Regulation of mitochondrial function by folate enzyme ALDH1L2 in health and disease

叶酸酶 ALDH1L2 在健康和疾病中对线粒体功能的调节

基本信息

批准号：
10117233
负责人：
SERGEY A KRUPENKO
金额：
$ 47.58万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-01 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10117233
关键词：
Acids Amino Acids Anabolism Animal Model Carbon Carbon Dioxide Cell Maintenance Cells Coenzyme A Cytoplasm Dermatitis Diagnosis Diet Disease Enzymes Equilibrium Etiology Fathers Fibroblasts Folic Acid Folic Acid Deficiency Formyltetrahydrofolates Functional disorder Gene Duplication Generations Genes Glutathione Disulfide Health High Fat Diet Human Hydrolase Impairment Individual Knockout Mice Knowledge Link Lipids Maintenance Mediating Metabolic Metabolism Mitochondria Mus Mutation NADP Neurologic Outcome Oxidation-Reduction Oxidative Stress Pathway interactions Patients Phenotype Physiological Pilot Projects Play Production Reaction Regulation Role Sjogren-Larsson Syndrome Spleen Sulfhydryl Compounds Syndrome Testing Tetrahydrofolates Ulcer autism spectrum disorder base cell type clinically relevant diet-induced obesity dietary experimental study fatty acid metabolism fatty acid oxidation folic acid metabolism human disease insight knockout gene metabolic phenotype metabolomics mitochondrial dysfunction mutant oxidation rare genetic disorder response restoration

项目摘要

The physiological role of the mitochondrial folate enzyme ALDH1L2, discovered by the PI's lab in 2010, is not well understood. This enzyme catalyzes the reaction: NADP+ + 10-formyltetrahydrofolate → NADPH + CO2 + tetrahydrofolate, which can be important for the mitochondrial NADPH production from the oxidation of folate- bound one-carbon groups. In support of this function, our recent gene knockout experiments show that deletion of Aldh1l2 in mice causes increased oxidative stress. Furthermore, Aldh1l2-/- mice develop ulcerative dermatitis, and have highly enlarged (4-fold) spleen and extensively altered metabotype. The mechanistic basis underlying these phenotypes is currently unknown but has clinical relevance given the recent identification of patients with ALDH1L2 mutations who were diagnosed with a rare neurocutaneous disease or autistic spectrum disorder. Our metabolomics analysis of patient's fibroblasts identified dramatic changes in the cellular lipid repertoire, the outcome most likely caused by the impairment of mitochondrial CoA-dependent fatty acid metabolism. This leads to mitochondrial dysfunction, which is manifested as insufficient energy production and oxidative stress. In further support of this mechanism, fibroblasts from ALDH1L2-deficient patients have fragmented mitochondria and show the accumulation of lipid droplets. Importantly, the restoration of the ALDH1L2 enzyme in these fibroblasts rescues the phenotype and metabotype, making these cells similar to fibroblasts from healthy individuals. Based on these findings, we hypothesize that ALDH1L2 serves distinct metabolic function in the cell, the maintenance of redox state through the mitochondrial NADPH generation linked to the folate cycle. The loss of ALDH1L2 leads to mitochondrial dysfunction, energy disbalance and oxidative stress. Thus, deleterious mutations in the ALDH1L2 gene are underlying cause of mitochondria-related human disorders/diseases. This proposal will determine the role of ALDH1L2 in cellular metabolism and will link its mutations as causative factor of human diseases through the following aims: (1) Test the hypothesis that ALDH1L2 maintains mitochondrial redox balance and controls coenzyme A biosynthesis and fatty acid oxidation. (2) Define the role of ALDH1L2 in partitioning of one-carbon groups between energy production or mitochondria to cytoplasm shuttling. (3) Establish ALDH1L2 deficiency as the cause of rare genetic disorders in humans and explore underlying mechanisms. It is now clear that mitochondrial dysfunction is an important component in the pathophysiology of numerous diseases that had not been previously identified. The role of ALDH1L2 in maintenance of mitochondrial function, as well as in mitochondria-related diseases, is largely unexplored. This proposal will fill this knowledge gap and will provide mechanistic insight into the role of ALDH1L2 in human diseases.

Pi's Lab在2010年发现的线粒体叶酸酶ALDH1L2的物理作用尚不清楚。这酶催化了反应：NADP + + 10型甲基四氢叶酸溶质→NADPH + CO2 +四氢叶酸盐，这对于从叶酸一结合的一碳基的氧化中对线粒体NADPH产生很重要。为了支持该功能，我们最近的基因敲除实验表明，小鼠中ALDH1L2的缺失会导致氧化物胁迫增加。此外，Aldh1l2 - / - 小鼠会出现溃疡性皮炎，并具有高度增强（4倍）sleen和广泛改变的代谢型。这些表型的基础机械基础目前尚不清楚，但鉴于最近鉴定出患有ALDH1L2突变的患者被诊断出患有罕见神经皮肤病或加速谱系障碍的患者。我们对患者成纤维细胞的代谢组学分析确定了细胞脂质库的急剧变化，这很可能是由于线粒体COA依赖性脂肪酸代谢的损害引起的。这导致线粒体功能障碍，这表现为能量产生和氧化应激不足。为了进一步支持这种机制，来自ALDH1L2缺陷患者的成纤维细胞具有分散的线粒体，并显示了脂质液滴的积累。重要的是，这些成纤维细胞中AldH1L2酶的恢复反应了表型和分类型，使这些细胞类似于健康个体的成纤维细胞。基于这些发现，我们假设ALDH1L2在细胞中具有独特的代谢功能，通过线粒体NADPH生成与叶酸周期相关的氧化还原状态。 ALDH1L2的丧失会导致线粒体功能障碍，能量破坏和氧化应激。这是ALDH1L2基因中缺失的突变是线粒体相关的人类疾病/疾病的根本原因。该建议将确定ALDH1L2在细胞代谢中的作用，并将其突变与以下目的联系起来的人类疾病的严重因素：（1）检验AldH1L2维持线粒体氧化还原平衡和控制辅酶A的生物合成和脂肪酸氧化的假设。（2）定义AldH1L2在能量产生或线粒体之间分配到细胞质中的一碳基中的作用。（3）将ALDH1L2缺乏症确立为人类罕见遗传疾病的原因并探索潜在的机制。现在很明显，线粒体功能障碍是许多先前尚未鉴定出的许多疾病的病理生理学中的重要组成部分。 ALDH1L2在维持线粒体功能以及与线粒体相关疾病中的作用是意外的。该建议将填补这一知识差距，并将提供有关ALDH1L2在人类疾病中的作用的机械洞察力。