Hatching is modulated by microRNA-378a-3p derived from extracellular vesicles secreted by blastocysts
Krishna Chaitanya Pavani, Tim Meese, Osvaldo Bogado Pascottini, Xuefeng Guan, Xiaoyuan Lin, Luc Peelman, J. Hamacher, Filip Van Nieuwerburgh, Dieter Deforce, Annekatrien Boel, Björn Heindryckx, Kelly Tilleman, Ann Van Soom, Bart M. Gadella, An Hendrix, Katrien Smits
Abstract
SignificanceHatching from the zona pellucida is a prerequisite for embryo implantation and is less likely to occur in vitro for reasons unknown. Extracellular vesicles (EVs) are secreted by the embryo into the culture medium. Yet the role that embryonic EVs and their cargo microRNAs (miRNAs) play in blastocyst hatching has not been elucidated, partially due to the difficulties of isolating them from low amounts of culture medium. Here, we optimized EV-miRNA isolation from medium conditioned by individually cultured bovine embryos and subsequently showed that miR-378a-3p, which was up-regulated in EVs secreted by blastocysts, plays a crucial role in promoting blastocyst hatching. This demonstrates the regulatory effect of miR-378-3p on hatching, which is an established embryo quality parameter linked with implantation.