title: Effect of TGF beta1, BMP-2 and hydraulic pressure on chondrogenic differentiation of bovine bone marrow mesenchymal stromal cells.
abstract: Bioactive factors, such as TGF beta 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 beta, 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 beta1, 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 beta1 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.
authors.affiliation: AO Research Institute, Davos, Switzerland. stephan.zeiter@aofoundation.org
authors.forename: Stephan
authors.initials: S
authors.lastname: Zeiter
authors.forename: Patrick
authors.initials: P
authors.lastname: Lezuo
authors.forename: Keita
authors.initials: K
authors.lastname: Ito
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D002417:Cattle; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D020219:Chondrogenesis / Q000187:drug effects / Q000502:physiology; D040542:Mechanotransduction, Cellular; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000502:physiology*; D018709:Statistics, Nonparametric; D013314:Stress, Mechanical; D023822:Tissue Engineering / Q000379:methods; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*
chemical_list: D055396:Bone Morphogenetic Protein 2; D053773:Transforming Growth Factor beta1