Alteration of selenoprotein expression during stress and in aging
Résumé
Selenium (Se) is an essential trace element implicated in many facets of human health and disease. Most of its beneficial effects are attributed to its presence as selenocysteine in a small, but vital group of proteins, namely the selenoproteins. They are implicated in antioxidant defense, redox homeostasis, redox signaling and possibly other cellular processes. The selenoproteome is primarily controlled by Se bioavailability that induces prioritization of protein biosynthesis, when this trace element is deficient. The hierarchical regulation of the selenoproteome by other exogenous stimuli, cellular stressors or pathophysiological conditions is poorly understood. Understanding biological causes of aging also remains challenging, although several theories and concepts have emerged in the past decades. Characterization of biomarkers of aging is controversial even with the impressive amount of ‘omic’ analyses performed in many living organisms. Accumulation of age-related damage, including oxidative-induced cellular damage, and the decreasing efficiency in elimination and repair systems have been extensively reported, being either a cause or consequence of the aging phenomenon. In this regard, and given the role of Se in redox biology of organisms, studying regulation of the selenoproteome in response to oxidative stress and aging is essential. This chapter reviews the current knowledge in this area.