Pathogenesis of chronic obstructive pulmonary disease

Differences in Airway Remodeling and Emphysematous Lesions between Rats Exposed to Smoke from New-Type and Conventional Tobacco Varieties

Genes from Perilla frutescens and Ocimum basilicum were introduced into N. tabacum L. var. HHY via distant hybridization, and the new-type tobacco varieties "Zisu" and "Luole" were developed, with noticeable differences in chemical composition. Smoking is the leading cause of chronic obstructive pulmonary disease (COPD), and its pathogenesis is complex. In the present study, 48 male Sprague-Dawley (SD) rats were randomly divided into four groups, namely, the control, "HHY", "Zisu" and "Luole", and then exposed to fresh air/cigarette smoke (CS) for 30 days and 60 days. The COPD model was constructed, and their health hazards were compared and evaluated. CS from different tobacco varieties influenced rats in varying degrees at the tissue, cell and molecular levels. The rats in the "HHY" group showed obvious symptoms, such as cough and dyspnea, which were less severe in the "Zisu" and "Luole" groups. Pathological and morphological analyses, including scores, MLI, MAN, WAt/Pbm and WAm/Pbm, showed that "Zisu" and "Luole" caused less damage to the airways and lung parenchyma than "HHY". Significant increases in the numbers of total leukocytes and neutrophils in the BALF were found in "HHY" compared to those in "Zisu" and "Luole". Moreover, they caused less oxidative stress and apoptosis in lung tissues, as reflected by indicators such as ROS, MDA, T-AOC, GSH, the apoptotic index and the ratio of Bcl-2 to Bax. "Zisu" and "Luole" even altered the ratios of MMP-9/TIMP-1 and IFN-γ/IL-4 in lung tissues to a lesser degree. These differences between CS-exposed rats may be closely related to the altered expression of Nrf2, p38 MAPK and p-p38 MAPK. Changes in chemical composition via introducing genes from some medicinal plants may be an attractive strategy for tobacco harm reduction.

Alterations in the molecular control of mitochondrial turnover in COPD lung and airway epithelial cells

Abnormal mitochondria have been observed in bronchial- and alveolar epithelial cells of patients with chronic obstructive pulmonary disease (COPD). However, it is unknown if alterations in the molecular pathways regulating mitochondrial turnover (mitochondrial biogenesis vs mitophagy) are involved. Therefore, in this study, the abundance of key molecules controlling mitochondrial turnover were assessed in peripheral lung tissue from non-COPD patients (n = 6) and COPD patients (n = 11; GOLDII n = 4/11; GOLDIV n = 7/11) and in both undifferentiated and differentiated human primary bronchial epithelial cells (PBEC) from non-COPD patients and COPD patients (n = 4-7 patients/group). We observed significantly decreased transcript levels of key molecules controlling mitochondrial biogenesis (PPARGC1B, PPRC1, PPARD) in peripheral lung tissue from severe COPD patients. Interestingly, mRNA levels of the transcription factor TFAM (mitochondrial biogenesis) and BNIP3L (mitophagy) were increased in these patients. In general, these alterations were not recapitulated in undifferentiated and differentiated PBECs with the exception of decreased PPARGC1B expression in both PBEC models. Although these findings provide valuable insight in these pathways in bronchial epithelial cells and peripheral lung tissue of COPD patients, whether or not these alterations contribute to COPD pathogenesis, underlie changes in mitochondrial function or may represent compensatory mechanisms remains to be established.

Early detection and prediction of acute exacerbation of chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary Disease (COPD) is characterized by persistent respiratory symptoms and airflow limitation. Acute exacerbation of COPD (AECOPD) is an acute worsening of respiratory symptoms, which needs additional treatment and can result in worsening health status, increasing risks of hospitalization and mortality. Therefore, it is necessary to early recognize and diagnose exacerbations of COPD. This review introduces the updated definition of COPD exacerbations, the current clinical assessment tools, and the current potential biomarkers. The application of mobile health care in COPD management for early identification and diagnosis is also included in this review.

The potential role of pumpkin seeds oil on methotrexate-induced lung toxicity

Many chemotherapeutic drugs cause adverse pulmonary reactions leading to severe pulmonary disease. Though methotrexate (MTX) is used for the treatment of cancer and other diseases, it is highly toxic with multiple adverse effects including pulmonary toxicity. Essential oils represent an open frontier for pharmaceutical sciences due to their wide range of pharmacological properties. Pumpkin seeds oil (PSO) was used to investigate its ability to alleviate methotrexate-induced lung toxicity in rats. Lung tissue from MTX-treated group revealed a decrease in malondialdehyde, glutathione, and nitric oxide accompanied by a marked inhibition in cholinesterase activity, and enhanced catalase activity, tumor necrosis factor-α, interleukin-6 and vascular endothelial growth factor levels. Analysis of PSO revealed that the oil was rich in hexadecanoic acid, decane methyl esters, squalene, polydecane, docosane, and other derivatives. Administration of PSO ameliorated the oxidant/antioxidant and proinflammatory changes induced by MTX in the lung tissue. Histological examinations confirmed the potency of PSO in reducing the histopathological alterations induced by MTX. Immunohistochemical analysis showed decreased nuclear factor-kappa B and caspase 3 expression after PSO. The present data indicated the protective efficiency of PSO against MTX-induced lung injury by decreasing oxidative damage, inflammation and apoptosis and could thus be recommended as an adjuvant therapy.

Smoking-Associated Exposure of Human Primary Bronchial Epithelial Cells to Aldehydes: Impact on Molecular Mechanisms Controlling Mitochondrial Content and Function

Chronic obstructive pulmonary disease (COPD) is a devastating lung disease primarily caused by exposure to cigarette smoke (CS). During the pyrolysis and combustion of tobacco, reactive aldehydes such as acetaldehyde, acrolein, and formaldehyde are formed, which are known to be involved in respiratory toxicity. Although CS-induced mitochondrial dysfunction has been implicated in the pathophysiology of COPD, the role of aldehydes therein is incompletely understood. To investigate this, we used a physiologically relevant in vitro exposure model of differentiated human primary bronchial epithelial cells (PBEC) exposed to CS (one cigarette) or a mixture of acetaldehyde, acrolein, and formaldehyde (at relevant concentrations of one cigarette) or air, in a continuous flow system using a puff-like exposure protocol. Exposure of PBEC to CS resulted in elevated IL-8 cytokine and mRNA levels, increased abundance of constituents associated with autophagy, decreased protein levels of molecules associated with the mitophagy machinery, and alterations in the abundance of regulators of mitochondrial biogenesis. Furthermore, decreased transcript levels of basal epithelial cell marker KRT5 were reported after CS exposure. Only parts of these changes were replicated in PBEC upon exposure to a combination of acetaldehyde, acrolein, and formaldehyde. More specifically, aldehydes decreased MAP1LC3A mRNA (autophagy) and BNIP3 protein (mitophagy) and increased ESRRA protein (mitochondrial biogenesis). These data suggest that other compounds in addition to aldehydes in CS contribute to CS-induced dysregulation of constituents controlling mitochondrial content and function in airway epithelial cells.

Small airway determinants of airflow limitation in chronic obstructive pulmonary disease

BACKGROUND

Although a variety of pathological changes have been described in small airways of patients with COPD, the critical anatomic features determining airflow limitation remain incompletely characterised.

METHODS

We examined lung tissue specimens from 18 non-smokers without chronic lung disease and 55 former smokers with COPD for pathological features of small airways that could contribute to airflow limitation. Morphometric evaluation was performed for epithelial and subepithelial tissue thickness, collagen and elastin content, luminal mucus and radial alveolar attachments. Immune/inflammatory cells were enumerated in airway walls. Quantitative emphysema scoring was performed on chest CT scans.

