Mechanisms and metabolic implications of LRP130 in NAFLD

LRP130 在 NAFLD 中的机制和代谢意义

• 批准号: 8708849
• 负责人: Marcus P Cooper
• 金额: $ 35.42万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8708849
• 关键词: Attenuated; Bioenergetics; Biological Assay; Cell Respiration; Cells; Cirrhosis; Clinical; Complement; Complex; Data; Defect; Dependovirus; Development; Diabetes Mellitus; Diet; Disease; Disease Progression; Ectopic Expression; Electron Microscopy; Epidemic; Euglycemic Clamping; Evaluation; Fatty Liver; Fatty acid glycerol esters; Genes; Genetic; Genetic Transcription; Glucose Clamp; Heart Diseases; Hepatic; Histology; Inflammation; Inflammatory; Insulin Resistance; Link; Lipids; Liver; Liver Mitochondria; Liver diseases; Measurement; Measures; Membrane Potentials; Metabolic; Mitochondria; Mitochondrial DNA; Modeling; Molecular; Mus; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Oxygen Consumption; Prevalence; Primary carcinoma of the liver cells; Production; Reactive Oxygen Species; Reporter; Respiration; Respiratory Chain; Role; Source; Superoxides; Testing; Therapeutic; Transcriptional Regulation; Transgenic Mice; Transgenic Model; United States; Viral Vector; base; chromatin immunoprecipitation; cytokine; feeding; gain of function; gel electrophoresis; human subject; insulin sensitivity; insulin signaling; interest; liver inflammation; loss of function; mitochondrial dysfunction; mitochondrial genome; mouse model; non-alcoholic fatty liver; nonalcoholic steatohepatitis; novel; programs; public health relevance; respiratory; small hairpin RNA

DESCRIPTION (provided by applicant): Non-alcoholic fatty liver disease (NAFLD) is the leading cause of liver disease in the United States. It spans a clinical spectrum from fatty liver to superimposed inflammation called NASH (non-alcoholic steatohepatitis). NASH predisposes to irreversible cirrhosis and hepatocellular carcinoma, which highlights the need to identify underlying mechanisms. In NAFLD, defective mitochondria liberate excess reactive oxygen species (ROS). Mitochondrial ROS is of interest, because it is implicated in insulin resistance and inflammation, two key features of NAFLD. The mechanism for mitochondrial dysfunction is unknown; hence, understanding its mechanistic basis may mitigate NAFLD. Our preliminary data indicate that LRP130 is an important regulator of mitochondrial function and ROS. In NAFLD, we observed that LRP130 is attenuated in a disease specific manner. Notably, depletion of LRP130 in mouse liver induced insulin resistance and inflammation. Mechanistically, LRP130 regulates the entire mitochondrial genome. Notably, LRP130 profoundly influences respiratory chain formation, respiration and superoxide formation. We hypothesize that LRP130 is a molecular link between defective mitochondria in liver and progression of NAFLD. We propose three Aims to query our hypothesis: (1) Evaluate the role of LRP130 in mitochondrial function and superoxide formation. The impact of LRP130 on mitochondrial bioenergetics will be evaluated using loss- and gain-of-function models in cells and mice. We will evaluate respiratory chain supercomplexes using blue native gel electrophoresis. Mitochondrial function will be measured by oxygen consumption, complex activity, membrane potential and superoxide measurements. (2) Evaluate the role of LRP130 in non-alcoholic fatty liver disease. Fatty liver will be induced by challenging mice with a high fat diet. Mice deficient for LRP130 in liver will be evaluated for insulin sensitivity and inflammation using a complement of assays: hyperinsulinemic-euglycemic clamp, immunodetection of insulin signaling, histological evaluation of inflammation and cytokine profiling. Parallel studies will be conducted with a liver specific LRP130 transgenic model. (3) Evaluate transcriptional and inflammatory control of LRP130. We hypothesize that cytokines attenuate transcription of LRP130, and may link cytokines to defective mitochondria and excess superoxide. We will use genetic studies, reporter assays and chromatin immunoprecipitation to test this hypothesis. Therapeutic manipulation of ROS in NAFLD is impeded by an insufficient understanding of basic mechanisms. Our novel findings on LRP130 will advance new paradigms on the role of mitochondria in NAFLD.

描述（由申请人提供）：非酒精性脂肪肝病（NAFLD）是美国肝病的主要原因。它跨越了从脂肪肝脏到叠加的炎症的临床光谱，称为NASH（非酒精性脂肪性肝炎）。 NASH倾向于不可逆的肝硬化和肝细胞癌，这突出了识别潜在机制的需求。在NAFLD中，有缺陷的线粒体释放过多的活性氧（ROS）。线粒体ROS引起了人们的关注，因为它与胰岛素抵抗和炎症有关，这是NAFLD的两个关键特征。线粒体功能障碍的机制尚不清楚。因此，了解其机械基础可能会减轻NAFLD。我们的初步数据表明LRP130是线粒体功能和ROS的重要调节剂。在NAFLD中，我们观察到LRP130以疾病的特定方式减弱。值得注意的是，小鼠肝脏中LRP130的耗竭诱导的胰岛素抵抗和炎症。从机械上讲，LRP130调节整个线粒体基因组。值得注意的是，LRP130深刻影响呼吸链形成，呼吸和超氧化物的形成。我们假设LRP130是肝脏中有缺陷的线粒体与NAFLD进展之间的分子联系。我们提出三个旨在查询我们的假设的目的：（1）评估LRP130在线粒体功能和超氧化物形成中的作用。 LRP130对线粒体生物能学的影响将使用细胞和小鼠的损失和功能获得模型进行评估。我们将使用蓝色天然凝胶电泳评估呼吸链超复合物。线粒体功能将通过氧气消耗，复杂活性，膜电位和超氧化物测量来测量。 （2）评估LRP130在非酒精性脂肪肝病中的作用。高脂饮食挑战小鼠会引起脂肪肝。使用辅助分析的补充：高胰岛素血糖夹，胰岛素信号传导的免疫试验，炎症和细胞因子分析的组织学评估，将评估缺乏LRP130的小鼠肝脏敏感性和炎症的胰岛素敏感性和炎症。平行研究将使用肝特异性LRP130转基因模型进行。 （3）评估LRP130的转录和炎症控制。我们假设细胞因子会减弱LRP130的转录，并可能将细胞因子与有缺陷的线粒体和过量的超氧化物联系起来。我们将使用遗传研究，报告基因测定和染色质免疫沉淀来检验该假设。对NAFLD中ROS的治疗操纵受到对基本机制的理解不足的阻碍。我们在LRP130上的新发现将推动有关线粒体在NAFLD中作用的新范式。