Lysosomal Damage, Impaired Autophagy, and Alcoholic Pancreatitis

溶酶体损伤、自噬受损和酒精性胰腺炎

基本信息

批准号：
8420545
负责人：
ILYA GUKOVSKY
金额：
$ 24.47万
依托单位：
BRENTWOOD BIOMEDICAL RESEARCH INSTITUTE
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：
2011-02-01 至 2016-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8420545
关键词：
Acinar Cell Acute Affect Alcohol abuse Alcoholic Pancreatitis Alcohols Autophagocytosis Autophagosome Cathepsins Cholecystokinin Data Disease Dose Endotoxemia Ethanol Ethanol toxicity Event Exocrine pancreas Experimental Models Functional disorder Genetic Goals Golgi Apparatus Human Hydrolase Impairment In Vitro Knock-out LAMP-2 Lead Life Lysosomes Mediating Mediator of activation protein Membrane Proteins Mitochondria Modeling Mus Organ Organelles Pancreas Pancreatitis Pathogenesis Pathologic Pathway interactions Process Proteins Rattus Resolution Risk Factors Rodent Role Sincalide Stress Testing Trypsin Trypsinogen Vacuole acute pancreatitis alcohol effect analog base feeding in vivo insight late endosome mouse model new therapeutic target non-alcoholic novel novel therapeutic intervention overexpression public health relevance response stressor trafficking

Acinar Cell Acute Affect Alcohol abuse Alcoholic Pancreatitis Alcohols Autophagocytosis Autophagosome Cathepsins Cholecystokinin Data Disease Dose Endotoxemia Ethanol Ethanol toxicity Event Exocrine pancreas Experimental Models Functional disorder Genetic Goals Golgi Apparatus Human Hydrolase Impairment In Vitro Knock-out LAMP-2 Lead Life Lysosomes Mediating Mediator of activation protein Membrane Proteins Mitochondria Modeling Mus Organ Organelles Pancreas Pancreatitis Pathogenesis Pathologic Pathway interactions Process Proteins Rattus Resolution Risk Factors Rodent Role Sincalide Stress Testing Trypsin Trypsinogen Vacuole acute pancreatitis alcohol effect analog base feeding in vivo insight late endosome mouse model new therapeutic target non-alcoholic novel novel therapeutic intervention overexpression public health relevance response stressor trafficking

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项目摘要

DESCRIPTION (provided by applicant): Pancreatitis is a potentially fatal disease of exocrine pancreas the pathogenesis of which remains obscure and for which no specific treatment has been developed. Alcohol abuse is a major etiologic factor for pancreatitis; however, the mechanisms by which alcohol predisposes to this disease remain elusive. Here we propose a novel hypothesis for the pathogenesis of alcoholic pancreatitis stating that a combination of two events is critical for pancreatitis: 1) induction of autophagy and 2) impaired lysosomal function which makes autophagy defective. Autophagy (a.k.a. macroautophagy) is the main cellular degradative, lysosome-driven process. Our recent study has revealed a profound impairment of autophagy in experimental models of nonalcoholic acute pancreatitis. We found that autophagy is activated but its progression/resolution is impaired. Autophagy impairment is caused by lysosomal dysfunction a prominent manifestation of which is defective processing/maturation of cathepsins, major lysosomal hydrolases. Further, our findings revealed that impaired autophagy mediates 2 key pathologic responses of pancreatitis: acinar cell vacuolation and intra- acinar trypsinogen activation. Our results indicate that ethanol feeding alone causes lysosomal dysfunction in pancreas similar to that we found in nonalcoholic pancreatitis. However, ethanol per se does not induce pancreatitis because it does not activate autophagy. Thus, in conditions of basal unstimulated autophagy, the consequences of ethanol- induced lysosomal dysfunction are limited. However, a combination of ethanol feeding, which causes lysosomal dysfunction, and stresses that induce autophagy leads to defective autophagy and thus pancreatitis. Our results suggest that this is the mechanism through which ethanol feeding "sensitizes" rats or mice to pancreatitis induced by low-dose cerulein (CR; a CCK-8 analog) that by itself does not elicit pancreatitis. We propose that similar mechanism mediates pancreatitis induced by the combination of ethanol feeding and endotoxemia (i.e., LPS), the other available "in vivo sensitization" model of alcoholic pancreatitis. Our results indicate that ethanol causes dysregulation of endolysosomal trafficking and the Golgi, associated with defective processing and activity of cathepsins and decreased level of LAMP-2, a major lysosomal membrane protein. We further propose that manipulating the level of autophagy (by, respectively, inhibiting autophagy through Atg5 knockout or stimulating it through overexpression of Atg8/LC3, a critical autophagy mediator) ameliorates or worsens alcoholic pancreatitis. The Specific Aims for the project are: 1. Determine the effects of ethanol feeding alone and experimental alcoholic pancreatitis (i.e., ethanol feeding combined with low-dose CR or LPS) on lysosomal dysfunction in pancreas, and the role of LAMP-2 in these effects. 2. Determine the effects of ethanol feeding alone and experimental alcoholic pancreatitis on endolysosomal trafficking and the Golgi. 3. Determine the effects of ethanol feeding alone and experimental alcoholic pancreatitis on autophagy induction and progression, and the role of LAMP-2 in these effects. 4. Determine the effects of genetically inhibiting or stimulating autophagy on alcoholic pancreatitis. The proposed studies elucidate ethanol's effects on lysosomes, the Golgi, and autophagy in pancreas; suggest a new model for alcoholic pancreatitis; and indicate novel targets for therapeutic approaches to treat or mitigate this disease. Further, similar mechanisms involving ethanol-induced lysosomal dysfunction may mediate alcohol toxicity to other organs.

