Function and Structure Adaptations in Forebrain Development

前脑发育中的功能和结构适应

基本信息

批准号：
8231457
负责人：
PAT LEVITT
金额：
$ 54.18万
依托单位：
UNIVERSITY OF SOUTHERN CALIFORNIA
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-07-01 至 2014-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8231457
关键词：
Address Affect Alleles Anxiety Apical Architecture Area Autopsy Basic Science Binding Binding Sites Biochemical Biological Assay Biological Models Blood Cells Brain Cell Line Cells Cellular Morphology Centers for Disease Control and Prevention (U.S.)Cerebral cortex Characteristics Child Clinical Clinical Research Complex CpG Islands Data Dendrites Development Disease Dorsal Electrophoretic Mobility Shift Assay Engineering Epigenetic Process Excitatory Synapse Forebrain Development Fragile X Syndrome Gene Expression Gene Expression Regulation Gene Targeting Genes Genetic Genetic Transcription Goals Growth Health Hepatocyte Growth Factor Hippocampus (Brain)Human Human Genetics Immunoprecipitation In Situ Hybridization In Vitro Individual Injection of therapeutic agent Interneurons Knock-in Mouse Knockout Mice Lead Ligands MET gene Methylation Molecular Mus Mutate Neocortex Neuraxis Neurons Nuclear Extract Nucleic Acid Regulatory Sequences Patients Peripheral Phosphorylation Process Prosencephalon Pyramidal Cells Receptor Protein-Tyrosine Kinases Regulation Reporting Research Research Proposals Risk Role SP1 gene Seizures Signal Transduction Signaling Protein Single Nucleotide Polymorphism Small Interfering RNA Social Behavior Structure Synapses System Temporal Lobe Time Tissues Transcript Transcription Initiation Site Transcriptional Regulation Translating United States Urokinase Plasminogen Activator Receptor Variant Western Blotting autism spectrum disorder brain tissue calmodulin-dependent protein kinase II developmental neurobiology disorder control functional disability gene environment interaction genetic manipulation hippocampal pyramidal neuron in vivo in vivo Model insight lucifer yellow meetings mouse model neocortical nervous system development neuron development overexpression postnatal prenatal pro-hepatocyte growth factor promoter protein expression receptor social synaptic function transcription factor translational study

项目摘要

DESCRIPTION (provided by applicant): There are two related long-term goals of the proposed research. First, to determine the mechanisms through which the receptor tyrosine kinase Met signaling system influences forebrain development. Second, to define the relationship between MET gene regulation and altered forebrain development that may lead to functional impairments characteristic of autism spectrum disorder (ASD). MET and its ligand, hepatocyte growth factor (HGF), have been implicated in the development and maturation of neuronal circuits in vitro. In vivo, indirect genetic manipulation of HGF-Met signaling results in alterations in cortical interneuron development, intermittent seizures, increased anxiety and reduced social behavior in mice. Our preliminary data from the conditional deletion of Met in the neocortex provides direct evidence that Met signaling is involved in the structural and biochemical maturation of synapses. Moreover, we discovered that a single nucleotide polymorphism (SNP rs1858830) in the 52 transcriptional regulatory region of the human MET gene is strongly associated with ASD (P=5X10-6). This variant is functional, as it reduces gene transcription by interfering with transcription factor binding. This has clinical validity, as we have shown recently that MET protein expression is reduced to 50% of control levels in the temporal cortex of subjects with ASD compared to controls. The convergence of the human genetic and biochemical studies in ASD and basic developmental neurobiology suggests that MET signaling is important for the proper assembly of forebrain circuits, with dysregulation leading to functional disruptions in both model systems and in humans. In this renewal application, we propose to take advantage of the convergence of basic and clinical research data, organized around three specific aims to address the role of MET in neocortical development, the factors that contribute to MET gene regulation, and the influence of the ASD-associated human genetic regulatory variant on MET-related forebrain ontogeny. Aim 1 will determine the impact of direct elimination of Met signaling in the cerebral cortex using mice in which Emx1Cre conditionally deletes Met from the dorsal pallium. The goal of these studies is to define changes in dendritic and synaptic architecture, and in synaptic signaling systems. Aim 2 will define and experimentally manipulate, in cell lines, the transcription factors and assembled complex that regulate human MET gene transcription. The regulation of MET by epigenetic mechanisms in ASD cases of postmortem brains and peripheral cells from patients will be examined in methylation studies of the extensive CpG island in the 52 regulatory region of the gene. In Aim 3, new `humanized' mouse lines will be engineered that contain the human 52 regulatory sequence that has either the `G' or `C' rs1858830 allele and the CpG island. The goals of this aim are to determine how the ASD-associated `C' allele influences MET gene transcription and brain development in an in vivo model system, and to define the influence of epigenetic regulation of gene expression over time. PUBLIC HEALTH RELEVANCE: The CDC notes that ASD affects 1 in every 150 children in the United States. The research proposal will directly investigate directly a risk gene for ASD by determining how alterations in gene expression impact brain development. This project includes basic and clinical translational studies that will provide insight into gene- gene and gene-environment interactions that may underlie atypical brain functions in ASD.

