Regulation of Wnt signaling in tooth development and regeneration

Wnt信号在牙齿发育和再生中的调节

• 批准号: 8855271
• 负责人: Sarah E. Millar
• 金额: $ 40万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8855271
• 关键词: 3-Dimensional; Accidents; Adult; Affect; Biomedical Engineering; Blood Vessels; Cell Line; Cell Polarity; Cells; Data; Defect; Dental; Dental Enamel; Dental Implants; Development; Ectodermal Dysplasia; Embryo; Endogenous Factors; Epithelial; Epithelial Cells; Epithelium; Failure; Family; Family member; Genes; Genetic; Goals; Growth; Health; Human; Hypodontia; Image; Implant; In Vitro; Incisor; Individual; Infection; Inherited; Jaw; Life; Ligands; Light; Mandible; Mechanics; Mediating; Mesenchymal Stem Cells; Mesenchyme; Microfluidics; Molar tooth; Morphogenesis; Movement; Mus; Mutation; Natural regeneration; Nerve; Odontogenesis; Operative Surgical Procedures; Oral; Pathway interactions; Patients; Pattern; Phenotype; Plant Roots; Play; Population; Property; Proteins; Publishing; Recombinants; Regulation; Relative (related person); Reporter; Rodent; Role; Shapes; Signal Transduction; Site; Staging; Structure; Syndrome; System; Testing; Tooth Germ; Tooth Loss; Tooth structure; WNT10A gene; Wnt proteins; base; beta catenin; bone; bone loss; cell motility; implantation; in vivo; inhibitor/antagonist; loss of function; mouse crinkled protein; mutant; oral tissue; receptor; research study; tooth cusp

DESCRIPTION (provided by applicant): Tooth loss through decay or accident is a major health problem in the USA, and genetic oligodontia occurs in almost 1% of the population. Current therapies rely on surgical implants that suffer from lack of sensitivity, mechanical failur and restricted utility in cases of bone loss. A long term goal of dental bioengineering is to use a patient's own cells for in vitro regeneration of tooth buds that can develop into normally functioning teeth following implantation. Recent progress towards this goal includes successful regeneration of rodent tooth buds from dissociated embryonic dental cells, or embryonic dental epithelia combined with adult mesenchymal stem cells, and implantation of these reconstructs to produce tooth structures that are innervated and vascularized. However, the sizes and shapes of these reconstructed structures are variable, indicating a need to identify endogenous factors that control these properties and could be applied in bioengineering strategies. Mutations of Wnt/beta-catenin pathway components in human patients are associated with dental defects. In particular, mutations in WNT10A are present in more than 50% of congenital non-syndromic hypodontia cases, as well as in a subset of ectodermal dysplasia syndromes. Genetic loss of function experiments in mice reveal requirements for Wnt/beta-catenin signaling at early stages of tooth development, and for formation of both cusp and root structures. Conversely, forced activation of oral epithelial beta-catenin in mouse embryos activates a cascade of downstream dental regulators, stimulating continuous tooth development, and in adults causes formation of embryonic-like tooth buds from incisor epithelia. The structures resulting from embryonic or adult activation of oral epithelial beta-catenin are, respectively, unicuspid, or ca mineralize but do not erupt. Thus, Wnt signaling must be tightly controlled for normal tooth morphogenesis. Wnt/beta-catenin activity is modulated by secreted antagonists, and by competition with alternate, beta-catenin independent pathways that are activated by specific combinations of Wnt ligands, receptors and co-factors. Based on published data and our preliminary studies we hypothesize that Wnt10a and its relative Wnt10b promote tooth development and molar cusp formation by activating beta-catenin signaling, and compete with secreted Sostdc1, Wif1 and Dkk family inhibitors to pattern tooth and cusp development. We further hypothesize that the Wnt receptor Fzd2 mediates non- canonical signaling by Wnt5a, which antagonizes the beta-catenin pathway and plays a critical role in tooth growth and cusp formation. We will test these hypotheses using genetic loss of function and rescue experiments and in vitro approaches. We will further utilize spatially and temporally-controlled delivery systems to determine whether recombinant WNT10A and Wnt10B proteins can be used to promote, and SOSTDC1, WIF1 and DKK proteins to inhibit, growth and cusp formation in embryonic tooth germs and tooth reconstructs in 3-D culture. Results from these experiments will suggest potential strategies for bioengineering teeth of defined size and shape, and for treating inherited conditions that affect tooth development.

