Mechanisms regulating afferent innervation in the dental pulp

调节牙髓传入神经支配的机制

基本信息

批准号：
10214592
负责人：
Sarah Peters
金额：
$ 24.63万
依托单位：
OHIO STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2023-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10214592
关键词：
Adult Automobile Driving Axon Biological Assay Cells Cementoclast Chronic Disease Coculture Techniques Complex Data Defect Dental Dental Pulp Dental caries Dental crowns Dentin Deposition Development Developmental Gene Embryo Endodontics Enterobacteria phage P1 Cre recombinase Eph Family Receptors Epithelial Exposure to Extracellular Matrix Proteins Future Ganglia Generations Genetic Transcription Goals Image In Vitro Injury Investigation Knockout Mice Laboratories Life Maintenance Mediating Mesenchymal Mesenchyme Modeling Mus Mutant Strains Mice NTN1 gene Natural regeneration Nerve Nerve Fibers Nerve Regeneration Nervous system structure Neurites Neurons Odontoblasts Organ Organism Pain Pain management Paracrine Communication Pathway interactions Pattern Penetration Perinatal mortality demographics Phosphoproteins Plant Roots RNA Reader Recombinants Regulation Reporting Research Role Sensory Signal Transduction Stimulus Structure Structure of trigeminal ganglion Temperature Testing Therapeutic Tissues Tooth Germ Tooth structure Trigeminal nerve structure Viral Visualization afferent nerve axon guidance axonal sprouting base bone experimental study ganglion cell improved in vivo knock-down mRNA sequencing migration mouse model mutant nerve stem cell nerve supply neuroblast neurogenesis neuron development neurotransmission neurotrophic factor new therapeutic target osteopontin overexpression postnatal postnatal development preservation pressure promoter regenerative approach response skeletal

项目摘要

Project Summary/Abstract Since teeth are exposed to environmental stimuli, tooth innervation is crucial to their protection and usage throughout the life of an organism. The tooth is primarily innervated with sensory nerve fibers from the trigeminal ganglion (TG) that protect the tooth organ by relaying noxious stimuli. The dental pulp (DP) secretes neurotrophic factors to guide axonal penetration and sprouting within the tooth during postnatal development in a highly regulated manner. Research has shown that secreted phosphoprotein, osteopontin (OPN), promotes neuronal migration, proliferation, and survival [2–6]. The long-term goal of this project is to understand the mesenchymal-neuronal signals that promote and maintain sensory innervation of the teeth. The overall objective is to determine the role of DP in regulating tooth innervation during development and regeneration. Our central hypothesis is that Tgfbr2 in the dental mesenchyme governs paracrine signaling via OPN to guide tooth sensory innervation. Our laboratory has established a mouse model in which Tgfbr2 is conditionally deleted in odontoblast-producing mesenchyme using an osterix promoter driven Cre recombinase (Tgfbr2cko). These mice survive postnatally but with significant defects in bones and teeth [7,8]. We performed an mRNA- Seq analysis using control and mutant postnatal day 7 DP and found that neuronal maintenance and developmental genes were most highly regulated, including OPN. Immunofluorescent images indicated reduced innervation throughout the DP in Tgfbr2cko mice. Preliminary experiments with DP and primary TG nerves demonstrated increased axonal sprouting when TG cells were cultured with DP. Guided by these data, we will test our hypothesis with the following two specific aims: 1) test the hypothesis that Tgfbr2 is necessary to promote sensory innervation; 2) test the hypothesis that OPN signaling from the DP guides sensory innervation. In both aims, we propose to cross Tg(Thy1-YFP)16Jrs mice, which express a high level of YFP throughout the nervous system [9] to optimize visualization of the neurons. Under the first aim, a well- characterized neurite outgrowth assay will first be used to co-culture TG neurons with DP where Tgf signals are manipulated in the DP. In the second part of the first aim, we will use an in vivo dental injury model and investigate neuronal regeneration in Tgfbr2cko and WT mice. Under the second aim, we will similarly co-culture TG neurons with OPN-deleted DP cells +/- TGF1 and Tgfbr2-deleted cells supplemented with recombinant OPN to investigate developmental neurogenesis in the DP. We will perform the dental injury assay on OPN-/- mice to examine the mechanisms driving neuronal regeneration. The proposed research is significant because it is expected to advance and expand understanding of how DP cells protect the tooth organ via axonal guidance mechanisms. Such information will enhance our understanding of the complex interplay of mesenchymal-neuronal interactions in the tooth that could serve as a basis for future preventative, therapeutic, and regenerative strategies in endodontics and improve the preservation of teeth.

项目摘要/摘要由于牙齿暴露于环境刺激，因此牙齿支架对于保护和使用至关重要在有机体的整个生命中。牙齿主要是用感官神经纤维支配的三叉神经节（TG）通过中继有害刺激来保护牙科器官。牙纸浆（DP）分泌神经营养因素在产后发育过程中指导轴突渗透和发芽高度监管的方式。研究表明，分泌的磷蛋白骨桥蛋白（OPN）促进神经元迁移，增殖和生存[2-6]。该项目的长期目标是了解促进和维持牙齿感觉神经的间充质神经元信号。总体目的是确定DP在发育和再生过程中调节牙齿神经的作用。我们的中心假设是牙齿间充质中的TGFBR2通过OPN控制旁分泌信号传导以指导牙齿感觉神经。我们的实验室已经建立了一个鼠标模型，其中TGFBR2有条件地使用Osterix启动子驱动的CRE重组酶（TGFBR2CKO）中删除在产生Odontoblast的间质中。这些小鼠在产后生存，但在骨骼和牙齿中存在明显的缺陷[7,8]。我们进行了mRNA- 使用对照和突变体后第7天DP进行SEQ分析，发现神经元维护和发育基因受到高度调节，包括OPN。指示的免疫荧光图像在TGFBR2CKO小鼠中，整个DP的神经支配减少。 DP和初级TG的初步实验当TG细胞用DP培养时，神经表现出轴突发芽的增加。在这些数据的指导下，我们将通过以下两个具体目的检验我们的假设：1）检验TGFBR2有必要的假设促进感觉神经； 2）检验以下假设，即来自DP引导感觉的OPN信号传导神经。在这两个目标中，我们都建议穿越TG（THY1-YFP）16JRS小鼠，该小鼠表达高水平的YFP 在整个神经系统[9]中，以优化神经元的可视化。在第一个目标下，一个很好的特征神经落出分析将首先用于与DP共同培养TG神经元，其中TGF信号在DP中被操纵。在第一个目标的第二部分中，我们将使用体内牙科损伤模型，并研究TGFBR2CKO和WT小鼠的神经元再生。在第二个目标下，我们将同样共同培养带有OPN删除DP细胞的TG神经元+/-TGF1和TGFBR2删除的细胞，并补充了重组 OPN研究DP中的发育神经发生。我们将对OPN进行牙齿损伤评估 - / - 小鼠检查驱动神经元再生的机制。拟议的研究很重要，因为预计它将推进并扩展对DP细胞如何通过轴突保护牙齿器官的理解指导机制。这样的信息将增强我们对复杂相互作用的理解牙齿中的间充质 - 神经元相互作用，可以作为未来预防性，治疗的基础以及牙髓学中的再生策略，并改善牙齿的制备。