Cellular and Structural Bases of Chronic Obstructive Pulmonary Disease

The impact of traditional mind-body exercises on pulmonary function, exercise capacity, and quality of life in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis of randomized controlled trials

Background

Chronic Obstructive Pulmonary Disease (COPD) is a chronic condition characterized primarily by airflow obstruction, significantly impacting patients' quality of life. Traditional mind-body exercises, as a non-pharmacological intervention for COPD, have become a new research focus.

Objective

To assess the impact of traditional mind-body exercises (Tai Chi, Qigong, Yoga) on pulmonary function, exercise capacity, and quality of life in COPD patients. Additionally, to identify the most suitable form of traditional mind-body exercise for different indicators.

Methods

Searches were conducted in databases such as Web of Science, PubMed, EBSCOhost, CNKI, etc., to collect randomized controlled trials (RCTs) evaluating the intervention of traditional mind-body exercises (Tai Chi, Yoga, Qigong) in COPD. The Cochrane evaluation tool was applied for methodological quality assessment of the included literature. Statistical analysis and sensitivity analysis were performed using Revman 5.4 software, while publication bias was assessed using R software.

Results

This study included 23 studies with a total of 1862 participants. Traditional mind-body exercises improved patients' FEV1% index (WMD = 4.61, 95%CI [2.99, 6.23]), 6-min walk distance (SMD = 0.83, 95%CI [0.55, 1.11]), and reduced patients' SGRQ score (SMD = -0.79, 95%CI [-1.20, -0.38]) and CAT score (SMD = -0.79, 95%CI [-1.20, -0.38]). Qigong showed the most significant improvement in FEV1% and 6MWT, while Tai Chi primarily improved 6MWT, and the effect of Yoga was not significant. Sensitivity analysis indicated stable and reliable research conclusions.

Conclusion

Traditional mind-body exercises are effective rehabilitation methods for COPD patients, significantly improving pulmonary function, exercise capacity, and quality of life. They are suitable as complementary interventions for standard COPD treatment.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display-record.php?ID=CRD42023495104], identifier [CRD42023495104].

Nanocurcumin modulates Th17 cell responses in moderate and severe COPD patients

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory process in the airways that results in airflow obstruction. It is mainly linked to cigarette smoke exposure. Th17 cells have a role in the pathogenesis of COPD by secreting pro-inflammatory cytokines, which cause hyperinflammation and progression of the disease. This study aimed to assess the potential therapeutic effects of nanocurcumin on the Th17 cell frequency and its responses in moderate and severe COPD patients. This study included 20 patients with severe COPD hospitalized in an intensive care unit (ICU) and 20 patients with moderate COPD. Th17 cell frequency, Th17-related factors gene expression (RAR-related orphan receptor t (RORγt), IL-17, IL-21, IL-23, and granulocyte-macrophage colony-stimulating factor), and serum levels of Th17-related cytokines were assessed before and after treatment in both placebo and nanocurcumin-treated groups using flow cytometry, real-time PCR, and ELISA, respectively. According to our findings, in moderate and severe nanocurcumin-treated COPD patients, there was a substantial reduction in the frequency of Th17 cells, mRNA expression, and cytokines secretion level of Th17-related factors compared to the placebo group. Furthermore, after treatment, the metrics mentioned above were considerably lower in the nanocurcumin-treated group compared to before treatment. Nanocurcumin has been shown to decrease the number of Th17 cells and their related inflammatory cytokines in moderate and severe COPD patients. As a result, it might be used as an immune-modulatory agent to alleviate the patient's inflammatory state.

N-acetyl cysteine augments adipose tissue-derived stem cell efficacy on inflammatory markers and regulatory T cell system balance in an allergic asthma model

BACKGROUND

Allergic asthma is a destructive inflammatory process in the respiratory system. The anti-inflammatory and antioxidant effects of N-acetylcysteine (NAC) have been reported in patients with obstructive pulmonary disease. On the other hand, several studies have shown the modulatory effects of mesenchymal stem cells on the immune system and inflammatory responses. Accordingly, the purpose of the current study was to evaluate the effect of administration of adipose tissue-derived stem cells (ADSCs) plus NAC on regulatory T cell system balance in an allergic asthma model.

METHODS

Eighty Sprague- Dawley rats were randomly divided into the following groups: Control, Plasmalite, Allergic asthma, Allergic asthma + ADSCs, NAC, Allergic asthma + NAC, Allergic asthma + ADSCs + NAC and Allergic asthma + Prednisolone. at the end of the experiment, arterial blood gas analysis, inflammatory cell counts in bronchoalveolar lavage fluid (BALF), inflammatory cytokine concentration, total IgE and specific OVA-IgE levels, gene expression levels of CD4+-T cell subsets, pulmonary indicators, edema, and lung histopathology were evaluated in all groups.

RESULTS

Administration of NAC plus ADSCs demonstrated a significant decrease in total WBC and eosinophil counts, which was in line with remarkable decrease in IL-17 and TNF-α concentrations and increases in IL-10 level compared with other treated groups. NAC plus ADSC treatment showed significant increases in Treg gene expression, although Th17 and Th2 expression significantly decreased compared with that in prednisolone- treated rats.

CONCLUSION

The results of the present study documented that the administration of ADSCs plus NAC has an inhibitory effect on the inflammation caused by allergic asthma in a rat model. The improvement of inflammatory indexes was significantly higher than that with prednisolone treatment.

A GMR enzymatic assay for quantifying nuclease and peptidase activity

Hydrolytic enzymes play crucial roles in cellular processes, and dysregulation of their activities is implicated in various physiological and pathological conditions. These enzymes cleave substrates such as peptide bonds, phosphodiester bonds, glycosidic bonds, and other esters. Detecting aberrant hydrolase activity is vital for understanding disease mechanisms and developing targeted therapeutic interventions. This study introduces a novel approach to measuring hydrolase activity using giant magnetoresistive (GMR) spin valve sensors. These sensors change resistance in response to magnetic fields, and here, they are functionalized with specific substrates for hydrolases conjugated to magnetic nanoparticles (MNPs). When a hydrolase cleaves its substrate, the tethered magnetic nanoparticle detaches, causing a measurable shift in the sensor's resistance. This design translates hydrolase activity into a real-time, activity-dependent signal. The assay is simple, rapid, and requires no washing steps, making it ideal for point-of-care settings. Unlike fluorescent methods, it avoids issues like autofluorescence and photobleaching, broadening its applicability to diverse biofluids. Furthermore, the sensor array contains 80 individually addressable sensors, allowing for the simultaneous measurement of multiple hydrolases in a single reaction. The versatility of this method is demonstrated with substrates for nucleases, Bcu I and DNase I, and the peptidase, human neutrophil elastase. To demonstrate a clinical application, we show that neutrophil elastase in sputum from cystic fibrosis patients hydrolyze the peptide-GMR substrate, and the cleavage rate strongly correlates with a traditional fluorogenic substrate. This innovative assay addresses challenges associated with traditional enzyme measurement techniques, providing a promising tool for real-time quantification of hydrolase activities in diverse biological contexts.

Machine learning-based prediction of in-hospital mortality in patients with pneumonic chronic obstructive pulmonary disease exacerbations

OBJECTIVE

While linear regression and LASSO models have been established for predicting in-hospital mortality, there is currently no validated clinical prediction algorithm to predict in-hospital mortality for patients with chronic obstructive pulmonary disease (COPD) exacerbations using machine learning. Thus, we will evaluate the BAP-65 and CURB-65, and construct a novel prediction model using the random forest (RF) technique.

METHODS

A dataset of 1,418 patients with COPD exacerbations was collected. Age, gender, mental status, vital signs, and laboratory results were all taken into account for predictors. The categorical outcome variable was hospital-based mortality of people over 65 years. The dataset was divided randomly into a training dataset (70%) and a testing dataset (30%). We trained three prediction models, BAP-65, CURB-65, and the RF model, estimated the area under the receiver operating characteristic curve (AUROC) for the entire dataset. We also conducted a comparison of the AUROC values using the Delong test.

RESULTS

A total of 658 individuals with COPD acute exacerbations were enrolled. Our analysis using the receiver operating characteristic curve demonstrated that the RF model exhibited excellent performance, with an AUROC of 0.80 (95% confidence interval: 0.75-0.84). In comparison, the BAP-65 prediction model yielded an AUROC of 0.72 (0.68-0.75), while the CURB-65 prediction model achieved an AUROC of 0.69 (0.67-0.73).