RESULTS

Small airways from patients with COPD showed thickening of epithelial and subepithelial tissue, mucus plugging and reduced collagen density in the airway wall (in severe COPD). In patients with COPD, we also observed a striking loss of alveolar attachments, which are connective tissue septa that insert radially into the small airway adventitia. While each of these parameters correlated with reduced airflow (FEV1), multivariable regression analysis indicated that loss of alveolar attachments was the major determinant of airflow limitation related to small airways. Neutrophilic infiltration of airway walls and collagen degradation in airway adventitia correlated with loss of alveolar attachments. In addition, quantitative analysis of CT scans identified an association between the extent of emphysema and loss of alveolar attachments.

CONCLUSION

In COPD, loss of radial alveolar attachments in small airways is the pathological feature most closely related to airflow limitation. Destruction of alveolar attachments may be mediated by neutrophilic inflammation.

The Dark Side of the Force: When the Immune System Is the Fuel of Tumor Onset

Nowadays, it is well accepted that inflammation is a critical player in cancer, being, in most cases, the main character of the process. Different types of tumor arise from sites of infection or chronic inflammation. This non-resolving inflammation is responsible for tumor development at different levels: it promotes tumor initiation, as well as tumor progression, stimulating both tumor growth and metastasis. Environmental factors, lifestyle and infections are the three main triggers of chronic immune activation that promote or increase the risk of many different cancers. In this review, we focus our attention on tumor onset; in particular, we summarize the knowledge about the cause and the mechanisms behind the inflammation-driven cancer development.

Prevention of Acute Exacerbation in Subjects with Moderate-to-very Severe COPD by Modulating Lower Respiratory Microbiome: Protocol of a Prospective, Multicenter, Randomized Controlled Trial

Background

COPD is a global respiratory disease that has produced a worldwide health care burden. Acute exacerbation of COPD (AECOPD) is the leading cause of death in patients with COPD and accounts for the majority of expenditure of COPD management. The colonization of potential pathogenic bacteria in the lower respiratory tract is an important cause of the acute exacerbation especially in patients with moderate and severe COPD. Some clinical studies have shown the potential of oral probiotics, aerosol-inhaled amikacin and combined vaccination to prevent AECOPD.

Methods and Analysis

We hypothesize that patients with stable COPD will benefit from aerosol-inhaled amikacin, oral probiotics or combined vaccination in terms of preventing acute exacerbation of COPD, slowing the progression of the disease and improving their quality of life. The trial aimsto investigate the efficacy and safety of the above interventions to decolonize bacteria in the lower respiratory tract and prevent acute exacerbation of COPD. In the study, 144 patients with stable phase of moderate-to-very severe COPD will be recruited and randomized into aerosol-inhaled amikacin group, oral probiotics group, combined vaccination group and the control group at a 1:1:1:1 ratio. The primary outcome is time to the first COPD exacerbation. Other endpoints include colonization of potential pathogenic bacteria in induced sputum, microbiome in induced sputum, pulmonary function and symptoms of patients, inflammation level and adverse events, serious adverse events, and death.

ADAM17 protects against elastase-induced emphysema by suppressing CD62L+ leukocyte infiltration in mice

Pulmonary emphysema is a major manifestation of chronic obstructive pulmonary disease and is associated with chronic pulmonary inflammation caused by cigarette smoking, with contributions from immune cells such as neutrophils, macrophages, and lymphocytes. Although matrix metalloproteinases are well known to contribute to emphysema progression, the role of a disintegrin and metalloproteinase (ADAM) family proteins, other major metalloproteinases, in disease pathogenesis is largely unknown. ADAM17 is a major sheddase that cleaves various cell surface proteins, including CD62L, an adhesion molecule that plays a critical role in promoting the migration of immune cells to the site of inflammation. In the present study, we aimed to investigate the potential role of ADAM17 and CD62L in the development of elastase-induced emphysema. Control and Adam17^flox/flox/Mx1-Cre (Adam17^ΔMx1) mice (8-10 wk old) were intratracheally injected with 5 units of porcine pancreas elastase and monitored for 35 days after injection. Lung alveolar destruction was evaluated by analyzing the mean linear intercepts of lung tissue specimens and by histopathological examination. Mean linear intercepts data indicated that the degree of elastase-induced emphysema was significantly more severe in Adam17^ΔMx1 mice. Furthermore, flow cytometry showed that CD62L⁺ neutrophil, CD62L⁺ macrophage, and CD62L⁺ B lymphocyte numbers were significantly increased in Adam17^ΔMx1 mice. Moreover, the pharmacological depletion of CD62L⁺ cells with a CD62L-neutralizing antibody ameliorated the extent of emphysema in Adam17^ΔMx1 mice. Collectively, these results suggest that ADAM17 possibly suppresses the progression of emphysema by proteolytically processing CD62L in immune cells and that ADAM17 and CD62L could be novel therapeutic targets for treating pulmonary emphysema.

Pulmonary hypertension in chronic obstructive pulmonary disease

Even mild pulmonary hypertension (PH) is associated with increased mortality and morbidity in patients with chronic obstructive pulmonary disease (COPD). However, the underlying mechanisms remain elusive; therefore, specific and efficient treatment options are not available. Therapeutic approaches tested in the clinical setting, including long-term oxygen administration and systemic vasodilators, gave disappointing results and might be only beneficial for specific subgroups of patients. Preclinical studies identified several therapeutic approaches for the treatment of PH in COPD. Further research should provide deeper insight into the complex pathophysiological mechanisms driving vascular alterations in COPD, especially as such vascular (molecular) alterations have been previously suggested to affect COPD development. This review summarizes the current understanding of the pathophysiology of PH in COPD and gives an overview of the available treatment options and recent advances in preclinical studies. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

Therapeutic potential of BLT1 antagonist for COPD: involvement of inducing autophagy and ameliorating inflammation

Purpose

Leukotriene B4 (LTB4) is a major pro-inflammatory mediator that leads to the persistence of chronic inflammation in chronic obstructive pulmonary disease (COPD). The purpose of this study was to evaluate therapeutic potential of BLT1 antagonist for cigarette smoke (CS)-induced COPD and to explore the underlying mechanism.

Materials and methods

In vitro, autophagy proteins were determined by Western blotting in RAW264.7 macrophages treated with U75302 (BLT1 antagonist) or autophagy inhibitor in cigarette smoke extract-induced inflammation. In vivo, C57BL/6J mice were randomly divided into three groups: Control group, CS group and CS+U75302 group. After 12-week exposure, histological analysis and lung function tests were performed to evaluate the inflammatory infiltration and emphysema. The expression of inflammatory cytokines was measured by real-time PCR and enzyme-linked immunosorbent assay. Immunohistochemical analysis and Western blotting detected the expression of autophagy-related proteins. Transmission electron microscopy (TEM) showed the alterations of autophagosomes and lysosomes.

Results

Lower levels of inflammatory factors and autophagy markers were detected in U75302-treated cells and mice after CS exposure than control. In vitro, LC3 mRNA expression was elevated when treated with U75302. Autophagy inhibition resulted in augmented inflammatory response and autophagy proteins even with U75302 treatment. Furthermore, BLT1 antagonist decreased the number of lysosomes and autophagosomes in alveolar macrophages of mice and potentially enhanced the expression of transcriptional activation of transcription factor-EB (TFEB) in vitro and vivo.

Conclusion

Insufficient autophagy of macrophages was associated with LTB4-mediated inflammation in CS-exposure models. BLT1 antagonist ameliorated inflammatory response through inducing autophagy.

