3Development of an in vitro model for human embryo implantation and progesterone regulation

Aim:  Develop an in vitro 3D-model for human embryo implantation on receptive endometrial construct.
Material and Methods:  Three-dimensional in vitro endometrial construct (n=12) was developed by culturing isolated human endometrial stromal cells in collagen matrix overlaid with epithelial cells. After priming hormonally, human blastocysts were placed and cultured in alpha-medium. Attachment of embryo was confirmed using cytokeratin-7 and expression of endometrial receptivity markers using immunohistochemistry. Antiprogestin mifepristone was used to test implantation and receptivity.
Results:  Embryos attached to receptive endometrial construct . Epithelial and stromal cells of endometrial construct expressed ER-α, ER-β, PR-(A+B), PR-B, VEGF, LIF, IL-1beta and COX-2. Epithelial cells expressed AR, integrinα_Vβ₃ and MUC1. Mifepristone inhibited blastocyst attachment, up-regulated epithelial ER-β, PR-B; down regulated stromal VEGF, MUC1 and integrin α_Vβ₃ as observed in vivo .
Conclusion:  An in vitro human embryo implantation model, regulated by progesterone was developed and tested. This could be further used to understand molecular basis of human embryo implantation .