Extracellular vesicles (EVs), including exosomes (30-150 nm) and microvesicles (100-1,500 nm) play important roles in mediating cell-cell communication. Such particles package distinct cargo elements including lipids, proteins, mRNAs, miRNAs and DNA, that vary depending on the cell of origin and its phenotype. This cargo can be horizontally transferred to target cells where its components can reprogram the recipient cell to modify its function. EVs have been identified within the uterine cavity of women, sheep and mice, where they contribute to the microenvironment of sperm transport, and of blastocyst and endometrial preparation for implantation. It is likely that exosomes and microvesicles carry different cargo and coordinate different roles in this intrauterine environment. Understanding and defining these subtypes of EVs is important for future functional studies and clinical translation. Here we critically review the various purification and validation procedures for EV analysis, discuss what is known of endometrial-derived exosome cargo, and that they are hormonally regulated.
EVs provide inter-cellular communication both between the inner cell mass (icm) of the blastocyst and trophectoderm and within the uterine cavity, between endometrial epithelium and the trophectodermal cells, to favour implantation potential.