Physical Science and Technical College, Shenyang Normal University, No. 253 Huanghe North Street, Huanggu District, Shenyang City, 110034, Liaoning Province, China.
Department of Histology and Embryology, School of Basic Medical Sciences, Peking University Health Science Center, No. 38 Xueyuan Road, Haidian District, Beijing, 100191, China.
BMC Mol Cell Biol. 2020 Jul 3;21(1):51. doi: 10.1186/s12860-020-00298-7.
Methotrexate (MTX) is an antifolate agent which is widely used in clinic for treating malignancies, rheumatoid arthritis and ectopic pregnancy. As reported, MTX has side effects on gastrointestinal system, nervous system and reproductive system, while its potential damages on oocyte quality are still unclear. It is known that oocyte quality is essential for healthy conception and the forthcoming embryo development. Thus, this work studied the effects of MTX on the oocyte quality.
We established MTX model mice by single treatment with 5 mg/Kg MTX. Both morphological and molecular biology studies were performed to assess the in-vivo matured oocytes quality and to analyze the related mechanisms. The in-vivo matured oocytes from MTX-treated mice had poor in-vitro fertilization ability, and the resulting embryo formation rates and blastocyst quality were lower than the control group. We found that the in-vivo matured MTX-treated mouse oocytes displayed abnormal transcript expressions for genes of key enzymes in the folate cycles. MTX increased the rate of abnormal chromosome alignment and affected the regulation of chromosome separation via disrupting the spindle morphology and reducing the mRNA expressions of MAD2 and Sgo1. MTX reduced the DNA methylation levels in the in-vivo matured oocytes, and further studies showed that MTX altered the expressions of DNMT1 and DNMT 3b, and may also affect the levels of the methyl donor and its metabolite.
MTX impaired the in-vivo matured mouse oocyte quality by disturbing folate metabolism and affecting chromosome stability and methylation modification.
甲氨蝶呤（MTX）是一种广泛用于治疗恶性肿瘤、类风湿性关节炎和宫外孕的抗叶酸药物。据报道，MTX 对胃肠道、神经系统和生殖系统有副作用，但其对卵母细胞质量的潜在损害尚不清楚。众所周知，卵母细胞质量对健康受孕和随后的胚胎发育至关重要。因此，本研究探讨了 MTX 对卵母细胞质量的影响。
我们通过单次给予 5mg/Kg MTX 建立了 MTX 模型小鼠。通过形态学和分子生物学研究评估体内成熟卵母细胞的质量，并分析相关机制。来自 MTX 处理小鼠的体内成熟卵母细胞体外受精能力差，胚胎形成率和囊胚质量均低于对照组。我们发现，体内成熟的 MTX 处理小鼠卵母细胞中叶酸循环关键酶的基因转录表达异常。MTX 通过破坏纺锤体形态和降低 MAD2 和 Sgo1 的 mRNA 表达，增加了异常染色体排列的发生率，并影响了染色体分离的调节。MTX 降低了体内成熟卵母细胞的 DNA 甲基化水平，进一步的研究表明，MTX 改变了 DNMT1 和 DNMT3b 的表达，并且可能还影响了甲基供体及其代谢物的水平。
MTX 通过干扰叶酸代谢以及影响染色体稳定性和甲基化修饰，损害了体内成熟的小鼠卵母细胞质量。
