Role of the ER acetyl CoA transporter in alcoholic pancreatitis

ER 乙酰 CoA 转运蛋白在酒精性胰腺炎中的作用

基本信息

批准号：
10358591
负责人：
GUY E GROBLEWSKI
金额：
$ 48.4万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-03-01 至 2026-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10358591
关键词：
Abdominal Pain Acetyl Coenzyme A Acetylation Acetylesterase Acinar Cell Acute Alcohol abuse Alcohol consumption Alcoholic Pancreatitis Alcoholic beverage heavy drinker Alcohols Animals Attenuated Automobile Driving Binding Proteins Biochemical Body of pancreas Carrier Proteins Cell Death Cell Fractionation Cellular Stress Cholelithiasis Chronic Cytoplasm Data Development Diet Disease Disease Outcome Disease Progression Edema Endoplasmic Reticulum Environmental Risk Factor Enzymes Exhibits Exocrine pancreas Experimental Models Factor X Fibrosis Food Functional disorder Genes Genetic Genetic Transcription Gland Golgi Apparatus Heavy Drinking Hereditary Spastic Paraplegia Human Immunologics Immunoprecipitation Individual Inflammation Inflammatory Knockout Mice Link Liquid substance Longevity LoxP-flanked allele Lysine Mediating Membrane Proteins Messenger RNA Modeling Molecular Molecular Chaperones Molecular Target Monitor Morphology Mus Mutation Names Neurodegenerative Disorders Onset of illness Oxidative Stress PERK kinase Pain Pancreas Pancreatic Diseases Pancreatitis Pathologic Pathology Pathway interactions Peptide Initiation Factors Process Production Protein Acetylation Proteins Proteomics Quality Control RNA Splicing Recovery Regulation Risk Factors Role Severities Side Signal Transduction Smoking Stress System Tamoxifen Testing Tobacco smoking behavior Toxic effect Transcriptional Regulation Translations Up-Regulation Weight Work activating transcription factor acute pancreatitis alcohol response biological adaptation to stress chronic alcohol ingestion chronic pancreatitis disorder risk drinking effective therapy endoplasmic reticulum stress environmental stressor experimental study feeding in vivo inhibitor insight misfolded protein mouse model mutant polarized cell prevent problem drinker programs protein degradation protein expression protein folding protein transport response secretory protein sensor stressor transcription factor transcription factor CHOP treatment strategy

项目摘要

ABSTRACT Chronic pancreatitis (CP), a painful, debilitating disorder of the exocrine pancreas, lacks treatments and strategies to prevent disease progression. Alcohol abuse and smoking are common causes of CP but the mechanisms underlying their toxic effects on the pancreas are unclear. Recently, adaptive mechanisms that prevent pancreatitis with stressors such as alcohol were identified in the pancreatic acinar cell. These adaptive mechanisms involve the endoplasmic reticulum (ER) Unfolded Protein Response (UPR) and the UPR transcription factor, X-box binding protein 1 (XBP1s) that upregulates ER chaperones, ER transporters, and quality control machinery to maintain ER function. Our previous work showed that alcohol administration induces oxidative stress but also upregulates XBP1s and a protective UPR that prevents pathology, while smoking inhibits alcohol induced XBP1s formation, and upregulates a pathologic UPR signal mediated by C/EBP homologous protein (CHOP) resulting in ER dysfunction and pancreatitis. This project investigates molecular determinants of pancreatitis associated with alcohol abuse, smoking and perturbed ER protein folding and trafficking. Reversible Nε-lysine acetylation regulates the efficiency of ER protein transit to Golgi and the secretory pathway. Acetylation of properly folded proteins enables ER-to-Golgi exit, while non- acetylated, misfolded proteins divert to protein degradation systems. Thus, disruption of ER protein acetylation perturbs ER function and protein trafficking. The acetyl CoA transporter, AT-1 mediates ER entry of acetyl CoA from cytoplasm to provide substrate for acetylation. In humans, the AT-1-S113R mutant reduces AT-1 transport capacity, and individuals with this mutant exhibit neurodegenerative disorders. We found that XBP1s regulates AT-1 levels in acinar cells. Moreover, AT-1S113r/+ or acinar-specific AT-1 deficient mice develop mild/ moderate CP and chronic ER stress with elevated XBP1s. Strikingly, AP induction in these mice decreases XBP1s levels and markedly exacerbates CP progression. Our results indicate AT-1 and XBP1s are interdependent and important for pancreas adaption in response to alcohol but when overwhelmed by environmental stressors these adaptive systems fail leading to pathology. Our overarching hypothesis is that chronic acinar cell stress and reduced XBP1s protective programs by drinking/smoking attenuate AT-1 expression, disrupting ER acetylation and ER function, and inducing severe CP. Using experimental models of alcoholic + smoking CP, we will pursue 3 aims. Aim 1 will test whether alcohol consumption/smoking converts mild/moderate CP into severe disease in acinar-specific AT-1 KO mice. Aim 2 will evaluate whether enhanced XBP1s expression or CHOP genetic deletion partially mitigates CP severity in AT-1 KO mice. Aim 3 will investigate ER acetylation pathway regulation of ER protein folding and trafficking as well as ER protein degradation. We expect this project to provide insights into the pathways driving CP development, and pinpoint molecular targets for strategies to halt CP progression.

