Fig. 2: Engulfment of myelin debris by reactive astrocytes in vivo and in vitro.
From: Astrocytic phagocytosis contributes to demyelination after focal cortical ischemia in mice
A Histological analysis of the internalization of myelin debris (MBP, green) by GFAP+ (red) astrocytes (white arrows). Myelin debris were located in lysosomes (LAMP1, cyan). Scale bar, 20 μm. B Representative images of myelin debris (dMBP, green) and lysosomes (LAMP1, cyan) co-positive hypertrophic astrocytes (GFAP+, red; white arrows) in the ipsilateral CC after dMCAO. Scale bar, 20 μm. C Quantitative analysis for engulfment of myelin debris by hypertrophic astrocytes in sham and dMCAO mice (n = 5 mice; mean ± S.D.; ***P < 0.001 vs. sham; paired t-test). D Representative EM images of astrocytic phagocytosis in sham and dMCAO groups. Left, the image of an astrocyte in intact CC; Middle, the image of an astrocyte in the ipsilateral CC 7 days after stroke; Right, high-magnification image shown in the middle panel (N nucleus, M mitochondria, in phagocytic inclusion). Red arrows indicated phagocytic inclusions with myelin-like structures. Scale bar, 2 μm. E Representative images displaying the engulfment of CFSE-labeled myelin debris (green) by LPS-induced astrocytes (GFAP-positive, gray) after exposure to myelin debris, lysosomes (LysoTracker Red dye, red) containing engulfed myelin debris (n = 5 independent primary cell cultures). Scale bar, 20 μm. F ELISA detection of intracellular MBP in primary astrocytes treated with or without LPS before exposure to myelin debris (n = 5 independent primary cell cultures; mean ± S.D.; ***P < 0.001 vs. Ctrl; ###P < 0.001 vs. myelin; one-way ANOVA, Tukey post hoc test). G, H Flow cytometry and quantitative analysis of the percentage of astrocytes with CFSE-labeled myelin debris in different groups (n = 5 independent primary cell cultures; mean ± S.D.; *P < 0.05, ***P < 0.001 vs. Ctrl; ###P < 0.001 vs. myelin; one-way ANOVA, Tukey post hoc test). In the box plots (F, H), the middle bar represents the median, the box represents the interquartile range, and whiskers indicate the maximum and minimum values. Dots are all the data points including outliers. Source data are provided as a Source Data file.
