Inflammatory endotypes in COPD

Εosinophilic Chronic Obstructive Pulmonary Disease. What Do We Know So Far?

The latest advances in asthma treatment have highlighted the significance of eosinophilia and the possible role of some pro-eosinophilic mediators, like interleukins (IL) IL-5, IL-4/IL-13, and IL-33 in the disease's pathogenesis. Considering that a subgroup of patients with chronic obstructive pulmonary disease (COPD) may have blood eosinophilia akin to that seen in asthma, numerous studies in the last decade have suggested that eosinophilic COPD is a separate entity. While the exact role of blood eosinophils in the pathophysiology of COPD remains unclear, eosinophilia seems to increase the effectiveness of corticosteroid therapy. Currently, monoclonal antibodies targeting the interleukins (IL-5, IL-4, IL-13, and IL-33) or their receptors are being investigated in patients with COPD belonging in T2-high endotype. This review focuses on the mechanisms of eosinophilia in COPD, the effects of eosinophilia on disease outcome, and examines the most recent data on the use of peripheral blood eosinophilia in treating patients with COPD. Finally, we emphasize the current implication of monoclonal antibodies in COPD in the context of eosinophilic airway inflammation.

Challenges in treating patients with comorbid asthma and bronchiectasis

The management of patients with overlapping asthma and bronchiectasis requires a tailored approach, starting with a comprehensive assessment of the patient's clinical profile, including the severity of asthma and the extent of bronchiectasis. Inhaled corticosteroids (ICS) are often recommended, but their use should be carefully monitored because of the risk of increased infection. If asthma is well controlled and bronchiectasis remains stable, a gradual reduction in the dose of ICS may be considered. Adjunctive therapies such as macrolides, which have anti-inflammatory and antimicrobial effects, or leukotriene receptor antagonists (LTRAs) may be beneficial. However, LTRAs should be used with caution in patients with bronchiectasis. Long-acting muscarinic antagonists (LAMA), especially in combination with ICS and long-acting beta-agonists (LABA), can improve bronchodilation and reduce inflammation. Although triple therapy (ICS/LABA/LAMA) is promising, its efficacy in bronchiectasis has not yet been confirmed by randomised controlled trials (RCTs). Ongoing monitoring is essential to adjust treatment as the patient's condition evolves. Preventive measures, including vaccination and regular sputum cultures, are important to minimize the risk of infection. Further research and RCTs are needed to better understand the role of dual bronchodilators and triple therapy in the management of overlapping asthma-bronchiectasis.

Characterizing COPD phenotypes with a targeted signaling lipids metabolomics approach

AIMS

This study aimed to elucidate clinically-relevant classifications of COPD using a targeted metabolomics approach focusing on signaling lipids.

MATERIALS AND METHODS

Using a targeted LC-MS/MS platform, 166 metabolites including free fatty acids, prostaglandins, isoprostanes, lysophospholipids, endocannabinoids, and bile acids were profiled in a cohort of 49 COPD patients. The study integrated metabolomic data with clinical parameters to identify key metabolites and related pathways for various COPD classification systems including Global Initiative for Chronic Obstructive Lung Disease (GOLD) grading stages, Koninklijk Nederlands Genootschap voor Fysiotherapie (KNGF, Royal Dutch Society for Physiotherapy) profiles, and Systemic (SYS) subtypes and explored the association of these classification systems.

KEY FINDINGS

The GOLD stages showed correlations with 15 metabolites, including lysophospholipids, oxylipins, and bile acids. KNGF profiles were linked to 13 metabolites, predominantly lysophospholipids, while SYS subtypes were associated with 9 metabolites, mainly oxylipins. A specific cluster of oxylipins, including HETEs and HDoHEs, was notably correlated to prognostic factors of COPD.

SIGNIFICANCE

This study identified distinct metabolic patterns associated with GOLD stages, KNGF profiles, and SYS subtypes. Additionally, the findings indicate that 14-HDoHE/DHA may serve as a potential biomarker for COPD exacerbation and suggest possible therapeutic targets for COPD, including pathways involving lipoxygenases, G-protein coupled receptors, and the Farnesoid X receptor.

Animal models of chronic obstructive pulmonary disease and their role in drug discovery and development: a critical review

INTRODUCTION

The use of laboratory animals is essential to understand the mechanisms underlying COPD and to discover and evaluate new drugs. However, the complex changes associated with the disease in humans are difficult to fully replicate in animal models.

AREAS COVERED

This review examines the most recent literature on animal models of COPD and their implications for drug discovery and development.

EXPERT OPINION

Recent advances in animal models include the introduction of transgenic mice with an increased propensity to develop COPD-associated features, such as emphysema, and animals exposed to relevant environmental agents other than cigarette smoke, in particular biomass smoke and other air pollutants. Other animal species, including zebrafish, pigs, ferrets and non-human primates, are also increasingly being used to gain insights into human COPD. Furthermore, three-dimensional organoids and humanized mouse models are emerging as technologies for evaluating novel therapeutics in more human-like models. However, despite these advances, no model has yet fully captured the heterogeneity and progression of COPD as observed in humans. Therefore, further research is needed to develop improved models incorporating humanized elements in experimental animals, that may better predict therapeutic responses in clinic settings and accelerate the development of new treatments for this debilitating disease.

Prognostic value of composite inflammatory markers in patients with chronic obstructive pulmonary disease: A retrospective cohort study based on the MIMIC-IV database

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease, and inflammation plays a key role in the pathogenesis of COPD. The aim of this study is to investigate the association between systemic immune inflammation index (SII), systemic inflammatory response index (SIRI),pan-immune inflammation value (PIV), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) and all-cause mortality in patients with chronic obstructive pulmonary disease (COPD), and to evaluate the effect of composite inflammatory markers on the prognosis of COPD patients. We obtained data on COPD patients from the Medical Information Mart for Intensive Care (MIMIC) -IV database and divided patients into four groups based on quartiles of baseline levels of inflammatory markers, The primary outcomes were in-hospital and ICU mortality. We comprehensively explored the association between composite inflammatory markers and mortality in patients with COPD using restricted cubic splints (RCS), COX proportional hazards regression models, Kaplan-Meier curves, receiver operating characteristic (ROC), and subgroup analyses. A total of 1234 COPD patients were included in this study. RCS results showed that SII, SIRI, PLR, PIV and NLR were positively and non-linearly correlated with the increased risk of in-hospital mortality in COPD patients. Multivariate COX regression analysis showed that compound inflammatory markers were independent risk factors for in-hospital mortality in COPD patients. The KM curve results showed that COPD patients with higher SII, SIRI, PLR and PIV had a significantly lower survival probability. 5 kinds of compound between inflammatory markers and mortality in patients with COPD is related to nonlinear correlation, can increase the risk of mortality in patients with COPD is a risk factor for the prognosis of patients with COPD, and may serve as potential biomarkers for clinical COPD risk stratification and treatment management in critical patients.

Prospects of neutrophilic implications against pathobiology of chronic obstructive pulmonary disease: Pharmacological insights and technological advances

Chronic obstructive pulmonary disease (COPD) is a prevalent chronic inflammatory condition that affects the lungs globally. A key feature of this inflammatory response is the migration and aggregation of polymorphonuclear neutrophils (PMNs). The presence of neutrophilic inflammation within the airways is as distinguishing characteristic of COPD. As research advances, PMNs and their products emerge as central players in the airway inflammatory cascade of COPD patients. Their involvement in phagocytosis, degranulation, and the formation of neutrophil extracellular traps (NETs) significantly contributes to the pathogenesis of COPD. Moreover, studies have shown that excessive biological activities of neutrophils in the lungs can result in airway epithelial injury, emphysema, and mucus hypersecretion. Currently, there is growing empirical support for the moderate targeting neutrophils in the clinical management of COPD. This article delves into the pivotal role of neutrophils in COPD, emphasizing the urgency for novel therapeutic approaches that specifically target neutrophils. Additionally, it explores the potential of utilizing single-cell RNA sequencing to further investigate neutrophils and relevant risk genes as potential biomarkers for COPD treatment. By elucidating these mechanisms, this review aims to pave the way for future strategies to modulate neutrophil function, thereby addressing the pressing need for more effective COPD therapies.

Impact of Triple Inhaler Therapy on COPD Patients with Non-Small Cell Lung Cancer After Radical Surgery: A Single-Centre Retrospective Analysis

Background: Chronic obstructive pulmonary disease (COPD) is among the most relevant comorbidity associated with lung cancer. The advent of innovative triple treatment approaches for COPD has significantly improved patients' quality of life and outcomes. Few data are available regarding the impact of triple inhaler therapy on patients featuring COPD and lung cancer. Methods: We retrospectively evaluated the impact of triple inhale bronchodilators in a cohort of 56 patients with treated COPD who underwent lung surgery for primary cancer. Results: Triple bronchodilation can help to relieve the symptoms of the disease and improve lung function, allowing people with lung cancer to reduce the risk of serious exacerbations and improve their quality of life. Conclusions: Within the limits of the study, it should be underlined that bronchodilators can effectively affect the outcome and performance status after thoracic surgery.

