Oxidative Stress, Environmental Pollution, and Lifestyle as Determinants of Asthma in Children

Gold nanowires-based sensor for quantification of H2O2 released by human airway epithelial cells

Hydrogen peroxide (H2O2) is a biomarker relevant for oxidative stress monitoring. Most chronic airway diseases are characterized by increased oxidative stress. To date, the main methods for the detection of this analyte are expensive and time-consuming laboratory techniques such as fluorometric and colorimetric assays. There is a growing interest in the development of electrochemical sensors for H2O2 detection due to their low cost, ease of use, sensitivity and rapid response. In this work, an electrochemical sensor based on gold nanowire arrays has been developed. Thanks to the catalytic activity of gold against hydrogen peroxide reduction and the high surface area of nanowires, this sensor allows the quantification of this analyte in a fast, efficient and selective way. The sensor was obtained by template electrodeposition and consists of gold nanowires about 5 μm high and with an average diameter of about 200 nm. The high active surface area of this electrode, about 7 times larger than a planar gold electrode, ensured a high sensitivity of the sensor (0.98 μA μM-1cm-2). The sensor allows the quantification of hydrogen peroxide in the range from 10 μM to 10 mM with a limit of detection of 3.2 μM. The sensor has excellent properties in terms of reproducibility, repeatability and selectivity. The sensor was validated by quantifying the hydrogen peroxide released by human airways A549 cells exposed or not to the pro-oxidant compound rotenone. The obtained results were validated by comparing them with those obtained by flow cytometry after staining the cells with the fluorescent superoxide-sensitive Mitosox Red probe giving a very good concordance.

Association of Socioeconomic Status and a Broad Combination of Lifestyle Factors With Adult-Onset Asthma: A Cohort Study

BACKGROUND

The prevalence of asthma is gradually increasing worldwide, and there are socioeconomic inequalities in the risk of developing asthma.

OBJECTIVE

To evaluate whether the lifestyle is associated with asthma in adults, as well as whether and to what extent healthy lifestyles may modify socioeconomic status (SES) inequities in asthma.

METHODS

This study included a total of 223,951 participants from the UK Biobank. Smoking, physical activity, alcohol consumption, healthy diet patterns, sedentary time, and sleep duration items were used to construct the lifestyle score. Income, education, and occupation were used to assess SES. Cases of adult-onset asthma were identified on the basis of electronic health records. The Cox proportional hazards regression was used to explore the association of socioeconomic inequality and lifestyle factors with asthma.

RESULTS

Compared with the most healthy lifestyle category, the hazard ratios (95% CIs) of the moderately healthy lifestyle and least healthy lifestyle categories for asthma were 1.08 (1.01-1.15) and 1.29 (1.20-1.39), respectively. A significant interaction (Pinteraction < .05) was found between lifestyle categories and SES, and the association between them was more pronounced in participants with low SES (hazard ratioleast healthy vs most healthy, 1.58; 95% CI, 1.40-1.80). The joint analysis revealed that the risk of asthma was highest among participants with the lowest SES and the least healthy lifestyles (hazard ratio, 2.02; 95% CI, 1.74-2.33).

CONCLUSIONS

Unhealthy lifestyle factors are associated with an increased risk of asthma in adults, and socioeconomically disadvantaged groups are more negatively affected by unhealthy lifestyles. Public health strategies for asthma prevention may need to be tailored according to SES, and social policies to reduce poverty are needed alongside lifestyle interventions in areas of deprivation.

Pediatric asthma and altitude: a complex interplay between different environmental factors

Asthma is one of the most common non-communicable diseases, and its prevalence and morbidity are influenced by a wide array of factors that are only partially understood. In addition to individual predisposition linked to genetic background and early life infections, environmental factors are crucial in determining the impact of asthma both on an individual patient and on a population level.Several studies have examined the role of the environment where asthmatic subjects live in the pathogenesis of asthma. This review aims to investigate the differences in the prevalence and characteristics of asthma between the pediatric population residing at higher altitudes and children living at lower altitudes, trying to define factors that potentially determine such differences. For this purpose, we reviewed articles from the literature concerning observational studies assessing the prevalence of pediatric asthma in these populations and its characteristics, such as spirometric and laboratory parameters and associated sensitization to aeroallergens.Despite the heterogeneity of the environments examined, the hypothesis of a beneficial effect of residing at a higher altitude on the prevalence of pediatric asthma could be confirmed, as well as a good profile on airway inflammation in asthmatic children. However, the possibility of a higher hospitalization risk for asthma in children living at higher altitudes was demonstrated. Moreover, a positive association between residing at a higher altitude and sensitization to pollens and between lower altitude and sensitization to house dust mites could be confirmed in some pediatric patients, even if the results are not homogeneous, probably due to the different geographical and climatic regions considered. Nonetheless, further studies, e.g., extensive and international works, need to be conducted to better understand the complex interplay between different environmental factors, such as altitude, and the pathogenesis of asthma and how its prevalence and characteristics could vary due to climate change.

