BS18 Profiling endothelial gene expression in coronary atherosclerotic plaques in a human-like D374Y-PCSK9 hyperlipidaemic porcine model

Abstract

Introduction Endothelial dysfunction is central to the development of atherosclerosis. Previous approaches studying endothelial gene expression in relation to atherogenesis have utilised in vitro cell culture or in vivo models sampling endothelium from the carotid arteries or aortic arch. Endothelial gene expression studies in coronary atherosclerotic plaques in vivo have not been previously characterised. We have developed a human-like advanced coronary atherosclerotic porcine model in which we aimed to address this knowledge gap by characterising changes in local gene expression in endothelium sampled from control coronary arteries and from advanced coronary atherosclerotic plaques. Methods and Results A protocol was optimised to perform laser capture microdissection for isolation of endothelium in under 20 minutes, from snap-frozen porcine coronary artery cross-sections for total RNA sequencing (n=5 D374Y-PCSK9 hyperlipidaemic minipigs fed on a high fat high cholesterol diet; 10 vessels). Endothelium was sampled from control left anterior descending arteries consisting of no plaque, and from overlying advanced atherosclerotic plaque in stenotic right coronary arteries. Differential gene expression and gene ontology enrichment analyses revealed the upregulation of numerous atheroprone inflammatory genes in diseased endothelium overlying atherosclerotic plaque compared to healthy endothelium (figure 1: ptable 1: enrichment score >3). Biological pathways to which differentially expressed genes belong to Conclusions We report in vivo changes in gene expression in diseased endothelium overlying advanced coronary atherosclerotic plaques, with upregulation of inflammatory genes. The differentially expressed genes are enriched in processes related to atherosclerosis, suggesting the validity of this approach to study how gene expression changes during coronary atherosclerotic plaque development in vivo. Our model system allows for further studies coupling together these readouts to a fully validated 3D vessel reconstruction method to co-register gene expression profiles to local blood flow data, as a novel methodology for understanding the mechanisms by which local flow disturbances may affect atherogenesis. This will provide new insights into how disturbed flow and coronary atherosclerotic plaque development are causally related. Conflict of Interest None