神经干细胞移植对大鼠脊髓损伤后胶质细胞源性神经营养因子与生长相关蛋白43基因表达的影响

目的研究海马源性神经干细胞(neuralstemcells,NSCs)移植对大鼠脊髓损伤(spinalcordinjury,SCI)后胶质细胞源性神经营养因子(glialcellline-derivedneurotrophicfactor,GDNF)及生长相关蛋白43(growth associatedprotein43,GAP-43)基因表达的影响,探讨NSCs移植修复大鼠脊髓损伤的机制。方法新生一日龄Wistar大鼠6只,提取海马区NSCs,进行培养及鉴定。Wistar成年大鼠以改良Allen打击装置制成SCI模型。将Wistar大鼠60只分为3组:A组NSCs移植(n=24)、B组单纯损伤DMEM填充(n=24)、C组正常对照组(n=12)。于术后第1、3及7天应用RT-PCR法观察,各组大鼠脊髓区GDNF和GAP-43基因表达的变化。结果移植术后第1天,A组GDNF mRNA的表达量较B组平均增加23.3%;第3天,较B组平均增加26.8%;第7天,较B组平均增加32.7%。移植术后第1天,A组GAP-43mRNA的表达量较B组平均增加19.5%;第3天,较B组平均增加21.6%;第7天,较B组平均增加23.1%。A组较B组明显增强了GDNFmRNA和GAP-43mRNA的表达,组间差异均具有统计学意义(P<0.05)。C组各时间点GDNF及GAP-43mRNA的表达量差异无统计学意义(P>0.05)。结论NSCs移植后改变脊髓损伤区局部的微环境,上调GDNFmRNA,促进GAP-43mRNA的表达,是修复脊髓损伤的机制之一。

EFFECTS OF NEURAL STEM CELLS TRANSPLANTATION ON GLIAL CELL LINE-DERIVED NEUROTROPHIC FACTOR AND GROWTH ASSOCIATED PROTEIN 43 AFTER SPINAL CORD INJURY IN RATS

Objective To observe the effects of neural stem cells(NSCs) transplantation on the glial cell line-derived neurotrophic factor (GDNF) and growth associated protein 43(GAP-43) after the spinal cord injury(SCI), and to investigate the mechanism of repairing the SCI by NSCs transplantation. Methods The neural stem cells from the hippocampus of rats' embryo were cultured and identified by immunocytochemistry. The SCI model was made by the modified Allen device. Sixty adult Wistar rats were randomly divided into three groups: spinal cord injury was treated with transplantation of NSCs (group A, n=24), with DMEM solution (group B, n=24) and normal control group without being injured(group C, n=12). Seven days after the operation of SCI, the NSCs were transplanted into the injured site. Then GAP-43 and GDNF expressions were tested by RT-PCR and immunohistochemistry. Results Compared with group B, the GDNF mRNA expression of group A increased by 23.3% on the 1st day, by 26.8% on the 3rd day and by 32.7% on the 7th day; the GAP-43 mRNA expression increased by 19.5% on the 1st day, 21.6% on the 3rd day and 23.1% on the 7th day. There were statistically significant differences(P<0.05). Conclusion The transplantation of NSCs can change the micro-environment injured site and promote the regeneration of axon by enhancing the expressions of GDNF mRNA and GAP-43 mRNA. It is one of the mechanisms of repairing the SCI by NSCs transplantation.