MSCs静脉移植对周围神经再生的作用

The effect of intravenous administration of mesenchymal stem cells on peripheral nerve regeneration in rats

目的 检测间充质干细胞（mesenchymal stem cells，MSCs）经静脉移植后在周围神经损伤模型内的迁移、分布情况，并评价其对轴突、靶器官的保护作用。方法 经尾静脉注射BrdU标记的IVISCs入大鼠坐骨神经损伤模型内（实验组）。术后自神经断端、肌肉组织取材检测BrdU阳性细胞，评价坐骨神经指数（Slq）、肌纤维横截面积及肌细胞凋亡数量。结果 术后4、8周从神经断端、肌肉组织内检测到BrdU阳性细胞。实验组的SFI、肌纤维横截面积明显高于对照组（不注入MSCs），细胞凋亡数量低于对照组，两组差异均有统计学意义（P〈0．05，P〈0．01）。结论 MSCs静脉移植至体内能归巢到损伤的神经断端、肌肉组织，具有促进轴突再生、延缓肌萎缩的作用。

Objective To investigate the rmgration and distribution of bone marrow mesenchymal stem cells （MSCs） in the peripheral nerve after intravenous administration and evaluate the effect on peripheral nerve regeneration and denervation muscle atrophy. Methods Eighty female Sprague-Dawley rats were randomly divided into 2 groups, with 40 in each. All the sciatic nerves were transected and sutured with 8-0 nylon suture. The transplanted group received an infusion d BrdU-labelled MSCs via the tail vein. The sciatic function index （SFI） was assessed by walking tract test once a week until 12 weeks after the surgery. Samples from the nerve and muscle were harvested for HE staining, BrdU and TUNEL immunohistechemical staining. Results BrdU- labeled cells were detected at the nerve stumps and in the denervated muscles at 4 weeks and 8 weeks. MSCs transplantation group had a better recovery of the sciatic nerve function index, bigger muscle fiber cross-sectional area, and fewer number of apoptotic cells as compared with that of the control group. Conclusion Intravenously administered MSCs are capable of in vivo homing to the nerve stumps and denervation muscles after peripheral nerve injury via the blood circulation, and have a therapeutic benefit on promoting peripheral nerve regeneration and delaying denervafion muscle atrophy.