight the complex role of the MICA/sMICA system in SLE.

Deoxyribonuclease 1-Mediated Clearance of Circulating Chromatin Prevents From Immune Cell Activation and Pro-inflammatory Cytokine Production, a Phenomenon Amplified by Low Trap1 Activity: Consequences for Systemic Lupus Erythematosus

Increased concentrations of circulating chromatin, especially oligo-nucleosomes, are observed in sepsis, cancer and some inflammatory autoimmune diseases like systemic lupus erythematosus (SLE). In SLE, circulating nucleosomes mainly result from increased apoptosis and decreased clearance of apoptotic cells. Once released, nucleosomes behave both as an autoantigen and as a damage-associated molecular pattern (DAMP) by activating several immune cells, especially pro-inflammatory cells. Deoxyribonuclease 1 (DNase1) is a major serum nuclease whose activity is decreased in mouse and human lupus. Likewise, the mitochondrial chaperone tumor necrosis factor (TNF) receptor-associated protein-1 (Trap1) protects against oxidative stress, which is increased in SLE. Here, using wild type, DNase1-deficient and DNase1/Trap1-deficient mice, we demonstrate that DNase1 is a major serum nuclease involved in chromatin degradation, especially when the plasminogen system is activated. In vitro degradation assays show that chromatin digestion is strongly impaired in serum from DNase1/Trap1-deficient mice as compared to wild type mice. In vivo, after injection of purified chromatin, clearance of circulating chromatin is delayed in DNase1/Trap1-deficient mice in comparison to wild type mice. Since defective chromatin clearance may lead to chromatin deposition in tissues and subsequent immune cell activation, spleen cells were stimulated in vitro with chromatin. Splenocytes were activated by chromatin, as shown by interleukin (IL)-12 secretion and CD69 up-regulation. Moreover, cell activation was exacerbated when Trap1 is deficient. Importantly, we also show that cytokines involved in lupus pathogenesis down-regulate Trap1 expression in splenocytes. Therefore, combined low activities of both DNase1 and Trap1 lead to an impaired degradation of chromatin in vitro, delayed chromatin clearance in vivo and enhanced activation of immune cells. This situation may be encountered especially, but not exclusively, in SLE by the negative action of cytokines on Trap1 expression.

Prevalence, risk factors and proteomic bioprofiles associated with heart failure in rheumatoid arthritis: The RA-HF study

BACKGROUND

Rheumatoid arthritis (RA) patients have high risk of heart failure (HF).

AIMS

Identifying the risk factors and mechanistic pathways associated with HF in patients with RA.

METHODS

Cohort study enrolling 355 RA patients. HF was defined according to the ESC criteria. 93 circulating protein-biomarkers (91CVDIIOlink®+troponin-T+c-reactive protein) were measured. Regression modeling (multivariate and multivariable) were built and network analyses were performed - based on the identified relevant protein biomarkers.

RESULTS

115 (32.4%) patients fulfilled the ESC criteria for HF, but only 24 (6.8%) had a prior HF diagnosis. Patients with HF were older (67 vs. 55yr), had a longer RA duration (10 vs. 14yr), had more frequently diabetes, hypertension, obesity, dyslipidemia, atrial fibrillation, and ischemic arterial disease. Several protein-biomarkers remained independently associated with HF, the top (FDR1%) were adrenomedullin, placenta-growth-factor, TNF-receptor-11A, and angiotensin-converting-enzyme-2. The networks underlying the expression of these biomarkers pointed towards congestion, apoptosis, inflammation, immune system signaling and RAAS activation as central determinants of HF in RA. Similar HF-associated biomarker-pathways were externally found in patients without RA. Having RA plus HF increased the risk of cardiovascular events compared to RA patients without RF; adjusted-HR (95%CI)=2.37 (1.07-5.30), p=0.034 CONCLUSION: Age, cardiovascular risk factors, and RA duration increase the HF odds in patients with RA. Few RA patients had a correct prior HF diagnosis, but the presence of HF increased the patients` risk. RA patients with HF largely share the mechanistic pathways of HF patients without RA. Randomized HF trials should include patients with RA. CLINICALTRIALS.

