Blood vessels form through a complex series of interactions among cells called “crosstalk.” Researchers led by Hyung J. Chun, M.D., associate professor of medicine, have identified a crucial player in the process: a tiny RNA molecule known as miR-139-5p. The researchers studied mice that lacked either the gene apelin (APLN) or its receptor (APLNR), and found the retinal vasculature of these mice to be severely underdeveloped. They also found in the blood vessels of these mice that the expression of a related gene that directs a distinct set of cellular signaling, known as CXCR4, was aberrantly increased. The crosstalk between these molecules was mediated by miR-139-5p, which controls expression of CXCR4 and is essential for normal vascular development.
The finding demonstrates a novel mechanism by which interdependence between signaling pathways is established in the developing blood vessels. The findings, published April 12 in Nature Communications, have implications for conditions including heart disease, cancer, and blinding diseases of the retina.