An Orally Active Allosteric GLP-1 Receptor Agonist Is Neuroprotective in Cellular and Rodent Models of Stroke

PLoS One. 2016 Feb 10;11(2):e0148827. doi: 10.1371/journal.pone.0148827. eCollection 2016.

Abstract

Diabetes is a major risk factor for the development of stroke. Glucagon-like peptide-1 receptor (GLP-1R) agonists have been in clinical use for the treatment of diabetes and also been reported to be neuroprotective in ischemic stroke. The quinoxaline 6,7-dichloro-2-methylsulfonyl-3-N-tert- butylaminoquinoxaline (DMB) is an agonist and allosteric modulator of the GLP-1R with the potential to increase the affinity of GLP-1 for its receptor. The aim of this study was to evaluate the neuroprotective effects of DMB on transient focal cerebral ischemia. In cultured cortical neurons, DMB activated the GLP-1R, leading to increased intracellular cAMP levels with an EC50 value about 100 fold that of exendin-4. Pretreatment of neurons with DMB protected against necrotic and apoptotic cell death was induced by oxygen-glucose deprivation (OGD). The neuroprotective effects of DMB were blocked by GLP-1R knockdown with shRNA but not by GLP-1R antagonism. In C57BL/6 mice, DMB was orally administered 30 min prior to middle cerebral artery occlusion (MCAO) surgery. DMB markedly reduced the cerebral infarct size and neurological deficits caused by MCAO and reperfusion. The neuroprotective effects were mediated by activation of the GLP-1R through the cAMP-PKA-CREB signaling pathway. DMB exhibited anti-apoptotic effects by modulating Bcl-2 family members. These results provide evidence that DMB, a small molecular GLP-1R agonist, attenuates transient focal cerebral ischemia injury and inhibits neuronal apoptosis induced by MCAO. Taken together, these data suggest that DMB is a potential neuroprotective agent against cerebral ischemia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Allosteric Regulation
  • Animals
  • Apoptosis / drug effects
  • Blood Glucose
  • Brain / blood supply
  • Brain / drug effects
  • Brain / pathology
  • Cell Survival / drug effects
  • Cells, Cultured
  • Drug Evaluation, Preclinical
  • Exenatide
  • Glucagon-Like Peptide-1 Receptor / agonists*
  • Infarction, Middle Cerebral Artery / blood
  • Infarction, Middle Cerebral Artery / drug therapy*
  • Inhibitory Concentration 50
  • Insulin / blood
  • Male
  • Mice, Inbred C57BL
  • Neurons / drug effects
  • Neurons / physiology
  • Neuroprotective Agents / administration & dosage*
  • Peptides / pharmacology
  • Primary Cell Culture
  • Quinoxalines / administration & dosage*
  • Reperfusion Injury / prevention & control
  • Sulfones / administration & dosage*
  • Venoms / pharmacology

Substances

  • 3-(tert-butylamino)-6,7-dichloro-2-(methylsulfonyl)quinoxaline
  • Blood Glucose
  • Glp1r protein, mouse
  • Glucagon-Like Peptide-1 Receptor
  • Insulin
  • Neuroprotective Agents
  • Peptides
  • Quinoxalines
  • Sulfones
  • Venoms
  • Exenatide

Grants and funding

This work was supported by National Natural Science Foundation of China Nos. 81571278 (Xue Ma), 81471093 (Jingru Meng) and 81402931 (Ying Zhou).