Pathogenesis Of Chronic Obstructive Pulmonary Disease Research Articles

Alterations in the molecular regulation of mitochondrial metabolism in human alveolar epithelial cells in response to cigarette- and heated tobacco product emissions

Mitochondrial abnormalities in lung epithelial cells have been associated with chronic obstructive pulmonary disease (COPD) pathogenesis. Cigarette smoke (CS) can induce alterations in the molecular pathways regulating mitochondrial function in lung epithelial cells. Recently, heated tobacco products (HTPs) have been marketed as harm reduction products compared with regular cigarettes. However, the effects of HTP emissions on human alveolar epithelial cell metabolism and on the molecular mechanisms regulating mitochondrial content and function are unclear. In this study, human alveolar epithelial cells (A549) were exposed to cigarette or HTP emissions in the form of liquid extracts. The oxygen consumption rate of differently exposed cells was measured, and mRNA and protein abundancy of key molecules involved in the molecular regulation of mitochondrial metabolism were assessed. Furthermore, we used a mitophagy detection probe to visualize mitochondrial breakdown over time in response to the extracts. Both types of extracts induced increases in basal-, maximal- and spare respiratory capacity, as well as in cellular ATP production. Moreover, we observed alterations in the abundancy of regulatory molecules controlling mitochondrial biogenesis and mitophagy. Mitophagy was not significantly altered in response to the extracts, as no significant differences compared to vehicle-treated cells were observed.

Construction of circRNA-mediated ceRNA network and immunoassay for investigating pathogenesis of COPD.

The chronic respiratory condition known as chronic obstructive pulmonary disease (COPD) was one of the main causes of death and disability worldwide. This study aimed to explore and elucidate new targets and molecular mechanisms of COPD by constructing competitive endogenous RNA (ceRNA) networks. GSE38974 and GSE106986 were used to select DEGs in COPD samples and normal samples. Cytoscape software was used to construct and present protein-protein interaction (PPI) network, mRNA-miRNA co-expression network and ceRNA network. The CIBERSORT algorithm and the Lasso model were used to screen the immune infiltrating cells and hub genes associated with COPD, and the correlation between them was analyzed. COPD cell models were constructed in vitro and the expression level of ceRNA network factors mediated by hub gene was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). In this study, 852 differentially expressed genes were screened in the GSE38974 dataset, including 439 upregulated genes and 413 downregulated genes. Gene clustering analysis of PPI network results was performed using the Minimum Common Tumor Data Element (MCODE) in Cytoscape, and seven hub genes were screened using five algorithms in cytoHubba. CCL20 was verified as an important hub gene based on mRNA-miRNA co-expression network, GSE106986 database validation and the analysis of ROC curve results. Finally, we successfully constructed the circDTL-hsa-miR-330-3p-CCL20 network by Cytoscape. Immune infiltration analysis suggested that CCL20 can co-regulate immune cell migration and infiltration through chemokines CCL7 and CXCL3. In vitro experiments, the expression of circDTL and CCL20 was increased, while the expression of hsa-miR-330-3p was decreased in the COPD cell model. By constructing the circDTL-hsa-miR-330-3p-CCL20 network, this study contributes to a better understanding of the molecular mechanism of COPD development, which also provides important clues for the development of new therapeutic strategies and drug targets.

Proteomic networks and related genetic variants associated with smoking and chronic obstructive pulmonary disease

BackgroundStudies have identified individual blood biomarkers associated with chronic obstructive pulmonary disease (COPD) and related phenotypes. However, complex diseases such as COPD typically involve changes in multiple molecules with interconnections that may not be captured when considering single molecular features.MethodsLeveraging proteomic data from 3,173 COPDGene Non-Hispanic White (NHW) and African American (AA) participants, we applied sparse multiple canonical correlation network analysis (SmCCNet) to 4,776 proteins assayed on the SomaScan v4.0 platform to derive sparse networks of proteins associated with current vs. former smoking status, airflow obstruction, and emphysema quantitated from high-resolution computed tomography scans. We then used NetSHy, a dimension reduction technique leveraging network topology, to produce summary scores of each proteomic network, referred to as NetSHy scores. We next performed a genome-wide association study (GWAS) to identify variants associated with the NetSHy scores, or network quantitative trait loci (nQTLs). Finally, we evaluated the replicability of the networks in an independent cohort, SPIROMICS.ResultsWe identified networks of 13 to 104 proteins for each phenotype and exposure in NHW and AA, and the derived NetSHy scores significantly associated with the variable of interests. Networks included known (sRAGE, ALPP, MIP1) and novel molecules (CA10, CPB1, HIS3, PXDN) and interactions involved in COPD pathogenesis. We observed 7 nQTL loci associated with NetSHy scores, 4 of which remained after conditional analysis. Networks for smoking status and emphysema, but not airflow obstruction, demonstrated a high degree of replicability across race groups and cohorts.ConclusionsIn this work, we apply state-of-the-art molecular network generation and summarization approaches to proteomic data from COPDGene participants to uncover protein networks associated with COPD phenotypes. We further identify genetic associations with networks. This work discovers protein networks containing known and novel proteins and protein interactions associated with clinically relevant COPD phenotypes across race groups and cohorts.

