Expression of Down Syndrome Critical Region 1 Represses Vascular Branching in Xenopus laevis Larva

A variety of morphological differences exist in blood vessels. Among them for example, large vessels such as aorta and small vessels such as capillaries differ in their sizes and branching frequencies. Although intense investigations have increased our understanding of molecular mechanisms in blood vessel formation, regulative mechanisms of either size or branching frequency of blood vessels still remains to be uncovered. Understanding these unexplained mechanisms may enable us to induce blood vessels of desired size and branching frequency which ultimately lead to new angiogenic therapies targeted to cure morphologically heterogenic vessels. In order to isolate genes regulating the size and branching of vessels, models for large vessels with low branching frequencies and small vessels with high branching frequencies were developed using fibrin gel assay. Specifically, these two vascular structures were constructed from human umbilical vein endothelial cells (HUVECs) cultured on Cytodex 3 beads. HUVEC /Cytodex 3 beads were then embedded in fibrin gel and treated with different doses of vascular endothelial growth factor (VEGF) for 7 days to produce the two distinct vascular structures.