ENZYMATIC SYSTEM OF PROTECTION AGAINST OXIDATIVE STRESS

Sirtuin genes are reported to act as sensors that detect the availability of cellular energy, leading to metabolic benefits, as calorie restriction prolongs life expectancy in organisms ranging from yeast to mammals. It has been shown that the mammalian orthologue Sir2, SIRT1 (sirtuin 1), activates a critical component of calorie restriction in mammals, that is, fat mobilization in white adipocytes. Recent studies suggest a key role of mammalian SIRT1 in an adequate cellular response to metabolic stress, such as nutrient deficiency or overload, and that SIRT1 and its activators play a role in protecting against the harmful effects of metabolic stressors