Determinação do tamanho e quantificação dos exossomos uterinos em gestações bovinas produzidas por inseminação artificial e por fertilização In Vitro

Abstract

Molecular basis involved in successful pregnancy is not fully defined in all species. Uterine fluid contains a variety of nutrients, proteins, lipids and extracellular vesicles, including the exosomes, excreted by different cell types of maternal or fetal origin. The exosomes present in uterine fluid modulate maternal-fetal communication, transporting proteins, mARN molecules and microARNs. The objective of this study was to determine the size and quantify the exosomes present in the uterine fluid of non-pregnant and pregnant cows from artificial insemination (AI) and in vitro fertilization (IVF), in different gestational periods. The uterine fluid was collected by uterine lavage on day 18 of the estrous cycle and at 18 and 32 days of gestation. Extracellular uterine microvesicles were isolated by centrifugation; the size and concentration of the exosomes were analyzed using the NanoSight NS300. There was a significant increase in the concentration of exosomes from group AI18 to AI32 and a tendency of concentration increase from group IVF 18 to group IVF 32. Data indicate that the concentration of uterine exosomes increases with the evolution of gestation. Studies in other gestational ages and studies that determine the content and origin of these exosomes are necessary, contributing to elucidate questions related to maternal-fetal communication, as well as the differences observed in the viability of pregnancies obtained by artificial insemination and in vitro fertilization.