Transketolase and vitamin B1 influence on ROS-dependent neutrophil extracellular traps (NETs) formation

Neutrophil glucose flux as a therapeutic target in antiphospholipid syndrome

Neutrophil hyperactivity and neutrophil extracellular trap release (NETosis) appear to play important roles in the pathogenesis of the thromboinflammatory autoimmune disease known as antiphospholipid syndrome (APS). The understanding of neutrophil metabolism has advanced tremendously in the past decade, and accumulating evidence suggests that a variety of metabolic pathways guide neutrophil activities in health and disease. Our previous work characterizing the transcriptome of APS neutrophils revealed that genes related to glycolysis, glycogenolysis, and the pentose phosphate pathway (PPP) were significantly upregulated. Here, we found that neutrophils from patients with APS used glycolysis more avidly than neutrophils from people in the healthy control group, especially when the neutrophils were from patients with APS with a history of microvascular disease. In vitro, inhibiting either glycolysis or the PPP tempered phorbol myristate acetate- and APS IgG-induced NETosis, but not NETosis triggered by a calcium ionophore. In mice, inhibiting either glycolysis or the PPP reduced neutrophil reactive oxygen species production and suppressed APS IgG-induced NETosis ex vivo. When APS-associated thrombosis was evaluated in mice, inhibiting either glycolysis or the PPP markedly suppressed thrombosis and circulating NET remnants. In summary, these data identify a potential role for restraining neutrophil glucose flux in the treatment of APS.

Colchicine Alleviates Rosacea by Inhibiting Neutrophil Inflammation Activated by the TLR2 Pathway

Rosacea is a chronic facial inflammatory skin disease that occurs with dysfunction of the immune system. Colchicine was reported to have anti-inflammatory properties. However, the impact of colchicine on rosacea remains unclear. In the present study, the phenotype of rosacea lesions was evaluated by the redness score, inflammatory biomarkers were analyzed by reverse transcription PCR (RT‒PCR), and the infiltration of inflammatory cells was assessed by IHC analysis and immunofluorescence in a rosacea-like mouse model. In vitro, RT‒PCR was used to identify the inflammatory factors that Toll-like receptor 2 (TLR2) agonist caused neutrophils to produce, and immunofluorescence and coimmunoprecipitation were used to identify putative signalling pathways. We found that skin erythema and histopathological alterations, as well as elevated proinflammatory factors (IL-1β, IL-6, TNFα, CXCL2) and CAMP, were significantly ameliorated by colchicine treatment in LL37-induced rosacea-like mice. In addition, colchicine reduced the colocalization of TLR2 and neutrophils and the formation of neutrophil extracellular trap networks (NET) in mouse lesions. In neutrophils, colchicine markedly reduced TLR2 agonist-induced inflammatory biomarker expression, NET formation, and ROS production. Moreover, we found that LL37 could bind to TLR2 upon activation of TLR2 in neutrophils. Importantly, colchicine could repress the combination of TLR2 and LL37 in vivo. Finally, bioinformatics methods further validated the key molecules of neutrophil-related inflammation in rosacea, which is consistent with our experimental findings. Collectively, colchicine ameliorated rosacea-like dermatitis by regulating the neutrophil immune response activated by the TLR2 pathway, indicating that it could be an effective therapeutic option for patients with rosacea.

Mapping the cellular landscape of Atlantic salmon head kidney by single cell and single nucleus transcriptomics

Single-cell transcriptomics is the current gold standard for global gene expression profiling, not only in mammals and model species, but also in non-model fish species. This is a rapidly expanding field, creating a deeper understanding of tissue heterogeneity and the distinct functions of individual cells, making it possible to explore the complexities of immunology and gene expression on a highly resolved level. In this study, we compared two single cell transcriptomic approaches to investigate cellular heterogeneity within the head kidney of healthy farmed Atlantic salmon (Salmo salar). We compared 14,149 cell transcriptomes assayed by single cell RNA-seq (scRNA-seq) with 18,067 nuclei transcriptomes captured by single nucleus RNA-Seq (snRNA-seq). Both approaches detected eight major cell populations in common: granulocytes, heamatopoietic stem cells, erythrocytes, mononuclear phagocytes, thrombocytes, B cells, NK-like cells, and T cells. Four additional cell types, endothelial, epithelial, interrenal, and mesenchymal cells, were detected in the snRNA-seq dataset, but appeared to be lost during preparation of the single cell suspension submitted for scRNA-seq library generation. We identified additional heterogeneity and subpopulations within the B cells, T cells, and endothelial cells, and revealed developmental trajectories of heamatopoietic stem cells into differentiated granulocyte and mononuclear phagocyte populations. Gene expression profiles of B cell subtypes revealed distinct IgM and IgT-skewed resting B cell lineages and provided insights into the regulation of B cell lymphopoiesis. The analysis revealed eleven T cell sub-populations, displaying a level of T cell heterogeneity in salmon head kidney comparable to that observed in mammals, including distinct subsets of cd4/cd8-negative T cells, such as tcrγ positive, progenitor-like, and cytotoxic cells. Although snRNA-seq and scRNA-seq were both useful to resolve cell type-specific expression in the Atlantic salmon head kidney, the snRNA-seq pipeline was overall more robust in identifying several cell types and subpopulations. While scRNA-seq displayed higher levels of ribosomal and mitochondrial genes, snRNA-seq captured more transcription factor genes. However, only scRNA-seq-generated data was useful for cell trajectory inference within the myeloid lineage. In conclusion, this study systematically outlines the relative merits of scRNA-seq and snRNA-seq in Atlantic salmon, enhances understanding of teleost immune cell lineages, and provides a comprehensive list of markers for identifying major cell populations in the head kidney with significant immune relevance.

