Figure 1.

Human ApoE isoforms differentially modulate brain energy metabolism. A, Schematic representation of brain energy substrate uptake and generation of acetyl-CoA. Hexokinase catalyzes the conversion of glucose to glucose-6-phosphate, a “branch-point” metabolite that has alternative metabolic fates. Acetyl-CoA is a critical point of convergence of glucose and ketone body metabolism. Brain glucose and ketone body uptake are strictly controlled by their respective transporters, GLUTs, and MCTs. The figure shows the key enzymes involved in the glucose and ketone body metabolic pathways. B, Gene expression profiles on energy substrate uptake and metabolism in the cortices of 6-month-old hApoE-TR female mice. The group heat map shows the expression of genes involved in glucose and ketone body transport and metabolism for all three ApoE genotypes. n = 4 per ApoE genotype. A complete list of the 48 genes grouped according to the functional class can be found in Figure 1-1. The relative expression (FC) with the corresponding p value are indicated in Figure 1-2.