Feng Yuxin, Wang Heran, Hu Yazhuo, Zhang Xiaoxue, Miao XiuLing, Li Zihan, Jia JianJun
Medical School of Chinese People's Liberation Army, Beijing, China.
Institute of Geriatrics, The 2nd Medical Center, China National Clinical Research Center for Geriatric Disease, Chinese People's Liberation Army General Hospital, Beijing, China.
Bioorg Chem. 2025 Feb;155:108119. doi: 10.1016/j.bioorg.2024.108119. Epub 2024 Dec 30.
Hederagenin (HG), derived from ivy seeds, is known to offer protection against Alzheimer's disease (AD). However, the specific molecular pathways through which it counters ferroptosis-induced neurotoxicity are not fully elucidated. This investigation seeks to delineate the processes by which HG mitigates neurotoxic effects in HT22 cells subjected to glutamate (Glu)-induced ferroptosis.
HT22 cell ferroptosis was prompted by Glu exposure. Cell viability was assessed using CCK-8 and LDH assays, while Fe fluorescence and assays of iron-related proteins served to gauge intracellular Fe concentrations. Evaluations of mitochondrial structure and functionality employed JC-1 staining and transmission electron microscopy. Assessments of ROS, lipid peroxidation, MDA, 4-HNE, and the GSSG/GSH ratio were conducted to ascertain HG's antioxidative efficacy. The expression of proteins within the PPARα/Nrf2/GPX4 pathway was quantified via western blotting, with molecular docking (MD), and molecular dynamics simulations (MDS) used to explore protein interactions.
HG diminished the cellular toxicity triggered by Glu in HT22 cells, lowered Fe within cells, and rejuvenated mitochondrial morphology and performance. Concurrently, it modulated proteins critical to Fe metabolism, diminished ROS and lipid peroxidation, and elevated GSH/GSSG ratios. Enhanced PPARα/Nrf2/GPX4 protein levels were corroborated by western blot results. Furthermore, molecular docking revealed favorable binding of HG to the proteins PPARα, Nrf2, and GPX4, with binding energies of -7.751, -7.535, and -7.414 kcal/mol, respectively. MDS confirmed robust interactions between HG and these pivotal targets.
The evidence suggests that HG effectively mitigates Glu-induced ferroptosis in HT22 cells by activating the PPARα/Nrf2/GPX4 signaling pathway. These findings endorse HG's potential as a nutritional adjunct for AD management.
常春藤皂苷元（HG）源自常春藤种子，已知其对阿尔茨海默病（AD）具有保护作用。然而，其对抗铁死亡诱导的神经毒性的具体分子途径尚未完全阐明。本研究旨在阐明HG减轻谷氨酸（Glu）诱导的铁死亡对HT22细胞神经毒性作用的过程。
通过Glu暴露诱导HT22细胞铁死亡。使用CCK-8和LDH检测评估细胞活力，同时用铁荧光和铁相关蛋白检测来测定细胞内铁浓度。采用JC-1染色和透射电子显微镜对线粒体结构和功能进行评估。对活性氧（ROS）、脂质过氧化、丙二醛（MDA）、4-羟基壬烯醛（4-HNE）以及谷胱甘肽二硫化物/谷胱甘肽（GSSG/GSH）比值进行检测，以确定HG的抗氧化功效。通过蛋白质印迹法定量PPARα/Nrf2/GPX4途径内蛋白质的表达，并利用分子对接（MD）和分子动力学模拟（MDS）来探索蛋白质相互作用。
HG减轻了Glu在HT22细胞中引发的细胞毒性，降低了细胞内铁含量，并使线粒体形态和功能恢复活力。同时，它调节了对铁代谢至关重要的蛋白质，减少了ROS和脂质过氧化，并提高了GSH/GSSG比值。蛋白质印迹结果证实了PPARα/Nrf2/GPX4蛋白水平的升高。此外，分子对接显示HG与PPARα、Nrf2和GPX4蛋白具有良好的结合，结合能分别为-7.751、-7.535和-7.414千卡/摩尔。MDS证实了HG与这些关键靶点之间有强大的相互作用。
证据表明，HG通过激活PPARα/Nrf2/GPX4信号通路有效减轻了Glu诱导的HT22细胞铁死亡。这些发现支持了HG作为AD管理营养辅助剂的潜力。
