Abstract

Extracellular vesicles (EVs), nano-sized (30-to-1000 nm) membrane vesicles secreted by all functional cells, are essential intercellular mediators, modulating several physiological and pathological processes. According to their size and biogenic pathway, EVs released by living cells are classically categorized into exosomes (small EVs) and microvesicles (large EVs). EVs has been isolated from all biofluids, including seminal plasma (SP), a fluid composed by secretions from accessory sex glands that accompanies sperm during and after ejaculation. Seminal EVs modulate several sperm physiological processes, and female reproductive tract immune environment, which is required for successful embryo development. Evidence supports that SP may also affect ovarian function. This study evaluated the potential effect of supplementing with two SP-EVs subsets (small (S-EVs) and large (L-EVs)) during in vitro maturation (IVM) of porcine oocytes on gene expression of cumulus cells. Four pathways were investigated using a total of nine genes: i) cell apoptosis using B-cell lymphoma 2 (BCL2) and BCL2 Associated X (BAX); ii) cell proliferation using Cyclin B1 (CCNB1); iii) oocyte maturation through Connexin 43 (CX43), Hyaluronan Synthase 2 (HAS2) and Stearoyl-CoA desaturase 1 (SCD1); and iv) steroidogenesis using Cytochrome P450 Family 11 Subfamily A Member 1 (CYP11A1), Hydroxy-Delta-5-Steroid Dehydrogenase 3 Beta (HSD3B1) and aromatase (CYP19A1). All genes, including housekeeping 60S Ribosomal Protein L18 (RPL19), were selected based on previous literature. The mRNA levels were assessed by quantitative real-time PCR.