Particulate Matter From Saudi Arabia Induces Genes Involved in Inflammation, Metabolic Syndrome and Atherosclerosis

Abstract

Airborne particulate matter (PM) exposure is a major environmental health concern and is linked to metabolic disorders, such as cardiovascular diseases (CVD) and diabetes, which are on the rise in the Kingdom of Saudi Arabia. This study investigated changes in mouse lung gene expression produced by administration of PM₁₀ collected from Jeddah, Saudi Arabia. FVB/N mice were exposed to 100 μg PM₁₀ or water by aspiration and euthanized 24 h later. The bronchoalveolar lavage fluid (BALF) was collected and analyzed for neutrophil concentration and tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels. RNA was extracted from lungs and whole transcript was analyzed using Affymetrix Mouse Gene 1.0 ST Array. Mice exposed to PM₁₀ displayed an increase in neutrophil concentration and elevated TNF-α and IL-6 levels. Gene expression analysis revealed that mice exposed to PM₁₀ displayed 202 genes that were significantly upregulated and 40 genes that were significantly downregulated. PM₁₀ induced genes involved in inflammation, cholesterol and lipid metabolism, and atherosclerosis. This is the first study to demonstrate that Saudi Arabia PM₁₀ increases in vivo expression of genes located in pathways associated with diseases involving metabolic syndrome and atherosclerosis.