FIG 9.

Effects of IL-1α alone on BBB permeability and tight junction integrity. Four-week-old Axl^−/− mice received an i.p. injection of recombinant mouse IL-1α (200 ng per mouse) or vehicle (sterile normal saline). At 6 h posttreatment, BBB permeability was gauged by an EB leakage test, and brain tight junction proteins were observed by IF staining. (A) Representative image showing EB leakage into brain parenchyma. (B) BBB permeability change after IL-1α treatment; n = 5, and the data were compared by unpaired t test. (C) mRNA abundance of claudin-5, occludin, and ZO-1 in mouse brains after IL-1α treatment, normalized to the average of vehicle-treated mice; n = 5, and the data were compared by unpaired t test. (D) IF staining of claudin-5, occludin, and ZO-1 (red); CD31 (microvascular endothelial cell marker, green); and DAPI (nucleus, blue); scale bar = 20 μm. (E) Quantification of the IF staining intensity of claudin-5, occludin, and ZO-1; n = 5 for each group, and the data were compared by unpaired t test. All the data are expressed as the means ± SEM; *, P < 0.05; **, P < 0.01; each result is the representative of three independent experiments.