Urinary Proteome and Exosome Analysis Protocol for the Discovery of Respiratory Diseases Biomarkers

This study aims to develop a protocol for respiratory disease-associated biomarker discovery by combining urine proteome studies with urinary exosome components analysis (i.e., miRNAs). To achieve this, urine was DTT treated to decrease uromodulin, then concentrated and ultracentrifuged. Proteomic analyses of exosome-free urine were performed using LC-MS/MS. Simultaneously, miRNA expression from urine exosomes was measured using either RTqPCR (pre-amplification) or nCounter Nanostring (non-amplication) analyses. We detected 548 different proteins in exosome-free urine samples (N = 5) with high confidence (FDR < 1%), many of them being expressed in different non-renal tissues. Specifically, lung-related proteins were overrepresented (Fold enrichment = 1.31; FDR = 0.0335) compared to whole human proteome, and 10-15% were already described as protein biomarkers for several pulmonary diseases. Urine proteins identified belong to several functional categories important in respiratory pathology. We could confirm the expression of miRNAs previously connected to respiratory diseases (i.e., miR-16-5p, miR-21-5p, miR-146a-5p, and miR-215-5p) in urine exosomes by RTqPCR. Finally, we detected 333 miRNAs using Nanostring, 15 of them up-regulated in T2high asthma (N = 4) compared to T2low asthma (N = 4) and healthy subjects (N = 4). Therefore, this protocol combining the urinary proteome (exosome free) with the study of urinary exosome components (i.e., miRNAs) holds great potential for molecular biomarker discovery of non-renal and particularly respiratory pathologies.

Clinical Characteristics of Chronic Obstructive Pulmonary Disease according to Smoking Status

Chronic obstructive pulmonary disease (COPD) can be caused by various factors, including lung infections, asthma, air pollution, childhood growth disorders, and genetic factors, though smoking is the predominant risk factor. The main pathological mechanisms in COPD involve small airway disease, emphysema, mucus hypersecretion, and vascular disorders. COPD in non-smokers is characterized by a normal 1-second forced expiratory volume decline, equal sex distribution, younger age of onset, fewer comorbidities, milder airflow obstruction, preserved diffusing capacity of the lungs for carbon monoxide, and radiological features such as more air-trapping and less severe emphysema compared to COPD in smokers. Nevertheless, non-smokers with COPD still experience a high prevalence of acute exacerbations, nearly equal to that of smokers with COPD. Moreover, COPD itself is an independent risk factor for developing lung cancer, regardless of smoking status. Given that COPD coexists with numerous comorbidities, effectively managing these comorbidities is crucial, requiring multifaceted efforts for comprehensive treatment.

Dupilumab reduces exacerbations and improves lung function in patients with chronic obstructive pulmonary disease and emphysema: Phase 3 randomized trial (BOREAS)

BACKGROUND

Dupilumab, a fully human monoclonal antibody that blocks the shared receptor component for interleukin-4 and interleukin-13, reduced exacerbations and improved lung function in patients with chronic obstructive pulmonary disease (COPD) and type 2 inflammation in the phase 3 BOREAS trial.

OBJECTIVE

To assess clinical outcomes in patients from BOREAS by emphysema status.

METHODS

Patients with COPD and type 2 inflammation (screening blood eosinophils ≥300 cells/μL) on maximal inhaled therapy were randomized to add-on dupilumab 300 mg or placebo every 2 weeks for 52 weeks. We assessed the annualized moderate/severe COPD exacerbation rates over 52 weeks and change from baseline to Week 12 in prebronchodilator forced expiratory volume in 1 s (FEV1) in patients with and without investigator-reported emphysema.

RESULTS

Investigator-reported emphysema was present in 306/939 patients (32.6 %) at baseline. Dupilumab reduced exacerbation rates vs placebo by 29 % (relative risk [RR] 0.71 [95 % CI 0.53-0.95]) and 31 % (RR 0.69 [95 % CI 0.53-0.89]) in patients with and without emphysema, respectively. Prebronchodilator FEV1 least squares mean difference from baseline to Week 12 for dupilumab vs placebo was 0.07 L ([95 % CI 0.002-0.14]) and 0.09 L ([95 % CI 0.04-0.14]) in patients with and without emphysema, respectively. No treatment by emphysema interaction effect was observed for the annualized rate of exacerbations (P value for interaction = 0.8296) or change in prebronchodilator FEV1 (P value for interaction = 0.6438).

CONCLUSION

Dupilumab efficacy was similar in patients with COPD and type 2 inflammation, with or without investigator-reported emphysema.

The precision medicine strategy to treat COPD pulmonary traits in clinical practice: The role of N-acetylcysteine

Chronic obstructive pulmonary disease (COPD) is a progressive lung condition and a leading cause of physical decline and death. COPD prevalence is expected to increase steadily in the coming years, and as a result, the healthcare and social burden of this condition will intensify. In this scenario, a patient-centric approach, the treatable trait (TT) strategy, based on the identification of traits that are clinically relevant, identifiable, monitorable and treatable, has emerged. The TT strategy, which considers behavioral/risk factors, as well as pulmonary and extrapulmonary traits, has shown to be a promising strategy in COPD management. This work reviews the TT strategy in COPD, giving special attention to the most relevant pulmonary traits, such as frequent productive cough, chronic bronchitis, type 2 inflammation, neutrophilic inflammation, lung hyperinflation, bronchiectasis, exacerbations and non-reversible airflow limitation. N-acetylcysteine (NAC), a widely used mucolytic agent, might be a major player in this strategy. Indeed, through a thorough review of the literature, it has been possible to highlight that, besides being essential in the treatment of frequent productive cough, NAC could bring benefits in case of airflow limitations, airways inflammation, exacerbations and bronchiectasis. A clinical case in which the TT strategy was able to reduce symptoms and improve lung function and quality of life, minimizing unnecessary medication and side effects, is also presented. The identification of TTs and their proper treatment through personalized medicine remarkably ameliorates COPD management. Of note, the mucolytic, antioxidant, and anti-inflammatory activities of NAC might have beneficial effects on several TTs.

Identification and experimental validation of PYCARD as a crucial PANoptosis-related gene for immune response and inflammation in COPD

Chronic inflammatory and immune responses play key roles in the development and progression of chronic obstructive pulmonary disease (COPD). PANoptosis, as a unique inflammatory cell death modality, is involved in the pathogenesis of many inflammatory diseases. We aim to identify critical PANoptosis-related biomarkers and explore their potential effects on respiratory tract diseases and immune infiltration landscapes in COPD. Total microarray data consisting of peripheral blood and lung tissue datasets associated with COPD were obtained from the GEO database. PANoptosis-associated genes in COPD were identified by intersecting differentially expressed genes (DEGs) with genes involved in pyroptosis, apoptosis, and necroptosis after normalizing and removing the batch effect. Furthermore, GO, KEGG, PPI network, WGCNA, LASSO-COX, and ROC curves analysis were conducted to screen and verify hub genes, and the correlation between PYCARD and infiltrated immune cells was analyzed. The effect of PYCARD on respiratory tract diseases and the potential small-molecule agents for the treatment of COPD were identified. PYCARD expression was verified in the lung tissue of CS/LPS-induced COPD mice. PYCARD was a critical PANoptosis-related gene in all COPD patients. PYCARD was positively related to NOD-like receptor signaling pathway and promoted immune cell infiltration. Moreover, PYCARD was significantly activated in COPD mice mainly by targeting PANoptosis. PANoptosis-related gene PYCARD is a potential biomarker for COPD diagnosis and treatment.

Neuropeptides or their receptors in pathogenesis of lung diseases and therapeutic potentials

There are complex interactions between the immune system and the nervous system in the lung. The nervous system perceives environmental stimuli and transmits these signals to immune cells via neurotransmitters, which is essential for effective immunity and environmental balance. Neuropeptides are important neurotransmitters in the lung, where they regulate immune responses through direct and indirect mechanisms, affecting the occurrence and development of lung diseases. In this review, we emphasize the role of neuropeptides in the pathogeneis of lung diseases and their potential therapeutic value for lung diseases.

Stability of Neutrophil to Lymphocyte Ratio in Acute Exacerbation of Chronic Obstructive Pulmonary Disease and Its Relationship with Clinical Outcomes: A Retrospective Cohort Study

Background

More studies have focused on the clinical value of the measurement of the neutrophil-to-lymphocyte ratio (NLR) in acute exacerbations of chronic obstructive pulmonary disease (AECOPD). This study aims to assess the stability of NLR in hospitalized AECOPD patients and its relationship with clinical prognosis.

Methods

This retrospective observational study recruited patients hospitalized with AECOPD from January 2020 to December 2023. Using receiver operating characteristic curves, we determined the optimal NLR cutoff, categorizing NLR stability into four groups: persistent high (NLR ≥ 3.8), increased (NLR < 3.8 at admission but ≥ 3.8 at discharge), decreased (NLR ≥ 3.8 at admission but < 3.8 at discharge), and persistent low (NLR < 3.8). Adverse hospital outcomes included hospital mortality, transfer to the intensive care unit (ICU), invasive mechanical ventilation (IMV), and length of hospital stay (LOS) ≥ 14 days. The associations between NLR stability and these outcomes were analyzed using multivariable logistic regression and Cox hazard analysis.

Results

Among 841 patients hospitalized for AECOPD, the mean age was 72.1±9.5 years, with 644 males (76.6%) and 197 females (23.4%). The proportions and distribution for groups: persistent high, decreased, increased, and persistent low groups were 109 (12.9%), 175 (20.8%), 216 (25.7%), and 341 (40.5%), respectively. The persistent high group had the worst outcomes, including higher IMV use, ICU transfer, LOS > 14 days, and hospital cost, compared to the persistent low group. Compared to the persistent high group, the persistent low group (HR: 0.13; 95% CI: 0.10-0.24) and the decreased group (HR: 0.40; 95% CI: 0.22-0.73) are statistically significant for the risk of death, while the increased group (HR: 0.63; 95% CI: 0.37-1.04) does not show a statistically significant difference.

Conclusion

AECOPD patients who have persistent low NLR group face a low risk of adverse hospital outcomes and mortality after 6 months after discharge. The stability of NLR may serve as a novel biomarker for identifying AECOPD patients at increased risk of poor hospital outcomes.

