VEGFR2 Mediates Endothelial Permeability by OxPAPC Figure 4. Effect of VEGFR2 depletion on actin remodeling in pulmonary EC exposed to high OxPAPC concentration. HPAECs were transfected with VEGFR2-specific siRNA. Control cells were treated with non-specific RNA. A - After 72 hrs of transfection cells were stimulated with OxPAPC (75 mg/ml, 120 min) or vehicle followed by immunofluorescence staining for F-actin. Paracellular gaps are marked by arrows. Insets depict higher magnification images of cell boundaries showing increased gap formation in Ox-PAPC challenged EC treated with nsRNA, which was dramatically reduced in EC treated with VEGFR2 siRNA. B - Quantitative analysis of gap formation in OxPAPC treated HPAEC transfected with nsRNA PLoS ONE | www.plosone.org 6 January 2012 | Volume 7 | Issue 1 | e30957