Smoking-related Chronic Obstructive Pulmonary Disease Research Articles

Chronic Airflow Limitation, Emphysema and Impaired Diffusing Capacity in Relation to Smoking Habits in a Swedish Middle-Aged Population.

Chronic obstructive pulmonary disease (COPD) includes respiratory symptoms and chronic airflow limitation (CAL). In some cases, emphysema and impaired diffusing capacity for carbon monoxide (DLCO) are present, but characteristics and symptoms vary with smoking exposure. To study the prevalence of CAL, emphysema and impaired DLCO in relation to smoking and respiratory symptoms in a middle-aged population. We investigated 28,746 randomly invited individuals (52% women) aged 50-64 years across six Swedish sites. We performed spirometry, DLCO, high-resolution computed tomography (HRCT) and asked for smoking habits and respiratory symptoms. CAL was defined as post-bronchodilator forced expiratory volume in 1 second divided by forced expiratory volume (FEV1/FVC)<0.7. The overall prevalence was for CAL 8.8%, for impaired DLCO (DLCO<LLN) 5.7% and for emphysema 8.8%, with a higher prevalence in current smokers than in ex-smokers and never-smokers. The proportion of never-smokers among those with CAL, emphysema and impaired DLCO was 32%, 19% and 31% respectively. Regardless of smoking habits, the prevalence of respiratory symptoms was higher among people with CAL and impaired DLCO, compared to those with normal lung function. Asthma prevalence in never-smokers with CAL was 14%. In this group, asthma associated with lower FEV1 and more respiratory symptoms. In this large population-based study of middle-aged people, CAL and impaired DLCO were associated with common respiratory symptoms. Self-reported asthma was not associated with CAL in never-smokers. Our findings suggest that CAL in never-smokers signifies a separate clinical phenotype that may be monitored and, possibly, treated differently from smoking-related COPD. This article is open access and distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).

CAPN5 attenuates cigarette smoke extract-induced apoptosis and inflammation in BEAS-2B cells.

Apoptosis and chronic inflammation are the main phenotypes in chronic obstructive pulmonary disease (COPD) pathogenesis. Cigarette smoke exposure is the leading risk factor for COPD, which causes aberrant airway epithelial structure and function. As a non-classical calpain, the molecular function of calpain5 (CAPN5) in COPD remains unclear. This study investigated the role of CAPN5 in mediating cigarette smoke extract (CSE)-induced apoptosis and inflammation. Immunohistochemistry (IHC) and Western blotting (WB) were performed to detect the location and expression of CAPN5. In vitro, BEAS-2B cells were transfected with CAPN5 siRNA or CAPN5 plasmid, followed by phosphate-buffered saline (PBS) or cigarette smoke extract (CSE) treatment. The protein expression levels of CAPN5, NF-κB p65, p-p65, IκBα, p-IκBα and apoptosis proteins (BCL-2, BAX) were measured by WB. Flow cytometry (FCM) was performed to analyze the cell apoptosis index. CAPN5 was mainly expressed in the airway epithelium and significantly decreased in the COPD-smoker and emphysema-mouse groups. Silencing CAPN5 significantly decreased the protein expression of BCL-2, IκBα, and increased p-p65 and BAX protein expression. Additionally, an increased apoptosis index was detected after silencing CAPN5. Moreover, overexpression of CAPN5 partly inhibited IκBα degradation and p65 activation, and reduced CSE-induced inflammation and apoptosis. These combined results indicate that CAPN5 could protect against CSE-induced apoptosis and inflammation, which may provide a potential therapeutic target for smoking-related COPD.

Exploring the shared gene signatures of smoking-related osteoporosis and chronic obstructive pulmonary disease using machine learning algorithms.

Objectives: Cigarette smoking has been recognized as a predisposing factor for both osteoporosis (OP) and chronic obstructive pulmonary disease (COPD). This study aimed to investigate the shared gene signatures affected by cigarette smoking in OP and COPD through gene expression profiling. Materials and methods: Microarray datasets (GSE11784, GSE13850, GSE10006, and GSE103174) were obtained from Gene Expression Omnibus (GEO) and analyzed for differentially expressed genes (DEGs) and weighted gene co-expression network analysis (WGCNA). Least absolute shrinkage and selection operator (LASSO) regression method and a random forest (RF) machine learning algorithm were used to identify candidate biomarkers. The diagnostic value of the method was assessed using logistic regression and receiver operating characteristic (ROC) curve analysis. Finally, immune cell infiltration was analyzed to identify dysregulated immune cells in cigarette smoking-induced COPD. Results: In the smoking-related OP and COPD datasets, 2858 and 280 DEGs were identified, respectively. WGCNA revealed 982 genes strongly correlated with smoking-related OP, of which 32 overlapped with the hub genes of COPD. Gene Ontology (GO) enrichment analysis showed that the overlapping genes were enriched in the immune system category. Using LASSO regression and RF machine learning, six candidate genes were identified, and a logistic regression model was constructed, which had high diagnostic values for both the training set and external validation datasets. The area under the curves (AUCs) were 0.83 and 0.99, respectively. Immune cell infiltration analysis revealed dysregulation in several immune cells, and six immune-associated genes were identified for smoking-related OP and COPD, namely, mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), tissue-type plasminogen activator (PLAT), sodium channel 1 subunit alpha (SCNN1A), sine oculis homeobox 3 (SIX3), sperm-associated antigen 9 (SPAG9), and vacuolar protein sorting 35 (VPS35). Conclusion: The findings suggest that immune cell infiltration profiles play a significant role in the shared pathogenesis of smoking-related OP and COPD. The results could provide valuable insights for developing novel therapeutic strategies for managing these disorders, as well as shedding light on their pathogenesis.

