A scientific breakthrough was made in 2001 when lifespan extension induced by caloric restriction was clearly linked to the expression of sirtuins—a recently discovered family of proteins. This discovery opened new areas of investigation in the fight against aging.
The Role of Sirtuins
SIRT1 is the human homologue of Sir2, a key regulator of cell defense and survival in response to stress involved in diverse biological functions including cell development, metabolism, gene silencing, DNA repair, cell cycle progression, apoptosis, heterochromatin formation and especially longevity.1–5 Recent studies have demonstrated the role of sirtuin proteins (the Sir2 gene protein) in life extension induced by caloric restriction.6–10 These findings on the relationship between sirtuins and cell survival extension have attracted a great deal of attention by establishing a direct link between life extension and Sir2 gene expression. In order to better understand the role of sirtuins in aging and longevity, in the last few years, many studies have investigated the presence of SIRT1 in different human tissues, including human skin.