Oxidant/antioxidant imbalance in smokers and chronic obstructive pulmonary disease

The Role of Exhaled Breath Condensate in Chronic Inflammatory and Neoplastic Diseases of the Respiratory Tract

Asthma and chronic obstructive pulmonary disease (COPD) are among the most common chronic respiratory diseases. Chronic inflammation of the airways leads to an increased production of inflammatory markers by the effector cells of the respiratory tract and lung tissue. These biomarkers allow the assessment of physiological and pathological processes and responses to therapeutic interventions. Lung cancer, which is characterized by high mortality, is one of the most frequently diagnosed cancers worldwide. Current screening methods and tissue biopsies have limitations that highlight the need for rapid diagnosis, patient differentiation, and effective management and monitoring. One promising non-invasive diagnostic method for respiratory diseases is the assessment of exhaled breath condensate (EBC). EBC contains a mixture of volatile and non-volatile biomarkers such as cytokines, leukotrienes, oxidative stress markers, and molecular biomarkers, providing significant information about inflammatory and neoplastic states in the lungs. This article summarizes the research on the application and development of EBC assessment in diagnosing and monitoring respiratory diseases, focusing on asthma, COPD, and lung cancer. The process of collecting condensate, potential issues, and selected groups of markers for detailed disease assessment in the future are discussed. Further research may contribute to the development of more precise and personalized diagnostic and treatment methods.

Oxidative Stress and Total Phenolics Concentration in COPD Patients-The Effect of Exercises: A Randomized Controlled Trial

Patients with chronic obstructive pulmonary disease (COPD) suffer from exercise intolerance, the sensation of dyspnea, and fatigue, which are the main reasons for limiting their physical activity. In addition to changes in the respiratory and circulatory systems in patients with COPD, peripheral muscle dysfunction, with numerous metabolic dysfunctions, is observed. One of the symptoms of the described anomalies, among others, is an antioxidative and prooxidative imbalance. The aim of the study was to demonstrate the impact of endurance training, carried out in the extended pulmonary rehabilitation program in COPD patients, on the imbalance between prooxidants and antioxidants in their bodies. Methods: The tests were carried out on a group of patients (n = 32) with COPD; 20 randomly selected people underwent a modified rehabilitation program during their rehabilitation stay, and the obtained results were compared with the results of 12 patients (control group) who were treated without endurance training. At the beginning and at the end of the study, spirometry and cardiopulmonary exercise tests (CPET) were performed. Oxidative stress (allantoin (All) and substances which react with thiobarbituric acid) and antioxidant (ferric reducing ability of plasma and total phenolics) parameters’ concentrations were determined in the venous blood. Results: In the study group, greater post-training increases of VO2max (p = 0.0702) and FEV1/FVC (p < 0.05; ES: 0.436) were reported. The applied CPET at each time caused an increase in the All concentration (p < 0.05) in the study and control groups. Conclusions: Endurance training applied as a part of the rehabilitation process did not cause the additional aggravation of oxidative stress and blood total phenolics concentration.

The alterations of retinal vasculature detected on optical coherence tomography angiography associated with chronic obstructive pulmonary disease

OBJECTIVES

This study aimed to evaluate the retinal vasculature of the macula and optic disc in patients with chronic obstructive pulmonary disease (COPD) by optical coherence tomography angiography (OCTA).

METHODS

The right eyes of 70 COPD patients and 71 healthy individuals were evaluated. These patients had moderate airflow limitation and mean PO2 of 60 mmHg, and their average age was less than 60 years. Superficial and deep capillary plexus vascular densities, foveal avascular zone (FAZ) width, and optic disc parameters were measured with OCTA. In addition, the correlation between the PO2 level in COPD patients and superficial, deep, and peripapillary vascular densities and FAZ was examined in the study.

RESULTS

The COPD group had a significant decrease in the vascular density in the superficial (fovea [p = 0.019]; parafovea [p = 0.013]; and perifovea [p = 0.001]) and deep capillary plexus (fovea [p = 0.028]; parafovea [p = 0.005]; and perifovea [p = 0.002]). Also, the enlargement of the FAZ (p = 0.002) and a decrease in the peripapillary vascular density (p = 0.006) were observed in the COPD group. There was a positive correlation between PO2 level and superficial, deep, and peripapillary vascular densities in COPD patients and a negative correlation with FAZ (r = 0.559-0.900).

CONCLUSION

Hypercapnia, respiratory acidosis, and chronic hypoxia associated with COPD may affect the macula and optic nerve, resulting in a serious decrease in vascular density, and OCTA can be a very important tool in the follow-up and treatment of these patients.

Characterization of the COPD alveolar niche using single-cell RNA sequencing

Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide, however our understanding of cell specific mechanisms underlying COPD pathobiology remains incomplete. Here, we analyze single-cell RNA sequencing profiles of explanted lung tissue from subjects with advanced COPD or control lungs, and we validate findings using single-cell RNA sequencing of lungs from mice exposed to 10 months of cigarette smoke, RNA sequencing of isolated human alveolar epithelial cells, functional in vitro models, and in situ hybridization and immunostaining of human lung tissue samples. We identify a subpopulation of alveolar epithelial type II cells with transcriptional evidence for aberrant cellular metabolism and reduced cellular stress tolerance in COPD. Using transcriptomic network analyses, we predict capillary endothelial cells are inflamed in COPD, particularly through increased CXCL-motif chemokine signaling. Finally, we detect a high-metallothionein expressing macrophage subpopulation enriched in advanced COPD. Collectively, these findings highlight cell-specific mechanisms involved in the pathobiology of advanced COPD.

Tocotrienols: Dietary Supplements for Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death worldwide. Emphysema and chronic bronchitis are the two major phenotypes of COPD, which have many symptoms, such as dyspnea, chronic cough, and mucus overproduction. Emphysema is characterized by the destruction of the alveolar wall, while chronic bronchitis is characterized by limitations in expiratory airflow. Cigarette smoking is the most significant risk factor for the pathogenesis of COPD in the developed world. Chronic inflammation contributes to the onset and progression of the disease and furthers the risk of comorbidities. Current treatment options and prevention strategies for COPD are very limited. Tocotrienols are a group of vitamin E molecules with antioxidant and anti-inflammatory properties. Individual tocotrienols (α, γ, and δ) have shown their ability to attenuate inflammation specifically via suppressing nuclear factor-κB-mediated cytokine production. The δ- and γ-forms of tocotrienols have been indicated as the most effective in the prevention of macrophage infiltration, production of reactive oxygen species, and cytokine secretion. This review briefly discusses the pathogenesis of COPD and the role of inflammation therein. Furthermore, we summarize the in vitro and in vivo evidence for the anti-inflammatory activity of tocotrienols and their potential application to COPD management. Coupled with the bioavailability and safety profile of tocotrienols, the ability of these compounds to modulate COPD progression by targeting the inflammation pathways renders them potential candidates for novel therapeutic approaches in the treatment of COPD patients.

Smoking Reduces Plasma Bilirubin: Observational and Genetic Analyses in the Copenhagen General Population Study

INTRODUCTION

Observational studies have found lower concentrations of plasma bilirubin in current smokers compared with former and never smokers. However, whether there is a causal relationship between smoking and bilirubin is unknown. In a Mendelian randomization analysis, we tested the hypothesis that higher tobacco consumption is causally associated with lower concentrations of plasma bilirubin.

METHODS

We genotyped 103 557 individuals aged 20-100 years from the Copenhagen General Population Study for the CHRNA3 rs1051730 genotype, known to be associated with higher tobacco consumption. Tobacco consumption was defined as daily and cumulative tobacco consumption.

