抄録
Aerobes conduct high-level vital activities by means of energy metabolism that uses the chemical reactivity of molecular oxygen (oxidation-reduction: redox activity). Reactive oxygen species (ROS), reduced derivatives of molecular oxygen (e.g., superoxide, hydrogen peroxide), are produced during energy metabolism and infection defense processes in cells and tissues. ROS have been thought to be noxious agents that mediate oxygen toxicity (ROS toxicity theory). Several isoforms of ROS-producing enzymes, called Nox, the NADPH oxidase (and Duox), have been recognized. Expressed by many types of cells, these isoforms have not only antimicrobial actions but also other biological functions in various organisms. As a result of evolving ROS toxicology, it is now thought that ROS may play important roles in regulation of physiological cell signal transductions. In fact, in a wide variety of life science fields, the recognition of 'the physiological cell signaling functions of ROS' has greatly advanced. My talk will overview the ROS signaling occurring in mammalian systems, as a new paradigm evolving from the changing concept of ROS toxicity.
