Molecular mechanisms of oral deficiencies in Down syndrome

唐氏综合症口腔缺陷的分子机制

• 批准号: 10658410
• 负责人: Rodrigo S. Lacruz
• 金额: $ 151.33万
• 依托单位: NEW YORK UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10658410
• 关键词: Address; Ameloblasts; Amylases; Area; Biogenesis; Calcineurin; Calcineurin inhibitor; Calcium Signaling; Carbachol; Cell Line; Cells; Chromosome 21; Confocal Microscopy; Crystal Formation; Data; Defect; Dental; Dental Enamel; Development; Down Syndrome; Elements; Enamel Formation; Enzyme-Linked Immunosorbent Assay; Enzymes; Feedback; Fluids and Secretions; Foundations; Gene Dosage; General Population; Generations; Genes; Gland; Glycolysis; Goals; Growth; Health; Heterozygote; Histology; Human Chromosomes; Image; Individual; Infection; Knockout Mice; Knowledge; Label; Longevity; Maturation-Stage Ameloblast; Measures; Mechanics; Mediating; Membrane Potentials; Mitochondria; Mitochondrial Matrix; Modeling; Molecular; Morphology; Mus; NADH; Oral; Oral cavity; Oral health; Osmosis; Oxygen Consumption; PPP3CA gene; Parotid Gland; Pathology; Patients; Phase; Pilocarpine; Predisposition; Process; Production; Property; Protein Secretion; Protein phosphatase; Proteins; Publishing; Quality of life; Quantitative Reverse Transcriptase PCR; Reporter; Reporting; Research; Research Personnel; Role; Saliva; Salivary Glands; Secondary to; Secretory Vesicles; Signal Transduction; Sorting; Speech; Taste Perception; Testing; Thinness; Time; Tooth structure; Trisomy; United States National Institutes of Health; Vesicle; Xerostomia; antimicrobial; calcification; deciduous tooth; dosage; experimental study; induced pluripotent stem cell; mechanical properties; mineralization; mitochondrial dysfunction; mitochondrial membrane; mouse model; nanoindentation; overexpression; permanent tooth; prevent; response; saliva secretion; skeletal; solute; trafficking; transcriptome sequencing; transcriptomic profiling; uptake; water channel

Project Summary/Abstract: Individuals with Down syndrome (DS) contend with a diversity of oral anomalies including poor saliva production and enamel defects that manifest as hypoplasia (thinner enamel) and hypomineralization. The molecular mechanisms responsible for these alterations are not known. DS enamel defects are developmental and not simply secondary to hyposalivation. Saliva is essential to overall oral health, keeping the oral cavity moist and providing important support for speech and taste. It also contains solutes and enzymes that help prevent bacterial attack. Tooth enamel and saliva together provide a barrier against bacterial attack and can have a significant impact on health and quality of life. Regulator of calcineurin 1 (RCAN1) is a gene on human chromosome 21 (Hsa21), trisomy of which causes DS. RCAN1 is a feed-back inhibitor of calcineurin (Cn) a Ca2+-activated protein phosphatase that is central to a diversity of intracellular signaling cascades. Loss of Cn function has been shown to alter the water channel aquaporin, and in salivary glands, disrupts vesicle trafficking essential for saliva protein secretion. The goal of this proposal is to understand how salivary gland and enamel formation are altered in DS on a molecular level and to define the role of RCAN1/Cn in this process. In strong support, our preliminary data show that Dp16 mice [Dp(16)1Yey] an established mouse model of DS, have mechanically weak and morphologically abnormal enamel. We show that RCAN1 expression is upregulated in the mineralization phase and that overexpressing RCAN1 in an ameloblast cell line significantly alters mitochondrial function and increases ROS generation. Our co-investigator has demonstrated that changes in RCAN1 gene dosage are sufficient to alter mitochondrial dynamics and function in induced pluripotent stem cells (iPSCs) derived from individuals with DS. There are two central testable hypotheses in the proposed studies: 1) RCAN1 disrupts enamel crystal formation in DS by altering mitochondrial function in ameloblasts and 2) RCAN1 suppression of Cn signaling in DS disrupts Ca2+ signaling in salivary glands leading to hyposalivation. We will use DS mouse models (Dp16 mice, Rcan1-KO mice, Dp16 x Rcan1-KO mice) to address the role of mitochondria in the ameloblasts of these mice and will use mice expressing fluorescently labelled secretory and maturation stage. To address the role of RCAN1 trisomy in salivary glands (SG), we will use the Dp16 mice and will cross them with GFP mice highlighting secretory vesicles in SG to analyze calcium signaling, salivation as well as protein and solute content in saliva. The proposed studies are significant because they will both advance our understanding of the mechanisms through which perturbation of normal mitochondrial function, such as occurs in DS, can impact dental health ameloblast mitochondria and will elucidate the mechanisms contributing to hyposalivation in DS.

