COPD: balancing oxidants and antioxidants

Bronchoscopic Lung Volume Reduction: A Review

Bronchoscopic lung volume reduction (BLVR) is an established treatment modality for the management of advanced chronic obstructive pulmonary disease complicated by severe emphysema and hyperinflation refractory to other therapies. BLVR aims to reduce hyperinflation and residual volume, thereby improving pulmonary function, symptom control, and quality of life. Multiple distinct devices and technologies, including endobronchial coils, thermal vapor ablation, bio-lung volume reduction, and airway bypass stenting, have been developed to achieve lung volume reduction with varying degrees of accessibility and evidence. The most promising BLVR treatment modality to date has been the placement of one-way endobronchial valves (EBVs), with more than 25,000 cases performed worldwide. Identifying symptomatic patients who would benefit from BLVR is challenging and can be time and resource intensive, and candidacy may be limited by physiologic parameters. Additional new technologies may be able to improve the identification and evaluation of candidates as well as increase the portion of evaluated patients who ultimately qualify for BLVR. In this review, we aim to provide historical context to BLVR, summarize the available evidence regarding its use, discuss potential complications, and provide readers with a clear guide to patient selection and referral for BLVR, with a focus on EBV placement. In addition, we will highlight potential future directions for the field.

Aucubin Alleviates Chronic Obstructive Pulmonary Disease by Activating Nrf2/HO-1 Signaling Pathway

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common chronic respiratory disease with high death rates. Aucubin is an iridoid glycoside extracted from Eucommia ulmoides with antioxidative and anti-inflammatory properties in human diseases. This study aimed to investigate its specific function in mouse and cell models of COPD.

METHODS

The COPD mouse model was established by exposing mice to a long-term cigarette smoke (CS). The number of inflammatory cells and the contents of inflammatory factors tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and IL-8 in bronchoalveolar lavage fluid (BALF) of CS-exposed mice were measured. The levels of superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), and myeloperoxidase (MPO) in the lung tissues were estimated. Masson staining and hematoxylin-eosin (H&E) staining were utilized to evaluate pulmonary fibrosis and emphysema in CS-treated mice. Cell apoptosis in the lung tissues was estimated by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay. Western blot was applied to quantify protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and apoptotic markers. COPD cell model was established by exposing mouse lung epithelial cells (MLE12) with cigarette smoke extract to further verify the properties of aucubin in vitro.

RESULTS

Aucubin reduced the number of inflammatory cells and decreased the contents of TNF-α, IL-6, and IL-8 in BALF of CS-treated mice. The oxidative stress, lung emphysema, fibrosis, and lung cell apoptosis induced by CS exposure were ameliorated by aucubin administration. Aucubin activated the Nrf2/HO-1 signaling pathway in vitro and in vivo. Pretreatment with ML385, a specific Nrf2 inhibitor, antagonized the protective effects of aucubin on inflammation, oxidative stress, fibrosis, and cell apoptosis in COPD.

CONCLUSION

Aucubin alleviates inflammation, oxidative stress, apoptosis, and pulmonary fibrosis in COPD mice and CSE-treated MLE12 cells by activating the Nrf2/HO-1 signaling pathway.

Propofol modulates Nrf2/NLRP3 signaling to ameliorate cigarette smoke-induced damage in human bronchial epithelial cells

Cigarette smoke extract (CSE) is known as a significant contributor to chronic obstructive pulmonary disease (COPD). Propofol, an anesthetic agent, has been studied for its potential protective effects against lung damage. This study aimed to elucidate the protective mechanisms of propofol against CSE-induced damage in human bronchial epithelial 16HBE cells. In CSE-induced 16HBE cells treated by propofol with or without transfection of nuclear factor erythroid 2-related factor 2 (Nrf2) interference plasmids, CCK-8 assay and lactate dehydrogenase (LDH) assay evaluated cytotoxicity. TUNEL assay and Western blot appraised cell apoptosis. ELISA and relevant assay kits severally measured inflammatory and oxidative stress levels. DCFH-DA fluorescent probe detected intracellular reactive oxygen species (ROS) activity. Immunofluorescence staining and Western blot estimated pyroptosis. Also, Western blot analyzed the expression of Nrf2/NLR family pyrin domain containing 3 (NLRP3) signaling-related proteins. Propofol was found to enhance the viability, reduce LDH release, and alleviate the apoptosis, inflammatory response, oxidative stress and pyroptosis in CSE-induced 16HBE cells in a concentration-dependent manner. Meanwhile, propofol decreased NLRP3 expression while raised Nrf2 expression. Further, after Nrf2 was silenced, the impacts of propofol on Nrf2/NLRP3 signaling, LDH release, apoptosis, inflammatory response, oxidative stress and pyroptosis in CSE-exposed 16HBE cells were eliminated. Conclusively, propofol may exert protective effects against CSE-induced damage in 16HBE cells, partly through the modulation of the Nrf2/NLRP3 signaling pathway, suggesting a potential therapeutic role for propofol in CSE-induced bronchial epithelial cell damage.

Evaluation of Oxidative Stress and Antioxidant Biomarkers in Chronic Cigarette Smokers: A Pilot Study

Introduction The present study was undertaken to assess the status of oxidative stress in chronic cigarette smokers. Materials and methods Thirty adult male chronic cigarette smokers and an equal number of age and sex-matched normal subjects from the Deoghar district of Jharkhand state, India, were included in the study. The status of lipid peroxidation was determined using malondialdehyde (MDA), and the activities of enzymic antioxidants, such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), were determined using standard protocols. Results Results showed that the serum MDA levels were significantly increased, and the enzymic antioxidants were markedly decreased in chronic cigarette smokers compared to the normal subjects. Conclusion Our study demonstrated that oxidative stress is more pronounced in cigarette smokers compared to non-smokers. The number of cigarettes smoked plays a crucial role in increasing the reactive oxygen species and decreasing the cellular antioxidants.

Immune Dysregulation in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a disease whose incidence increase with age and is characterised by chronic inflammation and significant immune dysregulation. Inhalation of toxic substances cause oxidative stress in the lung tissue as well as airway inflammation, under the recruitment of chemokines, immune cells gathered and are activated to play a defensive role. However, persistent inflammation damages the immune system and leads to immune dysregulation, which is mainly manifested in the reduction of the body's immune response to antigens, and immune cells function are impaired, further destroy the respiratory defensive system, leading to recurrent lower respiratory infections and progressive exacerbation of the disease, thus immune dysregulation play an important role in the pathogenesis of COPD. This review summarizes the changes of innate and adaptive immune-related cells during the pathogenesis of COPD, aiming to control COPD airway inflammation and improve lung tissue remodelling by regulating immune dysregulation, for further reducing the risk of COPD progression and opening new avenues of therapeutic intervention in COPD.

Discriminative potential of exhaled breath condensate biomarkers with respect to chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) affecting 334 million people in the world remains a major cause of morbidity and mortality. Proper diagnosis of COPD is still a challenge and largely solely based on spirometric criteria. We aimed to investigate the potential of nitrosative/oxidative stress and related metabolic biomarkers in exhaled breath condensate (EBC) to discriminate COPD patients.

METHODS

Three hundred three participants were randomly selected from a 15,000-transit worker cohort within the Respiratory disease Occupational Biomonitoring Collaborative Project (ROBoCoP). COPD was defined using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria as post-bronchodilator ratio of Forced Expiratory Volume in 1st second to Forced Vital Capacity < 0.7 in spirometry validated by an experienced pulmonologist. Discriminative power of biomarker profiles in EBC was analyzed using linear discriminant analyses.

RESULTS

Amongst 300 participants with validated spirometry, 50.3% were female, 52.3 years old in average, 36.0% were current smokers, 12.7% ex-smokers with mean tobacco exposure of 15.4 pack-years. Twenty-one participants (7.0%) were diagnosed as COPD, including 19 new diagnoses, 12 of which with a mild COPD stage (GOLD 1). Amongst 8 biomarkers measured in EBC, combination of 2 biomarkers, Lactate and Malondialdehyde (MDA) significantly discriminated COPD subjects from non-COPD, with a 71%-accuracy, area under the receiver curve of 0.78 (p-value < 0.001), and a negative predictive value of 96%.

CONCLUSIONS

These findings support the potential of biomarkers in EBC, in particular lactate and MDA, to discriminate COPD patients even at a mild or moderate stage. These EBC biomarkers present a non-invasive and drugless technique, which can improve COPD diagnosis in the future.

Inflammation as the nexus: exploring the link between acute myocardial infarction and chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD), particularly following acute exacerbations (AE-COPD), significantly heightens the risks and mortality associated with acute myocardial infarction (AMI). The intersection of COPD and AMI is characterised by a considerable overlap in inflammatory mechanisms, which play a crucial role in the development of both conditions. Although extensive research has been conducted on individual inflammatory pathways in AMI and COPD, the understanding of thrombo-inflammatory crosstalk in comorbid settings remains limited. The effectiveness of various inflammatory components in reducing AMI infarct size or slowing COPD progression has shown promise, yet their efficacy in the context of comorbidity with COPD and AMI is not established. This review focuses on the critical importance of both local and systemic inflammation, highlighting it as a key pathophysiological connection between AMI and COPD/AE-COPD.

