iPS Cells for Investigation of HDL2 and HD Pathogenesis

用于研究 HDL2 和 HD 发病机制的 iPS 细胞

• 批准号: 8642390
• 负责人: RUSSELL L MARGOLIS
• 金额: $ 24.3万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8642390
• 关键词: 16q24; African; Agonist; Alleles; Biological Models; Brain; Brain-Derived Neurotrophic Factor; CAG repeat; Cell Line; Cells; Cessation of life; Chromosomes; Cognition; Corpus striatum structure; Disease; Disease Progression; Emotions; Exons; Exploratory/Developmental Grant; Fibroblasts; Generations; Genes; Glutamates; Goals; Human; Human Herpesvirus 4; Huntington Disease; Individual; Inherited; Investigation; Karyotype; Lead; Length; Modeling; Movement; Mus; Mutation; Nerve Degeneration; Neurobiology; Neurodegenerative Disorders; Neurons; Onset of illness; Pathogenesis; Patients; Pattern; Phenotype; Positioning Attribute; Process; Property; Protocols documentation; Public Health; RNA; RNA Processing; Relative (related person); Risk; Role; System; Testing; Therapeutic; Toxic effect; Transcript; Triplet Multiple Birth; Withdrawal; Work; Yang; base; falls; human Huntingtin protein; improved; induced pluripotent stem cell; insight; junctophilin; mutant; neuropathology; neurotoxicity; new therapeutic target; pluripotency; polyglutamine; protein aggregate; public health relevance; research study; therapeutic target; tool; vector

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease, characterized by abnormalities of movement, cognition and emotion, with relentless progression until death ~20 years after disease onset. HD is caused by expanded CAG repeats in exon 1 of the Huntingtin (HTT) gene. Substantial advances have been made into understanding the neurobiology of HD. Nonetheless, as of yet no treatment exists that stops or substantially slows disease progression, and it has proven difficult to prioritize among the >100 proposed pathogenic mechanisms to focus on those most likely to lead to therapeutic advances. HDL2, discovered and genetically defined by the Margolis group, is a rare, autosomal dominant neurodegenerative disorder, clinically and neuropathologically very similar from HD. Like HD, the neuropathology of HDL2 is characterized by cortical and striatal neurodegeneration and the presence of neuronal protein aggregates. HDL2 is caused by a CTG/CAG expansion on chromosome 16q24. Normal alleles contain 6-28 triplets, while pathogenic repeats range from 40-59 triplets, again remarkably similar to HD. In the CTG orientation, the repeat falls in the gene junctophilin-3 (JPH3). We have hypothesized that the HDL2 mutation leads to neurodegeneration via a combination of loss of JPH3 expression, toxicity of the sense strand transcript containing an expanded CUG repeat, and expression of polyglutamine from a cryptic gene on the antisense strand. The relative contribution and interactions of these mechanisms remains unknown, and modeling HDL2 has proven challenging. We now propose (Aim 1) to generate and characterize induced pluripotent cells from fibroblasts of individuals with HDL2. The pluripotency of the cells will be systematically investigated. In aim 2, we will then differentiate the iPS cells into neurons, including a subpopulation with a striatal phenotype. Cells will be characterized with neuronal and striatal-specific markers to determine the differentiation pattern, and we will determine the extent to which these cells recapitulate findings observed in HDL2 brain and model systems. We will determine the survival, electrophysiological profiles, vulnerability to glutamate toxicity, and vulnerability to BDNF withdrawal of these cells compared to controls. The public health implications of developing HDL2 iPS cells as a tool for studying HDL2 are several fold: improved understanding of HDL2 itself, new insights into fundamental pathogenic processes relevant to other repeat expansion diseases, and the opportunity to find pathogenic points of convergence between HD and HDL2 that will lead to a focus on therapeutic targets of most promise for both diseases.

亨廷顿病（HD）是一种常染色体显性遗传的神经退行性疾病，其特征在于 运动、认知和情感异常，不断发展，直到死亡约20年后 发病HD是由亨廷顿蛋白（HTT）基因外显子1中的CAG重复序列扩增引起的。 对HD的神经生物学的理解已经取得了实质性的进展。尽管如此，截至 然而，目前还没有治疗方法可以阻止或大大减缓疾病的进展，而且已经证明很难 优先考虑>100种拟议的致病机制，重点关注那些最有可能导致 治疗进展HDL 2，由马戈利斯小组发现和遗传定义，是一种罕见的， 常染色体显性遗传神经退行性疾病，临床和神经病理学与HD非常相似。 与HD一样，HDL 2的神经病理学特征为皮质和纹状体神经变性， 神经元蛋白聚集体的存在。HDL 2是由染色体上的CTG/CAG扩增引起的 16q24。正常等位基因包含6-28个三联体，而致病重复序列范围为40-59个三联体，再次 与HD非常相似。在CTG方向，重复福尔斯落在基因junctophilin-3（JPH 3）中。我们 我假设HDL 2突变通过JPH 3缺失和 表达，含有扩增的CUG重复序列的有义链转录物的毒性，以及 反义链上的隐蔽基因的多聚谷氨酰胺。的相对贡献和相互作用 这些机制仍然是未知的，HDL 2的建模已经证明是具有挑战性的。我们现建议 (Aim 1）从具有HDL 2的个体的成纤维细胞产生并表征诱导的多能细胞。 将系统地研究细胞的多能性。在目标2中，我们将区分 iPS细胞转化为神经元，包括具有纹状体表型的亚群。将对细胞进行表征 与神经元和纹状体特异性标志物，以确定分化模式，我们将确定 这些细胞在多大程度上再现了在HDL 2脑和模型系统中观察到的发现。我们将 确定存活率、电生理特征、对谷氨酸毒性的脆弱性和对 与对照组相比，这些细胞的BDNF撤退。发展HDL 2的公共卫生意义 iPS细胞作为研究HDL 2的工具有几个方面：提高对HDL 2本身的理解， 深入了解与其他重复扩张性疾病相关的基本致病过程， 有机会找到HD和HDL 2之间的致病点，这将导致关注 这两种疾病最有希望的治疗目标。