电针刺激对神经干细胞移植治疗脊髓损伤大鼠后肢功能的影响

摘要

背景：单纯的神经干细胞移植对受损脊髓组织的修复作用并不理想，为了进一步提高移植细胞在体内的存活、增殖及定向分化为神经元的比例，必须进一步改善脊髓损伤区的微环境。　　目的：观察神经干细胞移植联合电针刺激对脊髓损伤大鼠后肢功能及电生理的影响。　　方法：将脊髓损伤模型SD大鼠72只按随机数字表法分为4组：对照组尾静脉注入培养液，神经干细胞组经尾静脉注入等体积神经干细胞悬液，电针刺激组自模型完成6 h起采用督脉加体穴电针1周，联合组尾静脉注射神经干细胞后，同时采用督脉加体穴电针1周。分别于造模前、造模后1，3 d、1-4周通过BBB评分、斜板试验进行运动功能评定。造模后4周取材行病理切片苏木精-伊红染色，荧光显微镜观测CM-Dil 标记的神经干细胞存活及分布情况，辣根过氧化物酶示踪观察神经纤维再生情况，运动诱发电位和体感诱发电位观察大鼠神经电生理恢复情况。　　结果与结论：造模后2-4周大鼠下肢运动功能评价联合组优于神经干细胞组及电针刺激组，神经干细胞组和电针刺激组优于对照组。造模后4周，神经干细胞组和电针刺激组损伤区可见少量神经轴索样结构，脊髓空洞较小，联合组可见较多神经轴索样结构，未见脊髓空洞。造模后4周，CM-Dil 阳性细胞和辣根过氧化物酶阳性神经纤维数：联合组>神经干细胞组与电针刺激组>对照组，各组之间差异有显著性意义(P <0.05)。运动诱发电位和体感诱发电位的潜伏期：联合组<神经干细胞组与电针刺激组<对照组，各组之间差异有显著性意义(P <0.05)；运动诱发电位和体感诱发电位的波幅：联合组>神经干细胞组与电针刺激组>对照组，各组之间差异有显著性意义(P <0.05)。结果提示神经干细胞移植的同时联合电针刺激能够促进脊髓损伤大鼠神经突触的再生，改善其大鼠肢体运动功能及电生理功能。%BACKGROUND:Neural stem cel transplantation alone has achieved unsatisfactory outcomes in the repair of damaged spinal cord tissues. To promote the survival, proliferation and neuronal differentiation of transplanted cels in vivo, it is necessary to further improve the micro-environment of spinal cord injury. OBJECTIVE:To investigate the effect of neural stem cel transplantation plus electroacupuncture on the hindlimb function and electrophysiological changes of rats with spinal cord injury. METHODS: Animal models of spinal cord injury were made in 72 Sprague-Dawley rats and randomized into four groups: control group with injection of culture mediumvia the tail vein; neural stem cel group with injection of neural stem cel suspensionvia the tail vein; electroacupuncture group given 1-week electroacupuncture atDu meridian and body points starting from 6 hours after modeling; combined group given injection of neural stem cel suspension via the tail vein+1-week electroacupuncture atDu meridian and body points starting from 6 hours after modeling. Motor functional recovery in rats was assessed by Basso-Beattie-Bresnahan score and inclined plane test before and at 1, 3 days and 1-4 weeks after modeling. At 4 weeks after modeling, hematoxylin-eosin staining was performed for pathological observation; fluorescence microscope was used to observe the survival and distribution of CM-Dil-labeled neural stem cels; horseradish peroxidase tracer was used to observe nerve fiber regeneration; rat neurophysiological recovery was assessed by determining motor evoked potentials and somatosensory evoked potentials. RESULTS AND CONCLUSION:At 2-4 weeks after modeling, the hindlimb function was better in the combined group than the neural stem cel group and electroacupuncture group; while it was better in the neural stem cel group and electroacupuncture group than the control group. At 4 weeks after modeling, there were few nerve axon-like structures and smal voids in the spinal cord of the neural stem cel group and electroacupuncture group; however, in the combined group, there were more nerve axon-like structures and no void in the spinal cord. At 4 weeks after modeling, the number of nerve fibers positive for CD-Dil and horseradish peroxidase was ranked as folows: combined group > neural stem cel group and electroacupuncture group > control group, and there were significant differences between groups (P < 0.05). The latencies of motor and somatosensory evoked potentials were significantly lower in the combined group than the neural stem cel group and electroaucpuncture group folowed by the control group (P < 0.05), whereas the amplitudes of motor and somatosensory evoked potentials were significantly higher in the combined group than the neural stem cel group and electroacupuncture group folowed by the control group (P < 0.05). In conclusion, these findings indicate that neural stem cel transplantation combined with electroacupuncture can promote synaptic regeneration and improve the motor and electrophysiological functions of rats.