The expression and function of VEGF at embryo implantation “window” in the mouse

Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen that plays a critical role in angiogenesis. Recent reports indicated that VEGF was closely involved in embryo implantation and embryonic vasculogenesis. However, very little information is available about the detailed expression and function of VEGF at implantation “window”. In this work, VEGFs were primarily present on uterine epithelial cell monolayer and blastocysts including the outgrew trophoblasts at implantation window. VEGF antibodies decreased the number of mice embryos implanted and the percentage of blastocysts with attachment and outgrowth in a co-culture model in a dose-dependant manner. These findings demonstrate that VEGF is one of the essential cytokines for embryo implantation in mouse. VEGF may act as a local mediator to regulate the maternal-fetal interaction, and facilitate blastocyst implantation.