Cellular Stress Responses: Cell Survival and Cell Death

Figure 4

Oxidative stress and cell death. There is a plethora of stimuli that can trigger the generation of reactive oxygen species (ROS), among them irradiation, toxins, and also normal metabolic processes. A range of different ROS species have been identified, which are kept in check by antioxidant defenses. These include several detoxifying enzymes, for example, catalase, GSH peroxidase, and superoxide dismutase (SOD). If these antioxidants defense mechanisms are too weak, ROS-mediated damage to cellular macromolecules will eventually lead to cell death.