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 牙萌出对人类的生存至关重要，它直接影响到基本功能，如 面部下部生长发育，咀嚼营养/能量摄入，言语和美容 有效沟通。与牙萌出有关的疾病在普通公众中以各种形式流行。 延迟萌出、异位萌出、萌出失败等(恒磨牙2~4%)。其中许多都受到了影响 牙齿对正畸的机械力反应不佳，经常导致强直。提取这些信息 牙齿会导致发病率，随后需要使用功能较差的假体，从而损害 患者的生活质量。因此，需要更有效的方法来促进或重新启动牙齿萌出。这个 发育中牙齿周围的牙囊(DF)协调牙齿萌出和牙根形成。DF 促进破骨细胞的形成，这些破骨细胞吸收牙槽骨以创建喷发途径，并包括 间充质祖细胞为成牙骨质细胞和牙周膜(PDL)细胞。这些DF祖细胞 细胞对牙周组织的发育至关重要，而牙周组织在牙周发育后期尤为重要。 长牙了。甲状旁腺素/甲状旁腺素受体(PPR)功能缺失突变导致牙齿原发衰竭 在人类中，皮疹(PFE)可能是一种依赖于PPR的调节DF祖细胞的机制 牙萌出与牙根形成的耦合作用。在这个项目中，我们假设DF 祖细胞是牙齿萌发和牙根形成的中心调节者，因此PTHrP-PPR信号转导 发挥重要的调节作用，以维持这些细胞的独特性质。在Aim1中，我们将确定 牙囊前体细胞在体内的分子特征。工作假说是DF细胞 表达一组独特的转录因子，维持其作为间充质祖细胞的特性。 利用DF特异的PTHrP-Creer转基因株系，我们将确定个体DF的基因表达谱 基于单细胞RNA-seq分析的祖细胞，随后对这些基因进行原位验证。此外， 我们将建立一个细胞培养模型来研究DF祖细胞的异质性和特性 克隆选择和鉴定。在AIM2中，我们将确定PTH/PTHrP受体在DF前体中的作用 牙萌出中的细胞。工作假说是，在DF祖细胞中PTHrP-PPR信号是必不可少的 以维持其自我更新和分化为牙周膜(PDL)细胞的能力。使用鼠标 我们已经成功地建立了PFE模型，我们将确定PPR缺乏对细胞命运的影响 利用体外细胞培养系统进行DF祖细胞的决定和自我更新。此外，使用 比较rna-seq分析，我们将确定PPR靶基因对小鼠PFE表型的影响 在这种情况下，牙齿萌出与牙根形成是分离的。作为未来的研究计划，我们将进一步调查 调控DF祖细胞命运决定的关键分子机制。我们将特别关注 PPR信号下游的转录因子。