Evaluation of Bioactive Effects of Five Plant Extracts with Different Phenolic Compositions against Different Therapeutic Targets

Plant extracts rich in phenolic compounds have been reported to exert different bioactive properties. Despite the fact that there are plant extracts with completely different phenolic compositions, many of them have been reported to have similar beneficial properties. Thus, the structure-bioactivity relationship mechanisms are not yet known in detail for specific classes of phenolic compounds. In this context, this work aims to demonstrate the relationship of extracts with different phenolic compositions versus different bioactive targets. For this purpose, five plant matrices (Theobroma cacao, Hibiscus sabdariffa, Silybum marianum, Lippia citriodora, and Olea europaea) were selected to cover different phenolic compositions, which were confirmed by the phytochemical characterization analysis performed by HPLC-ESI-qTOF-MS. The bioactive targets evaluated were the antioxidant potential, the free radical scavenging potential, and the inhibitory capacity of different enzymes involved in inflammatory processes, skin aging, and neuroprotection. The results showed that despite the different phenolic compositions of the five matrices, they all showed a bioactive positive effect in most of the evaluated assays. In particular, matrices with very different phenolic contents, such as T. cacao and S. marianum, exerted a similar inhibitory power in enzymes involved in inflammatory processes and skin aging. It should also be noted that H. sabdariffa and T. cacao extracts had a low phenolic content but nevertheless stood out for their bioactive antioxidant and anti-radical capacity. Hence, this research highlights the shared bioactive properties among phenolic compounds found in diverse matrices. The abundance of different phenolic compound families highlights their elevated bioactivity against diverse biological targets.

The genomic landscape of chronic obstructive pulmonary disease: Insights from nutrigenomics

Chronic obstructivе pulmonary disеasе (COPD), a rеspiratory disеasе, is influenced by a combination of gеnеtic and еnvironmеntal factors. Thе fiеld of nutrigеnomics, which studiеs thе intеrplay bеtwееn diеt and gеnеs, provides valuable insights into thе gеnomic landscapе of COPD and its implications for production and managеmеnt. This rеviеw providеs a comprеhеnsivе ovеrviеw of thе gеnеtic aspеcts of COPD and thе rolе of nutrigеnomics in advancing our undеrstanding of thе undеrlying mеchanisms. Through studies of gеnomе-widе associations, researchers have identified gеnеtic factors that contribute to suscеptibility to COPD. Thеsе gеnеs arе associatеd with oxidativе strеss, inflammation, and antioxidant dеfеnsе mеchanisms. Nutrigеnomics rеsеarch is currеntly invеstigating how diеtary componеnts interact with gеnеtic variations to modulatе thе dеvеlopmеnt of COPD. Antioxidants, omеga-3 fatty acids and vitamin D havе dеmonstratеd potеntial bеnеfits in rеducing inflammation, improving lung function, and minimizing еxacеrbations in patients with COPD. Therefore, there are sеvеral challеngеs that must be added to the nutrigеnomic rеsеarch. The challenges include thе nееd for largеr clinical trials, adding hеtеrogеnеity and validating biomarkеrs. In the tеrms of futurе dirеctions, prеcision nutrition, gеnе-basеd thеrapiеs, biomarkеr dеvеlopmеnt, intеgration of multi-omics data, systеms biology analysis, longitudinal studiеs, and public hеalth implications arе important arеas to еxplorе. Pеrsonalizеd nutritional intеrvеntions based on an individual's gеnеtic profilе hold grеat promisе for optimizing COPD managеmеnt. In conclusion, nutrigеnomics provides valuable insights into the gеnomic landscapе of COPD and its intеraction with the disease. This knowlеdgе can guidе thе dеvеlopmеnt of pеrsonalizеd diеtary stratеgiеs and gеnе-basеd thеrapiеs for thе prеvеntion and managеmеnt of COPD. Howеvеr, morе rеsеarch is nееdеd to validatе thеsе findings, dеvеlop еffеctivе intеrvеntions, and implеmеnt thеm еffеctivеly in clinical practicе to improvе thе quality of lifе for pеoplе with COPD.

Honokiol ameliorates cigarette smoke-induced damage of airway epithelial cells via the SIRT3/SOD2 signalling pathway

Cigarette smoking can cause damage of airway epithelial cells and contribute to chronic obstructive pulmonary disease (COPD). Honokiol is originally isolated from Magnolia obovata with multiple biological activities. Here, we investigated the protective effects of honokiol on cigarette smoke extract (CSE)-induced injury of BEAS-2B cells. BEAS-2B cells were treated with 300 mg/L CSE to construct an in vitro cell injury model, and cells were further treated with 2, 5 and 10 μM honokiol, then cell viability and LDH leakage were analysed by CCK-8 and LDH assay kits, respectively. Apoptosis was detected by flow cytometry analysis. ELISA was used to measure the levels of tumour necrosis factor (TNF)-ɑ, IL-1β, IL-6, IL-8 and MCP-1. The results showed that honokiol (0.5-20 μM) showed non-toxic effects on BEAS-2B cells. Treatment with honokiol (2, 5 and 10 μM) reduced CSE (300 mg/L)-induced decrease in cell viability and apoptosis in BEAS-2B cells. Honokiol also decreased CSE-induced inflammation through inhibiting expression and secretion of inflammatory cytokines, such as TNF-ɑ, IL-1β, IL-6, IL-8 and MCP-1. Moreover, honokiol repressed CSE-induced reactive oxygen species (ROS) production, decrease of ATP content and mitochondrial biogenesis, as well as mitochondrial membrane potential. Mechanistically, honokiol promoted the expression of SIRT3 and its downstream target genes, which are critical regulators of mitochondrial function and oxidative stress. Silencing of SIRT3 reversed the protective effects of honokiol on CSE-induced damage and mitochondrial dysfunction in BEAS-2B cells. These results indicated that honokiol attenuated CSE-induced damage of airway epithelial cells through regulating SIRT3/SOD2 signalling pathway.

Eosinophil values in exacerbation and stable chronic obstructive pulmonary disease and its relationship to maintenance therapy in stable chronic obstructive pulmonary disease patients

Background

Chronic obstructive pulmonary disease (COPD) is characterised by persistent and progressive airflow limitations. The study aimed to determine the relationship between eosinophil values in patients with stable and exacerbated COPD, and the relationship of eosinophil values with two drug regimens used as maintenance therapy in stable COPD.

Materials and methods

This cross-sectional study and the variables used in this study were eosinophil counts in stable and exacerbated COPD patients.

Results

Eighty-three patients with stable and exacerbated COPD were included. Stable COPD (63.9%) was predominant, with the highest degree of symptoms in group A 18 patients (34%) and Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2; 35 patients (66%). The degree of COPD exacerbation was dominated by Type II COPD 15 patients (50%). Eosinophil counts in patients with stable COPD were less than 100 cells/mm3 37 patients (44.6%), while in patients with COPD exacerbation, it was greater than 100 cells/mm3 with a total of 30 patients (36.1%). Long acting muscarinic antagonist class of drugs was the most used treatment as maintenance therapy in stable COPD 34 patients (64.2%).

Conclusion

The eosinophil counts in patients with COPD exacerbation were significantly higher than those in patients with stable COPD. The provision of maintenance therapy in the long acting β-2 agonist + inhaled glucocorticosteroid group of stable COPD patients was generally provided to COPD patients with eosinophil values greater than 100 cells/mm3, and the provision of long-term maintenance therapy in stable COPD patients was generally given to COPD patients with eosinophil values less than 100 cells/mm3.

Osthole, an ingredient from Cnidium monnieri, reduces the pyroptosis and apoptosis in bronchial epithelial cells

Osthole is the prominent active ingredient isolated from Cnidium. The role of osthole in chronic obstructive pulmonary disease (COPD) was investigated herein. Bronchial epithelial 16HBE cells were exposed to cigarette smoke extract (CSE) to generate injury models. The concentration of CSE had an inverse correlation with cell viability. Osthole suppressed inflammation, oxidative stress, apoptosis, and pyroptosis in 16HBE cells, along with a decrease in RIPK2 level. RIPK2 overexpression reversed the effects of osthole on the abovementioned aspects. This study found that the osthole could reduce RIPK2 level, inhibit pyroptosis, and alleviate the damage in 16HBE cells under CSE stimulation.

Can Hydrogen Water Enhance Oxygen Saturation in Patients with Chronic Lung Disease? A Non-Randomized, Observational Pilot Study

BACKGROUND

Recently, chronic lung diseases have been found to be associated with marked inflammation and oxidative stress, which leads to fibrosis in the lungs and chronic respiratory failure. This study aims to determine if hydrogen-rich water (HRW) can enhance oxygen saturation among patients with chronic lung diseases.

METHODS

Ten patients with chronic lung diseases due to COPD (n = 7), bronchial asthma (n = 2), and tuberculosis of the lung (n = 1) with oxygen saturation of 90-95% were provided high-concentration (>5 mM) HRW using H2-producing tablets for 4 weeks. Oxygen saturation was measured via oximeter and blood pressure via digital automatic BP recorder.

RESULTS

HRW administration was associated with a significant increase in oxygen saturation (SpO2) and decrease in TBARS, MDA, and diene conjugates, with an increase in vitamin E and nitrite levels, compared to baseline levels. Physical training carried out after HRW therapy appeared to increase exercise tolerance and decrease hypoxia, as well as delay the need for oxygen therapy.

CONCLUSION

Treatment with HRW in patients with hypoxia from chronic lung diseases may decrease oxidative stress and improve oxygen saturation in some patients. HRW therapy may also provide increased exercise tolerance in patients with chronic hypoxia, but further research is needed.