GOV ID

NCT03960515.

Machine Learning Identifies Complicated Sepsis Course and Subsequent Mortality Based on 20 Genes in Peripheral Blood Immune Cells at 24 H Post-ICU Admission

A complicated clinical course for critically ill patients admitted to the intensive care unit (ICU) usually includes multiorgan dysfunction and subsequent death. Owing to the heterogeneity, complexity, and unpredictability of the disease progression, ICU patient care is challenging. Identifying the predictors of complicated courses and subsequent mortality at the early stages of the disease and recognizing the trajectory of the disease from the vast array of longitudinal quantitative clinical data is difficult. Therefore, we attempted to perform a meta-analysis of previously published gene expression datasets to identify novel early biomarkers and train the artificial intelligence systems to recognize the disease trajectories and subsequent clinical outcomes. Using the gene expression profile of peripheral blood cells obtained within 24 h of pediatric ICU (PICU) admission and numerous clinical data from 228 septic patients from pediatric ICU, we identified 20 differentially expressed genes predictive of complicated course outcomes and developed a new machine learning model. After 5-fold cross-validation with 10 iterations, the overall mean area under the curve reached 0.82. Using a subset of the same set of genes, we further achieved an overall area under the curve of 0.72, 0.96, 0.83, and 0.82, respectively, on four independent external validation sets. This model was highly effective in identifying the clinical trajectories of the patients and mortality. Artificial intelligence systems identified eight out of twenty novel genetic markers (SDC4, CLEC5A, TCN1, MS4A3, HCAR3, OLAH, PLCB1, and NLRP1) that help predict sepsis severity or mortality. While these genes have been previously associated with sepsis mortality, in this work, we show that these genes are also implicated in complex disease courses, even among survivors. The discovery of eight novel genetic biomarkers related to the overactive innate immune system, including neutrophil function, and a new predictive machine learning method provides options to effectively recognize sepsis trajectories, modify real-time treatment options, improve prognosis, and patient survival.

Neutrophil extracellular traps, disease severity, and antibiotic response in bronchiectasis: an international, observational, multicohort study

BACKGROUND

Bronchiectasis is predominantly a neutrophilic inflammatory disease. There are no established therapies that directly target neutrophilic inflammation because little is understood of the underlying mechanisms leading to severe disease. Neutrophil extracellular trap (NET) formation is a method of host defence that has been implicated in multiple inflammatory diseases. We aimed to investigate the role of NETs in disease severity and treatment response in bronchiectasis.

METHODS

In this observational study, we did a series of UK and international studies to investigate the role of NETs in disease severity and treatment response in bronchiectasis. First, we used liquid chromatography-tandem mass spectrometry to identify proteomic biomarkers associated with disease severity, defined using the bronchiectasis severity index, in patients with bronchiectasis (n=40) in Dundee, UK. Second, we validated these biomarkers in two cohorts of patients with bronchiectasis, the first comprising 175 patients from the TAYBRIDGE study in the UK and the second comprising 275 patients from the BRIDGE cohort study from centres in Italy, Spain, and UK, using an immunoassay to measure NETs. Third, we investigated whether pathogenic bacteria had a role in NET concentrations in patients with severe bronchiectasis. In a separate study, we enrolled patients with acute exacerbations of bronchiectasis (n=20) in Dundee, treated with intravenous antibiotics for 14 days and proteomics were used to identify proteins associated with treatment response. Findings from this cohort were validated in an independent cohort of patients who were admitted to the same hospital (n=20). Fourth, to assess the potential use of macrolides to reduce NETs in patients with bronchiectasis, we examined two studies of long-term macrolide treatment, one in patients with bronchiectasis (n=52 from the UK) in which patients were given 250 mg of azithromycin three times a week for a year, and a post-hoc analysis of the Australian AMAZES trial in patients with asthma (n=47) who were given 500 mg of azithromycin 3 times per week for a year.

