[Purification and characterization of growth factor extracted from bone].
Local metabolic balance between the bone formation and resorption is modulated by many growth factors present in the bone. The mechanism of this regulation has been investigated by many researchers but is not completely clarified yet. In this study, the author found the presence of several growth factors in the 1 M NaCl extract from the bovine bone and one of them was confirmed to be different from the factors previously reported in the bone tissue. This factor was purified by means of gel filtration and heparin-affinity chromatography and characterized in detail. The purified factor stimulated the proliferation of the fibroblast cell line, Balb/c3T3, but neither stimulated nor inhibited that of the osteoblast cell line, MC3T3-E1. The factor was stable against heat (65 degrees C), acid (2N HCl), 6M urea or 4M guanidine-HCl treatments. However, it was inactivated by trypsin. The molecular size of this factor was about 15,000 and had a high affinity for heparin. In contrast to aFGF or bFGF, the fibroblast-proliferating activity of this factor was suppressed dose-dependently by heparin addition. According to those properties, this factor was indicated to be different from TGF- beta, aFGF, bFGF, PDGF, IGF-I, IGF-II or BMP which were reported to be present in the bone tissue. It is suggested the presence of a new factor in the bone which may regulate the proliferation of fibroblasts in vivo.
Uchida
T
T
Department of Maxillofacial Surgery, Faculty of Dentistry, Tokyo Medical and Dental University.
D000818:Animals; D001842:Bone and Bones / Q000737:chemistry*; D002417:Cattle; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006133:Growth Substances / Q000302:isolation & purification*
D006133:Growth Substances