Spinal SNAP-25 regulates membrane trafficking of GluA1-containing AMPA receptors in spinal injury-induced neuropathic pain in rats.

Abstract

INTRODUCTION:

Synaptosomal associated proteins of 25 kDa (SNAP-25), as a member of stable soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex, is critical for membrane fusion and required for the release of neurotransmitters. The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor is implicated in pathologic pain. This study aimed to investigate whether and how SNAP-25 regulated AMPA receptors in neuropathic pain.

METHODS:

Male Sprague-Dawley rats underwent L4 spinal nerve ligation (SNL) or the sham procedure. After assessing mechanical allodynia and thermal sensitivity, the ipsilateral portion of the L4-5 spinal cord was harvested. The expression level of SNAP-25 was analyzed by Western blot analysis and real-time quantitative polymerase chain reaction. SNAP-25 phosphorylation and AMPA receptor membrane trafficking levels were evaluated with Western blot analysis. An association between SNAP-25 and AMPA membrane trafficking was confirmed by SNAP-25 expression or phosphorylation inhibition.

RESULTS:

The SNL procedure induced and maintained mechanical allodynia and thermal hyperalgesia. SNL increased the expression and phosphorylation of SNAP-25 and the membrane trafficking of AMPA receptors in the spinal cord. SNAP-25 expression or phosphorylation inhibition alleviated neuropathic pain and downregulated membrane trafficking of AMPA receptors after SNL. GluA1-containing AMPA receptor inhibition relieved mechanical allodynia and thermal hyperalgesia after SNL.

CONCLUSIONS:

The upregulation of SNAP-25-dependent membrane trafficking of AMPA receptors via SNAP-25 phosphorylation at Ser187 contributed to SNL-induced neuropathic pain. Thus, the inhibition of SNAP-25 expression or phosphorylation might serve as a treatment for neuropathic pain. However, the mechanism of GluA1-containing AMPA receptor membrane trafficking mediated by SNAP-25 phosphorylation in neuropathic pain deserves further exploration.

• Authors: Peng Liu, Chengcheng Song, Chunyan Wang, Yize Li, Lin Su, Jing Li, Qi Zhao, Zhen Wang, Mengxi Shen, Guolin Wang, Yonghao Yu, Linlin Zhang
• Journal: Neuroscience letters (Neurosci Lett) Vol. 715 Pg. 134616 (01 10 2020) ISSN: 1872-7972 [Electronic] Ireland
• PMID: 31705923 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2019 Elsevier B.V. All rights reserved.

Chemical References

• RNA, Small Interfering
• Receptors, AMPA
• Snap25 protein, rat
• Synaptosomal-Associated Protein 25
• glutamate receptor ionotropic, AMPA 1

Topics

• Animals
• Male
• Neuralgia (metabolism, prevention & control)
• Pain Measurement
• Phosphorylation (drug effects)
• RNA, Small Interfering (pharmacology)
• Rats
• Receptors, AMPA (antagonists & inhibitors, metabolism)
• Spinal Injuries (metabolism, physiopathology)
• Synaptosomal-Associated Protein 25 (antagonists & inhibitors, biosynthesis, physiology)