CONCLUSIONS

The RF model demonstrated superior predictive capabilities than the BAP-65 and CURB-65 models in predicting in-hospital mortality. The results further highlighted significant factors for predicting in-hospital mortality, including blood eosinophil count, systolic blood pressure, and prior history of asthma.

COX-2/sEH-Mediated Macrophage Activation Is a Target for Pulmonary Protection in Mouse Models of Chronic Obstructive Pulmonary Disease

Effective inhibition of macrophage activation is critical for resolving inflammation and restoring pulmonary function in patients with chronic obstructive pulmonary disease (COPD). In this study, we identified the dual-enhanced cyclooxygenase-2 (COX-2)/soluble epoxide hydrolase (sEH) as a novel regulator of macrophage activation in COPD. Both COX-2 and sEH were found to be increased in patients and mice with COPD and in macrophages exposed to cigarette smoke extract. Pharmacological reduction of the COX-2 and sEH by 4-(5-phenyl-3-{3-[3-(4-trifluoromethylphenyl)-ureido]-propyl}-pyrazol-1-yl)-benzenesulfonamide (PTUPB) effectively prevented macrophage activation, downregulated inflammation-related genes, and reduced lung injury, thereby improving respiratory function in a mouse model of COPD induced by cigarette smoke and lipopolysaccharide. Mechanistically, enhanced COX-2/sEH triggered the activation of the NACHT, LRR, and PYD domains-containing protein 3 inflammasome, leading to the cleavage of pro-IL-1β into its active form in macrophages and amplifying inflammatory responses. These findings demonstrate that targeting COX-2/sEH-mediated macrophage activation may be a promising therapeutic strategy for COPD. Importantly, our data support the potential use of the dual COX-2 and sEH inhibitor PTUPB as a therapeutic drug for the treatment of COPD.

A Comparative Inflammation-on-a-Chip with a Complete 3D Interface: Pharmacological Applications in COPD-Induced Neutrophil Migration

Chronic obstructive pulmonary disease (COPD) is a slow-progressing inflammatory lung disease that is associated with high mortality and disability. There is a lack of appropriate preclinical models of COPD, which hampers drug discovery efforts. Herein, a comparative inflammation-on-a-chip (IoC) is developed with a complete 3D interface without the formation of any micropillar and phaseguide structures that replicated chemoattractant-induced neutrophil transendothelial migration (NTEM), a key feature of COPD. The IoC model is used to evaluate the pharmacological effects of CXCR2 inhibitors (MK-7123, AZD5069, and SB225002) on the migration of neutrophil-like cells in the presence of plasma samples from patients with COPD. This is the first study to evaluate inhibitors of CXCR2-dependent NTEM in a comparative IoC model that mimics the physiological 3D microenvironment, consisting of an endothelial barrier, extracellular compartment, and inflammatory conditions. This IoC model will be useful to investigate COPD severity using patient samples, and will aid basic and translational research involving NTEM.

Implications of xenobiotic-response element(s) and aryl hydrocarbon receptor in health and diseases

The effect of air pollution on public health is severely detrimental. In humans; the physiological response against pollutants is mainly elicited via the activation of aryl hydrocarbon receptor (AhR). It acts as a prime sensor of xenobiotic chemicals, also functioning as a transcription factor regulating a variety of gene expressions. Along with AhR, another pivotal element of the pollution stress pathway is Xenobiotic Response Elements (XREs). XRE, as studied are some conserved sequences in the DNA, responsible for the physiological response against pollutants. XRE is present at the upstream of the inducible target genes of AhR and it regulates the function of the AhR. XRE(s) are highly conserved in species as it has only eight specific sequences found so far in humans, mice, and rats. Inhalation of toxicants like dioxins, gaseous industrial effluents, and smoke from burning fuel and tobacco leads to predominant damage to the lungs. However, scientists are exploring the involvement of AhR in chronic diseases for example chronic obstructive pulmonary disease (COPD) and also other lethal diseases like lung cancer. In this review, we summarise what is known at this time about the roles played by the XRE and AhR in our molecular systems that have a defined control in the normal maintenance of homeostasis as well as dysfunctions.

The role of Sirtuin 1 and its activators in age-related lung disease

Aging is a major driving factor in lung diseases. Age-related lung disease is associated with downregulated expression of SIRT1, an NAD⁺-dependent deacetylase that regulates inflammation and stress resistance. SIRT1 acts by inducing the deacetylation of various substrates and regulates several mechanisms that relate to lung aging, such as genomic instability, lung stem cell exhaustion, mitochondrial dysfunction, telomere shortening, and immune senescence. Chinese herbal medicines have many biological activities, exerting anti-inflammatory, anti-oxidation, anti-tumor, and immune regulatory effects. Recent studies have confirmed that many Chinese herbs have the effect of activating SIRT1. Therefore, we reviewed the mechanism of SIRT1 in age-related lung disease and explored the potential roles of Chinese herbs as SIRT1 activators in the treatment of age-related lung disease.

Uncovering the cytotoxic effects of air pollution with multi-modal imaging of in vitro respiratory models

Annually, an estimated seven million deaths are linked to exposure to airborne pollutants. Despite extensive epidemiological evidence supporting clear associations between poor air quality and a range of short- and long-term health effects, there are considerable gaps in our understanding of the specific mechanisms by which pollutant exposure induces adverse biological responses at the cellular and tissue levels. The development of more complex, predictive, in vitro respiratory models, including two- and three-dimensional cell cultures, spheroids, organoids and tissue cultures, along with more realistic aerosol exposure systems, offers new opportunities to investigate the cytotoxic effects of airborne particulates under controlled laboratory conditions. Parallel advances in high-resolution microscopy have resulted in a range of in vitro imaging tools capable of visualizing and analysing biological systems across unprecedented scales of length, time and complexity. This article considers state-of-the-art in vitro respiratory models and aerosol exposure systems and how they can be interrogated using high-resolution microscopy techniques to investigate cell-pollutant interactions, from the uptake and trafficking of particles to structural and functional modification of subcellular organelles and cells. These data can provide a mechanistic basis from which to advance our understanding of the health effects of airborne particulate pollution and develop improved mitigation measures.

cAMP-PDE signaling in COPD: Review of cellular, molecular and clinical features

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death among non-contagious diseases in the world. PDE inhibitors are among current medicines prescribed for COPD treatment of which, PDE-4 family is the predominant PDE isoform involved in hydrolyzing cyclic adenosine monophosphate (cAMP) that regulates the inflammatory responses in neutrophils, lymphocytes, macrophages and epithelial cells The aim of this study is to investigate the cellular and molecular mechanisms of cAMP-PDE signaling, as an important pathway in the treatment management of patients with COPD. In this review, a comprehensive literature review was performed about the effect of PDEs in COPD. Generally, PDEs are overexpressed in COPD patients, resulting in cAMP inactivation and decreased cAMP hydrolysis from AMP. At normal amounts, cAMP is one of the essential agents in regulating metabolism and suppressing inflammatory responses. Low amount of cAMP lead to activation of downstream inflammatory signaling pathways. PDE4 and PDE7 mRNA transcript levels were not altered in polymorphonuclear leukocytes and CD8 lymphocytes originating from the peripheral venous blood of stable COPD subjects compared to healthy controls. Therefore, cAMP-PDE signaling pathway is one of the most important signaling pathways involved in COPD. By examining the effects of different drugs in this signaling pathway critical steps can be taken in the treatment of this disease.

Airway microbiome-immune crosstalk in chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary Disease (COPD) has significantly contributed to global mortality, with three million deaths reported annually. This impact is expected to increase over the next 40 years, with approximately 5 million people predicted to succumb to COPD-related deaths annually. Immune mechanisms driving disease progression have not been fully elucidated. Airway microbiota have been implicated. However, it is still unclear how changes in the airway microbiome drive persistent immune activation and consequent lung damage. Mechanisms mediating microbiome-immune crosstalk in the airways remain unclear. In this review, we examine how dysbiosis mediates airway inflammation in COPD. We give a detailed account of how airway commensal bacteria interact with the mucosal innate and adaptive immune system to regulate immune responses in healthy or diseased airways. Immune-phenotyping airway microbiota could advance COPD immunotherapeutics and identify key open questions that future research must address to further such translation.

Increased airway resistance among exclusive waterpipe smokers detected using impulse oscillometry

INTRODUCTION

Waterpipe smoking is increasing in popularity, yet the evidence implicating waterpipe smoking in lung disease is limited. We hypothesized that impulse oscillometry (IOS) would detect airway abnormalities in waterpipe smokers (WPS).

