Lon-PDH axis

长PDH轴

• 批准号: 10652122
• 负责人: CAROLYN K SUZUKI
• 金额: $ 4.51万
• 依托单位: RBHS-NEW JERSEY MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10652122
• 关键词: Alleles; Architecture; Astrocytes; Atrophic; Catabolism; Cells; Cellular Stress; Cerebrum; Citric Acid Cycle; Dietary Intervention; Disease; Energy Metabolism; Failure; Fatty Acids; Fibroblasts; Functional disorder; Gatekeeping; Genes; Glucose; Glycolysis; Goals; Heart Diseases; Human; Impairment; Investigation; Ketone Bodies; Knowledge; Leucine; Link; Malignant Neoplasms; Mediating; Missense Mutation; Mitochondria; Molecular; Mutation; Nerve Degeneration; Neurologic; Neurons; Outcome; Parents; Pathogenicity; Patients; Peptide Hydrolases; Pharmacology; Positioning Attribute; Production; Proline; Pyruvate Dehydrogenase Complex; Regulation; Siblings; Skin; Stream; Testing; Variant; brain cell; endopeptidase La; induced pluripotent stem cell; mitochondrial metabolism; novel; oxidation; parent grant; proteostasis; pyruvate dehydrogenase; stem cell differentiation; therapeutic protein

SUMMARY From the parent grant R01 GM136905-01 entitled, “Mitochondrial metabolism and the Lon-PDH axis”. The human Lon protease is a master regulator of mitochondrial proteostasis, which is essential for regulating mitochondrial energy metabolism and mitigating cell stress. We recently identified a novel pathogenic variant in the LONP1 gene encoding Lon, in two siblings with profound neurologic impairment, cerebral and cerebellar atrophy, in which proline at position 761 was replaced by leucine (Lon-P761L). Primary skin fibroblasts from these siblings, showed substantially reduced activity of pyruvate dehydrogenase (PDH). Our results demonstrated that PDH deficiency was caused by the failure of Lon-P761L to degrade the phosphorylated E1a subunit of PDH, which accumulates and inhibits PDH activity. PDH is the central gatekeeper linking glycolysis to the tricarboxylic acid (TCA) cycle and a key regulatory node for glucose and fatty acid catabolism. Neurons generate ATP almost exclusively by glucose oxidation, thus fully active PDH is crucial. We hypothesize that wild type Lon regulates the activity and architecture of the PDH complex and is crucial for calibrating mitochondrial metabolism and energetics. In this project, we will employ patient- and parent- derived fibroblasts, and also induced pluripotent stem cells (iPSCs), which have been generated from these fibroblasts. The patient- and parent- derived iPSCs will be differentiated into neurons and astrocytes. Using these cells, Aim 1 will test the hypothesis that Lon-mediated degradation regulates the architecture and activity of the PDH complex. Aim 2 will identify the up- and down- stream modulators of the Lon-PDH axis, which are altered in cells expressing wild type Lon versus Lon-P761L. In Aim 3, we will investigate the regulation of PDH by Lon in iPSCs differentiated into neurons and astrocytes. Our investigation will establish new molecular mechanisms for the Lon-dependent regulation of PDH. The knowledge gained will also help to identify potential therapeutic protein targets, pharmacologic and dietary interventions for increasing PDH activity and/or for treating PDH deficiency associated with Lon dysfunction. These outcomes have a broader impact for understanding how PDH activity and mitochondrial metabolism can be calibrated in both rare and more common disorders such as heart disease, cancer and neurodegeneration.

概括 来自父母的授予R01 GM136905-01，标题为“线粒体代谢和LON-PDH轴”。 人类lon蛋白酶是线粒体蛋白质的主要调节剂，这对于 调节线粒体能量代谢和减轻细胞应激。我们最近确定了一本小说 LONP1基因的致病变异，编码LON，在具有深刻神经系统的两个兄弟姐妹中 损伤，大脑和小脑萎缩，其中761位的脯氨酸被亮氨酸取代 （LON-P761L）。这些兄弟姐妹的一级皮肤成纤维细胞，显示出大幅降低的活性 丙酮酸脱氢酶（PDH）。我们的结果表明，PDH缺乏症是由 LON-P761L未能降解PDH的磷酸化E1A亚基，该亚基积聚和 抑制PDH活性。 PDH是将糖酵解与三核酸（TCA）连接的中央守门人 周期和葡萄糖和脂肪酸分解代谢的关键调节节点。神经元几乎产生ATP 仅通过葡萄糖氧化，因此完全活跃的PDH至关重要。我们假设野生型LON 调节PDH复合物的活性和结构，对于校准线粒体至关重要 代谢和能量学。在这个项目中，我们将采用患者和父母衍生的成纤维细胞，以及 还诱导了由这些成纤维细胞产生的多能干细胞（IPSC）。 患者和父母衍生的IPSC将分为神经元和星形胶质细胞。使用这些细胞， AIM 1将检验以下假设：LON介导的降解调节 PDH复合物。 AIM 2将识别LON-PDH轴的上流和下游调节器，该调制器 在表达野生型LON与LON-P761L的细胞中发生了变化。在AIM 3中，我们将调查 IPSC中LON对PDH的调节分化为神经元和星形胶质细胞。我们的投资意志 为PDH的LON依赖性调节建立新的分子机制。知识获得了 还将有助于确定潜在的治疗蛋白靶标，药物和饮食干预措施 用于增加PDH活性和/或用于治疗与LON功能障碍相关的PDH缺乏。这些 结果对了解PDH活性和线粒体代谢有更广泛的影响 可以在罕见和更常见的疾病中校准，例如心脏病，癌症和 神经变性。