胶质细胞源性神经营养因子促进脊髓损伤后轴突再生的实验研究

Experimental Research of GDNF for Promoting the Axonal Regeneration after Spinal Cord Injury

目的探讨胶质细胞源性神经营养因子(GDNF)对轴突生长的促进作用。方法在体外培养胚胎大鼠脊神经后根神经节,随机分为两组,实验组加入GDNF,对照组只添加培养液,3天后用免疫荧光染色方法鉴定神经节轴突生长情况。在体内试验方面,36只成年SD大鼠建立脊髓半切损伤模型,随机分为两组,实验组移植含有GDNF的雪旺细胞微管,对照组仅移植雪旺细胞微管。移植术后2周、4周、6周取材,测量再生神经束的大小。结果 GDNF处理3天后,实验组脊髓后根神经节新生轴突的长度明显长于对照组,而且新生轴突的覆盖面积显著大于对照组。雪旺细胞微管移植后不同时间,含有GDNF的微管内再生神经束的截面积均显著大于对照组。结论 GDNF在体内外对轴突的生长都有显著的促进作用,有望成为治疗脊髓损伤的可选方法之一。

Objective To study the effect ofglial cell line derived neurotrophic factor （GDNF） on the promotion ofneurite outgrowth and axonal regeneration. Methods Dorsal root ganglions （DRG） fi＇om fetal rats were cultured and randomly divided into two groups. The control group was fed with culture media, and the GDNF group was fed with culture media plus GDNF. Three days after adding GDNF, the neurite outgrowth was evaluated by immunofluorescence staining. In vivo experiment, thirty-six adult SD rats were undergone T10 level right side spinal cord hemi-section, and randomly divided into two groups. The GDNF group transplanted with mini-channel filled with Schwann cells plus GDNF, while the control group had Schwann cells only. The sizes of regenerated axon cables were measured 2, 4, and 6 weeks after transplantation. Results Three days after GDNF addition, the neurites outgrowth in GDNF group was much longer than that in control group, as well as the area covered by these neurites. At different time points after transplantation, the sizes of regenerated axon cables in the Schwann cell channels containing GDNF were much bigger than those without GDNF. Conclusion GDNF has significant effect in the promotion ofneurites generation both in in vitro and in vivo, which can serve as candidate for the treatment of spinal cord injury.