International Journal of Nanomedicine (May 2022)
Loss of Renewal of Extracellular Vesicles: Harmful Effects on Embryo Development in vitro
Abstract
Pengxiang Qu,1,2 Jinpeng Zhao,1,2 Huizhong Hu,1,2 Wenbin Cao,1,2 Yanru Zhang,1,2 Jia Qi,1,2 Bin Meng,1,3 Juan Zhao,2,4 Shuangqing Liu,1 Chong Ding,1,2 Yuqi Wu,1,2 Enqi Liu1,2 1Laboratory Animal Center, Xi’an Jiaotong University Health Science Centre, Xi’an, Shaanxi, People’s Republic of China; 2Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China, Xi’an, Shaanxi, People’s Republic of China; 3The Assisted Reproduction Center, Northwest Women’s and Children’s Hospital, Xi’an, People’s Republic of China; 4Department of Hematology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, People’s Republic of ChinaCorrespondence: Enqi Liu, Email [email protected]: 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× 1011 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× 1012 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.Keywords: extracellular vesicles, hazardous effect, renewal, embryo, in vitro culture