METHODS

We studied 210 participants, 40 years or older, from the community, of whom 92 were exclusive WPS and 118 were never-smokers. Waterpipe smoking history was assessed using a validated questionnaire. All participants underwent spirometry, and IOS and absolute and percentage predicted results (for age, sex, height, and weight) were compared between WPS and nonsmokers. The association of IOS parameters with waterpipe smoking duration and extent (waterpipe smoked/day * smoking duration) was evaluated using linear regression.

RESULTS

WPS smoked on average 1.8 ± 1.2 waterpipes/day, over an average duration of 23.3 ± 39.8 years. WPS and nonsmokers were largely asymptomatic and had similar age, body mass index, sex distribution, and spirometric values. Nevertheless, WPS had higher IOS measured resistance at 5Hz compared to nonsmokers, (0.53 ± 0.2 vs. 0.48 ± 0.2 kPa/L/s, P = 0.03) and higher percentage-predicted resistance (124.5 ± 36.3 vs. 115.7% ± 35.6%, P = 0.04). Waterpipe smoking duration was also associated with resistance (β = 0.04 kPa/L/s/year, P = 0.01) and with percentage-predicted resistance (β = 0.05/year, P = 0.02). Waterpipe smoking extent was associated with resistance (β = 0.009 kPa/L/s/waterpipe-year, P = 0.04), while the association with percentage-predicted resistance was near significance (β = 0.009/waterpipe-year, P = 0.07).

CONCLUSIONS

Waterpipe smoking is associated with increased airway resistance assessed by IOS but not by spirometry in largely asymptomatic individuals from the community.

Analysis of the Clinical Efficacy and Molecular Mechanism of Xuefu Zhuyu Decoction in the Treatment of COPD Based on Meta-Analysis and Network Pharmacology

Background

Chronic obstructive pulmonary disease (COPD) is becoming a major public health burden worldwide. It is urgent to explore more effective and safer treatment strategy for COPD. Notably, Xuefu Zhuyu Decoction (XFZYD) is widely used to treat respiratory system diseases, including COPD, in China.

Objective

This study is aimed at comprehensively evaluating the therapeutic effects and molecular mechanism of XFZYD on COPD.

Methods

Original clinical studies were searched from eight literature databases. Meta-analysis was conducted using the Review Manager software (version 5.4.1). Network pharmacology and molecular docking experiments were utilized to explore the mechanisms of action of XFZYD.

Results

XFZYD significantly enhanced the efficacy of clinical treatment and improved the pulmonary function and hypoventilation of COPD patients. In addition, XFZYD significantly improved the hypercoagulability of COPD patients. The subgroup analysis suggested that XFZYD exhibited therapeutic effects on both stable and acute exacerbation of COPD. XFZYD exerted its therapeutic effects on COPD through multicomponent, multitarget, and multipathway characteristics. The intervention of the PI3K-AKT pathway may be the critical mechanism.

Conclusion

The application of XFZYD based on symptomatic relief and supportive treatment is a promising clinical decision. More preclinical and clinical studies are still needed to evaluate the safety and therapeutic effects of long-term use of XFZYD on COPD.

Plasma Extracellular Vesicle miRNA Profiles Distinguish Chronic Obstructive Pulmonary Disease Exacerbations and Disease Severity

Purpose

Molecular biomarkers for chronic obstructive pulmonary disease (COPD) severity have been difficult to identify. We aimed to assess extracellular vesicle miRNAs’ potential as a blood biomarker in discriminating disease severity in participants with COPD.

Patients and Methods

Plasma extracellular vesicles (EVs) were obtained from two COPD cohorts (n = 20 during an exacerbation event, n = 20 during stable state), with varying disease severity (GOLD stages). The miRCURY LNA miRNA Serum/Plasma assay, specific to 179 targets, was used to evaluate EV miRNA expression. The miRNAs that were significantly dysregulated were further assessed for discriminatory power using ROC curve analysis, as well as their role in relevant biological pathways.

Results

One miRNA was significantly dysregulated between moderate GOLD participants compared to severe/very severe GOLD participants, with an AUC of 0.798, p = 0.01 for miR-374b-5p. Five miRNAs were significantly dysregulated between exacerbating and stable COPD participants, with miR-223-3p resulting in the highest AUC (0.755, p = 0.006) for a single miRNA, with a combination of three miRNAs (miR-92b-3p, miR-374a-5p and miR-106b-3p) providing the highest discriminatory power (AUC 0.820, p = 0.001). The “cytokine–cytokine receptor interaction” (hsa04060 pathway) was the most significant KEGG pathway enriched for three out of the five miRNAs associated with COPD exacerbations.

Conclusion

This initial small-scale study suggests that the bioactive cargo (miRNAs) in plasma EVs holds specific biological information for the severity of airflow obstruction and COPD exacerbations, warranting further investigation.

Screening and identification of tissue-infiltrating immune cells and genes for patients with emphysema phenotype of COPD

Objective

To study the tissue-infiltrating immune cells of the emphysema phenotype of chronic obstructive pulmonary disease (COPD) and find the molecular mechanism related to the development of emphysema to offer potential targets for more precise treatment of patients with COPD.

Methods

Combined analyses of COPD emphysema phenotype lung tissue-related datasets, GSE47460 and GSE1122, were performed. CIBERSORT was used to assess the distribution of tissue-infiltrating immune cells. Weighted gene co-expression network analysis (WGCNA) was used to select immune key genes closely related to clinical features. Rt-qPCR experiments were used for the validation of key genes. Emphysema risk prediction models were constructed by logistic regression analysis and a nomogram was developed.

Results

In this study, three immune cells significantly associated with clinical features of emphysema (FEV1 post-bronchodilator % predicted, GOLD Stage, and DLCO) were found. The proportion of neutrophils (p=0.025) infiltrating in the emphysema phenotype was significantly increased compared with the non-emphysema phenotype, while the proportions of M2 macrophages (p=0.004) and resting mast cells (p=0.01) were significantly decreased. Five immune-related differentially expressed genes (DEGs) were found. WGCNA and clinical lung tissue validation of patients with emphysema phenotype were performed to further screen immune-related genes closely related to clinical features. A key gene (SERPINA3) was selected and included in the emphysema risk prediction model. Compared with the traditional clinical prediction model (AUC=0.923), the combined prediction model, including SERPINA3 and resting mast cells (AUC=0.941), had better discrimination power and higher net benefit.

Conclusion

This study comprehensively analyzed the tissue-infiltrating immune cells significantly associated with emphysema phenotype, including M2 macrophages, neutrophils, and resting mast cells, and identified SERPINA3 as a key immune-related gene.

Therapeutic Potential of Small Molecules Targeting Oxidative Stress in the Treatment of Chronic Obstructive Pulmonary Disease (COPD): A Comprehensive Review

Chronic obstructive pulmonary disease (COPD) is an increasing and major global health problem. COPD is also the third leading cause of death worldwide. Oxidative stress (OS) takes place when various reactive species and free radicals swamp the availability of antioxidants. Reactive nitrogen species, reactive oxygen species (ROS), and their counterpart antioxidants are important for host defense and physiological signaling pathways, and the development and progression of inflammation. During the disturbance of their normal steady states, imbalances between antioxidants and oxidants might induce pathological mechanisms that can further result in many non-respiratory and respiratory diseases including COPD. ROS might be either endogenously produced in response to various infectious pathogens including fungi, viruses, or bacteria, or exogenously generated from several inhaled particulate or gaseous agents including some occupational dust, cigarette smoke (CS), and air pollutants. Therefore, targeting systemic and local OS with therapeutic agents such as small molecules that can increase endogenous antioxidants or regulate the redox/antioxidants system can be an effective approach in treating COPD. Various thiol-based antioxidants including fudosteine, erdosteine, carbocysteine, and N-acetyl-L-cysteine have the capacity to increase thiol content in the lungs. Many synthetic molecules including inhibitors/blockers of protein carbonylation and lipid peroxidation, catalytic antioxidants including superoxide dismutase mimetics, and spin trapping agents can effectively modulate CS-induced OS and its resulting cellular alterations. Several clinical and pre-clinical studies have demonstrated that these antioxidants have the capacity to decrease OS and affect the expressions of several pro-inflammatory genes and genes that are involved with redox and glutathione biosynthesis. In this article, we have summarized the role of OS in COPD pathogenesis. Furthermore, we have particularly focused on the therapeutic potential of numerous chemicals, particularly antioxidants in the treatment of COPD.

Exposure to second-hand smoke is an independent risk factor of small airway dysfunction in non-smokers with chronic cough: A retrospective case-control study

Objectives

This study aimed to identify the potential risk factors for small airway dysfunction (SAD) in non-smokers with chronic cough.

