NGF、BDNF基因修饰嗅鞘细胞脊髓内移植对损伤脊髓细胞的保护作用

目的：观察神经生长因子(nerve growth factor，NGF)和脑源性神经营养因子(brain-derived neurotmphic fac-tor，BDNF)基因修饰的嗅神经鞘细胞(Olfactory ensheathing cells，OECs)移植对损伤脊髓组织的保护作用。方法：将脊髓半横断伤SD大鼠模型，随机分为：NGF、BDNF基因修饰的OECs移植组(A组)、OECs移植组(B组)、损伤对照组(C组)和正常对照组(D组)。24h后每组8只动物取伤段标本，测水离子含量。其余动物第6周和12周每组8只动物爬坡试验，评价下肢运动功能及运动诱发电位(MEP)检测。结果：脊髓损伤(SCI)后组织水肿，Na^ 、Ca^2 离子浓度升高，K^ 、Mg^2 离子浓度降低。NGF、BDNF、基因修饰的OECs脊髓内移植后显著改善这些变化，且使SCI后神经功能有显著恢复。结论：NGF、BDNF基因修饰的OECs脊髓内移植对SCI有保护作用。其机制可能与减少神经细胞离子失衡，改善细胞内环境有关。

Protective Effects of Intracord Transplantation of NGF、 BDNF Genes Modified Olfactory Ensheathing Cells on Spinal

Objective: To study the protective effects of the intracord transplantation of nerve growth factor(NGF) , brain-drived neurotrophic factor(BDNF) genes modified olfactory ensheathing cell(OECs) on spinal cord injury(SCI). Methods:Rats with semi-division(SD) of the spinal cord was divided into 3 groups. Group A consisted of the rat with SD treated with the transplantation of modified NGF,BDNF genes OECs,group B of the rats with SD treated with transplantation of OECs without genetic modification,group C of the rat with SD without treatment and group D was the normal control,24h after operation,8 rats of each group were killed and the injured segment of the spinal cord was resected to be examined with atomic absorption spectrophotometry. At 6 weeks and 12 weeks after transplantation, the anather rats were examined with neurological function test and MEP monitoring. Result:There was a significant increase of water content and Na+ ,Ca2+ ions and decrease of K+ , Mg2+ ions in the injured cord segment of group C and a statistically significant recovery was observed in group A. The intracord transplantation of modified OECs improved the neurological outcome of injured spinal cord. Conclusion:The intracord transplantation of NGF,BDNF genes modified OECs exerts protective effects on injured segment of spinal cord through the improvement of the internal ion enviroment of spinal cord.