Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.
Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada.
Magn Reson Med. 2017 Aug;78(2):713-720. doi: 10.1002/mrm.26400. Epub 2016 Sep 9.
Cellular MRI) was used to detect implanted human mesenchymal stem cells (hMSCs) and the resulting macrophage infiltration that occurs in response to xenotransplantation.
Human mesenchymal stem cells were prelabeled with a fluorine-19 ( F) agent prior to implantation, allowing for their visualization and quantification over time. Following implantation of 1 × 10 F-labeled hMSCs into the mouse hind limb, longitudinal imaging was performed to monitor the stem cell graft. Macrophages were labeled in situ by the intravenous administration of an ultrasmall superparamagentic iron oxide (USPIO), allowing for tracking of the inflammatory response.
Quantification of F MRI on day 0 agreed with the implanted number of cells, and F signal decreased over time. By day 14, only 22% ± 11% of the original F signal remained. In a second group, USPIO were administered intravenously after implantation of F-labeled hMSCs. When imaged on day 2, a significant decrease in F signal was observed compared to the first group alongside a large signal void region in the corresponding proton images. Immunohistochemistry confirmed the presence of iron-labeled macrophages in the stem cell tract.
A dual-labeling technique was used to noninvasively track two distinct cell populations simultaneously. This information could be used to provide additional insight into the cause of graft failure. Magn Reson Med 78:713-720, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
利用细胞 MRI 检测异种移植后植入的人间质干细胞（hMSCs）及其引发的巨噬细胞浸润。
在植入前用氟-19（F）剂对人间质干细胞进行预标记，从而可以随时间可视化和定量观察。将 1×10 F 标记的 hMSCs 植入小鼠后肢后，进行纵向成像以监测干细胞移植物。通过静脉内给予超顺磁氧化铁（USPIO）原位标记巨噬细胞，从而可以跟踪炎症反应。
第 0 天的 F MRI 定量与植入的细胞数量一致，F 信号随时间逐渐下降。到第 14 天，原始 F 信号仅剩下 22%±11%。在第二组中，在植入 F 标记的 hMSCs 后静脉内给予 USPIO。与第一组相比，在第 2 天成像时，F 信号明显下降，并且在相应的质子图像中有一个大的信号缺失区域。免疫组织化学证实了铁标记的巨噬细胞存在于干细胞移植物中。
使用双重标记技术非侵入性地同时跟踪两种不同的细胞群体。这些信息可用于提供对移植物失败原因的更多了解。磁共振医学 78：713-720，2017。©2016 国际磁共振学会。
