Vascular endothelial growth factor and bone–vascular interactions

Abstract It has been long established that a functional vascular system is crucial for skeletal development and homeostasis. Skeletal blood vessels not only supply oxygen and nutrients to ensure proper functioning of bone-forming and bone-resorbing cells, but also deliver calcium and phosphate to sites of active bone mineralization, together with hormones and growth factors that regulate the function of skeletal cells. Moreover, the bone marrow vasculature provides a niche for skeletal stem and progenitor cells next to blood-forming hematopoietic stem cells. Particular to the skeleton is that in contrast to the highly vascularized bone tissue, the cartilaginous part is avascular. The intimate connection of the vascular system with bone cells occurs not only during development, but also during bone repair, indicating that a better understanding of the mechanisms that couple bone and blood vessels may provide new therapeutic options for skeletal pathologies.