Ferroportin-Dependent Iron Homeostasis Protects against Oxidative Stress-Induced Nucleus Pulposus Cell Ferroptosis and Ameliorates Intervertebral Disc Degeneration In Vivo.
Ferroportin-Dependent Iron Homeostasis Protects against Oxidative Stress-Induced Nucleus Pulposus Cell Ferroptosis and Ameliorates Intervertebral Disc Degeneration In Vivo.
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铁转运蛋白依赖性铁稳态可防止氧化应激诱导的髓核细胞铁死亡并改善体内椎间盘退变
DOI：
10.1155/2021/6670497
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发表时间：
2021
影响因子：
--
通讯作者：
Yang C
中科院分区：
文献类型：
--
作者：
Lu S;Song Y;Luo R;Li S;Li G;Wang K;Liao Z;Wang B;Ke W;Xiang Q;Chen C;Wu X;Zhang Y;Ling L;Yang C
铁凋亡是一种特殊形式的调节性细胞死亡，其特征是铁依赖性致死性脂质过氧化，这是一种与多种疾病相关的过程。然而，其在椎间盘退变（IVDD）的发病机制中的作用很少被研究。本研究旨在探讨氧化应激（OS-）诱导的髓核细胞（NPC）凋亡中的铁蛋白缺乏（ferroptosis，FMT）在髓核细胞（NPC）凋亡中的作用及IVDD的发病机制，并探讨其调控机制。我们使用叔丁基过氧化氢（TBHP）来模拟人类NPC周围的OS条件。采用流式细胞仪和透射电镜检测细胞内铁蛋白的表达，用铁试剂盒、Perl染色和Western blotting检测细胞内铁的含量。构建了一个ferroportin-（FPN-）慢病毒和FPN-siRNA，并用于探索FPN，细胞内铁稳态和铁凋亡之间的关系。此外，扁柏酚，一种已知特异性抵抗OS和恢复FPN功能的生物活性化合物，被评价其在体外和体内IVDD中的治疗作用。结果表明，细胞间铁超载在TBHP诱导的人NPC铁凋亡中起重要作用。在机制上，FPN失调是OS下细胞间铁超载的原因。金属调节转录因子1（MTF 1）核转位的增加恢复了FPN的功能，消除了细胞间铁超载，保护细胞免受铁细胞下垂。此外，扁柏酚通过抑制JNK通路促进MTF 1的核转位，改善体内IVDD的进展。综上所述，我们的研究结果表明，铁凋亡和FPN功能障碍参与了NPC耗竭和OS下IVDD的发病机制。据我们所知，这是第一个研究证明FPN在NPC铁凋亡中的保护作用，这表明其可能作为一种新的治疗靶点。
Ferroptosis is a specialized form of regulated cell death that is charactered by iron-dependent lethal lipid peroxidation, a process associated with multiple diseases. However, its role in the pathogenesis of intervertebral disc degeneration (IVDD) is rarely investigated. This study is aimed at investigating the role of ferroptosis in oxidative stress- (OS-) induced nucleus pulposus cell (NPC) decline and the pathogenesis of IVDD and determine the underlying regulatory mechanisms. We used tert-butyl hydroperoxide (TBHP) to simulate OS conditions around human NPCs. Flow cytometry and transmission electron microscopy were used to identify ferroptosis, while iron assay kit, Perl's staining, and western blotting were performed to assay the intracellular iron levels. A ferroportin- (FPN-) lentivirus and FPN-siRNA were constructed and used to explore the relationship between FPN, intracellular iron homeostasis, and ferroptosis. Furthermore, hinokitiol, a bioactive compound known to specifically resist OS and restore FPN function, was evaluated for its therapeutic role in IVDD both in vitro and in vivo. The results indicated that intercellular iron overload plays an essential role in TBHP-induced ferroptosis of human NPCs. Mechanistically, FPN dysregulation is responsible for intercellular iron overload under OS. The increase in nuclear translocation of metal-regulatory transcription factor 1 (MTF1) restored the function of FPN, abolished the intercellular iron overload, and protected cells against ferroptosis. Additionally, hinokitiol enhanced the nuclear translocation of MTF1 by suppressing the JNK pathway and ameliorated the progression of IVDD in vivo. Taken together, our results demonstrate that ferroptosis and FPN dysfunction are involved in the NPC depletion and the pathogenesis of IVDD under OS. To the best of our knowledge, this is the first study to demonstrate the protective role of FPN in ferroptosis of NPCs, suggesting its potential used as a novel therapeutic target against IVDD.