Targeting the IGF-1/insulin signaling pathway to treat mtDNA disease

靶向IGF-1/胰岛素信号通路治疗线粒体DNA疾病

基本信息

批准号：
9765341
负责人：
Marc Vermulst
金额：
$ 29.98万
依托单位：
UNIVERSITY OF SOUTHERN CALIFORNIA
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-01 至 2021-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9765341
关键词：
ATP Synthesis Pathway Adult Affect Aging Alleles Ally Animal Model Apoptosis Autophagocytosis Biological Process Biology Blindness CRISPR/Cas technology Caenorhabditis elegans Cells Child Communities Consumption DNA polymerase gamma Data Disease Enzymes Etiology FRAP1 gene Functional disorder Genes Genetic Genetic Engineering Genome Goals Hand Health Human Inherited Insulin Signaling Pathway Insulin-Like Growth Factor I Libraries Longevity Mammals Medicine Microscopy Mitochondria Mitochondrial DNA Mitochondrial Diseases Mitochondrial Proteins Modeling Molecular Molecular Biology Mus Muscle function Muscular Atrophy Mutation Myopathy Nematoda Nerve Degeneration Organelles Organism Pathology Pathway interactions Patients Pharmaceutical Preparations Play Positioning Attribute Problem Solving Production Protein Biosynthesis Proteins Quality Control RNA Interference RNA interference screen Respiration Role Severities Signal Transduction Testing Therapeutic Time Tubular formation age related combat deafness design experimental study flexibility follow-up insight insulin signaling mitochondrial DNA mutation mitochondrial dysfunction mitochondrial genome mouse model mutant neuromuscular novel prevent programs reduce symptoms response therapeutic evaluation trend tumor progression

项目摘要

ABSTRACT Genetic instability of the mitochondrial genome (mtDNA) plays an important role in human aging and disease. For example, mtDNA instability causes blindness, deafness, myopathy and severe encephalomyopathy in children, and contributes to muscle wasting, cancer progression, and neurodegeneration in aging adults. To this day though, no child has ever been cured or successfully treated for an inherited mtDNA disease, nor does a treatment exist for the mtDNA component of age-related diseases. To successfully design a therapeutic strategy, it will be important to identify molecular mechanisms that can either increase or decrease the pathology that is caused by mtDNA instability. We may then manipulate these pathways with drugs to prevent or delay these diseases. Identifying these pathways requires a flexible animal model that is well suited for “discovery experiments”; therefore, we created a new animal model of mtDNA instability in the nematode C. elegans. Using CRISPR/Cas9 technology, we created an error prone allele of DNA polymerase gamma (polg- 1D207A), the enzyme that replicates the mitochondrial genome. Worms that carry this allele display an elevated rate of mtDNA mutation and depletion, two types of genetic instability that cause mtDNA disease in humans. Because of this genetic instability, polg-1D207A worms suffer from an age-related decline in mitochondrial respiration and muscle function, mimicking the pathology seen in human patients. We propose to screen these worms by RNAi to identify genes that can either increase or decrease the severity of mtDNA disease. With this strategy, we have already discovered that IGF-1/insulin signaling, mitochondrial protein quality control, mitochondrial dynamics, mTor signaling, autophagy and apoptosis, all control the severity of mtDNA disease in worms. The strongest modulator of mtDNA disease that we identified thus far, is the IGF-1/insulin signaling pathway. It has long been known that reduced IGF-1/insulin signaling has beneficial effects for the overall health of organisms; however, we have now identified a discrete set of diseases for which reduced IIS activity may have a direct therapeutic application. Since this pathway is well-understood, and numerous drugs and genetic mutants are available for experimentation, we are in a unique position to rapidly transform these initial observations into a comprehensive program that has immediate translational relevance. To initiate this program, we propose to dissect the molecular mechanisms by which reduced IGF-1/insulin signaling rescues worms from mtDNA disease. These experiments will provide deep insight into the etiology of mtDNA disease and demonstrate that the IIS pathway modulates mtDNA disease by numerous mechanisms, at multiple levels of organization. In addition, we will test the therapeutic potential of our findings by investigating whether reduced IIS activity can ameliorate mtDNA disease in mice as well. We anticipate that these experiments will demonstrate that reduced IGF-1/insulin signaling has broad beneficial effects for all forms mtDNA disease, and will thus be a powerful ally in our battle against mitochondrial disorders.

抽象的线粒体基因组（mtDNA）的遗传不稳定性在人类衰老和疾病中发挥着重要作用。例如，线粒体DNA不稳定会导致失明、耳聋、肌病和严重的脑肌病。儿童，并导致老年人的肌肉萎缩、癌症进展和神经退行性变。但时至今日，还没有任何儿童的遗传性线粒体 DNA 疾病被治愈或成功治疗，也没有存在一种针对年龄相关疾病的 mtDNA 成分的治疗方法成功设计一种治疗方法。战略，重要的是确定可以增加或减少的分子机制然后我们可以用药物操纵这些途径来预防由 mtDNA 不稳定引起的病理。或延迟这些疾病的识别需要一个非常适合的灵活的动物模型。 “发现实验”；因此，我们创建了一种新的线虫线粒体DNA不稳定性动物模型。使用 CRISPR/Cas9 技术，我们创建了 DNA 聚合酶 γ (polg-) 的易错等位基因。 1D207A），携带该等位基因的复制线粒体基因组的酶表现出升高。 mtDNA 突变和耗竭率，这是导致人类 mtDNA 疾病的两种遗传不稳定性。由于这种遗传不稳定性，polg-1D207A 线虫会遭受与年龄相关的线粒体衰退。呼吸和肌肉功能，模仿人类患者的病理学，我们建议对其进行筛查。通过 RNAi 来识别线虫，以识别可以增加或减少 mtDNA 疾病严重程度的基因。策略，我们已经发现 IGF-1/胰岛素信号传导、线粒体蛋白质量控制、线粒体动力学、mTor 信号传导、自噬和细胞凋亡都控制着 mtDNA 疾病的严重程度迄今为止，我们发现的最强的 mtDNA 疾病调节剂是 IGF-1/胰岛素信号传导。人们早就知道 IGF-1/胰岛素信号传导的减少对整体有有益的影响。生物体的健康；然而，我们现在已经确定了一组离散的 IIS 活性降低的疾病由于该途径已被充分了解，并且有许多药物和药物，因此可能具有直接的治疗应用。基因突变体可用于实验，我们处于独特的地位，可以快速转变这些初始突变体将观察结果纳入具有直接转化相关性的综合计划中以启动此项目。计划中，我们建议剖析减少 IGF-1/胰岛素信号传导的分子机制这些实验将深入了解线粒体DNA疾病的病因学。并证明 IIS 通路通过多种机制在多个水平上调节 mtDNA 疾病此外，我们将通过调查是否可以测试我们的研究结果的治疗潜力。减少 IIS 活性也可以改善小鼠的 mtDNA 疾病，我们预计这些实验也能改善这种情况。证明减少 IGF-1/胰岛素信号对所有形式的 mtDNA 疾病具有广泛的有益作用，并且因此，它将成为我们对抗线粒体疾病的强大盟友。