Differentiation-dependent up-regulation of BMP-2, TGF-beta1, and VEGF expression by FGF-2 in human bone marrow stromal cells.
BACKGROUND
Bone tissue formation by bone marrow stromal cells may be supported and enhanced by multiple growth factors, particularly in cases of a compromised local microenvironment. In this study, the authors hypothesized that fibroblast growth factor (FGF)-2 can stimulate the production by human bone marrow stromal cells of osteogenic [i.e., bone morphogenetic protein (BMP)-2 and transforming growth factor (TGF)-beta1] and angiogenic [i.e., vascular endothelial growth factor (VEGF)] factors.


METHODS
Human bone marrow stromal cells from six donors were expanded for two passages (expansion phase) and subsequently cultivated in osteogenic medium containing ascorbic acid, beta-glycerophosphate, and dexamethasone (differentiation phase). After each phase, cells were transferred into serum-free medium with or without FGF-2 at different concentrations and for different times, and the expression of BMP-2, TGF-beta1, and VEGF was quantified at the mRNA level by real-time quantitative reverse-transcriptase polymerase chain reaction. The amounts of TGF-beta1 and VEGF released in the culture medium were assessed using enzyme-linked immunosorbent assay kits and normalized to the DNA content.


RESULTS
In response to 5 ng/ml FGF-2 for 24 hours, the mRNA expression of VEGF increased at both culture phases (up to 6.1 fold), whereas that of BMP-2 and TGF-beta1 significantly increased only after the expansion (3.1-fold) or differentiation phase (2.1-fold), respectively. Similar trends were observed in the amounts of proteins measured in the culture medium.


CONCLUSIONS
The authors' results indicate that FGF-2 up-regulates the expression of BMP-2, TGF-beta1, and VEGF in human bone marrow stromal cells, in a pattern dependent on the cell-differentiation stage. These findings prompt for in vivo investigations on the delivery of FGF-2 for the temporally/functionally regulated enhancement of bone marrow stromal cell-based bone induction.
Farhadi
Jian
J
Department of Surgery, University Hospital Basel, Basel, Switzerland.
Jaquiery
Claude
C
Barbero
Andrea
A
Jakob
Marcel
M
Schaeren
Stefan
S
Pierer
Gerhard
G
Heberer
Michael
M
Martin
Ivan
I
D001854:Bone Marrow Cells / Q000502:physiology*; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D016222:Fibroblast Growth Factor 2 / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D010012:Osteogenesis / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017154:Stromal Cells / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D053773:Transforming Growth Factor beta1; D015854:Up-Regulation / Q000502:physiology*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2