Osteoblast-secreted factors promote proliferation and osteogenic differentiation of bone marrow stromal cells via VEGF/heme-oxygenase-1 pathway

PLoS One. 2014 Jun 18;9(6):e99946. doi: 10.1371/journal.pone.0099946. eCollection 2014.

Abstract

The hypoxia-inducible factors (HIFα) are the critical factors that couple angiogenesis and osteogenesis by activating transcription of VEGF in osteoblasts. Mice lacking von Hippel-Lindau gene (Vhl), thus overexpressing HIFα in osteoblasts develop extremely dense and highly vascularized long bones. Here we provide evidence that osteoblasts lacking Vhl overexpress and secrete high levels of VEGF, which subsequently promotes the proliferation and osteogenic differentiation of bone marrow stromal cells (BMSC) by promoting expression of Heme oxygenase-1 (HO-1) in BMSC. Conditioned medium from osteoblasts Vhl (CM-CRE) promoted the proliferation and osteogenic differentiation of BMSC, in comparison with conditioned medium derived from normal osteoblasts (CM-GFP). Recombinant VEGF stimulated the proliferation and osteogenic differentiation of BMSC culturing in CM-GFP. By contrast, VEGF-neutralizing antibody inhibited the proliferation and osteogenic differentiation of BMSC culturing in CM-CRE. Treatment with a HO-1 inhibitor, SnPP, significantly inhibited VEGF-induced BMSC proliferation and osteogenic differentiation. On the contrary, activation of HO-1 with CoPP reversed the suppressing of VEGF-antibody on the proliferation and osteogesis of BMSC culturing in CM-CRE. These studies suggest that osteoblasts promote the proliferation and osteogenic differentiation of BMCS by VEGF/HO-1 pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipogenesis / drug effects
  • Animals
  • Cell Differentiation* / drug effects
  • Cell Proliferation / drug effects
  • Culture Media, Conditioned / pharmacology
  • Heme Oxygenase-1 / metabolism*
  • Mesenchymal Stem Cells / cytology*
  • Mesenchymal Stem Cells / drug effects
  • Mesenchymal Stem Cells / metabolism*
  • Mice
  • Models, Biological
  • Osteoblasts / drug effects
  • Osteoblasts / metabolism*
  • Real-Time Polymerase Chain Reaction
  • Signal Transduction / drug effects
  • Vascular Endothelial Growth Factor A / metabolism*
  • Von Hippel-Lindau Tumor Suppressor Protein / metabolism

Substances

  • Culture Media, Conditioned
  • Vascular Endothelial Growth Factor A
  • Heme Oxygenase-1
  • Von Hippel-Lindau Tumor Suppressor Protein
  • VHL protein, mouse

Grants and funding

This work was supported by the funds from the International Cooperation and Exchange of the National Natural Science Foundation of China (No. 81061160510), the Foundation of Science and Technology Commission of Shanghai Municipality (No. 12JC1408200, No. 13431900702), and the Graduate Student Innovation Fund of Shanghai Jiao Tong University School of Medicine (No. BXJ201242). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.