[Age-dependent oxidative stress: toward an irreversible failure in endothelial maintenance].

In order to maintain cellular homeostasis against endogenous and exogenous aggressions, different cellular mechanisms of defence, maintenance and repair are continuously activated throughout life. Hormesis, a concept based on the fact that mild stresses protect cells against subsequent stresses, amplifies the efficacy of the cellular mechanisms of defence and repair. Ageing, senescence and ultimately death, result from the exhaustion of these mechanisms maintaining cellular functions. One of the major sources of vascular endothelial damage is oxidative stress. The age-dependent shift in the redox environment towards pro-oxidation contributes to a progressive compensatory remodelling of the endothelium, an accumulation of damages, and its dysfunction, the premises for atherosclerosis. We propose that in agreement with the concept of hormesis, a moderate exposure during endothelial maturation to mild physiological oxidative stressors determines -vascular longevity.