Dorsal horn neurons release extracellular ATP in a VNUT-dependent manner that underlies neuropathic pain

Nat Commun. 2016 Aug 12:7:12529. doi: 10.1038/ncomms12529.

Abstract

Activation of purinergic receptors in the spinal cord by extracellular ATP is essential for neuropathic hypersensitivity after peripheral nerve injury (PNI). However, the cell type responsible for releasing ATP within the spinal cord after PNI is unknown. Here we show that PNI increases expression of vesicular nucleotide transporter (VNUT) in the spinal cord. Extracellular ATP content ([ATP]e) within the spinal cord was increased after PNI, and this increase was suppressed by exocytotic inhibitors. Mice lacking VNUT did not show PNI-induced increase in [ATP]e and had attenuated hypersensitivity. These phenotypes were recapitulated in mice with specific deletion of VNUT in spinal dorsal horn (SDH) neurons, but not in mice lacking VNUT in primary sensory neurons, microglia or astrocytes. Conversely, ectopic VNUT expression in SDH neurons of VNUT-deficient mice restored PNI-induced increase in [ATP]e and pain. Thus, VNUT is necessary for exocytotic ATP release from SDH neurons which contributes to neuropathic pain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • Animals
  • Astrocytes / metabolism
  • Disease Models, Animal
  • Exocytosis / drug effects
  • Exocytosis / physiology
  • Female
  • Humans
  • Hypersensitivity / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Microglia / metabolism
  • Neuralgia / etiology
  • Neuralgia / pathology*
  • Nucleotide Transport Proteins / genetics
  • Nucleotide Transport Proteins / metabolism*
  • Peripheral Nerve Injuries / etiology
  • Peripheral Nerve Injuries / pathology*
  • Posterior Horn Cells / metabolism
  • Posterior Horn Cells / pathology*
  • Sensory Receptor Cells / metabolism
  • Tetanus Toxin / pharmacology

Substances

  • Nucleotide Transport Proteins
  • Slc17a9 protein, mouse
  • Tetanus Toxin
  • Adenosine Triphosphate