Extracellular Vesicles as Central Mediators of COPD Pathophysiology

Extracellular Vesicle-Encapsulated microRNAs and Respiratory Health Among American Indians in the Strong Heart Study

BACKGROUND

American Indian populations have experienced marked disparities in respiratory disease burden. Extracellular vesicle-encapsulated microRNAs (EV-miRNAs) are a novel class of biomarkers that may improve recognition of lung damage in indigenous populations.

RESEARCH QUESTION

Are plasma EV-miRNAs viable biomarkers of respiratory health in American Indian populations?

STUDY DESIGN AND METHODS

The Strong Heart Study (SHS) is a prospective cohort study that enrolled American Indians aged 45 to 74 years. EV-miRNA expression was measured in plasma (1993-1995). Respiratory health outcomes, including pre-bronchodilator FEV1, FVC, and respiratory symptom burden, were ascertained in the same study visit. Club cell secretory protein (CC-16), an antiinflammatory pneumoprotein implicated in COPD pathogenesis, was measured in serum. Linear and logistic regression were used for statistical analyses. Biological pathway analyses were used to elucidate gene targets of significant EV-miRNAs.

RESULTS

Among 853 American Indian adults, three EV-miRNAs were associated with FEV1, four EV-miRNAs were associated with FVC, and one EV-miRNA was associated with FEV1/FVC (P < .05). Increased miR-1294 expression was associated with higher odds of airflow limitation (OR, 1.29; 95% CI, 1.07-1.55), whereas increased expression of miR-1294 (OR, 1.32; 95% CI, 1.07-1.63) and miR-532-5p (OR, 1.57; 95% CI, 1.02-2.40) was associated with higher odds of restriction. Increased miR-451a expression was associated with lower odds of exertional dyspnea (OR, 0.71; 95% CI, 0.59-0.85). Twenty-two EV-miRNAs were associated with serum CC-16 levels (q < 0.05), suggesting that EV-miRNAs may play a role in the pathway linking CC-16 to COPD pathogenesis. A pathway analysis showed key EV-miRNAs targeted biological pathways that modulate inflammation, immunity, and structural integrity in the lungs.

INTERPRETATION

Circulating EV-miRNAs are novel mechanistic biomarkers of respiratory health and may facilitate the early detection and treatment of lung damage in American Indian populations that have been disproportionately affected by chronic lung diseases.

Metabolic pathways in immune senescence and inflammaging: Novel therapeutic strategy for chronic inflammatory lung diseases. An EAACI position paper from the Task Force for Immunopharmacology

The accumulation of senescent cells drives inflammaging and increases morbidity of chronic inflammatory lung diseases. Immune responses are built upon dynamic changes in cell metabolism that supply energy and substrates for cell proliferation, differentiation, and activation. Metabolic changes imposed by environmental stress and inflammation on immune cells and tissue microenvironment are thus chiefly involved in the pathophysiology of allergic and other immune-driven diseases. Altered cell metabolism is also a hallmark of cell senescence, a condition characterized by loss of proliferative activity in cells that remain metabolically active. Accelerated senescence can be triggered by acute or chronic stress and inflammatory responses. In contrast, replicative senescence occurs as part of the physiological aging process and has protective roles in cancer surveillance and wound healing. Importantly, cell senescence can also change or hamper response to diverse therapeutic treatments. Understanding the metabolic pathways of senescence in immune and structural cells is therefore critical to detect, prevent, or revert detrimental aspects of senescence-related immunopathology, by developing specific diagnostics and targeted therapies. In this paper, we review the main changes and metabolic alterations occurring in senescent immune cells (macrophages, B cells, T cells). Subsequently, we present the metabolic footprints described in translational studies in patients with chronic asthma and chronic obstructive pulmonary disease (COPD), and review the ongoing preclinical studies and clinical trials of therapeutic approaches aiming at targeting metabolic pathways to antagonize pathological senescence. Because this is a recently emerging field in allergy and clinical immunology, a better understanding of the metabolic profile of the complex landscape of cell senescence is needed. The progress achieved so far is already providing opportunities for new therapies, as well as for strategies aimed at disease prevention and supporting healthy aging.

Extracellular vesicle dynamics in COPD: understanding the role of miR-422a, SPP1 and IL-17 A in smoking-related pathology

BACKGROUND

Chronic obstructive pulmonary disease (COPD) induced by smoking poses a significant global health challenge. Recent findings highlight the crucial role of extracellular vesicles (EVs) in mediating miRNA regulatory networks across various diseases. This study utilizes the GEO database to uncover distinct expression patterns of miRNAs and mRNAs, offering a comprehensive understanding of the pathogenesis of smoking-induced COPD. This study aims to investigate the mechanisms by which extracellular vesicles (EVs) mediate the molecular network of miR-422a-SPP1 to delay the onset of COPD caused by smoking.

