Mouse Models of Alexander Disease

亚历山大病小鼠模型

• 批准号: 7418931
• 负责人: ALBEE MESSING
• 金额: $ 35.05万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7418931
• 关键词: Adolescent; Adult; Affect; Alexander Disease; Animal Model; Antioxidants; Astrocytes; Behavioral; Binding; Biochemical; Blood Vessels; Cells; Child; Code; Collaborations; Crystallins; Deposition; Disease; Fiber; Functional disorder; Genes; Genetic; Glial Fibrillary Acidic Protein; Goals; Health; Heat shock proteins; Human; Intermediate Filaments; Knock-in Mouse; Knock-out; Mediating; Modeling; Mus; Mutation; Pathogenesis; Pathologic; Pathway interactions; Patients; Phenotype; Point Mutation; Production; Property; Proteins; Range; Reporter Genes; Response Elements; Role; Specificity; Stress; Testing; Therapeutic Intervention; Transgenic Organisms; Ventricular; base; biological adaptation to stress; gain of function; in vitro Model; in vivo; leukodystrophy; mouse model; mutant; novel; programs; stress protein; transcription factor

DESCRIPTION (provided by applicant): Alexander disease (AxD) patients carry heterozygous mutations within the coding region of GFAP. To facilitate mechanistic studies on the pathogenesis of AxD, and provide animal models suitable for testing potential therapies, our long-term goal has been to generate mouse models for this disorder. We have now generated knock-in lines of mice carrying several of the most common GFAP mu-tations found in human AxD (equivalent to R79H, R239H, R239C, and R416W), and found that expression of the mutant GFAPs induces Rosenthal fibers (the hallmark pathologic feature), but the mice are viable. Moreover, expressing the mutant GFAPs in the context of appropriate genetic modifiers (such as elevating wild type GFAP) results in a lethal phenotype. In addition, altering GFAP expression either by simple over-expression or production of mutant GFAPs leads to induction of multiple stress pathways (aB-crystallin, Nrf2) that suggest specific hypotheses about pathogenesis and, ultimately, strategies for therapy. With the goals of understanding more precisely the consequences of abnormal GFAP expression in astrocytes, and of generating mouse models that reflect key phenotypic features of AxD in humans, we propose the following specific aims: In Aim 1 we will test the consequences of expressing mutant GFAP protein and/or GFAP over-expression, for comparison with known features of the Alexander phenotype in humans. These studies will include both in vitro models using primary cultures of mouse astrocytes, as well as the in vivo knock-in models carrying point mutations in the endogenous mouse GFAP gene. A range of properties will be examined, including biochemical, functional, and behavioral. Reversibility will also be assessed. In Aims 2 and 3 we will test the roles of the small stress protein aB-crystallin, and the transcription factor Nrf2, respectively, as modifiers, by crossing the GFAP mice with knockouts or with newly generated transgenics that over-express the two genes. Specific mechanisms by which excess aB-crystallin or Nrf2 might achieve rescue will be evaluated. These studies promise novel information on the pathological significance of mutant intermediate filament expression in astrocytes, will suggest mechanisms by which primary astrocyte dysfunction leads to generalized CMS disease, and will identify critical stress pathways that could ultimately serve as the basis for therapeutic interventions to mitigate the devastating effects of this disease.

描述（由申请人提供）：亚历山大病（AxD）患者在 GFAP 编码区内携带杂合突变。为了促进 AxD 发病机制的机制研究，并提供适合测试潜在疗法的动物模型，我们的长期目标是建立这种疾病的小鼠模型。我们现在已经生成了携带人类 AxD 中发现的几种最常见 GFAP 突变（相当于 R79H、R239H、R239C 和 R416W）的小鼠敲入系，并发现突变 GFAP 的表达诱导了 Rosenthal 纤维（标志性病理特征），但小鼠仍能存活。此外，在适当的遗传修饰剂（例如提高野生型 GFAP）的背景下表达突变 GFAP 会导致致命的表型。此外，通过简单的过表达或突变 GFAP 的产生来改变 GFAP 表达会导致多种应激途径（aB-晶状体蛋白、Nrf2）的诱导，从而提出有关发病机制的具体假设，并最终提出治疗策略。为了更准确地了解星形胶质细胞中 GFAP 表达异常的后果，并生成反映人类 AxD 关键表型特征的小鼠模型，我们提出以下具体目标：在目标 1 中，我们将测试表达突变 GFAP 的后果蛋白质和/或 GFAP 过度表达，用于与人类 Alexander 表型的已知特征进行比较。这些研究将包括使用小鼠星形胶质细胞原代培养物的体外模型，以及携带内源性小鼠 GFAP 基因点突变的体内敲入模型。将检查一系列特性，包括生化、功能和行为。还将评估可逆性。在目标 2 和 3 中，我们将通过将 GFAP 小鼠与敲除小鼠或新生成的过度表达这两个基因的转基因小鼠杂交，分别测试小应激蛋白 aB-晶状体蛋白和转录因子 Nrf2 作为修饰剂的作用。将评估过量的 aB-晶状体蛋白或 Nrf2 可能实现救援的具体机制。这些研究有望提供关于星形胶质细胞中突变中间丝表达的病理学意义的新信息，将提出原发性星形胶质细胞功能障碍导致全身性 CMS 疾病的机制，并将确定关键的应激途径，最终可以作为治疗干预的基础，以减轻这种疾病的破坏性影响。