Monocytes and Macrophages in Atherosclerosis

This chapter reviews the role of monocytes and macrophages in atherogenesis including cell origin, differentiation, and transcriptional regulation. It also emphasizes monocyte and macrophage heterogeneity, subset characterization, and functional implication in pathological conditions, such as hyperlipidemia and hyperhomocysteinemia. Experimental and clinical studies strongly suggest that monocytes and macrophages are not only present in atherosclerosis but also significantly contribute to its initiation and progression. The interaction of inflammatory monocyte and the endothelium determines vascular inflammation in the early stage of atherosclerosis. Recent global transcriptome analysis revealed profound changes in gene expression during monocyte-to-macrophage terminal differentiation. Although the control of risks factors are still the major prevention of atherosclerosis, clinical treatments are mainly focused on lowering blood lipid levels, maintaining blood pressure, and managing thrombotic complications.