Sodium pyruvate exerts protective effects against cigarette smoke extract-induced ferroptosis in alveolar and bronchial epithelial cells through the GPX4/Nrf2 axis

BACKGROUND

Ferroptosis in alveolar and bronchial epithelial cells is one of the main mechanisms underlying the development of chronic obstructive pulmonary disease (COPD). Sodium pyruvate (NaPyr) is a natural antioxidant in the body, exhibiting anti-inflammatory and antioxidant activities. NaPyr has been used in a Phase II clinical trial as a novel therapy for COPD; however, the mechanism underlying NaPyr-mediated therapeutic benefits in COPD is not well understood.

OBJECTIVE

We aimed to assess the protective effects of NaPyr and elucidate its potential mechanism in cigarette smoke extract (CSE)-induced ferroptosis.To minic the inflammatory response and ferroptosis triggered by cigarette smoke in COPD in an invitro cell based system, we expose a human bronchial epithelial cells to CSE.

METHODS

To minic the inflammatory response and ferroptosis triggered by cigarette smoke in COPD in an invitro cell based system, the A549 (human lung carcinoma epithelial cells) and BEAS-2B (bronchial epithelial cells) cell lines were cultured, followed by treatment with CSE. To measure cellular viability and iron levels, we determined the levels of malondialdehyde (MDA), glutathione (GSH), reactive oxygen species (ROS), mitochondrial superoxide (MitoSOX), membrane potential (MMP), and inflammatory factors (tumor necrosis factor [TNF] and interleukin [IL]-8), and examined CSE-induced pulmonary inflammation and ferroptosis. To clarify the molecular mechanisms of NaPyr in COPD therapy, we performed western blotting and real-time PCR (qPCR) to determine the expression of glutathione peroxidase 4 (GPX4), nuclear factor E2-related factor 2 (Nrf2), and cyclooxygenase 2 (COX2).

RESULTS

We found that NaPyr effectively mitigated CSE-induced apoptosis and improved apoptosis induced by erastin, a ferroptosis inducer. NaPyr significantly decreased iron and MDA levels and increased GSH levels in CSE-induced cells. Furthermore, NaPyr suppressed ferroptosis characteristics, such as decreased levels of ROS, MitoSOX, and MMP. NaPyr significantly increases the expression levels of GPX4 and Nrf2, indicating that activation of the GPX4/Nrf2 axis could inhibit ferroptosis in alveolar and bronchial epithelial cells. More importantly, NaPyr inhibited the secretion of downstream inflammatory factors, including TNF and IL-8, by decreasing COX2 expression levels to suppress CSE-induced inflammation.

CONCLUSION

Accordingly, NaPyr could mitigate CSE-induced ferroptosis in alveolar and bronchial epithelial cells by activating the GPX4/Nrf2 axis and decreasing COX2 expression levels. In addition, NaPyr reduced the secretion of inflammatory factors (TNF and IL-8), affording a novel therapeutic candidate for COPD.

Use of thiols and implications for the use of inhaled corticosteroids in the presence of oxidative stress in COPD

BACKGROUND

Oxidative stress and persistent airway inflammation are thought to be important contributors to the development of chronic obstructive pulmonary disease (COPD). This review summarizes the evidence for targeting oxidative stress and inflammation in patients with COPD with mucolytic/antioxidant thiols and inhaled corticosteroids (ICS), either alone or in combination.

MAIN BODY

Oxidative stress is increased in COPD, particularly during acute exacerbations. It can be triggered by oxidant air pollutants and cigarette smoke and/or by endogenous reactive oxygen species (ROS) released from mitochondria and activated inflammatory, immune and epithelial cells in the airways, together with a reduction in endogenous antioxidants such as glutathione (GSH). Oxidative stress also drives chronic inflammation and disease progression in the airways by activating intracellular signalling pathways and the release of further inflammatory mediators. ICS are anti-inflammatory agents currently recommended for use with long-acting bronchodilators to prevent exacerbations in patients with moderate-to-severe COPD, especially those with eosinophilic airway inflammation. However, corticosteroids can also increase oxidative stress, which may in turn reduce corticosteroid sensitivity in patients by several mechanisms. Thiol-based agents such as erdosteine, N-acetyl L-cysteine (NAC) and S-carboxymethylcysteine (S-CMC) are mucolytic agents that also act as antioxidants. These agents may reduce oxidative stress directly through the free sulfhydryl groups, serving as a source of reducing equivalents and indirectly though intracellular GSH replenishment. Few studies have compared the effects of corticosteroids and thiol agents on oxidative stress, but there is some evidence for greater antioxidant effects when they are administered together. The current Global Initiative for Chronic Obstructive Lung Disease (GOLD) report supports treatment with antioxidants (erdosteine, NAC, S-CMC) in addition to standard-of-care therapy as they have been demonstrated to reduce COPD exacerbations. However, such studies have demonstrated that NAC and S-CMC reduced the exacerbation risk only in patients not treated with ICS, whereas erdosteine reduced COPD exacerbations irrespective of concomitant ICS use suggesting that erdosteine has additional pharmacological actions to ICS.

CONCLUSIONS

Further clinical trials of antioxidant agents with and without ICS are needed to better understand the place of thiol-based drugs in the treatment of patients with COPD.

Back to the Basics: Usefulness of Naturally Aged Mouse Models and Immunohistochemical and Quantitative Morphologic Methods in Studying Mechanisms of Lung Aging and Associated Diseases

Aging-related molecular and cellular alterations in the lung contribute to an increased susceptibility of the elderly to devastating diseases. Although the study of the aging process in the lung may benefit from the use of genetically modified mouse models and omics techniques, these approaches are still not available to most researchers and produce complex results. In this article, we review works that used naturally aged mouse models, together with immunohistochemistry (IHC) and quantitative morphologic (QM) methods in the study of the mechanisms of the aging process in the lung and its most commonly associated disorders: cancer, chronic obstructive pulmonary disease (COPD), and infectious diseases. The advantage of using naturally aged mice is that they present characteristics similar to those observed in human aging. The advantage of using IHC and QM methods lies in their simplicity, economic accessibility, and easy interpretation, in addition to the fact that they provide extremely important information. The study of the aging process in the lung and its associated diseases could allow the design of appropriate therapeutic strategies, which is extremely important considering that life expectancy and the number of elderly people continue to increase considerably worldwide.

Animal models and mechanisms of tobacco smoke-induced chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, and its global health burden is increasing. COPD is characterized by emphysema, mucus hypersecretion, and persistent lung inflammation, and clinically by chronic airflow obstruction and symptoms of dyspnea, cough, and fatigue in patients. A cluster of pathologies including chronic bronchitis, emphysema, asthma, and cardiovascular disease in the form of hypertension and atherosclerosis variably coexist in COPD patients. Underlying causes for COPD include primarily tobacco use but may also be driven by exposure to air pollutants, biomass burning, and workplace related fumes and chemicals. While no single animal model might mimic all features of human COPD, a wide variety of published models have collectively helped to improve our understanding of disease processes involved in the genesis and persistence of COPD. In this review, the pathogenesis and associated risk factors of COPD are examined in different mammalian models of the disease. Each animal model included in this review is exclusively created by tobacco smoke (TS) exposure. As animal models continue to aid in defining the pathobiological mechanisms of and possible novel therapeutic interventions for COPD, the advantages and disadvantages of each animal model are discussed.

Mitochondria-Targeted Antioxidants as a Therapeutic Strategy for Chronic Obstructive Pulmonary Disease

Oxidative stress is a major hallmark of COPD, contributing to inflammatory signaling, corticosteroid resistance, DNA damage, and accelerated lung aging and cellular senescence. Evidence suggests that oxidative damage is not solely due to exogenous exposure to inhaled irritants, but also endogenous sources of oxidants in the form of reactive oxygen species (ROS). Mitochondria, the major producers of ROS, exhibit impaired structure and function in COPD, resulting in reduced oxidative capacity and excessive ROS production. Antioxidants have been shown to protect against ROS-induced oxidative damage in COPD, by reducing ROS levels, reducing inflammation, and protecting against the development of emphysema. However, currently available antioxidants are not routinely used in the management of COPD, suggesting the need for more effective antioxidant agents. In recent years, a number of mitochondria-targeted antioxidant (MTA) compounds have been developed that are capable of crossing the mitochondria lipid bilayer, offering a more targeted approach to reducing ROS at its source. In particular, MTAs have been shown to illicit greater protective effects compared to non-targeted, cellular antioxidants by further reducing apoptosis and offering greater protection against mtDNA damage, suggesting they are promising therapeutic agents for the treatment of COPD. Here, we review evidence for the therapeutic potential of MTAs as a treatment for chronic lung disease and discuss current challenges and future directions.

Mediterranean Diet and Lung Function in Adults Current Smokers: A Cross-Sectional Analysis in the MEDISTAR Project

BACKGROUND

Previous studies have shown that adherence to the Mediterranean Diet (MeDi) has a positive impact on lung function in subjects with lung disease. In subjects free of respiratory diseases, but at risk, this association is not yet well established.