SARS-CoV-2 infection aggravates cigarette smoke-exposed cell damage in primary human airway epithelia

BackgroundThe coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a worldwide pandemic with over 627 million cases and over 6.5 million deaths. It was reported that smoking-related chronic obstructive pulmonary disease (COPD) might be a crucial risk for COVID-19 patients to develop severe condition. As cigarette smoke (CS) is the major risk factor for COPD, we hypothesize that barrier dysfunction and an altered cytokine response in CS-exposed airway epithelial cells may contribute to increased SARS-CoV-2-induced immune response that may result in increased susceptibility to severe disease. The aim of this study was to evaluate the role of CS on SARS-CoV-2-induced immune and inflammatory responses, and epithelial barrier integrity leading to airway epithelial damage.MethodsPrimary human airway epithelial cells were differentiated under air-liquid interface culture. Cells were then exposed to cigarette smoke medium (CSM) before infection with SARS-CoV-2 isolated from a local patient. The infection susceptibility, morphology, and the expression of genes related to host immune response, airway inflammation and damages were evaluated.ResultsCells pre-treated with CSM significantly caused higher replication of SARS-CoV-2 and more severe SARS-CoV-2-induced cellular morphological alteration. CSM exposure caused significant upregulation of long form angiotensin converting enzyme (ACE)2, a functional receptor for SARS-CoV-2 viral entry, transmembrane serine protease (TMPRSS)2 and TMPRSS4, which cleave the spike protein of SARS-CoV-2 to allow viral entry, leading to an aggravated immune response via inhibition of type I interferon pathway. In addition, CSM worsened SARS-CoV-2-induced airway epithelial cell damage, resulting in severe motile ciliary disorder, junctional disruption and mucus hypersecretion.ConclusionSmoking led to dysregulation of host immune response and cell damage as seen in SARS-CoV-2-infected primary human airway epithelia. These findings may contribute to increased disease susceptibility with severe condition and provide a better understanding of the pathogenesis of SARS-CoV-2 infection in smokers.

Akkermansia muciniphila Ameliorates Lung Injury in Smoke-Induced COPD Mice by IL-17 and Autophagy

Objective. Smoking is a primary hazard factor for chronic obstructive pulmonary disease (COPD), which induced a decrease in intestinal Akkermansia muciniphila abundance and Th17 imbalance in COPD. This study analyzed the changes of gut microbiota metabolism and Akkermansia abundance in patients with smoking-related COPD and explored the potential function of Akkermansia muciniphila in smoke-induced COPD mice. Methods. Gut microbiota diversity and metabolic profile were analyzed by 16S rRNA sequence and metabolomics in COPD patients. The IL-1β, IL-17, TNF-α, and IL-6 levels were tested by ELISA. Lung tissue damage was observed by HE staining. The expression of cleave-caspase 3, trophoblast antigen 2 (TROP2), and LC3 in lung tissues were analyzed by IHC or IF. The p-mTOR, mTOR, p62, and LC3 expression in lung tissues were tested by western blot. Results. The levels of IL-17, IL-1β, TNF-α, and IL-6 in the peripheral blood of COPD patients increased significantly. The number and alpha diversity of gut microbiota were decreased in COPD patients. The abundance of Akkermansia muciniphila in gut of COPD patients was decreased, and the metabolic phenotype and retinol metabolism were changed. In the retinol metabolism, the retinol and retinal were significantly changed. Akkermansia muciniphila could improve the alveolar structure and inflammatory cell infiltration in lung tissue, reduce the IL-17, TNF-α, and IL-6 levels in peripheral blood, promote the p-mTOR expression, and inhibit the expression of autophagy-related proteins in smoke-induced COPD mice. Conclusion. The number and alpha diversity of gut microbiota were decreased in patients with smoking-related COPD, accompanied by decreased abundance of Akkermansia muciniphila, and altered retinol metabolism function. Gut Akkermansia muciniphila ameliorated lung injury in smoke-induced COPD mice by inflammation and autophagy.

