Department of Otolaryngology Head and Neck Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China.
Department of Otolaryngology Head and Neck Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China.
Biochim Biophys Acta Mol Basis Dis. 2024 Mar;1870(3):167024. doi: 10.1016/j.bbadis.2024.167024. Epub 2024 Jan 17.
Oxidative stress is the common mechanism of sensorineural hearing loss (SNHL) caused by many factors, such as noise, drugs and ageing. Here, we used tert-butyl hydroperoxide (t-BHP) to cause oxidative stress damage in HEI-OC1 cells and in an in vitro cochlear explant model. We observed lipid peroxidation, iron accumulation, mitochondrial shrinkage and vanishing of mitochondrial cristae, which caused hair cell ferroptosis, after t-BHP exposure. Moreover, the number of TUNEL-positive cells in cochlear explants and HEI-OC1 cells increased significantly, suggesting that t-BHP caused the apoptosis of hair cells. Administration of deferoxamine (DFOM) significantly attenuated t-BHP-induced hair cell loss and disordered hair cell arrangement in cochlear explants as well as HEI-OC1 cell death, including via apoptosis and ferroptosis. Mechanistically, we found that DFOM treatment reduced t-BHP-induced lipid peroxidation, iron accumulation and mitochondrial pathological changes in hair cells, consequently mitigating apoptosis and ferroptosis. Moreover, DFOM treatment alleviated GSH depletion caused by t-BHP and activated the Nrf2 signalling pathway to exert a protective effect. Furthermore, we confirmed that the protective effect of DFOM mainly depended on its ability to chelate iron by constructing Fth1 knockout (KO), TfR1 KO and Nrf2 KO HEI-OC1 cell lines using CRISPR/Cas9 technology and a Flag-Fth1 (overexpression) HEI-OC1 cell line using the FlpIn™ System. Our findings suggest that DFOM is a potential drug for SNHL treatment due to its ability to inhibit apoptosis and ferroptosis by chelating iron and scavenging reactive oxygen species (ROS).
氧化应激是许多因素(如噪声、药物和衰老)引起的感觉神经性听力损失(SNHL)的共同机制。在这里,我们使用叔丁基过氧化氢(t-BHP)在 HEI-OC1 细胞和体外耳蜗外植体模型中引起氧化应激损伤。我们观察到 t-BHP 暴露后脂质过氧化、铁积累、线粒体收缩和线粒体嵴消失,导致毛细胞发生铁死亡。此外,耳蜗外植体和 HEI-OC1 细胞中 TUNEL 阳性细胞的数量显著增加,表明 t-BHP 引起了毛细胞的凋亡。铁螯合剂去铁胺(DFOM)的给药显著减轻了 t-BHP 诱导的耳蜗外植体中毛细胞丢失和毛细胞排列紊乱以及 HEI-OC1 细胞死亡,包括通过凋亡和铁死亡。在机制上,我们发现 DFOM 处理减轻了 t-BHP 诱导的毛细胞中脂质过氧化、铁积累和线粒体病理变化,从而减轻了凋亡和铁死亡。此外,DFOM 处理缓解了 t-BHP 引起的 GSH 耗竭,并激活了 Nrf2 信号通路发挥保护作用。此外,我们通过使用 CRISPR/Cas9 技术构建 Fth1 敲除(KO)、TfR1 KO 和 Nrf2 KO HEI-OC1 细胞系以及使用 FlpIn™ System 构建 Flag-Fth1(过表达)HEI-OC1 细胞系,证实了 DFOM 的保护作用主要取决于其螯合铁的能力。我们的研究结果表明,DFOM 是一种治疗 SNHL 的潜在药物,因为它通过螯合铁和清除活性氧(ROS)来抑制凋亡和铁死亡。