Variation in doses and duration of particulate matter exposure in bronchial epithelial cells results in upregulation of different genes associated with airway disorders.

Exposure to particulate matter < 2.5 μm (PM) is associated with a variety of airway diseases. Although studies have demonstrated that high doses of PM cause cytotoxicity and changes to gene expression in bronchial epithelial cells， the effect of lower doses and repeated exposure to PM are less well studied. Here， we treated BEAS-2B cells with varying doses of PM for 1-7 days and examined the expression of a variety of genes implicated in airway disorders. At high doses， PM increased the expression of IL6， TNF， TSLP， CSF2， PTGS2， IL4R， and SPINK5. Other genes such as ADAM33， ORMDL3， DPP10 and CYP1A1， however， were increased by PM at much lower doses (≤1 μg/cm). Repeated exposure to PM at 1 or 5 μg/cm every day for 7 days increased the sensitivity and magnitude of change for all of the aforementioned genes. Genes such as IL13 and TGFB1， increased only when cells were repeatedly exposed to PM. Treatment with an antioxidant， or inhibitors to aryl hydrocarbon receptor or NF-κB attenuated the effect of PM. These data demonstrate that PM exerts pleiotropic actions that differ by dose and duration that affect a variety of genes important to the development of airway disease.