Reactive nitrogen species in the respiratory tract

Primary ciliary dyskinesia: Aetiology, diagnosis and clinical management

Primary ciliary dyskinesia (PCD) is a rare genetic disorder characterised by abnormal function of motile cilia. The condition usually manifests in early life with neonatal distress, chronic sinopulmonary disease and organ laterality disorders. In adults, it is an underdiagnosed cause of bronchiectasis as well as subfertility. This review provides an overview of PCD for clinicians. We discuss its aetiology, its presentation, how it is diagnosed and its multidisciplinary clinical management.

Joint effects of air pollution and diet patterns on the risk of chronic obstructive pulmonary disease

Diet patterns and air pollution have been recognized as factors that affect the onset of chronic obstructive pulmonary disease (COPD). However, the combined effects of these factors on COPD incidence remain unclear. On the basis of a large prospective cohort from UK Biobank, we explored the independent and joint effects of diet patterns and air pollution on the risk of COPD. A total of 314,226 participants from UK Biobank, who were recruited between 2006 and 2010, were included in this study. The participants were randomly divided into the training (70%) and validation (30%) sets, with the air pollution score calculated using the training set. A diet pattern score was constructed in accordance with the intake of fruits, vegetables, fish, processed meat, unprocessed red meat, whole grains, and refined grains. Meanwhile, an air pollution score was calculated by determining the exposure levels to four components: fine particulate matter (PM2.5), PM2.5-10, NO2, and NOx. Cox proportional hazard models with hazard ratios (HRs) and 95% confidence intervals (CIs) were applied to examine the independent effects of diet patterns and air pollution on COPD incidence. Interaction analyses at the multiplicative and additive scales were also applied to assess the joint effects of diet patterns and air pollution on COPD risk. The above analyses were performed on both the training and validation datasets to verify the robustness of the results. In the training set, 6,696 participants were diagnosed with COPD during a median follow-up duration of 13.9 years. In the fully adjusted model, participants with intermediate and low diet pattern scores had higher COPD risk compared with those with high diet pattern score, with HRs being 1.11 (95% CI: 1.05 to 1.17) and 1.31 (95% CI: 1.21 to 1.42), respectively. Moreover, heavier exposure to air pollution was associated with higher COPD risk, with HRs being 1.06 (95% CI: 1.03, 1.14) and 1.13 (95% CI: 1.05, 1.22) for quintiles Q4 and Q5, respectively, compared with that for quintile Q1. Similar results were observed in the validation dataset. Analyses revealed limited evidence of significant joint effects between diet pattern and air pollution scores on either the multiplicative or additive scales, both in the training and validation sets. Targeted intervention on modifiable diet patterns may offset the adverse effect of air pollution exposure on COPD risk.

Chemometrical assessment of adverse effects in lung cells induced by vehicle engine emissions

Vehicle engine exhausts contain complex mixtures of gaseous and particulate pollutants, which are known to affect lung functions adversely. Many in vitro studies have shown that exposure to engine exhaust can induce oxidative stress in lung cells, leading to cellular inflammation and cytotoxicity. However, it remains challenging to identify key harmful components and their specific adverse effects via traditional toxicological assessments. Machine learning (ML) methods offer new ways of analyzing such complex datasets and have gained attention in predicting toxicity outcomes and identifying key pollutants in mixtures responsible for adverse effects in a non-biased way. This study aims to understand the contribution of exhaust components to lung cell toxicity using ML techniques. Data were reanalyzed from previous studies (2015-2018), where a 3D human epithelial airway tissue model was exposed to gasoline and diesel engine exhausts under air-liquid interface (ALI) conditions with different fuels and exhaust after-treatment systems. This dataset included exhaust characteristics (particle number (PN), carbon monoxide (CO), total gaseous hydrocarbons (THC), and nitrogen oxides (NOx) levels) and corresponding biological responses (cytotoxicity, oxidative stress, and inflammatory responses). The relationships between pollutants and biological responses were explored using ML techniques, including hierarchical and nonhierarchical clustering and principal component analysis. The findings reveal both gaseous (CO, THC, and NOx) and particulate pollutants contribute to oxidative stress, inflammation, and cytotoxicity in lung cells, highlighting the significant role of each gaseous component. In addition, unmeasured factors beyond CO, THC, NOx, and PN likely contribute to biological effects, indicating the need for a more detailed characterization of exhaust parameters in ML analysis. By successfully integrating ML techniques, this study shows the potential of ML in identifying pollutant-specific contributions to cell toxicity. These insights can guide the analysis of complex exposure scenarios and inform regulatory measures and technical developments in emission control.

Modulation of pulmonary immune functions by the Pseudomonas aeruginosa secondary metabolite pyocyanin

Pseudomonas aeruginosa is a prevalent opportunistic Gram-negative bacterial pathogen. One of its key virulence factors is pyocyanin, a redox-active phenazine secondary metabolite that plays a crucial role in the establishment and persistence of chronic infections. This review provides a synopsis of the mechanisms through which pyocyanin exacerbates pulmonary infections. Pyocyanin induces oxidative stress by generating reactive oxygen and nitrogen species which disrupt essential defense mechanisms in respiratory epithelium. Pyocyanin increases airway barrier permeability and facilitates bacterial invasion. Pyocyanin also impairs mucociliary clearance by damaging ciliary function, resulting in mucus accumulation and airway obstruction. Furthermore, it modulates immune responses by promoting the production of pro-inflammatory cytokines, accelerating neutrophil apoptosis, and inducing excessive neutrophil extracellular trap formation, which exacerbates lung tissue damage. Additionally, pyocyanin disrupts macrophage phagocytic function, hindering the clearance of apoptotic cells and perpetuating inflammation. It also triggers mucus hypersecretion by inactivating the transcription factor FOXA2 and enhancing the IL-4/IL-13-STAT6 and EGFR-AKT/ERK1/2 signaling pathways, leading to goblet cell metaplasia and increased mucin production. Insights into the role of pyocyanin in P. aeruginosa infections may reveal potential therapeutic strategies to alleviate the severity of infections in chronic respiratory diseases including cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD).

Low-carbohydrate diet score and chronic obstructive pulmonary disease: a machine learning analysis of NHANES data

Background

Recent research has identified the Low-Carbohydrate Diet (LCD) score as a novel biomarker, with studies showing that LCDs can reduce carbon dioxide retention, potentially improving lung function. While the link between the LCD score and chronic obstructive pulmonary disease (COPD) has been explored, its relevance in the US population remains uncertain. This study aims to explore the association between the LCD score and the likelihood of COPD prevalence in this population.

Methods

Data from 16,030 participants in the National Health and Nutrition Examination Survey (NHANES) collected between 2007 and 2023 were analyzed to examine the relationship between LCD score and COPD. Propensity score matching (PSM) was employed to reduce baseline bias. Weighted multivariable logistic regression models were applied, and restricted cubic spline (RCS) regression was used to explore possible nonlinear relationships. Subgroup analyses were performed to evaluate the robustness of the results. Additionally, we employed eight machine learning methods-Boost Tree, Decision Tree, Logistic Regression, MLP, Naive Bayes, KNN, Random Forest, and SVM RBF-to build predictive models and evaluate their performance. Based on the best-performing model, we further examined variable importance and model accuracy.

Results

Upon controlling for variables, the LCD score demonstrated a strong correlation with the odds of COPD prevalence. In compared to the lowest quartile, the adjusted odds ratios (ORs) for the high quartile were 0.77 (95% CI: 0.63, 0.95), 0.74 (95% CI: 0.59, 0.93), and 0.61 (95% CI: 0.48, 0.78). RCS analysis demonstrated a linear inverse relationship between the LCD score and the odds of COPD prevalence. Furthermore, the random forest model exhibited robust predictive efficacy, with an area under the curve (AUC) of 71.6%.

Conclusion

Our study of American adults indicates that adherence to the LCD may be linked to lower odds of COPD prevalence. These findings underscore the important role of the LCD score as a tool for enhancing COPD prevention efforts within the general population. Nonetheless, additional prospective cohort studies are required to assess and validate these results.

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.

Total sputum nitrate/nitrite is associated with exacerbations and Pseudomonas aeruginosa colonisation in bronchiectasis

Background

Sputum nitrate/nitrite, which is the main component of reactive nitrogen species, is a potential biomarker of disease severity and progression in bronchiectasis. This study aimed to determine the association between nitrate/nitrite and exacerbations and airway microbiota in bronchiectasis.

Methods

We measured total nitrate/nitrite concentration in sputum samples collected from 85 patients with stable bronchiectasis, performed 16S ribosomal RNA sequencing of sputum samples and predicted the denitrification ability of airway microbiota using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt). Relationships between sputum total nitrate/nitrite and disease severity, exacerbations and airway microbiota were examined.

