Novel role of the nociceptin system as a regulator of glutamate transporter expression in developing astrocytes

Glia. 2017 Dec;65(12):2003-2023. doi: 10.1002/glia.23210. Epub 2017 Sep 14.

Abstract

Our previous results showed that oligodendrocyte development is regulated by both nociceptin and its G-protein coupled receptor, the nociceptin/orphanin FQ receptor (NOR). The present in vitro and in vivo findings show that nociceptin plays a crucial conserved role regulating the levels of the glutamate/aspartate transporter GLAST/EAAT1 in both human and rodent brain astrocytes. This nociceptin-mediated response takes place during a critical developmental window that coincides with the early stages of astrocyte maturation. GLAST/EAAT1 upregulation by nociceptin is mediated by NOR and the downstream participation of a complex signaling cascade that involves the interaction of several kinase systems, including PI-3K/AKT, mTOR, and JAK. Because GLAST is the main glutamate transporter during brain maturation, these novel findings suggest that nociceptin plays a crucial role in regulating the function of early astrocytes and their capacity to support glutamate homeostasis in the developing brain.

Keywords: GLAST; astrocytes; brain development; glutamate transporters; nociceptin.

MeSH terms

  • Aldehyde Dehydrogenase 1 Family
  • Amino Acid Transport System X-AG / metabolism*
  • Animals
  • Animals, Newborn
  • Astrocytes / drug effects
  • Astrocytes / metabolism*
  • Cells, Cultured
  • Enzyme Inhibitors / pharmacology
  • Fetus / cytology
  • Gene Expression Regulation, Developmental / genetics*
  • Glial Fibrillary Acidic Protein / metabolism
  • Glutamic Acid / metabolism
  • Humans
  • Hydroxylamines / pharmacology
  • Mice, Knockout
  • Neurons / drug effects
  • Neurons / metabolism
  • Nociceptin
  • Nociceptin Receptor
  • Opioid Peptides / metabolism*
  • Opioid Peptides / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Opioid / deficiency*
  • Receptors, Opioid / genetics
  • Retinal Dehydrogenase / metabolism
  • Signal Transduction / drug effects
  • Signal Transduction / physiology

Substances

  • (+-)-E-4-methyl-2-((E)-hydroxylamino)-5-nitro-6-methoxy-3-hexanamide
  • Amino Acid Transport System X-AG
  • Enzyme Inhibitors
  • Glial Fibrillary Acidic Protein
  • Hydroxylamines
  • Opioid Peptides
  • Receptors, Opioid
  • Glutamic Acid
  • Aldehyde Dehydrogenase 1 Family
  • Aldh1a1 protein, rat
  • Retinal Dehydrogenase
  • Nociceptin Receptor