Molecular Basis of Tooth Eruption

牙齿萌出的分子基础

• 批准号: 7030329
• 负责人: GARY E WISE
• 金额: $ 28.71万
• 依托单位: LOUISIANA STATE UNIV A&M COL BATON ROUGE
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7030329
• 关键词: biological signal transduction; colony stimulating factor; dental development; dental research; enzyme linked immunosorbent assay; gene expression; genetically modified animals; immunocytochemistry; laboratory mouse; laboratory rat; microarray technology; molecular biology; nuclear factor kappa beta; osteoclasts; osteogenesis; osteoprotegerin; polymerase chain reaction; protein structure function; tissue /cell culture; tooth

DESCRIPTION (provided by applicant): To help determine the molecular basis of tooth eruption, this proposal will focus on how a requirement of eruption, osteoclastogenesis, is regulated at the molecular level. The dental follicle (DF), a loose connective tissue sac that surrounds the unerupted tooth, recruits mononuclear cells to the follicle where they fuse to form osteoclasts necessary to form an eruption pathway. A molecule produced by the DF, colony-stimulating factor-1 (CSF-1), is required for tooth eruption. Another molecule found in the DF, osteoprotegerin (OPG), inhibits osteoclastogenesis. In the first mandibular molar of the rat or mouse, the maximal number of osteoclasts is present either at day 3 (rat) or day 5 (mouse) on the alveolar bone, a time that correlates with maximal gene expression of CSF-1 in the adjacent follicle and minimal gene expression of OPG. It is postulated that the downregulation of OPG expression allows the maximal osteoclastogenesis and that this decrease in OPG expression is regulated by CSF-1. To test this hypothesis, osteopetrotic mice that have impaired CSF-1 production and inhibited tooth eruption will be examined to determine if OPG expression in the DF remains elevated at day 5, in contrast to its reduced expression in normal mice. Because injections of CSF-1 accelerate the time of eruption, it will be determined if such injections also reduce OPG gene expression. Conversely, injections with OPG will be done to determine if increased levels of OPG delay or inhibit eruption in normal mice and rats. Laser-capture microdissection techniques will be employed to resolve in what dental tissues of the rat receptor activator of nuclear factor-kappaB ligand is expressed to actively promote osteoclast formation. The final aim will determine what molecules may be involved in the secondary minor burst of osteoclastogenesis seen at day 10 postnatally in the 1st mandibular molar. Real-time PCR and microarray techniques will determine what genes are maximally expressed in the DF at this time. In vitro studies will determine if such gene products can support osteoclast formation. Understanding the molecular regulation of osteoclastogenesis during eruption may explain why impacted teeth (e.g., 3rd molars) do not erupt, as well as explain the causes of various eruption disorders. A molecular approach to induce eruption is a long-term goal. In addition, understanding the molecular basis of bone resorption may aid in determining what factors cause alveolar bone loss such as is seen in periodontitis.

描述（由申请人提供）：为了帮助确定牙齿喷发的分子基础，该建议将集中于在分子水平上调节喷发的需求，破骨细胞生成。牙齿卵泡（DF）是一种围绕未强化的牙齿的松散结缔组织囊，将单核细胞募集到卵泡中，在那里它们融合起来形成形成喷发途径所需的破骨细胞。 DF产生的分子是牙齿喷发所需的菌落刺激因子-1（CSF-1）。在DF骨蛋白蛋白（OPG）中发现的另一个分子抑制破骨细胞生成。在大鼠或小鼠的第一个下颌摩尔中，在肺泡骨上的第3（大鼠）或第5（小鼠）的最大破骨细胞数量存在，这是一个与邻近卵泡中CSF-1的最大基因表达相关的时代，并且OPG的最小基因表达。据推测，OPG表达的下调允许最大的破骨细胞生成，并且OPG表达的这种降低受CSF-1的调节。为了检验这一假设，将检查损伤CSF-1产生和抑制牙齿喷发的骨质术小鼠，以确定DF中的OPG表达是否在第5天保持升高，与其在正常小鼠中降低的表达相反。由于注射CSF-1加速了喷发时间，因此将确定这种注射是否还会减少OPG基因表达。相反，将进行OPG注射，以确定正常小鼠和大鼠的OPG延迟水平是否增加或抑制喷发。将采用激光捕获微分解技术来解决核因子-Kappab配体的大鼠受体激活剂的牙科组织，以积极促进破骨细胞的形成。最终目的将确定在第1章中第10天，在第10天，在第10天，在第10天的下颌磨牙中可能涉及哪些分子。实时PCR和微阵列技术将在此时最大程度地表达哪些基因。体外研究将确定这种基因产物是否可以支持破骨细胞的形成。了解喷发过程中破骨细胞生成的分子调节可以解释为什么影响的牙齿（例如，第三磨牙）不会爆发，也可以解释各种喷发障碍的原因。诱导喷发的分子方法是一个长期目标。此外，了解骨吸收的分子基础可能有助于确定哪些因素会导致牙槽骨质流失，例如牙周炎中可见。