Feasibility of deriving a novel imaging biomarker based on patient-specific lung elasticity for characterizing the degree of COPD in lung SBRT patients

OBJECTIVE:

Lung tissue elasticity is an effective spatial representation for Chronic Obstructive Pulmonary Disease phenotypes and pathophysiology. We investigated a novel imaging biomarker based on the voxel-by-voxel distribution of lung tissue elasticity. Our approach combines imaging and biomechanical modeling to characterize tissue elasticity.

METHODS:

We acquired 4DCT images for 13 lung cancer patients with known COPD diagnoses based on GOLD 2017 criteria. Deformation vector fields (DVFs) from the deformable registration of end-inhalation and end-exhalation breathing phases were taken to be the ground-truth. A linear elastic biomechanical model was assembled from end-exhalation datasets with a density-guided initial elasticity distribution. The elasticity estimation was formulated as an iterative process, where the elasticity was optimized based on its ability to reconstruct the ground-truth. An imaging biomarker (denoted YM_1-3) derived from the optimized elasticity distribution, was compared with the current gold standard, RA₉₅₀ using confusion matrix and area under the receiver operating characteristic (AUROC) curve analysis.

RESULTS:

The estimated elasticity had 90 % accuracy when representing the ground-truth DVFs. The YM_1-3 biomarker had higher diagnostic accuracy (86% vs 71 %), higher sensitivity (0.875 vs 0.5), and a higher AUROC curve (0.917 vs 0.875) as compared to RA₉₅₀. Along with acting as an effective spatial indicator of lung pathophysiology, the YM_1-3 biomarker also proved to be a better indicator for diagnostic purposes than RA₉₅₀.

CONCLUSIONS:

Overall, the results suggest that, as a biomarker, lung tissue elasticity will lead to new end points for clinical trials and new targeted treatment for COPD subgroups.

ADVANCES IN KNOWLEDGE:

The derivation of elasticity information directly from 4DCT imaging data is a novel method for performing lung elastography. The work demonstrates the need for a mechanics-based biomarker for representing lung pathophysiology.

Roles of Myeloid and Lymphoid Cells in the Pathogenesis of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is currently the third largest cause of human mortality in the world after stroke and heart disease. COPD is characterized by sustained inflammation of the airways, leading to destruction of lung tissue and declining pulmonary function. The main risk factor is known to be cigarette smoke currently. However, the strategies for prevention and treatment have not altered significantly for many years. A growing body of evidences indicates that the immune system plays a pivotal role in the pathogenesis of COPD. The repeated and progressive activation of immune cells is at least in part the source of this chronic inflammation. In this review paper, we have conducted an extensive literature search of the studies of immune cells in COPD patients. The objective is to assess the contributions of different immune cell types, the imbalance of pro/anti-inflammatory immune cells, such as M1/M2 macrophages, Tc1/Tc10, and Th17/Treg, and their mediators in the peripheral blood as well as in the lung to the pathogenesis of COPD. Therefore, understanding their roles in COPD development will help us find the potential target to modify this disease. This review focuses predominantly on data derived from human studies but will refer to animal studies where they help understand the disease in humans.

Tobacco Smoke Induces and Alters Immune Responses in the Lung Triggering Inflammation, Allergy, Asthma and Other Lung Diseases: A Mechanistic Review

Many studies have been undertaken to reveal how tobacco smoke skews immune responses contributing to the development of chronic obstructive pulmonary disease (COPD) and other lung diseases. Recently, environmental tobacco smoke (ETS) has been linked with asthma and allergic diseases in children. This review presents the most actual knowledge on exact molecular mechanisms responsible for the skewed inflammatory profile that aggravates inflammation, promotes infections, induces tissue damage, and may promote the development of allergy in individuals exposed to ETS. We demonstrate how the imbalance between oxidants and antioxidants resulting from exposure to tobacco smoke leads to oxidative stress, increased mucosal inflammation, and increased expression of inflammatory cytokines (such as interleukin (IL)-8, IL-6 and tumor necrosis factor α ([TNF]-α). Direct cellular effects of ETS on epithelial cells results in increased permeability, mucus overproduction, impaired mucociliary clearance, increased release of proinflammatory cytokines and chemokines, enhanced recruitment of macrophages and neutrophils and disturbed lymphocyte balance towards Th2. The plethora of presented phenomena fully justifies a restrictive policy aiming at limiting the domestic and public exposure to ETS.

Variable Susceptibility to Cigarette Smoke-Induced Emphysema in 34 Inbred Strains of Mice Implicates Abi3bp in Emphysema Susceptibility

Chronic obstructive pulmonary disease (COPD) is caused by a complex interaction of environmental exposures, most commonly cigarette smoke, and genetic factors. Chronic cigarette smoke exposure in the mouse is a commonly used animal model of COPD. We aimed to expand our knowledge about the variable susceptibility of inbred strains to this model and test for genetic variants associated with this trait. To that end, we sought to measure differential susceptibility to cigarette smoke-induced emphysema in the mouse, identify genetic loci associated with this quantitative trait, and find homologous human genes associated with COPD. Alveolar chord length (CL) in 34 inbred strains of mice was measured after 6 months of exposure to cigarette smoke. After testing for association, we connected a murine candidate locus to a published meta-analysis of moderate-to-severe COPD. We identified deleterious mutations in a candidate gene in silico and measured gene expression in extreme strains. A/J was the most susceptible strain in our survey (Δ CL 7.0 ± 2.2 μm) and CBA/J was the least susceptible (Δ CL -0.3 ± 1.2 μm). By integrating mouse and human genome-wide scans, we identified the candidate gene Abi3bp. CBA/J mice harbor predicted deleterious variants in Abi3bp, and expression of the gene differs significantly between CBA/J and A/J mice. This is the first report of susceptibility to cigarette smoke-induced emphysema in 34 inbred strains of mice, and Abi3bp is identified as a potential contributor to this phenotype.

(-)-Epigallocatechin-3-gallate Reduces Cigarette Smoke-Induced Airway Neutrophilic Inflammation and Mucin Hypersecretion in Rats

Background: Cigarette smoking is the leading cause of chronic obstructive pulmonary disease. (-)-Epigallocatechin-3-gallate (EGCG), the major catechins in Chinese green tea, has been studied for its anti-oxidative and anti-inflammatory properties in cell and animal models. In this study, we aimed to analyze the effects of EGCG on cigarette smoke (CS)-induced airway inflammation and mucus secretion in the CS-exposed rat model. Methods: Male Sprague-Dawley rats were randomly divided into either sham air (SA) or CS exposure. EGCG (50 mg/kg b.wt.) was given by oral gavage every other day in both SA and CS-exposed animals. Oxidative stress and inflammatory markers were determined in serum and/or bronchoalveolar lavage fluid by biochemical assays or ELISA. Lung morphological changes were examined by Periodic Acid-Schiff, Masson's Trichrome staining and immunohistochemical analysis. Western blot analysis was performed to explore the effects of EGCG on epidermal growth factor receptor (EGFR)-mediated signaling pathway. Results: (-)-Epigallocatechin-3-gallate treatment attenuated CS-induced oxidative stress, lung cytokine-induced neutrophil chemoattractant-1 release and neutrophil recruitment. CS exposure caused an increase in the number of goblet cells in line with MUC5AC upregulation, and increased lung collagen deposition, which were alleviated in the presence of EGCG. In addition, CS-induced phosphorylation of EGFR in rat lung was abrogated by EGCG treatment. Conclusion: (-)-Epigallocatechin-3-gallate treatment ameliorated CS-induced oxidative stress and neutrophilic inflammation, as well as airway mucus production and collagen deposition in rats. The present findings suggest that EGCG has a therapeutic effect on chronic airway inflammation and abnormal airway mucus production probably via inhibition of EGFR signaling pathway.

