Cajas Y N, Burbano K, Nuñéz-Puente C, Millán de la Blanca M G, Iniesta-Cuerda M, Soler A J, Arévalo L, Rizos D, Rebollar P G, Cañón-Beltrán K
Department of Agrarian Production, Universidad Politécnica de Madrid (UPM), 28040, Madrid, Spain; Department of Biological Science, Technical University of Loja (UTPL), 1101608, Loja, Ecuador.
Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA-CSIC), Cta de La Coruña Km 5.9, 28040, Madrid, Spain.
Theriogenology. 2025 Oct 1;245:117528. doi: 10.1016/j.theriogenology.2025.117528. Epub 2025 Jun 7.
The oviduct and uterus provide a supportive environment for early embryonic development, where effective embryo-maternal communication is essential for pregnancy success. Extracellular vesicles (EVs) from oviductal (OF) and uterine fluids (UF) are key mediators of this communication, transporting bioactive molecules such as proteins, lipids, DNA, and regulatory RNAs. Among these, microRNAs (miRNAs) are particularly interesting due to their role in modulating reproductive processes. Although underrepresented in EVs research, the rabbit offers a robust model owing to its inducible ovulation, controlled reproductive physiology, and similarities to human implantation dynamics. This study aims to uncover, in does, how EVs could influence key reproductive processes by isolating, characterizing, and analyzing the miRNA cargo from OF- and UF-EVs. We identified 388 miRNAs in both OF-EVs and UF-EVs, 18 miRNAs were significantly more abundant in UF-EVs, while 5 were less abundant compared to OF-EVs group, suggesting distinct roles in embryo-maternal communication. The most abundant miRNAs, included ocu-miR-148a-3p, ocu-let-7i-5p, and ocu-miR-10b-5p, related to embryo development and implantation. Target gene prediction analysis revealed that OF-EVs miRNAs are linked to MAPK, Hippo, TGF-β, Ras, PI3K-Akt, and mTOR pathways, while UF-EVs are associated with Hippo, PI3K-Akt, FoxO, endocytosis, and mTOR pathways, essential for cell proliferation, differentiation, immune regulation, and embryo-maternal interactions. Our findings suggest that EVs in rabbit reproductive fluids could play a fundamental role in early embryonic development. Future research should focus on the functional validation of these key candidate miRNAs, particularly those involved in reproductive physiology, offering promising insights for reproductive biotechnology and veterinary medicine.
输卵管和子宫为早期胚胎发育提供了一个支持性环境，其中有效的胚胎与母体间的交流对于妊娠成功至关重要。来自输卵管液（OF）和子宫液（UF）的细胞外囊泡（EVs）是这种交流的关键介质，可运输蛋白质、脂质、DNA和调节性RNA等生物活性分子。其中，微小RNA（miRNAs）因其在调节生殖过程中的作用而特别引人关注。尽管在EVs研究中代表性不足，但兔子因其诱导排卵、可控的生殖生理以及与人类着床动态的相似性，提供了一个强大的模型。本研究旨在通过分离、表征和分析OF-EVs和UF-EVs中的miRNA货物，揭示母兔中EVs如何影响关键生殖过程。我们在OF-EVs和UF-EVs中均鉴定出388种miRNAs，其中18种miRNAs在UF-EVs中显著更丰富，而与OF-EVs组相比，有5种miRNAs含量较少，这表明它们在胚胎与母体交流中具有不同作用。最丰富的miRNAs包括ocu-miR-148a-3p、ocu-let-7i-5p和ocu-miR-10b-5p，与胚胎发育和着床有关。靶基因预测分析表明，OF-EVs中的miRNAs与MAPK、Hippo、TGF-β、Ras、PI3K-Akt和mTOR通路相关，而UF-EVs与Hippo、PI3K-Akt、FoxO、内吞作用和mTOR通路相关，这些通路对于细胞增殖、分化、免疫调节和胚胎与母体相互作用至关重要。我们的研究结果表明，兔生殖液中的EVs可能在早期胚胎发育中发挥重要作用。未来的研究应侧重于这些关键候选miRNAs的功能验证，特别是那些涉及生殖生理的miRNAs，这为生殖生物技术和兽医学提供了有前景的见解。
