Fig. 3

Activation of the NF-kB pathway in reactive white matter astrocytes during chronic hypoperfusion. a Reactive GFAP-positive astrocytes (green) in the corpus callosum of mice subjected to BCAS are positive for the active p65 (RelA) subunit of NF-kB (red). p65 was localised to astroglial nuclei (arrows), indicated by co-localisation with the nuclear marker Hoechst 33258 (blue). b Astrocytes were rarely positive for p65 in sham-treated mice, and the signal was diffuse and localised to the cytosol (arrowheads), indicating non-activity. c Biochemical determination of NF-kB activity in brain homogenates showed strong activation of the NF-kB pathway in wildtype mice subjected to BCAS but not in GFAP-IkBα-dn mice subjected to BCAS or sham-treated wildtype mice (n = 6 for each group; Kruskal-Wallis test followed by Dunn’s multiple comparisons test). d Within the corpus callosum of GFAP-IkBα-dn mice subjected to BCAS, immunohistochemistry for active p65 was also negative. Scale bars, 100 μm. Insets in A-B correspond to dashed squares and are 80 μm in width. Yellow dashed lines indicate location of the corpus callosum