Cigarette smoke extract mediates cell premature senescence in chronic obstructive pulmonary disease patients by up-regulating USP7 to activate p300-p53/p21 pathway

ObjectivesTobacco hazard is one of the most severe public health issues in the world. It is believed that smoking is the most important factor leading to chronic obstructive pulmonary disease (COPD). Endothelial progenitor cells (EPCs) originate from the bone marrow and can effectively repair vascular endothelial damage and improve vascular endothelial function. Current studies suggest that EPCs senescence and EPCs depletion exist in smoking-related COPD, but the molecular mechanism remains unclear. MethodsCo-immunoprecipitation was used to detect the interaction between USP7 and p300. EPCs from smoking COPD patients were isolated, and the expressions of USP7 and p300 were detected by RT-PCR and Western Blot. Different concentrations of cigarette smoke extract (CSE) and USP7 or p300 inhibitors were used to treat EPCs, then the expression of p53, p53 target genes and aging-related genes were detected. Cell Counting Kit - 8 (CCK8) was used to detect cell proliferation, flow cytometry was used to detect cell cycle distribution, β-galactosidase (β-gal) staining and Lamp1 immunofluorescence was used to detect the proportion of aging cells. COPD mouse models were used to confirm the molecular mechanism. ResultsUSP7 and p300 interacted with each other, and USP7 affected the protein stability of p300 by regulating the ubiquitination of p300. There existed high expressions of USP7 and p300 proteins in EPCs of smoking COPD patients and COPD mouse model. CSE promoted the high expressions of USP7 and p300 in EPCs. Further studies showed that CSE mediated the USP7/p300-dependent high expression of p53 and activated the expression of p53 target genes especially p21. Activation of p53 - p21 pathway finally inhibited cell activity, led to cell cycle arrest and premature senescence of EPCs. ConclusionCSE mediated up-regulation of USP7 and p300 activated p53 - p21 pathway was a molecular mechanism that might lead to COPD.

Flavonoid intakes inversely associate with COPD in smokers.

IntroductionHigher flavonoid intakes are beneficially associated with pulmonary function parameters; however, their association with chronic obstructive pulmonary disease (COPD) is unknown. This study aimed to examine associations between intakes of 1) total flavonoids, 2) flavonoid subclasses and 3) major flavonoid compounds with incident COPD in participants from the Danish Diet, Cancer and Health study.MethodsThis prospective cohort included 55 413 men and women without COPD, aged 50–65 years at recruitment. Habitual flavonoid intakes at baseline were estimated from a food frequency questionnaire using Phenol-Explorer. Danish nationwide registers were used to identify incident cases of COPD. Associations were modelled using restricted cubic splines within Cox proportional hazards models.ResultsDuring 23 years of follow-up, 5557 participants were diagnosed with COPD. Of these, 4013 were current smokers, 1062 were former smokers and 482 were never-smokers. After multivariable adjustments, participants with the highest total flavonoid intakes had a 20% lower risk of COPD than those with the lowest intakes (quintile 5 versus quintile 1: HR 0.80, 95% CI 0.74–0.87); a 6–22% lower risk was observed for each flavonoid subclass. The inverse association between total flavonoid intake and COPD was present in both men and women but only in current smokers (HR 0.77, 95% CI 0.70–0.84) and former smokers (HR 0.82, 95% CI 0.69–0.97), not never-smokers. Furthermore, higher flavonoid intakes appeared to lessen, but not negate, the higher risk of COPD associated with smoking intensity.ConclusionDietary flavonoids may be important for partially mitigating the risk of smoking-related COPD. However, smoking cessation should remain the highest priority.

Current-Smoking-Related COPD or COPD With Acute Exacerbation is Associated With Poorer Survival Following Oral Cavity Squamous Cell Carcinoma Surgery.

