Intrauterine devices containing copper placement will release a large amount of Cu2+ into the uterine fluid, leading to local endometrial damage and inflammation, which is considered to be one of the causes of abnormal uterine bleeding. Studies have shown that the metabolism and function of metal ions are related to the regulation of microRNA. The aims of this study were to investigate changes in endometrial microRNA levels after implantation of an intrauterine device containing copper and to preliminarily explore the signalling pathways involved in abnormal uterine bleeding. The subjects were fertile women, aged 25–35, without major obstetrics and gynaecology diseases. Human endometrial tissues were collected before implantation or removal of the intrauterine device containing copper. High-throughput microRNA sequencing was performed on human endometrial tissues, and real-time quantitative PCR, western blotting and immunohistochemistry were used to detect the expression of relevant genes. MicroRNA sequencing results showed that 72 miRNAs were differentially expressed in the endometrial tissue after the insertion of the intrauterine device containing copper. Implantation of an intrauterine device containing copper implantation can up-regulate the expression of miR-144-3p in endometrial tissue, and therefore, decreases the mRNA and protein expression levels of genes related to endometrial injury and tissue repair, including the MT/NF-κB/MMP damage pathway and the THBS-1/TGF-β/SMAD3 repair pathway. In this study, the molecular mechanisms of abnormal uterine bleeding due to an intrauterine device containing copper were preliminarily investigated. The information will be beneficial for the clinical treatment of abnormal uterine bleeding caused by intrauterine device.

中文翻译：

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植入含铜宫内节育器后人子宫内膜微RNA的差异表达

含铜的宫内节育器会释放大量的Cu2+进入子宫液，导致局部子宫内膜损伤和炎症，这被认为是异常子宫出血的原因之一。研究表明，金属离子的代谢和功能与microRNA的调控有关。本研究的目的是调查植入含铜宫内节育器后子宫内膜 microRNA 水平的变化，并初步探索异常子宫出血所涉及的信号通路。受试者为 25-35 岁、无重大妇产科疾病的有生育能力的女性。在植入或取出含铜宫内节育器之前收集人体子宫内膜组织。对人子宫内膜组织进行高通量microRNA测序，利用实时定量PCR、蛋白质印迹和免疫组化检测相关基因的表达。MicroRNA测序结果显示，插入含铜宫内节育器后，72个miRNA在子宫内膜组织中出现差异表达。植入含铜的宫内节育器可上调子宫内膜组织中 miR-144-3p 的表达，从而降低与子宫内膜损伤和组织修复相关的基因的 mRNA 和蛋白表达水平，包括 MT/NF- κB/MMP 损伤通路和 THBS-1/TGF-β/SMAD3 修复通路。在这项研究中，初步研究了含铜宫内节育器异常子宫出血的分子机制。该信息将有助于宫内节育器引起的异常子宫出血的临床治疗。