Methods

Non-smokers with chronic cough who underwent lung function tests at Xiangya Hospital from May 2019 to May 2020 were enrolled, and divided into the derivation and validation cohorts based on their hospital admission time. SAD was determined based on the presence of at least two of the following three indicators of lung function being less than 65% of predicted: maximal mid-expiratory flow, forced expiratory flow at 50% of forced vital capacity (FVC), and forced expiratory flow at 75% of FVC. Clinical data of these patients were collected. Risk factors for SAD were identified by logistic regression analysis in the derivation cohort and further confirmed in the validation cohort.

Results

In total, 316 patients (152 in the non-SAD group and 164 in the SAD group) were included in the derivation cohort. Compared with the non-SAD group, the SAD group had a higher proportion of female patients (82.3 vs. 59.2%, P < 0.001), was more commonly exposed to second-hand smoke (SHS) (61.6 vs. 27.6%, P < 0.001), and tended to be older (median age, 45.5 vs. 40.0 years old, P = 0.004). The median FVC, forced expiratory volume in one second (FEV₁) % pred, FEV₁/FVC ratio, and peak expiratory flow (PEF) % pred were slightly lower in the SAD group. Multivariable logistic analysis showed that exposure to SHS was an independent risk factor (OR 4.166 [95% CI 2.090–8.302], P < 0.001) for SAD in non-smokers with chronic cough after adjusting for related variables. In the validation cohort (n = 146), patients with SHS exposure had a relative risk of 1.976 (95% CI 1.246–3.135, P = 0.004) for SAD compared to those without SHS exposure. Multivariable logistic analysis consistently confirmed that exposure to SHS was an independent risk factor (OR 3.041 [95% CI 1.458–6.344], P = 0.003) for SAD in non-smokers.

Conclusions

Exposure to SHS is independently associated with a higher risk of SAD in non-smokers with chronic cough. Reduction in SHS exposure may ameliorate lung function, thus lowering the risk of irreversible airway obstruction.

Impaired Alveolar Re-Epithelialization in Pulmonary Emphysema

Alveolar type II (ATII) cells are progenitors in alveoli and can repair the alveolar epithelium after injury. They are intertwined with the microenvironment for alveolar epithelial cell homeostasis and re-epithelialization. A variety of ATII cell niches, transcription factors, mediators, and signaling pathways constitute a specific environment to regulate ATII cell function. Particularly, WNT/β-catenin, YAP/TAZ, NOTCH, TGF-β, and P53 signaling pathways are dynamically involved in ATII cell proliferation and differentiation, although there are still plenty of unknowns regarding the mechanism. However, an imbalance of alveolar cell death and proliferation was observed in patients with pulmonary emphysema, contributing to alveolar wall destruction and impaired gas exchange. Cigarette smoking causes oxidative stress and is the primary cause of this disease development. Aberrant inflammatory and oxidative stress responses result in loss of cell homeostasis and ATII cell dysfunction in emphysema. Here, we discuss the current understanding of alveolar re-epithelialization and altered reparative responses in the pathophysiology of this disease. Current therapeutics and emerging treatments, including cell therapies in clinical trials, are addressed as well.

Lung tissue shows divergent gene expression between chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) are characterized by shared exposures and clinical features, but distinct genetic and pathologic features exist. These features have not been well-studied using large-scale gene expression datasets. We hypothesized that there are divergent gene, pathway, and cellular signatures between COPD and IPF.

METHODS

We performed RNA-sequencing on lung tissues from individuals with IPF (n = 231) and COPD (n = 377) compared to control (n = 267), defined as individuals with normal spirometry. We grouped the overlapping differential expression gene sets based on direction of expression and examined the resultant sets for genes of interest, pathway enrichment, and cell composition. Using gene set variation analysis, we validated the overlap group gene sets in independent COPD and IPF data sets.

RESULTS

We found 5010 genes differentially expressed between COPD and control, and 11,454 genes differentially expressed between IPF and control (1% false discovery rate). 3846 genes overlapped between IPF and COPD. Several pathways were enriched for genes upregulated in COPD and downregulated in IPF; however, no pathways were enriched for genes downregulated in COPD and upregulated in IPF. There were many myeloid cell genes with increased expression in COPD but decreased in IPF. We found that the genes upregulated in COPD but downregulated in IPF were associated with lower lung function in the independent validation cohorts.

CONCLUSIONS

We identified a divergent gene expression signature between COPD and IPF, with increased expression in COPD and decreased in IPF. This signature is associated with worse lung function in both COPD and IPF.

Dysregulated Cell Signaling in Pulmonary Emphysema

Pulmonary emphysema is characterized by the destruction of alveolar septa and irreversible airflow limitation. Cigarette smoking is the primary cause of this disease development. It induces oxidative stress and disturbs lung physiology and tissue homeostasis. Alveolar type II (ATII) cells have stem cell potential and can repair the denuded epithelium after injury; however, their dysfunction is evident in emphysema. There is no effective treatment available for this disease. Challenges in this field involve the large complexity of lung pathophysiological processes and gaps in our knowledge on the mechanisms of emphysema progression. It implicates dysregulation of various signaling pathways, including aberrant inflammatory and oxidative responses, defective antioxidant defense system, surfactant dysfunction, altered proteostasis, disrupted circadian rhythms, mitochondrial damage, increased cell senescence, apoptosis, and abnormal proliferation and differentiation. Also, genetic predispositions are involved in this disease development. Here, we comprehensively review studies regarding dysregulated cell signaling, especially in ATII cells, and their contribution to alveolar wall destruction in emphysema. Relevant preclinical and clinical interventions are also described.

Adipose-derived mesenchymal stem cells protects renal function in a rat model of emphysema

BACKGROUND AND OBJECTIVE

The link between lung disease and kidney disorders has already been confirmed. Previous studies have documented that obstructive pulmonary disease is an independent predictor of decreased renal function, which reduces glomerular filtration rate. Recently, mesenchymal stem cells are the most important cell used in cell therapy. Accordingly, the present experiment was designed to evaluate the efficacy of adipose-derived mesenchymal stem cells (AMSCs) on improvement of renal function in elastase induced-pulmonary emphysema rats.

MATERIALS AND METHODS

Thirty male Sprague-Dawley rats divided into the 3 groups. Following intra-tracheal administration of elastase, the in vivo emphysema model established and confirmed according to the specific markers. Subsequently, systemic AMSCs injection was developed. the kidney injuries markers such as Blood urea nitrogen (BUN), creatinine, sodium and potassium as well as the kidney histopathologic parameters were assessed in all groups. Moreover, the oxidative stress markers levels including Malondialdehyde (MDA), Total antioxidant capacity (TAC), Catalase (CAT) and Glutathione peroxidase (GPx) were measured in kidney tissue and also inflammatory cytokines including IL-10, IL-6, and IFN-Ƴ were assessed in serum samples.

RESULTS

The marked rise in kidney injuries markers were observed which showed by enhancement of BUN and Creatinine levels in emphysema rats compared to the control. Furthermore, the results demonstrated increases in MDA levels and decreases in antioxidant activity which was in line with increases in inflammation cytokines in renal tissue. Conversely, AMSCs treatment improved renal function as shown by the decreases BUN, Creatinine and proteinuria. Furthermore, renal histological assay demonstrate improvement in glomerular and tubular damage and inflammatory cells accumulation.

CONCLUSIONS

Our results documented the promising kidney-protective properties of Adipose-Derived Mesenchymal Stem Cells in the kidney injuries induced by emphysema.

Emphysema-Predominant COPD Had a Greater 5-Year Mortality and a Worse Annual Decline in Lung Function Than Airway Obstruction-Predominant COPD or Asthma at Initial Same Degree of Airflow Obstruction

Background and Objectives: We studied whether the extent of exertional oxygen desaturation and emphysema could cause greater mortality in COPD and asthma independent of airflow obstruction. Materials and Methods: We performed a 5-year longitudinal observational study in COPD and asthma patients who matched for airflow obstruction severity. All subjects performed a 6-min walk test (6MWT) and high-resolution computed tomography (HRCT) and followed spirometry and oxygen saturation (SpO₂) during the 6MWT every 3–6 months. Overall survival was recorded. Cumulative survival curves were performed according to the Kaplan–Meier method and compared with the log-rank test. Results: The COPD group had higher emphysema scores, higher Δinspiratory capacities (ICs) and lower SpO₂ during the 6MWT, which showed a greater yearly decline in FEV₁ (40.6 mL) and forced vital capacity (FVC) (28 mL) than the asthma group (FEV₁, 9.6 mL; FVC, 1.2 mL; p < 0.05). The emphysema-predominant COPD group had an accelerated annual decline in lung function and worse survival. The nadir SpO₂ ≤ 80% and a higher emphysema score were the strong risk factors for mortality in COPD patients. Conclusions: The greater structural changes with a higher emphysema score and greater desaturation during the 6MWT in COPD may contribute to worse yearly decline in FEV₁ and higher five-year mortality than in asthma patients with a similar airflow obstruction. The lowest SpO₂ ≤ 80% during the 6MWT and emphysema-predominant COPD were the strong independent factors for mortality in chronic obstructive airway disease patients.

