Pyruvate dehydrogenase encephalopathy: mechanisms and therapy

丙酮酸脱氢酶脑病：机制和治疗

• 批准号: 10225409
• 负责人: Juan M. Pascual
• 金额: $ 35.44万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10225409
• 关键词: Acetates; Acetyl Coenzyme A; Address; Beds; Biochemical; Biochemistry; Biological Assay; Brain; Brain Diseases; Carbon; Caring; Cell Culture Techniques; Cerebral cortex; Cerebrum; Child; Citric Acid Cycle; Clinical; Clinical Trials; Consumption; Data; Development; Dietary Fats; Disease; Disease model; Disorder of neurometabolic regulation; Electrodes; Electroencephalography; Electrophysiology (science); Encephalopathies; Energy Metabolism; Equilibrium; Fatty Acids; Fatty acid glycerol esters; Food; Functional disorder; Generations; Genes; Glucose; Glutamates; Glycolysis; Goals; Health; Human; Impairment; In Vitro; Infant; Intellectual functioning disability; Investigation; Ketone Bodies; Ketones; Knowledge; Label; Laboratories; Lead; Life; Medical; Metabolic; Metabolic Diseases; Metabolic dysfunction; Metabolism; Mission; Modeling; Motor; Mus; Mutation; NMR Spectroscopy; Neuroglia; Neurologic Dysfunctions; Neurons; Neurophysiology - biologic function; Neurotransmitters; Patients; Performance; Pharmaceutical Preparations; Process; Reaction; Refractory; Resources; Seizures; Sensory; Slice; System; Testing; Therapeutic; Thick; Tricarboxylic Acids; United States National Institutes of Health; Work; awake; base; brain metabolism; brain tissue; clinical investigation; cohort; dietary; disabling disease; epileptic encephalopathies; gamma-Aminobutyric Acid; in vivo; in vivo evaluation; intervention effect; ketogenic diet; liver metabolism; mouse model; neocortical; neural circuit; novel; novel therapeutics; optogenetics; palliative; prenatal; preservation; prevent; programs; pyruvate dehydrogenase; relating to nervous system; synaptic function; therapeutic development; virtual

ABSTRACT This proposal constitutes one of the first mechanistic investigations of pyruvate dehydrogenase (PDH) deficiency encephalopathy (PDHD), an inborn developmental brain disorder. PDHD leads to impaired brain metabolism and neurological dysfunction that manifests as intellectual disability and intractable seizures in infants and children. The elementary biochemical framework has been elucidated primarily in vitro using cell cultures and homogenates. Normally PDH receives about 80% of the brain’s glucose metabolic flux, converting it into substrate for the tricarboxylic acid (TCA) cycle. The TCA cycle is responsible for brain energy generation and also for the synthesis of the neurotransmitters glutamate and GABA, which regulate excitability. The remainder 20% of brain glucose refills natural TCA cycle precursor loss, which is accomplished through a separate process known as anaplerosis. Yet, anaplerosis can also be secondarily downregulated in PDHD. Nevertheless, despite these long-established biochemical principles, it is unknown how PDHD causes encephalopathy. In particular, very little is known about metabolism or excitability within PDHD brain tissue and even less is known in an in vivo context. This knowledge gap drastically limits therapy, as illustrated by the drug-refractoriness of PDHD seizures. The objectives of this application are to characterize in vivo abnormal neural excitability and metabolism in a novel, robust PDHD mouse model and to mitigate them by stimulating both the TCA cycle and anaplerosis with alternative dietary substrates. Our preliminary results include abnormal neocortical excitability in PDHD in vivo and amelioration of brain TCA cycle precursor depletion, and thus justify investigating these mechanisms in greater depth. This leads to a first general hypothesis that metabolic fuel-dependent (rather than fixed) cortical dysfunction is a central feature of disease pathophysiology. The proposal also includes the therapeutic consideration that ketone bodies containing an even number of carbons, generated from common dietary fats or a ketogenic diet, can fuel the TCA cycle and ameliorate seizures in PDHD patients, but cannot correct anaplerotic deficits. In contrast, our data that exogenous anaplerotic fat metabolites containing an odd number of carbons can additionally refill brain TCA cycle precursors, lead to a second general hypothesis: That odd-carbon fat restores neural function in PDHD more effectively via anaplerosis than even-carbon fat. These two general hypotheses will be tested in three aims: 1) Investigate the electrophysiological bases of cortical hyperexcitability in PDHD; 2) Test key metabolic mechanisms relevant to synaptic function; 3) Restore brain metabolism and excitability via anaplerotic odd-carbon fat derivatives. In summary, we expect to help define PDHD as an excitability disorder and establish the therapeutic value of anaplerotic modulation, thus initiating the first step of a medical practice transformation by capitalizing on metabolic or excitable targets.

