Physiologic Role of Decidual β_1 Integrin and Focal Adhesion Kinase in Embryonic Implantation

摘要

Implantation refers to a series of interactions between embryo and endometrium including hatching, attachment, and outgrowth. We investigated the expression and function of β_1 integrin and focal adhesion kinase (FAK) in human decidual cells during implantation. Immunofluorescent staining localized β_1 integrin to surfaces of cultured decidual cells. Double staining for β_1 integrin and mediators of intracellular signaling involving β_1 integrin, such as FAK and vinculin, colocalized β_1 integrin with these substances, suggesting that human decidual cells express β_1 integrin in the focal adhesion region. We next investigated the actions of β_1 integrin and FAK in implantation by co-culturing mouse embryos and human decidual cells. Mouse blastocysts attached to cultured decidual cells after embryo hatching, usually within 24 h of culture initiation. Blastocysts attached to decidual cells exhibited extensive outgrowth at 48 h. Treatment of decidual cells with an antibody against β_1 integrin or with an antisense FAK oligonucleotide did not affect hatching or attachment of blastocysts, but either one could inhibit outgrowth. Thus, it was concluded that human decidual β_1 integrin and FAK participate in this final step of implantation.