衰变加速因子在神经病理性疼痛中的作用

Effect of decay accelerating factor on neuropathic pain

目的观察衰变加速因子(DAF)在2种外周神经损伤模型大鼠脊髓背角的表达情况,旨在探索它在神经病理性疼痛(NPP)发病机制中的作用。方法将60只健康雄性SD大鼠分为假手术组、CCI组和SNI组3组,按分组制作模型,分别于术前及术后1,3,7 d,用热刺激和机械刺激法测定大鼠的痛阈值变化,评估其可靠性后,于术后7 d处死大鼠,取L4—6段脊髓背角,用Western-blot和免疫组化两种技术测定其DAF蛋白含量。结果 CCI组和SNI组大鼠于术后1,3,7 d痛阈值降低,与假手术组比较有显著性差异,表明模型制作成功。Western-blot检测显示,3组模型大鼠脊髓背角DAF表达发生不同程度降低,CCI组和SNI组与假手术组相比有显著性差异。免疫组化染色显示:CCI组、SNI组大鼠脊髓背角DAF阳性细胞较假手术组显著减少。结论 NPP大鼠脊髓背角CD55蛋白表达下降,可能是此处发生补体级联反应的重要原因,CD55在NPP的形成中发挥作用。

Objective It is to observe the expression of decay accelerating factor （DAF） in spinal cord of two peripheral nerve injury model rats, and investigate its action on the pathological mechanism of neuropathic pain. Methods Sixty healthy male Sprague-Dawley rats were divided randomly into sham-operation group, CCI group and SNI group. Animal models were made according to the group. Pain threshold by thermal and mechanical stimulation were recorded at pre-operation and 1, 3, 7 days after operation, while the level of DAF CD55 protein in spinal cord was detected by western-blot and immunohistochem- ical method. Results Pain threshold by thermal and mechanical stimulation were reduced obviously at 1 , 3, 7 days after opera- tion in CCI group and SN[ group, but it was not exhibited obviously in sham-operation group. While in western-blot, compared to sham-operation group, the expressions of CD55 protein in spinal cord were showed down-regulation in CCI group and SNI group. In immunohistochemical method, the expressions in spinal cord were markedly decreased in CCI group and SNI group than that in sham-operation. Conclusion The CD55 protein may play a key role on abnormal complement activation in spinal cord, which explores the relation between the change of CD55 protein and neuropathie pain.