Fig. 1

Macrophage Classification Modes. a M0 macrophages can be polarized into M1 macrophages by LPS/IFN-γ stimulation. M1 macrophages are pro-inflammatory subtypes that secrete pro-inflammatory cytokines such as IL-6, IL-12, and IL-1β. M0 macrophages can be polarized into M2 macrophages by IL-4 stimulation. M2 macrophages are associated with inflammation resolution and tissue repair through the secretion of anti-inflammatory cytokines such as IL-10, VEGF, and TGF-β. b Cardiac macrophages can be classified into CCR2⁺ monocyte-derived macrophage and CX3CR1⁺ resident macrophage according to their function and origins. Monocyte-derived macrophages are pro-inflammatory and lack reparative activities, whereas resident macrophages promote cardiac repair through anti-inflammatory activities, angiogenesis, and cardiomyocyte proliferation. Furthermore, TIMD4⁺ macrophages are regarded as a pure population of resident macrophages that reside in cardiac tissue. CD72^hi macrophages are pro-inflammatory macrophage subsets