RESULTS

In observational multivariable-adjusted analyses, a 10 g/day higher daily tobacco consumption was associated with a 0.28 µmol/L (95% confidence interval = 0.20 to 0.35) lower concentration of plasma bilirubin in current smokers, and a 10 pack-year higher cumulative tobacco consumption was associated with a 0.19 µmol/L (0.17 to 0.21) lower concentration of plasma bilirubin in former and current smokers. Using the CHRNA3 rs1051730 genotype as a proxy for daily and cumulative tobacco consumption, the difference in plasma bilirubin per T-allele was -0.12 µmol/L (-0.23 to -0.002) in current smokers and -0.09 µmol/L (-0.15 to -0.01) in current and former smokers combined. Furthermore, observationally bilirubin concentrations increased with time from smoking cessation in former smokers.

CONCLUSION

Higher daily and cumulative tobacco consumption were associated with lower concentrations of plasma bilirubin in observational and genetic analyses, suggesting that the association is causal.

IMPLICATIONS

Our results are compatible with two possible interpretations of previous observational studies, either that bilirubin is a mediator of smoking-induced respiratory disease or that the association between plasma bilirubin and respiratory disease stems from residual confounding because of smoking. Future studies should examine whether bilirubin is a causal risk factor for respiratory disease, or merely a marker of smoking status.

Regulation of the Proteolytic Activity of Cysteine Cathepsins by Oxidants

Besides their primary involvement in the recycling and degradation of proteins in endo-lysosomal compartments and also in specialized biological functions, cysteine cathepsins are pivotal proteolytic contributors of various deleterious diseases. While the molecular mechanisms of regulation via their natural inhibitors have been exhaustively studied, less is currently known about how their enzymatic activity is modulated during the redox imbalance associated with oxidative stress and their exposure resistance to oxidants. More specifically, there is only patchy information on the regulation of lung cysteine cathepsins, while the respiratory system is directly exposed to countless exogenous oxidants contained in dust, tobacco, combustion fumes, and industrial or domestic particles. Papain-like enzymes (clan CA, family C1, subfamily C1A) encompass a conserved catalytic thiolate-imidazolium pair (Cys25-His159) in their active site. Although the sulfhydryl group (with a low acidic pKa) is a potent nucleophile highly susceptible to chemical modifications, some cysteine cathepsins reveal an unanticipated resistance to oxidative stress. Besides an introductory chapter and peculiar attention to lung cysteine cathepsins, the purpose of this review is to afford a concise update of the current knowledge on molecular mechanisms associated with the regulation of cysteine cathepsins by redox balance and by oxidants (e.g., Michael acceptors, reactive oxygen, and nitrogen species).

Extracorporeal Membrane Oxygenation in Severe Acute Eosinophilic Pneumonia

Acute Eosinophilic Pneumonia (AEP) is a potentially fatal cause of hypoxemic respiratory failure characterized by fever, diffuse bilateral pulmonary infiltrates, and pulmonary eosinophilia. Shown to be associated with a number of environmental exposures and lifestyle choices, AEP has a good prognosis when diagnosed early and treated with corticosteroids. In this clinical case report, we detail the presentation, evaluation, diagnosis, and management of a 40-year old male who presented to the emergency department with dyspnea, chills, and diaphoresis. He had a history of pulmonary embolism 8 years prior but was otherwise healthy, though he had re-started smoking cigarettes a week prior to presentation. Initial chest CT scan revealed widespread mixed groundglass and solid airspace opacities; over the next 12 hours, he rapidly decompensated and after not responding to other invasive mechanical ventilation, was emergently cannulated for veno-venous extracorporeal membrane oxygenation (V-V ECMO). Bronchoalveolar lavage later revealed pulmonary eosinophilia, and after an infectious workup was negative, a diagnosis of AEP was reached and the patient was started on corticosteroids. To our knowledge, this is one of few published cases of AEP requiring V-V ECMO for clinical stabilization, highlighting the utility of this treatment modality in severe disease.

Effects of Roflumilast on Rehospitalization and Mortality in Patients

Introduction: Hospitalization for chronic obstructive pulmonary disease (COPD) exacerbation portends the greatest risk of rehospitalization and mortality. Treatments that prevent hospitalizations could significantly lessen COPD morbidity and mortality. Methods: We performed a prospective, randomized, double-blind, placebo-controlled study of roflumilast 500 ug daily versus placebo in patients hospitalized for acute COPD exacerbation. Primary outcome was time to all-cause mortality or non-elective rehospitalization at 180 days post-randomization. Secondary outcomes were death or hospitalization from a respiratory cause, quality of life, change in health status, forced expiratory volume in 1 second (FEV1) and roflumilast tolerance. Results: A total of 64 patients with moderate to severe COPD (FEV1, 37.6 ± 16.4% predicted; 61% female, 61.6 ± 7.9 years old) were assigned to roflumilast or placebo. No deaths occurred in the follow-up period. There was no difference in the time to first readmission between the roflumilast and placebo groups (46.1 days versus 47.3 days respectively, p=0.93). There were 29 and 30 readmissions in the roflumilast and placebo groups, respectively (p=0.47). The St George's Respiratory Questionnaire (SGRQ) decreased 10.8 points and 7.8 points in the roflumilast and placebo groups, respectively and were not different. EuroQuality of Life Five Dimension scale (EQ5D) scores improved, but not significantly in either group. Weight loss and nausea were more common with roflumilast but not different from placebo. Change in glycosylated hemoglobin percentage (HgbA1C%) was not different between groups. Sub-analysis for the impact of chronic bronchitis did not affect outcomes. Conclusion: In this pilot study conducted in patients hospitalized with an exacerbation of COPD, roflumilast did not affect time to all-cause rehospitalization, quality of life, FEV1 or any other measured parameter.

Effect of nitroso-redox imbalance on male reproduction

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are byproducts of normal metabolic processes. They are necessary for normal cellular function and are kept in balance by antioxidant mechanisms. Alterations in levels of ROS and RNS can lead to nitroso-redox imbalance that in turn can negatively affect male reproduction. Strategies to decrease ROS/RNS involve evasion of exposures (smoking, meat intake, pollution, calorie-dense diet), managing lifestyle, and increasing the consumption of antioxidants (vitamin C, vitamin E, alpha-lipoic acid, taurine, quercetin). Targeted therapies focusing on nitroso-redox imbalance can be critical for treatment of male reproductive dysfunction. This review outlines endogenous and exogenous sources of ROS/RNS, adverse effect on male reproduction, and strategies to control nitroso-redox imbalance.

Macrophage Rac2 Is Required to Reduce the Severity of Cigarette Smoke-induced Pneumonia

RATIONALE

Cigarette smoking is prevalent in the United States and is the leading cause of preventable diseases. A prominent complication of smoking is an increase in lower respiratory tract infections (LRTIs). Although LRTIs are known to be increased in subjects that smoke, the mechanism(s) by which this occurs is poorly understood.

OBJECTIVES

Determine how cigarette smoke (CS) reduces reactive oxygen species (ROS) production by the phagocytic NOX2 (NADPH oxidase 2), which is essential for innate immunity in lung macrophages.

METHODS

NOX2-derived ROS and Rac2 (Ras-related C3 botulinum toxin substrate 2) activity were determined in BAL cells from wild-type and Rac2-/- mice exposed to CS or cadmium and in BAL cells from subjects that smoke. Host defense to respiratory pathogens was analyzed in mice infected with Streptococcus pneumoniae.

MEASUREMENTS AND MAIN RESULTS

NOX2-derived ROS in BAL cells was reduced in mice exposed to CS via inhibition of the small GTPase Rac2. These mice had greater bacterial burden and increased mortality compared with air-exposed mice. BAL fluid from CS-exposed mice had increased levels of cadmium, which mediated the effect on Rac2. Similar observations were seen in human subjects that smoke. To support the importance of Rac2 in the macrophage immune response, overexpression of constitutively active Rac2 by lentiviral administration increased NOX2-derived ROS, decreased bacterial burden in lung tissue, and increased survival compared with CS-exposed control mice.

