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.

项目摘要 /摘要 鉴定能够引起Odontoblasts分泌的间质干细胞（MSC）种群 生长过程中的牙本质（原发性牙本质生成）和修复（修复性牙齿发生）至关重要 开发改进的纸浆疗法，牙本质再生以及功能性的生物工程 牙齿。尽管在体内识别小鼠门牙内的MSC方面取得了重大进展，但我们知道 与门牙不同的小鼠磨牙中的MSC少得多，并且不断增长，并且更多 类似于人类的牙列。本研究的目的是检查目前有争议的角色 刺猬（HH）信号通路和GLI1，这是一种转录因子，是激活的下游效应子 小鼠磨牙中原发性和修复性牙毒发生中的规范HH信号通路。两个具体的目标 已经提出了。 AIM 1中的实验旨在检验以下假设：在生长的小鼠磨牙中， HH信号传导和GLI1表达牙齿间充质的细胞会引起原代牙本质细胞。使用血统 跟踪和gli1-creert2; AI9记者小鼠我们将研究表达Gli1-cre-tdtomato的贡献 细胞到原代牙本质细胞以及Hhantag抑制HH信号的影响，Hhantag有效的小分子 SHH途径的抑制剂，关于GLI1-CRE-TDTOMATO+细胞的激活及其对初级的贡献 Odontoblasts。 AIM 2中的实验旨在检验以下假设：在成年小鼠磨牙中，HH信号传导 牙髓中的GLI1表达细胞参与第二代牙本质细胞的形成 和修复性牙本质发生。我们将在体内进行实验性果肉暴露，并 检查果肉暴露后SHH配体和GLI1的表达。 Gli1-cre-tdtomato的贡献 在修复性牙本质发生过程中向第二代牙糖细胞表达细胞 抑制HH信号对修复性牙本质发生的抑制作用以及表达Gli1-Cre-TDTOMATO的贡献 细胞到第二代牙植物细胞将通过在GLI1-中进行细胞谱系追踪实验检查 creert2; AI9记者小鼠。在小鼠磨牙中提出的研究，这些研究并非不断增长， 与人类牙齿更相似，将使我们能够更好地了解HH信号和GLI1的作用 在原发性和修复性牙毒发生中表达细胞，这是以前从未研究过的区域。