Edaravone alleviated allergic airway inflammation by inhibiting oxidative stress and endoplasmic reticulum stress

Oxidative stress and endoplasmic reticulum stress (ERS) was associated with the development of asthma. Edaravone (EDA) plays a classical role to prevent the occurrence and development of oxidative stress-related diseases. Herein, we investigated the involvement and signaling pathway of EDA in asthma, with particular emphasis on its impact on type 2 innate lymphoid cells (ILC2) and CD4+T cells, and then further elucidated whether EDA could inhibit house dust mite (HDM)-induced allergic asthma by affecting oxidative stress and ERS. Mice received intraperitoneally injection of EDA (10 mg/kg, 30 mg/kg), dexamethasone (DEX) and N-acetylcysteine (NAC), with the latter two used as positive control drugs. DEX and high dose of EDA showed better therapeutic effects in alleviating airway inflammation and mucus secretion in mice, along with decreasing eosinophils and neutrophils in bronchoalveolar lavage fluid (BALF) than NAC. Further, the protein levels of IL-33 in lung tissues were inhibited by EDA, leading to reduced activation of ILC2s in the lung. EDA treatment alleviated the activation of CD4+ T cells in lung tissues of HDM-induced asthmatic mice and reduced Th2 cytokine secretion in BALF. ERS-related markers (p-eIF2α, IRE1α, CHOP, GRP78) were decreased after treatment of EDA compared to HDM group. Malondialdehyde (MDA), glutathione (GSH), hydrogen peroxide (H2O2), and superoxide dismutase (SOD) were detected to evaluate the oxidant stress in lung tissues. EDA showed a protective effect against oxidant stress. In conclusion, our findings demonstrated that EDA could suppress allergic airway inflammation by inhibiting oxidative stress and ERS, suggesting to serve as an adjunct medication for asthma in the future.

Air pollution and oxidative stress in adults suffering from airway diseases. Insights from the Gene Environment Interactions in Respiratory Diseases (GEIRD) multi-case control study

Air pollution is a leading risk factor for global mortality and morbidity. Oxidative stress is a key mechanism underlying air-pollution-mediated health effects, especially in the pathogenesis/exacerbation of airway impairments. However, evidence lacks on subgroups at higher risk of developing more severe outcomes in response to air pollution. This multi-centre study aims to evaluate the association between air pollution and oxidative stress in healthy adults and in patients affected by airway diseases from the Italian GEIRD (Gene Environment Interactions in Respiratory Diseases) multi-case control study. Overall, 1841 adults (49 % females, 20-83 years) were included from four Italian centres: Pavia, Sassari, Turin, and Verona. Following a 2-stage screening process, we identified 1273 cases of asthma, chronic bronchitis, rhinitis, or COPD and 568 controls. Systemic oxidative stress was quantified by urinary 8-isoprostane and 8-OH-dG. Individual residential exposures to NO2, PM10, PM2.5, and O3 were derived using an innovative five-stage machine-learning-based approach. Linear mixed regression models tested the association between oxidative stress biomarkers and air pollution tertiles, adjusting by age, sex, BMI, smoking, education and season, with recruiting centres as random intercept. Only cases exhibited higher levels of log-transformed 8-isoprostane and 8-OH-dG in association with NO2 (β: 0.30 95 % CI: 0.08-0.52 and 0.20 95 % CI: 0.03-0.37), PM10 (0.34 95 % CI: 0.12-0.55 and 0.21 95 % CI: 0.05-0.37) and PM2.5 (0.27 95 % CI: 0.09-0.49 and 0.18 95 % CI: 0.02-0.34) as compared to the first tertile of exposure. No significant associations were observed for summer O3. Our findings suggest that exposure to air pollution may increase systemic oxidative stress levels in people suffering from airway diseases. This introduces a potential novel approach available for future epidemiological studies and Public Health for effective prevention strategies oriented at the quantification of early biological effects in susceptible people, whose additional risk level might be currently underrated. Air-pollution-mediated exacerbations, driven by oxidative stress, still deserve our attention.

Advances in the Relationship between Respiratory Viruses and Asthma

Several studies have reported that viral infection is closely associated with the onset, progression, and exacerbation of asthma. The purpose of this review is to summarize the role that viral infections have in the pathogenesis of asthma onset and exacerbations, as well as discuss interrelated protective and risk factors of asthma and current treatment options. Furthermore, we present current knowledge of the innate immunological pathways driving host defense, including changes in the epithelial barrier. In addition, we highlight the importance of the genetics and epigenetics of asthma and virus susceptibility. Moreover, the involvement of virus etiology from bronchiolitis and childhood wheezing to asthma is described. The characterization and mechanisms of action of the respiratory viruses most frequently related to asthma are mentioned.