Dysregulated phosphoinositide 3-kinase signaling in microglia: shaping chronic neuroinflammation

Table 1 Key cell surface receptors on microglia that utilize PI3K-AKT signaling

Receptor	Ligands	Disease implication	Key references
CSF-1 receptor	CSF-1, IL-34	Reduced signaling: blunted brain development, leukoencephalopathy, olfactory deficits Increased signaling: progressive MS, AD	[86,87,88,89,90]
CX3CR1	CX3CL1	Reduced signaling: PD, ALS	[91]
Fibroblast growth factor receptor 2	Fibroblast growth factor	Reduced signaling: MS	[92]
IL-4 receptor	IL-4	Reduced signaling: AD, MS	[93, 94]
Insulin receptor	Insulin	Reduced signaling: AD	[95, 96]
TLR4	LPS, LTA	Increased signaling: AD, PD, ALS	[97,98,99]
TREM2	LPS, bacterial products, DNA, phospholipids, lipoproteins, sulfatides, Aβ plaques	Reduced signaling: AD, Nasu-Kakola disease	[100,101,102,103]

Aβ plaques amyloid beta plaques, AD Alzheimer’s disease, ALS amyotrophic lateral sclerosis, CSF-1 colony stimulating factor 1, CX3CL1 C–X3–C motif ligand 1, DNA deoxyribonucleic acid, IL interleukin-, LPS lipopolysaccharide, LTA lipoteichoic acid, MS multiple sclerosis, PD Parkinson’s disease, TLR Toll-like receptor, TREM2 triggering receptors expressed on myeloid cells 2

ISSN: 1742-2094