Liraglutide, a glucagon-like peptide-1 receptor agonist, induces ADAM10-dependent ectodomain shedding of RAGE via AMPK activation in human aortic endothelial cells

Abstract

Aims: Glucagon-like peptide-1 alleviates the deleterious effects of advanced glycation end products (AGEs), but the underlying mechanisms are not fully understood. In this study, we investigated the protective mechanism using liraglutide, a glucagon-like peptide-1 receptor agonist, in cultured human aortic endothelial cells (HAECs).

Main methods: Following liraglutide treatment in HAECs, the receptor for AGEs (RAGE) was measured in both cell lysate and culture supernatant, the cytosolic free Ca2+ level was monitored using Fluo-4 AM, the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) was analyzed, and immunofluorescence staining was used to visualize a disintegrin and metalloprotease 10 (ADAM10) on the cell surface.

Key findings: Liraglutide (100 nM) induced ectodomain shedding of RAGE within 30 min and inhibited the expression of intercellular adhesion molecule-1 (ICAM-1) induced by AGEs of bovine serum albumin (AGE-BSA). Further experiments revealed that liraglutide rapidly increases extracellular Ca2+ influx through L-type calcium channels and activates AMPK, resulting in the translocation of ADAM10 to the cell surface, whereas siRNA-mediated ADAM10 depletion prevents liraglutide-induced ectodomain shedding of RAGE and eliminates liraglutide's inhibitory effect on AGE-BSA-induced ICAM-1 expression. Moreover, compound C-mediated AMPK inhibition and siRNA-mediated AMPK depletion both prevented ADAM10 translocation to the cell surface and ADAM10-mediated ectodomain shedding of RAGE.

Significance: Liraglutide reduces the number of intact RAGE on the cell surface by inducing ADAM10-mediated ectodomain shedding, which decreases the inflammatory effects of AGEs. AMPK activated by extracellular Ca2+ influx is critically involved in the translocation of ADAM10 to the cell surface, where it cleaves RAGE.