Lipolysis engages CD36 to promote ZBP1-mediated necroptosis-impairing lung regeneration in COPD

Lung parenchyma destruction represents a severe condition commonly found in chronic obstructive pulmonary disease (COPD), a leading cause of morbidity and mortality worldwide. Promoting lung regeneration is crucial for achieving clinical improvement. However, no therapeutic drugs are approved to improve the regeneration capacity due to incomplete understanding of the underlying pathogenic mechanisms. Here, we identify a positive feedback loop formed between adipose triglyceride lipase (ATGL)-mediated lipolysis and overexpression of CD36 specific to lung epithelial cells, contributing to disease progression. Genetic deletion of CD36 in lung epithelial cells and pharmacological inhibition of either ATGL or CD36 effectively reduce COPD pathogenesis and promote lung regeneration in mice. Mechanistically, disruption of the ATGL-CD36 loop rescues Z-DNA binding protein 1 (ZBP1)-induced cell necroptosis and restores WNT/β-catenin signaling. Thus, we uncover a crosstalk between lipolysis and lung epithelial cells, suggesting the regenerative potential for therapeutic intervention by targeting the ATGL-CD36-ZBP1 axis in COPD.

Decoding LncRNA in COPD: Unveiling Prognostic and Diagnostic Power and Their Driving Role in Lung Cancer Progression.

Chronic obstructive pulmonary disease (COPD) and lung cancer represent formidable challenges in global health, characterized by intricate pathophysiological mechanisms and multifaceted disease progression. This comprehensive review integrates insights from diverse perspectives to elucidate the intricate roles of long non-coding RNAs (lncRNAs) in the pathogenesis of COPD and lung cancer, focusing on their diagnostic, prognostic, and therapeutic implications. In the context of COPD, dysregulated lncRNAs, such as NEAT1, TUG1, MALAT1, HOTAIR, and GAS5, emerge as pivotal regulators of genes involved in the disease pathogenesis and progression. Their identification, profiling, and correlation with the disease severity present promising avenues for prognostic and diagnostic applications, thereby shaping personalized disease interventions. These lncRNAs are also implicated in lung cancer, underscoring their multifaceted roles and therapeutic potential across both diseases. In the domain of lung cancer, lncRNAs play intricate modulatory roles in disease progression, offering avenues for innovative therapeutic approaches and prognostic indicators. LncRNA-mediated immune responses have been shown to drive lung cancer progression by modulating the tumor microenvironment, influencing immune cell infiltration, and altering cytokine production. Their dysregulation significantly contributes to tumor growth, metastasis, and chemo-resistance, thereby emphasizing their significance as therapeutic targets and prognostic markers. This review summarizes the transformative potential of lncRNA-based diagnostics and therapeutics for COPD and lung cancer, offering valuable insights into future research directions for clinical translation and therapeutic development.

Extracellular Vesicles Induce Nuclear Factor-κB Activation and Interleukin-8 Synthesis through miRNA-191-5p Contributing to Inflammatory Processes: Potential Implications in the Pathogenesis of Chronic Obstructive Pulmonary Disease.

