Defining molecular contributions of LINE-1 retrotransposons to AD / ADRD

定义 LINE-1 逆转录转座子对 AD / ADRD 的分子贡献

• 批准号: 10701914
• 负责人: John Paul LaCava
• 金额: $ 74.62万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-15 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10701914
• 关键词: Age; Aging; Alzheimer' s Disease; Alzheimer' s disease pathology; Alzheimer' s disease patient; Alzheimer' s disease related dementia; Astrocytes; Autopsy; Biological; Biological Assay; Biological Models; Brain; Cause of Death; Cell Aging; Cell Culture Techniques; Cell Nucleus; Cells; Cerebrospinal Fluid; Chromosomal Instability; Chronic stress; Clinical; Cytoplasm; Cytoplasmic Granules; Cytosol; DNA; DNA Damage; DNA replication fork; Data; Detection; Deterioration; Disease; Double-Stranded RNA; Elderly; Endogenous Retroviruses; Enzymes; Exhibits; Fibroblasts; Freezing; Frontotemporal Dementia; Functional disorder; Genes; Genome; Genomics; Growth Factor; Homeostasis; Human; Hybrids; Immunity; Immunoprecipitation; Impaired cognition; In Vitro; Individual; Induced pluripotent stem cell derived neurons; Inflammation; Inflammatory; Integration Host Factors; Interferons; Knowledge; Label; Lewy Body Dementia; Life; Life Cycle Stages; Location; Mass Spectrum Analysis; Modeling; Molecular; Molecular Genetics; Motivation; Mus; Neurodegenerative Disorders; Neurons; Normal Cell; Nucleic Acids; Onset of illness; Parasites; Pathologic; Pathology; Pathway interactions; Patients; Phase; Phenotype; Physiological; Play; Production; Property; Proteins; RNA; RNA Interference; RNA-Directed DNA Polymerase; RNA-Protein Interaction; Reactive Oxygen Species; Research; Retrotransposon; Ribonucleoproteins; Role; Sampling; Selfish DNA; Shotguns; Source; System; Techniques; Tissues; Titrations; age related; age related neurodegeneration; aged; brain tissue; candidate selection; cytokine; derepression; endonuclease; fly; genome integrity; immunogenic; improved; induced pluripotent stem cell; normal aging; overexpression; pathological aging; prevent; protein expression; senescence; tau Proteins

Project Summary: Alzheimer's Disease (AD) and AD-related dementias (ADRDs; e.g. Frontotemporal Dementia, Lewy Body Dementia, etc.) are crippling neurodegenerative disorders. The onset of these diseases is strongly correlated with aging. Cures for AD and ADRDs remain elusive; Alzheimer's has become the 6th most frequent cause of death in the USA. An emerging candidate contributor to Alzheimer's and ADRD is the L1 retrotransposon, which becomes dysregulated during aging and correlates with Alzheimer's / ADRD onset. One hypothetical mechanism by which L1 may contribute to Alzheimer's / ADRD is through its exacerbation of cellular senescence. Senescence is a phenomenon by which normal cells stop dividing; these cells accumulate with advancing age and are found at the locations of dysfunction in age-related diseases. In mice, senescent cells have been shown to shorten life and actively drive age-related neurodegeneration; preventing senescent cell accumulation decreases tau-dependent degeneration and cognitive decline. AD patients exhibit increased indicators of cellular senescence. It is increasingly clear that senescent cells are not inert, but instead drive tissue deterioration via the senescence-associated secretory phenotype - secreting a variety of growth factors and pro- inflammatory cytokines. L1 retrotransposons have recently been shown to drive progression of the senescence- associated secretory phenotype, and thus, L1 is an important agent of cellular senescence. L1 activation is also associated with AD-related Tau pathologies. The L1 encoded ORF2p enzyme (endonuclease and reverse transcriptase) is often flagged as a source of pathological cellular insults, e.g. via new, mutagenic L1 insertions and contributions to chromosomal instability. However, the effects of L1 expression extend beyond DNA damage. Numerous mechanisms may be at play, including the titration of normally homeostatic host factors away from their physiologic functions and into L1 ribonucleoprotein granules, as well as the production of immunity-and-inflammation-triggering cytoplasmic L1 DNA:RNA hybrids; indeed, the latter is now understood to be a key component of L1’s role in cellular senescence. Moreover, L1 also mobilizes Alu and other non- autonomous retrotransposons. Objectives: In Aim 1, we will use targeted mass spectrometry to profile L1 ORF1 protein expression in the cerebrospinal fluid (CSF) and post-mortem brain tissues of patients exhibiting AD/ADRD and cognitive decline, as well as in senescent cells and neuronal iPSCs; in Aim 2 (in vitro cell culture) and Aim 3 (clinical samples) we will profile L1-associated protein-protein and protein-RNA interactions in the same biological samples as Aim 1; and in Aim 4 we will take a candidate-based approach using molecular genetics to dissect the mechanisms of action of L1 in senescent cells.

项目摘要：阿尔茨海默病 (AD) 和 AD 相关痴呆 (ADRD；例如额颞叶痴呆 痴呆症、路易体痴呆等）是严重的神经退行性疾病。这些疾病的发作 与衰老密切相关。 AD 和 ADRD 的治疗方法仍然难以捉摸；阿尔茨海默病已成为第六大常见病 美国常见的死亡原因。 L1 是导致阿尔茨海默病和 ADRD 的一个新兴候选因素 逆转录转座子，在衰老过程中失调，并与阿尔茨海默病/ADRD 发病相关。一 L1 可能导致阿尔茨海默病/ ADRD 的假设机制是通过其加剧细胞 衰老。衰老是正常细胞停止分裂的一种现象。这些细胞积累 随着年龄的增长，并在与年龄相关的疾病的功能障碍部位发现。在小鼠中，衰老细胞 已被证明可以缩短寿命并积极驱动与年龄相关的神经退行性疾病；预防细胞衰老 积累可减少 tau 依赖性变性和认知能力下降。 AD患者表现出增加 细胞衰老的指标。越来越清楚的是，衰老细胞不是惰性的，而是驱动组织的 通过衰老相关的分泌表型而恶化 - 分泌多种生长因子和亲 炎症细胞因子。 L1 逆转录转座子最近被证明可以驱动衰老的进展 相关的分泌表型，因此，L1 是细胞衰老的重要因素。 L1 激活也是 与 AD 相关的 Tau 病理相关。 L1 编码 ORF2p 酶（核酸内切酶和反向酶） 转录酶）通常被标记为病理性细胞损伤的来源，例如通过新的诱变 L1 插入 以及对染色体不稳定的贡献。然而，L1 表达的影响超出了 DNA 范围 损害。许多机制可能在发挥作用，包括正常稳态宿主因子的滴定 远离其生理功能并进入 L1 核糖核蛋白颗粒，以及产生 免疫和炎症触发细胞质 L1 DNA:RNA 杂交体；事实上，后者现在被理解为 是 L1 在细胞衰老中发挥作用的关键组成部分。此外，L1还动员Alu和其他非 自主逆转录转座子。 目标：在目标 1 中，我们将使用靶向质谱法来分析 L1 ORF1 蛋白在 表现出 AD/ADRD 和认知能力下降的患者的脑脊液 (CSF) 和死后脑组织， 以及衰老细胞和神经元 iPSC；在目标 2（体外细胞培养）和目标 3（临床样本）中，我们 将在与目标 1 相同的生物样品中分析 L1 相关蛋白质-蛋白质和蛋白质-RNA 相互作用； 在目标 4 中，我们将采用基于候选的方法，利用分子遗传学来剖析 L1 在衰老细胞中的作用。