HRP神经逆行示踪评价GDNF修饰的神经移植复合体对大鼠脊髓运动神经元的保护作用

Protective effects of GDNF-modified nerve graft complexes on motoneuron of spinal cord in rats using HRP tracing technique

目的:采用大鼠坐骨神经缺损桥接动物模型,应用霍乱毒素B-辣根过氧化物酶(CB-HRP)神经逆行示踪技术对构建的GDNF修饰的神经移植复合体的运动神经元保护作用进行评价。方法:20只成年Wistar大鼠随机分为4组:A组(n=5)细胞外基质凝胶-PLGA管桥接组;B组(n=5)雪旺细胞-细胞外基质凝胶-PLGA管桥接组;C组(n=5)GDNF基因修饰的雪旺细胞-细胞外基质凝胶-PLGA管桥接组;D组(n=5)自体神经桥接组。损伤各组12周时应用辣根过氧化物酶神经逆行示踪技术进行脊髓前角运动神经元的再生评价。结果:12周时脊髓前角运动神经元再生评价结果提示:C组优于A、B组,而与D组相比差异无显著性意义。结论:雪旺细胞的转基因处理可能弥补单纯细胞移植神经营养因子含量的不足,而可能达到与自体神经移植相似的效果。

Objective： To evaluate the protective effects of GDNF-modified nerve graft complexes on spinal cord motoneurons in rats using HRP tracing technlque. Method： Twenty adult Wistar rats were divided into four groups randomly： nerve graft complexes, which fabricated by extracellular gel and PLGA conduits （group A N=5）, Schwann cells and extracellular gel and PLGA conduits（group B N=5） or GDNF-modified Schwann cells and extracellular gel and PLGA conduits （group C N=5） respectively, were used to repair sciatic nerve defects in rats; autograft serve as group D （N=5）. Regeneration rates of motoneurons in spinal cord were evaluated by using HRP tracing technique at 12 week postoperatively. Result： Higher number of labeled motoneurons in spinal cord were observed using PLGA conduits seeded with GDNF enhanced expressing Schwann cells（group C） than with PLGA conduits （group A） alone or PLGA conduits seeded with control Schwann cells（group B）, but there is no significant difference when compared with the group of autograft （group D）. Conclusion： These results suggest that using gene transfer techniques to increase neurotrophic factor expression in Schwann cells added to nerve grafts may be a promising methods for improving nerve regeneration.