Elucidating the mechanism by which Rap1 protects from obesity - Resubmission - 1

阐明 Rap1 预防肥胖的机制 - 重新提交 - 1

基本信息

批准号：
9760593
负责人：
Raymond Mario Barry-Herrera
金额：
$ 3.63万
依托单位：
NEW YORK UNIVERSITY SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-01 至 2021-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9760593
关键词：
Adaptor Signaling Protein Adipocytes Adipose tissue Adult Affect Age Aging Alleles Binding Binding Sites Biology Biotin Cell Culture Techniques Cell physiology Cells ChIP-seq Clustered Regularly Interspaced Short Palindromic Repeats Complex DNA-Protein Interaction Defect Deposition Diabetes Mellitus Dissection Dyslipidemias Ensure Equilibrium Exhibits Fatty acid glycerol esters Functional disorder Gene Activation Gene Expression Genes Genetic Transcription Genomics Glucose Glucose Intolerance Hepatic High Fat Diet High-Throughput Nucleotide Sequencing Homeostasis Hormonal Insulin Resistance Knock-in Knockout Mice Label Left Link Liver LoxP-flanked allele Malnutrition Mediating Metabolic Metabolic Control Metabolic Diseases Metabolic dysfunction Molecular Morphology Mouse Strains Mus Nutritional Obese Mice Obesity Obesity Epidemic Operative Surgical Procedures Organ Overnutrition Phenotype Physiological Physiology Prevalence Proteins Proteomics Repression Role Signal Transduction Site Skeletal Muscle Study models System Telomere Shortening Telomere-Binding Proteins Testing Time Tissues Transcription Factor AP-1 Transcriptional Regulation Weight Weight Gain activator 1 protein adipocyte differentiation aging population base combat effective therapy experimental study functional decline in vivo insight insulin tolerance interstitial lipid biosynthesis mouse model new therapeutic target novel programs promoter recruit response small hairpin RNA telomere transcriptome sequencing

项目摘要

Project Summary Metabolic dysregulation is linked to aging; however, the molecular mechanisms that mediate this time- dependent decline in metabolic homeostasis remain elusive. With an increasingly aging and obese population, it is critical to understand these mechanisms to develop effective therapies to combat metabolic disorders. Recent evidence from our lab and others has identified Rap1 (Repressor/Activator Protein 1), a conserved telomere binding protein with additional extratelomeric functions in gene activation/repression, as a novel regulator of metabolic gene transcription. Rap1 knockout mice (Rap1KO) exhibit adult-onset obesity coincident with metabolic breakdown characterized by glucose intolerance, insulin resistance, dyslipidemia, and hepatosteatosis. Principally, these mice suffer from altered hepatic and white adipose tissue (WAT) function evidenced morphologically and at the level of gene transcription. Gross examination upon surgical dissection shows significant expansion of WAT compartments and ectopic fat deposition in multiple vital organs. In addition, parallel ex vivo experiments suggest a cell-autonomous role for Rap1 in promoting an anti-adipogenic transcriptional program. Altogether, we hypothesize that WAT dysfunction due to improper transcriptional control is a major driver of metabolic derangement in Rap1-deficient mice. How Rap1, which is primarily found at telomeres, can maintain proper metabolic gene transcription of WAT in vivo remains unclear. We hypothesize that Rap1 promotes its metabolic functions by associating at discrete extratelomeric loci with a specific set of partners. To pursue this avenue of inquiry, cutting edge proteomics and high-throughput sequencing approaches will be employed to molecularly characterize Rap1 mechanism of action in regulating transcriptional networks. In addition, mouse model studies will be used to test these mechanisms in vivo. Specifically, this proposal aims to test whether: (i) Extra-telomeric Rap1 functions independent of telomere binding in vivo to control from obesity due to WAT dysfunction (ii) Rap1 acts as an adaptor protein to recruit transcriptional regulatory factors to metabolic gene promoters. By bridging gene promoters to telomeres, Rap1 provides an unprecedented link between telomere biology and metabolic signaling. Thus, this study will provide important insight into how aging and, thus, telomere shortening, drives changes in metabolic homeostasis and supply a potential new therapeutic target for treating metabolic disorders such as obesity and diabetes.

项目概要代谢失调与衰老有关；然而，介导这个时间的分子机制—— 代谢稳态的依赖性下降仍然难以捉摸。随着人口老龄化和肥胖人口的日益增多，了解这些机制对于开发对抗代谢紊乱的有效疗法至关重要。我们实验室和其他实验室的最新证据已鉴定出 Rap1（阻遏蛋白/激活蛋白 1），一种保守的蛋白端粒结合蛋白在基因激活/抑制中具有额外的端粒外功能，作为一种新型代谢基因转录的调节因子。 Rap1 基因敲除小鼠 (Rap1KO) 表现出与成年发病一致的肥胖症以葡萄糖不耐受、胰岛素抵抗、血脂异常为特征的代谢紊乱肝脂肪变性。主要是，这些小鼠的肝脏和白色脂肪组织（WAT）功能发生改变在形态学和基因转录水平上得到证实。手术解剖后的肉眼检查显示多个重要器官中 WAT 室显着扩张和异位脂肪沉积。此外，平行的离体实验表明 Rap1 在促进抗脂肪形成方面具有细胞自主作用转录程序。总而言之，我们假设 WAT 功能障碍是由于转录控制不当造成的是 Rap1 缺陷小鼠代谢紊乱的主要驱动因素。 Rap1 怎么样，主要位于端粒，能否维持体内WAT正常代谢基因的转录仍不清楚。我们假设 Rap1 通过在离散的端粒外基因座与一组特定的合作伙伴。为了追求这一探究途径，尖端蛋白质组学和高通量测序方法将用于分子表征 Rap1 在调节转录网络中的作用机制。此外，小鼠模型研究将用于在体内测试这些机制。具体而言，该提案旨在测试是否：(i) 端粒外 Rap1 的功能独立于体内端粒结合以控制肥胖由于 WAT 功能障碍 (ii) Rap1 作为衔接蛋白来招募转录调节因子代谢基因启动子。通过桥接基因启动子和端粒，Rap1 提供了前所未有的连接端粒生物学和代谢信号之间的关系。因此，这项研究将为衰老如何发生提供重要的见解。因此，端粒缩短会驱动代谢稳态的变化，并提供潜在的新治疗方法治疗肥胖和糖尿病等代谢性疾病的目标。