DMF alleviates reactive astrogliosis following systemic immune challenge. a Iba1+ MG and b GFAP+ astrocytes were examined by immunohistochemistry at 2 weeks after a single-dose LPS injection. DMF was administered every other day for 3 days following LPS injection. Representative images show the hippocampus of mice from three treatment groups, saline, LPS + VEH, LPS + DMF. N = 4–5 mice/group. High magnification images of circled areas are shown at the lower panel. Quantification results of c Iba1+ MG and d GFAP+ astrocytes are shown. *p < 0.05, **p < 0.01, and ***p < 0.001 by one-way ANOVA with Bonferroni’s post hoc multiple comparison test. Scale bar, 200 μm (low magnification) or 20 μm (high magnification). e The mRNA levels of inflammatory molecules, il1a and c1qa, in the brain were quantified using qPCR. N = 7 mice/group. *p < 0.05, ***p < 0.001, by one-way ANOVA with Bonferroni’s post hoc multiple comparison test. f Enriched astrocyte cultures were stimulated with TNFα (30 ng/ml) and IL-1α (3 ng/ml) in the absence or presence of DMF. The expressions of A1 signature genes were measured at 24 h after stimulation. The mRNA levels of ggta1, h2-d1, and serping1 were quantified using qPCR. Data presented are from three independent experiments. **p < 0.01, ***p < 0.001, by one-way ANOVA with Bonferroni’s post hoc multiple comparison test.