Fig. 6

Opposing effects of apoE2 and apoE4 on lipid droplet accumulation in the microglia of apoE-TR mice upon cuprizone-induced demyelination (A Heat map showing transcriptional changes (CPZ vs CTL groups) of selected genes associated with lipid metabolism identified from RNA-Sequencing. The scaled expression value (row Z score) is shown with a blue-red color scheme, denoting red as higher expression, and blue as lower expression. B Brain samples from CPZ-treated apoE-TR mice (n = 12–13/genotype) were subjected to immunofluorescence staining for Plin2 (for lipid droplets) and Iba1 (for microglia). Representative images of Plin2⁺ (Red) Iba1⁺ (Green) microglia in the CC region of apoE-TR mice treated with CPZ. Blue, DAPI. Scale bar, 15 µm. C Zoomed-in images for accumulated Plin2⁺ lipid droplets in microglia with different apoE genotypes. Scale bar, 10 µm. D The percentage of Plin2⁺ and Iba1⁺ microglia in the CC region of experimental mice were quantified. Values are mean ± SEM. One-way ANOVA. ** P < 0.01. E–F The expression of genes involved in microglial lipid metabolism (Lpl and Apoc1) was examined by real-time PCR. n = 5–6 mice per group. Values are mean ± SEM. Two-way ANOVA. ** P < 0.01. N.S., not significant