METHODS

Based on the reference data from the MEDISTAR clinical trial (Mediterranean Diet and Smoking in Tarragona and Reus; ISRCTN 03.362.372), an observational study was conducted with 403 middle-aged smokers without lung disease, treated at 20 centres of primary care in Tarragona (Catalonia, Spain). The degree of MeDi adherence was evaluated according to a 14-item questionnaire, and adherence was defined in three groups (low, medium, and high). Lung function were assessed by forced spirometry. Logistic regression and linear regression models were used to analyse the association between adherence to the MeDi and the presence of ventilatory defects.

RESULTS

Globally, the pulmonary alteration prevalence (impaired FEV1 and/or FVC) was 28.8%, although it was lower in participants with medium and high adherence to the MeDi, compared to those with a low score (24.2% and 27.4% vs. 38.5%, p = 0.004). Logistic regression models showed a significant and independent association between medium and high adherence to the MeDi and the presence of altered lung patterns (OR 0.467 [95%CI 0.266, 0.820] and 0.552 [95%CI 0.313, 0.973], respectively).

CONCLUSIONS

MeDi adherence is inversely associated with the risk impaired lung function. These results indicate that healthy diet behaviours can be modifiable risk factors to protect lung function and reinforce the possibility of a nutritional intervention to increase adherence to MeDi, in addition to promoting smoking cessation.

Periodontitis and the incidence of chronic obstructive pulmonary disease: A longitudinal study of an adult Japanese cohort

AIM

To examine the relationship between periodontitis as an independent effect of smoking and the development of chronic obstructive pulmonary disease (COPD) in Japanese people based on longitudinal data.

MATERIALS AND METHODS

We targeted 4745 people who underwent pulmonary function tests and dental check-ups at baseline and 8 years later. The Community Periodontal Index was used to assess periodontal status. A Cox proportional hazard model was used to examine the relationship between the incidence of COPD and periodontitis and smoking. To clarify the interaction between smoking and periodontitis, interaction analysis was performed.

RESULTS

In a multivariable analysis, both periodontitis and heavy smoking had significant effects on COPD development. When periodontitis was analysed as a continuous value (number of sextants with periodontitis) and as a category (presence or absence of periodontitis) in the multivariable analyses after adjusting for smoking, pulmonary function and other variables, periodontitis had significantly higher hazard ratios (HRs) for the incidence of COPD; the HRs were 1.09 (1.01-1.17) and 1.48 (1.09-2.02), respectively. Interaction analysis showed no significant interaction between heavy smoking and periodontitis on COPD.

CONCLUSIONS

These results suggest that periodontitis has no interaction with smoking but has an independent effect on developing COPD.

The telomerase activator TA-65 protects from cigarette smoke-induced small airway remodeling in mice through extra-telomeric effects

Small airway remodeling (SAR) is a key phenomenon of airflow obstruction in smokers, leading to chronic obstructive pulmonary disease (COPD). SAR results in an increased thickness of small airway walls, with a combination of peribronchiolar fibrosis with increased fibrous tissue and accumulation of mesenchymal and epithelial cells. SAR pathogenesis is still unclear but recent data suggest that alterations in telomerase activity could represent a possible underlying mechanism of SAR. Our study was dedicated to identify a potential protective role of TA-65, a pharmacological telomerase activator, in a cigarette smoke (CS) model of SAR in mice, and to further precise if extra-telomeric effects of telomerase, involving oxidative stress modulation, could explain it. C57BL/6J mice were daily exposed to air or CS during 4 weeks with or without a concomitant administration of TA-65 starting 7 days before CS exposure. Morphological analyses were performed, and mucus production, myofibroblast differentiation, collagen deposition, as well as transforming growth factor-β1 (TGF-β1) expression in the small airway walls were examined. In addition, the effects of TA-65 treatment on TGF-β expression, fibroblast-to-myofibroblast differentiation, reactive oxygen species (ROS) production and catalase expression and activity were evaluated in primary cultures of pulmonary fibroblasts and/or mouse embryonic fibroblasts in vitro. Exposure to CS during 4 weeks induced SAR in mice, characterized by small airway walls thickening and peribronchiolar fibrosis (increased deposition of collagen, expression of α-SMA in small airway walls), without mucus overproduction. Treatment of mice with TA-65 protected them from CS-induced SAR. This effect was associated with the prevention of CS-induced TGF-β expression in vivo, the blockade of TGF-β-induced myofibroblast differentiation, and the reduction of TGF-β-induced ROS production that correlates with an increase of catalase expression and activity. Our findings demonstrate that telomerase is a critical player of SAR, probably through extra-telomeric anti-oxidant effects, and therefore provide new insights in the understanding and treatment of COPD pathogenesis.

Oxidative Stress and Antioxidants in Chronic Rhinosinusitis with Nasal Polyps

Oxidative stress results from an imbalance between the production of reactive oxygen species and the body's antioxidant defense system. It plays an important role in the regulation of the immune response and can be a pathogenic factor in various diseases. Chronic rhinosinusitis (CRS) is a complex and heterogeneous disease with various phenotypes and endotypes. Recently, an increasing number of studies have proposed that oxidative stress (caused by both environmental and intrinsic stimuli) plays an important role in the pathogenesis and persistence of CRS. This has attracted the attention of several researchers. The relationship between the presence of reactive oxygen species composed of free radicals and nasal polyp pathology is a key topic receiving attention. This article reviews the role of oxidative stress in respiratory diseases, particularly CRS, and introduces potential therapeutic antioxidants that may offer targeted treatment for CRS.

Cigarette smoke extract-induced inflammatory response via inhibition of the TFEB-mediated autophagy in NR8383 cells

Objective: Chronic pulmonary inflammation caused by long-term smoking is the core pathology of COPD. Alveolar macrophages (AMs) are involved in the pulmonary inflammation of COPD. The accumulation of damaged materials caused by impaired autophagy triggers inflammatory response in macrophages. As a key transcription regulator, transcription factor EB (TFEB) activates the transcription of target genes related autophagy and lysosome by binding to promoters, whereas it is unclarified for the relationship between inflammatory response induced by cigarette smoke extract (CSE) and TFEB-mediated autophagy. Thus, we investigated the role of TFEB-mediated autophagy in inflammatory response induced by CSE in NR8383 cells, and to explore its potential mechanism. Methods: Based on cell viability and autophagy, cells treated with 20% concentration of CSE for 24 h were selected for further studies. Cells were divided into control group, chloroquine (CQ, the autophagy inhibitor) group, CSE group, CSE + rapamycin (the autophagy inducer) group and CSE + fisetin (the TFEB inducer) group. The levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6 in supernatant were detected by ELISA kits. The protein expressions were tested by western blot. The intensity of fluorescence of Lysosome-associated membrane protein 1 (LAMP1) and TFEB was detected by immunofluorescence. Lyso-Tracker Red staining was applied to detect the lysosome environment. Results: CSE inhibited the cell viability, increased the contents of TNF-α, IL-1β, IL-6, the ratio of LC3II/I, and the level of P62 protein. Besides, CSE decreased the fluorescence intensity of LAMP1 protein and Lyso-Tracker Red staining, as well as the ratio of nucleus/cytosol of TFEB protein. Activating autophagy with rapamycin alleviated CSE-induced inflammatory response. The activation of TFEB via fisetin alleviated CSE-induced autophagy impairment and lysosomal dysfunction, thus alleviated inflammatory response in NR8383 cells. Conclusion: CSE-induced inflammatory response in NR8383 cells, which may be related to the inhibition of TFEB-mediated autophagy.

The Serum Levels of the Heavy Metals Cu, Zn, Cd, and Pb and Progression of COPD-A Preliminary Study

There is evidence in previous studies that high levels of heavy metals may play a key role in the development of COPD due to the induction of chronic inflammation and oxidative stress. In this preliminary study, we used atomic absorption spectrophotometry to measure the levels of four heavy metals (Cu, Zn, Cd, and Pb) in blood serum of COPD patients and controls over 2 years. Clinical data on disease progression or absence were collected in patients living in the industrial region of Stara Zagora, Bulgaria. The mean values of Cu in the serum of patients with COPD and the control group were 374.29 ± 15.03 μg/L and 238.55 ± 175.31 μg/L, Zn—2010.435 ± 670.006 μg/L and 1672.78 ± 934.27 μg/L, Cd—0.334 ± 0.0216 μg/L and 0.395 ± 0.110 μg/L and Pb—0.0732 ± 0.009 μg/L and 0.075 ± 0.0153 μg/L. This is probably because these elements are biogenic and are used in the body for its anti-oxidant protection. In fact, it cannot be stated with certainty that elevated levels of Cu and Zn in the environment have a negative impact in COPD patients. There was a trend towards higher levels of the toxicants lead and cadmium in COPD patients compared to the control group of patients. There is a statistically unproven trend toward higher levels of lead and cadmium in COPD patients compared to controls, which to some extent supports our hypothesis that there is a relationship between environmental lead and cadmium levels and the COPD manifested. In COPD patients, a positive correlation was found between BMI and serum Cu levels (r = 0.413, p = 0.005). A higher concentration of serum Cu was found in men with BMI ≥ 30, compared to those with BMI < 30. There is also a positive correlation to a lesser extent between CRP and cadmium (r = 0.380; p = 0.019) and lead (r = 0.452; p = 0.004). The correlation of lead and cadmium with PSA also shows that these elements may also be associated with the presence of inflammatory processes. A significant negative correlation exists between Pb in the serum of patients with COPD and their blood hemoglobin (r = −356; p = 0.028). The results of our study suggest that higher doses of the trace elements Cu and Zn do not always have a negative effect in patients with COPD, while the toxicants Pb and Cd may be involved in COPD exacerbation and can be used as prognostic biomarkers for progression. Further studies are warranted to confirm these preliminary results.

