Neurobiological Mechanism of 15q11-13 Duplication Autism Spectrum Disorder

15q11-13重复自闭症谱系障碍的神经生物学机制

• 批准号: 7935498
• 负责人: MATTHEW P ANDERSON
• 金额: $ 30.45万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7935498
• 关键词: 15q; Adult; Affect; Alleles; Angelman Syndrome; Autistic Disorder; Behavior; Behavior Disorders; Behavior Therapy; Behavioral; Biological Models; Brain; Cells; Cellular Morphology; Child; Chromosomes; Communication; Data; Defect; Development; Electrophoresis; Electrophysiology (science); Epitopes; Family; Foundations; Gene Dosage; Gene Expression; Genes; Genetic Models; Glean; Grant; Heterogeneity; Hippocampus (Brain); Human; Impairment; Individual; Inherited; Inhibitory Synapse; Knock-out; Knockout Mice; Lead; Learning; Length; Life; Link; Manuscripts; Maps; Mass Spectrum Analysis; Measures; Mediating; Medicine; Mental disorders; Messenger RNA; Methods; Mission; Molecular; Morphology; Mothers; Motor; Mus; Nature; Neurons; Nuclear; Patients; Pattern; Perforant Pathway; Pharmaceutical Preparations; Physiology; Property; Protein Binding; Protein Biochemistry; Protein Region; Proteins; Proteomics; Quantitative Reverse Transcriptase PCR; Regulation; Role; Sensory; Series; Severity of illness; Slice; Social Interaction; Spectrum Analysis; Synapses; Transgenic Mice; Transgenic Organisms; Ubiquitination; Variant; Vertebral column; Western Blotting; autism spectrum disorder; biocytin; brain tissue; design; dosage; hippocampal pyramidal neuron; men; mouse model; multicatalytic endopeptidase complex; nervous system disorder; neural circuit; neurobiological mechanism; neuronal circuitry; postnatal; protein degradation; public health relevance; reconstitution; response; selective expression; synaptic function; trait; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): The ubiquitin E3 ligase Ube3a has been implicated in two severe neurological disorders, Angelman's syndrome (AS) and autism spectrum disorder caused by maternal 15q 11-13 duplication (15qASD). Cells from 15qASD and AS patients have excess and deficient UBE3A, respectively. Several lines of evidence indicate that this alteration in Ube3a dosage mediates the behavioral disturbances in 15q11-13 ASD and AS. Ube3a is the sole gene consistently shown to express selectively from the maternal allele in the brains of mice and men. The majority of children who inherit 15q11-13 duplications from their mothers develop ASD; the more copies inherited, the more severe the impairment. Angelman's Syndrome (AS), by contrast, results when children fail to inherit maternal 15q11-13 or a functional maternal UBE3A gene product. We hypothesize that excess Ube3a (created by extra copies of 15q11-13) contributes to ASD by increasing the ubiquitination and degradation of key brain proteins needed to preserve normal neuronal circuit function, and that deficient Ube3a contributes to Angelman's Syndrome through the same, but opposite mechanisms. Since the brain's circuitries are designed to quantitatively evaluate sensory information and to generate quantitative motor responses, there are likely many regulatory molecules within the neuronal circuitry that can cause graded changes in behavior when their quantities are varied. Such molecular quantity variation might underlie the intrinsic heterogeneity of psychiatric disorders like autism spectrum disorder. We propose Ube3a will become the first well-described example of this mechanism. The specific aims of this R21 grant follow: (1) identify the hippocampal CA1 pyramidal neuron proteins quantitatively regulated by varying excesses and deficiencies of Ube3a; and (2) identify the hippocampal CA1 circuit functions quantitatively regulated by varying excesses and deficiencies of Ube3a. Our methods will include using the 3xFLAG epitope tag to immunoprecipitate native hippocampal CA1 region proteins physically associated with Ube3a, and using mass- spectrometry to identify the protein interactors and potential targets. Targets will be directly assessed by comparing the level of proteins on 1-D or 2-D PAGE and identification of those showing bidirectional alterations. Slice electrophysiology and neuronal morphology will be used in our new Ube3a transgenic and existing Ube3a knockout mice to examine the effects of gene dosage on postnatal development and adult function of CA1 pyramidal neuron excitability and synaptic function (excitatory and inhibitory) in living brain tissues. Our seven (7) mouse lines with extra 15q11-13 gene copies and varying gene dosage permit us to evaluate the impact of gene copy number on circuit function. This project promotes the agency's mission to deepen the understanding of the neuronal cells and circuits involved in ASD via genetic models. By examining these model systems, we will glean information about the defects in molecular, cellular, and circuit function that underlie these debilitating mental disorders. PUBLIC HEALTH RELEVANCE: Autism spectrum disorder (ASD) is a heterogeneous group of related behavioral disorders, characterized by deficits in three core domains: communication, social interaction, and rigid behavior. This project seeks to learn how certain autism-related genes may affect proteins in the brain and the function of brain circuits that underlie these behavioral disturbances. This understanding may lead to the development of new drugs and behavioral interventions.

