Redox Biology and Diseases

Redox Biology explores the cellular and physiological functions of biological molecules having distinctive chemical reactivity and redox properties, in particular oxygen and derived reduced species (hydrogen peroxide or H₂O₂, the superoxide anion or O₂^–), iron and other biological redox metals, and the sulfur-containing amino acids methionine, with its S-methyl thioether side chain, and cysteine with its thiol (-SH) side chains. Due to their reactivity and redox properties, these molecules engage into redox reactions that are at the heart of multiple life-essential cellular enzymatic, metabolic and synthetic processes: energy production, DNA synthesis and repair, protein translation, protein secretion, stress protection and homeostasis, cellular signaling and biological clocks control. Cellular redox-based reactions have two general characteristics: (i) a high connective nature within each system, between these systems and with general cellular metabolism; (ii) the need for their strict cellular control due to the potential reactivity of reaction intermediates to avoid propagation of abnormal reactions that can lead to oxidative stress and cell death. In the past, these reactions were essentially considered by their enzymology and studied in vitro, and in Redox Biology they are repositioned in the context of the cell. As they pervade most if not all cellular processes, exploring these reactions in vivo requires integrated cellular approaches that consider the cell as a whole. Redox biology and its physiopathological impact is a fundamental issue in human health because deregulation underlies major diseases, mostly related to aging, such as cancers, neurodegenerative, metabolic and inflammatory diseases.