Mechanisms underlying circular RNA biogenesis in Alzheimer’s disease related genes

阿尔茨海默病相关基因中环状 RNA 生物发生的机制

• 批准号: 10665204
• 负责人: Paul Nils Valdmanis
• 金额: $ 22.77万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10665204
• 关键词: Affect; Alternative Splicing; Alzheimer' s Disease; Alzheimer' s Disease Pathway; Alzheimer' s disease brain; Alzheimer' s disease patient; Amyloid beta-Protein; Biogenesis; Brain; Cell Line; Cells; Code; Complement; Disease; Etiology; Evaluation; Event; Exons; Generations; Genes; Genetic Transcription; High-Throughput RNA Sequencing; Hippocampus; Human; Hypoxia; In Vitro; Individual; Knowledge; Large-Scale Sequencing; Late Onset Alzheimer Disease; Mediating; Messenger RNA; Neurodegenerative Disorders; Neurons; Oxidative Stress; Pathogenesis; Pathogenicity; Pathology; Patients; Prevalence; Process; Production; Protein Isoforms; Proteins; RNA; RNA Helicase; RNA Splicing; Regulation; Regulatory Element; Repetitive Sequence; Role; Sampling; Series; Study models; Synapses; Synaptosomes; Testing; Therapeutic; Tissues; Transcript; Translations; Untranslated RNA; Variant; abeta accumulation; brain tissue; circular RNA; design; differential expression; effective therapy; frontal lobe; glycogen synthase kinase 3 beta; glycogen synthase kinase 3 beta inhibitor; mRNA Translation; mouse model; novel; novel therapeutic intervention; physiologic stressor; presenilin-2; preservation; prevent; repository; tau Proteins; tau aggregation; tau expression; tau-1; transcriptome; transcriptome sequencing; vector

Alzheimer’s disease (AD) is a debilitating and pervasive neurodegenerative disorder with no effective treatments and is predicted to double in prevalence over the next 30 years. One of the first hallmarks of AD is loss of synapses followed by amyloid beta aggregation and tau neurofibrillary tangles. The steps leading to these aggregation events, especially in individuals with late-onset AD, are poorly understood. To better comprehend the transcriptional mechanisms associated with synapse loss, we isolated synapses in the form of synaptosomes and performed high throughput RNA sequencing. We found differentially expressed mRNAs associated with the synapse in AD patients with implications for synaptic transport and local mRNA translation. Notably, when interrogating the noncoding transcriptome, we found a widespread shift of distribution of circular RNAs (circRNAs) from cell bodies to synapses. CircRNAs are stable molecules formed from covalent linkages of conserved back-spliced exon junctions that can compete with linear counterparts. Interestingly among the top differentially expressed circRNAs were two circRNAs from GSK3β, which underwent a switch from one isoform significantly upregulated in AD to another significantly downregulated. GSK3β phosphorylation of tau is essential for its aggregation and GSK3β inhibitors have actively been pursued as translational targets for AD. Further evaluation of GSK3β and other circular RNAs in a large RNAseq repository revealed differentially expressed circRNAs in PSEN2 surrounding exons associated with hypoxia mediated alternative splicing. Therefore, key AD associated proteins have RNA counterparts at the synapse that are differentially expressed that may have critical modulatory roles. Our findings point to a novel mode of regulation at the RNA level. Through a series of in vitro studies and mouse models of tau pathology, we propose to therapeutically modulate the expression of circGSK3B and circPSEN2 isoforms to restore appropriate regulation of tau. We propose to ascertain whether regulatory features surrounding alternative GSK3β exons affect circRNA production and whether RNA helicases influence the GSK3β circRNA isoform switch that we observe. In addition, we will evaluate the relationship between PSEN2 circRNA biogenesis and the role of oxidative stress in affecting aberrant PSEN2 alternative splicing – a phenomenon we observe to be significantly enriched in sporadic AD. Collectively, we will leverage our understanding of the rules governing circRNA biogenesis and regulation to generate molecules capable of preserving appropriate expression of GSK3β and prevent tau aggregation.

阿尔茨海默氏病（AD）是一种令人衰弱和普遍的神经退行性疾病，无效 在未来30年内，治疗率将增加一倍。最早的标志之一 AD是突触的丧失，其次是淀粉样蛋白β聚集和Tau神经原纤维缠结。步骤 导致这些聚集事件，尤其是在迟发广告的个体中，对这些事件的理解很少。 为了更好地理解与突触损失相关的转录机制，我们隔离了突触 以突触体的形式进行，并进行了高吞吐量RNA测序。我们发现了差异 表达与AD患者突触相关的mRNA，对突触运输的影响和 局部mRNA翻译。值得注意的是，在询问非编码转录组时，我们发现了一个宽度 圆形RNA（CIRCRNA）分布从细胞体转移到突触。 Circrnas稳定 由构成的后部外显子连接的共价连接形成的分子，可以与 线性对应物。有趣的是，在表达不同的circrnas中，有两个来自 GSK3β，从一个同工型中进行了显着更新到另一个同工型的转换，从而显着更新 下调。 tau的GSK3β光磷酸化对于其聚集至关重要，而GSK3β抑制剂具有 积极地被追捕为AD的翻译目标。进一步评估GSK3β和其他圆形RNA 在一个大的RNASEQ存储库中显示出不同表达的circrnas周围外显子的circrnas 与缺氧介导的替代剪接有关。因此，关键AD相关蛋白具有RNA 突触的对应物以不同的表达，可能具有关键的调节作用。我们的 发现指出了一种新型的RNA水平调节方式。通过一系列体外研究和 Tau病理学的小鼠模型，我们建议热调节Crocgsk3b和 cippsen2同工型以恢复对tau的适当调节。我们建议确定是否监管 围绕替代GSK3β外显子的特征会影响CircRNA的产生以及RNA解旋酶是否会影响 影响我们观察到的GSK3βciRCRNA同工型开关。此外，我们将评估关系 在PSEN2 CIRCRNA生物发生与氧化应激在影响异常PSEN2中的作用之间 替代剪接 - 我们观察到的现象在弹性AD中显着富集。共同 我们将利用我们对控制Circrna生物发生和调节规则的理解来产生 能够保留GSK3β并防止Tau聚集的分子。