Systematic and mechanistic assessment of the roles of circRNAs in Alzheimer's Disease

项目总结 RNA新陈代谢的控制正在成为大脑调节的主要中枢。因此，它不是 令人惊讶的是，在RNA代谢紊乱和许多神经疾病之间有很强的联系 和神经退行性疾病。这些疾病包括阿尔茨海默病(AD)，其中Tau蛋白和A？42 已经证明片段直接或间接地与RNA结合蛋白和RNA相互作用和/或调节 新陈代谢一般。环状RNA(CircRNAs)是一种高度丰富的RNA，由环化作用产生 特定的外显子。有趣的是，CircRNA在神经组织中以年龄相关的方式积聚，这表明 它们与年龄相关的动态平衡和/或发病机制有关。事实上，特定的CircRNA在体内积累 帕金森氏症和阿尔茨海默病患者的大脑。然而，这些CircRNA是如何 参与这些和其他神经退行性疾病的发病机制在很大程度上是未知的。 我们最近开发了下调或上调果蝇CircRNA的系统。使用这些工具，我们 在体内展示了这些分子的功能。我们生成了一个资源来拆卸(KD) 110更丰富的CircRNAs，并发现特定CircRNAs的Kd导致不同的大脑相关 表型。有趣的是，我们确定了35个当被击倒时会改变寿命的CircRNA。进一步的数据 显示一些CircRNA的表达对衰老的果蝇是有毒的，与衰老有关，并可能 神经退行性变。此外，我们还发现一些CircRNA的Kd导致特定的行为和运动 缺陷，其中许多是年龄相关的。此外，我们还观察到了CircRNA水平的变化 阿尔茨海默病或其他神经生殖疾病的果蝇模型。在这里，我们的目标是揭示这些功能和 CircRNAs在AD过程中的作用机制。为此，我们将使用果蝇AD模型并执行 基因组筛选以确定单个CircRNA的调节是否可以改变进展和结果 这种疾病的危害。此外，我们还将测试CircRNAs改变AD的潜在机制，包括 聚集成核、改变线粒体功能、自噬、细胞凋亡和/或炎症。 总之，本提案将揭示CircRNAs在AD期间的新作用。因为我们将执行 在具有高水平和功能水平的CircRNAs(飞行CNS)的系统中进行的实验目前的结果将 是有意义的，并可能在以后扩展到哺乳动物模型。我们意识到AD的局限性 苍蝇模型，但这是唯一一个与大量CircRNA充分相互作用的系统 可以被评估。此外，正如我们已经发现的，一些环状RNA改变衰老， 成就率很高。这将是这一新的重要研究领域的开创性工作，我们正在 相信我们的发现将为研究CircRNAs在AD中的作用开辟一条新的途径。我们的项目 以令人振奋的初步结果和我们团队独特且不断发展的专业知识为基础。

PROJECT SUMMARY Control of RNA metabolism is emerging as a major hub for regulation in the brain. Therefore, it is not surprising that there is a strong link between perturbation of RNA metabolism and a number of neurological and neurodegenerative diseases. These include Alzheimer’s Disease (AD) in which Tau protein and Aß42 fragments have been shown to interact and/or modulate directly or indirectly RNA binding proteins and RNA metabolism in general. Circular RNAs (circRNAs) are highly abundant RNAs produced by circularization of specific exons. Interestingly, circRNAs accumulate in an age-dependent manner in neural tissues suggesting their relevance to age-related homeostasis and/or pathogenesis. Indeed, specific circRNAs accumulate in the brains of individuals with Parkinson’s and Alzheimer’s diseases. However, how these circRNAs are involved in the pathogenesis of those and other neurodegenerative diseases is largely unknown. We recently developed systems to down- or up-regulate circRNAs in Drosophila. Using these tools, we demonstrated the functionality of these molecules in vivo. We generated a resource to knock down (KD) the 110 more abundant circRNAs and found that KD of particular circRNAs results in different brain-related phenotypes. Interestingly, we identified 35 circRNAs that when knocked down alter lifespan. Further data shows that expression of some circRNAs is toxic for the aging fly, with links to aging and potentially neurodegeneration. In addition, we found that KD of some circRNAs lead to specific behavioral and motor defects, many of which are age-dependent. In addition, we observed changes in the levels of circRNAs in Drosophila models of AD or other neurogenerative diseases. Here we aim to uncover the functions and mechanisms of action of circRNAs during AD. To do so, we will use Drosophila AD models and perform a genomic screening to determine if modulation of individual circRNAs can alter the progression and outcome of the disease. Moreover, we will also test potential mechanisms by which circRNAs could alter AD including nucleation of aggregates, altering mitochondrial function, autophagy, apoptosis, and/or inflammation. In sum, the present proposal will reveal new roles of circRNAs during AD. As we will perform the experiments in a system that has high and functional levels of circRNAs (the fly CNS) the present results will be meaningful and could be later extended to mammalian models. We are aware of the limitations of the AD fly models but this is the only system in which the full extent of interaction with a large number of circRNAs can be assessed. Moreover, as we have already found that some circRNAs alter aging, the chances of success are high. This will be a pioneering work in this new and important area of research and we are confident that our findings will open a new pathway for studying the roles of circRNAs in AD. Our project builds on exciting preliminary results and the unique and constantly evolving expertise of our group.