Amifostine reduces lung vascular permeability via suppression of inflammatory signaling

¹ Section of Pulmonary and Critical Care Medicine, Dept of Medicine, University of Chicago, Chicago, Illinois 60637
² Dept of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois 60637

^* To whom correspondence should be addressed. E-mail: kbirukov{at}medicine.bsd.uchicago.edu.

	Abstract

Despite encouraging outcome of antioxidant therapy in animal models of acute lung injury, effective antioxidant agents for clinical application remain to be developed. We studied the effect of pretreatment with thiol antioxidant compound, amifostine, on lung endothelial barrier dysfunction induced by gram-negative bacteria wall lipopolysaccharide.

Endothelial permeability was monitored by changes in transendothelial electrical resistance. Cytoskeletal remodeling and reactive oxygen species production was examined by immunofluorescence. Cell signaling was assessed by western blot. Measurements of Evans blue extravasation, cell count and protein content in bronchoalveolar lavage fluid were used as in vivo parameters of lung vascular permeability.

Hydrogen peroxide, lipopolysaccharide, and interleukin-6 caused cytoskeletal reorganization and increased permeability in the pulmonary endothelial cells reflecting endothelial barrier dysfunction. These disruptive effects were inhibited by pretreatment with amifostine and linked to the amifostine-mediated abrogation of ROS production and redox-sensitive signaling cascades including p38, Erk1/2 MAP kinases, and NFB pathway. In vivo, concurrent amifostine administration inhibited LPS-induced oxidative stress and p38 MAP kinase activation, which was associated with reduced vascular leak and neutrophil recruitment to the lungs.

These studies demonstrate for the first time protective effects of amifostine against lipopolysaccharide-induced lung vascular leak in vitro and in animal models of LPS-induced acute lung injury.