CONCLUSIONS

These observations suggest that therapies to maintain Rac2 activity in lung macrophages restore host defense against respiratory pathogens and diminish the prevalence of LRTIs in subjects that smoke.

Airway reactivity to mannitol is similarly increased in chronic cigarette and water pipe smokers

Background

In contrast to cigarette smoking, the association between water pipe smoking and airway hyperresponsiveness remains widely unexplored.

Methods

A bronchoprovocation challenge with mannitol was performed in young adults recruited at the University of Basel, Switzerland. Subjects were categorized as acute water pipe smokers (single episode of water pipe smoking, no or <0.5 pack-years cigarette smoking); chronic water pipe smokers (weekly for ≥4 weeks, no or <0.5 pack-years cigarette smoking); cigarette smokers (no water pipe smokers); and never-smokers (no cigarette or water pipe smokers). Primary outcomes were airway reactivity as measured by the response-to-dose ratio (RDR) and airway responsiveness measured by the provocation dose to cause a 15% fall in forced expiratory volume in 1s (FEV₁; PD₁₅).

Results

Seventy-four subjects with a mean age of 22.5±2.5 years and FEV₁ % predicted 90.1%±8.6% were included. Subgroups were matched in terms of age, gender, and spirometry results. RDR in chronic water pipe smokers and cigarette smokers was similar (0.013%/mg [0.010–0.015] vs 0.023%/mg [0.011–0.051], respectively; p=0.12) but significantly higher than in never-smokers (0.007%/mg [0.005–0.010], p<0.01). Neither a history of asthma (p=0.88) nor a positive skin prick test (p=0.69) was associated with increased airway reactivity to the mannitol challenge test. PD₁₅ differed significantly between cigarette smokers and never-smokers (155 mg [115–395] vs 315 mg [155–475], respectively; p=0.04).

Conclusion

Weekly water pipe smoking may increase airway reactivity to a similar extent as cigarette smoking.

Cigarette smoke condensate attenuates phorbol ester-mediated neutrophil extracellular trap formation

BACKGROUND

Neutrophil extracellular traps (NETs) constitute a network of chromatin fibres containing histone and antimicrobial peptides that are released by activated neutrophils. NETs protect the host against infection by trapping and facilitating phagocytosis of potentially harmful pathogens.

OBJECTIVES

The aim of the current study was to investigate the effects of cigarette smoke condensate (CSC) on phorbol-ester (PMA)-mediated NETosis in vitro.

METHODS

Isolated human blood neutrophils were exposed to PMA (6.25 ng/ml) in the presence or absence of CSC (40-80 µg/ml) for 90 min at 37oC. NET formation was measured using a spectrofluorimetric procedure to detect extracellular DNA and fluorescence microscopy was used to visualize nets. Oxygen consumption by PMA-activated neutrophils was measured using an oxygen sensitive electrode.

RESULTS

Activation of neutrophils with PMA was associated with induction of NETosis that was significantly attenuated in the presence of CSC (40 and 80 µg/ml), with mean fluorescence intensities of 65% and 66% of that observed with untreated cells, respectively, and confirmed by fluorescence microscopy. The rate and magnitude of oxygen consumption by activated neutrophils pre-treated with CSC (80 µg/ml) was significantly less than that observed with untreated cells (73% of the control system), indicative of decreased production of reactive oxidants in the presence of CSC.

CONCLUSION

The inhibition of NETosis observed in the presence of CSC correlated with attenuation of oxygen consumption by PMA-activated neutrophils suggesting a mechanistic relationship between these events. If operative in vivo, smoking-related attenuation of NETosis may impair host immune responses and increase the risk of respiratory infections.

Hemosiderin in sputum macrophages may predict infective exacerbations of chronic obstructive pulmonary disease: a retrospective observational study

Background

Infective exacerbations of COPD are common and are accompanied by neutrophilic bronchitis in sputum. Increased respiratory iron content has been associated with respiratory tract infection, though it is unclear if this represents a predisposing factor for infection or the sequelae of inflammation. Iron overload, as assessed in the airways, may be an important biomarker for recurrent infective exacerbations of COPD. The purpose of our study was to determine if hemosiderin in sputum macrophages is related to infective exacerbations of COPD.

Methods

We undertook a retrospective observational study of 54 consecutive patients who presented with an exacerbation of COPD and had sputum examined including assessment for hemosiderin in alveolar macrophages. The relation between infective exacerbations in the previous two years and the percent of hemosiderin-positive macrophages was analyzed with linear regression. To account for the non-parametric distribution of infective exacerbations, negative binomial regression modelling was used to account for other covariates.

Results

The percent of hemosiderin positive alveolar macrophages (hemosiderin index), analyzed parametrically and non-parametrically, demonstrated a significant correlation with increasing numbers of infective exacerbations in the previous two years. In a multivariate regression analysis, hemosiderin index was an independent predictor of infective exacerbations. COPD patients with raised hemosiderin index (≥20%) had higher levels of sputum IL-6 compared to patients with lower levels (<20%).

Conclusions

High hemosiderin index in sputum alveolar macrophages measured at the time of AECOPD may be related to the frequency of infective exacerbations of COPD.

Acrolein and thiol-reactive electrophiles suppress allergen-induced innate airway epithelial responses by inhibition of DUOX1 and EGFR

Acrolein is a major thiol-reactive component of cigarette smoke (CS) that is thought to contribute to increased asthma incidence associated with smoking. Here, we explored the effects of acute acrolein exposure on innate airway responses to two common airborne allergens, house dust mite and Alternaria alternata, and observed that acrolein exposure of C57BL/6 mice (5 ppm, 4 h) dramatically inhibited innate airway responses to subsequent allergen challenge, demonstrated by attenuated release of the epithelial-derived cytokines IL-33, IL-25, and IL-1α. Acrolein and other anti-inflammatory thiol-reactive electrophiles, cinnamaldehyde, curcumin, and sulforaphane, similarly inhibited allergen-induced production of these cytokines from human or murine airway epithelial cells in vitro. Based on our previous observations indicating the importance of Ca²⁺-dependent signaling, activation of the NADPH oxidase DUOX1, and Src/EGFR-dependent signaling in allergen-induced epithelial secretion of these cytokines, we explored the impact of acrolein on these pathways. Acrolein and other thiol-reactive electrophiles were found to dramatically prevent allergen-induced activation of DUOX1 as well as EGFR, and acrolein was capable of inhibiting EGFR tyrosine kinase activity via modification of C797. Biotin-labeling strategies indicated increased cysteine modification and carbonylation of Src, EGFR, as well as DUOX1, in response to acrolein exposure in vitro and in vivo, suggesting that direct alkylation of these proteins on accessible cysteine residues may be responsible for their inhibition. Collectively, our findings indicate a novel anti-inflammatory mechanism of CS-derived acrolein and other thiol-reactive electrophiles, by directly inhibiting DUOX1- and EGFR-mediated airway epithelial responses to airborne allergens.

Enhanced Resolution of Hyperoxic Acute Lung Injury as a result of Aspirin Triggered Resolvin D1 Treatment

Acute lung injury (ALI), which presents as acute respiratory failure, is a major clinical problem that requires aggressive care, and patients who require prolonged oxygen exposure are at risk of developing this disease. Although molecular determinants of ALI have been reported, the molecules involved in disease catabasis associated with oxygen toxicity have not been well studied. It has been reported that lung mucosa is rich in omega-3 fatty acid dicosahexanoic acid (DHA), which has antiinflammatory properties. Aspirin-triggered resolvin D1 (AT-RvD1) is a potent proresolution metabolite of DHA that can curb the inflammatory effects in various acute injuries, yet the effect of AT-RvD1 on hyperoxic acute lung injury (HALI) or in the oxygen toxicity setting in general has not been investigated. The effects of AT-RvD1 on HALI were determined for the first time in 8- to 10-week-old C57BL/6 mice that were exposed to hyperoxia (≥95% O2) for 48 hours. Mice were given AT-RvD1 (100 ng) in saline or a saline vehicle for 24 hours in normoxic (≈21% O2) conditions after hyperoxia. Lung tissue and bronchoalveolar lavage (BAL) fluid were collected for analysis associated with proinflammatory signaling and lung inflammation. AT-RvD1 treatment resulted in reduced oxidative stress, increased glutathione production, and significantly decreased tissue inflammation. AT-RvD1 treatment also significantly reduced the lung wet/dry ratio, protein in BAL fluid, and decreased apoptotic and NF-κB signaling. These results show that AT-RvD1 curbs oxygen-induced lung edema, permeability, inflammation, and apoptosis and is thus an effective therapy for prolonged hyperoxia exposure in this murine model.

