Temporal Changes in MicroRNA Function During Tau tangle Accumulation

Tau 缠结积累过程中 MicroRNA 功能的时间变化

• 批准号: 7990606
• 负责人: CATHERINE L CLELLAND
• 金额: $ 20.53万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7990606
• 关键词: Age; Algorithms; Alzheimer' s Disease; Appearance; Biological Process; Brain; Cell Line; Cells; Cessation of life; Cognition; Cognitive deficits; Data; Data Set; Dendritic Spines; Development; Diagnosis; Disease; Engineering; Event; Frontotemporal Dementia; Funding; Genes; Human; Human Development; Impaired cognition; Lead; Learning; Literature; Measures; Memory; Memory Loss; Messenger RNA; MicroRNAs; Mission; Modeling; Mus; Nerve Degeneration; Neurofibrillary Tangles; Neuronal Dysfunction; Neurons; Oligonucleotides; Pathogenesis; Pathway Analysis; Patients; Pharmaceutical Preparations; Phenotype; Pilot Projects; Post-Transcriptional Regulation; Process; RNA; Reporting; Role; Sampling; Screening procedure; Sequence Analysis; Severity of illness; Site; Small RNA; Tauopathies; Temporal Lobe; Testing; Time; Tissues; Transfection; Transgenes; Transgenic Organisms; United States National Institutes of Health; abstracting; aged; base; clinically relevant; cognitive function; design; human disease; laser capture microdissection; mRNA Expression; neurofibrillary tangle formation; neuron loss; neuropathology; prevent; public health relevance; synaptogenesis; tau Proteins; tau aggregation; tau mutation; transgene expression

DESCRIPTION (provided by applicant): The neurodegenerative tauopathies Alzheimer's disease (AD) and Frontotemporal dementia (FTD), are characterized by the intracellular build-up of tau-containing neurofibrillary tangles (NFT), and progressive cognitive dysfunction and neuron death. Studies of the tau/tta-4510 mouse inducible tauopathy model, which closely mimics features of the human diseases, have shown that early accumulation of intermediate-tau species, prior to the formation of NFTs, promote the events leading to neuronal dysfunction and memory loss. miRNAs are a widespread class of small RNAs involved in post-transcriptional regulation, and data from recent studies have illustrated a specific regulatory role for some miRNAs during the neuronal processes involved in learning and memory. This proposed study is designed to test the hypothesis that tau-induced early dysregulation of miRNAs in the tau/tta-4510 model results in the cognitive deficits observed in these mice. The rationale behind this proposed study is based on our exciting pilot data showing multiple miRNAs, including miR-138 (that regulates synapse formation) are dysregulated in tau/tta mice engineered to express the mutant tau transgene and that manifest with cognitive deficits, when compared to age-matched control mice. In addition, many of the dysregulated miRNAs found in the initial pilot study are also abnormally expressed in the human AD brain and are significantly correlated with tangle load. To test our hypothesis, Under Aim 1 we propose to a) Measure miRNA levels in the aged murine tauopathy model via microarrays, utilizing our ability to temporally suppress transgene expression in the model to identify those miRNAs involved in cognition and neurodegeneration rather than those which correlate with NFT accumulation, and b) Compare to datasets of differentially expressed miRNAs in human FTD brains, to c) Identify miRNAs that are concordant between the species and have clinical relevance. Under Aim 2, the miRNAs defined under Aim 1 will be measured temporally during the period that early tau aggregated species begin to accumulate in the murine brain, plus during the onset of cognitive decline (1 month, 2.5 months and 4 months), but prior to extensive neuron loss and tangle formation. We will then use LCM to confirm that temporally dysregulated miRNAs are similarly altered in pre-tangle neurons (PHF1 positive), when compared to controls (PHF1negative). Under Aim 3 we will also identify the functional mRNA targets of the temporally dysregulated miRNAs, using an integrated experimental and computational approach. mRNAs found to be dysregulated in a neuronal cell line, following transfection of Pre-miR or anti-miR oligonucleotides, and also predicted as targets via SEED sequence analysis and assigned functional relevance, will then be validated in the murine tau/tta cortical PHF1 positive and negative neurons as miRNA- regulated targets. PUBLIC HEALTH RELEVANCE: The successful completion of this exploratory study will lead to the identification of clinically relevant miRNAs that are dysregulated during the development of human tauopathy-associated neuropathology and contribute to the cognitive decline seen in human tauopathies such as FTD and AD. We will also identify the mRNA targets of these dysregulated miRNAs. Elucidating the potential role of miRNAs in tauopathy may ultimately allow for the development of medications that can delay, for example, the onset of FTD and AD. Similarly, preventing the diseases and/or their progression, may become a possibility following the successful identification of new targets to prevent miRNA dysregulation and the associated cognitive deficits, and is of exceptional relevance to the mission of the NIH.

