Neutrophil-derived extracellular vesicles induce endothelial inflammation and damage through the transfer of miRNAs

Neutrophils in Type 1 Diabetes: Untangling the Intricate Web of Pathways and Hypothesis

Neutrophils are increasingly recognized as key contributors to the pathogenesis of Type 1 Diabetes (T1D), yet their precise mechanistic role in disease onset and progression remains incompletely understood. While these innate immune cells reside in pancreatic tissue and support tissue homeostasis under physiological conditions, they can also drive tissue damage by triggering innate immune responses and modulating inflammation. Within the inflammatory milieu, neutrophils establish complex, bidirectional interactions with various immune cells, including macrophages, dendritic cells, natural killer cells, and lymphocytes. Once activated, they may enhance the innate immune response through direct or indirect crosstalk with immune cells, antigen presentation, and β-cell destruction or dysfunction. These mechanisms underscore the multifaceted and dynamic role of neutrophils in T1D, shaped by their intricate immunological interactions. Further research into the diverse functional capabilities of neutrophils is crucial for uncovering novel aspects of their involvement in T1D, potentially revealing new therapeutic targets to modulate disease progression.

Study on the diagnostic role of exosome-derived miRNAs in postoperative septic shock and non-septic shock patients

BACKGROUND

Diagnosing septic shock promptly is essential but challenging, especially due to its clinical similarity to non-septic shock. Extracellular vesicle-derived miRNAs may serve as biomarkers to distinguish septic shock from non-septic shock, providing a more accurate diagnostic tool for postsurgical patients. This study aims to identify extracellular vesicle-derived miRNA signatures that differentiate septic shock from non-septic shock in postsurgical patients, potentially improving diagnostic accuracy and clinical decision-making.

METHODS

A multicentre, prospective study was conducted on miRNA profiles in shock patients. Two cohorts were recruited from the Intensive Care Units of two Spanish hospitals: a discovery cohort with 109 patients and a validation cohort with 52 patients. Plasma samples were collected within 24 h of shock diagnosis and subjected to miRNA sequencing. High-throughput sequencing data from the discovery cohort were analysed to identify differentially expressed miRNAs. These findings were validated via qPCR in the validation cohort.

RESULTS

Thirty miRNAs were identified as significantly differentially expressed between septic and non-septic shock patients. Among these, six miRNAs-miR-100-5p, miR-484, miR-10a-5p, miR-148a-3p, miR-342-3p, and miR-451a-demonstrated strong diagnostic capabilities for septic shock. A combination of miR-100-5p, miR-148a-3p, and miR-451a achieved an area under the curve of 0.894, with qPCR validation in the validation cohort yielding an area under the curve of 0.960.

CONCLUSIONS

This study highlights extracellular vesicle-derived miRNAs as promising biomarkers for differentiating septic from non-septic shock. The identified three-miRNA signature has significant potential to enhance septic shock diagnosis, thereby aiding in timely and appropriate treatment for postsurgical patients.

MiR-451 in Inflammatory Diseases: Molecular Mechanisms, Biomarkers, and Therapeutic Applications-A Comprehensive Review Beyond Oncology

MicroRNAs play crucial roles in regulating inflammatory responses and disease progression. Since its identification on chromosome 17q11.2 in 2005, miR-451 has emerged as a key regulator of multiple physiological and pathological processes. While its role in cancer has been extensively documented, accumulating evidence reveals miR-451's broader significance in inflammatory conditions through the regulation of NF-κB, AMPK, and PI3K signaling pathways. This comprehensive review systematically analyzes miR-451's multifaceted functions in inflammatory diseases, with particular focus on ischemia-reperfusion injury, arthritis, and acute organ injuries. We present compelling evidence for miR-451's potential as a diagnostic biomarker, demonstrating its distinctive expression patterns across various biological specimens and disease states. Furthermore, we elucidate how miR-451 modulates inflammatory responses through the regulation of immune cell populations, including microglia activation, macrophage polarization, and neutrophil chemotaxis. By integrating current evidence and bioinformatic analyses, we establish a theoretical framework linking miR-451's molecular mechanisms to its therapeutic applications. This review not only synthesizes the current understanding of miR-451 in inflammatory diseases but also provides critical insights for developing novel diagnostic tools and therapeutic strategies.

