BACKGROUND Premature ovarian failure (POF) has a great impact on reproductive endocrine function in females, and it is an important cause of infertility. Previous studies have demonstrated that small extracellular vesicles (sEVs) derived from stem cells play an important role in tissue regeneration. This study aimed to investigate the therapeutic effect of sEVs derived from embryonic stem cells (ESCs-sEVs) on damaged ovaries and explore the underlying molecular mechanisms. METHODS Mice POF models were established by injecting mice with cyclophosphamide and busulfan. Then, ESCs-sEVs were intravenously transplanted into POF mice. The plasma of mice was harvested at 1 and 2 weeks after treatment to analyze the levels of anti-Mullerian hormone (AMH), estradiol (E2), and follicle stimulating hormone (FSH) by ELISA. The morphology of ovaries and follicles was observed by H&E staining, and apoptosis of granulosa cells was detected by TUNEL. In vitro, EdU and CCK-8 tests were used to evaluate the proliferation of cultured granulosa cells stimulated by ESCs-sEVs. Western blotting was used to determine the expression of PI3K/AKT and apoptotic-related proteins. RESULTS After transplantation of ESCs-sEVs, the levels of serum sex hormones recovered to normal levels. In addition, the number of follicles was significantly increased, and the number of apoptotic cells was decreased. The results in vitro revealed that ESCs-sEVs could significantly improve the proliferation rate of granulosa cells and increase the expression of phosphorylated PI3K and AKT. Meanwhile, the positive effect on proliferation and the negative effect on apoptosis observed in granulosa cells were obviously decreased when the PI3K/AKT signaling pathway was inhibited. CONCLUSION Our findings suggested that ESCs-sEVs could improve ovarian function by regulating the PI3K/AKT signaling pathway, which could provide a promising clinical therapy for POF.

中文翻译：

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胚胎干细胞来源的小细胞外囊泡通过 PI3K/AKT 信号通路恢复卵巢早衰的卵巢功能。

背景技术卵巢早衰(POF)对女性生殖内分泌功能影响较大，是导致不孕的重要原因。先前的研究表明，源自干细胞的小细胞外囊泡（sEV）在组织再生中发挥着重要作用。本研究旨在探讨胚胎干细胞衍生的sEVs（ESCs-sEVs）对受损卵巢的治疗作用，并探讨其潜在的分子机制。方法通过注射环磷酰胺和白消安建立小鼠POF模型。然后，将ESCs-sEVs静脉移植到POF小鼠体内。治疗后1周和2周采集小鼠血浆，通过ELISA分析抗苗勒氏管激素（AMH）、雌二醇（E2）和卵泡刺激素（FSH）的水平。H&E染色观察卵巢和卵泡形态，TUNEL检测颗粒细胞凋亡。在体外，EdU 和 CCK-8 测试用于评估 ESC-sEV 刺激培养的颗粒细胞的增殖。Western blotting用于测定PI3K/AKT和凋亡相关蛋白的表达。结果 ESCs-sEVs移植后，血清性激素水平恢复至正常水平。此外，卵泡数量显着增加，凋亡细胞数量减少。体外结果显示ESCs-sEVs能够显着提高颗粒细胞的增殖率并增加磷酸化PI3K和AKT的表达。同时，当PI3K/AKT信号通路受到抑制时，颗粒细胞对增殖的积极作用和对凋​​亡的消极作用明显减弱。结论我们的研究结果表明ESCs-sEVs可以通过调节PI3K/AKT信号通路来改善卵巢功能，这可以为POF提供有前景的临床治疗。