Endothelial cells line the inside of blood vessels and play an important role in the formation and maintenance of blood vessels and vasculature. Endothelial cells have a relatively low turnover in adults since their proliferation is inhibited by contact with the capillary basement membrane.
Endothelial cells can switch between quiescent and angiogenic phenotypes. During angiogenesis, endothelial cells secrete matrix metalloproteases that break down the basal lamina of the capillary. The endothelial cells migrate towards growth factors signals, such as VEGF, they proliferate and new capillary sprouts form. The vessels fuse to form a new lumen and other cell types such as smooth muscle cells and pericytes are recruited to the new capillary. Once the capillary is established, endothelial cell migration and proliferation reduces significantly. Endothelial cells regulate the exchange of nutrients between the bloodstream and surrounding tissues. There is a lot of interest in studying the role of endothelial cells in tumour growth and progression given their role in angiogenesis and remodelling the tissue microenvironment. Endothelial cells are frequently used in co-culture studies with other cell types such as cardiomyocytes given their role in cardiac development, maintenance and repair.
