Electroacupuncture may alleviate neuropathic pain via suppressing P2X7R expression.

Abstract

Neuropathic pain is a severe problem that is difficult to treat clinically. Reducing abnormal remodeling of dendritic spines/synapses and increasing the anti-inflammatory effects in the spinal cord dorsal horn are potential methods to treat this disease. Previous studies have reported that electroacupuncture (EA) could increase the pain threshold after peripheral nerve injury. However, the underlying mechanism is unclear. P2X7 receptors (P2X7R) mediate the activation of microglia and participate in the occurrence and development of neuropathic pain. We hypothesized that the effects of EA on relieving pain may be related to the downregulation of the P2X7R. Spinal nerve ligation (SNL) rats were used as a model in this experiment, and 2'(3')-O-(4-benzoyl)benzoyl ATP (BzATP) was used as a P2X7R agonist. We found that EA treatment decreased dendritic spine density, inhibited synaptic reconstruction and reduced inflammatory response, which is consistent with the decrease in P2X7R expression as well as the improved neurobehavioral performance. In contrast to the beneficial effects of EA, BzATP enhanced abnormal remodeling of dendritic spines/synapses and inflammation. Furthermore, the EA-mediated positive effects were reversed by BzATP, which is consistent with the increased P2X7R expression. These findings indicated that EA improves neuropathic pain by reducing abnormal dendritic spine/synaptic reconstruction and inflammation via suppressing P2X7R expression.

• Authors: Qiaoyun Wu, Jingjing Yue, Li Lin, Xiaolan Yu, Ye Zhou, Xinwang Ying, Xiaolong Chen, Wenzhan Tu, Xinfa Lou, Guanhu Yang, Kecheng Zhou, Songhe Jiang
• Journal: Molecular pain (Mol Pain) 2021 Jan-Dec Vol. 17 Pg. 1744806921997654 ISSN: 1744-8069 [Electronic] United States
• PMID: 33626989 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Inflammation Mediators
• Nerve Tissue Proteins
• Receptors, Purinergic P2X7
• 3'-O-(4-benzoyl)benzoyladenosine 5'-triphosphate
• Adenosine Triphosphate

Topics

• Adenosine Triphosphate (analogs & derivatives, pharmacology)
• Animals
• Dendritic Spines (drug effects)
• Electroacupuncture
• Inflammation Mediators (metabolism)
• Ligation
• Male
• Models, Biological
• Nerve Tissue Proteins (metabolism)
• Neuralgia (metabolism, physiopathology, therapy)
• Neuronal Plasticity (drug effects)
• Neurons (drug effects, pathology)
• Pain Threshold (drug effects)
• Rats, Sprague-Dawley
• Receptors, Purinergic P2X7 (metabolism)
• Spinal Cord Dorsal Horn (drug effects, pathology)
• Spinal Nerves (drug effects, pathology, physiopathology)