Molecular team boosts bone repair

Large bone defects secondary to tumor or trauma and fracture-delayed unions often require bone regeneration enhancements, but the precise mechanisms involved in bone healing have remained clear. In September 15 Journal of Clinical Investigation, Hairong Peng and colleagues at the University of Pittsburgh, Pennsylvania, US, show that simultaneous expression of bone morphogenetic protein-4 (BMP-4) and vascular endothelial growth factor (VEGF) on stem cells potentiate bone formation and repair (J Clin Invest, 110:751-759, September 15 2002).

Hairong Peng et al. used muscle-derived stem cells genetically engineered to express human BMP-4, VEGF or VEGF-specific antagonist. They observed that although VEGF alone did not improve bone regeneration, it acted synergistically with BMP-4 to increase recruitment of mesenchymal stem cells, enhance cell survival and to augment cartilage formation in the early stages of endochondral bone formation.

In addition, they showed that the beneficial effect of VEGF on bone healing elicited by BMP4 depends critically ...