Eph/ephrin signaling in craniofacial development and disease

项目摘要/摘要 侯选人 杰弗里·O·布什是罗切斯特大学博士后，因工作原因获得博士学位。 在了解自发发生的舞蹈家突变小鼠的唇腭裂方面。这部作品 发现转录因子Tbx10的功能增强是唇腭裂的原因 的表型，并确定了极少数已知的遗传原因之一 老鼠。作为菲利普·索里亚诺实验室的博士后研究员，这位候选人专注于 了解eparin-B1在影响颅面发育的先天性疾病病因中的作用， 颅咽管综合征(CFNS)。这项研究表明，腭裂的表型与 EPhin-B1功能丧失是由前腭架发育和增殖缺陷引起的，作为一种 前向信令丢失的后果。候选人的短期职业目标是发展这些研究 成为一个独立的研究项目，研究Eph/EPhin信号在头面部发育中的作用，长期- 学期的职业目标是将这一研究项目扩展到研究其他颅面先天性缺陷，重点是 参与颅面发育和疾病的信号分子。 环境 拟议的工作将在以下部门的菲利普·索里亚诺教授的实验室进行 西奈山医学院的发育和再生生物学。实验室有一个世界- 在发育过程中信号功能的小鼠遗传学研究方面的成就的课堂记录，并 在理解整个过程中的血小板衍生生长因子信号方面做出了重大贡献 发育，包括头面部发育。发展与再生部 生物学包括14名全职教师，他们研究以发展为中心的各种问题， 器官的再生和构图。实验室和部门内部可用的资源将 在指导阶段和向独立的过渡阶段为候选人提供重要支持。 研究 颅面畸形极为常见，四分之三的先天畸形 出生时发现的异常。这些疾病包括腭裂，出生时口腔顶部未能连接 大约每1000名活产儿中就有一名发生这种情况。颅面部疾病的治疗涉及多个 侵入性手术，并对受影响个人的童年健康和家庭产生重大影响。一 这种遗传性疾病，颅咽管综合征(CFNS)是由ePhin-B1基因突变引起的。 这是一种X连锁的疾病，会导致许多头面部缺陷，包括，端头过长，鼻部 凹槽、冠状颅骨融合和唇腭裂。小鼠体内同一基因的突变会导致 同样的缺陷，支持了老鼠是研究这个和其他的很好的模式生物的想法 头面部疾病。Ephin-B1是通过激活EphB而起作用的信号分子家族的成员 感受器。该基因家族在多种发育和疾病中具有重要功能。 上下文。我们有数据表明，另一种eaffin基因ePhin-B2可能在 颅面发育和疾病。在本申请的第一个目的中，我建议研究ePhin-B2功能 通过研究从特定头面部组织中移除其功能的小鼠在头面部发育中的作用 在开发过程中。我将通过利用目前可用的等位基因从腭部移除ePhin-B2来做到这一点 货架上皮细胞，在那里它高度表达。此外，我将采取一种特定组织的救援策略来测试 在颧弓形成过程中对ePhin-B2的需求。根据初步表达数据，EphB4， 在其形成过程中，一种重要的肾上腺素-B2受体在上颌骨中高度表达。在第二个 目的，因此我建议测试EphB4在次级腭部形成过程中的作用，方法是产生一个 条件等位基因对神经脊来源的EphB4功能的组织特异性干扰 间充质的我。最后，我已经开始了研究，以确定Eph/EPhin信号的下游组件 通过开发一种基于质谱学的蛋白质组学方法来鉴定磷酸化靶点 EphB/ePhin-B在上颚发出信号。这种方法已经确定了大量优秀的 下游信号转导的候选分子。这些候选人的角色大多不为人知 在头面部发育方面，因此我建议在第三个目标中优先考虑和研究这些候选人， 其目标是研究控制腭部形成的ePhin-B信号下游的信号通路。 这项研究将极大地提高对腭裂遗传原因的理解，通过识别 EPhin-B2和EphB4在其发育过程中的重要性，以及通过鉴定新的基因 在颅面发育和疾病中的重要性未知。

Project Summary/Abstract Candidate Jeffrey O. Bush is a postdoctoral fellow who received his Ph.D. at the University of Rochester for work in understanding cleft lip and palate in the spontaneously-occurring Dancer mutant mouse. This work identified gain of function of the transcription factor Tbx10 as being causative to the cleft lip and palate phenotype in the Dancer mice and identified one of a very few known genetic causes for this phenotype in mice. As a postdoctoral fellow in the laboratory of Philippe Soriano, the candidate has focused on understanding ephrin-B1 function in the etiology of a congenital disorder affecting craniofacial development, Craniofrontonasal syndrome (CFNS). This work has shown that the cleft palate phenotype associated with ephrin-B1 loss of function is caused by defective anterior palatal shelf outgrowth and proliferation, as a consequence of loss of forward signaling. The candidate's short-term career goal is to evolve these studies into an independent research program studying Eph/ephrin signaling in craniofacial development, with a long- term career goal to expand this research program to study other craniofacial congenital defects with a focus on signaling molecules involved in craniofacial development and disease. Environment The proposed work will take place in the laboratory of Professor Philippe Soriano in the Department of Developmental and Regenerative Biology at the Mount Sinai School of Medicine. The laboratory has a world- class record of accomplishment in mouse genetics studies of signaling function during development, and has made significant contribution into the understanding of Platelet-Derived Growth Factor signaling throughout development, including craniofacial development. The Department