Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands.
Magn Reson Med. 2010 Mar;63(3):817-21. doi: 10.1002/mrm.22094.
Recently, debate has arisen about the usefulness of cell tracking using iron oxide-labeled cells. Two important issues in determining the usefulness of cell tracking with MRI are generally overlooked; first, the effect of graft rejection in immunocompetent models, and second, the necessity for careful histological confirmation of the fate of the labeled cells in the presence of iron oxide. Therefore, both iron oxide-labeled living as well as dead epicardium-derived cells (EPDCs) were investigated in ischemic myocardium of immunodeficient non-obese diabetic (NOD)/acid: non-obese diabetic severe combined immunodeficient (NOD/scid) mice with 9.4T MRI until 6 weeks after surgery, at which time immunohistochemical analysis was performed. In both groups, voids on MRI scans were observed that did not change in number, size, or localization over time. Based on MRI, no distinction could be made between living and dead injected cells. Prussian blue staining confirmed that the hypointense spots on MRI corresponded to iron-loaded cells. However, in the dead-EPDC recipients, all iron-positive cells appeared to be macrophages, while the living-EPDC recipients also contained engrafted iron-loaded EPDCs. Iron labeling is inadequate for determining the fate of transplanted cells in the immunodeficient host, since dead cells produce an MRI signal indistinguishable from incorporated living cells.
最近，关于使用氧化铁标记细胞进行细胞示踪的有用性的争论已经出现。在确定 MRI 细胞示踪的有用性时，通常会忽略两个重要问题；首先是免疫活性模型中移植物排斥的影响，其次是在存在氧化铁的情况下仔细进行组织学确认标记细胞命运的必要性。因此，在免疫缺陷型非肥胖型糖尿病（NOD）/酸：非肥胖型糖尿病严重联合免疫缺陷（NOD/scid）小鼠缺血性心肌中研究了铁氧化标记的活的和死的心外膜衍生细胞（EPDC），直到手术后 6 周，此时进行免疫组织化学分析。在两组中，MRI 扫描上观察到的空洞数量、大小或位置随时间没有变化。基于 MRI，无法区分活细胞和死细胞。普鲁士蓝染色证实 MRI 上的低信号点对应于含铁细胞。然而，在死亡 EPDC 受者中，所有铁阳性细胞似乎都是巨噬细胞，而在活 EPDC 受者中，还含有植入的含铁 EPDC。铁标记不足以确定免疫缺陷宿主中移植细胞的命运，因为死亡细胞产生的 MRI 信号与掺入的活细胞无法区分。
