Fig. 4.

Effects of DAPPD toward the microglial phagocytosis of Aβ and the expression of NLRP3 inflammasome-related proteins mediated by the NF-κB or cathepsin B pathways. (A) Immunostaining images of the colocalization of microglia (Iba1, red) with Aβ aggregates (6E10, green) and quantification of Aβ positive cells and microglia. (Scale bars, 10 μm.) (B) Immunofluorescence images of Aβ aggregates (6E10, green) encapsulated within phagolysosomes (Lamp1, blue) in microglia (Iba1, red) from the brains of vehicle- or DAPPD-treated APP/PS1 mice. Quantification of the microglial volume occupied by Lamp1⁺ phagolysosomes, percentage of the microglia containing Aβ-loaded phagolysosome, and Aβ encapsulated in phagolysosomes. (Low magnification: scale bars, 10 μm; high magnification: scale bars, 10 μm.) (C) Morphology of microglia (Iba1, red) surrounded by Aβ (6E10, green) in the cortices of vehicle- or DAPPD-treated APP/PS1 mice. (Scale bars, 10 μm.) Three-dimensional reconstruction from confocal image stacks. (D) Morphometric analysis of Aβ plaques in vehicle- or DAPPD-treated APP/PS1 mice. (E and F) Effects of DAPPD on the expression of the proteins related to NLRP3 inflammasome, NF-κB signaling, and cathepsin B in the cortices of WT and APP/PS1 mice. Animal number: A–F, n = 4 per group. Three-dimensional reconstruction from confocal image stacks for A–C. *P < 0.05; **P < 0.01 by one-way analysis of variance, Tukey’s post hoc test. All error bars indicate SEM.