Mechanisms of elesclomol-mediated copper delivery to cuproenzymes in cells

项目总结 铜是人体生长发育所必需的一种微量营养素。这个 对铜的需求归因于它作为催化辅因子的作用，参与了各种不同的 生理过程，包括线粒体能量产生，神经递质生物合成，以及 结缔组织形成。由于它在细胞和组织生理学中的不同作用，功能丧失 铜吸收或转运到铜酶所需基因的突变通常会导致婴儿死亡 精神错乱。例如，线粒体铜向细胞色素c输送途径中涉及的步骤缺陷 氧化酶(CcO)是一种线粒体铜酶，与一系列线粒体疾病有关，而 饮食中铜向不同器官系统输送的中断导致门克斯病。目前，治疗 这些疾病是实验性的，在预防早期死亡方面基本上无效。鉴定化合物 可以将铜输送到铜酶从而克服这些缺陷，我们进行了有针对性的筛查 并确定elesclomol(ES)是一种有效的铜转运分子。我们的 初步研究表明，低纳摩尔浓度的ES可以将铜输送到酵母、斑马鱼、 以及铜缺乏的小鼠模型。在取得这一突破之后，我们现在可以测试我们的 假设ES最初是作为一种抗癌药物开发的，可以被改变用途来安全地输送铜 以不同的铜酶和拯救与铜缺乏症相关的疾病表型。要做到这点， 我们将首先确定ES在细胞内释放铜的位置和方式，以及在没有ES的情况下能否实现这一点 破坏细胞。第二，我们将利用我们新构建的斑马鱼模型，这些模型具有特定的缺陷 全身性或线粒体铜代谢和小鼠Menkes病模型以测试ES对 通过将铜输送到铜酶来挽救线粒体、细胞和有机体的表型。因此， 拟议的工作将揭示ES介导的细胞内铜转运的机制，并提出一个有希望的 治疗衰弱和经常致命的铜缺乏症的治疗分子。

PROJECT SUMMARY Copper (Cu) is an essential micronutrient that is required for growth and development of humans. The requirement of Cu is attributed to its role as a catalytic cofactor for a number of enzymes involved in various physiological processes, including mitochondrial energy production, neurotransmitter biosynthesis, and connective tissue formation. Owing to its diverse roles in cellular and organismal physiology, loss-of-function mutations in genes required for Cu absorption or transport to cuproenzymes often result in fatal infantile disorders. For example, defects in the steps involved in the mitochondrial Cu delivery pathway to cytochrome c oxidase (CcO), a mitochondrial cuproenzyme, are associated with a subset of mitochondrial disorders, while disruption in delivering dietary Cu to different organ systems results in Menkes disease. Currently, therapies for these diseases are experimental and largely ineffective at preventing early mortality. To identify compounds that can deliver Cu to cuproenzymes and thus overcome these defects, we performed a targeted screen for Cu-binding pharmacological agents and identified elesclomol (ES) as a potent Cu-transporting molecule. Our initial studies have shown that low nanomolar concentrations of ES can deliver Cu to CcO in yeast, zebrafish, and mouse models of Cu deficiency. Having made this breakthrough, we are now in position to test our hypothesis that ES, which was originally developed as a cancer drug, can be repurposed to safely deliver Cu to different cuproenzymes and rescue disease phenotypes associated with Cu deficiency disorders. To do this, we will first determine where and how ES releases Cu inside cells and whether this can be achieved without damaging cells. Second, we will utilize our newly constructed zebrafish models with specific defects in systemic or mitochondrial Cu metabolism and a mouse model of Menkes disease to test the efficiency of ES in rescuing mitochondrial, cellular, and organismal phenotypes by delivering Cu to cuproenzymes. Thus, the proposed work will uncover the mechanism of ES-mediated intracellular Cu transport and advance a promising therapeutic molecule for the treatment of debilitating and frequently fatal Cu deficiency disorders.