The survival effect of smoking-related chronic obstructive pulmonary disease (COPD) and COPD with acute exacerbation (COPDAE) before surgery on patients with oral cavity squamous cell carcinoma (OCSCC) is unclear. Using the Taiwan Cancer Registry Database, we enrolled patients with OCSCC (pathologic stages I-IVB) receiving surgery. The Cox proportional hazards model was used to analyze all-cause mortality. We categorized the patients into 2 groups by using propensity score matching based on the pre-existing COPD status (≤1 year before surgery) to compare overall survival outcomes: Group 1 (never smokers without COPD) and Group 2 (current smokers with COPD). In multivariate Cox regression analyses, the adjusted hazard ratio (aHR; 95% confidence interval [CI]) of all-cause mortality in Group 2 compared with Group 1 was 1.07 (1.02-1.16, P = 0.041). The aHR (95% CIs) of all-cause mortality for ≥1 hospitalizations for COPDAE within 1 year before surgery for patients with OCSCC was 1.31 (1.02-1.64; P = 0.011) compared with no COPDAE in patients with OCSCC receiving surgery. Among patients with OCSCC undergoing curative surgery, current smokers with smoking-related COPD demonstrated poorer survival outcomes than did nonsmokers without COPD, for both OCSCC death and all-cause mortality. Hospitalization for COPDAE within 1 year before surgery was found to be an independent risk factor for overall survival in these patients with OCSCC. Prevention of COPD progression to COPDAE may lead to an increase in overall survival in patients with OCSCC receiving curative surgery.

Survival Impact of Current-Smoking-Related COPD or COPD with Acute Exacerbation on Bladder Preservation through Concurrent Chemoradiotherapy for Muscle-Invasive Bladder Urothelial Carcinoma.

PURPOSE: The survival effect of smoking-related chronic obstructive pulmonary disease (COPD) and COPD with acute exacerbation (COPDAE) on patients with muscle-invasive bladder urothelial carcinoma (MIBUC) receiving concurrent chemoradiotherapy (CCRT) for bladder preservation is unclear. METHODS: We recruited patients with MIBUC, clinical stages IIA–IVB, who had received maximal transurethral resection of bladder tumor (TURBT) followed by CCRT from the Taiwan Cancer Registry Database. The Cox proportional hazards model was used to analyze all-cause mortality. We categorized the patients into two groups by using propensity score matching based on the preexisting COPD status (within 1 year before CCRT) to compare overall survival outcomes: Group 1 (never smokers without COPD) and Group 2 (current smokers with COPD). RESULTS: In multivariate Cox regression analyses, the adjusted hazard ratio (aHR; 95% confidence interval (CI)) of all-cause mortality in Group 2 compared with Group 1 was 1.89 (1.12–3.18), p = 0.017. The aHRs (95% CIs) of all-cause mortality for ≥1 and ≥2 hospitalizations for COPDAE within 1 year before CCRT for bladder preservation were 3.26 (1.95–5.46) and 6.33 (3.55–11.281) compared with non-COPDAE patients with MIBUC undergoing CCRT for bladder preservation. CONCLUSIONS: Among patients with MIBUC undergoing TURBT followed by CCRT for bladder preservation, current smokers with smoking-related COPD had worse survival outcomes than did nonsmokers without COPD. CONDENSED ABSTRACT: This was the first study to estimate the survival impact of smoking-related chronic obstructive pulmonary disease (COPD) on patients with muscle-invasive bladder urothelial carcinoma (MIBUC) receiving maximal transurethral resection of bladder tumor (TURBT) followed by concurrent chemoradiotherapy (CCRT) for bladder preservation. Smoking-related COPD was a significant independent risk factor for all-cause mortality in patients with clinical stages IIA–IVB receiving TURBT followed by CCRT. Hospitalization frequency for COPD with at least one acute exacerbation within 1 year before CCRT was highly associated with high mortality for patients with MIBUC receiving CCRT for bladder preservation. Not only all-cause death but also bladder cancer death and COPD death were significantly higher in the current-smoking COPD group than in the never-smoking non-COPD group.

Survival Impact of Chronic Obstructive Pulmonary Disease or Acute Exacerbation on Patients with Rectal Adenocarcinoma Undergoing Curative Resection: A Propensity Score-Matched, Nationwide, Population-Based Cohort Study.

Simple SummaryThis study is the first to estimate the impact of smoking-related chronic obstructive pulmonary disease (COPD) in patients with rectal adenocarcinoma undergoing curative resection. In these patients, current smokers with smoking-related COPD had worse survival outcomes than nonsmokers without COPD. Moreover, hospitalization for COPD with acute exacerbation within 1 year before diagnosis was an independent risk factor for OS in these patients, with a higher number of hospitalizations being associated with poorer survival.Purpose: The survival effect of current smoking-related chronic obstructive pulmonary disease (COPD) and COPD with acute exacerbation (COPDAE) is unclear for patients with rectal adenocarcinoma undergoing curative resection. Methods: We recruited patients with clinical stage I–IIIC rectal adenocarcinoma from the Taiwan Cancer Registry Database who had received surgery. The Cox proportional hazards model was used to analyze all-cause mortality. We categorized the patients into two groups by using propensity score matching based on COPD status to compare overall survival outcomes: Group 1 (current smokers with COPD) and Group 2 (nonsmokers without COPD). Results: In the multivariate Cox regression analyses, the adjusted hazard ratio (aHR; 95% confidence interval (CI)) of all-cause mortality for Group 1 compared with Group 2 was 1.25 (1.04–1.51). The aHRs (95% cis) of all-cause mortality for frequency of ≥1 hospitalizations for COPDAE or ≥2 hospitalizations within 1 year before diagnosis were 1.17 (1.05–1.51) and 1.48 (1.03–2.41) compared with no COPDAE in patients with rectal adenocarcinoma undergoing curative resection. Conclusion: In patients with rectal adenocarcinoma undergoing curative resection, being a current smoker with COPD (Group 1) was associated with worse survival outcomes than being a nonsmoker without COPD (Group 2). Being hospitalized at least once for COPDAE within 1 year before the diagnosis of rectal adenocarcinoma is an independent risk factor for poor overall survival in these patients, and a higher number of hospitalizations for COPDAE within 1 year before diagnosis was associated with poorer survival.

