Extended Data Fig. 2: Gas6 and PtdSer decoration of Aβ plaques.

a, Gas6 protein (green) decorates 6E10⁺ plaques (white) on sections of postmortem cortex from human patients with advanced (BRAAK stage 6) AD (left panels), but is not evident in the plaque-free cortex of cognitively normal age-matched controls (right panels). Representative images obtained from immunostaining of >3 sections from 3 individuals of each condition. b, Visualization of externalized PtdSer in 15 mo APP/PS1 cortex following stereotaxic injection of pSIVA (green, left panel). pSIVA binds to externalized PtdSer in the needle track of the injection, where cells are damaged and undergoing apoptosis, and also to the PtdSer associated with all 6E10⁺ amyloid plaques adjacent to the injection site (white, right panel). (c) A similar pSIVA injection in 15 mo WT mice labels only the needle track of the injection, since there are no plaques in these mice. (d) Airyscan super-resolution image of the juxtaposition of plaque-associated microglia (Iba1, red), Gas6 (green), and Aβ plaque (6E10, white) in 12 mo APP/PS1 mice (n = 5). Scale bars: 100 μm (a), 50 μm (b), 200 μm (c), 10 μm (d). n = 3 and 2 for APP/PS1 and WT control, respectively (b, c) from two independent experiments.