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

• 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
• 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

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.

摘要 线粒体基因组的遗传不稳定性(MtDNA)在人类衰老和疾病中起着重要作用。 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，并导致肌肉萎缩、癌症进展和老年人的神经退化。至 然而，今天，还没有一个孩子被治愈或成功地治疗了遗传性线粒体DNA疾病，也没有 有一种治疗方法可以治疗与年龄相关的疾病的线粒体DNA成分。为了成功地设计出一种治疗方法 战略，重要的是要确定分子机制，可以增加或减少 线粒体DNA不稳定引起的病理改变。然后我们可能会用药物来操纵这些通路，以防止 或者推迟这些疾病的发生。识别这些途径需要一种灵活的动物模型，该模型非常适合于 因此，我们建立了一种新的线虫线粒体DNA不稳定性动物模型。 优雅女装。利用CRISPR/Cas9技术，我们创造了一个容易出错的DNA聚合酶伽马等位基因(Polg- 1D207A)，复制线粒体基因组的酶。携带该等位基因的蠕虫表现出升高的 线粒体DNA突变和耗竭的比率，这是导致人类线粒体DNA疾病的两种类型的遗传不稳定。 由于这种遗传不稳定性，Polg-1D207A蠕虫患有与年龄相关的线粒体下降 呼吸和肌肉功能，模拟人类患者的病理。我们建议对这些进行筛选 通过RNAi来识别可以增加或减少mtDNA疾病严重程度的基因。有了这个 策略，我们已经发现IGF-1/胰岛素信号转导，线粒体蛋白质质量控制， 线粒体动力学、mTOR信号、自噬和细胞凋亡都控制着线粒体DNA疾病的严重程度。 虫子。到目前为止，我们确定的线粒体DNA疾病最强的调节剂是IGF-1/胰岛素信号。 路径。人们早就知道，减少IGF-1/胰岛素信号转导对整体 生物体的健康；然而，我们现在已经确定了一组离散的疾病，这些疾病的IIS活动减少 可能有直接的治疗作用。由于这一途径已经被很好地理解，许多药物和 基因突变可以用于实验，我们处于一个独特的位置来迅速改变这些最初的 将观察结果转化为一个与翻译直接相关的综合计划。要发起这一行动 计划中，我们建议剖析减少IGF-1/胰岛素信号转导拯救的分子机制 线粒体DNA病的虫子。这些实验将为mtDNA疾病的病因学提供深入的见解。 并证明了IIS途径通过多种机制在多个水平上调控mtDNA疾病 对组织的影响。此外，我们将通过调查以下情况来测试我们的发现的治疗潜力 IIS活性降低也可以改善小鼠的mtDNA疾病。我们预计这些实验将 证明减少的IGF-1/胰岛素信号对所有形式的mtDNA疾病有广泛的有益影响，以及 因此将成为我们与线粒体疾病作斗争的强大盟友。