Early-life exposure to three size-fractionated ultrafine and fine atmospheric particulates in Beijing exacerbates asthma development in mature mice

• DOI: 10.1186/s12989-018-0249-1
• Publication Date: 2018-03-14T07:18:06Z
• Authors: Mei Mei; Haojun Song; Lina Chen; Bin Hu; Ru Bai; Diandou Xu; Ying Liu; Yuliang Zhao; Chunying Chen
• Keywords: Inhalation exposure

Epidemiological studies have suggested that elevated levels of air pollution contribute to an increased incidence or severity asthma. Although late-onset adult asthma seems be more attributable environmental risk factors, limited data is available on the impact early-life exposure size-fractionated ambient particulate matter (PM) in adults. We aimed determine effect development and exacerbation after mice were exposed as juveniles three particulates collected from Beijing. The urban Beijing winter, heavily affected by traffic coal-fired emissions. typical morphological major chemical components PM characterized first. Oxidative stress expression DNA methyltransferases (DNMTs) then examined vitro lungs mouse pups 48 h oropharyngeal aspiration. When control juvenile matured adulthood, antigen-induced model was established relevant bio-indices assessed. with different granularities can induce oxidative stress; particular, F1, smallest size (< 0.49 μm), decreased mRNA DNMTs vivo most significantly. In mice, previous caused peribronchiolar inflammation, airway mucus secretion, production Th2 cytokines chemokines. general, F1 F2 (aerodynamic diameter < 0.95 μm) murine seriously than F3 (0.95–1.5 μm). Moreover, led inflammation form both neutrophils eosinophils BALF. activation TGF-β1/Smad2 Smad3/Stat3 signaling pathways leading fibrosis profoundly induced F1. This study demonstrated enhanced development, shown responses, which might associated persistent effects resulting gene exposure. observed differences between attributed particle sizes constituents, including heavy metals also PAHs, since amounts PAH severe toxicity enriched equivalently fractions. Relative often mentioned PM2.5, aerodynamic smaller μm had a aggravating development.