Molecular profile of osteoprogenitor cells seeded on allograft bone

J Tissue Eng Regen Med. 2011 Oct;5(9):704-11. doi: 10.1002/term.367. Epub 2010 Dec 30.


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-β1, 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-β1 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-β1 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone and Bones / cytology
  • Bone and Bones / drug effects
  • Bone and Bones / physiology*
  • Cell Differentiation / drug effects
  • Cells, Cultured
  • Culture Media / pharmacology
  • Gene Expression Profiling*
  • Gene Expression Regulation / drug effects
  • Male
  • Mesenchymal Stem Cells / cytology*
  • Mesenchymal Stem Cells / drug effects
  • Mesenchymal Stem Cells / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Osteoblasts / cytology
  • Osteoblasts / drug effects
  • Osteoblasts / metabolism
  • Osteocalcin / metabolism
  • Osteogenesis / drug effects
  • Osteogenesis / genetics
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Statistics, Nonparametric
  • Transplantation, Homologous


  • Culture Media
  • RNA, Messenger
  • Osteocalcin