Fig. 1

Origin, phenotype and function of macrophages in cardiovascular system under homeostasis, MI and AS. a In cardiac homeostasis, three types of resident macrophages exist in the heart. CCR2^-MHC^low macrophages and CCR2^-MHC^high macrophages are derived from yolk sac cells and fetal liver monocytes and maintain the number of subpopulations through self-renewal, while monocytes also contribute a small amount to the number of subpopulations. CCR2⁺MHC^high macrophages are derived from fetal liver monocytes and are gradually replaced by circulating monocytes during development. Artery-resident macrophages, predominantly located in the adventitia during homeostasis, are derived from yolk sac cells, fetal liver monocytes and bone marrow (after birth). Main functions and transcriptome signature of each subset are highlighted in the colored corresponding boxes. b When MI occurs, cardiac TLF⁺ macrophages undergo self-renewal. In addition, a large number of Ly6C^high monocytes infiltrate into the heart and mainly differentiate into three types of macrophages, including MHC⁺ macrophages, ISG⁺ macrophages and Trem2⁺ macrophages. In AS, macrophages can be classified into four main subsets, including proliferating macrophages, inflammatory macrophages, IFNIC and foamy/TREM2⁺ macrophages. Proliferating macrophages maintain the number of subpopulations through completely self-renewal and other subsets are derived from Ly6C^high monocytes. Main location, functions and transcriptome signature of each subset are highlighted in the colored corresponding boxes. (Created with BioRender.com)