FINDINGS

Sputum proteomics identified that NET-associated proteins were the most abundant and were the proteins most strongly associated with disease severity. This finding was validated in two observational cohorts, in which sputum NETs were associated with bronchiectasis severity index, quality of life, future risk of hospital admission, and mortality. In a subgroup of 20 patients with acute exacerbations, clinical response to intravenous antibiotic treatment was associated with successfully reducing NETs in sputum. Patients with Pseudomonas aeruginosa infection had a lessened proteomic and clinical response to intravenous antibiotic treatment compared with those without Pseudomonas infections, but responded to macrolide therapy. Treatment with low dose azithromycin was associated with a significant reduction in NETs in sputum over 12 months in both bronchiectasis and asthma.

INTERPRETATION

We identified NETs as a key marker of disease severity and treatment response in bronchiectasis. These data support the concept of targeting neutrophilic inflammation with existing and novel therapies.

FUNDING

Scottish Government, British Lung Foundation, and European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC).

The impact of neutrophil extracellular trap from patients with systemic lupus erythematosus on the viability, CD11b expression and oxidative burst of healthy neutrophils

Background

NET (neutrophil extracellular trap) has been shown to directly influence inflammation; in SLE (systemic lupus erythematosus), it is reportedly a plausible cause for the broken self-tolerance that contributes to this pathology. Meanwhile, the role of NET is not easily explicable, and there is a serious discrepancy in the role of NET in SLE pathology and generally inflammation; in particular, the interactions of neutrophils with NET have been rarely inspected. This study evaluates the effect of NET on neutrophils in the context of SLE. The neutrophils were incubated by the collected NET (from SLE patients and healthy controls) and their expression of an activation marker, viability and oxidative burst ability were measured.

Results

The level of cell mortality, CD11b expression and the oxidative burst capacity were elevated in NET-treated neutrophils. Also, the elevation caused by the SLE NET was higher than that produced by the healthy NET.

Conclusion

The decreased neutrophil viability was not due to the increase in apoptosis; rather, it was because of the augmentation of other inflammatory cell-death modes. The upregulation of CD11b implies that NET causes neutrophils to more actively contribute to inflammation. The increased oxidative burst capacity of neutrophils can play a double role in inflammation. Overall, the effects induced by NET on neutrophils help prolong inflammation; accordingly, the NET collected from SLE patients is stronger than the NET from healthy individuals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-021-00402-2.

Cytokine Storm as a Cellular Response to dsDNA Breaks: A New Proposal

Pathogenesis of cytokine storm is poorly understood. In this article we propose a new mechanism and suggest innovative therapeutic avenues for its prevention. We have reported that particles of cell-free chromatin (cfCh) that are released from the billions of cells that die in the body everyday can illegitimately integrate into genomes of healthy cells to trigger dsDNA breaks. The latter leads to apoptosis and/or intense activation of inflammatory cytokines in the affected cells. We hypothesise that a similar phenomenon of dsDNA breaks and inflammation is involved in cytokine storm. The abundant cfCh particles that are released from dying host cells following viral/microbial invasion initiate a cascading effect of more cell death resulting in a vicious cycle of further DNA damage, apoptosis and hyper-inflammation which culminate in cytokine storm. We propose that this unrelenting vicious cycle of cellular DNA damage and cytokine storm may be the underlying cause of high mortality from severe COVID-19. We discuss results of our preclinical studies wherein we have shown that endotoxin induced cytokine storm in mice can be reversed by three different agents that have the ability to inactivate cfCh. These agents may be worthy of investigation in clinical trials to reduce mortality from COVID-19.

Is gene expression among women with rheumatoid arthritis dysregulated during a postpartum flare?

Background

To evaluate our hypotheses that, when rheumatoid arthritis (RA) flares postpartum, gene expression patterns are altered compared to (a) healthy women, (b) RA women whose disease activity is low or in remission postpartum, and (c) pre-pregnancy expression profiles.