Sirtuin 1 and aging theory for chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary disease (COPD) is an inflammatory syndrome that represents an increasing health problem, especially in the elderly population. Drug therapies are symptomatic and inadequate to contrast disease progression and mortality. Thus, there is an urgent need to clarify the molecular mechanisms responsible for this condition in order to identify new biomarkers and therapeutic targets. Processes including oxidant/antioxidant, protease/antiprotease, and proliferative/antiproliferative balance and control of inflammatory response become dysfunctional during aging as well as in COPD. Recently it was suggested that Sirtuin 1 (SIRT1), an antiaging molecule involved in the response to oxidative stress and chronic inflammation, is implicated in both development and progression of COPD. The present review focuses on the involvement of SIRT1 in the regulation of redox state, inflammation, and premature senescence, all crucial characteristics of COPD phenotypes. Recent evidence corroborating the statement of the “aging theory for COPD” was also discussed.

Effects of cigarette smoking on HDL quantity and function: implications for atherosclerosis

Cigarette smoking has been identified as an independent and preventable risk factor for atherosclerosis and cardiovascular disease. Population studies have shown that plasma high density lipoprotein (HDL) cholesterol levels are inversely related to the risk of developing cardiovascular disease. Cigarette smoking is associated with reduced HDL cholesterol levels. Cigarette smoking can alter the critical enzymes of lipid transport, lowering lecithin: cholesterol acyltransferase (LCAT) activity and altering cholesterol ester transfer protein (CETP) and hepatic lipase activity, which attributes to its impact on HDL metabolism and HDL subfractions distribution. In addition, HDL is susceptible to oxidative modifications by cigarette smoking, which makes HDL become dysfunctional and lose its atheroprotective properties in smokers. Therefore, cigarette smoking has a negative impact on both HDL quantity and function, which can explain, in part, the increased risk of cardiovascular disease in smokers.

Processed meat consumption and lung function: modification by antioxidants and smoking

Unhealthy dietary patterns are associated with poor lung function. It is not known whether this is due to low consumption of antioxidant-rich fruit and vegetables, or is a consequence of higher intakes of harmful dietary constituents, such as processed meat. We examined the individual and combined associations of processed meat, fruit and vegetable consumption and dietary total antioxidant capacity (TAC) with lung function among 1551 males and 1391 females in the UK in the Hertfordshire Cohort Study. Diet was assessed using a food frequency questionnaire. After controlling for confounders, processed meat consumption was negatively associated with forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC ratio in males and females, while fruit and vegetable consumption and dietary TAC were positively associated with FEV1 and FVC, but not FEV1/FVC ratio. In males, the negative association between processed meat consumption and FEV1 was more marked in those who had low fruit and vegetable consumption (p=0.035 for interaction), and low dietary TAC (p=0.025 for interaction). The deficit in FEV1/FVC associated with processed meat consumption was larger in males who smoked (p=0.022 for interaction). Higher processed meat consumption is associated with poorer lung function, especially in males who have lower fruit and vegetable consumption or dietary TAC, and among current smokers.

Prolonged cigarette smoke exposure alters mitochondrial structure and function in airway epithelial cells

BACKGROUND

Cigarette smoking is the major risk factor for COPD, leading to chronic airway inflammation. We hypothesized that cigarette smoke induces structural and functional changes of airway epithelial mitochondria, with important implications for lung inflammation and COPD pathogenesis.

METHODS

We studied changes in mitochondrial morphology and in expression of markers for mitochondrial capacity, damage/biogenesis and fission/fusion in the human bronchial epithelial cell line BEAS-2B upon 6-months from ex-smoking COPD GOLD stage IV patients to age-matched smoking and never-smoking controls.

RESULTS

We observed that long-term CSE exposure induces robust changes in mitochondrial structure, including fragmentation, branching and quantity of cristae. The majority of these changes were persistent upon CSE depletion. Furthermore, long-term CSE exposure significantly increased the expression of specific fission/fusion markers (Fis1, Mfn1, Mfn2, Drp1 and Opa1), oxidative phosphorylation (OXPHOS) proteins (Complex II, III and V), and oxidative stress (Mn-SOD) markers. These changes were accompanied by increased levels of the pro-inflammatory mediators IL-6, IL-8, and IL-1β. Importantly, COPD primary bronchial epithelial cells (PBECs) displayed similar changes in mitochondrial morphology as observed in long-term CSE-exposure BEAS-2B cells. Moreover, expression of specific OXPHOS proteins was higher in PBECs from COPD patients than control smokers, as was the expression of mitochondrial stress marker PINK1.

CONCLUSION

The observed mitochondrial changes in COPD epithelium are potentially the consequence of long-term exposure to cigarette smoke, leading to impaired mitochondrial function and may play a role in the pathogenesis of COPD.

Biomarkers in Exhaled Breath Condensate and Serum of Chronic Obstructive Pulmonary Disease and Non-Small-Cell Lung Cancer

Chronic obstructive pulmonary disease (COPD) and lung cancer are leading causes of deaths worldwide which are associated with chronic inflammation and oxidative stress. Lung cancer, in particular, has a very high mortality rate due to the characteristically late diagnosis. As such, identification of novel biomarkers which allow for early diagnosis of these diseases could improve outcome and survival rate. Markers of oxidative stress in exhaled breath condensate (EBC) are examples of potential diagnostic markers for both COPD and non-small-cell lung cancer (NSCLC). They may even be useful in monitoring treatment response. In the serum, S100A8, S100A9, and S100A12 of the S100 proteins are proinflammatory markers. They have been indicated in several inflammatory diseases and cancers including secondary metastasis into the lung. It is highly likely that they not only have the potential to be diagnostic biomarkers for NSCLC but also prognostic indicators and therapeutic targets.

Oxidative stress and chromatin remodeling in chronic obstructive pulmonary disease and smoking-related diseases

SIGNIFICANCE

Chronic obstructive pulmonary disease (COPD) is predominantly a tobacco smoke-triggered disease with features of chronic low-grade systemic inflammation and aging (inflammaging) of the lung associated with steroid resistance induced by cigarette smoke (CS)-mediated oxidative stress. Oxidative stress induces various kinase signaling pathways leading to chromatin modifications (histone acetylation/deacetylation and histone methylation/demethylation) in inflammation, senescence, and steroid resistance.

RECENT ADVANCES

Histone mono-, di-, or tri-methylation at lysine residues result in either gene activation (H3K4, H3K36, and H3K79) or repression (H3K9, H3K27, and H3K20). Cross-talk occurs between various epigenetic marks on histones and DNA methylation. Both CS and oxidants alter histone acetylation/deacetylation and methylation/demethylation leading to enhanced proinflammatory gene expression. Chromatin modifications occur in lungs of patients with COPD. Histone deacetylase 2 (HDAC2) reduction (levels and activity) is associated with steroid resistance in response to oxidative stress.

CRITICAL ISSUES

Histone modifications are associated with DNA damage/repair and epigenomic instability as well as premature lung aging, which have implications in the pathogenesis of COPD. HDAC2/SIRTUIN1 (SIRT1)-dependent chromatin modifications are associated with DNA damage-induced inflammation and senescence in response to CS-mediated oxidative stress.