The relevance of eosinophils in chronic obstructive pulmonary disease: inflammation, microbiome, and clinical outcomes

Chronic obstructive pulmonary disease is caused by the inhalation of noxious particles such as cigarette smoke. The pathophysiological features include airway inflammation, alveolar destruction, and poorly reversible airflow obstruction. A subgroup of patients with chronic obstructive pulmonary disease has higher blood eosinophil counts, associated with an increased response to inhaled corticosteroids and increased biomarkers of pulmonary type 2 inflammation. Emerging evidence shows that patients with chronic obstructive pulmonary disease with increased pulmonary eosinophil counts have an altered airway microbiome. Higher blood eosinophil counts are also associated with increased lung function decline, implicating type 2 inflammation in progressive pathophysiology in chronic obstructive pulmonary disease. We provide a narrative review of the role of eosinophils and type 2 inflammation in the pathophysiology of chronic obstructive pulmonary disease, encompassing the lung microbiome, pharmacological targeting of type 2 pathways in chronic obstructive pulmonary disease, and the clinical use of blood eosinophil count as a chronic obstructive pulmonary disease biomarker.

Immune system benefits of pulmonary rehabilitation in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a respiratory disease characterized by pulmonary and systemic inflammation. Inflammatory mediators show relationships with shortness of breath, exercise intolerance and health related quality of life. Pulmonary rehabilitation (PR), a comprehensive education and exercise training programme, is the most effective therapy for COPD and is associated with reduced exacerbation and hospitalization rates and increased survival. Exercise training, the primary physiological intervention within PR, is known to exert a beneficial anti-inflammatory effect in health and chronic diseases. The question of this review article is whether exercise training can also make such a beneficial anti-inflammatory effect in COPD. Experimental studies using smoke exposure mice models suggest that the response of the immune system to exercise training is favourably anti-inflammatory. However, the evidence about the response of most known inflammatory mediators (C-reactive protein, tumour necrosis factor α, interleukin 6, interleukin 10) to exercise training in COPD patients is inconsistent, making it difficult to conclude whether regular exercise training has an anti-inflammatory effect in COPD. It is also unclear whether COPD patients with more persistent inflammation are a subgroup that would benefit more from hypothesized immunomodulatory effects of exercise training (i.e., personalized treatment). Nevertheless, it seems that PR combined with maintenance exercise training (i.e., lifestyle change) might be more beneficial in controlling inflammation and slowing disease progress in COPD patients, specifically in those with early stages of disease.

Personalized COPD Care: The Future of Precision-Based Therapies

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory illness characterized by long-standing respiratory symptoms and airflow limitation. It is a major contributor to respiratory disease-related deaths and currently ranked as the sixth leading cause of mortality in the United States. Approved pharmacological therapies for the stable disease primarily consist of inhaled short and long-acting bronchodilators, inhaled corticosteroids, azithromycin, and roflumilast. In recent years, significant progress has been made in the management of COPD through the identification of different COPD phenotypes and endotypes, which allows for a more personalized treatment approach. While earlier studies investigating targeted therapies were less promising, recent data on drugs targeting type 2 inflammatory pathways have shown promising results in carefully selected patients. In this article, we will review the available data on targeted therapies as well as the ongoing clinical studies of novel targeted therapies for COPD. Understanding and implementing these advancements hold promise for improving outcomes and quality of life for individuals living with COPD.

Induction of chronic asthma up regulated the transcription of senile factors in male rats

BACKGROUND

The main characteristic of asthma is chronic inflammation. We examined cellular senescence by histology and molecular assay in the lungs of a rat model of asthma. This model comprises sensitization by several intraperitoneal injections of ovalbumin with aluminium hydroxide, followed by aerosol challenges every other day.

RESULTS

Data showed that asthma induction caused histological changes including, hyperemia, interstitial pneumonia, fibrinogen clots, and accumulation of inflammatory cells in the pleura. There is an elevation of IL-1β and NF-kB proteins in the asthmatic group (P < 0.001) compared to the control group. The expression of ß-galactosidase increased (P < 0.01), while the expression of Klotho and Sox2 genes was decreased in the lung tissue of the asthmatic group (P < 0.01).

CONCLUSION

Taken together, these findings suggest that asthmatic conditions accelerated the cellular senescence in the lung tissue.

Blood eosinophil count correlates with alveolar damage in emphysema-predominant COPD

BACKGROUND

Although blood eosinophil count is recognized as a useful biomarker for the management of chronic obstructive pulmonary disease (COPD), the impact of eosinophils in COPD has not been fully elucidated. Here we aimed to investigate the relationships between the blood eosinophil count and various clinical parameters including lung structural changes.

METHODS

Ninety-three COPD patients without concomitant asthma were prospectively enrolled in this study. Blood eosinophil count, serum IgE level, serum periostin level, and chest computed tomography (CT) scans were evaluated. Eosinophilic COPD was defined as COPD with a blood eosinophil count ≧ 300/µL. We examined the correlation between the blood eosinophil count and structural changes graded by chest CT, focusing specifically on thin airway wall (WT thin) and thick airway wall (WT thick) groups. In a separate cohort, the number of eosinophils in the peripheral lungs of COPD patients with low attenuation area (LAA) on chest CT was assessed using lung resection specimens.

RESULTS

The mean blood eosinophil count was 212.1/µL, and 18 patients (19.3%) were categorized as having eosinophilic COPD. In the whole group analysis, the blood eosinophil count correlated only with blood white blood cells, blood basophils, C-reactive protein level, and sputum eosinophils. However, the blood eosinophil count positively correlated with the percentage of LAA and negatively correlated with the diffusing capacity for carbon monoxide in the WT thin group. Lung specimen data showed an increased number of eosinophils in the peripheral lungs of COPD patients with LAA on chest CT scans compared to normal controls.

CONCLUSIONS

Some COPD patients without concomitant asthma showed a phenotype of high blood eosinophils. Alveolar damage may be related to eosinophilic inflammation in patients with COPD without asthma and thickening of the central airway wall.

Signature Proteins in Small Extracellular Vesicles of Granulocytes and CD4+ T-Cell Subpopulations Identified by Comparative Proteomic Analysis

Several studies have described the proteomic profile of different immune cell types, but only a few have also analysed the content of their delivered small extracellular vesicles (sEVs). The aim of the present study was to compare the protein signature of sEVs delivered from granulocytes (i.e., neutrophils and eosinophils) and CD4+ T cells (i.e., TH1, TH2, and TH17) to identify potential biomarkers of the inflammatory profile in chronic inflammatory diseases. Qualitative (DDA) and quantitative (DIA-SWATH) analyses of in vitro-produced sEVs revealed proteome variations depending on the cell source. The main differences were found between granulocyte- and TH cell-derived sEVs, with a higher abundance of antimicrobial proteins (e.g., LCN2, LTF, MPO) in granulocyte-derived sEVs and an enrichment of ribosomal proteins (RPL and RPS proteins) in TH-derived sEVs. Additionally, we found differentially abundant proteins between neutrophil and eosinophil sEVs (e.g., ILF2, LTF, LCN2) and between sEVs from different TH subsets (e.g., ISG15, ITGA4, ITGB2, or NAMPT). A "proof-of-concept" assay was also performed, with TH2 biomarkers ITGA4 and ITGB2 displaying a differential abundance in sEVs from T2high and T2low asthma patients. Thus, our findings highlight the potential use of these sEVs as a source of biomarkers for diseases where the different immune cell subsets studied participate, particularly chronic inflammatory pathologies such as asthma or chronic obstructive pulmonary disease (COPD).

Activated eosinophils in early life impair lung development and promote long-term lung damage

Exaggeration of type 2 immune responses promotes lung inflammation and altered lung development; however, eosinophils, despite expansion in the postnatal lung, have not been specifically assessed in the context of neonatal lung disease. Furthermore, early life factors including prematurity and respiratory infection predispose infants to chronic obstructive pulmonary disease later in life. To assess eosinophils in the developing lung and how they may contribute to chronic lung disease, we generated mice harboring eosinophil-specific deletion of the negative regulatory enzyme SH2 domain-containing inositol 5' phosphatase-1. This increased the activity and number of pulmonary eosinophils in the developing lung, which was associated with impaired lung development, expansion of activated alveolar macrophages (AMφ), multinucleated giant cell formation, enlargement of airspaces, and fibrosis. Despite regression of eosinophils following completion of lung development, AMφ-dominated inflammation persisted, alongside lung damage. Bone marrow chimera studies showed that SH2 domain-containing inositol 5' phosphatase-1-deficient eosinophils were not sufficient to drive inflammatory lung disease in adult steady-state mice but once inflammation and damage were present, it could not be resolved. Depletion of eosinophils during alveolarization alleviated pulmonary inflammation and lung pathology, demonstrating an eosinophil-intrinsic effect. These results show that the presence of activated eosinophils during alveolarization aggravates AMφs and promotes sustained inflammation and long-lasting lung pathology.

Esketamine mitigates mechanical ventilation-induced lung injury in chronic obstructive pulmonary disease rats via inhibition of the MAPK/NF-κB signaling pathway and reduction of oxidative stress

PURPOSE

To investigate esketamine's impact on inflammation and oxidative stress in ventilated chronic obstructive pulmonary disease (COPD) rats, examining its regulatory mechanisms.

METHODS

Rats were divided into four groups: control group (Con), COPD model group (M), COPD model with saline treatment group (M+S), and COPD model with esketamine treatment group (M+K), with 12 rats in each group. After two months, all rats underwent anesthesia and mechanical ventilation. Group M+K received 5 mg/kg esketamine intravenously, while Group M+S received the same volume of saline. Lung tissues were collected for analysis two hours later, including airway peak pressure, wet-to-dry(W/D) ratio, lung permeability index(LPI), hematoxylin and eosin(H&E) staining, and transmission electron microscopy(TEM). Tumor necrosis factor-alpha(TNF-α), interleukin-6(IL-6), interleukin-8(IL-8), and interleukin-10(IL-10) levels were determined by enzyme-linked immunosorbent assay(ELISA); phosphorylated Nuclear Factor Kappa B(p-NF-κB), mitogen-activated protein kinase 14(p38), phosphorylated p38 (p-p38), c-Jun N-terminal kinase(JNK), and phosphorylated JNK (p-JNK) expressions by Western blotting and immunohistochemistry; and malondialdehyde(MDA), myeloperoxidase(MPO), and superoxide dismutase(SOD) levels were also measured by corresponding biochemical assays.

