Chromatin remodeling in multipotent neural crest formation and CHARGE syndrome

描述（由申请人提供）：编码CHD7的基因杂合突变，CHD7是一种atp依赖性染色质重塑因子，与果蝇三胸蛋白Kismet同源，导致称为CHARGE综合征的复杂先天性异常星座，这是一种散发的常染色体显性疾病，以颅面结构、周围神经系统、耳朵、眼睛和心脏畸形为特征。初步研究表明，神经嵴形成缺陷与CHARGE综合征的病因有关。神经嵴是一种起源于外胚层的短暂细胞群，但经过主要的转录重编程，获得了非常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、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尚不清楚。该应用程序解决了CHARGE综合征中CHD7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。同时，将利用青蛙胚胎模型研究电荷相关CHD7突变在体内的影响。这项研究将辅以人类细胞中CHD7突变体的生化分析。最后，基因组方法将被用于人类神经嵴细胞中活性调控元件的全基因组鉴定。这种分析将精确定位基因组序列，其变异可以赋予一些最常见的出生缺陷的易感性，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。

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.