Monocyte Recruitment, Specification, and Function in Atherosclerosis

Atherosclerotic lesions progress through the continued recruitment of circulating blood monocytes that differentiate into macrophages within plaque. Lesion-associated macrophages are the primary immune cells present in plaque, where they take up cholesterol and store lipids in the form of small droplets resulting in a unique morphology termed foam cell. Recent scientific advances have used single-cell gene expression profiling, live-cell imaging, and fate mapping approaches to describe macrophage and monocyte contributions to pro- or anti-inflammatory mechanisms, in addition to functions of motility and proliferation within lesions. Yet, many questions regarding tissue-specific regulation of monocyte-to-macrophage differentiation and the contribution of recruited monocytes at stages of atherosclerotic disease progression remain unknown. In this review, we highlight recent advances regarding the role of monocyte and macrophage dynamics in atherosclerotic disease and identify gaps in knowledge that we hope will allow for advancing therapeutic treatment or prevention strategies for cardiovascular disease.

Automated summary

Atherosclerotic lesions progress due to the recruitment and differentiation of circulating monocytes into macrophages within plaques, forming foam cells. Recent studies have used single-cell gene expression profiling to investigate the roles of macrophages and monocytes in inflammatory mechanisms, motility, and proliferation within lesions, but questions remain about tissue-specific regulation and the contribution of recruited monocytes during disease progression. Further research is needed to advance therapeutic strategies for cardiovascular disease based on these findings.