A humanized mouse model for UBQLN2-associated ALS-dementia

UBQLN2 相关 ALS 痴呆的人源化小鼠模型

基本信息

批准号：
10754023
负责人：
Randal Scot Tibbetts
金额：
$ 42.76万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-01 至 2025-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10754023
关键词：
Alleles Behavior Behavior assessment Behavioral Birth Cell model Cells Client Clinical Cognitive Defect Dementia Disease Disease Pathway Drosophila genus Enterobacteria phage P1 Cre recombinase Evaluation Exhibits Frontotemporal Dementia Gene Dosage Gene Targeting Genes Genetic Glean Goals Histopathology Homeostasis Human Knock-in Learning Legal patent Link Mammals Masks Memory Modeling Molecular Chaperones Motor Motor Neurons Mouse Strains Mus Mutation Nerve Degeneration Nervous Mouse Nervous System Neurodegenerative Disorders Neurologic Other Genetics Pathway interactions Phenotype Point Mutation Primary Lateral Sclerosis Proline Protein Overexpression Proteins Rodent Rodent Model Sclerosis Site Solubility Spastic Paraplegia Study models Switch Genes Testing Tissues Toxic effect Transgenic Organisms Ubiquitin Work combinatorial constitutive expression embryonic stem cell expectation fly frontotemporal lobar dementia amyotrophic lateral sclerosis human disease human model humanized mouse induced pluripotent stem cell motor behavior motor neuron degeneration mouse model multicatalytic endopeptidase complex mutant nestin protein neurodegenerative phenotype overexpression protein aggregation targeted treatment tool ubiquilin

项目摘要

Abstract The objective of this R21 proposal is to develop a humanized mouse model for UBQLN2-associated amyotrophic sclerosis (ALS) and frontotemporal dementia (FTD), devastating neurodegenerative disorders that lie on either end of a clinical disease spectrum. Among more than 20 different genes implicated in ALS/FTD, X-linked mutations in the ubiquitin (Ub) chaperone UBQLN2 cause diverse neurologic phenotypes, ranging from pure ALS with or without FTD, to primary lateral sclerosis and spastic paraplegia. ALS/FTD-associated mutations in UBQLN2 disrupt its folding and promote its aggregation; however, the mechanisms whereby UBQLN2 mutations instigate neurodegeneration in ALS/FTD are unclear. UBQLN2 mutant transgenic rodents recapitulated UBQLN2 histopathology but manifested highly discrepant neurological phenotypes ranging from patent motor neuron degeneration to no observable phenotype. A caveat to these studies—and transgenic rodent models in general—is that overexpression of wild-type UBQLN2 also elicits toxicity, likely through disruption of Ub homeostasis. On the other hand, while there is a strong need for models in which culprit ALS mutations are expressed at endogenous levels, mice harboring ALS-associated UBQLN2 knockin mutations exhibit weak phenotypes, precluding mechanistic studies. This has been a general problem for mouse models of human neurodegenerative diseases. In an attempt to augment UBQLN2 toxicity at endogenous expression levels, our group developed a combinatorial UBQLN2 mutant (UBQLN24XALS) harboring four different clinical mutations that reduce its solubility in a semi-additive manner. UBQLN24XALS caused enhanced toxicity relative to wild-type UBQLN2 or UBQLN2 clinical mutants when overexpressed in Drosophila or when expressed from a UBQLN2 knockin allele in iPS-derived motor neurons (iMNs). Genetic suppressors of UBQLN24XALS toxicity in Drosophila also suppressed its toxicity in iMNs suggesting that UBQLN24XALS toxicity mechanism is at least partially conserved in flies and mammals. Here, we propose to generate a conditional, humanized UBQLN24XALS mouse model to allow spatially and temporally controlled UBQLN24XALS in the mouse nervous system. After a full evaluation of neurodegenerative phenotypes, UBQLN24XALS mice will be used as a tool to decipher ALS disease pathways using ‘omics approaches and information gleaned from orthologous studies in Drosophila and cellular models of ALS-UBQLN2. Information learned should also inform ALS/FTD arising sporadically and from other genetic causes. The objectives of the proposal are to: 1) Generate conditional, humanized UBQLN2WT to UBQLN24XALS gene switch mice; 2) Histopathologic and behavioral assessment of Nestin (Nes)-Cre, UBQLN24XALS mice.

抽象的该 R21 提案的目标是开发 UBQLN2 相关的人源化小鼠模型肌萎缩性硬化症（ALS）和额颞叶痴呆（FTD），破坏性神经退行性疾病位于临床疾病谱的两端。涉及 20 多个不同基因。 ALS/FTD、泛素 (Ub) 伴侣 UBQLN2 中的 X 连锁突变导致多种神经系统疾病表型范围从伴有或不伴有 FTD 的纯 ALS，到原发性侧索硬化和痉挛性截瘫。 UBQLN2 中的 ALS/FTD 相关突变会破坏其折叠并促进其聚集； UBQLN2 突变引发 ALS/FTD 神经变性的机制尚不清楚。突变转基因啮齿动物重现了 UBQLN2 组织病理学，但表现出高度差异神经表型范围从明显的运动神经元变性到无可观察到的表型 A。这些研究以及一般的转基因啮齿动物模型需要注意的是，野生型的过度表达另一方面，UBQLN2 也可能通过破坏 Ub 稳态而引起毒性。强烈需要在内源水平表达罪魁祸首 ALS 突变的模型，小鼠携带 ALS 相关 UBQLN2 敲入突变的人表现出弱表型，排除了机制这一直是人类神经退行性疾病小鼠模型的普遍问题。为了在内源表达水平上增强 UBQLN2 毒性，我们的小组开发了一种组合 UBQLN2 突变体 (UBQLN24XALS) 含有四种不同的临床突变，可降低其相对于野生型 UBQLN2，UBQLN24XALS 的溶解度增强。或 UBQLN2 在果蝇中过表达或从 UBQLN2 表达时的临床突变体 UBQLN24XALS 毒性的基因敲击果蝇还抑制了其在 iMN 中的毒性，表明 UBQLN24XALS 毒性机制至少是在这里，我们建议产生一个有条件的、人源化的。 UBQLN24XALS 小鼠模型允许在小鼠神经中进行空间和时间控制的 UBQLN24XALS 在对神经退行性表型进行全面评估后，UBQLN24XALS 小鼠将被用作工具。使用组学方法和从直系同源收集的信息破译 ALS 疾病途径果蝇和 ALS-UBQLN2 细胞模型的研究也应提供信息。 ALS/FTD 偶发且由其他遗传原因引起该提案的目标是： 1) 生成有条件的人源化 UBQLN2WT 至 UBQLN24XALS 基因转换小鼠 2) 组织病理学和 Nestin (Nes)-Cre、UBQLN24XALS 小鼠的行为评估。