The mechanism of AMPA receptor subunit GluR1 in electroacupuncture treatment of acute spinal cord injury in rats

Wenci Chen; Chuyong Lin; Xiaofeng Wang; Shixuan Chen; Bin Zhu; Suncheng Wang; Liping Liu; Jing Ji

doi:10.1016/j.brainres.2021.147519

The mechanism of AMPA receptor subunit GluR1 in electroacupuncture treatment of acute spinal cord injury in rats

Brain Res. 2021 May 12:147519. doi: 10.1016/j.brainres.2021.147519. Online ahead of print.

Authors

Wenci Chen¹, Chuyong Lin¹, Xiaofeng Wang², Shixuan Chen¹, Bin Zhu¹, Suncheng Wang³, Liping Liu¹, Jing Ji⁴

Affiliations

¹ Department of Rehabilitation, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine affiliated to Shanghai University, China.
² Department of Orthopedics, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine, affiliated to Shanghai University, China.
³ Department of Massage, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine, affiliated to Shanghai University, China.
⁴ Department of Rehabilitation, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine affiliated to Shanghai University, China. Electronic address: wzjijing@163.com.

PMID: 33991493
DOI: 10.1016/j.brainres.2021.147519

Abstract

Glutamate excitotoxicity plays a role in spinal cord injury (SCI). This study aimed to explore whether electroacupuncture (EA) improved the functional recovery of spinal cord anterior horn neurons of rats with acute SCI by regulating the GluR1 AMPA subunit in the SCI area. Eighty Sprague-Dawley rats were randomly divided into 5 groups: sham operation, model, AMPA antagonist (DNQX), EA and DNQX+EA group (n=16/group). The models were obtained by using the modified Allen's impact method. DNQX was given by intrathecal injection 0.5 h after modeling. EA was performed at the "Dazhui" and "Mingmen" acupoints for 30 min at 0.5, 12, and 24 h. The BBB scores were evaluated before modeling and at 6, 24, and 48 h after modeling. Histopathological changes were evaluated. GluR1 expression was evaluated through immunofluorescence and western blot. Compared to the sham group, the BBB scores at 6, 24, and 48 h in the model group were all lower. The BBB scores and histopathological changes in the EA, DNQX and DNQX+EA group were between that of the sham and model group. GluR1 expression in the model group was higher than the sham group. Compared with the model group, the expression of GluR1 protein in the EA, DNQX, and DNQX+EA group was decreased, but similar among the three treatment groups, supporting the histopathological observations. In conclusion, these findings indicated that EA treatment might inhibit GluR1 expression, thus contributing to prevention of secondary nerve injury after primary acute SCI.

Keywords: GluR1 subunit; acute spinal cord injury; electroacupuncture; glutamate excitotoxicity; α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor.