Osteogenic Differentiation of Bone Mesenchymal Stem Cells Regulated by Osteoblasts under EMF Exposure in a Co-culture System

• Published in: Journal of Huazhong University of Science and Technology. Medical sciences Vol. 34; no. 2; pp. 247 - 253
• Main Author: 虞冀哲 吴华 杨勇 刘朝旭 刘阳
• Format: Journal Article
• Language: English
• Published: Heidelberg Huazhong University of Science and Technology 01.04.2014; Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
• Subjects: Alkaline Phosphatase - biosynthesis; Animals; Bone Marrow Cells - cytology; Bone Marrow Cells - radiation effects; Cell Differentiation - genetics; Cell Differentiation - radiation effects; Cell Proliferation - radiation effects; Coculture Techniques; Electromagnetic Fields; Medicine; Medicine & Public Health; Mesenchymal Stromal Cells - radiation effects; mRNA表达水平; Osteoblasts - radiation effects; Osteogenesis - genetics; Osteogenesis - radiation effects; Rats; 共培养系统; 成骨分化; 成骨细胞; 电磁场; 骨髓基质干细胞; 骨髓基质细胞; 骨髓间充质干细胞; osteogenic mechanism; osteoblast; electromagnetic fields; co-culture; bone marrow mesenchymal stem cell
• ISSN: 1672-0733; 1993-1352
• DOI: 10.1007/s11596-014-1266-4

This study examined the osteogenic effect of electromagnetic fields （EMF） under the simulated in vivo conditions. Rat bone marrow mesenchymal stem cells （BMSCs） and rat osteoblasts were co-cultured and exposed to 50 Hz, 1.0 mT EMF for different terms. Unexposed single-cultured BMSCs and osteoblasts were set as controls. Cell proliferation features of single-cultured BMSCs and osteoblasts were studied by using a cell counting kit （CCK-8）. For the co-culture system, cells in each group were randomly chosen for alkaline phosphatase （ALP） staining on the day 7. When EMF exposure lasted for 14 days, dishes in each group were randomly chosen for total RNA extraction and von Kossa staining. The mRNA expression of osteogenic markers was detected by using real-time PCR. Our study showed that short-term EMF exposure （2 h/day） could obviously promote prolifera- tion of BMSCs and osteoblasts, while long-term EMF （8 h/day） could promote osteogenic differen- tiation significantly under co-cultured conditions. Under EMF exposure, osteogenesis-related mRNA expression changed obviously in co-cultured and single-cultured cells. It was noteworthy that most osteogenic indices in osteoblasts were increased markedly after co-culture except Bmp2, which was increased gradually when ceils were exposed to EMF. Compared to other indices, the expression of Bmp2 in BMSCs was increased sharply in both single-cultured and co-cultured groups when they were exposed to EMF. The mRNA expression of Bmp2 in BMSCs was approximately four times higher in 8-h EMF group than that in the unexposed group. Our results suggest that Bmp2-mediated cellular interaction induced by EMF exposure might play an important role in the osteogenic differ- entiation of BMSCs.