Abstract
PURPOSE OF REVIEW: To highlight recent conceptual and technological advances that have positioned the field to interrogate the cellular and molecular mechanisms contributing to the initiation of atherosclerosis, including intimal lipid accumulation, inflammation, and lesion growth. RECENT FINDINGS: Advances in the understanding of endothelial LDL transcytosis and rapid lipid uptake by intimal macrophages provide mechanistic insights into intimal LDL accumulation and the initiation of atherogenesis. Recent studies have used unbiased single-cell approaches, such as single-cell RNA sequencing and CyTOF, to characterize the cellular components of the normal intima and atherosclerotic lesions. In-vitro studies and high-resolution transcriptomic analysis of aortic intimal lipid-loaded versus lipid-poor myeloid populations in vivo suggest that lipid-loaded macrophages may not be the primary drivers of inflammation in atherosclerotic lesions. SUMMARY: A new perspective on the complex cellular landscape of the aorta, specifically the atherosclerosis-prone regions, confirm that intimal accumulation of lipid, monocyte recruitment, and macrophage accumulation are key events in atherogenesis triggered by hypercholesterolemia. Targeting these early events may prove to be a promising strategy for the attenuation of lesion development; however, the specific details of how hypercholesterolemia acts to initiate early inflammatory events remain to be fully elucidated.