Cigarette smoke attenuates phagocytic ability of macrophages through down-regulating Milk fat globule-EGF factor 8 (MFG-E8) expressions

Chronic obstructive pulmonary disease (COPD) is one of the most common inflammatory diseases resulting from habitual smoking. Impaired clearance of apoptotic cell by airway macrophages contributes to lung inflammation. Milk fat globule-EGF factor 8 (MFG-E8), as a link between apoptotic cells and phagocytes, facilitates clearance of apoptotic cells and attenuates inflammation. We sought to investigate altered expression and potential role of MFG-E8 in COPD. In this study, apoptosis was increased and the level of MFG-E8 was decreased while HMGB1 expression was increased in lung tissues of CS-exposed mice. Compared with CS-exposed WT mice, more apoptotic cells were accumulated in lung tissues of CS-exposed MFG-E8 deficiency mice. Exposure of a range of macrophages to cigarette smoke extract (CSE) resulted in decreased MFG-E8 expression. Administration of rmMFG-E8 ameliorated phagocytic ability of RAW264.7 cells and suppressed inflammatory response induced by CS-exposure. 10% CSE stimulation suppressed Rac1 membrane localization in RAW264.7 cells which was restored by administration of rmMFG-E8. MFG-E8 deficiency diminished uptake of apoptotic thymocytes by peritoneal macrophages upon CSE exposure. Overall, the findings in current work provide a novel target for diagnosing and treating COPD.

MKK3 influences mitophagy and is involved in cigarette smoke-induced inflammation

Cigarette smoking is the primary risk factor for COPD which is characterized by excessive inflammation and airflow obstruction of the lung. While inflammation is causally related to initiation and progression of COPD, the mitochondrial mechanisms that underlie the associated inflammatory responses are poorly understood. In this context, we have studied the role played by Mitogen activated protein (MAP) kinase kinase 3 (MKK3), a dual-specificity protein kinase, in cigarette smoke induced-inflammation and mitochondrial dysfunction. Serum pro-inflammatory cytokines were significantly elevated in WT but not in MKK3-/- mice exposed to Cigarette smoke (CS) for 2 months. To study the cellular mechanisms of inflammation, bone marrow derived macrophages (BMDMs), wild type (WT) and MKK3-/-, were exposed to cigarette smoke extract (CSE) and inflammatory cytokine production and mitochondrial function assessed. The levels of IL-1β, IL-6, and TNFα were increased along with higher reactive oxygen species (ROS) and P-NFκB after CSE treatment in WT but not in MKK3-/- BMDMs. CSE treatment adversely affected basal mitochondrial respiration, ATP production, maximum respiratory capacity, and spare respiratory capacity in WT BMDMs only. Mitophagy, clearance of dysfunctional mitochondria, was up regulated in CS exposed WT mice lung tissue and CSE exposed WT BMDMs, respectively. The proteomic analysis of BMDMs by iTRAQ (isobaric tags for relative and absolute quantitation) showed up regulation of mitochondrial dysfunction associated proteins in WT and higher OXPHOS (Oxidative phosphorylation) and IL-10 signaling proteins in MKK3-/- BMDMs after CSE exposure, confirming the critical role of mitochondrial homeostasis. Interestingly, we found increased levels of p-MKK3 by immunohistochemistry in COPD patient lung tissues that could be responsible for insufficient mitophagy and disease progression. This study identifies MKK3 as a negative regulator of mitochondrial function and inflammatory responses to CS and suggests that MKK3 could be a therapeutic target.

Prognostic role of D-dimer for in-hospital and 1-year mortality in exacerbations of COPD

Background and objective

Serum D-dimer is elevated in respiratory disease. The objective of our study was to investigate the effect of D-dimer on in-hospital and 1-year mortality after acute exacerbations of chronic obstructive pulmonary disease (AECOPD).

Methods

Upon admission, we measured 343 AECOPD patients’ serum D-dimer levels and arterial blood gas analysis, and recorded their clinical characteristics. The level of D-dimer that discriminated survivors and non-survivors was determined using a receiver operator curve (ROC). The risk factors for in-hospital mortality were identified through univariate analysis and multiple logistic regression analyses. To evaluate the predictive role of D-dimer for 1-year mortality, univariate and multivariate Cox regression analyses were performed.

Results

In all, 28 patients died, and 315 patients survived in the in-hospital period. The group of dead patients had lower pH levels (7.35±0.11 vs 7.39±0.05, P<0.0001), higher D-dimer, arterial carbon dioxide tension (PaCO₂), C-reactive protein (CRP), and blood urea nitrogen (BUN) levels (D-dimer 2,244.9±2,310.7 vs 768.2±1,078.4 µg/L, P<0.0001; PaCO₂: 58.8±29.7 vs 46.1±27.0 mmHg, P=0.018; CRP: 81.5±66, P=0.001; BUN: 10.20±6.87 vs 6.15±3.15 mmol/L, P<0.0001), and lower hemoglobin levels (118.6±29.4 vs 128.3±18.2 g/L, P=0.001). The areas under the ROC curves of D-dimer for in-hospital death were 0.748 (95% confidence interval (CI): 0.641–0.854). D-dimer ≥985 ng/L was a risk factor for in-hospital mortality (relative risk =6.51; 95% CI 3.06–13.83). Multivariate logistic regression analysis also showed that D-dimer ≥985 ng/L and heart failure were independent risk factors for in-hospital mortality. Both univariate and multivariate Cox regression analyses showed that D-dimer ≥985 ng/L was an independent risk factor for 1-year death (hazard ratio (HR) 3.48, 95% CI 2.07–5.85 for the univariate analysis; and HR 1.96, 95% CI 1.05–3.65 for the multivariate analysis).

Conclusion

D-dimer was a strong and independent risk factor for in-hospital and 1-year death for AECOPD patients.

Reduction of neutrophilic lung inflammation by inhalation of the compatible solute ectoine: a randomized trial with elderly individuals

Background

Compatible solutes are natural substances that are known to stabilize cellular functions. Preliminary ex vivo and in vivo studies demonstrated that the compatible solute ectoine restores natural apoptosis rates of lung neutrophils and contributes to the resolution of lung inflammation. Due to the low toxicity and known compatibility of the substance, an inhalative application as an intervention strategy for humans suffering from diseases caused by neutrophilic inflammation, like COPD, had been suggested. As a first approach to test the feasibility and efficacy of such a treatment, we performed a population-based randomized trial.

Objective

The objective of the study was to test whether the daily inhalation of the registered ectoine-containing medical device (Ectoin^® inhalation solution) leads to a reduction of neutrophilic cells and interleukin-8 (IL-8) levels in the sputum of persons with mild symptoms of airway disease due to lifelong exposure to environmental air pollution.

Methods

A double-blinded placebo-controlled trial was performed to study the efficacy and safety of an ectoine-containing therapeutic. Prior to and after both inhalation periods, lung function, inflammatory parameters in sputum, serum markers, and quality-of-life parameters were determined.

Results

While the other outcomes revealed no significant effects, sputum parameters were changed by the intervention. Nitrogen oxides (nitrate and nitrite) were significantly reduced after ectoine inhalation with a mean quotient of 0.65 (95% confidence interval 0.45–0.93). Extended analyses considering period effects revealed that the percentage of neutrophils in sputum was significantly lower after ectoine inhalation than in the placebo group (P=0.035) even after the washout phase.

