磁标记猪骨髓间充质干细胞自体肝内移植后MR活体示踪研究

IN VIVO MR TRACKING OF MAGNETICALLY LABLED SWINE MESENCHYMAL STEM CELLS AFTER AUTOLOGOUS TRANSPLANTATION INTO LIVER

目的探讨利用磁共振成像对移植肝脏的磁标记猪骨髓间充质干细胞进行活体示踪的可行性。方法获取猪自体骨髓间充质干细胞,分离、培养、扩增。应用菲立磁(Feridex)标记细胞,普鲁士蓝染色鉴定,标记细胞组(n=6)和未标记细胞组(n=4)行经门静脉行肝内移植,分别于移植前,移植后6h、3d、7d行磁共振T1WI,T2WI,GRE序列成像,7d后行组织切片普鲁士蓝染色。结果:普鲁士蓝染色表明MSCs的标记率达接近100%,磁标记MSCs肝内移植后行磁共振T2*WI序列呈明显低信号改变,并持续至细胞移植后7d,组织切片普鲁士蓝染色显示7d后肝内仍有移植的磁标记细胞存在于肝实质及肝窦中。结论利用SPIO可以在体外成功标记猪骨髓间充质干细胞,磁共振成像可以对经门静脉移植到肝内的磁标记MSCs进行活体示踪。

Aim To evaluate in vivo magnetic resonance imaging（MRI） for depiction and tracking of superparamagnetic iron oxide（SPIO） labeled swine mesenchymal stem cells（MSCs） in liver. Methods Mesenchymal stem cells （MSCs） were isolated from swine, cultured and expanded, then incubated with SPIO （ Feridex I. V. ）. Prussian blue stain was performed for showing intracelluar irons. MSCs（ labled cells in six, unlabled cells in four）were injected into swines liver via portal veins. MRI including T1 weighted imaging（T1WI）, T2 weighted imaging（T2WI） and gradient-echo （GRE） sequences was performed before cells transplantation and 6 hours, 3, 7 days after transplantation. MR imaging ？ndings were compared histologically. Results Prussian blue staining of SPIO labled MSCs demonstrating cells could be effectively labeled and the labeling efficiency was almost 100%. SPIO labeling caused signal intensity loss in liver on GRE MR images. The signal change persisted until 7 days after transplantation. Prussian blue staining of histological analysis showed homing of labeled MSCs in liver after 7 days, primarily distributing in hepatic sinusoids and liver parenchyma. Conclusion SPIO can be used to label MSCs in vitro successfully. MRI can monitor magnetically labeled MSCs transplanted into liver.