Fig. 5

AIBP deficiency triggers ER swelling in activated microglia. (A, D, G) A representative SBEM image plane from female WT microglial cell showing a typical ER structure (A). Images for cross-section (D) and 3D rendering (G) of thin ER cisternae in WT microglia. (B, E, H) Activated microglia phenotype and dystrophic neurites (arrows) in female APP/PS1 mice, showing no evidence of the dilation in ER cisternae. (C, F, I) Swollen ER cisternae morphology in microglia from female Apoa1bp^−/− APP/PS1 mice. Note that ER dilation was profound near the amyloid plague (arrows). (J) Quantification of the ER width in female WT, APP/PS1, and Apoa1bp^−/− APP/PS1 microglia; violin plot (n = 250–259 per group; lumen width was measured for 68–96 ER segments per microglial cell; 3 microglial cells from 2 mouse brains per group). Mean ± SEM. One-way ANOVA with Tukey’s multiple comparisons test. Scale bar, 1 μm