比较不同方式移植的人间充质干细胞在大鼠失神经支配的骨骼肌的分布及对坐骨神经损伤的影响

目的:探讨干细胞治疗神经肌肉疾病的更为可能而有效的给药途径及对坐骨神经损伤后修复的影响.方法:体外分离培养人间充质干细胞,经鉴定标记后备用.将54只SD大鼠随机分为肌肉注射干细胞组(肌注组)、静脉注射干细胞组(静脉组)和肌肉注射生理盐水组(对照组),每组18只.所有大鼠均建立坐骨神经损伤模型,3天之后,将106个干细胞通过肌肉注射和静脉注射分别移植到损伤大鼠模型中,于移植后3、7、14、21、28、60 d,观察坐骨神经功能指数、电生理指标和肌肉病理结果.结果:三组大鼠在观察期间均呈不同程度的失神经和神经再生现象.肌注组的腓肠肌肌电图自发电位减少,且动作电位出现的时间早于静脉组和对照组.移植后14 d开始,肌注组大鼠的传导速度明显快于静脉组和对照组[分别为(32.27±7.42) m/s,(22.92±7.34) m/s和(17.67±5.52) m/s; F=5.661,P=0.042],60 d时,三组的传导速度差异无统计学意义(P＞0.05),而波幅改变肌注组为(12.50±2.06) mV,静脉组为(1.50±0.20) mV,对照组为(10.13±4.04) mV,差异仍有统计学意义(F=6.347, P=0.033).肌注组至少在3周内均可见干细胞的存活,其在光镜下呈幼稚状态,大部分在肌细胞周边,少数散在肌细胞内.静脉组在腓肠肌中未见标记细胞.60 d时肌注组腓肠肌的萎缩程度比静脉组和对照组轻,三组肌纤维直径的差异有统计学意义(F=4.537,P=0.021).结论:肌肉注射人间充质干细胞对大鼠坐骨神经损伤和腓肠肌失神经萎缩具有促修复作用;肌肉注射是比较有效的一个给药途径.

Comparison of distributions of muscle injection and intravenous administration of human mesenchymal stem cells in denervated muscles of the sciatic nerve injured rats

OBJECTIVE: To explore the better transplantation way of mesenchymal stem cells (MSCs) in neuromuscular disease and its effect on the recovery of injured sciatic nerves. METHODS: Human MSCs were isolated, cultured and fluorescently labeled in vitro. Fifty-four rats were randomly divided into MSC intramuscular (ims), intravenous (iv) and saline administration groups. The sciatic nerve was crashed by hemostat for 5 min. MSCs (10(6)) were injected 3 days after injury. Sciatic nerve function index (SFI), electromyography and muscle biopsy specimens were recorded on ad3, ad7,ad14, ad21, ad28 and ad60. RESULTS: Denervation and regeneration of nerves were observed in the three groups. Spontaneous activity and action potential happened earlier in ims injected group than in the other two groups. The nerve conductivity velocity of ims injected rats was significantly faster than those of the iv group and the control group on d14 [(32.27+/-7.42) m/s,(22.92+/-7.34) m/s and (17.67+/-5.52) m/s; F=5.661,P=0.042]. On d60, the conduction velocity was about the same among the three groups(P>0.05). However, compound muscle action potential (CMAP) amplitude in ims injected group was significantly higher as compared with the other two groups[ims injected group (12.50+/-2.06) mV, iv group (1.50+/-0.20) mV, control group (10.13+/-4.04) mV, F=6.347, P=0.033]. The MSCs were able to be observed only in ims injected tissues 3 weeks after implantation (A large number of small undifferentiated cells were found outside the myofibers and some were found between the cells.) The atrophy of gastrocnemius in ims injected group was much less severe than that of the other 2 groups. The diameter of muscle fibers was significantly longer on d60 (F=4.537, P=0.021). CONCLUSION: Intramuscular injection of MSC was well distributed in denervated muscle, which provides a new way of nerve regeneration in the rat model of sciatic nerve injury.