Characterization of the roles and regulation of Draxin in cranial neural crest

Draxin 在颅神经嵴中的作用和调节的表征

• 批准号: 10400365
• 负责人: Erica Hutchins
• 金额: $ 8.56万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10400365
• 关键词: 3' Untranslated Regions; Affect; Award; COVID-19; Cartilage; Cephalic; Cleft Palate; Craniofacial Abnormalities; Defect; Development; DiGeorge Syndrome; Disease; Down-Regulation; Embryo; Epithelial; Equilibrium; Face; Faculty; Fluorescence Resonance Energy Transfer; Funding; Genetic Transcription; Goals; Head; Knowledge; Lead; Mandibulofacial Dysostosis; Mediating; Mesenchymal; Microscopy; Molecular; Mutation; Names; Neural Crest; Neural Crest Cell; Neural tube; Neuraxis; Parents; Phase; Population; Positioning Attribute; Proteins; Publications; Publishing; RNA immunoprecipitation sequencing; RNA-Binding Proteins; Regulation; Research; Role; Secure; Signal Transduction; Skeleton; Techniques; Time; Translational Research; Universities; WNT Signaling Pathway; Work; career; craniofacial; craniofacial structure; epithelial to mesenchymal transition; experimental study; in vivo; malformation; migration; molecular imaging; neuroepithelium; post-doctoral training; programs; public health relevance; single molecule; skills; spatiotemporal; stem cell population; tenure track

PROJECT SUMMARY/ABSTRACT The neural crest (NC) is a stem cell population that originates within the forming central nervous system. NC cells delaminate from the neuroepithelium by undergoing a spatiotemporally regulated epithelial— mesenchymal transition (EMT) to exit from the neural tube. Cranial NC cells, which arise in the head region of the embryo and are the only NC population in vivo with the ability to differentiate into craniofacial skeleton and cartilage, are indispensable for the development of the face; mutations affecting NC development result in numerous diseases and malformations affecting the craniofacial structures. The focus of my postdoctoral work has been to study the mechanisms that control and facilitate cranial NC EMT. During the first phase of my postdoctoral training, I have shown that this developmental EMT program is controlled by temporally restricted expression of the Wnt antagonist, Draxin. A hallmark of Draxin's function during EMT is its transient expression and rapid downregulation; perdurance of Draxin has deleterious effects on cranial NC EMT through dysregulation of downstream targets of canonical Wnt signaling. Through the support of the K99, I discovered that the transience of Draxin expression in cranial NC is mediated post-transcriptionally via its 3'-untranslated region (UTR). Importantly, Draxin is stabilized by the RNA-binding protein Elavl1/HuR at the premigratory stage, then targeted to cytoplasmic processing bodies (P-bodies) for decay to drive proper cranial NC EMT. Collectively, these discoveries begin to unravel a new mechanism whereby cranial NC EMT is regulated through post-transcriptional regulatory mechanisms balancing stability and decay of a molecular rheostat, Draxin. COVID-19 research restrictions and university closures severely delayed my career plans and development. Through the support of the K99, I completed many of the goals proposed in Aims 1 and 3 of my original proposal, which sought to illuminate the interaction between Draxin and Wnt signaling, and the regulation Draxin expression, respectively. However, COVID-19 research restrictions severely delayed the completion of Aim 1 and progress of Aim 2, which sought to apply time-lapse and advanced microscopy techniques (e.g. FRET) to more fully explore Draxin function. Further, completion of Aim 3 and publication of these studies requires additional experiments in single-molecule imaging and RIP-seq. A funding extension would allow me to develop critical new skills in advanced microscopy and RIP-seq to gain a mechanistic understanding of Draxin activity during cranial NC EMT, and allow me to comple the revision experiments necessary to publish the work performed under the parent K99 award to help me secure a tenure-track faculty position, establish a vibrant independent research program in the developmental signaling field, and better equip me with the knowledge necessary to transition into the study of cranial NC development and migration.

项目概要/摘要 神经嵴 (NC) 是起源于正在形成的中枢神经系统的干细胞群 NC 细胞通过时空调节的上皮细胞从神经上皮中分层—— 间充质转化（EMT）从神经管中退出，出现在头部区域。 胚胎，是体内唯一具有分化为颅面骨骼和能力的 NC 群体 软骨，对于面部的发育是不可或缺的；影响 NC 发育的突变导致 许多影响颅面结构的疾病和畸形是我博士后工作的重点。 在我的第一阶段，我一直在研究控制和促进颅脑 NC EMT 的机制。 博士后培训，我已经证明这个发展性的 EMT 计划是受时间限制的控制的 Wnt 拮抗剂 Draxin 的表达 Draxin 在 EMT 过程中的功能标志是其瞬时表达。 Draxin 的快速下调对颅脑 NC EMT 产生有害影响； 通过 K99 的支持，我发现了规范 Wnt 信号下游靶点的失调。 颅内 NC 中 Draxin 表达的短暂性是通过其 3'-非翻译蛋白在转录后介导的 重要的是，Draxin 在迁移前被 RNA 结合蛋白 Elavl1/HuR 稳定。 阶段，然后针对细胞质加工体（P 体）进行衰变，以驱动适当的颅脑 NC EMT。 总的来说，这些发现开始揭示一种调节颅脑 NC EMT 的新机制 通过转录后调节机制平衡分子变阻器的稳定性和衰减， Draxin。COVID-19 研究限制和大学关闭严重推迟了我的职业计划和 通过K99的支持，我完成了目标1和目标3中提出的许多目标。 最初的提案试图阐明 Draxin 和 Wnt 信号传导之间的相互作用，以及 然而，COVID-19 研究限制严重推迟了 Draxin 表达。 目标 1 的完成和目标 2 的进展，旨在应用延时和先进的显微镜技术 技术（例如 FRET）来更全面地探索 Draxin 功能，进一步完成目标 3 并发表 这些研究需要单分子成像和 RIP-seq 方面的额外实验 A 资助延期。 将使我能够开发先进显微镜和 RIP-seq 方面的关键新技能，以获得机制 了解颅脑 NC EMT 期间的 Draxin 活动，并允许我完成修订实验 有必要发表在家长 K99 奖项下所做的工作，以帮助我获得终身教授职位 的地位，在发育信号领域建立一个充满活力的独立研究项目，并更好地 为我提供了过渡到颅脑 NC 发展和迁移研究所需的知识。