Extended Data Fig. 4: Oligodendrocytes acquire an Aβ-dependent signature and do not cluster around plaques in the 5XFAD model.

a, Box plots showing average gene expression across oligodendrocyte nuclei isolated from each mouse in the 7-month-old cohort. Floating bars show the min and max and black line shows the mean. Each dot represents one mouse. n = 3 biologically independent mice per genotype. b, Violin plots showing expression of C4b, Serpina3n and H2-D1 in all oligodendrocytes from the 15-month-old cohort. Violin plots are presented with floating boxes showing median (middle line) and quartiles (top and bottom). Minima and maxima are shown as the bottom and top of the violin plots. n = 617 WT, 298 Trem2^–/–, 160 WT 5XFAD and 308 Trem2^–/– 5XFAD oligodendrocytes, pooled from 3 mouse brains per genotype. c, RT–qPCR from human oligodendrocyte cell line (HOG) treated with Aβ oligomers or fibrils at the indicated concentrations for 18 h showing Aβ directly induces C4. n = 3 biologically independent cell cultures. d, RT–qPCR from HOG treated with soluble factors (GPNMB or alpha-2-macroglobulin) for 24 h or a cocktail of cytokines (IL-1β, IL-6, TNF-α, IFN-α, IFN-γ) for 8 h showing induced C4. n = 3 biologically independent cell cultures. e, Representative immunofluorescence images of Olig2 and plaque staining in 5-month-old WT 5XFAD and Trem2^–/– 5XFAD cortices. n = 6 mice per genotype. Scale bar, 50 μm. f, Quantification of density of Olig2⁺ nuclei within 15 μm or 30 μm shell around plaque surfaces in the cortex in e, n = 6 mice per genotype. g, Quantification of total number of CA2⁺ oligodendrocytes in all 4 genotypes at 7 months of age. n = 3 mice per genotype. h, Representative immunofluorescence images of Serpina3n staining in 7-month-old mice of all genotypes showing colocalization of Serpina3n with oligodendrocyte marker CA2. White arrow heads indicate colocalization. n = 3 mice per genotype. Scale bar, 15 μm. i, Automated quantification of Serpina3n intensity in CA2⁺ oligodendrocytes in h. n = 3 mice per genotype. j, Representative confocal images showing colocalization of Serpina3n with GFAP⁺ astrocytes in 15-month-old 5XFAD mice. n = 3 mice per genotype. CC, corpus callosum. Scale bar, 50 μm. Inset, enlarged image detail. k, Representative confocal images showing colocalization of Serpina3n with X04⁺ plaques in 15-month-old 5XFAD mice. IV, V and VI indicate corresponding cortical layers. n = 3 mice per genotype. Scale bar, 60 μm. l, Thioflavin T fluorescence of Aβ42 aggregation with the addition of combinations of proteins at indicated concentrations in microplate shaking assay. n = 5 independent wells for the aggregation reactions; data represent two independent experiments. P value by one-way ANOVA, Tukey’s multiple comparisons test (a,g,i) or unpaired t-test, two-tailed (c). All data are presented as mean ± s.e.m.