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 来自母基金 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稳态的主要调节因子，对于维持线粒体功能至关重要。 我们最近发现了一种新的方法来调节线粒体能量代谢和减轻细胞应激。 两个患有严重神经系统疾病的兄弟姐妹中编码 Lon 的 LONP1 基因的致病性变异 损伤、大脑和小脑萎缩，其中 761 位脯氨酸被亮氨酸取代 (Lon-P761L) 来自这些兄弟姐妹的原代皮肤成纤维细胞的活性显着降低。 我们的结果表明，丙酮酸脱氢酶（PDH）缺乏是由丙酮酸脱氢酶（PDH）引起的。 Lon-P761L 未能降解 PDH 的磷酸化 E1a 亚基，该亚基会积累并 抑制 PDH 活性 PDH 是连接糖酵解和三羧酸 (TCA) 的中心看门人。 循环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。 我们完全通过葡萄糖氧化，因此充分激活PDH是至关重要的。 调节 PDH 复合物的活性和结构，对于校准线粒体至关重要 在这个项目中，我们将使用患者和父母来源的成纤维细胞，以及 还诱导了由这些成纤维细胞产生的多能干细胞（iPSC）。 使用这些细胞，患者和父母来源的 iPSC 将分化为神经元和星形胶质细胞。 目标 1 将检验 Lon 介导的降解调节结构和活性的假设 目标 2 将识别 Lon-PDH 轴的上游和下游调制器。 在表达野生型 Lon 与 Lon-P761L 的细胞中发生改变 在目标 3 中，我们将研究 Lon 在分化为神经元和星形胶质细胞的 iPSC 中对 PDH 的调节。 建立 PDH 的 Lon 依赖性调节的新分子机制。 还将有助于确定潜在的治疗蛋白靶标、药理学和饮食干预措施 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。 结果对于了解 PDH 活性和线粒体代谢如何产生更广泛的影响 可以在罕见和更常见的疾病（例如心脏病、癌症和 神经变性。