Table 1.
Receptors involved in microglial phagocytosis
| Receptors | Stimulus | Cell types expressed | Diseases/animal models | References |
|---|---|---|---|---|
| TLRs | α-Synuclein | Microglia | alpha-Synucleinopathies, Alzheimer’s disease | [23, 120–122] |
| Fibrillar Aβ | Astrocytes | |||
| Bacterial strains | Oligodendrocytes | CNS infections, spinal cord injury, and neuronal injury | ||
| LPS | Neurons | |||
| TREM-2 | Amyloid protein | Microglia | Alzheimer’s disease | [34, 123] |
| Macrophages | Nasu-Hakola disease | |||
| Monocyte-derived dendritic cells | Multiple sclerosis/EAE | |||
| Osteoclasts | ||||
| Fc receptors (FcγR) | α-Synuclein | Neurons | Parkinson’s disease | [124, 125] |
| Astrocytes | Multiple sclerosis | |||
| Microglia | Alzheimer’s disease | |||
| Oligodendrocytes | ||||
| Complement receptors (CR3 (CD11b/CD18), CR4 (CD11c/CD18)) | Degenerated myelin | Microglia | Alzheimer’s disease | [126, 127] |
| Aβ | Macrophages | Wallerian degeneration | ||
| Apoptotic cells | Multiple sclerosis | |||
| Scavenger receptors (SR-A, SR-BI, CD36, RAGE) | Degenerated myelin | Microglia, astrocytes, mato cells, cerebral microvascular endothelial cells, cerebral arterial smooth muscle cells, retinal pigment epithelial cells | Multiple sclerosis/EAE | [128–131] |
| fAβ, thrombospondin-1 | Amyotrophic lateral sclerosis | |||
| Anionic polysaccharide | Alzheimer’s disease | |||
| Polynucleotides | ||||
| Chemically modified proteins | ||||
| Apoptotic cells | ||||
| Bacteria | ||||
| P2RY6 | ATP and other nucleotides | Microglia | Neuropathic pain | [37, 132] |
| Galectin-3/MAC-2 | Degenerated myelin | Microglia | Traumatic brain injury | [133, 134] |
| Macrophages | Spinal cord injury | |||
| Schwann cells | Multiple sclerosis/EAE | |||
| LRP receptors (low-density lipoprotein receptor-related protein-1) | LPS or Aβ | Neurons | Alzheimer’s disease | [135–137] |
| Brain capillary endothelium | ||||
| Phosphatidylserine receptors (phosphatidyl-serine-specific receptor) | Apoptotic and necrotic neurons | Macrophages | Alzheimer’s disease | [138, 139] |
| Fibroblasts | ||||
| Epithelial cells | ||||
| Dendritic cells | ||||
| Mannose receptors | Soluble immune components, cell debris, cytotoxic substances, myelin glycoproteins, degrading enzymes, microbial ligands | Astrocytes | Ischemia | [140, 141] |
| Perivascular | ||||
| Meningeal | ||||
| Choroid plexus macrophages |