中文摘要：

目的探讨移植在脊髓损伤处的神经营养素-3（NT-3）基因修饰及维甲酸（RA）预诱导的骨髓间充质干细胞（MSCs）分化为神经元样细胞的潜能。方法将MSCs、RA诱导的MSCs、LacZ基因修饰的MSCs、NT-3基因修饰的MSCs和NT-3基因修饰及RA预诱导的MSCs分别立即移植到脊髓全横断处（T10脊髓）,术后67d取材和冷冻切片,用免疫荧光组织化学染色方法检测MSCs的分化潜能,计算各细胞移植组脊髓损伤处的MSCs分化为神经元样细胞的百分率。结果移植的MSCs在受损伤的脊髓内可分化为神经干细胞（nestin阳性）、神经胶质样细胞（GFAP阳性）和神经元样细胞（NF和MAP2阳性）,有些还可以向含有某种神经递质和有形成突触潜能的神经元样细胞分化（ChAT、5-HT和PSD95阳性）。联合应用NT-3基因修饰和RA预诱导的MSCs能在受损伤的脊髓内更有效地提高MSCs向神经元样细胞分化的百分率。结论NT-3基因修饰和RA预诱导的MSCs能在脊髓损伤处更好地分化为神经元样细胞。

英文摘要：

Objective To explore the potential of bone marrow mesenchymal stem cells （MSCs） to be modified by neurotrophin-3 （NT-3） gene and pretreated with retinoic acid （RA） to differentiate into neuron-like cells in the transplanted site of the spinal cord injury. Methods MSCs, RA-induced MSCs, LacZ gene modified MSCs, NT-3 gene modified MSCs, and MSCs both modified by NT-3 gene and pretreated with RA were immediately transplanted respectively into the completely transected site （T10 spinal segment） of spinal cord. On the 67th day after the operation, the spinal cord segment was removed and frozenly sectioned. The differentiation potential of MSCs was examined by immunofluorescence histochemistry and the percentage was calculated of neuron-like cells that were differentiated from MSCs among all the transplanted cells groups. Results Transplanted MSCs could differentiate into neural stem cells （nestin-positive）, neuroglial cells （GFAP-positive） and neuron-like cells （NF and MAP2-positive） in the injured spinal cord. Some of them also differentiated into the neuron-like cells which contained some neurotransmitters （ChAT and 5-HT positive） or had the potential to form a synapse （PSD95-positive）. The percentage of neuron-like cells differentiated from MSCs modified by NT-3 gene and pretreated with RA was the highest among all the transplanted cell groups. Conclusion MSCs modified by NT-3 gene and pretreated with RA could better to differentiate into neuron-like cells in the injured spinal cord.