Results

Higher total sputum nitrate/nitrite was associated with more severe bronchiectasis defined by E-FACED (exacerbation, forced expiratory volume in 1 s, age, chronic colonisation by Pseudomonas aeruginosa, radiological extension and dyspnoea) (p=0.003) or Bronchiectasis Severity Index (p=0.006) and more exacerbations in the prior 12 months (p=0.005). Moreover, total sputum nitrate/nitrite was significantly higher in patients with worse cough score (p=0.03), worse sputum purulence score (p=0.01) and worse Medical Research Council dyspnoea score (p=0.02). In addition, the total sputum nitrate/nitrite of the P. aeruginosa colonised (PA) group was higher than that of the non-P. aeruginosa colonised (NPA) group (p=0.04), and the relative abundance of P. aeruginosa was positively correlated with total nitrate/nitrite (r=0.337, p=0.002). Denitrification module (M00529) was also significantly enriched in the PA group compared to the NPA group through PICRUSt analyses. Using receiver-operating characteristic analysis, total nitrate/nitrite was associated with exacerbations during 1-year follow-up (area under the curve 0.741, p=0.014).

Conclusions

Sputum nitrate/nitrite is a biomarker of disease severity and associated with P. aeruginosa colonisation in bronchiectasis.

Exhaled Nitric Oxide Reflects the Immune Reactions of the Airways in Early Rheumatoid Arthritis

Patients with rheumatoid arthritis (RA) have altered levels of exhaled nitric oxide (NO) compared with healthy controls. Here, we investigated whether the clinical features of and immunological factors in RA pathogenesis could be linked to the NO lung dynamics in early disease. A total of 44 patients with early RA and anti-citrullinated peptide antibodies (ACPAs), specified as cyclic citrullinated peptide 2 (CCP2), were included. Their exhaled NO levels were measured, and the alveolar concentration, the airway compartment diffusing capacity and the airway wall concentration of NO were estimated using the Högman-Meriläinen algorithm. The disease activity was measured using the Disease Activity Score for 28 joints. Serum samples were analysed for anti-CCP2, rheumatoid factor, free secretory component, secretory component containing ACPAs, antibodies against Porphyromonas gingivalis (Rgp) and total levels of IgA, IgA1 and IgA2. Significant negative correlations were found between the airway wall concentration of NO and the number of swollen joints (Rho -0.48, p = 0.004), between the airway wall concentration of NO and IgA rheumatoid factor (Rho -0.41, p = 0.017), between the alveolar concentration and free secretory component (Rho -0.35, p = 0.023) and between the alveolar concentration and C-reactive protein (Rho -0.36, p = 0.016), but none were found for anti-CCP2, IgM rheumatoid factor or the anti-Rgp levels. In conclusion, altered NO levels, particularly its production in the airway walls, may have a role in the pathogenesis of ACPA-positive RA.

The Role of Nutrition in the Development and Management of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a prevalent lung condition associated with significant morbidity and mortality. The management of COPD classically involves pulmonary rehabilitation, bronchodilators, and corticosteroids. An aspect of COPD management that is currently lacking in the literature is nutritional management, despite the prevalence of inadequate nutritional status in patients with COPD. In addition, certain nutritional imbalances have been reported to increase the risk of COPD development. This review summarizes the current literature on the role diet and nutrients may play in the risk and management of COPD development.

Exploring the association between ultra-processed foods and COPD: a case-control study

BACKGROUND

While it is known that the overconsumption of ultra-processed foods (UPFs) is associated with a heightened risk of respiratory ailments, the specific effects of UPF intake on COPD remain unclear. This study was designed to explore the potential link between COPD and the consumption of UPFs among adult individuals in Iran.

METHODS

In this hospital-based case-control study conducted at Alzahra University Hospital in Isfahan, Iran, we enrolled 84 patients newly diagnosed with COPD, along with 252 healthy controls matched for age and sex. COPD was defined based on the results of spirometry tests, specifically when the forced expiratory volume per second (FEV1) was less than 80% or the ratio of FEV1 to forced vital capacity (FVC) was less than 70%. To evaluate the dietary intake of the participants, we utilized a validated food frequency questionnaire (FFQ) consisting of 168 items. Additionally, we gathered data on potential confounding factors using a pre-tested questionnaire.

RESULTS

The mean ages for the case and control groups were 57.07 and 55.05 years, respectively. Our study found no significant association between the intake of ultra-processed foods (UPFs) and the likelihood of COPD, with an odds ratio (OR: 0.78, 95% CI: 0.34-1.77). This lack of association persisted even after adjusting for factors such as energy intake, sex, and age (OR: 0.48; 95% CI: 0.19-1.21). Further controlling for potential confounders like body mass index (BMI), physical activity, and smoking status did not alter this finding (OR: 0.367; 95% CI: 0.123-1.1008, P = 0.074).

CONCLUSIONS

In our study, we observed no significant association between the intake of Ultra-Processed Foods (UPFs) and the odds of Chronic Obstructive Pulmonary Disease (COPD). This finding remained consistent even after adjusting for factors such as energy intake, sex, age, Body Mass Index (BMI), physical activity, and smoking status. Therefore, within the scope of our study, it appears that the consumption of UPFs does not significantly impact the likelihood of developing COPD. However, we recommend further research to deepen our understanding of the intricate relationship between dietary habits and respiratory health.

Exploring a Potential Causal Link Between Dietary Intake and Chronic Obstructive Pulmonary Disease: A Two-Sample Mendelian Randomization Study

Background

Chronic Obstructive Pulmonary Disease (COPD), the most prevalent chronic respiratory condition, significantly impairs patients' quality of life. The pivotal element in disease management lies in prevention, underscoring the paramount importance of employing a scientific approach to investigate early prevention strategies for COPD.

Methods

This study delved into the causal link between 28 dietary intakes and COPD employing two-sample Mendelian randomization. We primarily utilized the Inverse Variance Weighted (IVW) method as the main outcome, complemented by Weighted Median (WM), MR-Egger method, along with several sensitivity analysis techniques, all accompanied by visual representations.

Results

We identified higher odds of COPD following exposure to green beans (OR=1.381, 95% CI=1.119-1.704, P=0.003) and pork intake (OR=2.657, 95% CI=1.203-5.868, P=0.016). In contrast, the odds of developing COPD were lower following exposure to dried fruit (OR=0.481, 95% CI=0.283-0.819, P=0.007), cereal (OR=0.560, 95% CI=0.356-0.880, P=0.012), and whole egg consumption (OR=0.700, 95% CI=0.504-0.972, P=0.033).

Conclusion

In light of our study's findings, we anticipate that strategically modifying dietary choices may offer an avenue for early COPD prevention in the future.

Exacerbation-prone pediatric asthma is associated with arginine, lysine, and methionine pathway alterations

BACKGROUND

The asthma of some children remains poorly controlled, with recurrent exacerbations despite treatment with inhaled corticosteroids. Aside from prior exacerbations, there are currently no reliable predictors of exacerbation-prone asthma in these children and only a limited understanding of the potential underlying mechanisms.

OBJECTIVE

We sought to quantify small molecules in the plasma of children with exacerbation-prone asthma through mass spectrometry-based metabolomics. We hypothesized that the plasma metabolome of these children would differ from that of children with non-exacerbation-prone asthma.

METHODS

Plasma metabolites were extracted from 4 pediatric asthma cohorts (215 total subjects, with 41 having exacerbation-prone asthma) and detected with a mass spectrometer. High-confidence annotations were retained for univariate analysis and were confirmed by a sensitivity analysis in subjects receiving high-dose inhaled corticosteroids. Metabolites that varied by cohort were excluded. MetaboAnalyst software was used to identify pathways of interest. Concentrations were calculated by reference standardization.

RESULTS

We identified 32 unique, cohort-independent metabolites that differed in children with exacerbation-prone asthma compared to children with non-exacerbation-prone asthma. Comparison of metabolite concentrations to literature-reported values for healthy children revealed that most metabolites were decreased in both asthma groups, but more so in exacerbation-prone asthma. Pathway analysis identified arginine, lysine, and methionine pathways as most impacted.

CONCLUSIONS

Several plasma metabolites are perturbed in children with exacerbation-prone asthma and are largely related to arginine, lysine, and methionine pathways. While validation is needed, plasma metabolites may be potential biomarkers for exacerbation-prone asthma in children.