描述（由申请人提供）：泛素 E3 连接酶 Ube3a 与两种严重的神经系统疾病有关，即天使综合征 (AS) 和由母体 15q 11-13 重复 (15qASD) 引起的自闭症谱系障碍。来自 15qASD 和 AS 患者的细胞分别具有过量和缺陷的 UBE3A。多项证据表明，Ube3a 剂量的这种变化介导了 15q11-13 ASD 和 AS 的行为障碍。 Ube3a 是唯一一个始终显示在小鼠和人类大脑中从母体等位基因选择性表达的基因。大多数从母亲那里遗传 15q11-13 重复的孩子都会患上自闭症谱系障碍 (ASD)；遗传的副本越多，损伤就越严重。相比之下，当儿童未能遗传母体 15q11-13 或功能性母体 UBE3A 基因产物时，就会导致天使综合症 (AS)。我们假设过量的 Ube3a（由 15q11-13 的额外拷贝产生）通过增加维持正常神经元回路功能所需的关键脑蛋白的泛素化和降解而导致自闭症谱系障碍，而缺陷的 Ube3a 通过相同但相反的机制导致天使综合症。由于大脑电路的设计目的是定量评估感觉信息并产生定量的运动反应，因此神经元电路中可能存在许多调节分子，当它们的数量变化时，它们会导致行为的分级变化。这种分子数量的变化可能是自闭症谱系障碍等精神疾病内在异质性的基础。我们建议 Ube3a 将成为该机制的第一个详细描述的例子。本次 R21 资助的具体目标如下：（1）确定海马 CA1 锥体神经元蛋白受 Ube3a 不同过量和缺乏的定量调节； (2) 确定由不同的 Ube3a 过量和缺乏定量调节的海马 CA1 回路功能。我们的方法将包括使用 3xFLAG 表位标签来免疫沉淀与 Ube3a 物理相关的天然海马 CA1 区蛋白，并使用质谱法来识别蛋白相互作用物和潜在靶标。通过比较 1-D 或 2-D PAGE 上的蛋白质水平并识别那些显示双向改变的蛋白质，可以直接评估目标。切片电生理学和神经元形态学将用于我们新的 Ube3a 转基因小鼠和现有的 Ube3a 敲除小鼠，以检查基因剂量对活体脑组织中 CA1 锥体神经元兴奋性和突触功能（兴奋性和抑制性）的出生后发育和成年功能的影响。我们的七 (7) 个小鼠品系具有额外的 15q11-13 基因拷贝和不同的基因剂量，使我们能够评估基因拷贝数对电路功能的影响。该项目推动了该机构的使命，即通过遗传模型加深对自闭症谱系障碍中涉及的神经元细胞和回路的了解。通过检查这些模型系统，我们将收集有关这些使人衰弱的精神障碍的分子、细胞和回路功能缺陷的信息。 公共健康相关性：自闭症谱系障碍 (ASD) 是一组异质性相关行为障碍，其特征是三个核心领域的缺陷：沟通、社交互动和僵化行为。该项目旨在了解某些与自闭症相关的基因如何影响大脑中的蛋白质以及构成这些行为障碍的大脑回路的功能。这种理解可能会导致新药物和行为干预措施的开发。