Lipid Peroxidation and its Inhibition: Mechanisms and Molecules

自氧化是所有碳氢化合物产品变质的主要原因，并与衰老、癌症和退化性疾病(DD)有关。因此，抗氧化剂是必不可少的产品添加剂，被认为对人类健康起着关键的预防作用。在上一次资助期间，我们开发了新的方法来研究自氧化作用，并用它们来阐明机制和设计新的分子来更好地控制它。在下一个赠款期间，我们建议利用这一专业知识来更好地了解脂质过氧化(LPO)及其抑制在氧化性细胞死亡(铁下垂)和相关的DD中的作用。该提案的第一部分涉及开发研究过氧化脂质及其抑制的新工具。具体地说，我们建议开发一种高通量表征LPO抑制剂的新方法(我们之前报告的第二代荧光启用抑制自氧化或Fenix方法)，一种用于这种方法的新启动系统以及直接在细胞中启动LPO，并开发使用共聚焦显微镜对活细胞中的LPO进行成像的新工具。这些工具将使铁性下垂的诱导、执行和抑制的机制研究成为可能，并极大地帮助开发治疗DD的药物。该提案的第二部分涉及研究新的分子和新的机制来对抗LPO和相关的细胞死亡。具体地说，我们建议使用我们的Fenix方法来反筛选来自40,000个化合物库的细胞救援屏幕上的命中，并对可能通过新机制操作的有效命中进行机制研究。我们进一步建议探索CuATSM和相关神经保护剂的独特机制，最后建议说明基于反应性考虑的铁下垂抑制剂的合理设计，以确定是否通常有可能进一步提高RTA活性和反铁下垂的效力，或者是否存在内在或外在的限制。这项研究将揭示新的机制，并提供新的分子，使铁性下垂的进一步特征，并可用于未来的设计预防和/或治疗药物的DD。该提案的最后部分涉及一般的烯基醚的自氧化，特别是血浆丙二醇脂(Pls)的自氧化。尽管它们丰富，但对pls的研究很少，矛盾的是，它们被归因于保护(即抗氧化剂)和致病作用。具体地说，我们建议测定烯基醚自氧化的动力学、机理(S)和产物，阐明PLS抑制LPO的机制(S)，并系统地探讨PLS对铁链细胞死亡的影响。这项研究将建立烯基醚自氧化的动力学和机理，这对于了解pls在LPO和铁性下垂中的作用以及在pls丰富的组织中如何促进DD是必要的。

Autoxidation is primarily responsible for the deterioration of all hydrocarbon-based products and is implicated in aging, cancer and degenerative disease (DD). Accordingly, antioxidants are indispensable product additives, and are believed to play key preventive roles in human health. In the last grant period, we developed new methods to study autoxidation, and used them to elucidate mechanisms and design novel molecules to better control it. In the next grant period, we propose to parlay this expertise to better understand the role of lipid peroxidation (LPO) and its inhibition in oxidative cell death (ferroptosis) and associated DD. The first part of the proposal involves the development of new tools for studying LPO and its inhibition. Specifically, we propose to develop a new approach for the high-throughput characterization of inhibitors of LPO (a second generation of our previously reported Fluorescence-Enabled Inhibited autoxidation, or FENIX, methodology), a new initiating system for use with this approach as well as initiating LPO directly in the cell, and to develop new tools for imaging LPO in live cells using confocal microscopy. These tools will enable mechanistic studies of ferroptosis induction, execution and suppression and greatly aid in the development of drugs for DD. The second part of the proposal involves the study of new molecules and new mechanisms to combat LPO and associated cell death. Specifically, we propose to use our FENIX methods to counter-screen hits from a cell-rescue screen of a 40,000-compound library and carry out mechanistic studies on potent hits which are likely to operate via new mechanisms. We further propose to explore the unique mechanism of CuATSM and related neuroprotective agents, and lastly, propose to illustrate the rational design of a ferroptosis inhibitor based upon reactivity considerations to determine if further gains in RTA activity and anti-ferroptotic potency are generally possible, or if there are intrinsic - or extrinsic - limitations. This research will uncover new mechanisms and provide new molecules to enable further characterization of ferroptosis, and which can be exploited for the future design of preventive and/or therapeutic agents for DD. The final part of the proposal involves studies on the autoxidation of alkenyl ethers, in general, and plasmalogen lipids (PLs), in particular. Despite their abundance, PLs are poorly studied, and have paradoxically been ascribed both protective (i.e. antioxidant) and pathogenic roles. Specifically, we propose to determine the kinetics, mechanism(s) and products of alkenyl ether autoxidation, elucidate the mechanism(s) by which PLs inhibit LPO, and systematically explore the impact of PLs on ferroptotic cell death. This research will establish the kinetics and mechanism of alkenyl ether autoxidation, which is necessary to understand the role of PLs on LPO and ferroptosis and how it contributes to DD in tissues where PLs are abundant.