RNA decay in amyotrophic lateral sclerosis and frontotemporal lobar degeneration

摘要 RNA稳态的维持涉及RNA合成和周转之间的动态平衡。 这种平衡对于转录活跃的细胞如神经元至关重要， 成分可导致RNA错误加工和细胞死亡。我们的初步证据表明， 在RNA中，衰变代表了一种基本且迄今未被认识到的驱动神经元功能障碍的机制 肌萎缩侧索硬化症（ALS）和额颞叶神经退行性疾病 变性（FTLD）。我们的目标是阐明RNA衰变在发病机制中的作用 的ALS和FTLD，并调查一个独特的和有前途的治疗策略影响RNA衰变。基于 根据初步研究的结果，我们提出在ALS和最常见的FTLD亚型中， 其特征在于RNA结合蛋白TDP 43的神经元沉积，RNA稳态被一种 TDP 43和RNA解旋酶UPF 1之间的不适当相互作用，最终导致 神经变性我们将通过i）确定TDP 43-UPF 1相互作用对 ii）评估缺乏RNA衰变是否足以和/或必需用于神经元存活和RNA衰变， iii）评估UPF 1表达是否改善神经元的病理性TDP 43沉积， 通过恢复TDP 43和RNA稳态来存活。我们将通过以下方式实现这些目标： 来源于ALS和FTLD患者的人类神经元的纵向单细胞显微镜，CRISPR/Cas9 基因组编辑和脉冲标记RNA的高通量测序。所提议的多方面办法 这里有望揭示控制健康细胞和受影响细胞中神经元存活的关键途径 ALS和FTLD，并将使我们更接近实现我们的长期目标，即开发一种有效的 治疗这些和其他无情的进展性神经退行性疾病。

Abstract Maintenance of RNA homeostasis involves a dynamic balance between RNA synthesis and turnover. This balance is critical for transcriptionally active cells such as neurons, as disruptions to any individual component can lead to RNA misprocessing and cell death. Our preliminary evidence indicates that deficiencies in RNA decay represent a fundamental and heretofore unrecognized mechanism driving neuronal dysfunction and death in the neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Our goals with this proposal are to elucidate the role of RNA decay in the pathogenesis of ALS and FTLD, and investigate a unique and promising therapeutic strategy affecting RNA decay. Based upon the results of initial studies, we propose that in ALS and the most common subtype of FTLD, characterized by neuronal deposits of the RNA binding protein TDP43, RNA homeostasis is disrupted by an inappropriate interaction between TDP43 and the RNA helicase UPF1, ultimately resulting in neurodegeneration. We will test this model by i) determining the impact of the TDP43-UPF1 interaction on neuronal survival and RNA decay, ii) evaluating if deficient RNA decay is sufficient and/or necessary for pathologic TDP43 deposition in neurons, and iii) assessing whether UPF1 expression improves neuronal survival by restoring TDP43 and RNA homeostasis. We will pursue these aims using a combination of longitudinal single-cell microscopy of human neurons derived from ALS and FTLD patients, CRISPR/Cas9 genome editing and high-throughput sequencing of pulse-labeled RNA. The multifaceted approach proposed here promises to uncover key pathways controlling neuronal survival in healthy cells and in those affected by ALS and FTLD, and will bring us one step closer to achieving our long-term goal of developing an effective treatment for these and other relentlessly progressive neurodegenerative disorders.