Integrins and vascular development in differentiated embryonic stem cells in vitro.

The development of techniques for the in vitro differentiation of mouse embryonic stem (ES) cells has provided researchers with the tools to investigate vascular development as would occur in an early embryo. Mice lacking the vascular integrins have various defects in the vasculature, including defects in vessel architecture and hemorrhage: some animals die before birth. Using homozygous null ES cells for these integrins and in vitro differentiation of vascular networks in embryoid bodies, we can recapitulate the defects that give rise to embryonic lethality in mice. This allows the investigation of the molecular and cellular mechanisms responsible for the vascular defects that arise in the embryo.