Cleavage of Occludin by Cigarette Smoke-Elicited Cathepsin S Increases Permeability of Lung Epithelial Cells

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is an irreversible disease mainly caused by smoking. COPD is characterized by emphysema and chronic bronchitis associated with enhanced epithelial permeability.

HYPOTHESIS

Lung biopsies from smokers revealed a decreased expression level of occludin, which is a protein involved in the cohesion of epithelial tight junctions. Moreover, the occludin level correlated negatively with smoking history (pack-years), COPD grades, and cathepsin S (CatS) activity. Thus, we examined whether CatS could participate in the modulation of the integrity of human lung epithelial barriers.

METHODS AND RESULTS

Cigarette smoke extract (CSE) triggered the upregulation of CatS by THP-1 macrophages through the mTOR/TFEB signaling pathway. In a co-culture model, following the exposure of macrophages to CSE, an enhanced level of permeability of lung epithelial (16HBE and NHBE) cells towards FITC-Dextran was observed, which was associated with a decrease in occludin level. Similar results were obtained using 16HBE and NHBE cells cultured at the air-liquid interface. The treatment of THP-1 macrophages by CatS siRNAs or by a pharmacological inhibitor restored the barrier function of epithelial cells, suggesting that cigarette smoke-elicited CatS induced an alteration of epithelial integrity via the proteolytic injury of occludin.

CONCLUSIONS

Alongside its noteworthy resistance to oxidative stress induced by cigarette smoke oxidants and its deleterious elastin-degrading potency, CatS may also have a detrimental effect on the barrier function of epithelial cells through the cleavage of occludin. The obtained data emphasize the emerging role of CatS in smoking-related lung diseases and strengthen the relevance of targeting CatS in the treatment of emphysema and COPD.

Effective-component compatibility of Bufei Yishen formula III ameliorated COPD by improving airway epithelial cell senescence by promoting mitophagy via the NRF2/PINK1 pathway

Background

Effective-component compatibility of Bufei Yishen formula III (ECC-BYF III) demonstrates positive effects on stable chronic obstructive pulmonary disease (COPD).

Purpose

To investigate the mechanisms of ECC-BYF III on COPD rats from the aspect of airway epithelial cell senescence.

Methods

COPD model rats (Sprague-Dawley rat) were treated with ECC-BYF III for 8 weeks, and the efficacy was evaluated. Cigarette smoke extract (CSE)-induced senescence model of airway epithelial cells was treated with ECC-BYF III, and related enzymes and proteins involved in oxidative stress and mitophagy were detected.

Results

ECC-BYF III markedly rescued pulmonary function and histopathological changes, which might be associated with the amelioration of lung senescence, including the reduction of malondialdehyde (MDA) and tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and matrix metalloproteinase (MMP)-9 levels, increase of the level in total superoxide dismutase (T-SOD), and decease in the p21 level in the airways. Furthermore, ECC-BYF III suppressed p16 and p21 expressions and senescence-associated β-galactosidase (SA-β-Gal) in CSE-induced airway epithelial cells. Moreover, ECC-BYF III upregulated mitophagy-related proteins, including the co-localizations of TOM20 and LC3B, PINK1 and PARK2, and improved mitochondrial function by upregulating mitochondrial mitofusin (MFN)2 and reducing dynamin-related protein 1 (DRP1) expression. ECC-BYF III enhanced the activities of T-SOD and GSH-PX by up-regulating NRF2, thus inhibiting oxidative stress. After intervention with NRF2 inhibitor, the regulation effects of ECC-BYF III on oxidative stress, mitophagy and senescence in airway epithelial cells were significantly suppressed.

Conclusions

ECC-BYF III exerts beneficial effects on COPD rats by ameliorating airway epithelial cell senescence, which is mediated by inhibiting oxidative stress and subsequently enhancing mitophagy through the activation of NRF2 signaling.

K63 Ubiquitination of P21 Can Facilitate Pellino-1 in the Context of Chronic Obstructive Pulmonary Disease and Lung Cellular Senescence

Chronic obstructive pulmonary diseases (COPD) is a kind of age-related, airflow-obstruction disease mostly caused by cigarette smoke. However, the relationship between COPD and lung cellular senescence is still not fully understood. Here, we found silencing Pellino-1 could inhibit the protein level of P21. Then, through constructing cell lines expressed ubiquitin-HA, we found that the E3 ubiquitin ligase Pellino-1 could bind to senescence marker p21 and modify p21 by K63-site ubiquitination by co-IP assays. Furthermore, we found that p21-mediated lung cellular senescence could be inhibited by silencing Pellino-1 in a D-galactose senescence mice model. Moreover, by constructing a COPD mouse model with shPellino-1 adenovirus, we found that silencing Pellino-1 could inhibit COPD and inflammation via reduction of SASPs regulated by p21. Taken together, our study findings elucidated that silencing E3 ligase Pellino-1 exhibits therapeutic potential for treatment to attenuate the progression of lung cellular senescence and COPD.

Nanocarrier-based approaches to combat chronic obstructive pulmonary disease

Abnormalities in airway mucus lead to chronic disorders in the pulmonary system such as asthma, fibrosis and chronic obstructive pulmonary disease (COPD). Among these, COPD is more prominent worldwide. Various conventional approaches are available in the market for the treatment of COPD, but the delivery of drugs to the target site remains a challenge with conventional approaches. Nanocarrier-based approaches are considered the best due to their sustained release properties to the target site, smaller size, high surface-to-volume ratio, patient compliance, overcoming airway defenses and improved pharmacotherapy. This article provides updated information about the treatment of COPD along with nanocarrier-based approaches as well as the potential of gene therapy and stem cell therapy to combat the COPD.

Association of SRXN1 Receptor Gene Polymorphism with Susceptibility to Periodontitis

Background

Emerging evidence suggests that oxidative stress forms a key component in the etiopathogenesis of periodontitis. Literature evidence have shown potential antioxidants responsible for combating the pro-oxidants which stress the periodontium, but the peroxiredoxin-sulfiredoxin system is explored very minimally in periodontal disease. Thus, the present study was aimed to evaluate the genetic association of SRXN1 receptor gene polymorphism (rs6053666).

Materials and Methods

A total of 100 subjects were recruited for this study, which included 50 Periodontitis patients (Stage II and above based on the criteria of American Association of Periodontology-2018) and 50 periodontally healthy or mild gingivitis. Genomic DNA was extracted from the whole blood collected from the subjects. DNA was amplified using specific primers flanking the BtgI region of the SRXN1 receptor gene. The amplicon was further subjected to genotyping using restriction fragment length using BtgI enzyme. The genotype obtained based on the restriction fragment length polymorphism pattern was recorded and used for statistical analysis. The distribution of genotypes and allele frequencies in the periodontitis and control groups were compared using the Chi-square test. The risk associated with individual alleles or genotypes was calculated as the odds ratio with 95% confidence intervals. Statistical significance in all tests was determined at P < 0.05.

Results

The genotype frequency and distributions of SRXN1 receptor BtgI polymorphism did not differ significantly at ꭕ2df (P = 0.557). Our study results showed that homozygous and heterozygous mutant genotypes had no significant difference (CC vs. CT + TT) between the periodontitis patients and control group with a P = 0.4266. The detected frequency of CT (38% vs. 34%) and TT (42% vs. 52%) genotype showed no significant difference between control and test group. There was no significant difference in C allele (39% vs. 31%) and T allele (61% vs. 69%) between the test and control group.

Conclusion

The present study denotes that SRXN1 receptor gene polymorphism is not associated with periodontitis in the study group analyzed.

Green Tea Polyphenol (-)-Epigallocatechin-3-Gallate (EGCG): A Time for a New Player in the Treatment of Respiratory Diseases?

(-)-Epigallocatechin-3-gallate (EGCG) is a major polyphenol of green tea that possesses a wide variety of actions. EGCG acts as a strong antioxidant which effectively scavenges reactive oxygen species (ROS), inhibits pro-oxidant enzymes including NADPH oxidase, activates antioxidant systems including superoxide dismutase, catalase, or glutathione, and reduces abundant production of nitric oxide metabolites by inducible nitric oxide synthase. ECGC also exerts potent anti-inflammatory, anti-fibrotic, pro-apoptotic, anti-tumorous, and metabolic effects via modulation of a variety of intracellular signaling cascades. Based on this knowledge, the use of EGCG could be of benefit in respiratory diseases with acute or chronic inflammatory, oxidative, and fibrotizing processes in their pathogenesis. This article reviews current information on the biological effects of EGCG in those respiratory diseases or animal models in which EGCG has been administered, i.e., acute respiratory distress syndrome, respiratory infections, COVID-19, bronchial asthma, chronic obstructive pulmonary disease, lung fibrosis, silicosis, lung cancer, pulmonary hypertension, and lung embolism, and critically discusses effectiveness of EGCG administration in these respiratory disorders. For this review, articles in English language from the PubMed database were used.

