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.

总结 来自题为“线粒体代谢和Lon-PDH轴”的母基金R 01 GM 136905 -01。 人Lon蛋白酶是线粒体蛋白质稳态的主要调节剂，其对于维持线粒体的蛋白质稳态是必需的。 调节线粒体能量代谢，缓解细胞应激。我们最近发现了一本小说 编码Lon的LONP 1基因的致病性变异，在两个患有严重神经系统疾病的兄弟姐妹中 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）。来自这些兄弟姐妹的原代皮肤成纤维细胞显示出显著降低的 丙酮酸脱氢酶（PDH）。我们的结果表明，PDH缺乏是由 Lon-P761 L不能降解磷酸化的PDH的E1 a亚基，其积累并 抑制PDH活性。HH是连接糖酵解与三羧酸（TCA）的中央守门人 循环和葡萄糖和脂肪酸催化剂的关键调控节点。神经元产生ATP几乎 因此，完全活性的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 新陈代谢和能量学。在这个项目中，我们将采用患者和父母来源的成纤维细胞， 也诱导多能干细胞（iPSC），其已经从这些成纤维细胞产生。的 患者和亲本来源的iPSC将分化成神经元和星形胶质细胞。利用这些细胞， 目的1将检验Lon介导的降解调节蛋白质的结构和活性的假设。 PDH复合体目标2将确定Lon-PDH轴的上游和下游调制器， 在表达野生型Lon与Lon-P761 L的细胞中改变。在目标3中，我们将研究 在分化成神经元和星形胶质细胞的iPSC中，Lon对PDH的调节。我们的调查将 为PDH的Lon-dependent调节建立新的分子机制。获得的知识 还将有助于确定潜在的治疗蛋白质靶点、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缺陷。这些 结果对于理解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，如心脏病，癌症和 神经变性