Table 2.

Factors regulating microglia.

Microglial regulation	Function
CD200 [82]	Helps to maintain resting state
CX3CR1 [85]	Regulate microglia recruitment to the site of neuroinflammation
CD47 [84]	Neuronal protein sends “do not eat me” signals to microglia via CD172a/Sirp alpha interaction
PRC2 [91]	PRC2 enzyme catalyzes H3K27me3 modification
TREM2 [93, 94]	Role in phagocytosis of debris and reducing proinflammatory cytokines
CSF1 [95]	Regulate the survival of myeloid lineage
Runx1, ETS, PU.1, Irf8, Hoxb8 [15, 22]	Regulating differentiation processes during the embryonic development
C‐myb [97]	Essential for microglia health, regulates proliferation, and survival in the CNS
Ionotropic receptors [98, 99]	Calcium influx and the release of pro‐inflammatory molecules
Metabotropic receptors [98, 99]	Activate intracellular signaling cascades that contribute to microglial activation and inflammation
Nerve Growth Factor [100]	Regulate microglial activation and survival
Prostaglandins E2 [101]	Modulate microglial activation and pro‐inflammatory responses
Gamma‐aminobutyric acid (GABA) [105]	Modulate microglial activation and inflammatory responses
Glucocorticoids [106]	Suppresses microglia activation and inflammation via glucocorticoid receptor binding
Estrogen [106]	Modulates microglia activation, migration, and phagocytic activity
Brain‐derived Neurotropic factor (BDNF) [107]	Modulate microglial function by influencing their activation, proliferation, and release of pro‐inflammatory cytokines
Norepinephrine [108, 109]	Controls the release of inflammatory factors like interleukin 6 (IL‐6), interleukin 1β (IL‐1β), and tumor necrosis factor α (TNF‐α)
Histamine and serotonin [111]	Increases of calcium in the microglia