The role of PHD12 in epigenetic control of cranial neural crest EMT

PHD12在颅神经嵴EMT表观遗传控制中的作用

• 批准号: 8153053
• 负责人: Marianne Bronner
• 金额: $ 7.17万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-02 至 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8153053
• 关键词: Address; Affect; Ameloblasts; Anterior; Binding; Boxing; Branchial arch structure; Cadherins; Cartilage; Cell Polarity; Cells; Cephalic; Chick Embryo; Chromatin; Cleft Palate; Co-Immunoprecipitations; Complex; Congenital Abnormality; Craniofacial Abnormalities; Data; Deacetylation; Defect; Development; Dorsal; Down-Regulation; Embryo; Epigenetic Process; Epithelial; Event; Face; Family; Family member; Gene Targeting; Genes; Genetic Transcription; Goals; Histone Deacetylation; Histones; Immigration; Lead; Location; Long-Term Effects; Mesenchymal; Modification; Multipotent Stem Cells; Multiprotein Complexes; Names; Neural Crest; Neural Crest Cell; Neural tube; Neuroepithelial Cells; Neuroglia; Neurons; Odontoblasts; Osteogenesis; Peripheral Nervous System; Phase; Plants; Population; Primordium; Process; Reading; Recruitment Activity; Reporting; Repression; Role; Signal Transduction; Site; Skeleton; Smooth Muscle; Snails; Staging; Structure; Testing; Time; Tooth structure; Work; base; blastomere structure; bone; cancer cell; cancer type; cell type; craniofacial; cranium; epithelial to mesenchymal transition; face bone structure; gene discovery; homeodomain; in vivo; knock-down; loss of function; melanocyte; member; migration; palatal shelves; programs; promoter; research study

DESCRIPTION (provided by applicant): Neural crest (NC) is a transient embryonic multipotent group of cells that arises within the dorsal neural tube, to forms cartilage and bone of the craniofacial skeleton, among other derivatives in vertebrate embryos. Therefore, craniofacial abnormalities are usually attributed to problems in neural crest cell development and depending of which phase of neural crest cell development is disrupted, very different craniofacial anomalies can manifest. Epithelial-to-mesenchymal transition (EMT) is one of the first events before initiation of the bona fide neural crest program, and the disruption of this step can result in very severe craniofacial anomalies. EMT is accompanied by changes in expression of members of the cadherin family molecules, including the down-regulation of Cad6B prior NC delamination. This process is regulated by Snail family members, which directly bind the Cad6B promoter and repress its transcription. However, the mechanisms underlying the role of repressive and activating signals in EMT are likely to be complex and involve multiple and interconnected factors. Here, we explore the possible role of epigenetic modification in this process and specifically the role of PHD12 (named for homology to plant homeodomain 12), a gene discovered as upregulated during neural crest induction, in cooperation with Snail2. Different studies have demonstrated that both Snail and PHD12 can recruit Sin3A/HDAC complex. This large multiprotein complex is able to deacetylate the histones located on the proximity of promoters to repress the target gene. Although Snail2 can bind to the E-boxes of Cad6B, we hypothesize it requires a partner able to read the epigenetic marks and recruit the repressive complex Sin3A. The goal of this application is to demonstrate that the direct interaction between Snail2 and PHD12 makes possible to recruit the repressive complex Sin3A/HDAC to complete shutdown Cad6B expression via histone deacetylation. This application involves three specific aims that include: Aim 1, characterize the role of PHD12 in NC EMT. Our preliminary data show that PHD12 is expressed in a time and location appropriate to be associated with NC prior their delamination. We hypothesize and will test whether the presence of PHD12 affects the NC EMT related genes. In the Specific Aim 2, we will determine the mechanistic analysis of Snail2, PHD12 and Sin3A interaction, and their role in Cad6B repression. Our preliminary ChIP experiments provide evidence that PHD12 interacts with Cad6B locus. We hypothesize and will test the interaction between Snail2-PHD12-Sin3A as well as the requirement of this interaction to bind to the Cad6B locus to repress it via promoter deacetylation. Finally, in the Specific Aim 3 will determine the role of PHD12 in the migration of NC cells and the formation of craniofacial derivatives. We will focus on the role of PHD12 in long term effects on neural crest migration to the branchial arches and subsequent differentiation. To extend this to later times when neural crest cells are forming critical craniofacial derivatives, chick embryos will be allowed to develop in ovo to later stages (e.g. branchial arch stages; cartilage and bone formation; palatal shelf formation) to test if early knockdown leads to later problems in migration and/or formation of facial derivatives. Taking together we will systematically address the epigenetic role of PHD12 on NC EMT and it implication on the formation of craniofacial derivatives. PUBLIC HEALTH RELEVANCE: Most of the craniofacial skeleton arises from the neural crest (NC), a multipotent stem-cell-like population that migrates extensively and gives rise to an amazingly diverse set of derivatives. In addition to specific components of the craniofacial skeleton, neural crest cells also form melanocytes, neurons and glia of the peripheral nervous system, and smooth muscle. Moreover, many craniofacial abnormalities have their origin in problems at different phase of neural crest cell development ranging from initial formation, to migration or differentiation. One major contributor to craniofacial defects occurs during their departure from the neural tube, which involves a classic epithelial-to-mesenchymal transition (EMT). This application examines epigenetic role of PHD12 in NC EMT and its long term effects on formation and development of the face. Because neural crest-derived cells are involved in a variety of birth defects such as cleft palate and various types of cancer, our results on the normal mechanisms of neural crest development will provide important clues regarding the mistakes that may lead to abnormal development or loss of the differentiated state.

