Fig. 1
sTREM2 reduces amyloid plaque deposition and increases the number of plaque-associated microglia. a The 5×FAD mice at 7-month-old age were injected with vehicle (PBS) in the left hemisphere and 6 μg of sTREM2 protein in the right hemisphere. b Coronal sections of vehicle- or sTREM2-injected 5×FAD mice were stained with DAPI (blue) for nuclei and MOAB-2 (green) for Aβ. Representative z-stack images of the hippocampus regions are shown. Original magnification ×20; scale bar, 100 μm. c Quantitation of amyloid plaque deposition in b (n = 6 mice, 28 fields of each group for analysis, paired Student’s t test). d Quantitation of the number of plaques with different sizes in b (n = 6 mice, 28 fields of each group for analysis, paired Student’s t test). e Coronal sections from sTREM2-injected 5×FAD mice were stained with DAPI (blue) for nuclei, MOAB-2 (green) for Aβ, and Iba1 (red) for microglia. Representative z-stack images of the hippocampus regions are shown. Scale bar, 25 μm. f Quantitation of the number of plaque-associated microglia in e (n = 4 mice, 58 plaques of vehicle and 41 plaques of sTREM2 for analysis, paired Student’s t test). Plaques with 50 μm in diameter were selected for analysis. g Coronal sections from sTREM2-injected 5×FAD mice were stained with DAPI (blue) for nuclei, MOAB-2 (green) for Aβ, Iba1 (red) for microglia, and Lamp1 (white) for dystrophic neurites. Representative z-stack images of the hippocampus regions are shown. Original magnification ×20; scale bar, 100 μm. Zoom-in images on the right with a scale bar equal to 25 μm. h Quantitation of the total area of Lamp1-positive dystrophic neurites in g (n = 6 mice, 20 fields of each group for analysis, paired Student’s t test). i Quantitation of the area of Lamp1-positive dystrophic neurites within each plaque in g (n = 6 mice, 40 plaques of vehicle and 41 plaques of sTREM2 for analysis, paired Student’s t test). All data are presented as mean ± SEM. *p < 0.05; **p < 0.01; ****p < 0.0001; ns, not significant
