mRNA Targets for TDP-43 and FUS/TLS: Identifying Key RNA-Processing Errors in ALS

描述（由申请人提供）：肌萎缩性侧索硬化症（ALS）是一种成人发病的神经退行性疾病，其上部和下部运动神经元过早丧失导致致命的瘫痪，典型病程为1至5年。从2006年发现TDP-43是ALS和额颞叶痴呆（FTLD）患者受影响神经元中泛素化包涵体的主要蛋白质成分开始，人们普遍认为这是我们对神经退行性疾病理解的范式转变突破。事实上，现在已经确定TDP-43，一种通常主要定位于细胞核的rna结合蛋白，在多种不同的神经退行性疾病中形成细胞质聚集体，改变其亚细胞定位，包括ALS， FTLD，阿尔茨海默病和帕金森病。此外，不仅在TDP-43中发现了引起ALS的突变，最近在另一种rna结合蛋白FUS/TLS中也发现了引起ALS的突变，证实了这些蛋白在ALS发病机制中的主要作用。此外，这些发现巩固了rna加工改变对神经变性机制的关键贡献的信息。我计划定义一组与疾病相关的TDP-43和/或FUS/ tls依赖性rna加工改变。我建议利用现有的转基因小鼠系以及新开发的方法，包括高通量测序和诱导多能干细胞，以确定TDP-43和FUS/TLS在小鼠正常中枢神经系统中调节RNA代谢的作用，2)鉴定转基因小鼠中TDP-43和FUS/TLS携带致病突变的表达引起的RNA加工改变，3)测试小鼠中发现的RNA加工变化。4)确定观察到的疾病相关rna加工改变的机制，并在细胞培养和小鼠模型中测试阻断化合物对定义机制的功效。

DESCRIPTION (provided by applicant): Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disorder in which premature loss of upper and lower motor neurons leads to fatal paralysis with a typical disease course of one to five years. Starting from 2006 with the identification of TDP-43 as the major protein component of the ubiquitinated inclusions occurring in affected neurons of ALS and Frontotemporal Lobar Dementia (FTLD) patients, there has been what is widely recognized to be a paradigm-shifting breakthrough in our understanding of neurodegeneration. Indeed, it has now been established that TDP-43, an RNA-binding protein that is normally localized mainly in the nucleus, forms cytoplasmic aggregates, which alter its subcellular localization in a variety of different neurodegenerative conditions, including ALS, FTLD, Alzheimer's and Parkinson's disease. In addition, identification of ALS-causing mutations not only in TDP-43, but more recently, also in another RNA-binding protein, namely FUS/TLS, confirmed the primary role of these proteins in the pathogenesis of ALS. Furthermore, these discoveries solidified the message of a key contribution of RNA-processing alterations to mechanisms of neurodegeneration. I plan to define a set of disease-relevant TDP-43- and/or FUS/TLS-dependent RNA-processing alterations. I propose to utilize existing transgenic mouse lines along with newly developed methodologies including high-throughput sequencing and induced pluripotent stem (iPS) cells to 1) determine the role of TDP-43 and FUS/TLS in the regulation of RNA metabolism in the normal central nervous system in mice, 2) identify RNA-processing alterations caused by expression of TDP-43 and FUS/TLS carrying disease-causing mutations in transgenic mice, 3) test the RNA-processing changes found in mice, in human motor neurons produced from iPS cells, and 4) identify the mechanisms underlying the observed disease-related RNA-processing alterations and test the efficacy of blocking compounds on the defined mechanisms in cell culture and mouse models. PUBLIC HEALTH RELEVANCE: Statement of Relevance to Public Health Amyotrophic Lateral Sclerosis, also called 'Lou Gehrig's disease', is a devastating disease causing muscle weakness progressing to paralysis and death within 1-5 years from diagnosis. There are no effective treatments for this disease that affects 1 in approximately 55,000 people in USA every year. The proposed work will contribute to our understanding of the chain of events leading to this disease and to uncover targets for therapeutic interventions.