Conclusion

The current study is the first human trial in which the effects of inhaled ectoine on neutrophilic lung inflammation were investigated. Besides demonstrating beneficial effects on inflammatory sputum parameters, the study proves the feasibility of the therapeutic approach in an aged study group.

Clinical-Radiologic-Pathologic Correlation of Smoking-Related Diffuse Parenchymal Lung Disease

The direct toxicity of cigarette smoke and the body's subsequent response to this lung injury leads to a wide array of pathologic manifestations and disease states that lead to both reversible and irreversible injury to the large airways, small airways, alveolar walls, and alveolar spaces. These include emphysema, bronchitis, bronchiolitis, acute eosinophilic pneumonia, pulmonary Langerhans cell histiocytosis, respiratory bronchiolitis, desquamative interstitial pneumonia, and pulmonary fibrosis. Although these various forms of injury have different pathologic and imaging manifestations, they are all part of the spectrum of smoking-related diffuse parenchymal lung disease.

The Role of Interleukin-23 in the Early Development of Emphysema in HIV1(+) Smokers

Rationale. Matrix metalloproteinase-9 (MMP-9) expression is upregulated in alveolar macrophages (AM) of HIV1⁺ smokers who develop emphysema. Knowing that lung epithelial lining fluid (ELF) of HIV1⁺ smokers contains increased levels of inflammatory cytokines compared to HIV1⁻ smokers, we hypothesized that upregulation of lung cytokines in HIV1⁺ smokers may be functionally related to increased MMP-9 expression. Methods. Cytokine arrays evaluated cytokine protein levels in ELF obtained from 5 groups of individuals: HIV1⁻ healthy nonsmokers, HIV1⁻ healthy smokers, HIV1⁻ smokers with low diffusing capacity (DL_CO), HIV1⁺ nonsmokers, and HIV1⁺ smokers with low DL_CO. Results. Increased levels of the Th17 related cytokine IL-23 were found in HIV1⁻ smokers with low DL_CO and HIV1⁺ smokers and nonsmokers. Relative IL-23 gene expression was increased in AM of HIV1⁺ individuals, with greater expression in AM of HIV1⁺ smokers with low DL_CO. Infection with HIV1 in vitro induced IL-23 expression in normal AM. IL-23 stimulation of AM/lymphocyte cocultures in vitro induced upregulation of MMP-9. Lung T lymphocytes express receptor IL-23R and interact with AM in order to upregulate MMP-9. Conclusion. This mechanism may contribute to the increased tissue destruction in the lungs of HIV1⁺ smokers and suggests that Th17 related inflammation may play a role.

Convergence in the Epidemiology and Pathogenesis of COPD and Pneumonia

Chronic obstructive pulmonary disease (COPD) is one of the main causes of human mortalities globally after heart disease and stroke. There is increasing evidence of an aetiological association between COPD and pneumonia, the leading infectious cause of death globally in children under 5 years. In this review, we discuss the known risk factors of COPD that are also shared with pneumonia including smoking, air pollution, age and immune suppression. We review how lung pathology linked to a previous history of pneumonia may heighten susceptibility to the development of COPD in later life. Furthermore, we examine how specific aspects of COPD immunology could contribute to the manifestation of pneumonia. Based on the available evidence, a convergent relationship is becoming apparent with respect to the pathogenesis of COPD and pneumonia. This has implications for the management of both diseases, and the development of new interventions.

Combining systems pharmacology, transcriptomics, proteomics, and metabolomics to dissect the therapeutic mechanism of Chinese herbal Bufei Jianpi formula for application to COPD

Bufei Jianpi formula (BJF) has long been used as a therapeutic agent in the treatment of COPD. Systems pharmacology identified 145 active compounds and 175 potential targets of BJF in a previous study. Additionally, BJF was previously shown to effectively prevent COPD and its comorbidities, such as ventricular hypertrophy, by inhibition of inflammatory cytokine production, matrix metalloproteinases expression, and other cytokine production, in vivo. However, the system-level mechanism of BJF for the treatment of COPD is still unclear. The aim of this study was to gain insight into its system-level mechanisms by integrating transcriptomics, proteomics, and metabolomics together with systems pharmacology datasets. Using molecular function, pathway, and network analyses, the genes and proteins regulated in COPD rats and BJF-treated rats could be mainly attributed to oxidoreductase activity, antioxidant activity, focal adhesion, tight junction, or adherens junction. Furthermore, a comprehensive analysis of systems pharmacology, transcript, protein, and metabolite datasets is performed. The results showed that a number of genes, proteins, metabolites regulated in BJF-treated rats and potential target proteins of BJF were involved in lipid metabolism, cell junction, oxidative stress, and inflammatory response, which might be the system-level therapeutic mechanism of BJF treatment.

Epidemiology of Lung Cancer

Lung cancer continues to be one of the most common causes of cancer death despite understanding the major cause of the disease: cigarette smoking. Smoking increases lung cancer risk 5- to 10-fold with a clear dose-response relationship. Exposure to environmental tobacco smoke among nonsmokers increases lung cancer risk about 20%. Risks for marijuana and hookah use, and the new e-cigarettes, are yet to be consistently defined and will be important areas for continued research as use of these products increases. Other known environmental risk factors include exposures to radon, asbestos, diesel, and ionizing radiation. Host factors have also been associated with lung cancer risk, including family history of lung cancer, history of chronic obstructive pulmonary disease and infections. Studies to identify genes associated with lung cancer susceptibility have consistently identified chromosomal regions on 15q25, 6p21 and 5p15 associated with lung cancer risk. Risk prediction models for lung cancer typically include age, sex, cigarette smoking intensity and/or duration, medical history, and occupational exposures, however there is not yet a risk prediction model currently recommended for general use. As lung cancer screening becomes more widespread, a validated model will be needed to better define risk groups to inform screening guidelines.

Immune Dysfunction in Patients with Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a complex chronic disease. Chronic inflammation is the hallmark of COPD, involving the interplay of a wide variety of cells in the lung microenvironment. Cigarette smoke (CS) induces chronic lung inflammation and is considered a key etiological factor in the development and pathogenesis of COPD. Structural and inflammatory cells in the lung respond to CS exposure by releasing proinflammatory mediators that recruit additional inflammatory immune cells, which collectively contribute to the establishment of a chronic inflammatory microenvironment. Chronic inflammation contributes to lung damage, compromises innate and adaptive immune responses, and facilitates the recurrent episodes of respiratory infection that punctuate and further contribute to the pathological manifestations of the stable disease. A number of studies support the conclusion that immune dysfunction leads to exacerbations and disease severity in COPD. Our group has clearly demonstrated that CS exacerbates lung inflammation and compromises immunity to respiratory pathogens in a mouse model of COPD. We have also investigated the phenotype of immune cells in patients with COPD compared with healthy control subjects and found extensive immune dysfunction due to the presence and functional activity of T regulatory cells, CD4(+)PD-1(+) exhausted effector T cells and myeloid-derived suppressor cells. Manipulation of these immunosuppressive networks in COPD could provide a rational strategy to restore functional immune responses, reduce exacerbations, and improve lung function. In this review, we discuss the role of immune dysfunction in COPD that may contribute to recurrent respiratory infections and disease severity.

