应用MRI活体示踪干细胞心肌移植可行性的实验研究

Investigation of feasibility of in vivo tracking stem cell with MRI

目的:探讨应用MRI活体示踪干细胞心肌移植的可行性。方法:选择8只雌性家猪,体重35～45kg,经导管应用球囊封堵前降支动脉建立心肌梗死模型后,将存活的7只随机分为Feridex标记的干细胞移植组(n=4)和Feridex未标记的干细胞移植组(n=3)。建立模型2周后开胸,在梗死区中央及梗死边缘区共5个点注射骨髓间充质干细胞(BMSC)(1.25～7.54×106)。于移植前及移植后1h、1周、2周分别行心脏MRI检查,比较移植前后MRI心脏影像学变化。移植后2周,取心脏组织行HE染色和普鲁士蓝染色。结果:移植后1h,Feridex标记的干细胞移植组中4只动物(100%)间充质干细胞移植区在MRI上呈明显的低信号改变,术后1周示心脏低信号改变达100%(4只动物),术后2周示2只动物(50%)细胞移植区有低信号改变。病理检查示梗死区内大量炎性细胞浸润,Feridex标记的干细胞移植组心脏注射点处的组织普鲁士蓝染色阳性。结论:Feridex标记的干细胞在MRI上呈低信号改变,应用MRI活体示踪BMSC是可行的。

Objective： To investigate the feasibility of in vivo tracking for mesenchymal stem cell delivered to infracted myocardium by MRI. Methods： Eight pigs, weight 35-45 kg were used. The acute myocardial infarction （AMI） model was set up by occlution anterior descending coronary artery with balloon. The bone marrow mesenchymal stem cells （BMSC） that labeled by MRI contrast Feridex were injected into myocardium of 4 pigs while stem cells without labeling were injected in to other 3 pigs. The heart was checked by MRI before transplant, one hour, one week and two weeks after transplant. The pigs were sacrificed for histological examination and Prussian blue stain two weeks post MI. Results： The mesenchymal stem cells were transplanted successfully at 7 pigs. Injection sites in group injected with Feridex labeled stem cells can be tracked by MRI in all 4 animals after one hour of transplant and the same rate after one week of transplant. After two weeks, injection sites in this group still can be find by MRI in 2 animals. But there are none injection sites in other group can be found by MRI post operation. Prussian blue stain is positive in the injection sites of the group that injected with Feridex labeled stem cells. Conclusion： In vivo tracking Feridex labeled stem cells by MRI can be an effectively and feasible way.