Sirtuins in Adipose Tissue Metabolism

Obesity, a complex metabolic disorder linked to the development of several diseases, is characterized by both hypertrophy and hyperplasia of adipocytes. While white adipose tissue (WAT) is an energy storage site, brown adipose tissue (BAT) activation generates heat from nutrients by non-shivering thermogenesis. The human orthologue of silencing information regulator 2 (Sir2) which was recognized as a regulator of life span in S. cerevisiae, includes seven sirtuins which are NAD+-dependent protein deacetylases distributed in different subcellular compartments. Sirtuins, particularly Sirt1, have emerged as important nutrient sensors and regulators of metabolism. Sirt1 has been shown to play a role in retarding the expansion of WAT while stimulating both differentiation and activation of brown adipose tissue as well as browning of WAT. This chapter focuses on the role of sirtuins in adipose tissue biology, their implications in obesity and potential as therapeutic targets.