Fig. 6.

Bacterial LPS induces NADPH oxidase 2 (Nox2)-dependent superoxide production and monolayer permeability in HLMVEC in vitro. A: Western blot analysis of Nox2 expression in the presence or absence of LPS (1 μg/ml for 4 h) after siRNA incubation. B and C: Nox2-dependent superoxide production (DCF fluorescence) and permeability (basilar dextran fluorescence), respectively, in HLMVEC exposed to LPS (1 μg/ml for 4 h) in vitro in the presence or absence of Nox2 inhibition by specific peptide (Nox2ds-tat, 10 μM) or RNA silencing. Bars represent mean data from n ≥ 11 individual experiments. Statistical analysis performed by 1-way ANOVA. Permeability in Nox2-silenced cells was normalized to isolate the LPS effect, as Nox2 silencing altered baseline dextran fluorescence in vitro. The change in dextran permeability induced by LPS in Nox2-deficient cells is significantly lower than the change in control cells (*P = 0.04 by Student's t-test).