Mechanism of ER protein misfolding-induced mitochondrial dysfunction

ER蛋白错误折叠导致线粒体功能障碍的机制

基本信息

批准号：
9448713
负责人：
RANDAL J. KAUFMAN
金额：
$ 61.44万
依托单位：
SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-18 至 2021-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9448713
关键词：
Acetaminophen Acute Address Affect Antioxidants Apoptotic Attenuated Biochemical Bioenergetics Blood Coagulation Factor CCAAT-Enhancer-Binding Proteins Cell Culture Techniques Cell Death Cessation of life Chronic Cirrhosis Clinical Research Complex Data Degenerative Disorder Development Diet Disease Electron Transport Endoplasmic Reticulum Environment Epidemic Ethanol toxicity Etiology Event F8 gene Factor VIII Failure Fibrosis Fructose Functional disorder Genetic Genetic Models Grant Heat shock proteins Hemophilia A Hepatic Hepatocyte Homologous Protein Image Analysis Impairment Incidence Inflammation Lead Link Liver Liver Failure Liver diseases Mediating Membrane Metabolic Metabolic Diseases Metabolic syndrome Metabolism Mitochondria Mitochondrial Matrix Modeling Molecular Monitor Mus Obesity Organelles Oxidative Stress Pathway interactions Patients Pharmacology Phosphorylation Population Prevalence Primary carcinoma of the liver cells Process Production Protein Biosynthesis Proteins Reactive Oxygen Species Reperfusion Injury Signal Pathway Signal Transduction Superoxides System Techniques Technology Testing Toxic effect Variant Viral Virus Diseases Western World activating transcription factor 4 cell type endoplasmic reticulum stress experimental study extracellular genetic approach improved in vitro Model in vivo insight liver injury metabolomics misfolded protein mitochondrial dysfunction mouse model non-alcoholic fatty liver nonalcoholic steatohepatitis novel novel therapeutics nutrition oxidative damage prevent protein aggregation protein folding protein misfolding response tool transcription factor transcriptome sequencing

项目摘要

PROJECT SUMMARY The prevalence of non-alcoholic fatty liver disease (NAFLD) is almost 30% in the western world and is expected to rise in the next decade. NAFLD is characterized by protein misfolding in the endoplasmic reticulum (ER) activating the unfolded protein response (UPR). Prolonged ER stress conditions further lead to oxidative stress, protein aggregation, organelle damage, cellular bioenergetic collapse, and eventually cell death. Recent studies indicate that protein misfolding in the ER contributes to hepatocyte failure associated with NAFLD, non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). Through detailed characterization of hepatocyte function, our preliminary results lead us to propose that ER protein misfolding causes mitochondrial dysfunction that leads to further protein misfolding culminating in hepatocyte failure. Although previous studies demonstrated that protein misfolding in the ER of hepatocytes is associated with metabolic syndrome and NAFLD, there has never been a careful characterization of how ER protein misfolding causes catastrophic cellular events leading to oxidative damage, fibrosis and cell death. We have shown that misfolding of coagulation factor VIII (FVIII) in the ER disrupts complex 1 of the electron transport chain. Amazingly, we demonstrated that treatment with a mitochondrial-targeted antioxidant corrects he defective mitochondrial function and also improves FVIII folding in the ER in cell culture. This unprecedented finding indicates an unappreciated association between ER protein misfolding and defective mitochondrial bioenergetics. In the proposed studies, we will use two separate models to induce ER stress in vivo in hepatocytes; (i) excess nutrition of a high fructose diet, or (ii) expression of FVIII to elucidate how ER protein misfolding disrupts mitochondrial bioenergetics and dynamics. Presently, ongoing clinical studies are using viral delivery of FVIII to hepatocytes in hemophilia A patients. Furthermore, we will apply non-biased technologies of metabolomics and RNA-Seq using novel genetic murine models to elucidate how protein misfolding causes Ca2+ leak from the ER and entry into the mitochondrial matrix to disrupt mitochondrial bioenergetics and/or dynamics. Evidence supports that ER protein misfolding and defective mitochondrial function exist in all degenerative diseases. In addition, extensive findings demonstrate that protein misfolding in the ER is associated with liver failure in a number of common acute conditions including viral infection, ethanol toxicity, acetaminophen toxicity and ischemia reperfusion injury. Our fundamental novel exploration into unchartered territory will undoubtedly generate new hypotheses concerning the impact of ER protein misfolding on the mitochondrial electron transport chain. The studies will provide fundamental mechanistic insight into how ER and mitochondrial functions are reciprocally regulated and lead to novel therapies for NAFLD and other diseases of protein misfolding.

项目摘要在西方世界中，非酒精性脂肪肝病（NAFLD）的患病率几乎为30％，是预计将在未来十年中升高。 NAFLD的特征是蛋白质在内质中脱折叠网状（ER）激活展开的蛋白质反应（UPR）。长时间的ER应力条件进一步铅氧化应激，蛋白质聚集，细胞器损伤，细胞生物能崩溃，最终细胞死亡。最近的研究表明，ER中的蛋白质折叠折叠有助于肝衰竭与NAFLD，非酒精性脂肪性肝炎（NASH）和肝细胞癌（HCC）相关。通过详细的肝细胞功能表征，我们的初步结果使我们提出了ER 蛋白质错误折叠会导致线粒体功能障碍，从而导致进一步的蛋白质折叠折叠的最终形式肝细胞衰竭。尽管以前的研究表明蛋白质在肝细胞的ER中折叠率错折叠与代谢综合征和NAFLD有关，从未有过仔细的表征 ER蛋白折叠折叠会导致灾难性细胞事件，导致氧化损伤，纤维化和细胞死亡。我们已经表明，ER中凝血因子VIII（FVIII）的错误折叠破坏了复合物1 电子传输链。令人惊讶的是，我们证明了用线粒体靶向的治疗抗氧化剂纠正他有缺陷的线粒体功能，还可以改善细胞中ER中的FVIII折叠文化。这一前所未有的发现表明ER蛋白质折叠率无关紧要线粒体生物能学。在拟议的研究中，我们将使用两个单独的模型来在肝细胞中诱导体内急诊胁迫；（i）高果糖饮食过多的营养或（ii）FVIII的表达为了阐明ER蛋白的错误折叠如何破坏线粒体生物能学和动力学。目前，正在进行的临床研究正在使用FVIII的病毒递送到血友病A患者的肝细胞。此外，我们将使用新的遗传来应用非代谢组学和RNA-seq的无偏见技术鼠模型以阐明蛋白质错误折叠如何导致Ca2+从ER泄漏并进入线粒体基质破坏线粒体生物能学和/或动力学。证据支持蛋白质错误折叠和线粒体功能都存在于所有退行性疾病中。此外，广泛的发现表明，ER中的蛋白质折叠与肝衰竭有关常见的急性疾病，包括病毒感染，乙醇毒性，对乙酰氨基酚毒性和缺血性再灌注损伤。我们对未经宪章领土的基本小说探索无疑会产生关于ER蛋白折叠对线粒体电子传输的影响的新假设链。这些研究将提供有关ER和线粒体功能的基本机械洞察力相互调节并导致NAFLD和其他蛋白质疾病折叠式疾病的新型疗法。