Manipulation of beta-catenin signaling in adult oral cells for tooth regeneration

描述(由申请人提供)：本申请涉及广泛的挑战领域(14)干细胞和(11)再生医学和具体挑战主题14-DE-101*：口腔和颅面组织细胞的精确重新编程和11-DE-101：头面部组织再生。该项目的最终目标是建立从成人口腔组织中生物工程牙齿的方法。在美国，牙齿缺失是一个主要的健康问题，在一些州，高达42%的人口患有牙齿缺失，并对少数族裔和经济困难社区造成不成比例的影响。目前最先进的治疗方法依赖于人工钛/陶瓷种植体，这些种植体存在需要大量手术干预、缺乏敏感性、对机械故障和细菌定植敏感，以及在骨骼恶化或损坏的情况下使用受限等缺点。用完整的牙齿再生来替换丢失的牙齿是牙科技术的最终目标之一，理想的做法是使用成人细胞来完成，以避免使用人类胚胎组织的实际和伦理问题，以及移植排斥问题。虽然成体间充质干细胞可以参与牙芽的形成，但成体上皮细胞的合适来源尚未确定。来自我们和其他实验室的最新数据表明，上皮性连环蛋白信号的激活是胚胎牙齿发育的关键启动事件，这表明在成人口腔上皮细胞中操纵这一途径可能使它们能够参与新生牙齿的发育。这项建议的目的是检验这一假设，并描绘出从连环蛋白激活的胚胎和成年小鼠口腔细胞和人类细胞系再生牙芽的最佳条件。具体地说，我们将：(1)确定来自成年小鼠的口腔细胞是否携带上皮β-catenin不可逆转的激活突变，是否能够支持体外和体内的牙齿发育；(2)确定激活的β-catenin的可逆口腔上皮表达是否允许正常大小和形状的牙齿的从头发育；以及(3)确定培养的小鼠和人类成人口腔上皮细胞是否能够启动上皮β-catenin信号的激活。这些研究有可能改变我们治疗人类患者牙齿缺失的方法，使用患者自己的细胞再生牙齿，使其完全融入患者的组织、循环系统和神经系统，而不是依赖人工合成植入物。7.叙述性牙齿缺失项目是美国的一个主要健康问题，在一些州，高达42%的人口经历了这一问题，并对少数族裔和经济困难社区造成了不成比例的影响。牙种植体是目前最先进的牙齿缺失治疗方法，但容易发生机械故障和感染，难以用于骨丢失严重的个人。这项建议的目的是开发在成人口腔细胞中重新激活胚胎牙齿信号通路的方法，以再生天然牙齿及其相关的支持组织，包括骨、血管、神经和牙周膜，从而提供更好的功能、敏感性、耐用性和外观。

DESCRIPTION (provided by applicant): This application addresses broad Challenge Areas (14) Stem Cells and (11) Regenerative Medicine and the specific Challenge Topics 14-DE-101*: Precise Reprogramming of Cells from Oral and Craniofacial Tissues and 11-DE-101: Craniofacial Tissue Regeneration. The ultimate goal of this project is to establish methods for bioengineering teeth from adult oral tissues. Tooth loss is a major health problem in the USA, experienced by up to 42% of the population in some states and disproportionately affecting minority and economically disadvantaged communities. Current state-of-the-art therapy relies on artificial titanium/ceramic dental implants that suffer from drawbacks including requiring significant surgical intervention, lack of sensitivity, susceptibility to mechanical failure and bacterial colonization, and restricted use in cases of bone deterioration or damage. The replacement of lost teeth by whole tooth regeneration is one of the ultimate goals of dental technology, and will ideally be accomplished using adult cells to avoid practical and ethical issues surrounding the use of human embryonic tissues, and problems of graft rejection. While adult mesenchymal stem cells can participate in tooth bud formation, a suitable source of adult epithelial cells has not been identified. Recent data from our and other labs indicate that activation of epithelial ¿-catenin signaling is a key initiating event in embryonic tooth development, suggesting that manipulation of this pathway in adult oral epithelial cells might render them capable of participating in de novo tooth development. The objective of this proposal is to test this hypothesis, and to delineate the optimal conditions for tooth bud regeneration from ¿-catenin activated embryonic and adult mouse oral cells and human cell lines. Specifically we will: (1) Determine whether oral cells from adult mice carrying an irreversible activating mutation in epithelial ¿-catenin can support tooth development in vitro and in vivo; (2) Determine whether reversible oral epithelial expression of activated ¿-catenin permits de novo development of teeth with normal size and shape; and (3) Determine whether cultured mouse and human adult oral epithelial cells can initiate following activation of epithelial ¿-catenin signaling. These investigations have the potential to alter our approach to treating tooth loss in human patients, by using the patient's own cells to regenerate teeth that become fully integrated into the patient's tissue, circulatory system and nervous system, rather than relying on artificial synthetic implants. 7. Project Narrative Tooth loss is a major health problem in the USA, experienced by up to 42% of the population in some states and disproportionately affecting minority and economically disadvantaged communities. Dental implants are the current state-of-the-art treatment for missing teeth, but are prone to mechanical failure and infections, and are difficult to use in individuals with significant bone loss. The aim of this proposal is to develop methods for reactivating embryonic dental signaling pathways in adult oral cells for regeneration of natural teeth and their associated support tissues, including bone, blood vessels, nerves and periodontal ligament, providing improved function, sensitivity, durability and appearance.