描述（由申请人提供）：在美国，由于腐烂或事故造成的牙齿脱落是一个主要的健康问题，遗传性少牙症发生在近 1% 的人口中。目前的治疗方法依赖于外科植入物，但这些植入物缺乏敏感性、机械故障以及在骨质流失情况下的实用性受到限制。牙科生物工程的一个长期目标是利用患者自身的细胞进行牙芽的体外再生，牙芽在植入后可以发育成功能正常的牙齿。实现这一目标的最新进展包括从分离的胚胎牙细胞或胚胎牙上皮与成体间充质干细胞结合成功再生啮齿动物牙芽，以及植入这些重建物以产生受神经支配和血管化的牙齿结构。然而，这些重建结构的大小和形状是可变的，这表明需要确定控制这些特性的内源因素，并可应用于生物工程策略。人类患者中 Wnt/β-连环蛋白通路成分的突变与牙齿缺陷相关。特别是，WNT10A 突变存在于超过 50% 的先天性非综合征性牙齿发育不全病例以及一部分外胚层发育不良综合征中。小鼠遗传功能丧失实验揭示了牙齿发育早期阶段对 Wnt/β-catenin 信号传导以及牙尖和牙根结构形成的需求。相反，在小鼠胚胎中强制激活口腔上皮β-连环蛋白会激活一系列下游牙齿调节因子，刺激牙齿持续发育，而在成人中则导致门牙上皮形成胚胎样牙芽。由口腔上皮β-连环蛋白的胚胎或成体激活产生的结构分别是单尖瓣或钙矿化但不萌发。因此，为了正常的牙齿形态发生，必须严格控制 Wnt 信号传导。 Wnt/β-连环蛋白活性通过分泌的拮抗剂以及与由 Wnt 配体、受体和辅因子的特定组合激活的替代、β-连环蛋白独立途径的竞争来调节。根据已发表的数据和我们的初步研究，我们假设 Wnt10a 及其相关 Wnt10b 通过激活 β-catenin 信号传导促进牙齿发育和磨牙尖形成，并与分泌的 Sostdc1、Wif1 和 Dkk 家族抑制剂竞争以模式牙齿和尖尖发育。我们进一步假设 Wnt 受体 Fzd2 通过 Wnt5a 介导非经典信号传导，Wnt5a 拮抗 β-连环蛋白途径，在牙齿生长和牙尖形成中发挥关键作用。我们将使用遗传功能丧失和拯救实验以及体外方法来测试这些假设。我们将进一步利用空间和时间控制的递送系统来确定重组 WNT10A 和 Wnt10B 蛋白是否可用于促进胚胎牙胚和 3D 培养中牙齿重建的生长和牙尖形成，以及 SOSTDC1、WIF1 和 DKK 蛋白是否可用于抑制。这些实验的结果将为确定尺寸和形状的生物工程牙齿以及治疗影响牙齿发育的遗传性疾病提出潜在的策略。

项目成果

Ultrananocrystalline diamond tip integrated onto a heated atomic force microscope cantilever.

超纳米晶金刚石尖端集成到加热原子力显微镜悬臂上。

• DOI: 10.1088/0957-4484/23/49/495302
• 发表时间: 2012
• 期刊: Nanotechnology
• 影响因子: 3.5
• 作者: Kim,HoeJoon;Moldovan,Nicolaie;Felts,JonathanR;Somnath,Suhas;Dai,Zhenting;Jacobs,TevisDB;Carpick,RobertW;Carlisle,JohnA;King,WilliamP
• 通讯作者: King,WilliamP

Role of surface-bound intermediates in the oxygen-assisted synthesis of amides by metallic silver and gold.

表面结合中间体在金属银和金氧辅助合成酰胺中的作用。

• DOI: 10.1021/ja303178z
• 发表时间: 2012
• 期刊: Journal of the American Chemical Society
• 影响因子: 15
• 作者: Siler,CassandraGF;Xu,Bingjun;Madix,RobertJ;Friend,CynthiaM
• 通讯作者: Friend,CynthiaM