Evaluating real time intracellular redox toxicology using live-cell imaging approaches

Intracellular oxidative stress is a common mechanism of cellular dysregulation as a result of supraphysiological levels of reactive oxygen species (ROS). Imbalances in redox homeostasis underly adverse responses arising from exposure to a wide variety of xenobiotics and environmental exposures. Observing oxidative cellular events in real time poses multiple analytical challenges, requiring sensitive and specific methodologies that are capable of detecting transient events with high spatiotemporal resolution. We review here the advantages that live-cell imaging offers as a non-destructive approach that is well suited for redox toxicology studies. The effectiveness of this approach is heavily reliant on the use of fluorescent redox sensitive probes, such as small molecule and genetically encoded sensors that report on specific ROS and redox couples. We discuss a variety of small molecule and genetically encoded sensors that are used in redox toxicology, as well as the caveats and limitations posed by their use.