LAUSR

STRACT The Spring Festival is the most important holiday in China. In the time, the levels of particulate matter (PM) as well as gaseous co-pollutants significantly increase because of the widespread enjoyment of fireworks. The expression patterns of microRNAs may serve as valuable signatures of exposure to environmental constituents. We exposed macrophages to the whole stream of outdoor air at the air-liquid interface aiming at closely approximating the physiological conditions and the inhalation situation in the lung. 58 miRNAs were up-regulated, and 68 miRNAs were down-regulated in the night of the New Year's Eve (the exposure group E2N1) compared to filtered-air exposed control cells. The target genes of the up-regulated miRNAs were enriched in immunity- and inflammation-linked pathways, such as TLR-NF-κB pathway. Compared to the group E2N1, 29 miRNAs were up-regulated, and 23 miRNAs were down-regulated in the cells exposed to air from the day-time of the Chinese New Year with higher concentrations of particles, SO2 and nitrogen oxide. The target genes of the up-regulated miRNAs were mostly enriched in apoptosis, adhesion and junction-related pathways. These results preliminarily unravel part of the toxic mechanisms of air constituents and provide clues for discovering the main drivers of air pollution-induced disorders.