神经生长因子和脑源性神经营养因子基因修饰的雪旺细胞和胚胎脊髓细胞悬液植入促进大鼠脊髓损伤修复的研究

The implantation of suspension of Schwann cell modified by nerve growth factor and brain-derived neurtrophic factor and fetal spinal cord cells for the promotion of repairing spinal cord injuries in rats

目的从转基因角度探讨治疗脊髓损伤的有效性。方法用改良Allen打击法制作脊髓损伤动物模型,1周后将神经生长因子nervegrowthfactorNGF和脑源性神经营养因子brainderivedneurotrophicfactorBDNF基因修饰的雪旺细胞(Schwanncells,SCs)和胚胎脊髓细胞悬液(fetalspinalcordcellsuspension,FSCS)移植联合植入脊髓损伤部位,1个月和3个月后用免疫组化方法观察神经丝蛋白NF、胶质纤维酸性蛋白GFAP、髓基质蛋白MBP、5-羟色胺5HT、NGF和BDNF的变化,并根据图像分析各实验组的免疫阳性反应变化;通过光电镜观察脊髓组织形态学改变。结果将转NGF和BDNF基因的SCs与FSCS联合植入脊髓损伤部位有以下优点:1移植物能很好地与宿主融合和存活,2能发挥FSCS的“桥接”、“中介”作用,3SCs可以起到神经轴突的“导管”、“导向”作用,4神经营养因子(neurotrophicfactors,NTFs)NGF和BDNF可以刺激轴突的生长和挽救受损的神经元。结论将NGF和BDNF基因修饰的SCs和FSCS移植联合起来,让局部释放的NTFs不断刺激、引导宿主纤维和移植物的整合与联系,以促进脊髓损伤的修复。此方法为将来治疗脊髓损伤提供线索。

Objective An investigation of the effectiveness of treatment of spinal cord injuries(SCI) from the point of view of the transforming factor. Methods Animal model of SCI was made by modified Allens method. Mixed grafts of Schwann cells(SCs) modified with nerve growth factor(NGF) and brain derived neurotrophic factor(BDNF) genes along with fetal spinal cord cell suspension(FSCS) were transplanted into SCI site after 1 month and 3 months. Immunocytochemical staining was conducted for neurofilament(NF), glial fibrillary acidic protein(GFAP), myelin basic protein(MBP), 5 hydroxytryptamine/serotonin(5 HT), NGF, BDNF and the results analyzed with image pattern analysis. Pathological changes of spinal cord tissues were observed with light and electronic microscopy. Results These findings demonstrate the advantages of using mixed grafts of NGF and BDNF genetically modified SCs with FSCS in SCI in the rat: 1) They can be well integrated with the host and survive, 2) FSCS plays the role of bridging and mesomerism, 3) SCs can act as canal tubes and guides for the axons, 4)NGF and BDNF may stimulate the growth of axons and salvage the injuried neruron. Conclusion Mixed grafts of SCs genetically modified with NGF and BDNF genes along with FSCS may be effective measures for the treatment of SCI.