Oral cavity response to air pollutant exposure and association with pulmonary inflammation and symptoms in asthmatic children

Combined exposure of MAHs and PAHs enhanced amino acid and lipid metabolism disruption in epithelium leading asthma risk

Monoaromatic hydrocarbons (MAHs) and polycyclic aromatic hydrocarbons (PAHs) are ubiquitous air pollutants from industry, with multiple adverse effects on respiratory system. However, the underlying mechanisms of their mixture to induce asthma is still unclear. Here, we examined mixture of 8 MAHs, mixture of 16 PAHs and a total mixture (MIX) on human bronchial epithelial (16-HBE) cells. Exposure to MIX resulted in increased expressions of asthma alarm cytokines (TSLP, IL-25 and IL-33), indicating potential asthma risk. Exposure to MIX led to significant upregulation of transcriptional level of oxidative stress and inflammation biomarkers through aryl hydrocarbon receptor activation, including SOD-2, NQO-1, IL-1β, IL-6 and IL-8 with 3.1, 19.9, 3.5, 23.4, 18.7, 28.1-fold change, indicated asthma related epithelial cell lesions. A total of 25, 49 and 59 differential metabolites were identified in cells response to MAH, PAH and MIX exposure, respectively, and enrichment analysis demonstrated MIX exposure disturbing alanine, aspartate and glutamate metabolism, glutathione metabolism, methionine metabolism and sphingolipid metabolism, involved in antioxidative defense and inflammation response. Combined exposure of MAHs and PAHs may result in increased toxic risks, and provide evidence to asthma onset and deterioration.

Biomarkers of the relationship of particulate matter exposure with the progression of chronic respiratory diseases

A high level of particulate matter (PM) in air is correlated with the onset and development of chronic respiratory diseases. We conducted a systematic literature review, searching the MEDLINE, EMBASE, and Cochrane databases for studies of biomarkers of the effect of PM exposure on chronic respiratory diseases and the progression thereof. Thirty-eight articles on biomarkers of the progression of chronic respiratory diseases after exposure to PM were identified, four of which were eligible for review. Serum, sputum, urine, and exhaled breath condensate biomarkers of the effect of PM exposure on chronic obstructive pulmonary disease (COPD) and asthma had a variety of underlying mechanisms. We summarized the functions of biomarkers linked to COPD and asthma and their biological plausibility. We identified few biomarkers of PM exposure-related progression of chronic respiratory diseases. The included studies were restricted to those on biomarkers of the relationship of PM exposure with the progression of chronic respiratory diseases. The predictive power of biomarkers of the effect of PM exposure on chronic respiratory diseases varies according to the functions of the biomarkers.

Prediction of Asthma Exacerbations in Children

Asthma exacerbations are common in asthmatic children, even among those with good disease control. Asthma attacks result in the children and their parents missing school and work days; limit the patient's social and physical activities; and lead to emergency department visits, hospital admissions, or even fatal events. Thus, the prompt identification of asthmatic children at risk for exacerbation is crucial, as it may allow for proactive measures that could prevent these episodes. Children prone to asthma exacerbation are a heterogeneous group; various demographic factors such as younger age, ethnic group, low family income, clinical parameters (history of an exacerbation in the past 12 months, poor asthma control, poor adherence to treatment, comorbidities), Th2 inflammation, and environmental exposures (pollutants, stress, viral and bacterial pathogens) determine the risk of a future exacerbation and should be carefully considered. This paper aims to review the existing evidence regarding the predictors of asthma exacerbations in children and offer practical monitoring guidance for promptly recognizing patients at risk.

Associations between personal apparent temperature exposures and asthma symptoms in children with asthma

Ambient temperature and relative humidity can affect asthma symptoms. Apparent temperature is a measure of temperature perceived by humans that takes into account the effect of humidity. However, the potential link between personal exposures to apparent temperature and asthma symptoms has not been investigated. We conducted a panel study of 37 asthmatic children, aged 5-11 years, during an early spring season (average daily ambient temperature: 14°C, range: 7-18°C). Asthma symptoms were measured 4 times for each participant with a 2-week interval between consecutive measurements using the Childhood Asthma-Control Test (C-ACT). Average, minimum, and maximum personal apparent temperature exposures, apparent temperature exposure variability (TV), and average ambient temperature were calculated for the 12 hours, 24 hours, week, and 2 weeks prior to each visit. We found that a 10°C lower in 1-week and 2-week average & minimum personal apparent temperature exposures, TV, and average ambient temperature exposures were significantly associated with lower total C-ACT scores by up to 2.2, 1.4, 3.3, and 1.4 points, respectively, indicating worsened asthma symptoms. Our results support that personal apparent temperature exposure is potentially a stronger driver than ambient temperature exposures for the variability in asthma symptom scores. Maintaining a proper personal apparent temperature exposure could be an effective strategy for personalized asthma management.

