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

• 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
• 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

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）占肝硬化导致死亡的约50％，所有与肝脏有关的约30％ 在美国死亡。乙醇如何损害肝脏的理解水平不足，缺乏疗法或 未经证实。我们的目标是了解ALD的发病机理。我们观察到了广泛的，可逆的肝 线粒体去极化（MTDEPO），线粒体负担增加和血清线粒体DNA升高 乙醇处理后小鼠（mtDNA）。我们建议检验乙醇代谢的新假设 诱导mtdepo，进而刺激线粒体。明显增加了线突负担 压倒了溶酶体处理自噬体的能力，尤其是在处理 在线粒体中去极化线粒体进入线粒体，然后在溶酶体中被损害 慢性乙醇暴露，导致细胞外线粒体的细胞外释放，线粒体 和/或含有线粒体损伤相关的分子模式（mTDAMP）的自体染色体 分子引起纤维化炎症反应和肝损伤。在特定目标1中使用 插入性多光子显微镜，我们将探索慢性乙醇后活小鼠中MTDEPO是否发生 加剧了暴饮暴食，在独特的纤维化诱导乙醇/胆固醇模型中加剧了我们 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 探索是否通过酒精脱氢酶和CYP2E1缺乏症抑制乙醛（ACALD）形成 通过Alda-1加速ACALD氧化，而FK506（去极化的阻滞剂）降低了mtdepo和肝脏 慢性乙醇后的损伤/炎症/纤维化。在AIM 2中，我们将确定mtdepo与 线粒体。将遗传和药理干预措施与插入式和电子结合使用 显微镜和线粒体通量分子指标的分析，我们将阐明乙醇诱导的 MTDEPO启动线粒体或如果线粒体会导致mtdepo。我们将确定线粒体/线粒体是否 慢性，慢性加胆固醇和慢性乙醇的加工钝化，并进一步探索是否 自噬加工的抑制加剧了慢性乙醇后的肝损伤/炎症/纤维化。目标 3，我们将表征MTDEPO和损害线粒体/加工有助于mTDAMP释放 乙醇之后。我们将表征急性乙醇和慢性慢性之后释放到mtdamps的血清 加上胆固醇和慢性加饮食乙醇，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mtdepo，mitophagy和 线粒体的加工会改变乙醇后的mtdamp释放。这项研究将阐明一个新的链接 在与乙醇代谢相关的早期线粒体变化与肝脏的后期发展之间 损伤/炎症/纤维化，从而填补了理解ALD发病机理的关键空白。这项研究应该 还可以确定ALD的新治疗靶标和新型生物标志物，以监测ALD严重性/进展。