Effects of platelet-derived growth factor on bone formation in vitro

✍ Scribed by Ernesto Canalis; Thomas L. McCarthy; Michael Centrella

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 751 KB
• Volume: 140
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041400319

✦ Synopsis

Platelet-derived growth factor (PDGF) is a polypeptide found in a variety of tissues, including bone, where it could act as an autologous regulator of skeletal remodeling. Therefore, a recombinant B chain homodimer of human PDGF was studied for its effects on bone formation in cultured rat calvariae. PDGF at 10-100 ng/ml stimulated [3H]thymidine incorporation into DNA by up to sixfold and increased the DNA content and the number of colcemid-induced metaphase arrested cells. This effect was observed in the fibroblast and precursor cell-rich periosteum. As a result of its mitogenic actions, PDGF enhanced [ 3 H ] p r ~l i n e incorporation into collagen, an effect that was observed primarily in the osteoblast-rich central bone. The effect of PDGF was not specilic for collagen since it also increased noncollagen protein synthesis. In addition, PDGF increased bone collagen degradation. PDGF and insulin-like growth factor (IGF) I had additive effects on calvarial DNA synthesis, but PDGF opposed the stirnulatory effect of IGF I on collagen synthesis and IGF I prevented the PDGF effect on collagen degradation.

In conclusion, PDGF stimulates calvarial DNA synthesis which causes an increased number of collagen-synthesizing cells, but PDGF also enhances bone collagen degradation.