Reproductive Medicine Center, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Hum Reprod. 2021 Nov 18;36(12):3095-3107. doi: 10.1093/humrep/deab217.
Is CDC26 a key factor in human oocyte aging?
The lack of CDC26 disrupts the oocytes maturation process, leading to oocyte aging, but these defects could be partially rescued by overexpression of the CDC26 protein.
Age-related oocyte aging is the main cause of female fertility decline. In mammalian oocytes, aberrant meiosis can cause chromosomal abnormalities that might lead to infertility and developmental disorders. CDC26 participates in the meiosis process.
STUDY DESIGN, SIZE, DURATION: Differential gene expression in young and old women oocytes were screened by single-cell RNA-seq technology, and the functions of differentially genes were verified on mouse oocytes. Finally, transfection technology was used to evaluate the effect of a differentially expressed gene in rescuing human oocyte from aging.
PARTICIPANTS/MATERIALS, SETTING, METHODS: Discarded human oocytes were collected for single-cell RNA-seq, q-PCR and immunocytochemical analyses to screen for and identify differential gene expression. Female KM mice oocytes were collected for IVM of oocytes, q-PCR and immunocytochemical analyses to delineate the relationships between oocyte aging and differential gene expression. Additionally, recombinant lentiviral vectors encoding CDC26 were transfected into the germinal vesicle oocytes of older women, to investigate the effects of the CDC26 gene expression on oocyte development.
Many genes were found to be differentially expressed in the oocytes of young versus old patients via RNA-seq technology. CDC26 mRNA and protein levels in aged oocytes were severely decreased, when compared with the levels observed in young oocytes. Moreover, aged oocytes lacking CDC26 were more prone to aneuploidy. These defects in aged oocytes could be partially rescued by overexpression of the CDC26 protein.
N/A.
LIMITATIONS, REASONS FOR CAUTION: Our study delineated key steps in the oocyte aging process by identifying the key role of CDC26 in the progression of oocyte maturation. Future studies are required to address whether other signaling pathways play a role in regulating oocyte maturation via CDC26 and which genes are the direct molecular targets of CDC26.
Our results using in vitro systems for both mouse and human oocyte maturation provide a proof of principle that CDC26 may represent a novel therapeutic approach against maternal aging-related spindle and chromosomal abnormalities.
STUDY FUNDING/COMPETING INTEREST(S): This work was supported by grants from the National Natural Science Foundation of China (81571442 and 81170571), the outstanding Talent Project of Shanghai Municipal Commission of Health (XBR2011067) and Clinical Research and Cultivation Project in Shanghai Municipal Hospitals (SHDC12019X32). The authors declare no conflict of interest.
CDC26 是否是人类卵母细胞衰老的关键因素？
缺乏 CDC26 会破坏卵母细胞的成熟过程，导致卵母细胞衰老，但通过过表达 CDC26 蛋白可以部分挽救这些缺陷。
与年龄相关的卵母细胞衰老是女性生育能力下降的主要原因。在哺乳动物卵母细胞中，异常减数分裂会导致染色体异常，可能导致不孕和发育障碍。CDC26 参与减数分裂过程。
研究设计、规模、持续时间：通过单细胞 RNA-seq 技术筛选年轻和老年女性卵母细胞中的差异基因表达，并在小鼠卵母细胞上验证差异基因的功能。最后，使用转染技术评估差异表达基因在挽救人类卵母细胞衰老中的作用。
参与者/材料、设置、方法：收集废弃的人类卵母细胞进行单细胞 RNA-seq、q-PCR 和免疫细胞化学分析，以筛选和鉴定差异基因表达。收集 KM 小鼠卵母细胞进行体外成熟（IVM）、q-PCR 和免疫细胞化学分析，以阐明卵母细胞衰老与差异基因表达之间的关系。此外，将编码 CDC26 的重组慢病毒载体转染到老年女性的生发泡卵母细胞中，以研究 CDC26 基因表达对卵母细胞发育的影响。
通过 RNA-seq 技术发现年轻患者和老年患者的卵母细胞中有许多基因表达存在差异。与年轻卵母细胞相比，衰老卵母细胞中 CDC26 mRNA 和蛋白水平严重降低。此外，缺乏 CDC26 的衰老卵母细胞更容易出现非整倍体。通过过表达 CDC26 蛋白，这些衰老卵母细胞中的缺陷可以部分得到挽救。
无。
局限性、谨慎的原因：我们的研究通过鉴定 CDC26 在卵母细胞成熟过程中的关键作用，描绘了卵母细胞衰老过程中的关键步骤。未来的研究需要确定是否有其他信号通路通过 CDC26 调节卵母细胞成熟，以及哪些基因是 CDC26 的直接分子靶标。
我们使用小鼠和人类卵母细胞成熟的体外系统的研究结果提供了一个原理证明，即 CDC26 可能代表一种针对母体衰老相关纺锤体和染色体异常的新型治疗方法。
研究资金/竞争利益：本工作得到国家自然科学基金（81571442 和 81170571）、上海市卫生健康委员会优秀人才计划（XBR2011067）和上海市医院临床研究培育项目（SHDC12019X32）的资助。作者声明没有利益冲突。
