神经干细胞移植延缓失神经肌萎的作用机制

目的 研究脊髓神经干细胞移植到外周神经后延缓失神经肌萎的作用及机制.方法 取孕10～12 d的SD孕鼠,提取、培养及纯化脊髓神经干细胞,传2～3代后,将分散成单细胞的神经干细胞(106/μl×5μl)移植到胫神经切断模型的远端;设立对照组,移植5μl干细胞培养液.术后分别于3、5个月取材,观察移植神经干细胞的分化;比较干细胞移植能否延缓失神经肌萎;观察靶肌肉中突触(神经肌肉接头)的变化情况.结果 移植后3、5个月,发现移植组小腿三头肌萎缩较对照组减轻(P<0.05);移植组中的突触后膜退变萎缩明显好于对照组,术后5个月出现了新的突触结构.结论 神经干细胞移植可以延缓失神经肌萎的程度,有效保护失神经肌肉突触后膜的结构,并能形成新的突触.

The mechanism of neural stem cell transplantation in delaying muscle denervation atrophy

Objective To study the effect and mechanism of transplanting spinal fetal neural stem cells (NSCs) into the peripheral nerve for delaying muscle denervation atrophy. Methods Spinal. fetal NSCs were separated from spinal cord of enceinte 10 to 12 days SD rats, cultured and purified. After three passages, the formed NSC spheres were blew into single cell suspension ( 106/μl×5 μl) and transplanted into the distal part of the transected tibial nerve. 5 μl of cell culture medium was injected into the distal tibial nerve in the control group. Three and 5 months after the transplantation, the distal part of the tibial nerve and the triceps suraes were harvested and identified with specific markers, by means of indirect immunofluorescent staining to evaluate survival and differentiation of transplanted NSCs in the nerve, and to observe the neuromuscular junctions.Results Compare to the control group, atrophy of the triceps suraes muscle was less severe 3 and 5 months after NSCs transplantation. Postsynaptic membrane was also better preserved in NSCs transplanted group. Five months after NSCs transplantation, new synapses (neuromuscular junction) formed in the denervated muscle.Conclusion NSCs transplantation can delay atrophy denervated muscles. NSCs transplantation can not only maintain the structure of postsynaptic membrane, but also form new synapse with the denervated muscle.