Fig. 5.

SIK3-cKO inhibited excessive phagocytosis of myelin sheath and promoted normal phagocytosis of myelin debris by inhibiting Mi/MΦ pro-inflammatory heterogenization. a Representative images of Iba1/MBP immunostaining (middle panel, scale bar: 100 µm) in STR (left panel) and four typical phagocytic states (right panel, scale bar: 10 µm) 3d after tFCI. b Correlation of myelin integrity and Mi/MΦ activation/heterogenization in the penumbra of STR (0–400 µm and 400–800 µm from the damaged edge) 3d after tFCI. c Heat map of demyelination- and remyelination-related genes in the pro-, anti-inflammatory, and the transitional phenotypic Mi/MΦ. d Quantification of the percentage of “Internal phagocytosis,” “External phagocytosis,” “Enwrap,” “Touch,” and “No Touch” phagocytic states of Mi/MΦ in 0–400 µm of STR from the damaged edge 3d after tFCI. e Representative images of Iba1/MBP immunostaining (scale bar: 50 µm) of primary microglia 4 h after adding myelin debris. f 3D rendered images of Iba1/MBP immunostaining (scale bar: 20 µm) of primary microglia in WT-LPS and cKO-LPS groups 4 h after adding myelin debris. g Quantification of the percentage of MBP⁺ area versus Iba1⁺ area 4 h after adding myelin debris (8 h after LPS treatment). n = 8/group. h Heat map of “myelin debris and myelin sheath” and “myelin sheath”-related genes in the pro-, anti-inflammatory, and the transitional phenotypic Mi/MΦ. i Quantifications of the percentage of CD16⁺/CD16⁻ in 5 phagocytic types of Mi/MΦ in the area 0–400 µm from the damaged edge in the penumbra of STR 3d after tFCI. j Correlation analysis of the Anti, Transit, rest phenotypes, percentage of Iba1⁺CD16⁺ and myelin integrity with phagocytic types of Mi/MΦ in the area 0–400 µm and 400–800 µm from the damaged edge of STR 3d after tFCI. n = 4–6/group. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, as indicated. Multiple t tests and Bonferroni post hoc were used for statistical analysis