Cell-secreted vesicles containing microRNAs as regulators of gamete maturation

Abstract

Mammalian gamete maturation requires extensive signaling between germ cells and their surrounding somatic cells. In the ovary, theca cells, mural granulosa cells, cumulus cells and the oocyte all secrete factors throughout follicle growth and maturation that are critical for ovulation of a high-quality oocyte with the competence to develop into an embryo. Similarly, maturation of sperm occurs as it transits the epididymis during which epididymal epithelium and sperm exchange secretory factors that are required for sperm to gain motility and fertility. Recent studies in a variety of species have uncovered the presence of cell-secreted vesicles in follicular fluid (microvesicles and exosomes) and epididymal fluid (epididymosomes). Moreover, these cell-secreted vesicles contain small non-coding regulatory RNAs called microRNAs, which can be shuttled between maturing gametes and surrounding somatic cells. Although little is known about the exact mechanism of how microRNAs are loaded into these cell-secreted vesicles or are transferred and modulate gene expression and function in gametes, recent studies clearly suggest that cell-secreted vesicle microRNAs play a role in oocyte and sperm maturation. Moreover, a role for cell-secreted vesicular microRNAs in gamete maturation provides for novel opportunities to modulate and discover new diagnostic markers associated with male or female fertility. This manuscript provides an overview of cell-secreted vesicles in ovarian follicular fluid and epididymal fluid and microRNAs and discusses recent discoveries on the potential function of cell-secreted vesicles as carriers of microRNAs in oocyte and sperm maturation.

Embryotrophic effects of extracellular vesicles derived from outgrowth embryos in pre‐ and peri‐implantation embryonic development in mice

“…A communication between embryos and maternal uterine milieu through secreting signals is required for proper mammalian development (O'Neill, ). Recent studies observed that EVs are secreted from various somatic cells including human embryonic stem cell (Mardpour et al, ), induced pluripotent stem cell (Bobis‐Wozowicz et al, ), ovarian follicle (da Silveira et al, ), and even embryos (Qu et al, ). Our previous study also demonstrated that membrane budding microvesicles from outgrowth embryos improved developmental competence in vitro and the implantation potential of cocultured embryos in utero as well (Kim et al, ).…”

S100‐A9 protein in exosomes derived from follicular fluid promotes inflammation via activation of NF‐κB pathway in polycystic ovary syndrome

“…These compositions can be transferred between different types of cells and influence biological activities . Recently, some studies uncovered the potential function of exosomes derived from FF as carriers of miRNAs in steroidogenesis, follicular development and other pathological conditions …”

“…[21][22][23] Recently, some studies uncovered the potential function of exosomes derived from FF as carriers of miRNAs in steroidogenesis, follicular development and other pathological conditions. [24][25][26][27] Although proteome and peptidome were identificated in human FF, [28][29][30][31][32][33] little was known about the proteomic analysis of exosomes in follicular fluid and their potential roles in follicular development and reproduction-related disorders. Therefore, we used an TMT-tagged quantitative proteomic approach to compare the proteomic profile of exosomes derived from FF of PCOS and healthy women.…”

Updating the markers for oocyte quality evaluation: intracellular temperature as a new index

“…In the ovary, from the theca cells, mural granulosa cells, cumulus cells, and oocyte secrete factors that are critical for ovulation of high‐quality oocyte, throughout follicle growth and oocyte maturation. Recent studies of a variety of species have uncovered the presence of cell‐secreted vesicles in follicular fluid . These cell‐secreted vesicles contain small non‐coding regulatory RNAs called microRNAs, which can be shuttled between maturing gametes and surrounding somatic cells .…”

“…However, recent studies suggest that microRNAs in cell‐secreted vesicles are involved in oocyte maturation. These microRNAs involved in gamete maturation are potential therapeutic targets and diagnostic markers associated with fertility …”