阿司匹林诱生型脂氧素A4对小鼠脊髓撞击损伤后神经病理性疼痛的影响及机制探讨

Effect of ALT on neuropathic pain after spinal cord injury in mice

摘要:

目的  评估阿司匹林诱生型脂氧素A4（ATL）对小鼠脊髓损伤（SCI）模型中神经炎症和神经病理痛的影响。方法  成年FVB小鼠T10节段脊髓进行改良Allen'脊髓撞击损伤。小鼠随机分成ATL组和Vehicle组，分别在SCI手术后4和24 h鞘内注射ATL（300 pmol）或vehicle。采用von Frey方法评估两组小鼠后脚机械刺激的敏感性；采用PCR方法检测两组小鼠脊髓小胶质细胞标记物和细胞因子信使核糖核酸（mRNA）表达；此外，通过小鼠大脑皮层组织小胶质细胞培养来评估ATL对小胶质细胞的激活和肿瘤坏死因子-α（TNF-α）释放的直接影响。结果  与Vehicle组小鼠比较，ATL处理导致SCI诱导的小鼠机械痛敏降低；脊髓小胶质细胞标记物和促炎性细胞因子mRNA水平也下降。而且，ATL处理对小胶质细胞标记物IBA-1和促炎性因子TNF-α表达影响。此外，原代皮层小胶质细胞表达ATL相应受体ALX，ATL通过ALX发挥抗炎作用。结论  ATL通过ALX受体调节小胶质细胞激活和TNF-α释放，最终降低小鼠SCI后神经病理性疼痛。

Abstract:

Objective To evaluate the effects of aspirin-triggered lipoxin A4 (ATL) on spinal neuroinflammation and neuropathic pain in mice model of spinal cord injury (SCI). Methods Modified Allen' hit model at T10 was carried out in adult FVB mice. To test if ATL can reduce neuroinflammation and neuropathic pain, each mouse received two intrathecal injections of ATL (300 pmol) or vehicle at 4 and 24 h after SCI. Sensitivity to mechanical stimulation of the hind paws was evaluated by von Frey monofilaments, and the neuro-inflammation was tested by measuring the mRNA expression levels of microglial markers and cytokines in the spinal cord samples after SCI. Also, microglia cultures prepared from mice cortical tissue were used to assess the direct effects of ATL on microglial activation and release of pro-inflammatory TNF-α. Results ATL treatment caused significant reductions in the intensity of mechanical pain hypersensitivity and spinal expression levels of microglial markers and pro-inflammatory cytokines induced by SCI, when compared to the control group. Notably, the increased expressions of the microglial marker IBA-1 and pro-inflammatory cytokine TNF-α were affected by the ATL treatment mostly. Conclusions Our results suggest that ATL can effectively modu-late microglial activation and TNF-α release through ALX receptors, ultimately reduce neuropathic pain in mice after SCI.