Abstract WP229: Eicosapentaenoic Acid (EPA) Modulates Expression Of Thrombotic And Metabolic Proteins In Brain Endothelium Following Cytokine Challenge

Abstract

Background: During inflammation, vascular endothelial cells (ECs) release vasoconstrictive and thrombotic factors that promote abnormal blood flow and atherothrombosis. The omega-3 fatty acid (n3FA) eicosapentaenoic acid (EPA) reduced first and total ischemic strokes each by 36% in patients with elevated cardiovascular risk (REDUCE-IT) when administered as icosapent ethyl. We measured the effects of EPA on expression of proteins involved in cytoprotection, thrombosis, and fatty acid metabolism in human brain ECs subjected to inflammation. Methods: Human brain microvascular ECs (HBECs) were first challenged with IL-6 at 12 ng/ml for 2 hr and then treated with EPA (40 μM) for 24 hr. Global proteomic analysis was performed using LC/MS to measure relative expression levels of >1,000 proteins simultaneously. Only significant (p<0.05) changes in expression between treatment groups >1-fold were analyzed. Results: EPA treatment significantly modulated the expression of 504 proteins (212 increased expression, 292 decreased expression) in HBECs compared with IL-6 alone. EPA treatment increased expression of the cytoprotective enzyme heme oxygenase-1 by 1.5-fold (p = 4.7 х 10 -16 ) relative to IL-6 alone. Additionally, IL-6 increased expression of prothrombin (clotting factor II) 1.3-fold relative to control (p = 1.41 х 10 -20 ), and EPA decreased expression of prothrombin by 1.3-fold relative to IL-6 (p = 2.10 х 10 -24 ). EPA also reduced expression of fatty acid desaturase 1 & 2 by 1.4-fold and 2.6-fold, respectively, which may lead to changes in intracellular fatty acid levels. Conclusions: EPA significantly modulated expression of cytoprotective, thrombotic, and metabolic proteins in brain ECs under conditions of inflammation with IL-6. These effects of EPA on inflammation have implications for ischemic disease, including stoke, as demonstrated in large outcome trials.