慢病毒介导RNA干扰Cdh1的表达对大鼠脊髓损伤的修复作用

Lentivirus-mediated RNA interference inhibits Cdh1 expression in recovery of spinal cord injury in rats

目的:观察大鼠脊髓损伤后皮层体感运动区Cdh1mRNA的表达变化,探讨慢病毒介导RNA干扰Cdh1的表达对脊髓损伤修复的作用.方法:15只雄性SD大鼠随机分成对照组和手术组,手术组采用Allen氏法建立脊髓打击损伤模型(T10～T11).荧光定量PCR检测脊髓损伤后大鼠体感运动皮层区Cdh1mRNA表达变化.30只雄性SD大鼠随机分为A组、B组和C组,建模1wk时分别注射生理盐水、空慢病毒和重组慢病毒.术后每周进行BBB评分,荧光定量PCR检测注射10d后Cdh1mRNA的表达,损伤后6wk同法注射BDA-TR,8wk取脊髓冰冻切片.结果:手术组的Cdh1mRNA表达高于对照组(P<0.05),注射药物10d后C组Cdh1mRNA表达低于A组及B组(P<0.05).损伤6wk后C组运动功能评分均高于另两组(P<0.05),且在脊髓空洞区可见更多神经纤维通过.结论:APC-Cdh1在抑制轴突生长方面可能起着重要的作用.

AIM： To investigate the expression of Cdhl in the sensorimotor cortical of rats after spinal cord injury and to study the repairing effect of silencing the expression of Cdhl by lentivirusmediated RNAi. METHODS： Fifteen male Sprague-Dawley rats were randomly divided into normal group and operation group. The injury models in the operation group were made with Allen method（T10-T11 ） and the expression of Cdhl in the sensorimotor cortical was examined by quantitive real-time PCR. Another 30 male Sprague-Dawley rats were divided into group A, group B and group C. At 7 d after surgery, the rats of the 3 groups received in- jection respectively of normal saline, lentivirus vector and recombinant lentivirus. The behavior was evaluated with Basso- Beattie-Bresnahan（BBB） every week. Ten days after injection, the expression of Cdhl was examined by quantitive real-time PCR. Six weeks after injury, the animals received injection of BDA-TR and at 8 weeks, fresh frozen sections were prepared from the spinal cord tissue. RESULTS： The expression of Cdhl mRNA in operation group was significantly higher than that in normal group （ P 〈 0.05 ）. The expression of Cdhl mRNA in group C was lower than that in group A or group B 10 d after injection（P 〈 0.05 ）. Six weeks after injury, the BBB assessment in group C was higher than that in group A or group B （ P 〈 0.05 ） and more nerve fibers were observed extending past the lesion in group C. CONCLUSION ： APC-Cdhl may play an important role in inhibiting the axonal growth.