Neutrophil/Lymphocyte Ratio and All-Cause Mortality in Diabetic Kidney Disease: A Retrospective Cohort Study

Background

Diabetic kidney disease (DKD) is a significant contributor to the development of end-stage renal disease and cardiovascular disease (CVD), with inflammation being a critical factor in its pathogenesis. The aim of this study is to examine the relationship between the neutrophil-to-lymphocyte ratio (NLR), a new inflammatory marker, and mortality from all causes and CVD in patients with DKD.

Methods

This multicenter, retrospective cohort study utilized data from the China Renal Data System (CRDS) on patients with DKD hospitalized between January 1, 2000, and February 28, 2023. The patients' demographic information, along with their initial clinical and laboratory results, were collected and recorded. Follow-up continued until July 1, 2023, and patients were categorized into two groups based on the median baseline NLR. The Cox proportional hazards regression, Restricted cubic spline (RCS) curves, The Kaplan-Meier curve, Fine-Gray competing risk model, Time-dependent ROC and subgroup analysis were used to analyze the association between all-cause mortality and CVD mortality in patients having DKD with varying NLR.

Results

This study included 11,427 patients who had been clinically diagnosed with DKD. Baseline NLR was associated with C-reactive protein, procalcitonin, high-sensitivity C-reactive protein, plasma D-dimer, cystatin C, creatinine, urea nitrogen, brain natriuretic peptide, and eGFR. We selected the demographic characteristics, differential factors from univariate analysis, and clinically DKD-related laboratory indicators as covariates for Cox analysis. Results indicated that NLR was an independent risk factor for both all-cause and CVD mortality after adjusting for the relevant variables. The risk of all-cause death and CVD death in the high NLR group was 4.688 and 2.141 times higher, respectively, compared to the low NLR group (HR = 4.688, 95% CI 1.153-19.061, P = 0.031; HR = 2.141, 95% CI 1.257-3.644, P = 0.005). However, potential confounding factors and biases, such as unmeasured variables and the influence of treatment interventions, could not be fully accounted for.

Conclusion

NLR can independently predict the risk of all-cause and CVD mortality in patients with DKD. Identifying individuals with a high NLR and providing further intervention could be crucial measures to reduce both all-cause and CVD mortality. However, the results should be interpreted with caution due to the study's limitations.

In a sticky situation: pro-coagulant properties expand the importance of neutrophil EVs in driving tissue injury

Inflammatory and microbial stimuli prompt a neutrophil extracellular vesicle signature capable of driving disease processes.

The negative effects of extracellular vesicles in the immune system

Immunity is a critical self-defense mechanism of the human body, wherein immune cells and immune molecules play a crucial role. Extracellular vesicles (EVs), derived from immune cells or other cells, play a significant role in tumors, autoimmune diseases and other immune-related disorders by serving as carriers and facilitating intercellular communication through the transfer of cargoes. Numerous studies have revealed that EVs can exacerbate disease development by modulating immune responses. Therefore, this paper focuses on the effects of EVs on the number, activity and function of different types of immune cells and the release of immune molecules (such as cytokines, antigens, antibodies, etc) in various diseases, as well as the roles of EVs associated with different types of immune cells in various diseases. We aim to provide a comprehensive review of the negative effects that EVs play in the immune system to provide more ideas and strategies for the management of clinical immune diseases.

Exosomal miR-4745-5p/3911 from N2-polarized tumor-associated neutrophils promotes gastric cancer metastasis by regulating SLIT2

Tumor cells remodel the phenotype and function of tumor microenvironment (TME) cells to favor tumor progression. Previous studies have shown that neutrophils in TME are polarized to N2 tumor-associated neutrophils (TANs) by tumor derived factors, thus promoting tumor growth and metastasis, angiogenesis, therapy resistance, and immunosuppression. Exosomes act as critical intercellular messengers in human health and diseases including cancer. So far, the biological roles of exosomes from N2 TANs in gastric cancer have not been well characterized. Herein, we represented the first report that exosomes from N2 TANs promoted gastric cancer metastasis in vitro and in vivo. We found that exosomes from N2 TANs transferred miR-4745-5p/3911 to gastric cancer cells to downregulate SLIT2 (slit guidance ligand 2) gene expression. Adenovirus-mediated overexpression of SLIT2 reversed the promotion of gastric cancer metastasis by N2 TANs derived exosomes. We further revealed that gastric cancer cells induced glucose metabolic reprogramming in neutrophils through exosomal HMGB1 (high mobility group protein B1)/NF-κB pathway, which mediated neutrophil N2 polarization and miR-4745-5p/3911 upregulation. We further employed ddPCR (droplet digital PCR) to detect the expression of miR-4745-5p/3911 in N2 TANs exosomes from human serum samples and found their increased levels in gastric cancer patients compared to healthy controls and benign gastric disease patients. Conclusively, our results indicate that N2 TANs facilitate cancer metastasis via regulation of SLIT2 in gastric cancer cells by exosomal miR-4745-5p/3911, which provides a new insight into the roles of TME cells derived exosomes in gastric cancer metastasis and offers a potential biomarker for gastric cancer diagnosis.

