Modular control of jaw tendon specification by the Nr5a2 orphan nuclear receptor

Nr5a2 孤儿核受体对颌肌腱规范的模块化控制

• 批准号: 10115696
• 负责人: Gage D Crump
• 金额: $ 37.98万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-01 至 2023-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10115696
• 关键词: ATAC-seq; Address; Binding; Biological Assay; Body part; Cartilage; Cell Count; Cells; Cephalic; ChIP-seq; Chromatin; Clinic; Data; Defect; Development; Enhancers; Expression Profiling; Face; Fishes; Future; Generations; Genes; Genetic; Genetic Enhancer Element; Genetic Transcription; Genomics; Head; Image; In Situ; Injury; Jaw; Knock-in; Knowledge; Limb structure; Logic; Mammals; Mandible; Mesoderm; Modeling; Morphology; Mus; Muscle; NR5A2 gene; Neural Crest; Neural Crest Cell; Nuclear Orphan Receptor; Prevalence; Regenerative Medicine; Regulation; Regulatory Element; Reporter; Role; Signal Transduction; Skeletal Development; Skeleton; Specific qualifier value; Specificity; Techniques; Technology; Temporomandibular Joint Disorders; Tendon Injuries; Tendon structure; Testing; Transgenic Organisms; Validation; Vertebral column; Zebrafish; chronic pain; comparative; conditional mutant; innovation; jaw movement; middle ear; mutant; novel; repaired; scleraxis; single-cell RNA sequencing; skeletal; tendon development; transcription factor; transcriptome sequencing

Project Summary In order for the jaw to properly function, the jaw skeleton must be integrated to the underlying muscles through tendons. The prevalence of tendon injuries is high and in some cases can contribute to temporomandibular joint disorders, yet both the development and repair of tendons are largely understudied. The skeleton and tendons of the jaw are derived from cranial neural crest cells (CNCCs), in contrast to the skeleton and tendons of the fins/limbs and spine that are derived from mesoderm. Do tendons derived from different lineages depend on similar or distinct upstream signals for their specification? This proposal tests the innovative idea that tendon specification is modular, with head- and trunk-specific transcription factors initiating tendon development through head- and trunk-specific enhancers of critical tenocyte factors such as Scleraxis. By conducting single-cell RNA expression profiling of CNCC derivatives in the developing zebrafish face, we have found that expression of the nr5a2 orphan nuclear receptor marks cells along a developmental trajectory toward jaw tendon fate. Utilizing mutant and transgenic zebrafish models, we find that Nr5a2 is necessary and sufficient for specification of jaw tendon at the expense of cartilage fates. In addition, by assaying open chromatin indicative of active enhancers in CNCCs, as well as head versus trunk tenocytes, we find a number of putative head- and trunk-specific enhancers of scleraxis-a. In this proposal, we use transgenic and cutting- edge genomics techniques to test that Nr5a2 directly binds and activates jaw-specific scleraxis-a enhancers. We also use conditional genetics in mouse to test that Nr5a2 has a conserved role in specifying jaw and middle ear tendons derived from the mandibular arch in mammals. Completion of these aims will reveal the regulatory logic by which tendons are specified in different parts of the body, as well as a highly specific role for the Nr5a2 orphan nuclear receptor in promoting jaw tendon formation.

项目摘要 为了使颌骨正常工作，颌骨骨骼必须通过以下方式与底层肌肉整合在一起： 肌腱肌腱损伤的患病率很高，在某些情况下， 关节疾病，但肌腱的发育和修复在很大程度上都没有得到充分研究。骨架和 与骨骼和肌腱不同，颌骨的肌腱来源于颅神经嵴细胞（CNCC） 鳍/肢和脊椎的结构。来自不同血统的肌腱 类似或不同的上游信号的规格？这一提议验证了一个创新的想法， 肌腱特化是模块化的，头部和躯干特异性转录因子启动肌腱 通过头部和躯干特异性增强关键腱细胞因子，如Scleraxis的发展。通过 进行单细胞RNA表达谱CNCC衍生物在发展中的斑马鱼面对，我们有 发现nr 5a 2孤儿核受体的表达标志着细胞沿着发育轨迹 下巴肌腱的命运利用突变和转基因斑马鱼模型，我们发现Nr 5a 2是必需的， 足以以软骨命运为代价来规范颌腱。此外，通过分析开放式 染色质指示CNCC中的活性增强子，以及头部与躯干肌腱细胞，我们发现了一些 推测的巩膜轴-a的头部和躯干特异性增强子。在这个建议中，我们使用转基因和切割- 边缘基因组学技术来测试Nr 5a 2直接结合并激活颌骨特异性巩膜轴-a增强子。 我们还在小鼠中使用条件遗传学来测试Nr 5a 2在指定颌和 从哺乳动物的下颌弓衍生的中耳腱。这些目标的实现将揭示 肌腱在身体的不同部位被指定的调节逻辑，以及肌腱的高度特异性作用， Nr 5a 2孤儿核受体促进颌腱形成。