Chronic obstructive pulmonary disease: a concise review

Poor Translatability of Biomedical Research Using Animals - A Narrative Review

The failure rate for the translation of drugs from animal testing to human treatments remains at over 92%, where it has been for the past few decades. The majority of these failures are due to unexpected toxicity - that is, safety issues revealed in human trials that were not apparent in animal tests - or lack of efficacy. However, the use of more innovative tools, such as organs-on-chips, in the preclinical pipeline for drug testing, has revealed that these tools are more able to predict unexpected safety events prior to clinical trials and so can be used for this, as well as for efficacy testing. Here, we review several disease areas, and consider how the use of animal models has failed to offer effective new treatments. We also make some suggestions as to how the more human-relevant new approach methodologies might be applied to address this.

A Review of Non-Invasive Drug Delivery through Respiratory Routes

With rapid and non-invasive characteristics, the respiratory route of administration has drawn significant attention compared with the limitations of conventional routes. Respiratory delivery can bypass the physiological barrier to achieve local and systemic disease treatment. A scientometric analysis and review were used to analyze how respiratory delivery can contribute to local and systemic therapy. The literature data obtained from the Web of Science Core Collection database showed an increasing worldwide tendency toward respiratory delivery from 1998 to 2020. Keywords analysis suggested that nasal and pulmonary drug delivery are the leading research topics in respiratory delivery. Based on the results of scientometric analysis, the research hotspots mainly included therapy for central nervous systems (CNS) disorders (Parkinson's disease, Alzheimer's disease, depression, glioblastoma, and epilepsy), tracheal and bronchial or lung diseases (chronic obstructive pulmonary disease, asthma, acute lung injury or respiratory distress syndrome, lung cancer, and idiopathic pulmonary fibrosis), and systemic diseases (diabetes and COVID-19). The study of advanced preparations contained nano drug delivery systems of the respiratory route, drug delivery barriers investigation (blood-brain barrier, BBB), and chitosan-based biomaterials for respiratory delivery. These results provided researchers with future research directions related to respiratory delivery.

Clinical Effects of Rehabilitation on Balance in People With Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Background

Patients with chronic obstructive pulmonary disease (COPD) have systemic damage secondary to the primary pulmonary impairment, expressed in impaired peripheral musculature and a deficit in postural control compared to healthy subjects. This study aimed to determine the effects of rehabilitation on balance in patients with COPD.

Methods

An exhaustive search was conducted in four databases (Pubmed, Cochrane Library, EMBASE, Web of Science). Articles with a population of COPD receiving rehabilitation (therapeutic exercise, pulmonary rehabilitation, or physical therapy modalities) in an outpatient setting were included. Two independent reviewers selected and assessed the study quality. The risk of bias was assessed with the Cochrane Risk of Bias Tool for Randomized Controlled Trials.

Results

A total of eight studies involving 284 patients were included in the qualitative synthesis. The meta-analysis showed an overall result in favor of balance training for the Berg Balance Scale (mean difference 3.91 points; 95% CI: 1.51 to 6.31; P = 0.001), Timed Up and Go test (mean difference -1.58 s; 95% CI: -2.63 to -0.53; P = 0.003) and Unipedal stance test (mean difference 3.56 s, 95% CI: 2.58 to 4.54; P).

Conclusion

This meta-analysis revealed that rehabilitation improve static and dynamic balance in patients with COPD.

Systematic Review Registration

PROSPERO ID: CRD42020218367.

The Effect of Ocimum basilicum L. and Its Main Ingredients on Respiratory Disorders: An Experimental, Preclinical, and Clinical Review

Ocimum basilicum L. (O. basilicum) and its constituents show anti-inflammatory, immunomodulatory, and antioxidant effects. The plant has been mainly utilized in traditional medicine for the treatment of respiratory disorders. In the present article, effects of O. basilicum and its main constituents on respiratory disorders, assessed by experimental and clinical studies, were reviewed. Relevant studies were searched in PubMed, Science Direct, Medline, and Embase databases using relevant keywords including “Ocimum basilicum,” “basilicums,” “linalool,” “respiratory disease,” “asthma,” “obstructive pulmonary disease,” “bronchodilatory,” “bronchitis,” “lung cancer,” and “pulmonary fibrosis,” and other related keywords.The reviewed articles showed both relieving and preventing effects of the plant and its ingredients on obstructive pulmonary diseases such as chronic obstructive pulmonary disease (COPD), asthma, and other respiratory disorders such as bronchitis, aspergillosis tuberculosis, and lung cancer. The results of the reviewed articles suggest the therapeutic potential of O. basilicum and its constituent, linalool, on respiratory disorders.

