Elucidating a novel function for slco1a2, an organic anion transporter, in left-right patterning and cardiac development

 描述（由申请人提供）：先天性心脏病（CHD）是最常见的出生缺陷，影响美国约1%的活产婴儿，是婴儿死亡的主要原因之一。严重形式的CHD可由异位（Htx）引起，这是胚胎发育期间左右（LR）模式的障碍。最近对异位症患者的遗传分析确定了一个新的CHD候选基因，slco 1a 2。Slco 1a 2编码有机阴离子转运蛋白Oatp 1a 2，其对于各种内源性分子以及药物跨顶膜的转运是重要的。然而，它在LR模式或胚胎发育中没有已知的作用。在高通量人类疾病模型非洲爪蟾中使用不同的敲除/敲除策略，slco 1a 2的丢失导致LR图案缺陷，重现患者的表型。该建议的总体目标是阐明slco 1a 2影响爪蟾（青蛙）模型系统中LR模式和心脏发育的分子机制。第一个目标将使用功能丧失实验来确定slco 1a 2在心脏发育过程中所需的作用，然后通过测试分子标记物，研究该基因在LR模式级联中的哪一步起作用。第二个目标是研究slco 1a 2 mRNA在整个胚胎中的时空表达，并检查蛋白质在这些组织/时间中的亚细胞定位。第三个目标将通过突变影响蛋白质转运特定底物能力的关键氨基酸残基来确定蛋白质的已知转运功能是否对其在LR模式和心脏发育中的作用很重要。总之，这些实验将提高我们对心脏发育和slco 1a 2在CHD发病机制中的作用的理解。在未来，这将有利于基因检测和咨询，以及改善冠心病的结果，因为治疗可以针对基因型而不仅仅是冠心病表型。此外，该申请详细说明了申请人的培训计划，包括研究指导，高级课程，新技术培训以及科学专业，写作和数据展示技能的发展。本申请中概述的研究和培训将使申请人能够作为独立的医生-科学家从事患者驱动的研究。

 DESCRIPTION (provided by applicant): Congenital Heart Disease (CHD) is the most common birth defect affecting approximately 1% of all live births in the US and is one of the leading causes of infant mortality. A severe form of CHD can result from Heterotaxy (Htx), a disorder of Left-Right (LR) patterning during embryonic development. A recent genetic analysis of heterotaxy patients identified a novel CHD candidate gene, slco1a2. Slco1a2 encodes the organic anion transporter Oatp1a2, which is important for the transport of various endogenous molecules as well as drugs across the apical membrane. However, it has no known role in LR patterning or embryonic development. Using different knockdown/knockout strategies in the high-throughput human disease model, Xenopus, loss of slco1a2 leads to LR patterning defects, recapitulating the patient's phenotype. The overall goal of this proposal is to investigat the molecular mechanism by which slco1a2 affects LR patterning and heart development in the Xenopus (frog) model system. The first aim will use loss of function experiments to determine the required role of slco1a2 during cardiac development and then, by testing molecular markers, investigate at which step in the LR patterning cascade the gene plays a role. The second aim will investigate the spatial-temporal expression of slco1a2 mRNA in the whole embryo and examine the protein's sub-cellular localization in those tissues/times. The third aim will determine if the protein's known transport function is important for its role in LR patterning and cardiac development by mutating critical amino acid residues that affect the protein's ability to transport specific substrates. Altogether, these experiments will improve our understanding of cardiac development and the role of slco1a2 in the pathogenesis of CHD. In the future, this will benefit genetic testing and counseling, as well as improve outcomes in CHD because treatments can be tailored to genotype rather than solely on CHD phenotype. In addition, this application details the applicant's training plan including research mentorship, advanced coursework, training in new techniques, and the development of skills in scientific professionalism, writing, and presentation of data. The research and training outlined in this application will prepare the applicant to pursue a career performing patient-driven research as an independent physician- scientist.