FIG 2.

TNF-α moderately increases the permeability of HBMEC monolayers. The changes in HBMEC monolayer integrity were determined using (A and C to E) xCELLigence RTCA Biosensor technology or (B) leakage of FITC-dextran in a filter assay after addition of increasing concentrations of (A and B) TNF-α, (C) IFN-γ, (D) IL-6, or (E) IL-1β. Cell index values are proportional to the monolayer integrity. Results are expressed as fold change relative to the medium control and represent the average from at least 3 independent experiments with standard deviations. Statistical significance was determined by (A) the Kruskal-Wallis test or (B) the Friedman test with Dunn’s multiple-comparison test (*, P < 0.05; **, P < 0.01; ***, P < 0.001).