RESULTS

Lung specimens from groups M, M+S, and M+K manifested hallmark histopathological features of COPD. Compared with group Con, group M displayed increased peak airway pressure, W/D ratio, and LPI. In group M+K, compared with group M, esketamine significantly reduced the W/D ratio, LPI, and concentrations of pro-inflammatory cytokines TNF-α, IL-6, and IL-8 while concurrently elevating IL-10 levels. Furthermore, the treatment attenuated the activation of the NF-κB and MAPK pathways, indicated by decreased levels of p-NF-κB, p-p38, and p-JNK.Additionally, compared to group M, group M+K showed decreased MDA and MPO levels and increased SOD levels in lung tissue.

CONCLUSION

Esketamine attenuates mechanical ventilation-induced lung injury in COPD rat models by inhibiting the MAPK/NF-κB signaling pathway and reducing oxidative stress.

Diagnostic Challenges and Pathogenetic Differences in Biomass-Smoke-Induced versus Tobacco-Smoke-Induced COPD: A Comparative Review

Background: Chronic Obstructive Pulmonary Disease (COPD) is a major global health challenge, primarily driven by exposures to tobacco smoke and biomass smoke. While Tobacco-Smoke-Induced COPD (TSCOPD) has been extensively studied, the diagnostic challenges and distinct pathogenesis of Biomass-Smoke-Induced COPD (BSCOPD), particularly in low- and middle-income countries, remain underexplored. Objective: To explore the differences in clinical manifestations, pulmonary function, and inflammatory profiles between BSCOPD and TSCOPD and highlight the diagnostic complexities of BSCOPD. Methods: This review analyzes the current literature comparing BSCOPD with TSCOPD, focusing on distinctive pathophysiological mechanisms, inflammatory markers, and oxidative stress processes. Results: BSCOPD presents differences in clinical presentation, with less emphysema, smaller airway damage, and higher rates of pulmonary hypertension compared to TSCOPD. BSCOPD is also characterized by bronchial hyperresponsiveness and significant hypoxemia, unlike TSCOPD, which exhibits severe airflow obstruction and emphysema. Additionally, the inflammatory profile of BSCOPD includes distinct mucous hypersecretion and airway remodeling. Conclusions: The unique genetic, epigenetic, and oxidative stress mechanisms involved in BSCOPD complicate its diagnosis and management. Biomass smoke's underrecognized impact on accelerated lung aging and exacerbation mechanisms emphasizes the need for targeted research to refine diagnostic criteria and management strategies for BSCOPD. Future directions: Further research should focus on identifying specific biomarkers and molecular pathways to enhance early diagnosis and improve clinical outcomes in populations exposed to biomass smoke.

Dietary inflammatory index and all-cause mortality in adults with COPD: a prospective cohort study from the NHANES 1999-2018

Background

Chronic inflammation is closely linked to Chronic Obstructive Pulmonary Disease (COPD); however, the impact of the Dietaryq Inflammatory Index (DII) on mortality among COPD patients remains uncertain.

Objective

To assess the correlation between the DII and all-cause mortality in COPD patients using data from the National Health and Nutrition Examination Survey (NHANES).

Methods

We conducted a retrospective cohort study on 1,820 COPD patients from the NHANES dataset (1999-2018). The influence of DII on mortality was evaluated using multivariate Cox regression, smoothing spline fitting, and threshold effect analysis. Additionally, Kaplan-Meier survival analysis was performed to compare survival curves among different DII groups. Subgroup analyses and E-values identified sensitive cohorts and assessed unmeasured confounding.

Results

Over an average follow-up of 91 months, multivariate Cox regression models revealed a significant positive correlation between DII scores and mortality risk, with each unit increase in DII associated with a 10% higher risk of death (HR: 1.10, 95% CI: 1.03-1.16; P = 0.002). Among the DII tertiles, individuals in the second tertile (T2: 1.23-2.94) experienced a 67% increase in mortality risk compared to those in the lowest tertile (T1: -5.28-1.23) (HR: 1.67, 95% CI: 1.26-2.21; p < 0.001). The third tertile (T3) did not show a statistically significant increase in mortality risk (HR: 1.30, 95% CI: 0.98-1.72; p=0.074). A restricted cubic spline analysis indicated a significant nonlinear association between DII and all-cause mortality (p = 0.021). Threshold effect analysis further revealed that below a DII of 2.19, there was a significant increase in all-cause mortality risk (HR = 1.19, 95% CI: 1.07-1.33; p = 0.002), while at or above this threshold, the risk increase was not statistically significant (HR=0.89, 95% CI: 0.68-1.15; p = 0.380). Kaplan-Meier analysis revealed significant differences in survival curves among DII tertiles (p < 0.001), with the lowest DII tertile showing the highest survival probability. Both subgroup and sensitivity analyses confirmed the robustness of these findings.

Conclusion

DII is positively correlated with mortality risk in COPD patients, showing nonlinear characteristics and threshold effects, underscoring its prognostic value.

Inflammatory and Immune Mechanisms in COPD: Current Status and Therapeutic Prospects

Background

Chronic obstructive pulmonary disease (COPD) currently ranks among the top three causes of mortality worldwide, presenting as a prevalent and complex respiratory ailment. Ongoing research has underscored the pivotal role of immune function in the onset and progression of COPD. The immune response in COPD patients exhibits abnormalities, characterized by diminished anti-infection capacity due to immune senescence, heightened activation of neutrophils and macrophages, T cell infiltration, and aberrant B cell activity, collectively contributing to airway inflammation and lung injury in COPD.

Objective

This review aimed to explore the pivotal role of the immune system in COPD and its therapeutic potential.

Methods

We conducted a review of immunity and COPD published within the past decade in the Web of Science and PubMed databases, sorting through and summarizing relevant literature.

Results

This article examines the pivotal roles of the immune system in COPD. Understanding the specific functions and interactions of these immune cells could facilitate the development of novel therapeutic strategies and interventions aimed at controlling inflammation, enhancing immune function, and mitigating the impact of respiratory infections in COPD patients.

mRNA expression insights: Unraveling the relationship between COPD and lung cancer

BACKGROUND

Lung cancer is a prevalent form of cancer worldwide. A possible link between lung cancer and chronic obstructive pulmonary disease (COPD) has been suggested by recent studies. The objective of our research was to analyze the mRNA expression patterns in both situations, with a specific emphasis on their biological functions and the pathways they are linked to.

METHOD

Data on COPD mRNA expression was collected from the NCBI-GEO database, while information regarding lung cancer mRNA was acquired from The Cancer Genome Atlas database. To examine the association of COPD-related scores in lung cancer patients, we utilized the ssGSEA algorithm for single sample gene set enrichment analysis. The possible routes were examined through the utilization of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis. Risk models were developed using Cox and least absolute shrinkage and selection operator (LASSO) regression analyses. Moreover, a GSEA was performed to investigate significant pathways among various risk groups.

RESULT

After identifying 17 genes that were differentially expressed and linked to COPD, we found that they met the criteria of having a false discovery rate < 0.05 and an absolute log2 fold change > 0.585. By utilizing the ssGSEA algorithm, it became possible to classify individuals with lung cancer into two distinct groups based on their COPD status. Consequently, a seven-gene risk model was developed specifically for these patients. The risk score was determined by applying the given formula: risk score = AC022784.1 × 0.0423737993775888 + CRISP3 × 0.0415322046890524 + MELTF × 0.0661848418476596 + MT2P1 × 0.111843227536117 + FAM83A-AS1 × 0.045295939710361 + ZNF506 × -0.309489953363417 + ITGA6 × 0.01813978449589. The risk model associated with COPD showed a notable connection with different immune cells found in the lung cancer sample, including macrophages of M0/M1/M2 types, hematopoietic stem cells, mast cells, NK T cells and regulatory T cells. Overexpression of crucial genes was seen to enhance cell proliferation and invasive potential in the lung cancer sample. In the lung cancer sample, it was observed that an increase in ZNF506 expression enhanced both cell proliferation and invasion.

CONCLUSION

In conclusion, this study effectively examines the potential correlation between COPD and lung cancer. A prognostic model based on seven COPD-associated genes demonstrated robust predictive potential in the lung cancer sample. Our analysis offers comprehensive insights for lung cancer patients.

Shengmai Powder regulates alveolar macrophage PPAR-γ and improves the chronic inflammatory state of chronic obstructive pulmonary disease

This study examines the therapeutic effects of Shengmai Powder (SMP) on both in vitro and in vivo models of chronic obstructive pulmonary disease (COPD) and the underlying mechanisms. Cigarette smoke and cigarette extracts were used to create in vitro and in vivo models of COPD. ELISA was used to measure the levels of pro-inflammatory factors (IL-6, TNF-α, and IL-1β) in mouse lung tissue and alveolar macrophages. Flow cytometry assessed the phagocytic capacity of alveolar macrophage. Western blotting was used to analyze the expression of RhoA, PPARγ, IκBα, p-IκBα, P65, and p-P65 in alveolar. The results show that SMP reversed the increased levels of pro-inflammatory factors (IL-6, TNF-α, and IL-1β) in mouse lung tissue and alveolar macrophages induced by cigarette smoke and cigarette extract. SMP also restored the decreased fluorescence intensity and RhoA levels in alveolar macrophages caused by cigarette extract. Additionally, SMP increased PPARγ expression and decreased IκBα and P65 phosphorylation in alveolar macrophages exposed to cigarette extract. Also, the effects of SMP were reversed by PPARγ inhibitors. The study concluded that SMP regulates alveolar macrophage phagocytic function through the PPAR-γ/NF-κB pathway, thereby improving the chronic inflammatory state of COPD.

