Background Macrophages/microglia are important effector cells at the site of spinal cord injury (SCI). M1-type macrophages facilitate innate immunity to remove foreign microbes and wound debris from the injury site. M2-type macrophages exhibit tissue repair properties and attenuate production of pro-inflammatory cytokines. Regulation of the polarisation of M1/M2 macrophages may affect the inflammatory response in SCI and may be related to neurotrophin-3 (NT-3). Electroacupuncture (EA) at GV acupuncture points can be used as an adjuvant therapy for SCI.
Aim To investigate the effects of EA on Basso, Beattie and Bresnahan (BBB) functional evaluation and inflammatory cytokines (tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-10), and on the proportions of M1/M2 macrophages, and to provide a greater understanding of the mechanisms underlying the potential clinical treatment of SCI.
Methods A rat SCI model was induced by spinal segment transection at T10 in 16 Sprague-Dawley rats. A further eight rats were included as a Control group. Ten surviving SCI model rats were divided into two groups (n=5 each): an SCI group that remained untreated; and an SCI+EA group that received EA at GV6 and GV9.
Results EA improved BBB scores, inhibited the proportion of M1 macrophages and TNF-α, IL-1β and IL-6 levels, and downregulated the M1 marker CD86. By contrast, EA enhanced IL-10, the proportion of M2 macrophages and upregulated the M2 marker CD206 and NT-3 expression.
Conclusions EA had a positive impact on SCI model rats. This may be related to the neuroprotective effect of NT-3, which may increase the polarisation of M2 microglia/macrophages.
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JZ and RZ contributed equally.
Correction notice This article has been updated since it published Online First. Rongyi Zhang has been removed as author and is now acknowledged by the authors at the end of the paper.
Acknowledgements The authors would like to thank Rongyi Zhang for his contribution to this article.
Contributors JZ and YL participated in the design of the study and performed the statistical analysis. JZ carried out the study, together with RZ, collected important background information and drafted the manuscript. LW and YL conceived the study, participated in its design and helped to draft the manuscript. All authors read and approved the final manuscript.
Funding This work was financially supported by Anhui province science and technology research projects (reference no. 1301042204).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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