Extracellular vesicles (EVs) play a pivotal role in a variety of physiologically relevant processes, including lung inflammation. Recent attention has been directed toward EV-derived microRNAs (miRNAs), such as miR-191-5p, particularly in the context of inflammation. Here, we investigated the impact of miR-191-5p-enriched EVs on the activation of NF-κB and the expression of molecules associated with inflammation such as interleukin-8 (IL-8). To this aim, cells of bronchial epithelial origin, 16HBE, were transfected with miR-191-5p mimic and inhibitor and subsequently subjected to stimulations to generate EVs. Then, bronchial epithelial cells were exposed to the obtained EVs to evaluate the activation of NF-κB and IL-8 levels. Additionally, we conducted a preliminary investigation to analyze the expression profiles of miR-191-5p in EVs isolated from the plasma of patients diagnosed with chronic obstructive pulmonary disease (COPD). Our initial findings revealed two significant observations. First, the exposure of bronchial epithelial cells to miR-191-5p-enriched EVs activated the NF-kB signaling and increased the synthesis of IL-8. Second, we discovered the presence of miR-191-5p in peripheral blood-derived EVs from COPD patients and noted a correlation between miR-191-5p levels and inflammatory and functional parameters. Collectively, these data corroborate and further expand the proinflammatory role of EVs, with a specific emphasis on miR-191-5p as a key cargo involved in this process. Consequently, we propose a model in which miR-191-5p, carried by EVs, plays a role in airway inflammation and may contribute to the pathogenesis of COPD.

Impact of photoaging on the chemical and cytotoxic properties of nanoscale zeolitic imidazolate framework-8

This study investigated the influence of photoaging on a nanoscale metal-organic framework (MOF), truncated rhombic dodecahedron nano-zeolitic imidazolate framework-8 (nZIF-8), focusing on its oxidative stress, inflammation, and implications for pulmonary diseases. We observed significant photodegradation-induced transformations in nZIF-8, characterized by a reduction in particle size from 200.5 to 101.4 nm and notable structural disintegration after prolonged exposure to simulated solar radiation. This alteration resulted in a marked decrease in oxidative cytotoxicity in BEAS-2B cells, which was attributed to changes in surface properties and reduced reactive oxygen species (ROS) production. Gene expression analysis further revealed a decrease in cytotoxic and inflammatory responses, which potentially lowers the risk of chronic obstructive pulmonary disease (COPD). Aged nZIF-8 also showed diminished capacity to induce pro-inflammatory cytokines and influence COPD-related gene expression, reducing its potential to exacerbate COPD pathogenesis. Our findings highlight the critical need for comprehensive safety evaluations of these materials, while considering their long-term environmental and biological impacts. The diminished cytotoxicity and inflammatory potential of aged nZIF-8 highlighted its enhanced suitability for broader applications, indicating that photoaging may lead to safer and more sustainable material utilization.

Gut Microbiota Modulation in the Management of Chronic Obstructive Pulmonary Disease: A Literature Review.

Chronic obstructive pulmonary disease (COPD) represents a significant global health burden, characterized by progressive airflow limitation and exacerbations that significantly impact patient morbidity and mortality. Recent research has investigated the interplay between the gut and the lungs, known as the gut-lung axis, highlighting the role of the gut microbiome in COPD pathogenesis. Dysbiosis, characterized by microbial imbalance, has implications for COPD, influencing disease progression and susceptibility to exacerbations. This comprehensive review integrates current scientific literature on gut microbiota modulation as a therapeutic avenue for COPD management. Through a thorough discussion of studies investigating probiotics, prebiotics, synbiotics, antibiotics, dietary fiber, and fecal microbiota transplantation, this review summarizes the influence of these interventions on COPD via the gut-lung axis through the modulation of systemic inflammation, mucosal immunity, and metabolic processes. The interventions highlighted here show potential in preventing COPD exacerbations, preserving lung function, and improving patient quality of life. By compiling the latest scientific evidence, this review provides a comprehensive framework for physicians and researchers to deduce the effectiveness of gut microbiome modulation as an adjunctive therapeutic strategy in COPD management.

Cell death crosstalk in respiratory diseases: unveiling the relationship between pyroptosis and ferroptosis in asthma and COPD.

Asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous obstructive diseases characterized by airflow limitations and are recognized as significant contributors to fatality all over the globe. Asthma accounts for about 4, 55,000 deaths, and COPD is the 3rd leading contributor of mortality worldwide. The pathogenesis of these two obstructive disorders is complex and involves numerous mechanistic pathways, including inflammation-mediated and non-inflammation-mediated pathways. Among all the pathological categorizations, programmed cell deaths (PCDs) play a dominating role in the progression of these obstructive diseases. The two major PCDs that are involved in structural and functional remodeling in the progression of asthma and COPD are Pyroptosis and Ferroptosis. Pyroptosis is a PCD mechanism mediated by the activation of the Nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome, leading to the maturation and release of Interleukin-1β and Interleukin-18, whereas ferroptosis is a lipid peroxidation-associated cell death. In this review, the major molecular pathways contributing to these multifaceted cell deaths have been discussed, and crosstalk among them regarding the pathogenesis of asthma and COPD has been highlighted. Further, the possible therapeutic approaches that can be utilized to mitigate both cell deaths at once have also been illustrated.

