Project 2: Tau metabolism: Quantifying tau half-life and secretion

项目 2：Tau 代谢：量化 tau 半衰期和分泌

基本信息

批准号：
10493244
负责人：
Celeste Marie Karch
金额：
$ 46.96万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-27 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10493244
关键词：
Address Alleles Antisense Oligonucleotides Binding Biochemical Brain Brain region CRISPR/Cas technology Cell Nucleus Cerebrospinal Fluid Characteristics Communities Databases Defect Disease Dominant Genes Enzymes Event Exhibits Frontotemporal Lobar Degenerations Gene Mutation Genes Genetic Genomics Goals Half-Life Haplotypes Human Impairment Induced pluripotent stem cell derived neurons Inherited Kinetics Lysosomes MAPT gene Maps Messenger RNA Metabolism Methods Modification Molecular Molecular Chaperones Molecular Profiling Molecular Structure Monitor Mutagenesis Mutation Nerve Degeneration Neuronal Dysfunction Neurons Pathogenesis Pathologic Pathway interactions Peptide Hydrolases Post-Translational Protein Processing Progressive Supranuclear Palsy Protein Isoforms RNA Splicing Regulation Resources Risk Stable Isotope Labeling Structure Tauopathies Technology Testing Therapeutic Toxic effect Variant Work brain tissue corticobasal degeneration design disorder risk extracellular induced pluripotent stem cell mRNA Precursor mutant novel novel therapeutic intervention polygenic risk score proteostasis tau Proteins tau aggregation tau-1 therapeutic target transcriptome transcriptome sequencing transcriptomics

项目摘要

ABSTRACT Tauopathies may occur by familial mechanisms in which mutations in the MAPT gene are dominantly inherited causing frontotemporal lobar degeneration (FTLD-tau) or by sporadic mechanisms in which MAPT haplotypes are associated with increased disease risk (e.g. progressive supranuclear palsy and corticobasal degeneration). MAPT mutations and risk haplotypes have been proposed to drive disease pathogenesis through proteoforms that contain 3-microtubue binding domain repeats (3R tau), 4R tau, or both. However, the contribution of specific tau forms (proteoforms) to tau toxicity and the mechanisms by which tauopathies occur remains poorly understood. We hypothesize that MAPT mutations drive tau aggregation and neuronal dysfunction by altering tau metabolism and overall proteostasis at one of several potential nodes of regulation. In preliminary studies, we have shown that induced pluripotent stem cell derived-neurons expressing MAPT mutations exhibit changes in tau turnover compared to isogenic, control neurons, and we observed differences in the turnover of specific tau proteoforms in mutant neurons. Neurons expressing MAPT mutations exhibit enlarged lysosomal structures and secondary elevation of lysosomal enzymes, markers of lysosomes that are unable to properly degrade their contents. Correction of the mutant allele was sufficient to restore these lysosomal defects. This suggests that altered tau kinetics may be due to defects in the endolysosomal pathway. Thus, a unifying feature by which MAPT mutations drive tauopathy is through disrupted proteostasis. The objective of this study is to extend our preliminary findings to define the nodes and mechanisms by which tau proteoforms disrupt proteostasis in tauopathies. We hypothesize that specific tau proteoforms are sufficient to destabilize proteostasis, alter tau half-life and secretion, and to result in the accumulation of tau in vulnerable brain regions. To test this hypothesis, we will determine the extent to which MAPT mutations and genetic modifiers disrupt tau kinetics and how impaired proteostasis impacts tau secretion. We will also generate a systematic genetic interaction map to elucidate connections between MAPT mutations, alterations in the tau metabolism pathway, and associated therapeutic targets. Together, this study will reveal novel mechanisms underlying tauopathy that are driven by specific tau proteoforms and whether therapeutics designed to block specific tau proteoforms impact pathologic events. Project 2 will work synergistically with the Administration Core (Core A), Macromolecular Structure (Core B), Genomics and Transcriptomics Cores (Core C) and Project 1 to address the overall hypothesis that proper tau metabolism requires the precise, coordinated action of molecular chaperones, co-chaperones and lysosomal proteases. Tau Metabolism and Variant database (TMVdb) and Tau Polygenic Risk Score (TPRS) generated from this project will be an invaluable resource for the broader scientific community.

抽象的家族机制可能会发生TAUOPATHIES，其中MAPT基因中的突变主要是遗传引起额颞叶变性（FTLD-TAU）或通过零星机制单倍型与疾病风险增加有关（例如，进行性核上麻痹和皮质虫退化）。已经提出了MAPT突变和风险单倍型来驱动疾病发病机理通过包含3-微管结合结构域重复序列（3R tau），4R tau或两者的蛋白质类型。但是，特定的tau形式（蛋白质成型）对tau毒性的贡献以及发生auopathies的机制仍然很了解。我们假设MAPT突变驱动Tau聚集和神经元通过在调节的几个潜在节点之一中改变tau代谢和总体蛋白质的功能障碍。在初步研究中，我们已经表明，诱导的表达MAPT的多能干细胞衍生的神经元与等源性神经元相比在突变神经元中特定的tau蛋白基础的周转中。表达MAPT突变的神经元表现出溶酶体结构的肿大和溶酶体酶的继发升高，溶酶体的标志物无法正确降低其内容。校正突变等位基因足以恢复这些溶酶体缺陷。这表明改变的tau动力学可能是由于内溶血中的缺陷路径。因此，统一的特征通过启动tauopathy的统一特征是通过破坏的蛋白质症。这项研究的目的是扩展我们的初步发现，以定义节点和机制 tau蛋白质成型化合物破坏了tauopathies中的蛋白质抑制作用。我们假设特定的tau蛋白质成型足够破坏蛋白质的稳定，改变tau的半衰期和分泌，并导致tau的积累脆弱的大脑区域。为了检验这一假设，我们将确定mapt突变和遗传修饰剂破坏了tau动力学以及蛋白质的受损如何影响tau的分泌。我们也会生成系统的遗传相互作用图，以阐明MAPT突变之间的连接在TAU代谢途径和相关的治疗靶标中。这项研究将共同揭示新颖由特异性tau蛋白质型驱动的tauopathy的机制以及治疗剂是否驱动旨在阻止特定的TAU蛋白质成型影响病理事件。项目2将与给药核心（核心A），大分子结构（核心B），基因组学和转录组核（核心 c）和项目1解决总体假设，即适当的tau代谢需要确切的假设，分子伴侣，共伴侣和溶酶体蛋白酶的协调作用。 tau代谢和该项目生成的变体数据库（TMVDB）和TAU多基因风险评分（TPRS）将是一个对更广泛的科学界的宝贵资源。