Fig. 5

APOE4 mice exhibit impaired closure of the BBB and delayed pericyte recovery after TBI. (a) APOE3 and APOE4 mice were subject to TBI, before BBB permeability in the ipsilateral cortex analyzed at 3 and 10 days post-injury using Evans Blue extravasation (n = 5, ***p < 0.001, *p < 0.05 vs genotype sham, ^^^p < 0.001 vs APOE3 day 3). (b) APOE mRNA expression in isolated microvessels (n = 4–6, *p < 0.05 vs genotype sham; ⁺p < 0.05 vs relevant timepoint). (c) Western blot and densitometry analysis of PDGFRβ expression in the ipsilateral cortex of APOE3 and APOE4 mice following TBI (n = 4, *p < 0.05 vs genotype sham; ⁺⁺p < 0.01 vs relevant timepoint). (d-e) Immunohistochemistry displaying reduced PDGFRβ expression in the ipsilateral cortex of APOE4 compared with APOE3 mice at 7-days post-TBI. Scale bar: 200 μm. (n = 4 per genotype, **p < 0.01). (f) Pdgfrβ mRNA expression in microvessels isolated from ipsilateral cortex of APOE3 and APOE4 mice after TBI (n = 4–6, **p < 0.01, *p < 0.05 vs genotype sham; ⁺⁺⁺⁺p < 0.0001, ⁺p < 0.05 vs relevant timepoint). Data expressed as mean ± S.E.M. Two-way ANOVA with Bonferroni post-hoc test