New mechanisms of heterotaxy and congenital heart disease: nucleoporins at cilia

 描述(申请人提供)：先天性心脏病是美国婴儿死亡和发病的主要原因之一。然而，我们对这种疾病的遗传原因知之甚少。为了更好地了解先天性心脏病，我们分析了人类心脏畸形的遗传学。特别是，我们研究了先天性心脏病的异位症患者的拷贝数变异。心脏发育异位是一种左-右模式的紊乱，由于心环形态发生失败而改变心脏发育。在一名异型患者中，我们发现了NUP188基因的重复，该基因编码核孔复合体的一种成分，称为核孔蛋白。然后，我们在非洲爪哇建立了这种心血管疾病的模型，通过敲除nup188来建立模型，nup188概括了人类的异质性表型。这项提议的主要目标是分析核孔素在左-右模式和先天性心脏病中的作用。我们的初步数据表明，核孔素对纤毛很重要。纤毛是左右排列的关键调节器，因此纤毛的丧失可以解释左右翼的表型。在这个建议中，我们有三个主要目的：1)分析多个核孔素，看看它们是否也改变了左右的图案和纤毛；2)使用超分辨率成像来确定纤毛底部的核孔素的结构；3)确定核孔素对纤毛功能的作用机制。

 DESCRIPTION (provided by applicant): Congenital heart disease is one of the major causes of infant mortality and morbidity in the US. However, we know little about the genetic causes of this disease. In order to better understand congenital heart disease, we analyzed the human genetics of cardiac malformations. In particular, we studied heterotaxy patients with congenital heart disease for copy number variations. Heterotaxy is a disorder of left-right patterning and alters cardiac development due to failure of cardiac looping morphogenesis. In a heterotaxy patient, we identified duplication in the NUP188 gene, which encodes a component of the nuclear pore complex known as a nucleoporin. We then modeled this cardiovascular disease in Xenopus by knocking down nup188, which recapitulated the human heterotaxy phenotype. The main goal of this proposal is to analyze the role of nucleoporins in left-right patterning and congenital heart disease. Our preliminary data suggest that nucleoporins are important for cilia. Cilia are critical regulators of left-right patterning and so loss of cilia could explain the left-ight phenotype. In this proposal, we have three main aims: 1) Analyze multiple nucleoporins to see if they also alter left-right patterning and cilia 2) use super-resolution imaging to define the structure of nucleoporins at the base of the cilium and 3) determine the mechanism by which nucleoporins contribute to the function of cilia.