Sirtuin (SIRT)-1: At the crossroads of puberty and metabolism

In the arcuate nucleus of the hypothalamus reside two neuronal systems in charge of regulating feeding control and reproductive development. The melanocortin system responds to metabolic fluctuations adjusting food intake, whereas kisspeptin neurons are in charge of the excitatory control of gonadotropin hormone–releasing hormone (GnRH) neurons. While it is known that the melanocortin system regulates GnRH neuronal activity, it was recently demonstrated that kisspeptin neurons not only innervate melanocortin neurons but also play an active role in the control of metabolism. These two neuronal systems are intricately interconnected forming loops of stimulation and inhibition according to metabolic status. Furthermore, intracellular and epigenetic pathways respond to external environmental signals by changing DNA conformation and gene expression. Here, we review the role of silent mating type information regulation 2 homolog 1, a class III nicotinamide adenine dinucleotide–dependent protein deacetylase, in the arcuate nucleus control of pubertal development and feeding behavior.