Chloride intracellular channel 4 participates in the regulation of lipopolysaccharide-induced inflammatory responses in human bronchial epithelial cells

The airway epithelium is located at the interactional boundary between the external and internal environments of the organism and is often exposed to harmful environmental stimuli. Inflammatory response that occurs after airway epithelial stress is the basis of many lung and systemic diseases. Chloride intracellular channel 4 (CLIC4) is abundantly expressed in epithelial cells. The purpose of this study was to investigate whether CLIC4 is involved in the regulation of lipopolysaccharide (LPS)-induced inflammatory response in airway epithelial cells and to clarify its potential mechanism. Our results showed that LPS induced inflammatory response and decreased CLIC4 levels in vivo and in vitro. CLIC4 silencing aggravated the inflammatory response in epithelial cells, while overexpression of CLIC4 combined with LPS exposure significantly decreased the inflammatory response compared with cells exposed to LPS without CLIC4 overexpression. By labeling intracellular chloride ions with chloride fluorescent probe MQAE, we showed that CLIC4 mediated intracellular chloride ion-regulated LPS-induced cellular inflammatory response.

The role of neutrophils in autoimmune diseases

Historically, neutrophils have been primarily regarded as short-lived immune cells that act as initial responders to antibacterial immunity by swiftly neutralizing pathogens and facilitating the activation of adaptive immunity. However, recent evidence indicates that their roles are considerably more complex than previously recognized. Neutrophils comprise distinct subpopulations and can interact with various immune cells, release granular proteins, and form neutrophil extracellular traps. These functions are increasingly recognized as contributing factors to tissue damage in autoimmune diseases. This review comprehensively examines the physiological functions and heterogeneity of neutrophils, their interactions with other immune cells, and their significance in autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, antiphospholipid syndrome, antineutrophil cytoplasmic antibody-associated vasculitis, multiple sclerosis, and others. This review aims to provide a deeper understanding of the function of neutrophils in the development and progression of autoimmune disorders.

Exosome-Derived microRNA: Potential Target for Diagnosis and Treatment of Sepsis

Exosome-derived microRNAs (miRNAs) are emerging as pivotal players in the pathophysiology of sepsis, representing a new frontier in both the diagnosis and treatment of this complex condition. Sepsis, a severe systemic response to infection, involves intricate immune and nonimmune mechanisms, where exosome-mediated communication can significantly influence disease progression and outcomes. During the progress of sepsis, the miRNA profile of exosomes undergoes notable alterations, is reflecting, and may affect the progression of the disease. This review comprehensively explores the biology of exosome-derived miRNAs, which originate from both immune cells (such as macrophages and dendritic cells) and nonimmune cells (such as endothelial and epithelial cells) and play a dynamic role in modulating pathways that affect the course of sepsis, including those related to inflammation, immune response, cell survival, and apoptosis. Taking into account these dynamic changes, we further discuss the potential of exosome-derived miRNAs as biomarkers for the early detection and prognosis of sepsis and advantages over traditional biomarkers due to their stability and specificity. Furthermore, this review evaluates exosome-based therapeutic miRNA delivery systems in sepsis, which may pave the way for targeted modulation of the septic response and personalized treatment options.

Regulation of immune cells by miR-451 and its potential as a biomarker in immune-related disorders: a mini review

In 2005, Altuvia and colleagues were the first to identify the gene that encodes miR-451 in the human pituitary gland, located in chromosome region 17q11.2. Subsequent studies have confirmed that miR-451 regulates various immune cells, including T cells, B cells, microglia, macrophages, and neutrophils, thereby influencing disease progression. The range of immune-related diseases affected encompasses various cancers, lymphoblastic leukemia, and injuries to the lungs and spinal cord, among others. Moreover, miR-451 is produced by immune cells and can regulate both their own functions and those of other immune cells, thus creating a regulatory feedback loop. This article aims to comprehensively review the interactions between miR-451 and immune cells, clarify the regulatory roles of miR-451 within the immune system, and assess its potential as both a therapeutic target and a biomarker for immune-related diseases.

