神经干细胞移植治疗大鼠脊髓损伤的体内示踪

Tracing of neural stem cells transplantation in the treatment of spinal cord injury in rats

目的:探讨观察神经干细胞(NSCs)移植到大鼠损伤脊髓(SCI)后迁徙情况的方法。方法:体外培养大鼠NSCs,应用超顺磁性氧化铁(super paramagnet iciron oxide,SPIO)及多聚左旋赖氨酸(PLL)标记NSCs,分别进行普鲁士蓝染色、电子显微镜观察NSCs在体外标记情况。66只SD大鼠随机分为假损伤组(A组)、脊髓损伤对照组(B组)、脊髓损伤后NSCs移植治疗组(C组),分别在细胞移植术后第7d、14d、21d、28d及35d,按照改良Tarlov评分法和Rivlin斜板试验观察大鼠神经功能恢复情况,B、C组术后第7、21、35d行MRI检查,扫描序列包括T1WI、T2WI、T2*WI。结果:(1)普鲁士蓝染色证实SPIO和PLL标记NSCs的有效率为100%。(2)细胞移植后7～35d,C组与B组动物运动功能均有不同程度恢复,但B组恢复较慢,14d、21d、28d和35d时C组Tarlov评分和斜板试验角度与B组相比差异有统计学意义(P<0.05)。(3)1.5TMRI检查,C组移植处在T2*WI序列呈低信号改变,第21d低信号向损伤区扩大,第35d损伤区见到低信号改变。B组相同时间点无低信号改变。第35天时与B组相比,C组3个扫描序列中信号强度分别下降32.55%、54.14%、62.27%,T2*WI的信号强度变化最大,T1WI变化最小。结论:磁共振技术可以追踪SPIO及PLL标记的移植在体内的NSCs。

Objective：To Study the feasibility of tracing of neural stem eells（NSCs） transplantation on spinal cord injury（SCI） in vivo.Method：NSCs were cultured in vitro,and coated by the marker of neural stem cells, poly-L-lysine（PLL） and super paramagnetie iron oxide（SPIO）,Prussian blue staining was used to label the cells.In vetro the labeling was checked under electroscope.66 SD rats were randomly divided into sham injury group （group A）,spinal cord injury without treatment as the control （group B）,spinal cord injury with NSCs transplantation as the treatment group （group C）,The neurofunetion of spinal cord was evaluated by modified Tarlov score and Rivlin platform test at 7d,14d,21d,28d and 35d after transplantation.Group B and C were examined by MR] in sequences of T1WI,T2WI,T2＊WI at 7d,21d and 35d.Result：（1）Neural stem cells could be labeled with SPIO and PLL labeling efficiency was 100%.Prussian blue staining showed there were numer- ous blue stained iron particles in the cytoplasm.（2）7 to 35 clays after cell transplantation,motor function of the animals in group C and group B recovered to some extent,but the recovery in group B was slower than that in group C,the difference was significant （P〈0.05）.（3）On 1.5T MRI examination,transplantation area in group C in T2＊WI sequence showed low signal change,and the low signal area expanded to the injured re- gion in 21days,furthermore,the low signal could be seen in the injured area after 35 days.Group B did not show any low signal.The signal intensity in three sequences in group C decreased 32.55%,54.14% ,62.27% respectively the change of signal intensity in T2＊WI was most,T2WI was moderate,and T1WI was less.Con- clusion：In vivo NSCs labeled with SPIO after transplantation in the treatment of spinal cord injury can be traced by MRI technology,NSCs transplantation for spinal cord injury in rats is conducive to the restoration of hind limb function.