VEGFR2 Mediates Endothelial Permeability by OxPAPC Figure 1. Dose dependent effects of OxPAPC on transendothelial electrical resistance of human pulmonary artery and aortic endothelial cells. A - Human pulmonary artery endothelial cells (HPAEC); and B - human aorta endothelial cells (HAEC) were seeded in polycarbonate wells with gold microelectrodes. After 24 hr of culture, HPAEC were stimulated with various OxPAPC concentrations (5, 10, 25, 50 and 100 mg/ml) or vehicle at the time indicated by arrow, and measurements of transendothelial electrical resistance (TER) were monitored over 4 hrs using an electrical cell-substrate impedance sensing system (ECIS). Results are representative of five independent experiments. doi:10.1371/journal.pone.0030957.g001 and a maximum response by 1 hour (Figure 5A). Of note, OxPAPC at barrier protective concentration (10 mg/ml) did not induce MYPT or MLC phosphorylation. To further verify the involvement of Rho signaling in stress fiber formation induced by high OxPAPC doses, we pretreated HAEC with Rho Kinase inhibitor Y-27632 prior to OxPAPC treatment. Inhibition of Rho PLoS ONE | www.plosone.org 3 January 2012 | Volume 7 | Issue 1 | e30957