Table 1.

Characteristics of M1 and M2 microglia.

	Stimulus	Phenotypic markers	Substances produce	Function
M1	IFN-γ, LPS	iNOS, TNF-α, MHCII, CD86	IL-23, IL-18, IL-12, IL-1β, IL-6, TNF-α, NO, CCL2, CXCL10, ROS, MMP9, MMP3	Proinflammatory, Phagocytosis, Cytotoxicity, Present antigens, Kill intracellular pathogens
M2a	IL-4, IL-13	Arg-1, Fizz-1, Chitinase3-like 3, Chemokines IGF-1, CD206,	Extracellular matrix proteins	Tissue repair; Remodeling of extracellular matrix; Phagocytosis
M2b	Immune complex, TLRs agonists	IL-10, Cyclooxyge- nase 2, Sphingosine kinase, suppressor of cytokine signaling 3	IL-1β, IL-6, IL-10, TNF-a	Phagocytosis Removal of tissue debris
M2c	IL-10, TGF-β, glucocorticoid	CD163	IL-10, TGF-β	Anti-inflammatory Phagocytosis