Mechanism(s) of Alcoholic Pancreatitis

描述(申请人提供)：慢性胰腺炎是一种严重而痛苦的胰腺外分泌紊乱，没有有效的治疗措施。慢性酒精滥用是导致慢性胰腺炎的第二大原因，仅次于胆道疾病。胰腺炎的经济和社会影响是毁灭性的，因为这种疾病具有不可逆转的性质，以及相关的高死亡率和包括消化不良、糖尿病和胰腺癌在内的共病。胰腺外分泌物中消化酵素的激活导致胰腺组织的自身消化被认为是导致胰腺炎的原因。然而，酒精性胰腺炎的代谢基础相对较模糊。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)在胰腺炎的发生和发展中的作用“是NIAAA赞助的研究项目(PA-09-164)的重点领域之一。在初步的剂量依赖研究中，我们发现，给予3.5%乙醇(最佳耐受量)2个月(亚慢性暴露)的肝脏酒精脱氢酶缺陷(ADH-)与正常ADH(ADH+)鹿小鼠的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，乙醇的非氧化脂代谢产物)和内质网(ER)应激的显著增加。然而，两个品系的鹿鼠的血液乙醛水平被发现是相似的。根据我们在鹿鼠模型上的初步数据，以及我们等人报道的FAEEs对胰腺腺泡细胞的细胞毒作用，我们推测，在肝脏ADH抑制的情况下，慢性乙醇暴露通过在胰腺外分泌物中内源性形成乙醇的非氧化脂代谢产物而诱导ER应激，从而导致酒精性胰腺炎的发生和发展。在目标1中，我们将表征慢性酒精暴露3个月和6个月后ADH-鹿小鼠胰腺中脂代谢的变化和FAEEs的增加。我们将通过质子和/或31P核磁共振波谱来评估胰腺中脂肪变化和内源性FAEE的水平。在目标2中，我们将研究酒精喂养的ADH-鹿小鼠胰腺损伤、内质网应激和促炎反应的进展。胰腺损伤将通过形态计量学和损伤标志物来评估，胰腺内质网应激通过检测葡萄糖调节蛋白78和相关的细胞死亡途径的过度表达来评估，以及通过促炎转录因子和细胞因子在胰腺和/或血浆中的炎症反应来评估。我们的血浆损伤标记物和脂代谢组变化数据可用于早期发现发育性胰腺炎。这两个目标的联合结果应该确定FAEEs在酒精性胰腺炎的发生和发展中的作用/贡献，并确定其生物标记物。这些信息将被用于开发酒精性胰腺炎的早期发现和干预的转化性研究项目。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唯一有资格从事这一项目。 公共卫生相关性：叙述：酒精性胰腺炎是一种毁灭性的疾病，胰腺外分泌的疼痛障碍通常会导致高死亡率，并与消化不良、糖尿病和胰腺癌等并存疾病相关。在本项目中，我们将建立酒精性胰腺炎的代谢基础，并寻找酒精性胰腺损伤的早期标志物，为酒精性胰腺炎的早期发现和预防提供翻译研究项目。

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.