Regulation of GLP-1 and Glucagon Receptor Function by β-Arrestins in Metabolically Important Cell Types.

Glucagon-like peptide-1 (GLP-1) and glucagon (GCG) are polypeptides derived from a common precursor (preproglucagon) that modulates the activity of numerous cell types involved in regulating glucose and energy homeostasis. GLP-1 and GCG exert their biological functions via binding to specific G protein-coupled receptors (GLP-1Rs and GCGRs). Ligand-activated GLP-1Rs and GCGRs preferentially activate the heterotrimeric G protein G, resulting in increased cytosolic cAMP levels.

Inhibition of high-fat diet-induced inflammatory responses in adipose tissue by SF1-expressing neurons of the ventromedial hypothalamus.

Inflammation and thermogenesis in white adipose tissue (WAT) at different sites influence the overall effects of obesity on metabolic health. In mice fed a high-fat diet (HFD), inflammatory responses are less pronounced in inguinal WAT (ingWAT) than in epididymal WAT (epiWAT). Here we show that ablation and activation of steroidogenic factor 1 (SF1)-expressing neurons in the ventromedial hypothalamus (VMH) oppositely affect the expression of inflammation-related genes and the formation of crown-like structures by infiltrating macrophages in ingWAT, but not in epiWAT, of HFD-fed mice, with these effects being mediated by sympathetic nerves innervating ingWAT.