Oral Candidal Load and Oral Health Status in Chronic Obstructive Pulmonary Disease (COPD) Patients: A Case-Cohort Study

Objective

The objective of this study was to determine the candidal load of the patients with Chronic Obstructive Pulmonary Disease (COPD) and evaluate the oral health status of subjects with COPD. Material and Methods. N = 112 COPD subjects and N = 100 control subjects were included in the study. The selection of COPD cases was confirmed based on the set criteria from the American College of Physicians. The oral health status was assessed as per WHO criteria to determine the score of decayed, missing, and filled teeth (DMFT), significant caries index (SiC), community periodontal index and treatment needs (CPITN), and oral hygiene index-simplified (OHI-S). Gram staining was performed to identify Candida using the whole saliva. Quantitative evaluation of the candidal load was carried out using Sabouraud Dextrose Agar (SDA). Chrome agar was used to differentiate between the commensal carriages. A statistical analysis paired t-test and 95% confidence interval (CI) for proportions was carried out using STATA software.

Results

Candidal growth was found in 21.42% (n = 24) of COPD cases and 1.1% (n = 11) of control cases (p < 0.05) (95% CI 0.45, 0.59). The DMFT score was 8.26 in COPD subjects and 4.6 in controls, the SiC score was 16.42 in COPD subjects and 10.25 in controls, and the CPITN score for both COPD and control cases was score 2.

Conclusion

In conclusion, there was a higher candidal load among subjects suffering from COPD. Theophylline medication can be a risk factor for increased candidal load in COPD patients.

Pulmonary route of administration is instrumental in developing therapeutic interventions against respiratory diseases

Pulmonary route of drug delivery has drawn significant attention due to the limitations associated with conventional routes and available treatment options. Drugs administered through pulmonary route has been an important research area that focuses on to developing effective therapeutic interventions for asthma, chronic obstructive pulmonary disease, tuberculosis, lung cancer etc. The intravenous route has been a natural route of delivery of proteins and peptides but associated with several issues including high cost, needle-phobia, pain, sterility issues etc. These issues might be addressed by the pulmonary administration of macromolecules to achieving an effective delivery and efficacious therapeutic impact. Efforts have been made to develop novel drug delivery systems (NDDS) such as nanoparticles, microparticles, liposomes and their engineered versions, polymerosomes, micelles etc to achieving targeted and sustained delivery of drug(s) through pulmonary route. Further, novel approaches such as polymer-drug conjugates, mucoadhesive particles and mucus penetrating particles have attracted significant attention due to their unique features for an effective delivery of drugs. Also, use of semi flourinated alkanes is in use for improvising the pulmonary delivery of lipophilic drugs. Present review focuses on to unravel the mechanism of pulmonary absorption of drugs for major pulmonary diseases. It summarizes the development of interventional approaches using various particulate and vesicular drug delivery systems. In essence, the orchestrated attempt presents an inflammatory narrative on the advancements in the field of pulmonary drug delivery.

Therapeutic effects of black seed oil supplementation on chronic obstructive pulmonary disease patients: A randomized controlled double blind clinical trial

This study sought to examine whether supplementation of Black Seed Oil (BSO) can improve pulmonary function tests (PFTs), inflammation, and oxidant-antioxidant markers in COPD patients. The study involved 100 patients of mild to moderate COPD divided randomly into 2 groups who were appointed to receive standard medication only (control group) or with additional Black Seed Oil (BSO group). They were assessed initially and after 3 months, 44 patients responded in control group and 47 patients in BSO group. BSO group evidenced a significant decreasing in oxidant and inflammatory markers; thiobarbituric acid reactive-substances (TBARS), protein carbonyl (PC) content, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), a significant increase in antioxidants; superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GPx), vitamin C, and E, and a significant improvement in PFTs versus control group and baseline levels. Supplementation of Black Seed Oil may be an effective adjunct therapy to improve pulmonary functions, inflammation, and oxidant-antioxidant imbalance in COPD patients.

HSP90AA1, ADRB2, TBL1XR1 and HSPB1 are chronic obstructive pulmonary disease-related genes that facilitate squamous cell lung cancer progression

Chronic obstructive pulmonary disease (COPD) and squamous cell lung carcinoma (SCC) are smoking-related diseases. However, the connection between the two is poorly understood. Microarray gene expression profiles in bronchial epithelium from patients with SCC with or without COPD were downloaded from the Gene Expression Omnibus repository. Differentially expressed genes associated with COPD and SCC were identified and visualized using the Advanced Network Merger module in Cytoscape. COPD-associated genes in SCC progression were further identified using the BisoGenet plug-in in Cytoscape. The genetic interaction network was predicted using the Network Analysis function. Heat shock protein 90 α family class A member 1 (HSP90AA1), adrenoceptor β2 (ADRB2), transducin β like 1 X-linked receptor 1 (TBL1XR1) and heat shock protein family B (small) member 1 (HSPB1) were identified to be differentially expressed in SCC and COPD cases. The overall survival rate associated with the gene signatures was investigated using clinical samples from patients with SCC and COPD from the PROGgene database. The results suggest that the pathogenesis of SCC caused by COPD is regulated by HSP90AA1, ADRB2, TBL1XR1 and HSPB1. These genes may serve as potential therapeutic targets for the treatment of patients with COPD-related SCC.