Impact of Smoking-Related Chronic Obstruction Pulmonary Disease on Mortality of Invasive Ductal Carcinoma Patients Receiving Standard Treatments: Propensity Score-Matched, Nationwide, Population-Based Cohort Study.

Simple SummaryThis study is the first to estimate the impact of smoking-related chronic obstructive pulmonary disease (COPD) on invasive ductal carcinoma (IDC) patients receiving standard treatments. Smoking-related COPD was not a significant independent risk factor for all-cause mortality in women with stage I–III IDC receiving standard treatments. The frequency of hospitalization for COPD with at least one acute exacerbation within one year before breast surgery was highly associated with high mortality for women with IDC receiving standard treatments.Purpose: the survival effect of smoking-related chronic obstructive pulmonary disease (COPD) and COPD with acute exacerbation (COPDAE) is unclear for patients with invasive ductal carcinoma (IDC) receiving standard treatments. Methods: we recruited women with clinical stage I–III IDC from the Taiwan Cancer Registry Database who had received standard treatments between 1 January 2009 and 31 December 2018. The time-dependent Cox proportional hazards model was used to analyze all-cause mortality. To reduce the effects of potential confounders when all-cause mortality between Groups 1 and 2 were compared, 1:2 propensity score matching (PSM) was performed. We categorized the patients into two groups based on COPD status to compare overall survival outcomes: Group 1 (current smokers with COPD) and Group 2 (nonsmokers without COPD group). Results: PSM yielded 2319 patients with stage I–III IDC (773 and 1546 in Groups 1 and 2, respectively) eligible for further analysis. In the multivariate time-dependent Cox regression analyses, the adjusted hazard ratio (aHR; 95% confidence interval (CI)) of all-cause mortality for Group 1 compared with Group 2 was 1.04 (0.83–1.22). The aHRs (95% CIs) of all-cause mortality for ≥1 hospitalization for COPDAE within one year before breast surgery was 1.51 (1.18–2.36) compared with no COPDAE. Conclusion: smoking-related COPD was not a significant independent risk factor for all-cause mortality in women with stage I–III IDC receiving standard treatments. Being hospitalized at least once for COPDAE within one year before breast surgery is highly associated with high mortality for women with IDC receiving standard treatments. The severity of smoking-related COPD before treatments for breast cancer might be an important prognostic factor of survival. Thus, the information of the severity of COPD before treatment for breast cancer might be valuable for increasing the survival rate in treatment of breast cancer, especially in the prevention of progress from COPD to COPDAE.

Evaluation of tuberculosis associated chronic pulmonary disease at community health care: a case control study

Background: Chronic obstructive pulmonary disease (COPD) is known to occur in patients with previous history of pulmonary TB. It is still not very well known if there is any difference of clinical presentation between smoking related COPD or/and TB associated COPD. Methods: The present case control study was conducted at CHC Katra, Department of Medicine, over a period of 6 months from August 2018 to February 2018, on 100 patients; 50 suffering from COPD and 50 healthy individuals. Detailed clinical history for duration of symptoms, previous hospitalizations, and exposure to smoking along with the history of TB and ATT courses was recorded.Results: History of TB was found in 17 patients among cases and 7 patients among controls. In TB associated COPD, the pack years of smoking in case of smokers was 22.4±19.2. 44% (15/34) having exposure to smoking had history of TB. Mean age of patients exposed to smoking was (53.3±7.4) and that of non-smokers (60.1±8.2). A positive correlation with age, BMI, and duration of symptoms was found. Our results showed that almost one-third of COPD patients (34%) had history of TB. TB-associated COPD patients had similar symptoms in our study except for high frequency of hemoptysis.Conclusions: A detailed population survey is needed on COPD patients with history of TB. A larger group study among never-smokers is also needed. Finally, it is concluded that the case burden of TB associated COPD is real, huge and an urgent policy decision in this regard is mandated.

Hedgehog signaling modulates cigarette-induced COPD development.

