Epigenetic Regulation by FoxO1 in Pancreatic Beta Cells

FoxO1 在胰腺 Beta 细胞中的表观遗传调控

基本信息

批准号：
10435937
负责人：
Taiyi Diana Kuo
金额：
$ 7.68万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-07-01 至 2021-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10435937
关键词：
Ablation Adenoviruses Affect Aging Alpha Cell Arginine B Cell Proliferation B-Cell Development Beta Cell Binding Sites Candidate Disease Gene Cell Nucleus Cell physiology Cells Characteristics Coupled Cytoplasm DNA Methylation Data Development Diabetes Mellitus Endocrine Enhancers Epigenetic Process FOXO1A gene Failure Female Functional disorder GC gene Gene Expression Genes Genetic Epistasis Genetic Transcription Glucose Glucose Clamp Glucose tolerance test Goals HNF4A gene Health Hi-C High Fat Diet Histones Human Immunohistochemistry Insulin Intercistronic Region Islet Cell Knockout Mice Knowledge Link Maintenance Maps Mature B-Lymphocyte Metabolic Metabolic Diseases Modification Multiparity Mus Natural regeneration Non-Insulin-Dependent Diabetes Mellitus Pathogenesis Pattern Play Process Proteins RNA Regulation Regulatory Element Reporting Repression Research Research Personnel Research Training Role Stress Structure of beta Cell of islet Therapeutic Transcriptional Activation career career development cell dedifferentiation cell type chromatin remodeling chromosome conformation capture diabetic epigenetic regulation epigenome epigenomics functional genomics gene repression genetic signature genome sequencing genome-wide histone modification improved in vivo insulin secretion interest islet male overexpression pandemic disease progenitor promoter response stressor transcription factor transcriptome sequencing

项目摘要

Project Summary Over the last 30 years, diabetes has become a pandemic. Type 2 diabetes is the most common form of diabetes, and pancreatic β cell failure is pivotal in the pathogenesis of this metabolic disorder. Restoring β cell function has taken center stage in developing therapeutics to “cure” diabetes, through inducing β cell proliferation, re-differentiation, and regeneration. However, the quality and quantity of “β cell” obtained are less than ideal. One critical aspect to facilitate these processes to generating “perfect” β cell is to understand the epigenetic changes involved in β cell formation and maintenance. More and more evidence suggests that histone modification and chromatin remodeling play critical roles in β cell development, cell fate commitment, proliferation, and regeneration. Key β cell transcription factor FoxO1 is required to maintain β cell maturity. Ablation of FoxO1 in β cells leads to β cell dedifferentiation, a process where mature β cells lose their identity and ability to produce and secret insulin. In healthy β cells, FoxO1 is inactive and resides in the cytoplasm. In response to stressors, such as aging and multiparity, FoxO1 translocates into the nucleus, and elicits transcriptional networks to defend β cell health. In advanced type 2 diabetes, FoxO1 disappears from β cells as a result of increased degradation, leading to metabolic inflexibility and paving the way for dedifferentiation. However, whether the protective role of FoxO1 against β cell failure involves maintaining the epigenomic landscape has not been studied. The proposed studies will fill the gap of knowledge between FoxO1, epigenetics, functional genomics, and diabetes. The PI presented preliminary data to establish a role of FoxO1 in epigenetics with RNAseq and histone modification ChIPseq (i.e., H3K4me3, H3K27me3, and H3K27ac) using FAC sorted β cells in β cell-specific FoxO1 KO mice. The PI will continue to build the integrative regulatory map of FoxO1 in pancreatic β-cell with Hi-C, DNA methylation, and FoxO1 ChIPseq. H3K27ac motif analysis and RNA profiling suggest an imbalanced regulation between FoxO1 and Hnf4α, therefore, the PI will perform glucose clamps, glucose tolerance test, glucose- and arginine-stimulated insulin secretion in isolated islets, and RNAseq using β cell-specific FoxO1 and Hnf4α double KO mice to determine the epistasis of FoxO1 and Hnf4α. The PI will also functionally characterize FoxO1 targets to identify genes of therapeutic interest. The tailored research training and career development activities will assist the PI to achieve her career goals: becoming an independent academic investigator and advancing the field of diabetes research.

项目概要过去 30 年来，糖尿病已成为一种流行病，2 型糖尿病是最常见的形式。糖尿病和胰腺 β 细胞衰竭是这种代谢紊乱的发病机制的关键。通过诱导 β 细胞，功能已成为开发“治愈”糖尿病疗法的中心舞台但获得的“β细胞”的质量和数量较少。促进这些过程产生“完美”β细胞的一个关键方面是了解越来越多的证据表明，表观遗传变化涉及β细胞的形成和维持。组蛋白修饰和染色质重塑在 β 细胞发育、细胞命运决定、增殖和再生需要关键的β细胞转录因子FoxO1来维持β细胞的成熟。 β 细胞中 FoxO1 的消除会导致 β 细胞去分化，这是成熟 β 细胞失去其身份的过程以及产生和分泌胰岛素的能力在健康的 β 细胞中，FoxO1 不活跃并驻留在细胞质中。为了应对应激源，例如衰老和多产，FoxO1 易位到细胞核中，并引发在晚期 2 型糖尿病中，FoxO1 从 β 细胞中消失。由于降解加剧，导致代谢不灵活并为去分化铺平道路。然而，FoxO1 对 β 细胞衰竭的保护作用是否涉及维持表观基因组景观尚未被研究。拟议的研究将填补 FoxO1 之间的知识空白，表观遗传学、功能基因组学和糖尿病。 PI 提供了初步数据来确定 FoxO1 的作用。表观遗传学中使用 RNAseq 和组蛋白修饰 ChIPseq（即 H3K4me3、H3K27me3 和 H3K27ac）在 β 细胞特异性 FoxO1 KO 小鼠中使用 FAC 分选的 β 细胞 PI 将继续构建整合的系统。胰腺 β 细胞中 FoxO1 的调控图谱，包含 Hi-C、DNA 甲基化和 FoxO1 ChIPseq H3K27ac 基序。分析和 RNA 分析表明 FoxO1 和 Hnf4α 之间的调节不平衡，因此，PI 将进行葡萄糖钳夹、葡萄糖耐量试验、葡萄糖和精氨酸刺激的胰岛素分泌分离胰岛和RNAseq使用β细胞特异性FoxO1和Hnf4α双KO小鼠来确定上位性 FoxO1 和 Hnf4α 还将对 FoxO1 靶标进行功能表征，以识别治疗基因。量身定制的研究培训和职业发展活动将帮助 PI 实现其职业生涯。目标：成为一名独立的学术研究者并推进糖尿病研究领域。