摘要 该提议构成了丙酮酸脱氢酶（PDH）缺乏症的首批机制研究之一 脑病（PDHD），一种先天性脑发育障碍。PDHD导致大脑代谢受损 和神经功能障碍，表现为婴儿智力残疾和顽固性癫痫发作， 孩子基本的生物化学框架已经主要在体外使用细胞培养物和 匀浆。正常情况下，PDH接收大脑葡萄糖代谢流量的80%，将其转化为 三羧酸（TCA）循环的底物。TCA循环负责大脑能量的产生， 也用于合成调节兴奋性的神经递质谷氨酸和GABA。其余部分 20%的大脑葡萄糖补充天然TCA循环前体损失，这是通过一个单独的过程完成的 称为回补。然而，回补也可以在PDHD中二次下调。然而，尽管 这些长期建立的生物化学原理，目前还不清楚PDHD如何导致脑病。特别是， 关于PDHD脑组织内的代谢或兴奋性知之甚少， 体内环境。这一知识缺口极大地限制了治疗，如PDHD的药物难治性所示 癫痫发作本申请的目的是表征体内异常神经兴奋性， 在一种新的，强大的PDHD小鼠模型中的代谢，并通过刺激TCA循环和 回补与替代饮食基质。我们的初步结果包括新皮层兴奋性异常 在体内PDHD和改善脑TCA循环前体消耗，因此证明研究这些 更深入的机制。这导致了第一个一般假设，即代谢燃料依赖性（而不是代谢燃料依赖性）是一种生物学效应。 固定的）皮质功能障碍是疾病病理生理学的中心特征。该提案还包括 治疗上的考虑是，酮体含有偶数个碳，由常见的 膳食脂肪或生酮饮食可以促进TCA循环并改善PDHD患者的癫痫发作，但不能 纠正回补缺陷。相反，我们的数据表明，外源性回补脂肪代谢物含有一个奇怪的 大量的碳可以额外地重新填充大脑TCA循环前体，导致第二个一般假设： 奇数碳脂肪通过回补作用比偶数碳脂肪更有效地恢复PDHD的神经功能。这些 本研究将从三个方面对两个基本假设进行检验：1）研究皮层神经元的电生理基础， PDHD的过度兴奋; 2）测试与突触功能相关的关键代谢机制; 3）恢复大脑 代谢和兴奋性通过回补奇数碳脂肪衍生物。总之，我们希望帮助定义 PDHD作为一种兴奋性障碍，并建立了回补调节的治疗价值，从而启动了 通过利用代谢或易兴奋的目标，迈出了医疗实践转型的第一步。

项目成果

Development and validation of a LC-MS/MS method for quantitation of 3-hydroxypentanoic acid and 3-oxopentanoic acid in human plasma and its application to a clinical study of glucose transporter type I deficiency (G1D) syndrome.

• DOI: 10.1016/j.jpba.2021.114335
• 发表时间: 2021-10-25
• 期刊: Journal of pharmaceutical and biomedical analysis
• 影响因子: 3.4
• 作者: Kallem RR;Primeaux S;Avila A;Pascual JM;Putnam WC
• 通讯作者: Putnam WC

Mitochondrial disease manifestations in relation to transcriptome location and function.

• DOI: 10.1016/j.ymgme.2021.12.008
• 发表时间: 2022-01
• 期刊: Molecular genetics and metabolism
• 影响因子: 3.8
• 作者: Jakkamsetti V;Balasubramaniam S;Grover N;Pascual JM
• 通讯作者: Pascual JM

Quantification of early learning and movement sub-structure predictive of motor performance.

• DOI: 10.1038/s41598-021-93944-9
• 发表时间: 2021-07-13
• 期刊: Scientific reports
• 影响因子: 4.6
• 作者: Jakkamsetti V;Scudder W;Kathote G;Ma Q;Angulo G;Dobariya A;Rosenberg RN;Beutler B;Pascual JM
• 通讯作者: Pascual JM