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

• 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
• 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

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，导致数千人死亡，数亿美元的医疗保健费用。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）在酒精性肝损伤过程中被激活，在肝纤维化的发展中起着重要作用。我们的长期目标是了解如何刺激HSC激活以响应酒精;进展将导致酒精性肝病的新的，有针对性的干预措施。其他人发表的一项研究将脂滴损失描述为自噬的一个特征，这激发了我们的想法，即自噬是HSC激活的一个组成部分。自噬是一种高度调节的细胞反应，在细胞应激或增强的代谢需求期间已经进化为维持能量稳态，并且其特征与HSC活化的特征显著平行。该项目的目标是实现我们的长期目标的下一步，是描述自噬对酒精性肝损伤中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活化的关键和必要组成部分。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活化的乙醇特异性培养模型，定义与酒精性肝损伤相关的刺激物，这些刺激物引起HSC中的自噬，其中自噬将通过以下方式记录：Western印迹检测LC 3-I蛋白向LC 3-II的转化，超微结构和脂质含量减少。2.通过表征对来自乙醇喂养小鼠的HSC中Atg 7或Atg 5的siRNA敲低的响应来确定体内HSC活化期间自噬的哪些特征是酒精依赖性的，并通过定量PCR和Western针对已知活化标记物以及针对新靶点的外显子阵列来定义自噬调节途径。3.通过阻断酒精喂养小鼠的自噬，建立体内酒精相关HSC活化对自噬的依赖性。这些研究应该揭示与酒精在肝脏中的作用特别相关的星状细胞活化的基本新途径，从而为酒精性肝病患者提供创新的治疗方法。