From Biomarkers to Novel Therapeutic Approaches in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a heterogeneous and complex disorder. In this review, we provided a comprehensive overview of biomarkers involved in COPD, and potential novel biological therapies that may provide additional therapeutic options for COPD. The complex characteristics of COPD have made the recommendation of a generalized therapy challenging, suggesting that a tailored, personalized strategy may lead to better outcomes. Existing and unmet needs for COPD treatment support the continued development of biological therapies, including additional investigations into the potential clinical applications of this approach.

Implication of RAGE Polymorphic Variants in COPD Complication and Anti-COPD Therapeutic Potential of sRAGE

Chronic obstructive pulmonary disease (COPD) is a slowly progressive and poorly reversible airway obstruction disease. It is caused either alone or in combination of emphysema, chronic bronchitis (CB), and small airways disease. COPD is thought to be a multi-factorial disorder in which genetic susceptibility, environmental factors and tobacco exposure could be doubly or simultaneously implicated. Available medicines against COPD include anti-inflammatory drugs, such as β2-agonists and anticholinergics, which efficiently reduce airflow limitation but are unable to avert disease progression and mortality. Advanced glycation end products (AGE) and their receptors i.e. receptor for advanced glycation end products (RAGE) are some molecules that have been implicated in the complication of COPD. Several RAGE single nucleotide polymorphic (SNP) variants are produced by the mammalian cells. Based on the ethnicity some SNPs aggravate the COPD severity. Mammalian cells produce several alternative RAGE splice variants including a soluble RAGE (sRAGE) and an endogenous soluble RAGE (esRAGE). Both of these act as decoy receptor and thus may help to arrest the COPD complications. Several lines of evidences indicate a decreased level of sRAGE in the COPD subjects. One of the new strategies to reduce COPD complication may be sRAGE therapeutic administration to the COPD subjects. This comprehensive discussion sheds light on the role of RAGE and its polymorphic variants in the COPD complication along with sRAGE therapeutic significance in the COPD prevention.

Expression/Activation of PAR-1 in Airway Epithelial Cells of COPD Patients: Ex Vivo/In Vitro Study

The role of PAR-1 expression and activation was described in epithelial cells from the central and distal airways of COPD patients using an ex vivo/in vitro model. PAR-1 immunoreactivity was studied in epithelial cells from surgical specimens of the central and distal airways of COPD patients and healthy control (HC). Furthermore, PAR-1 expression and activation were measured in both the human bronchial epithelial cell line (16HBE) and normal human bronchial epithelial cells (NHBEs) exposed to cigarette smoke extract (CSE) (10%) or thrombin. Finally, cell proliferation, apoptosis, and IL-8 release were detected in stimulated NHBEs. We identified higher levels of PAR-1 expression/activation in epithelial cells from the central airways of COPD patients than in HC. Active PAR-1 increased in epithelial cells from central and distal airways of COPD, with higher levels in COPD smokers (correlated with pack-years) than in COPD ex-smokers. 16HBE and NHBEs exposed to CSE or thrombin showed increased levels of active PAR-1 (localized in the cytoplasm) than baseline conditions, while NHBEs treated with thrombin or CSE showed increased levels of IL-8 proteins, with an additional effect when used in combination. Smoking habits generate the upregulation of PAR-1 expression/activation in airway epithelial cells, and promoting IL-8 release might affect the recruitment of infiltrating cells in the airways of COPD patients.

Mechanisms, Pathophysiology and Currently Proposed Treatments of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is one of the leading global causes of morbidity and mortality. A hallmark of COPD is progressive airflow obstruction primarily caused by cigarette smoke (CS). CS exposure causes an imbalance favoring pro- over antioxidants (oxidative stress), leading to transcription factor activation and increased expression of inflammatory mediators and proteases. Different cell types, including macrophages, epithelial cells, neutrophils, and T lymphocytes, contribute to COPD pathophysiology. Alteration in cell functions results in the generation of an oxidative and inflammatory microenvironment, which contributes to disease progression. Current treatments include inhaled corticosteroids and bronchodilator therapy. However, these therapies do not effectively halt disease progression. Due to the complexity of its pathophysiology, and the risk of exacerbating symptoms with existing therapies, other specific and effective treatment options are required. Therapies directly or indirectly targeting the oxidative imbalance may be promising alternatives. This review briefly discusses COPD pathophysiology, and provides an update on the development and clinical testing of novel COPD treatments.

Musculoskeletal Disorders in Chronic Obstructive Airway Diseases: A Neglected Clinical Entity

Chronic obstructive pulmonary disease (COPD) is a lung disease that can affect various extra-pulmonary organs; one being the musculoskeletal system. Skeletal muscle dysfunction and osteoporosis are two important musculoskeletal disorders that have an impact on the quality of life in COPD patients in terms of morbidity and mortality. Treatment related adverse effects of COPD such as steroid-induced myopathy and osteoporosis are well recognised. Other comorbidities like sarcopenia, cardiovascular disease, metabolic diseases (diabetes mellitus, obesity, and thyroid diseases), chronic kidney disease, sleep apnoea, anaemia, and depression are also noted, which can contribute to impaired health status, increased healthcare utilisation, and even mortality. As well, it has been shown that autoimmunity and autoimmune rheumatic diseases (AIRDs) are linked to COPD. In this mini-review, we intend to give an overview of different types of musculoskeletal disorders associated with COPD.

Interleukin-13: A pivotal target against influenza-induced exacerbation of chronic lung diseases

Non-communicable, chronic respiratory diseases (CRDs) affect millions of individuals worldwide. The course of these CRDs (asthma, chronic obstructive pulmonary disease, and cystic fibrosis) are often punctuated by microbial infections that may result in hospitalization and are associated with increased risk of morbidity and mortality, as well as reduced quality of life. Interleukin-13 (IL-13) is a key protein that regulates airway inflammation and mucus hypersecretion. There has been much interest in IL-13 from the last two decades. This cytokine is believed to play a decisive role in the exacerbation of inflammation during the course of viral infections, especially, in those with pre-existing CRDs. Here, we discuss the common viral infections in CRDs, as well as the potential role that IL-13 plays in the virus-induced disease pathogenesis of CRDs. We also discuss, in detail, the immune-modulation potential of IL-13 that could be translated to in-depth studies to develop IL-13-based therapeutic entities.

Effect modification of the association between comorbidities and severe course of COVID-19 disease by age of study participants: a systematic review and meta-analysis

BACKGROUND

Comprehensive evidence synthesis on the associations between comorbidities and behavioural factors with hospitalisation, intensive care unit (ICU) admission, and death due to COVID-19 is required for deriving national and international recommendations on primary targets for non-pharmacological interventions (NPI) and vaccination strategies.

METHODS

We performed a rapid systematic review and meta-analysis on studies and publicly accessible data to quantify associations between predisposing health conditions, demographics, behavioural factors on the one hand and hospitalisation, ICU admission, and death from COVID-19 on the other hand. We provide ranges of reported and calculated effect estimates and pooled relative risks derived from a meta-analysis and meta-regression.

RESULTS

Seventy-five studies were included in qualitative and 74 in quantitative synthesis, with study populations ranging from 19 to 44,672 COVID-19 cases. The risk of dying from COVID-19 was significantly associated with cerebrovascular [pooled relative risk (RR) 2.7 (95% CI 1.7-4.1)] and cardiovascular [RR 3.2 (CI 2.3-4.5)] diseases, hypertension [RR 2.6 (CI 2.0-3.4)], and renal disease [RR 2.5 (CI 1.8-3.4)], with high heterogeneity in pooled estimates, partly but not solely explained by age of study participants. For some comorbidities, our meta-regression showed a decrease in effect on the severity of disease with a higher median age of the study population. Compared to death, associations between several comorbidities and hospitalisation and ICU admission were less pronounced.

