Affiliations: AO Research Institute, Davos, Switzerland | Department of Biomedical Engineering, Eindhoven University of Technology, The Netherlands
Note: [] Address for correspondence: Stephan Zeiter, AO Research Institute, Clavadelerstrasse 8, 7270 Davos Platz, Switzerland. Tel.: +41 81 414 23 11; Fax: +41 81 414 22 88; E-mail: stephan.zeiter@aofoundation.org.
Abstract: Bioactive factors, such as TGF β and BMP-2, as well as mechanical factors i.e. compressive loading and hydraulic pressure, have been shown to induce and/or modulate chondrogenesis of bone marrow derived mesenchymal stromal cells (BMSCs). Since these factors are intracellularly transduced through different mechanisms, it is hypothesized that TGF β, BMP-2 and hydraulic pressure may act synergistically on chondrogenic differentiation of BMSCs. Aggregates of bovine BMSC were cultured in the presence of 10 ng/ml TGF β1, 50 ng/ml BMP-2 or both. Half of the samples were loaded for 4 hours per day with 0.5–3 MPa cyclic hydraulic pressure at 1 Hz. After 14 days of culture/loading, gene expression of chondrogenic genes was assessed. DNA as well as glycosaminoglycan (GAG) content of the pellets were analysed. Neither pressure nor BMP-2 had an influence on GAG/DNA content. However, cells responded to the presence of TGF β1 with an up-regulation of chondrogenic genes and GAG/DNA of the aggregates increased compared to controls demonstrating the cells ability to respond to external stimuli. The used concentrations of BMP-2 and parameters for pressure were neither able to induce nor modulate chondrogenesis of bovine BMSCs and thus no synergistic effects were observed.
Keywords: Chondrogenesis, mechanobiology, bone marrow, stem cell, growth factors
DOI: 10.3233/BIR-2009-0520
Journal: Biorheology, vol. 46, no. 1, pp. 45-55, 2009