Hedgehog (Hh) signaling is involved in early embryogenesis and maintains quiescence in the adult lungs. The interruption of Hh signaling may lead to the development of chronic obstructive pulmonary disease (COPD). The current study aimed to assess whether the Hh pathway affects cigarette-induced emphysema and airway inflammation by regulating inflammatory cytokines. C57BL/6J mice were randomized into control, cigarette smoke (CS) or CS + cyclopamine (CSC) groups. Control mice were exposed to normal room air, CS mice were exposed to tobacco smoke and CSC mice were exposed to CS and received cyclopamine treatment. Histopathological examination of lung tissues was performed, and the expression of sonic hedgehog (HH), glioma-associated oncogene homolog 1 (Gli1), hedgehog-interacting protein (HIP) and several inflammatory mediators (intracellular adhesion molecule-1, IL-6, IL-8 and TNF-α) were compared using reverse transcription-quantitative PCR and western blotting. The emphysema of lung tissues by histopathological examination demonstrated partial amelioration in the CSC group compared with that in the CS group. Additionally, expression levels of SHH, Gli1 and inflammatory mediators were significantly higher in the CS group compared with the control group but were significantly decreased in the CSC group. The expression of HIP was decreased in the CS group, but significantly increased in the CSC group. Hh signaling may serve an important role in cigarette-induced emphysema and airway inflammation by regulating inflammatory cytokines in animal models. Therefore, diminishing the activation of the Hh signal may serve as a novel therapeutic strategy for patients suffering from smoking-related COPD.

Cathelicidin induces epithelial-mesenchymal transition to promote airway remodeling in smoking-related chronic obstructive pulmonary disease

BackgroundEpithelial-mesenchymal transition (EMT) is an important characteristic in the remodeling of airways that occurs in chronic obstructive pulmonary disease (COPD). Cigarette smoke is a potential driving factor of this EMT in COPD. However, the mechanisms by which cigarette smoke induce EMT remain uncertain. Cathelicidin has been implicated as a causal factor of airway inflammation and mucus hypersecretion in smoking-related COPD. This study aimed to investigate whether cathelicidin induces EMT to promote airway remodeling in this disease.MethodsHuman lung tissue was collected from smokers with COPD and smokers without COPD. The EMT markers E-cadherin and vimentin were examined by immunohistochemistry. Mouse models of COPD were established by taking mice with airway cathelin-related antimicrobial peptide (CRAMP), the murine homologue of cathelicidin, either upregulated or downregulated by intranasal introduction of lentiviral vectors and then exposing them to cigarette smoke. E-cadherin and vimentin expression in the airways of the model mice was examined using immunofluorescence. Tumor necrosis factor alpha (TNF-α) converting enzyme (TACE), transforming growth factor alpha (TGF-α), and epidermal growth factor receptor (EGFR) expression was analyzed by Western blot. Additionally, NCI-H292 human airway epithelial cells, both with and without cathelicidin downregulation, were stimulated with cigarette smoke extract (CSE) and LL-37 synthetic peptide, a bioactive fragment of cathelicidin. This was done to confirm that the TACE/TGF-α/EGFR signaling pathway is activated in humans exposed to cigarette smoke.ResultsSignificant EMT was found in the small airways of smokers both with and without COPD, as well as in the airways of COPD model mice. Downregulation of CRAMP in COPD mice, however, ameliorated airway EMT induced by cigarette smoke. Conversely, upregulation of CRAMP enhanced airway EMT in vivo; TACE, TGF-α, and EGFR were found to be involved in this process. In vitro, EMT induced by CSE and LL-37 was inhibited by blocking TACE, TGF-α, and EGFR expression.ConclusionsCathelicidin promotes airway EMT by activating the TACE/TGF-α/EGFR signaling pathway. This mediates smoking-induced airway remodeling in the pathogenesis of COPD.

Never-smokers with occupational COPD have better exercise capacities and ventilatory efficiency than matched smokers with COPD.

