The circulatory system not only supplies the body with oxygen and nutrients, but might also carry toxic compounds and pathogens. To enhance protection of the brain, cerebral blood vessels build the so-called blood-brain barrier. Our studies of the zebrafish brain vasculature show that blood vessel growth and building of the blood-brain barrier are coordinated by two interacting signaling pathways. As the same principles also apply to mammalian cells, the balance of these signaling pathways could be of relevance for human pathological conditions and their treatment.
Blood vessels provide the whole organism with essential oxygen and nutrients, but are also an important source of regulatory cues in many organs. In the skeletal system, specialized capillaries release signals that control bone-forming progenitor cells and thereby bone growth. The aging organism lacks such specialized blood vessels and shows a detrimental decline in bone renewal. New results indicate that the stimulation of blood vessel growth in such conditions might be therapeutically beneficial.