Oviduct cells produce a favorable environment for the development of gametes by generating multiple growth factors. Particularly, in canine species, immature oocytes undergo serial maturation processes in the oviduct, while the other mammals already possess matured oocytes in ovulatory follicles. However, little is known about the potential effect exhibited by the components released from canine oviduct cells (OCs) for modulating the biological function of oocytes. Recently, exosomes are regarded as promising extracellular vesicles because they represent considerable data for molecular cargo. Therefore, we first investigated the effect of canine oviductal exosomes (OC-Exo) on oocyte development via EGFR/MAPK pathway. Our results showed that OC-Exo labeled with PHK67 are successfully incorporated with cumulus cells and oocytes during IVM. Also, OC-Exo markedly increased the proportion of cumulus-oocyte complexes (COCs) exhibiting cumulus expansion as well as cumulus cell proliferation and maturation rate of oocytes (p < 0.05). Furthermore, gene expression patterns related with EGFR/MAPK pathway including EGFR, PKA, TACE/ADAM17, MAPK1/3, MAPK14, PTGS2, TNFAIP6, GDF9, and BMP15 were positively modified in COCs cultured with OC-Exo (p < 0.05). In addition, OC-Exo significantly up-regulated the protein expression levels of p-EGFR, p-MAPK1/3, GDF9 and BMP15 in COCs (p < 0.05). Consequently, the current study provides a model for understanding the roles of OC-Exo as bioactive molecules for canine oocyte maturation via EGFR/MAPK pathway, which would open a new avenue for the application of exosomes to improve assisted reproductive technology in mammals, including humans.

中文翻译：

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犬输卵管外泌体通过 EGFR/MAPK 信号通路改善卵母细胞发育

输卵管细胞通过产生多种生长因子为配子的发育创造了有利的环境。特别是在犬科动物中，未成熟的卵母细胞在输卵管中经历了一系列的成熟过程，而其他哺乳动物在排卵卵泡中已经拥有成熟的卵母细胞。然而，关于犬输卵管细胞 (OCs) 释放的成分对调节卵母细胞生物学功能的潜在作用知之甚少。最近，外泌体被认为是有前途的细胞外囊泡，因为它们代表了大量的分子货物数据。因此，我们首先通过 EGFR/MAPK 通路研究了犬输卵管外泌体（OC-Exo）对卵母细胞发育的影响。我们的结果表明，在 IVM 期间，用 PHK67 标记的 OC-Exo 成功地与卵丘细胞和卵母细胞结合。还，OC-Exo 显着增加了卵丘 - 卵母细胞复合体 (COC) 的比例，表现出卵丘扩张以及卵母细胞的卵丘细胞增殖和成熟率 (p < 0.05)。此外，与 EGFR/MAPK 通路相关的基因表达模式，包括 EGFR、PKA、TACE/ADAM17、MAPK1/3、MAPK14、PTGS2、TNFAIP6、GDF9 和 BMP15，在用 OC-Exo 培养的 COC 中得到了积极修饰（p < 0.05）。此外，OC-Exo 显着上调 COC 中 p-EGFR、p-MAPK1/3、GDF9 和 BMP15 的蛋白表达水平（p < 0.05）。因此，目前的研究提供了一个模型，用于理解 OC-Exo 作为生物活性分子通过 EGFR/MAPK 途径促进犬卵母细胞成熟的作用，这将为应用外泌体改善包括人类在内的哺乳动物的辅助生殖技术开辟一条新途径。 .