Suppression of SNARE-dependent exocytosis in retinal glial cells and its effect on ischemia-induced neurodegeneration

Glia. 2017 Jul;65(7):1059-1071. doi: 10.1002/glia.23144. Epub 2017 Apr 3.

Abstract

Nervous tissue is characterized by a tight structural association between glial cells and neurons. It is well known that glial cells support neuronal functions, but their role under pathologic conditions is less well understood. Here, we addressed this question in vivo using an experimental model of retinal ischemia and transgenic mice for glia-specific inhibition of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-dependent exocytosis. Transgene expression reduced glutamate, but not ATP release from single Müller cells, impaired glial volume regulation under normal conditions and reduced neuronal dysfunction and death in the inner retina during the early stages of ischemia. Our study reveals that the SNARE-dependent exocytosis in glial cells contributes to neurotoxicity during ischemia in vivo and suggests glial exocytosis as a target for therapeutic approaches.

Keywords: Müller cell; gliotransmitter; glutamate; ischemia; retina.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium-Binding Proteins / metabolism
  • Disease Models, Animal
  • Doxycycline / therapeutic use
  • Ependymoglial Cells / metabolism
  • Exocytosis / genetics*
  • Glial Fibrillary Acidic Protein / genetics
  • Glial Fibrillary Acidic Protein / metabolism
  • Glutamic Acid / metabolism
  • Intermediate Filaments / metabolism
  • Ischemia / complications*
  • Ischemia / pathology
  • Light
  • Mice
  • Mice, Transgenic
  • Microfilament Proteins / metabolism
  • Nerve Degeneration / etiology*
  • Protein Kinase C-alpha / metabolism
  • Receptors, Purinergic P2Y1 / deficiency
  • Receptors, Purinergic P2Y1 / genetics
  • Retina / pathology*
  • Retinal Ganglion Cells / metabolism*
  • SNARE Proteins / genetics
  • SNARE Proteins / metabolism*
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • Aif1 protein, mouse
  • Calcium-Binding Proteins
  • Glial Fibrillary Acidic Protein
  • Microfilament Proteins
  • Receptors, Purinergic P2Y1
  • SNARE Proteins
  • Vascular Endothelial Growth Factor A
  • Glutamic Acid
  • Protein Kinase C-alpha
  • Doxycycline