The mechanism of Rett Syndrome rescue by astrocytes

星形胶质细胞拯救雷特综合征的机制

• 批准号: 9242037
• 负责人: PAUL BREHM
• 金额: $ 56.31万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-19 至 2020-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9242037
• 关键词: Address; Alpha Cell; Astrocytes; Behavioral; Benchmarking; Brain; Brain Stem; Candidate Disease Gene; Cell Communication; Cells; Chemicals; Communication; Conditioned Culture Media; Defect; Dendrites; Disease; Electrophysiology (science); Eye; Genes; Goals; Head; Heterogeneity; Hippocampus (Brain); Human; Immunohistochemistry; Individual; Knock-out; Measurement; Mediating; Membrane; Membrane Proteins; Messenger RNA; Methyl-CpG-Binding Protein 2; Microarray Analysis; Mitochondrial Proteins; Molecular; Molecular and Cellular Biology; Morphology; Mus; Mutation; Nervous system structure; Neurodevelopmental Disorder; Neuroglia; Neuronal Dysfunction; Neurons; Output; Pathway Analysis; Pathway interactions; Patients; Phenotype; Physiological; Physiology; Population; Process; Property; Proteins; Proteome; Proteomics; Recovery; Research Personnel; Rett Syndrome; Role; Signal Pathway; Signal Transduction; Slice; Symptoms; Synapses; Testing; Therapeutic; Therapeutic Intervention; Transcript; Work; Xenograft procedure; base; cell type; cohesion; functional outcomes; gamma-Aminobutyric Acid; girls; in vivo; induced pluripotent stem cell; innovation; interest; mouse model; mutant; nervous system disorder; neuropathology; public health relevance; response; restoration; transcription factor; transcriptome; transcriptome sequencing; transcriptomics

 DESCRIPTION (provided by applicant): Despite advances in identifying defective genes underlying neuropathologies, how these defects underlie symptoms is not known, and this gap is a formidable stumbling block for therapeutics. A case in point is Rett Syndrome (RTT), a severe neurological disease in girls. The disease is due to sporadic mutations in the transcription factor, MeCP2, but why loss of MeCP2 causes neuropathology is enigmatic. Further, RTT holds a unique place in neurological disease because key symptoms are reversible in mice by expressing MeCP2 throughout the brain or just in astrocytes, the prominent glial cell type in brain. The rescue opens the door to therapeutic approaches, but requires a better understanding of what is deficient in RTT and precisely what is rescued upon MeCP2 restoration. Traditional approaches, such as microarray analysis, have focused almost exclusively on individual gene transcript changes, primarily in neurons. This approach has not led to clear answers about the functions of MeCP2 or the cellular basis of the disease, in part due to cellular heterogeneity. It also ignores work indicating a role for astrocytes in contributin to symptoms. In no case is there a molecular benchmark for extent of rescue. Our goal is to attack these issues head on by focusing specifically on rescue of RTT symptoms by astrocytes. Here, we perform a co-expression network analysis, using RNA seq combined with membrane proteomics, on brain and on pure populations of cells sorted from murine brain (aim 1). With an eye towards human-specific therapies, we identify the molecular and cellular consequences of loss and gain of MeCP2 in neural cells from RTT patient IPSCs, and test predictions from these studies in human/mouse xenografts (aim 2). Finally, we test a new hypothesis (aim 3), based on recent preliminary results, that reduced excitatory signaling between astrocytes and neurons may be a functional outcome of the alterations in molecular and membrane properties of these cells (aims 1 and 2).

 描述（由申请人提供）：尽管在识别神经病理学缺陷基因方面取得了进展，但这些缺陷如何导致症状尚不清楚，并且这一差距是治疗的巨大绊脚石。一个典型的例子是雷特综合症（RTT），这是一种严重的女孩神经系统疾病。这种疾病是由转录因子 MeCP2 的零星突变引起的，但为什么 MeCP2 的缺失会导致神经病理学仍然是个谜。此外，RTT 在神经系统疾病中占有独特的地位，因为通过在整个大脑或仅在星形胶质细胞（大脑中主要的神经胶质细胞类型）中表达 MeCP2，小鼠的关键症状是可逆的。这种挽救为治疗方法打开了大门，但需要更好地了解 RTT 的缺陷以及 MeCP2 恢复后准确挽救的内容。传统方法，例如微阵列分析，几乎完全关注单个基因转录本的变化，主要是神经元中的变化。这种方法尚未得出有关 MeCP2 功能或疾病细胞基础的明确答案，部分原因是细胞异质性。它还忽略了表明星形胶质细胞在导致症状中所起作用的研究。在任何情况下都不存在救援程度的分子基准。我们的目标是通过专门关注星形胶质细胞拯救 RTT 症状来正面解决这些问题。在这里，我们使用 RNA seq 与膜蛋白质组学相结合，对大脑和从小鼠大脑中分选的纯细胞群进行共表达网络分析（目标 1）。着眼于人类特异性疗法，我们确定了 RTT 患者 IPSC 神经细胞中 MeCP2 丢失和增加的分子和细胞后果，并在人/小鼠异种移植物中测试这些研究的预测（目标 2）。最后，我们根据最近的初步结果测试了一个新假设（目标 3），即星形胶质细胞和神经元之间的兴奋性信号传导减少可能是这些细胞的分子和膜特性改变的功能结果（目标 1 和 2）。