Metabolomic analysis of porcine intestinal epithelial cells during swine acute diarrhea syndrome coronavirus infection

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is an enveloped, positive single-stranded RNA virus belonging to Coronaviridae family, Orthocoronavirinae subfamily, Alphacoronavirus genus. As one of the main causes of swine diarrhea, SADS-CoV has brought huge losses to the pig industry. Although we have a basic understanding of SADS-CoV, the research on the pathogenicity and interactions between host and virus are still limited, especially the metabolic changes induced by SADS-CoV infection. Here, we utilized a combination of untargeted metabolomics and lipomics to analyze the metabolic alteration in SADS-CoV infected cells. Significant changes were observed in 1257 of 2225 metabolites identified in untargeted metabolomics, while the number of lipomics was 435 out of 868. Metabolic pathway enrichment analysis showed that amino acid metabolism, tricarboxylic acid (TCA) cycle and ferroptosis were disrupted during viral infection, suggesting that these metabolic pathways may partake in pathological processes related to SADS-CoV pathogenesis. Collectively, our findings gain insights into the cellular metabolic disorder during SADS-CoV infection, offer a valuable resource for further exploration of the relationship between virus and host metabolic activities, and provide potential targets for the development of antiviral drugs.

Nitrative inactivation of thioredoxin-1 loses its protective effect in bleomycin-induced pulmonary fibrosis

Pulmonary fibrosis is common in the development of inflammatory lung diseases with no effective clinical drug treatment currently. As an essential redox enzyme, thioredoxin (Trx) has been reported to be involved in pulmonary fibrosis, but the mechanism is to be revealed. Therefore, in bleomycin-indued pulmonary fibrosis model in C57 mice, Trx activity and nitrated Trx were examined.,p38-MAPK apoptosis pathway was determined in lung tissues. Additionally, before BLM administration, C57/BL6 mice were treated with aminoguanidine (AG, a peroxynitrite scavenger), recombinant human Trx-1 (rhTrx-1), or SIN-1 (a peroxynitrite donor) nitrated Trx-1 (N-Trx-1). In bleomycin (BLM)-induced pulmonary fibrosis model in C57/BL6 mice, we observed that nitrated Trx increased, while its activity decreased, with the increase of alveolar epithelial cells (AECs)apoptosis by p38-MAPK pathway. We demonstrated that AG or rhTrx-1, but not N-Trx-1 significantly reduced pulmonary fibrosis. Taken together, the results above revealed that blockade of Trx-1 nitration, or supplementation of exogenous rhTrx-1, might represent novel therapies to attenuate pulmonary fibrosis in idiopathic pulmonary fibrosis patients.

Oxidative stress and impaired insulin secretion in cystic fibrosis pig pancreas

Cystic fibrosis-related diabetes (CFRD) is one the most common comorbidities in cystic fibrosis (CF). Pancreatic oxidative stress has been postulated in the pathogenesis of CFRD, but no studies have been done to show an association. The main obstacle is the lack of suitable animal models and no immediate availability of pancreas tissue in humans. In the CF porcine model, we found increased pancreatic total glutathione (GSH), glutathione disulfide (GSSG), 3-nitrotyrosine- and 4-hydroxynonenal-modified proteins, and decreased copper zinc superoxide dismutase (CuZnSOD) activity, all indicative of oxidative stress. CF pig pancreas demonstrated increased DHE oxidation (as a surrogate marker of superoxide) in situ compared to non-CF and this was inhibited by a SOD-mimetic (GC4401). Catalase and glutathione peroxidase activities were not different between CF and non-CF pancreas. Isolated CF pig islets had significantly increased DHE oxidation, peroxide production, reduced insulin secretion in response to high glucose and diminished secretory index compared to non-CF islets. Acute treatment with apocynin or an SOD mimetic failed to restore insulin secretion. These results are consistent with the hypothesis that CF pig pancreas is under significant oxidative stress as a result of increased O2 ●- and peroxides combined with reduced antioxidant defenses against reactive oxygen species (ROS). We speculate that insulin secretory defects in CF may be due to oxidative stress.

Predictors of Low and High Exhaled Nitric Oxide Values in Asthma: A Real-World Study

BACKGROUND

In asthma, exhaled nitric oxide (FENO) is a clinically established biomarker of airway T2 inflammation and an indicator for anti-inflammatory therapy.

OBJECTIVES

The aim of the study was to identify, in an observational real-world cross-sectional study, the main characteristics of patients with asthma as classified by their FENO level.

METHOD

We stratified 398 patients with stable mild-to-severe asthma according to FENO level as low (≤25 ppb) versus elevated (>25 ppb), subdividing the latter into two subgroups: moderately elevated (26-50 ppb) versus very high FENO (>50 ppb). Clinical, functional, and blood parameters were extrapolated from patients' chart data and compared with the FENO stratification. Predictors of low and elevated FENO asthma were detected by logistic regression model.

RESULTS

Low BMI, higher blood eosinophilia, allergen poly-sensitization, the severest airflow obstruction (FEV1/FVC), and anti-leukotriene use are predictors of elevated FENO values in asthma, as well as persistent rhinitis and chronic rhinosinusitis with or without nasal polyps. Beyond these, younger age, more than 2 asthma exacerbations/year, higher airflow reversibility (post-bronchodilator ∆FEV1), and oral corticosteroid dependence are predictors of very high FENO values. In contrast, obesity, obstructive sleep apnoea syndrome, gastroesophageal reflux disease, arterial hypertension, and myocardial infarction are predictors of low FENO asthma. In our population, FENO correlated with blood eosinophils, airflow obstruction, and reversibility and negatively correlated with age and BMI.

CONCLUSIONS

Stratifying patients by FENO level can identify specific asthma phenotypes with distinct clinical features and predictors useful in clinical practice to tailor treatment and improve asthmatic patients' outcomes.

Exhaled nitric oxide in early rheumatoid arthritis and effects of methotrexate treatment

Patients with established rheumatoid arthritis (RA) and disease modifying treatments have lower nitric oxide (NO) levels in the alveolar compartment (C_ANO) and in the airway wall (C_awNO), but also higher diffusion capacities for NO in the airways (D_awNO) compared to matched controls. The aim of the present study was to investigate the NO lung dynamics in patients with recent onset RA before and after immune suppression with methotrexate therapy. Patients with early RA and antibodies against anticitrullinated peptides (ACPA) were recruited. Measurement of exhaled NO and inflammatory markers in serum were performed. Clinical disease activity was evaluated with Disease Activity Score for 28 joints. Healthy individuals were used as matched controls. Data are presented as median (lower quartile, upper quartile) values. RA patients (n = 44) had lower exhaled NO (F_ENO₅₀) 16 (10–24) ppb compared to controls 21 (15, 29) ppb, p = 0.013. In NO-dynamics, C_ANO was lower in RA patients 1.6 (1.0, 2.2) ppb compared to the control subjects 2.3 (1.3, 3.1) ppb, p = 0.007. C_awNO was also lower in the RA patients 55 (24, 106) ppb compared to control subjects 124 (110, 170) ppb, p < 0.001, but D_awNO was higher 17 (8, 30) mL/s and 9 (5, 11) mL/s respectively, p < 0.001. Methotrexate treatment for three months reduced disease activity, but did not change the NO dynamics. In conclusion, the altered NO dynamics of the lung in ACPA-positive RA patients are already present in the early stages of the disease before any treatments and do not change after methotrexate therapy suggesting a role in the pathogenesis.

Molecular hydrogen is a promising therapeutic agent for pulmonary disease

Molecular hydrogen exerts biological effects on nearly all organs. It has anti-oxidative, anti-inflammatory, and anti-aging effects and contributes to the regulation of autophagy and cell death. As the primary organ for gas exchange, the lungs are constantly exposed to various harmful environmental irritants. Short- or long-term exposure to these harmful substances often results in lung injury, causing respiratory and lung diseases. Acute and chronic respiratory diseases have high rates of morbidity and mortality and have become a major public health concern worldwide. For example, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic. An increasing number of studies have revealed that hydrogen may protect the lungs from diverse diseases, including acute lung injury, chronic obstructive pulmonary disease, asthma, lung cancer, pulmonary arterial hypertension, and pulmonary fibrosis. In this review, we highlight the multiple functions of hydrogen and the mechanisms underlying its protective effects in various lung diseases, with a focus on its roles in disease pathogenesis and clinical significance.

Targeting Oxidative Stress as a Therapeutic Approach for Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease characterized by an abnormal reepithelialisation, an excessive tissue remodelling and a progressive fibrosis within the alveolar wall that are not due to infection or cancer. Oxidative stress has been proposed as a key molecular process in pulmonary fibrosis development and different components of the redox system are altered in the cellular actors participating in lung fibrosis. To this respect, several activators of the antioxidant machinery and inhibitors of the oxidant species and pathways have been assayed in preclinical in vitro and in vivo models and in different clinical trials. This review discusses the role of oxidative stress in the development and progression of IPF and its underlying mechanisms as well as the evidence of oxidative stress in human IPF. Finally, we analyze the mechanism of action, the efficacy and the current status of different drugs developed to inhibit the oxidative stress as anti-fibrotic therapy in IPF.