Oral infection with periodontal pathogens induced chronic obstructive pulmonary disease-like lung changes in mice

BackgroundEpidemiological studies have demonstrated that periodontitis is an independent risk factor for chronic obstructive pulmonary disease (COPD). However, the mechanism underlying the association between these two diseases remains unclear. The lung microbiota shares similarities with the oral microbiota, and there is growing evidence to suggest that the lung microbiome could play a role in the pathogenesis of COPD. This study aimed to investigate whether periodontal pathogens could contribute to the pathogenesis of COPD in a mouse model.MethodsWe established mouse models with oral infection by typical periodontal pathogens, porphyromonas gingivalis (Pg group) or fusobacterium nucleatum (Fn group), over a three-month period. Mice that did not receive oral infection were set as the control group (C group). We assessed the level of alveolar bone resorption, lung function, and histological changes in the lungs of the mice. Additionally, we measured the levels of inflammatory factors and tissue damage associated factors in the lung tissues.ResultsLung function indices, including airway resistance, peak inspiratory/expiratory flow and expiratory flow-50%, were significantly reduced in the Fn group compared to the C group. Additionally, histological examination revealed an increased number of inflammatory cells and bullae formation in the lung tissue sections of the Fn group. Meanwhile, levels of inflammatory factors such as IL-1β, IL-6, IFN-γ, and TNF-α, as well as tissue damage associated factors like matrix metalloproteinase-8 and neutrophil elastase, were significantly elevated in the lung tissue of the Fn group in comparison to the C group. The Pg group also showed similar but milder lung changes compared to the Fn group. Pg or Fn could be detected in the lungs of both oral infected groups.ConclusionThe results indicated that oral periodontal pathogens infection could induce COPD-like lung changes in mice, and they may play a biological role in the association between periodontitis and COPD.

Dynamics of Inflammatory and Pathological Changes Induced by Single Exposure of Particulate Matter (PM2.5) in Mice: Potential Implications in COPD.

Chronic Obstructive Pulmonary Disease (COPD) is a progressive disorder of lungs marked by chronic bronchitis and emphysema. Particulate matter (PM2.5), a major component of air pollution has been correlated with COPD incidence. The present work aimed to understand dynamics of cellular/molecular players behind PM2.5-mediated COPD pathogenesis in mice by conducting dose and time-course studies. Single intratracheal exposure of PM2.5 at a dose of either 100 or 200 μg induced inflammatory response in lungs at 4 days. Time course studies showed that inflammation once triggered by PM2.5 is progressive in nature as reflected by data on BALF inflammatory cells at 7/14 days. Similarly, various cytokines/chemokines (KC/IL-6/TNF-α/IL-1β/G-CSF/MCP-1) peak at either 7 or 14 days. However, inflammation declined sharply at 21 days. Data on LPO/GSH and activities of SOD/Catalase show induction of continuous oxidative stress in lung tissue. Next, enhanced mtROS in the CD11b+ inflammatory cells confirms the redox imbalance in neutrophils/macrophages. A continuous decline in lung function was observed till 28 days. Further, histological analysis of lung tissues at 28 days confirmed the presence of emphysematous lesions, validating the potency of PM2.5 to cause irreversible damage to lungs through complex interplay of various cellular/molecular players which may be exploited as potential preventive/therapeutic targets.

In Vitro Model for Studying Differentiation and Changes of Multi-Omics on Murine Airway Epithelial Cells Stimulated with Cigarette Smoke Extract.

