Oviductal Extracellular Vesicles Enhance Porcine In Vitro Embryo Development by Modulating the Embryonic Transcriptome

Abstract

Oviductal extracellular vesicles (oEVs) have been identified as important components of the oviductal fluid (OF) and have been pointed to as key modulators of gamete/embryo-maternal interactions. Here, we determined the functional impact of oEVs on embryo development and the embryonic transcriptome in porcine. Experiment 1 examined the effect of oEVs and OF on embryo development. In vitro-produced embryos were cultured with oEVs or OF for 2 or 7 days using an in vitro sequential system or without supplementation (control). Experiment 2 analyzed transcriptomic alterations of EV-treated embryos versus control and the oEVs RNA cargo by RNA-sequencing. Two days of EV treatment enhanced embryo development over time when compared to other treatments. Different RNA expression profiles between embryos treated with EVs for two or seven days and untreated controls were obtained, with 54 and 59 differentially expressed (DE) genes and six and seven DE miRNAs, respectively. In oEV RNA cargo, 12,998 RNAs and 163 miRNAs were identified. Integrative analyses pointed to specific oEV components that might act as modulators of the embryonic transcriptome, such as S100A11, ANXA2 or miR-21-5p. Overall, the findings suggested that oEVs could be a potential strategy to improve porcine IVP outcomes, particularly by using two days of EV treatment.

Follicular Fluid-Derived Extracellular Vesicles Influence on In Vitro Maturation of Equine Oocyte: Impact on Cumulus Cell Viability, Expansion and Transcriptome

“…The manner of interaction and physiological homogeneity of EVs are currently the subject of many studies in relation to folliculogenesis, gametogenesis, and embryo development in diverse animal species [ 29 , 33 , 34 , 35 ]. Several studies in mice, pigs, and cattle have shown that EVs can significantly affect changes in the transcriptome during gamete and embryo development [ 35 , 36 , 37 ]. Moreover, in recent years, EVs extracted from FF have been shown to affect the gene expression [ 32 , 38 ], expansion [ 39 ], and proliferation [ 40 ] of cultured bovine CCs.…”

Oviductal extracellular vesicles miRNA cargo varies in response to embryos and their quality

“…Further comparisons with EVs from bovine oviductal fluid across the estrous cycle showed an overlap of 35 (42%) miRNAs [ 32 ] and 31 (37%) miRNAs when only the ipsilateral oviduct was considered [ 63 ] (Supplementary data S 3 – Table 1). Additionally, 35 miRNAs (42%) were found in common to EVs derived from porcine oviductal fluid at the pre-ovulatory stage [ 30 ] (Supplementary data S 3 – Table 1).…”

“…Therefore, the different abundance of miR-34b-5p in BGE vs. BPE could indicate a differential response of BOEC via the EVs miRNA cargo to embryo quality. This miRNA was also detected in oEVs from pregnant and non-pregnant heifers (annotated as miR-34b [ 34 ]), in oEVs from cyclic sows [ 30 ], and also in oEVs from cyclic mice [ 78 ]. In our study, miR-34b-5p was also detected in 8-cell embryos, but with no differences related to embryo quality.…”

“…They also have an impact during fertilization, for example, by reducing polyspermy [ 26 ]. Oviductal EVs can also be taken up by embryos at different developmental stages [ 27 , 28 ], boosting their development, cryotolerance [ 27 , 29 , 30 ] and regulating their transcriptome [ 30 , 31 ]. To understand their functional effects, the molecular cargo of oEVs from cyclic and pregnant animals has been examined, pointing to a variety of cargo: from proteins, mRNA, miRNAs to metabolites as potential molecules supporting gametes/embryo-oviductal interactions and embryo development [ 32 – 34 ].…”

Messenger roles of extracellular vesicles during fertilization of gametes, development and implantation: Recent advances

“…The oviduct is the site of zygote birth as well as preembryonic development. Current research indicates that O-EVs can improve embryo blastocyst formation rate, embryo survival rate, embryo hatching rate, and post-embryo transfer birth rate ( Almiñana et al, 2017 ; Qu et al, 2019 ; Fang et al, 2022b ; de Alcântara-Neto et al, 2022 ). Furthermore, O-EVs can improve embryo development after cryopreservation and survival rate after vitrification ( Lopera-Vasquez et al, 2017 ; Leal et al, 2022 ; Sidrat et al, 2022 ).…”