Metabolic Reprogramming for Photoreceptor Neuroprotection

光感受器神经保护的代谢重编程

• 批准号: 9816328
• 负责人: Cagri Besirli
• 金额: $ 39万
• 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/9816328
• 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; 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; Patients; Pharmacology; Photoreceptors; Protein Isoforms; Proto-Oncogene Proteins c-akt; Public Health; Pyruvate Kinase; Recombinant adeno-associated virus (rAAV); Regulation; Research; Retinal; Retinal Cone; Retinal Detachment; Retinal Diseases; Role; Signal Transduction; Stress; Testing; Therapeutic; Vision; aerobic glycolysis; base; detection of nutrient; improved; inhibitor/antagonist; innovation; neuroprotection; neurotrophic factor; novel; novel strategies; nutrient deprivation; overexpression; prevent; response; retinal apoptosis; retinal rods; treatment strategy; visual process

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 in retinal diseases.

项目摘要 在我们开发成功的治疗策略以防止感光细胞的能力方面， (PR)丧失和恢复视力。为了解决这一差距，我们提出了新的策略来重新编程代谢 提高公关生存率PR具有独特的代谢适应性，并利用有氧糖酵解来预算其代谢。 代谢需要基于营养素的可用性，平衡氨基酸、核苷酸和脂质的合成 能源生产的先驱。PR通过表达己糖激酶2（HK2）进行有氧糖酵解， 丙酮酸激酶肌肉2（PKM 2）。HK2是糖酵解的第一个酶，它起着细胞内变阻器的作用， 独特的非酶功能，通过调节细胞凋亡和自噬将代谢状态与生存联系起来。 PKM2是能量代谢的守门人，控制有氧糖酵解通量。HK2表达至关重要 对于PR的存活，因为用HK 1同种型替换HK 2增加了应激后的细胞凋亡。此外，委员会认为， 用其高活性亚型PKM1取代低活性PKM2可增加PR中的总PKM活性， 营养剥夺后的生存。这一建议的过度假设是， 通过调节HK和PKM，PR的重编程将通过酶促作用增强应激PR的存活， 通过糖酵解增加能量产生，以及通过抑制能量产生过程中的死亡信号而非酶促产生 危机本研究的目的是：1）利用基因和药理学操作PKM和HK 功能和预防视网膜脱离诱导的PR死亡的代谢重编程;和2）确定非- 实验性视网膜脱离期间调节PR存活的HK的酶功能。 目的1：验证通过改变PKM功能来增强能量稳态的假说 会提高压力下的PR存活率我们的假设预测，增加总PKM活性提供了 通过改变PR代谢，更有效地从细胞凋亡中产生ATP， 有限能量基质。这些研究将测量糖酵解通量，ATP生成和细胞死亡， Pkm1过表达或PKM2药理学活化后的急性PR应激模型。 目的2：检验HK2是将代谢状态与代谢相关的分子变阻器的假设。 PR凋亡和自噬。我们的假设预测HK2将PR代谢需求与生存联系起来， HK2到HK1的重编程将解耦凋亡和自噬的代谢调节。这些研究 将确定HK2与PR中细胞凋亡和自噬的关键调节因子之间的联系，并将测量 HK2到HK1重编程对糖酵解、生物合成和PR细胞死亡的影响。 我们的方法是创新的，因为我们将PR的独特能量代谢直接连接到细胞 通过操纵有氧糖酵解的关键介质，即PKM 2和HK 2来调节死亡。拟议 这项研究的意义在于它将提供关于PR独特的代谢适应性的关键信息， 影响细胞存活，并为未来探索新陈代谢之间联系的研究奠定基础。 和视网膜疾病的PR存活率。