Calcium Control of Enamel Development

牙釉质发育的钙控制

• 批准号: 9124353
• 负责人: Rodrigo S. Lacruz
• 金额: $ 39.63万
• 依托单位: NEW YORK UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-07 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9124353
• 关键词: Address; Adult; Affect; Agonist; Ameloblasts; Amelogenesis Imperfecta; Animals; Biological Process; Birth; Buffers; Calcified; Calcineurin; Calcium; Caries prevention; Cells; Cellular Stress; Clinical; Control Animal; Data; Defect; Dental Enamel; Development; Down Syndrome; Dyes; Electron Microscopy; Enamel Formation; Endoplasmic Reticulum; Environment; Frequencies; Fura-2; Gene Expression; Gene-Modified; Genes; Goals; Growth; Hardness Tests; Health; Hereditary Disease; Homeostasis; Hour; Human Genetics; ITPR1 gene; Indium; Inositol; Knockout Mice; Knowledge; Lead; Link; Measurement; Mediating; Monitor; Mus; Mutation; NFAT Pathway; Oral; Organ; Pathway interactions; Patients; Pattern; Physiological; Preventive; Process; Proteins; Reporting; Role; Second Messenger Systems; Skin; Staging; Sweat Glands; Testing; Tissues; Tooth Diseases; Tooth structure; Western Blotting; Work; biophysical techniques; bone; gene function; inhibitor/antagonist; interest; microCT; mineralization; oral bacteria; overexpression; paralogous gene; public health relevance; ratiometric; receptor; research study; second messenger

 DESCRIPTION (provided by applicant): Calcium (Ca2+) is a key regulator of a broad range of biological functions and is also a key element in the composition of dental enamel. Ca2+ must reach the forming enamel layer but how this process is regulated in ameloblasts is poorly understood. Our goal is to identify key pathways used by ameloblasts to regulate Ca2+ dynamics, in particular the required mechanisms for Ca2+ entry and pathways activated upon increases in cytosolic Ca2+ concentration. Deficiencies in the normal functioning of these pathways result in abnormal enamel that is prone to dental disease which can act as a host environment for oral bacteria. The focus of this proposal is to identify the functions of the store operated Ca2+ release-activated Ca2+ (CRAC) channels in enamel development. CRAC channels comprise important Ca2+ influx mechanisms activated following Ca2+ release from the endoplasmic reticulum (ER). The importance of Ca2+ influx via CRAC channels pathway in ameloblasts is understood by clinical reports describing hypo-calcified amelogenesis imperfecta in patients with mutations to STIM1 and ORAI1. However our understanding of CRAC channels function in enamel is limited as Stim1-/- and Orai1-/- animals die around birth. To address this problem, we developed several conditional knockout mice that specifically analyze the function of CRAC channels with particular reference to dental enamel formation. The ensuing Ca2+ entry via CRAC activates the calcineurin-NFAT pathway, which up-regulates the regulator of calcineurin (RCAN1). Although we find that NFAT and RCAN1 are expressed in enamel cells, and that this pathway is active during enamel development, the functions of these genes in enamel development are unknown. We are particularly interested in RCAN1 as Down syndrome patients present with a host of enamel deficiencies including abnormal mineralization and thinner enamel. Down syndrome is one of the most common human genetic disorders (frequency is 1 in ~700 births) characterized by elevated levels of RCAN1 in several tissues. The cause of growth alterations in the enamel of Down syndrome patients remains unknown. Our proposed studies will increase our understanding of enamel development. Such knowledge will impact caries prevention and has broader implications in bone homeostasis/development and in the development of ectodermal organs as some of these pathways are shared. The proposed work will also lead to a better understanding of systemic effects of CRAC channel function.

 描述（由申请人提供）：钙（Ca 2+）是广泛生物功能的关键调节剂，也是牙釉质组成中的关键元素。Ca 2+必须到达形成的釉质层，但这一过程在成釉细胞中是如何调节的，目前还知之甚少。我们的目标是确定成釉细胞用于调节Ca 2+动力学的关键途径，特别是Ca 2+进入所需的机制和细胞溶质Ca 2+浓度增加时激活的途径。这些途径的正常功能的缺陷导致异常的牙釉质，其易于发生牙病，可以作为口腔细菌的宿主环境。这个建议的重点是确定商店的功能 在釉质发育过程中，钙释放激活的钙通道（CRAC）。CRAC通道包括在Ca 2+从内质网（ER）释放后激活的重要Ca 2+内流机制。通过描述STIM 1和ORAI 1突变患者中低钙化成釉细胞增殖的临床报告，了解了成釉细胞中通过CRAC通道途径的Ca 2+内流的重要性。然而，我们对CRAC通道在釉质中的功能的理解是有限的，因为Stim 1-/-和Orai 1-/-动物在出生前后死亡。为了解决这个问题，我们开发了几种条件性基因敲除小鼠，专门分析CRAC通道的功能，特别是牙釉质形成。随后通过CRAC的Ca 2+进入激活钙调神经磷酸酶-NFAT途径，其上调钙调神经磷酸酶（RCAN 1）的调节剂。虽然我们发现NFAT和RCAN 1在釉质细胞中表达，并且该途径在釉质发育过程中是活跃的，但这些基因在釉质发育中的功能尚不清楚。我们对RCAN 1特别感兴趣，因为唐氏综合征患者存在大量牙釉质缺陷，包括异常矿化和较薄的牙釉质。唐氏综合征是最常见的人类遗传性疾病之一（频率为1/700），其特征是几种组织中RCAN 1水平升高。唐氏综合症患者牙釉质生长改变的原因尚不清楚。我们提出的研究将增加我们对牙釉质发育的了解。这些知识将影响龋齿预防，并在骨稳态/发育和外胚层器官的发育中具有更广泛的意义，因为其中一些途径是共享的。拟议的工作也将导致更好地了解CRAC通道功能的系统效应。