METHODS

The smoking-related miRNA chip GSE38974-GPL7723 was obtained from the GEO database, and candidate miRs were retrieved from the Vesiclepedia database. Downstream target genes of the candidate miRs were predicted using mRNA chip GSE38974-GPL4133, TargetScan, miRWalk, and RNA22 databases. This prediction was integrated with COPD-related genes from the GeneCards database, downstream target genes predicted by online databases, and key genes identified in the core module of WGCNA analysis to obtain candidate genes. The candidate genes were subjected to KEGG functional enrichment analysis using the "clusterProfiler" package in R language, and a protein interaction network was constructed. In vitro experiments involved overexpressing miRNA or extracting extracellular vesicles from bronchial epithelial cell-derived exosomes, co-culturing them with myofibroblasts to observe changes in the expression levels of the miR-422a-SPP1-IL-17 A regulatory network, and assessing protein levels of fibroblast differentiation-related factors α-SMA and collagen I using Western blot analysis.

RESULTS

The differential gene analysis of chip GSE38974-GPL7723 and the retrieval results from the Vesiclepedia database identified candidate miRs, specifically miR-422a. Subsequently, an intersection was taken among the prediction results from TargetScan, miRWalk, and RNA22 databases, the COPD-related gene retrieval results from GeneCards database, the WGCNA analysis results of chip GSE38974-GPL4133, and the differential gene analysis results. This intersection, combined with KEGG functional enrichment analysis, and protein-protein interaction analysis, led to the final screening of the target gene SPP1 and its upstream regulatory gene miR-422a. KEGG functional enrichment analysis of mRNAs correlated with SPP1 revealed the IL-17 signaling pathway involved. In vitro experiments demonstrated that miR-422a inhibition targets suppressed the expression of SPP1 in myofibroblasts, inhibiting differentiation phenotype. Bronchial epithelial cells, under cigarette smoke extract (CSE) stress, could compensate for myofibroblast differentiation phenotype by altering the content of miR-422a in their Extracellular Vesicles (EVs).

CONCLUSION

The differential gene analysis of Chip GSE38974-GPL7723 and the retrieval results from the Vesiclepedia database identified candidate miRs, specifically miR-422a. Further analysis involved the intersection of predictions from TargetScan, miRWalk, and RNA22 databases, gene search on COPD-related genes from the GeneCards database, WGCNA analysis from Chip GSE38974-GPL4133, and differential gene analysis, combined with KEGG functional enrichment analysis and protein interaction analysis. Ultimately, the target gene SPP1 and its upstream regulatory gene miR-422a were selected. KEGG functional enrichment analysis on mRNAs correlated with SPP1 revealed the involvement of the IL-17 signaling pathway. In vitro experiments showed that miR-422a targeted inhibition suppressed the expression of SPP1 in myofibroblast cells, inhibiting differentiation phenotype. Furthermore, bronchial epithelial cells could compensate for myofibroblast differentiation phenotype under cigarette smoke extract (CSE) stress by altering the miR-422a content in their extracellular vesicles (EVs).

The role of extracellular vesicles in COPD and potential clinical value

Chronic obstructive pulmonary disease (COPD) is a heterogeneous lung disease and a major health burden worldwide. Extracellular vesicles (EVs) are nanosized vesicles which possess a lipid bilayer structure that are secreted by various cells. They contain a variety of bioactive substances, which can regulate various physiological and pathological processes and are closely related to the development of diseases. Recently, EVs have emerged as a novel tool for intercellular crosstalk, which plays an essential role in COPD development. This paper reviews the role of EVs in the development of COPD and their potential clinical value, in order to provide a reference for further research on COPD.