Oxidative stress links the tumour suppressor p53 with cell apoptosis induced by cigarette smoke

This study was to investigate the effects of oxidative stress in cigarette smoke (CS)-induced cell apoptosis in mice with emphysema. Thirty-two mice were divided into four groups: the control group, the CS group, the CS + Pifithrin-α group, and the CS + NAC group. Pathological changes and apoptosis in lung tissue of mice were detected. The activity of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (T-AOC) were measured using spectrophotometer. The proteins expression of p53, Bcl-2, Bax, and caspase-3 were determined by western blot. The results showed that cell apoptosis, lung structural damage, and the activity of MDA, as well as the expression of apoptosis-related proteins Bax, total caspase-3, and cleaved caspase-3 were increased in CS-treated mice. The activity of SOD, CAT, and T-AOC, as well as the expression of anti-apoptosis protein Bcl-2 were decreased in CS-treated mice when compared with the control group. However, Pifithrin-α (p53 inhibitor) and N-Acetylcysteine (NAC) could reduce cell apoptosis, lung structural damage and oxidative stress, accelerate the expression of Bcl-2, while suppressing the expression of Bax, total caspase-3 and cleaved caspase-3. More importantly, the treatment with NAC even inhibited the expression of p53. In conclusions, oxidative stress linking the p53 is involved in cell apoptosis in CS-treated emphysema mice.

Serum Derivatives of Reactive Oxygen Metabolites are Associated with Severity of Chronic Obstructive Pulmonary Disease and Affected by a p53 Gene Polymorphism

Purpose

Oxidative stress is known to activate tumor suppressor p53, which inhibits cell cycle progression and induces apoptosis. Levels of p53 in lung tissues from patients with chronic obstructive pulmonary disease (COPD) are increased compared with levels in nonsmokers or smokers without emphysema. A polymorphism in p53 codon 72 (rs1042522) is associated with emphysematous changes in patients with COPD. However, whether oxidative stress in the serum is associated with the p53 polymorphism and disease severity in COPD patients is unclear.

Patients and Methods

A total of 251 patients with a history of smoking more than 10 pack-years were enrolled in this study, and serum levels of derivatives of reactive oxygen metabolites (d-ROMs), biological antioxidant potential (BAP), and d-ROMs/BAP ratio (oxidative stress index; OSI) were measured. The percent low-attenuation area (LAA%) and cross-sectional area of the erector spinae muscles (ESM_CSA) at the Th₁₂ level were calculated from chest high-resolution computed tomography images. p53 codon 72 C/G genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism analysis.

Results

In patients carrying the p53 GG genotype, LAA% was significantly higher than in those carrying the CC genotype. d-ROM levels and OSI were associated with COPD severity and correlated with airflow limitation and markers of muscle atrophy (ESM_CSA and creatinine/cystatin C ratio). Associations between markers of oxidative stress and COPD severity were observed primarily in patients carrying the p53 codon 72 GG genotype.

Conclusion

Susceptibility to pulmonary emphysema and responses to oxidative stress may be affected by the p53 gene polymorphism.

Effects of the intranasal application of gold nanoparticles on the pulmonary tissue after acute exposure to industrial cigarette smoke

Inhalation of harmful particles appears as a primary factor for the onset and establishment of chronic obstructive pulmonary disease (COPD). Cigarette smoke acutely promotes an exacerbated inflammatory response with oxidative stress induction with DNA damage. Administration of Gold Nanoparticles (GNPs) with 20 nm in different concentrations can revert damages caused by external aggravations. The effects of GNPs in a COPD process have not been observed until now. The objective of this work was to evaluate the therapeutic effects of intranasal administration of different doses of GNPs after acute exposure to industrial cigarette smoke. Thirty male Swiss mice were randomly divided into five groups: Sham; cigarette smoke (CS); CS + GNPs 2.5 mg/L; CS + GNPs 7.5 mg/L and CS + GNPs 22.5 mg/L. The animals were exposed to the commercial cigarette with filter in an acrylic inhalation chamber and treated with intranasal GNPs for five consecutive days. The results demonstrate that exposure to CS causes an increase in inflammatory cytokines, histological changes, oxidative and nitrosive damage in the lung, as well as increased damage to the DNA of liver cells, blood plasma and lung. Among the three doses of GNPs (2.5, 7.5, and 22.5 mg/L) used, the highest dose had better anti-inflammatory effects. However, GNPs at a dose of 7.5 mg/L showed better efficacies in reducing ROS formation, alveolar diameter, and the number of inflammatory cells in histology, in addition to significantly reduced rate of DNA damage in lung cells without additional systemic genotoxicity already caused by cigarette smoke.

Cigarette Smoke Exposure Induces Neurocognitive Impairments and Neuropathological Changes in the Hippocampus

Background and Objective

Neurocognitive dysfunction is present in up to ∼61% of people with chronic obstructive pulmonary disease (COPD), with symptoms including learning and memory deficiencies, negatively impacting the quality of life of these individuals. As the mechanisms responsible for neurocognitive deficits in COPD remain unknown, we explored whether chronic cigarette smoke (CS) exposure causes neurocognitive dysfunction in mice and whether this is associated with neuroinflammation and an altered neuropathology.

Methods

Male BALB/c mice were exposed to room air (sham) or CS (9 cigarettes/day, 5 days/week) for 24 weeks. After 23 weeks, mice underwent neurocognitive tests to assess working and spatial memory retention. At 24 weeks, mice were culled and lungs were collected and assessed for hallmark features of COPD. Serum was assessed for systemic inflammation and the hippocampus was collected for neuroinflammatory and structural analysis.

Results

Chronic CS exposure impaired lung function as well as driving pulmonary inflammation, emphysema, and systemic inflammation. CS exposure impaired working memory retention, which was associated with a suppression in hippocampal microglial number, however, these microglia displayed a more activated morphology. CS-exposed mice showed changes in astrocyte density as well as a reduction in synaptophysin and dendritic spines in the hippocampus.

Conclusion

We have developed an experimental model of COPD in mice that recapitulates the hallmark features of the human disease. The altered microglial/astrocytic profiles and alterations in the neuropathology within the hippocampus may explain the neurocognitive dysfunction observed during COPD.

Natural products in the treatment of pulmonary emphysema: Therapeutic effects and mechanisms of action

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a class of lung diseases including chronic bronchitis, asthma, and emphysema. Long-time smoking is considered the main reason for developing emphysema. Emphysema can be defined as damage to the walls of the air sacs (alveoli) of the lung. It has been demonstrated that natural compounds with antioxidant and anti-inflammatory effects can effectively improve or protect the lung against this disease. This paper is dedicated to systematically review the effective natural compounds in the treatment of pulmonary emphysema.

PURPOSE

This is the first systematic and comprehensive review on the role of plant-derived secondary metabolites in managing and/or treating pulmonary emphysema STUDY DESIGN AND METHODS: A systematic and comprehensive review was done based on Scopus, PubMed, and Cochrane Library databases were searched using the "emphysema", "plant", "herb", and "phytochemical" keywords. Non-English, review, and repetitive articles were excluded from the study. Search results were included in the Prisma diagram.

RESULTS

From a total of 1285 results, finally, 22 articles were included in the present study. The results show that some herbs such as Scutellaria baicalensis Georgi and Monascus adlay and some phytochemicals such as gallic acid and quercetin and blackboard tree indole alkaloids affect more factors in improving the lung emphysema. Also, some natural compounds such as marijuana smoke and humic acid also play an aggravating role in this disease. It also seems that some of the medicinal plants such as PM014 herbal formula, pomegranate juice and açaí berry sometimes have side effects that are inconsistent with their therapeutic effects.

CONCLUSION

We concluded that natural compounds can effectively improve pulmonary emphysema due to their antioxidant, anti-inflammatory, and anti-apoptotic properties. However, additional studies are suggested to prove efficacy and side effects.

Machine-Learning Algorithm-Based Prediction of Diagnostic Gene Biomarkers Related to Immune Infiltration in Patients With Chronic Obstructive Pulmonary Disease

Objective

This study aims to identify clinically relevant diagnostic biomarkers in chronic obstructive pulmonary disease (COPD) while exploring how immune cell infiltration contributes towards COPD pathogenesis.

Methods

The GEO database provided two human COPD gene expression datasets (GSE38974 and GSE76925; n=134) along with the relevant controls (n=49) for differentially expressed gene (DEG) analyses. Candidate biomarkers were identified using the support vector machine recursive feature elimination (SVM-RFE) analysis and the LASSO regression model. The discriminatory ability was determined using the area under the receiver operating characteristic curve (AUC) values. These candidate biomarkers were characterized in the GSE106986 dataset (14 COPD patients and 5 controls) in terms of their respective diagnostic values and expression levels. The CIBERSORT program was used to estimate patterns of tissue infiltration of 22 types of immune cells. Furthermore, the in vivo and in vitro model of COPD was established using cigarette smoke extract (CSE) to validated the bioinformatics results.

Results

80 genes were identified via DEG analysis that were primarily involved in cellular amino acid and metabolic processes, regulation of telomerase activity and phagocytosis, antigen processing and MHC class I-mediated peptide antigen presentation, and other biological processes. LASSO and SVM-RFE were used to further characterize the candidate diagnostic markers for COPD, SLC27A3, and STAU1. SLC27A3 and STAU1 were found to be diagnostic markers of COPD in the metadata cohort (AUC=0.734, AUC=0.745). Their relevance in COPD were validated in the GSE106986 dataset (AUC=0.900 AUC=0.971). Subsequent analysis of immune cell infiltration discovered an association between SLC27A3 and STAU1 with resting NK cells, plasma cells, eosinophils, activated mast cells, memory B cells, CD8+, CD4+, and helper follicular T-cells. The expressions of SLC27A3 and STAU1 were upregulated in COPD models both in vivo and in vitro. Immune infiltration activation was observed in COPD models, accompanied by the enhanced expression of SLC27A3 and STAU1. Whereas, the knockdown of SLC27A3 or STAU1 attenuated the effect of CSE on BEAS-2B cells.

