体外磁共振观察胎鼠神经干细胞的标记

In vitro labeled neural stem cells of fetal rats:MRI observation

背景:神经干细胞移植后的细胞存活、识别和迁移需动态监控。目的:通过体外磁共振技术对胎鼠神经干细胞体外标记,为神经干细胞在神经系统修复中的应用提供依据。方法:采用胎鼠神经干细胞的分离与培养标记、染色剂鉴定及神经干细胞的活性检测,构建大鼠脑缺血再灌注模型,采用超顺磁性氧化铁颗粒体外标记胎鼠的神经干细胞并移植至模型大鼠左侧脑内,未标记的胎鼠神经干细胞移植至右侧脑中,对标记的细胞进行普鲁士蓝染色,观察其定植和迁移情况,并通过磁共振示踪动态的监测神经干细胞在活体移植之后的信号改变情况。结果与结论:超顺磁性氧化铁颗粒体外标记胎鼠神经干细胞的方法效率达95%以上,电镜结果显示超顺磁性氧化铁颗粒体外标记胎鼠的神经干细胞内含铁颗粒,且集中在溶酶体和内涵体当中,磁共振结果显示胎鼠标记的神经干细胞呈现低信号改变,细胞活性的影响与未标记组差异无显著性意义,但标记的胎鼠神经干细胞T2WI与T2*WI信号降低。证实超顺磁性氧化铁颗粒体外标记胎鼠的神经干细胞可高效表达,磁共振的监控可以用于神经干细胞的活体示踪。

BACKGROUND：It is necessary to dynamicaly monitor the survival, recognition and migration of neural stem cels after implantation. OBJECTIVE：Toin vitro label fetal rat neural stem cels using MRI technology so as to provide applied evidence of neural stem cels in nervous system repair. METHODS：Fetal rat neural stem cels were isolated, cultured and labeled folowed by identification and cel viability detection. A rat model of cerebral ischemia-reperfusion injury was established. Fetal neural stem cels labeled by superparamagnetic iron oxide particlesin vitro were transplanted into the left brain of model rats, and unlabeled fetal rat neural stem cels transplanted into the right brain. Prussian blue staining was used to observe the colonization and migration of implanted neural stem cels. MRI tracing was employed to monitor the signal changes of neural stem cels dynamicaly afterin vivo transplantation. RESULTS AND CONCLUSION：Over 95% fetal rat neural stem cels were labeled successfuly by superparamagnetic iron oxide particles, and under electron microscope, there were iron particles in labeled neural stem cels, which were concentrated in the lysosome and endosome. MRI results showed that the labeled neural stem cels had a changing trend of low signals. No difference was found in the cel viability between labeled and unlabeled cels, but T2WI and T2＊WI signals were reduced in labeled neural stem cels. These findings confirm that superparamagnetic iron oxide-labeled fetal rat neural stem cels can highly express, and MRI tracing can be used forin vivo monitoring of neural stem cels.