描述（由申请人提供）：拟议的研究有两个相关的长期目标。首先，为了确定受体酪氨酸激酶符合信号系统影响前脑发育的机制。其次，为了定义MET基因调节与前脑发育改变之间的关系，这可能导致自闭症谱系障碍（ASD）的功能障碍特征。 MET及其配体，肝细胞生长因子（HGF）与在体外神经元电路的发展和成熟有关。在体内，HGF-MET信号传导的间接基因操纵导致皮质间神经元发育，间歇性癫痫发作，增加焦虑和社会行为减少小鼠的改变。我们来自新皮层中MET条件缺失的初步数据提供了直接证据，表明MET信号传导参与了突触的结构和生化成熟。此外，我们发现人类MET基因的52个转录调节区域中的单个核苷酸多态性（SNP rs1858830）与ASD密切相关（p = 5x10-6）。该变体具有功能性，因为它通过干扰转录因子结合来降低基因转录。这具有临床有效性，正如我们最近表明的那样，与对照组相比，在患有ASD的受试者的颞叶皮层中，MET蛋白表达降低至对照水平的50％。 ASD和基本发育神经生物学中人类遗传学和生化研究的融合表明，MET信号传导对于前脑电路的适当组装至关重要，并且失调导致模型系统和人类的功能破坏。在此续签应用中，我们建议利用基本和临床研究数据的收敛性，围绕三个特定目的组织了MET在新皮质发展中的作用，有助于MET Gene调控的因素以及与ASD相关的人类遗传调节性变体对MET相关的前脑对与MET相关的前脑的影响。 AIM 1将使用eMX1CRE有条件地从背胸膜中删除EMX1CRE的小鼠直接消除MET信号传导的影响。这些研究的目的是定义树突状结构和突触信号系统的变化。 AIM 2将在细胞系中定义并实验操纵转录因子和组装的复合物，这些复合物调节了人类MET基因转录。在该基因52个调节区域的广泛的CpG岛的甲基化研究中，将检查通过表观遗传机制通过表观遗传机制对患者的ASD表观遗传机制调节。在AIM 3中，将设计新的“人性化”小鼠系，其中包含人类52调节序列，该序列具有“ G”或“ C” RS1858830等位基因和CPG岛。该目标的目标是确定与ASD相关的“ C”等位基因如何影响体内模型系统中的基因转录和脑发育，并定义基因表达的表观遗传调节的影响。公共卫生相关性：CDC指出，ASD在美国每150名儿童中会影响1个。研究建议将通过确定基因表达的变化如何影响大脑发育直接直接研究ASD的风险基因。该项目包括基本和临床翻译研究，这些研究将提供对基因和基因环境相互作用的见解，这些相互作用可能是ASD中非典型大脑功能的基础。