G protein-coupled receptor 18: A potential role for endocannabinoid signalling in metabolic dysfunction.

Endocannabinoids are products of dietary fatty acids that are modulated by an alteration in food intake levels. Overweight and obese individuals have substantially higher circulating levels of the arachidonic acid-derived endocannabinoids, anandamide and 2-arachidonoyl glycerol, and show an altered pattern of cannabinoid receptor expression. These cannabinoid receptors are part of a large family of G protein-coupled receptors (GPCRs). GPCRs are major therapeutic targets for various diseases within the cardiovascular, neurological, gastrointestinal and endocrine systems, as well as metabolic disorders such as obesity and type 2 diabetes mellitus. Obesity is considered a state of chronic low grade inflammation elicited by an immunological response. Interestingly, the newly deorphanised G protein-coupled receptor GPR18, which is considered to be a putative cannabinoid receptor, is proposed to have an immunological function. In this review, the current scientific knowledge on GPR18 is explored including its localisation, signalling pathways and pharmacology. Importantly, the involvement of nutritional factors and potential dietary regulation of GPR18 and its (patho)physiological roles are described. Further research on this receptor and its regulation will enable a better understanding of the complex mechanisms of GPR18 and its potential as a novel therapeutic target for treating metabolic disorders. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.