FUTURE DIRECTIONS

Understanding CS/oxidative stress-mediated chromatin modifications and the cross-talk between histone acetylation and methylation will demonstrate the involvement of epigenetic regulation of chromatin remodeling in inflammaging. This will lead to identification of novel epigenetic-based therapies against COPD and other smoking-related lung diseases. Pharmacological activation of HDAC2/SIRT1 or reversal of their oxidative post-translational modifications may offer therapies for treatment of COPD and CS-related diseases based on epigenetic histone modifications.

Oxidative/Nitrosative stress and the pathobiology of chronic obstructive pulmonary disease

The understanding of the pathobiology of Chronic Obstructive Pulmonary Disease (COPD) has undergone a major change in the past three decades. The classical 'protease-antiprotease' hypothesis still holds true, nevertheless, the sequence of the biochemical events which lead to the protease/antiprotease imbalance have been unraveled. For instance, tobacco smoke, a primary risk factor for COPD, contains a plethora of reactive Oxygen/Nitrogen Species (ROS/RNS) that serve to initiate the oxidant/antioxidant imbalance in the respiratory tract of chronic smokers, a phenomenon that is amplified if certain other risk factors co-exist (e.g. a genetic deficiency of the major antiproteases, a suboptimal antioxidant defense system, airway hyper responsiveness etc.). The inflammatory response that ensues as a result of the initial occult exogenous oxidative/ nitrosative stress becomes a secondary endogenous source of ROS/RNS. This perpetuates the ongoing lung damage, even though the primary insult may no longer be present (abstinence). Depletion of the pulmonary antioxidants, damage to the local antiprotease protective screen, a decreased immune response, hypersecretion of mucus, superadded infections, oxygen therapy-induced oxidant production, etc. are some of the critical factors which account for the oxidative/ nitrosative stress-mediated pulmonary as well as extrapulmonary features of COPD. In the light of the recent developments, remarkable efforts are being made, either to develop novel therapeutic strategies or to improve the existing ones, which are aimed at treating different aspects of the disease. Thus, it is reasonable to recommend antioxidants as a useful adjunct to the more conventional treatment options, keeping in view the 'oxidant/antioxidant' hypothesis as a unifying theme for the 'protease/antiprotease' theory of COPD.

Serum mineral status of long-term cigarette smokers

This study was carried out to investigate comparatively some serum mineral levels of cigarette smokers. A total of 25 nonsmokers (control group) and 50 long-term cigarette smokers (smoking for at least 15 years; smoker group) were participated in the study. Subjects were between 25 and 40 years old. Control and smoker groups were matched for age, sex and body mass index status. The blood samples were taken from smokers and nonsmokers after 12 h of fasting period. The levels of zinc (Zn), copper (Cu), iron (Fe), magnesium (Mg), calcium (Ca), potassium (K), chlorine (Cl), sodium (Na) and phosphorus (P) were measured by autoanalyzer using commercial kits. Student’s t test was used to compare the control and smoker groups, and p < 0.05 indicated a significant difference. Pearson’s correlation coefficient was used to demonstrate the relationship among parameters in smoker and control groups. Although there was no statistical difference ( p > 0.05) between the groups regarding the levels of K, P, Mg, Na, Cl, Zn, Fe, Ca and Cu, some positive correlations were observed in controls but not in smokers. Therefore, it was concluded that smoking does not affect the serum mineral levels. However, it may negatively affect some important positive correlations among minerals observed in healthy individuals.

Evaluation of the oxidant and antioxidant balance in the pathogenesis of chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary Disease (COPD) is one of the most common chronic diseases and a major cause of morbility and mortality. An imbalance between oxidants and antioxidants (oxidative stress) has been proposed as a critical event in the pathogenesis of COPD. The increased oxidative stress in patients with COPD is the result of exogenous oxidants namely pollutants and cigarette smoke as well as endogenous oxidant production during inflammation. The aim of the present study was to clarify the hypothesis about the presence of an imbalance between oxidants and the antioxidant defences associated to COPD. In this study, we evaluated a biomarker of oxidative stress (malondialdehyde, a lipid peroxidation derived product) and non-enzymatic antioxidants (vitamin C and the sulphydryl groups) in COPD patients and healthy controls. The marker of oxidative stress was found to be significantly (p<0,001) higher in COPD patients when compared with the control group. No age dependent changes in the plasma levels of lipid peroxidation products were found. COPD patients had a significant (p<0,001) decrease in antioxidant status compared with control group. Our results show that oxidative stress is an important pathophysiologic change in COPD.

Comparative antioxidant effects of lycopene, apo-10'-lycopenoic acid and apo-14'-lycopenoic acid in human macrophages exposed to H2O2 and cigarette smoke extract

Much of the beneficial effects of tomato lycopene in the prevention of chronic diseases has been attributed to its antioxidant properties, which could be mediated by its metabolites and/or oxidation products. However, the biological functions of these lycopene derivatives remain still unknown. In the present study, we evaluated and compared the antioxidant efficacy of the lycopene eccentric cleavage products apo-10'-lycopenoic acid and apo-14'-lycopenoic acid in counteracting the oxidative effects of H(2)O(2) and cigarette smoke extract (CSE) in THP-1 macrophages. Both apo-10'-lycopenoic acid and apo-14'-lycopenoic acid were able to inhibit spontaneous and H(2)O(2)-induced ROS production in a dose-dependent manner. Such an effect was accompanied by an inhibition of MAPK phosphorylation, by NF-κB inactivation, and by inhibition of hsp-70 and hsp-90 expressions. Both apo-lycopenoic acids also decreased CSE-induced ROS production, 8-OHdG formation and reduced the increase in NOX-4 and COX-2 expressions caused by CSE. However, in both the models of oxidative stress, apo-14'-lycopenoic acid was much more potent as an antioxidant than apo-10'-lycopenoic acid, showing antioxidant properties similar to lycopene. These data strongly suggest that apo-lycopenoic acids, and particularly apo-14'-lycopenoic acid, may mediate some of the antioxidant functions of lycopene in cells.

Developmental cigarette smoke exposure: kidney proteome profile alterations in low birth weight pups

The Brenner hypothesis states that a congenital reduction in nephron number predisposes to adult-onset hypertension and renal failure. The reduction in nephron number induced by proportionally smaller kidney mass may predispose offspring to glomerular hyperfiltration with maturity onset obesity. Developmental cigarette smoke exposure (CSE) results in intrauterine growth retardation with a predisposition to obesity and cardiovascular disease at maturity. Utilizing a mouse model of 'active' developmental CSE (gestational day [GD] 1-postnatal day [PD] 21; cotinine>50 ng/mL) characterized by persistently smaller offspring with proportionally decreased kidney mass, the present study examined the impact of developmental CSE on the abundance of proteins associated with cellular metabolism in the kidney. Following cessation of CSE on PD21, kidney tissue was collected from CSE and Sham exposed pups for 2D-SDS-PAGE based proteome profiling with statistical analysis by partial least squares-discriminant analysis (PLS-DA) with affected molecular pathways identified by ingenuity pathway analysis. Proteins whose expression in the kidney were affected by developmental CSE belonged to the inflammatory disease, cell to cell signaling/interaction, lipid metabolism, small molecule biochemistry, cell cycle, respiratory disease, nucleic acid and carbohydrate metabolism networks. The present findings indicate that developmental CSE alters the kidney proteome. The companion paper details the liver proteome alterations in the same offspring.

Current controversies and future perspectives in chronic obstructive pulmonary disease

Over the past decade there has been much research and interest in COPD. As a result, the understanding and management of the disease has improved significantly. Yet, there are many uncertainties and controversies that require further work. This review discusses these controversies and anticipates some of the changes that may occur in the near future in the field of COPD.

