Ferroptosis of vascular smooth muscle cells (VSMCs) is related to the incidence of aortic dissection (AD). Long non-coding RNA (lncRNA) NORAD plays a crucial role in the progression of various diseases. The present study aimed to investigate the effects of NORAD on the ferroptosis of VSMCs and the molecular mechanisms. The expression of NORAD, HUR, and GPX4 was detected using quantitative real-time PCR (qPCR) or western blot. Ferroptosis was evaluated by detecting lactate dehydrogenase (LDH) activity, lipid reactive oxygen species (ROS), malonaldehyde (MDA) content, L-Glutathione (GSH) level, Fe²⁺ content, and ferroptosis-related protein levels. The molecular mechanism was assessed using RNA pull-down, RNA-binding protein immunoprecipitation (RIP), and luciferase reporter assay. The histology of aortic tissues was assessed using H&E, elastic Verhoeff–Van Gieson (EVG), and Masson staining assays. The data indicated that NORAD was downregulated in patients with AD and AngII-treated VSMCs. Overexpression of NORAD promoted VSMC growth and inhibited the ferroptosis induced by AngII. Mechanistically, NORAD interacted with HUR, which promoted GPX4 mRNA stability and elevated GPX4 levels. Knockdown of GPX4 abrogated the effects of NORAD on cell growth and ferroptosis of AngII-treated VSMCs. Moreover, METTL3 promoted m6A methylation of NORAD in an YTHDF2-dependent manner. In addition, NORAD attenuated AAD symptoms, incidence, histopathology, inflammation, and ferroptosis in AAD mice. In conclusion, METTL3-mediated NORAD inhibited ferroptosis of VSMCs via the HUR/GPX4 axis and decelerated AAD progression, suggesting that NORAD may be an AD therapeutic target.

血管平滑肌细胞 （VSMC） 的铁死亡与主动脉夹层 （AD） 的发病率有关。长链非编码 RNA （lncRNA） NORAD 在各种疾病的进展中起着至关重要的作用。本研究旨在探讨 NORAD 对 VSMCs 铁死亡的影响及其分子机制。使用定量实时 PCR （qPCR） 或 western blot 检测 NORAD 、 HUR 和 GPX4 的表达。通过检测乳酸脱氢酶 （LDH） 活性、脂质活性氧 （ROS） 、丙二醛 （MDA） 含量、L-谷胱甘肽 （GSH） 水平、Fe²⁺ 含量和铁死亡相关蛋白水平来评估铁死亡。使用 RNA pull-down 、 RNA 结合蛋白免疫沉淀 （RIP） 和荧光素酶报告基因测定评估分子机制。使用 H&E 、弹性 Verhoeff-Van Gieson （EVG） 和 Masson 染色测定法评估主动脉组织的组织学。数据表明，NORAD 在 AD 和 AngII 治疗的 VSMC 患者中下调。NORAD 的过表达促进 VSMC 生长并抑制 AngII 诱导的铁死亡。从机制上讲，NORAD 与 HUR 相互作用，从而促进 GPX4 mRNA 稳定性和 GPX4 水平升高。GPX4 的敲除消除了 NORAD 对 AngII 处理的 VSMC 细胞生长和铁死亡的影响。此外，METTL3 以 YTHDF2 依赖性方式促进 NORAD 的 m6A 甲基化。此外，NORAD 减轻了 AAD 小鼠的 AAD 症状、发病率、组织病理学、炎症和铁死亡。总之，METTL3 介导的 NORAD 通过 HUR/GPX4 轴抑制 VSMC 的铁死亡并减缓 AAD 进展，表明 NORAD 可能是 AD 治疗靶点。