描述（由申请人提供）：胰腺炎是一种潜在的外分泌胰腺致命疾病，其发病机理仍然晦涩难懂，尚未开发出特定的治疗。酗酒是胰腺炎的主要病因。但是，酒精易于使用的机制仍然难以捉摸。在这里，我们提出了一个新的假设，用于酒精性胰腺炎的发病机理，指出两个事件的组合对于胰腺炎至关重要：1）自噬诱导和2）溶酶体功能受损，这会使自噬有缺陷。自噬（又称大噬菌）是主要的细胞降解，溶酶体驱动的过程。我们最近的研究表明，在非酒精性急性胰腺炎的实验模型中，自噬严重受损。我们发现自噬被激活，但其进展/分辨率受到损害。自噬损伤是由溶酶体功能障碍引起的，其明显的表现是组织蛋白酶（主要溶酶体水解酶）的处理/成熟。此外，我们的发现表明，自噬受损介导了2个胰腺炎的关键病理反应：刺激性细胞的液泡和粉刺内胰蛋白酶原活化。我们的结果表明，单独的乙醇喂养会引起胰腺中的溶酶体功能障碍，类似于我们在非酒精性胰腺炎中发现的溶酶体功能障碍。但是，乙醇本身不会诱导胰腺炎，因为它不会激活自噬。因此，在基础未刺激的自噬条件下，乙醇诱导的溶酶体功能障碍的后果受到限制。然而，乙醇喂养的组合会导致溶酶体功能障碍，并诱导自噬的压力会导致自噬有缺陷，从而导致胰腺炎。我们的结果表明，这是低剂量cerulein（Cr; a cck-8类似物）诱导的乙醇将大鼠或小鼠喂食的机制本身不会引起胰腺炎。我们提出，相似的机制介导乙醇喂养和内毒素血症（即LPS）的组合诱导的胰腺炎，这是其他可用的酒精胰腺炎模型的“体内敏化”模型。我们的结果表明，乙醇会导致内溶液体运输和高尔基体的失调，与组织蛋白酶的缺陷和活性以及LAMP-2的降低有关，LAMP-2的水平降低，这是一种主要的溶酶体膜蛋白。我们进一步提出，操纵自噬水平（分别通过ATG5敲除抑制自噬或通过过度表达ATG8/LC3，一种关键的自噬介质）可以改善或恶化酒精pancrestisis。该项目的具体目的是：1。确定单独进食乙醇的影响和实验性的酒精性胰腺炎（即，乙醇喂养与低剂量CR或LPS结合）对胰腺中溶酶体功能障碍的影响，以及LAMP-2在这些作用中的作用。 2。确定单独进食乙醇和实验性酒精性胰腺炎对内溶性贩运和高尔基体的影响。 3。确定单独进食乙醇和实验性酒精性胰腺炎对自噬诱导和进展的影响，以及LAMP-2在这些作用中的作用。 4。确定遗传抑制或刺激自噬对酒精性胰腺炎的影响。拟议的研究阐明了乙醇对胰腺中溶酶体，高尔基体和自噬的影响。提出了一种用于酒精性胰腺炎的新模型；并指出治疗或减轻这种疾病的治疗方法的新靶标。此外，涉及乙醇诱导的溶酶体功能障碍的类似机制可能介导对其他器官的酒精毒性。