Dynamic Mechanisms of Vitamin D-Induced Gene Expression

维生素 D 诱导基因表达的动态机制

• 批准号: 8079067
• 负责人: J WESLEY PIKE
• 金额: $ 38.18万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8079067
• 关键词: Bioinformatics; Biological; Bone Surface; Calcitriol; Cell Count; Cell Survival; Cell physiology; Cells; Chromatin; Coupling; Custom; DNA; DNA Microarray Chip; Development; Employee Strikes; Epigenetic Process; Evaluation; Gene Chips; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Genome; Growth; Health; Homeostasis; Hormones; Individual; Informatics; Life; Maintenance; Mediating; Medicine; Mesenchymal; Metabolic; Minerals; Modification; Molecular; Molecular Target; Nature; Osteoblasts; Osteoclasts; Output; Parathyroid gland; Pharmaceutical Preparations; Play; Process; Production; Proliferating; Property; RNA Polymerase II; Receptor Activation; Regulation; Relative (related person); Research; Role; Series; Site; Structure; Techniques; Therapeutic; Tissues; Undifferentiated; Veins; Vitamin D; Vitamin D Analog; Vitamin D3 Receptor; autocrine; base; bone; bone cell; cell growth; cell type; cellular targeting; chromatin immunoprecipitation; comparative; cytokine; density; design; genome wide association study; genome-wide; histone modification; insight; novel; osteoblast differentiation; paracrine; peptide hormone; precursor cell; receptor; skeletal; steroid hormone; tool; transcription factor

DESCRIPTION (provided by applicant): Bone is a dynamic tissue which is remodeled throughout life as a result of the biological activities of osteoblasts and osteoclasts. The production and survival of these cells as well as their metabolic activities are all highly regulated by local and systemic factors that include growth modulators, cytokines and steroid and peptide hormones. 1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) together with parathyroid hormone play an integral role in many of these processes. Indeed, 1,25(OH)2D3 is known to influence the cellular activity of mature osteoblasts and to modulate the proliferation and differentiation of early precursors. Despite a general description of vitamin D action on bone, the mechanisms that permit orchestration of these activities by 1,25(OH)2D3 at the genome-wide level remain unclear. Striking technological advances have emerged which now permit such evaluations. As a consequence, we propose three specific aims. Specific Aim 1: To identify the 1,25(OH)2D3-independent and -dependent vitamin D receptor (VDR) cistromes and their properties in osteoblast precursors and to assess the changes that occur to these cistromes during differentiation. Genome-wide chromatin immunoprecipitation (ChIP)-DNA microarray (chip) (ChIP-chip) and gene expression techniques together with a series of bioinformatic tools will be used to identify and contrast the VDR cistromes in osteoblast precursors and in fully differentiated osteoblasts. The genome-wide properties and nature of these cistromes will be assessed. Specific Aim 2: To explore the molecular mechanisms associated with the regulation by VDR of selected gene targets in both osteoblast precursors and differentiated osteoblasts. DNA fragment and BAC clone analyses, together with ChIP-chip analysis using customized tiled arrays will be used to assess the role and mechanisms of action of VDR at representative classes of target genes in undifferentiated and differentiated osteoblasts. Specific Aim 3: To establish principles for the regulation of gene expression by 1,25(OH)2D3 and its receptor in osteoblasts at the genome-wide level. ChIP-chip approaches will be used to extend, genome-wide, the general features of VDR-mediated gene regulation identified in Aims 1 and 2 in osteoblast precursors and fully differentiated osteoblasts. The role of 1,25(OH)2D3 in the regulation of transcription factor co-recruitment, epigenetic modification and RNA polymerase II modulation will be assessed. The research proposed herein is likely to provide novel insight into the gene targets and underlying mechanisms that mediate the pleiotropic activities 1,25(OH)2D3 at the genome level in osteoblasts. The studies will also provide new information relevant to the design, development and potential therapeutic application of new vitamin D analogs. PUBLIC HEALTH RELEVANCE: Vitamin D plays significant roles both in the maintenance of mineral homeostasis and in the control of cellular growth and function. The studies herein seek to enhance our understanding of the mechanisms that underlie vitamin D action in bone cells such that better and more selective medicines can be created.

描述（由申请人提供）：骨骼是一种动态组织，由于成骨细胞和破骨细胞的生物学活性，它在整个生命中都经过重塑。这些细胞的产生和存活及其代谢活性都受到局部和系统因素的高度调节，包括生长调节剂，细胞因子以及类固醇和肽激素。 1,25-二羟基维生素D3（1,25（OH）2d3）与甲状旁腺激素一起在许多此类过程中起着不可或缺的作用。实际上，已知1,25（OH）2d3会影响成熟成骨细胞的细胞活性，并调节早期前体的增殖和分化。尽管对骨骼的维生素D作用进行了一般描述，但在全基因组水平上允许这些活性编排1,25（OH）2d3的机制尚不清楚。出现了惊人的技术进步，现在可以进行此类评估。结果，我们提出了三个具体目标。具体目的1：确定1,25（OH）2d3独立和依赖性维生素D受体（VDR）Cistromes及其在成骨细胞前体中的特性，并评估分化过程中这些Cistromes发生的变化。全基因组染色质免疫沉淀（CHIP） - DNA微阵列（芯片）（芯片芯片）和基因表达技术以及一系列生物信息学工具将用于识别和对比成骨细胞前体中的VDR Cistromes，并在完全区分的成蛋白细胞中。这些Cistromes的全基因组特性和性质将被评估。具体目的2：探索与成骨细胞前体和分化成骨细胞中所选基因靶标的调节相关的分子机制。 DNA片段和BAC克隆分析以及使用定制瓷砖阵列的芯片芯片分析将用于评估VDR在未分化和分化成骨细胞中靶基因代表性类别中VDR的作用和机理。具体目的3：建立通过1,25（OH）2d3调节基因表达的原理，其受体在整个基因组水平的成骨细胞中。芯片芯片方法将用于扩展整个基因组，这是在成骨细胞前体中AIMS 1和2中鉴定出的VDR介导的基因调节的一般特征和完全分化的成骨细胞。将评估1,25（OH）2d3在转录因子共同摄取，表观遗传学修饰和RNA聚合酶II调节中的作用。本文提出的研究很可能会提供对介导多效性活性的基因靶标和基本机制的新见解，而在成骨细胞中，基因组水平为1,25（OH）2d3。这些研究还将提供与新维生素D类似物的设计，开发和潜在治疗应用有关的新信息。公共卫生相关性：维生素D在维持矿物稳态以及控制细胞生长和功能方面都起着重要作用。本文的研究试图增强我们对骨细胞中维生素D作用的机制的理解，从而可以产生更好，更有选择性的药物。