Placental Trophoblast Derived Exosomes Regulate Endometrial Epithelial Receptivity in Dairy Cows During Pregnancy

Abstract

Background Inadequate feto-maternal interaction will directly lead to the failures of pregnancy and bring serious damage to dairy cows. Exosomes are widely involved in endometrial matrix remodeling, immune function changes, placental development, and other processes of embryo implantation and pregnancy of dairy cows. However, the role of placental trophoblast cells derived exosomes is still unclear in regulating the receptivity of endometrial cells and facilitating the interaction between mother and fetus. Methods In this study, bovine trophoblast cells (BTCs) were obtained from bovine placenta and immortalized through the transfection of telomerase reverse transcriptase (TERT) gene. After that, the effect of trophoblast derived exosomes (TDEs) on endometrial receptivity in endometrial epithelial cells (EECs) was detected and the mechanism explored that TDEs and their proteins participated in feto-maternal interaction during bovine pregnancy. EECs were co-cultured with the exosomes derived from progesterone (P4) and treated with BTCs. Results Immortalized BTCs still possessed the basic and key properties of primary BTCs without showing a neoplastic transformation sign. Exosomes derived from P4 and treated with BTCs enhanced the expression of endometrial receptivity factors in EECs by changing the extracellular environment, metabolism and redox balance in EECs with proteome alignment, compared with those untreated according to the DIA quantitation analysis. Conclusions Our study found that trophoblast derived exosomal proteins are one of the most critical elements in feto-maternal interaction and their changes act as a key signal in altering endometrial receptivity and provided a potential target for improving fertility.