描述（由申请人提供）：神经嵴（NC）是在背神经管内产生的短暂胚胎多能细胞群，以形成颅面骨骼的软骨和骨，以及脊椎动物胚胎中的其他衍生物。因此，颅面异常通常归因于神经嵴细胞发育的问题，并且取决于神经嵴细胞发育的哪个阶段被破坏，可以表现出非常不同的颅面异常。上皮-间质转化（EMT）是真正的神经嵴程序开始之前的第一个事件之一，这一步骤的中断可能导致非常严重的颅面异常。EMT伴随着钙粘蛋白家族分子成员表达的变化，包括在NC分层之前Cad 6 B的下调。这一过程由Snail家族成员调节，其直接结合Cad 6 B启动子并抑制其转录。然而，抑制和激活信号在EMT中的作用机制可能是复杂的，涉及多个相互关联的因素。在这里，我们探讨了表观遗传修饰在这一过程中可能发挥的作用，特别是PHD 12（命名为同源植物同源结构域12），一个基因发现在神经嵴诱导上调，与蜗牛2合作的作用。不同的研究表明Snail和PHD 12都可以募集Sin 3A/HDAC复合物。这种大的多蛋白复合物能够使位于启动子附近的组蛋白脱乙酰化以抑制靶基因。尽管Snail 2可以与Cad 6 B的E盒结合，但我们假设它需要一个能够读取表观遗传标记并招募抑制复合物Sin 3A的伴侣。本申请的目的是证明Snail 2和PHD 12之间的直接相互作用使得有可能通过组蛋白脱乙酰化来募集抑制性复合物Sin 3A/HDAC以完全关闭Cad 6 B表达。本申请涉及三个具体目标，包括：目标1，表征PHD 12在NC EMT中的作用。我们的初步数据表明，PHD 12是在适当的时间和位置表示与NC之前，他们的分层。我们假设并将测试PHD 12的存在是否影响NC EMT相关基因。在具体目标2中，我们将确定Snail 2，PHD 12和Sin 3A相互作用的机制分析，以及它们在Cad 6 B抑制中的作用。我们的初步ChIP实验提供了PHD 12与Cad 6 B位点相互作用的证据。我们假设并将测试Snail 2-PHD 12-Sin 3A之间的相互作用以及这种相互作用结合Cad 6 B位点以通过启动子脱乙酰化来抑制它的要求。最后，在特定目标3中，将确定PHD 12在NC细胞迁移和颅面衍生物形成中的作用。我们将重点关注PHD 12在神经嵴迁移到鳃弓和随后分化的长期影响中的作用。为了将其扩展到神经嵴细胞形成关键颅面衍生物的后期，将允许鸡胚在卵内发育到后期阶段（例如鳃弓阶段;软骨和骨形成;腭架形成），以测试早期敲除是否导致面部衍生物的迁移和/或形成的后期问题。综上所述，我们将系统地阐述PHD 12在NC EMT中的表观遗传作用及其对颅面衍生物形成的影响。 公共卫生相关性：大部分颅面骨骼来自神经嵴（NC），这是一种多能干细胞样群体，可以广泛迁移，并产生一系列令人惊讶的多样化衍生物。除了颅面骨骼的特定成分外，神经嵴细胞还形成周围神经系统的黑色素细胞、神经元和神经胶质以及平滑肌。此外，许多颅面畸形的起源问题，在不同阶段的神经嵴细胞的发展，从最初的形成，迁移或分化。颅面缺损的一个主要原因发生在它们离开神经管的过程中，这涉及经典的上皮-间充质转化（EMT）。本申请研究了PHD 12在NC EMT中的表观遗传作用及其对面部形成和发育的长期影响。由于神经嵴来源的细胞参与了各种出生缺陷，如腭裂和各种类型的癌症，我们对神经嵴发育的正常机制的研究结果将提供有关可能导致异常发育或分化状态丧失的错误的重要线索。