Nutriepigenomics and chronic obstructive pulmonary disease: potential role of dietary and epigenetics factors in disease development and management

Over recent decades, a number of studies have revealed the possible role of different types of diets, as well as the nutritional elements they are made up of, in the pathogenesis of chronic obstructive pulmonary disease (COPD). To date, dietary factors have been identified to play a role in the prevention of COPD, with evidence from antioxidant nutrients, vitamins, and fiber intake. Additionally, certain dietary patterns such as the Mediterranean diet, together with other Western diets, provide evidence of the influence on COPD development, promoting lung health through nutritional approaches, and giving us an opportunity for intervention. The effect of diet on COPD is conveyed by 3 mechanisms: regulation of inflammation, oxidative stress, and carbon dioxide produced/oxygen intake. Current advances have begun to highlight the possible role of diet in modifying gene expression in certain individuals that predisposes them to COPD through epigenetic modifications. The relation between dietary intake and epigenetic factors has therefore outlined nutriepigenomics as a possible missing link in the relation between environmental exposure to smoke and the appearance of a subsequent chronic bronchial obstruction. This review summarizes the evidence regarding the influence of dietary patterns and nutrients and epigenetic regulatory mechanisms on COPD development and prevention with the aim of encouraging clinical research on the impact of dietary modifications on COPD-related clinical outcomes. This review highlights the importance of proposing and carrying out future studies focused on the modulating effects of certain nutrients on epigenetic changes in patients with specific COPD phenotypes (bronchiectasis, emphysema, asthma/COPD, chronic bronchitis), and their individual responses to cigarette smoking, environmental pollution, or other noxious particles. The objectives of these future studies must be directed to the development of novel therapeutic approaches and personalized management of COPD.

Nutrition as a modifiable factor in the onset and progression of pulmonary function impairment in COPD: a systematic review

CONTEXT

Chronic obstructive lung disease (COPD) is a progressive lung disease characterized by persistent airflow limitation. An increasing amount of evidence suggests an effect of dietary quality on the risk of COPD in the general population and pulmonary function decline in patients with COPD.

OBJECTIVE

The association of dietary intake and nutrient status with COPD risk and onset, as well as pulmonary function decline (change in forced expiratory volume in 1 second, forced vital capacity, or the ratio of the former to the latter) in patients with COPD was investigated in this systematic review.

DATA SOURCES

The PubMed database was searched by combining terms of pulmonary function or COPD with diet, nutrient status, or nutritional supplementation.

DATA EXTRACTION

Original studies and systematic reviews and meta-analyses were included. Articles obtained were independently screened for relevance on the bases of title and abstract by 2 researchers. Eventually, 89 articles were included in the analysis.

RESULTS

The unhealthy Western-style diet is associated with an increased risk of COPD and an accelerated decline of pulmonary function. Intake of fruit, vegetables, dietary fibers, vitamins C and E, polyphenols, and β-carotene were individually associated with lower COPD risk, whereas consumption of processed meat was associated with higher COPD risk. Data on the effect of dietary quality on pulmonary function decline in patients with COPD are limited and inconsistent. Strong evidence for beneficial effects on pulmonary function decline was found only for vitamin D supplementation.

CONCLUSION

Considering the increasing burden of COPD, more attention should be given to dietary quality as a modifiable factor in disease development and progression in patients with COPD.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021240183.

Amino acid metabolism and signalling pathways: potential targets in the control of infection and immunity

Defences to pathogens such as SarCoV2 in mammals involves interactions between immune functions and metabolic pathways to eradicate infection while preventing hyperinflammation. Amino acid metabolic pathways represent with other antimicrobial agent potential targets for therapeutic strategies. iNOS-mediated production of NO from Arg is involved in the innate inflammatory response to pathogens and NO overproduction can induce hyperinflammation. The two Arg- and Trp-catabolising enzymes Arg1 and IDO1 reduce the hyperinflammation by an immunosuppressive effect via either Arg starvation (for Arg1) or via the immunoregulatory activity of the Trp-derived metabolites Kyn (for IDO1). In response to amino acid abundance mTOR activates the host protein translation and Coronaviruses use this machinery for their own protein synthesis and replication. In contrast GCN2, the sensor of amino acid starvation, activates pathways that restrict inflammation and viral replication. Gln depletion alters the immune response that become more suppressive, by favouring a regulatory T phenotype rather than a Th1 phenotype. Proliferating activated immune cells are highly dependent on Ser, activation and differentiation of T cells need enough Ser and dietary Ser restriction can inhibit their proliferation. Cys is strictly required for T-cell proliferation because they cannot convert Met to Cys. Restricting Met inhibits both viral RNA cap methylation and replication, and the proliferation of infected cells with an increased requirement for Met. Phe catabolism produces antimicrobial metabolites resulting in the inhibition of microbial growth and an immunosuppressive activity towards T lymphocytes.

Amino acid metabolism and signalling pathways: potential targets in the control of infection and immunity

Defences to pathogens such as SarCoV2 in mammals involves interactions between immune functions and metabolic pathways to eradicate infection while preventing hyperinflammation. Amino acid metabolic pathways represent with other antimicrobial agent potential targets for therapeutic strategies. iNOS-mediated production of NO from Arg is involved in the innate inflammatory response to pathogens and NO overproduction can induce hyperinflammation. The two Arg-catabolising enzymes Arg1 and IDO1 reduce the hyperinflammation by an immunosuppressive effect via either Arg starvation (for Arg1) or via the immunoregulatory activity of the Arg-derived metabolites Kyn (for IDO1). In response to amino acid abundance mTOR activates the host protein translation and Coronaviruses use this machinery for their own protein synthesis and replication. In contrast GCN2, the sensor of amino acid starvation, activates pathways that restrict inflammation and viral replication. Gln depletion alters the immune response that become more suppressive, by favouring a regulatory T phenotype rather than a Th1 phenotype. Proliferating activated immune cells are highly dependent on Ser, activation and differentiation of T cells need enough Ser and dietary Ser restriction can inhibit their proliferation. Cys is strictly required for T-cell proliferation because they cannot convert Met to Cys. Restricting Met inhibits both viral RNA cap methylation and replication, and the proliferation of infected cells with an increased requirement for Met. Phe catabolism produces antimicrobial metabolites resulting in the inhibition of microbial growth and an immunosuppressive activity towards T lymphocytes.

BRD4 targeting nanotherapy prevents lipopolysaccharide induced acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a life threatening respiratory disease associated with pulmonary edema, alveolar dysfunction, hypoxia, and inflammatory cell accumulation. The most contagious form of COVID-19 associated with ARDS caused by SARS-CoV-2. SARS-CoV-2 majorly produces the cytokine storm and severe lung inflammation and ultimately leads to respiratory failure. ARDS is a complex disease and there is no proper therapeutics for effective therapy. Still, there is a huge scope to identify novel targets to combat respiratory illness. In the current study, we have identified the epigenetic regulating protein BRD4 and developed siRNA based nanomedicine to treat the ARDS. The liposomes were prepared by thin-film hydration method, where BRD4 siRNA complexed with cationic lipid and exhibited 96.24 ± 18.01 nm size and stable even in the presence of RNase. BRD4 siRNA lipoplexes (BRD4-siRNA-LP) inhibited inflammatory cells in lungs and suppressed the lipopolysaccharide (LPS) induced the neutrophil infiltration and mast cell accumulation. Also, BRD4 siRNA based nanomedicine significantly reduced the LPS induced cytokine storm followed by inflammatory signaling pathways. Interestingly, BRD4-siRNA-LP suppressed the LPS-induced p65 and STAT3 nuclear translocation and ameliorated the lung inflammation. Thus, BRD4-siRNA-LP could be a plausible therapeutic option for treating ARDS and might be useful for combating the COVID-19 associated respiratory illness.

The Influence of Eating at Home on Dietary Diversity and Airway Inflammation in Portuguese School-Aged Children

Considering the negative impact of a lack of dietary diversity on children’s nutritional status, we aimed to describe dietary variety according to eating at home frequency and assessed its association with respiratory outcomes in school-aged children. This cross-sectional study included 590 children (49% girls) aged 7 to 12 years from 20 public schools located in city of Porto, Portugal. Daily frequency of eating at home groups were calculated and dietary diversity was calculated using a 10-food group score from a 24 h recall questionnaire. Spirometry and exhaled nitric oxide levels (eNO; <35 and ≥35 ppb) were assessed. The comparison of diet diversity according to the groups was performed by ANOVA and ANCOVA. The association between dietary diversity and respiratory outcomes was examined using regression models. In multivariate analysis, children in the highest group of eating at home episodes (≥4 occasions) obtained the lowest dietary diversity mean score, while the lowest group (<2) had the highest mean score (p-value 0.026). After adjustment for confounders, higher diet diversity (≥5 food groups) significantly decreased the odds of having an eNO ≥35. Diet diversity might decrease the chance of airway inflammation among children. However, having more eating episodes at home could be a barrier to a more diverse diet.

