Mitochondrial depolarization, mitophagy, and mitochondrial DAMPs in ALD

ALD 中的线粒体去极化、线粒体自噬和线粒体 DAMP

基本信息

批准号：
10155373
负责人：
John J Lemasters
金额：
$ 33.64万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2023-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10155373
关键词：
1-Phosphatidylinositol 3-Kinase Acetaldehyde Acute Acute Alcoholic Hepatitis Agonist Alcohol dehydrogenase Alcoholic Hepatitis Alcoholic Liver Diseases Autophagosome Biological Markers CYP2E1 gene Cardiolipins Cessation of life Characteristics Cholesterol Chronic Cirrhosis Development Electron Microscopy Ethanol Ethanol Metabolism FK506 Fasting Fibrosis GLP-I receptor Genetic Glucagon Goals Hepatic Hepatocyte Impairment Individual Inflammation Inflammatory Inflammatory Response Injury Intervention Lead Link Liver Liver Mitochondria Liver diseases Lysosomes Mediator of activation protein Mitochondria Mitochondrial DNA Modality Modeling Molecular Molecular Analysis Monitor Mus Neuromuscular Depolarizing Agents Pathogenesis Pattern Pharmacology Pioglitazone Prevention Prevention strategy Process Role Serum Severities Severity of illness Testing Therapeutic Agents Transgenic Mice Work alcohol exposure aldehyde dehydrogenases binge drinking cytochrome c disorder prevention experimental study extracellular feeding hepatocellular injury in vivo innovation intravital microscopy liver development liver injury mortality multiphoton microscopy new therapeutic target nonalcoholic steatohepatitis novel novel marker oxidation parkin gene/protein prevent response

项目摘要

Alcoholic liver disease (ALD) accounts for ~50% of deaths due to cirrhosis and ~30% of all liver-related deaths in the US. How ethanol damages the liver remains poorly understood, and therapies are lacking or unproven. Our goal is to understand the pathogenesis of ALD. We observed widespread, reversible hepatic mitochondrial depolarization (mtDepo), increased mitophagic burden and elevated serum mitochondrial DNA (mtDNA) in mice after ethanol treatment. We propose to test the novel hypothesis that ethanol metabolism induces mtDepo, which in turn stimulates mitophagy. Markedly increased mitophagic burden overwhelms the capacity of lysosomes to process autophagosomes, particularly when processing of depolarized mitochondria into mitophagosomes and then into lysosomes is compromised after chronic ethanol exposure, leading to extracellular release of damaged mitochondria, mitophagosomes and/or autolysosomes containing mitochondrial damage-associated molecular pattern (mtDAMP) molecules to cause a profibrotic inflammatory response and liver injury. In Specific Aim 1 using intravital multiphoton microscopy, we will explore if mtDepo occurs in living mice after chronic ethanol and is exacerbated by superimposed binge drinking and in an unique fibrosis-inducing ethanol/cholesterol model we developed. We will determine the relation of mtDepo to hepatic injury, inflammation and fibrosis. We will also explore if inhibition of acetaldehyde (AcAld) formation by alcohol dehydrogenase and CYP2E1 deficiency, accelerated AcAld oxidation by Alda-1, and FK506 (blocker of depolarization) decrease mtDepo and liver injury/inflammation/fibrosis after chronic ethanol. In Aim 2, we will determine the relation of mtDepo to mitophagy. Using genetic and pharmacological interventions in combination with intravital and electron microscopy and analyses of molecular indicators of mitophagic flux, we will elucidate if ethanol-induced mtDepo initiates mitophagy or if mitophagy causes mtDepo. We will determine if mitophagy/mitophagosome processing is blunted by chronic, chronic plus cholesterol and chronic plus binge ethanol and further explore if inhibition of autophagic processing exacerbates liver injury/inflammation/fibrosis after chronic ethanol. In Aim 3, we will characterize how mtDepo and compromised mitophagy/processing contribute to mtDAMP release after ethanol. We will characterize release into serum of mtDAMPs after acute ethanol and chronic, chronic plus cholesterol and chronic plus binge ethanol to determine the relationship of mtDAMP release to liver injury/inflammation/fibrosis. We will also determine how up and down-modulation of mtDepo, mitophagy and processing of mitophagosomes alters mtDAMP release after ethanol. This study will elucidate a novel link between early mitochondrial changes associated with ethanol metabolism and the later development of liver injury/inflammation/fibrosis and thus fill a critical gap in understanding ALD pathogenesis. This study should also identify new therapeutic targets of ALD and novel biomarkers for monitoring ALD severity/progression.

酒精性肝病 (ALD) 约占肝硬化死亡人数的 50%，约占所有肝脏相关死亡人数的 30% 美国的死亡人数。乙醇如何损害肝脏仍知之甚少，并且缺乏或缺乏治疗方法未经证实。我们的目标是了解 ALD 的发病机制。我们观察到广泛的、可逆的肝线粒体去极化 (mtDepo)、线粒体自噬负担增加和血清线粒体 DNA 升高 (mtDNA) 乙醇处理后的小鼠。我们建议测试乙醇代谢的新假设诱导 mtDepo，进而刺激线粒体自噬。线粒体自噬负担显着增加压倒了溶酶体处理自噬体的能力，特别是在处理去极化线粒体进入线粒体吞噬体，然后进入溶酶体后受到损害慢性乙醇暴露，导致受损线粒体、线粒体自噬体释放到细胞外和/或含有线粒体损伤相关分子模式（mtDAMP）的自溶酶体分子引起促纤维化炎症反应和肝损伤。在具体目标 1 中使用活体多光子显微镜，我们将探讨长期乙醇作用后活体小鼠体内是否发生 mtDepo，并且是否存在叠加的暴饮暴食和独特的诱导纤维化的乙醇/胆固醇模型加剧了这种情况发达。我们将确定 mtDepo 与肝损伤、炎症和纤维化的关系。我们也会探索乙醇脱氢酶和 CYP2E1 缺陷是否会抑制乙醛 (AcAld) 形成， Alda-1 加速 AcAld 氧化，FK506（去极化阻断剂）降低 mtDepo 和肝脏慢性乙醇后损伤/炎症/纤维化。在目标 2 中，我们将确定 mtDepo 与线粒体自噬。结合活体和电子技术使用遗传和药物干预显微镜检查和线粒体自噬流分子指标分析，我们将阐明乙醇诱导的 mtDepo 启动线粒体自噬，或者如果线粒体自噬导致 mtDepo。我们将确定是否有线粒体自噬/线粒体自噬体慢性、慢性加胆固醇和慢性加狂饮乙醇会削弱加工能力，并进一步探讨是否自噬过程的抑制会加剧慢性乙醇后的肝损伤/炎症/纤维化。瞄准 3，我们将描述 mtDepo 和受损的线粒体自噬/加工如何促进 mtDAMP 释放乙醇之后。我们将描述急性乙醇和慢性乙醇后 mtDAMP 释放到血清中的特征。加胆固醇和慢性加狂饮乙醇以确定 mtDAMP 释放与肝脏的关系损伤/炎症/纤维化。我们还将确定如何上调和下调 mtDepo、线粒体自噬和线粒体吞噬体的加工改变乙醇后 mtDAMP 的释放。这项研究将阐明一个新的联系与乙醇代谢相关的早期线粒体变化与肝脏的后期发育之间损伤/炎症/纤维化，从而填补了理解 ALD 发病机制的关键空白。这项研究应该还确定了 ALD 的新治疗靶点和用于监测 ALD 严重程度/进展的新生物标志物。