Characterization of a novel Drosophila disease model for CHARGE Syndrome

描述(申请人提供)：Charge综合征(CS)是一种罕见的常染色体显性遗传性疾病，以各种临床症状为特征。其中最常见的包括缺损、后鼻孔闭锁、异常半规管、心脏缺陷、智力低下、生长迟缓以及生殖器和耳朵畸形，使CS成为先天性畸形的常见原因。它在每10,000名活产儿中大约有1例流行，很大程度上是由于人类CHD7基因功能突变的丧失(CHD7中的单倍体不足)。CHD7的突变约占所有被诊断为CS的患者的三分之二，尽管人们对这种蛋白质调节的基因(和细胞过程)知之甚少。该项目的长期目标是通过一种新的果蝇疾病模型的表征和应用来更深入地了解CS的发病机制(S)。我们希望，这里提出的研究将最终为CS患者的治疗带来新的诊断工具和/或治疗靶点。通过对模式生物的研究，人们试图了解许多人类疾病的复杂病因。果蝇，黑腹果蝇，在加深我们对各种人类疾病机制的理解方面发挥了极其重要的作用和影响。利用RNA干扰(RNAi)基因敲除策略，我们在成年果蝇中建立了第一个CS的果蝇模型。由于KIS及其人类同系物CHD7编码转录因子，因此识别其表达受这些转录因子调控的生物学相关靶基因，以及其功能与疾病病理有关的基因，对于更好地理解该病的发病机制，以及更好地合理设计治疗干预和/或诊断和预后指标将是至关重要的。果蝇作为一种模式生物，在基因发现和功能基因分析方面具有不可替代的作用。通过对果蝇的遗传筛选和基因芯片分析，我们已经确定了一些受KIS功能调控的靶基因。这些靶基因中的许多都有可能对疾病病理的一个或多个方面做出贡献。我们希望通过以下具体目的进一步测试我们已确定的哪些基因可能对CS疾病病理的特定方面起作用：利用遗传、行为和细胞生物学方法进一步鉴定哪些Kismet靶基因可能与CS中观察到的疾病症状具有生物学相关性。我们将特别集中于粗大运动功能障碍、智力残疾和神经元形态缺陷的分析。 与公共卫生相关：果蝇，黑腹果蝇，在加深我们对各种人类疾病的机制的理解方面具有极其重要和有影响力的作用，包括神经退行性疾病和遗传性智力低下(MR)的形式。因此，我们创建了第一个果蝇模型来治疗充电综合征，这是一种不常见的常染色体显性智力低下形式。使用我们的新模型，我们将确定哪些基因在功能上与果蝇的电荷综合征有关，希望拟议的研究将为电荷综合征患者带来新的诊断工具和/或治疗目标。

DESCRIPTION (provided by applicant): CHARGE Syndrome (CS) is a rare, autosomal dominant disorder that is characterized by a variety of clinical symptoms. The most common of these include Coloboma, Choanal atresia, abnormal semicircular canals, heart defects, mental retardation, retardation of growth, and genital and ear anomalies, making CS a common cause of congenital anomalies. It is prevalent in approximately 1 in every 10,000 live births, and is caused in large part by loss of function mutations in the human Chd7 gene (haploinsufficiency in Chd7). Mutations in Chd7 account for some 2/3 of all patients diagnosed with CS, though little is known about the genes (and cellular processes) this protein regulates. The long term goal of this project is a deeper understanding of the mechanism(s) of pathogenesis of CS through characterization and application of a novel Drosophila model of the disease. Our hope is that research proposed here will ultimately lead to new diagnostic tools and/or therapeutic targets for treatment in patients with CS. Attempts to understand the complex etiology of many human diseases have been improved through the study of model organisms. The fruit fly, Drosophila melanogaster, has been tremendously important and influential in furthering our understanding of the mechanisms of a variety of human diseases. Using an RNA-interference (RNAi) gene knockdown strategy, we have created the first Drosophila model for CS in adult flies. Because kis, and its human homolog Chd7, encode transcription factors, the identification of biologically relevant target genes whose expression is regulated by these transcription factors, and whose function also contributes towards disease pathology will be critically required for a better understanding of this disease's pathogenesis, as well as a better rational design towards therapeutic intervention and/or diagnostic and prognostic indicators. As a model organism, Drosophila are unsurpassed as a tool of gene discovery and functional gene analysis. Using both genetic screening and microarray analysis in Drosophila, we have identified a number of target genes whose expression is regulated by kis function. Many of these target genes have the potential to contribute to one or more aspects of disease pathology. We wish to further test which of the genes that we have identified might contribute to specific aspects of disease pathology in CS through the following specific aim: to employ genetic, behavioral, and cell biological methods to further characterize which Kismet target genes may be biologically relevant to the disease symptoms observed in CS. We will specifically focus our analysis on gross motor dysfunction, intellectual disability, and defects in neuronal morphology. PUBLIC HEALTH RELEVANCE: The fruit fly, Drosophila melanogaster, has been tremendously important and influential in furthering our understanding of the mechanisms of a variety of human diseases, including neurodegenerative diseases, and forms of hereditary mental retardation (MR). Thus, we have created the first Drosophila model for CHARGE Syndrome, an uncommon autosomal dominant form of mental retardation. Using our new model, we will determine what genes functionally contribute to CHARGE Syndrome in flies, with the hope that the research proposed will lead to novel diagnostic tools and/or therapeutic targets for patients with CHARGE Syndrome.