Extracellular vesicles from bovine follicular fluid support cumulus expansion
WT Hung, X Hong, LK Christenson… - Biology of …, 2015 - academic.oup.com
WT Hung, X Hong, LK Christenson, LK McGinnis
Biology of reproduction, 2015•academic.oup.comExpansion of the cumulus complex surrounding the oocyte is critical for ovulation of a
fertilizable egg. The ovulation-inducing surge of luteinizing hormone leads to an increased
expression of genes such as prostaglandin-endoperoxide synthase 2 (Ptgs2), pentraxin-
related protein 3 (Ptx3), and tumor necrosis factor alpha-induced protein 6 (Tnfaip6) that
support cumulus expansion. Factors released by mural granulosa and cumulus granulosa
cells into the follicular fluid induce paracrine signaling within the follicular compartment. The …
fertilizable egg. The ovulation-inducing surge of luteinizing hormone leads to an increased
expression of genes such as prostaglandin-endoperoxide synthase 2 (Ptgs2), pentraxin-
related protein 3 (Ptx3), and tumor necrosis factor alpha-induced protein 6 (Tnfaip6) that
support cumulus expansion. Factors released by mural granulosa and cumulus granulosa
cells into the follicular fluid induce paracrine signaling within the follicular compartment. The …
Abstract
Expansion of the cumulus complex surrounding the oocyte is critical for ovulation of a fertilizable egg. The ovulation-inducing surge of luteinizing hormone leads to an increased expression of genes such as prostaglandin-endoperoxide synthase 2 (Ptgs2), pentraxin-related protein 3 (Ptx3), and tumor necrosis factor alpha-induced protein 6 (Tnfaip6) that support cumulus expansion. Factors released by mural granulosa and cumulus granulosa cells into the follicular fluid induce paracrine signaling within the follicular compartment. The follicular fluid that separates these distinct granulosa cell types is an enriched fluid containing numerous proteins, nucleic acids, and other macromolecules. Extracellular vesicles (EVs) are also present; however, no physiologically relevant functions of follicular EVs have yet been demonstrated. In our study, the effect of follicular EVs on cumulus-oocyte complex (COC) expansion and relevant gene expression was assayed. Follicular EVs were isolated using ultracentrifugation from follicular fluid of small (3–5 mm) and large (>9 mm) antral bovine follicles, then characterized by nanoparticle tracking analysis, electron microscopy, and Western blot analysis. To test for bioactivity, mouse and bovine COCs were cultured with follicular EVs. Cumulus expansion and Ptgs2, Ptx3, and Tnfaip6 gene expression were measured following COC maturation culture. The results demonstrated that follicular EVs can support both measurable cumulus expansion and increased gene expression.