Partial agonism improves the anti-hyperglycaemic efficacy of an oxyntomodulin-derived GLP-1R/GCGR co-agonist

Research output: Contribution to journalArticlepeer-review

Authors

  • Philip Pickford
  • Maria A. Lucey
  • Roxana-Maria Rujan
  • Emma R. McGlone
  • Stavroula Bitsi
  • Ivan R Corrêa
  • Giuseppe Deganutti
  • Christopher A Reynolds
  • Bryn Owen
  • Tricia M. Tan
  • James Minnion
  • Ben Jones
  • Stephen R. Bloom

External organisations

  • Imperial College London
  • University College London
  • University of Essex

Abstract

Objective: Glucagon-like peptide-1 and glucagon receptor (GLP-1R/GCGR) co-agonism can maximise weight loss and improve glycaemic control in type 2 diabetes and obesity. In this study, we investigated the cellular and metabolic effects of modulating the balance between G protein and β-arrestin-2 recruitment at GLP-1R and GCGR using oxyntomodulin (OXM)-derived co-agonists. This strategy has been previously shown to improve the duration of action of GLP-1R mono-agonists by reducing target desensitisation and downregulation.

Methods: Dipeptidyl dipeptidase-4 (DPP-4)-resistant OXM analogues were generated and assessed for a variety of cellular readouts. Molecular dynamic simulations were used to gain insights into the molecular interactions involved. In vivo studies were performed in mice to identify the effects on glucose homeostasis and weight loss.

Results: Ligand-specific reductions in β-arrestin-2 recruitment were associated with slower GLP-1R internalisation and prolonged glucose-lowering action in vivo. The putative benefits of GCGR agonism were retained, with equivalent weight loss compared to the GLP-1R mono-agonist liraglutide despite a lesser degree of food intake suppression. The compounds tested showed only a minor degree of biased agonism between G protein and β-arrestin-2 recruitment at both receptors and were best classified as partial agonists for the two pathways measured.

Conclusions: Diminishing β-arrestin-2 recruitment may be an effective way to increase the therapeutic efficacy of GLP-1R/GCGR co-agonists. These benefits can be achieved by partial rather than biased agonism.

Details

Original languageEnglish
Article number101242
JournalMolecular metabolism
Volume51
Early online date30 Apr 2021
Publication statusPublished - Sep 2021

Keywords

  • GLP-1, Glucagon, Oxyntomodulin, Biased agonism, Partial agonism, β-arrestin

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