Fig. 4: Increased astrocyte reactivity in FGF21^−/− mice after stroke.

a Representative images of astrocytes immunostaining (GFAP, red; Hoechst, blue) in the perifocal cortex of WT and FGF21^−/− mice that were taken at days 3 and 14 after tMCAO. Scale bar=500 μm or 250 μm. b Quantitative assessment of the relative area of cells positive for GFAP in the indicated region of WT and FGF21^−/− mice. n = 6/group. ^*P < 0.05, ^****P < 0.0001, determined by 2way-ANOVA with Sidak’s multiple comparison. c Representative FACS plots and gate strategy of GFAP⁺ astrocyte in the ipsilesional and contralesional hemisphere of FGF21^−/− and WT mice at 3 d after tMCAO. ^*P < 0.05, ^****P < 0.0001, determined by 2way-ANOVA with Tukey’s multiple comparison. Results are presented as mean ± SD. d Astrocytes from the brain were isolated by MACS, and the purity of was verified by FACS analysis. e, g Representative Gene Ontology (GO) enrichment analysis of upregulated e and downregulated g genes expressed in astrocytes obtained from the ipsilesional brain of FGF21^−/− mice versus WT mice. f, h Heatmap showing the upregulated genes categorized in immune response f, and downregulated genes correlated with neuronal functions h. i RNA-sequencing data revealed the expression of PAN-reactive, A1- and A2-specific genes in the sorted astrocytes in the ipsilesional hemisphere of WT and FGF21^−/− mice at 3 d after tMCAO. q Value < 0.05, and Fold change > 2, for FGF21^−/− vs. WT group.