Redox Status and Bioenergetics Liaison in Cancer and Neurodegeneration

During the last decades, the involvement of redox reactions in each aspect of cellular physiology has emerged, rapidly steadied, and is currently assuming extensive connotations. From a mere pathological condition leading to widespread biomolecules damage and cell degeneration, (over)production of reactive oxygen and nitrogen species (ROS and RNS, resp.) is now also deemed to be among the early upstream events of signal transduction pathways governing cellular response. It is now well established that the thiol moiety of reactive cysteines is the main molecular switch selected by the evolution to transduce a redox signal. Even at physiological pH, the sulfhydryl group of these residues is present under thiolate form and primed to be modified by ROS and RNS in a reversible manner. S-nitrosylation, S-hydroxylation, and S-glutathionylation are, indeed, all oxidations that meet the conditions of specificity and reversibility required for a chemical modification (signal) being transduced in a biological event (response).