EGF Inhibits The Expression Of FUT1/FUT4 LeY And Increase The Adhesion Of The Embryo To The Uterine Endometrial Epithelial Cells

Implantation is a complex and dynamic psychological process. It begins as recognition, location and adhesion between the wandering blastocyst and the endometrium cells. Blastocyst can penetrate the endometrium surface, and then bury itself in the embryonic trophoblastic cell of endometrium matrix. The adhesion which relies on the synchronization between invasion of blastocyst and receptivity of endometrium is regulated by many factors, e.g., hormones, cytosines and oligosaccharides, which are critical for a successful implantation.Fucosyltransferases are the key enzymes that participate in the synthesis of fucosylated glycans.α1,2-fucosyltransferases(FUT1)andα1,3-fucosyltransferases(FUT4)involve in the synthesis of LeY oligosaccharide on cell membrane. Previous researches reveal that specific and periodic expression of the LeY oligosaccharide contributes to embryo implantation. LeY oligosaccharide mediates molecular recognition between mother and fetus for the necessity of implantation, and also functions as a signal molecule in regulatory networks of implantation, as well as modulates other related molecules in implantation.As a nutrition factor in maternal environment, epidermal growth factor (EGF), which is polypeptide hormone with 53 amino acids, is the major member of growth factor family. EGF and EGFR exist widely in the germinal tissues, e.g., endometrium, deciduas, preimplantation embryo and trophoblast. Either acting alone or functioning in cytosine network, EGF participates in embryo implantation by the pathway known as autocrine, paracrine or endocrine.This research used the implantation model of human endometrium cells(RL95-2)and embryonic cells(JAR)in vitro. After the administration of EGF, we investigate the expression of the FUT1/FUT4 and their possible effects on the synthesis of LeY by RT-PCR, Western blot, flow cytometery and indirect immunofluorescence. We detected the effects of EGF on implantation by embryo adhesion test. Results showed that EGF increased the expression of the FUT1/FUT4 genes and protein synthesis, elevated the synthesis of LeY oligosaccharide antigen on cell membrane, and augmented the adhesion rate of JAR and RL95-2, which shows the most significant impacts at the dose of 100ng/ml EGF. EGFR antibody inhibits expression of the FUT1/FUT4 gene in RL95-2, synthesis of related protein and synthesis of LeY oligosaccharide antigen on cell membrane.EGF modulates the adhesion of embryonic cell and endometrium cell by promoting the expression of FUT1/FUT4 in endometrium cell and LeY oligosaccharide antigen on cell membrane. Researches on the expression of fucosyltransferases and its regulation can enlighten us on the function of oligosaccharide during implantation and the further intervention of implantation by glycobiological methods.