Isosteroid alkaloids from Fritillaria cirrhosa bulbus as inhibitors of cigarette smoke-induced oxidative stress

Fritillaria cirrhosa bulbus is a Chinese folk herb famous for its antitussive, expectorant, anti-asthma and anti-inflammatory properties, and is widely used to treat respiratory diseases. However, the impacts of F. cirrhosa bulbus on oxidative stress are still unkown. In the present study, we investigated the potential effect and mechanism of six isosteroid alkaloids with different chemical structures from F. cirrhosa bulbus on protection against cigarette smoke-induced oxidative stress in RAW264.7 macrophages. The results showed that six isosteroid alkaloids reduced reactive oxygen species (ROS) production, elevated glutathione (GSH) level and promoted heme oxygenase (HO-1) expression, which is in association with induction of NF-E2-related factor 2 (Nrf2) nuclear translocation and up-regulation of Nrf2 expression. Among these alkaloids, verticinone, verticine, imperialine-3-β-D-glucoside, delavine and peimisine exhibited more potent effect against CSE-induced oxidative stress than that of imperialine. These findings for the first time demonstrated that F. cirrhosa bulbus may play a protective role in cellular oxidative stress by activating Nrf2-mediated antioxidant pathway. Furthermore, the differences in antioxidant effects of these alkaloids were compared, as well as the corresponding structure-activity relationships were preliminarily elucidated. This suggested that F. cirrhosa bulbus might be a promising therapeutic treatment for the prevent of oxidative stress-related diseases.

Functional variations of the TLR4 gene in association with chronic obstructive pulmonary disease and pulmonary tuberculosis

Objective

Chronic obstructive pulmonary disease (COPD) and pulmonary tuberculosis (PTB) share a number of common risk factors, including innate immunity-related genetic factors. In the present study, we compared the role of genetic variations of the TLR4 gene in susceptibility to COPD and PTB and illuminated the underlying molecular mechanism of functional single-nucleotide polymorphisms (SNPs).

Methods

A population-based case control study was performed in a Chinese Han population and included 152 COPD cases, 1601 PTB cases and 1727 controls. Five SNPs in the TLR4 gene (rs10759932, rs2737190, rs7873784, rs11536889, and rs10983755) were genotyped using TaqMan allelic discrimination technology. We estimated the effects of SNPs using the odds ratio (OR) together with 95% confidence interval (CI). Dual-luciferase reporter vectors expressing different genotypes of SNPs were constructed and transfected into the human HEK 293 T cell line to explore their effects on potential transcription activity.

Results

After Bonferroni correction, the genetic polymorphisms of all five SNPs remained significantly associated with COPD, while rs10759932 and rs2737190 were also associated with PTB. Compared with rs10759932-TT, individuals carrying TC (OR: 0.42, 95% CI: 0.28–0.64) or CC (OR: 0.24, 95% CI: 0.09–0.63) had a significantly reduced risk of COPD. However, individuals carrying TC (OR: 1.28, 95% CI: 1.11–1.49) or CC (OR: 1.26, 95% CI: 0.98–1.62) had an increased risk of PTB. The OR (95% CI) for allele rs10759932-C was 0.45 (0.32–0.62) for COPD and 1.18 (1.07–1.32) for PTB. For rs2737190, heterozygous AG was related to a decreased risk of COPD (OR: 0.32, 95% CI: 0.21–0.49) and an increased risk of PTB (OR: 1.30, 95% CI: 1.11–1.52). The dual-luciferase reporter assay showed decreased transcription activity caused by rs10759932-C and rs2737190-G.

Conclusion

Genetic polymorphisms of rs10759932 and rs2737190 in TLR4 are significantly related to both COPD and PTB but with inverse effects. The altered transcription activity caused by mutations in these two loci may partly explain the observed relationship.

Stem cell-based Lung-on-Chips: The best of both worlds?