Protease-armed, Pathogenic Extracellular Vesicles Link Smoking and Chronic Obstructive Pulmonary Disease

Rationale: Mounting evidence demonstrates a role for extracellular vesicles (EVs) in driving lung disorders, such as chronic obstructive pulmonary disease (COPD). Although cigarette smoke (CS) is the primary risk factor for COPD, a link between CS and the EVs that could lead to COPD is unknown. Objective: To ascertain whether exposure to CS elicits a proteolytic EV signature capable of driving disease pathogenesis. Methods: Protease expression and enzymatic activity were measured in EVs harvested from the BAL fluid of smoke-exposed mice and otherwise healthy human smokers. Pathogenicity of EVs was examined using pathological tissue scoring after EV transfer into naive recipient mice. Measurements and Main Results: The analyses revealed a unique EV profile defined by neutrophil- and macrophage-derived EVs. These EVs are characterized by abundant surface expression of neutrophil elastase (NE) and matrix metalloproteinase 12 (MMP12), respectively. CS-induced mouse or human-derived airway EVs had a robust capacity to elicit rapid lung damage in naive recipient mice, with an additive effect of NE- and MMP12-expressing EVs. Conclusions: These studies demonstrate the capacity of CS to drive the generation of unique EV populations containing NE and MMP12. The coordinated action of these EVs is completely sufficient to drive emphysematous disease, and their presence could operate as a prognostic indicator for COPD development. Furthermore, given the robust capacity of these EVs to elicit emphysema in naive mice, they provide a novel model to facilitate preclinical COPD research. Indeed, the development of this model has led to the discovery of a previously unrecognized CS-induced protective mechanism against EV-mediated damage.

Engineered extracellular vesicles as therapeutics of degenerative orthopedic diseases

Degenerative orthopedic diseases, as a global public health problem, have made serious negative impact on patients' quality of life and socio-economic burden. Traditional treatments, including chemical drugs and surgical treatments, have obvious side effects and unsatisfactory efficacy. Therefore, biological therapy has become the focus of researches on degenerative orthopedic diseases. Extracellular vesicles (EVs), with superior properties of immunoregulatory, growth support, and drug delivery capabilities, have emerged as a new cell-free strategy for the treatment of many diseases, including degenerative orthopedic diseases. An increasing number of studies have shown that EVs can be engineered through cargo loading, surface modification, and chemical synthesis to improve efficiency, specificity, and safety. Herein, a comprehensive overview of recent advances in engineering strategies and applications of engineered EVs as well as related researches in degenerative orthopedic diseases, including osteoarthritis (OA), osteoporosis (OP), intervertebral disc degeneration (IDD) and osteonecrosis of the femoral head (ONFH), is provided. In addition, we analyze the potential and challenges of applying engineered EVs to clinical practice.

Extracellular vesicles isolated from hyperuricemia patients might aggravate airway inflammation of COPD via senescence-associated pathway

BACKGROUNDS

Chronic obstructive pulmonary disease (COPD) is a major health issue resulting in significant mortality worldwide. Due to the high heterogeneity and unclear pathogenesis, the management and therapy of COPD are still challenging until now. Elevated serum uric acid(SUA) levels seem to be associated with the inflammatory level in patients with COPD. However, the underlying mechanism is not yet clearly established. In the current research, we aim to elucidate the effect of high SUA levels on airway inflammation among COPD patients.

METHODS

Through bioinformatic analysis, the common potential key genes were determined in both COPD and hyperuricemia (HUA) patients. A total of 68 COPD patients aged 50-75-year were included in the study, and their clinical parameters, including baseline characteristics, lung function test, as well as blood chemistry test were recorded. These parameters were then compared between the COPD patients with and without HUA. Hematoxylin & Eosin (HE), immunofluorescence (IF), and Masson trichrome staining were performed to demonstrate the pathological changes in the lung tissues. Furthermore, we isolated extracellular vesicles (EVs) from plasma, sputum, and bronchoalveolar lavage fluid (BALF) samples and detected the expression of inflammatory factor (Interleukin-6 (IL-6), IL-8 and COPD related proteases (antitrypsin and elastase) between two groups. Additionally, we treated the human bronchial epithelial (HBE) cells with cigarette smoke extract (CSE), and EVs were derived from the plasma in vitro experiments. The critical pathway involving the relationship between COPD and HUA was eventually validated based on the results of RNA sequencing (RNA-seq) and western blot (WB).

RESULTS

In the study, the COPD patients co-existing with HUA were found to have more loss of pulmonary function compared with those COPD patients without HUA. The lung tissue samples of patients who had co-existing COPD and HUA indicated greater inflammatory cell infiltration, more severe airway destruction and even fibrosis. Furthermore, the high SUA level could exacerbate the progress of airway inflammation in COPD through the transfer of EVs. In vitro experiments, we determined that EVs isolated from plasma, sputum, and BALF played pivotal roles in the CSE-induced inflammation of HBE. The EVs in HUA patients might exacerbate both systemic inflammation and airway inflammatory response via the senescence-related pathway.

