Hou Ming-Jie, Guo Qiushi, Zhu Bao Ting
Shenzhen Key Laboratory of Steroid Drug Discovery and Development, School of Medicine, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China.
Shenzhen Key Laboratory of Steroid Drug Discovery and Development, School of Medicine, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China; Shenzhen Bay Laboratory, Shenzhen 518172, China.
Free Radic Biol Med. 2025 May 31;237:631-649. doi: 10.1016/j.freeradbiomed.2025.05.426.
Under pathogenic conditions, the endogenous neurotransmitters dopamine and norepinephrine can readily undergo auto-oxidation to generate reactive oxygen species (ROS), culminating in glutathione depletion and oxidative neuronal injury. Recently, we have revealed that protein disulfide isomerase (PDI) is a mediator of glutathione depletion-associated oxidative ferroptosis, which is also a novel target for ferroptosis protection. In this study, we identify that three chemicals of the endogenous catecholamine family, i.e., norepinephrine, dopamine and N-methyldopamine, are capable of inhibiting PDI and can effectively protect against oxidative ferroptosis in cultured HT22 hippocampal neurons after challenged with different ferroptosis inducers, including erastin, RSL3, glutamate, sulfasalazine and l-buthionine-(S,R)-sulfoximine. Evidence is presented to show that norepinephrine, dopamine and N-methyldopamine can directly bind to PDI in live HT22 cells, and covalently modify the free thiol groups in PDI's catalytic sites, likely through electrophilic attacks. PDI knockdown attenuates the protective effect of norepinephrine, dopamine and N-methyldopamine against chemically-induced ferroptosis in these cells. Mechanistically, inhibition of PDI by norepinephrine, dopamine and N-methyldopamine or PDI knockdown by siRNAs each markedly reduces iNOS and nNOS activation (dimerization) and NO accumulation, and these changes are associated with reduced accumulation of cellular reactive oxygen species (ROS) and lipid-ROS and alleviation of chemically-induced ferroptotic neuronal death. Collectively, the findings of this study reveal that certain oxidative derivatives of catecholamine neurotransmitters, which may be highly cytotoxic, also possess the unique ability to rescue neuronal cells from glutathione depletion-associated oxidative ferroptosis, and PDI serves as a key mechanistic target which mediates their cytoprotective actions.
在致病条件下，内源性神经递质多巴胺和去甲肾上腺素很容易发生自氧化，产生活性氧（ROS），最终导致谷胱甘肽耗竭和氧化性神经元损伤。最近，我们发现蛋白二硫键异构酶（PDI）是与谷胱甘肽耗竭相关的氧化性铁死亡的介质，也是铁死亡保护的新靶点。在本研究中，我们确定内源性儿茶酚胺家族的三种化学物质，即去甲肾上腺素、多巴胺和N-甲基多巴胺，能够抑制PDI，并能在不同的铁死亡诱导剂（包括埃拉司亭、RSL3、谷氨酸、柳氮磺胺吡啶和L-丁硫氨酸-（S，R）-亚砜亚胺）攻击后，有效保护培养的HT2海马神经元免受氧化性铁死亡。有证据表明，去甲肾上腺素、多巴胺和N-甲基多巴胺可以直接与活的HT2细胞中的PDI结合，并共价修饰PDI催化位点中的游离巯基，可能是通过亲电攻击。PDI基因敲低减弱了去甲肾上腺素、多巴胺和N-甲基多巴胺对这些细胞化学诱导的铁死亡的保护作用。从机制上讲，去甲肾上腺素、多巴胺和N-甲基多巴胺对PDI的抑制或siRNA对PDI的基因敲低均显著降低诱导型一氧化氮合酶（iNOS）和神经元型一氧化氮合酶（nNOS）的激活（二聚化）以及一氧化氮的积累，这些变化与细胞活性氧（ROS）和脂质ROS积累的减少以及化学诱导的铁死亡性神经元死亡的减轻有关。总的来说，本研究结果表明，儿茶酚胺神经递质的某些氧化衍生物虽然可能具有高度细胞毒性，但也具有将神经元细胞从与谷胱甘肽耗竭相关的氧化性铁死亡中拯救出来的独特能力，而PDI是介导其细胞保护作用的关键机制靶点。