Cigarette smoke and α,β-unsaturated aldehydes elicit VEGF release through the p38 MAPK pathway in human airway smooth muscle cells and lung fibroblasts

BACKGROUND AND PURPOSE

Vascular endothelial growth factor (VEGF) is an angiogenic factor known to be elevated in the sputum of asymptomatic smokers as well as smokers with bronchitis type of chronic obstructive pulmonary disease. The aim of this study was to investigate whether acute exposure to cigarette smoke extract altered VEGF production in lung parenchymal cells.

EXPERIMENTAL APPROACH

We exposed human airway smooth muscle cells (ASMC), normal human lung fibroblasts (NHLF) and small airways epithelial cells (SAEC) to aqueous cigarette smoke extract (CSE) in order to investigate the effect of cigarette smoke on VEGF expression and release.

KEY RESULTS

Vascular endothelial growth factor release was elevated by sub-toxic concentrations of CSE in both ASMC and NHLF, but not in SAEC. CSE-evoked VEGF release was mimicked by its component acrolein at concentrations (10-100 µM) found in CSE, and prevented by the antioxidant and α,β-unsaturated aldehyde scavenger, N-acetylcysteine (NAC). Both CSE and acrolein (30 µM) induced VEGF mRNA expression in ASMC cultures, suggesting an effect at transcriptional level. Crotonaldehyde and 4-hydroxy-2-nonenal, an endogenous α,β-unsaturated aldehyde, stimulated VEGF release, as did H(2)O(2). CSE-evoked VEGF release was accompanied by rapid and lasting phosphorylation of p38 MAPK (mitogen-activated protein kinase), which was abolished by NAC and mimicked by acrolein. Both CSE- and acrolein-evoked VEGF release were blocked by selective inhibition of p38 MAPK signalling.

CONCLUSIONS AND IMPLICATIONS

α,β-Unsaturated aldehydes and possibly reactive oxygen species contained in cigarette smoke stimulate VEGF expression and release from pulmonary cells through p38 MAPK signalling.

Lycopene inhibits NF-kB-mediated IL-8 expression and changes redox and PPARγ signalling in cigarette smoke-stimulated macrophages

Increasing evidence suggests that lycopene, the major carotenoid present in tomato, may be preventive against smoke-induced cell damage. However, the mechanisms of such a prevention are still unclear. The aim of this study was to investigate the role of lycopene on the production of the pro-inflammatory cytokine IL-8 induced by cigarette smoke and the possible mechanisms implicated. Therefore, human THP-1 macrophages were exposed to cigarette smoke extract (CSE), alone and following a 6-h pre-treatment with lycopene (0.5–2 µM). CSE enhanced IL-8 production in a time- and a dose-dependent manner. Lycopene pre-treatment resulted in a significant inhibition of CSE-induced IL-8 expression at both mRNA and protein levels. NF-kB controlled the transcription of IL-8 induced by CSE, since PDTC prevented such a production. Lycopene suppressed CSE-induced NF-kB DNA binding, NF-kB/p65 nuclear translocation and phosphorylation of IKKα and IkBα. Such an inhibition was accompanied by a decrease in CSE-induced ROS production and NOX-4 expression. Lycopene further inhibited CSE-induced phosphorylation of the redox-sensitive ERK1/2, JNK and p38 MAPKs. Moreover, the carotenoid increased PPARγ levels which, in turn, enhanced PTEN expression and decreased pAKT levels in CSE-exposed cells. Such effects were abolished by the PPARγ inhibitor GW9662. Taken together, our data indicate that lycopene prevented CSE-induced IL-8 production through a mechanism involving an inactivation of NF-kB. NF-kB inactivation was accompanied by an inhibition of redox signalling and an activation of PPARγ signalling. The ability of lycopene in inhibiting IL-8 production, NF-kB/p65 nuclear translocation, and redox signalling and in increasing PPARγ expression was also found in isolated rat alveolar macrophages exposed to CSE. These findings provide novel data on new molecular mechanisms by which lycopene regulates cigarette smoke-driven inflammation in human macrophages.

Maternal active or passive smoking causes oxidative stress in placental tissue

The aim of this study was to assess the influence of active and passive maternal smoking on placenta total oxidant/antioxidant status in term infants. The levels of cord blood total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) were measured in samples of fetal placental tissue, cord blood, and the maternal peripheral blood serum and from 19 mothers who were active smokers, 19 who were passive smokers, and 22 who were nonsmokers (not exposed to active or passive smoking). The pregnancies were between 37 and 40 weeks' gestation, were uncomplicated, and the infants were delivered vaginally. Birth weight and head circumference in the active smokers were significantly (P < 0.001) lower than those in the controls. Placenta, cord blood, and the maternal peripheral TAC levels were significantly lower in the active smokers compared with the controls (P < 0.001), while TOS and OSI levels were significantly higher in the active and passive smokers than in the controls (P < 0.001). A positive significant correlation was found between active maternal smoking and placenta TOS and OSI levels (P < 0.016), and a significant negative correlation was found between number of cigarettes exposed to and birthweight and head circumference (P < 0.05). In conclusion, active or passive maternal smoking is associated with important alterations in oxidant and antioxidant balance in fetal placental tissue and causes potent oxidative stress.

Differential adaptation of microbial pathogens to airways of patients with cystic fibrosis and chronic obstructive pulmonary disease

Cystic fibrosis (CF), the most common autosomal recessive disorder in Caucasians, and chronic obstructive pulmonary disease (COPD), a disease of adults, are characterized by chronic lung inflammation, airflow obstruction and extensive tissue remodelling, which have a major impact on patients' morbidity and mortality. Airway inflammation is stimulated in CF by chronic bacterial infections and in COPD by environmental stimuli, particularly from smoking. Pseudomonas aeruginosa is the major bacterial pathogen in CF, while in COPD, Haemophilus influenzae is most frequently observed. Molecular studies indicate that during chronic pulmonary infection, P. aeruginosa clones genotypically and phenotypically adapt to the CF niche, resulting in a highly diverse bacterial community that is difficult to eradicate therapeutically. Pseudomonas aeruginosa clones from COPD patients remain within the airways only for limited time periods, do not adapt and are easily eradicated. However, in a subgroup of severely ill COPD patients, P. aeruginosa clones similar to those in CF persist. In this review, we will discuss the pathophysiology of lung disease in CF and COPD, the complex genotypic and phenotypic adaptation processes of the opportunistic bacterial pathogens and novel treatment options.

Correlation of EPHX1, GSTP1, GSTM1, and GSTT1 genetic polymorphisms with antioxidative stress markers in chronic obstructive pulmonary disease

This study was undertaken to ascertain if a relationship existed between oxidative status and polymorphisms of microsomal epoxide hydrolase X1 (EPHX1), glutathione S-transferase P1 (GSTP1), GSTM1, and GSTT1 in chronic obstructive pulmonary disease (COPD). Erythrocyte glutathione peroxidase (GSH-px), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), and plasma GST activities and total antioxidant status (TAS) as antioxidative stress markers were determined and compared either with individual and combined genotypes of EPHX1 exon 3, GSTP1 exon 5, GSTM1, and GSTT1 polymorphisms in COPD patients and healthy controls from the central area of Tunisia. Statistical data processing revealed significantly lower GSH-px, GR, SOD, CAT, GST, and TAS values in COPD patients in comparison to the control group (P < .001). As for genotypes, there was a no significant association in each of the 6 parameters and individual genotypes (P > .05). A significant correlation between the studied parameters and combined null GSTM1/null GSTT1 (GSH-px: P < .001, GR: P = .026, CAT: P = .018, GST: P = .022, TAS: P = .046), His113His EPHX1/null GSTM1 (GSH-px: P = .001, GST: P = .0012, TAS: P = .013), His113His EPHX1/Val105Val GSTP1 (GSH-px: P = .048, CAT: P = .026, GST: P = .031), and null GSTM1/Val105Val GSTP1 (GSH-px: P = .011, GR: P = .0028, GST: P = .0054, TAS: P = .032) was found in patients. In conclusion, combined genetic polymorphisms of GSTM1, GSTT1, GSTP1, and EPHX1 may have favorable effects on redox balance in COPD patients.

