Dental Follicle: A Central Regulator of Tooth Eruption and Root Formation

牙囊：牙齿萌出和牙根形成的中央调节器

• 批准号: 9598677
• 负责人: Wanida Ono
• 金额: $ 15.6万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-06-09 至 2020-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9598677
• 关键词: Affect; Alleles; Alveolar; Ankylosis; Candidate Disease Gene; Cell Culture System; Cell Culture Techniques; Cell Line; Cells; Cementoblast; Characteristics; Communication; Computer Retrieval of Information on Scientific Projects Database; Coupling; Data; Dental Sac; Development; Disease; Energy Intake; Esthetics; Expression Profiling; Face; Failure; Foundations; Future; Gene Expression; Gene Targeting; General Population; Genes; Growth and Development function; Heterogeneity; Human; Hypercementosis; In Situ; In Vitro; Individual; Inferior; Innovative Therapy; Intervention; Knowledge; LoxP-flanked allele; Mastication; Mesenchymal; Mesenchymal Stem Cells; Modality; Modeling; Molecular; Molecular Analysis; Morbidity - disease rate; Mus; Orthodontic; Osteoblasts; Osteoclasts; Parathyroid Hormone Receptor; Pathway interactions; Patients; Periodontal Ligament; Pharmacology; Phenotype; Plant Roots; Play; Property; Prosthesis; Quality of life; Receptor Gene; Receptor Signaling; Role; Signal Pathway; Speech; Stem cells; Tamoxifen; Technology; Tissues; Tooth Diseases; Tooth Extraction; Tooth eruption; Tooth root structure; Tooth structure; Transgenic Organisms; Validation; alveolar bone; base; bone; clinical application; comparative; experimental study; genetic signature; in vivo; loss of function mutation; mechanical force; mouse model; mutant; novel; nutrition; parathyroid hormone-related protein; progenitor; receptor; self-renewal; single-cell RNA sequencing; therapeutic target; transcription factor; transcriptome sequencing

PROJECT SUMMARY/ABSTRACT Tooth eruption is essential for survival of humans, with direct impact on the fundamental functions such as growth and development of the lower face, mastication for nutrition/energy intake, speech and esthetics for effective communication. Disorders involving tooth eruption are prevalent among the general public in a variety of forms such as delayed, ectopic and failure of eruption (2~4% for permanent molars). Many of these affected teeth do not respond well to orthodontic mechanical forces, often resulting in ankylosis. Extraction of these teeth results in morbidity and subsequently requires prostheses with inferior function, thus compromising patients' quality of life. Thus, more effective modalities to facilitate or reactivate tooth eruption are needed. The dental follicle (DF) surrounding the developing tooth coordinates tooth eruption and root formation. DF facilitates formation of osteoclasts that resorb alveolar bones to create the eruption pathway, and includes mesenchymal progenitor cells for cementoblasts and periodontal ligament (PDL) cells. These DF progenitor cells are crucial for development of periodontal tissues, which are particularly important for the later stage of tooth eruption. As loss-of-function mutations in PTH/PTHrP receptor (PPR) cause primary failure of tooth eruption (PFE) in humans, a PPR-dependent mechanism regulating DF progenitor cells is likely to play important roles for the coupling of tooth eruption and root formation. In this project, we hypothesize that DF progenitor cells are the central regulators of tooth eruption and root formation, whereby PTHrP-PPR signaling exerts important regulatory roles to maintain their unique properties of these cells. In Aim1, we will determine molecular characteristics of dental follicle progenitor cells in vivo. The working hypothesis is that DF cells express a unique set of transcription factors that maintain their properties as mesenchymal progenitor cells. Using the DF-specific PTHrP-creER transgenic line, we will define the gene expression profiles of individual DF progenitor cells based on a single cell RNA-seq analysis, followed by in situ validation of these genes. Further, we will establish a cell culture model to investigate heterogeneity and properties of DF progenitor cells through clonal selection and characterization. In Aim2, we will define roles of the PTH/PTHrP receptor in DF progenitor cells in tooth eruption. The working hypothesis is that PTHrP-PPR signaling in DF progenitor cells is essential to maintain their ability to self-renew and differentiate into periodontal ligament (PDL) cells. Using the mouse PFE model we have successfully established, we will determine the impact of PPR-deficiency on cell fate decision and self-renewal of DF progenitor cells using ex vivo cell culture systems. Further, using a comparative RNA-seq analysis, we will identify PPR-target genes responsible for the mouse PFE phenotypes in which tooth eruption is uncoupled from root formation. As a future research plan, we will further investigate key molecular mechanisms that regulate cell fate decisions of DF progenitor cells. We will particular focus on transcription factors downstream of PPR signaling.

项目摘要/摘要 牙齿喷发对于人类的生存至关重要，对基本功能的直接影响，例如 下面的生长和发展，营养/能量摄入的咀嚼，语音和审美 有效的沟通。涉及牙齿喷发的疾病在各种各样的公众中普遍存在 诸如延迟，异位和喷发失败的形式（永久磨牙的2〜4％）。其中许多受到影响 牙齿对正畸机械力的反应不佳，通常导致连直链病。这些提取 牙齿导致发病率，随后需要具有劣等功能的假体 患者的生活质量。因此，需要更有效的方式来促进或重新激发牙齿喷发。这 发育中的牙齿围绕牙齿坐标的牙齿卵泡（DF）牙齿喷发和根部形成。 DF 促进将牙槽骨骼的破骨细胞形成以创建喷发途径，并包括 用于牙骨质细胞和牙周韧带（PDL）细胞的间充质祖细胞。这些DF祖先 细胞对于牙周组织的发展至关重要，这对于后期尤其重要 牙齿喷发。作为PTH/PTHRP受体（PPR）的功能丧失突变导致牙齿的主要故障 人类喷发（PFE），调节DF祖细胞的PPR依赖机制可能会发挥作用 牙齿爆发和根形成偶联的重要作用。在这个项目中，我们假设DF 祖细胞是牙齿爆发和根形成的中心调节剂，从而通过PTHRP-PPR信号传导 发挥重要的调节作用，以维持其这些细胞的独特特性。在AIM1中，我们将确定 体内牙齿卵泡祖细胞的分子特征。工作假设是DF细胞 表达一组独特的转录因子，这些因子将其特性作为间充质祖细胞保持。 使用DF特异性PTHRP-creer转基因线，我们将定义单个DF的基因表达谱 祖细胞基于单个细胞RNA-seq分析，然后是原位验证这些基因。更远， 我们将建立一个细胞培养模型，以研究DF祖细胞的异质性和特性 克隆选择和表征。在AIM2中，我们将定义DF祖细胞中PTH/PTHRP受体的作用 牙齿喷发中的细胞。工作假设是DF祖细胞中的PTHRP-PPR信号传导是必不可少的 保持其自我更新和分化为牙周韧带（PDL）细胞的能力。使用鼠标 我们已经成功建立的PFE模型，我们将确定PPR缺陷对细胞命运的影响 使用离体细胞培养系统对DF祖细胞的决策和自我更新。此外，使用 比较RNA-seq分析，我们将确定负责小鼠PFE表型的PPR靶标基因 其中牙齿喷发与根部形成脱在一起。作为未来的研究计划，我们将进一步调查 调节DF祖细胞的细胞命运决策的关键分子机制。我们将特别关注 PPR信号下游的转录因子。