Placental Trophoblast Cells-derived Exosomal MicroRNA-1290 Regulate The Endometrial Receptivity By Targeting LHX6

Embryo implantation is an important reproductive event in the early pregnancy of mammals,and it is also a key node.Most pregnancy failures in both human and domestic animals occur during this period,which greatly affects the reproductive efficiency of mammals.During the implantation period,the communication between the mother and the fetus has an important effect on the process,and is necessary for a successful pregnancy establishment.However,its particular mechanism is complicated and not yet fully understood.Therefore,understanding the mother-fetal communication during embryo implantation has an important role in improving pregnancy success rate.Exosomes are a type of extracellular vesicles,which are secreted by cells and contain active molecules.They play a role in cell-to-cell communication in the physiological and pathological conditions of the body.They are also biological markers for a variety of physiological and pathological conditions.A large number of studies have confirmed that exosomes are involved in the early pregnancy process,and exosomes derived from the mother side can promote embryo implantation.However,the contribution of placental trophoblast-derived exosomes in regulation of embryo implantation and its mechanism are still unclear.In this study,ultracentrifugation was used to isolate exosomes derived from placental trophoblast cells(HTR8/SVneo).Exosomes were identified with WB,TEM and NTA.The uptake and co-culture experiments were used to study the effect of exosomes derived from trophoblast cells in epithelial-mesenchymal transition of endometrial cells.After that,the second-generation high-throughput sequencing technology was used to screen and identify the miRNA molecules specifically loaded in exosomes,and the dual-luciferase experiment was used to study miRNA target genes.The results showed that trophoblast cell-derived exosomes can be taken up by endometrial epithelial cells(HEC-1-A),and co-culture with exosomes can promote the migration and epithelial-mesenchymal transition of HEC-1-A cells.The results of miRNA sequencing and q PCR verification show that compared with HTR8/SVneo cells,miR-1290 is specifically enriched in exosomes.Moreover,after transfection of miR-1290 mimic,cell migration and epithelial-mesenchymal transition were significantly enhanced in HEC-1-A cells.Finally,by querying the Targetscan database,it was found that miR-1290 targets LHX6,and the dual luciferase experiment verified their targeting relationship.We found that interfering with the expression of LHX6 significantly inhibited the migration ability and epithelial-mesenchymal transition of HEC-1-A cells,indicating that exosomal miR-1290 targets LHX6 to regulate epithelial-mesenchymal transition of endometrial epithelial cells HEC-1-A.In addition,this study also found that exosomal miR-1290 can promote the migration,proliferation and angiogenesis of human umbilical vein endothelial cells(HUVEC)in vitro.In summary,this study confirms that the embryonic trophoblast-derived exosomes are specifically loaded with miR-1290 and can be taken up by endometrial epithelial cells.The epithelial-mesenchymal transition of endometrial cells is regulated by exosomal miR-1290 targeting the expression of LHX6 gene.In addition,Exosomes can also promote angiogenesis and play an important role in promoting embryo implantation in early pregnancy.This study provides new insights into the mechanism of trophoblast cell-derived exosomes regulating mother-fetal communication,and provides a new idea to deal with the problem of low implantation rates in mammals such as livestock.