Mayer-Wagner Susanne, Passberger Alice, Sievers Birte, Aigner Joachim, Summer Burkhard, Schiergens Tobias S, Jansson Volkmar, Müller Peter E
Department of Orthopaedic Surgery, Campus Großhadern, Ludwig-Maximilians-University, Munich, Germany.
Bioelectromagnetics. 2011 May;32(4):283-90. doi: 10.1002/bem.20633. Epub 2010 Dec 22.
Electromagnetic fields (EMF) have been shown to exert beneficial effects on cartilage tissue. Nowadays, differentiated human mesenchymal stem cells (hMSCs) are discussed as an alternative approach for cartilage repair. Therefore, the aim of this study was to examine the impact of EMF on hMSCs during chondrogenic differentiation. HMSCs at cell passages five and six were differentiated in pellet cultures in vitro under the addition of human fibroblast growth factor 2 (FGF-2) and human transforming growth factor-β(3) (TGF-β(3) ). Cultures were exposed to homogeneous sinusoidal extremely low-frequency magnetic fields (5 mT) produced by a solenoid or were kept in a control system. After 3 weeks of culture, chondrogenesis was assessed by toluidine blue and safranin-O staining, immunohistochemistry, quantitative real-time polymerase chain reaction (PCR) for cartilage-specific proteins, and a DMMB dye-binding assay for glycosaminoglycans. Under EMF, hMSCs showed a significant increase in collagen type II expression at passage 6. Aggrecan and SOX9 expression did not change significantly after EMF exposure. Collagen type X expression decreased under electromagnetic stimulation. Pellet cultures at passage 5 that had been treated with EMF provided a higher glycosaminoglycan (GAG)/DNA content than cultures that had not been exposed to EMF. Chondrogenic differentiation of hMSCs may be improved by EMF regarding collagen type II expression and GAG content of cultures. EMF might be a way to stimulate and maintain chondrogenesis of hMSCs and, therefore, provide a new step in regenerative medicine regarding tissue engineering of cartilage.
电磁场（EMF）已被证明对软骨组织具有有益作用。如今，分化的人间充质干细胞（hMSCs）被视为软骨修复的一种替代方法。因此，本研究的目的是检查EMF在hMSCs软骨形成分化过程中的影响。在添加人成纤维细胞生长因子2（FGF-2）和人转化生长因子-β（3）（TGF-β（3））的情况下，将第5和第6代细胞传代的hMSCs在体外进行微团培养分化。将培养物暴露于由螺线管产生的均匀正弦极低频磁场（5 mT）中，或将其置于对照系统中。培养3周后，通过甲苯胺蓝和番红O染色、免疫组织化学、针对软骨特异性蛋白的定量实时聚合酶链反应（PCR）以及用于糖胺聚糖的DMMB染料结合测定来评估软骨形成。在EMF作用下，第6代hMSCs的II型胶原蛋白表达显著增加。暴露于EMF后，聚集蛋白聚糖和SOX9表达没有明显变化。在电磁刺激下，X型胶原蛋白表达下降。与未暴露于EMF的培养物相比，经EMF处理的第5代微团培养物的糖胺聚糖（GAG）/DNA含量更高。就培养物的II型胶原蛋白表达和GAG含量而言，EMF可能会改善hMSCs的软骨形成分化。EMF可能是刺激和维持hMSCs软骨形成的一种方法，因此，在软骨组织工程的再生医学方面提供了新的进展。
