The role of the transcriptional repressor ZEB2 in human neural crest cell formation and craniofacial pathology

项目摘要 本研究的目的是阐明转录抑制因子ZEB 2在人类神经细胞凋亡中的作用。 嵴细胞形成、颅面分化和Mowat-Wilson综合征。神经嵴是一种多能的 脊椎动物特有的胚胎细胞群，广泛迁移并分化成各种 衍生物，包括大部分颅面骨、软骨和牙器官组织。许多人类 病理学与异常神经嵴细胞发育有关，包括最近描述的 Mowat-Wilson综合征（MWS）。MWS是一种罕见的新生杂合子引起的综合征， ZEB 2突变导致独特的面部表型，牙齿畸形，智力残疾和其他 包括Hirschprung病在内的异常，表明多个轴向水平的神经嵴细胞缺陷。 然而，在MWS患者中观察到显著的基因型和表型变异， 导致这种疾病的潜在机制还不清楚。此外，虽然ZEB 2 被认为是神经系统和神经嵴细胞的主要发育调节因子 上皮细胞向间充质细胞的转化和迁移：我们人类神经嵴细胞模型的最新证据 表明ZEB 2在神经板边缘和神经嵴的早期形成中起着至关重要的作用。ZEB 2已知 负性调节TGF β超家族信号，其调节对于适当的神经嵴至关重要 形成和分化。因此，假设ZEB 2粘附性地起作用以建立细胞内的细胞膜。 压抑的后生景观整个神经嵴细胞的形成和颅面发育， 调节适当的TGFb超家族信号传导，并且这种调节的失败强调了MWS 病理为了检验这一假设，提出了三个具体目标。目标1将检查模块化功能 ZEB 2在调节整个野生型人颅神经嵴细胞TGF β信号传导的适当水平中的作用 阵特别是，ZEB 2和TGF β受体之间的顺式调节相互作用激活了Smad 蛋白质和辅阻遏物的功能需求，导致染色质可及性的变化， 描绘的。在目标2中，将通过建立诱导的多能干细胞来解决MWS病理学。 来自不同基因型的MWS患者的干细胞。使用这些工具，精确的转录组和表观遗传 在基于MWS的神经嵴细胞形成过程中的失调将被询问，提供急需的 深入了解这个未被充分研究的病理学。在本提案的目标3中，ZEB 2在野生型和 MWS人类牙齿的形成将通过建立基于人类神经嵴细胞的 牙齿类器官模型这些结果将首次揭示这种转录抑制因子的分子作用 贯穿人神经嵴细胞形成、分化和病理学的多个阶段。

Project Summary The objective of this proposal is to delineate the role of the transcriptional repressor ZEB2 during human neural crest cell formation, craniofacial differentiation, and Mowat-Wilson Syndrome. The neural crest is a multipotent embryonic cell population unique to vertebrates which migrates extensively and differentiates into a variety of derivatives, including most of the craniofacial bone, cartilage, and dental organ tissues. Numerous human pathologies are associated with abnormal neural crest cell development, including the recently delineated neurocristopathy Mowat-Wilson Syndrome (MWS). MWS is a rare syndrome caused by de novo heterozygous mutations in ZEB2 leading to a distinct facial phenotype, dental abnormalities, intellectual disability, and other anomalies including Hirschprung disease which are indicative of neural crest cell defects at multiple axial levels. However, significant genotypic and phenotypic variability has been observed among MWS patients, and the underlying mechanisms that contribute to this disease are not well understood. Furthermore, while ZEB2 has been implicated as a major developmental regulator of the nervous system as well as in neural crest cell epithelial-to-mesenchymal transition and migration, recent evidence in our human neural crest cell model indicates a crucial role for ZEB2 in the early formation of the neural plate border and neural crest. ZEB2 is known to negatively regulate TGFb superfamily signaling, whose modulation is essential for proper neural crest formation and differentiation. Therefore, it is hypothesized that ZEB2 functions reiteratively to establish the repressive epigenetic landscape throughout neural crest cell formation and craniofacial development by modulating proper TGFb superfamily signaling, and that the failure of this regulation underscores the MWS pathology. To test this hypothesis, three specific aims are proposed. Aim 1 will examine the modular functionality of ZEB2 in regulating the proper levels of TGFb signaling throughout wild-type human cranial neural crest cell formation. In particular, the cis-regulatory interactions between ZEB2 and TGFb receptor activated Smad proteins and the functional requirement of co-repressors leading to changes in chromatin accessibility will be delineated. In Aim 2, the MWS pathology will be addressed through the establishment of induced pluripotent stem cells from MWS patients of diverse genotypes. Using these tools, the precise transcriptomic and epigenetic misregulation during MWS-based neural crest cell formation will be interrogated, providing much needed molecular insight into this understudied pathology. In Aim 3 of this proposal, the role of ZEB2 in wild-type and MWS human tooth formation will be interrogated through the establishment of a human neural crest cell-based tooth organoid model. These results will reveal for the first time the molecular role of this transcriptional repressor throughout multiple stages of human neural crest cell formation, differentiation, and pathology.