Zfp423 Mechanisms in Joubert Syndrome and Related Disorders

项目摘要： 这个项目的重点是细胞，遗传和分子机制，发展的基础 ZNF 423相关纤毛病变的异常。睫状体病包括一系列疾病， 是由初级纤毛的缺陷造成的临床表现包括原发性单个器官受累 (most通常是后脑、肾、肝或眼）到更严重的表现，如梅克尔综合征， 在几个器官中具有严重和多效性的发育表型。一些基因已经被 被鉴定为纤毛病疾病，其中绝大多数编码的物理成分， 初级纤毛控制纤毛依赖性信号传导的调节基因和 控制睫状体缺陷的结果只是开始与致病机制有关。这 该项目的重点是ZNF 423的作用和机制，ZNF 423是一种组成型核转录因子， Joubert综合征（JBTS 19）和肾单位结核（NPHP 14）患者中突变的调节蛋白。 ZNF 423被认为在几个转录复合体中包含一个整合节点， 对典型的发育信号做出反应由于ZNF 423的表达也是发育动态的， 表型是细胞自主的程度，而不是相互细胞间的缺陷。 信号，目前还不清楚。目标1将使用最近开发的遗传工具（MADM）来评估细胞 通过建立一个简单的平台，诱导和标记有丝分裂克隆原位自主。因为 患者突变是个体罕见的，通常仅在一个等位基因上发现，并且在具有以下特征的受试者中发现： 目前尚不清楚哪些患者可归因于ZNF 423，哪些患者可归因于ZNF 423。 ZNF423突变是真正的致病性。Aim 2将使用基因组编辑技术， 小鼠模型，以测试患者来源的突变的表型效应。目前尚不清楚具体 ZNF 423活性的靶点可能能够调节表型。目标3将决定是否 新发现的ZNF 423抑制基因的活性降低，其表达在两种细胞中均增加， 敲低细胞和突变动物，可以改善纤毛依赖性功能和紧急 Zfp423小鼠模型中的表型。

Project Summary: This project focuses on cellular, genetic, and molecular mechanisms that underlie developmental abnormalities in ZNF423-realted ciliopathy. The ciliopathies comprise a spectrum of disorders unified by defects in primary cilia. Clinical presentations range from primary involvement of a single organ (most often hindbrain, kidney, liver or eye) to more severe presentations, such as Meckel syndrome, with severe and pleiotropic developmental phenotypes in several organs. Several genes have been identified for ciliopathy disorders, with the overwhelming majority encoding physical components of primary cilia. Regulatory genes that control cilium-dependent signaling and genetic modifiers that control the outcome of ciliary defects are only beginning to be tied to pathogenic mechanisms. This project focuses on the role and mechanisms of ZNF423, a constitutively nuclear transcriptional regulatory protein mutated in Joubert syndrome (JBTS19) and nephronophthisis (NPHP14) patients. ZNF423 is thought to comprise an integrative node among several transcriptional complexes that respond to classical developmental signals. As ZNF423 expression is also developmentally dynamic, the extent to which phenotypes are cell autonomous, rather than defects in reciprocal intercellular signaling, remains unclear. Aim 1 will use recently developed genetic tools (MADM) to assess cell autonomy by creating a simple platform for inducing and marking mitotic clones in situ. Because patient mutations are individually rare, often found on only one allele, and found in subjects with a range of presentations, it remains unclear what fraction of patients is attributable to ZNF423 and which ZNF423 mutations are truly pathogenic. Aim 2 will use genome editing in a sensitive and well-validated mouse model to test phenotypic effect of patient-derived mutations. It remains unclear whether specific targets of ZNF423 activity might be able to modulate phenotype. Aim 3 will determine whether decreasing activity of newly identified ZNF423-repressed genes, whose expression is increased in both knockdown cell and mutant animals, can improve cilium-dependent functions and emergent phenotypes in the Zfp423 mouse model.