The modification of meteorological factors on the relationship between air pollution and periodontal diseases: an exploration based on different interaction strategies

We aimed to characterize the association between air pollutants exposure and periodontal diseases outpatient visits and to explore the interactions between ambient air pollutants and meteorological factors. The outpatient visits data of several large stomatological and general hospitals in Hefei during 2015-2020 were collected to explore the relationship between daily air pollutants exposure and periodontal diseases by combining Poisson's generalized linear model (GLMs) and distributed lag nonlinear model (DLNMs). Subgroup analysis was performed to identify the vulnerability of different populations to air pollutants exposure. The interaction between air pollutants and meteorological factors was verified in both multiplicative and additive interaction models. An interquartile range (IQR) increased in nitrogen dioxide (NO2) concentration was associated with the greatest lag-specific relative risk (RR) of gingivitis at lag 3 days (RR = 1.087, 95% CI 1.008-1.173). Fine particulate matter (PM2.5) exposure also increased the risk of periodontitis at the day of exposure (RR = 1.049, 95% CI 1.004-1.096). Elderly patients with gingivitis and periodontitis were both vulnerable to PM2.5 exposure. The interaction analyses showed that exposure to high levels of NO2 at low temperatures was related to an increased risk of gingivitis, while exposure to high levels of NO2 and PM2.5 may also increase the risk of gingivitis and periodontitis in the high-humidity environment, respectively. This study supported that NO2 and PM2.5 exposure increased the risk of gingivitis and periodontitis outpatient visits, respectively. Besides, the adverse effects of air pollutants exposure on periodontal diseases may vary depending on ambient temperature and humidity.

Sestrin2/Keap1/Nrf2 pathway regulates mucus hypersecretion in pulmonary epithelium induced by traffic-related PM2.5 and water-soluble extracts

The involvement of fine particulate matter (PM2.5) exposure in the progression of asthma has been extensively discussed in epidemiological and experimental evidence, which aroused widespread attention. Asthma is characterized by mucus hypersecretion. This study investigates the underlying toxic mechanism of traffic-related PM2.5 (TRPM2.5) and water-soluble extracts (WSE) on mucus hypersecretion in the lungs of rats with asthma and 16HBE cells. The ovalbumin-induced rats were administrated by instillation of TRPM2.5 and WSE in the trachea once three days for eight times. The results showed that TRPM2.5 and WSE had an adverse impact on mucus secretion. Specifically, conspicuous mucus stains and increased goblet cells in the bronchial epithelium by PAS staining were found in lung tissues of rats with asthma; MUC5AC gene and protein expression levels in lung tissues of rats with asthma and 16HBE cells were elevated. In addition, TRPM2.5 and WSE triggered oxidative damage via upregulation of malondialdehyde and myeloperoxidase as well as activation of the Sestrin2/Keap1/Nrf2 signaling pathway. Conversely, the knockdown of Sestrin2 effectively inhibited TRPM2.5 and WSE-induced mucus hypersecretion, oxidative stress, and Keap1/Nrf2 signaling pathway and its downstream target gene NQO1. Collectively, it was demonstrated that TRPM2.5 and WSE induced mucus hypersecretion mediated by the Sestrin2/Keap1/Nrf2 pathway.

Association between short-term exposure to ambient air pollution and outpatient visits for pulpitis in Hefei, China: a time series study

Evidence suggests a possible association between ambient air pollutants and oral diseases. Nevertheless, information regarding the relationship between air pollutants and pulpitis is scarce and inconclusive. In view of this, the present study aimed to investigate the relationship between short-term exposure to air pollution and outpatient visits for pulpitis. Daily data on outpatient visits for pulpitis, air pollutants, and meteorological data in Hefei, China, was collected from January 1, 2015 to December 31, 2021. The association between exposure to air pollutants and pulpitis outpatient visits was evaluated using distributed lag non-linear model (DLNM) and a generalized linear model (GLM). Furthermore, stratified analyses were performed by gender, age and season. A total of 93,324 records of outpatient visits for pulpitis were included in this study. The results showed that exposure to NO₂, PM_2.5, and CO were positively correlated with an increased risk of pulpitis outpatient visits. Each 10 μg/m³ increase in NO₂ and PM_2.5 concentration, at lag 0-2 day, was associated with a 2.4% (relative risk (RR) = 1.024, 95% confidence interval (CI): 1.014-1.035) and 0.5% (RR = 1.005, 95% CI: 1.000-1.010) increase in pulpitis outpatient visits, respectively. With a 1 mg/m³ increase in CO concentration, the risk of pulpitis outpatient visits increased by 9.1% (RR = 1.091, 95% CI: 1.031-1.154, lag 0-1 day). Intriguingly, exposure to O₃ was associated with a decreased risk of pulpitis outpatient visits (RR = 0.990, 95% CI: 0.984-0.995, lag 0-5 day). Subgroup analysis revealed that in the warm season, exposure to PM_2.5, O₃, and CO was related with a significantly higher outpatient risk of pulpitis than in the cold season. Additionally, the influence of PM_2.5 and CO exposure at age < 65 years was significantly stronger than at age ≥ 65 years. In conclusion, exposure to ambient NO₂, PM_2.5, and CO is associated with an increase in pulpitis outpatient visits in Hefei, China. Conversely, exposure to O₃ reduces the risk of outpatient visits for pulpitis. Age and season are effect modifiers of these associations.