Department of Biochemistry and Molecular Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, No. 17, Section 3, Ren Min Nan Lu, Chengdu, 610041, Sichuan, People's Republic of China.
Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China.
J Mol Histol. 2024 Dec;55(6):1163-1175. doi: 10.1007/s10735-024-10257-7. Epub 2024 Sep 11.
Methyltransferase-like 3 (METTL3) is extensively reported to be involved in organ fibrosis. Ovarian fibrosis is a main characteristic of polycystic ovary syndrome (PCOS). However, the reaction mechanism of METTL3 in PCOS is poorly investigated. This paper was intended to reveal the role and the mechanism of METTL3 in PCOS. Animal and cell models of PCOS were induced by dehydroepiandrosterone (DHEA). H&E staining was performed to detect the pathological alterations in ovary tissues. Masson staining, immunofluorescence, along with western blot measured fibrosis both in vitro and in vivo. To evaluate estrous cycle, vaginal smear was performed. Lipid peroxidation and ferroptosis were evaluated by MDA assay kits, GSH assay kits, immunohistochemistry, Prussian blue staining and western blot. qRT-PCR and western blot were adopted to estimate METTL3 and GPX4 expression. The m6A and hormone secretion levels were respectively assessed by m6A RNA Methylation Quantitative Kit and corresponding kits. The interaction between METTL3 and GPX4 was testified by immunoprecipitation. The fibrosis and ferroptosis were aggravated and m6A and METTL3 expression were increased in ovarian tissues of DHEA-induced PCOS mice. METTL3 silencing alleviated pathological changes, affected hormone secretion level, and repressed fibrosis, lipid peroxidation and ferroptosis in the ovarian tissues of PCOS mice. In vitro, DHEA stimulation increased m6A and METTL3 expression and induced ferroptosis and fibrosis. METTL3 knockdown promoted GPX4 expression in DHEA-induced granulosa cells by m6A modification and restrained DHEA-induced fibrosis, lipid peroxidation and ferroptosis in granulosa cells via elevating GPX4. METTL3 silence inhibited ovarian fibrosis in PCOS, which was mediated through suppressing ferroptosis by upregulating GPX4 in m6A-dependent manner.
甲基转移酶样蛋白 3（METTL3）广泛报道参与器官纤维化。卵巢纤维化是多囊卵巢综合征（PCOS）的主要特征。然而，METTL3 在 PCOS 中的反应机制研究甚少。本文旨在揭示 METTL3 在 PCOS 中的作用和机制。采用脱氢表雄酮（DHEA）诱导 PCOS 动物和细胞模型。进行 H&E 染色以检测卵巢组织的病理改变。进行 Masson 染色、免疫荧光和 Western blot 以评估体外和体内的纤维化。进行阴道涂片以评估动情周期。通过 MDA 试剂盒、GSH 试剂盒、免疫组化、普鲁士蓝染色和 Western blot 评估脂质过氧化和铁死亡。采用 qRT-PCR 和 Western blot 评估 METTL3 和 GPX4 的表达。采用 m6A RNA 甲基化定量试剂盒和相应试剂盒评估 m6A 和激素分泌水平。通过免疫沉淀验证 METTL3 和 GPX4 之间的相互作用。在 DHEA 诱导的 PCOS 小鼠的卵巢组织中，纤维化和铁死亡加重，m6A 和 METTL3 表达增加。METTL3 沉默减轻了病理变化，影响了激素分泌水平，并抑制了 PCOS 小鼠卵巢组织中的纤维化、脂质过氧化和铁死亡。在体外，DHEA 刺激增加了 m6A 和 METTL3 的表达，并诱导了铁死亡和纤维化。METTL3 敲低通过 m6A 修饰促进了 DHEA 诱导的颗粒细胞中 GPX4 的表达，并通过提高 GPX4 抑制了 DHEA 诱导的颗粒细胞中的纤维化、脂质过氧化和铁死亡。METTL3 沉默抑制了 PCOS 中的卵巢纤维化，这是通过 m6A 依赖性方式上调 GPX4 抑制铁死亡来介导的。
