Identification of Presinilin downstream targets in neuronal survival

神经元存活中 Presinilin 下游靶点的鉴定

基本信息

批准号：
9325265
负责人：
NORBERT PERRIMON
金额：
$ 67.82万
依托单位：
BRIGHAM AND WOMEN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-03-15 至 2022-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9325265
关键词：
APLP1 gene APLP2 gene Active Sites Adult Aging Alzheimer&apos s Disease Amyloid beta-Protein Precursor Apoptosis Behavioral Bioinformatics Biological Assay Brain Caenorhabditis elegans Cerebral cortex Code Collaborations Data Defect Dementia Disease Drosophila genus Drosophila inturned protein Employee Strikes Exhibits Family member Functional disorder G-substrate Genes Genetic Genetic Screening Genotype Gliosis Impairment Individual Inflammatory Response Inherited Integral Membrane Protein Knock-in Knock-in Mouse Knock-out Knockout Mice Laboratories Learning Link Longevity Mammalian Cell Mediating Mediator of activation protein Memory Missense Mutation Modeling Molecular Mus Mutation Nerve Degeneration Neurites Neurodegenerative Disorders Neurons Notch Signaling Pathway Orthologous Gene Pathogenesis Pathway interactions Perinatal Phenotype Physiological Presenile Alzheimer Dementia Protein Family RNA Interference RNA interference screen Regulation Role Signal Transduction Testing Transgenic Mice Validation age related base conditional mutant familial Alzheimer disease fly gamma secretase genome-wide genome-wide analysis in vivo knock-down loss of function mouse model mutant neurogenesis neuronal survival new therapeutic target nicastrin protein notch protein novel null mutation presenilin presenilin-1 prevent receptor screening small hairpin RNA synaptic function tau Proteins whole genome

项目摘要

Alzheimer's disease (AD) is the most common cause of dementia and neurodegeneration, but no disease-modifying therapy is available. The Presenilin (PSEN) genes harbor ~90% of the mutations linked to familial AD (FAD), highlighting its importance in AD pathogenesis. These FAD PSEN mutations are mostly missense mutations (>260) scattered throughout the coding sequence, consistent with a loss-of-function mechanism. Presenilin (PS) is essential for learning and memory, synaptic function and neuronal survival during aging, and contains the active site of γ-secretase. Presenilin conditional double knockout (PS cDKO) mice lacking PS expression in the adult cerebral cortex recapitulate key features of AD, including profound age-dependent neurodegeneration, gliosis, inflammatory responses and tau hyperphosphorylation. Studies in C. elegans, Drosophila and cultured mammalian cells showed that FAD mutations impair PS function and γ- secretase activity. We recently developed two knockin (KI) mice expressing FAD PSEN1 mutations, L435F and C410Y, and homozygous KI/KI mice show striking resemblance to PS1-/- mice, including perinatal lethality, abolished γ-secretase activity, impaired neurogenesis and decreased Notch signaling, demonstrating that FAD mutations resemble the PS1-null mutation in vivo. The molecular mechanism by which PS maintains neuronal function and survival is unclear. Identification of PS downstream targets and γ-secretase substrates will not only elucidate the molecular mechanism underlying PS function and dysfunction, but may provide novel therapeutic targets as well. In the current application, we will take advantage of the power of fly genetics to identify PS downstream targets and γ-secretase substrates involved in the regulation of neuronal survival and longevity. Specifically, we will generate conditional mutant flies, in which Presenilin ortholog (Psn) or Nicastrin ortholog (Nct) are inducibly knocked down by shRNA in adult neurons, and then use these mutant flies to screen for γ-secretase substrates involved in mediating neuronal survival and lifespan followed by validation in fly and mouse models (Aim 1). We will also perform whole-genome RNAi-based genetic screens in Drosophila primary cultured neurons to identify RNAi lines that can correct PS dysfunction, and then validate the identified genes in fly models for their abilities to restore PS dysfunction (Aim 2). Completion of the proposed studies will elucidate the molecular pathways by which PS protects neuronal survival during aging and may provide novel targets that can be further explored for disease-modifying therapy of AD.

阿尔茨海默氏病（AD）是痴呆和神经退行性的最常见原因，但没有可以使用疾病改良疗法。寄生虫（PSEN）基因含有约90％的突变家族性AD（FAD），强调了其在AD发病机理中的重要性。这些时尚的psen突变主要是散布在整个编码顺序的错义突变（> 260），与功能丧失一致机制。 Presenilin（PS）对于学习和记忆，突触功能和神经元生存至关重要在衰老过程中，并包含γ-分泌酶的活性位点。 Presenilin有条件双重敲除（PS CDKO）在成年大脑皮层中缺乏PS表达的小鼠概括了AD的关键特征，包括深刻年龄依赖性神经变性，神经胶质病，炎症反应和TAU高磷酸化。研究秀丽隐杆线虫，果蝇和培养的哺乳动物细胞表明，时尚突变会损害PS功能和γ- 分泌酶活性。我们最近开发了两只表达FAD PSEN1突变，L435F和 C410Y和纯合ki/ki小鼠与PS1 - / - 小鼠相似，包括围产期致死性，废除γ-分泌酶活性，神经发生受损并改善了缺口信号，表明了时尚突变类似于体内的PS1无效突变。 PS维持神经元的分子机制功能和生存尚不清楚。鉴定PS下游靶标和γ-分泌酶底物将不仅阐明PS功能和功能障碍的分子机制，而且可以提供新型热目标。在当前的应用中，我们将利用苍蝇的力量遗传学以鉴定参与神经元调节的PS下游靶标和γ-分泌酶底物生存和寿命。具体而言，我们将产生有条件的突变蝇，其中presenilin presenilin（PSN）或尼卡斯特林直系同源物（NCT）在成年神经元中被shRNA诱导，然后使用这些突变体捕获γ-分泌酶底物的果蝇，参与介导神经元存活和寿命，然后在苍蝇和鼠标模型中验证（AIM 1）。我们还将执行全基因组RNAi的遗传筛选在果蝇中培养的神经元中，可以识别可以纠正PS功能障碍的RNAi系，然后验证在飞行模型中确定的基因恢复了PS功能障碍的能力（AIM 2）。完成拟议的研究将阐明PS在衰老过程中保护神经元存活的分子途径并可能提供新的靶标，可以进一步探索用于修改AD的疾病治疗。