Figure 6.

AAV-BACE1 improved RPE junctional integrity and reduced microglial changes in SOD2 KD mice

RPE flat mounts were prepared 6 months after AAV1-BACE1 and stained with an anti-ZO-1 antibody as a marker of tight junctions. Immunostaining (red) was evenly distributed at the lateral borders of RPE cells in normal eyes but was diffuse and highly disorganized in SOD KD eyes (A). RPE flat-mounts demonstrated that the severe loss of ZO-1 in SOD2 KD eyes was prevented by BACE1 overexpression (A). Furthermore, anti-IBa1 immunostaining (red) in RPE flat-mounts (B) demonstrated an dramatic increase in fluorescence intensity of Iba1+ microglia 6 months after SOD2 KD that exhibited morphological characteristics of ramified and activated microglia which, following AAV-BACE1, demonstrated reduced fluorescence intensity for IBa1 microglial staining together with a lesser dendritic morphology in SOD KD animals compared with untreated SOD2 KD animals that was significant at p < 0.05, mean ± SEM, n = 5 (C).