长时间坐骨神经横断伤后远侧端雪旺氏细胞活性变化

Changes of activity of Schwann cells in distal stumps of sciatic nerve being transected for long term

目的:研究坐骨神经长时间损伤不同时间后远侧端雪旺氏细胞(Schwann cells,SCs)的活性变化。方法:根据坐骨神经横断时间,SD大鼠分4组:正常对照组(A组)、损伤1月组(B组)、损伤2月组(C组)和损伤3月组(D组)。取坐骨神经损伤远侧端和正常坐骨神经进行SCs培养;S-100免疫细胞化学染色等形态学观察细胞形态;应用CCK8试剂检测SCs活力;ELISA定量检测SCs分泌的神经生长因子(nerve growth factor,NGF);以神经元的突起长度为指标来检测各组SCs来源的条件培养液对运动神经元的营养作用。结果:坐骨神经损伤后,其远侧端SCs形态发生改变,其中B组最明显;B组SCs活力最强,C、D组与B组相比均明显下降(P<0.05);SCs分泌的NGF量随着损伤时间的延长而逐渐下降(P<0.05);B组SCs来源的条件培养基中生长的神经元突起长度最长,C、D组与B组相比均短(P<0.05)。结论:周围神经长时间损伤后远侧端SCs发生了形态的改变;其细胞活力,分泌NGF以及促进神经元突起生长方面的能力都发生下降,但并未完全随着损伤时间延长而进一步下降。

Objective：To observe the activity changes of Schwann cells（SCs） in distal stumps of sciatic nerves after different long periods of time following transection.Methods：According to the terms of denervation,SD rats were divided into four groups：normal control group（group A）,denervated for 1 month（group B）,denervated for 2 months（group C） and denervated for 3 months（group D）.SCs were obtained from the distal stumps of transected sciatic nerves and normal sciatic nerves.The morphology of SCs was observed after S-100 immunocytochemistry staining.CCK8 reagent was used to detect vitality of SCs.ELISA was carried out to quantitative NGF secreted by SCs.With process length of motoneurons as index,trophic action of SCs derived conditional medium on motoneurons was assessed.Results：After sciatic nerves transection,morphological changes of SCs in distal stumps were visualized,particularly in group B.Vitality of SCs in group B was the most energetic among three experimental groups,which was much weaker in group C and D（P〈0.05）.Over denervation time,a progressive decrease in quantity of NGF produced by SCs was found（P〈0.05）.The process length of motoneurons cultured in derived conditional medium from SCs of group B was the longest in three experimental groups.Compared with group B,that of group C and group D（P〈0.05） was shorter.Conclusion：There were changes in morphology of SCs from the distal stumps of transected sciatic nerves.The vitality,the quantity of NGF and the ability to promote process growth of motoneurons of SCs decreased notably,but the degression did not continue with time of transection