Mitochondrial metabolism and the Lon-PDH axis

线粒体代谢和 Lon-PDH 轴

基本信息

批准号：
10620384
负责人：
CAROLYN K SUZUKI
金额：
$ 8.68万
依托单位：
RBHS-NEW JERSEY MEDICAL SCHOOL
依托单位国家：
美国
项目类别：
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/10620384
关键词：
Administrative Supplement Alleles Architecture Astrocytes Atrophic Catabolism Cells Cellular Stress Cerebrum Citric Acid Cycle Dietary Intervention Disease Energy Metabolism Equipment Failure Fatty Acids Fibroblasts Functional disorder Gatekeeping Genes Glucose Glycolysis Heart Diseases Human Impairment Induced pluripotent stem cell derived neurons Investigation Knowledge Leucine Link Malignant Neoplasms Mediating Metabolic Mitochondria Molecular Mutation Nerve Degeneration Neurologic Neurologic Dysfunctions Neurons Outcome Parents Pathogenicity Patients Peptide Hydrolases Pharmacology Positioning Attribute Proline Pyruvate Dehydrogenase Complex Regulation Siblings Skin Stream Testing Variant developmental disease endopeptidase La induced pluripotent stem cell mitochondrial metabolism mutant novel oxidation parent grant proteostasis pyruvate dehydrogenase therapeutic protein

项目摘要

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. It is also a key regulatory node for glucose and fatty acid catabolism. Neurons generate ATP almost exclusively by glucose oxidation, thus fully functional PDH activity 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 (1) patient- and parent- derived fibroblasts, and (2) induced pluripotent stem cells (iPSCs) reprogrammed from these fibroblasts. The iPSCs will be differentiated into neurons and astrocytes. Using these cells, Aim 1 will test the hypothesis that Lon-mediated degradation regulates the activity and architecture 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; and Aim 3 will investigate the regulation and dysregulation of PDH by wild type and mutant Lon in iPSC-derived 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 (e.g. PDK, PDP, Lon), 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。它也是葡萄糖和脂肪酸分解代谢的关键调节节点。几乎完全通过葡萄糖氧化，因此功能齐全的 PDH 活性至关重要。野生型 Lon 调节 PDH 复合物的活性和结构，对于校准至关重要在这个项目中，我们将采用（1）患者和父母来源的线粒体代谢和能量学。成纤维细胞，以及（2）由这些成纤维细胞重新编程的诱导多能干细胞（iPSC）。 iPSC 将分化为神经元和星形胶质细胞，目标 1 将检验这一假设。 Lon 介导的降解调节 PDH 复合物的活性和结构；识别 Lon-PDH 轴的上游和下游调节剂，这些调节剂在表达的细胞中发生改变野生型 Lon 与 Lon-P761L；目标 3 将通过以下方式研究 PDH 的调节和失调：我们的研究将在 iPSC 衍生的神经元和星形胶质细胞中建立新的野生型和突变型 Lon。获得的知识也将有助于了解 PDH 的 Lon 依赖性调节的分子机制。识别潜在的治疗蛋白靶标（例如 PDK、PDP、Lon）、药理学和饮食增加 PDH 活性和/或治疗与 Lon 相关的 PDH 缺乏的干预措施这些结果对于了解 PDH 活性和功能障碍具有更广泛的影响。线粒体代谢可以在罕见和更常见的疾病（例如心脏病）中进行校准疾病、癌症和神经退行性疾病。