What every clinician should know about inflammation in COPD

Inflammation drives COPD pathogenesis and exacerbations. Although the conceptual framework and major players in the inflammatory milieu of COPD have been long established, the nuances of cellular interactions and the etiological differences that create heterogeneity in inflammatory profiles and treatment response continue to be revealed. This wealth of data and understanding is not only a boon to the researcher but also provides guidance to the clinician, moving the field closer to precision medicine. It is through this lens that this review seeks to describe the inflammatory processes at play in COPD, relating inflammation to pathological and functional changes, identifying patient-specific and disease-related factors that may influence clinical observations, and providing current insights on existing and emerging anti-inflammatory treatments and treatment targets, including biological therapies and phosphodiesterase (PDE) inhibitors.

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.

Inflammation mechanism and research progress of COPD

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease characterized by irreversible progressive airflow limitation, often manifested by persistent cough, sputum production and other respiratory symptoms that pose a serious threat to human health and affect the quality of life of patients. The disease is associated with chronic inflammation, which is associated with the onset and progression of COPD, but anti-inflammatory therapy is not first-line treatment. Inflammation has multiple manifestations and phenotypes, and this heterogeneity reveals different patterns of inflammation, making treatment difficult. This paper aims to explore the direction of more effective anti-inflammatory treatment by analyzing the nature of inflammation and the molecular mechanism of disease occurrence and development in COPD patients, and to provide new ideas for the treatment of COPD patients.

Relationship between Respiratory Microbiome and Systemic Inflammatory Markers in COPD: A Pilot Study

The respiratory microbiome may influence the development and progression of COPD by modulating local immune and inflammatory events. We aimed to investigate whether relative changes in respiratory bacterial abundance are also associated with systemic inflammation, and explore their relationship with the main clinical COPD phenotypes. Multiplex analysis of inflammatory markers and transcript eosinophil-related markers were analyzed on peripheral blood in a cohort of stable COPD patients (n = 72). Respiratory microbiome composition was analyzed by 16S rRNA microbial sequencing on spontaneous sputum. Spearman correlations were applied to test the relationship between the microbiome composition and systemic inflammation. The concentration of the plasma IL-8 showed an inverted correlation with the relative abundance of 17 bacterial genera in the whole COPD cohort. COPD patients categorized as eosinophilic showed positive relationships with blood eosinophil markers and inversely correlated with the degree of airway obstruction and the number of exacerbations during the previous year. COPD patients categorized as frequent exacerbators were enriched with the bacterial genera Pseudomonas which, in turn, was positively associated with the severity of airflow limitation and the prior year's exacerbation history. The associative relationships of the sputum microbiome with the severity of the disease emphasize the relevance of the interaction between the respiratory microbiota and systemic inflammation.

Potential association between obstructive lung diseases and cognitive decline

Introduction

Chronic obstructive lung diseases, such as asthma and COPD, appear to have a more extensive impact on overall functioning than previously believed. The latest data from clinical trials suggests a potential link between cognitive deterioration and chronic obstructive inflammatory lung disease. This raises the question of whether these diseases affect cognitive functions and whether any relevant biomarker may be identified.

Methods

This prospective observational study included 78 patients divided equally into asthma, COPD, and control groups (n=26, 27 and 25 respectively). The participants underwent identical examinations at the beginning of the study and after at least 12 months. The test battery comprised 16 questionnaires (11 self-rated, 5 observer-rated, assessing cognition and mental state), spirometry, and blood samples taken for PKA and CREB mRNA evaluation.

Results

A 2.3-fold increase in CREB mRNA was observed between examinations (p=0.014) for all participants; no distinctions were observed between the asthma, COPD, and control groups. Pooled, adjusted data revealed a borderline interaction between diagnosis and CREB expression in predicting MMSE (p=0.055) in COPD, CREB expression is also associated with MMSE (β=0.273, p=0.034) like with the other conducted tests (β=0.327, p=0.024) from COPD patients. No correlations were generally found for PKA, although one significant negative correlation was found between the first and second time points in the COPD group (β=-0.4157, p=0.049),.

Discussion

Chronic obstructive lung diseases, such as asthma and COPD, may have some linkage to impairment of cognitive functions. However, the noted rise in CREB mRNA expression might suggest a potential avenue for assessing possible changes in cognition, especially in COPD; such findings may reveal additional transcription factors linked to cognitive decline.

Association between nutrition-related indicators with the risk of chronic obstructive pulmonary disease and all-cause mortality in the elderly population: evidence from NHANES

Background

This study aims to use six nutrition-related indicators to assess the relationship between nutritional status and the risk of COPD as well as the all-cause mortality rate, and to determine the most reliable predictive indicators.

Methods

Data from the National Health and Nutrition Examination Survey (NHANES) spanning the years 2013 to 2018 were extracted. Nutritional status was evaluated using Controlling nutritional status (CONUT) score, Geriatric Nutritional Risk Index (GNRI), Advanced Lung Cancer Inflammation Index (ALI), Prognostic Nutritional Index (PNI), Triglycerides (TG) × Total Cholesterol (TC) × Body Weight (BW) Index (TCBI), and Albumin-to-Globulin Ratio (AGR) nutritional-related indicators. Multivariate weighted logistic and Cox regression models were employed to assess the correlation between the six nutritional-related indicators and the risk of COPD and as all-cause mortality. The restricted cubic spline tests were applied to explore potential nonlinear relationships, and ROC curves and C-index analyses were conducted to compare the predictive capabilities of different indicators. Stratified analysis and propensity score matching (PSM) to assess the robustness of the results.

Results

In this study, Lower ALI, lower GNRI, and higher CONUT scores were positively correlated with an increased risk of COPD (OR: 1.77, 95% CI: 1.10-2.84) (OR: 8.66, 95% CI: 2.95-25.5), and (OR: 5.11, 95% CI: 1.72-15.2), respectively. It was found that ALI and GNRI had a non-linear relationship with the risk of COPD. After propensity score matching (PSM), the associations between ALI, GNRI, CONUT scores, and COPD remained consistent. Lower ALI, PNI, and GNRI scores were positively associated with all-cause mortality in COPD patients (HR: 2.41, 95% CI: 1.10-5.27), (HR: 3.76, 95% CI: 1.89-7.48), and (HR: 4.55, 95% CI: 1.30-15.9), respectively, with GNRI displaying a non-linear relationship with all-cause mortality. ROC curve and C-index analyses indicated that ALI had the best predictive ability for both COPD risk and all-cause mortality.

Conclusion

ALI, GNRI, and CONUT scores are correlated with the risk of COPD, while ALI, PNI, and GNRI scores are associated with all-cause mortality in COPD patients. Compared to other nutritional scores, ALI may provide more effective predictive value for both risk and all-cause mortality.

Relationship between social participation and depressive symptoms in patients with multimorbidity: the chained mediating role of cognitive function and activities of daily living

OBJECTIVE

The potential mechanisms linking social participation and depressive symptoms in Chinese individuals with multimorbidity are not yet fully understood. This study aims to explore how cognitive function and activities of daily living (ADLs) mediate the relationship between social participation and depressive symptoms in individuals with multimorbidity.

METHODS

We selected 3782 participants with multimorbidity from the 2018 China Health and Retirement Longitudinal Study. Data related to social participation, cognitive function, ADLs, and depressive symptoms were extracted. Regression and Bootstrap analyses were used to explore the sequential mediating effects of social participation, cognitive function, ADLs, and depressive symptoms.

RESULTS

(1) There was a significant correlation between social participation, cognitive function, activities of daily living, and depressive symptoms (p < 0.01). (2) Social participation directly affected depressive symptoms (β = -0.205, p < 0.05). (3) Cognitive function (β = -0.070, p < 0.01) and activities of daily living (β = -0.058, p < 0.01) played separate mediating roles in the effect of social participation on depressive symptoms. (4) Cognitive function and activities of daily living had a chain-mediated role in the relationship between social participation and depressive symptoms in patients with multimorbidity (β = -0.020, p < 0.01).

CONCLUSION

A chained mediating effect was found between cognitive function, ADLs, social participation, and depressive symptoms in patients with multimorbidity. Social participation was found to improve the cognitive function of patients with multimorbidity, which in turn enhanced their daily life activities and ultimately alleviated their depressive symptoms.

Towards precision medicine in COPD: Targeting type 2 cytokines and alarmins

Chronic obstructive pulmonary disease (COPD) is a main global epidemic increasing as population age and affecting approximately 10% of subjects over 45 years. COPD is a heterogeneous inflammatory disease with several endo-phenotypes and clinical presentations. Although neutrophilic inflammation is canonically considered a hallmark of COPD, eosinophilic inflammation can also be present in a subgroup of patients. Several other immune cells and cytokines play a key role in orchestrating and perpetuating the inflammatory pathways in COPD, making them attractive targets for treating this disorder. Recent studies have started to evaluate the possible role of type 2 (T2) inflammation and epithelial-derived alarmins (TSLP and IL-33) in COPD. Two phase III randomized clinical trials (RCTs) showed a modest reduction in exacerbations in COPD patients with eosinophilic phenotype treated with mepolizumab (anti-IL-5) or benralizumab (anti-IL-5Rα). A phase III RCT showed a 30% reduction in exacerbations in COPD patients with ≥ 300 eosinophils/μL treated with dupilumab (anti-IL-4Rα). These results suggest that blocking a single cytokine (e.g., IL-5) or its main target (i.e., IL-5Rα) is less promising than blocking a wider spectrum of cytokines (i.e., IL-4 and IL-13) in COPD. TSLP and IL-33 are upstream regulators of T2-high and T2-low immune responses in airway inflammation. Several ongoing RCTs are evaluating the efficacy and safety of anti-TSLP (tezepelumab), anti-IL-33 (itepekimab, tozorakimab), and anti-ST2 (astegolimab) in patients with COPD, who experience exacerbations. In conclusion, targeting T2 inflammation or epithelial-derived alarmins might represent a step forward in precision medicine for the treatment of a subset of COPD.

