Jang Kyung-Sool, Lee Kwan-Sung, Yang Seung-Ho, Jeun Sin-Soo
Department of Neurosurgery, Institute of Catholic Integrative Medicine (ICIM) of Incheon St. Mary's Hospital, The Catholic University of Korea, Incheon, Korea.
J Korean Neurosurg Soc. 2010 Nov;48(5):391-8. doi: 10.3340/jkns.2010.48.5.391. Epub 2010 Nov 30.
This study was designed to validate the cell trafficking efficiency of the in vivo bioluminescence image (BLI) study in the setting of transplantation of the luciferase expressing bone marrow-derived mesenchymal stem cells (BMSC), which were delivered at each different time after transient middle cerebral artery occlusion (MCAO) in a mouse model.
Transplanting donor BMSC were prepared by primary cell culture from transgenic mouse expressing luciferase (LUC). Transient focal infarcts were induced in 4-6-week-old male nude mice. The experiment mice were divided into five groups by the time of MSC transplantation : 1) sham-operation group, 2) 2-h group, 3) 1-day group, 4) 3-day group, and 5) 1- week group. BLI for detection of spatial distribution of transplanted MSC was performed by detecting emitted photons. Migration of the transplanted cells to the infarcted area was confirmed by histological examinations. Differences between groups were evaluated by paired t-test.
A focal spot of bioluminescence was observed at the injection site on the next day after transplantation by signal intensity of bioluminescence. After 4 weeks, the mean signal intensities of 2-h, 1-day, 3-day, and 1-week group were 2.6×10(7) ± 7.4×10(6), 6.1×10(6) ± 1.2×10(6), 1.7×10(6) ± 4.4×10(5), and 8.9×10(6) ± 9.5×10(5), respectively. The 2-h group showed significantly higher signal intensity (p < 0.01). The engrafted BMSC showed around the infarct border zones on immunohistochemical examination. The counts of LUC-positive cells revealed the highest number in the 2-h group, in agreement with the results of BLI experiments (p < 0.01).
In this study, the results suggested that the transplanted BMSC migrated to the infarct border zone in BLI study and the higher signal intensity of LUC-positive cells seen in 2 hrs after MSC transplantation in MCAO mouse model. In addition, noninvasive imaging in real time is an ideal method for tracking stem cell transplantation. This method can be widely applied to various research fields of cell transplantation therapy.
本研究旨在验证在小鼠模型中，于短暂性大脑中动脉闭塞（MCAO）后不同时间点递送表达荧光素酶的骨髓间充质干细胞（BMSC）的情况下，体内生物发光成像（BLI）研究的细胞转运效率。
通过从表达荧光素酶（LUC）的转基因小鼠进行原代细胞培养来制备供体BMSC。在4-6周龄的雄性裸鼠中诱导短暂性局灶性梗死。根据MSC移植时间将实验小鼠分为五组：1）假手术组，2）2小时组，3）1天组，4）3天组，5）1周组。通过检测发射的光子进行BLI以检测移植的MSC的空间分布。通过组织学检查确认移植细胞向梗死区域的迁移。组间差异通过配对t检验进行评估。
移植后第二天，通过生物发光信号强度在注射部位观察到一个生物发光焦点。4周后，2小时组、1天组、3天组和1周组的平均信号强度分别为2.6×10(7) ± 7.4×10(6)、6.1×10(6) ± 1.2×10(6)、1.7×10(6) ± 4.4×10(5)和8.9×10(6) ± 9.5×10(5)。2小时组显示出显著更高的信号强度（p < 0.01）。免疫组织化学检查显示植入的BMSC位于梗死边缘区周围。LUC阳性细胞计数显示2小时组数量最高，与BLI实验结果一致（p < 0.01）。
在本研究中，结果表明在BLI研究中移植的BMSC迁移至梗死边缘区，并且在MCAO小鼠模型中MSC移植后2小时观察到LUC阳性细胞的信号强度更高。此外，实时无创成像为追踪干细胞移植提供了一种理想方法。该方法可广泛应用于细胞移植治疗的各个研究领域。