Conclusion

STUA1 and SLC27A3 are valuable diagnostic biomarkers of COPD. COPD pathogenesis is heavily influenced by patterns of immune cell infiltration. This study provides a molecular biology insight into COPD occurrence and in exploring new therapeutic means useful in COPD.

Medicinal Foods, YT and RH Combination, Suppress Cigarette Smoke-Induced Inflammation and Oxidative Stress by Inhibiting NF-κB/ERK Signaling Pathways

Background

Cigarette smoke is a risk factor for Chronic Obstructive Pulmonary Disease (COPD). Given the lack of COPD curative treatment, dietary management for COPD patients has become important. This study investigated whether the medicinal foods (YT and RH) could suppress cigarette smoke exposure-induced inflammation and oxidative stress.

Methods

Chronic pulmonary inflammation in male C57 mice was induced by a 4-week exposure to cigarette smoke (CS). The medicinal foods YT and RH were orally administered 1 week prior to CS exposure. The protective effects were assessed by measuring the pulmonary function and histopathological evaluations. Inflammatory cell numbers and cytokines levels in BALF and blood serum were analyzed by enzyme-linked immunosorbent assay (ELISA). Malondialdehyde (MDA) and superoxide dismutase (SOD) levels of the lung were analyzed. Furthermore, the levels of phosphorylated ERK and NF-κB in both the mice lungs and RAW264.7 cells were also detected.

Results

YT and RH combination (YT + RH) significantly improved pulmonary function and suppressed the inflammation, including cell number and cytokines in BALF relative to the CS group; histological examination revealed protective effects of YT + RH in the lungs of mice exposed to CS. Moreover, the MDA level in the lung of the YT + RH group of mice was lower, the SOD activity was higher, and in vitro treatment of YT and RH combination attenuated reactive oxygen species (ROS) expression in mouse macrophage RAW264.7 cells stimulated with cigarette smoke (CSE). YT + RH combination significantly reduced the expression of pNF-κB and pERK in the lung tissues and macrophage stimulated with CSE.

Conclusions

YT and RH combination attenuates cigarette smoke-induced inflammation and oxidative stress through inhibition of the NF-κB/ERK signaling pathway.

Prohibitin Protects Pulmonary Microvascular Endothelial Cells Against Cigarette Smoke Extract-Induced Cell Apoptosis and Inflammation

Background

Prohibitin has been identified to play roles in cell survival and apoptosis. Here, this study aimed to clarify the role of prohibitin in cigarette smoke extract (CSE)-induced endothelial cell apoptosis.

Methods

The protein level of prohibitin was assessed by Western blot in lung tissues from emphysema and control mice. CSE-induced human pulmonary microvascular endothelial cells (hPMECs) were applied to mimic smoke-related cell apoptosis in vitro. Prohibitin was overexpressed in hPMECs with or without CSE. Mitochondrial function was analyzed by JC-1 staining and ATP assay kits. Oxidative stress was assessed by flow cytometry, fluorescence staining and immunocytochemistry. Apoptosis was analyzed by flow cytometry, Western blot and caspase-3 activity assays. In addition, the expression of inflammatory markers was assessed by Western blot and real-time polymerase chain reaction (PCR). The secretion of inflammatory cytokines was measured by ELISA.

Results

Prohibitin was downregulated in emphysema mouse tissues compared with control experiments. Consistently, CSE inhibited both the protein and RNA levels of prohibitin in hPMECs in a dose-dependent manner. Gain-of-function experiments indicated that CSE induced collapse of mitochondrial membrane potential (MMP) and loss of ATP, while prohibitin improved mitochondrial function. CSE induced robust ROS production and oxidative DNA damage, while prohibitin decreased this damage. Upregulation of prohibitin protected the apoptosis of hPMECs from CSE. Overexpression of prohibitin significantly reduced the levels of the main proinflammatory cytokines. Finally, prohibitin inhibited nuclear factor-kappa B (NF-κB) p65 accumulation and IκBα degradation induced by CSE.

Conclusion

The current findings suggest that CSE-mediated mitochondrial dysfunction, oxidative stress, cell apoptosis and inflammation in hPMECs were reduced by overexpression of prohibitin. We identified prohibitin as a novel regulator of endothelial cell apoptosis and survival in the context of CSE exposure.

Intermittent administration of peracetic acid is a mild environmental stressor that elicits mucosal and systemic adaptive responses from Atlantic salmon post-smolts

Background

Fish encounter oxidative stress several times during their lifetime, and it has a pervasive influence on their health and welfare. One of the triggers of oxidative stress in fish farming is the use of oxidative disinfectants to improve rearing conditions, especially in production systems employing recirculation technology. Here we report the physiological and morphological adaptive responses of Atlantic salmon (Salmo salar L.) post-smolts to intermittent exposure to a potent oxidative agent peracetic acid (PAA). Fish reared in semi-commercial scale brackish water recirculating aquaculture system (RAS) were exposed to 1 ppm PAA every 3 days over 6 weeks. Mucosal and systemic responses were profiled before exposure, 22 and 45 days during the intermittent PAA administration.

Results

Oxidative stress was likely triggered as plasma antioxidant capacity increased significantly during the exposure period. Adaptive stress response to the periodic oxidant challenge was likewise demonstrated in the changes in plasma glucose and lactate levels. PAA-induced alterations in the transcription of antioxidants, cytokines, heat shock proteins and mucin genes showed a tissue-specific pattern: downregulation was observed in the gills and olfactory rosette, upregulation occurred in the skin, and no substantial changes in the liver. Further, PAA exposure resulted in histological changes in key mucosal organs (i.e. olfactory rosette, skin and gills); pathological alterations were predominant in the gills where cases of epithelial lifting, hypertrophy and clubbing were prevalent. In addition, intermittent PAA administration resulted in an apparent overproduction of mucus in the nasal mucosa. Lastly, PAA did not dramatically alter the ability of salmon to mount a physiological stress response in the presence of a secondary stressor, though some subtle interference was documented in the kinetics and magnitude of plasma cortisol and glucose response post-stress.

Conclusions

The present study collectively demonstrated that intermittent oxidant exposure was a mild environmental stressor that salmon could mount strong adaptive responses at systemic and mucosal levels. The results will be valuable in optimising the rearing conditions of post-smolts in RAS, especially in adopting water treatment strategies that do not considerably interfere with fish health and welfare.

Serum 8-Hydroxy-2'-deoxyguanosine Predicts Severity and Prognosis of Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

BACKGROUND

Oxidative stress is involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). 8-Hydroxy-2'-deoxyguanosine (8-OHdG) is recognized as a biomarker of oxidative stress and is implicated in several pulmonary diseases. Nonetheless, the role of 8-OHdG remains unclear in COPD patients. This research aimed to evaluate the correlations between serum 8-OHdG on admission and the severity and prognosis of hospitalized COPD patients with acute exacerbation.

METHODS

A total of 150 COPD hospitalized patients and 150 healthy individuals were recruited. Serum 8-OHdG was measured by ELISA and the length of hospital stay was calculated. The number of acute exacerbations of COPD was tracked within 1 year after this hospitalization.

RESULTS

The levels of serum 8-OHdG were elevated in COPD patients compared with the control group. Serum 8-OHdG was gradually elevated with decreased pulmonary function in COPD patients. Furthermore, Pearson linear association found that the levels of serum 8-OHdG were inversely correlated with pulmonary function and positively correlated with inflammatory cytokines in COPD patients. In addition, logistic regression analysis revealed that serum 8-OHdG elevation was a risk factor for pulmonary function decline in COPD patients. The length of hospital stay was tracked at this time. Higher serum 8-OHdG on admission increased the length of hospital stay among COPD patients.

CONCLUSION

Serum 8-OHdG on admission is positively correlated with the severity and adverse prognosis among COPD patients, suggesting that 8-OHdG may be involved in the pathogenesis of COPD. Serum 8-OHdG may be a biomarker to predict the progression of COPD.

The role of FUNDC1 in mitophagy, mitochondrial dynamics and human diseases

Mitochondria are the principal sites of energy metabolism and provide most of the energy needed for normal cellular function. They are dynamic organelles that constantly undergo fission, fusion and mitophagy to maintain their homeostasis and function. However, dysregulated mitochondrial dynamics and mitophagy leads to reduced ATP generation and mutation of their DNA, which ultimately leads to cell death. Increasing evidence has shown that the FUN14 domain-containing protein 1 (FUNDC1), a novel mitophagy receptor, participates in the process of mitochondrial dynamics and mitophagy and plays a critical role in various human diseases. Herein, we review the role of FUNDC1 in mitophagy and mitochondrial dynamics, thus providing a better understanding of the relationship between the two processes. Moreover, we summarize the treatments targeting FUNDC1, and suggest that FUNDC1 may represent a promising therapeutic target for the treatment of several human diseases such as cardiovascular diseases, metabolic syndrome, cancer and chronic obstructive pulmonary disease (COPD).