DACH1 Attenuates Airway Inflammation in Chronic Obstructive Pulmonary Disease by Activating NRF2 Signaling

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease of the airways characterized by impaired lung function induced by cigarette smoke (CS). Reduced DACH1 (dachshund homolog 1) expression has a detrimental role in numerous disorders, but its role in COPD remains understudied. This study aimed to elucidate the role and underlying mechanism of DACH1 in airway inflammation in COPD by measuring DACH1 expression in lung tissues of patients with COPD. Airway epithelium-specific DACH1-knockdown mice and adenoassociated virus-transfected DACH1-overexpressing mice were used to investigate the role of DACH1 and the potential for therapeutic targeting in experimental COPD caused by CS. Furthermore, we discovered a potential mechanism of DACH1 in inflammation induced by CS extract stimulation in vitro. Compared with nonsmokers and smokers without COPD, patients with COPD had reduced DACH1 expression, especially in the airway epithelium. Airway epithelium-specific DACH1 knockdown aggravated airway inflammation and lung function decline caused by CS in mice, whereas DACH1 overexpression protected mice from airway inflammation and lung function decline. DACH1 knockdown and overexpression promoted and inhibited IL-6 and IL-8 secretion, respectively, in 16HBE human bronchial epidermal cells after CS extract stimulation. NRF2 (nuclear factor erythroid 2-related factor 2) was discovered to be a novel downstream target of DACH1, which binds directly to its promoter. By activating NRF2 signaling, DACH1 induction reduced inflammation. DACH1 levels are lower in smokers and nonsmoking patients with COPD than in nonsmokers. DACH1 has protective effects against inflammation induced by CS by activating the NRF2 signaling pathway. Targeting DACH1 is a potentially viable therapeutic approach for COPD treatment.

Pseudomonas aeruginosa in chronic lung disease: untangling the dysregulated host immune response

Pseudomonas aeruginosa is a highly adaptable opportunistic pathogen capable of exploiting barriers and immune defects to cause chronic lung infections in conditions such as cystic fibrosis. In these contexts, host immune responses are ineffective at clearing persistent bacterial infection, instead driving a cycle of inflammatory lung damage. This review outlines key components of the host immune response to chronic P. aeruginosa infection within the lung, beginning with initial pathogen recognition, followed by a robust yet maladaptive innate immune response, and an ineffective adaptive immune response that propagates lung damage while permitting bacterial persistence. Untangling the interplay between host immunity and chronic P. aeruginosa infection will allow for the development and refinement of strategies to modulate immune-associated lung damage and potentiate the immune system to combat chronic infection more effectively.

Rheumatoid arthritis and changes on spirometry by smoking status in two prospective longitudinal cohorts

OBJECTIVE

To compare longitudinal changes in spirometric measures between patients with rheumatoid arthritis (RA) and non-RA comparators.

METHODS

We analysed longitudinal data from two prospective cohorts: the UK Biobank and COPDGene. Spirometry was conducted at baseline and a second visit after 5-7 years. RA was identified based on self-report and disease-modifying antirheumatic drug use; non-RA comparators reported neither. The primary outcomes were annual changes in the per cent-predicted forced expiratory volume in 1 s (FEV1%) and per cent predicted forced vital capacity (FVC%). Statistical comparisons were performed using multivariable linear regression. The analysis was stratified based on baseline smoking status and the presence of obstructive pattern (FEV1/FVC <0.7).

RESULTS

Among participants who underwent baseline and follow-up spirometry, we identified 233 patients with RA and 37 735 non-RA comparators. Among never-smoking participants without an obstructive pattern, RA was significantly associated with more FEV1% decline (β=-0.49, p=0.04). However, in ever smokers with ≥10 pack-years, those with RA exhibited significantly less FEV1% decline than non-RA comparators (β=0.50, p=0.02). This difference was more pronounced among those with an obstructive pattern at baseline (β=1.12, p=0.01). Results were similar for FEV1/FVC decline. No difference was observed in the annual FVC% change in RA versus non-RA.

CONCLUSIONS

Smokers with RA, especially those with baseline obstructive spirometric patterns, experienced lower FEV1% and FEV1/FVC decline than non-RA comparators. Conversely, never smokers with RA had more FEV1% decline than non-RA comparators. Future studies should investigate potential treatments and the pathogenesis of obstructive lung diseases in smokers with RA.

Association between systemic inflammatory markers and chronic obstructive pulmonary disease: A population-based study

Objective

To investigate whether inflammatory indices, including the systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), product of platelet and neutrophil count (PPN), and lymphocyte-to-monocyte ratio (LMR), correlate with chronic obstructive pulmonary disease (COPD).

Methods

This was a cross-sectional study from the National Health and Nutrition Examination Survey (NHANES) database 2007-2018. The SII, NLR, PLR, PPN and LMR were calculated based on blood cell counts and were log2-transformed. COPD was diagnosed via a questionnaire or spirometry examination. Multivariate logistic regression, sensitivity analysis, subgroup analyses, and interaction tests were performed to evaluate the relationships.

Results

23,875 participants, including 1000 COPD patients (453 diagnosed via spirometry examination, 547 diagnosed via a questionnaire), were enrolled in this study. Positive associations were observed between SII (OR 1.231, 95 % CI 1.081,1.401), NLR (OR 1.223, 95 % CI 1.064,1.405), PLR (OR 1.325, 95 % CI 1.086,1.617), PPN (OR 1.157, 95 % CI 1.031,1.298) and COPD, while a negative association was obtained between LMR and COPD (OR 0.794, 95 % CI 0.666,0.948) after covariate adjustments. When divided COPD patients into spirometry-based and questionnaire-based, only SII (OR 1.310, 95%CI 1.122,1.529), PLR (OR 1.669, 95%CI 1.272,2.191) and PPN (OR 1.218, 95%CI 1.050,1.412) significantly correlated with spirometry-based COPD, while only NLR (OR 1.303, 95%CI 1.055,1.609) and LMR (OR 0.524, 95%CI 0.406,0.677) significantly correlated with questionnaire-based COPD after covariate adjustments.

Conclusion

Significant associations are observed between different inflammation indices and COPD. Heterogeneity exists between spirometry-based and questionnaire-based COPD patients. Future studies are needed to verify the results.

Association of dietary inflammatory indices with sarcopenia and all-cause mortality in COPD patients

Background

Sarcopenia frequently occurs as a comorbidity in individuals with COPD. However, research on the impact of Appendicular Skeletal Muscle Mass (ASM) on survival in COPD patients is scarce. Moreover, there is a lack of research on the association between dietary pro-inflammatory capacity and sarcopenia in COPD.

Methods

We analyzed data from the National Health and Nutrition Examination Survey (NHANES) covering the years 1999 to 2006 and 2011 to 2018. We aimed to investigate the relationship between the Dietary Inflammatory Index (DII) and sarcopenia prevalence among adults diagnosed with COPD in the United States. Furthermore, we sought to explore the relationship between sarcopenia, ASMI, and all-cause mortality. The study included a total of 1,429 eligible adult participants, divided into four groups based on quartiles of DII, with adjustments for sample weights. Methodologically, we used multivariable logistic regression analyses and to examine the association between DII and sarcopenia. Additionally, we used restricted cubic spline (RCS) tests to evaluate potential non-linear relationships. To assess the effect of sarcopenia on overall all-cause mortality, we used Kaplan-Meier models and Cox proportional hazards models. Moreover, we used RCS analyses to investigate potential non-linear relationships between ASMI and all-cause mortality. Subgroup analyses were conducted to confirm the reliability of our study findings.

Results

In our COPD participant cohort, individuals with higher DII scores were more likely to be female, unmarried, have lower educational attainment, and show lower ASMI. Using multivariable logistic regression models, we found a positive association between the highest quartile of DII levels and sarcopenia incidence [Odds Ratio (OR) 2.37; 95% Confidence Interval (CI) 1.26-4.48; p = 0.01]. However, analysis of RCS curves did not show a non-linear relationship between DII and sarcopenia. Throughout the entire follow-up period, a total of 367 deaths occurred among all COPD patients. Kaplan-Meier survival curves showed a significantly higher all-cause mortality rate among individuals with concurrent sarcopenia (p < 0.0001). Cox proportional hazards model analysis showed a 44% higher risk of all-cause mortality among COPD patients with sarcopenia compared to those without sarcopenia [Hazard Ratio (HR): 1.44; 95% CI 1.05-1.99; p < 0.05]. Additionally, our final RCS analyses revealed a significant non-linear association between ASMI levels and all-cause mortality among COPD patients, with a turning point identified at 8.32 kg/m2. Participants with ASMI levels above this inflection point had a 42% lower risk of all-cause mortality compared to those with ASMI levels below it (HR 0.58; 95% CI 0.48-0.7).

Conclusion

We observed a significant association between concurrent sarcopenia and an increased risk of all-cause mortality in COPD patients within the United States. Moreover, ASMI demonstrated a non-linear association with all-cause mortality, with a critical threshold identified at 8.32 kg/m2. Our findings also revealed an association between DII and the presence of sarcopenia. Consequently, further investigations are warranted to explore the feasibility of dietary DII adjustments as a means to mitigate muscle wasting and enhance the prognosis of COPD.

