经冠状动脉内移植骨髓间充质干细胞在体示踪及体内再分布的实验研究

目的探讨利用心脏磁共振成像（MRI）对经冠状动脉内注射的超顺磁性氧化铁颗粒（SPIO）标记的骨髓间充质干细胞（bone marrow mesenchymal stem cells，BMMScs）进行在体示踪的可行性，观察移植细胞在体内的再分布情况。方法从猪的髂骨处抽取骨髓，分离、培养BMMSCs。用SPIO和CM—DiI（Cell Tracker^TM C-7001，Molecular Probe）对细胞进行双重标记。通过导管将标记的细胞注射到冠状动脉左前降支内，分别在细胞移植后当天、移植后1周、3周通过MRI检查对移植细胞进行在体示踪；并分别取不同器官的组织标本进行组织病理学检查。结果冠状动脉内注射的SPIO标记的BMMSCs可在心脏MRI上显影，表现为散在分布的点状信号缺失或低密度影像，并可持续3周。病理检查发现移植细胞较为均匀的分布在移植冠状动脉相关的心肌组织内，在移植后1周可见细胞进入冠状静脉系统内。移植细胞在体内能分布至肺、脾和肾，而在肝组织中很少见。结论用MRI技术可对经冠状动脉内注射的SPIO标记的BMMSCs进行在体示踪；移植细胞在体内有向非靶器官再分布的情况，相关器官组织形态学未见明显的改变。

The Experimental Study of Imaging and Redistribution of Bone Marrow Mesenchymal Stem Cells Transplanted into Coronary Artery in Vivo

Objective To investigate the feasibility of imaging of bone marrow mesenchymal stem cells （BMMSCs） labeled with superparamagnetic iron oxide （SPIO） transplanted into coronary artery in vivo using magnetic resonance imaging （MRI）, and the redistribution of the cells into other organs. Methods BMMSCs were isolated, cultured from bone marrow of Chinese mini swine, and double labeled with SPIO and CM-DiI （Cell Tracker^TM C-7001）. The labeled cells were injected into left anterior descending coronary artery through a catheter. The injected cells were detected by using MRI at 1 week, 3weeks after transplantation. And different organs were harvested and evaluated the redistribution of transplanted cells through pathology. Results The SPIO labeled BMMSCs injected into coronary artery could be detected through MRI and confirmed by pathology and maintained more than 3 weeks. The SPIO labeled cells could be clearly imaged as signal void lesions in the related artery. The pathology showed that the injected cells could be distributed into the area of related artery, and the cells injected into coronary artery could be found in the lung, spleen, kidney, but scarcely in the liver, the structures of these organs remained normal. Conclusion The SPIO labeled BMMSCs injected into coronary artery can be detected by using MRI, the transplanted cells can be redistributed into the non-targeted organs.