Fig. 8
From: Reactive astrocytes function as phagocytes after brain ischemia via ABCA1-mediated pathway
ABCA1 mediates astrocytic phagocytosis in vivo. a, b Serial electron microscopic images were acquired from the ischemic penumbra of control and ABCA1-cKO (cKO) mice, and three-dimensionally reconstructed (7 days after MCAO). Ischemic penumbra of control contains extracellular debris (a, green, arrows), and astrocyte processes (a, b, left, blue) with glycogen granules (a, asterisks) include cellular debris (a, b, red, arrowheads). By contrast, ischemic penumbra of cKO contains numerous extracellular debris (a, green, arrows), but the astrocyte processes (a, b, yellow) rarely contains debris. Bars: 1 μm a or 2 μm b. c, d Dot plots c and scatter plots d of debris densities (number/volume (µm3)) in astrocytes in control (blue) and cKO (red) mice (n = 12, 11 cells, three, four mice, respectively. ***P < 0.001 vs. control, Mann–Whitney U-test). e Dot plots show extracellular debris densities (%: volume/volume). The % volume occupied by extracellular debris tended to be higher in cKO, although the difference was not significant because of a large variance (n = 19, 22 regions, three, four mice, respectively. Mann–Whitney U-test). f Small debris densities in microglia are shown in a dot plot (n = 7 cells, three, four mice, respectively. Mann–Whitney U-test). These data excluded that microglia engulfed large cellular debris (maximum Feret diameter > 4 µm; control = 3, cKO = 3 cells). g Dot plots replotted from c and f show small debris densities in astrocytes and microglia in control mice (n = 12, 7 cells, three mice each. Mann–Whitney U-test)
