AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
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Toxicogenomic Profiling to Assess the Biological Effects upon Exposure to Isoprene-Derived Secondary Organic Aerosol (SOA) in Human Lung Cells
YING-HSUAN LIN, Maiko Arashiro, Kenneth Sexton, Avram Gold, Ilona Jaspers, Rebecca Fry, Jason Surratt, University of North Carolina at Chapel Hill
Abstract Number: 252 Working Group: Health Related Aerosols
Abstract Secondary organic aerosols (SOA) derived from isoprene photooxidation represent a substantial organic aerosol mass fraction in atmospheric fine particulate matter (PM2.5). The formation processes of isoprene SOA are largely influenced by anthropogenic emissions through multiphase chemistry. Considering the occurrence and abundance of isoprene SOA in the troposphere, it is crucial to understand the health effects induced by inhalation exposure to mitigate its potential impact on public health. In this study, we assessed the toxicogenomic effects in response to isoprene SOA exposure in human airway epithelial cells (BEAS-2B) through a direct air-liquid interface exposure. Pathway-focused gene expression profiling was performed using Qiagen Human Oxidative Stress Plus RT² Profiler PCR Array and NanoString nCounter® Human Inflammation v2 Panel, which include 84 oxidative stress and 249 inflammation human genes, respectively. Our results show that the expression levels of 31 genes were significantly altered (fold change> 1.5, p<0.05) upon isoprene SOA exposure under non-cytotoxic conditions. Gene-set analysis for functional enrichment and induced network modules identify the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) mediated signaling pathway as a predominant defense mechanism for cell survival. Various molecular functions, transcription factors, and biological pathways are also found to be enriched, including glutathione metabolism for detoxification, as well as the Toll-like receptor cascade for inflammatory signaling. Together with detailed characterization of SOA constituents, our findings highlight the importance of linking PM2.5 source, composition, early biological responses and potential health outcomes.