Chronic obstructive pulmonary disease (COPD) is largely attributed to tobacco smoke exposure. Investigating how airway epithelial cells functionally adapt to tobacco smoke is crucial for understanding the pathogenesis of COPD. The present study was to set up an in vitro model using primary murine airway epithelial cells to mimic the real-life impact of tobacco smoke. Unlike established cell lines, primary cells retain more in vivo-like properties, including growth patterns, aging, and differentiation. These cells exhibit a sensitive inflammatory response and efficient differentiation, thus closely representing physiological conditions. In this model, primary murine airway epithelial cells were cultured for 28 days under an air-liquid interface with an optimal concentration of cigarette smoke extract (CSE), which led to the transformation of a monolayer of undifferentiated cells into a pseudostratified columnar epithelium, indicative of CSE acclimation. Comprehensive multi-omics analyses were then applied to elucidate the mechanisms by which CSE influences the differentiation of basal airway cells. These insights provide a deeper understanding of the cellular processes underpinning COPD progression in response to tobacco smoke exposure.

Exploring Molecular Mechanisms and Biomarkers in COPD: An Overview of Current Advancements and Perspectives.

Chronic obstructive pulmonary disease (COPD) plays a significant role in global morbidity and mortality rates, typified by progressive airflow restriction and lingering respiratory symptoms. Recent explorations in molecular biology have illuminated the complex mechanisms underpinning COPD pathogenesis, providing critical insights into disease progression, exacerbations, and potential therapeutic interventions. This review delivers a thorough examination of the latest progress in molecular research related to COPD, involving fundamental molecular pathways, biomarkers, therapeutic targets, and cutting-edge technologies. Key areas of focus include the roles of inflammation, oxidative stress, and protease-antiprotease imbalances, alongside genetic and epigenetic factors contributing to COPD susceptibility and heterogeneity. Additionally, advancements in omics technologies-such as genomics, transcriptomics, proteomics, and metabolomics-offer new avenues for comprehensive molecular profiling, aiding in the discovery of novel biomarkers and therapeutic targets. Comprehending the molecular foundation of COPD carries substantial potential for the creation of tailored treatment strategies and the enhancement of patient outcomes. By integrating molecular insights into clinical practice, there is a promising pathway towards personalized medicine approaches that can improve the diagnosis, treatment, and overall management of COPD, ultimately reducing its global burden.

Molecular Detection of Chlamydia pneumoniae, Haemophilus influenza, and Streptococcus pneumoniae and Expression of miR-146, miR-16, and miR-221 in Patients with Chronic Obstructive Pulmonary Diseases

Abstract Background: Chronic obstructive pulmonary disease (COPD) is a debilitating respiratory condition characterized by persistent airflow limitation and chronic inflammation. Microbial infections and dysregulated microribonucleic acid (miRNA) expression have been implicated in COPD pathogenesis. This study aimed to investigate the molecular detection of three respiratory pathogens, Chlamydia pneumoniae, Haemophilus influenzae, and Streptococcus pneumoniae, in the respiratory secretions of COPD patients. In addition, it evaluated the expression levels of miR-146, miR-16, and miR-221 in the peripheral blood of COPD patients. Methods: Peripheral blood and respiratory secretions were collected from 40 healthy individuals and 40 COPD patients. The messenger ribonucleic acid expression levels of miR-146, miR-16, and miR-221 were determined using real-time polymerase chain reaction. Statistical analyses, including t-test, binomial test, and Pearson correlation, were performed. Results: H. influenzae, S. pneumoniae, and C. pneumoniae were detected in the sputum of 12.5%, 17.5%, and 7.5% of COPD patients, respectively. The expression of miR-146, miR-221, and miR-16 was observed in 65%, 15%, and 85% of COPD patients, respectively, compared to 13%, 80%, and 15% of healthy subjects. While miR-221 was downregulated in COPD patients, miR-16 and miR-146 were upregulated. No significant differences were found in the expression of these miRNAs between infected and noninfected COPD patients. Conclusion: The molecular detection of respiratory pathogens and the expression profiles of miR-146, miR-16, and miR-221 in COPD patients may have potential diagnostic value. Further research is needed to elucidate the role of these markers in COPD pathogenesis.