Effects of Chung-Pae Inhalation Therapy on a Mouse Model of Chronic Obstructive Pulmonary Disease

Chung-pae (CP) inhalation therapy is a method frequently used in Korea to treat lung disease, especially chronic obstructive pulmonary disease (COPD). This study investigated the effects of CP inhalation on a COPD animal model. C57BL/6 mice received porcine pancreatic elastase (PPE) and lipopolysaccharide (LPS) alternately three times for 3 weeks to induce COPD. Then, CP (5 or 20 mg/kg) was administered every 2 h after the final LPS administration. The effect of CP was evaluated by bronchoalveolar lavage (BAL) fluid analysis, histological analysis of lung tissue, and reverse transcription polymerase chain reaction analysis of mRNA of interleukin- (IL-) 1β, tumor necrosis factor- (TNF-) α, IL-6, and tumor growth factor- (TGF-) β. Intratracheal CP administration reduced the number of leukocytes and neutrophils in BAL fluid, inhibited the histological appearance of lung damage, and decreased the mRNA levels of the proinflammatory cytokines IL-1β, TNF-α, IL-6, and TGF-β. Intratracheal CP administration effectively decreased the chronic inflammation and pathological changes in a PPE- and LPS-induced COPD mouse model. Therefore, we suggest that CP is a promising strategy for COPD.

Evaluation of von Willebrand factor in COPD patients

OBJECTIVE

To compare the absolute serum von Willebrand factor (vWF) levels and relative serum vWF activity in patients with clinically stable COPD, smokers without airway obstruction, and healthy never-smokers.

METHODS

The study included 57 subjects, in three groups: COPD (n = 36); smoker (n = 12); and control (n = 9). During the selection phase, all participants underwent chest X-rays, spirometry, and blood testing. Absolute serum vWF levels and relative serum vWF activity were obtained by turbidimetry and ELISA, respectively. The modified Medical Research Council scale (cut-off score = 2) was used in order to classify COPD patients as symptomatic or mildly symptomatic/asymptomatic.

RESULTS

Absolute vWF levels were significantly lower in the control group than in the smoker and COPD groups: 989 ± 436 pg/mL vs. 2,220 ± 746 pg/mL (p < 0.001) and 1,865 ± 592 pg/mL (p < 0.01). Relative serum vWF activity was significantly higher in the COPD group than in the smoker group (136.7 ± 46.0% vs. 92.8 ± 34.0%; p < 0.05), as well as being significantly higher in the symptomatic COPD subgroup than in the mildly symptomatic/asymptomatic COPD subgroup (154 ± 48% vs. 119 ± 8%; p < 0.05). In all three groups, there was a negative correlation between FEV1 (% of predicted) and relative serum vWF activity (r2 = -0.13; p = 0.009).

CONCLUSIONS

Our results suggest that increases in vWF levels and activity contribute to the persistence of systemic inflammation, as well as increasing cardiovascular risk, in COPD patients.

Therapeutic effects of amniotic fluid-derived mesenchymal stromal cells on lung injury in rats with emphysema

Background

In chronic obstructive pulmonary disease (COPD), two major pathological changes that occur are the loss of alveolar structure and airspace enlargement. To treat COPD, it is crucial to repair damaged lung tissue and regenerate the lost alveoli. Type II alveolar epithelial cells (AECII) play a vital role in maintaining lung tissue repair, and amniotic fluid-derived mesenchymal stromal cells (AFMSCs) possess the characteristics of regular mesenchymal stromal cells. However, it remains untested whether transplantation of rat AFMSCs (rAFMSCs) might alleviate lung injury caused by emphysema by increasing the expression of surfactant protein (SP)A and SPC and inhibiting AECII apoptosis.

Methods

We analyzed the phenotypic characteristics, differentiation potential, and karyotype of rAFMSCs, which were isolated from pregnant Sprague–Dawley rats. Moreover, we examined the lung morphology and the expression levels of SPA and SPC in rats with emphysema after cigarette-smoke exposure and intratracheal lipopolysaccharide instillation and rAFMSC transplantation. The ability of rAFMSCs to differentiate was measured, and the apoptosis of AECII was evaluated.

Results

In rAFMSCs, the surface antigens CD29, CD44, CD73, CD90, CD105, and CD166 were expressed, but CD14, CD19, CD34, and CD45 were not detected; rAFMSCs also strongly expressed the mRNA of octamer-binding transcription factor 4, and the cells could be induced to differentiate into adipocytes and osteocytes. Furthermore, rAFMSC treatment up-regulated the levels of SPA, SPC, and thyroid transcription factor 1 and inhibited AECII apoptosis, and rAFMSCs appeared to be capable of differentiating into AECII-like cells. Lung injury caused by emphysema was alleviated after rAFMSC treatment.

Conclusions

rAFMSCs might differentiate into AECII-like cells or induce local regeneration of the lung alveolar epithelium in vivo after transplantation and thus could be used in COPD treatment and lung regenerative therapy.

Cigarette-smoke-induced priming of neutrophils from smokers and non-smokers for increased oxidative burst response is mediated by TNF-α

In vitro treatment of human peripheral blood neutrophils from smokers and non-smokers with an aqueous cigarette smoke (CS) extract resulted in a concentration-dependent increase in surface expression of CD11b and CD66b and a corresponding decrease of CD62L, together with a concentration-dependent release of MMP-8, MMP-9, and lactoferrin, indicating considerable activation and degranulation. However, the burst response to N-formyl-methionyl-leucyl-phenylalanine (fMLP) was unchanged in CS-stimulated neutrophils from both smokers and non-smokers. When supernatants from CS-treated monocytic MonoMac-6 (MM6) cells were used for activation of neutrophils, concentration-dependent changes in surface marker expression, granule protein release, and the oxidative burst response to fMLP were observed, again with no major differences between smokers and non-smokers. CS-treated MM6 cells released significant amounts of IL-8 and TNF-α into the culture supernatant. However, antibody blocking experiments showed that only TNF-α mediated the increased burst response in neutrophils. These data show that, in the presence of secondary cells, CS is able to prime neutrophils for an increased burst response to fMLP which is mediated by TNF-α, released from the secondary cells in response to CS. Following stimulation with priming agents, peripheral blood neutrophils from healthy smokers show an equal burst response compared to those from non-smokers.

Nicotine alters mucin rheological properties

Tobacco smoke exposure, the major cause of chronic obstructive pulmonary disease (COPD), instigates a dysfunctional clearance of thick obstructive mucus. However, the mechanism underlying the formation of abnormally viscous mucus remains elusive. We investigated whether nicotine can directly alter the rheological properties of mucin by examining its physicochemical interactions with human airway mucin gels secreted from A549 lung epithelial cells. Swelling kinetics and multiple particle tracking were utilized to assess mucin gel viscosity change when exposed to nicotine. Herein we show that nicotine (≤50 nM) significantly hindered postexocytotic swelling and hydration of released mucins, leading to higher viscosity, possibly by electrostatic and hydrophobic interactions. Moreover, the close association of nicotine and mucins allows airway mucus to function as a reservoir for prolonged nicotine release, leading to correlated pathogenic effects. Our results provide a novel explanation for the maltransport of poorly hydrated mucus in smokers. More importantly, this study further indicates that even low-concentration nicotine can profoundly increase mucus viscosity and thus highlights the health risks of secondhand smoke exposure.

The pro-proliferative effects of nicotine and its underlying mechanism on rat airway smooth muscle cells

Recent studies have shown that nicotine, a major component of cigarette smoke, can stimulate the proliferation of non-neuronal cells. Cigarette smoking can promote a variety of pulmonary and cardiovascular diseases, such as chronic obstructive pulmonary disease (COPD), atherosclerosis, and cancer. A predominant feature of COPD is airway remodeling, which includes increased airway smooth muscle (ASM) mass. The mechanisms underlying ASM remodeling in COPD have not yet been fully elucidated. Here, we show that nicotine induces a profound and time-dependent increase in DNA synthesis in rat airway smooth muscle cells (RASMCs) in vitro. Nicotine also significantly increased the number of RASMCs, which was associated with the increased expression of Cyclin D1, phosphorylation of the retinoblastoma protein (RB) and was dependent on the activation of Akt. The activation of Akt by nicotine occurred within minutes and depended upon the nicotinic acetylcholine receptors (nAchRs). Activated Akt increased the phosphorylation of downstream substrates such as GSK3β. Our data suggest that the binding of nicotine to the nAchRs on RASMCs can regulate cellular proliferation by activating the Akt pathway.

