The FMR1 CGG repeat as functional element and therapeutic target in Fragile X associated disorders

FMR1 CGG 重复序列作为脆性 X 相关疾病的功能元件和治疗靶点

基本信息

批准号：
10669050
负责人：
Peter K Todd
金额：
$ 50.83万
依托单位：
BAYLOR COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-25 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10669050
关键词：
5&apos Untranslated Regions Antisense Oligonucleotides Biological Assay Biological Models CGG repeat CGG repeat expansion CRISPR/Cas technology Cell Line Data Dendrites Disease Elements FMR1 FMR1 repeat FMRP FXTAS Fragile X Premutation Fragile X Syndrome Gene Expression Regulation Genetic Transcription Goals Human Human Genome Impairment Inherited Initiator Codon Intellectual functioning disability Knock-in Mouse Learning Long-Term Depression Memory Metabotropic Glutamate Receptors Microsatellite Repeats Modeling Mus Nerve Degeneration Neurobiology Neuronal Plasticity Neurons Open Reading Frames Pathogenesis Pathway interactions Patients Phenotype Phosphorylation Physiologic pulse Play Process Protein Biosynthesis Proteins Receptor Activation Regulation Repetitive Sequence Reporter Role Series Short Tandem Repeat Site Small Interfering RNA Synaptic plasticity System Testing Translational Repression Translations age related neurodegeneration autism spectrum disorder cryptic protein genome-wide human disease human embryonic stem cell improved induced pluripotent stem cell innovation mouse model nervous system disorder novel strategies novel therapeutics prevent response synaptic function therapeutic development therapeutic target tool

项目摘要

The FMR1 repeat as functional element and therapeutic target in Fragile X disorders. Short Tandem repeat (STR) expansions cause ~50 inherited neurological diseases. However, disease associated loci represent only a small fraction of the ~3 million STRs present in the human genome. Despite their importance in human disease, the broader question of what intrinsic roles these repetitive elements play in normal neurobiology is largely unexplored. We recently discovered a conserved and native function for CGG repeats in the 5’ UTR of FMR1. This repeat expands in Fragile X Syndrome (FXS, a common cause of autism and intellectual disability) and Fragile X-associated Tremor/Ataxia Syndrome (FXTAS, an age related neurodegenerative disorder). At normal and expanded sizes, FMR1 CGG repeats trigger translation of multiple cryptic proteins in the absence of an AUG start codon (CGG RAN translation). We recently described how CGG repeats and RAN translation act as an upstream open reading frame (uORF) to impede translation of the fragile X protein, FMRP. Using a combination of reporter assays as well as RAN translation blocking antisense oligonucleotides (RAN ASOs) in human neurons, we found that both the CGG repeats and RAN translation inhibit FMRP synthesis basally. This inhibition is alleviated by metabotropic glutamate receptor (mGluR) activation, which underlies a form of synaptic plasticity important for learning and memory and implicated in Fragile X-associated disorders. Based on these findings, our central hypothesis is that RAN translation and tandem microsatellite repeats have native functions in the regulation of the genes in which they reside, and that aberrancies in these native functions contribute to human disease. Our goals in this project are 3 fold: 1) Determine the mechanisms by which CGG repeats and RAN translation regulate FMRP synthesis, 2) investigate what consequences result from disrupting this regulatory loop in both mouse models and human neurons, and 3) evaluate whether ASOs can be used to simultaneously suppress RAN translation and activate FMRP synthesis in FXS and FXTAS human neurons as a step towards novel therapeutic development.

FMR1在脆弱的X疾病中重复作为功能元件和治疗靶标。短串联重复（STR）膨胀导致〜50种遗传神经局部疾病。与疾病相关的基因座仅占约300万个Str中的一小部分人类基因组，尽管在人类疾病中很重要固有的角色在正常的神经生物学中发挥作用最近在FMR1的5'UTR中发现了CGG重复的保守和天然函数。这种重复症在脆弱的X综合征中扩展（FXS，自闭症和智力的常见原因残疾）和脆弱的X相关震颤/共济失调综合征（FXTAS，ANGE相关神经退行性障碍）。在没有Aug Start密码子（CGG RAN）的情况下，多种隐秘蛋白的翻译翻译）。开放式阅读框（UORF）阻碍了脆弱X蛋白FMRP的翻译。记者分析的组合屁股和lanslation阻止反义寡核苷酸（在人类神经元中进行ASOS），我们。抑制FMRP的合成基本上是由代谢性谷氨酸受体缓解的（mglur）激活，它的基础是一种突触塑料形式，对学习和学习很重要记忆并与X相关的疾病与我们的中心相关。假设是，lansalation和串联微卫星重复性具有天然功能对其居住的基因的调节，以及TESE本地功能中的畸变为人类疾病做出贡献。通过该CGG重复和lanslation调节FMRP合成，2）研究什么后果是由于破坏了小鼠穆斯和人的规律性循环而导致的后果神经元和3）评估是否可以使用ASO同时抑制RAN FXS和FXTAS人神经元中的FMRP合成并激活FMRP合成，作为迈向的一步新颖的治疗发展。