Targeting Protein Arginine Methylation in HD

HD 中的靶向蛋白质精氨酸甲基化

基本信息

批准号：
9890027
负责人：
Tamara Ratovitski
金额：
$ 20.47万
依托单位：
JOHNS HOPKINS UNIVERSITY
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：
2019-03-15 至 2023-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9890027
关键词：
Affect Amyotrophic Lateral Sclerosis Antibodies Arginine Biogenesis Biological Assay Biology Brain Diseases Cell Line Cell model Cell physiology Cells Development Disease Disease model Enzymes Expression Profiling Frontotemporal Lobar Degenerations Genetic Transcription Histones Human Huntington Disease Huntington gene Huntington protein Impairment In Vitro Intervention Label Mass Spectrum Analysis Mediating Methods Methylation Modification Molecular Target Nerve Degeneration Neurodegenerative Disorders Neurons Outcome Study Pathogenesis Pathogenicity Play Post-Translational Protein Processing Process Protein Methylation Proteins Proteome Proteomics RNA Processing RNA Splicing RNA Transport RNA methylation RNA-Binding Proteins Reaction Recombinant Proteins Role Testing Therapeutic Intervention Therapeutic Studies Toxic effect Transcriptional Regulation Western Blotting Work base brain tissue cancer therapy demethylation epigenetic regulation gene product histone methylation in vitro activity induced pluripotent stem cell inhibitor/antagonist interest knock-down messenger ribonucleoprotein mouse model mutant neuronal survival new therapeutic target novel overexpression polyglutamine pre-clinical sarcoma small hairpin RNA synthetic peptide

项目摘要

Huntington’s disease (HD) is a progressive autosomal dominant neurodegenerative disorder caused by a polyglutamine expansion in the HD gene product, huntingtin (Htt). Mechanisms of HD cellular pathogenesis remain elusive, with no disease-modifying treatments for HD available today. Studies using cellular and mouse models of HD have revealed disruptions in many cellular processes and functions, likely mediated by abnormal protein interactions of polyQ-expanded Htt. Transcriptional dysregulation is widely implicated in HD pathogenesis, and epigenetic regulation of transcription was found to play a role in transcriptional abnormalities in HD. Arginine methylation is an important post-translational modification of proteins with an emerging role in neurodegeneration. In addition to providing a key level of epigenetic regulation, this modification found on many non-histone RNA-binding proteins mediates RNA processing and splicing. However, despite the fact that both gene transcription and RNA processing abnormalities have been widely associated with HD, there is very little information on the role of arginine methylation in HD pathogenesis. This project is a continuation of our previous findings that arginine dimethylation of endogenous substrates is impaired in HD models due to aberrant interactions of mutant Htt with the enzyme that carries out these modifications, PRMT5. Our findings of the PRMT5/Htt functional interaction raise the possibility that mutant Htt exerts its effects on transcription and RNA processing via direct interaction with histone-modifying enzymes, and by modulating their activity. We think this warrants further studies evaluating dimethylation of arginine, and the modifying enzymes, as potential new therapeutic targets for HD. Arginine methylation is a reversible modification, and several enzymes capable of arginine demethylation have been described. Thus, if arginine methylation of certain key targets is decreased in HD, there is a potential for reversal using the inhibitors of demethylases, several of which are available today, and some are being tested for cancer therapies. In Aim 1, we will assess proteome-wide changes in protein arginine methylation in HD, and will identify key players, focusing on histones and RNA-binding proteins involved in RNA processing and splicing. We will use novel methods of quantitative mass spectrometry, and our novel HD iPS cell lines, as well as human HD brain. In Aim 2, we will evaluate if Htt is directly involved in the methylation of the key substrates, identified in Aim 1. In Aim 3 we will evaluate approaches to reverse methylation deficiencies, and will test if such intervention is beneficial for neuronal survival. Taken together, these studies will provide novel information of the changes in arginine methylation of proteins in HD models and will elucidate whether abnormalities in epigenetic regulation of transcription and RNA processing represent a unifying pathogenic mechanism yielding novel therapeutic targets. The outcomes of these studies will reveal novel enzymatic targets, methyl-modifying enzymes, modulated by Htt, potentially providing a proof of principle towards novel molecular targets for preclinical therapeutic studies.

亨廷顿氏病（HD）是一种渐进的常染色体显性神经退行性疾病。 HD基因产物Huntingtin（HTT）中的聚谷氨酰胺扩展。 HD细胞发病机理的机理保持难以捉摸，今天没有针对高清疾病的治疗方法。使用细胞和小鼠的研究高清模型揭示了许多细胞过程和功能中的破坏，可能是由异常介导的 polyq扩展的HTT的蛋白质相互作用。转录失调在高清中广泛实现发现发病机理和转录的表观遗传调节在转录异常中起作用在高清。精氨酸甲基化是对蛋白质的重要后翻译后修饰，在神经变性。除了提供表观遗传调节的关键水平外，此修改还可以非搭酮RNA结合蛋白介导RNA的加工和剪接。但是，要做两个事实基因转录和RNA处理异常已与HD广泛相关，很少关于精氨酸甲基化在HD发病机理中的作用的信息。这个项目是我们以前的延续由于异常，HD模型中内源性底物的精氨酸二甲基化受损突变体HTT与进行这些修饰的酶的相互作用，PRMT5。我们关于 PRMT5/HTT功能相互作用增加了突变体HTT对转录和RNA的影响的可能性通过直接与组蛋白修饰酶进行处理，并通过调节其活性来处理。我们认为这一点保证进一步评估精氨酸二甲基化和修饰酶的研究作为潜在的新酶高清的治疗靶标。精氨酸甲基化是一种可逆的修饰，几种能够已经描述了精氨酸脱甲基化。如果某些关键靶标的精氨酸甲基化减少高清，使用脱甲基酶的抑制剂有可能逆转，其中几种可用，有些正在接受癌症疗法的测试。在AIM 1中，我们将评估蛋白质蛋白质的变化高清精氨酸甲基化，并将识别关键参与者，重点关注组蛋白和RNA结合蛋白在RNA处理和剪接中。我们将使用新颖的定量质谱法和我们的小说高清IPS细胞系以及人类高清脑。在AIM 2中，我们将评估HTT是否直接参与甲基化在AIM 1中确定的关键基材。在AIM 3中，我们将评估逆转甲基化的方法缺陷，并将测试这种干预是否对神经元生存有益。一起进行这些研究将提供HD模型中蛋白质蛋白精氨酸甲基化变化的新信息，并将阐明转录和RNA处理的表观遗传调节异常是否代表统一致病机制产生新的治疗靶标。这些研究的结果将揭示新颖的由HTT调节的酶促靶标，甲基修饰的酶，有可能提供原理证明朝着临床前治疗研究的新型分子靶标。