(a)
(b)
Figure 4: Redox potential controls cell fate. One of the hallmarks of aging is the increase in ROS levels production. New approaches define this increase as a compensatory cellular response with the original purpose to maintain cellular homeostasis and, from a certain limit, as a factor that aggravates aging. (a) The increase in ROS levels, first as a factor that activates survival pathways, continues to increase as a consequence of the deficiency in the antioxidant system, generating other cellular responses such as apoptosis, with a failure in apoptotic signalling, and driving towards severe cellular damage, such as necrosis. (b) Several sources of ROS contribute to the increase of redox potential, a factor that shifts the balance to the transcription of pro-inflammatory factors, while the antioxidant genes are silenced, connecting ROS and inflammation to aging.