of Developmental and Regenerative Biology includes fourteen full-time faculty that study various questions centered on the development, regeneration, and patterning of organs. The resources available within the laboratory and the department will provide significant support to the candidate during the mentored phase and transition to independence. Research Craniofacial malformations are extremely common, identified in three quarters of all congenital abnormalities identified at birth. These include cleft palate, a failure of the roof of the mouth to join at birth which occurs in approximately 1 in 1000 live births. The treatment of craniofacial conditions involves multiple invasive surgeries, and has a dramatic impact on an affected individual's childhood health and family. One such genetic disorder, Craniofrontonasal syndrome (CFNS) is caused by mutations in the ephrin-B1 gene. This is an X-linked disorder that causes a number of craniofacial defects including, hypertelorism, nasal grooves, coronal craniosynostosis and cleft lip and palate. Mutations in the same gene in mice cause the same defects, supporting the idea that the mouse is a good model organism for studying this and other craniofacial diseases. Ephrin-B1 is a member of a family of signaling molecules that act by activating EphB receptors. This family of genes have important functions in a wide variety of developmental and disease contexts. We have data indicating that an additional ephrin gene, ephrin-B2, may play important roles in craniofacial development and disease. In the first aim of this application, I propose to study ephrin-B2 function in craniofacial development by studying mice in which its function is removed from specific craniofacial tissues during development. I will do this by utilizing currently available alleles to remove ephrin-B2 from the palatal shelf epithelium, where it is highly expressed. Additionally, I will take a tissue-specific rescue strategy to test for requirement for ephrin-B2 during branchial arch formation. Based on preliminary expression data, EphB4, an important receptor for ephrin-B2 is highly expressed within the palate during its formation. In the second aim, I therefore propose to test for a role of EphB4 during formation of the secondary palate by generating a conditional allele to perform tissue-specific disruption of EphB4 function in the neural crest-derived mesenchyme. Finally, I have initiated studies to identify downstream components of the Eph/ephrin signaling network by developing a mass-spectrometry based proteomic approach to identify phosphorylation targets of EphB/ephrin-B signaling in the palate. This approach has already identified a large number of excellent candidate molecules for transduction of downstream signaling. These candidates have mostly unknown roles in craniofacial development, and I therefore propose in the third aim to prioritize and study these candidates, with the goal of elaborating signaling pathways downstream of ephrin-B signaling that control palate formation. This study will greatly enhance understanding of the genetic causes of cleft palate by identifying the importance of ephrin-B2 and EphB4 in its development, and by characterizing new genes with previously unknown importance in craniofacial development and disease.