Efficacy of tiotropium bromide combined with different doses of fluticasone plus salmeterol DPI in the treatment of stable COPD

OBJECTIVE

To explore the efficacy of tiotropium bromide combined with different doses of fluticasone plus salmeterol DPI (dry powder for inhalation) in treating stable moderate to severe chronic obstructive pulmonary disease (COPD) and its influence on pulmonary function.

METHODS

From August 2017 to November 2019, 105 patients with stable moderate to severe COPD in our hospital were enrolled and divided into three groups: group A (GA), group B (GB) and group C (GC). In GA, patients received tiotropium bromide combined with low dose of fluticasone plus salmeterol. In GB, patients received tiotropium bromide combined with medium dose of fluticasone plus salmeterol. In GC, patients received tiotropium bromide combined with high dose of fluticasone plus salmeterol. The baseline data and adverse reactions were observed in each group. After therapy, the improvement of clinical symptoms, quality of life, pulmonary function index and therapeutic effect were observed in each group.

RESULTS

There was no difference in the general data of patients among the groups (P>0.05). The improvement of clinical symptoms in GB was better than that in GA, and that in GC was better than that in GB (P<0.05). There was no difference in adverse reactions among the groups (P>0.05). After treatment, IL-8, MPO, LTB4 and the number of inflammatory cells in sputum in the three groups decreased; the four in GB group were dramatically lower than those in GA group, and those in GC group were dramatically lower than those in GB group. The lung function indexes of patients in GB were better than those in GA, and those in GC were better than those in GB (P<0.05). The efficacy in GB was better than that in GA, and that in GC was better than that in GB (P<0.05). The quality of life scores in GB were higher than those in GA, and those in GC were higher than those in GB (P<0.05).

CONCLUSION

Tiotropium bromide combined with high dose of salmeterol xinafoate (SX) and fluticasone propionate (FP) powder for inhalation can effectively improve the pulmonary function of patients with moderate to severe stable COPD.

Effect of Antioxidants in the Treatment of COPD Patients: Scoping Review

Chronic obstructive pulmonary disease (COPD) is a common, preventable, treatable lung disease characterized by persistent respiratory symptoms and airflow limitation and multiorgan impact. This affects the nutritional status of patients and requires multidimensional interventions including nutritional interventions according to individual metabolic needs. Our scoping review determined the effects of antioxidants in the treatment of COPD patients and their role in the decrease in the probability of exacerbations, hospital readmissions, and changes in lung function. The sources MEDLINE, LILACS, and Google Scholar were consulted and 19 studies were selected. The most indicated antioxidants are N-Acetylcysteine, vitamins E and D, and Zinc. Other antioxidants from plants or fruits extracts are also being investigated. The beneficial effect of antioxidants in stable or exacerbated patients is not clear, but theoretical and biological arguments of benefit justify lines of research that specify the impact on reducing oxidative stress and negative effects in COPD.

Screening and Identification of Hub Genes in the Corticosteroid Resistance Network in Human Airway Epithelial Cells via Microarray Analysis

Background and Objective: Corticosteroid resistance is a major barrier to chronic obstructive pulmonary disease (COPD), but the exact mechanism of corticosteroid resistance in COPD has been less well studied. Methods: The microarray dataset GSE11906, which includes genomic and clinical data on COPD, was downloaded from the Gene Expression Omnibus (GEO) database, and the differentially expressed genes (DEGs) were identified using R software. Gene set enrichment analysis (GSEA) and Kyoto Encyclopedia of Genes (KEGG) were utilized to enrich and analyze the gene cohort related to the response to steroid hormones, respectively. The Connectivity Map (CMap) database was used to screen corticosteroid resistance-related drugs that might exert a potential therapeutic effect. STRING was used to construct a protein-protein interaction (PPI) network of the gene cohort, and the CytoHubba plug-in of Cytoscape was used to screen the hub genes in the PPI network. The expression levels of hub genes in cigarette smoke extract (CSE)-stimulated bronchial epithelial cells were assayed by quantitative real-time PCR and western blotting. Results: Twenty-one genes were found to be correlated with the response to steroid hormones. In the CMap database, 32 small-molecule compounds that might exert a therapeutic effect on corticosteroid resistance in COPD were identified. Nine hub genes were extracted from the PPI network. The expression levels of the BMP4, FOS, FN1, EGFR, and SPP1 proteins were consistent with the microarray data obtained from molecular biology experiments. Scopoletin significantly restrained the increases in the levels of AKR1C3, ALDH3A1, FN1 and reversed the decreases of phosphorylated GR and HDAC2 caused by CSE exposure. Conclusion: The BMP4, FOS, FN1, EGFR, and SPP1 genes are closely correlated with CSE-induced glucocorticoid resistance in airway epithelial cells. Scopoletin may be a potential drug for the treatment of glucocorticoid resistance caused by CSE.

Cigarette Smoke Promotes Interleukin-8 Production in Alveolar Macrophages Through the Reactive Oxygen Species/Stromal Interaction Molecule 1/Ca2+ Axis

Chronic obstructive pulmonary disease (COPD), primarily attributed to cigarette smoke (CS), is characterized by multiple pathophysiological changes, including oxidative stress and inflammation. Stromal interaction molecule 1 (STIM1) is a Ca²⁺ sensor that regulates Ca²⁺ entry in different types of cells. The present study aimed to explore the relationship between CS-induced oxidative stress and inflammation, as well as the functional role of STIM1 thereinto. Our results showed that the reactive oxygen species (ROS)/STIM1/Ca²⁺ axis played a critical role in CS-induced secretion of interleukin (IL)-8 in human alveolar macrophages. Specifically, smokers with COPD (SC) showed higher levels of ROS in the lung tissues compared with healthy non-smokers (HN). STIM1 was upregulated in the lung tissues of COPD patients. The expression of STIM1 was positively associated with ROS levels and negatively correlated with pulmonary function. The expression of STIM1 was also increased in the bronchoalveolar lavage fluid (BALF) macrophages of COPD patients and PMA-differentiated THP-1 macrophages stimulated by cigarette smoke extract (CSE). Additionally, CSE-induced upregulation of STIM1 in PMA-differentiated THP-1 macrophages was inhibited by pretreatment with N-acetylcysteine (NAC), a ROS scavenger. Transfection with small interfering RNA (siRNA) targeting STIM1 and pretreatment with NAC alleviated CSE-induced increase in intracellular Ca²⁺ levels and IL-8 expression. Furthermore, pretreatment with SKF-96365 and 2-APB, the inhibitors of Ca²⁺ influx, suppressed CSE-induced secretion of IL-8. In conclusion, our study demonstrates that CSE-induced ROS production may increase the expression of STIM1 in macrophages, which further promotes the release of IL-8 by regulating Ca²⁺ entry. These data suggest that STIM1 may play a crucial role in CSE-induced ROS production and inflammation, and participate in the pathogenesis of COPD.

Accelerated immunosenescence, oxidation and inflammation lead to a higher biological age in COPD patients

Chronic obstructive pulmonary disease (COPD) is characterised by inflammatory and oxidative alterations in the lung and extrapulmonary compartments, through involvement of the immune system. Several leukocyte functions are health markers and good predictors of longevity, and high pro-inflammatory and oxidative states are related to more aged profiles. Here, we aimed to investigate the aging rate in terms of immunosenescence in COPD men with respect to healthy age-matched controls. Several neutrophil (adherence, chemotaxis, phagocytosis, superoxide anion stimulated production) and lymphocyte (adherence, chemotaxis, lymphoproliferation, natural killer activity) functions, cytokine concentrations released in response to lipopolysaccharide (tumor necrosis factor-alpha, interleukin (IL)-6, IL-8, IL-10) and redox parameters (intracellular glutathione content, basal superoxide anion level) were assessed in circulating leukocytes of men with moderate and severe stages of COPD, and compared to healthy age-matched volunteers. The biological age or aging rate in each participant was determined using the values of leukocyte functions. The results indicated impairment of immune functions in COPD patients, both in innate and adaptive immunity, and higher pro-inflammatory and oxidative states in peripheral leukocytes than controls. In general, these changes were more remarkable at the severe stage of airway obstruction. Importantly, COPD patients were found to be aging at a faster rate than age-matched healthy counterparts.

Novel pharmacological strategies to treat cognitive dysfunction in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a major incurable global health burden and currently the 3rd largest cause of death in the world, with approximately 3.23 million deaths per year. Globally, the financial burden of COPD is approximately €82 billion per year and causes substantial morbidity and mortality. Importantly, much of the disease burden and health care utilisation in COPD is associated with the management of its comorbidities and viral and bacterial-induced acute exacerbations (AECOPD). Recent clinical studies have shown that cognitive dysfunction is present in up to 60% of people with COPD, with impairments in executive function, memory, and attention, impacting on important outcomes such as quality of life, hospitalisation and survival. The high prevalence of cognitive dysfunction in COPD may also help explain the insufficient adherence to therapeutic plans and strategies, thus worsening disease progression in people with COPD. However, the mechanisms underlying the impaired neuropathology and cognition in COPD remain largely unknown. In this review, we propose that the observed pulmonary oxidative burden and inflammatory response of people with COPD 'spills over' into the systemic circulation, resulting in damage to the brain and leading to cognitive dysfunction. As such, drugs targeting the lungs and comorbidities concurrently represent an exciting and unique therapeutic opportunity to treat COPD and cognitive impairments, which may lead to the production of novel targets to prevent and reverse the debilitating and life-threatening effects of cognitive dysfunction in COPD.