(CCSP121) EICOSAPENTAENOIC ACID (EPA) MODULATED EXPRESSION OF PROTEINS LINKED TO PLATELET ACTIVATION IN VASCULAR ENDOTHELIAL CELLS DURING INFLAMMATION

Background: Vascular endothelial dysfunction leads to platelet activation and thrombus formation during ischemic disease. Inflammation is mediated by factors such as angiotensin II (Ang II) and cytokines. The early procoagulant response is inhibited by tissue factor pathway inhibitor (TFPI) released by endothelial cells. The omega-3 fatty acid EPA administered in a highly purified form of icosapent ethyl (IPE) reduced ischemic events in high-risk cardiovascular disease patients (REDUCE-IT). We measured the effects of EPA on expression of proteins involved in platelet function and activation using vascular endothelial cells (ECs) following stimulation of inflammation with cytokine (IL-6) and Ang II challenge.

METHODS AND RESULTS: Human umbilical vein ECs (HUVECs) were challenged with either cytokine IL-6 (12 ng/ml) or Ang II (100 nM) for 2 hours and then treated with EPA (40 µM) for 24 hours. Global proteomic analysis was performed using LC/MS to measure relative expression levels simultaneously. Only significant (p < 0.05) changes in expression between treatment groups >1-fold were analyzed by differential enrichment analysis of proteomics data (DEP) and included in gene set enrichment analyses (GSEA). EPA treatment significantly down/up-regulated expression of 507/505 and 544/472 proteins, respectively, compared to Ang II and IL-6. In particular, EPA significantly affected 19 proteins in the “platelet degranulation” with Ang II and IL-6 (GO: 0002576) pathway (adjusted p value = 0.002 and 0.003, respectively). Four common proteins were increased relative to Ang II but decreased relative to IL-6, including CD9, thrombospondin-1, and CD109. Additionally, EPA increased expression of TFPI relative to Ang II by 1.1-fold (p = 0.040) and modulated 8 proteins within the “platelet aggregation” pathway (GO: 0070527, adjusted-p value = 0.007).

Conclusion: EPA affected expression of proteins and related pathways involved in platelet activation under inflammatory conditions, including increased TFPI levels, in vascular ECs. These findings indicate antithrombotic mechanisms for EPA that may contribute to reduced vascular ischemic events.