Evidence-based risk assessment and recommendations for physical activity clearance: respiratory disease

The 2 most common respiratory diseases are chronic obstructive pulmonary disease (COPD) and asthma. Growing evidence supports the benefits of exercise for all patients with these diseases. Due to the etiology of COPD and the pathophysiology of asthma, there may be some additional risks of exercise for these patients, and hence accurate risk assessment and clearance is needed before patients start exercising. The purpose of this review was to evaluate the available literature regarding the risks of exercise for patients with respiratory disease and provide evidence-based recommendations to guide the screening process. A systematic review of 4 databases was performed. The literature was searched to identify adverse events specific to exercise. For COPD, 102 randomized controlled trials that involved an exercise intervention were included (n = 6938). No study directly assessed the risk of exercise, and only 15 commented on exercise-related adverse events. For asthma, 30 studies of mixed methodologies were included (n = 1278). One study directly assessed the risk of exercise, and 15 commented on exercise-related adverse events. No exercise-related fatalities were reported. The majority of adverse events in COPD patients were musculoskeletal or cardiovascular in nature. In asthma patients, exercise-induced bronchoconstriction and (or) asthma symptoms were the primary adverse events. There is no direct evidence regarding the risk of exercise for patients with COPD or asthma. However, based on the available literature, it would appear that with adequate screening and optimal medical therapy, the risk of exercise for these respiratory patients is low.

STAT3 modulates cigarette smoke-induced inflammation and protease expression

Signal transducer and activator of transcription-3 (STAT3) regulates inflammation, apoptosis, and protease expression, which are critical processes associated with airway injury and lung tissue destruction. However, the precise role of STAT3 in the development of airway diseases such as chronic obstructive pulmonary disease (COPD) has not been established. This study shows that cigarette smoke activates STAT3 in the lungs of mice. Since cigarette smoke activated STAT3 in the lung, we then evaluated how the loss of STAT3 would impact on smoke-mediated lung inflammation, protease expression, and apoptosis. STAT3^+/+ and STAT3^−/− mice were exposed to 8 days of cigarette smoke. Compared to the STAT3^+/+ mice bronchoalveolar lavage fluid (BALF) cellularity was significantly elevated in the STAT3^−/− mice both before and after cigarette smoke exposure, with the increase in cells primarily macrophages. In addition, smoke exposure induced significantly higher BALF protein levels of Interleukin-1α (IL-1α), and monocyte chemotactic protein-1 (MCP-1) and higher tissue expression of keratinocyte chemoattractant (KC) in the STAT3^−/− mice. Lung mRNA expression of MMP-12 was increased in STAT3^−/− at baseline. However, the smoke-induced increase in MMP-10 expression seen in the STAT3^+/+ mice was not observed in the STAT3^−/− mice. Moreover, lung protein levels of the anti-inflammatory proteins SOCS3 and IL-10 were markedly lower in the STAT3^−/− mice compared to the STAT3^+/+ mice. Lastly, apoptosis, as determined by caspase 3/7 activity assay, was increased in the STAT3^−/− at baseline to levels comparable to those observed in the smoke-exposed STAT3^+/+ mice. Together, these results indicate that the smoke-mediated induction of lung STAT3 activity may play a critical role in maintaining normal lung homeostasis and function.

Inflammation and immune response in COPD: where do we stand?

Increasing evidence indicates that chronic inflammatory and immune responses play key roles in the development and progression of COPD. Recent data provide evidence for a role in the NLRP3 inflammasome in the airway inflammation observed in COPD. Cigarette smoke activates innate immune cells by triggering pattern recognition receptors (PRRs) to release “danger signal”. These signals act as ligands to Toll-like receptors (TLRs), triggering the production of cytokines and inducing innate inflammation. In smokers who develop COPD there appears to be a specific pattern of inflammation in the airways and parenchyma as a result of both innate and adaptive immune responses, with the predominance of CD8+ and CD4+ cells, and in the more severe disease, with the presence of lymphoid follicles containing B lymphocytes and T cells. Furthermore, viral and bacterial infections interfere with the chronic inflammation seen in stable COPD and exacerbations via pathogen-associated molecular patterns (PAMPs). Finally, autoimmunity is another novel aspect that may play a critical role in the pathogenesis of COPD. This review is un update of the currently discussed roles of inflammatory and immune responses in the pathogenesis of COPD.

T cell depletion protects against alveolar destruction due to chronic cigarette smoke exposure in mice

The role of T cells in chronic obstructive pulmonary disease (COPD) is not well understood. We have previously demonstrated that chronic cigarette smoke exposure can lead to the accumulation of CD4+ and CD8+ T cells in the alveolar airspaces in a mouse model of COPD, implicating these cells in disease pathogenesis. However, whether specific inhibition of T cell responses represents a therapeutic strategy has not been fully investigated. In this study inhibition of T cell responses through specific depleting antibodies, or the T cell immunosuppressant drug cyclosporin A, prevented airspace enlargement and neutrophil infiltration in a mouse model of chronic cigarette smoke exposure. Furthermore, individual inhibition of either CD4+ T helper or CD8+ T cytotoxic cells prevented airspace enlargement to a similar degree, implicating both T cell subsets as critical mediators of the adaptive immune response induced by cigarette smoke exposure. Importantly, T cell depletion resulted in significantly decreased levels of the Th17-associated cytokine IL-17A, and of caspase 3 and caspase 7 gene expression and activity, induced by cigarette smoke exposure. Finally, inhibition of T cell responses in a therapeutic manner also inhibited cigarette smoke-induced airspace enlargement, IL-17A expression, and neutrophil influx in mice. Together these data demonstrate for the first time that therapeutic inhibition of T cell responses may be efficacious in the treatment of COPD. Given that broad immunosuppression may be undesirable in COPD patients, this study provides proof-of-concept for more targeted approaches to inhibiting the role of T cells in emphysema development.

Prothrombotic state in senile patients with acute exacerbations of chronic obstructive pulmonary disease combined with respiratory failure

The aim of this study was to study the clinical value of prethrombotic state and treatment with low molecular weight heparin (LMWH) in senile patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) combined with respiratory failure. Hemorheological markers (hematocrit, blood viscosity and plasma viscosity), fibrinogen (FIB), D-dimer and gas analysis were evaluated in 30 senile patients with AECOPD combined with respiratory failure and compared with those in 30 cases without respiratory failure. A total of 30 cases with AECOPD combined with respiratory failure were randomly divided into treatment and control groups. The two groups received conventional treatment. The treatment group also received LMWH injections every 12 h for 6 days and the clinical effect was observed. The levels of FIB, D-dimer, hematocrit, blood viscosity and plasma viscosity were significantly higher in the patients with AECOPD combined with respiratory failure compared with those in the patients without respiratory failure. The plasma D-dimer and FIB levels had significantly positive correlations with the partial pressure of CO₂ (PaCO₂) and negative correlations with the partial pressure of O₂ (PaO₂) in the patients with AECOPD combined with respiratory failure. The curative effect was improved in the treatment group, compared with that in the control group without side-effects. However, no significant changes in activated partial thromboplastin time (APTT) and international normalized ratio (INR) were observed between the treatment and control groups. The senile patients with AECOPD combined with respiratory failure suffered from hypercoagulation. Early detection and diagnosis of the prethrombotic state and timely treatment with LMWH may benefit these patients without side-effects.

