RT Journal Article SR Electronic T1 Catalase and SOD conjugated with PECAM antibody distinctly alleviate abnormal endothelial permeability caused by exogenous ROS and vascular endothelial growth factor JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP jpet.111.180620 DO 10.1124/jpet.111.180620 A1 Jingyan Han A1 Vladimir V Shuvaev A1 Vladimir R Muzykantov YR 2011 UL http://jpet.aspetjournals.org/content/early/2011/04/07/jpet.111.180620.abstract AB Reactive oxygen species (ROS) superoxide anion (O2-.) and hydrogen peroxide (H2O2) produced by activated leukocytes and endothelial cells in sites of inflammation or ischemia cause the endothelial barrier dysfunction that may lead to tissue edema. Antioxidant enzymes (AOE) superoxide dismutase (SOD) and catalase conjugated with antibodies to platelet-endothelial cell adhesion molecule-1 (PECAM-1) specifically bind to endothelium, quench the corresponding ROS and alleviate vascular oxidative stress and inflammation. In the present work, we studied effect of anti-PECAM/catalase and anti-PECAM/SOD conjugates on the abnormal permeability manifested by TEER decline, increased FITC-dextran influx and redistribution of VE-cadherin in human umbilical vein endothelial cell (HUVEC) monolayer. Anti-PECAM/catalase protected HUVEC monolayer against H2O2-induced endothelial barrier dysfunction. PEG-conjugated catalase exerted orders of magnitude lower endothelial uptake and no protective effect, similarly to IgG-catalase. Anti-PECAM/catalase, but not anti-PECAM/SOD, alleviated endothelial hyper-permeability caused by exposure to hypoxanthine/xanthine oxidase, implicating primarily H2O2 in disruption of endothelial barrier in this model. Thrombin-induced endothelial permeability was not affected by treatment with anti-PECAM/AOE or NADPH oxidase inhibitor apocynin or over-expression of AOEs, indicating that the endogenous ROS play no key role in thrombin-mediated endothelial barrier dysfunction. In contrast, anti-PECAM/SOD, but not anti-PECAM/catalase, inhibited VEGF-induced increase in endothelial permeability, identifying a key role of endogenous O2-. in the VEGF-mediated regulation of endothelial barrier function. Therefore, AOE targeted to endothelial cells provide versatile molecular tools for testing role of specific ROS in vascular pathology and may be translated into the remedy for these ROS-induced abnormalities.