Loss of Renewal of Extracellular Vesicles: Harmful Effects on Embryo Development in vitro

Abstract

Background Extracellular vesicles (EVs), as a promising platform for drug delivery, have attracted much attention. Degradation and regeneration of EVs maintain their homeostasis in vivo, but this regeneration is missing in the in vitro culture (IVC) system, which is likely to lead to negative effects. It is particularly concerning that most studies involving the addition of EVs in IVC seem to overlook this point. Methods We used rabbit embryos and oviduct fluid EVs as a model of embryo development to examine the effect of loss or gain of EV functionality in an IVC system. Embryonic development ratios were determined in each group. Malondialdehyde and ammonium ions in the culture medium were measured. RNA-seq, reactive oxygen species (ROS) staining, immunofluorescence of LC3 and H3K36me3, and qPCR of oxidative stress-related genes and autophagy-related genes of blastocysts in the in vivo group, non-EVs group, con-EVs group, and R-EVsM group was implemented. Results Incubation of embryos with 9.1×10 11 EV particles/mL had a positive effect at 48 h and 72 h, which disappeared by 96 h, however. EVs at a concentration of 9.1×10 12 particles/mL even showed a negative effect at 96 h. As culture time in the IVC system was increased, the amount of malondialdehyde and ammonium ions in the culture medium was increased, and there was a decrease in embryonic development activity of EVs. Lack of EV renewal in the IVC system impaired embryonic development competence, while replacement of EVs and medium during IVC could sustain embryonic development. Loss or gain of renewal in the IVC system affected EVs’ influence on embryo transcriptome, embryonic ROS, autophagy, epigenetic state and apoptosis. Conclusion Loss of renewal in the IVC system affected EVs’ role in embryonic development by causing an imbalance in ROS, autophagy, abnormal H3K36me3 levels and apoptosis, while gain of renewal in the IVC system reduced these adverse effects and ensured the beneficial function of EVs.

Oviduct Epithelial Cell-Derived Extracellular Vesicles Improve Porcine Trophoblast Outgrowth

“…The pig is the best cloned animal species, but the low implantation ability of cloned embryos has been a major obstacle to its development [31]. There are many differences in the extracellular environment between embryos grown in vitro and those grown in vivo [32]. On one hand, in the early stage of embryo development, cloned embryos grown in vitro have stable MAPK level loss compared to IVF embryos [33,34].…”

“…Relevant data have shown that OEC EVs can greatly improve the success rate of embryo IVF and reduce the rate of multiple sperm entry [39]. Other relevant data indicate that the loss of OEC EVs has a significant impact on embryo development [32]. OEC EVs can reduce the damage caused by reactive oxygen species.…”

Functional Roles of Exosomes in Allergic Contact Dermatitis

“…Superoxide dismutase 2 (SOD2) and glutathione peroxidase 3 (GPX3) are present in exosomes, and both proteins are involved in antioxidant defense [ 93 , 94 ]. During pro-inflammatory conditions, proteins such as SOD2 and GPX3 are upregulated.…”