Kraitchman Dara L, Tatsumi Mitsuaki, Gilson Wesley D, Ishimori Takayoshi, Kedziorek Dorota, Walczak Piotr, Segars W Paul, Chen Hunter H, Fritzges Danielle, Izbudak Izlem, Young Randell G, Marcelino Michelle, Pittenger Mark F, Solaiyappan Meiyappan, Boston Raymond C, Tsui Benjamin M W, Wahl Richard L, Bulte Jeff W M
Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Circulation. 2005 Sep 6;112(10):1451-61. doi: 10.1161/CIRCULATIONAHA.105.537480. Epub 2005 Aug 29.
Recent results from animal studies suggest that stem cells may be able to home to sites of myocardial injury to assist in tissue regeneration. However, the histological interpretation of postmortem tissue, on which many of these studies are based, has recently been widely debated.
With the use of the high sensitivity of a combined single-photon emission CT (SPECT)/CT scanner, the in vivo trafficking of allogeneic mesenchymal stem cells (MSCs) colabeled with a radiotracer and MR contrast agent to acute myocardial infarction was dynamically determined. Redistribution of the labeled MSCs after intravenous injection from initial localization in the lungs to nontarget organs such as the liver, kidney, and spleen was observed within 24 to 48 hours after injection. Focal and diffuse uptake of MSCs in the infarcted myocardium was already visible in SPECT/CT images in the first 24 hours after injection and persisted until 7 days after injection and was validated by tissue counts of radioactivity. In contrast, MRI was unable to demonstrate targeted cardiac localization of MSCs in part because of the lower sensitivity of MRI.
Noninvasive radionuclide imaging is well suited to dynamically track the biodistribution and trafficking of mesenchymal stem cells to both target and nontarget organs.
动物研究的近期结果表明，干细胞可能能够归巢至心肌损伤部位以协助组织再生。然而，许多此类研究所基于的死后组织的组织学解释最近受到了广泛争议。
利用单光子发射计算机断层扫描（SPECT）/CT联合扫描仪的高灵敏度，动态测定了用放射性示踪剂和磁共振造影剂共标记的同种异体间充质干细胞（MSC）向急性心肌梗死部位的体内运输情况。静脉注射后，在24至48小时内观察到标记的MSC从最初在肺部的定位重新分布到肝脏、肾脏和脾脏等非靶器官。注射后最初24小时内，梗死心肌中MSC的局灶性和弥漫性摄取在SPECT/CT图像中已可见，并持续至注射后7天，且通过放射性组织计数得到证实。相比之下，MRI无法显示MSC的靶向心脏定位，部分原因是MRI的灵敏度较低。
非侵入性放射性核素成像非常适合动态追踪间充质干细胞在靶器官和非靶器官中的生物分布和运输情况。
