PO.ET06.01 · 实验与分子治疗
线粒体非依赖性铜死亡（cuproptosis）的机制
Mechanism of mitochondria-independent cuproptosis
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
铜是一种必需的微量元素，作为众多代谢和解毒酶的辅因子发挥功能。然而，铜过量时会对癌细胞产生显著的细胞毒性，并可诱导一种近期被表征的调控性细胞死亡形式，称为铜死亡（cuproptosis）。目前认为，铜死亡依赖于线粒体活性，涉及二价铜离子还原为一价，随后通过脂酰化DLAT（二氢硫辛酰转乙酰酶）的寡聚化和铁硫簇蛋白的丧失产生毒性效应。在此，我们评估了几种铜离子载体的铜络合形式，包括双（二乙基二硫代氨基甲酸盐）（CuET）、pyrithione（吡硫翁）、NSC319726和8-hydroxyquinoline（8-羟基喹啉），以评估它们诱导铜死亡的能力。令人意外的是，它们的细胞毒性效应在依赖氧化磷酸化的癌细胞和以糖酵解为主的对应细胞中相当。与此一致，无论是对单个线粒体复合体的化学抑制，还是使用线粒体DNA缺陷的Rho0细胞，均未显示出敏感性的差异。相反，所有受试的离子载体均诱导必需的p97辅因子NPL4的聚集和固定，与此前关于CuET报道的机制一致。NPL4功能障碍破坏p97/蛋白酶体轴，其聚集与细胞毒性结局密切相关。离子载体处理还触发了经典的蛋白毒性应激通路，包括未折叠蛋白反应、热休克反应以及多聚泛素化蛋白的累积。重要的是，额外用无毒、更强效的二价铜螯合剂dibenzyldithiocarbamate（二苄基二硫代氨基甲酸盐）处理可逆转NPL4聚集和离子载体诱导的细胞毒性。总之，这些发现通过揭示与靶向NPL4相关的二价铜的显著蛋白毒性成分，完善了铜依赖性细胞杀伤的机制框架。这一见解强化了将铜调控的蛋白稳态通路作为潜在抗癌策略加以靶向的理论依据。
查看英文原文 English abstract
Copper is an essential trace element that functions as a cofactor for numerous metabolic and detoxification enzymes. In excess, however, copper exerts marked cytotoxicity in cancer cells and can induce a recently characterized form of regulated cell death termed cuproptosis . Currently, cuproptosis is believed to depend on mitochondrial activity, involving the reduction of bivalent copper ions to monovalent, leading to subsequent toxic effects via the oligomerization of lipoylated DLAT (dihydrolipoyl transacetylase) and the loss of iron-sulfur cluster proteins. Here, we evaluated several copper ionophores in their copper-complexed forms, including bis(diethyldithiocarbamate) (CuET), pyrithione, NSC319726, and 8-hydroxyquinoline, to assess their ability to induce cuproptosis. Surprisingly, their cytotoxic effects were comparable in oxidative-phosphorylation-dependent cancer cells and in glycolysis-driven counterparts. Consistently, neither chemical inhibition of individual mitochondrial complexes nor the use of mitochondrial DNA-deficient Rho0 cells revealed differential sensitivity. Instead, all tested ionophores induced aggregation and immobilization of the essential p97 cofactor NPL4, mirroring the mechanism previously reported for CuET. NPL4 dysfunction disrupts the p97/proteasome axis, and its aggregation strongly correlates with cytotoxic outcomes. Ionophore treatment also triggered canonical proteotoxic stress pathways, including the unfolded protein response, the heat-shock response, and accumulation of polyubiquitinated proteins. Importantly, additional treatment with the non-toxic, more potent divalent copper chelator, dibenzyldithiocarbamate, reversed NPL4 aggregation and ionophore-induced cytotoxicity. Together, these findings refine the mechanistic framework of copper-dependent cell killing by revealing a prominent proteotoxic component of bivalent copper associated with targeting the NPL4. This insight strengthens the rationale for targeting copper-regulated proteostasis pathways as a potential anticancer strategy.
利益披露 Disclosure
M. Mistrik, None..
M. Loffelmann, None..
P. Dzubak, None..
M. Hajduch, None..
J. Srovnal, None..
Z. Skrott, None..
L. Beresova, None..
T. Pluhacek, None..
P. Tarkowski, None.