Atherosclerosis—Multiple Pathways to Lesional Macrophages

Atherosclerosis is a chronic inflammatory disease that manifests in multiple vascular beds and frequently culminates in ischemic events, including myocardial infarction. Blood monocytes that are recruited to the inflamed vascular wall develop into inflammatory macrophages and foam cells, which contribute to pathogenesis at many stages of this disease and, therefore, represent a target for therapeutic interventions. Recently, alternate sources of macrophages have been identified. Here, we discuss the origin and molecular regulation of macrophages and highlight recent conceptual changes that may shape the development of effective treatments.