The role of Pdx1-recruited Chd4:NuRD complex in controlling mature #-cell function

Pdx1招募的Chd4:NuRD复合物在控制成熟中的作用

• 批准号: 10634693
• 负责人: Jason M Spaeth
• 金额: $ 39.58万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10634693
• 关键词: ATAC-seq; ATP phosphohydrolase; Adult; Affect; American; Beta Cell; Binding; Biochemical; Biological Assay; Blood Glucose; CHD4 gene; Calcium; Calcium Signaling; Cell Line; Cell physiology; ChIP-seq; Chromatin; Complex; Data; Deacetylase; Development; Diabetes Mellitus; Disease; Duodenum; Excision; Functional disorder; Future; G6PC2 gene; Gene Expression; Gene Expression Profile; Genes; Genetic; Genetic Transcription; Glucose; Glucose Intolerance; Goals; Grant; Health; Health Care Costs; High Fat Diet; Homeobox; Human; Hyperglycemia; Impairment; In Situ; In Vitro; Individual; Influentials; Insulin; Insulin Resistance; Islets of Langerhans; Knockout Mice; Knowledge; Ligation; Link; Mediating; Metabolic stress; Methods; Mitochondria; Mus; Non-Insulin-Dependent Diabetes Mellitus; Nucleosomes; Organ Donor; Outcome; Pancreas; Pathogenesis; Pathway interactions; Patients; Peripheral; Physiological; Production; Proteins; RNA; Regulator Genes; Research; Rodent; Rodent Model; Role; Signal Transduction; Structure of beta Cell of islet; Tamoxifen; Testing; Transcriptional Regulation; blood glucose regulation; chromatin remodeling; conditional knockout; diabetes mellitus therapy; diabetes pathogenesis; diabetic patient; diabetogenic; economic cost; endoplasmic reticulum stress; gene repression; genome-wide; glucose metabolism; glucose tolerance; human tissue; impaired glucose tolerance; improved outcome; in vivo; in vivo Model; insight; insulin secretion; islet; knock-down; mouse model; non-diabetic; novel; postnatal; programs; recruit; response; stressor; transcription factor; transcriptome sequencing

PROJECT SUMMARY Pancreatic β-cells within the islets of Langerhans are required for glucose-stimulated insulin secretion and glucose homeostasis. Dysfunctional β-cell activity and identity results in diabetes, a growing disease affecting millions of Americans, thus creating an enormous fiscal and health burden. Strategies to improve outcomes for the mounting number of diabetic patients requires understanding the complex programs that coordinate a proper insulin release in response to changing blood glucose levels. Developing upon existing knowledge of how islet enriched transcription factors (TFs) coordinate signals that influence gene regulatory programs will allow us to understand how such programs are dramatically altered in islet β-cells of diabetes patients. Pdx1, one of the most important TFs in the developing and postnatal β-cell, has been shown to recruit a diverse set of coregulators which could potentially modulate its activity. This proposal is focused around how Pdx1 interactions with the Nucleosome Remodeling and Deacetylase (NuRD) complex are influential to normal β-cell function and are altered in pathophysiological conditions associated with the development of Type 2 diabetes (T2D). The central ATPase subunit of the NuRD complex, Chd4, was found to interact with and control a subset of Pdx1 target genes and is recruited to genes important for normal β-cell function in vitro. Preliminary studies demonstrate that conditional removal of Chd4 from mature islet β-cells significantly impacts glucose tolerance in vivo. This proposal will test the overall hypothesis that Pdx1-bound Chd4:NuRD complex controls chromatin accessibility and gene expression programs important for physiological β-cell function which are compromised during the development of diabetes. In Aim 1, we will fully characterize how β-cell dysfunction occurs due to the absence of Chd4 in a new conditional Chd4-deleted mouse model and in Aim 2 we will uncover the mechanistic actions of Chd4 in controlling chromatin accessibility and gene expression using unbiased genome-wide RNA-, ATAC- and ChIP-Sequencing approaches. The influence of Chd4:NuRD on human Pdx1 and β-cell action will be investigated. Aim 3 will evaluate how T2D associated stressors influence Pdx1:Chd4 interactions using biochemical and in situ methods from rodent and human islets, in vivo models of T2D and primary human tissues. Upon successful completion of this grant, we will have determined the mechanistic actions of Chd4:NuRD on controlling Pdx1 activity and β-cell function, and defined how stressors associated with diabetes development impact the vital Pdx1:Chd4 regulatory mechanisms. This research will identify critical targets that contribute to the pathogenesis of T2D, which will open new avenues for diabetes research.

项目概要 朗格汉斯岛内的胰腺 β 细胞是葡萄糖刺激的胰岛素分泌所必需的 β细胞活性和身份功能失调会导致糖尿病这一日益严重的疾病。 影响数百万美国人，从而造成巨大的财政和健康负担。 越来越多的糖尿病患者的结果需要了解复杂的计划 根据现有的血糖水平协调适当的胰岛素释放。 了解胰岛富集转录因子 (TF) 如何协调影响基因调控的信号 程序将使我们能够了解这些程序如何在糖尿病的胰岛β细胞中发挥显着作用 Pdx1 是发育中和出生后 β 细胞中最重要的 TF 之一，已被证明可以招募患者。 该提案的重点是如何调节其活动。 Pdx1 与核小体重塑和脱乙酰酶 (NuRD) 复合物的相互作用对正常有影响 β 细胞功能，并在与 2 型发展相关的病理生理条件下发生改变 糖尿病（T2D）。 NuRD 复合物的中心 ATP 酶亚基 Chd4 被发现与一个子集相互作用并控制 Pdx1 靶基因，并被招募到对体外正常 β 细胞功能重要的基因。 证明从成熟胰岛 β 细胞中条件性去除 Chd4 会显着影响 该提案将检验 Pdx1 结合的 Chd4:NuRD 复合物控制染色质的总体假设。 对生理 β 细胞功能很重要的可及性和基因表达程序受到损害 在目标 1 中，我们将全面描述糖尿病发展过程中 β 细胞功能障碍是如何发生的。 在新的条件性 Chd4 删除小鼠模型中缺乏 Chd4，在目标 2 中我们将揭示其机制 Chd4 在使用无偏全基因组 RNA 控制染色质可及性和基因表达中的作用， ATAC 和 ChIP 测序方法将影响 Chd4:NuRD 对人类 Pdx1 和 β 细胞作用的影响。 目标 3 将评估 T2D 相关压力因素如何影响 Pdx1:Chd4 相互作用。 来自啮齿动物和人类胰岛、T2D 体内模型和原代人体组织的生化和原位方法。 成功完成这笔资助后，我们将确定 Chd4:NuRD 的机械作用 控制 Pdx1 活性和 β 细胞功能，并定义压力源如何与糖尿病发展相关 这项研究将确定有助于 Pdx1:Chd4 调控机制的关键目标。 T2D 的发病机制，这将为糖尿病研究开辟新途径。