Inborn Errors of Long Chain Fat Metabolism

 描述(由申请人提供) 线粒体疾病(FAO)是美国通过新生儿筛查发现的最常见的疾病之一。粮农组织传统上被视为一种产生能量、分解代谢的途径，但这一途径的中间体可以作为合成其他复杂脂质的关键底物。该项目的长期目标是确定粮农组织蛋白质在中间代谢中的作用，以及由于先天缺陷造成的蛋白质缺乏对临床的影响。在这些目标上取得的进展为我们提供了对线粒体能量代谢的分子结构的革命性见解，并使我们能够利用这些知识开发治疗长链脂肪酸氧化障碍的新疗法。这一更新应用的总体目标是利用整合生物学来表征线粒体能量代谢的分子结构，并了解由于缺乏单酶紊乱而导致的整体代谢缺陷。具体目标1是确定稳定大分子线粒体能量复合体的关键蛋白质相互作用。根据我以前的发现，我将研究三组特定蛋白质之间的相互作用。具体目标1a是利用蛋白质组学技术检测对粮农组织长链蛋白质的形成和稳定性至关重要的氨基酸残基。具体目标1b是直接检查多功能能量复合体的三维结构。具体目标2是检查长链粮农组织蛋白突变对大分子线粒体能量复合体的影响。我推测，一些突变不仅会使突变的蛋白失活，还会破坏大分子线粒体能量复合体的稳定性和功能。具体目标2a是为了研究患者和CRISPR/Cas9诱导的突变对细胞系和Fod小鼠模型中长链FAO复合体核心蛋白与其结合伙伴相互作用的影响。特异靶2b是检测ETFDH突变对其与复合体III相互作用的影响。特异靶2c是表征FAOD患者的新突变。目标3是开发新型小分子化合物来处理长链脂肪酸。我之前曾使用分子建模和体外细胞系统来确定潜在的治疗性小分子伴侣蛋白和肽，这些蛋白可以稳定常见的Glu304Lys突变MCAD蛋白，其中一种目前正在患者的临床试验中。我和我的合作者还 研究表明，一些ACAD9突变可以通过补充过量的核黄素来稳定下来，这与一些ETFDH突变的发现类似。我推测，额外的治疗分子有可能稳定其他突变的脂肪酸氧化蛋白，并缓解VLCAD缺乏症的非典型炎症过程。具体目标3a是检查已知的影响FAOD患者细胞能量代谢和炎症的新型药物的使用。具体目标3b是检查这些化合物在FAOD小鼠模型中的效果，以便为可能的患者临床试验做准备。

 DESCRIPTION (provided by applicant) Disorders of mitochondrial (FAO) are among the most frequent identified through newborn screening in the US. FAO is traditionally viewed as an energy-generating, catabolic pathway but intermediates of this pathway can serve as key substrates for synthesis of other complex lipids. The long range objective of this project is to define the role of FAO proteins in intermediary metabolism and the clinical impact of their deficiency due to inborn errors. Progress made on these aims has provided revolutionary insight into the molecular architecture of mitochondrial energy metabolism and positions us to leverage this knowledge for the development of novel therapies for long chain fatty acid oxidation disorders. The overall goal of this renewal application is to use integrative biology to characterize the molecular architecture of mitochondrial energy metabolism and to understand the global metabolic defects induced by deficiency of single enzyme disorders. Specific Aim 1 is to identify the key protein interactions that stabilize the macromolecular mitochondrial energy complex. I will examine the interactions of three specific sets of proteins based on my previous findings Specific Aim 1a is to use proteomics techniques to examine amino acid residues critical to the formation and stability of the proteins of long chain FAO. Specific Aim 1b is to directly examine the three dimensional structure of the multifunctional energy complex. Specific Aim 2 is to examine the effects of mutations in long chain FAO proteins on the macromolecular mitochondrial energy complex. I hypothesize that some mutations will not only inactivate the mutated protein, but also disrupt the stability and function of the macromolecular mitochondrial energy complex Specific Aim 2a is to examine the effects of patient and CRISPR/Cas9 induced mutations in cell lines and an FAOD mouse model on interaction of the long chain FAO complex core proteins with their binding partners.. Specific Aim 2b is to examine the effects of mutations in ETFDH on its interaction with complex III. Specific Specific Aim 2c is to characterize new mutations in patients with FAODs. Aim 3 is to develop novel small molecule compounds to treat long chain FAODs. I have previously used molecular modeling and an in vitro cell system to identify potential therapeutic small molecule chaperonins and peptides that stabilizes the common Glu304Lys mutant MCAD protein, one of which is currently in clinical trials in patients. My collaborators and I have also shown that some ACAD9 mutations are stabilized by supplementation with excess riboflavin, similar to a finding with some ETFDH mutations. I hypothesize that additional therapeutic molecules have the potential to stabilize other mutant fatty acid oxidation proteins and mitigate the atypical inflammatory process seen in VLCAD deficiency. Specific Aim 3a is to examine the use of novel pharmaceutical agents known to affect energy metabolism and inflammation in cells from patients with FAODs. Specific Aim 3b is to examine the effect of these compounds in mouse models of FAODs in order to prepare for possible clinical trials in patients.