The Expression Of LPAR3、COX-2and VEGF In Endometrial Implantation Window Period Of Repeated Implantation Failure Patients

BackgroundDuring recent thirty years,IVF-ET technology has developed rapidly.As we allknow, embryo quality and endometrial receptivity are the two most important factorswhich are closely related to the pregnancy rate in assisted reproductivetechnology(ART)．With the improvement of embryonic laboratory technology,embryoquality improved greatly.The application of controlled ovarian hyperstimulation alsoenhance quality of embryo in clinical Though the implantation rate of IVF-ET is stillon a low level.As a result, the problem of endometrium receptivity defects isincreasingly prominent.Some scholars reported that more than half of the transplantfailure is due to the receptivity of endometrium reduced.The endometrium receptivityrefers to the acceptability of endometrium that can accept embryos in relatively shortperiod,this often happens on the6-10d after the peak of LH,the menstrual cycle20~24d, known as the "window period"implantation of the embryo. At present,authoritative reports, transplant are more than3times or the number of high qualityembryos transplanted are greater than10failed to successfully pregnant,known as therepeated implantation failure(RIF).Study of RIF mainly concentrated on the womb environment, ovarian steroid hormone secretion, autoimmune, tubal factors and psychological factors lead to theendometrium receptivity defects.But this still can’t effectively solve the the clinicalproblems of transplant failure.Repeated implantation failure bring huge economicpressure and mental stress to the patients.The establishment of the receptivity of endometrium is a series of steroidhormone, adhesion protein, cell factor, the result of mutual synergy.In recent years,some scholars found that planting of embryo and invasion of tumor cells are verysimilar.Lysophosphatidic acid was found to be a new factor in ovarian cancerascites.It is with the function like growth factor and play specific biological effects,combined with its receptors.In the known6kinds of receptors, LPAR3receptor isclosely related to the female sex most,which mainly exist in the female ovary,placenta, and endometrial tissue.Studies by LPAR3gene knock out female micedemonstrate that the expression of Cyclooxygenase-2and PGI are bothlower.Implantaion delay was found in the meanwhile.This suggests LPAR3-COX2-PGS downstream signaling pathways regulating embryo cultivation.And studies haveshown that synthesis of vascular endothelial growth factor closely related to theendometrial vascularization is regulated by the cox-2synthesis of PGs.Theestablishment of embryonic implantation site endometrial vascular network andendometrial decidual occurred, is one of the important conditions for successfulblastocyst adhesion.So how LPAR3、 COX-2、 VEGF express in endometrialimplantion window period of implantation failure patients.Whether they affectthe endometrium receptivity of RIF patients.This topic will discuss the issue.The experiment studies the expression and significance of LPAR3、COX-2andVEGF in endometrial implantation window period of RIF patients who will accept thetreatment of ART in the First Affiliated Hospital of ZhengZhou University.Thepurpose of the experiment is to provide theoretical basis for the research ofendometrium receptivity and improve clinical pregnancy rate in assisted reproductivetechnology. ObjectiveTo investigate the expression and significance of LPAR3、COX-2and VEGF inendometrial implantation window period.Explore the damage mechanism of repeatedimplantation failure.Provide theoretical basis for improving endometrium receptivityand implantation rate.Material and MethodsPatients who will accept the treatment of IVF-ET/ICSI-ET/Thaw-ET in theFirst Affiliated Hospital of ZhengZhou University between January2014and March2014are selected.The patients who have pregnanted with IVF before and chooseanother cycle are selected as control group and the RIF patients are experimentalgroup. Inclusion criteria:(1)Based on the normal endocrine (2)Normal menstrualcycles,28~35days(3)Did not use steroids for nearly three months (4) Normal uterinecavity form, no uterine malformation, endometrial polyps etc by hysteroscopy(5)NoChromosome disease, autoimmune disease, infectious disease activity, etc.Thepatients who are conformed to all standards will accept endometrial biopsy on21st~22nd day after proposed cases.After collecting endometrium,some are put in95%alcohol to pathological examination and remaining samples are divided into twoparts.One of the part are fixed in4%paraformaldehyde for immunohistochemicaldetection experiment and the other part are cryopreservated in-80℃refrigeratorafter washed with physiological saline for western blot experiment. The elbow venousblood is collected on an empty stomach when endometrial biopsy start.Then detectprogesterone (P) and estrogen (E2) levels and measure endometrial thickness.SPSSl2.0statistical data analysis software is used in the experiment.Results1. Immunohistochemical results show that the LPAR3, COX-2and VEGF areexpressed in endometrium of both groups in endometrial implantation window period,especially in endometrial glandular epithelial cells.LPAR3and cox-2are alsoexpressed in endometrial cavity epithelium and stromal cells.And VEGF is expressedin part in patina mesenchymal cells and vascular endothelial cells.Comparing theaverage optical density value,the expression of LPAR3, COX-2and VEGF in RIFgroup is significantly lower than the control group.There are statistically significantdifferences（P<0.01).2. According to the results of Western blot,LPAR3, cox-2and VEGF are alldetected in two groups of endometrium.But the expression of LPAR3, COX-2andVEGF in RIF group is significantly lower than the control group.There arestatistically significant differences（LAR3：0.354±0.053VS0.279±0.041，P<0.01；COX-2：0.571±0.087VS0.165±0.022，P<0.01；VEGF：0.627±0.096VS0.313±0.045，P<0.01）。Conclusions1. The express parts and characteristics of LPAR3in endometrial implantationwindow period are same with this of VEGF which reflects endometriumreceptivity.According to the results of the experiment,LPAR3can be used as potentialmarker of endometrium receptivity.2. The expressions of LPAR3, COX-2and VEGF in endometrial implantationwindow period of RIF group are significantly lower.This suggest that endometriumreceptivity of patients with RIF decrease.As a result,This may be the cause ofrepeated implantation faliure.3. Lower expressions of LPAR3, COX-2and VEGF in RIF group show thatLPAR3, COX-2and VEGF may be a mechanism to regulate the production ofendometrial blood vessels to participate in the embryo of planting.