Oxidant signaling in vascular cell growth, death, and survival - A review of the roles of reactive oxygen species in smooth muscle and endothelial cell mitogenic and apoptotic signaling

Reactive oxygen species (ROS) have been traditionally regarded as toxic byp roducts of aerobic metabolism. However, ROS can also act as intracellular s ignaling molecules in vascular cells. ROS can mediate phenotypes in vascula r endothelial and smooth muscle cells that may be considered both physiolog ical and pathophysiological. Among these are growth, apoptosis, and surviva l. The specific response elicited by reactive oxygen intermediaries is dete rmined by their specific intracellular target(s). This, in turn, is depende nt on the species of oxidant(s) produced, the source and therefore subcellu lar localization of the oxidant(s), the kinetics of production, and the qua ntities produced. A fuller understanding of how ROS regulate mitogenesis an d apoptosis in vascular smooth muscle and endothelial cells will permit the development of novel strategies to modify or prevent vascular diseases in which these phenotypes predominate.