Figure 3. The accumulation of IBA-1 positive cells on the RPE flat mounts and beneath the RPE/BrM interface complex in aged APP/PS1 mice.

A, D, G, J and B, E, H, K, L came from NTG and APP/PS1 mice respectively. Confocal immunofluorescence images depicting IBA-1 (red) and ZO-1 (green) that were detected on RPE flat mounts obtained from NTG (A) and APP/PS1 mice (B). The depicted histogram showed an increase in IBA-1 positive cells on RPE flat mounts, but with no statistical significance (C, P=0.2575). D, E demonstrated the IBA-1 positive cells beneath the RPE layer elucidated in the Z-stack (triangle), and the green/red line indicated the Z-stack scanning surface (D, E). The graph in F revealed an increase in IBA-1-positive cells beneath the RPE layer. Transmission electron micrograph of the RPE/BrM interface came from NTG (G) and APP/PS1 mice (H). Some cells can be observed (triangle), the thickened BrM was indicated with a double-headed arrow; I: The thickness of the BrM in APP/PS1 mice was greater than that in NTG mice; J, K: The images were overlaid with L at a higher magnifications of K (in rectangle), indicating IBA-1 positive cells co-stained with Aβ deposition (A-B_1-2, D-E_1-2, J-K_1-2). Separate channels for each staining. RPE: Retinal pigment epithelium; BrM: Bruch membrane. Error bars=Means±SEM; Scale bars=20 µm (A-E, J-L), 1 µm (G, H). ^aP<0.001.