The Glucagon-Like Peptide-1 Receptor in the Ventromedial Hypothalamus Reduces Short-Term Food Intake in Male Mice by Regulating Nutrient Sensor Activity.
AJP Endocrinology and Metabolism
Published online on August 15, 2017
Abstract
Pharmacological activation of the glucagon-like peptide 1 receptor (GLP-1R) in the ventromedial hypothalamus (VMH) reduces food intake. Here, we assessed whether suppression of food intake by GLP-1R agonists (GLP-1RA) in this region is dependent upon AMP-activated protein kinase (AMPK) and mammalian Target of Rapamycin (mTOR). We found that pharmacological inhibition of glycolysis and, thus, activation of AMPK, in the VMH attenuates the anorectic effect of the GLP-1R agonist exendin-4 (Ex4), indicating that glucose metabolism and inhibition of AMPK are both required for this effect. Furthermore, we found that Ex4-mediated anorexia in the VMH involved mTOR but not ACC, two downstream targets of AMPK. We support this by showing that Ex4 activates mTOR signaling in the VMH and CHOK1 cells. In contrast to the clear acute pharmacological impact of the these receptors on food intake, knockdown of the VMH Glp1r conferred no changes in energy balance in either chow- or high fat diet-fed mice, and the acute anorectic and glucose tolerance effects of peripherally-dosed GLP-1RA were preserved. These results show that the VMH GLP-1R regulates food intake by engaging key nutrient sensors but is dispensable for the effects of GLP-1RA on nutrient homeostasis.