Fig. 6.

Effect of IQGAP1 depletion on OxPAPC-mediated protection against thrombin-induced EC barrier dysfunction. A: EC transfected with nonspecific RNA or IQGAP1-specific siRNA were subjected to thrombin stimulation (0.3 U/ml, 15 min) with or without OxPAPC pretreatment (10 μg/ml, 30 min). F-actin was visualized by immunofluorescence staining with Texas Red-phalloidin. Paracellular gaps are marked by arrows. Bar = 10 μm. B: bar graphs represent quantitative analysis of gap formation in control and treated HPAEC monolayers. Data are expressed as means ± SD of 3 independent experiments; *P < 0.05. C: phosphorylation of myosin light chain (p-MLC) was detected by Western blot with specific antibody. Probing for β-actin was used as a normalization control. IQGAP1 protein depletion was confirmed by Western blot.