Antioxidant and antiasthmatic effects of saucerneol D in a mouse model of airway inflammation

Chronic airway inflammation is a hallmark of asthma, which is an immune-based disease. We evaluated the ability of saucerneol D, a tetrahydrofuran-type sesquilignan isolated from Saururus chinensis, to regulate airway inflammation in an ovalbumin (OVA)-induced airway inflammation model. Furthermore, we determined whether heme oxygenase (HO)-1 was required for the protective activity of saucerneol D. The airways of OVA-sensitized mice exposed to an OVA challenge developed eosinophilia and mucus hypersecretion and exhibited increased cytokine levels. Mice were administered saucerneol D orally at doses of 20 and 40mg/kg once daily on days 26-30. Saucerneol D administered orally significantly inhibited the number of OVA-induced inflammatory cells and the production of immunoglobulin E as well as Th2-type cytokines. Histopathology studies revealed a marked decrease in lung inflammation and goblet cell hyperplasia after saucerneol D treatment. In addition, saucerneol D induced HO-1 and led to a marked decrease in OVA-induced reactive oxygen species and malondialdehyde and an increase in superoxide dismutase and glutathione in lung tissues. These antioxidant effects were correlated with HO-1 induction. In our experiments, saucerneol D treatment reduced airway inflammation and suppressed oxidative stress in an OVA-induced asthma model.

Oxidative modification of albumin in the parenchymal lung tissue of current smokers with chronic obstructive pulmonary disease

Background

There is accumulating evidence that oxidative stress plays an important role in the pathophysiology of chronic obstructive pulmonary disease (COPD). One current hypothesis is that the increased oxidant burden in these patients is not adequately counterbalanced by the lung antioxidant systems.

Objective

To determine the levels of oxidised human serum albumin (HSA) in COPD lung explants and the effect of oxidation on HSA degradation using an ex vivo lung explant model.

Methods

Parenchymal lung tissue was obtained from 38 patients (15F/23M) undergoing lung resection and stratified by smoking history and disease using the GOLD guidelines and the lower limit of normal for FEV₁/FVC ratio. Lung tissue was homogenised and analysed by ELISA for total levels of HSA and carbonylated HSA. To determine oxidised HSA degradation lung tissue explants were incubated with either 200 μg/ml HSA or oxidised HSA and supernatants collected at 1, 2, 4, 6, and 24 h and analysed for HSA using ELISA and immunoblot.

Results

When stratified by disease, lung tissue from GOLD II (median = 38.2 μg/ml) and GOLD I (median = 48.4 μg/ml) patients had lower levels of HSA compared to patients with normal lung function (median = 71.9 μg/ml, P < 0.05). In addition the number of carbonyl residues, which is a measure of oxidation was elevated in GOLD I and II tissue compared to individuals with normal lung function (P < 0.05). When analysing smoking status current smokers had lower levels of HSA (median = 43.3 μg/ml, P < 0.05) compared to ex smokers (median = 71.9 μg/ml) and non-smokers (median = 71.2 μg/ml) and significantly greater number of carbonyl residues per HSA molecule (P < 0.05). When incubated with either HSA or oxidised HSA lung tissue explants rapidly degraded the oxidised HSA but not unmodified HSA (P < 0.05).

Conclusion

We report on a reliable methodology for measuring levels of oxidised HSA in human lung tissue and cell culture supernatant. We propose that differences in the levels of oxidised HSA within lung tissue from COPD patients and current smokers provides further evidence for an oxidant/antioxidant imbalance and has important biological implications for the disease.

Increased matriptase zymogen activation in inflammatory skin disorders

Matriptase, a type 2 transmembrane serine protease, and its inhibitor hepatocyte growth factor activator inhibitor (HAI)-1 are required for normal epidermal barrier function, and matriptase activity is tightly regulated during this process. We therefore hypothesized that this protease system might be deregulated in skin disease. To test this, we examined the level and activation state of matriptase in examples of 23 human skin disorders. We first examined matriptase and HAI-1 protein distribution in normal epidermis. Matriptase was detected at high levels at cell-cell junctions in the basal layer and spinous layers but was present at minimal levels in the granular layer. HAI-1 was distributed in a similar pattern, except that high-level expression was retained in the granular layer. This pattern of expression was retained in most skin disorders. We next examined the distribution of activated matriptase. Although activated matriptase is not detected in normal epidermis, a dramatic increase is seen in keratinocytes at the site of inflammation in 16 different skin diseases. To gain further evidence that activation is associated with inflammatory stimuli, we challenged HaCaT cells with acidic pH or H(2)O(2) and observed matriptase activation. These findings suggest that inflammation-associated reactive oxygen species and tissue acidity may enhance matriptase activation in some skin diseases.

[Role of inflammation in the etiopathogenesis of COPD]

Inflammation is one of the first immune system responses to any type of aggression. As with any type of aggression, the lesion produced by inhalation of tobacco smoke prompts an innate inflammatory response. Subsequently, this lesion is stimulated by the release of various chemical factors that enhance the inflammatory response and, finally--depending on the type of aggression--acquired immunity is activated, which, mediated by lymphocyte participation, serves to establish a physical barrier against the propagation of the lesion and to aid repair of the damaged pulmonary tissue. However, the balance between inflammation and repair is not always maintained, as is the case in chronic obstructive pulmonary disease (COPD), in which marked changes appear in the architecture of the airways, alveolar spaces and pulmonary arteries, forming the structural background of the functional changes characteristic of this disease. COPD is basically a pulmonary disease but data are available on the existence of associated systemic inflammation. The origins of this systemic inflammation are unclear: some information indicates that tobacco smoke is a direct origin common to local and systemic inflammation, while other data point to primary pulmonary inflammation that secondarily produces systemic involvement. The present review describes the main mechanisms involved in both pulmonary and systemic inflammation in COPD.

Mechanisms and modification of chlorine-induced lung injury in animals

Chlorine (Cl(2)) is a reactive oxidant gas used extensively in industrial processes. Exposure of both humans and animals to high concentrations of Cl(2) results in acute lung injury, which may resolve spontaneously or progress to acute respiratory failure. Injury to airway and alveolar epithelium may result from chemical reactions of Cl(2), from HOCl (the hydrolysis product of Cl(2)), and/or from the various reaction products, such as chloramines, that are formed from the reactions of these chlorinating species with biological molecules. Subsequent reactions may initiate self-propagating reactions and induce the production of inflammatory mediators compounding injury to pulmonary surfactant, ion channels, and components of lung epithelial and airway cells. Low-molecular-weight antioxidants, such as ascorbate, glutathione, and urate, present in the lung epithelial lining fluid and tissue, remove Cl(2) and HOCl and thus decrease injury to critical target biological targets. However, levels of lung antioxidants of animals exposed to Cl(2) in concentrations likely to be encountered in the vicinity of industrial accidents decrease rapidly and irreversibly. Our measurements show that prophylactic administration of a mixture containing ascorbate and desferal N-acetyl-cysteine, a precursor of reduced glutathione, prevents Cl(2)-induced injury to the alveolar epithelium of rats exposed to Cl(2). The clinical challenge is to deliver sufficient quantities of antioxidants noninvasively, after Cl(2) exposure, to decrease morbidity and mortality.

