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.

项目摘要 胰岛内的胰腺β细胞是葡萄糖刺激的胰岛素分泌所必需的 和葡萄糖稳态。功能失调的β细胞活性和身份导致糖尿病，一种生长性疾病 影响了数百万美国人，从而造成了巨大的财政和健康负担。战略来改进 越来越多的糖尿病患者需要了解复杂的程序， 协调适当的胰岛素释放以响应血糖水平的变化。在现有基础上发展 了解胰岛富集转录因子（TF）如何协调影响基因调控的信号 程序将使我们了解这些程序是如何在糖尿病的胰岛β细胞中发生显着改变的 患者Pdx 1是发育和出生后β细胞中最重要的转录因子之一， 一组不同的辅助调节因子，可能潜在地调节其活性。该提案的重点是如何 Pdx 1与核小体重塑和脱乙酰酶（NuRD）复合物的相互作用对正常的 β细胞功能，并在与2型糖尿病发展相关的病理生理条件下发生改变 糖尿病（T2 D）。 NuRD复合物的中心ATP酶亚基Chd 4被发现与一个子集相互作用并控制该子集 Pdx 1靶基因的表达，并被募集到对体外正常β细胞功能重要的基因。初步研究 证明从成熟胰岛β细胞中有条件地去除Chd 4显著影响葡萄糖耐量， vivo.该提案将检验Pdx 1结合的Chd 4：NuRD复合物控制染色质的总体假设 可及性和基因表达程序对生理β细胞功能很重要， 在糖尿病的发展过程中。在目标1中，我们将充分描述β细胞功能障碍是如何由于β-细胞功能障碍而发生的。 在一个新的条件性Chd 4缺失小鼠模型中Chd 4的缺失，在目标2中，我们将揭示Chd 4缺失的机制。 Chd 4在控制染色质可及性和基因表达中的作用， ATAC和ChIP测序方法。Chd 4：NuRD对人Pdx 1和β细胞作用的影响将 追究目标3将评估T2 D相关应激源如何影响Pdx 1：Chd 4相互作用， 来自啮齿动物和人胰岛的生物化学和原位方法、T2 D的体内模型和原代人组织。 在成功完成这项资助后，我们将确定Chd 4：NuRD的机械作用 控制Pdx 1活性和β细胞功能，并定义了压力源如何与糖尿病发展相关 影响重要的Pdx 1：Chd 4调节机制。这项研究将确定关键目标，有助于 T2 D的发病机制，这将为糖尿病研究开辟新的途径。