Fan Yuan, Pavani Krishna Chaitanya, Smits Katrien, Van Soom Ann, Peelman Luc
Department of Veterinary and Biosciences, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820, Merelbeke, Belgium.
Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
J Anim Sci Biotechnol. 2024 Mar 1;15(1):23. doi: 10.1186/s40104-024-00997-7.
Transfer RNA-derived small RNAs (tsRNAs) have been shown to be involved in early embryo development and repression of endogenous retroelements in embryos and stem cells. However, it is unknown whether tsRNAs also regulate embryo hatching. In this study, we mined the sequencing data of a previous experiment in which we demonstrated that the microRNA (miRNA) cargo of preimplantation embryonic extracellular vesicles (EVs) influences embryo development. We thus profiled the tsRNA cargo of EVs secreted by blastocysts and non-blastocysts. The majority of tsRNAs was identified as tRNA halves originating from the 5´ ends of tRNAs. Among the 148 differentially expressed tsRNAs, the 19 nt tRNA fragment (tRF) tDR-14:32-Glu-CTC-1 was found to be significantly up-regulated in EVs derived from non-blastocysts. RT-qPCR assays confirmed its significant up-regulation in non-blastocyst embryos and their conditioned medium compared to the blastocyst group (P < 0.05). Inhibition of tDR-14:32-Glu-CTC-1 by supplementing antagomirs to the conditioned medium improved embryo hatching (P < 0.05). Transcriptomic analysis of embryos treated with tDR-14:32-Glu-CTC-1 antagomirs further showed differential expression of genes that are associated with embryo hatching and implantation. In summary, tDR-14:32-Glu-CTC-1 is up-regulated in non-blastocyst embryos and their secretions, and inhibition of tDR-14:32-Glu-CTC-1 promotes embryo hatching, while influencing embryo implantation-related genes and pathways. These results indicate that embryonic EVs containing specific tRFs may regulate preimplantation embryo development.
转移RNA衍生的小RNA（tsRNAs）已被证明参与早期胚胎发育以及胚胎和干细胞中内源性逆转录元件的抑制。然而，tsRNAs是否也调节胚胎孵化尚不清楚。在本研究中，我们挖掘了先前一项实验的测序数据，在该实验中我们证明了植入前胚胎细胞外囊泡（EVs）中的微小RNA（miRNA）成分会影响胚胎发育。因此，我们分析了囊胚和非囊胚分泌的EVs中的tsRNA成分。大多数tsRNAs被鉴定为源自tRNA 5´端的tRNA半体。在148个差异表达的tsRNAs中，发现19 nt的tRNA片段（tRF）tDR-14:32-Glu-CTC-1在源自非囊胚的EVs中显著上调。RT-qPCR分析证实，与囊胚组相比，其在非囊胚胚胎及其条件培养基中显著上调（P < 0.05）。通过向条件培养基中添加拮抗剂抑制tDR-14:32-Glu-CTC-1可改善胚胎孵化（P < 0.05）。用tDR-14:32-Glu-CTC-1拮抗剂处理的胚胎的转录组分析进一步显示了与胚胎孵化和着床相关的基因的差异表达。总之，tDR-14:32-Glu-CTC-1在非囊胚胚胎及其分泌物中上调，抑制tDR-14:32-Glu-CTC-1可促进胚胎孵化，同时影响与胚胎着床相关的基因和途径。这些结果表明，含有特定tRFs的胚胎EVs可能调节植入前胚胎发育。
