Metabolic Reprogramming for Photoreceptor Neuroprotection

光感受器神经保护的代谢重编程

• 批准号: 10555429
• 负责人: Cagri Besirli
• 金额: $ 1.95万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10555429
• 关键词: Acute; Address; Aerobic; Amino Acids; Anabolism; Apoptosis; Apoptosis Regulation Gene; Apoptotic; Autophagocytosis; Bioenergetics; Blindness; Budgets; Cell Death; Cell Survival; Cessation of life; Disease; Energy Metabolism; Enzymes; Equilibrium; Foundations; Future; Gatekeeping; Generations; Genetic; Glycolysis; Goals; HK2 gene; Hexokinase 2; Homeostasis; Inherited; Intervention; Knockout Mice; Knowledge; Link; Lipids; Macular degeneration; Measures; Mediating; Mediator of activation protein; Metabolic; Metabolic dysfunction; Metabolism; Mitochondria; Modality; Modeling; Molecular; Mus; Muscle; Neuroprotective Agents; Nucleotides; Nutrient; Pharmacology; Photoreceptors; Protein Isoforms; Proto-Oncogene Proteins c-akt; Public Health; Pyruvate Kinase; Recombinant adeno-associated virus (rAAV); Regulation; Research; Retina; Retinal Cone; Retinal Detachment; Rod; Role; Signal Transduction; Stress; Testing; aerobic glycolysis; base; detection of nutrient; improved; inhibitor; innovation; neuroprotection; neurotrophic factor; novel; novel strategies; nutrient deprivation; overexpression; prevent; response; retinal apoptosis; retinal rods; sight restoration; treatment strategy

PROJECT SUMMARY A key gap remains in our ability to develop successful treatment strategies to prevent photoreceptor (PR) loss and restore vision. To address this gap, we are proposing novel strategies to reprogram metabolism and boost PR survival. PRs have unique metabolic adaptations and utilize aerobic glycolysis to budget their metabolic needs based on nutrient availability, balancing the synthesis of amino acid, nucleotide and lipid precursors with energy generation. PRs perform aerobic glycolysis by expressing hexokinase 2 (HK2) and pyruvate kinase muscle 2 (PKM2). HK2, the first enzyme of glycolysis, acts as an intracellular rheostat, a unique non-enzymatic function that links metabolic status to survival by regulating apoptosis and autophagy. PKM2 is the gatekeeper of energy metabolism and controls aerobic glycolytic flux. HK2 expression is critical for the survival of PRs, as replacing HK2 with HK1 isoform increases apoptosis after stress. Furthermore, replacing low-activity PKM2 with its high-activity isoform PKM1 increases total PKM activity in PRs and boosts survival after nutrient deprivation. The over-arching hypothesis of this proposal is that metabolic reprogramming of PRs, by modulating HKs and PKMs, will enhance survival of stressed PRs, enzymatically by increasing energy generation via glycolysis, and non-enzymatically by inhibiting death signals during energy crisis. The objectives in this project are to: 1) utilize genetic and pharmacologic manipulation of PKM and HK function and prevent retinal detachment induced PR death by metabolic reprograming; and 2) identify non-enzymatic functions of HKs that regulate PR survival during experimental retinal detachment. Aim 1: To test the hypothesis that augmenting energy homeostasis by altering PKM function will enhance PR survival during stress. Our hypothesis predicts that increasing total PKM activity provides survival advantage during apoptotic stress by shifting PR metabolism to more efficiently generate ATP from limited energy substrates. These studies will measure glycolytic flux, ATP generation, and cell death in an acute PR stress model upon Pkm1 overexpression or pharmacologic activation of PKM2. Aim 2: To test the hypothesis that HK2 is the molecular rheostat that links metabolic status to PR apoptosis and autophagy. Our hypothesis predicts that HK2 links PR metabolic needs to survival and that HK2 to HK1 reprograming will decouple metabolic regulation of apoptosis and autophagy. These studies will identify the links between HK2 and key regulators of apoptosis and autophagy in PRs and will measure the effect of HK2 to HK1 reprogramming on glycolysis, biosynthesis, and PR cell death. Our approach is innovative as we will connect the unique energy metabolism of PRs directly to cell death regulation via manipulating the key mediators of aerobic glycolysis, i.e. PKM2 and HK2. The proposed research is significant in that it will provide critical information on how unique metabolic adaptations of PRs influence cell survival and lay the foundation for future studies exploring the connections between metabolism and PR survival.

项目摘要 我们制定成功治疗策略以防止感光器（PR）的关键差距仍然存在 损失和恢复视力。为了解决这一差距，我们正在提出新颖的策略来重编代谢和 增强PR生存。 PRS具有独特的代谢适应性，并利用有氧糖酵解来预算其代谢 基于养分可用性的需求，平衡氨基酸，核苷酸和脂质前体的合成 能源产生。 PRS通过表达己糖酶2（HK2）和丙酮酸激酶进行有氧糖酵解 肌肉2（PKM2）。 hk2是糖酵解的第一种酶，充当细胞内的恒星，一种独特的非酶 通过调节细胞凋亡和自噬将代谢状态与生存联系起来的功能。 PKM2是看门人 能量代谢并控制有氧糖酵解通量。 HK2表达对于PR的生存至关重要，如 用HK1同工型代替HK2会增加压力后的凋亡。此外，用 它的高活动性同工型PKM1增加了PRS中的总PKM活性，并在营养剥夺后提高了存活率。 该提案的总体假设是通过调节HK和 PKMS，将通过糖酵解来增加酶促的酶促生存，并通过糖酵解来增加酶促的生存。 通过抑制能源危机期间的死亡信号而非酶。该项目的目标是：1） 利用PKM和HK功能的遗传和药理学操纵，并防止视网膜脱离引起 通过代谢重编程死亡的PR死亡； 2）确定调节PR存活的HK的非酶函数 在实验性视网膜脱离过程中。 目的1：检验以下假设，即通过改变PKM功能来增强能量稳态会 在压力期间增强PR存活。我们的假设预测，增加的总PKM活性提供了 通过将PR代谢转移到更有效地从中产生ATP，在凋亡应激期间的生存优势 能量底物有限。这些研究将在急性中测量糖酵解通量，ATP产生和细胞死亡 PKM1过表达或PKM2药物激活后的PR应力模型。 目的2：检验HK2是将代谢状态连接到PR的分子变势的假设 凋亡和自噬。我们的假设预测HK2将PR代谢需要生存需要，并且HK2 HK1重编程将使凋亡和自噬的代谢调节分解。这些研究将确定 HK2与PRS中凋亡和自噬的关键调节剂之间的联系，将测量HK2的效果 HK1在糖酵解，生物合成和PR细胞死亡上进行重编程。 我们的方法具有创新性，因为我们将把PR的独特能量代谢与细胞死亡联系起来 通过操纵有氧糖酵解的关键介质（即PKM2和HK2）进行调节。拟议的研究 重要的是，它将提供有关PRS独特的代谢适应如何影响细胞的关键信息 生存并为未来的研究奠定了基础，探讨了新陈代谢与PR生存之间的联系。