Isolation and Localization of Basic Fibroblast Growth Factor-Immunoreactive Substance in the Epiphyseal Growth Plate

J Bone Miner Res. 1994 Nov;9(11):1737-44. doi: 10.1002/jbmr.5650091110.

Abstract

Previous research in our laboratory has shown basic fibroblast growth factor (bFGF) to be a permissive mitogen for isolated avian growth plate chondrocytes. The present study was conducted to determine whether bFGF is present in avian growth plate and, if present, to determine its localization within the tissue. Immunohistochemical studies revealed that bFGF is present in the resting proliferative and hypertrophic calcifying zones of the growth plate but is absent from the prehypertrophic zone. Basic FGF appears to be associated with the extracellular matrix of the proliferative zone, but it is predominantly intracellular in the hypertrophic and mineralizing zone chondrocytes. Partial purification of cartilage-derived bFGF was performed on crude extracts of cartilage using heparin-Sepharose affinity chromatography. The presence of bFGF in the heparin-Sepharose column fractions was confirmed by immunoblotting and radioimmunoassay. Furthermore, western blot analysis of the extracts showed multiple protein bands having bFGF immunoreactivity, in the molecular weight range 14.4-18 kD. The data support the hypothesis that bFGF has a dual role in the growth plate. In the proliferative zone it acts as a chondrocyte mitogen, whereas when released from terminal hypertrophic chondrocytes, bFGF may serve as a chemotactic signal for metaphyseal blood vessel proliferation.

MeSH terms

  • Animals
  • Blotting, Western
  • Cell Division / physiology
  • Chickens
  • Chromatography, Affinity
  • Electrophoresis, Polyacrylamide Gel
  • Fibroblast Growth Factor 2 / isolation & purification
  • Fibroblast Growth Factor 2 / metabolism*
  • Growth Plate / cytology
  • Growth Plate / embryology
  • Growth Plate / metabolism*
  • Immunohistochemistry
  • Male
  • Mitogens / metabolism
  • Molecular Weight
  • Radioimmunoassay
  • Tissue Distribution

Substances

  • Mitogens
  • Fibroblast Growth Factor 2