Anethole dithiolethione regulates oxidant-induced tyrosine kinase activation in endothelial cells

Interaction between neutrophils and endothelial cells is one of the first steps in the functional response of polymorphonuclear neutrophils (PMN), and is necessary for their migration toward damaged tissues. PMN activation, leading to their adhesion to and migration between endothelial cells, is part of a complex phenomenon that can be altered in pathological situations such as the ischemia-reperfusion syndrome, in which large numbers of PMN are recruited to the tissue and release reactive oxygen species (ROS) near the vessel wall. ROS have been implicated in the pathogenesis of various inflammatory diseases. The increased adhesion of PMN to ROS-stimulated endothelial cells involves an increase in tyrosine phosphorylation of a tyrosine kinase focal adhesion kinase (p125FAK) and several cytoskeleton proteins, including paxillin and p130 cas. We examined the role of glutathione (GSH) in the regulation of this adhesion phenomenon and in the increased tyrosine phosphorylation induced by ROS. For this purpose we used anethole dithiolthione (ADT), which increases the glutathione synthesis by activating gamma-glutamyl-cysteine synthetase. We found that ADT reduced both PMN adhesion to ROS-stimulated human umbilical vein endothelial cells (HUVEC) and tyrosine phosphorylation of p125FAK and paxillin. ADT increased redox status by increasing intracellular GSH content in oxidized cells. These results show that GSH can reverse the effect of oxidation on tyrosine kinase activation and phosphorylation, and thus plays an important role in cell signaling. They also confirm the antioxidant activity of ADT.