Characterization of radioiodinated recombinant human TGF-β1 binding to bone matrix within rabbit skull defects
| Autor: | Thomas F. Zioncheck, Wyne P. Leeè, Edward P. Amentoè, Yvette Xuè, Louise Richardson, Leo Deguzmanè, L. Steven Beckè |
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| Rok vydání: | 2009 |
| Předmět: |
Male
Endocrinology Diabetes and Metabolism Calvaria Bone healing law.invention Iodine Radioisotopes Transforming Growth Factor beta law medicine Animals Orthopedics and Sports Medicine Binding site Fracture Healing Periosteum Lagomorpha biology Chemistry Skull Osteoblast Anatomy biology.organism_classification Molecular biology medicine.anatomical_structure Recombinant DNA Rabbits |
| Zdroj: | Journal of Bone and Mineral Research. 8:1407-1414 |
| ISSN: | 0884-0431 |
| Popis: | Bone healing is regulated in part by the local production of TGF-β1 and other growth factors produced by cells at the site of injury. The single application of recombinant human TGF-β1 (rhTGF-β1) to calvarial defects in rabbits induces an accelerated recruitment and proliferation of osteoblasts within 3 days. This ultimately results in the formation of new bone and the complete closure of the defect within 28 days. The persistence and localization of [125I]rhTGF-β1 within an osseous defect was investigated after applying a single dose of [125I]rhTGF-β1 formulated in a 3% methylcellulose vehicle. Normal bone encompassing the defect site, the periosteum, and the gel film covering the dura were harvested at 0, 4, 8, and 24 h and 3, 7, and 16 days after [125I]rhTGF-β1 application. The defect site-associated radioactivity was quantitated, visualized by autoradiography, and characterized by TCA precipitation and SDS-PAGE. Radioactivity was observed in autoradiographs of gross specimens, histologic sections of the bone matrix, and periosteal tissue surrounding the defect. There was a time-dependent decrease in TCA-precipitable radioactivity; however, radioactivity was still associated with the bone matrix 16 days after application of [125I]rhTGF-β1. SDS-PAGE and autoradiography of the radioactivity in homogenized bone and periosteal samples revealed a 25 kD band, suggesting that the radioactivity remaining at the defect site represented intact [125I]rhTGF-β1. Results of this study indicate that rhTGF-β1 may bind tightly to bone matrix in its active form, and this binding may be associated with the observed increase in osteoblast number and bone matrix within the calvarial defects. |
| Databáze: | OpenAIRE |
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