Delling Uta, Brehm Walter, Metzger Marco, Ludewig Eberhard, Winter Karsten, Jülke Henriette
University of Leipzig, Faculty of Veterinary Medicine, Large Animal Clinic for Surgery, Leipzig, Germany.
Cell Transplant. 2015;24(11):2379-90. doi: 10.3727/096368914X685654. Epub 2014 Dec 12.
In this study, superparamagnetic iron oxide (SPIO) particle-labeled mesenchymal stromal cells (MSCs) were injected intra-articularly into osteoarthritic knee joints. Their fate and distribution were evaluated using magnetic resonance imaging (MRI) and macroscopic and histologic postmortem examination. Osteoarthritis was induced in 12 sheep by bilateral meniscectomy. After 6 weeks, one knee joint received 10 × 10(6) SPIO-labeled MSCs (Molday Ion Rhodamine B). Contralateral knees received a control injection of a) PBS, b) SPIO in PBS, c) 10 × 10(6) nonvital SPIO-labeled MSCs in PBS, or d) no injection. MR images were acquired immediately after injection and 1, 4, 8, and 12 weeks thereafter using a 0.5-T unit and a T2* sequence. Signal intensity of synovial fluid and synovial lining was assessed semiquantitatively using a scoring system. Viable SPIO-labeled MSCs produced a strong hypointense signal in the synovial fluid immediately after injection, but normal signal intensity of the synovial fluid was observed 1 week later. Synovial lining maintained its hypointensity throughout the study period. Nonvital SPIO-labeled MSCs induced hypointense signals of the synovial fluid; synovial lining appeared weak and inconsistently hypointense in the following weeks. Pure SPIO produced a strong hyperintense signal in the synovial fluid at the time of injection only. Histologically, in all knee joints receiving viable SPIO-labeled MSCs, SPIO particles were detected (Prussian blue) within the synovial lining, dorsal fat pad, and neomeniscus tissue, but not in osteochondral samples. Few SPIO particles were detected in joints injected with nonvital SPIO-labeled MSCs. Immunohistologically, no increased cell death (TUNEL) was observed in the area of detected SPIO particles, but we did observe potential chondrogenic cell differentiation (Safranin O or S100β). We conclude that viable SPIO-labeled MSCs remain detectable within the joint for 12 weeks and attach themselves to some but not all diseased joint structures.
在本研究中，将超顺磁性氧化铁（SPIO）颗粒标记的间充质基质细胞（MSCs）关节腔内注射到骨关节炎膝关节中。使用磁共振成像（MRI）以及大体和组织学尸检评估它们的转归和分布。通过双侧半月板切除术在12只绵羊中诱导骨关节炎。6周后，一个膝关节接受10×10⁶个SPIO标记的MSCs（莫尔戴伊离子罗丹明B）。对侧膝关节接受以下对照注射：a）磷酸盐缓冲液（PBS），b）PBS中的SPIO，c）PBS中10×10⁶个无活力的SPIO标记的MSCs，或d）不注射。注射后立即以及此后1、4、8和12周使用0.5-T设备和T2*序列采集MR图像。使用评分系统对滑液和滑膜衬里的信号强度进行半定量评估。有活力的SPIO标记的MSCs在注射后立即在滑液中产生强烈低信号，但1周后观察到滑液信号强度正常。在整个研究期间滑膜衬里保持其低信号强度。无活力的SPIO标记的MSCs诱导滑液出现低信号；在接下来的几周里，滑膜衬里显得微弱且低信号不一致。纯SPIO仅在注射时在滑液中产生强烈高信号。组织学上，在所有接受有活力的SPIO标记的MSCs的膝关节中，在滑膜衬里、背侧脂肪垫和新生半月板组织中检测到SPIO颗粒（普鲁士蓝），但在骨软骨样本中未检测到。在注射无活力的SPIO标记的MSCs的关节中检测到少量SPIO颗粒。免疫组织学上，在检测到SPIO颗粒的区域未观察到细胞死亡增加（TUNEL），但我们确实观察到了潜在的软骨生成细胞分化（番红O或S100β）。我们得出结论，有活力的SPIO标记的MSCs在关节内可检测到12周，并附着于部分而非全部患病关节结构。
