Suberoylanilide Hydroxamic Acid Triggers Autophagy by Influencing the mTOR Pathway in the Spinal Dorsal Horn in a Rat Neuropathic Pain Model

  • Xiang-Lan Feng
  • Hong-Bo Deng
  • Zheng-Gang Wang
  • Yun Wu
  • Jian-Juan Ke
  • Xiao-Bo FengEmail author
Original Paper


Histone acetylation levels can be upregulated by treating cells with histone deacetylase inhibitors (HDACIs), which can induce autophagy. Autophagy flux in the spinal cord of rats following the left fifth lumber spinal nerve ligation (SNL) is involved in the progression of neuropathic pain. Suberoylanilide hydroxamic acid (SAHA), one of the HDACIs can interfere with the epigenetic process of histone acetylation, which has been shown to ease neuropathic pain. Recent research suggest that SAHA can stimulate autophagy via the mammalian target of rapamycin (mTOR) pathway in some types of cancer cells. However, little is known about the role of SAHA and autophagy in neuropathic pain after nerve injury. In the present study, we aim to investigate autophagy flux and the role of the mTOR pathway on spinal cells autophagy activation in neuropathic pain induced by SNL in rats that received SAHA treatment. Autophagy-related proteins and mTOR or its active form were assessed by using western blot, immunohistochemistry, double immunofluorescence staining and transmission electron microscopy (TEM). We found that SAHA decreased the paw mechanical withdrawal threshold (PMWT) of the lower compared with SNL. Autophagy flux was mainly disrupted in the astrocytes and neuronal cells of the spinal cord dorsal horn on postsurgical day 28 and was reversed by daily intrathecal injection of SAHA (n = 100 nmol/day or n = 200 nmol/day). SAHA also decreased mTOR and phosphorylated mTOR (p-mTOR) expression, especially p-mTOR expression in astrocytes and neuronal cells of the spinal dorsal horn. These results suggest that SAHA attenuates neuropathic pain and contributes to autophagy flux in astrocytes and neuronal cells of the spinal dorsal horn via the mTOR signaling pathway.


Histone deacetylase inhibitor Autophagy flux Mammalian target of rapamycin Spinal dorsal horn Neuropathic pain 



Suberoylanilide hydroxamic acid


Mammalian target of rapamycin


Phosphorylated mTOR


Paw mechanical withdrawal threshold


Spinal nerve ligation


Histone deacetylation inhibitor


Histone deacetylase


Microtubule associated protein light chain 3


Central nervous system



This work was supported by the National Nature Science Foundation of China (No. 81471858) and the Scientific Research Program of Hubei Health and Family Planning Committee (No. WJ2017M036).

Compliance with Ethical Standards

Conflict of interest

There are no conflicts of interest.


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© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of AnesthesiologyZhongnan Hospital of Wuhan UniversityWuhanChina

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