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.
In the US, the most common cause of death in infants is birth defects, and chief among these is congenital heart disease, or 'holes in the heart.' The genetic basis for congenital heart disease is not well established, but our interdisciplinary team of physicians and basic cell biologists promises to shed light on at least one potential cause. Our hope is to provide patients and parents with a better understanding of the disease, genetic counseling, and to improve the long-term outcome of these patients.
|Griffin, John N; Del Viso, Florencia; Duncan, Anna R et al. (2018) RAPGEF5 Regulates Nuclear Translocation of ?-Catenin. Dev Cell 44:248-260.e4|
|Garfinkel, Alexandra MacColl; Khokha, Mustafa K (2017) An interspecies heart-to-heart: Using Xenopus to uncover the genetic basis of congenital heart disease. Curr Pathobiol Rep 5:187-196|
|Duncan, Anna R; Khokha, Mustafa K (2016) Xenopus as a model organism for birth defects-Congenital heart disease and heterotaxy. Semin Cell Dev Biol 51:73-9|
|Del Viso, Florencia; Huang, Fang; Myers, Jordan et al. (2016) Congenital Heart Disease Genetics Uncovers Context-Dependent Organization and Function of Nucleoporins at Cilia. Dev Cell 38:478-92|
|Huang, Fang; Sirinakis, George; Allgeyer, Edward S et al. (2016) Ultra-High Resolution 3D Imaging of Whole Cells. Cell 166:1028-1040|
|Reza, Nooreen; Khokha, Mustafa K; Del Viso, Florencia (2016) Nucleoporin gene expression in Xenopus tropicalis embryonic development. Int J Dev Biol 60:181-8|
|Endicott, S Joseph; Basu, Basudha; Khokha, Mustafa et al. (2015) The NIMA-like kinase Nek2 is a key switch balancing cilia biogenesis and resorption in the development of left-right asymmetry. Development 142:4068-79|