Exposome: Epigenetics and autoimmune diseases

Systemic autoimmune diseases are complex conditions characterized by an immune system dysregulation and an aberrant activation against self-antigens, leading to tissue and organ damage. Even though genetic predisposition plays a role, it cannot fully explain the onset of these diseases, highlighting the significant impact of non-heritable influences such as environment, hormones and infections. The exposome represents all those factors, ranging from chemical pollutants and dietary components to psychological stressors and infectious agents. Epigenetics, which studies changes in gene expression without altering the DNA sequence, is a crucial link between exposome and the development of autoimmune diseases. Key epigenetic mechanisms include DNA methylation, histone modifications, and non-coding RNAs. These epigenetic modifications could provide a potential piece of the puzzle in understanding systemic autoimmune diseases and their connection with the exposome. In this work we have collected the most important and recent evidence in epigenetic changes linked to systemic autoimmune diseases (systemic lupus erythematosus, idiopathic inflammatory myopathies, ANCA-associated vasculitis, and rheumatoid arthritis), emphasizing the roles these changes may play in disease pathogenesis, their potential as diagnostic biomarkers and their prospective in the development of targeted therapies.

Nanoparticle-neutrophils interactions for autoimmune regulation

Neutrophils play an essential role as 'first responders' in the immune response, necessitating many immune-modulating capabilities. Chronic, unresolved inflammation is heavily implicated in the progression and tissue-degrading effects of autoimmune disease. Neutrophils modulate disease pathogenesis by interacting with the inflammatory and autoreactive cells through effector functions, including signaling, degranulation, and neutrophil extracellular traps (NETs) release. Since the current gold standard systemic glucocorticoid administration has many drawbacks and side effects, targeting neutrophils in autoimmunity provides a new approach to developing therapeutics. Nanoparticles enable targeting of specific cell types and controlled release of a loaded drug cargo. Thus, leveraging nanoparticle properties and interactions with neutrophils provides an exciting new direction toward novel therapies for autoimmune diseases. Additionally, recent work has utilized neutrophil properties to design novel targeted particles for delivery into previously inaccessible areas. Here, we outline nanoparticle-based strategies to modulate neutrophil activity in autoimmunity, including various nanoparticle formulations and neutrophil-derived targeting.

Interaction between miR-142-3p and BDNF Val/Met Polymorphism Regulates Multiple Sclerosis Severity

MiR-142-3p has recently emerged as key factor in tailoring personalized treatments for multiple sclerosis (MS), a chronic autoimmune demyelinating disease of the central nervous system (CNS) with heterogeneous pathophysiology and an unpredictable course. With its involvement in a detrimental regulatory axis with interleukin-1beta (IL1β), miR-142-3p orchestrates excitotoxic synaptic alterations that significantly impact both MS progression and therapeutic outcomes. In this study, we investigated for the first time the influence of individual genetic variability on the miR-142-3p excitotoxic effect in MS. We specifically focused on the single-nucleotide polymorphism Val66Met (rs6265) of the brain-derived neurotrophic factor (BDNF) gene, known for its crucial role in CNS functioning. We assessed the levels of miR-142-3p and IL1β in cerebrospinal fluid (CSF) obtained from a cohort of 114 patients with MS upon diagnosis. By stratifying patients according to their genetic background, statistical correlations with clinical parameters were performed. Notably, in Met-carrier patients, we observed a decoupling of miR-142-3p levels from IL1β levels in the CSF, as well as from of disease severity (Expanded Disability Status Score, EDSS; Multiple Sclerosis Severity Score, MSSS; Age-Related Multiple Sclerosis Severity Score, ARMSS) and progression (Progression Index, PI). Our discovery of the interference between BDNF Val66Met polymorphism and the synaptotoxic IL1β-miR-142-3p axis, therefore hampering miR-142-3p action on MS course, provides valuable insights for further development of personalized medicine in the field.