Oxidative and Nitrosative Stress in the Pathogenesis of Obstructive Lung Diseases of Increasing Severity

The imbalance between increased oxidative agents and antioxidant defence mechanisms is central in the pathogenesis of obstructive lung diseases such as asthma and COPD. In these patients, there are increased levels of reactive oxygen species. Superoxide anions (O₂ -), Hydrogen Peroxide (H₂O₂) and hydroxyl radicals (•OH) are critical for the formation of further cytotoxic radicals in the bronchi and lung parenchyma. Chronic inflammation, partly induced by oxidative stress, can further increase the oxidant burden through activated phagocytic cells (neutrophils, eosinophils, macrophages), particularly in severer disease states. Antioxidants and anti-inflammatory genes are, in fact, frequently downregulated in diseased patients. Nrf2, which activates the Antioxidant Response Element (ARE) leading to upregulation of GPx, thiol metabolism-associated detoxifying enzymes (GSTs) and stressresponse genes (HO-1) are all downregulated in animal models and patients with asthma and COPD. An exaggerated production of Nitric Oxide (NO) in the presence of oxidative stress can promote the formation of oxidizing reactive nitrogen species, such as peroxynitrite (ONO₂ -), leading to nitration and DNA damage, inhibition of mitochondrial respiration, protein dysfunction, and cell damage in the biological systems. Protein nitration also occurs by activation of myeloperoxidase and H₂O₂, promoting oxidation of nitrite (NO₂ -). There is increased nitrotyrosine and myeloperoxidase in the bronchi of COPD patients, particularly in severe disease. The decreased peroxynitrite inhibitory activity found in induced sputum of COPD patients correlates with pulmonary function. Markers of protein nitration - 3- nitrotyrosine, 3-bromotyrosine, and 3-chlorotyrosine - are increased in the bronchoalveolar lavage of severe asthmatics. Targeting the oxidative, nitrosative stress and associated lung inflammation through the use of either denitration mechanisms or new drug delivery strategies for antioxidant administration could improve the treatment of these chronic disabling obstructive lung diseases.

Cellular and Biochemical Analysis of Bronchoalveolar Lavage Fluid from Murine Lungs

Bronchoalveolar lavage (BAL) is a technique used to collect the contents of the airways. The fluid recovered, called BAL fluid (BALF), serves as a dynamic tool to identify various disease pathologies ranging from asthma to infectious diseases to cancer in the lungs. A wide array of tests can be performed with BALF, including total and differential leukocyte counts (DLC), enzyme-linked immunosorbent assays (ELISA) or flow-cytometric quantitation of inflammatory mediators, such as cytokines, chemokines and adhesion molecules, and assessment of nitrate and nitrite content for estimation of nitric oxide synthase (NOS) activity. Here, we describe a detailed procedure for the collection of BALF for a variety of downstream usages, including DLC by cytological and flow-cytometry-based methods, multiplex cytokine analysis by flow cytometry, and NOS activity analysis by determining nitrate and nitrite levels.

Increased Oxidative Stress Underlies Abnormal Pain Threshold in a Normoglycemic Japanese Population

Normal-high HbA1c levels are a risk factor for attenuated pain sensation in normoglycemic subjects. It is unclear, however, what mechanisms underlie the pathogenesis of attenuated pain sensation in such a population. We, therefore, explored the relationship between oxidative stress (OS) and pain sensation in a rural Japanese population. A population-based study of 894 individuals (average age 53.8 ± 0.5 years) and 55 subjects with impaired fasting glucose (IFG) were enrolled in this study. Individuals with diabetes were excluded. Relationships between pain threshold induced by intraepidermal electrical stimulation (PINT) and clinico-hematological parameters associated with OS were evaluated. Univariate linear regression analyses revealed age, BMI, HbA1c, the OS biomarker urine 8-hydroxy-2'-deoxyguanosine (8-OHdG), systolic blood pressure, and decreased Achilles tendon reflex on the PINT scores. Adjustments for age, gender, and multiple clinical measures confirmed a positive correlation between PINT scores and urine 8-OHdG (β = 0.09, p < 0.01). Urine 8-OHdG correlated positively with higher HbA1c levels and age in the normoglycemic population. Unlike in the normoglycemic population, both inflammation and OS were correlated with elevated PINT scores in IFG subjects. OS may be a major contributing factor to elevated PINT scores in a healthy Japanese population.

Arginine depletion as a therapeutic approach for patients with COVID-19

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a source of significant morbidity and death worldwide, and effective treatments are urgently needed. Clinical trials have focused largely on direct antiviral therapies or on immunomodulation in patients with severe manifestations of COVID-19. One therapeutic approach that remains to be clinically investigated is disruption of the host-virus relationship through amino acid restriction, a strategy used successfully in the setting of cancer treatment. Arginine is an amino acid that has been shown in nonclinical studies to be essential in the life cycle of many viruses. Therefore, arginine depletion may be an effective therapeutic approach against SARS-CoV-2. Several arginine-metabolizing enzymes in clinical development may be a viable approach to induce a low arginine environment to treat COVID-19 and other viral diseases. Herein, we explore the rationale for arginine depletion as a therapeutic approach for COVID-19.

Long-term dietary fiber intake and risk of chronic obstructive pulmonary disease: a prospective cohort study of women

PURPOSE

Until now, only two prospective cohort studies have investigated dietary fiber intake in relation to risk of chronic obstructive pulmonary disease (COPD), but neither examined long-term fiber intake. Both studies reported that total fiber intake was associated with decreased COPD risk; however, results for specific fiber sources were inconsistent. Thus, we prospectively evaluated the association between baseline and long-term intake of dietary fiber and COPD risk in a population-based prospective cohort of 35,339 Swedish women.

METHODS

Dietary fiber intake was assessed in 1987 and 1997 with a food frequency questionnaire. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During follow-up (2002-2014), 1557 COPD cases were identified via linkage to the Swedish National Patient Register. Long-term high dietary fiber intake (≥ 26.5 vs. < 17.6 g/day) was associated with a 30% (95% CI 17-41%) lower risk of COPD. For specific fiber sources, cereal (≥ 16.3 vs. < 9.4 g/day; HR 0.67, 95% CI 0.55-0.81) and fruit fiber (≥ 7.6 vs. < 2.6 g/day; HR 0.65, 95% CI 0.5-0.81), but not vegetable fiber intake (≥ 5.4 vs. < 2.2 g/day; HR 1.03, 95% CI 0.81-1.28) were associated with lower COPD risk. Current and ex-smokers with low long-term total fiber intake (< 17.6 g/day) compared to never smokers with high intake (≥ 26.5 g/day) had a 33-fold (95% CI 23.6-46.6) and tenfold (95% CI 7.0-16.3), respectively, higher risk of COPD.

CONCLUSIONS

Our findings indicate that high fiber intake is a modifiable lifestyle factor which may decrease COPD risk primarily in current and ex-smokers.

Myxopyrum serratulum ameliorates airway inflammation in LPS-stimulated RAW 264.7 macrophages and OVA-induced murine model of allergic asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Myxopyrum serratulum A. W. Hill. (Oleaceae) is a traditionally used Indian medicinal plant for the treatment of cough, asthma and many other inflammatory diseases.

AIM OF THE STUDY

In this study, the protective effects of M. serratulum on airway inflammation was investigated in ovalbumin (OVA)-induced murine model of allergic asthma and lipopolysaccharide (LPS)-stimulated inflammation in RAW 264.7 murine macrophages, and the possible mechanisms were elucidated.

MATERIALS AND METHODS

The phytochemicals present in the methanolic leaf extract of M. serratulum (MEMS) were identified by reverse phase high performance liquid chromatography (RP-HPLC) analysis. In vitro anti-inflammatory activity of MEMS were evaluated by estimating the levels of nitric oxide (NO), reactive oxygen species (ROS) and cytokines (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, IL-17A, IFN-γ, TNF-α, G-CSF and GM-CSF) in LPS-stimulated RAW 264.7 macrophages. In vivo anti-asthmatic activity of MEMS was studied using OVA-induced murine model. Airway hyperresponsiveness (AHR), was measured; total and differential cell counts, eosinophil peroxidase (EPO), prostaglandin E2 (PGE2), NO, ROS, and cytokines (IL-4, IL-5 and IL-13), were estimated in bronchoalveolar lavage fluid (BALF). Serum total IgE level was measured; and the histopathological changes of lung tissues were observed. The expressions of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in lung tissue homogenates were detected by Western blot.

RESULTS

The chromatographic analysis of MEMS identified the presence of gallic acid, protocatechuic acid, catechin, ellagic acid, rutin, p-coumaric acid, quercetin, naringenin and apigenin. MEMS (125 and 250 μg/mL) dose-dependently reduced the levels of NO, ROS and pro-inflammatory cytokines in LPS-stimulated RAW 264.7 macrophages. MEMS (200 and 400 mg/kg, p.o.) significantly (p < 0.05) alleviated AHR; number of inflammatory cells, EPO, PGE2, NO, ROS, and cytokines (IL-4, IL-5 and IL-13) in BALF; serum total IgE and the histopathological changes associated with lung inflammation. Western blot studies showed that MEMS substantially suppressed COX-2 and iNOS protein expressions in the lung tissues of OVA-sensitized/challenged mice.

