Origins of Brain Somatic Mosaicism in Developmental Brain Disease

发育性脑疾病中脑体细胞嵌合的起源

基本信息

批准号：
10669715
负责人：
JOSEPH G GLEESON
金额：
$ 30.88万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-08-10 至 2026-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10669715
关键词：
Adult Algorithms Alleles Anatomy Animal Model Astrocytes Autopsy Bar Codes Behavior Blood Brain Brain Diseases Cadaver Candidate Disease Gene Cell Lineage Cell Size Cell division Cells Chemicals Childhood Clinical Complex Cortical Dysplasia DNA DNA Damage DNA Methylation DNA Sequence Alteration Data Databases Detection Development Developmental Process Disease Dysplasia Electroencephalography Electroporation Embryo Embryonic Development Evaluation Excision Exposure to FRAP1 gene Freezing Frequencies Functional disorder Funding Genetic Genetic Variation Genomics Genotype Goals Growth Human Individual Intractable Epilepsy Investments Knowledge Life Maps Metabolic stress Methods Microglia Minority Modeling Mosaicism Mus Mutation Neocortex Neurodevelopmental Disorder Neurons Nuclear Oligodendroglia Organism Outcome Pathogenicity Pathway interactions Patients Pattern Phenotype Predisposition Recording of previous events Regional Anatomy Resected Sampling Shapes Signal Transduction Somatic Cell Somatic Mutation Sorting Synapses Testing Tissues Variant Work brain cell brain circuitry brain surgery cell type clinically significant cohort daughter cell deep sequencing demethylation disability gene function genome sequencing genomic variation human model in utero interest loss of function mTOR Inhibitor migration mosaic variant mouse model mutant neocortical neural neurogenesis neuron development neuronal circuitry neuropathology neuropsychiatric disorder neuropsychiatry novel pharmacologic recruit repaired resilience response success synaptic function

项目摘要

Abstract Brain somatic mosaicism (BSM) refers to the accumulation of mutations within any of the billions of cells in the human brain, which can occur from embryogenesis through adulthood. The extent, impact and mechanisms of BSM on brain disease remain poorly understood. Prior work from the Brain Somatic Mosaicism Network (BSMN), on which the PI served, made critical breakthroughs in reliability of mosaicism detection, but also raised new questions, including the degree to which BSM exists in the healthy brain, and the mechanisms by which BSM mutations explain disease. Focal cortical dysplasia (FCD) is associated with substantial neuropsychiatric disability, and is the most common cause of intractable epilepsy in childhood. Neuropsychiatric features are seen in 15-59% of patients 5-7, and neuropathologically shows disrupted neurogenesis, migration, differentiation, and altered neural excitability. We and others previously identified mosaic mutations in the mTOR pathway in a minority of FCD cases, but most cases remain unsolved, and fundamental mechanisms are lacking. We hypothesize that: 1] FCD mutations are similar to neutral somatic mutations in their patterns and distributions, dictated by developmental processes, but differ in their functional effect. 2] BSM patterns, allelic fractions (AFs) and allele sharing between cells can reconstruct cellular lineages and migratory histories. 3] Study of FCD resected tissue can uncover novel causes of disease that would not be tolerated if present in every cell. 4] BSM modeling in mouse can unravel disrupted signaling networks of complex mosaic mutations. Our preliminary data shows: 1] From a post-mortem control cadaver, we validated 259 somatic variants using 300X genome sequencing, and started to use these variants as ‘barcodes’ to reconstruct lineage histories. 2] Deep sequencing from 314 FCD patient brain resections identified 12 new candidate genes, highlighting signaling and synaptic dysfunction, and a novel ‘two-hit’ disease mechanisms. 3] We established in utero mouse electroporation models to assess putative FCD variants as gain or loss of function, and to assess effects of ‘single-hit’ and ‘two-hit’ mutations. We propose three aims: 1] From control cadavers, we will reconstruct cell lineage across anatomical domains using BSM as barcodes. 2] With this lineage information, we will study the origins of BSM mutations in FCD, by recruiting new patients, performing both targeted and unbiased sequencing, and identifying novel causes. 3] We will functionally validate putative deleterious alleles in animal models for both ‘single-hit’ and ‘two-hit’ causes. The goal is to achieve a mechanistic understanding of the extent of BSM in control individuals, to reconstruct neural lineages and to identify novel mechanisms in developmental brain disease.

抽象的大脑体细胞镶嵌（BSM）是指突变在数十亿个细胞中的积累人脑，可能是由于胚胎发生到成年而发生的。程度，影响和 BSM在脑疾病上的机制仍然了解不足。大脑的先前工作 PI提供的镶嵌网络（BSMN）在镶嵌性的可靠性方面取得了关键的突破检测，但还提出了新问题，包括BSM在健康大脑中存在的程度，以及 BSM突变解释疾病的机制。局灶性皮质发育不良（FCD）与实质性神经精神疾病有关，并且是一种最常见的原因是童年时期顽固性癫痫。 15-59％的神经精神特征可见患者5-7和神经病理学表明神经发生，迁移，分化和改变。神经令人兴奋。我们和其他人以前在MTOR途径中识别出少数族的镶嵌突变在FCD病例中，但大多数病例仍未解决，并且缺乏基本机制。我们假设：1] FCD突变类似于其模式中的中性体细胞突变，并且分布，由发展过程决定，但其功能效果不同。 2] BSM模式，等位基因细胞之间的分数（AFS）和等位基因共享可以重建细胞谱系和迁移历史。 3] FCD切除组织的研究可以发现新的疾病原因，如果存在于每个单元格。 4]小鼠中的BSM建模可以揭示复杂镶嵌突变的信号传导网络。我们的初步数据显示：1]来自验尸后的尸体，我们验证了259个躯体使用300倍基因组测序的变体，并开始使用这些变体作为“条形码”来重建血统历史。 2]从314个FCD患者脑切除率的深度测序确定了12个新候选者基因，突出了信号传导和突触功能障碍，以及一种新颖的“两击”疾病机制。 3]我们在子宫小鼠电穿孔模型中建立，以评估假定的FCD变体作为功能的增益或丧失，并评估“单击”和“两击”突变的影响。我们提出了三个目标：1]从控制尸体中，我们将在解剖学上重建细胞谱系使用BSM作为条形码的域。 2]有了这些谱系信息，我们将研究BSM的起源 FCD中的突变，招募新患者，进行靶向和公正的测序以及识别新的原因。 3]我们将在动物模型中功能验证推定的有害等位基因 “单次打击”和“两击”原因。目标是实现对对照个体中BSM的范围，重建神经谱系并确定新的机制发育性脑部疾病。

项目成果

期刊论文数量（4）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Control-independent mosaic single nucleotide variant detection with DeepMosaic.

DOI：
10.1038/s41587-022-01559-w
发表时间：
2023-06
期刊：
NATURE BIOTECHNOLOGY
影响因子：
46.9
作者：
Yang, Xiaoxu;Xu, Xin;Breuss, Martin W.;Antaki, Danny;Ball, Laurel L. V.;Chung, Changuk;Shen, Jiawei;Li, Chen;George, Renee D.;Wang, Yifan;Bae, Taejeong;Cheng, Yuhe;Abyzov, Alexej M.;Wei, Liping;Alexandrov, Ludmil B.;Sebat, Jonathan L.;Gleeson, Joseph G.
通讯作者：
Gleeson, Joseph G.