CONCLUSIONS

We obtained robust estimates on the magnitude of risk for COVID-19 hospitalisation, ICU admission, and death associated with comorbidities, demographic, and behavioural risk factors and show that these estimates are modified by age of study participants. This interaction is an important finding to be kept in mind for current vaccination strategies and for the protection of individuals with high risk for a severe COVID-19 course.

Haemophilus influenzae causes cellular trans-differentiation in human bronchial epithelia

Non-typeable Haemophilus influenzae (NTHi) is the most common respiratory pathogen in patients with chronic obstructive disease. Limited data is available investigating the impact of NTHi infections on cellular re-differentiation processes in the bronchial mucosa. The aim of this study was to assess the effects of stimulation with NTHi on the bronchial epithelium regarding cellular re-differentiation processes using primary bronchial epithelial cells harvested from infection-free patients undergoing bronchoscopy. The cells were then cultivated using an air-liquid interface and stimulated with NTHi and TGF-β. Markers of epithelial and mesenchymal cells were analyzed using immunofluorescence, Western blot and qRT-PCR. Stimulation with both NTHi and TGF-ß led to a marked increase in the expression of the mesenchymal marker vimentin, while E-cadherin as an epithelial marker maintained a stable expression throughout the experiments. Furthermore, expression of collagen 4 and the matrix-metallopeptidases 2 and 9 were increased after stimulation, while the expression of tissue inhibitors of metallopeptidases was not affected by pathogen stimulation. In this study we show a direct pathogen-induced trans-differentiation of primary bronchial epithelial cells resulting in a co-localization of epithelial and mesenchymal markers and an up-regulation of extracellular matrix components.

T cell responses in respiratory viral infections and chronic obstructive pulmonary disease

ABSTRACT

Respiratory viruses are major human pathogens that cause approximately 200 million pneumonia cases annually and induce various comorbidities with chronic obstructive pulmonary disease (COPD), resulting in significant health concerns and economic burdens. Clinical manifestations in respiratory viral infections and inflammations vary from asymptomatic, mild, to severe, depending on host immune cell responses to pathogens and interactions with airway epithelia. We critically review the activation, effector, and regulation of T cells in respiratory virus infections and chronic inflammations associated with COPD. Crosstalk among T cells, innate immune cells, and airway epithelial cells is discussed as essential parts of pathogenesis and protection in viral infections and COPD. We emphasize the specificity of peptide antigens and the functional heterogeneity of conventional CD4+ and CD8+ T cells to shed some light on potential cellular and molecular candidates for the future development of therapeutics and intervention against respiratory viral infections and inflammations.

Extracellular matrix remodelling in COPD

The extracellular matrix (ECM) of the lung plays several important roles in lung function, as it offers a low resistant pathway that allows the exchange of gases, provides compressive strength and elasticity that supports the fragile alveolar-capillary intersection, controls the binding of cells with growth factors and cell surface receptors and acts as a buffer against retention of water.COPD is a chronic inflammatory respiratory condition, characterised by various conditions that result in progressive airflow limitation. At any stage in the course of the disease, acute exacerbations of COPD may occur and lead to accelerated deterioration of pulmonary function. A key factor of COPD is airway remodelling, which refers to the serious alterations of the ECM affecting airway wall thickness, resistance and elasticity. Various studies have shown that serum biomarkers of ECM turnover are significantly associated with disease severity in patients with COPD and may serve as potential targets to control airway inflammation and remodelling in COPD. Unravelling the complete molecular composition of the ECM in the diseased lungs will help to identify novel biomarkers for disease progression and therapy.

Tiotropium/Olodaterol treatment reduces cigarette smoke extract-induced cell death in BEAS-2B bronchial epithelial cells

BACKGROUND

Cigarette smoking is a critical risk factor for the destruction of lung parenchyma or the development of emphysema, which is characteristic of COPD. Disruption of epithelial layer integrity may contribute to lung injury following cigarette smoke extract (CSE) exposure. Tiotropium/olodaterol acts as a bronchodilator for COPD treatment; however, the effect of dual bronchodilators on epithelial cell injury and its underlying mechanism remain unclear. In this study, we evaluated the effect of tiotropium/olodaterol on CSE-mediated cell death and the underlying mechanisms.

METHODS

Cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis, necrosis, and autophagy were evaluated using flow cytometry. Autophagy-related protein, phosphorylated ERK, expression was determined using Western blotting.

RESULTS

Tiotropium/olodaterol significantly inhibited CSE-induced cell death, mitochondria dysfunction, and autophagy, which had no significant effect on apoptosis or necrosis in BEAS-2B human bronchial epithelial cells. Moreover, tiotropium/olodaterol attenuated CSE-induced upregulation of JNK.

CONCLUSIONS

CSE induced cell death and caused consistent patterns of autophagy and JNK activation in BEAS-2B human bronchial epithelial cells. Tiotropium/olodaterol treatment protected bronchial epithelial cells from CSE-induced injury and inhibited activation of autophagy and upregulation of JNK phosphorylation. These results indicate that tiotropium/olodaterol may protect epithelial cells from the deleterious effects of CSE exposure, which is associated with the regulation of autophagy and JNK activation.

Progress in the mechanism and targeted drug therapy for COPD

Chronic obstructive pulmonary disease (COPD) is emphysema and/or chronic bronchitis characterised by long-term breathing problems and poor airflow. The prevalence of COPD has increased over the last decade and the drugs most commonly used to treat it, such as glucocorticoids and bronchodilators, have significant therapeutic effects; however, they also cause side effects, including infection and immunosuppression. Here we reviewed the pathogenesis and progression of COPD and elaborated on the effects and mechanisms of newly developed molecular targeted COPD therapeutic drugs. Among these new drugs, we focussed on thioredoxin (Trx). Trx effectively prevents the progression of COPD by regulating redox status and protease/anti-protease balance, blocking the NF-κB and MAPK signalling pathways, suppressing the activation and migration of inflammatory cells and the production of cytokines, inhibiting the synthesis and the activation of adhesion factors and growth factors, and controlling the cAMP-PKA and PI3K/Akt signalling pathways. The mechanism by which Trx affects COPD is different from glucocorticoid-based mechanisms which regulate the inflammatory reaction in association with suppressing immune responses. In addition, Trx also improves the insensitivity of COPD to steroids by inhibiting the production and internalisation of macrophage migration inhibitory factor (MIF). Taken together, these findings suggest that Trx may be the ideal drug for treating COPD.

Risk Factors Associated With Frequent Acute Exacerbations of Asthma

Introduction: Asthma can lead to fatigue, frequent hospital visits, psychological problems, and learning problems in children. One of the complications of asthma is its life-threatening acute exacerbation. It is important to identify precipitating factors responsible for frequent acute exacerbations of asthma.

Methods: This case-control study was conducted in the pulmonology ward of Liaquat University of Medical and Health Sciences, Jamshoro, from May 2019 to February 2020. Sampling was done by convenient probability technique. The case group was identified as patients with two or more episodes of acute exacerbation of asthma and the control group was identified as asthmatic patients without acute exacerbation in the last year.

Results: Factors leading to acute exacerbation of asthma include number of asthma attacks in the past seven days (4.9 ± 3.4 vs. 2.2 ± 2.0; p < 0.0001) and number of nights with troublesome cough in the past 28 days (12.2 ± 8.1 vs. 4.3 ± 3.1; p < 0.0001). Participants with recent upper respiratory tract infection (38.4% vs. 10%; odds ratio [OR] 5.62), smoking history (30.7% vs. 12%; OR 3.25), gastroesophageal reflux disease (26.9% vs. 8.0%; OR 4.2) and non-adherence to medication (26.9% vs. 8.0%; OR 4.2) were more likely to experience from exacerbation of asthma.

Conclusion: It is important to identify risk factors that may cause acute exacerbation of asthma in the patients. Patients should be educated of the risk factors and complications of the exacerbation episode of asthma.

