Ephrin-B3沉默对大鼠脊髓损伤后功能修复及Gap-43表达的影响

 目的 观察Ephrin-B3基因沉默后对脊髓损伤(SCI)功能恢复的影响。方法 构建3组针对Ephrin-B3基因的siRNA干扰质粒（用于实验组：A，B，C组）及1组乱序siRNA干扰质粒（用于对照组D组），体外克隆并提取质粒后包装慢病毒颗粒。半横切法制作成年大鼠SCI模型，将病毒颗粒注入SCI处。分别在注入1，2，4，8周后，采用BBB评分法比较大鼠肢体功能恢复情况；采用Real-time PCR法检测伤后各组脊髓组织Ephrin-B3 mRNA表达情况；采用免疫组化法观察脊髓组织Gap-43的表达变化。结果 Ephrin-B3 mRNA在正常大鼠脊髓内呈相对低表达，D组表达水平呈上升趋势，实验组大鼠出现Ephrin-B3沉默效果，B组尤为明显。转染后1～4周，B组大鼠BBB评分呈持续升高趋势，高于其他3组，D组明显低于实验组，4周时各组恢复效果都进入平台期。免疫组化结果显示，B组脊髓组织内Gap-43表达最明显，表达趋势从转染后1周持续至4周，8周时有所下降，而D组呈持续性弱表达。结论 沉默Ephrin-B3能够促进大鼠SCI早期功能修复并上调脊髓组织内Gap-43的表达。

Effects of Silence Ephrin-B3 on Functional Recovery and Expression of Growth Associated Protein-43 after the Spinal Cord Injury in Rats

Objective To observe the effects of silence Ephrin-B3 on functional recovery after spinal cord injury(SCI) in rats.Methods Three groups of siRNA interference plasmid for Ephrin-B3(used in three experimental group: A,B,C) and one group of siRNA interference plasmid(used in control group: D) were constructed,cloned in vitro,extracted and packed into slow virus particles.Adult rat SCI model was established by half-crosscut and injected with slow virus particles.One,two,four and eight weeks after the injection respectively,BBB evaluation method was used to compare limb functional recovery in four groups.Real-time PCR method was used to detect the expression of Ephrin-B3 mRNA in spinal tissues after injury.Immunohistochemical method was used to observe the expression of Gap-43 changes in spinal tissues.Results The expression of Ephrin-B3 was relatively low in normal rats,showed clear ascendant trend in group D and silenced in experimental groups,especially in group B.During the first four weeks after the transfection,BBB score of group B kept rising,higher than those in other three groups,while that in group D was significantly lower than the experimental groups.At the end of the fourth week after the transfection,the recovery of all the groups entered the platform stage.Immunohistochemical results showed Gap-43 was expressed most significantly in group B and the expression continued to increase during the first four weeks after the transfection and decreased at the eighth week.Conclusion Silence Ephrin-B3 can promote the functional recovery after SCI in rats at early stage,and raise the expression of Gap-43 in spinal tissues.