Metabolic Reprogramming for Photoreceptor Neuroprotection

光感受器神经保护的代谢重编程

• 批准号: 10200068
• 负责人: Cagri Besirli
• 金额: $ 37.83万
• 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/10200068
• 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; Retina; Retinal Cone; Retinal Detachment; Retinal Diseases; Rod; Role; Signal Transduction; Stress; Testing; Therapeutic; 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; sight restoration; 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 我们制定成功治疗策略以防止感光器的关键差距仍然存在 （PR）损失和恢复视力。为了解决这一差距，我们正在提出新型策略来重新编程代谢 并提高公关生存。 PR具有独特的代谢适应，并利用有氧糖酵解来预算 基于养分可用性的代谢需求，平衡氨基酸，核苷酸和脂质的合成 能量产生的前体。 PRS通过表达己糖酶2（HK2）和 丙酮酸激酶肌肉2（PKM2）。 HK2是糖酵解的第一种酶，充当细胞内的风湿病，A 通过调节凋亡和自噬将代谢状态与生存联系起来的独特非酶功能。 PKM2是能量代谢的看门人，控制有氧糖酵解通量。 HK2表达很关键 对于PR的存活，随着用HK1同工型替换HK2会增加压力后的凋亡。此外， 用其高活性同工型PKM1替换低活动性PKM2会增加PRS的总PKM活性 营养剥夺后的生存。该提议的总体假设是代谢 通过调节HK和PKM的重新编程PR，将通过酶促通过 通过糖酵解增加能量的产生，并通过抑制能量期间的死亡信号而非酶 危机。该项目的目标是：1）利用PKM和HK的遗传和药理操作 功能并防止视网膜脱离通过代谢重编程引起的PR死亡； 2）确定非 - 在实验性视网膜脱离过程中调节PR存活的HK的酶促功能。 目标1：测试通过改变PKM功能来增强能量稳态的假设 将在压力期间提高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。这些研究将测量糖酵解通量，ATP产生和细胞死亡 PKM1过表达或PKM2的药物激活后，急性PR应激模型。 目的2：检验假设HK2是将代谢状态联系起来的分子变势 PR凋亡和自噬。我们的假设预测，HK2将PR代谢需求与生存和 HK2至HK1重编程将使细胞凋亡和自噬的代谢调节结构化。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，并将测量 HK2对HK1重编程对糖酵解，生物合成和PR细胞死亡的影响。 我们的方法具有创新性，因为我们将直接将PR的独特能量代谢与细胞联系起来 通过操纵有氧糖酵解的关键介质（即PKM2和HK2）来调节死亡调节。提议 研究很重要，因为它将提供有关PRS独特代谢适应的关键信息 影响细胞存活，并为未来的研究奠定基础，以探索新陈代谢之间的联系 和视网膜疾病中的PR存活。