CONCLUSIONS

The present study corroborates for the first time the ameliorative effects of MEMS on airway inflammation by reducing the levels of oxidative stress, pro-inflammatory cytokines and inhibiting COX-2, iNOS protein expressions, thereby validating the ethnopharmacological uses of M. serratulum.

Processed Meat Intake and Risk of Chronic Obstructive Pulmonary Disease among Middle-aged Women

BACKGROUND

Processed meat intake may increase the risk of chronic obstructive pulmonary disease (COPD). However, the magnitude of this association may depend on smoking and unhealthy diet. Our aims were to determine whether processed meat intake increased the risk of COPD among middle-aged women, and to estimate the combined impact of high processed meat intake, smoking and unhealthy diet on the risk of COPD.

METHODS

Analyses included 87,032 registered nurses from the Nurses' Health Study II (baseline mean age 36.8 years). Over 2,296,894 person-years (1991-2017), we documented 634 incident cases of COPD. Cumulative average of processed meat intake (every 4 years) was divided into never/almost never, < 1 or ≥ 1 servings/week. A score was created to study the impact of 3-risk lifestyle factors.

FINDINGS

In multivariable-adjusted Cox proportional hazards models, after careful adjustment for smoking and unhealthy diet, we observed a positive association between processed meat intake and the risk of COPD: Hazard Ratio (HR, 95%CI) for ≥ 1 servings/week vs. never/almost never = 1.29 (1.00-1.65). In analyses stratified according to smoking or unhealthy diet, processed meat intake was associated with increased risk of COPD only among ever smokers (HR 1.37 [1.01-1.86]), and among women with unhealthy diet (HR 1.39 [1.04-1.85]). The multivariable-adjusted HR for COPD in participants with all 3 high-risk lifestyle factors compared with none was 6.32 (3.67-10.87).

INTERPRETATION

Processed meat intake was associated with elevated risk of developing COPD in middle-aged women, especially in presence of other high-risk lifestyle factors (smoking, unhealthy diet).

FUNDINGS

US CDC and NIH.

Long-term consumption of fruits and vegetables and risk of chronic obstructive pulmonary disease: a prospective cohort study of women

Background

Fruits and vegetables, due to high antioxidant capacity, may protect the lung from oxidative damage caused by tobacco smoke and potentially prevent chronic obstructive pulmonary disease (COPD). Only one study based on baseline diet has examined fruit and vegetable consumption in relation to risk of COPD, and no previous studies have examined long-term diet.

Methods

We investigated whether long-term fruit and vegetable consumption was associated with COPD incidence among 34 739 women (age 48-83 years) in the population-based prospective Swedish Mammography Cohort. Fruit and vegetable consumption was assessed twice (1987, 1997) with a self-administered questionnaire. Cases of COPD were identified by linkage to the Swedish health register. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

During follow-up from 2002 to 2014, 1512 women were diagnosed with COPD. Long-term fruit was associated with lower risk of COPD; women in the highest vs lowest quintile of consumption (≥2.5 vs <0.8 servings/day) had a 37% lower risk of COPD (95% CI: 25-48%; P-trend < 0.0001). No association was observed with long-term vegetable intake. Current and ex-smokers with low long-term consumption of fruits (<1 serving/day) in comparison to never smokers with high consumption (≥3 servings/day) had a 38-fold (HR: 38.1; 95% CI: 20.2-71.7) and 13-fold (HR: 12.5, 95% CI: 6.5-24.1) higher risk of COPD, respectively. However, no significant interaction between smoking status and fruit intake in relation to COPD incidence was observed (P-interaction = 0.95).

Conclusions

In this prospective cohort of middle-age and older women, long-term consumption of fruits but not vegetables was inversely associated with COPD incidence.

Association between processed meat intake and asthma symptoms in the French NutriNet-Santé cohort

PURPOSE

Processed meat intake may adversely affect lung health, but data on asthma remains sparse. The magnitude of the processed meat-asthma association may also depend on other unhealthy behaviors. We investigated the association between processed meat intake and the asthma symptom score, and the combined role of unhealthy weight, smoking, low diet quality, and high processed meat intake on the asthma score.

METHODS

In 2017, 35,380 participants to the NutriNet-Santé cohort answered a detailed respiratory web-questionnaire. Asthma was defined by the asthma symptom score (sum of 5 questions; continuous variable). Based on repeated 24-h dietary records collected on a dedicated website, processed meat consumption was classified as 0, < 2, 2-5, > 5 servings/week. We examined the combined role of body mass index (BMI) (< 25 vs. ≥ 25 kg/m²), smoking (never vs. ever), diet quality score (highest vs. lowest), and processed meat (≤ 5 vs. > 5 servings/week) on the asthma symptom score.

RESULTS

Participants were aged 54 on average (women: 75%, smokers: 49%, BMI ≥ 25: 32%, ≥ 1 asthma symptoms: 27%). After adjustment for confounders, processed meat intake was positively and significantly associated with asthma symptom score: odds ratios (ORs) (95% CI) for > 5 vs. 0 servings/week were 1.15 (1.04-1.27) in women; 1.23 (1.01-1.50) in men. Compared to participants with 0 unhealthy behaviors, ORs for the asthma symptom score among participants with the 4 combined unhealthy behaviors were 2.18 (1.91-2.48) in women; 2.70 (2.10-3.45) in men.

CONCLUSION

High processed meat consumption was associated with higher asthma symptoms, and combining overweight/obesity, smoking, low diet quality, with high processed meat intake was strongly associated with asthma symptoms.

Prediction of O3 in the respiratory system of children using the artificial neural network model and with selection of input based on gamma test, Ahvaz, Iran

In recent years, concerns over the issue of air pollution have increased as one of the significant environmental and health problems. Air pollutants can be toxic or harmful to the life of plants, animals, and humans. Contrast to primary pollutants, ozone is a secondary pollutant that is produced by the reaction between primary precursors in the atmosphere. The average of air pollutant data was compiled for the purpose of analyzing their correlation with the pulmonary function of students and the FENO biomarker from the air pollutants of the Environmental Protection Agency. According to the average of 3 days, the concentration of ozone in the (S₃) region was higher than the other regions, and this level was significantly different from the ANOVA test (p < 0.05). The results of artificial neural network modeling for three particular combinations in the cold season, two hidden layers with 9 and 12 neurons, with R² = 0.859 and in the warm season, layer with 13 neurons, with R² = 0.74, showed the best performance.

Gene silencing of receptor-interacting protein 2 protects against cigarette smoke-induced acute lung injury

BACKGROUND AND PURPOSE

Chronic obstructive pulmonary disease (COPD) is characterized by progressive alveolar damage and generally irreversible airflow limitation. Nuclear factor-κB (NF-κB) plays a critical role in COPD pathogenesis. Receptor-interacting protein 2 (Rip2), a 60 kDa adaptor protein, is a positive regulator of NF-κB pathway and also an inducible transcriptional product of NF-κB activation. We sought to investigate if Rip2 gene silencing could protect against cigarette smoke (CS)-induced acute lung injury.

EXPERIMENTAL APPROACH

Gene silencing efficacy of Rip2 siRNA was characterized in mouse macrophage and mouse lung epithelial cell lines, and in a CS-induced acute lung injury mouse model. Bronchoalveolar lavage (BAL) fluid cell counts, levels of pro-inflammatory and oxidative damage markers, lung section inflammatory and epithelium thickness scorings, and nuclear NF-κB translocation were measured.

KEY RESULTS

CS was found to upregulate Rip2 level in mouse lungs. Rip2 siRNA was able to suppress Rip2 levels in both macrophage and lung epithelial cell lines and in mouse lungs, block CS extract (CSE)-induced mediator release by the cultured cells, and abate neutrophil counts in BAL fluid from CS-challenged mice. Rip2 siRNA suppressed CS-induced inflammatory and oxidative damage markers, and nuclear p65 accumulation and transcriptional activation in lung tissues. Besides, Rip2 siRNA was able to disrupt CSE-induced NF-κB activation in a NF-κB reporter gene assay.

CONCLUSIONS AND IMPLICATIONS

Taken together, we report for the first time that Rip2 gene silencing ameliorated CS-induced acute lung injury probably via disruption of the NF-κB activity, postulating that Rip2 may be a novel therapeutic target for COPD.

