CD55蛋白的表达在大鼠神经病理性疼痛发病机制中的作用

Effect of CD55 Protein Expression on Nosogenesis of Neuropathic Pain in Rats

目的观察CD55蛋白在2种神经病理性疼痛模型(NPP)大鼠脊髓背角的表达情况,旨在探索它在NPP发病机制中的作用。方法 60只健康雄性SD大鼠随机分为假手术组、慢性坐骨神经缩窄损伤模型(CCI)组、保留性脊神经损伤模型(SNI)组,每组20只。分别于术前、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,术后第7天处死大鼠,用Western-blot和免疫组化两种技术测定大鼠脊髓中的CD55蛋白表达情况。结果 CCI组和SNI组大鼠术后1、3、7 d痛阈值与本组术前比较显著降低,术后3、7 d较假手术组同时点有显著差异(P<0.05),模型制作成功。免疫组化染色显示:CCI组、SNI组大鼠脊髓背角CD55蛋白表达阳性细胞较假手术组显著减少(P<0.05)。Western-blot检测显示,3组模型大鼠脊髓背角CD55蛋白表达发生不同程度降低,CCI组、SNI组与假手术组相比有统计学差异(P<0.05)。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 To observe the expression of CD55 protein in cornu dorsale medullae spinalis in rats with 2 types of neuropathic pain （NNP） in order to explore its effect on the NPP nosogenesis. Methods Sixty healthy male Sprague-Dawley （SD） rats were randomly divided into sham-operation group （n =20） , chronic constrictive injury of the sciatic nerve group （ CCI group, n = 20） and spared nerve injury group （ SNI group, n = 20）. Changes of pain threshold value were recorded by thermal and mechanical stimulation methods before operation and 1st, 3rd, 7th d after operation,and the rats were killed at postoperative 7th d after dependability evaluation. Expression of CD55 protein in rats＇spinal cord was detected by the western-blot and immunohistochemically techniques. Results In CCI and SNI group, pain threshold values 1st, 3rd 7th , d after operation were obviously reduced compared with those before operation in the same group , and the differences between the two groups and sham-operation group showed statistical significance 3rd and 7th d after operation （P 〈 0. 05）. Animal models were buih successfully. Immunohistochemically technique showed that positive cells by expressions of CD55 protein in rats^spinal cord were significantly reduced in CCI and SNI group compared with that in sham-operation group （ P 〈 0. 05 ）. The western-blot detection showed that expressions of CD55 protein in rats＇ spinal cord were reduced with different levels in the three groups; the differences between the other two groups with the sham-operation group were statistical significant （P 〈 0. 05）. Conclusion The reduction of CD55 protein in spinal cord of rats with NPP may show that there is alexinic cascade reaction, in which CD55 protein plays an role on neuropathic pain.