Abstract WP210: Eicosapentaenoic Acid (EPA) Decreases Cytokine Release And Inflammatory Proteins In Brain Vascular Endothelium During Inflammation

Abstract

Background: Brain vascular endothelial cell (EC) dysfunction is characterized by release of pro-inflammatory mediators that contribute to atherosclerosis and ischemic stroke. Treatment with icosapent ethyl (IPE), the ethyl ester of the omega-3 fatty acid, eicosapentaenoic acid (EPA), reduced first and total ischemic strokes each by 36%, without increasing hemorrhagic stroke, in statin-treated patients with elevated cardiovascular risk (REDUCE-IT). We tested the effects of EPA on cytokine release and expression of inflammatory proteins from brain microvascular ECs during inflammation. Methods: Human brain microvascular endothelial cells (HBECs) were pretreated with the cytokine IL-6 at 12 ng/ml for 2 h before treatment with EPA (40 μM) for 24 h. Proteomic analysis was performed using LC/MS to capture relative expression levels. Only significant changes in protein expression between treatment groups >1-fold were analyzed. Gene set enrichment analysis was also performed on all significantly regulated proteins to identify groups of proteins (pathways) that were affected. Levels of soluble intercellular adhesion molecule-1 (sICAM-1) and tumor necrosis factor-α (TNF-α) were measured by immunochemistry (ELISA). Results: IL-6 exposure produced increased levels of sICAM-1 and TNF-α by 102% and 147% (p<0.001), respectively, in brain ECs compared with vehicle. EPA treatment reduced release of sICAM-1 by 43% (p<0.001) and TNF-α by 52% (p<0.001) compared to IL-6 alone. EPA also downregulated 43 proteins involved in the “neutrophil degranulation” pathway in brain ECs (p-adjusted = 2.63 х 10 -12 ), including heat shock protein 90-alpha and beta by 1.1-fold each relative to IL-6 alone. Conclusions: In brain vascular ECs, EPA significantly reduced expression of pro-inflammatory mediators and proteins associated with neutrophil degranulation under inflammatory conditions. The ability of EPA to reverse brain EC dysfunction during inflammatory may contribute to reductions in stroke risk.