Endogenous regulation of huntingtin expression as a therapeutic target for Huntington's disease

亨廷顿蛋白表达的内源调节作为亨廷顿病的治疗靶点

基本信息

批准号：
9444258
负责人：
RUSSELL L MARGOLIS
金额：
$ 47.03万
依托单位：
JOHNS HOPKINS UNIVERSITY
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：
2017-09-15 至 2022-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9444258
关键词：
Adult Alleles Antibodies Attention Behavioral Brain Brain-Derived Neurotrophic Factor CAG repeat Cell model Cells Cessation of life Chromatin Chromatin Structure Clinical Data Development Disease Disease Progression Effectiveness Exons Face Funding Future Genes Huntington Disease Huntington gene Individual Inherited Lead Mediating Methods Molecular Molecular Biology Mutation Neurodegenerative Disorders Oligonucleotides Onset of illness Pathogenesis Pathogenicity Pathway interactions Phase Phenotype Pilot Projects Promoter Regions Property Proteins Protocols documentation RNA Splicing Regulation Research Role Series Small Interfering RNA Specificity Structure Testing Therapeutic Therapeutic Agents Toxic effect Transcript Variant Withdrawal Work base brain cell chromatin remodeling experimental study high throughput screening human disease induced pluripotent stem cell knock-down lymphoblast mouse model mutant neurotoxic new therapeutic target novel overexpression prevent programs promoter protein expression small molecule therapeutic target tool validation studies

项目摘要

Summary. Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder, characterized by relentless progression to death ~20 years after disease onset. HD is caused by an expanded CAG repeat in exon 1 of the huntingtin (HTT) gene. Disease pathogenesis is largely a result of expression of the mutant transcript and protein, which have neurotoxic properties. Suppressing the expression of the mutant allele is therefore a promising therapeutic approach, thus far pursued with antibody, oligonucleotide and siRNA strategies. As with any knockdown approach, especially in the CNS, problems of delivery, reversibility, and off-target effects using these methods remain problematic. Surprisingly, relatively little is known about the regulation of the HD locus, and in particular on the mechanisms that regulate HTT expression. We have recently discovered a gene on the strand antisense to HTT at the HD locus, which we have termed huntingtin antisense (HTT-AS). We have demonstrated that increasing expression of HTT-AS decreases expression of HTT, and that HTT-AS expression can be manipulated using small molecules. We hypothesize that HTT-AS itself, and the components that regulate its expression and interaction with HTT, will provide novel therapeutic targets for suppression of HTT expression and hence treatment of HD. A corollary to this hypothesis is that a better understanding of the HD locus, in this case the role of HTT-AS, will be critical in the interpretation of any HTT suppression strategy. We will test this hypothesis with a series of experiments organized into three specific aims, each built on compelling preliminary data. In Aim 1, we will determine if additional HTT-AS exons, splice variants, and promoters exist, determine the effect of repeat expansion on HTT-AS expression, and identify protein factors that regulate HTT-AS promoter activity. In Aim 2, we will determine the mechanisms by which HTT-AS suppresses HTT, including the quantitative effect of different HTT-AS transcripts on the suppression of HTT, and the role of chromatin remodeling on HTT expression. In Aim 3, we will collaborate with NCATS and CHDI to perform a large scale high throughput screen to find and characterize compounds that decrease expression of HTT by specifically increasing expression of HTT-AS. Selected compounds will be validated in cell and mouse models.

概括。亨廷顿病 (HD) 是一种常染色体显性遗传性神经退行性疾病，其特征为发病后约 20 年，无情地进展至死亡。 HD 是由扩张的 CAG 引起的在亨廷顿蛋白 (HTT) 基因的外显子 1 中重复。疾病发病机制很大程度上是表达的结果突变转录物和蛋白质，具有神经毒性。抑制表达因此，突变等位基因是一种有前途的治疗方法，迄今为止一直在用抗体进行研究，寡核苷酸和 siRNA 策略。与任何击倒方法一样，尤其是在中枢神经系统中，使用这些方法的递送、可逆性和脱靶效应的问题仍然存在问题。令人惊讶的是，人们对 HD 基因座的调控知之甚少，特别是在调节 HTT 表达的机制。我们最近在链上发现了一个基因 HD 基因座上 HTT 的反义，我们称之为亨廷顿反义 (HTT-AS)。我们有证明增加 HTT-AS 的表达会降低 HTT 的表达，并且 HTT-AS 可以使用小分子来操纵表达。我们假设 HTT-AS 本身以及调节其表达以及与 HTT 相互作用的成分将提供新的治疗靶点用于抑制 HTT 表达，从而治疗 HD。这个假设的一个推论是更好地了解 HD 基因座，在本例中是 HTT-AS 的作用，对于对任何 HTT 抑制策略的解释。我们将通过一系列实验来检验这个假设分为三个具体目标，每个目标都建立在令人信服的初步数据之上。在目标 1 中，我们将确定是否存在额外的 HTT-AS 外显子、剪接变体和启动子，确定重复扩展 HTT-AS 表达，并鉴定调节 HTT-AS 启动子的蛋白因子活动。在目标 2 中，我们将确定 HTT-AS 抑制 HTT 的机制，包括不同HTT-AS转录本对HTT抑制的定量作用，以及染色质的作用 HTT 表达的重构。在目标 3 中，我们将与 NCATS 和 CHDI 合作开展大型大规模高通量筛选，以发现和表征通过以下途径降低 HTT 表达的化合物特异性增加 HTT-AS 的表达。选定的化合物将在细胞和小鼠中进行验证模型。