Stroh Albrecht, Boltze Johannes, Sieland Katharina, Hild Katharina, Gutzeit Cindy, Jung Tobias, Kressel Jenny, Hau Susann, Reich Doreen, Grune Tilman, Zimmer Claus
Institute of Neuroscience, Technical University Munich, Munich, Germany.
Mol Imaging. 2009 May-Jun;8(3):166-78.
Magnetic resonance imaging (MRI) of magnetically labeled stem cells has become a valuable tool in the understanding and evaluation of experimental stem cell-based therapies of degenerative central nervous system disorders. This comprehensive study assesses the impact of magnetic labeling of both human and rodent stem cell-containing populations on multiple biologic parameters as maintenance of stemness and oxidative stress levels. Cells were efficiently magnetically labeled with very small superparamagnetic iron oxide particles. Only under the condition of tailored labeling strategies can the impact of magnetic labeling on vitality, proliferation, pluripotency, and oxidative stress levels be minimized. In a rat model of Parkinson disease, magnetically labeled mouse embryonic stem cells were tracked by high-field MRI for 6 months. Significant interindividual differences concerning the spatial distribution of cells became evident. Histologically, transplanted green fluorescent protein-positive iron oxide-labeled cells were clearly identified. No significant increase in oxidative stress levels at the implantation site and no secondary uptake of magnetic label by host phagocytotic cells were observed. Our study strongly suggests that molecular MRI approaches must be carefully tailored to the respective cell population to exert minimal physiologic impact, ensuring the feasibility of this imaging approach for clinical applications.
对磁性标记干细胞进行磁共振成像（MRI）已成为理解和评估基于干细胞的退行性中枢神经系统疾病实验性治疗方法的一项重要工具。这项综合性研究评估了磁性标记人和啮齿动物含干细胞群体对多种生物学参数的影响，如干性维持和氧化应激水平。细胞用超小型超顺磁性氧化铁颗粒进行了高效磁性标记。只有在采用定制标记策略的情况下，磁性标记对活力、增殖、多能性和氧化应激水平的影响才能降至最低。在帕金森病大鼠模型中，通过高场MRI对磁性标记的小鼠胚胎干细胞进行了6个月的追踪。细胞空间分布方面的显著个体差异变得明显。组织学上，清晰鉴定出了移植的绿色荧光蛋白阳性氧化铁标记细胞。未观察到植入部位氧化应激水平有显著升高，也未观察到宿主吞噬细胞对磁性标记的二次摄取。我们的研究强烈表明，分子MRI方法必须针对各自的细胞群体进行精心定制，以使其生理影响最小化，从而确保这种成像方法在临床应用中的可行性。