Pathologies of the respiratory system such as lung infections, chronic inflammatory lung diseases, and lung cancer are among the leading causes of morbidity and mortality, killing one in six people worldwide. Development of more effective treatments is hindered by the lack of preclinical models of the human lung that can capture the disease complexity, highly heterogeneous disease phenotypes, and pharmacokinetics and pharmacodynamics observed in patients. The merger of two novel technologies, Organs-on-Chips and human stem cell engineering, has the potential to deliver such urgently needed models. Organs-on-Chips, which are microengineered bioinspired tissue systems, recapitulate the mechanochemical environment and physiological functions of human organs while concurrent advances in generating and differentiating human stem cells promise a renewable supply of patient-specific cells for personalized and precision medicine. Here, we discuss the challenges of modeling human lung pathophysiology in vitro, evaluate past and current models including Organs-on-Chips, review the current status of lung tissue modeling using human pluripotent stem cells, explore in depth how stem-cell based Lung-on-Chips may advance disease modeling and drug testing, and summarize practical consideration for the design of Lung-on-Chips for academic and industry applications.

Altered serum levels of type I collagen turnover indicators accompanied by IL-6 and IL-8 release in stable COPD

BACKGROUND

COPD, characterized by chronic inflammation and airway remodeling, has significant pathological alterations in composition and deposition of the extracellular matrix. The expression of procollagen 1 C-terminal peptide (PICP) and collagen type 1 C-terminal telopeptide (ICTP), two major by-products in the synthesis and degradation of collagen, was shown to be positively correlated with inflammatory mediator levels in previous studies.

PURPOSE

In this study, we investigated whether the serum concentrations of PICP and ICTP were associated with the inflammation level for patients with stable COPD.

PATIENTS AND METHODS

We collected serum samples from 25 control subjects and 20 patients with stable COPD from December 2011 to October 2012 in Shanghai Zhongshan Hospital and Shanghai Dahua Hospital. We determined concentrations of PICP, ICTP, C-reactive protein (CRP), IL-6, IL-8, and tumor necrosis factor (TNF)-α by using enzyme-linked immunosorbent assay methods.

RESULTS

Demographic characteristics were comparable between the two groups. In patients with stable COPD, serum levels of CRP, IL-6, IL-8, and TNF-α were all elevated compared to control subjects, but only changes of IL-6 achieved statistical significance. Serum concentration of PICP was significantly elevated in patients with COPD, and level of ICTP was slightly decreased. Moreover, serum concentrations of PICP were positively correlated with the levels of both IL-6 and IL-8.

CONCLUSION

The increased levels of serum PICP in COPD might indicate the condition of airway remodeling, and IL-6 and/or IL-8 might play an important role in stimulating collagen synthesis.

Clinical, demographic and radiological profile of smoker COPD versus nonsmoker COPD patients at a tertiary care center in North India

Introduction

Cigarette smoking is the most predominant risk factor for development of chronic obstructive pulmonary disease (COPD). However, a considerable amount of patients do develop COPD without exposure to cigarette smoking. We aimed to analyze the incidence, demographic and clinical profile of nonsmoker COPD subjects at a tertiary care center.

Methods

In this prospective observational study, 410 patients were screened for dyspnea. On the basis of spirometry findings, 360 patients were diagnosed as COPD and enrolled into the study. Patients were categorized into 2 groups on the basis of smoking habits (smoker and nonsmoker COPD). Clinical and demographic attributes were compared in between these two groups. This study was conducted over a period of one year, from August 2014 to July 2015. All statistical analyses were performed using Statistical Package for the Social Sciences version 19.0 (SPSS Inc, Chicago, IL, USA). Values were considered to be statistically significant at P < 0.05.

Results

Out of 360 COPD cases, about 2/3^rd (60%) were smokers and the rest nonsmokers. Majority of the patients were in the age group of 51-70 years. The mean age of smokers with COPD was significantly higher than nonsmokers with COPD (59.29 ± 10.28 years vs. 53.90 ± 8.77 years; P = 0.0001). Overall, males were predominant (57.2%) but there were higher number of female patients in nonsmoker group (25% vs. 70%; P = 0.001). At presentation, majority of nonsmoker with COPD were in GOLD severity grade II while in the smoking cohort majority were in GOLD severity Grade III. Among the 144 nonsmoker COPD patients, the most important and statistically significant risk factor was exposure to biomass smoke (68.06%). Other risk factors were long-standing asthma (37.50%), lower respiratory tract infection in childhood (32.60%), exposure to outdoor air pollution (17.92%).

Conclusion

Nonsmoker COPD is emerging as a distinctive phenotype. They have less impairment in airflow limitation, and a lower prevalence of emphysema, chronic cough, and sputum compared with their smoking counterparts.

A machine learning approach to triaging patients with chronic obstructive pulmonary disease

COPD patients are burdened with a daily risk of acute exacerbation and loss of control, which could be mitigated by effective, on-demand decision support tools. In this study, we present a machine learning-based strategy for early detection of exacerbations and subsequent triage. Our application uses physician opinion in a statistically and clinically comprehensive set of patient cases to train a supervised prediction algorithm. The accuracy of the model is assessed against a panel of physicians each triaging identical cases in a representative patient validation set. Our results show that algorithm accuracy and safety indicators surpass all individual pulmonologists in both identifying exacerbations and predicting the consensus triage in a 101 case validation set. The algorithm is also the top performer in sensitivity, specificity, and ppv when predicting a patient's need for emergency care.

