Figure 2. APOE isoforms impact communication between glia and neurons.
(A) Astrocytes provide metabolic support to neurons by supplying neurons with lipids such as cholesterol and metabolizing lipid species secreted by neurons. These activities are impaired by APOE4. (B) APOE4, but not APOE3, impairs calcium signaling in both microglia and neurons. APOE4 microglia also accumulate triglycerides, exhibit decreased purinergic signaling, and secrete proinflammatory cytokines. (C) Oligodendrocytes myelinate neurons. APOE4 oligodendrocytes display lower viability and intracellular cholesterol accumulation which leads to decreased myelination capacity. This figure was created using Biorender.com.