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

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.

• Authors: Takahiro Masuda, Yui Ozono, Satsuki Mikuriya, Yuta Kohro, Hidetoshi Tozaki-Saitoh, Ken Iwatsuki, Hisayuki Uneyama, Reiko Ichikawa, Michael W Salter, Makoto Tsuda, Kazuhide Inoue
• Journal: Nature communications (Nat Commun) Vol. 7 Pg. 12529 (08 12 2016) ISSN: 2041-1723 [Electronic] England
• PMID: 27515581 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

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

Topics

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