项目摘要/摘要：唐氏综合症 (DS) 患者面临着多种口腔问题 异常现象，包括唾液分泌不足和牙釉质缺陷，表现为发育不全（较薄） 牙釉质）和矿化不足。造成这些改变的分子机制并不 已知。 DS 牙釉质缺陷是发育性的，而不仅仅是继发于唾液分泌不足。唾液是 对整体口腔健康至关重要，保持口腔湿润并为言语提供重要支持 和味道。它还含有有助于防止细菌侵袭的溶质和酶。牙釉质和 唾液共同提供了抵御细菌攻击的屏障，并对健康和健康产生重大影响。 生活质量。钙调神经磷酸酶调节因子 1 (RCAN1) 是人类 21 号染色体 (Hsa21) 上的一个基因，三体性 其中导致DS。 RCAN1 是钙调磷酸酶 (Cn) 的反馈抑制剂，钙调神经磷酸酶是一种 Ca2+ 激活蛋白 磷酸酶是多种细胞内信号级联的核心。 Cn 功能丧失 被证明可以改变水通道蛋白，并在唾液腺中扰乱囊泡运输 用于唾液蛋白分泌。该提案的目标是了解唾液腺和牙釉质如何 DS 中的形成在分子水平上发生改变，并定义了 RCAN1/Cn 在此过程中的作用。在 强有力的支持，我们的初步数据表明 Dp16 小鼠 [Dp(16)1Yey] 是一种已建立的小鼠模型 DS，牙釉质机械脆弱且形态异常。我们展示了 RCAN1 表达 在矿化阶段上调，并且在成釉细胞系中过度表达 RCAN1 显着改变线粒体功能并增加 ROS 的产生。我们的合作研究员有 证明 RCAN1 基因剂量的变化足以改变线粒体动力学 DS 患者衍生的诱导多能干细胞 (iPSC) 中的功能。有两个中央 拟议研究中可检验的假设：1) RCAN1 通过以下方式破坏 DS 中牙釉质晶体的形成 改变成釉细胞中的线粒体功能和 2) RCAN1 抑制 DS 中的 Cn 信号传导 破坏唾液腺中的 Ca2+ 信号传导，导致唾液分泌不足。我们将使用 DS 鼠标型号 （Dp16 小鼠、Rcan1-KO 小鼠、Dp16 x Rcan1-KO 小鼠）解决线粒体在 这些小鼠的成釉细胞，并将使用表达荧光标记的分泌和成熟的小鼠 阶段。为了解决 RCAN1 三体性在唾液腺 (SG) 中的作用，我们将使用 Dp16 小鼠，并将 将它们与 GFP 小鼠杂交，突出显示 SG 中的分泌囊泡，以分析钙信号传导、唾液分泌 以及唾液中蛋白质和溶质的含量。拟议的研究意义重大，因为它们将 两者都增进了我们对扰乱正常线粒体的机制的理解 功能，例如 DS 中发生的功能，可以影响牙齿健康成釉细胞线粒体，并将阐明 导致 DS 唾液分泌不足的机制。