CONCLUSION

The pulmonary function and clinical indicators of COPD patients with HUA were worse than those without HUA, which may be caused by the increased airway inflammatory response through the EVs in the patient's peripheral blood. Moreover, it might mediate the EVs via senescence-related pathways in COPD patients with HUA.

Combining single-cell RNA sequencing of peripheral blood mononuclear cells and exosomal transcriptome to reveal the cellular and genetic profiles in COPD

Background

It has been a long-held consensus that immune reactions primarily mediate the pathology of chronic obstructive pulmonary disease (COPD), and that exosomes may participate in immune regulation in COPD. However, the relationship between exosomes and peripheral immune status in patients with COPD remains unclear.

Methods

In this study, we sequenced plasma exosomes and performed single-cell RNA sequencing on peripheral blood mononuclear cells (PBMCs) from patients with COPD and healthy controls. Finally, we constructed competing endogenous RNA (ceRNA) and protein–protein interaction (PPI) networks to delineate the interactions between PBMCs and exosomes within COPD.

Results

We identified 135 mRNAs, 132 lncRNAs, and 359 circRNAs from exosomes that were differentially expressed in six patients with COPD compared with four healthy controls. Functional enrichment analyses revealed that many of these differentially expressed RNAs were involved in immune responses including defending viral infection and cytokine–cytokine receptor interaction. We also identified 18 distinct cell clusters of PBMCs in one patient and one control by using an unsupervised cluster analysis called uniform manifold approximation and projection (UMAP). According to resultant cell identification, it was likely that the proportions of monocytes, dendritic cells, and natural killer cells increased in the COPD patient we tested, meanwhile the proportions of B cells, CD4 + T cells, and naïve CD8 + T cells declined. Notably, CD8 + T effector memory CD45RA + (Temra) cell and CD8 + effector memory T (Tem) cell levels were elevated in patient with COPD, which were marked by their lower capacity to differentiate due to their terminal differentiation state and lower reactive capacity to viral pathogens.

Conclusions

We generated exosomal RNA profiling and single-cell transcriptomic profiling of PBMCs in COPD, described possible connection between impaired immune function and COPD development, and finally determined the possible role of exosomes in mediating local and systemic immune reactions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02182-8.

Role of extracellular vesicles in lung diseases

ABSTRACT

Extracellular vesicles (EVs) are anuclear particles composed of lipid bilayers that contain nucleic acids, proteins, lipids, and organelles. EVs act as an important mediator of cell-to-cell communication by transmitting biological signals or components, including lipids, proteins, messenger RNAs, DNA, microRNAs, organelles, etc, to nearby or distant target cells to activate and regulate the function and phenotype of target cells. Under physiological conditions, EVs play an essential role in maintaining the homeostasis of the pulmonary milieu but they can also be involved in promoting the pathogenesis and progression of various respiratory diseases including chronic obstructive pulmonary disease, asthma, acute lung injury/acute respiratory distress syndrome, idiopathic pulmonary fibrosis (IPF), and pulmonary artery hypertension. In addition, in multiple preclinical studies, EVs derived from mesenchymal stem cells (EVs) have shown promising therapeutic effects on reducing and repairing lung injuries. Furthermore, in recent years, researchers have explored different methods for modifying EVs or enhancing EVs-mediated drug delivery to produce more targeted and beneficial effects. This article will review the characteristics and biogenesis of EVs and their role in lung homeostasis and various acute and chronic lung diseases and the potential therapeutic application of EVs in the field of clinical medicine.

The Emerging Role of Macrophages in Chronic Obstructive Pulmonary Disease: The Potential Impact of Oxidative Stress and Extracellular Vesicle on Macrophage Polarization and Function

Chronic obstructive pulmonary disease (COPD) is one of the most common airway diseases, and it is considered a major global health problem. Macrophages are the most representative immune cells in the respiratory tract, given their role in surveying airways, removing cellular debris, immune surveillance, and resolving inflammation. Macrophages exert their functions by adopting phenotypical changes based on the stimuli they receive from the surrounding tissue. This plasticity is described as M1/M2 macrophage polarization, which consists of a strictly coordinated process leading to a difference in the expression of surface markers, the production of specific factors, and the execution of biological activities. This review focuses on the role played by macrophages in COPD and their implication in inflammatory and oxidative stress processes. Particular attention is on macrophage polarization, given macrophage plasticity is a key feature in COPD. We also discuss the regulatory influence of extracellular vesicles (EVs) in cell-to-cell communications. EV composition and cargo may influence many COPD-related aspects, including inflammation, tissue remodeling, and macrophage dysfunctions. These findings could be useful for better addressing the role of macrophages in the complex pathogenesis and outcomes of COPD.