Avian uterine fluid proteome: Exosomes and biological processes potentially involved in sperm survival

Abstract

Uterine fluid is an aqueous milieu to which sperm are exposed during their storage and ascent. In this study, a bottom-up proteomic strategy and bioinformatic analysis of hen uterine fluid was performed to improve the understanding of this fluid and its potential role in sperm survival mechanisms. The proteomic data were submitted to ProteomeXchange. Among the 913 proteins identified, 160 are known to be secreted and 640 are referenced in exosomes databases. We isolated exosomes from the avian uterine fluid, analyzed them using electron microscopy, and targeted several exosomes markers (ANXA1/2/4/5, VCP, HSP90A, HSPA8, PARK7, and MDH1) using immunoblotting. Electron microscopy and immunohistochemistry were also used to analyze uterovaginal junctions for the exosomal proteins ANXA4, VCP, and PARK7. Exosomes were observed both at the surface epithelium and inside sperm storage tubules. Our data were compared with two previously published studies on proteomic of hen uterine fluid, and with one study describing the proteomic content of rooster seminal plasma and sperm. In conclusion, we demonstrated for the first time that avian uterine fluid contains exosomes. These may play a key role in preserving sperm functions within the female genital tract. Their presence in the sperm storage tubules may represent an important mechanism regarding interaction between the female genital tract and sperm. K E Y W O R D S avian, exosomes, proteome, sperm, uterine fluid

The Biological Function of Extracellular Vesicles during Fertilization, Early Embryo—Maternal Crosstalk and Their Involvement in Reproduction: Review and Overview

“…EVs Extracellular vesicles in seminal fluids were observed to modulate sperm capacitation in man [82] and pigs [83] and to influence female physiology by modulating immune-related gene expression in the porcine endometrium [68]. In return, oviductal EV (oEV) secretion was observed to regulate sperm motility and capacitation in mouse [69,70], cat [71] and bovine [72] sperm and EVs from avian uterine fluid may play an essential role in the preservation of sperm functions [81]. During oogenesis, follicle growth and oocyte maturation required a constant signal exchange in which there is a mutual recognition of diffusible or EV-mediated molecules produced by somatic cells (granulosa, cumulus and theca) and by germ cells (oocytes) present in the follicular fluids (FF).…”

Characterization and proteomics of chicken seminal plasma extracellular vesicles

“…The chicken SPEV proteome was compared with hen uterine fluid proteome and the SP proteome (Li et al., 2020; Riou et al., 2020), and the results showed that some overlapping proteins described in chicken SPEVs had been identified in hen uterine fluid (545) and chicken SP (284) (Figure 4a). GO enrichment analysis was performed for the overlapping proteins (Figure 4b–d) and found that both CCs were consistent with the SPEV results, and they were mainly enriched in the cytosol, cytoplasm and plasma membrane.…”

Extracellular Vesicles, the Road toward the Improvement of ART Outcomes

“…Although this review focused on EVs used to enhance ART outcome in mammals, it should be noted that EVs have also drawn the attention of the avian reproduction sector as it has been recently postulated that uterosomes might have a role on avian sperm survival [95]. All the information described above should be considered for the development of improved media such as gamete collection, IVF, and embryo culture media used in vitro for ART.…”