Chronic obstructive pulmonary disease (COPD) in never-smokers exposed to organic dusts is still poorly characterized. Therapeutic strategies in COPD are only evaluated in smoking-related COPD. Understanding how never-smokers with COPD behave during exercise is an important prerequisite for optimal management. The objective of this study was to compare physiological parameters measured during exercise between never-smokers with COPD exposed to organic dusts and patients with smoking-related COPD matched for age, sex, and severity of airway obstruction. Healthy control subjects were also studied. Dyspnea (Borg scale), exercise tolerance, and ventilatory constraints were assessed during incremental cycle cardiopulmonary exercise testing in COPD patients at mild to moderate stages [22 exposed to organic dusts: postbronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) z score -2.44 ± 0.72 and FEV1z score -1.45 ± 0.78; 22 with smoking-related COPD: FEV1/FVC z score -2.45 ± 0.61 and FEV1z score -1.43 ± 0.69] and 44 healthy control subjects (including 22 never-smokers). Despite the occurrence of similar significant dynamic hyperinflation, never-smoker COPD patients exposed to organic dusts had lower dyspnea ratings than those with smoking-related COPD. They also had better ventilatory efficiency, higher peak oxygen consumption and peak power output than smoking-related COPD patients, all these parameters being similar to control subjects. Differences in exercise capacity between the two COPD groups were mainly driven by better ventilatory efficiency stemming from preserved diffusion capacity. Never-smokers exposed to organic dusts with mild to moderate COPD have better exercise capacities, better ventilatory efficiency, and better diffusion capacity than matched patients with smoking-related COPD.NEW & NOTEWORTHY It is unknown whether or not never-smokers with chronic obstructive pulmonary disease (COPD) behave like their smoking counterparts during exercise. This is the first study showing that never-smokers with mild to moderate COPD [defined by a postbronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < lower limit of normal] have preserved exercise capacities. They also have lower exertional dyspnea than patients with smoking-related COPD. This suggests that the two COPD groups should not be managed in the same way.

Diagnostic ability of the Timed Up & Go test for balance impairment prediction in chronic obstructive pulmonary disease.

BackgroundBalance assessment is now recommended by clinical practice guidelines, specific tests have yet to be suggested. The Timed Up and Go (TUG) test is a simple measure of balance status and functional mobility. Nowadays, we need more data of an optimum cut off point of TUG time for detecting balance impairment in patients with chronic obstructive pulmonary disease (COPD). Thus the aim of this study was to evaluate the diagnostic ability relative to balance impairment of the TUG in subjects with COPD.MethodsThe cross-sectional study was conducted in stable COPD patient at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand from November 2015 to October 2017. Balance impairment test was measured using the Berg Balance Scale (BBS), a score of ≤45 indicates balance impairment. The TUG was evaluated using sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR−), Youden’s index, and the area under receiver operating characteristic curve (AUROC) from various points of TUG to identify the optimum cut-off point for detecting balance impairment. Multivariable logistic regressions were performed to identify the optimum cut off point of TUG test time for prediction of balance impairment in COPD.ResultsOne hundred and eighteen smoking related COPD subjects 86 (72.9% male) with a mean age of 73.5±8.1 years were included in this study. Univariable analysis showed that the AUROC of TUG test to indicate those who had impaired balance was 0.93 [95% confidence interval (CI): 0.88, 0.98]. A cut off point of TUG test time ≥12 seconds had sensitivity, specificity, LR+, LR−, Youden’s index, and AUROC of 95.8%, 90.4%, 10.01, 0.05, 86.2, and 0.93 for detecting balance impairment, respectively. Multivariable analysis identified the TUG test time ≥12 seconds was the best predictor of balance impairment in COPD patients with adjusted risk ratio (RR) of 25.2 (95% CI: 1.6, 312.0, P=0.021) and, the AUROC was 0.98 (95% CI; 0.96, 1.00).ConclusionsOur study indicates the TUG test time ≥12 seconds has a high diagnostic ability for balance impairment prediction in COPD. The result supports a potential role for this simple test to be incorporated into routine COPD assessment to stratify patients’ balance.

Investigation of the Obesity Paradox in Chronic Obstructive Pulmonary Disease, According to Smoking Status, in the United States.

An obesity paradox in chronic obstructive pulmonary disease (COPD), whereby overweight/obese individuals have improved survival, has been well-described. These studies have generally included smokers. It is unknown whether the paradox exists in individuals with COPD arising from factors other than smoking. Nonsmoking COPD is understudied yet represents some 25%-45% of the disease worldwide. To determine whether the obesity paradox differs between ever- and never-smokers with COPD, 1,723 adult participants with this condition were examined from 2 iterations of the National Health and Nutrition Examination Survey (1988-1994, 2007-2010), with mortality outcomes followed through December 2011. Using Cox proportional hazards models, adjusted for sociodemographic factors, lung function, and survey cycle, ever/never-smoking was found to modify the association between body mass index and hazard of death. Compared with normal-weight participants, overweight/obese participants had lower hazard of death among ever-smokers (for overweight, adjusted hazard ratio (aHR) = 0.56, 95% confidence interval (CI): 0.43, 0.74; for obesity, aHR = 0.66, 95% CI: 0.48, 0.92), but never-smokers did not (overweight, aHR = 1.41, 95% CI: 0.66, 3.03; obesity, aHR = 1.29, 95% CI: 0.48, 3.48). An obesity paradox appeared to be absent among never-smokers with COPD. This, to our knowledge, novel finding might be explained by pathophysiological differences between smoking-related and nonsmoking COPD or by smoking-associated methodological biases.

