大鼠嗅鞘细胞移植对脊髓横断损伤的修复作用

Repairing Effect of OECs Transplantation for Spinal Cord Injury

目的观察嗅鞘细胞(OECs)移植后在体内的存活情况和对脊髓横断伤的修复作用。方法4月龄SD大鼠,体质量250g左右。显露T9段脊髓,完全横行切断脊髓。A组(20只)在损伤远近端注射由成年SD大鼠嗅球分离、培养、纯化的OECs,B组(20只)在相同位置注射DMEM培养液,C组(10只)单纯做T9节段的椎板减压。术后观察动物脊髓功能恢复情况,每2周测定1次后肢运动功能(BBB评分法),共12周。术后3个月取损伤段及其临近脊髓标本,做HE染色、嗜银染色、抗NF和p75免疫组化染色。利用p75免疫组化染色来观察OECs在体内存活情况。结果手术后4周开始有运动功能恢复,在各个时间段BBB运动功能得分A组均显著高于B组(均P<0.001)。A、B组都有神经纤维进入损伤区,在损伤近端,神经纤维数量A组显著多于B组(P<0.001),但都显著少于相应节段的C组(P<0.001)。经过p75免疫组化的OECs存在于脊髓损伤段周围,最远可到距离损伤区边缘1.0cm处。脊髓损伤再生神经纤维的数量与运动功能恢复成正相关(P<0.01)。结论OECs移植具有明显促进脊髓横断伤神经纤维再生和功能恢复的作用。

Objective To observe olfactory ensheating cells（OECs）survival and repairing effect in vivo for spinal cord transection after transplantation.Methods The T9 spinal cords of 4 months SD rats was exposed,then complete transection was performed in group A and group B.In group A（20 rats）,OECs was transplanted.In group B（20 rats）,DMEM was injected.In group C（10 rats）,T9 laminectomies were done without cord transection.The functional recovery of the spinal cord injury was evaluated with BBB locomotion score.HE staining,silver staining,NF and p75 immunohistochemical staining were performed respectively to observe the pathological changes and axon regeneration.The survival of OECs was observed by p75 staining under the microscope.Results The experiment showed that locomotion behaviour had improved 4 weeks after operation.The BBB score of group A was higher than that in group B in all periods and the number of regenerated nerve fibers of group A was more than that in group B（P0.001）,but less than that in group C（P0.001）.By p75 immunohistochemical staining,the OECs could be observed around spinalinjury area through the microscope,and could migrate to 1.0 cm far from the injury area.There was positive correlation between the number of regeneration axons and the recovery of locomotion function（P0.01）.Conclusion For spinal cord transection,OECs can promote the axons regeneration and the recovery of locomotion function.