Role of non-coding RNAs and exosomal non-coding RNAs in vasculitis: A narrative review

A category of very uncommon systemic inflammatory blood vessel illnesses known as vasculitides. The pathogenesis and etiology of vasculitis are still poorly known. Despite all of the progress made in understanding the genetics and causes behind vasculitis, there is still more to learn. Epigenetic dysregulation is a significant contributor to immune-mediated illnesses, and epigenetic aberrancies in vasculitis are becoming more widely acknowledged. Less than 2 % of the genome contains protein-encoding DNA. Studies have shown that a variety of RNAs originating from the non-coding genome exist. Long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) have attracted the most attention in recent years as they are becoming more and more important regulators of different biological processes, such as diseases of the veins. Extracellular vehicles (EVs) such as exosomes, are membrane-bound vesicular structures that break free either during programmed cell death, such as apoptosis, pyroptosis, and necroptosis or during cell activation. Exosomes may be involved in harmful ways in inflammation, procoagulation, autoimmune reactions, endothelial dysfunction/damage, intimal hyperplasia and angiogenesis, all of which may be significant in vasculitis. Herein, we summarized various non-coding RNAs that are involved in vasculitides pathogenesis. Moreover, we highlighted the role of exosomes in vasculitides.

The critical role of neutrophil-endothelial cell interactions in sepsis: new synergistic approaches employing organ-on-chip, omics, immune cell phenotyping and in silico modeling to identify new therapeutics

Sepsis is a global health concern accounting for more than 1 in 5 deaths worldwide. Sepsis is now defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Sepsis can develop from bacterial (gram negative or gram positive), fungal or viral (such as COVID) infections. However, therapeutics developed in animal models and traditional in vitro sepsis models have had little success in clinical trials, as these models have failed to fully replicate the underlying pathophysiology and heterogeneity of the disease. The current understanding is that the host response to sepsis is highly diverse among patients, and this heterogeneity impacts immune function and response to infection. Phenotyping immune function and classifying sepsis patients into specific endotypes is needed to develop a personalized treatment approach. Neutrophil-endothelium interactions play a critical role in sepsis progression, and increased neutrophil influx and endothelial barrier disruption have important roles in the early course of organ damage. Understanding the mechanism of neutrophil-endothelium interactions and how immune function impacts this interaction can help us better manage the disease and lead to the discovery of new diagnostic and prognosis tools for effective treatments. In this review, we will discuss the latest research exploring how in silico modeling of a synergistic combination of new organ-on-chip models incorporating human cells/tissue, omics analysis and clinical data from sepsis patients will allow us to identify relevant signaling pathways and characterize specific immune phenotypes in patients. Emerging technologies such as machine learning can then be leveraged to identify druggable therapeutic targets and relate them to immune phenotypes and underlying infectious agents. This synergistic approach can lead to the development of new therapeutics and the identification of FDA approved drugs that can be repurposed for the treatment of sepsis.

Intravenous injection of tumor extracellular vesicles suppresses tumor growth by reducing the regulatory T cell phenotype

BACKGROUND

Colorectal cancer is a disease of unmet medical need. Although extracellular vesicles (EVs) have been implicated in anti-tumor responses, discrepancies were observed among studies. We analyzed the role of tumor-derived EVs (TEVs) in tumor progression in vivo by focusing on regulatory T (Treg) cells, which play essential roles in tumor development and progression.

METHODS

A mouse model of colorectal cancer lung metastasis was generated using BALB/c mice by tail vein injection of the BALB/c colon adenocarcinoma cell line Colon-26. TEVs derived from Colon-26 and BALB/c lung squamous cell carcinoma ASB-XIV were retrieved from the culture media supernatants. A TEV equivalent to 10 µg protein was injected every other day for 2 weeks.

RESULTS

Histology and immunohistochemistry studies revealed that lung tumors reduced in the Colon-26-EV group when compared to the phosphate-buffered saline (PBS) group. The population of CD4 + FoxP3 + cells in the lung was upregulated in the PBS group mice when compared to the healthy mice (P < 0.001), but was significantly downregulated in the Colon-26-EV group mice when compared to the PBS group mice (P < 0.01). Programmed cell death protein 1, glucocorticoid-induced TNFR-related protein, and CD69 expression in lung Treg cells were markedly upregulated in the PBS group when compared to the healthy mice, but downregulated in the Colon-26-EV group when compared to the PBS group. The changes in expression were dose-dependent for Colon-26-EVs. ASB-EVs also led to significantly downregulated Treg cell expression, although non-cancer line 3T3-derived EVs did not.