Comparison of oxidant/antioxidant balance in COPD and non-COPD smokers

Background/aimOxidative stress plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Smoking is the leading source of oxidants in lungs. However, it is currently unknown why some individuals are more resistant to the detrimental effects of smoking and do not develop COPD. The aim in this study is to measure and compare the oxidant/antioxidant balance between in non-COPD individuals who smoke and COPD patients who smoke. Materials and methodsIncluded in the study were 137 patients with COPD and 102 healthy individuals. Participants were divided into groups as COPD patients (former and current smokers), non-COPD individuals who smoke and non-smokers healthy persons. In the following stage, the total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) levels were measured in serum for all participants. ResultsIn the current-smoker COPD group, the level of oxidant status were significantly higher than the former-smoker COPD group (p < 0.001). Similarly, oxidant levels were significantly high in current-smoker healthy group than never smoker healthy group. According to these results TOS was associated with especially smoking status rather than COPD. Antioxidant status were similar between former-smoker COPD group and current-smoker COPD group. The antioxidant levels were found significantly low in current-smoker COPD patients, compared to the current-smoker non-COPD individuals (p = 0.007). Nevertheless, no significant difference was found in OSI levels between two groups. Briefly, high TOS and OSI values were correlated with only smoking, independently from COPD. ConclusionIt was concluded that there are complex pathogenetic mechanisms, including genetic and individual variations other than oxidant/antioxidant balance, involved in the development of smoking-related COPD. TOS and OSI values are not predictive parameters for the development of COPD, but high level of TAS in non-COPD smokers is promising for future studies.

DNA Methylation Changes in Regional Lung Macrophages Are Associated with Metabolic Differences.

A number of pulmonary diseases occur with upper lobe predominance, including cystic fibrosis and smoking-related chronic obstructive pulmonary disease. In the healthy lung, several physiologic and metabolic factors exhibit disparity when comparing the upper lobe of the lung to lower lobe, including differences in oxygenation, ventilation, lymphatic flow, pH, and blood flow. In this study, we asked whether these regional differences in the lung are associated with DNA methylation changes in lung macrophages that could potentially lead to altered cell responsiveness upon subsequent environmental challenge. All analyses were performed using primary lung macrophages collected via bronchoalveolar lavage from healthy human subjects with normal pulmonary function. Epigenome-wide DNA methylation was examined via Infinium MethylationEPIC (850K) array and validated by targeted next-generation bisulfite sequencing. We observed 95 CpG loci with significant differential methylation in lung macrophages, comparing upper lobe to lower lobe (all false discovery rate < 0.05). Several of these genes, including CLIP4, HSH2D, NR4A1, SNX10, and TYK2, have been implicated as participants in inflammatory/immune-related biological processes. Functionally, we identified phenotypic differences in oxygen use, comparing upper versus lower lung macrophages. Our results support a hypothesis that epigenetic changes, specifically DNA methylation, at a multitude of gene loci in lung macrophages are associated with metabolic differences regionally in lung.

Using Hyperpolarized Xenon-129 MRI to Quantify Early-Stage Lung Disease in Smokers

Hyperpolarized xenon-129 magnetic resonance (MR) provides sensitive tools that may detect early stages of lung disease in smokers before it has progressed to chronic obstructive pulmonary disease (COPD) apparent to conventional spirometric measures. We hypothesized that the functional alveolar wall thickness as assessed by hyperpolarized xenon-129 MR spectroscopy would be elevated in clinically healthy smokers before xenon MR diffusion measurements would indicate emphysematous tissue destruction. Using hyperpolarized xenon-129 MR we measured the functional septal wall thickness and apparent diffusion coefficient of the gas phase in 16 subjects with smoking-related COPD, 9 clinically healthy current or former smokers, and 10 healthy never smokers. All subjects were age-matched and characterized by conventional pulmonary function tests. A total of 11 data sets from younger healthy never smokers were added to determine the age dependence of the septal wall thickness measurements. In healthy never smokers the septal wall thickness increased by 0.04 μm per year of age. The healthy smoker cohort exhibited normal pulmonary function test measures that did not significantly differ from the never-smoker cohort. The age-corrected septal wall thickness correlated well with diffusion capacity for carbon monoxide (R2 = 0.56) and showed a highly significant difference between healthy subjects and COPD patients (8.8 μm vs 12.3 μm; p < 0.001), but was the only measure that actually discriminated healthy subjects from healthy smokers (8.8 μm vs 10.6 μm; p < 0.006). Functional alveolar wall thickness assessed by hyperpolarized xenon-129 MR allows discrimination between healthy subjects and healthy smokers and could become a powerful new measure of early-stage lung disease.