Airway inflammation in a novel mouse model of asthma-COPD overlap induced by co-exposure to papain and tobacco smoke

Asthma and chronic obstructive pulmonary disease (COPD) are respiratory diseases associated with airway inflammation, which is the main pathogenesis. Although their causes and characteristics differ, in some cases, asthma and COPD may coexist in the same patient in a condition called asthma-COPD overlap (ACO). The prognosis of ACO is more unfavourable than those of asthma or COPD alone, without any treatment strategies demonstrating efficacy. Owing to its intricate spectrum of features, the detailed pathogenesis of how ACO exacerbates respiratory features remains unclear. In this study, we exposed papain-induced asthma model mice to tobacco smoke to establish an ACO mouse model, in which features of airway inflammation observed in both asthma and COPD were incorporated. This model exhibited distinctive mixed and corticosteroid-resistant airway inflammation and emphysematous changes that are characteristic of ACO. The novel mouse model established here is expected to significantly contribute to elucidating the mechanisms of the broad pathologies of ACO and identifying potential therapeutic targets.

Aerobic exercise training engages the canonical wnt pathway to improve pulmonary function and inflammation in COPD

BACKGROUND

We studied whether the exercise improves cigarette smoke (CS) induced chronic obstructive pulmonary disease (COPD) in mice through inhibition of inflammation mediated by Wnt/β-catenin-peroxisome proliferator-activated receptor (PPAR) γ signaling.

METHODS

Firstly, we observed the effect of exercise on pulmonary inflammation, lung function, and Wnt/β-catenin-PPARγ. A total of 30 male C57BL/6J mice were divided into the control group (CG), smoke group (SG), low-intensity exercise group (LEG), moderate-intensity exercise group (MEG), and high-intensity exercise group (HEG). All the groups, except for CG, underwent whole-body progressive exposure to CS for 25 weeks. Then, we assessed the maximal exercise capacity of mice from the LEG, MEG, and HEG, and performed an 8-week treadmill exercise intervention. Then, we used LiCl (Wnt/β-catenin agonist) and XAV939 (Wnt/β-catenin antagonist) to investigate whether Wnt/β-catenin-PPARγ pathway played a role in the improvement of COPD via exercise. Male C57BL/6J mice were randomly divided into six groups (n = 6 per group): CG, SG, LiCl group, LiCl and exercise group, XAV939 group, and XAV939 and exercise group. Mice except those in the CG were exposed to CS, and those in the exercise groups were subjected to moderate-intensity exercise training. All the mice were subjected to lung function test, lung histological assessment, and analysis of inflammatory markers in the bronchoalveolar lavage fluid, as well as detection of Wnt1, β-catenin and PPARγ proteins in the lung tissue.

RESULTS

Exercise of various intensities alleviated lung structural changes, pulmonary function and inflammation in COPD, with moderate-intensity exercise exhibiting significant and comprehensive effects on the alleviation of pulmonary inflammation and improvement of lung function. Low-, moderate-, and high-intensity exercise decreased β-catenin levels and increased those of PPARγ significantly, and only moderate-intensity exercise reduced the level of Wnt1 protein. Moderate-intensity exercise relieved the inflammation aggravated by Wnt agonist. Wnt antagonist combined with moderate-intensity exercise increased the levels of PPARγ, which may explain the highest improvement of pulmonary function observed in this group.

CONCLUSIONS

Exercise effectively decreases COPD pulmonary inflammation and improves pulmonary function. The beneficial role of exercise may be exerted through Wnt/β-catenin-PPARγ pathway.

Inflammation mediates the association between furan exposure and the prevalence and mortality of chronic obstructive pulmonary disease: National Health and Nutrition Examination Survey 2013-2018

BACKGROUND

Although extensive research has established associations between chronic obstructive pulmonary disease (COPD) and environmental pollutants, the connection between furan and COPD remains unclear. This study aimed to explore the association between furan and COPD while investigating potential mechanisms.

METHODS

The study involved 7,482 adults from the National Health and Nutrition Examination Survey 2013-2018. Exposure to furan was assessed using blood furan levels. Participants were categorized into five groups based on quartiles of log10-transformed blood furan levels. Logistic regression and restricted cubic spline regression models were used to assess the association between furan exposure and COPD risk. Mediating analysis was performed to assess the contribution of inflammation to the effects of furan exposure on COPD prevalence. Cox regression was used to assess the association between furan exposure and the prognosis of COPD.

RESULTS

Participants with COPD exhibited higher blood furan levels compared to those without COPD (P < 0.001). Log10-transformed blood furan levels were independently associated with an increased COPD risk after adjusting for all covariates (Q5 vs. Q1: OR = 4.47, 95% CI = 1.58-12.66, P = 0.006, P for trend = 0.001). Inflammatory cells such as monocytes, neutrophils, and basophils were identified as mediators in the relationship between furan exposure and COPD prevalence, with mediated proportions of 8.73%, 20.90%, and 10.94%, respectively (all P < 0.05). Moreover, multivariate Cox regression analysis revealed a positive correlation between log10-transformed blood furan levels and respiratory mortality in COPD patients (HR = 41.00, 95% CI = 3.70-460.00, P = 0.003).

CONCLUSIONS

Exposure to furan demonstrates a positive correlation with both the prevalence and respiratory mortality of COPD, with inflammation identified as a crucial mediator in this relationship.

Chronic obstructive pulmonary disease and the airway microbiome: A review for clinicians

Chronic obstructive pulmonary disease (COPD) is a complex heterogeneous disease characterized by progressive airflow limitation and chronic inflammation. The progressive development and long-term repeated acute exacerbation of COPD make many patients still unable to control the deterioration of the disease after active treatment, and even eventually lead to death. An increasing number of studies have shown that the occurrence and development of COPD are closely related to the composition and changes of airway microbiome. This article reviews the interaction between COPD and airway microbiome, the potential mechanisms of interaction, and the treatment methods related to microbiome. We elaborated the internal correlation between airway microbiome and different stages of COPD, inflammatory endotypes, glucocorticoid and antibiotic treatment, analyze the pathophysiological mechanisms such as the "vicious cycle" hypothesis, abnormal inflammation-immune response of the host and the "natural selection" of COPD to airway microbiome, introduce the treatment of COPD related to microbiome and emphasize the predictive value of airway microbiome for the progression, exacerbation and prognosis of COPD, as well as the guiding role for clinical management of patients, in order to provide a new perspective for exploring the pathogenesis of COPD, and also provide clues and guidance for finding new treatment targets.

Molecular mechanism of Jianpiyifei II granules in the treatment of chronic obstructive pulmonary disease: Network pharmacology analysis, molecular docking, and experimental assessment

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is defined by persistent airway and lung inflammation, excessive mucus production, remodeling of the airways, and damage to the alveolar tissue. Based on clinical experience, it has been observed that Jianpiyifei II (JPYF II) granules exhibit a significant therapeutic impact on individuals suffering from stable COPD. Nevertheless, the complete understanding of JPYF II's potential mode of action against COPD remains to be further clarified.

PURPOSE

To further investigate the underlying mechanism of JPYF II for treating COPD and clarify the role of the IL-17 pathway in the treatment.

METHODS

A variety of databases were utilized to acquire JPYF II's bioactive components, as well as related targets of JPYF II and COPD. Cytoscape was utilized to establish multiple interaction networks for the purpose of topological analyses and core-target screening. The Metascape was utilized to identify the function of target genes and crucial signaling pathways. To evaluate the interactions between bioactive ingredients and central target proteins, molecular docking simulations were conducted. Following that, a sequence of experiments was conducted both in the laboratory and in living organisms, which included analyzing the cell counts in bronchoalveolar lavage fluid (BALF), examining lung tissue for histopathological changes, conducting immunohistochemistry, RT‒qPCR, ELISA, and Western blotting.

RESULTS

In JPYF II, 88 bioactive ingredients were predicted to have a total of 342 targets. After conducting Venn analysis, it was discovered that 284 potential targets of JPYF II were linked to the provision of defensive benefits against COPD. The PPI network yielded a total of twenty-four core targets. The findings from the analysis of enrichment and gene‒pathway network suggested that JPYF II targeted Hsp90, MAPKs, ERK, AP-1, TNF-α, IL-6, COX-2, CXCL8, and MMP-9 as crucial elements for COPD treatment through the IL-17 pathway. Additionally, JPYF II might modulate MAPK signaling pathways and the downstream transcription factor AP-1 via IL-17 regulation. According to the findings from molecular docking, it was observed that the 24 core target proteins exhibited robust binding affinities towards the top 10 bioactive compounds. Furthermore, the treatment of COPD through the regulation of MAPKs in the IL-17 pathway was significantly influenced by flavonoids and sterols found in JPYF II. In vitro, these observations were further confirmed. In vivo results demonstrated that JPYF II reduced inflammatory cell infiltration in pulmonary tissues and the quantity of inflammatory cells in BALF obtained from LPS- and CS-stimulated mice. Moreover, the administration of JPYF II resulted in the inhibition of IL-17 mRNA and protein levels, phosphorylation levels of MAPK proteins, and expression of phosphorylated AP-1 proteins. It also suppressed the expression of downstream effector genes and proteins associated with the IL-17/MAPK/AP-1 signaling axis in lung tissues and BALF.

CONCLUSION

This research reveals that JPYF II improves COPD by controlling the IL-17/MAPK/AP-1 signaling axis within the IL-17 pathway for the first time. These findings offer potential approaches for the creation of novel medications that specifically target IL-17 and proteins involved in the IL-17 pathway to address COPD.

A novel quinoline with airway relaxant effects and anti-inflammatory properties

BACKGROUND

In chronic pulmonary diseases characterized by inflammation and airway obstruction, such as asthma and COPD, there are unmet needs for improved treatment. Quinolines is a group of small heterocyclic compounds that have a broad range of pharmacological properties. Here, we investigated the airway relaxant and anti-inflammatory properties of a novel quinoline (RCD405).