Proliferation of mammalian cells with Chlorococcum littorale algal compounds without serum support

In recent years, serum-free medium for mammalian cell cultivation has attracted a lot of attention, considering the high cost of production and environmental load involved in developing the conventional animal sera. The use of alternative growth-promoting products in mammalian cell cultivation such as extracts from microalgae has proven to be quite beneficial and environmental-friendly. This research aims to cultivate mammalian cells with growth-promoting factors derived from Chlorococcum littorale. We have established a simple extraction using the ultrasonication method and applied the extract in place of serum on mammalian C2C12 cell lines, 3T3 cell lines, and CHO cell lines to compare and analyze the effectiveness of the extract. Cell passage was conducted in a suspended culture condition with the addition of the extract. The results indicate that the extract from microalgae shows a high proliferation rate in all cell lines without fetal bovine serum. Moreover, it is eco-friendly and has huge potential to replace the traditional cell culture system. It could be applied in the fields of regenerative medicine, gene/cell therapies, as well as cultured meat production.

The importance of thiamine (vitamin B1) in humans

Thiamine (thiamin, B1) is a vitamin necessary for proper cell function. It exists in a free form as a thiamine, or as a mono-, di- or triphosphate. Thiamine plays a special role in the body as a coenzyme necessary for the metabolism of carbohydrates, fats and proteins. In addition, it participates in the cellular respiration and oxidation of fatty acids: in malnourished people, high doses of glucose result in acute thiamine deficiency. It also participates in energy production in the mitochondria and protein synthesis. In addition, it is also needed to ensure the proper functioning of the central and peripheral nervous system, where it is involved in neurotransmitter synthesis. Its deficiency leads to mitochondrial dysfunction, lactate and pyruvate accumulation, and consequently to focal thalamic degeneration, manifested as Wernicke's encephalopathy or Wernicke-Korsakoff syndrome. It can also lead to severe or even fatal neurologic and cardiovascular complications, including heart failure, neuropathy leading to ataxia and paralysis, confusion, or delirium. The most common risk factor for thiamine deficiency is alcohol abuse. This paper presents current knowledge of the biological functions of thiamine, its antioxidant properties, and the effects of its deficiency in the body.

Bioinformatics analysis of copper death gene in diabetic immune infiltration

BACKGROUND

Copper plays an important role in the human body and is potentially related to the development of diabetes. The mechanism of copper death gene regulating immune infiltration in diabetes has not been studied.

METHODS

Download microarray data from healthy normal and diabetic patients from the GEO database. The identification of differentially expressed genes (DEGs) was analyzed by gene enrichment. Using String online database and Cytoscape software to interact with the protein interaction network and make visual analysis. Using Wilcox analyze the correlation between the copoer death gene and diabetic mellitus. Analysis of the correlation between immune penetration cells and functions, and the difference between the diabetes group and the control group, screening the copper death gene associated with diabetes, and predicting the upper top of microRNA (miRNA) through the Funrich software.

RESULTS

According to the identification of differential genes in 25 samples of GSE25724 and GSE95849 data sets, 328 differential genes were identified by consensus, including 190 up-regulated genes and 138 down-regulated genes (log2FC = 2, P < .01). KEGG results showed that neurodegeneration-multiple disease pathways were most significantly upregulated, followed by Huntington disease. According to Cytohubba, the TOP10 genes HCK, FPR1, MNDA, AQP9, TLR8, CXCR1, CSF3R, VNN2, TLR4, and CCR5 are down-regulated genes, which are mostly enriched in neutrophils. Immunoinfiltration-related heat maps show that Macrophage was strongly positively correlated with Activated dendritic cell, Mast cell, Neutrophil, and Regulatory T cell showed a strong positive correlation. Neutrophil was strongly positively correlated with Activated dendritic cell, Mast cell, and Regulatory T cell. Differential analysis of immune infiltration showed that Neutroph, Mast cell, Activated B cell, Macrophage and Eosinophil were significantly increased in the diabetic group. Central memory CD4 T cell (P < .001), Plasmacytoid dendritic cell, Immature dendritic cell, and Central memory CD8 T cell, etal were significantly decreased. DBT, SLC31A1, ATP7A, LIAS, ATP7B, PDHA1, DLST, PDHB, GCSH, LIPT1, DLD, FDX1, and DLAT genes were significantly associated with one or more cells and their functions in immune invasion. Forty-one miRNA.

