Biase Fernando H, Moorey Sarah E, Schnuelle Julie G, Rodning Soren, Ortega Martha Sofia, Spencer Thomas E
School of Animal Sciences, Virginia Polytechnic Institute and State University, 175 W Campus Dr, Blacksburg, VA, 24061, USA.
Department of Animal Science, University of Tennessee, Knoxville, TN, 37996, USA.
J Anim Sci Biotechnol. 2024 Sep 13;15(1):130. doi: 10.1186/s40104-024-01083-8.
MicroRNAs (miRNAs) are presented in the uterine lumen of many mammals, and in vitro experiments have determined that several miRNAs are important for the regulation of endometrial and trophoblast functions. Our aim was to identify and contrast the miRNAs present in extracellular vesicles (EVs) in the uterine lumen fluid (ULF) at the onset of attachment in cattle pregnancies (gestation d 18) initiated by artificial insemination (AI) or by the transfer of an in vitro-produced blastocyst (IVP-ET). A third group had no conceptus after the transfer of an IVP embryo.
The abundance of 263 annotated miRNAs was quantified in the EVs collected from ULF. There was an increase in the transcript abundance of 20 miRNAs in the ULF EVs from the AI pregnant group, while 4 miRNAs had a lower abundance relative to the group not containing a conceptus. Additionally, 4 miRNAs were more abundant in ULF EVs in the AI pregnant group relative to IVP-ET group (bta-mir-17, bta-mir-7-3, MIR7-1, MIR18A). Specific miRNAs in the ULF EVs were co-expressed with messenger RNAs expressed in extra-embryonic tissues and endometrium, including genes that are known to be their targets.
The results provide biological insights into the participation of miRNAs in the regulation of trophoblast proliferation and differentiation, as well as in endometrium receptivity. The knowledge that in vitro cultured embryos can contribute to the altered abundance of specific miRNAs in the uterine lumen can lead to the development of corrective approaches to reduce conceptus losses during the first month of pregnancy in cattle.
微小RNA（miRNA）存在于许多哺乳动物的子宫腔中，体外实验已确定几种miRNA对子宫内膜和滋养层功能的调节很重要。我们的目的是鉴定和对比在人工授精（AI）或体外生产的囊胚移植（IVP-ET）启动的牛妊娠（妊娠第18天）着床开始时子宫腔液（ULF）中细胞外囊泡（EV）中存在的miRNA。第三组在移植IVP胚胎后未怀孕。
对从ULF收集的EV中263种注释的miRNA丰度进行了定量。AI妊娠组ULF EV中20种miRNA的转录本丰度增加，而相对于未怀孕组，4种miRNA的丰度较低。此外，与IVP-ET组相比，AI妊娠组ULF EV中4种miRNA更丰富（bta-mir-17、bta-mir-7-3、MIR7-1、MIR18A）。ULF EV中的特定miRNA与在胚外组织和子宫内膜中表达的信使RNA共表达，包括已知是其靶标的基因。
这些结果为miRNA参与滋养层增殖和分化的调节以及子宫内膜容受性提供了生物学见解。体外培养的胚胎可导致子宫腔中特定miRNA丰度改变这一认识，可能会促使开发纠正方法，以减少牛妊娠第一个月的胚胎损失。
