Characterization of mitogenic activities extracted from bovine bone matrix

Area of Science:

• Biochemistry
• Cell Biology
• Orthopedics

Background:

• Bone matrix contains proteins with potential mitogenic activity.
• Ethylenediaminetetraacetate (EDTA) demineralization releases these proteins.

Purpose of the Study:

• To examine the mitogenic activity of proteins released from adult bovine bone matrix.
• To identify growth factors present in bovine bone extract (BBE).

Main Methods:

• Proteins were extracted from adult bovine bone matrix using EDTA demineralization.
• Cell proliferation and DNA synthesis were measured in various cell types exposed to BBE.
• Beta transforming growth factor (TGF) activity was assessed using NRK cell colony formation assay.

Main Results:

• BBE stimulated proliferation and DNA synthesis in bone cells, cartilage, skin, muscle, and fibroblast cell lines.
• BBE demonstrated beta TGF activity and contained previously described bone-derived growth factors.
• BBE's maximal stimulation of chick embryo calvarial cell DNA synthesis equaled or exceeded that of known non-osseous growth factors.

Conclusions:

• BBE contains multiple growth factors, including beta TGF and non-bone-specific factors.
• BBE appears to contain all previously described bone-derived growth factors.
• Combinations of bone-derived and systemic factors can coordinately stimulate bone cell proliferation.