Gene expression profiling and pathway analysis of human bronchial epithelial cells exposed to airborne particulate matter collected from Saudi Arabia

Whole transcript expression was profiled using the Affymetrix 1.0 array in human bronchial epithelial cells exposed to PM collected from Saudi Arabia for 1 or 4 days. The differentially expressed genes were identified and analyzed for enriched networks and pathways using Ingenuity Pathway Analysis (IPA). We have identified 140 and 230 genes that significantly changed more than 1.5 fold after PM exposure for 1 or 4 days, respectively. IPA analysis revealed that different exposure durations triggered distinct pathways. Genes involved in NRF2-mediated response to oxidative stress were up-regulated after 1 day exposure. In contrast, cells exposed for 4 days exhibited significantly changes in genes related to cholesterol and lipid synthesis pathways. We analyzed gene expression profiles from 12 samples collected at two different time points, including 2 untreated controls, 2 normal PM treated samples and 2 storm PM treated samples for each time point.