Transcriptional Mechanisms Governing Beta Cell Differentiation

控制β细胞分化的转录机制

• 批准号: 7627368
• 负责人: Raghavendra G Mirmira
• 金额: $ 27.38万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7627368
• 关键词: Address; Animals; Applications Grants; Beta Cell; Biochemical; Biological Assay; Cell Differentiation process; Cell Line; Cell physiology; Cells; Chromatin; Chromatin Structure; Classification; Complex; Development; Diabetes Mellitus; Embryonic Development; Euchromatin; Event; Fluorescence; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Genetic Models; Genetic Transcription; Heterochromatin; Holoenzymes; Image; Imaging Techniques; In Vitro; Insulin; Lead; Left; Life; Link; Mammalian Cell; Mediating; Molecular; Mus; Nature; Pathogenesis; Pattern; Proteins; Publishing; RNA Polymerase II; RNA Processing; Recruitment Activity; Relative (related person); Research; Role; Small Interfering RNA; Structure of beta Cell of islet; Testing; Text; Transcription Coactivator; base; cell type; cellular imaging; chromatin immunoprecipitation; chromatin remodeling; cofactor; endocrine pancreas development; homeodomain; insulin secretion; islet; mouse model; novel strategies; physical state; research study; transcription factor

DESCRIPTION (provided by applicant): The absolute or relative deficiency of insulin secretion by the pancreatic beta cell underlies the pathogenesis of most forms of diabetes mellitus. Promising new approaches to the treatment or cure of diabetes will come from attempts recapitulate beta cell gene expression patterns in non-beta cell types. The long-range objective of this ongoing grant application is to define the biochemical mechanisms by which transcription factors direct gene expression in the developing and mature beta cell. In this application, we propose to extend upon our published studies of the mechanisms underlying the beta cell transcription factors Nkx6.1 and Pdx-1, and thereby merge established concepts in beta cell gene regulation with exciting and emerging themes in transcriptional complex formation and chromatin structure. Nkx6.1 and Pdx-1 are necessary for both the embryonic development and eventual function of beta cells. We hypothesize that these factors participate in key transcriptional complexes that are responsible for the remodeling of chromatin and the subsequent recruitment of basal transcriptional machinery. These effects result in either the activation or silencing of selective genes that lead to normal beta cell development and function. To test this hypothesis, our specific aims are directed toward a systematic analysis of the transcriptional complexes mediated by Pdx-1 and Nkx6.1 (Aim 1), the consequences of these complexes on chromatin structure (Aim 2), and their effects on the recruitment/activation of basal transcriptional machinery (Aim 3). Aim 1: Characterize transcriptional complexes involving Pdx-1 and Nkx6.1 and determine how they regulate target gene expression in the beta cell. Aim 2: Determine the role of Pdx-1 and Nkx6.1 complexes in modulating chromatin structure at target genes. Aim 3: Determine the role of Pdx-1 and Nkx6.1 complexes in the recruitment of basal transcriptional machinery. We propose to use a combination of biochemical assays and live cell imaging techniques in both cell lines and primary isolated islets to address each of these aims. We believe that the proposed studies will provide the framework for elucidating the molecular events governing ¿ cell development and function.

描述（由申请人提供）：胰腺β细胞分泌胰岛素的绝对或相对缺乏是大多数糖尿病发病机制的基础。有希望的治疗或治愈糖尿病的新方法将来自于在非β细胞类型中重现β细胞基因表达模式的尝试。这项正在进行的拨款申请的长期目标是确定转录因子在发育和成熟的β细胞中直接基因表达的生化机制。在本申请中，我们建议扩展我们已发表的β细胞转录因子Nkx6.1和Pdx-1机制的研究，从而将β细胞基因调控的既定概念与转录复合体形成和染色质结构中令人兴奋的新兴主题结合起来。Nkx6.1和Pdx-1对于胚胎发育和β细胞的最终功能都是必需的。我们假设这些因子参与了负责染色质重塑和随后基础转录机制募集的关键转录复合物。这些影响导致导致正常β细胞发育和功能的选择性基因的激活或沉默。为了验证这一假设，我们的具体目标是系统分析由Pdx-1和Nkx6.1介导的转录复合物（目的1），这些复合物对染色质结构的影响（目的2），以及它们对基础转录机制的招募/激活的影响（目的3）。目的1：表征涉及Pdx-1和Nkx6.1的转录复合物，并确定它们如何调节β细胞中的靶基因表达。目的2：确定Pdx-1和Nkx6.1复合物在调节靶基因染色质结构中的作用。目的3：确定Pdx-1和Nkx6.1复合物在基础转录机制募集中的作用。我们建议在细胞系和原代分离胰岛中结合使用生化分析和活细胞成像技术来解决这些问题。我们相信所提出的研究将为阐明控制细胞发育和功能的分子事件提供框架。