Neural Crest Modulates FGF Signaling in the Pharynx

神经嵴调节咽部 FGF 信号传导

• 批准号: 7841929
• 负责人: Margaret Loewy Kirby
• 金额: $ 38.4万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2011-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7841929
• 关键词: Ablation; Affect; Antibodies; Aorta; Cardiac; Cell Death; Cell Line; Cells; Chick Embryo; Child; Childhood; Chimera organism; Coculture Techniques; Code; Congenital Heart Defects; Data; Defect; Depressed mood; Development; Double Outlet Right Ventricle; Ectoderm; Embryo; Embryonic Development; Endocytosis; Endoderm; Event; FGF8 gene; Failure; Fibroblast Growth Factor; Floor; Gene Expression; Gene Targeting; Genetic Transcription; Heart; In Situ Hybridization; In Vitro; Infant; Investigation; Label; Laboratories; Lead; Measures; Mediating; Mesenchyme; Modeling; Morbidity - disease rate; Myocardial; Myocardium; Neural Crest; Neural Crest Cell; Operative Surgical Procedures; Pharyngeal structure; Plasmids; Positioning Attribute; Production; Protein Isoforms; Proteins; Quail; Regulation; Reporter; Role; Signal Transduction; Smooth Muscle Myocytes; Source; Staging; Testing; Time; Tissues; Vesicle; base; cardiogenesis; in vivo; insight; laser capture microdissection; malformation; migration; mortality; novel; overexpression; research study; response

DESCRIPTION (provided by applicant): Conotruncal malformations are severe congenital cardiac defects that require surgery early in childhood. Infants born with these defects suffer from significant morbidity and mortality. Abnormal embryonic development of the outflow tract (a region defined as the outflow vessels including the junction with the myocardium, called the arterial pole) produces these defects. In recent studies of the neural crest-ablation model in chick embryos, we have discovered a secondary heart field (SHF) in the ventral pharyngeal mesenchyme that provides myocardial and smooth muscle cells to the arterial pole of the developing heart. After neural crest ablation, myocardium from the SHF is not added to the growing arterial pole and this results in conotruncal malalignment defects such as overriding aorta and double outlet right ventricle. Our preliminary results indicate that the failure of myocardial addition to the outflow tract and subsequent malalignment defects are due to elevated FGF signaling in the caudal pharynx after neural crest ablation based on four pieces of evidence from investigations performed in this laboratory: 1) FGF target genes are elevated after neural crest ablation; 2) Fgf8b, the most active isoform of FGF8 is elevated; 3) a reporter cell line for FGF registers elevated FGF8b signaling in the ventral pharynx; and 4) blocking FGF8 signaling restores addition of the myocardium from the SHF and normal alignment of the outflow tract in neural crest- ablated embryos. These preliminary data support our overall hypothesis that normal development of the arterial pole depends on the regulation of FGF8b signaling in the pharynx by cardiac neural crest cells. We will test the specific hypotheses: that elevated FGF8b leads to abnormal arterial pole development by affecting proliferation, migration and/or differentiation of the myocardial component of the secondary heart field (aim 1); neural crest cells normally depress FGF8 signaling in the caudal pharynx by endocytosis of the FGF protein and/or by decreasing the transcription of the Fgf8b isoform (aim 2). In aim 1, we will expose explanted SHF to various concentrations of FGF8b and determine its effect on phospho-ERK, proliferation, migration, cell death and differentiation. We will electroporate an FGF8b expressing plasmid into the pharyngeal endoderm of chick embryos in ovo to correlate developmental events in the secondary heart field with outflow alignment. In aim 2, we will determine the dynamics of FGF8b endocytosis in vitro followed by blocking endocytosis in vivo to determine its role in outflow alignment. Finally we will determine the relationship of neural crest with endoderm and ectoderm in controling FGF8b isoform expression. Together these studies will advance the mechanistic understanding of neural crest function in heart development and will provide insight into factors that cause conotruncal malformations.

描述（由申请人提供）：骨膜畸形是严重的先天性心脏缺陷，需要在儿童早期进行手术。患有这些缺陷的婴儿患有明显的发病率和死亡率。流出道的异常胚胎发育（一个定义为与心肌连接在内的流出容器，称为动脉极）会产生这些缺陷。在对雏鸡胚胎中神经波峰模型的最新研究中，我们在腹咽间质中发现了一个次生心脏场（SHF），该心脏是为心脏的动脉极提供心肌和平滑肌细胞的。神经波峰消融后，SHF的心肌不会添加到生长的动脉极中，这会导致孔隙不符合不符缺陷，例如覆盖主动脉和双出口右心室。我们的初步结果表明，心肌在流出道中的添加失败以及随后的恶意缺陷，是由于神经波峰消融后的尾骨咽的FGF信号升高所致，基于该实验室中进行的研究的四个证据：1）FGF靶基因升高后FGF靶基因升高后，Neural Crest Crest crest crest crest crest crest a Blest Abletation ablest Neural Crest Abletation ablestation ablest ablest abletation ablest ablest abletation ablest ablest ablest abletation ablest ablest ablest ablest ablest。 2）FGF8B，FGF8最活跃的同工型升高； 3）FGF登记板的记者细胞系升高FGF8B信号传导； 4）阻断FGF8信号传导可恢复SHF中的心肌的添加，并在神经crest的胚胎中恢复流出道的正常比对。这些初步数据支持我们的总体假设，即动脉极的正常发育取决于心脏神经crest细胞中FGF8B信号传导的调节。我们将检验特定的假设：升高的FGF8B通过影响次级心脏场的心肌成分的增殖，迁移和/或分化而导致动脉极发育异常（AIM 1）；神经rest细胞通常通过FGF蛋白的内吞作用和/或降低FGF8B同工型的转录（AIM 2）来降低尾咽中的FGF8信号传导。在AIM 1中，我们将使外植的SHF暴露于各种浓度的FGF8B，并确定其对磷酸化，增殖，迁移，细胞死亡和分化的影响。我们将在OVO中的小鸡胚胎的咽内胚层中进行电燃料，以将次级心脏场中的发育事件与流出比对相关联。在AIM 2中，我们将在体外确定FGF8B内吞作用的动力学，然后确定体内内吞作用，以确定其在流出排列中的作用。最后，我们将确定神经rest与内胚层和外胚层控制FGF8B同工型表达的关系。这些研究将共同​​提高对心脏发育中神经rest功能的机械理解，并将洞悉引起构成畸形的因素。

项目成果

Signals controlling neural crest contributions to the heart.

• DOI: 10.1002/wsbm.8
• 发表时间: 2009-09
• 期刊: WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE
• 影响因子: 7.9
• 作者: Scholl, Ann Marie;Kirby, Margaret L.
• 通讯作者: Kirby, Margaret L.

Mouse models of congenital heart defects: what's missing?

• DOI: 10.1161/circimaging.110.956979
• 发表时间: 2010-05
• 期刊: Circulation. Cardiovascular imaging
• 作者: Kirby ML;Sahn DJ
• 通讯作者: Sahn DJ

Epicardium and myocardium separate from a common precursor pool by crosstalk between bone morphogenetic protein- and fibroblast growth factor-signaling pathways.

• DOI: 10.1161/circresaha.109.203083
• 发表时间: 2009-08-28
• 期刊: Circulation research
• 影响因子: 20.1
• 作者: van Wijk B;van den Berg G;Abu-Issa R;Barnett P;van der Velden S;Schmidt M;Ruijter JM;Kirby ML;Moorman AF;van den Hoff MJ
• 通讯作者: van den Hoff MJ