Chromatin remodeling in multipotent neural crest formation and CHARGE syndrome

描述(申请人提供)：编码CHD7的基因杂合突变，CHD7是一种依赖于ATP的染色质重构体，与果蝇三胸组蛋白Kismet同源，导致一系列称为Charge综合征的先天性异常，这是一种散发的常染色体显性疾病，特征是头面部结构、外周神经系统、耳朵、眼睛和心脏的畸形。初步研究表明，在Charge综合征的病因学中，神经脊的形成存在缺陷。神经脊是一种瞬时细胞群体，起源于外胚层，但经历了一次重大的转录重新编程，以获得非常广泛的分化潜力和在全身迁移的能力，从而形成颅面部骨骼和软骨、周围神经系统和心脏结构。然而，染色质重塑在这一过程中的作用还不是很清楚。该应用程序解决了CHD7功能障碍在Charge综合征中的潜在机制。将开发电荷患者特异性诱导的多能干细胞系，并将其用作疾病建模和表征与电荷基因相关的细胞和分子缺陷的工具。同时，青蛙胚胎模型将被用来研究体内电荷相关CHD7突变的影响。这项研究将得到人类细胞中CHD7突变体的生化分析的补充。最后，基因组学方法将被用来在全基因组范围内鉴定活跃在人类神经脊细胞中的调节元件。这项分析将精确定位基因组序列，其变异可能使人对一些最常见的出生缺陷易感性，例如包括唇裂和/或腭裂在内的颅面畸形、心脏畸形和周围神经系统缺陷。 与公共卫生相关：这里提出的研究将揭示Charge综合征背后的分子和细胞机制，Charge综合征是聋盲、先天性心脏病和颅面畸形的主要原因。我们的工作将促进对这种多系统综合征的理解和诊断，并可能导致改善对患者的临床干预。此外，我们将确定一组候选基因组序列，其突变可能使人对一些最常见的出生缺陷易感性，例如包括唇裂和/或腭裂在内的颅面畸形、心脏畸形和周围神经系统缺陷。

DESCRIPTION (provided by applicant): Heterozygous mutations in the gene encoding CHD7, an ATP-dependent chromatin remodeler homologous to the Drosophila trithorax group protein Kismet, result in a complex constellation of congenital anomalies called CHARGE syndrome, a sporadic, autosomal dominant disorder characterized by malformations of the craniofacial structures, peripheral nervous system, ears, eyes and heart. Preliminary work implicated defective formation of the neural crest in CHARGE syndrome etiology. Neural crest is a transient cell population that is ectodermal in origin, but undergoes a major transcriptional reprogramming to acquire a remarkably broad differentiation potential and ability to migrate throughout the body to give rise to craniofacial bones and cartilages, peripheral nervous system, and cardiac structures. However, the role of chromatin remodeling in this process is not well understood. This application addresses mechanisms underlying CHD7 dysfunction in CHARGE syndrome. CHARGE-patient specific induced pluripotent stem cell lines will be developed, and used as a tool for disease modeling and characterization of cellular and molecular deficits associated with CHARGE genotypes. In parallel, frog embryo model will be used to study effects of CHARGE-associated CHD7 mutations in vivo. This studies will be complemented by biochemical analyses of CHD7 mutants in human cells. Finally, genomic approaches will be utilized for genome-wide identification of regulatory elements active in human neural crest cells. This analysis will pinpoint genomic sequences whose variation can confer susceptibility to some of the most common birth defects, such as craniofacial dysmorphisms including cleft lip and/or palate, heart malformations and peripheral nervous system defects. PUBLIC HEALTH RELEVANCE: Research proposed here will uncover molecular and cellular mechanisms underlying CHARGE syndrome, a leading cause of deaf-blindness, congenital heart disease and craniofacial malformations. Our work will advance understanding and diagnosis of this multisystemic syndrome and may lead to improved clinical interventions in patients. In addition, we will identify a set of candidate genomic sequences whose mutations may confer susceptibility to some of the most common birth defects, such as craniofacial dysmorphisms including cleft lip and/or palate, heart malformations and peripheral nervous system defects.