Molecular and Cellular Basis of Craniosynostosis

颅缝早闭的分子和细胞基础

• 批准号: 9407492
• 负责人: Yang Chai
• 金额: $ 8.82万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9407492
• 关键词: Address; Adult; Affect; Alleles; Binding; Bone Growth; Brain; Calvaria; Cell Maintenance; Cells; ChIP-seq; Child; Chotzen Syndrome; Complex; Complication; Congenital Abnormality; Congenital abnormal Synostosis; Craniofacial Abnormalities; Craniosynostosis; Defect; Development; Developmental Process; Dimerization; Embryo; Embryonic Development; Etiology; Fibrinogen; Fishes; Functional disorder; Genes; Genetic; Genetic Models; Genomic Segment; Genomics; Growth; Human; Imaging Techniques; Individual; Inherited; Intervention; Joint structure of suture of skull; Knock-in; Lead; Learning; Left; Life; Maintenance; Mammals; Mental Retardation; Mesenchyme; Mesoderm; Modeling; Molecular; Molecular Target; Mus; Mutation; Neural Crest; Nucleic Acid Regulatory Sequences; Operative Surgical Procedures; Organ; Osteoblasts; Patients; Pattern; Play; Population; Positioning Attribute; Postoperative Period; Prevention; Process; Recurrence; Regulation; Reporter; Research; Research Personnel; Role; Stem cells; Structure; Surgical sutures; System; TWIST1 gene; Testing; Time; Tissues; Work; Yang; Zebrafish; base; bone; cell behavior; cohort; coronal suture; coronal synostosis; craniofacial; cranium; dimer; flat bone; imaging genetics; imaging modality; in vivo; in vivo imaging; insight; mouse model; mutant; novel; operation; osteoblast differentiation; osteogenic; postnatal; premature; prevent; progenitor; skeletal; spatiotemporal; suture fusion; transcription factor; transcriptome sequencing

This is a proposal to investigate the role of stem cell regulation in cranial suture development and maintenance, and its pathophysiology in craniosynostosis. More broadly, this proposal focuses on how stem cells are controlled in space and time to promote the development and maintenance of vertebrate organs. Our recent results show that heterozygous loss of either of two related transcription factors, TWIST1 and TCF12, account for coronal suture defects in the majority of Saethre-Chotzen patients. Using sophisticated in vivo imaging and genetics in mice and zebrafish, we will test that Tcf12 modifies the function of Twist1 to maintain skeletal progenitors during both the specification and maintenance of sutures. A common role for Twist1 and Tcf12 in the developing and postnatal coronal suture would have the potential to explain both the initial synostosis and the high recurrence rate of postoperative synostosis in patients. A particular strength of our research plan is the complementary expertise of three accomplished investigators in craniofacial genetics. Rob Maxson has long-standing expertise in mouse models of synostosis, having contributed to the identification of TWIST1 and TCF12 as the two most affected genes in Saethre-Chotzen syndrome. Yang Chai recently identified a population of Gli1+ stem cells in the suture that are required for long-term suture patency and calvarial bone growth. Gage Crump has pioneered in vivo imaging techniques in zebrafish to examine the cellular basis of craniofacial defects. First, this team will test that Twist1 and Tcf12 function in the same tissues to repress the Ihh-driven differentiation of sutural progenitors into osteoblasts, as predicted if Tcf12 serves as a suture-specific dimerization partner for Twist1. Second, we will examine continuous requirements for Twist1 and Tcf12 in suture maintenance by conditionally deleting these genes in postnatal Gli1+ sutural stem cells. Third, we will use new knock-in tagged alleles of Twist1 and Tcf12 to identify the direct genomic targets of Twist1-Tcf12 dimers in postnatal sutural stem cells, as well as how Tcf12 modifies the ability of Twist1 to engage regulatory regions necessary for suture maintenance. Fourth, we will use powerful imaging techniques to reveal the in vivo spatial patterns of Twist1-Tcf12 dimers within sutures. Fifth, we will take advantage of the first zebrafish model of Saethre-Chotzen syndrome to directly visualize over time how changes in the pattern and timing of osteoblast differentiation result in later coronal suture defects. The results of these aims will test our model that Tcf12 functions as a suture-specific partner for Twist1, in part by guiding Twist1 to particular genomic regions necessary to inhibit premature osteoblast differentiation in suture mesenchyme. These new insights into the long-term requirements of synostosis genes in suture maintenance will have the potential to lead to new ways of preventing post-operative synostosis, thus reducing the number of risky operations currently performed on young children with Saethre-Chotzen syndrome.

这是调查干细胞调节在颅骨发育中的作用和 维持及其在颅突变中的病理生理学。从更广泛的角度来看，该提议的重点是如何干扰 细胞在时空受到控制，以促进脊椎动物器官的发展和维护。我们的 最近的结果表明，两个相关转录因子中的任何一个杂合损失，Twist1和Tcf12， 大多数塞斯雷 - chotzen患者的冠状缝合线缺陷。使用复杂的体内 在小鼠和斑马鱼中的成像和遗传学，我们将测试TCF12修改Twist1的功能以维持 缝合线规范和维护期间的骨骼祖细胞。 Twist1和 发育中和产后冠状缝合线中的TCF12有可能解释初始的 术后突出术的平均复发率和高复发率。我们的特殊优势 研究计划是三名颅面遗传学研究人员的补充专业知识。抢 麦克斯森（Maxson Twist1和TCF12是Saethre-Chotzen综合征中受影响最大的两个基因。 Yang Chai最近 确定了缝合线中缝合缝合缝线中的Gli1+干细胞群 颅骨生长。量子crump在斑马鱼中开创了体内成像技术，以检查 颅面缺陷的细胞基础。首先，该团队将在同一组织中测试Twist1和TCF12的功能 抑制IHH驱动的缝合祖细胞的IHH驱动的分化为成骨细胞，如TCF12作为一个 Twist1的缝合特异性二聚合作伙伴。其次，我们将研究Twist1的连续要求1 通过在产后GLI1+杂质干细胞中有条件地删除这些基因，在缝合维持中进行TCF12。 第三，我们将使用twist1和tcf12的新敲入标记等位基因来识别直接的基因组靶标 Twist1-TCF12二聚体在产后缝合干细胞中，以及TCF12如何修饰扭曲的能力 参与缝合维护所需的监管区域。第四，我们将使用强大的成像技术 揭示缝合线中扭曲1-TCF12二聚体的体内空间模式。第五，我们将利用 Saethre-Chotzen综合征的第一个斑马鱼模型，随着时间的流逝直接可视化模式如何变化 成骨细胞分化的时机导致后来的冠状缝合缺陷。这些目标的结果将测试 我们的模型TCF12是Twist1的特定于缝合的合作伙伴的模型，部分是通过引导twist1 抑制缝合缝隙间质中过早成骨细胞分化所必需的基因组区域。这些新 对缝合缝合基因的长期需求的见解将有可能 导致新的预防术后阴影的方法，从而减少了风险操作的数量 目前对患有Saethre-Chotzen综合征的幼儿表演。