Oxidative/nitrosative stress, autophagy and apoptosis as therapeutic targets of melatonin in idiopathic pulmonary fibrosis

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease associated with disruption of alveolar epithelial cell layer and expansion of fibroblasts/myofibroblasts. Excessive levels of oxidative/nitrosative stress, induction of apoptosis, and insufficient autophagy may be involved in IPF pathogenesis; hence, the targeting of these pathways may ameliorate IPF. Areas covered: We describe the ameliorative effect of melatonin on IPF. We summarize the research on IPF pathogenesis with a focus on oxidative/nitrosative stress, autophagy and apoptosis pathways and discuss the potential effects of melatonin on these pathways. Expert opinion: Oxidative/nitrosative stress, apoptosis and autophagy could be interesting targets for therapeutic intervention in IPF. Melatonin, as a potent antioxidant, induces the expression of antioxidant enzymes, scavenges free radicals and modulates apoptosis and autophagy pathways. The effect of melatonin in the induction of autophagy could be an important mechanism against fibrotic process in IPF lungs. Further clinical studies are necessary to determine if melatonin could be a candidate for treating IPF.

DNA damage protection by bulk and nano forms of quercetin in lymphocytes of patients with chronic obstructive pulmonary disease exposed to the food mutagen 2-amino-3-methylimidazo [4,5-f]quinolone (IQ)

Chronic obstructive pulmonary disease (COPD) in humans, describes a group of lung conditions characterised by airflow limitation that is poorly reversible. The airflow limitation usually progresses slowly and is related to an abnormal inflammatory response of the lung to toxic particles. COPD is characterised by oxidative stress and an increased risk of lung carcinoma. The 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) is one of a number of mutagenic/carcinogenic heterocyclic amines found mainly in well-cooked meats which are thus part of the regular diet. Antioxidants are very important in order to protect the cells against oxidative damage. The aim of the present study was to assess the effects of IQ on the level of DNA damage and susceptibility to a potent mutagen in peripheral blood cells of COPD patients. DNA damage and the frequency of micronuclei (MNi) were evaluated using the Comet and micronucleus assays, respectively. Differential expressions of both mRNA and protein of the endogenous antioxidant enzyme catalase were evaluated with quantitative polymerase chain reaction (qPCR) and Western blot analysis, respectively. Furthermore, the effect of bulk and nano forms of quercetin and their combination with IQ were examined. Results of the present study clearly demonstrated that MNi frequency in the peripheral blood lymphocytes exhibited a positive correlation with the DNA damage as evident from the different Comet assay parameters. Increase of the endogenous antioxidant catalase also showed there was a stimulation of this enzyme system by IQ. Whereas, the endogenous antioxidant quercetin significantly reduced oxidative stress in COPD patients and healthy individuals.

TRP Channels as Sensors of Bacterial Endotoxins

The cellular and systemic effects induced by bacterial lipopolysaccharides (LPS) have been solely attributed to the activation of the Toll-like receptor 4 (TLR4) signalling cascade. However, recent studies have shown that LPS activates several members of the Transient Receptor Potential (TRP) family of cation channels. Indeed, LPS induces activation of the broadly-tuned chemosensor TRPA1 in sensory neurons in a TLR4-independent manner, and genetic ablation of this channel reduced mouse pain and inflammatory responses triggered by LPS and the gustatory-mediated avoidance to LPS in fruit flies. LPS was also shown to activate TRPV4 channels in airway epithelial cells, an effect leading to an immediate production of bactericidal nitric oxide and to an increase in ciliary beat frequency. In this review, we discuss the role of TRP channels as sensors of bacterial endotoxins, and therefore, as crucial players in the timely detection of invading gram-negative bacteria.

Bradykinin in asthma: Modulation of airway inflammation and remodelling

Bradykinin, a pro-inflammatory molecule, and its related peptides have been studied for their effects on acute reactions in upper and lower airways, where they can be synthesised and metabolized after exposure to different stimuli including allergens and viral infection. Bradykinin B₁ and B₂ receptors are constitutively expressed in the airways on several residential and/or immune cells. Their expression can also be induced by inflammatory mediators, usually associated with eosinophil and neutrophil recruitment, such as IL-4, IL-13, TNF-α, IL-6 and IL-8, via intracellular MAPK and NF-κB signalling. In turn, the latters up-regulate both bradykinin receptors. Bradykinin activates epithelial/endothelial and immune cells, neurons and mesenchymal cells (such as fibroblasts, myofibroblasts and smooth muscle cells), which are implicated in the development of airway chronic inflammation, responsiveness and remodelling (a major feature of severe asthma). This review highlights the role of bradykinin and its receptors in respect to chronic inflammatory response involving eosinophils/neutrophils and to vascular/matrix-related airway remodelling in asthmatic airways. This scenario is especially important for understanding the mechanisms involved in the pathogenesis of eosinophilic and/or neutrophilic asthma and hence their therapeutic approach.

Long-term unprocessed and processed red meat consumption and risk of chronic obstructive pulmonary disease: a prospective cohort study of women

Purpose

Limited studies have examined red meat consumption in relation to risk of chronic obstructive pulmonary disease (COPD), and none have examined the impact of long-term diet on COPD risk. We sought to investigate the association between long-term red meat consumption and risk of COPD.

Methods

The population-based prospective Swedish Mammography Cohort included 34,053 women, aged 48–83 years, followed for the current analyses from 2002 to 2014. Unprocessed and processed red meat consumption was assessed with a self-administered questionnaire in 1987 and 1997. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

Over a mean follow-up of 11.6 years (2002–2014; 393,831 person-years), 1488 COPD cases were ascertained via linkage to the Swedish health registers. A positive association between long-term processed red meat (average from 1987 to 1997) and risk of COPD was observed. In contrast, no association was observed with unprocessed red meat with corresponding HRs of 1.36 (95% CI 1.03–1.79) for processed and 0.87 (95% CI 0.74–1.02) for unprocessed red meat among women who consumed ≥ 50 g/day compared to < 25 g/day. The observed association with processed meat was confined to ex-smokers (P for interaction = 0.30); women consuming of ≥ 50 g/day of processed meat had a 2.3-fold (95% CI 1.24–4.12) higher risk of COPD than those consuming < 25 g/day. No similar associations were observed among current or never smokers.

Conclusion

In this prospective cohort of women with moderate red meat consumption, long-term processed red meat consumption was associated with an increased risk of COPD particularly among ex-smokers.

Electronic supplementary material

The online version of this article (10.1007/s00394-018-1658-5) contains supplementary material, which is available to authorized users.

Altered levels of exhaled nitric oxide in rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disorder characterized by bone and joint destruction, but other organ systems can also be involved. Recent studies have suggested that the disease may start in the lungs. Exhaled nitric oxide (F_ENO) is a marker of inflammation. The aims of the study were to compare the NO parameters between subjects with RA and healthy control subjects, and to examine whether the NO parameters correlated with lung function and disease activity in the subjects with RA.

METHODS

Subjects with RA (n = 35) were recruited during their regular outpatient visits to the rheumatology department. The nitric oxide (NO) parameters: alveolar NO concentration (C_ANO), airway compartment diffusing capacity of NO (D_awNO), and tissue concentration of NO in the airway wall (C_awNO), were algorithmically estimated. Healthy subjects (n = 35) matched by age, gender and height were used as controls. Data are given in median, (quartile 25, 75). Wilcoxon Matched Pairs test was used for group comparisons. Mann-Whitney U test was used to make comparisons between any two groups and for pairwise comparisons. Correlations were tested with Spearman rank order correlation.

RESULTS

C_ANO was significantly lower in the RA subjects compared with healthy subjects; 1.1 (0.5, 1.8) ppb versus 2.4 (2.0, 3.0) ppb, (p < 0.001). C_awNO was significantly lower in the RA subjects with 51 (22, 87) ppb versus 120 (76, 162) ppb in the control group. D_awNO was significantly higher at 25 (15, 36) mL/s in the RA group versus the control group's 7.7 (5.3, 10.7) mL/s.

CONCLUSIONS

There are significant differences between subjects with RA and matched healthy control subjects regarding the exhaled NO parameters. It is unclear if this can be explained by the pathogenesis of RA, consequences of long-term disease, and/or due to drug treatment.

Dietary nutrients associated with preservation of lung function in Hispanic and non-Hispanic white smokers from New Mexico

Background

COPD is the third leading cause of death in the United States. Cigarette smoking accelerates the age-related forced expiratory volume in 1 s (FEV₁) decline, an important determinant for the genesis of COPD. Hispanic smokers have lower COPD prevalence and FEV₁ decline than non-Hispanic whites (NHWs).

Patients and methods

A nutritional epidemiological study was conducted in the Lovelace Smokers cohort (LSC; n=1,829) and the Veterans Smokers cohort (n=508) to identify dietary nutrients (n=139) associated with average FEV₁ and its decline and to assess whether nutrient intakes could explain ethnic disparity in FEV₁ decline between Hispanics and NHW smokers.

