Mechanism(s) of Alcoholic Pancreatitis

描述（由申请人提供）：慢性胰腺炎是一种严重而痛苦的外分泌胰腺疾病，目前尚无有效的治疗措施。继胆管疾病之后，慢性酒精滥用是慢性胰腺炎的第二大原因。由于这种疾病的不可逆性以及相关的高死亡率和合并症，包括消化不良、糖尿病和胰腺癌，胰腺炎的经济和社会影响是毁灭性的。胰脏组织的自体消化是由外分泌胰腺的消化酶原激活引起的，已知可引起胰腺炎。然而，酒精性胰腺炎的代谢基础相对模糊。乙醇代谢物、乙醛（氧化代谢物）和脂肪酸乙酯（FAEEs，非氧化脂质代谢物）在胰腺炎发生和发展中的作用是NIAAA资助的研究项目的重点领域之一（PA-09-164）。在初步的剂量依赖性研究中，我们发现肝脏酒精脱氢酶（ADH）缺陷（ADH-）与正常ADH （ADH+）相比，连续2个月（亚慢性暴露）喂食3.5%乙醇（最佳耐受剂量）的鹿小鼠，胰腺损伤伴随着血液酒精浓度（BAC）和胰腺脂质、脂肪酸乙酯（FAEEs，乙醇的非氧化脂质代谢产物）和内质网（ER）应激的显著增加。然而，在饲喂乙醇的两种鹿鼠中，血液中乙醛的含量是相似的。根据我们在鹿小鼠模型中的初步数据以及我们和其他人在胰腺腺泡细胞中报道的FAEEs的细胞毒性作用，我们假设慢性乙醇暴露在肝脏ADH抑制下诱导内源性内源性内源性乙醇非氧化脂质代谢物形成外分泌胰腺导致酒精性胰腺炎的开始和进展。在Aim 1中，我们将描述慢性乙醇暴露3和6个月后ADH鹿小鼠胰腺脂质代谢组学变化的进展和FAEEs的增加。我们将通过质子和/或31磷核磁共振波谱评估胰腺脂肪变化和内源性FAEEs水平。在Aim 2中，我们将从Aim 1中研究乙醇喂养的ADH鹿小鼠的胰腺损伤，内质网应激和促炎反应的进展。胰腺损伤将通过形态测量和损伤标志物来评估，通过测量葡萄糖调节蛋白78的过度表达和相关细胞死亡途径来评估胰腺内质网应激，通过胰腺和/或血浆中的促炎转录因子和细胞因子来评估炎症反应。我们关于损伤标志物和脂质代谢组变化的血浆数据可用于发育性胰腺炎的早期检测。这两个目标的综合结果应确定faes在酒精性胰腺炎的发生和进展中的作用/贡献，并确定其生物标志物。这一信息将用于制定酒精性胰腺炎早期发现和干预的转化研究项目。我们现有强大的跨学科研究团队和鹿鼠模型的初步数据使我们有资格从事这个项目。

DESCRIPTION (provided by applicant): Chronic pancreatitis is a serious and painful disorder of exocrine pancreas with no effective therapeutic measures. After biliary duct disease, chronic alcohol abuse is the second major cause of chronic pancreatitis. The economic and social impact of pancreatitis is devastating due to irreversible nature of the disease and related high mortality and co-morbidities including maldigestion, diabetes, and pancreatic cancer. Autodigestion of pancreatic tissue due to the activation of digestive zymogens in the exocrine pancreas is known to cause pancreatitis. However, metabolic basis of alcoholic pancreatitis is relatively obscure. Role of ethanol metabolites, acetaldehyde (oxidative metabolite) and fatty acid ethyl esters (FAEEs, nonoxidative lipid metabolites) in the initiation and progression of pancreatitis" is one of the focus areas of NIAAA sponsored research programs (PA-09-164). In preliminary dose-dependent studies, we found that pancreatic injury along with substantial increases in blood alcohol concentration (BAC) and pancreatic lipids, fatty acid ethyl esters (FAEEs, nonoxidative lipid metabolites of ethanol) and endoplasmic reticulum (ER) stress in hepatic alcohol dehydrogenase (ADH)-deficient (ADH-) vs. normal ADH (ADH+) deer mice fed 3.5% ethanol (an optimal tolerable dose) for 2 months (subchronic exposure). However, the levels of blood acetaldehyde were found to be similar in both strains of deer mice fed ethanol. Based upon our preliminary data in deer mouse model and the cytotoxic effects of FAEEs reported by us and others in pancreatic acinar cells, we hypothesize that chronic ethanol exposure under hepatic ADH inhibition induces ER stress due to endogenous formation of nonoxidative lipid metabolites of ethanol in the exocrine pancreas resulting in initiation and progression of alcoholic pancreatitis. In Aim 1, we will characterize progression of lipid metabolomic changes and increases in FAEEs in the pancreas of ADH- deer mice after chronic ethanol exposure for 3 and 6 months. We will assess fatty changes and endogenous levels of FAEEs in the pancreas by proton and/or 31phosphorus nuclear magnetic resonance spectroscopy. In Aim 2, we will examine the progression of pancreatic injury, ER stress and proinflammatory responses in ethanol fed ADH- deer mice from Aim 1. Pancreatic injury will be evaluated by morphometry and injury markers, pancreatic ER stress by measuring the over expression of glucose regulated protein 78 and related cell death pathways, and inflammatory responses by proinflammatory transcription factors and cytokines in the pancreas and/or plasma. Our plasma data on markers of injury and changes in lipid metabolome can be utilized for early detection of developmental pancreatitis. The combined results of both aims should determine role/contribution of FAEEs in initiation and progression of alcoholic pancreatitis and identify its biomarkers. This information will be utilized to develop a translational research project for the early detection and intervention of alcoholic pancreatitis. Our strong existing interdisciplinary team of investigators and preliminary data in deer mouse model make us uniquely qualified to pursue this project. PUBLIC HEALTH RELEVANCE: NARRATIVE: Alcoholic pancreatitis is a devastating disease and painful disorder of exocrine pancreas often causes high mortality and associated with co-morbidities including maldigestion, diabetes, and pancreatic cancer. In this project, we will establish metabolic basis of alcoholic pancreatitis, and identify early markers of ethanol-induced pancreatic injury for a translational research project for early detection and prevention of alcoholic pancreatitis.