Alteration of tau splicing to identify and treat tauopathies

描述（由申请人提供）：以微管相关蛋白tau的细胞内积累为代表的神经退行性疾病，统称为tau蛋白病，在临床和病理上都具有破坏性。神经原纤维缠结形成 通过异常的过度磷酸化和tau的沉积，提示了tau介导的疾病机制，因此是开发有效疗法的主要目标。有趣的是，选择tau蛋白病存在tau亚型沉积的不平衡，表现出主要的4 R或3R tau内含物。该提议的总体假设是，更大的4 R：3R tau比率诱导tau发病机制，并且剪接改变以降低4 R：3R比率将减轻神经退行性缺陷。我们计划使用反义寡核苷酸（ASO）来操纵tau的剪接模式，以促进或预防小鼠模型中的疾病状态，随后对人类tau蛋白病中的tau亚型表达进行全面评估，以帮助指导ASO治疗策略。我们的研究结果将是必不可少的，在牵连一个更大的4 R：3R tau比率作为致病性和确定一个新的目标，用于治疗tau蛋白病。 目的1将在以升高的4 R表达为特征的FTDP-17小鼠模型中使用降低4 R：3R比率的ASO。初步研究已经显示，当在病理学发作之前开始阿索治疗时，行为缺陷和tau病理学改善。在所提出的实验中，将ASO施用于老年小鼠以证明疾病进展后tau病理学减少和功能改善。这一结果将有助于支持4 R tau蛋白病的4 R tau导向疗法。为了明确地暗示更大的4 R：3R比率为致病性，将在人tau表达小鼠模型中使用驱动4 R表达而不改变总tau的ASO（目的2）。预期增加的4 R：3R比率将诱导更大的过度磷酸化tau和生化tau病理学。随后，目标3将全面检查人类tau蛋白病中3R和4 R tau亚型表达的RNA和蛋白质组成。我们将分析tauopathies和健康对照的死后人体组织，以研究同种型特异性病理学是否由tau同种型的转录或翻译变化介导。这些信息将帮助 定义tau蛋白病的阿索疗法的性质和未来方向。在完成这些目标后，我们将确定4 R：3R tau比例对人类神经退行性变模型中年龄相关的tau病理学和认知的影响。这些研究也可能为ASO作为4 R tau蛋白病的一种有前途的新型疗法提供关键支持。

DESCRIPTION (provided by applicant): Neurodegenerative diseases typified by the intracellular accumulation of the microtubule-associated protein tau, collectively known as tauopathies, are both clinically and pathologically devastating. The neurofibrillary tangles formed by the abnormal hyperphosphorylation and deposition of tau suggests a tau- mediated mechanism of disease and, therefore, is a primary target of interest for the development of effective therapies. Interestingly, select tauopathies present with an imbalance of tau isoform deposition, exhibiting either predominant 4R or 3R tau inclusions. The overall hypothesis of this proposal is that a greater 4R:3R tau ratio induces tau pathogenesis, and splicing alterations to reduce the 4R:3R ratio will mitigate neurodegenerative deficits. We plan to use antisense oligonucleotides (ASOs) to manipulate the splicing patterns of tau to promote or prevent a diseased state in mouse models and subsequently performs a comprehensive evaluation of tau isoform expression in human tauopathy to help direct ASO-treatment strategies. Our results will be essential in implicating a greater 4R:3R tau ratio as pathogenic and identifying a novel target for the treatment of tauopathies. Aim 1 will use ASOs that decrease the 4R:3R ratio in a mouse model of FTDP-17 characterized by elevated 4R expression. Preliminary studies have shown amelioration of behavioral deficits and tau pathology when ASO treatment was initiated prior to the onset of pathology. In the proposed experiments, ASOs will be administered to aged mice to demonstrate reduced tau pathology and functional improvement following disease progression. This result will help support a 4R tau-directed therapy for 4R tauopathies. To specifically implicate a greater 4R:3R ratio as pathogenic, ASOs that drive 4R expression without changes to total tau will be used in a human tau-expressing mouse model (Aim 2). The expectation is that an increased 4R:3R ratio will induce greater hyperphosphorylated tau and biochemical tau pathology. Subsequently, Aim 3 will comprehensively examine the RNA and protein composition of 3R and 4R tau isoform expression in human tauopathies. We will analyze postmortem human tissues from tauopathies and healthy controls to investigate whether isoform-specific pathology is mediated by transcriptional or translational changes in tau isoforms. This information will help define the nature and future directions of ASO therapies for tauopathies. Upon completion of these aims, we will have determined the influence of 4R:3R tau ratio on age-related tau pathology and cognition in models of human neurodegeneration. These studies also may lend critical support for ASOs as a promising, novel therapy for 4R tauopathies.