Investigating the roles of Hh signaling and Gli1+ cells in primary and reparative dentinogenesis in mouse molars

研究 Hh 信号传导和 Gli1 细胞在小鼠磨牙初级和修复性牙本质发生中的作用

• 批准号: 9767762
• 负责人: Mina Mina
• 金额: $ 24.6万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9767762
• 关键词: Adult; Area; Biomedical Engineering; Cell Lineage; Cells; Data; Dental; Dental Pulp; Dentin; Dentinogenesis; Dentition; Development; Endodontics; Generations; Goals; Growth; Hair follicle structure; Human; Incisor; LacZ Genes; Ligands; Mesenchymal Stem Cells; Mesenchyme; Mus; Natural regeneration; Odontoblasts; Organ; Pattern; Pericytes; Population; Reporter; Reporting; Role; SHH gene; Smooth Muscle Actin Staining Method; Sonic Hedgehog Pathway; Stem cells; Testing; Tissues; Tooth structure; afferent nerve; design; experimental study; improved; in vivo; neurovascular; regenerative; repaired; response; small molecule inhibitor; smoothened signaling pathway; stem cell population; transcription factor

PROJECT SUMMARY / ABSTRACT Identification of the mesenchymal stem cell (MSC) population capable of giving rise to odontoblasts secreting dentin during growth (primary dentinogenesis) and repair (reparative dentinogenesis) is critical for the development of improved pulp therapy, regeneration of dentin and ultimately the bioengineering of functional teeth. Despite significant progress in the identification of MSCs within the mouse incisors in vivo, we know much less about MSCs in mouse molars that, unlike incisors, are not continuously growing and are more similar to human dentition. The goal of the present study is to examine the currently controversial roles of the Hedgehog (Hh) signaling pathway and Gli1, a transcription factor that is a downstream effector of the activated canonical Hh signaling pathway in primary and reparative dentinogenesis in mouse molars. Two specific aims have been proposed. Experiments in Aim 1 are designed to test the hypothesis that in growing mice molars, Hh signaling and Gli1 expressing cells in dental mesenchyme give rise to primary odontoblasts. Using lineage tracing and Gli1-CreERT2; Ai9 reporter mice we will examine the contribution of Gli1-Cre-tdTomato expressing cells to primary odontoblasts and the effects of inhibition of Hh signaling by HhAntag, a potent small molecule inhibitor of the Shh pathway, on the activation of Gli1-Cre-tdTomato+ cells and their contribution to primary odontoblasts. Experiments in Aim 2 are designed to test the hypothesis that in adult mice molars, Hh signaling and Gli1 expressing cells in the dental pulp are involved in the formation of second-generation odontoblasts and reparative dentinogenesis. We will perform experimental pulp exposure in adult molars in vivo and examine the expression of Shh ligand and Gli1 after pulp exposure. The contribution of Gli1-Cre-tdTomato expressing cells to second generation of odontoblasts during reparative dentinogenesis and the effects of inhibition of Hh signaling on reparative dentinogenesis and the contribution of Gli1-Cre-tdTomato expressing cells to second generation of odontoblasts will be examined by cell lineage-tracing experiments in GLi1- CreERT2; Ai9 reporter mice. The proposed studies in mouse molars that are not continuously growing and more similar to human dentition will enable us to gain a better understanding of roles of Hh signaling and Gli1 expressing cells in primary and reparative dentinogenesis, an area that has not been studies before.

项目总结/摘要 间充质干细胞（MSC）群体的鉴定能够产生成牙本质细胞分泌 牙本质在生长（原发性牙本质形成）和修复（修复性牙本质形成）期间对于 发展改进的牙髓治疗，牙本质再生和最终的功能性生物工程 牙齿.尽管在体内小鼠切牙中鉴定MSC的进展很大，我们知道， 更不用说小鼠磨牙中的MSC了，与门牙不同，它不是连续生长的， 类似于人类的齿系。本研究的目的是探讨目前有争议的作用， Hedgehog（Hh）信号通路和Gli 1（一种转录因子，是激活的Hh信号通路的下游效应子） 经典Hh信号通路在小鼠磨牙牙本质发生中的作用两个具体目标 已提出目的1中的实验被设计为检验以下假设：在生长的小鼠磨牙中， 牙齿间充质中的Hh信号和Gli 1表达细胞产生初级成牙本质细胞。使用世系 追踪和Gli 1-CreERT 2; Ai 9报告小鼠，我们将检查Gli 1-Cre-tdTomato表达的贡献。 细胞向原代成牙本质细胞的转化以及HhAntag抑制Hh信号传导的作用 Shh通路的抑制剂，对Gli 1-Cre-tdTomato+细胞的活化及其对原代细胞增殖的贡献 成牙本质细胞目的2中的实验被设计为检验以下假设：在成年小鼠磨牙中，Hh信号传导 牙髓中表达Gli 1的细胞参与第二代成牙本质细胞的形成 和修复性牙本质形成。我们将进行实验性的牙髓暴露在成人磨牙在体内， 检测牙髓暴露后Shh配体和Gli 1的表达。Gli 1-Cre-td番茄的贡献 修复性牙本质形成过程中第二代成牙本质细胞的表达及 Hh信号对修复性牙本质形成的抑制作用及Gli 1-Cre-tdTomato表达的作用 细胞到第二代成牙本质细胞将通过GLi 1- CreERT 2; Ai 9报告基因小鼠。在小鼠磨牙中进行的拟议研究不是连续生长的， 更接近人类牙列将使我们能够更好地了解Hh信号和Gli 1的作用 表达细胞在原发性和修复性牙本质形成中的作用，这是一个以前没有研究过的领域。