Immunoactive signatures of circulating tRNA- and rRNA-derived RNAs in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is the most prevalent lung disease, and macrophages play a central role in the inflammatory response in COPD. We here report a comprehensive characterization of circulating short non-coding RNAs (sncRNAs) in plasma from patients with COPD. While circulating sncRNAs are increasingly recognized for their regulatory roles and biomarker potential in various diseases, the conventional RNA-seq method cannot fully capture these circulating sncRNAs due to their heterogeneous terminal structures. By pre-treating the plasma RNAs with T4 polynucleotide kinase, which converts all RNAs to those with RNA-seq susceptible ends (5'-phosphate and 3'-hydroxyl), we comprehensively sequenced a wide variety of non-microRNA sncRNAs, such as 5'-tRNA halves containing a 2',3'-cyclic phosphate. We discovered a remarkable accumulation of the 5'-half derived from tRNA ValCAC in plasma from COPD patients, whereas the 5'-tRNA GlyGCC half is predominant in healthy donors. Further, the 5'-tRNA ValCAC half activates human macrophages via Toll-like receptor 7 and induces cytokine production. Additionally, we identified circulating rRNA-derived fragments that were upregulated in COPD patients and demonstrated their ability to induce cytokine production in macrophages. Our findings provide evidence of circulating, immune-active sncRNAs in patients with COPD, suggesting that they serve as inflammatory mediators in the pathogenesis of COPD.

Exosome microRNA-125a-5p derived from epithelium promotes M1 macrophage polarization by targeting IL1RN in chronic obstructive pulmonary disease

BackgroundThe interplay between airway epithelium and macrophages plays a pivotal role in Chronic Obstructive Pulmonary Disease (COPD) pathogenesis. Exosomes, which transport miRNA cargo, have emerged as novel mediators of intercellular communication. MicroRNA-125a-5p (miR-125a-5p) has been implicated in macrophage polarization.This study aims to investigate the role of exosomal miR-125a-5p in the dysfunctional epithelium-macrophage cross-talk in cigarette smoke (CS)-induced COPD. MethodsIn cell models, THP-1 monocytic cells were differentiated into macrophages (M0). Human bronchial epithelial cells treated with CS extract (CSE) were co-cultured with M0. Exosomes were isolated from culture media using commercial kits and characterized using nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Exosomes labeled with PKH26 red fluorescent cell linker kits were incubated with macrophages. Luciferase reporter assay was used to confirm the target gene of miR-125a-5p. In mouse experiments, inhibiting miR-125a-5p was utilized to examine its role in macrophage polarization. Furthermore, the underlying mechanism was explored. ResultsIn vitro results indicated that CSE treatment led to upregulation of miR-125a-5p in HBE cells, and exosomes contained miR-125a-5p. PKH26-labeled exosomes were internalized by macrophages. Co-culture experiments between bronchial epithelial cells and miR-125a-5p mimic resulted in significant increase in M1 macrophage markers (TNF-α, iNOS-2, IL-1β) and decrease in M2 markers (IL-10 and Arg-1). In COPD mouse models, miR-125a-5p inhibitor reduced levels of TNF-α, IL-1β, and IL-6. Luciferase assays revealed that miR-125a-5p inhibitors enhanced the relative luciferase activity of IL1RN. Mechanistic experiments demonstrated that HBE-derived exosomes transfected with miR-125a-5p mimics promoted upregulation of MyD88, TRAF6, p65, iNOS-2, and downregulation of Arg-1. ConclusionThis study suggests that exosomal miR-125a-5p may act as a mediator in the cross-talk between airway epithelium and macrophage polarization in COPD. Exosomal miR-125a-5p targeting IL1RN may promote M1 macrophage polarization via the MyD88/NF-κB pathway.

Altered Extracellular Vesicle-Derived Protein and microRNA Signatures in Bronchoalveolar Lavage Fluid from Patients with Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is a progressive lung disease for which there is no cure. Accumulating research results suggest a role for extracellular vesicles (EVs) in the pathogenesis of COPD. This study aimed to uncover the involvement of EVs and their molecular cargo in the progression of COPD by identification of EV-associated protein and microRNA (miRNA) profiles. We isolated EVs from the bronchial alveolar lavage fluid (BALF) of 18 patients with COPD and 11 healthy controls using size-exclusion chromatography. EV isolates were characterized using nanoparticle tracking analysis and protein content. Proteomic analysis revealed a higher abundance of 284 proteins (log2FC > 1) and a lower abundance of 3 proteins (log2FC < -1) in EVs derived from patients with COPD. Ingenuity pathway analysis showed that proteins enriched in COPD-associated EVs trigger inflammatory responses, including neutrophil degranulation. Variances in surface receptors and ligands associated with COPD EVs suggest a preferential interaction with alveolar cells. Small RNAseq analysis identified a higher abundance of ten miRNAs and a lower abundance of one miRNA in EVs from COPD versus controls (Basemean > 100, FDR < 0.05). Our data indicate that the molecular composition of EVs in the BALF of patients with COPD is altered compared to healthy control EVs. Several components in COPD EVs were identified that may perpetuate inflammation and alveolar tissue destruction.

