Magnitsky Sergey, Walton Raquel M, Wolfe John H, Poptani Harish
Department of Radiology, School of Medicine, University of Pennsylvania, B6 Blockley Hall, 423 Guardian Drive, Philadelphia, PA 19104, USA.
Acad Radiol. 2008 Oct;15(10):1269-81. doi: 10.1016/j.acra.2008.05.003.
The study was performed to evaluate the effect of magnetic resonance imaging (MRI) contrast agent (super paramagnetic iron oxide [SPIO]) on differentiation and migration of primary murine neural stem cells (NSCs) in comparison to a neural stem cell line (C17.2). Because detection of labeled cells depends on the concentration of SPIO particles per imaging voxel, the study was performed at various concentrations of SPIO particles to determine the concentration that could be used for in vivo detection of small clusters of grafted cells.
Murine primary NSCs or C17.2 cells were labeled with different concentrations of SPIO particles (0, 25, 100, and 250 microg Fe/mL) and in vitro assays were performed to assess cell differentiation. In vivo MRI was performed 7 weeks after neonatal transplantation of labeled cells to evaluate the difference in migration capability of the two cell populations.
Both the primary NSCs and the C17.2 cells differentiated to similar number of neurons (Map2ab-positive cells). Similar patterns of engraftment of C17.2 cells were seen in transplanted mice regardless of the SPIO concentration used. In vivo MRI detection of grafted primary and C17.2 cells was only possible when cells were incubated with 100 microg/mL or higher concentration of SPIO. Extensive migration of C17.2 cells throughout the brain was observed, whereas the migration of the primary NSCs was more restricted.
Engraftment of primary NSCs can be detected noninvasively by in vivo MRI, and the presence of SPIO particles do not affect the viability, differentiation, or engraftment pattern of the donor cells.
本研究旨在评估磁共振成像（MRI）造影剂（超顺磁性氧化铁[SPIO]）对原代小鼠神经干细胞（NSCs）与神经干细胞系（C17.2）分化和迁移的影响。由于标记细胞的检测取决于每个成像体素中SPIO颗粒的浓度，因此本研究在不同浓度的SPIO颗粒下进行，以确定可用于体内检测移植细胞小簇的浓度。
用不同浓度的SPIO颗粒（0、25、100和250μg Fe/mL）标记小鼠原代NSCs或C17.2细胞，并进行体外试验以评估细胞分化。在标记细胞新生期移植7周后进行体内MRI，以评估这两种细胞群体迁移能力的差异。
原代NSCs和C17.2细胞分化为相似数量的神经元（Map2ab阳性细胞）。无论使用何种SPIO浓度，在移植小鼠中均观察到C17.2细胞相似的植入模式。只有当细胞与100μg/mL或更高浓度的SPIO孵育时，才能在体内通过MRI检测到移植的原代细胞和C17.2细胞。观察到C17.2细胞在整个大脑中广泛迁移，而原代NSCs的迁移则更受限制。
通过体内MRI可以无创检测原代NSCs的植入，并且SPIO颗粒的存在不影响供体细胞的活力、分化或植入模式。
