骨髓基质细胞体外诱导分化移植治疗大鼠脊髓损伤的活体示踪研究

目的研究利用超顺磁性氧化铁(PIO)标记大鼠骨髓基质细胞来源的神经细胞样细胞(神经干细胞及其分化的细胞)移植治疗大鼠脊髓损伤的可行性。方法体外条件下诱导MSCs向神经细胞样细胞分化,并用SPIO标记。实验动物分为3组:细胞移植组(A)、模型对照组(B)、正常对照组(C);A、B组采用改良Allen′s法建立大鼠急性脊髓损伤模型。伤后按照BBB法观察脊髓神经功能恢复情况,并于细胞移植后第1、3、5周行MRI检查。结果诱导7 d后有部分细胞具备神经细胞样细胞形态;细胞移植后1~5周,A、B组动物运动功能均有不同程度恢复,但B组恢复较慢,BBB评分差异有统计学意义(P<0.05);1.5 T MRI检查见移植处在T2WI序列呈低信号改变,第3周时低信号向损伤区扩大,第5周时可在损伤区见到低信号改变。结论bFGF、EGF和RA可以联合诱导BMSCs向神经细胞样细胞分化。将其移植于大鼠脊髓损伤区,MR技术可以活体追踪干细胞显示:随着损伤处移植细胞的生长和增殖,损伤的脊髓功能可逐渐恢复。

Bone marrow stromal cells transplantation after differentiation in the treatment of spinal cord injury in rats in vivo traced

Objective To explore the use of magnetic resonance technology tracking stem cells in vivo and the feasibility of neural stem cell transplantation in rat functional recovery after spinal cord injuries.Methods Adult marrow stromal cells were cultured from bone marrow of four week-old SD rats.bFGF+EGF+RA were used to induce the third-generation BMSCs.A phase contrast microscope was used to observe the differentiation of BMSCs daily. Immunohistochemistry technique was used to identify the differentiated BMSCs with neuron specific enolase(NSE).The adult Wistar rats were randomly divided into three groups: spinal cord injury treated with transplants of BMSCs to injuried site(Group A),spinal cord injury received PBS solution(Group B),control group(Group C).We transplanted the induced BMSCs into the injured site immediately after the spinal cord injury model was made by Allen device.At 24 h,7 d,14 d,21 d,28 d and 35 d respectively after injury,the neurofunction of spinal cord was evaluated by Basso,Beattie and Bresnahan(BBB) method.Afted transplantation,MRI was performed in the 1st,3rd,5th week.Results After seven days of culture,some BMSCs tiik on typical morphological neuronal traits.Cell bodies appeared refractile,cone-like or spherical with long processes,and NSE was expressed.Animals in group A and group B recovered their motor functions in a varying degree.BBB score difference was significant(P<0.05).T2WI sequence presented hypointensity in the transplanted area,which expanded into injured areas in 3rd week.Hypointen-sity could be seen in the injured area in 5th week.Conclusion Combination of bFGF,EGF and RA can induce BMSCs to differentiate into NSCs and neurons,and can regulate the differentiation and promote the maturation of neurons.In vivo MRI technology can track stem cells.Neuron-like cells transplantation in the treatment of spinal cord injury in rats is conducive to the restoration of spinal cord function.