Methods

Twelve women with RA and five healthy women were included in this pilot study. RA disease activity and postpartum flare were assessed using the Clinical Disease Activity Index (CDAI). Total RNA from frozen whole blood was used for RNA sequencing. Differential gene expression within the same women (within-group) over time, i.e., postpartum vs. third trimester (T3) or pre-pregnancy (T0), were examined, using a significance threshold of q < 0.05 and fold-change ≥ 2.

Results

Nine of the women with RA experienced a flare postpartum (RA_Flare), while three had low disease activity or were in remission (RA_NoFlare) during that time frame. Numerous immune-related genes were differentially expressed postpartum (vs. T3) during a flare. Fold-changes in expression from T3 to postpartum were mostly comparable between the RA_Flare and healthy groups. At 3 months postpartum, compared to healthy women, several genes were significantly differentially expressed only among the RA_Flare women, and not among the RA_NoFlare women. Some of these genes were among those whose “normal” expression was significantly modulated postpartum, and the postpartum expression patterns were significantly altered during the RA flare. There were also some genes that were significantly differentially expressed in RA_Flare compared to both healthy and RA_NoFlare women, even though their expression was not significantly modulated postpartum. Furthermore, while postpartum expression profiles were similar to those at pre-pregnancy among healthy women, significant differences were found between those time points among the RA_Flare women.

Conclusions

The large majority of gene expression changes between T3 and 3 months postpartum among RA women who flared postpartum reflected normal postpartum changes also seen among healthy women. Nonetheless, during a postpartum flare, a set of immune-related genes showed dysregulated expression compared to healthy women and women with RA whose disease activity was low or in remission during the same time frame, while other genes demonstrated significant differences in expression compared to RA pre-pregnancy levels.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02418-w.

Two gene set variation indexes as potential diagnostic tool for sepsis

Accurate diagnosis of sepsis remains challenging, new markers or combinations of markers are urgently needed. In the present study, we screened differentially expressed genes (DEGs) between sepsis and non-sepsis blood samples across three previously published gene expression data sets. Common upregulated and downregulated DEGs were ranked according to their average functional similarity. The ten genes (OLFM4, ORM1, CEP55, S100A12, S100P, LRG1, CEACAM8, MS4A4A, PLSCR1, and IL1R2) with the largest average functional similarity among the common upregulated genes and another ten genes (THEMIS, IL2RB, CD2, IL7R, CD3E, KLRB1, PVRIG, CCRR3, TGFBR3, and PLEKHA1) with the largest average functional similarity among the common downregulated genes were separately identified as the upregulated crucial gene set and the downregulated crucial gene set. Gene set variation analysis (GSVA) was used to obtain the GSVA index of each sample against the two crucial gene sets. Both the two crucial GSVA indexes may be robust markers for sepsis with high area under ROC curve. The diagnostic utility of the upregulated GSVA index was validated in another independent data set. Functional analyses revealed several sepsis-related pathways. In conclusion, we proposed two sepsis-related gene sets across multiple data sets and created two GSVA indexes with promising diagnostic value.

The CoV-2 outbreak: how hematologists could help to fight Covid-19

COVID-19 is a medical emergency, with 20 % of patients presenting with severe clinical manifestations. From the pathogenetic point of view, COVID-19 mimics two other well-known diseases characterized by cytokine storm and hyper-activation of the immune response, with consequent organ damage: acute graft-versus-host disease (aGVHD) and macrophage activation syndrome (MAS). Hematologists are confident with these situations requiring a prompt therapeutic approach for switching off the uncontrolled cytokine release; here, we discuss pros and cons of drugs that are already employed in hematology in the light of their possible application in COVID-19. The most promising drugs might be: Ruxolitinib, a JAK1/2 inhibitor, with a rapid and powerful anti-cytokine effect, tyrosine kinase inhibitors (TKIs), with their good anti-inflammatory properties, and perhaps the anti-Cd26 antibody Begelomab. We also present immunological data from gene expression experiments where TKIs resulted effective anti-inflammatory and pro-immune drugs. A possible combined treatment algorithm for COVID-19 is here proposed.