Novel mechanism of aryl hydrocarbon receptor - mediated differential gene regulation

芳烃受体介导差异基因调控的新机制

基本信息

批准号：
10399477
负责人：
Aditya D Joshi
金额：
$ 26.1万
依托单位：
UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
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：
2019-07-12 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10399477
关键词：
ARNT gene ARNT protein Acetylation Acids Address Affect Agonist American Apoptosis Architecture Aryl Hydrocarbon Receptor Attenuated Binding Binding Proteins Biology CRISPR/Cas technology CYP11A1 gene CYP1A1 gene Cell Culture Techniques Cell Line Cell Nucleus Cells Chromatin Clustered Regularly Interspaced Short Palindromic Repeats Complex Cytoprotection DNA DNA Binding DNA Sequence Data Development Dioxins Epigenetic Process Ethanol Exhibits Future Gene Expression Gene Expression Regulation Genes Genetic Transcription Goals Hepatocyte Heterodimerization Histone H4 Histones In Vitro Intervention Libraries Ligand Binding Ligands Liver diseases Lysine Mass Spectrum Analysis Mediating Mediator of activation protein Metastasis-associated protein Modification Molecular Molecular Conformation Monitor Oxidative Stress Pathway interactions Peptide Signal Sequences Physiological Post-Translational Protein Processing Promoter Regions Property Proteins Quantitative Reverse Transcriptase PCR RNA Interference Reaction Reader Regulation Research Research Personnel Response Elements Role Signal Pathway Specificity Stress Testing Tetrachlorodibenzodioxin Therapeutic Tissue-Specific Gene Expression Toxic effect Transcriptional Regulation Tryptophan Up-Regulation Xenobiotic Metabolism Xenobiotics aryl hydrocarbon receptor ligand chromatin immunoprecipitation chromatin remodeling cofactor crosslink epigenetic regulation experimental study histone modification in vivo liver injury molecular targeted therapies novel promoter receptor binding recruit response screening stanniocalcin 2 stressor transcription factor translational research program

项目摘要

ABSTRACT Aryl hydrocarbon Receptor (AhR), a mediator of xenobiotic toxicity, is known to function as a ligand-activated transcription factor that binds to a xenobiotic response element (XRE, GCGTG motif) in association with its heterodimerization partner, the AhR nuclear translocator (Arnt) protein. This proposal is built on our observation that cinnabarinic acid (CA) mediated AhR-dependent induction of stanniocalcin 2 (stc2) attenuates stress induced apoptosis and protects against liver injury both in vitro and in vivo. stc2 induction was achieved in response to endogenous AhR agonist CA but not the classic exogenous AhR ligand 2,3,7,8- tetrachlorodibenzo-p-dioxin (TCDD). Moreover, CA in contrast to TCDD, was unable to trigger prototypical AhR target gene, cyp1a1 in hepatocytes and did not regulate xenobiotic metabolism. Therefore, stc2 and cyp1a1 genes exhibit mutually exclusive agonist-specific AhR-mediated transcriptional responsiveness with distinct physiological consequences. As a part of my K01 research, we observed interaction of Metastasis-associated protein 2 (MTA2), a known chromatin remodeling protein, with AhR exclusively upon CA treatment. AhR-MTA2 complex was recruited only to stc2, but not cyp1a1 promoter. In addition, CA treatment was able to exhibit histone H4 lysine 5 acetylation specifically at stc2 promoter concomitant with AhR-MTA2 complex recruitment. Our preliminary studies identified that chromatin architecture in addition to the primary DNA sequence significantly contributes to the agonist-specific differential gene expression. Building on our preliminary studies this proposal tests the hypothesis that CA-specific AhR-dependent epigenetic modifications and chromatin restructuring dictates transcription regulation of stc2, which in turn is responsible for cytoprotection following liver injury. Specific Aim 1 of this application will profile CA and TCDD specific epigenetic modifications as well as will identify the readers-writers-erasers of the histone modifications recruited to the XRE bounds AhR-MTA2 complex. Specific Aim 2 will determine role of chromatin architecture in agonist specific stc2 regulation by using CRISPR/Cas9 gene editing. Specific Aim 3 will interrogate mechanism by which CA-triggered stc2 protects against ethanol-induced apoptosis by identifying downstream cytoprotective pathway components activated by stc2. Therefore, the objective of this application is to decode CA-specific AhR-mediated transcription regulation of stc2 and decipher its cytoprotective function. Given stc2’s involvement in cytoprotection against liver injury, understanding its CA-specific regulation may serve as a key to developing future molecular therapeutics targeting hepatic diseases.

抽象的芳基烃受体（AHR）是一种异种毒性的介体，被称为配体激活与异种生物反应元件（XRE，GCGTG基序）结合的转录因子与其结合异二聚体伴侣，AHR核转运剂（ARNT）蛋白。该提议建立在我们的观察到霉菌酸（CA）介导的stanniocalcin 2（STC2）减弱的AHR依赖性诱导压力诱导的凋亡并预防体外和体内肝损伤。实现了STC2诱导为了响应内源性AHR激动剂Ca，但不经典的外源AHR配体2,3,7,8-- 四氯迪本佐-P-二恶英（TCDD）。此外，与TCDD相比，CA无法触发原型AHR 靶基因，肝细胞中的CYP1A1，不调节异种代谢。因此，STC2和CYP1A1 基因暴露了相互排斥的激动剂特异性AHR介导的转录响应能力，生理后果。作为我K01研究的一部分，我们观察到与转移相关的相互作用蛋白2（MTA2），一种已知的染色质重塑蛋白，仅在Ca处理后AHR。 AHR-MTA2 复合物仅被招募到STC2，但不招募CYP1A1启动子。此外，CA治疗能够退出组蛋白H4赖氨酸5乙酰化在STC2启动子伴有AHR-MTA2复合物募集的情况下特异性。我们的初步研究确定除了主要DNA序列外，染色质结构显着促进了激动剂特异性差异基因表达。基于我们的初步研究该提案检验了以下假设：CA特异性AHR依赖性表观遗传修饰和染色质重组决定了STC2的转录调节，这反过肝损伤。本应用的特定目的1也将介绍CA和TCDD特定的表观遗传修饰正如将确定募集到XRE边界AHR-MTA2的组蛋白修饰的读者培训者复杂的。特定的目标2将通过使用CRISPR/CAS9基因编辑。特定的目标3将询问CA触发的STC2的机制通过识别下游细胞保护途径成分来预防乙醇诱导的凋亡由STC2激活。因此，该应用的目的是解码CA特异性AHR介导的 STC2的转录调节并破译其细胞保护功能。鉴于STC2参与抗肝损伤的细胞保护作用，了解其特异性调节可能是发展的关键靶向肝病的未来分子疗法。