FFAR1

FFAR1 (free fatty acid receptor 1, also known as GPR40) is a G protein-coupled receptor predominantly expressed in pancreatic β-cells, where it functions as a lipid sensor for medium- and long-chain free fatty acids and amplifies glucose-stimulated insulin secretion (GSIS)^[1][2][3]. Mechanistically, FFAR1 activation couples primarily to Gα_q/11-dependent signaling, increases intracellular Ca²⁺ levels, and promotes insulin exocytosis under elevated glucose conditions, thereby linking nutrient sensing to β-cell secretory function^[3][4][5]. FFAR1 signaling also contributes to the regulation of incretin hormones, including glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), supporting coordinated control of glucose homeostasis and energy metabolism^[4][6][7]. In disease-relevant contexts, reduced β-cell function and impaired insulin secretion are central features of type 2 diabetes, and FFAR1 has therefore emerged as a key therapeutic target for restoring glucose-dependent insulin release while minimizing hypoglycemia risk^[6][8][9]. Compared with the related long-chain fatty acid receptor FFAR4 (GPR120), which is primarily associated with intestinal and macrophage functions, FFAR1 is distinguished by its predominant role in pancreatic β-cell-mediated insulin secretion^[10]. For experimental applications, selective FFAR1 agonists such as fasiglifam (TAK-875) and other synthetic ligands have been widely used to investigate receptor pharmacology, β-cell signaling mechanisms, incretin regulation, and anti-diabetic therapeutic strategies^[8][9][11].