Figure 5

Effect of human cytokines on HBMEC-3 mono-culture barrier and HBMEC-3/HFA co-culture barrier. a) Effect of human cytokines (TNF-α (20 ng/ml), IL-1β (20 ng/ml) and IFN-γ (1000 U/ml)) applied to apical + basal sides of human brain endothelial (HBMEC-3) mono-cultures. Resistance was recorded daily. No significant difference in the resistance of cytokine treated HBMEC-3 barrier to that of untreated HBMEC-3 barrier was noted in this experiment. Bars indicate standard error. Repeated measured ANOVA with Dunnett's post-hoc test. *p < 0.05 was considered to be statistically significant, **p < 0.01 very significant, and ***p < 0.001 highly significant. b) Effect of human cytokines (TNF-α (20 ng/ml), IL-1β (20 ng/ml) and IFN-γ (1000 U/ml)) on HBMEC-3/HFA co-culture barrier. Human cytokines were added to both apical and basal sides of the co-culture system and TEER recorded daily. Co-cultures treated with cytokines showed slightly lesser barrier integrity than untreated controls. The rank order of this experiment is Con> IL-1β ≈TNF-α> IFN-γ *p < 0.05 was considered to be statistically significant, **p < 0.01 very significant, and ***p < 0.001 highly significant. c) Effect of human cytokines (TNF-α (20 ng/ml), IL-1β (20 ng/ml) and IFN-γ (1000 U/ml)) on HCMEC-D3 metabolism. TNF-α (20 ng/ml), IL-1β (20 ng/ml) and IFN-γ (1000 U/ml)) significantly decreased mouse brain endothelial cell metabolism by 3 d.