Fig. 8

Conditioned media from Aβ-treated SREBF2 neurons inhibit phagocytosis in activated and cholesterol-enrichment microglia. Conditioned media were obtained from WT and SREBF2 primary neuronal cultures treated with Aβ (1 μM, 48 h). SIM-A9 cells were cholesterol-enriched with the CHO:MCD complex for 1 h and after 4-h recovery were primed with LPS (10 μg/ml) plus MDP (10 μg/ml) (L + M) for 16 h or Aβ (10 μM) for 24 h before exposure to conditioned media for 16 h. HiLyte Fluor 488-labeled Aβ (1 μM) was added for 4 h to evaluate phagocytosis by confocal microcopy. Shown are representative confocal micrographs from 2 independent experiments. Cells were counterstained with CellMask (cytosol/plasma membrane, red). Images from the green channel corresponding to fluorescent-labeled Aβ are shown in black and white. Scale bars: 15 μm. Plots represent Aβ phagocytosed per cell, quantified as the corrected total cell fluorescence (CTCF) of the green channel (n = 5 non-overlapping images). One-way ANOVA followed by the Tukey–Kramer test was applied to calculate statistical significance (*P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001)