Department of Pain Management, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021,China; Department of Pain Management, Weihai Municipal Hospital, Shandong University, Weihai, Shandong 264200,China.
Department of Pain Management, Weihai Municipal Hospital, Shandong University, Weihai, Shandong 264200,China.
Exp Neurol. 2023 Dec;370:114573. doi: 10.1016/j.expneurol.2023.114573. Epub 2023 Oct 18.
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-κB 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-κB-modulated miR-155 expression to activate anti-inflammatory microglia and then inhibit the inflammatory response and even mitigate neuropathic pain following SCI.
脊髓损伤（SCI）是一种致命且难以治愈的疾病，伴有慢性神经病理性疼痛的合并症。在这里，我们旨在探索 resolvin D2（RvD2）对 SCI 后神经病理性疼痛的治疗效果和潜在机制。建立创伤性 SCI 大鼠的体内模型。体外诱导新生大鼠原代小胶质细胞产生 TNF-α。通过 Basso-Beattie-Besnahan 评分评估运动能力。Hargreaves 方法和 Von Frey 纤维丝用于评估大鼠神经病理性疼痛的症状，包括痛觉过敏和痛觉超敏。MTT 测定法评估 RvD2 的细胞毒性。ELISA 试剂盒用于检测炎症因子的水平。通过 qRT-PCR、western blot 和免疫荧光染色测定相关 mRNA 和蛋白质的表达水平。通过双荧光素酶报告（DLR）测定法验证 miR-155 和 PTEN 之间的靶向关系。我们发现 RvD2 减轻了 SCI 大鼠的运动功能障碍、痛觉过敏和痛觉超敏。此外，RvD2 治疗抑制了小胶质细胞中促炎表型，但促进了抗炎分化。此外，RvD2 治疗抑制了 NF-κB 激活引起的 miR-155 表达上调，通过靶向 PTEN 恢复自噬流，从而减轻 TNF-α诱导的原代小胶质细胞中的炎症反应。总之，RvD2 治疗通过抑制 NF-κB 调节的 miR-155 表达来恢复自噬流，从而激活抗炎小胶质细胞，进而抑制炎症反应，甚至减轻 SCI 后的神经病理性疼痛。
