Molecular profile of osteoprogenitor cells seeded on allograft bone JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE Smith, K. E., Huang, Z., Ma, T., Irani, A., Smith, R. L., Goodman, S. B. 2011; 5 (9): 704-711


In order to optimize and modulate bone formation it is essential to understand the expression patterns of key bone-specific growth factors, as osteoprogenitor cells undergo the processes of proliferation, differentiation and maturation. This study reports the sequential expression of bone-related growth and transcription factors when bone marrow-derived osteoprogenitor cells from C57BL mice were cultured on allograft bone discs. Mineralization and osteocalcin protein levels were used to track osteogenic differentiation and maturation. Bone-related growth factors, such as Bmp-2, Bmp-7, Ctnnb-1, Fgf-2, Igf-1, Vegf-a and Tgf-ß1, and transcription factors, such as Runx-2 and osteocalcin, were examined by enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR). Total density of mineralized bone was significantly increased 7.6 ± 0.7% in allografts cultured with cells, compared with a 0.5 ± 2.0% increase in the controls without cells (p < 0.01). Osteocalcin protein levels peaked at day 4. Protein expression showed peaks of BMP-2 and TGF-ß1 on day 2, with VEGF peaking on day 8, and IGF-1 decreasing on day 2. mRNA for Pdgf-a peaked on day 2; Bmp-2 on days 4 and 16; Ctnnb-1 on days 8 and 20; Vegf-a, Fgf-2, Runx-2 and Igf-1 on day 12; Tgf-ß1 on day 16; and Pdgf-b on day 20. Osteogenic growth factors correlated with Runx-2 and Ctnnb-1, whereas a predominant vascular growth factor, Vegf-a, did not follow this pattern. Specific bone-related genes and proteins were expressed in a time-dependent manner when osteoprogenitor cells were cultured on cortico-cancellous bone discs in vitro.

View details for DOI 10.1002/term.367

View details for PubMedID 21953868