Dentin-pulp dynamics of aging teeth

项目摘要/摘要 利用牙本质-牙髓复合体的再生能力的新策略的引入可能会使 人类有可能在一生中保留他们的天然牙齿。研究表明， 牙髓干细胞保持了非凡的特性，可以为牙科护理提供临床选择 和修复。然而，目前尚不清楚老年患者是否也能够从这些技术中受益-- 抱歉。这个项目的长期目标是了解牙齿在整个成年人中是如何变化的。 为了开发可以保持或增强牙齿健康并允许在整个过程中保持牙齿的治疗方法 生命的长短。我们的目的是定性地分析年轻和老年啮齿动物磨牙的牙本质-牙髓界面。 确定牙本质-牙髓复合体的再生能力如何随年龄变化。我们的中心假设 与年龄相关的DP间充质、血管系统和神经支配的变化是否改变了分泌和有益于 牙本质中生物活性蛋白的能力(BPiD)和牙髓衰老，结合减少获得 BPiD，会随着年龄的增长而降低牙齿活力。这个项目的基本原理是，一个详细的科学框架 牙齿老化和再生可能会发现重要牙髓疗法的分子候选者。中央高铁- 假体测试将有以下特定目的：1)鉴定牙本质中分泌的生物活性蛋白 随着年龄的变化；以及2)分析牙齿随年龄的变化。在第一个目标下，年轻和年轻的磨牙 老年大鼠将被提取，分为树根和树冠部分，并碾碎，用于随后的蛋白质组学分析 牙本质成分。ELISA和/或免疫荧光将验证位置和丰度，以确定- Tify分泌的蛋白质可以调节损伤和/或再生过程中的神经血管反应。 对于第二个目的，将对3月和20月龄小鼠的磨牙牙本质进行手术损伤并进行分析 不同的时间点来评估：a)使用纳米压痕分析的弹性和硬度；b)矿化体积 和密度由微型计算机断层扫描(Micro-CT)确定；以及c)牙髓神经血管损伤 基于共聚焦成像的响应。本申请中提出的研究具有创新性，因为它促进了 使用几种应用于临床前小鼠模型的技术，全面展示牙齿老化的过程 从年轻的阶段到老年的阶段。这项拟议的研究具有重要意义，因为它有望识别重要的牙髓 治疗和再生牙髓学候选患者继续研究和未来的临床试验 在生命的不同阶段。最终，这些知识有可能提供新的牙科治疗方法来帮助 患者保持牙齿健康，并在晚年保留其天然牙齿。

PROJECT SUMMARY/ABSTRACT The introduction of new strategies harnessing the regenerative capacity of the dentin-pulp complex may make it possible for humans to retain their natural teeth throughout their lifespan. Research has demonstrated that dental pulp stem cells maintain extraordinary characteristics that can provide clinical options for dental care and restoration. However, it remains unknown whether older patients are also able to benefit from these tech- nologies. The long-term goal of this project is to gain an understanding of how teeth change throughout adult- hood in order to develop treatments that can preserve or enhance tooth health and permit retention throughout the lifespan. Our objective is to analyze the dentin-pulp interface in young and old rodent molars to qualitatively determine how the regenerative capacity of the dentin-pulp complex changes with age. Our central hypothesis is that age-related changes to the DP mesenchyme, vasculature, and innervation alter the secretion and avail- ability of bioactive proteins in dentin (BPiD) and that pulpal senescence, in combination with reduced access to BPiD, reduces tooth vitality with age. The rationale for this project is that a detailed scientific framework of tooth aging and regeneration is likely to uncover molecular candidates for vital pulp therapies. The central hy- pothesis will be tested with the following specific aims: 1) Identify secreted bioactive proteins in dentin that change with age; and 2) Analyze age-dependent changes in teeth. Under the first aim, molars from young and old rats will be extracted, divided into root and crown portions, and milled for subsequent proteomic analyses of the dentin composition. ELISA and/or immunofluorescence will verify location and abundance in order to iden- tify secreted proteins of interest that could regulate neurovascular responses during injury and/or regeneration. For the second aim, mouse molar dentin in 3- and 20-month mice will be surgically damaged and analyzed at varying time points to assess: a) elasticity and hardness using nanoindentation assays; b) mineralized volume and density determined by microcomputed tomography (micro-CT); and c) dental pulp neurovascular injury responses based on confocal imaging. The research proposed in this application is innovative because it pro- vides a comprehensive view of how teeth age using several techniques applied to preclinical murine models from young and elderly stages. The proposed research is significant because it is expected to identify vital pulp therapy and regenerative endodontics candidates for continued research and future clinical trials with patients in different stages of life. Ultimately, such knowledge has the potential to offer new dental treatments to help patients maintain their dental health and retain their natural teeth into old age.