描述（由申请人提供）：神经退行性tau蛋白病阿尔茨海默病（AD）和额颞叶痴呆（FTD）的特征在于含tau蛋白的神经元缠结（NFT）的细胞内积聚，以及进行性认知功能障碍和神经元死亡。tau/tta-4510小鼠诱导型tau蛋白病模型（其密切模拟人类疾病的特征）的研究已经表明，在NFT形成之前，中间体-tau种类的早期积累促进导致神经元功能障碍和记忆丧失的事件。miRNAs是一类广泛存在的参与转录后调控的小分子RNA，最近的研究数据表明，一些miRNAs在参与学习和记忆的神经元过程中具有特异性的调控作用。这项拟议的研究旨在检验tau/tta-4510模型中tau诱导的miRNA早期失调导致在这些小鼠中观察到的认知缺陷的假设。这项拟议研究背后的基本原理是基于我们令人兴奋的试点数据，这些数据显示，与年龄匹配的对照小鼠相比，多种miRNA，包括miR-138（调节突触形成）在设计表达突变tau转基因的tau/tta小鼠中失调，并表现出认知缺陷。此外，在最初的初步研究中发现的许多失调的miRNA也在人类AD大脑中异常表达，并且与缠结负荷显著相关。为了验证我们的假设，在目标1下，我们提出a）通过微阵列测量老年鼠tau蛋白病模型中的miRNA水平，利用我们暂时抑制模型中转基因表达的能力来鉴定参与认知和神经变性的那些miRNA，而不是与NFT积累相关的那些miRNA，和B）与人FTD脑中差异表达的miRNA的数据集相比，c）鉴定物种之间一致的并且具有临床相关性的miRNA。在目标2下，在目标1下定义的miRNA将在早期tau聚集种类开始在鼠脑中积累的时期期间，加上在认知下降的开始期间（1个月、2.5个月和4个月），但在广泛的神经元损失和缠结形成之前进行时间测量。然后，我们将使用LCM来证实，与对照组（PHF 1阴性）相比，在缠结前神经元（PHF 1阳性）中，时间失调的miRNA发生了类似的改变。在目标3下，我们还将使用综合实验和计算方法鉴定时间失调的miRNA的功能mRNA靶标。在转染Pre-miR或抗-miR寡核苷酸后，发现在神经元细胞系中失调的mRNA，并且还通过SEED序列分析预测为靶标并指定功能相关性，然后将在鼠tau/tta皮质PHF 1阳性和阴性神经元中验证为miRNA调节的靶标。 公共卫生相关性：本探索性研究的成功完成将导致鉴定出在人tau蛋白病相关神经病理学发展过程中失调并导致在人tau蛋白病（如FTD和AD）中观察到的认知下降的临床相关miRNA。我们还将鉴定这些失调的miRNAs的mRNA靶点。阐明miRNA在tau蛋白病中的潜在作用可能最终允许开发可以延迟例如FTD和AD发作的药物。类似地，预防疾病和/或其进展可能在成功鉴定新靶点以预防miRNA失调和相关的认知缺陷之后成为可能，并且与NIH的使命异常相关。