Down-regulation of RTEL1 Improves M1/M2 Macrophage Polarization by Promoting SFRP2 in Fibroblasts-derived Exosomes to Alleviate COPD.

Chronic obstructive pulmonary disease (COPD) is a common chronic respiratory disease worldwide. Macrophage polarization plays a substantial role in the pathogenesis of COPD. This study is aimed to explore the regulatory mechanism of regulator of telomere elongation 1 (RTEL1) in COPD. COPD model mouse was conducted by cigarette smoke (CS). The pathological features of lung in mice were observed by histological staining. After extracting exosomes, macrophages were co-cultured with fibroblasts-derived exosomes. Then, the effects of RTEL1 and exosomal secreted frizzled-related protein 2 (SFRP2) on macrophage proliferation, inflammation, apoptosis, and M1, M2 macrophage polarization (iNOS and CD206) were evaluated by cell counting kit-8, EdU assay, enzyme-linked immuno sorbent assay, and western blotting, respectively. CS-induced COPD model mouse was successfully constructed. Through in vitro experiments, knockdown of RTEL1 inhibited macrophage proliferation, inflammation (MMP9, IL-1β and TNF-α), and promoted apoptosis (Bax, cleaved-caspase3, Bcl-2) in CS extract-induced lung fibroblasts. Meanwhile, RTEL1 knockdown promoted M1 and suppressed M2 macrophage polarization in COPD. Additionally, silencing SFRP2 in fibroblasts-derived exosomes reversed the effects of RTEL1 knockdown on proliferation, inflammation, apoptosis, and M1, M2 macrophage polarization. Collectively, down-regulation of RTEL1 improved M1/M2 macrophage polarization by promoting SFRP2 in fibroblasts-derived exosomes to alleviate CS-induced COPD.

Potential marker genes for chronic obstructive pulmonary disease revealed based on single-cell sequencing and Mendelian randomization analysis.

Progress is being made in the prevention and treatment of chronic obstructive pulmonary disease (COPD), but it is still unsatisfactory. With the development of genetic technology, validated genetic information can better explain COPD. The study utilized scRNA-seq and Mendelian randomization analysis of eQTLs to identify crucial genes and potential mechanistic pathways underlying COPD pathogenesis. Single-cell sequencing data were used to identify marker genes for immune cells in the COPD process. Data on eQTLs for immune cell marker genes were obtained from the eQTLGen consortium. To estimate the causal effect of marker genes on COPD, we selected an independent cohort (ukb-b-16751) derived from the UK Biobank database for two-sample Mendelian randomization analysis. Subsequently, we performed immune infiltration analysis, gene set enrichment analysis (GSEA), and co-expression network analysis on the key genes. The 154 immune cell-associated marker genes identified were mainly involved in pathways such as vacuolar cleavage, positive regulation of immune response and regulation of cell activation. Mendelian randomization analysis screened four pairs of marker genes (GZMH, COTL1, CSTA and CD14) were causally associated with COPD. These four key genes were significantly associated with immune cells. In addition, we have identified potential transcription factors associated with these key genes using the Cistrome database, thus contributing to a deeper understanding of the regulatory network of these gene expressions. This eQTLs Mendelian randomization study identified four key genes (GZMH, COTL1, CSTA, and CD14) causally associated with COPD, providing new insights for prevention and treatment of COPD.

Macrophage Polarization and Functions in Pathogenesis of Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD), the major leading cause of mortality worldwide, is a progressive and irreversible respiratory condition characterized by peripheral airway and lung parenchymal inflammation, accompanied by fibrosis, emphysema, and airflow limitation, and has multiple etiologies, including genetic variance, air pollution, and repetitive exposure to harmful substances. However, the precise mechanisms underlying the pathogenesis of COPD have not been identified. Recent multiomics-based evidence suggests that the plasticity of alveolar macrophages contributes to the onset and progression of COPD through the coordinated modulation of numerous transcription factors. Therefore, this review focuses on understanding the mechanisms and functions of macrophage polarization that regulate lung homeostasis in COPD. These findings may provide a better insight into the distinct role of macrophages in COPD pathogenesis and perspective for developing novel therapeutic strategies targeting macrophage polarization.