A stress inducible Pdx1 transcriptional complex governing beta cell survival

应激诱导的 Pdx1 转录复合物控制 β 细胞存活

基本信息

批准号：
10596978
负责人：
DORIS A STOFFERS
金额：
$ 45.16万
依托单位：
UNIVERSITY OF PENNSYLVANIA
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：
2019-04-01 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10596978
关键词：
Alanine Alanine Transaminase Amino Acids Anabolism Apoptosis Base Pairing Beta Cell Binding CRISPR/Cas technology Cell Death Induction Cell Survival Cell physiology Cells Cellular Stress ChIP-seq Citric Acid Cycle Compensation Complex Data Dependence Diabetes Mellitus Diabetes prevention Diet Duodenum Failure GPT2 gene Gene Expression Regulation Gene Silencing Gene Targeting Genes Genetic Genetic Transcription Genomic approach Glutamates Glutamine Glutathione Growth Homeobox Human Impairment Insulin Insulin Resistance Intervention Maintenance Mass Spectrum Analysis Mediating Metabolic Metabolism Mitochondria Modification Mus Oxidative Stress Palmitates Pancreas Phenotype Physiological Positioning Attribute Post-Translational Protein Processing Predisposition Proliferating Proteins Proteomics Pyruvate Reaction Resolution Response Elements Role Site Stress Structure of beta Cell of islet Techniques Testing Work alpha ketoglutarate antioxidant enzyme biological adaptation to stress blood glucose regulation cancer cell design endoplasmic reticulum stress enzyme activity genetic approach genome-wide analysis in vivo insight islet mouse model novel nutrient deprivation prevent programs response small hairpin RNA transcription factor transcriptome sequencing translational applications

项目摘要

Project Summary Failure of pancreatic β cells underlies the progression of all forms of diabetes. β cells are uniquely susceptible to stress induced cell death due to the high demand of insulin biosynthesis and secretion and to oxidative stresses resulting from well-documented low antioxidant enzyme activity. Pancreatic and duodenal homeobox 1 (PDX1) is a human diabetes gene and transcription factor that is required for β cell function and survival during islet compensation for diet induced insulin resistance. We find Pdx1 in complex with Activating Transcription Factors (ATFs) which are well known to coordinate cellular stress responses. We hypothesize that PDX1, ATF4, and ATF5 form a stress responsive transcriptional regulatory complex that directs β cell fate under stress conditions. This will be tested in three Specific Aims: 1. Characterize the stress-induced PDX1 transcriptional complex, 2. Identify the transcriptional targets of the stress-induced PDX1 transcriptional complex, and 3. Elucidate the functional roles of PDX1 targets in β cell survival. We will employ cutting edge proteomic techniques to identify the components of the stress- induced PDX1 transcriptional complex and any associated post-translational modifications. Further, we will integrate ChIPExo and RNASeq profiles of mouse and human β cells under physiologically and pathophysiologically relevant stress to obtain a comprehensive genome wide identification of the transcriptional targets of this complex, leveraging the near base pair resolution of ChIP-Exo to resolve structurally distinct modes of transcription factor binding, thereby enabling new insights into stress responsive gene regulation in the beta cell. Finally, we will pursue the functional role of the Pdx1-Atf4-Atf5 target Gpt2 in primary mouse and human islets to test the hypothesis that the beta cell is metabolically reprogrammed by fuel excess in a manner analogous to what occurs during transformation of cancer cells. Together these results will describe new gene targets that regulate the cell fate decisions important for β cell survival in response to diabetes related stresses, and expand the translational applications for human diabetes of the PDX1 stress responsive transcriptional complex.

项目概要胰腺 β 细胞的衰竭是所有形式糖尿病进展的独特原因。由于胰岛素生物合成的高需求，容易受到应激诱导的细胞死亡的影响分泌和氧化应激引起的有据可查的低抗氧化酶胰腺和十二指肠同源盒 1 (PDX1) 是一种人类糖尿病基因和转录。饮食诱导的胰岛补偿过程中 β 细胞功能和存活所需的因子我们发现 Pdx1 与激活转录因子 (ATF) 形成复合物。众所周知，PDX1、ATF4 和 ATF4 可以协调细胞应激反应。 ATF5 形成应激反应性转录调节复合物，在压力下指导 β 细胞命运这将在三个具体目标中进行测试： 1. 描述压力引起的特征。 PDX1转录复合物，2.识别应激诱导的PDX1的转录靶点转录复合物，以及 3. 阐明 PDX1 靶标在 β 细胞存活中的功能作用。我们将采用尖端蛋白质组学技术来识别压力的组成部分诱导 PDX1 转录复合物和任何相关的翻译后修饰。此外，我们将整合小鼠和人类 β 细胞的 ChIPExo 和 RNASeq 图谱生理学和病理生理学相关的应激以获得全面的基因组范围利用近碱基对分辨率识别该复合物的转录靶标 ChIP-Exo 解析结构上不同的转录因子结合模式，从而使最后，我们将探索β细胞中应激反应基因调控的新见解。 Pdx1-Atf4-Atf5 靶标 Gpt2 在原代小鼠和人类胰岛中的功能作用，以测试假设β细胞因燃料过量而以类似的方式进行代谢重编程这些结果将共同描述癌细胞转化过程中发生的情况。调节细胞命运决定的基因靶标，对于 β 细胞的生存至关重要糖尿病相关的压力，并扩大人类糖尿病的转化应用 PDX1 应激反应转录复合物。