Dental Stem Induced tooth Regeneration

描述（由申请人提供）：本提案的长期目标是鉴定、分离和表征能够再生成熟牙齿器官的人类成人牙发育细胞干细胞系。体外和体内研究表明，胚胎和成人牙髓含有间充质干细胞，具有形成骨、软骨和牙本质的潜力。最近的体内研究表明，发育中的人类牙齿含有具有再生整个牙齿结构能力的细胞。基于这些发现，我们相信人类牙齿含有干细胞群，可以被诱导来改造整个牙齿结构。本申请的目的是为鉴定和表征人类牙齿干细胞提供必要的试点研究。我们的假设是人类牙齿器官含有干细胞群，包括间充质细胞和上皮细胞，它们能够完全再生牙齿组织。这一应用是基于我们建立牙髓间充质和牙釉质口腔上皮细胞系的丰富经验，这些细胞系来源于小鼠和人类牙齿组织的外植体。这些已建立的永生化牙细胞系被用于了解控制牙齿特异性基因表达、细胞外基质形成和生物矿化、细胞分化、修复/三级牙本质形成和牙齿再生的分子机制。基于对这些细胞系与大量新兴干细胞文献的关系的分析，我们将进行初步研究来验证我们的假设，即发育中的牙齿包含间充质和上皮干细胞群，当它们结合在一起时能够进行牙齿器官再生。为了验证这一假设，提出了两个具体目标：

DESCRIPTION (provided by applicant): The long-term goal of this proposal is to identify, isolate, and characterize human adult odontogenetic cell stem lines that are capable of regenerating mature tooth organs. In vitro and in vivo studies have shown that embryonic and adult pulp contain mesenchymal stem cells with the potential to form bone, cartilage and dentin. Recent in vivo studies have suggested that developing human teeth contain cells with the ability to regenerate entire tooth structure. Based on these findings we believe that the human tooth contains stem cell populations that can be induced to reform the entire tooth structure. The purpose of this application is to provide the necessary pilot studies to identify and characterize human tooth stem cells. Our hypothesis is that human tooth organs contain stem cell populations, both mesenchymal and epithelial, that are capable of total tooth tissue regeneration. This application is based on our extensive experience establishing dental pulp mesenchyme and enamel oral epithelium cell lines from primary cell cultures derived from mouse and human tooth tissue explants. These established immortalized dental cell lines are being used to understand the molecular mechanisms controlling tooth-specific gene expression, extracellular matrix formation and biomineralization, cell cytodifferentiation, reparative/tertiary dentin formation, and tooth regeneration. Based on the analysis of these cell lines in relationship to the extensive emerging stem cell literature, we will perform preliminary studies to test our hypothesis that developing teeth contain both mesenchymal and epithelial stem cell populations that when combined are capable of tooth organ regeneration. To test this hypothesis, two specific aims are proposed: 1. To isolate, identify and immortalize human odontogenetic (mesenchymal and epithelial) stem cell populations based on the emerging stem cell literature. 2. To characterize in vitro and in vivo the multipotent potential of these established odontogenetic stem cell lines to differentiate into various dental tissue phenotypes. Currently, no stable human odontogenetic stem cell lines exist and therefore progress in understanding the cell biology, biochemistry, development, and molecular biology of tooth formation and regeneration has been impeded. Cell lines resulting from this work will represent the only available clonal human stem cell lines. Identification, isolation and immortalization of such cell populations would allow detailed biochemical and molecular studies to be conducted on stable, homogeneous populations of cells. This study is innovative and of high risk but with the potential of significant impact on future tissue engineering and biomimetic approaches to clinical dentistry. Our hypothesis requires "proof-of-concept" studies to be performed that will allow future funding through more traditional R01 grant mechanisms.