Macrophage, a potential targeted therapeutic immune cell for cardiomyopathy

Figures

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  FIGURE 1. Functions and phenotype of macrophages. Macrophages are classified into M1 and M2 based on the stimulation type and function. M1 macrophages have pro-inflammatory activity, M2 macrophages have anti-inflammatory and tissue repair activity. These macrophages are divided into subtypes based on the stimulation. Proinflammatory M1 macrophages are divided into M1a macrophages stimulated by IFNγ and M1b macrophages stimulated by LPS. Anti-inflammatory M1 macrophages are divided into M2a macrophages stimulated by IL-4 and IL-13, M2b macrophages stimulated by LPS, M2c macrophages stimulated by IL-10, M2d macrophages stimulated by A2AR and TLR agonists and M2f macrophages stimulated by macrophage apoptotic clearance. M2a macrophages can suppress the inflammatory responses. M2b macrophages have pro- and anti-inflammatory activity. M2c macrophages can secrete TGFβ1 and glucocorticoids.

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  FIGURE 2. Functions and phenotype of macrophages during infection and tissue repair. When cardiomyocytes undergo injury, the heart recruit peripheral monocyte to differentiate M1 macrophages. M1 macrophages will activate CCL2 and NF-κB and promote TNF-α, IL-1β, and IL-6 to inhibit cardiac repair and aggravate cardiomyocytes necrosis. As time goes on, M1 macrophages can transform M2 macrophages through CB2 receptor axis. M2 macrophages can inhibit TNF-α, IL-1β, and IL-6 to promote cardiac repair. Meanwhile, M2 macrophages can promote angiogenesis and fibroblast formation. Cardiac resident-macrophages have the same effect as M2 macrophages.