(L-466) Hypoxia modifies endothelial cell behavior and encourages tube formation in vitro

Endothelial cells are found at a variety of oxygen concentrations in the body. However, despite their differences in native environment, they are typically cultured at 21% oxygen in vitro. Here, we culture juvenile lymphatic endothelial cells (LECs) at 21%, 5%, and 1% oxygen for 24 hours in order to study the changes in their gene expression under physiologically-relevant conditions. A tube formation assay will also be performed over the course of several days at these oxygen concentrations. We predict that the increased stability of transcription factor hypoxia-inducible factor 1 (HIF-1) at lower oxygen concentrations results and increase in LEC markers such as Prox1, LYVE1, and Podoplanin, as measured by PCR and immunofluorescent staining. The impact of hypoxia on metabolism markers such as GLUT1, BNIP3, BNIP3L, and ANGPT1 will also be investigated. Additionally, we predict an increased rate of lymphatic vessel formation at oxygen concentrations < 21%. As a result, hypoxic cell culture may provide a more efficient way of growing lymphatic vasculature in vitro for future clinical applications and research.