CONCLUSION

Our study suggests that TEVs possess components for tumor suppression.

CREB1-driven CXCR4hi neutrophils promote skin inflammation in mouse models and human patients

Neutrophils have a pathogenic function in inflammation via releasing pro-inflammatory mediators or neutrophil extracellular traps (NETs). However, their heterogeneity and pro-inflammatory mechanisms remain unclear. Here, we demonstrate that CXCR4hi neutrophils accumulate in the blood and inflamed skin in human psoriasis, and correlate with disease severity. Compared to CXCR4lo neutrophils, CXCR4hi neutrophils have enhanced NETs formation, phagocytic function, neutrophil degranulation, and overexpression of pro-inflammatory cytokines and chemokines in vitro. This is accompanied by a metabolic shift in CXCR4hi neutrophils toward glycolysis and lactate release, thereby promoting vascular permeability and remodeling. CXCR4 expression in neutrophils is dependent on CREB1, a transcription factor activated by TNF and CXCL12, and regulated by de novo synthesis. In vivo, CXCR4hi neutrophil infiltration amplifies skin inflammation, whereas blockade of CXCR4hi neutrophils through CXCR4 or CXCL12 inhibition leads to suppression of immune responses. In this work, our study identifies CREB1 as a critical regulator of CXCR4hi neutrophil development and characterizes the contribution of CXCR4hi neutrophils to vascular remodeling and inflammatory responses in skin.

Exosomal miRNAs assist in the crosstalk between tumor cells and immune cells and its potential therapeutics

Exosomes are small extracellular vesicles that carry active substances (including proteins, lipids, and nucleic acids) and are essential for homeostasis and signal transmission. Recent studies have focused on the function of exosomal miRNAs in tumor progression. Researchers have expanded the use of exosomes and miRNAs as potential therapeutic tools and biomarkers to detect tumor progression. Immune cells, as an important part of the tumor microenvironment (TME), secrete a majority of exosome-derived miRNAs involved in the biological processes of malignancies. However, the underlying mechanisms remain unclear. Currently, there is no literature that systematically summarizes the communication of exosome-derived miRNAs between tumor cells and immune cells. Based on the cell specificity of exosome-derived miRNAs, this review provides the first comprehensive summary of the significant miRNAs from the standpoint of exosome sources, which are tumor cells and immune cells. Furthermore, we elaborated on the potential clinical applications of these miRNAs, attempting to propose existing difficulties and future possibilities in tumor diagnostics and therapy.

miR-223: a key regulator of pulmonary inflammation

Small noncoding RNAs, known as microRNAs (miRNAs), are vital for the regulation of diverse biological processes. miR-223, an evolutionarily conserved anti-inflammatory miRNA expressed in cells of the myeloid lineage, has been implicated in the regulation of monocyte-macrophage differentiation, proinflammatory responses, and the recruitment of neutrophils. The biological functions of this gene are regulated by its expression levels in cells or tissues. In this review, we first outline the regulatory role of miR-223 in granulocytes, macrophages, endothelial cells, epithelial cells and dendritic cells (DCs). Then, we summarize the possible role of miR-223 in chronic obstructive pulmonary disease (COPD), acute lung injury (ALI), coronavirus disease 2019 (COVID-19) and other pulmonary inflammatory diseases to better understand the molecular regulatory networks in pulmonary inflammatory diseases.

Plasma Pattern of Extracellular Vesicles Isolated from Hepatitis C Virus Patients and Their Effects on Human Vascular Endothelial Cells

Hepatitis C virus (HCV) patients are at increased risk of cardiovascular disease (CVD). In this study, we aimed to evaluate the role of extracellular vesicles (EVs) as pathogenic factors for the onset of HCV-related endothelial dysfunction. Sixty-five patients with various stages of HCV-related chronic liver disease were enrolled in this case series. Plasma EVs were characterized and used to stimulate human vascular endothelial cells (HUVEC), which were examined for cell viability, mitochondrial membrane potential, and reactive oxygen species (ROS) release. The results showed that EVs from HCV patients were mainly of endothelial and lymphocyte origin. Moreover, EVs were able to reduce cell viability and mitochondrial membrane potential of HUVEC, while increasing ROS release. Those harmful effects were reduced by the pretreatment of HUVEC with the NLR family pyrin domain containing 3 (NLRP3)/AMP-activated protein kinase and protein kinase B blockers. In conclusion, in HCV patients, we could highlight a circulating pattern of EVs capable of inducing damage to the endothelium. These data represent a novel possible pathogenic mechanism underlying the reported increase of CVD occurrence in HCV infection and could be of clinical relevance also in relation to the widespread use of antiviral drugs.