Innate Immunity and Cell Surface Receptors in the Pathogenesis of COPD: Insights from Mouse Smoking Models

Chronic obstructive pulmonary disease (COPD) is mainly associated with smoking habit. Inflammation is the major initiating process whereby neutrophils and monocytes are attracted into the lung microenvironment by external stimuli present in tobacco leaves and in cigarette smoke, which promote chemotaxis, adhesion, phagocytosis, release of superoxide anions and enzyme granule contents. A minority of smokers develops COPD and different molecular factors, which contribute to the onset of the disease, have been put forward. After many years of research, the pathogenesis of COPD is still an object of debate. In vivo models of cigarette smoke-induced COPD may help to unravel cellular and molecular mechanisms underlying the pathogenesis of COPD. The mouse represents the most favored animal choice with regard to the study of immune mechanisms due to its genetic and physiological similarities to humans, the availability of a large variability of inbred strains, the presence in the species of several genetic disorders analogous to those in man, and finally on the possibility to create models “made-to-measure” by genetic manipulation. The review outlines the different response of mouse strains to cigarette smoke used in COPD studies while retaining a strong focus on their relatability to human patients. These studies reveal the importance of innate immunity and cell surface receptors in the pathogenesis of pulmonary injury induced by cigarette smoking. They further advance the way in which we use wild type or genetically manipulated strains to improve our overall understanding of a multifaceted disease such as COPD. The structural and functional features, which have been found in the different strains of mice after chronic exposure to cigarette smoke, can be used in preclinical studies to develop effective new therapeutic agents for the different phenotypes in human COPD.

The impact of COPD and smoking history on the severity of COVID-19: A systemic review and meta-analysis

Comorbidities are associated with the severity of coronavirus disease 2019 (COVID‐19). This meta‐analysis aimed to explore the risk of severe COVID‐19 in patients with pre‐existing chronic obstructive pulmonary disease (COPD) and ongoing smoking history. A comprehensive systematic literature search was carried out to find studies published from December 2019 to 22 March 2020 from five databases. The languages of literature included English and Chinese. The point prevalence of severe COVID‐19 in patients with pre‐existing COPD and those with ongoing smoking was evaluated with this meta‐analysis. Overall 11 case series, published either in Chinese or English language with a total of 2002 cases, were included in this study. The pooled OR of COPD and the development of severe COVID‐19 was 4.38 (fixed‐effects model; 95% CI: 2.34‐8.20), while the OR of ongoing smoking was 1.98 (fixed‐effects model; 95% CI: 1.29‐3.05). There was no publication bias as examined by the funnel plot and Egger's test (P = not significant). The heterogeneity of included studies was moderate for both COPD and ongoing smoking history on the severity of COVID‐19. COPD and ongoing smoking history attribute to the worse progression and outcome of COVID‐19.

Regional differences in airway susceptibility to cigarette smoke: An investigational case study of epithelial function and gene alterations inin vitroairway epithelial three-dimensional cultures

Cigarette smoke (CS) is a risk factor contributing to lung remodeling in chronic obstructive pulmonary disease (COPD). COPD is a heterogeneous disease because many factors contribute in varying degrees to the resulting airflow limitations in different regions of the respiratory tract. This heterogeneity makes it difficult to understand mechanisms behind COPD development. In the current study, we investigate the regional heterogeneity of the acute response to CS exposure between large and small airways using in vitro three-dimensional (3D) cultures. We used two in vitro 3D human airway epithelial tissues from large and small airway epithelial cells, namely, MucilAir™ and SmallAir™, respectively, which were derived from the same single healthy donor to eliminate donor differences. Impaired epithelial functions and altered gene expression were observed in SmallAir™ exposed to CS at the lower dose and earlier period following the last exposure compared with MucilAir™. In addition, severe damage in SmallAir™ was retained for a longer duration than MucilAir™. Transcriptomic analysis showed that although well-known CS-inducible biological processes (i.e. inflammation, cell fate, and metabolism) were disturbed with consistent activity in both tissues exposed to CS, we elucidated distinctively regulated genes in only MucilAir™ and SmallAir™, which were mostly related to catalytic and transporter activities. Our findings suggest that CS exposure elicited epithelial dysfunction through almost the same perturbed pathways in both airways; however, they expressed different genes related to metabolic and transporter activities in response to CS exposure which may contribute to cytotoxic heterogeneity to the response to CS in the respiratory tract.

Vitamin D, C-reactive protein, and oxidative stress markers in chronic obstructive pulmonary disease

Objective:

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Systemic inflammation and oxidant/antioxidant imbalance has been seen to play a key role in pathogenesis of COPD. The present study investigated the levels of inflammatory and antioxidant/oxidative stress biomarker in COPD patients and healthy subjects.

Materials and Methods:

The present study enrolled seventy COPD patients and seventy healthy controls from Department of Respiratory Medicine at a tertiary care hospital. Vitamin D, C-reactive protein (CRP), superoxide dismutase (SOD), catalase, and malondialdehyde (MDA) levels were measured in both cases and control. GraphPad PRISM version 6.01 was used for analysis of data.

Results:

The levels of Vitamin D, SOD, Catalase, were found to be significantly lower among the COPD patients in comparison to healthy controls while levels of MDA and CRP were significantly higher (P = 0.0001).

Conclusion:

The results showed oxidant/antioxidant imbalance and Vitamin D deficiency in COPD patients. Higher levels of CRP and oxidative stress markers were observed in COPD patients in comparison to healthy controls. A biomarker based study testing the efficacy of novel antioxidant or other agents will be helpful that can modify the course of this disease.

Asthma exacerbation related to viral infections: An up to date summary

Asthma exacerbation can be a major life threatening event. Viruses have been pinned as the cause behind the vast majority of these exacerbations. The purpose of this short review is to explore the mechanisms behind these exacerbations, focusing mostly on viral infections as triggers. We will also be discussing the phenotypes prone to asthma exacerbation, the pathophysiology of viral induced asthma and ventilation patterns of asthmatic lungs. This manuscript will assist primary care physicians in delineating the proper pathophysiology of the disease as well as the management.

VEGF and FGF-2: Promising targets for the treatment of respiratory disorders

The endothelial cells play a crucial role in the progression of angiogenesis, which causes cell re-modulation, proliferation, adhesion, migration, invasion and survival. Angiogenic factors like cytokines, cell adhesion molecules, growth factors, vasoactive peptides, proteolytic enzymes (metalloproteinases) and plasminogen activators bind to their receptors on endothelial cells and activate the signal transduction pathways like epidermal growth factor receptor (EGFR phosphatidylinositol 3-kinase and (PI3K)/AKT/mammalian target of rapamycin (mTOR) which initiate the process of angiogenesis. Cytokines that stimulate angiogenesis include direct and indirect proangiogenic markers. The direct proangiogenic group of markers consists of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (FGF-2) and hepatocyte growth factor (HGF) whereas the indirect proangiogenic markers include transforming growth factor-beta (TGF-β), interleukin 6 (IL-6), interleukin 8 (IL-8) and platelet-derived growth factor (PDGF). VEGF and FGF-2 are the strongest activators of angiogenesis which stimulate migration and proliferation of endothelial cells in existing vessels to generate and stabilize new blood vessels. VEGF is released in hypoxic conditions as an effect of the hypoxia-inducible factor (HIF-1α) and causes re-modulation and inflammation of bronchi cell. Cell re-modulation and inflammation leads to the development of various lung disorders like pulmonary hypertension, chronic obstructive pulmonary disease, asthma, fibrosis and lung cancer. This indicates that there is a firm link between overexpression of VEGF and FGF-2 with lung disorders. Various natural and synthetic drugs are available for reducing the overexpression of VEGF and FGF-2 which can be helpful in treating lung disorders. Researchers are still searching for new angiogenic inhibitors which can be helpful in the treatment of lung disorders. The present review emphasizes on molecular mechanisms and new drug discovery focused on VEGF and FGF-2 inhibitors and their role as anti-angiogenetic agents in lung disorders.

A six-month systems toxicology inhalation/cessation study in ApoE-/- mice to investigate cardiovascular and respiratory exposure effects of modified risk tobacco products, CHTP 1.2 and THS 2.2, compared with conventional cigarettes

Smoking is one of the major modifiable risk factors in the development and progression of chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD). Modified-risk tobacco products (MRTP) are being developed to provide substitute products for smokers who are unable or unwilling to quit, to lessen the smoking-related health risks. In this study, the ApoE-/- mouse model was used to investigate the impact of cigarette smoke (CS) from the reference cigarette 3R4F, or aerosol from two potential MRTPs based on the heat-not-burn principle, carbon heated tobacco product 1.2 (CHTP1.2) and tobacco heating system 2.2 (THS 2.2), on the cardiorespiratory system over a 6-month period. In addition, cessation or switching to CHTP1.2 after 3 months of CS exposure was assessed. A systems toxicology approach combining physiology, histology and molecular measurements was used to evaluate the impact of MRTP aerosols in comparison to CS. CHTP1.2 and THS2.2 aerosols, compared with CS, demonstrated lower impact on the cardiorespiratory system, including low to absent lung inflammation and emphysematous changes, and reduced atherosclerotic plaque formation. Molecular analyses confirmed the lower engagement of pathological mechanisms by MRTP aerosols than CS. Both cessation and switching to CHTP1.2 reduced the observed CS effects to almost sham exposure levels.