Temporal and Spatial Expression of Transforming Growth Factor-β after Airway Remodeling to Tobacco Smoke in Rats

Airway remodeling is strongly correlated with the progression of chronic obstructive pulmonary disease (COPD). In this study, our goal was to characterize progressive structural changes in site-specific airways, along with the temporal and spatial expression of transforming growth factor (TGF)-β in the lungs of male spontaneously hypertensive rats exposed to tobacco smoke (TS). Our studies demonstrated that TS-induced changes of the airways is dependent on airway generation and exposure duration for proximal, midlevel, and distal airways. Stratified squamous epithelial cell metaplasia was evident in the most proximal airways after 4 and 12 weeks but with minimal levels of TGF-β-positive epithelial cells after only 4 weeks of exposure. In contrast, epithelial cells in midlevel and distal airways were strongly TGF-β positive at both 4 and 12 weeks of TS exposure. Airway smooth muscle volume increased significantly at 4 and 12 weeks in midlevel airways. Immunohistochemistry of TGF-β was also found to be significantly increased at 4 and 12 weeks in lymphoid tissues and alveolar macrophages. ELISA of whole-lung homogenate demonstrated that TGF-β2 was increased after 4 and 12 weeks of TS exposure, whereas TGF-β1 was decreased at 12 weeks of TS exposure. Airway levels of messenger RNA for TGF-β2, as well as platelet-derived growth factor-A, granulocyte-macrophage colony-stimulating factor, and vascular endothelial growth factor-α, growth factors regulated by TGF-β, were significantly decreased in animals after 12 weeks of TS exposure. Our data indicate that TS increases TGF-β in epithelial and inflammatory cells in connection with airway remodeling, although the specific role of each TGF-β isoform remains to be defined in TS-induced airway injury and disease.

Antiinflammatory, Antioxidant, and Immunomodulatory Effects of Crocus sativus L. and its Main Constituents

Crocus sativus L. (C. sativus), commonly known as saffron, is used as a food additive, preservative, and medicinal herb. Traditionally, it has been used as an alternative treatment for different diseases. C. sativus' medicinal effects are related to its major constituents like crocins, crocetin, and safranal. According to the literature, C. sativus and its constituents could be considered as an effective treatment for neurodegenerative disorders, coronary artery diseases, asthma, bronchitis, colds, fever, diabetes, and so on. Recently, numerous studies have reported such medicinal properties and found that the underlying mechanisms of action may be mediated by antioxidant, inflammatory, and immunomodulatory effects. C. sativus enhances the antioxidant capacity and acts as a free radical scavenger. As an antiinflammatory and immunomodulatory agent, it modulates inflammatory mediators, humoral immunity, and cell-mediated immunity responses. This review highlights in vitro and animal findings regarding antiinflammatory, antioxidant, and immunomodulatory effects of C. sativus and its constituents. Present review found that the C. sativus and its main constituents such as safranal, crocins, and crocetin could be effective against various diseases because of their antioxidant, anti-inflammation, and immunomodulatory effects. Copyright © 2016 John Wiley & Sons, Ltd.

Burden of obstructive lung disease study in Tehran: Prevalence and risk factors of chronic obstructive pulmonary disease

Background:

Chronic obstructive pulmonary disease (COPD) was ranked the sixth-most common cause of death worldwide in 1990, but now it is the third-most common cause. The goal of the present study was to assess the prevalence and determine the causes and risk factors of COPD in Tehran.

Materials and Methods:

This study followed a stratified cluster sampling strategy with proportional allocation within strata. The target population was all non-institutionalized inhabitants, aged 18 to 40 in one group and over 40 in another who resided in Tehran in 2013. The core questionnaire was developed from pre-existing validated questionnaires that had already been used in multi-national studies. The single most important outcome measure obtained as part of this protocol was spirometry before and after the administration of 200 mg (two puffs) of salbutamol.

Results:

The most commonly reported respiratory symptoms were: sputum production in 291 patients (16.2%) [95% confidence interval (CI): 14.5-17.9%], chronic cough in 171 (9.5%) (95% CI: 8.2-10.9%), wheezing in 377 (21.0%) (95%CI: 19.1-22.9%) and dyspnea in 388 patients (21.6%) (95% CI: 19.7-23.5%). The overall COPD prevalence defined by the post-bronchodilator spirometric functional criteria was 9.2%. This value in men (10.1%) was higher than in women (8.5%); the prevalence was significantly higher in subjects aged over 55 years (P ≤ 0.002). The prevalence of COPD was strongly dependent on smoking status, especially in ex-smokers, and increased considerably with age. 69% of patients with COPD were non-smoker.

