Role of ectopic olfactory receptors in glucose and lipid metabolism.

The metabolic syndrome has become one of the major public health challenges in the world, and adjusting glucose and lipid levels to their normal values is crucial for treating the metabolic syndrome. Olfactory receptors (ORs) expressed in extra-nasal tissues participate in diverse biological processes, including the regulation of glucose and lipid metabolism. Ectopic ORs can regulate a variety of metabolic events including insulin secretion, glucagon secretion, fatty acid oxidation, lipogenesis and thermogenesis. Understanding the physiological function and deciphering the olfactory recognition code by suitable ligands make ectopic ORs potential targets for the treatment of the metabolic syndrome. In this review, we delineate the roles and mechanisms of ectopic ORs in the regulation of glucose and lipid metabolism, summarize the corresponding natural ligands, and discuss existing problems and the therapeutic potential of targeting ORs in the metabolic syndrome.