Metabolic regulation of MODS in pediatric mitochondrial disorders

项目摘要 破坏性的人类原发性线粒体疾病是由致病性mtDNA变异引起的， 演变为器官衰竭的简称，称为肾性多器官功能障碍综合征 （MIMODS）。潜在的病理生理机制比仅仅减少ATP原更为复杂， 但是，对于这些复杂的过程，以组织特异性的方式所知甚少。因此， 迫切需要评估多种组织中广泛存在的线粒体功能障碍的影响， 关于MIMODS我们已经证明了广泛的线粒体功能障碍的有害结果（降低 生物能量健康指数，异常线粒体形态，腐胺水平升高）， 携带独特致病性mtDNA变异的Ric PMD真皮成纤维细胞。基于我们的发现，我们假设 腐胺水平升高会导致氧化应激反应和广泛的线粒体功能障碍， 导致原发性线粒体疾病的细胞模型中的MIMODS。我们的合作团队将- 签署实验，并建立在线粒体遗传学和生理学，干细胞生物学， ogy和分化，下一代测序分析和代谢物分析，以解决以下问题 研究目的：在目的1中，我们将全面评估20例儿童疾病患者的线粒体功能障碍， 沿着五个年龄匹配的对照。我们会评估氧化- 抗应激标记物、NAD/NADH氧化还原生物化学、代谢组学、线粒体呼吸和形态学。 在目标2中，我们将试图了解与线粒体功能障碍相关的组织特异性异常， 神经元、心肌细胞和足细胞。在目标3中，我们将评估有针对性的干预措施的效果， 氧化应激和改善线粒体呼吸在多种分化的细胞类型，表现出ele- 腐胺水平;以及来自PMD的临床前小鼠模型的多种组织中。完成这些 aims将有助于更新对多种能量密集型细胞中腐胺代谢的理解 来源于患有小儿PMD的患者，以及其在触发MIMODS中的作用。从长远来看，我们的研究 有可能开发出用候选疗法对患者细胞进行个性化测试的策略， 合理的个性化治疗

PROJECT SUMMARY Devastating human primary mitochondrial disorders are caused by pathogenic mtDNA variants and frequently evolve into organ failures referred to, as mitochondrial-induced multiple organ dysfunction syndrome (MIMODS). The underlying pathophysiologic mechanisms are more complex than a mere decrease in ATP pro- duction and very little is known about these complex processes in a tissue-specific manner. There is thus an urgent unmet need to assess the impact of the widespread mitochondrial dysfunction in multiple tissues leading to MIMODS. We have demonstrated deleterious outcomes of widespread mitochondrial dysfunction (lowered bioenergetics health index, abnormal mitochondrial morphology, elevated putrescine levels) in multiple pediat- ric PMD dermal fibroblasts carrying unique pathogenic mtDNA variants. Based on our findings, we hypothesize that elevated putrescine levels cause oxidative stress response and widespread mitochondrial dysfunction that contributes to MIMODS in cellular models of primary mitochondrial disorders. Our collaborative team will de- sign experiments and build upon established expertise in mitochondrial genetics and physiology, stem cell biol- ogy and differentiation, next-generation sequencing analysis and metabolite profiling to address the following research aims: In Aim 1, we will comprehensively assess mitochondrial dysfunction in twenty pediatric diseased fibroblasts with a confirmed diagnosis of PMDs, along with five age matched controls. We will assess the oxida- tive stress markers, NAD/NADH redox biochemistry, metabolomics, mitochondrial respiration and morphology. In aim 2, we will seek to understand tissue-specific abnormalities associated with mitochondrial dysfunction in neurons, cardiomyocytes and podocytes. In aim 3, we will assess the effect of targeted interventions of reducing oxidative stress and improving mitochondrial respiration in multiple differentiated cell types that exhibit ele- vated putrescine levels; and in multiple tissues from preclinical mouse models of PMD. The completion of these aims will contribute to a newer understanding of putrescine metabolism in multiple energy-intensive cell types derived from patients with pediatric PMD and its role in triggering MIMODS. In the long-term, our studies have the potential to develop strategies for individualized testing of patient cells with candidate therapeutics to drive rational, personalized therapies.