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  2. Resolvin D2 activates anti-inflammatory microglia via restoring autophagy flux and alleviate neuropathic pain following spinal cord injury in rats

Resolvin D2 activates anti-inflammatory microglia via restoring autophagy flux and alleviate neuropathic pain following spinal cord injury in rats

  • Exp Neurol. 2023 Oct 17:114573. doi: 10.1016/j.expneurol.2023.114573.
Lei Yang 1 Xiaoming Gao 1 Demin Tian 1 Wenjie Yang 2 Song Xue 3 Zhenxin Cao 2 Tao Sun 4
Affiliations

Affiliations

  • 1 Department of Pain Management, Weihai Municipal Hospital, Shandong University, Weihai, Shandong 264200, China.
  • 2 Departments of Pain Management, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China.
  • 3 Departments of Pain Management, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, China.
  • 4 Departments of Pain Management, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China; Departments of Pain Management, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, China. Electronic address: [email protected].
Abstract

Spinal cord injury (SCI) is a fatal and intractable disease accompanied by the comorbidity of chronic neuropathic pain. Here, we purposed to explore the therapeutic effect and the underlying mechanism of Resolvin D2 (RvD2) on neuropathic pain after SCI. The in vivo model of traumatic SCI rats was established. Primary microglia isolated from neonatal rats were induced by TNF-α in vitro. The locomotor ability was assessed by the Basso-Beattie-Besnahan score. Hargreaves methods and Von Frey fibrofilaments were used to evaluate the symptoms of neuropathic pain including allodynia and hyperalgesia in rats. The cytotoxicity of RvD2 was evaluated by MTT assay. ELISA kit was applied to access the levels of inflammatory factors. And the expression levels of related mRNA and proteins were determined by qRT-PCR, western blotting and immunofluorescence staining. The targeting relationship between miR-155 and PTEN was verified by dual-luciferase reporter (DLR) assay. We found that RvD2 mitigated locomotor dysfunction, allodynia and hyperalgesia of SCI rats. In addition, RvD2 treatment suppressed pro-inflammatory phenotype but promoted anti-inflammatory differentiation in microglia. Furthermore, RvD2 treatment inhibited the upregulated expression level of miR-155 which was caused by NF/kB activation and then recovered the Autophagy flux via targeting PTEN, thereby relieving the inflammatory response in the TNF-α-induced primary microglia. In summary, RvD2 treatment could recover the Autophagy flux via suppressing NF/kB-modulated miR-155 expression to activate anti-inflammatory microglia and then inhibit the inflammatory response and even mitigate neuropathic pain following SCI.

Keywords

Autophagy flux; Microglia polarization; Neuropathic pain; Resolvin D2; miR-155.

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