miR-142-3p encapsulated in T lymphocyte-derived tissue small extracellular vesicles induces Treg function defect and thyrocyte destruction in Hashimoto's thyroiditis

BACKGROUND

Hashimoto's thyroiditis (HT) is an organ-specific autoimmune disease characterized by lymphocyte infiltration that destroys thyrocyte cells. The aim of the present study was to elucidate the role and mechanisms of tissue small extracellular vesicle (sEV) microRNAs (miRNAs) in the pathogenesis of HT.

METHODS

Differentially expressed tissue sEV miRNAs were identified between HT tissue and normal tissue by RNA sequencing in the testing set (n = 20). Subsequently, using quantitative real-time polymerase chain reaction (qRT‒PCR) assays and logistic regression analysis in the validation set (n = 60), the most relevant tissue sEV miRNAs to HT were verified. The parental and recipient cells of that tissue sEV miRNA were then explored. In vitro and in vivo experiments were further performed to elucidate the function and potential mechanisms of sEV miRNAs that contribute to the development of HT.

RESULTS

We identified that miR-142-3p encapsulated in T lymphocyte-derived tissue sEVs can induce Treg function defect and thyrocyte destruction through an intact response loop. Inactivation of miR-142-3p can effectively protect non-obese diabetic (NOD).H-2^h4 mice from HT development display reduced lymphocyte infiltration, lower antibody titers, and higher Treg cells. Looking at the mechanisms underlying sEV action on thyrocyte destruction, we found that the strong deleterious effect mediated by tissue sEV miR-142-3p is due to its ability to block the activation of the ERK1/2 signaling pathway by downregulating RAC1.

CONCLUSIONS

Our findings highlight the fact that tissue sEV-mediated miR-142-3p transfer can serve as a communication mode between T lymphocytes and thyrocyte cells in HT, favoring the progression of HT.

Cellular nanovesicles for therapeutic immunomodulation: A perspective on engineering strategies and new advances

Cellular nanovesicles which are referred to as cell-derived, nanosized lipid bilayer structures, have emerged as a promising platform for regulating immune responses. Owing to their outstanding advantages such as high biocompatibility, prominent structural stability, and high loading capacity, cellular nanovesicles are suitable for delivering various immunomodulatory molecules, such as small molecules, nucleic acids, peptides, and proteins. Immunomodulation induced by cellular nanovesicles has been exploited to modulate immune cell behaviors, which is considered as a novel cell-free immunotherapeutic strategy for the prevention and treatment of diverse diseases. Here we review emerging concepts and new advances in leveraging cellular nanovesicles to activate or suppress immune responses, with the aim to explicate their applications for immunomodulation. We overview the general considerations and principles for the design of engineered cellular nanovesicles with tailored immunomodulatory activities. We also discuss new advances in engineering cellular nanovesicles as immunotherapies for treating major diseases.

Rac1: A Regulator of Cell Migration and A Potential Target for Cancer Therapy

Cell migration is crucial for physiological and pathological processes such as morphogenesis, wound repair, immune response and cancer invasion/metastasis. There are many factors affecting cell migration, and the regulatory mechanisms are complex. Rac1 is a GTP-binding protein with small molecular weight belonging to the Rac subfamily of the Rho GTPase family. As a key molecule in regulating cell migration, Rac1 participates in signal transduction from the external cell to the actin cytoskeleton and promotes the establishment of cell polarity which plays an important role in cancer cell invasion/metastasis. In this review, we firstly introduce the molecular structure and activity regulation of Rac1, and then summarize the role of Rac1 in cancer invasion/metastasis and other physiological processes. We also discuss the regulatory mechanisms of Rac1 in cell migration and highlight it as a potential target in cancer therapy. Finally, the current state as well as the future challenges in this area are considered. Understanding the role and the regulatory mechanism of Rac1 in cell migration can provide fundamental insights into Rac1-related cancer progression and further help us to develop novel intervention strategies for cancer therapy in clinic.

