Dexamethasone modulates BMP-2 effects on mesenchymal stem cells in vitro

• Published in: Journal of orthopaedic research 2008-11, Vol.26 (11), p.1440-1448
• Main Authors: Jäger, Marcus, Fischer, Johannes, Dohrn, Wiebke, Li, Xinning, Ayers, David C., Czibere, Akos, Prall, Wolf Christian, Lensing-Höhn, Sabine, Krauspe, Rüdiger
• Format: Article
• Language: English
• Subjects: Anti-Inflammatory Agents - pharmacology; Biomarkers - metabolism; Bone Marrow Cells; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins - metabolism; Bone Morphogenetic Proteins - pharmacology; bone morphogenic protein; Cell Differentiation - drug effects; Cell Proliferation - drug effects; Cell Survival - drug effects; Cells, Cultured; Collagen Type I - genetics; Collagen Type I - metabolism; dexamethasone; Dexamethasone - pharmacology; Drug Combinations; Fluorescent Antibody Technique, Indirect; Gene Expression Regulation - drug effects; Humans; Immunoenzyme Techniques; mesenchymal stem cell; Mesenchymal Stromal Cells - cytology; Mesenchymal Stromal Cells - drug effects; Mesenchymal Stromal Cells - metabolism; osteoblast; Osteoblasts - cytology; Osteoblasts - drug effects; Osteoblasts - metabolism; Osteopontin - genetics; Osteopontin - metabolism; RANK Ligand - genetics; RANK Ligand - metabolism; RNA, Messenger - metabolism; Transforming Growth Factor beta - metabolism; Transforming Growth Factor beta - pharmacology
• ISSN: 0736-0266; 1554-527X
• DOI: 10.1002/jor.20565

Dexamethasone/ascorbic acid/glycerolphosphate (DAG) and bone morphogenic protein (BMP)‐2 are potent agents in cell proliferation and differentiation pathways. This study investigates the in vitro interactions between dexamethasone and BMP‐2 for an osteoblastic differentiation of mesenchymal stem cells (MSCs). Bone marrow‐derived human MSCs were cultured with DAG (group A), BMP‐2 + DAG (group B), and DAG + BMP‐2 combined with a porous collagen I/III scaffold (group C). RT‐PCR, ELISA, immuncytochemical stainings and flow cytometry analysis served to evaluate the osteogenic‐promoting potency of each of the above conditions in terms of cell morphology/viability, antigen presentation, and gene expression. DAG induced collagen I secretion from MSCs, which was further increased by the combination of DAG + BMP‐2. In comparison, the collagen scaffold and the control samples showed no significant influence on collagen I secretion of MSCs. DAG stimulation of MSCs led also to a steady but not significant increase of BMP‐2 level. A DAG and more, a DAG + BMP‐2, stimulation increased the number of mesenchymal cells (CD105+/CD73+). All samples showed mRNA of ALP, osteopontin, Runx2, Twist 1 and 2, Notch‐1/2, osteonectin, osteocalcin, BSP, and collagen‐A1 after 28 days of in vitro culture. Culture media of all samples showed a decrease in Ca2+ and PO 42− concentration, whereas a collagen‐I‐peak only occurred at day 28 in DAG‐ and DAG + BMP‐2‐stimulated bone marrow cells. In conclusion, BMP‐2 enhances DAG‐induced osteogenic differentiation in mesenchymal bone marrow cells. Both agents interact in various ways and can modify osteoblastic bone formation. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1440–1448, 2008