title: Targeted inactivation of GPR26 leads to hyperphagia and adiposity by activating AMPK in the hypothalamus.
abstract: G-protein coupled receptor 26 (GPR26) is a brain-specific orphan GPCR with high expression in the brain region that controls satiety. Depletion of GPR26 has been shown to increase fat storage in C. elegans, whereas GPR26 deficiency in the hypothalamus is associated with high genetic susceptibility to the onset of obesity in mice. However, the metabolic function of GPR26 in mammals remains elusive. Herein, we investigated a role of GPR26 in regulating energy homeostasis by generating mice with targeted deletion of the GPR26 gene. We show that GPR26 deficiency causes hyperphagia and hypometabolism, leading to early onset of diet-induced obesity. Accordingly, GPR26 deficiency also caused metabolic complications commonly associated with obesity, including glucose intolerance, hyperinsulinemia, and dyslipidemia. Moreover, consistent with hyperphagia in GPR26 null mice, GPR26 deficiency significantly increased hypothalamic activity of AMPK, a key signaling event that stimulates appetite. In further support of a regulatory role of GPR26 in satiety, GPR26 knockout mice also demonstrate hypersensitivity to treatment of rimonabant, an endocannabinoid receptor-1 antagonist commonly used to treat obesity by suppressing appetite in humans. Together, these findings identified a key role of GPR26 as a central regulator of energy homeostasis though modulation of hypothalamic AMPK activation.
authors: Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America.
authors: Daohong
authors: D
authors: Chen
authors: Xiaolei
authors: X
authors: Liu
authors: Weiping
authors: W
authors: Zhang
authors: Yuguang
authors: Y
authors: Shi
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D050154:Adiposity / Q000187:drug effects / Q000235:genetics*; D000818:Animals; D004032:Diet; D050171:Dyslipidemias / Q000150:complications / Q000473:pathology; D004734:Energy Metabolism / Q000235:genetics; D004789:Enzyme Activation / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D018390:Gene Targeting; D018149:Glucose Intolerance / Q000150:complications / Q000235:genetics; D006946:Hyperinsulinism / Q000150:complications / Q000473:pathology; D006963:Hyperphagia / Q000150:complications / Q000235:genetics / Q000473:pathology*; D007031:Hypothalamus / Q000187:drug effects / Q000201:enzymology / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000150:complications / Q000473:pathology; D010766:Phosphorylation / Q000187:drug effects; D010880:Piperidines / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D043884:Receptor, Cannabinoid, CB1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000172:deficiency / Q000235:genetics*; D000077285:Rimonabant; D015431:Weight Loss / Q000187:drug effects
chemical_list: C520707:G protein-coupled receptor GPR26, mouse; D010880:Piperidines; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; D043562:Receptors, G-Protein-Coupled; D055372:AMP-Activated Protein Kinases; D000077285:Rimonabant