Comparative Analysis of Porcine Follicular Fluid Proteomes of Small and Large Ovarian Follicles

Abstract

Ovarian follicular fluid is widely used for in vitro oocyte maturation, but its in-depth characterization to extract full beneficial effects remains unclear. Here, we performed both shotgun (nanoscale liquid chromatography coupled to tandem mass spectrometry or nanoLC-MS/MS) and gel-based (two dimension-differential in-gel electrophoresis or 2D-DIGE) proteomics, followed by functional bioinformatics to compare the proteomes of follicular fluids collected from small (<4 mm) and large (>6–12 mm) follicles of pig ovaries. A total of 2321 unique spots were detected with the 2D-DIGE across small and large follicles, while 2876 proteins with 88% successful annotations were detected with the shotgun approach. The shotgun and 2D-DIGE approaches revealed about 426 and 300 proteins that were respectively common across samples. Six proteins detected with both technical approaches were significantly differently expressed between small and large follicles. Pathways such as estrogen and PI3K-Akt signaling were significantly enriched in small follicles while the complement and coagulation cascades pathways were significantly represented in large follicles. Up-regulated proteins in small follicles were in favor of oocyte maturation, while those in large follicles were involved in the ovulatory process preparation. Few proteins with potential roles during sperm–oocyte interactions were especially detected in FF of large follicles and supporting the potential role of the ovarian FF on the intrafallopian sperm migration and interaction with the oocyte.

Follicular fluid aids cell adhesion, spreading in an age independent manner and shows an age-dependent effect on DNA damage in fallopian tube epithelial cells

“…Studies in bovine model have shown that vitronectin in FF contributes to follicle development [ 26 ]. Additionally, vitronectin promotes sperm-oocyte linking and fertilization [ [27] , [28] , [29] ].…”

Global proteomic analysis of preimplantational ovine embryos produced in vitro

“…As expected, increases in glutathione and ROS follow the development of the oocytes, their metabolic rate and demand for more energy. In addition, pathways involved in cellular components such as gap junctions indicate great activity and high responsiveness of cells to stimulus‐response, cell adhesion, differentiation and proliferation (Paes et al., 2020).…”

“…In addition, pathways involved in cellular components such as gap junctions indicate great activity and high responsiveness of cells to stimulus-response, cell adhesion, differentiation and proliferation (Paes et al, 2020).…”

In vitro maturation using αMEM with reduced NaCl enhances maturation and developmental competence of pig oocytes after somatic cell nuclear transfer

“…In another study, oocytes matured in a medium containing PFF showed enhanced embryonic development [ 34 ]. Generally, PFF is aspirated from the antral follicles, and the composition of PFF differs depending on the size of follicles [ 35 ]. A previous study reported that cumulus cell viability, monospermic fertilization of IVF embryos, and subsequent embryonic developmental competence are reduced in oocytes matured in medium containing PFF derived from small antral follicles (3–4 mm in diameter), compared to oocytes matured in medium containing larger (5–6 mm in diameter) follicle-derived PFF [ 36 ].…”