Figure 3

Exposure of Caco-2 cells to PM causes oxidant-dependent NF-κB activation and increased permeability. (A) NF-κB activation was measured in Caco-2 cells treated with vehicle (PBS) or different doses of PM in the absence or the presence of the combined superoxide dismutase and catalase mimetic, EUK -134 (20 μM). NF-κB activation was presented as % activation compared to H₂O₂ (positive control). To evaluate the permeability of the Caco-2 monolayer, cells were treated with either vehicle (media) or different concentrations of PM and (B) transepithelial electrical resistance (TEER) was measured over time. (C) TEER values compared to control (as percent control) at 2 hours are shown. (D) We also measured the apparent permeability co-efficient (Papp) of fluorescein sulfonic acid (FSA) in the apical to basolateral direction across the Caco-2 cells. (E) Percent change in Papp values at 2 hours is shown. (P < 0.05 *PM compared with PBS, **EUK-134 compared with vehicle, n ≥ 4).