College of Biophotonics, South China Normal University, Guangzhou 510631, China.
Exp Biol Med (Maywood). 2014 Jan;239(1):13-23. doi: 10.1177/1535370213508712. Epub 2013 Nov 13.
Dendritic cells (DCs) play an important role in atherosclerosis plaque formation, but the mechanism has not been elucidated clearly. This study is designed to establish a method for tracing DCs in vivo facilitating the investigation of the DCs' specific roles in atherosclerosis. Rabbit DCs labeled by different concentrations of ultra small superparamagnetic iron oxide (USPIO) were injected into atherosclerosis rabbit model and traced with magnetic resonance imaging (MRI). Results showed that USPIO labeling nearly have no cytotoxicity to DCs in low concentrations (<500 µg/mL) but induced some decrease of cell viability at high concentrations (>500 µg/mL). Moreover, USPIO labeling, from 200 to 2000 µg/mL, caused a dose-dependent decrease of the mitochondrial membrane potential in DCs. The high labeling concentration (2000 µg/mL) triggered necrosis instead of apoptosis in DCs. By T2WI and fs T2WI sequence imaging comparison, DCs were found to exist in rabbit abdominal artery plaques after 24 h of transplantation and in spleen after one week detected by Prussian blue staining of tissue sections. We concluded that about 200 µg/mL USPIO is ideal to effectively label DCs for MRI tracing in vivo without a threat to cell viability. Combining USPIO labeling and MRI to track the movement of injected DCs in vivo is a feasible method.
树突状细胞（DCs）在动脉粥样硬化斑块形成中起着重要作用，但具体机制尚未阐明。本研究旨在建立一种在体内追踪 DCs 的方法，以研究 DCs 在动脉粥样硬化中的特定作用。用不同浓度的超小超顺磁性氧化铁（USPIO）标记兔 DCs，注入动脉粥样硬化兔模型，并用磁共振成像（MRI）进行追踪。结果表明，USPIO 在低浓度（<500μg/mL）下对 DCs 几乎没有细胞毒性，但在高浓度（>500μg/mL）下会导致细胞活力略有下降。此外，USPIO 标记浓度从 200 到 2000μg/mL 会导致 DCs 线粒体膜电位呈剂量依赖性下降。高标记浓度（2000μg/mL）会导致 DCs 坏死而不是凋亡。通过 T2WI 和 fs T2WI 序列成像比较，发现移植后 24 小时 DCs 存在于兔腹主动脉斑块中，1 周后通过组织切片普鲁士蓝染色在脾脏中检测到 DCs。我们得出结论，约 200μg/mL 的 USPIO 是在不影响细胞活力的情况下对 DCs 进行体内 MRI 追踪的理想标记浓度。结合 USPIO 标记和 MRI 追踪体内注入的 DCs 的运动是一种可行的方法。
