澳门大学郑文华等研究人员合作发现，青蒿素通过靶向KEAP1抑制阿尔茨海默病模型中的神经元铁死亡。这一研究成果于2024年9月9日在线发表在国际学术期刊《中国药理学报》上。

研究人员探讨了青蒿素对神经元铁死亡的保护作用及其潜在机制。在海马HT22细胞中，青蒿素预处理以剂量依赖性方式保护细胞免受Erastin诱导的细胞死亡，EC₅₀值为5.032 µM，类似于铁死亡抑制剂ferrostatin-1（EC₅₀=4.39 µM）。研究人员证明青蒿素（10 μM）显著增加了Nrf2的核转位，并上调了HT22细胞中的SLC7A11和GPX4。敲低Nrf2、SLC7A11或GPX4阻断了青蒿素的保护作用，表明其抗铁死亡效果是通过Nrf2-SLC7A11-GPX4通路介导的。

分子对接和共免疫沉淀（Co-IP）分析显示，青蒿素与KEAP1竞争性结合，促进了KEAP1-Nrf2复合物的解离并抑制了Nrf2的泛素化。海马内注射咪唑-酮-Erastin（IKE）在小鼠中诱导铁死亡，并伴随认知缺陷，表现为在新物体和新物体位置探索中的偏好降低。青蒿素（5、10 mg/kg，腹腔注射）以剂量依赖性方式抑制了IKE诱导的海马CA1区铁死亡，并改善了学习和记忆障碍。

此外，研究人员证明青蒿素通过KEAP1-Nrf2通路逆转了Aβ1-42诱导的铁死亡、脂质过氧化和谷胱甘肽耗竭，在HT22细胞、原代海马神经元以及3×Tg小鼠中表现出显著效果。这些研究结果表明，青蒿素是一种新型的神经元铁死亡抑制剂，通过靶向KEAP1激活Nrf2-SLC7A11-GPX4通路。

据悉，铁死亡是一种以脂质过氧化为特征的细胞死亡形式，涉及阿尔茨海默病（AD）等神经退行性疾病。近期研究表明，一线抗疟药青蒿素能有效抵抗AD病理。

附：英文原文

Title: Artemisinin inhibits neuronal ferroptosis in Alzheimer’s disease models by targeting KEAP1

Author: Deng, Peng-xi, Silva, Marta, Yang, Na, Wang, Qing, Meng, Xin, Ye, Ke-qiang, Gao, Hong-chang, Zheng, Wen-hua

Issue&Volume: 2024-09-09

Abstract: Ferroptosis, a form of cell death characterized by lipid peroxidation, is involved in neurodegenerative diseases such as Alzheimer′s disease (AD). Recent studies have shown that a first-line antimalarial drug artemisinin is effective to counteract AD pathology. In this study, we investigated the protective effect of artemisinin against neuronal ferroptosis and the underlying mechanisms. In hippocampal HT22 cells, pretreatment with artemisinin dose-dependently protected against Erastin-induced cell death with an EC50 value of 5.032μM, comparable to the ferroptosis inhibitor ferrostatin-1 (EC50=4.39μM). We demonstrated that artemisinin (10μM) significantly increased the nuclear translocation of Nrf2 and upregulated SLC7A11 and GPX4 in HT22 cells. Knockdown of Nrf2, SLC7A11 or GPX4 prevented the protective action of artemisinin, indicating that its anti-ferroptosis effect is mediated by the Nrf2-SLC7A11-GPX4 pathway. Molecular docking and Co-Immunoprecipitation (Co-IP) analysis revealed that artemisinin competitively binds with KEAP1, promoting the dissociation of KEAP1-Nrf2 complex and inhibiting the ubiquitination of Nrf2. Intrahippocampal injection of imidazole-ketone-Erastin (IKE) induced ferroptosis in mice accompanied by cognitive deficits evidenced by lower preference for exploration of new objects and new object locations in the NOR and NOL tests. Artemisinin (5, 10mg/kg, i.p.) dose-dependently inhibited IKE-induced ferroptosis in hippocampal CA1 region and ameliorated learning and memory impairments. Moreover, we demonstrated that artemisinin reversed Aβ1-42-induced ferroptosis, lipid peroxidation and glutathione depletion in HT22 cells, primary hippocampal neurons, and 3×Tg mice via the KEAP1-Nrf2 pathway. Our results demonstrate that artemisinin is a novel neuronal ferroptosis inhibitor that targets KEAP1 to activate the Nrf2-SLC7A11-GPX4 pathway.

DOI: 10.1038/s41401-024-01378-6

Source: https://www.nature.com/articles/s41401-024-01378-6