Conclusion:

The high prevalence of verified COPD, a great deal of which was undiagnosed before by a physician, highlights the necessity of raising awareness of this disease among health professionals, and use of spirometry in the primary care setting. A future cross-sectional and prospective cohort study should be performed to explore all risk factors and their impact on decline in lung function and worsening of respiratory symptoms especially in non-smokers.

Bioactive lipid profiling reveals drug target engagement of a soluble epoxide hydrolase inhibitor in a murine model of tobacco smoke exposure

The inflammatory process underlying chronic obstructive pulmonary disease (COPD) may be caused by tobacco smoke (TS) exposure. Previous studies show that epoxyeicosatrienoic acids (EETs) possess promising anti-inflammatory properties, therefore stabilization of EETs and other fatty acid epoxides through inhibition of soluble epoxide hydrolase (sEH) was investigated in mouse models of acute and sub-chronic inflammation caused by TS exposure. During the entire TS exposure, the potent sEH inhibitor 1-(1-methylsulfonyl-piperidin-4-yl)-3-(4-trifluoromethoxy-phenyl)-urea (TUPS) was given via drinking water. To assess drug target engagement of TUPS, a tandem mass spectrometry method was used for bioactive lipid profiling of a broad range of fatty acid metabolites, including EETs, and their corresponding diols (DHETs) derived from arachidonic acid, as well as epoxides and diols derived from other fatty acids. Several, but not all, plasma epoxide/diol ratios increased in mice treated with sEH inhibitor, compared to non-treated mice suggesting a wider role for sEH involving more fatty acid precursors besides arachidonic acid. This study supports qualitative use of epoxide/diol ratios explored by bioactive lipid profiling to indicate drug target engagement in mouse models of TS exposure relevant to COPD, which may have ramifications for future therapeutic interventions of sEH.

Increased serum levels of lipocalin-1 and -2 in patients with stable chronic obstructive pulmonary disease

Despite a number of studies on biomarkers in chronic obstructive pulmonary disease (COPD), only a few disease-related markers have been identified, yet we still have no satisfactory markers specific to innate immune system and neutrophil activation, which is essential in airway inflammation in COPD. Recent biological studies indicated that lipocalins (LCNs) might be involved in airway inflammation and innate immunity; however, results from available studies on the association of LCNs with COPD are not consistent. We carried out a multicenter prospective observational cohort study to investigate the differences in serum levels of LCN1 and LCN2 between subjects with COPD (n=58) and healthy controls (n=29). Several validated inflammatory markers, including C-reactive protein, tumor necrosis factor-α, interleukin-6, and interleukin-8, were measured. The correlation of LCN1 and LCN2 with clinical features such as smoking habits, lung function, symptoms, and disease category was also analyzed. When comparing with healthy controls, serum levels of LCN1 (66.35±20.26 ng/mL versus 41.16±24.19 ng/mL, P<0.001) and LCN2 (11.29±3.92 ng/mL versus 6.09±5.13 ng/mL, P<0.001) were both elevated in subjects with COPD after adjusting for age, sex, smoking habits, and inflammatory biomarkers. Smoking history and tobacco exposure, as quantified by pack-year, had no impact on systemic expressions of LCN1 and LCN2 in our study. Blood levels of LCN1 and LCN2, respectively, were negatively correlated to COPD Assessment Test and Modified Medical British Research Council score (P<0.001). Disease category by Global Initiative for Chronic Obstructive Lung Disease grade 1–4 or group A–D was not associated with levels of LCNs. Patient-reported exacerbations and body mass index were also tested, but no relationship with LCNs was found. In summary, serum concentrations of LCN1 and LCN2 were both elevated in patients with COPD, with their levels correlating to COPD Assessment Test and Modified Medical British Research Council score. These findings warrant large-scale and longitudinal studies to validate LCNs as circulating biomarkers for COPD.

Bone mineral density and chronic lung disease mortality: the rotterdam study

CONTEXT

Low bone mineral density (BMD) has been associated with increased all-cause mortality. Cause-specific mortality studies have been controversial.

OBJECTIVE

The aim of the study was to investigate associations between BMD and all-cause mortality and in-depth cause-specific mortality.

DESIGN AND SETTING

We studied two cohorts from the prospective Rotterdam Study (RS), initiated in 1990 (RS-I) and 2000 (RS-II) with average follow-up of 17.1 (RS-I) and 10.2 (RS-II) years until January 2011. Baseline femoral neck BMD was analyzed in SD values. Deaths were classified according to International Classification of Diseases into seven groups: cardiovascular diseases, cancer, infections, external, dementia, chronic lung diseases, and other causes. Gender-stratified Cox and competing-risks models were adjusted for age, body mass index, and smoking.

