Free fatty acid receptors FFAR1 and GPR120 as novel therapeutic targets for metabolic disorders.

Free fatty acids (FFAs) are not only essential nutritional components, but they also act as signaling molecules in various physiological processes. Recently, a G-protein-coupled receptor deorphanizing strategy has successfully identified a family of receptors that are activated by FFAs. FFA receptors (FFARs) are proposed to play critical roles in a variety of physiological and pathophysiological processes, especially in metabolic disorders. Among the FFARs, FFAR1 (GPR40) and GPR120 are activated by medium- and long-chain FFAs. FFAR1 facilitates glucose-stimulated insulin secretion from pancreatic β-cells, whereas GPR120 regulates the secretion of glucagon-like peptide-1 in the intestine, as well as insulin sensitivity in macrophages. Because these receptors are potential therapeutic targets for metabolic disorders such as type 2 diabetes, selective ligands have been developed. In this review, we discuss recent advances in the identification of ligands, structure activity relationships, and pharmacological characterization of FFAR1 and GPR120, and we present a summary of recent progress in understanding their physiological roles and their potential as drug targets.