Study On The Relationship Between The Secretion Of Le～Y,MMP-9 Of Single Embryo And Embryo Development And Implantation And Its Functional Significance

Embryo implantation, which is the process of blastocyst adhere and invade endometrium, consists three parts of attachment hydrolysis of extracellular matrix (ECM) and invasion. Successful implantation results from the fine regulated co-operation between the invasive blastocyst and the receptive endometrium.It has known that many factors are crucial to implantation. Embryo can express and secret many cytokines to make itself alive, development and implantation. The study of human embryos cultured in vitro indicated that the survival rate and viability of embryos cultured in vitro is much lower than those in vivo. So raising the rate of implantation and improving the condition of culture in vitro is the key. Study of these related factors will help to resolve this problem.The implantation related factors include cytokines . growth factors. ECM. MMPs. oligosaccharides etc. The major study of recent years focus on the function of these factors, aimed to find out the key factors of embryo development and implantation (functional marker).The quality of embryo is positively related to the secretion level of growth factors of embryo. Oligosaccharide LeY is staged-specifically expressed on cell surface of the embryo and reaches the peak at the stage of blastocyst. It has been shown that oligosaccharide LeY antigen plays an essential role at the initial stage of implantation. It acts as a mediator molecule for adhesion between the surface of blastocyst and epithelial cell, and maybe involved in implantation regulation, MMP-9 is highly expressed and secreted by trophoblast cells, and the antibody of MMP-9 can inhibit theinvasion of the trophoblast This indicates MMP-9 is very important to the invasive embryo. The results of our study of last year found that the secretion levels of LeY and MMP-9 of the same morphology were different. By using highly sensitive dot blotting method, the difference can be clearly detected.Based on these studies, the functional significances of the difference of the secretion of level of LeY and MMP-9 were investigated. By using a highly sensitive dot blotting method, embryos were divided into two groups according to the level of LeY and MMP-9 secretion. Three items of the both groups were respectively detected. The major results are:1) In vitro culture system, a) LeY high secreted group developed significantly faster than low one. b) MMP-9 high secreted group developed significantly faster than low one.2) In the co-culture system , a) the attachment and outgrowth rate of LeY high secreted group (64.89%) were significantly higher than low secreted (14.29%) group, b) the outgrowth rate of MMP-9 high secreted group (65.42%) were significantly higher than low secreted (12.50%) group.3) In the embryo transplantation model, a) The implantation rate of LeY high secreted group (71.88%) was significantly high than low secreted group (31.25%). b) The implantation rate of MMP-9 high secreted group (79.17%) was significantly high than low secreted group (36.11%).For the first time these results improve that, embryo LeY and MMP-9 secretion level are closely related to the ability of embryo development and implantation. LeY and MMP-9 may be functional markers, In addition, a new method to study on functional markers of embryo development and implantation was established. By directly detection of implantation related factors which are secreted by embryo to analyze the ability of embryo development and implantation is specific, sensitive, fast and also no hurt to the embryo. This may have theoretical significance to the study of the regulation of early embryo development and may also have practical value to reproduction medicine.