A, Network showing the gene expression change in human
Alzheimer’s disease (AD) and Inpp5d knockdown mice
within the neighborhood of four steps of INPP5D. Node border
paint denotes the log2 fold-change (lfc) in human AD brains compared
to control brains. Node fill paint denotes the log2 fold-change
caused by Inpp5d in mice, with gray color denoting absence in
mouse data. B, Highlight of specific nodes from network in (A). Genes associated
with each node were enriched in cluster 26 from
PSAPP/Inpp5dfl/fl/Cx3xr1CreER+
(PSAPP)-tamoxifen (TAM) compared to PSAPP-corn oil (CO) mice (violin plots,
middle, P-values from unpaired t test) and can
be spatially resolved by probing for this module in spatial transcriptomic brain
sections (right). C, Violin plots of Cst7 in Cluster 26 across
PSAPP-CO and PSAPP-TAM shows increased expression in PSAPP-TAM plaque spots as
calculated with edgeR on sum of counts using
muscat. D, Cluster 26 marker gene Cst7
highlighted in wild-type (WT)-CO, WT-TAM, PSAPP-CO, and PSAPP-TAM brain
sections. E, RNAScope of Cst7 (red) and Aif1
(green) with Methoxy-XO4 (blue) staining in PSAPP-CO and PSAPP-TAM mouse cortex.
Scale bar = 100 μm. F, Left: Percentage expression of
the top Cluster 26 enriched genes in Cluster 26 (outer ring) versus the average
percentage expression in all other clusters (inner ring). Right: FeaturePlots
showing expression of Cst7 in all spots across WT-CO, WT-TAM,
PSAPP-CO, and PSAPP-TAM brain sections. G, CST7 antibody staining detected with
DAB and 6E10 in adjacent section from WT-CO, WT-TAM, PSAPP-CO, and PSAPP-TAM
hippocampus. Scale bar = 500 μm. H, Representative
images of latex bead phagocytosis assay on Inpp5d-WT mouse
primary microglia and Inpp5d-knockout (KO) primary microglia
with quantification of percentage IBA1+ cells with phagocytosed
fluorescent bead (right). Scale bar = 100 μm.
Quantification was performed from three to four wells per group; with
N = 3 independent experiments. Data points represent mean
normalized to Inpp5d-WT per experiment.
P-values calculated with unpaired t test.