PARTICIPANTS

The study included 5779 subjects from RS-I and 2055 from RS-II.

MAIN OUTCOME MEASUREMENTS

We measured all-cause and cause-specific mortality.

RESULTS

A significant inverse association between BMD and all-cause mortality was found in males [expressed as hazard ratio (95% confidence interval)]: RS-I, 1.07 (1.01-1.13), P = .020; RS-II, 1.31 (1.12-1.55), P = .001); but it was not found in females: RS-I, 1.05 (0.99-1.11), P = .098; RS-II, 0.91 (0.74-1.12), P = .362. An inverse association with chronic lung disease mortality was found in males [RS-I, 1.75 (1.34-2.29), P < .001; RS-II, 2.15 (1.05-4.42), P = .037] and in RS-I in females [1.72 (1.16-2.57); P = .008], persisting after multiple adjustments and excluding prevalent chronic obstructive pulmonary disease. A positive association between BMD and cancer mortality was detected in females in RS-I [0.89 (0.80-0.99); P = .043]. No association was found with cardiovascular mortality.

CONCLUSIONS

BMD is inversely associated with mortality. The strong association of BMD with chronic lung disease mortality is a novel finding that needs further analysis to clarify underlying mechanisms.

Comparison of clinical features between non-smokers with COPD and smokers with COPD: a retrospective observational study

Background

Smoking is a major risk factor for chronic obstructive pulmonary disease (COPD); however, the similarities and differences in clinical presentation between smokers and nonsmokers are not fully described in patients with COPD. This study was designed to address this issue in a general teaching hospital in the People’s Republic of China.

Methods

The medical records of patients hospitalized with a lung mass for further evaluation at Zhongshan Hospital, Fudan University, from January 2006 to December 2010 were reviewed and the data of interest were collected. The definition of COPD was according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) spirometric criteria. Participants who had a previous exacerbation within 4 weeks of admission, airflow limitation due to abnormalities in the large airways, or with other pulmonary diseases were excluded. Included subjects were divided into nonsmokers with COPD and smokers with COPD by a cutoff of a 5 pack-year smoking history.

Results

A total of 605 subjects were included in the final analysis. The average age was 64.8±8.5 years and 62.0% (375/605) were smokers. Eighty percent of the patients had mild to moderate disease (GOLD grade 1–2). Age and years with COPD were comparable between the two groups. Compared with smokers with COPD, nonsmokers with COPD were more likely to be female, reported less chronic cough and sputum, have less emphysema on radiologic examination, and higher measures of forced expiratory volume in the first second percent predicted (FEV₁), forced expiratory volume in one second/forced vital capacity (FEV₁/FVC%) percent predicted, maximal voluntary ventilation percent predicted, diffusing capacity of lung (DLCO) percent predicted, and DLCO/alveolar volume percent predicted, with lower levels of residual volume percent predicted and residual volume/total lung capacity percent predicted. There were no significant differences between the two groups with regard to distribution of disease severity, vital capacity percent predicted, total lung capacity percent predicted, PaO₂, PaCO₂, modified Medical Research Council dyspnea score, wheezing, airway reversibility, and comorbidities. Smoking amount (pack-years) was correlated negatively with FEV₁ percent predicted, FEV₁/FVC% percent predicted, inspiratory capacity percent predicted, inspiratory capacity/total lung capacity percent predicted, and DLCO percent predicted, and correlated positively with GOLD grade and symptoms.

Conclusion

Non-smokers with COPD had less impairment in airflow limitation and gas exchange, and a lower prevalence of emphysema, chronic cough, and sputum compared with their smoking counterparts. Tobacco cessation is warranted in smokers with COPD.

An omics strategy for discovering pulmonary biomarkers potentially relevant to the evaluation of tobacco products

Smoking is known to cause serious lung diseases including chronic bronchitis, chronic obstructive lung disease, obstruction of small airways, emphysema and cancer. Tobacco smoke is a complex chemical aerosol containing at least 8000 chemical constituents, either tobacco derived or added by tobacco product manufacturers. Identification of all of the toxic agents in tobacco smoke is challenging, and efforts to understand the mechanisms by which tobacco use causes disease will be informed by new biomarkers of exposure and harm. In 2009, President Obama signed into law the Family Smoking Prevention and Tobacco Control Act granting the US FDA the authority to regulate tobacco products to protect public health. This perspective article presents the background, rationale and strategy for using omics technologies to develop new biomarkers, which may be of interest to the FDA when implementing the Family Smoking Prevention and Tobacco Control Act.

