A Pharmaco-Epigenomic Intervention for the Mitochondrial Disorder MELAS

针对线粒体疾病的药物表观基因组干预 MELAS

基本信息

批准号：
8891656
负责人：
Anne Eliane CHIARAMELLO
金额：
$ 40.84万
依托单位：
GEORGE WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-06-15 至 2017-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8891656
关键词：
ATP Synthesis Pathway Affect American Bioenergetics Biogenesis Biopsy Butyrates Bypass Case Study Cells Cessation of life Child Childhood Chronic Clinical Clinical Research Collaborations Complex Confocal Microscopy Data Diffuse Disease Disease Progression Encephalopathies Energy Metabolism Ensure Exposure to Fatty Acids Fibroblasts Future Gene Expression Genes Histone Deacetylase Inhibitor Impaired cognition Individual Inherited Intervention Investigational New Drug Application Lactic Acidosis Leucine-Specific tRNA Life Lung diseases Mediating Medical center Membrane Potentials Metabolic Microarray Analysis Mission Mitochondria Mitochondrial DNA Mitochondrial Diseases Mutation Myopathy NADH dehydrogenase (ubiquinone)National Institute of Neurological Disorders and Stroke Neurodegenerative Disorders Neurologist Neurons Nuclear Organ failure Output Oxidative Phosphorylation Palliative Care Pathogenesis Pathway interactions Patients Phenotype Population Production Property Public Health Rare Diseases Recovery Recruitment Activity Regulation Reporting Research Residual state Respiration Disorders Seizures Seminal Skin Sodium Butyrate Staging Stroke Symptoms System Testing Therapeutic Translating Translational Research Tubular formation Up-Regulation Volatile Fatty Acids base bench to bedside disability driving force drug development early childhood effective therapy epigenomics fatty acid oxidation genome-wide innovation mitochondrial dysfunction mitochondrial genome mitochondrial membrane mutant novel nuclear reprogramming outcome forecast oxidation pediatrician pre-clinical premature prevent public health relevance respiratory sound tributyrin

项目摘要

DESCRIPTION (provided by applicant): The most common mitochondrial respiratory disorder is MELAS (Mitochondrial Encephalopathy Lactic Acidosis with Stroke-like Episodes), an incurable progressive neurodegenerative disease with early childhood onset. This orphan disease causes heterogeneous clinical symptoms, such as encephalopathy, seizures, stroke-like episodes, cognitive impairment, chronic lactic acidosis, and myopathy. Most MELAS patients harbor a maternally inherited mutation (A3243G) in the mitochondrial-encoded tRNALeu/UUR gene, which affects the oxidative phosphorylation (OXPHOS) system responsible for ATP synthesis. In MELAS cells, the multi-copy mitochondrial genome population is heterogeneous, with variable ratios of mutant mtDNAs and wild type (WT) mtDNAs, a state known as heteroplasmy. Individuals with the MELAS mutation become symptomatic only when the mutant load exceeds a certain threshold of heteroplasmy. Currently, no therapeutic options are available to prevent the progression of the disease, resulting in significant disability, a poo prognosis, and premature death. Our proposed novel pharmacological approach uses butyrates to promote nuclear and mitochondrial metabolic reprogramming by boosting mitochondrial biogenesis and maximizing residual ATP output. Using primary fibroblasts derived from a skin biopsy of two MELAS patients, we performed an Affymetrix-based genome-wide microarray analysis that revealed enrichment of pathways for mitochondrial biogenesis and bioenergetics upon exposure to butyrates. From live cell confocal microscopy, we found that butyrates restored the mitochondrial mass and the pool of bioenergetically competent mitochondria in MELAS fibroblasts. In healthy neuronal cells, we found that butyrates induced mitochondrial biogenesis via expression of essential nuclear-encoded regulators and augmented the pool of bioenergetic mitochondria and ATP levels. Thus, our collective preliminary data validate our pharmaco-epigenomic approach and establish proof-of-principle for the proposed studies. We hypothesize that butyrates can augment the functional mitochondrial mass in skin fibroblasts from 20 MELAS patients. Fibroblasts from this number of patients, each with different nuclear backgrounds and heteroplasmic loads, will ensure the findings extend beyond a case study into a statistically sound and broadly applicable report. We will test whether butyrates: (Aim 1) induce favorable mitochondrial biogenesis, thereby shifting heteroplasmy toward healthy mitochondria; and (Aim 2) maximize ATP output via optimization of OXPHOS activity and a metabolic shift toward fatty acid beta oxidation. We anticipate identifying the most promising butyrate candidate for alleviating the symptoms of the MELAS disease. The proposed study will set the stage for future clinical studies with the Children's National Medical Center and the North American Mitochondrial Disease Consortium, in concordance with the PAR-13-023 issued by the NINDS Office of Translational Research for R21 exploratory projects.

描述（由适用提供）：最常见的线粒体呼吸障碍是Melas（线粒体脑病乳酸性乳酸性酸中毒带有中风样发作），这是一种无法治愈的进行性神经退行性疾病，具有儿童早期的发作。这种孤儿疾病会导致异质临床症状，例如脑病，癫痫发作，类似中风样发作，认知障碍，慢性乳酸酸中毒和肌病。大多数MELAS患者都具有线粒体编码的Trnaleu/Uur基因中主要遗传的突变（A3243G），该突变影响负责ATP合成的氧化磷酸化（OXPHOS）系统。在Melas细胞中，多拷贝线粒体基因组群体是异质的，突变型mtdnas和野生型（WT）mtdnas的比例可变，该状态称为异质质。只有当突变载荷超过异质质阈值时，具有MELAS突变的个体才会有症状。当前，没有治疗选择可以防止疾病的进展，导致严重的残疾，便便进展和过早死亡。我们提出的新型药理学方法使用丁酸酯来通过增强线粒体生物发生并最大化残留ATP输出来促进核和线粒体代谢重编程。使用源自两名MELAS患者的皮肤活检的原发性成纤维细胞，我们进行了基于Affymetrix的基因组微阵列分析，该分析揭示了暴露于丁酸酯后的线粒体生物发生和生物能力的途径。从活细胞共聚焦显微镜中，我们发现丁酸酯恢复了Melas成纤维细胞中的线粒体质量和生物烯具有胜任的线粒体。在健康的神经元细胞中，我们发现丁乙酸会通过表达必需的核编码调节剂来诱导线粒体生物发生，并增强生物能线粒体和ATP水平的池。因此，我们的集体初步数据验证了我们的药物 - 基因组学方法，并为拟议的研究建立原则证明。我们假设丁乙酸可以增加20名Melas患者的皮肤成纤维细胞的功能性线粒体肿块。来自这一数量的患者的成纤维细胞，每个患者具有不同的核背景和异态负荷，将确保发现从案例研究中扩展到统计上的合理且广泛适用的报告中。我们将测试丁理酸酯是否：（目标1）诱导有利的线粒体生物发生，从而将异晶转向健康的线粒体；（AIM 2）通过优化OXPHOS活性和向脂肪酸β氧化的代谢转移来最大化ATP输出。我们预计将确定最有前途的丁酸酯候选者来减轻Melas疾病的症状。拟议的研究将在儿童国家医疗中心和北部为未来的临床研究奠定基础美国线粒体疾病财团与Ninds转化研究办公室针对R21探索性项目发行的PAR-13-023一致。