Results

Nutrients discovered and replicated to be significantly associated with better average FEV₁ included magnesium, folate, niacin, vitamins A and D, eicosenoic fatty acid (20:1n9), eicosapentaenoic acid (20:5n3), docosapentaenoic acid (DPA; 22:5n3), docosahexaenoic acid (22:6n3), and fiber. In addition, greater intakes of eicosenoic fatty acid and DPA were associated with slower FEV₁ decline in the LSC. Among omega 3 polyunsaturated fatty acids, DPA is the most potent nutrient associated with better average FEV₁ and slower FEV₁ decline. Adverse effect of continuous current smoking on FEV₁ decline was completely negated in LSC members with high DPA intake (>20 mg/day). Slower FEV₁ decline in Hispanics compared to NHWs may be due to the greater protection of eicosenoic fatty acid and DPA for FEV₁ decline rather than greater intake of protective nutrients in this ethnic group.

Conclusion

The protective nutrients for the preservation of FEV₁ in ever smokers could lay foundation for designing individualized nutritional intervention targeting “optimal physiological levels” in human to improve lung function in ever smokers. Ethnic disparity in FEV₁ decline may be explained by difference in magnitude of protection of dietary intakes of eicosenoic fatty acid and DPA between Hispanics and NHWs.

TRPV4 activation triggers protective responses to bacterial lipopolysaccharides in airway epithelial cells

Lipopolysaccharides (LPS), the major components of the wall of gram-negative bacteria, trigger powerful defensive responses in the airways via mechanisms thought to rely solely on the Toll-like receptor 4 (TLR4) immune pathway. Here we show that airway epithelial cells display an increase in intracellular Ca²⁺ concentration within seconds of LPS application. This response occurs in a TLR4-independent manner, via activation of the transient receptor potential vanilloid 4 cation channel (TRPV4). We found that TRPV4 mediates immediate LPS-induced increases in ciliary beat frequency and the production of bactericidal nitric oxide. Upon LPS challenge TRPV4-deficient mice display exacerbated ventilatory changes and recruitment of polymorphonuclear leukocytes into the airways. We conclude that LPS-induced activation of TRPV4 triggers signaling mechanisms that operate faster and independently from the canonical TLR4 immune pathway, leading to immediate protective responses such as direct antimicrobial action, increase in airway clearance, and the regulation of the inflammatory innate immune reaction.

LPS is a major component of gram-negative bacterial cell walls, and triggers immune responses in airway epithelium by activating TLR4. Here the authors show that LPS also activates TRPV4, thereby inducing fast defense responses such as nitric oxide production and increased ciliary beating in mice.

Adherence to Dietary Approaches to Stop Hypertension (DASH) Dietary Pattern in Relation to Chronic Obstructive Pulmonary Disease (COPD): A Case-Control Study

OBJECTIVE

This case-control study was designed to investigate the association between adherences to the Dietary Approaches to Stop Hypertension (DASH) diet in patients with chronic obstructive pulmonary disease (COPD) in comparison to subjects without COPD.

DESIGN

This is a case-control study. Usual dietary intake was assessed using a validated food frequency questionnaire. Lung function was evaluated with spirometry testing, and one of the researchers inquired about other respiratory symptoms, including chronic cough, sputum, and breathlessness. Adherence to the DASH dietary pattern was assessed according to the Fung method.

SETTING

This study was conducted at Alzahra University Hospital of Isfahan, Iran, in 2015.

SUBJECTS

Eight-four patients with COPD and 80 subjects without a history of COPD participated in study.

RESULTS

The mean age of participants was 57 years. Average smoking in the case group was about 27.5 pack-years. Spirometry tests including forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC were significantly lower in patients with COPD (p = 0.0001). Among COPD symptoms, cough was significantly decreased across tertiles of DASH score (p = 0.03). Significant differences were found for DASH score between patients with COPD and control subjects (19.82 + 3.63 vs 21.13 + 3.82, p = 0.02). Vitamin C, vitamin E, and dietary fiber intake were lower in patients with COPD (144.32 + 70.51 vs 166.97 + 71.88, p = 0.04, 7.49 + 3.91 vs 8.72 + 3.21, p = 0.02 and 19.34 + 7.05 vs 22.19 + 7.87, p = 0.01, respectively).

CONCLUSION

We observed that adherence to a DASH dietary pattern among patients with COPD was significantly lower compared to the control group. Cough was significantly decreased by increments in adherence to a DASH dietary pattern.

Carica papaya ameliorates allergic asthma via down regulation of IL-4, IL-5, eotaxin, TNF-α, NF-ĸB, and iNOS levels

BACKGROUND

Natural products have a prime importance as an essential source for new drug discovery. Carica papaya leaves (CPL) have been used to treat inflammation in traditional system of medicine.

AIM/HYPOTHESIS

Current study evaluates the anti-inflammatory and immunomodulatory effects of CPL extract using mouse model of ovalbumin- (OVA) induced allergic asthma.

METHODS

All the mice were intraperitoneally sensitized and subsequently given intranasal challenge with OVA except the control group. Group-III and -IV were treated for seven consecutive days with CPL extract and methylprednisolone (MP), respectively. At the end of study, histopathological examination of the lungs was performed and inflammatory cell counts were done in blood as well as bronchoalveolar lavage fluid (BALF). The mRNA expression levels of IL-4, IL-5, eotaxin, TNF-α, NF-ĸB, and iNOS were measured using reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Results showed significant attenuation of lung infiltration of inflammatory cells, alveolar thickening, and goblet cell hyperplasia after treatment with CPL extract. We also found significant suppression of total and differential leukocyte counts in both blood and BALF samples of CPL extract treated group. CPL extract also alleviated the expression levels of IL-4, IL-5, eotaxin, TNF-α, NF-ĸB, and iNOS. Similarly, treatment with MP, used as a reference drug, also significantly ameliorated all the pro-inflammatory markers.

CONCLUSION

Current study shows that CPL extract possesses anti-inflammatory effect in mouse model of allergic airway inflammation by down-regulating IL-4, IL-5, eotaxin, TNF-α, NF-ĸB, and iNOS expression levels.

Increased levels of alveolar and airway exhaled nitric oxide in runners

AIM

The objective of this study was to apply extended NO analysis for measurements of NO dynamics in the lung, divided into alveolar and airway contribution, in amateur runners and marathoners.

METHODS

The athletes participated in either a marathon or a half marathon. The athletes self-reported their age, weight, height, training distance per week, competing distance, cardio-pulmonary health, atopic status, and use of tobacco. Measurements of exhaled NO (F_ENO) with estimation of alveolar NO (C_ANO) and airway flux (J_awNO), ventilation, pulse oximetry, and peak flow were performed before, immediately after, and 1 hour after completing the race.

RESULTS

At baseline the alveolar NO was higher in amateur runners, 2.9 ± 1.1 ppb (p = 0.041), and marathoners, 3.6 ± 1.9 ppb (p = 0.002), than in control subjects, 1.4 ± 0.5 ppb. J_awNO was higher in marathoners, 0.90 ± 0.02 nL s^-1 (p = 0.044), compared with controls, 0.36 ± 0.02 nL s^-1, whereas the increase in amateur runners, 0.56 ± 0.02 nL s^-1, did not attain statistical significance (p = 0.165). Immediately after the race there was a decrease in F_ENO in both amateur runners and marathoners, whereas C_ANO and J_awNO were decreased in marathoners only.

CONCLUSION

Our results support the view that there is an adaptation of the lung to exercise. Thus strenuous exercise increased both airway and alveolar NO, and this might in turn facilitate oxygen uptake.

Cannabinoid CB1 receptor overactivity contributes to the pathogenesis of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a life-threatening disease without effective treatment, highlighting the need for identifying new targets and treatment modalities. The pathogenesis of IPF is complex, and engaging multiple targets simultaneously might improve therapeutic efficacy. To assess the role of the endocannabinoid/cannabinoid receptor 1 (endocannabinoid/CB1R) system in IPF and its interaction with inducible nitric oxide synthase (iNOS) as dual therapeutic targets, we analyzed lung fibrosis and the status of the endocannabinoid/CB1R system and iNOS in mice with bleomycin-induced pulmonary fibrosis (PF) and in lung tissue and bronchoalveolar lavage fluid (BALF) from patients with IPF, as well as controls. In addition, we investigated the antifibrotic efficacy in the mouse PF model of an orally bioavailable and peripherally restricted CB1R/iNOS hybrid inhibitor. We report that increased activity of the endocannabinoid/CB1R system parallels disease progression in the lungs of patients with idiopathic PF and in mice with bleomycin-induced PF and is associated with increased tissue levels of interferon regulatory factor-5. Furthermore, we demonstrate that simultaneous engagement of the secondary target iNOS by the hybrid CB1R/iNOS inhibitor has greater antifibrotic efficacy than inhibition of CB1R alone. This hybrid antagonist also arrests the progression of established fibrosis in mice, thus making it a viable candidate for future translational studies in IPF.