Role of tau circular RNAs in tauopathies

tau 环状 RNA 在 tau 病中的作用

• 批准号: 9809064
• 负责人: Stefan Stamm
• 金额: $ 22.95万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9809064
• 关键词: Adenine; Adenosine; Alternative Splicing; Alu Elements; Alzheimer' s Disease; Amino Acids; Animal Model; Antisense Oligonucleotides; Autopsy; Binding; Binding Proteins; Binding Sites; Biological Assay; Biology; Brain; Cells; Cellular Stress; Clinical; Data; Development; Disease; Elements; Epigenetic Process; Etiology; Event; Excision; Exons; FTD with parkinsonism; Fishes; Freezing; Frontotemporal Dementia; Gene Expression; Generations; Genes; Genetic; Genomics; Human; Interdisciplinary Study; Kentucky; Knowledge; Lead; Letters; Link; MAPT gene; Mass Spectrum Analysis; Messenger RNA; Methylation; Microtubules; Modeling; Modification; Molecular; Molecular Weight; Morphology; Motor Neurons; Mutation; Nerve Degeneration; Neurodegenerative Disorders; Neurofibrillary Tangles; Neurons; Open Reading Frames; Pathologic; Pathology; Peptide Initiation Factors; Physiological; Play; Polyadenylation; Polymers; Primates; Protein Isoforms; Proteins; RNA; RNA Processing; RNA methylation; Reader; Regulation; Reporting; Research; Ribosomes; Role; Sampling; Site; Stress; Structure; Tauopathies; Terminator Codon; Testing; Transgenic Organisms; Translating; Translations; Universities; Zebrafish; biobank; brain tissue; circular RNA; mRNA Precursor; mild cognitive impairment; mutant; nervous system disorder; neurochemistry; neurofibrillary tangle formation; neuropathology; novel; novel therapeutics; overexpression; paired helical filament; programs; protein expression; recruit; spatial memory; tRNA Methyltransferases; tau Proteins; tau aggregation; tau function; tissue culture

Microtubule associated protein tau (encoded by the MAPT gene) is a critical component in the etiology of Alzheimer's Disease (AD) and other tauopathies in which tau aggregates in neurofibrillary tangles. However, the basic regulation of MAPT gene expression is still imperfectly understood. It is not clear what causes the formation of neurofibrillary tangles, but tauopathic conditions show changes in tau mRNA isoforms, generated through alternative pre-mRNA processing. Furthermore, mutations changing alternative splicing of MAPT cause frontotemporal dementia, underscoring the importance of tau pre-mRNA processing. We have identified human-specific circular RNAs (circRNAs) formed by the tau-encoding mRNA from the MAPT locus generated by backsplicing of exon 10. Backsplicing forming circRNAs occurs when pre-mRNA forms loops, which is aided by primate-specific Alu elements in humans. The ground-breaking preliminary data demonstrate conclusive evidence of tau circRNAs derived from human brain samples. We hypothesize that Alu elements help forming human specific MAPT circRNAs, that likely after RNA methylation could be translated into proteins containing multimers of microtubule binding sites. We will use (a) minigenes in tissue culture for molecular mechanistic studies, to test whether MAPT circRNAs are translated into proteins after RNA methylation and to test tau circRNA's interaction with other RNAs and proteins. These data will be correlated with assessments in human brain tissue across the disease spectrum from pathologically-confirmed normal, MCI (mild cognitive impairment), and AD cases. To (b) test tau circRNA's physiological relevance, we have generated zebrafish lines expressing genomic parts of human MAPT that form circular RNAs in neurons, and observed abnormal neurons after introduction of FTDP-17 mutants in constructs that express only circRNAs. We will determine the expression of transgenic circRNAs, their encoded proteins, possible sequestration of other RNAs and proteins, changes in neuron morphology, tau pathology and correlate these data with spatial memory tests that take stress into account. These are the first reports and studies of human tau circular RNAs. These studies are significant, as they could provide a novel, human-specific molecular mechanism to alter MAPT gene expression, and possibly a new mechanism to promote the formation of tau aggregates. Our studies capitalize on the excellent brain bank at the University of Kentucky, headed by Co-I Dr. Nelson, and the zebrafish expertise of Co- I Dr. Blackburn.

微管相关蛋白tau（由MAPT基因编码）是微管相关性疾病的病因学中的关键组分。 阿尔茨海默病（AD）和其中tau聚集在神经元缠结中的其他tau蛋白病。 然而，MAPT基因表达的基本调控仍然不完全清楚。目前尚不清楚 是什么导致了神经元缠结的形成，但tau蛋白病的条件下显示tau蛋白的变化 mRNA亚型，通过替代前mRNA加工产生。此外，突变 改变MAPT的选择性剪接导致额颞叶痴呆，强调了 tau前mRNA加工。我们已经鉴定出了人类特异性环状RNA（circRNA）， 来自通过外显子10的反向剪接产生的MAPT基因座的tau编码mRNA。回接成形 当前体mRNA形成环时，circRNA发生，这是由灵长类特异性Alu元件辅助的， 人类突破性的初步数据证明了tau circRNA的决定性证据 是从人脑样本中提取的我们假设Alu元素有助于形成人类特异性的 MAPT circRNA，可能在RNA甲基化后可以翻译成含有 微管结合位点的多聚体。我们将在组织培养中使用（a）小基因进行分子生物学研究， 机制研究，以测试MAPT circRNA在RNA甲基化后是否被翻译成蛋白质 并测试tau circRNA与其他RNA和蛋白质的相互作用。这些数据将与 从病理学证实的正常， MCI（轻度认知障碍）和AD病例。为了（B）测试tau circRNA的生理相关性，我们 已经产生了表达人类MAPT基因组部分的斑马鱼品系，这些MAPT基因组部分形成环状RNA， 在构建体中引入FTDP-17突变体后观察到异常神经元， 只表达circRNA。我们将确定转基因circRNA的表达，其编码的 蛋白质，其他RNA和蛋白质的可能螯合，神经元形态的变化，tau蛋白 并将这些数据与考虑压力的空间记忆测试相关联。这些是 人类tau环状RNA的首次报道和研究。这些研究意义重大，因为它们可以 提供了一种新的，人类特异性的分子机制来改变MAPT基因表达，并可能 促进tau聚集体形成的新机制。我们的研究利用了 肯塔基州大学的脑库，由Co-I博士纳尔逊领导，以及Co-I的斑马鱼专业知识， 我布莱克本医生。