CONCLUSIONS

Copper death is closely related to the occurrence of diabetes. Copper death genes may play an important role in the immune infiltration of diabetes.

Neutrophil extracellular traps mediate deep vein thrombosis: from mechanism to therapy

Deep venous thrombosis (DVT) is a part of venous thromboembolism (VTE) that clinically manifests as swelling and pain in the lower limbs. The most serious clinical complication of DVT is pulmonary embolism (PE), which has a high mortality rate. To date, its underlying mechanisms are not fully understood, and patients usually present with clinical symptoms only after the formation of the thrombus. Thus, it is essential to understand the underlying mechanisms of deep vein thrombosis for an early diagnosis and treatment of DVT. In recent years, many studies have concluded that Neutrophil Extracellular Traps (NETs) are closely associated with DVT. These are released by neutrophils and, in addition to trapping pathogens, can mediate the formation of deep vein thrombi, thereby blocking blood vessels and leading to the development of disease. Therefore, this paper describes the occurrence and development of NETs and discusses the mechanism of action of NETs on deep vein thrombosis. It aims to provide a direction for improved diagnosis and treatment of deep vein thrombosis in the near future.

Antagonistic Effect of Selenium on Fumonisin B1 Promotes Neutrophil Extracellular Traps Formation in Chicken Neutrophils

Neutrophils are an important component of the innate immune system, and one of their defense mechanisms, neutrophil extracellular traps (NETs), is a hot topic of the current research. This study explored the effects of fumonisin B1 (FB1) on chicken neutrophil production of NETs and its possible molecular mechanism of action. Scanning electron microscopy and fluorescence microscopy were used to observe morphological changes in neutrophils, and a fluorescence microplate reader was used to detect reactive oxygen species (ROS) and extracellular DNA release from neutrophils. Quantitative PCR (qPCR) and western blot were used to determine the expression levels of selenoproteins. The results indicate that FB1 inhibited the zymosan-induced formation of NETs in chicken neutrophils by preventing ROS burst and histone H3 (H3) and neutrophil elastase (NE) release. Moreover, the mRNA expression levels of glutathione peroxidase (GPX), thioredoxin reductase (TXNRD), and deiodinase (DIO) were downregulated in the FB1 group. The protein expression levels of GPX1, GPX2, GPX3, DIO3, and TXNRD1 were consistent with the changes in their gene expressions, suggesting an abnormal selenoprotein expression in response to the toxic effects of FB1. Conversely, selenium (Se) supplementation reduced the toxic effects of FB1 and restored the NETs formation, indicating that Se can be used as a potential drug to prevent and control FB1 toxicity in livestock farming.

Physiological and Pathophysiological Roles of Metabolic Pathways for NET Formation and Other Neutrophil Functions

Neutrophils are the most numerous cells in the leukocyte population and essential for innate immunity. To limit their effector functions, neutrophils are able to modulate glycolysis and other cellular metabolic pathways. These metabolic pathways are essential not only for energy usage, but also for specialized effector actions, such as the production of reactive oxygen species (ROS), chemotaxis, phagocytosis, degranulation, and the formation of neutrophil extracellular traps (NETs). It has been demonstrated that activated viable neutrophils can produce NETs, which consists of a DNA scaffold able to bind granule proteins and microorganisms. The formation of NETs requires the availability of increased amounts of adenosine triphosphate (ATP) as it is an active cellular and therefore energy-dependent process. In this article, we discuss the glycolytic and other metabolic routes in association with neutrophil functions focusing on their role for building up NETs in the extracellular space. A better understanding of the requirements of metabolic pathways for neutrophil functions may lead to the discovery of molecular targets suitable to develop novel anti-infectious and/or anti-inflammatory drugs.

