Figure 5.

Generation and characterization of apoE-fKI/Dlx-Cre mice. A, B, Expression of ZsGreen1 (green) in the cortex and hippocampus of Dlx-Cre-positive (A) and -negative (B) ZsGreen1 reporter mice. Scale bars: 250 μm. C–F, ZsGreen1 was expressed in GABA-positive (C, E) and somatostatin (SOM)-positive (D, F) inhibitory interneurons in the cortex and hippocampus of Dlx-Cre-positive apoE-fKI mice. Scale bars: 15 μm. G, H, Anti-apoE immunostaining revealed the presence of apoE protein in GABA-positive hilar interneurons in aged apoE4-fKI mice (G), but not in apoE4-fKI/Dlx-Cre mice (H). Scale bars: 15 μm. I, Images of GABA-positive hilar interneurons before and after laser capture. Inhibitory interneuron were identified by anti-GABA immunostaining. Arrows indicate the cell before and after laser capture. Scale bars: 15 μm. J, Schematic of primers and their binding sites on the human APOE gene. K, PCR with primers 1 and 2 resulted in an amplified product in samples of apoE4-fKI mice, but not in samples of apoE4-fKI/Dlx-Cre mice (left). PCR with primers 1 and 3 resulted in an amplified product in samples of apoE4-fKI/Dlx-Cre mice, but not in samples of apoE4-fKI mice (right). Fifty nuclei per sample were used. L, Representative fluorescent Western blot of apoE (green) and GAPDH (red) in cortical and hippocampal lysates of 17-month-old female mice with different genotypes. M, N, Quantification of apoE protein levels relative to GAPDH protein levels in cortical (M) and hippocampal lysates (N) of 17-month-old mice (n = 5 per genotype). For both the cortex and the hippocampus, the apoE level in apoE3-fKI mice was normalized to 1, and apoE levels in other groups of mice were presented relative to those in apoE3-fKI mice. *p < 0.05, **p < 0.01, ***p < 0.001 (t test).