GPR120: Mechanism of action, role and potential for medical applications

G protein-coupled receptors (GPCRs) constitute a family of transmembrane proteins that mediate many cellular processes. GPR120/FFAR4, a receptor from this family that is activated by fatty acids, has received considerable attention recently. This paper presents a literature review concerning the role of GPR120 and its mechanism of action in animal and human studies as well as the potential use of GPR120 for the treatment of chronic diseases. Two electronic databases - Medline and Google Scholar - were searched for available studies addressing the review topic that were written in English and published from 2000 to June 2017. The following key terms were used in the search: GPR120, FFA4, GPR120 agonist, PUFAs, EPA, DHA, adipocyte, obesity, hyperlipidemia, inflammation, cancer, diabetes, insulin resistance, taste, atherogenesis, hepatis, central nervous system. In humans, GPR120 expression is expressed in macrophages, eosinophils, and adipose tissue, in cells of the tongue, liver, lungs, small and large intestine, gastric mucosa, and pancreas, in the central nervous system and placental microvilli. Medium- and long-chain fatty acids act as ligands for the receptor. Through the internalization of beta-arrestin-2 complex and the inhibition of NF-κB, GPR120 mediates the activation of the cell's anti-inflammatory mechanisms. The receptor is also involved in the maturation of adipocytes, the modulation of insulin signalling pathways, the regulation of glucose metabolism, and the secretion of intestinal hormones. GPR120 is a promising target for the treatment of numerous diseases, whose pathophysiology is associated with low-grade inflammation. As a result of intensive searches, a likely group of synthetic agonists of the receptor was determined with potential therapeutic applications in conditions such as obesity, impaired carbohydrate metabolism, inflammatory bowel diseases, cancer, mental disorders.