Autophagy during hepatic stellate cell activation in alcoholic liver injury

酒精性肝损伤肝星状细胞激活过程中的自噬

基本信息

批准号：
8705327
负责人：
SCOTT L. FRIEDMAN
金额：
$ 36.99万
依托单位：
ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-08-01 至 2016-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8705327
关键词：
1-Phosphatidylinositol 3-Kinase 3-methyladenine Acetaldehyde Address Adenoviruses Affect Alcohol abuse Alcohol consumption Alcohol dependence Alcoholic Liver Diseases Alcohols Antigen Presentation Apoptotic Attenuated Autophagocytosis Cell physiology Cellular Stress Chemicals Chloroquine Chronic Cicatrix Cirrhosis Collagen Complement Activation Data Defect Detection Development Disease Progression Epidemic Ethanol Ethanol Metabolism Exons Extracellular Matrix Fibrosis Genes Goals Health Care Costs Hepatic Hepatic Stellate Cell Histology Homeostasis Immune Injury Intervention Lead Light Link Lipids Liver Liver Cirrhosis Liver Fibrosis Liver diseases Mediating Metabolic Microtubules Modeling Mus Nutrient Oxidative Stress Pathway interactions Patients Phagolysosome Pharmaceutical Preparations Phosphatidylethanolamine Play Proteins Public Health Publishing Regulation Regulatory Pathway Research Risk Role Seminal Signal Transduction Small Interfering RNA Source Staging Starvation Stimulus TLR4 gene Testing Western Blotting Work alcohol effect alcohol response base cost cytokine deprivation endogenous digitalis-like factor feeding fibrogenesis genetic regulatory protein improved in vivo inhibitor/antagonist innovation insight liver injury liver repair mRNA Expression novel oxidant stress prevent problem drinker protein aggregate receptor response stellate cell

项目摘要

DESCRIPTION (provided by applicant): Progressive hepatic fibrosis and cirrhosis leading to end-stage liver disease are major consequences of chronic alcohol abuse that cost thousands of lives, and hundreds of millions of dollars in health care costs. Despite the clear link between alcohol, fibrosis and end-stage liver disease, there are no approved antifibrotic therapies that can delay disease progression or forestall complications of fibrosis, and thus progress is urgently needed. The hepatic stellate cell (HSC), following activation during alcoholic liver injury, plays a central role in the development of fibrosis. Our long-term goal is to understand how HSC activation is stimulated in response to alcohol; progress will lead to novel, targeted interventions for alcoholic liver disease. A study published by others describing loss of lipid droplets as a feature of autophagy sparked our idea that autophagy is a component of HSC activation. Autophagy is a highly regulated cellular response that has evolved to maintain energy homeostasis during cellular stress or enhanced metabolic demand, and its features remarkably parallel those of HSC activation. The objective of this project, which is the next step towards our long-term goal, is to characterize the contribution of autophagy to HSC activation in alcoholic liver injury. Our central hypothesis, therefore, is that autophagy is a critical and necessary component of HSC activation in alcoholic fibrosis. We will test our central hypothesis through the following interrelated Specific Aims: 1. Define stimuli associated with alcoholic liver injury that provoke autophagy in HSCs, by using ethanol-specific culture models of HSC activation in which autophagy will be documented by: Western blot to detect conversion of LC3-I protein to LC3-II, ultrastructure, and reduced lipid content. 2. Determine which features of autophagy during HSC activation in vivo are alcohol-dependent by characterizing the response to siRNA knockdown of Atg7 or Atg5 in HSCs from ethanol-fed mice, and define autophagy-regulated pathways by quantitative PCR and Western for known activation markers, and exon arrays for novel targets. 3. Establish the dependence of alcohol-related HSC activation on autophagy in vivo by blocking autophagy in alcohol-fed mice. These studies should uncover fundamental new pathways of stellate cell activation specifically related to alcohol's effects in the liver, leading to innovative treatment approaches for patients with alcoholic liver disease.

描述（由申请人提供）：导致终末期肝病的进行性肝纤维化和肝硬化是慢性酒精滥用的主要后果，导致数千人丧生，并造成数亿美元的医疗费用。尽管酒精、纤维化和终末期肝病之间存在明确的联系，但目前还没有批准的抗纤维化疗法可以延缓疾病进展或预防纤维化并发症，因此迫切需要取得进展。肝星状细胞（HSC）在酒精性肝损伤期间激活后，在纤维化的发展中发挥着核心作用。我们的长期目标是了解酒精如何刺激 HSC 激活；进展将为酒精性肝病带来新颖的、有针对性的干预措施。其他人发表的一项研究将脂滴的损失描述为自噬的一个特征，这引发了我们的想法，即自噬是 HSC 激活的一个组成部分。自噬是一种高度调控的细胞反应，其进化目的是在细胞应激或代谢需求增加时维持能量稳态，其特征与 HSC 激活的特征非常相似。该项目是我们实现长期目标的下一步，其目标是表征酒精性肝损伤中自噬对 HSC 激活的贡献。因此，我们的中心假设是，自噬是酒精性纤维化中 HSC 激活的关键且必要的组成部分。我们将通过以下相互关联的具体目标来检验我们的中心假设： 1. 通过使用 HSC 激活的乙醇特异性培养模型来定义与酒精性肝损伤相关的刺激，从而在 HSC 中引发自噬，其中自噬将通过以下方式记录： Western blot 检测LC3-I 蛋白转化为 LC3-II、超微结构和脂质含量降低。 2. 通过表征乙醇喂养小鼠 HSC 中 Atg7 或 Atg5 的 siRNA 敲低反应，确定 HSC 体内激活过程中自噬的哪些特征是酒精依赖性的，并通过定量 PCR 和 Western 确定已知激活标记物的自噬调节途径，以及新靶标的外显子阵列。 3. 通过阻断酒精喂养小鼠的自噬，建立体内酒精相关的 HSC 激活对自噬的依赖性。这些研究应该揭示与酒精对肝脏的影响特别相关的星状细胞激活的基本新途径，从而为酒精性肝病患者带来创新的治疗方法。