METHODS

The airway relaxant effect of RCD405 was examined in isolated airways from humans, dogs, rats and mice. Murine models of ovalbumin (OVA)-induced allergic asthma and LPS-induced airway inflammation were used to study the effects in vivo. RCD405 (10 mg/kg) or, for comparisons in selected studies, budesonide (3 mg/kg), were administered intratracheally 1 h prior to each challenge. Airway responsiveness was determined using methacholine provocation. Immune cell recruitment to bronchi was measured using flow cytometry and histological analyses were applied to investigate cell influx and goblet cell hyperplasia of the airways. Furthermore, production of cytokines and chemokines was measured using a multiplex immunoassay. The expression levels of asthma-related genes in murine lung tissue were determined by PCR. The involvement of NF-κB and metabolic activity was measured in the human monocytic cell line THP-1.

RESULTS

RCD405 demonstrated a relaxant effect on carbachol precontracted airways in all four species investigated (potency ranking: human = rat > dog = mouse). The OVA-specific IgE and airway hyperresponsiveness (AHR) were significantly reduced by intratracheal treatment with RCD405, while no significant changes were observed for budesonide. In addition, administration of RCD405 to mice significantly decreased the expression of proinflammatory cytokines and chemokines as well as recruitment of immune cells to the lungs in both OVA- and LPS-induced airway inflammation, with a similar effect as for budesonide (in the OVA-model). However, the effect on gene expression of Il-4, IL-5 and Il-13 was more pronounced for RCD405 as compared to budesonide. Finally, in vitro, RCD405 reduced the LPS-induced NF-κB activation and by itself reduced cellular metabolism.

CONCLUSIONS

RCD405 has airway relaxant effects, and it reduces AHR as well as airway inflammation in the models used, suggesting that it could be a clinically relevant compound to treat inflammatory airway diseases. Possible targets of this compound are complexes of mitochondrial oxidative phosphorylation, resulting in decreased metabolic activity of targeted cells as well as through pathways associated to NF-κB. However, further studies are needed to elucidate the mode of action.

Putative Molecular Mechanisms Underpinning the Inverse Roles of Mitochondrial Respiration and Heme Function in Lung Cancer and Alzheimer's Disease

Mitochondria are the powerhouse of the cell. Mitochondria serve as the major source of oxidative stress. Impaired mitochondria produce less adenosine triphosphate (ATP) but generate more reactive oxygen species (ROS), which could be a major factor in the oxidative imbalance observed in Alzheimer's disease (AD). Well-balanced mitochondrial respiration is important for the proper functioning of cells and human health. Indeed, recent research has shown that elevated mitochondrial respiration underlies the development and therapy resistance of many types of cancer, whereas diminished mitochondrial respiration is linked to the pathogenesis of AD. Mitochondria govern several activities that are known to be changed in lung cancer, the largest cause of cancer-related mortality worldwide. Because of the significant dependence of lung cancer cells on mitochondrial respiration, numerous studies demonstrated that blocking mitochondrial activity is a potent strategy to treat lung cancer. Heme is a central factor in mitochondrial respiration/oxidative phosphorylation (OXPHOS), and its association with cancer is the subject of increased research in recent years. In neural cells, heme is a key component in mitochondrial respiration and the production of ATP. Here, we review the role of impaired heme metabolism in the etiology of AD. We discuss the numerous mitochondrial effects that may contribute to AD and cancer. In addition to emphasizing the significance of heme in the development of both AD and cancer, this review also identifies some possible biological connections between the development of the two diseases. This review explores shared biological mechanisms (Pin1, Wnt, and p53 signaling) in cancer and AD. In cancer, these mechanisms drive cell proliferation and tumorigenic functions, while in AD, they lead to cell death. Understanding these mechanisms may help advance treatments for both conditions. This review discusses precise information regarding common risk factors, such as aging, obesity, diabetes, and tobacco usage.

Downregulated BMP-Smad1/5/8 signaling causes emphysema via dysfunction of alveolar type II epithelial cells

Bone morphogenetic protein (BMP)-Smad1/5/8 signaling plays a crucial regulatory role in lung development and adult lung homeostasis. However, it remains elusive whether BMP-Smad1/5/8 signaling is involved in the pathogenesis of emphysema. In this study, we downregulated BMP-Smad1/5/8 signaling by overexpressing its antagonist Noggin in adult mouse alveolar type II epithelial cells (AT2s), resulting in an emphysematous phenotype mimicking the typical pathological features of human emphysema, including distal airspace enlargement, pulmonary inflammation, extracellular matrix remodeling, and impaired lung function. Dysregulation of BMP-Smad1/5/8 signaling in AT2s leads to inflammatory destruction dominated by macrophage infiltration, associated with reduced secretion of surfactant proteins and inhibition of AT2 proliferation and differentiation. Reactivation of BMP-Smad1/5/8 signaling by genetics or chemotherapy significantly attenuated the morphology and pathophysiology of emphysema and improved the lung function in Noggin-overexpressing lungs. We also found that BMP-Smad1/5/8 signaling was downregulated in cigarette smoke-induced emphysema, and that enhancing its activity in AT2s prevented or even reversed emphysema in the mouse model. Our data suggest that BMP-Smad1/5/8 signaling, located at the top of the signaling cascade that regulates lung homeostasis, represents a key molecular regulator of alveolar stem cell secretory and regenerative function, and could serve as a potential target for future prevention and treatment of pulmonary emphysema. © 2023 The Pathological Society of Great Britain and Ireland.

Enhanced prothrombotic and proinflammatory activity of circulating extracellular vesicles in acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Acute exacerbations of chronic obstructive pulmonary disease (AE-COPD) are associated with a high rate of cardiovascular events. Thromboinflammation (the interplay between coagulation and inflammation) is probably involved in these events. Extracellular vesicles (EV) increase during AE-COPD, but their role in thromboinflammation in COPD is still unknown. We investigated EV-associated prothrombotic and proinflammatory activity in COPD.

METHODS

Patients with AE-COPD, stable COPD (sCOPD) and age- and sex-matched subjects (controls) were enrolled. AE-COPD patients were evaluated at hospital admission and 8 weeks after discharge (recovery; longitudinal arm). In a cross-sectional arm, AE-COPD were compared with sCOPD and controls. EV-mediated prothrombotic activity was tested by measuring the concentration of EV-associated phosphatidylserine, as assessed by a prothrombinase assay, and tissue factor, as assessed by a modified one-stage clotting assay (EV-PS and EV-TF, respectively). Synthesis of interleukin-8 (IL-8) and C-C motif chemokine ligand-2 (CCL-2) by cells of the human bronchial epithelial cell line 16HBE incubated with patients' EV was used to measure EV-mediated proinflammatory activity.

RESULTS

Twenty-five AE-COPD (median age [interquartile range] 74.0 [14.0] years), 31 sCOPD (75.0 [9.5] years) and 12 control (67.0 [3.5] years) subjects were enrolled. In the longitudinal arm, EV-PS, EV-TF, IL-8 and CCL-2 levels were all significantly higher at hospital admission than at recovery. Similarly, in the cross-sectional arm, EV-PS, EV-TF and cytokines synthesis were significantly higher in AE-COPD than in sCOPD and controls.

CONCLUSIONS

EV exert prothrombotic and proinflammatory activities during AE-COPD and may therefore be effectors of thromboinflammation, thus contributing to the higher cardiovascular risk in AE-COPD.

Exploring the importance of m5c in the diagnosis and subtype classification of COPD using the GEO database

BACKGROUND

5-Methylcytosine (m5C) is an mRNA modifier that is associated with the occurrence and development of viral infection, pulmonary fibrosis, lung cancer, and other diseases. However, the role of m5C regulators in chronic obstructive pulmonary disease (COPD) remains unknown.

METHODS

In this study, by analysing the GSE42057 dataset, the differential expression of m5c regulators in the COPD group and control group was obtained, and a correlation analysis was conducted. The random forest model and support vector machine model were used to predict the occurrence of COPD. A nomogram model was also constructed to predict the prevalence of COPD. The COPD patients were divided into subtypes by consistent cluster analysis based on m5c methylation regulators. Immune cell infiltration was performed on the m5c methylation subtypes. Differentially expressed genes (DEGs) between m5c methylation subtypes were screened, and the DEGs were analysed by Gene Ontology (GO) Kyoto Encyclopedia of Genes and Genomes (KEGG). Finally, we verified the expression of several m5C regulators and related pathways using a COPD cell model.

RESULTS

Seven m5c methylation regulators were differentially expressed. The random forest model based on the above genes was the most accurate for predicting the occurrence of COPD. A nomogram model based on the above genes could also accurately predict the prevalence of COPD, and the implementation of these models could benefit COPD patients. The consistent cluster analysis divided the COPD patients into two subtypes (Cluster A and Cluster B). The main component analysis algorithm determined the m5c methylation subtypes and found that patients in Cluster A had a higher m5c score than those in Cluster B. GO analysis of the DEGs between the m5c methylation COPD patient subtypes revealed that DEGS were mainly enriched in leukocyte-mediated immunity and regulation of T-cell activation. KEGG analysis revealed that DEGS were mainly enriched in Th1 and Th2 cell differentiation, neutrophil extracellular trap formation, and the NF-κB signalling pathway. Immunocyte correlation analysis revealed that Cluster B was associated with neutrophil- and macrophage-mediated immunity, while Cluster A was associated with CD4 + T-cell- and CD8 + T-cell-mediated immunity. Cell experiments have also verified some of the above research results.

CONCLUSION

The diagnosis and subtype classification of COPD patients based on m5c regulators may provide a new strategy for the diagnosis and treatment of COPD.