Neuroprotective effects of GPR68 against cerebral ischemia-reperfusion injury via the NF-κB/Hif-1α pathway

Brain Res Bull. 2024 Oct 1:216:111050. doi: 10.1016/j.brainresbull.2024.111050. Epub 2024 Aug 13.

Abstract

Background: G protein-coupled receptor 68 (GPR68), an orphan receptor, has emerged as a promising therapeutic target for mitigating neuronal inflammation and oxidative damage. This study explores the protective mechanisms of GPR68 in cerebral ischemia-reperfusion injury (CIRI).

Methods: An in vivo middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model was established. Mice received intraperitoneal injections of Ogerin, a selective GPR68 agonist. In vitro, GPR68 was overexpressed in SH-SY5Y and HMC3 cells, and the effects of oxygen-glucose deprivation/reperfusion (OGD/R) on cell viability were assessed using real-time quantitative polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), and flow cytometry.

Results: The expression of GPR68 was suppressed in cells subjected to OGD/R treatment, whereas its upregulation conferred protection to SH-SY5Y and HMC3 cells. In vivo, levels of GPR68 were reduced in brain tissues affected by MCAO/R, correlating with oxidative stress, inflammation, and neurological damage. Treatment with a GPR68 agonist decreased brain infarction, apoptosis, and dysregulated gene expression induced by MCAO/R. Mechanistically, GPR68 agonist treatment may inhibit the activation of the NF-κB/Hif-1α pathway, thereby reducing oxidative and inflammatory responses and enhancing protection against CIRI.

Conclusions: This study confirms that the GPR68/NF-κB/Hif-1α axis modulates apoptosis, inflammation, and oxidative stress in CIRI, indicating that GPR68 is a potential therapeutic target for CIRI.

Keywords: G protein-coupled receptor 68; Inflammation; Middle cerebral artery occlusion/reperfusion; Oxidation; Oxygen-glucose deprivation/reperfusion.

MeSH terms

  • Animals
  • Brain Ischemia / drug therapy
  • Brain Ischemia / metabolism
  • Cell Line, Tumor
  • Disease Models, Animal
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit* / metabolism
  • Infarction, Middle Cerebral Artery / drug therapy
  • Infarction, Middle Cerebral Artery / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • NF-kappa B* / metabolism
  • Neuroprotective Agents* / pharmacology
  • Oxidative Stress / drug effects
  • Receptors, G-Protein-Coupled* / agonists
  • Receptors, G-Protein-Coupled* / metabolism
  • Reperfusion Injury* / drug therapy
  • Reperfusion Injury* / metabolism
  • Signal Transduction / drug effects

Substances

  • Receptors, G-Protein-Coupled
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • NF-kappa B
  • Neuroprotective Agents
  • Hif1a protein, mouse
  • Hcar1 protein, mouse