Expression Of TACE In Mouse Uterine Epithelial Cell During Implantation Window Period And Effect Of TACE Antibody On The Embryo Implantation

Background:Blastocyst implantation is one of the earliest events in reproduction of humans and mammals that determines whether pregnancy will develop successfully or not. Successful implantation depends on invasive embryo, acceptive endometrium and their synchronization. There is an extremely short period in uterine receptivity for embryo implantation, which is called"implantation window". Implantation in all mammals involves shedding of zona pellucida, followed by orientation, attachment and adhesion, and invasion of the embryo to the endometrium. Blastocyst implantation is involved in the regulation of large number of genes and the enrollment of complicated regulatory systems.Tumour necrosis factor alpha converting enzyme (TACE) was identified by its ability to cleave tumor necrosis factor alpha at its physiological processing site[1]. It has common sequences of ADAMs: signal peptide, propeptide, catalytic domin, disintegrin domin, cysteine-rich domin, transmembrane domin, cytoplasmic domin[2,3]. By proteolytic removal of the extracellular domain of numerous transmembrane proteins, TACE can be concerned with cell adhesion, fusion, signal transduction and so on. Recent research indicated that TACE was overexpressed in most mammary tumors ,renal cell carcinomas, hepatic cellular cancers, prostatic carcinomas pancreatic carcinomas and colon carcinomas[4,5]. Now it is accepted that the process of embryo implantation is extremely similar with that of tumor invasion and metastasis. Our preliminary studies have shown that the expression of TACE in mouse endometrium during estrus cycle and early pregnancy had regular pattern.The expression in pregnant groups was higher than that in nonpregnant group. TACE expression appeared an increased trend as time passing by, and reached the maximum at pregnancy d 4,TACE expressed mainly in mouse uterine epithelial cell[6].So it is inferred that TACE may play the same role in the process of embryo implantation.Objective:To detect expression of tumor necrosis factor-converting enzyme(TACE) on the mouse uterine epithelial cell and the effect of implantation in vitro. TO analyze its role in blastocyst implantation and to investigate the relation TACE with implantation of mouse embryo.Methods:1.Co-culturing epithelial cells and blastocyst of the pregnant 4-day( d4) mouse in vitro to establish the simple and easy implantation model. 2. Endometrial epithelial cells was identified by Immunochemistry in the co-culture system .3.RT-PCR and Immunochemistry were used to detect the expression of TACE gene and protein in the system.4.Different concentrations of TACE antibody were added to the implantation model to observe effect of TACE antibody on mouse blastocyst implantation in vitro. Expression of TACE protein was detected by Immunochemistry in each antibody interference system.Results:1. Endometrial epithelial cells growed vigorously in vitro.. Keratin antibody showed positive expression, meanwhile, Vimentin antibody showed negative expression in the endometrial epithelial cells.2.PCR showed that the expression of TACE gene was high and results of Immunochemistry , Western-blot were consisted with PCR.3.The adhesion rate of mouse blastocyst was high in the co-culture system and decreased remarkably when TACE antibody was added (P<0.05). The adhesion rate of mouse blastocyst appeared a increased trend as the concentration of TACE antibody lowed. Immunochemistry also showed that expression of TACE protein rised as the concentration of TACE antibody lowed.Conclusion:TACE mRNA and protein expression in mouse endometrium epithelial cells of pregnancy d4 were both strongly high. The abscission of material covered endometrial cells induced by TACE might participate in the process which endometrium changes to the receptive one to accommodate blastocyst implantation. The adhesion rate of mouse blastocyst decreased remarkably when TACE antibody was added . We presumed that TACE participated in the process of mouse blastocyst implantation, which promoted adhesion and outgrowth of blastocyst to prepare for blastocyst implantation.