Differentiation of mouse epl (early primitive ectoderm like) cells into endothelial progenitors

Embryonic stem cell (ES) based therapies have gained significant interest due to their limitless self-renewal capabilities and potential formation of all tissue types. There is specific interest in our laboratory to produce endothelial cells (EC) from ES cells. Differentiation parameters that have been adapted have focused on the role of the vascular endothelial growth factor (VEGF). Recent studies and work done in our laboratory indicate that mouse ES cells, when grown on a collagen matrix, differentiate into EC progenitors as indicated by production of Flkl⁺ (VEGF-receptor) cells. We have a novel technique for culturing stable early primitive ectoderm like (EPL) cells, which are obligatory intermediates in differentiation pathways, and derived from ES cells. Mouse EPL cells were grown on a collagen matrix and Flkl expression was monitored over an 8-day time period. An early and increased production of Flkl⁺ cells when mouse ES cells are converted to EPL cells, was observed. When EPL cells were also exposes. to VEGF, endothelial tube structures started to form and networks of tubes were present after 4 days of VEGF in the culture medium. These results suggest that conversion of mouse ES cells to EPL cells could constitute an important step in the directed differentiation strategy towards EC´s.