Activated microglia and macrophage

Activated microglia and macrophage refer to innate immune cells within the central nervous system (CNS) that play crucial roles in both homeostasis and the immune response to injury, infection, neurodegeneration, or other pathological insults[1][2][6][7]. Microglia are resident macrophages of the CNS, performing surveillance, phagocytosis of debris and pathogens, synaptic pruning, and modulating neuroinflammation[5][6][7]. Upon activation by stimuli such as infection, injury, or disease, both microglia and infiltrating macrophages can adopt diverse phenotypes, loosely categorized as pro-inflammatory (M1) or anti-inflammatory/tissue-repairing (M2), although contemporary research recognizes more nuanced states than the classic M1/M2 model[1][5][7]. Activated microglia/macrophages are central to the pathogenesis of most neurodegenerative diseases (e.g., Alzheimer’s, Parkinson’s), CNS infections, trauma, and some psychiatric diseases due to their dual roles in neuroprotection and neurotoxicity; the balance of these effects is dictated by their state of activation, signaling pathways involved (e.g., Notch, NF-κB), and interactions with other CNS cells (astrocytes, neurons)[2][3][4][7]. Therapeutically, modulating microglial/macrophage activation is an area of active investigation in neuroinflammation and neurodegeneration, but there are challenges in selectively targeting pathological activation without compromising physiological CNS maintenance[3][7]. Additional notes: - Microglia and macrophages are cell types, not single gene/protein molecular targets, and include multiple dynamic states and phenotypes[6][7]. They are not a single canonical molecule or receptor. - For molecular targeting, it is more common to specify surface markers, signaling molecules, or receptors (e.g., CSF1R, Iba1, TREM2) rather than the generic “activated microglia and macrophage.” The current entry lacks molecular specificity. - “Activated microglia and macrophages” is thus not a canonical single-molecule target, so this designation is imprecise and potentially incorrect as a molecular target for therapeutic development.

Other names

MicrogliaCNS macrophagebrain macrophageCNS-resident macrophageactivated microglial cellreactive microgliaM1/M2 microgliaCNS-infiltrating macrophage

Inhibition of microglial/macrophage activation (by anti-inflammatory drugs, CSF1R inhibitors); Modulation of cytokine/receptor signaling pathways (e.g., Notch, NF-κB, MAPK, JNK); Promotion of M2/anti-inflammatory phenotype; Inhibition of pro-inflammatory (M1) polarization; Suppression of phagocytic and neuroinflammatory activity.