Embryonic Trophectoderm Secretomics Reveals Chemotactic Migration and Intercellular Communication of Endometrial and Circulating MSCs in Embryonic Implantation

Embryonic implantation is a key step in the establishment of pregnancy. In present work, we have carried out an in-depth proteomic analysis secretome (extracellular vesicles and soluble proteins) two bovine blastocysts embryonic trophectoderm primary cultures (BBT), confirming different epithelial–mesenchymal transition stages these cells. BBT-secretomes contain early pregnancy-related proteins angiogenic both as cargo EVs fraction. We demonstrated functional transfer protein-containing between maternal MSC vitro using BBT eight endometrial (eMSC) five peripheral blood (pbMSC) lines. observed that eMSC pbMSC chemotax to fraction secretome. addition, complementary direction, found pattern expression BBT-EVs changes depending on: (i) their phenotype; (ii) result uptake eMSC- or pbMSC-EV previously stimulated not with signals (IFN-); (iii) because stimulation cytokines uterine fluid peri-implantation period.