Effect of increased Rac1 activity on TNF-α-induced hyperpermeability of the primary RPMVEC monolayer.

<p>A: Effect on TER of the primary RPMVEC monolayer. Compared with controls, TER of primary RPMVEC monolayer challenged with TNF-α for 2 hours decreased significantly. Pretreatment of the primary RPMVEC with O-Me-cAMP (1 hour) significantly augmented TER and prevented TNF-α-induced the drop of TER. B: Effect on flux of FITC-BSA across the primary RPMVEC monolayer. Compared with untreated cells, the RPMVECs treated with TNF-α for 2 h had higher levels of FITC-BSA flux, whereas O-Me-cAMP treatment alone resulted in decrease FITC-BSA flux. Co-treatment with O-Me-cAMP and TNF-α [i.e., O-Me-cAMP +TNF-α] did not lead to increased endothelial permeability. Each bar represents mean ±SD of four independent trials; * denote <i>P</i><0.05, ** denote <i>P</i><0.01, *** denote <i>P</i><0.001.