Aging has detrimental effects on the ovary, such as a progressive reduction in fertility and decreased hormone production, that greatly reduce the quality of life of women. Thus, the current study was undertaken to investigate whether human placenta-derived mesenchymal stem cell (hPD-MSC) treatment can restore the decreases in folliculogenesis and ovarian function that occur with aging. Acclimatized 52-week-old female SD rats were randomly divided into four groups: single hPD-MSC (5 × 105) therapy, multiple (three times, 10-day intervals) hPD-MSC therapy, control (PBS), and non-treated groups. hPD-MSC therapy was conducted by tail vein injection into aged rats. The rats were sacrificed 1, 2, 3, and 5 weeks after the last injection. hPD-MSC tracking and follicle numbers were histologically confirmed. The serum levels of sex hormones and circulating miRNAs were detected by ELISA and qRT-PCR, respectively. TGF-β superfamily proteins and SMAD proteins in the ovary were detected by Western blot analysis. We observed that multiple transplantations of hPD-MSCs more effectively promoted primordial follicle activation and ovarian hormone (E2 and AMH) production than a single injection. After hPD-MSC therapy, the levels of miR-21-5p, miR-132-3p, and miR-212-3p, miRNAs associated with the ovarian reserve, were increased in the serum. Moreover, miRNAs (miR-16-5p, miR-34a-5p, and miR-191-5p) with known adverse effects on folliculogenesis were markedly suppressed. Importantly, the level of miR-145-5p was reduced after single- or multiple-injection hPD-MSC therapy, and we confirmed that miR-145-5p targets Bmpr2 but not Tgfbr2. Interestingly, downregulation of miR-145-5p led to an increase in BMPR2, and activation of SMAD signaling concurrently increased primordial follicle development and the number of primary and antral follicles. Our study verified that multiple intravenous injections of hPD-MSCs led to improved ovarian function via miR-145-5p and BMP-SMAD signaling and proposed the future therapeutic potential of hPD-MSCs to promote ovarian function in women at advanced age to improve their quality of life during climacterium.

中文翻译：

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人胎盘来源的间充质干细胞通过 miR-145 和老年大鼠的骨形态发生蛋白信号传导刺激卵巢功能

衰老对卵巢有不利影响，例如生育能力逐渐下降和激素产生减少，这大大降低了女性的生活质量。因此，目前的研究旨在调查人胎盘来源的间充质干细胞 (hPD-MSC) 治疗是否可以恢复随着衰老而发生的卵泡发生和卵巢功能的下降。适应环境的 52 周龄雌性 SD 大鼠随机分为四组：单次 hPD-MSC（5×105）治疗、多次（3 次，间隔 10 天）hPD-MSC 治疗、对照（PBS）和非治疗组。通过尾静脉注射到老年大鼠中进行 hPD-MSC 治疗。在最后一次注射后1、2、3和5周处死大鼠。组织学证实了 hPD-MSC 跟踪和卵泡数量。分别通过ELISA和qRT-PCR检测性激素和循环miRNA的血清水平。通过蛋白质印迹分析检测卵巢中的TGF-β超家族蛋白和SMAD蛋白。我们观察到，hPD-MSCs 的多次移植比单次注射更有效地促进了原始卵泡的激活和卵巢激素（E2 和 AMH）的产生。在 hPD-MSC 治疗后，血清中 miR-21-5p、miR-132-3p 和 miR-212-3p（与卵巢储备相关的 miRNA）的水平升高。此外，已知对卵泡发生有不利影响的 miRNA（miR-16-5p、miR-34a-5p 和 miR-191-5p）被显着抑制。重要的是，单次或多次注射 hPD-MSC 治疗后 miR-145-5p 水平降低，我们证实 miR-145-5p 靶向 Bmpr2 而不是 Tgfbr2。有趣的是，miR-145-5p 的下调导致 BMPR2 的增加，并且 SMAD 信号传导的激活同时增加了原始卵泡的发育以及初级和窦卵泡的数量。我们的研究证实，多次静脉注射 hPD-MSCs 可通过 miR-145-5p 和 BMP-SMAD 信号传导改善卵巢功能，并提出了 hPD-MSCs 在促进高龄女性卵巢功能以提高其质量方面的未来治疗潜力更年期的生活。