Sputum from chronic obstructive pulmonary disease patients inhibits T cell migration in a microfluidic device

Chronic obstructive pulmonary disease (COPD) is a common lung disease characterized by narrowed airways, resulting in serious breathing difficulty. Previous studies have demonstrated that inflammatory infiltration of leukocytes in the airway is associated with the pathogenesis of COPD. In the present study, we employed a microfluidic approach to assess the effect of COPD sputum on activated human peripheral blood T cell migration and chemotaxis under well-controlled gradient conditions. Our results showed considerable basal migration of T cells derived from peripheral blood of COPD patients and healthy controls in the medium control groups. By contrast, the migration of T cells from COPD patients and healthy controls was significantly inhibited in the presence of a gradient of sputum supernatant from COPD patients. Furthermore, chemotaxis of T cells from COPD patients or healthy subjects toward an SDF-1α gradient was clearly inhibited by sputum samples from the COPD patients. The inhibition effect revealed by the microfluidic cell migration experiments provides new information about the complex involvement of T cell trafficking in COPD.

Tissue-informed engineering strategies for modeling human pulmonary diseases

Chronic pulmonary diseases, including idiopathic pulmonary fibrosis (IPF), pulmonary hypertension (PH), and chronic obstructive pulmonary disease (COPD), account for staggering morbidity and mortality worldwide but have limited clinical management options available. Although great progress has been made to elucidate the cellular and molecular pathways underlying these diseases, there remains a significant disparity between basic research endeavors and clinical outcomes. This discrepancy is due in part to the failure of many current disease models to recapitulate the dynamic changes that occur during pathogenesis in vivo. As a result, pulmonary medicine has recently experienced a rapid expansion in the application of engineering principles to characterize changes in human tissues in vivo and model the resulting pathogenic alterations in vitro. We envision that engineering strategies using precision biomaterials and advanced biomanufacturing will revolutionize current approaches to disease modeling and accelerate the development and validation of personalized therapies. This review highlights how advances in lung tissue characterization reveal dynamic changes in the structure, mechanics, and composition of the extracellular matrix in chronic pulmonary diseases and how this information paves the way for tissue-informed engineering of more organotypic models of human pathology. Current translational challenges are discussed as well as opportunities to overcome these barriers with precision biomaterial design and advanced biomanufacturing techniques that embody the principles of personalized medicine to facilitate the rapid development of novel therapeutics for this devastating group of chronic diseases.

Effect of PM2.5 environmental pollution on rat lung

Particulate matter smaller than 2.5 μm (PM2.5) is a continuing challenge to pulmonary health. Here, we investigated the mechanisms involved in PM2.5 exposure-induced acute lung injury in rats. We analyzed biochemical and morphological changes following a 2-week "real-world" exposure. And then we found that PM2.5 exposure increased the concentrations of total protein, malondialdehyde, hydrogen peroxide, nitric oxide, and soluble elastin in bronchoalveolar lavage fluid, levels of cytokines in blood, and expression of MMP-9 in airways. Further, alveolar macrophage and neutrophil counts increased following PM2.5 exposure, and edema and lung lesions were observed. Our results suggest that PM2.5 exposure can induce oxidative stress and acute inflammatory responses, which can damage the micro-environment and decrease the repair ability of the lung, resulting in tissue damage.

Differential expression of heat shock proteins and activation of mitogen-activated protein kinases in A549 alveolar epithelial cells exposed to cigarette smoke extract

NEW FINDINGS

What is the central question of this study? What is the effect of cigarette smoke on cell death, oxidative damage, expression of heat shock proteins (HSPs) and activation of mitogen-activated protein kinases (MAPKs) in A549 alveolar epithelial cells? What is the main finding and its importance? Cigarette smoke induces cytotoxicity and oxidative damage to A549 cells, increases expression of different HSPs and activates MAPK signalling pathways. This could be related to inflammatory response and apoptosis observed in lungs of patients with smoking-related diseases.

ABSTRACT

Cigarette smoking is one of the main risk factors for development of chronic obstructive pulmonary disease (COPD). We previously reported that cigarette smoke (CS) induces damage to proteins and their ineffective degradation. Here, we hypothesize that CS could induce oxidative stress and cytotoxicity in lung epithelial cells through alterations of heat shock protein (HSP) expression and mitogen-activated protein kinase (MAPK) signalling pathways. We exposed A549 alveolar epithelial cells to various concentrations of cigarette smoke extract (CSE). Higher concentrations of CSE caused apoptosis of A549 cells after 4 h, while after 24 h cell viability was decreased, and lactate dehydrogenase in cell culture medium was increased as well as the number of necrotic cells. Concentrations of malondialdehyde (MDA) were elevated, while total thiol groups were decreased. Changes in the expression of HSPs (HSP70, HSP32 and HSP27) were time-dependent. After 6 h, CSE caused an increase in the expression of HSP70 and HSP32, while after 8 h all examined HSPs were up-regulated and remained increased up to 48 h. Treatment of A549 cells with CSE stimulated phosphorylation of extracellular signal-regulated kinase and p38 in a dose-dependent manner, while c-Jun N-terminal kinase activation was not detected. By using specific inhibitors, we demonstrated that MAPKs and HSPs interplay in CSE effects. In conclusion, our results show that MAPKs and HSPs are involved in the mechanism underlying CSE-induced cytotoxicity and oxidative damage to A549 alveolar epithelial cells. These processes could be related to inflammatory response and apoptosis observed in lungs of patients with smoking-related diseases, such as COPD.

TAILS proteomics reveals dynamic changes in airway proteolysis controlling protease activity and innate immunity during COPD exacerbations

Dysregulated protease activity is thought to cause parenchymal and airway damage in chronic obstructive pulmonary disease (COPD). Multiple proteases have been implicated in COPD, and identifying their substrates may reveal new disease mechanisms and treatments. However, as proteases interact with many substrates that may be protease inhibitors or proteases themselves, these webs of protease interactions make the wider consequences of therapeutically targeting proteases difficult to predict. We therefore used a systems approach to determine protease substrates and protease activity in COPD airways. Protease substrates were determined by proteomics using the terminal amine isotopic labeling of substrates (TAILS) methodology in paired sputum samples during stable COPD and exacerbations. Protease activity and specific protein degradation in airway samples were assessed using Western blotting, substrate assays, and ex vivo cleavage assays. Two hundred ninety-nine proteins were identified in human COPD sputum, 125 of which were proteolytically processed, including proteases, protease inhibitors, mucins, defensins, and complement and other innate immune proteins. During exacerbations, airway neutrophils and neutrophil proteases increased and more proteins were cleaved, particularly at multiple sites, consistent with degradation and inactivation. During exacerbations, different substrates were processed, including protease inhibitors, mucins, and complement proteins. Exacerbations were associated with increasing airway elastase activity and increased processing of specific elastase substrates, including secretory leukocyte protease inhibitor. Proteolysis regulates multiple processes including elastase activity and innate immune proteins in COPD airways and differs during stable disease and exacerbations. The complexity of protease, inhibitor, and substrate networks makes the effect of protease inhibitors hard to predict which should be used cautiously.

Blood Count of Eosinophil Polymorphonuclear Leucocytes and Bronchial Hyperreactivity in Chronic Obstructive Pulmonary Disease

Introduction:

Polymorphonuclear eosinophil leucocytes (eosinophils) are found in increased numbers in the circulation and sputum in asthma patients, usually in relation to the severity of asthma but it is the question whether they have a significant role in the development and level of bronchial hyperreactivity in patients with chronic obstructive pulmonary disease (COPD).

Objective:

to show the role of the eosinophils in the development and level of BHR in patients with COPD and so in the severity of illness.

Material and methods:

We observed 240 patients with COPD treated in Clinic for Pulmonary Diseases and TB «Podhrastovi» Sarajevo during five years: from 2012 to 2016. They were divided into groups and subgroups according to the first registration of BHR in the course of illness and to the number of exacerbations of the disease in one year. The number of blood eosinophils was measured at the onset of exacerbation of the disease before switching on any therapy, at the beginning and at the end of the research.

Results:

we did not find any significant difference in the eosinophil blood count between the COPD patients with and without BHR, nor according to the time of the first registration of BHR in the course of illness nor according to the number of exacerbations of illness per one year. There was not statistically significant difference in eosinophil count (increase-drop) within any of the groups or subgroups, or between the groups and subgroups between the first and last test.

Conclusion:

There is not significant correlation between the eosinophil blood count and the level of BHR, number of exacerbations and the severity of COPD.