Genetic epidemiology of cigarette smoke-induced lung disease

Chronic obstructive pulmonary disease (COPD) and lung cancer represent two diseases that share a strong risk factor in smoking, and COPD increases risk of lung cancer even after adjusting for the effects of smoking. These diseases not only occur jointly within an individual but also there is evidence of shared occurrence within families. Understanding the genetic contributions to these diseases, both individually and jointly, is needed to identify the highest risk group for screening and targeted prevention, as well as aiding in the development of targeted treatments. The chromosomal regions that have been identified as being associated either jointly or independently with lung cancer, COPD, nicotine addiction, and lung function are presented. Studies jointly measuring genetic variation in lung cancer and COPD have been limited by the lack of detailed COPD diagnosis and severity data in lung cancer populations, the lack of lung cancer-specific phenotypes (histology and tumor markers) in COPD populations, and the lack of inclusion of minorities. African Americans, who smoke fewer cigarettes per day and have different linkage disequilibrium and disease patterns than whites, and Asians, also with different patterns of exposure to lung carcinogens and linkage patterns, will provide invaluable information to better understand shared and independent genetic contributions to lung cancer and COPD to more fully define the highest risk group of individuals who will most benefit from screening and to develop molecular signatures to aid in targeted treatment and prevention efforts.

Suppressed expression of T-box transcription factors is involved in senescence in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a major global health problem. The etiology of COPD has been associated with apoptosis, oxidative stress, and inflammation. However, understanding of the molecular interactions that modulate COPD pathogenesis remains only partly resolved. We conducted an exploratory study on COPD etiology to identify the key molecular participants. We used information-theoretic algorithms including Context Likelihood of Relatedness (CLR), Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNE), and Inferelator. We captured direct functional associations among genes, given a compendium of gene expression profiles of human lung epithelial cells. A set of genes differentially expressed in COPD, as reported in a previous study were superposed with the resulting transcriptional regulatory networks. After factoring in the properties of the networks, an established COPD susceptibility locus and domain-domain interactions involving protein products of genes in the generated networks, several molecular candidates were predicted to be involved in the etiology of COPD. These include COL4A3, CFLAR, GULP1, PDCD1, CASP10, PAX3, BOK, HSPD1, PITX2, and PML. Furthermore, T-box (TBX) genes and cyclin-dependent kinase inhibitor 2A (CDKN2A), which are in a direct transcriptional regulatory relationship, emerged as preeminent participants in the etiology of COPD by means of senescence. Contrary to observations in neoplasms, our study reveals that the expression of genes and proteins in the lung samples from patients with COPD indicate an increased tendency towards cellular senescence. The expression of the anti-senescence mediators TBX transcription factors, chromatin modifiers histone deacetylases, and sirtuins was suppressed; while the expression of TBX-regulated cellular senescence markers such as CDKN2A, CDKN1A, and CAV1 was elevated in the peripheral lung tissue samples from patients with COPD. The critical balance between senescence and anti-senescence factors is disrupted towards senescence in COPD lungs.

Acute exacerbations of chronic obstructive pulmonary disease in the emergency department

Chronic obstructive pulmonary disease (COPD) is a significant cause of morbidity and mortality worldwide. Acute exacerbations of COPD (AECOPDs) are a common presentation to emergency departments and are an important cause of respiratory failure. This article discusses the disease process and diagnosis of COPD and AECOPD. A further in-depth discussion is undertaken of evidence-based treatments, palliation, and disposition of patients who present to emergency departments with AECOPD.

Targeted deletion of Jun/AP-1 in alveolar epithelial cells causes progressive emphysema and worsens cigarette smoke-induced lung inflammation

Chronic obstructive pulmonary disease appears to occur slowly and progressively over many years, with both genetic factors and environmental modifiers contributing to its pathogenesis. Although the c-Jun/activator protein 1 transcriptional factor regulates cell proliferation, apoptosis, and inflammatory responses, its role in lung pathogenesis is largely unknown. In this study, we report decreased expression levels of c-Jun mRNA and protein in the lung tissues of patients with advanced chronic obstructive pulmonary disease, and the genetic deletion of c-Jun specifically in alveolar epithelial cells causes progressive emphysema with lung inflammation and alveolar air space enlargement, which are cardinal features of emphysema. Although mice lacking c-Jun specifically in lung alveolar epithelial cells appear normal at the age of 6 weeks, when exposed to long-term cigarette smoke, c-Jun-mutant mice display more lung inflammation with perivascular and peribronchiolar infiltrates compared with controls. These results demonstrate that the c-Jun/activator protein 1 pathway is critical for maintaining lung alveolar cell homeostasis and that loss of its expression can contribute to lung inflammation and progressive emphysema.

Theaflavins extracted from black tea inhibit airway mucous hypersecretion induced by cigarette smoke in rats

Theaflavins isolated from black tea have been used in studies on the prevention of tumor growth. The aim of this study was to investigate whether treatment with theaflavins influences the mucus hypersecretion induced by cigarette smoke in the lungs of experimental rats. Firstly, cigarette smoke was aerosolized using a machine designed for inhalation by rats. The rats were divided into the negative control group, the cigarette smoke inhalation group, the theaflavins (TFs) treatment group, and the TFs +cigarette smoke inhalation group. The animals were sacrificed on day 60 of the experiment. Secondly, the rats were treated with theaflavins at different doses via a gastric tube and sacrificed on day 30. The changes in the levels of mucin 5AC (MUC5AC) and epidermal growth factor receptor (EGFR) in the airway were evaluated. Cigarette smoke induced a significant increase in the levels of MUC5AC and EGFR in all groups. These increases could be reversed by intragastric administration of theaflavins. The effect was more pronounced with the duration of treatment and coincided with a decrease in the expression of both targets. The rats showed various degrees of reduction in the expression of these parameters, which correlated with the theaflavin dose. TFs could inhibit the activation of EGFR, decrease the level of MUC5AC, and relieve airway mucous hypersecretion via the EGFR signaling pathway. These effects correlated directly with the duration of action and the dosage. In the future, oral theaflavins might be valuable in the treatment of chronic airway inflammation.

Impact of lung transplantation on serum lipids in COPD

BACKGROUND

Severe chronic obstructive pulmonary disease is associated with high HDL cholesterol (HDL-C). We sought to examine the effect of lung transplantation on lipid profiles in patients with COPD.

METHODS

We analyzed 101 lung transplant recipients in a retrospective cohort of patients from two centers in whom lipid values were available both before as well as after transplantation. Sixty-one subjects were transplanted for severe COPD (93% GOLD stage 4).

RESULTS

Eighty-nine percent of subjects with COPD exhibited a decline in HDL-C. Median decline for the COPD cohort was 25 mg/dL (IQR 12-38 mg/dL, p < 0.0001). Non-COPD subjects exhibited no significant changes in HDL-C. Other lipid changes in the COPD cohort included a rise in triglycerides of 70 mg/dL (IQR 35 to 140, p < 0.0001). Decreases in HDL-C levels were independent from the rise in triglyceride levels. Neither LDL-C nor non-HDL-C demonstrated significant changes. Subjects with greater increases in prednisone exposure post-transplant exhibited lesser declines in HDL-C. Compared with tacrolimus, cyclosporine had no effect on observed changes in HDL-C or triglycerides, but was associated with a greater median rise in LDL-C.

CONCLUSIONS

In patients with COPD, lung transplantation results in reductions in the serum levels of HDL-C. These changes are not observed in patients undergoing lung transplantation for diagnoses other than COPD.