Infertility is a prevalent female reproductive disease worldwide. Currently, there are many unknown etiologies of infertility. N6-methyladenosine (m6A) is the most prevalent modification of eukaryotic mRNA. This study intended to investigate the implications of m6A regulators in the uterus for pregnancy and infertility. Pregnant ICR mice on days (D) 0, 4, 6, 10, and 15 were used to monitor m6A methylation in the uterus by liquid chromatography-tandem mass spectrometry (LC–MS/MS), and then m6A methylation regulators were detected by real-time quantitative PCR (qPCR), western blot and immunohistochemistry (IHC). We found that m6A levels increased and that m6A regulators were expressed differently in the uterus during pregnancy. Then, we acquired expression data from endometrial tissue from women with infertility and recurrent pregnancy loss from the Gene Expression Omnibus (GEO) database. The expression of m6A regulators in infertility was significantly dysregulated according to the data mining technique. Specifically, the mRNA levels of METTL16 (p = 0.0147) and WTAP (p = 0.028) were lower and those of ALKBH5 (p = 0.0432) and IGF2BP2 (p = 0.0016) were higher in the endometrium of infertile patients. Meanwhile, many immunity-related pathways are abnormal in infertility, such as cytokine-cytokine receptor interactions, natural killer cell-mediated cytotoxicity and leukocyte transendothelial migration. In conclusion, we found that the m6A levels in the uterus increased as pregnancy progressed, and these regulators were dysregulated in the endometrium of infertility patients. These results suggest that m6A methylation may be very important in the establishment of implantation and maintenance of pregnancy and may become a new direction for research on infertility.

不孕症是世界范围内普遍存在的女性生殖疾病。目前，有许多未知的不孕症病因。N6-甲基腺苷 (m6A) 是最普遍的真核 mRNA 修饰。本研究旨在调查子宫中 m6A 调节剂对妊娠和不孕症的影响。第 0、4、6、10 和 15 天 (D) 的妊娠 ICR 小鼠用于通过液相色谱-串联质谱 (LC-MS/MS) 监测子宫中的 m6A 甲基化，然后通过以下方法检测 m6A 甲基化调节剂实时定量 PCR (qPCR)、蛋白质印迹和免疫组织化学 (IHC)。我们发现 m6A 水平增加，并且 m6A 调节剂在怀孕期间在子宫中表达不同。然后，我们从 Gene Expression Omnibus (GEO) 数据库中获得了患有不孕症和反复流产的女性的子宫内膜组织的表达数据。根据数据挖掘技术，m6A 调节剂在不孕症中的表达明显失调。具体来说，mRNA 水平在不孕症患者的子宫内膜中， METTL16 (p = 0.0147 ) 和WTAP (p = 0.028) 较低，ALKBH5 (p = 0.0432) 和IGF2BP2 (p = 0.0016) 较高。同时，不孕症中许多免疫相关通路异常，如细胞因子-细胞因子受体相互作用、自然杀伤细胞介导的细胞毒性和白细胞跨内皮迁移。总之，我们发现子宫中的 m6A 水平随着妊娠的进展而增加，并且这些调节剂在不孕症患者的子宫内膜中失调。这些结果表明，m6A甲基化可能对着床的建立和妊娠的维持非常重要，可能成为不孕症研究的新方向。