Chromatin remodeling in multipotent neural crest formation and CHARGE syndrome

描述（由申请人提供）：编码CHD 7（一种与果蝇三胸组蛋白Kismet同源的ATP依赖性染色质重塑物）的基因中的杂合突变导致称为CHARGE综合征的复杂先天性异常，这是一种散发性常染色体显性遗传疾病，特征为颅面结构、外周神经系统、耳、眼和心脏畸形。初步研究表明CHARGE综合征病因学中神经嵴形成缺陷。神经嵴是一种起源于外胚层的瞬时细胞群，但经历了主要的转录重编程以获得显著广泛的分化潜力和在全身迁移的能力，从而产生颅面骨和软骨、外周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清楚。本申请涉及CHARGE综合征中CHD 7功能障碍的潜在机制。将开发CHARGE患者特异性诱导多能干细胞系，并将其用作疾病建模和表征与CHARGE基因型相关的细胞和分子缺陷的工具。与此同时，青蛙胚胎模型将用于研究体内CHARGE相关CHD 7突变的影响。这项研究将通过对人类细胞中CHD 7突变体的生物化学分析来补充。最后，基因组方法将用于全基因组鉴定人类神经嵴细胞中的调控元件。这项分析将精确定位基因组序列，这些基因组序列的变异可能会导致一些最常见的出生缺陷的易感性，例如颅面畸形，包括唇裂和/或腭裂，心脏畸形和外周神经系统缺陷。 公共卫生相关性：这里提出的研究将揭示CHARGE综合征的分子和细胞机制，CHARGE综合征是致盲、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，并可能改善患者的临床干预措施。此外，我们将确定一组候选基因组序列，其突变可能会导致一些最常见的出生缺陷，如颅面畸形，包括唇裂和/或腭裂，心脏畸形和周围神经系统缺陷的易感性。

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.