Floating Harbor Syndrome as a paradigm for understanding the role of chromatin perturbation in human craniofacial disorders

浮港综合症作为理解染色质扰动在人类颅面疾病中的作用的范例

• 批准号: 9333119
• 负责人: Rachel Segal Greenberg
• 金额: $ 3.66万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9333119
• 关键词: ATAC-seq; Address; Alpha Cell; Animal Model; Biochemical; Biological; Biological Models; Biology; Birth; CREBBP gene; Cartilage; Cell model; Cells; ChIP-seq; Characteristics; Chromatin; Clinical; Congenital Abnormality; Congenital Disorders; Craniofacial Abnormalities; Defect; Deposition; Development; Developmental Process; Diagnosis; Dimerization; Disease; Disease model; Dorsal; Dysmorphology; Embryo; Embryonic Development; Enhancers; Epigenetic Process; Etiology; Face; Floating-Harbor syndrome; Gene Expression; Gene Proteins; Genes; Genetic Transcription; Genome; Goals; Growth; Head; Histone H2B; Histones; Human; Human Development; Impairment; In Vitro; Laboratories; Lead; Link; Methods; Modeling; Molecular; Morphogenesis; Mutation; Neural Crest; Neural Crest Cell; Neural tube; Nuclear Protein; Organ; Pear; Phenotype; Physiological; Play; Population; Prevention; Process; Promoter Regions; Protein Truncation; Proteins; Regulation; Research; Role; Structure; Symptoms; Syndrome; System; Technology; Testing; Tissues; Transcription Initiation Site; Transcriptional Regulation; Tube; Variant; Work; Xenopus; Xenopus laevis; craniofacial; craniofacial development; developmental disease; developmental plasticity; dimer; experimental study; face bone structure; genome editing; helicase; human embryonic stem cell; human embryonic stem cell line; in vitro Model; in vivo; in vivo Model; insight; knock-down; malformation; migration; migratory population; multipotent cell; mutant; programs; promoter; protein complex; public health relevance; spatiotemporal; transcriptome

 DESCRIPTION (provided by applicant): As the importance of various chromatin remodelers during early human development has become apparent, the biological explanation of why perturbations of these remodelers impact particular developmental process- es, specifically craniofacial development, remains a mystery. In fact, a number of chromatin remodelers, in- cluding Snf2-related CREBBP activator protein (SRCAP), are associated with human craniofacial disorders. Truncation mutations in the SRCAP gene have recently been shown to be the causative mutations in a disor- der called Floating-Harbor syndrome (FHS). Intriguingly, the many symptoms of FHS could be explained by the perturbation of a single population of cells - the neural crest. The neural crest is a transient population of mi- gratory cells arising from the dorsal part of the neural tube during weeks three to six of embryogenesis, making it exceeding difficult to study these cells in a human embryo. To address this issue, our lab has established an in vitro model of human neural crest differentiation, which, together with animal models, can be effectively used to study the biology of the neural crest. However, because neural crest cells contribute to such diverse tissues and organs, including craniofacial structures, they must demonstrate remarkable developmental plasticity and migratory potential, which requires careful execution of transcriptional programs. Indeed, neural crest cells ap- pear highly sensitive to even modest transcriptional perturbations, as mutations in many chromatin remodelers manifest in malformations of neural crest-derived craniofacial structures. SRCAP is known to play a significant role in the precise regulation of transcriptional programs as a part of a protein complex that facilitates active transcription by replacing the canonical H2A-H2B histone dimer with histone variant H2A.Z at transcription start sites and enhancers. The cellular origin of FHS leading to craniofacial defects has not previously been established, and the combination of an in vitro neural crest differentiation model and a high-throughput Xenopus lelvels animal model allows us to study this disorder at multiple levels, from molecular mechanism to cellular defects to disease state. We have recapitulated SRCAP FHS truncations both an in vivo embryological model that displays craniofacial dysmorphology consistent with the syndrome, as well as an in vitro cellular model. Proposed research will take advantage of these models to identify the underlying molecular, cellular, and developmental causes of FHS, thus providing potential targets for treatment. Ultimately, our research will contribute to a biological explanation for why perturbations of chromatin remodelers have such a pronounced impact on craniofacial development.

 描述（由申请人提供）：由于各种染色质重塑物在人类早期发育过程中的重要性已变得显而易见，因此这些重塑物的扰动为何会影响特定发育过程（特别是颅面发育）的生物学解释仍然是个谜。事实上，许多染色质重塑，包括Snf 2相关CREBBP激活蛋白（SRCAP），与人类颅面疾病有关。SRCAP基因的截短突变最近被证明是一种称为浮港综合征（FHS）的疾病的致病突变。有趣的是，FHS的许多症状可以用单一细胞群-神经嵴的扰动来解释。神经嵴是在胚胎发生的第三至第六周期间从神经管的背侧部分产生的迁移细胞的瞬时群体，使得在人类胚胎中研究这些细胞极其困难。为了解决这个问题，我们的实验室已经建立了一个体外模型的人神经嵴分化，它与动物模型一起，可以有效地用于研究神经嵴的生物学。然而，由于神经嵴细胞有助于这些不同的组织和器官，包括颅面结构，它们必须表现出显着的发育可塑性和迁移潜力，这需要仔细执行转录程序。事实上，神经嵴细胞对甚至适度的转录干扰都表现出高度敏感性，因为许多染色质重塑中的突变表现为神经嵴衍生的颅面结构的畸形。已知SRCAP在转录程序的精确调控中起重要作用，作为转录调控的一部分。 一种蛋白质复合物，其通过在转录起始位点和增强子处用组蛋白变体H2A.Z替换规范H2 A-H2 B组蛋白二聚体来促进活性转录。FHS导致颅面缺陷的细胞起源以前尚未建立，体外神经嵴分化模型和高通量非洲爪蟾动物模型的组合使我们能够在多个水平上研究这种疾病，从分子机制到细胞缺陷到疾病状态。我们已经概括了SRCAP FHS截断在体内胚胎模型，显示颅面畸形与综合征一致，以及在体外细胞模型。拟议的研究将利用这些模型来确定FHS的潜在分子，细胞和发育原因，从而提供潜在的治疗目标。最终，我们的研究将有助于从生物学上解释为什么染色质重塑的扰动对颅面发育有如此明显的影响。