HOXA10 Improves Endometrial Receptivity By Up-Regulating E-cadherin And Its Mechanism

Objective: Endometrial receptivity is an important factor affecting embryo implantation.The establishment and regulation mechanisms of endometrial receptivity is not yet clear.HOXA10 is not only an important receptivity marker but also an critical factor in regulating receptivity.This study explored the potential regulative function and underlying mechanisms of HOXA10 on the adhesion molecule E-cadherin,and broaden the regulating mechanisms of HOXA10 on endometrial receptivity.Methods: In the first part,RT-qPCR and Western blot were used to detect the changes in m RNA and protein expression levels of E-cadherin after silencing and overexpression of HOXA10 in human endometrial epithelial cells Ishikawa and RL95-2.In the second part,trophoblast cells JEG-3 adhere to endometrial epithelial cells Ishikawa and RL95-2 in vitro as embryo implantation models to explore whether there is a difference in the adhesive function of trophoblast cells after silencing and overexpression of HOXA10,and after the exogenous recovery/partial recovery of E-cadherin expression on the basis of silencing HOXA10,continue to observe the difference in adhesion rate.In the third part,the possible binding sites of HOXA10 in the E-cadherin promoter region were predicted and analyzed by bioinformatics,and then the chromatin immunoprecipitation assay was used to investigate whether there is a physiological binding between HOXA10 and E-cadherin,and then the dual luciferase reporter assay was used to verify the binding sites’ activity.In the fourth part,after transfection of si-HOXA10 in pregnant CD1 mice,the expression of E-cadherin on the endometrium was measured by immunohistochemical staining on the 4th day,and the number of embryo implantation and live birth were observed on the 8th day and later,by this,we further clarify the regulatory relationship between HOXA10 and E-cadherin in vivo.Results:1.In the endometrial cell lines Ishikawa and RL95-2,HOXA10 and E-cadherin are correlated with the expression levels of m RNA and protein.2.HOXA10 can promote the adhesion of trophoblast cells in vitro and promote the implantation of mouse uterine embryos.3.HOXA10 can target DNA fragments and bind to the E-cadherin promoter region and directly regulate its expression.4.E-cadherin has a positive regulatory relationship with HOXA10 in mouse endometrium.5.The expression location and correlation of HOXA10 and E-cadherin in mouse myometrium,luminal epithelium,glandular epithelium and stromal cells.Conclusion: HOXA10 is combined with the fragment of the E-cadherin promoter region to directly regulate its expression,thereby exerting the receptivity of HOXA10 in the endometrium and promoting the adhesion and implantation of embryos.