Discrepancy between mRNA and Protein Expression of Neutrophil Gelatinase-Associated Lipocalin in Bronchial Epithelium Induced by Sulfur Mustard

Sulfur mustard (SM) is a potent vesicant that has been employed as a chemical weapon in various conflicts during the 20th century. More recently, mustard was used in the Iraq conflict against Iranian troops and civilians. At the present time there are more than 40.000 people suffering from pulmonary lesions special bronchiolitis obliterans (BOs) due to mustard gas. SM increases the endogenous production of reactive oxygen species (ROS). Neutrophil Gelatinase-associated Lipocalin 2 (Lcn2, NGAL) is a member of the lipocalin superfamily for which a variety of functions such as cellular protection against oxidative stress have been reported. Ten normal and Twenty SM-induced COPD patient individuals were studied. Assessment of NGAL expressions in healthy and the patients endobrinchial biopsies were performed by semiquantitative RT-PCR, real-time RT-PCR, and Immunohistochemistry analysis. While Normal control samples expressed same level of mRNA NGAL, expression level of mRNA-NGAL was upregulated about 1.4- to 9.8-folds compared to normal samples. No significant immunoreactivity was revealed in both samples. As we are aware this is the first report of induction of NGAL in patients exposed to SM. NGAL may play an important role in cellular protection against oxidative stress toxicity induced by mustard gas in airway wall of patients.

The role of thymic stromal lymphopoietin in allergic inflammation and chronic obstructive pulmonary disease

Thymic stromal lymphopoietin (TSLP) primes dendritic cells to promote a Th2 inflammatory response. Its action is mediated by a heterodimeric receptor which consists of the interleukin-7 receptor alpha chain and the TSLP receptor chain (TSLPR). TSLPR resembles the common gamma chain subunit utilized by many type 1 cytokine receptors. Normal epithelial cells, keratinocytes, and stromal cells constitutively express TSLP. Dendritic cells that are activated by TSLP promote the development of CD4(+) T cells into pro-inflammatory Th2 cells. TSLP thus plays a potentially important role in the pathogenesis of allergic inflammation in asthma and atopic dermatitis. TSLP also has direct effects on other types of cells in the bronchial mucosa. It is over-expressed in the bronchial mucosa in chronic obstructive pulmonary disease (COPD), which is traditionally described as a Th1-related disease, as well as severe asthma, which is traditionally described as a Th2-related disease. In this review we will discuss TSLP expression, function, and available and potential mechanisms in both allergic inflammation and COPD.

Inhibition of lung fluid clearance and epithelial Na+ channels by chlorine, hypochlorous acid, and chloramines

We investigated the mechanisms by which chlorine (Cl(2)) and its reactive byproducts inhibit Na(+)-dependent alveolar fluid clearance (AFC) in vivo and the activity of amiloride-sensitive epithelial Na(+) channels (ENaC) by measuring AFC in mice exposed to Cl(2) (0-500 ppm for 30 min) and Na(+) and amiloride-sensitive currents (I(Na) and I(amil), respectively) across Xenopus oocytes expressing human alpha-, beta-, and gamma-ENaC incubated with HOCl (1-2000 microm). Both Cl(2) and HOCl-derived products decreased AFC in mice and whole cell and single channel I(Na) in a dose-dependent manner; these effects were counteracted by serine proteases. Mass spectrometry analysis of the oocyte recording medium identified organic chloramines formed by the interaction of HOCl with HEPES (used as an extracellular buffer). In addition, chloramines formed by the interaction of HOCl with taurine or glycine decreased I(Na) in a similar fashion. Preincubation of oocytes with serine proteases prevented the decrease of I(Na) by HOCl, whereas perfusion of oocytes with a synthetic 51-mer peptide corresponding to the putative furin and plasmin cleaving segment in the gamma-ENaC subunit restored the ability of HOCl to inhibit I(Na). Finally, I(Na) of oocytes expressing wild type alpha- and gamma-ENaC and a mutant form of beta ENaC (S520K), known to result in ENaC channels locked in the open position, were not altered by HOCl. We concluded that HOCl and its reactive intermediates (such as organic chloramines) inhibit ENaC by affecting channel gating, which could be relieved by proteases cleavage.

Molecular, genetic and epigenetic pathways of peroxynitrite-induced cellular toxicity

Oxidative stress plays a key role in the pathogenesis of cancer and many metabolic diseases; therefore, an effective antioxidant therapy would be of great importance in these circumstances. Nevertheless, convincing randomized clinical trials revealed that antioxidant supplementations were not associated with significant reduction in incidence of cancer, chronic diseases and all-cause mortality. As oxidation of essential molecules continues, it turns to nitro-oxidative stress because of the involvement of nitric oxide in pathogenesis processes. Peroxynitrite damages via several distinctive mechanisms; first, it has direct toxic effects on all biomolecules and causes lipid peroxidation, protein oxidation and DNA damage. The second mechanism involves the induction of several transcription factors leading to cytokine-induced chronic inflammation. Finally, it causes epigenetic perturbations that exaggerate nuclear factor kappa-B mediated inflammatory gene expression. Lessons-learned from the treatment of several chronic disorders including pulmonary diseases suggest that, chronic inflammation and glucocorticoid resistance are regulated by prolonged peroxynitrite production.

Antioxidant enzymes and melatonin levels in patients with bronchial asthma and chronic obstructive pulmonary disease during stable and exacerbation periods

An imbalance between oxidative stress and antioxidative capacity may play an important role in the development and progression of bronchial asthma (BA) and chronic obstructive pulmonary disease (COPD). We carried out a study to assess the systemic oxidant-antioxidant status during the exacerbation and the stable period in patients with BA and COPD. A total of 33 patients, 16 with BA and 17 with COPD were included in the study. During the exacerbation and the stable periods, levels of malondialdehyde (MDA), activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GRd), and catalase (CAT) in erythrocytes and serum melatonin concentrations were investigated. Blood counts, respiratory functions, and blood gases of the patients were also performed. During an exacerbation period of BA, despite the decreases in GSH-Px, GRd and melatonin levels, MDA and CAT levels, and the white blood cell count, the percentage of eosinophils were significantly higher than in the stable period. Also, it was found that FEV(1)/L (where FEV(1) is the forced expiratory volume in 1 s), FVC/L (where FVC is forced vital capacity), PEF/L/s (where PEF is peak expiratory flow), pO(2) (where pO(2) is oxygen pressure) levels increased during the stable period in patients with BA. MDA and SOD values were higher in the exacerbation period than in the stable period although GSH-Px, GRd, melatonin, pH, and pO(2) values were lower in the exacerbation period than in the stable period. The blood counts and the respiratory function tests did not change between the exacerbation and the stable period of patients with COPD significantly. In conclusion, we observed that oxidative stress in the exacerbation period of patients with BA and COPD increased whereas the antioxidant enzymes and melatonin values reduced. The episodes of BA or COPD might be associated with elevated levels of oxidative stress.

Serum trace element levels in COPD patient: the relation between trace element supplementation and period of mechanical ventilation in a randomized controlled trial

BACKGROUND AND OBJECTIVE

Many trace elements play important roles in activating or inhibiting enzymatic reactions, by competing with other elements and metalloproteins for binding sites, by affecting the permeability of cell membranes and by other mechanisms. They play important roles in the oxidant/antioxidant balance. As such, trace elements are thought to be involved directly or indirectly in the pathogenesis of several diseases. The aim of the present study is to investigate the effect trace elements (Se, Mn and Zn) intravenously administered on the period the COPD patients spend on mechanical ventilation.

METHODS

In a randomized double-blinded controlled trial a set of 120 subjects (40 normal volunteers and 80 COPD) were recruited. Serum concentration levels of Se, Mn and Zn were determined for all enrolled subjects with Inductively Coupled Plasma spectroscopy. COPD patients received intravenous supplementation of the above trace elements and the period the patients spent on mechanical ventilation was determined.

RESULTS

There was a significant reduction (P = 0.013) in the period the patients with COPD spent on the mechanical ventilation when received intravenous supplementation (9.4 +/- 7.3 days) compared with the COPD patients who received placebo (17.8 +/- 7.6 days).

CONCLUSIONS

Trace element (Se, Mn and Zn) status is altered in critically ill patients with COPD. The supplementation achieved a reduction in the period those patients spent on the mechanical ventilation. A larger multi-centre trial is required to confirm this preventive effect and to explore its applicability to other critical care conditions.