Targeting the Pentose Phosphate Pathway for SARS-CoV-2 Therapy

SARS-CoV-2 is causing the coronavirus disease 2019 (COVID-19) pandemic, for which effective pharmacological therapies are needed. SARS-CoV-2 induces a shift of the host cell metabolism towards glycolysis, and the glycolysis inhibitor 2-deoxy-d-glucose (2DG), which interferes with SARS-CoV-2 infection, is under development for the treatment of COVID-19 patients. The glycolytic pathway generates intermediates that supply the non-oxidative branch of the pentose phosphate pathway (PPP). In this study, the analysis of proteomics data indicated increased transketolase (TKT) levels in SARS-CoV-2-infected cells, suggesting that a role is played by the non-oxidative PPP. In agreement, the TKT inhibitor benfooxythiamine (BOT) inhibited SARS-CoV-2 replication and increased the anti-SARS-CoV-2 activity of 2DG. In conclusion, SARS-CoV-2 infection is associated with changes in the regulation of the PPP. The TKT inhibitor BOT inhibited SARS-CoV-2 replication and increased the activity of the glycolysis inhibitor 2DG. Notably, metabolic drugs like BOT and 2DG may also interfere with COVID-19-associated immunopathology by modifying the metabolism of immune cells in addition to inhibiting SARS-CoV-2 replication. Hence, they may improve COVID-19 therapy outcomes by exerting antiviral and immunomodulatory effects.

The Neutrophil

Neutrophils are immune cells with unusual biological features that furnish potent antimicrobial properties. These cells phagocytose and subsequently kill prokaryotic and eukaryotic organisms very efficiently. Importantly, it is not only their ability to attack microbes within a constrained intracellular compartment that endows neutrophils with antimicrobial function. They can unleash their effectors into the extracellular space, where, even post-mortem, their killing machinery can endure and remain functional. The antimicrobial activity of neutrophils must not be misconstrued as being microbe specific and should be viewed more generally as biotoxic. Outside of fighting infections, neutrophils can harness their noxious machinery in other contexts, like cancer. Inappropriate or dysregulated neutrophil activation damages the host and contributes to autoimmune and inflammatory disease. Here we review a number of topics related to neutrophil biology based on contemporary findings.

Biocultural pathways linking periodontal disease expression to food insecurity, immune dysregulation, and nutrition

OBJECTIVES

In this article, we test theoretical pathways leading to and resulting from periodontal disease to better understand how periodontal disease, which is measurable in both past and present populations, integrates biocultural context and affects whole-body physiology.

METHODS

We use data from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and logistic and linear regressions to test pathways linking psychosocial stress to periodontal disease, and periodontal disease to serum vitamin C levels. We then use causal mediation analysis to test the role of mediating variables in these pathways (n = 1853 individuals).

RESULTS

Food insecurity was positively associated with periodontal disease and negatively associated with serum counts of C-reactive protein (CRP) and neutrophils. Neither CRP nor neutrophils significantly mediated the relationship between food insecurity and periodontal disease. Periodontal disease was negatively associated with serum vitamin C levels and positively associated with neutrophil counts. Neutrophils may mediate the relationship between periodontal disease and vitamin C.

CONCLUSIONS

We identify two main findings: (a) periodontal disease contributes to and may result from immune dysregulation, particularly of neutrophils, and (b) an immune response to chronic infection such as periodontal disease is metabolically expensive for the body to maintain and likely depletes serum micronutrient levels. Both micronutrient status and serum neutrophil counts affect multiple skeletal and physiological phenotypes and thus position periodontal disease in whole-body context.

MiR-1696/GPx3 axis is involved in oxidative stress mediated neutrophil extracellular traps inhibition in chicken neutrophils

As an important immune mechanism of neutrophils, the release of Web-like chromatin structures known as neutrophil extracellular traps (NETs) can rapidly locate and capture invading pathogens, which has received sustained attention. There are still some fundamental questions surrounding established studies on the mechanism of balance between reactive oxygen species (ROS) dependent release and neutrophil antioxidant response. Glutathione peroxidase 3 (GPx3) is an important antioxidant protein and has been identified can regulate the immune response. However, the effect of GPx3 on the NETs formation and microRNA in this process remain poorly understood. In the present study, we used chicken peripheral blood neutrophils treated with Phorbol-12-myristate-13-acetate (PMA) for 3 h as NETs formation model. The result of morphological observation showed that GPx3 inactivation compromised the release of NETs. Further analysis revealed that knockdown of GPx3 significantly disturbed oxidative balance by inhibiting antioxidant enzymes activity and increasing H₂ O₂ content. Quantitative analysis of NETs-related genes found that the phosphorylation level of mitogen-activated protein kinase (MAPK) pathway genes (ERK, JNK, and p38) and expression of phosphoinositide-3-kinase (PI3K)/AKT pathway genes (PI3K and AKT) were suppressed with the downregulation of GPx3. Meanwhile, we identified that miR-1696 can target GPx3 expression by using dual luciferase reporter system. Additionally, overexpression of miR-1696 can not only inhibit the formation of NETs by restraining the expression of GPx3, interfering with the generation of ROS and activation of the MAPK and PI3K/AKT pathways, but also reducing the release of PMA-induced NETs promoted by overexpression of GPx3. These results provide evidence that miR-1696 targeted GPx3 activities in neutrophils could be used to regulate the NETs formation stimulated by PMA.