抽象的慢性胰腺炎 (CP) 是一种痛苦的、使人衰弱的胰腺外分泌疾病。预防疾病进展的策略酗酒和吸烟是 CP 的常见原因，但最近，其对胰腺的毒性作用的机制尚不清楚。通过酒精等压力源预防胰腺炎，在胰腺腺泡细胞中发现了这些适应性。机制涉及内质网 (ER) 未折叠蛋白反应 (UPR) 和 UPR 转录因子、上调 ER 伴侣、ER 转运蛋白的 X-box 结合蛋白 1 (XBP1) 我们之前的工作表明，酒精管理是维持 ER 功能的质量控制机制。诱导氧化应激，同时上调 XBP1 和预防病理的保护性 UPR，同时吸烟抑制酒精诱导的 XBP1 形成，并上调由以下因素介导的病理性 UPR 信号该项目研究导致 ER 功能障碍和胰腺炎的 C/EBP 同源蛋白 (CHOP)。与酗酒、吸烟和 ER 蛋白紊乱相关的胰腺炎的分子决定因素可逆的 Nε-赖氨酸乙酰化调节 ER 蛋白转运至高尔基体的效率。正确折叠的蛋白质的乙酰化使内质网能够退出到高尔基体，而非- 乙酰化、错误折叠的蛋白质转移至蛋白质降解系统，从而破坏内质网蛋白质乙酰化。干扰内质网功能和蛋白质运输乙酰辅酶 A 转运蛋白 AT-1 介导乙酰基进入内质网。来自细胞质的 CoA 为人类的 AT-1-S113R 突变体 AT-1 提供乙酰化底物。运输能力，并且具有这种突变体的个体表现出神经退行性疾病。此外，AT-1S113r/+ 或腺泡特异性 AT-1 缺陷小鼠会出现轻度/ 中度 CP 和慢性 ER 应激伴随 XBP1 升高，引人注目的是，这些小鼠的 AP 诱导减少。 XBP1s 水平升高并显着恶化 CP 进展。我们的结果表明 AT-1 和 XBP1s 是相关的。相互依存，对于胰腺对酒精的适应非常重要，但当被酒精淹没时这些适应性系统失败的环境压力会导致病理学。慢性腺泡细胞应激和饮酒/吸烟减少的 XBP1 保护程序会减弱 AT-1 表达，破坏 ER 乙酰化和 ER 功能，并诱导严重 CP。酒精+吸烟CP的实验模型，我们将追求3个目标，目标1将测试是否酒精。在腺泡特异性 AT-1 KO 小鼠中，消费/吸烟将轻度/中度 CP 转化为严重疾病。将评估增强的 XBP1s 表达或 CHOP 基因缺失是否可以部分减轻 CP 的严重程度 AT-1 KO 小鼠将研究 ER 蛋白质折叠和运输的 ER 乙酰化途径调节。我们希望这个项目能够深入了解 CP 的驱动途径。开发，并确定阻止 CP 进展策略的分子靶点。