Mechanism of Proteotoxicity and Experimental Therapeutic Approaches in Porphyria

卟啉症的蛋白质毒性机制和实验治疗方法

基本信息

批准号：
9469835
负责人：
Bishr Omary
金额：
$ 45.01万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
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：
2017-09-20 至 2020-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9469835
关键词：
Abbreviations Acute Acute Intermittent Porphyria Alanine Transaminase Aminolevulinic Acid Animal Model Binding Proteins Biochemical Bone Marrow Transplantation Cell Culture System Cell Culture Techniques Cell Death Cell Nucleus Cells Chemicals Cirrhosis Coupled Deferoxamine Disease Disease Progression Endoplasmic Reticulum Enzymes Erythropoietic Protoporphyria Fatty Acid-Binding Protein 1 Fatty Acids Fever Fishes Genetic Genomics Glycine Goals Hematoxylin and Eosin Staining Method Heme Hepatitis C Hereditary Disease Individual Infection Injury Intermediate Filament Proteins Investigational Therapies Keratin Knowledge Lead Liver Liver diseases Mammalian Cell Mass Spectrum Analysis Mediating Metabolic Metabolism Mitochondria Modeling Molecular Morbidity - disease rate Mus Mutation Organ Pathway interactions Patients Pharmaceutical Preparations Photosensitivity Pigments Porphyrias Porphyrins Post-Translational Protein Processing Preclinical Drug Evaluation Proteins Proteomics Protoporphyrins Publications Reactive Oxygen Species Risk Role Technology Tertiary Protein Structure Testing Therapeutic Tissues Toxic effect Transmission Electron Microscopy Uroporphyrins Work Zebrafish adduct biochemical model bone cell injury extracellular fatty acid-binding proteins improved liver injury long chain fatty acid neurotoxicity nonalcoholic steatohepatitis novel prevent protein K protein aggregate protein aggregation proteotoxicity relating to nervous system small molecule stem success succinyl-coenzyme A tool

项目摘要

Abstract Porphyrias are genetic disorders caused by mutations in enzymes involved in eight sequential biosynthetic conversions that combine glycine and succinyl coenzyme-A to generate heme. Porphyrin accumulation can result in `secondary porphyrias' in association with other diseases such as hepatitis C virus infection. Current major unmet needs with regard to the porphyria disorders are our present limited understanding of the molecular triggers of porphyria acute attacks, aside from indirect association with fever or drugs; the reasons why some individuals develop significant end-organ complications such as the need for liver or bone marrow transplantation while others do not; and importantly the limited availability of drugs to treat the different porphyrias. Our central hypothesis is that proteotoxic porphyrin-mediated damage, coupled with modifier effects, contributes to the cellular damage and morbidity that is associated with porphyrias. This hypothesis will be tested by pursuing three specific aims: (i) Define the mechanism of porphyria-induced protein aggregation; (ii) Characterize potential modifiers that promote or protect from porphyria-induced injury in cell culture and animal models; and (iii) Use zebrafish porphyria models to screen and characterize small- molecule compounds that prevent tissue porphyrin accumulation. We have assembled extensive preliminary results to support the likely success of our aims, including substantial evidence for porphyrin-mediated protein aggregation that is dependent on the mode of porphyrin accumulation, evidence for fatty acid binding protein- 1 as a modulator of porphyrin-mediated cell and liver injury, and two novel acute zebrafish porphyria models we generated that are amenable to high-throughput drug screening with potential positive compounds that we propose to validate and characterize. Completion of our proposed aims should provide fundamental knowledge regarding how porphyrins cause protein aggregation, the subcellular compartments that are involved, whether such aggregation is due to direct covalent porphyrin-protein adduct formation, and the mechanism of aggregate turnover. We also anticipate being able to characterize specific porphyrin-binding proteins that regulate the propensity to accumulate porphyrins in cells and tissues. This could provide potential clues as to why some individuals with porphyria develop end-stage liver disease in the absence of concomitant underlying liver disorders, while other patients are spared serious liver-related complications. Importantly, we anticipate that our proposal will allow us to use two powerful novel acute porphyria zebrafish models we have developed to identify potential compounds that may ultimately have therapeutic utility. This proposal uses state-of-the-art technologies, multiple biochemical and animal model tools including zebrafish and mice, and introduces the novel concept of proteotoxicity as an alternative mechanism for porphyria exacerbations and progression.

抽象的卟啉症是由参与八个顺序生物合成的酶突变引起的遗传疾病结合甘氨酸和琥珀酰辅酶A的转化率可产生血红素。卟啉积累可以导致与其他疾病（例如丙型肝炎病毒感染）相关的“继发性卟啉症”。当前的关于卟啉症疾病的主要未满足需求是我们目前对除了与发烧或药物的间接关联外，斑岩急性发作的分子触发因素；原因为什么有些人会出现明显的最终器官并发症，例如肝或骨髓的需求移植而其他人没有移植；重要的是，药物的可用性有限卟啉症。我们的中心假设是蛋白毒性卟啉介导的损伤，并与修饰符结合效果，有助于与卟啉相关的细胞损伤和发病率。这个假设将通过追求三个特定目标来测试：（i）定义卟啉诱导蛋白的机制聚合; （ii）表征促进或免受细胞中卟啉诱导损伤的潜在修饰符文化和动物模型；（iii）使用斑马鱼斑岩模型来筛选和表征小型分子化合物可预防组织卟啉积累。我们组装了广泛的初步支持我们目标可能成功的结果，包括卟啉介导的蛋白质的大量证据取决于卟啉积累模式的聚集，脂肪酸结合蛋白的证据 1作为卟啉介导的细胞和肝损伤的调节剂，以及两个新型的急性斑马鱼模型我们生成的，可以通过我们的高通量药物筛查，并具有潜在的阳性化合物提议验证和表征。我们提出的目标的完成应提供有关卟啉如何引起的基本知识蛋白质聚集，涉及的亚细胞隔室，是否是由于直接共价卟啉 - 蛋白质加合物的形成和骨料周转的机理。我们也是预计能够表征特定的卟啉结合蛋白，以调节在细胞和组织中积聚卟啉。这可以提供有关某些人的潜在线索在没有伴随潜在肝病的情况下，卟啉症患终末期肝病，而其他患者免于与肝脏有关的严重并发症。重要的是，我们预计我们的建议将允许我们使用两种强大的新型急性斑岩斑马鱼模型来识别潜力最终可能具有治疗效用的化合物。该建议使用最先进的技术，多种生化和动物模型工具，包括斑马鱼和小鼠，并介绍了新概念蛋白毒性是卟啉症加剧和进展的替代机制。