Neuroinflammation of traumatic brain injury: Roles of extracellular vesicles

Traumatic brain injury (TBI) is a major cause of neurological disorder or death, with a heavy burden on individuals and families. While sustained primary insult leads to damage, subsequent secondary events are considered key pathophysiological characteristics post-TBI, and the inflammatory response is a prominent contributor to the secondary cascade. Neuroinflammation is a multifaceted physiological response and exerts both positive and negative effects on TBI. Extracellular vesicles (EVs), as messengers for intercellular communication, are involved in biological and pathological processes in central nervous system (CNS) diseases and injuries. The number and characteristics of EVs and their cargo in the CNS and peripheral circulation undergo tremendous changes in response to TBI, and these EVs regulate neuroinflammatory reactions by activating prominent receptors on receptor cells or delivering pro- or anti-inflammatory cargo to receptor cells. The purpose of this review is to discuss the possible neuroinflammatory mechanisms of EVs and loading in the context of TBI. Furthermore, we summarize the potential role of diverse types of cell-derived EVs in inflammation following TBI.

Treponema pallidum lipoprotein Tp0768 promotes the migration and adhesion of THP-1 cells to vascular endothelial cells through stress of the endoplasmic reticulum and the NF-κB/HIF-1α pathway

Endothelial cell injury is a key factor in the spread of infection and pathogenicity of Treponema pallidum. The migration and adhesion reaction mediated by T. pallidum lipoprotein plays an important role. This study aimed to systematically explore the migration and adhesion effect of T. pallidum lipoprotein Tp0768 and its molecular mechanism. Stimulating vascular endothelial cells with Tp0768 increased the expression of ICAM-1, MCP-1, and IL-8. Moreover, it promoted the migration and adhesion of THP-1 cells to vascular endothelial cells. Our results revealed that Tp0768 promoted the THP-1 cells migrating and adhering to vascular endothelial cells by the PERK and IRE-1α pathways of endoplasmic reticulum (ER) stress. We further demonstrated that the inhibition of the NF-κB pathway and the downregulation of hypoxia-inducible factor 1 alpha (HIF-1α) reduced the mRNA levels of ICAM-1, MCP-1, and IL-8 induced by Tp0768. Also, the adhesion rate of THP-1 cells to endothelial cells decreased. After inhibiting ER stress, NF-κB p65 nuclear translocation was weakened, and the mRNA level of HIF-1α was also significantly downregulated. Our results indicated that T. pallidum lipoprotein Tp0768 promoted the migration and adhesion of THP-1 cells to vascular endothelial cells through ER stress and NF-κB/HIF-1α pathway.

Neutrophil Extracellular Vesicles: A Delicate Balance between Pro-Inflammatory Responses and Anti-Inflammatory Therapies

Extracellular vesicles (EVs) are released in the extracellular environment during cell activation or apoptosis. Working as signal transducers, EVs are important mediators of intercellular communication through the convoying of proteins, nucleic acids, lipids, and metabolites. Neutrophil extracellular vesicles (nEVs) contain molecules acting as key modulators of inflammation and immune responses. Due to their potential as therapeutic tools, studies about nEVs have been increasing in recent years. However, our knowledge about nEVs is still in its infancy. In this review, we summarize the current understanding of the role of nEVs in the framework of neutrophil inflammation functions and disease development. The therapeutic potential of nEVs as clinical treatment strategies is deeply discussed. Moreover, the promising research landscape of nEVs in the near future is also examined.

Neutrophil Extracellular Traps and Neutrophil-Derived Extracellular Vesicles: Common Players in Neutrophil Effector Functions

Neutrophil granulocytes are a central component of the innate immune system. In recent years, they have gained considerable attention due to newly discovered biological effector functions and their involvement in various pathological conditions. They have been shown to trigger mechanisms that can either promote or inhibit the development of autoimmunity, thrombosis, and cancer. One mechanism for their modulatory effect is the release of extracellular vesicles (EVs), that trigger appropriate signaling pathways in immune cells and other target cells. In addition, activated neutrophils can release bactericidal DNA fibers decorated with proteins from neutrophil granules (neutrophil extracellular traps, NETs). While NETs are very effective in limiting pathogens, they can also cause severe damage if released in excess or cleared inefficiently. Since NETs and EVs share a variety of neutrophil molecules and initially act in the same microenvironment, differential biochemical and functional analysis is particularly challenging. This review focuses on the biochemical and functional parallels and the extent to which the overlapping spectrum of effector molecules has an impact on biological and pathological effects.