Mitochondrial UCP2 in the central regulation of metabolism.

Uncoupling protein 2 (UCP2) is a mitochondrial anion carrier protein, which uncouples the oxidative phosphorylation from ATP production by dissipating the proton gradient generated across the mitochondrial inner membrane. UCP2 regulates not only mitochondrial ATP production, but also the generation of reactive oxygen species (ROS), considered important second-messenger signals within the cell. The importance of UCP2 was firstly reported in macrophages and pancreatic beta cells. However, several studies have revealed the important role of UCP2 in the Central Nervous System (CNS) in the regulation of homeostatic mechanisms including food intake, energy expenditure, glucose homeostasis and reward behaviors. The mechanisms by which central UCP2 affect these processes seem to be associated with synaptic and mitochondrial plasticity. In this review, we will describe recent findings on central UCP2 and discuss its role in CNS regulation of homeostasis.