N-acetylcysteine protects murine alveolar type II cells from cigarette smoke injury in a nuclear erythroid 2-related factor-2-independent manner

Emphysema is caused by the cigarette smoke (CS)-induced destruction of alveolar wall septa, and CS is the main risk factor for chronic obstructive pulmonary disease (COPD). To study the mechanisms of response to this insult, we focused on oxidant-induced lung injury and the potential role of nuclear erythroid 2-related factor-2 (Nrf2), which is a key regulator of the antioxidant defense system. We studied the protective role of N-acetylcysteine (NAC) against the injury of alveolar type II (ATII) cells induced by CS in vivo and in vitro. ATII cells were isolated and purified using magnetic MicroBeads (Miltenyi Biotec, Auburn, CA) from Nrf2(-/-) mice and wild-type mice. We analyzed pulmonary injury, inflammation, glutathione (GSH) concentrations, the expression of glutathione cysteine ligase catalytic subunit mRNA, glutathione cysteine ligase modifier subunit mRNA, and glutathione reductase mRNA, and Nrf2, heme oxygenase-1, and nicotinamide adenine dinucleotide phosphate-reduced:quinone oxireductase levels by Western blotting, TUNEL assay, and immunocytofluorescence for 4-hydroxynonenal as a marker of oxidative stress. We found that CS induced greater injury in ATII cells obtained from Nrf2(-/-) mice than from wild-type mice. Furthermore, NAC attenuated the injuries by CS in ATII cells obtained from wild-type mice both in vivo and in vitro. Moreover, NAC decreased the injury of ATII cells obtained from Nrf2(-/-) mice. Our results suggest that Nrf2-GSH signaling is important for the protective activity of NAC. In addition, in ATII cells deficient in Nrf2, this compound can provide partial protection through its reactive oxygen species-scavenging activities. Targeting the antioxidant system regulated by Nrf2 may provide an effective strategy against lung injury in COPD.

Adult stem cells underlying lung regeneration

Despite the massive toll in human suffering imparted by degenerative lung disease, including COPD, idiopathic pulmonary fibrosis and ARDS, the scientific community has been surprisingly agnostic regarding the potential of lung tissue, and in particular the alveoli, to regenerate. However, there is circumstantial evidence in humans and direct evidence in mice that ARDS triggers robust regeneration of lung tissue rather than irreversible fibrosis. The stem cells responsible for this remarkable regenerative process has garnered tremendous attention, most recently yielding a defined set of cloned human airway stem cells marked by p63 expression but with distinct commitment to differentiated cell types typical of the upper or lower airways, the latter of which include alveoli-like structures in vitro and in vivo. These recent advances in lung regeneration and distal airway stem cells and the potential of associated soluble factors in regeneration must be harnessed for therapeutic options in chronic lung disease.

Role of CXCL5 in leukocyte recruitment to the lungs during secondhand smoke exposure

Chronic obstructive pulmonary disease (COPD) is the third leading cause of mortality in the United States. The major cause of COPD is cigarette smoking. Extensive leukocyte influx into the lungs, mediated by chemokines, is a critical event leading to COPD. Although both resident and myeloid cells secrete chemokines in response to inflammatory stimuli, little is known about the role of epithelial-derived chemokines, such as CXC chemokine ligand (CXCL)5, in the pathogenesis of cigarette smoke-induced inflammation. To explore the role of CXCL5, we generated CXCL5 gene-deficient mice and exposed them to secondhand smoke (SHS) for 5 hours/day for 5 days/week up to 3 weeks (subacute exposure). We observed a reduced recruitment of leukocytes to the lungs of CXCL5(-/-) mice compared with their wild-type (WT) counterparts, and noted that macrophages comprised the predominant leukocytes recruited to the lungs. Irradiation experiments performed on CXCL5(-/-) or WT mice transplanted with WT or CXCL5(-/-) bone marrow revealed that resident but not hematopoietic cell-driven CXCL5 is important for mediating SHS-induced lung inflammation. Interestingly, we observed a significant reduction of monocyte chemotactic protein-1 (MCP-1/CC chemokine ligand 2) concentrations in the lungs of CXCL5(-/-) mice. The instillation of recombinant MCP-1 in CXCL5(-/-) mice reversed macrophage recruitment. Our results also show the reduced activation of NF-κB/p65 in the lungs, as well as the attenuated activation of C-Jun N-terminal kinase, p42/44, and p38 mitogen-activated protein kinases and the expression of intercellular adhesion molecule-1 in the lungs of SHS-exposed CXCL5(-/-) mice. Our findings suggest an important role for CXCL5 in augmenting leukocyte recruitment in SHS-induced lung inflammation, and provide novel insights into CXCL5-driven pathogenesis.