Fatty Acid Ethyl Esters in Ethanol-induced Pancreatitis

描述（申请人提供）：胰腺炎是酗酒者的主要健康问题，死亡率和发病率高，慢性酒精滥用是继胆管疾病之后的第二大慢性胰腺炎原因。然而，酒精性胰腺炎的机制尚不清楚。由乙醇脱氢酶（ADH）催化的乙醇氧化代谢在胰腺中可以忽略不计，而由FAEE合酶催化的乙醇到脂肪酸乙酯（FAEE）的非氧化代谢似乎是慢性酒精滥用期间胰腺中乙醇处置的主要机制。令人惊讶的是，关于内源性形成的faee在乙醇性胰腺炎中的作用知之甚少。我们的初步研究显示，与ADH正常的鹿小鼠相比，肝ADH缺乏（ADH-）鹿小鼠胰腺中的FAEE水平增加了14倍，并且在培养的ADH缺乏的人肝癌（HepG2）细胞暴露于乙醇后，FAEE的形成和FAEE诱导的凋亡具有剂量和时间依赖性，我们假设FAEE的形成增加是乙醇诱导的胰腺炎的触发事件。FAEE和FAEE合成酶可能是胰腺损伤的早期标志。我们的初步研究也表明faee在培养的大鼠胰腺肿瘤（AR42J）细胞中形成。因此，为了研究内源性FAEEs的毒性潜能并阐明其在乙醇诱导的胰腺损伤中的作用，我们将使用ADH-鹿小鼠和AR42J细胞。在Aim 1中，我们将以剂量和时间依赖的方式测定乙醇暴露后ADH-鹿小鼠血浆和胰腺中FAEEs的水平，并评估与胰腺损伤相关的生化和形态学参数。我们将评估乙醇暴露后ADH-鹿小鼠胰腺和AR42J细胞的凋亡情况（目的2）。FAEE合成酶抑制剂或诱导剂分别减弱或增加AR42J细胞中FAEE的形成，将用于进一步研究内源性FAEE在乙醇诱导的细胞凋亡和毒性中的作用（目的3）。实现我们的具体目标1-3应该建立FAEEs在乙醇诱导胰腺损伤中的作用，为未来的人体研究奠定基础，以开发这些参数作为乙醇诱导胰腺损伤的早期标志物，并最终有利于我们在胰腺发生不可逆损伤之前制定新的预防/治疗策略进行早期干预。

DESCRIPTION (provided by applicant): Pancreatitis is a major health problem in alcoholics that causes high mortality and morbidity, and after biliary duct diseases, chronic alcohol abuse is the second major cause of chronic pancreatitis. However, the mechanism of alcohol-induced pancreatitis is poorly understood. Oxidative metabolism of ethanol catalyzed by alcohol dehydrogenase (ADH) is negligible in the pancreas, while nonoxidative metabolism of ethanol to fatty acid ethyl esters (FAEEs), catalyzed by FAEE synthase, appears to be the major mechanism of ethanol disposition in the pancreas during chronic alcohol abuse. Surprisingly, very little is known regarding the role of endogenously formed FAEEs in ethanol-induced pancreatitis. Based upon our preliminary studies showing - 14-fold increase in FAEE levels in the pancreas of hepatic ADH-deficient (ADH-) deer mice as compared to those in ADH-normal deer mice, and a dose- and time-dependent formation of FAEEs and FAEE-induced apoptosis upon ethanol exposure of ADH-deficient human hepatocellular carcinoma (HepG2) cells in culture, we hypothesize that increased formation of FAEEs is a triggering event in ethanol-induced pancreatitis, and that FAEEs and FAEE synthase can be early markers of pancreatic injury. Our preliminary studies also indicate that FAEEs are formed in rat pancreatic tumor (AR42J) cells in culture. Therefore, to investigate the toxic potential of endogenously formed FAEEs and elucidate their role in ethanol-induced pancreatic injury, we will use ADH- deer mice and AR42J cells. In Aim 1, we will determine the levels of FAEEs in the plasma and pancreas of ADH- deer mice after ethanol exposure in a dose- and time-dependent manner, and evaluate the biochemical and morphological parameters associated with pancreatic injury. We will evaluate apoptosis in the pancreas of ADH- deer mice, and in AR42J cells, after ethanol exposure (Aim 2). Inhibitors or inducers of FAEE synthase to attenuate or augment formation of FAEEs in AR42J cells, respectively, will be used to further examine the role of endogenously formed FAEEs in ethanol-induced apoptosis and toxicity (Aim 3). Achieving our Specific Aims 1-3 should establish the role of FAEEs in ethanol-induced pancreatic injury, lay the foundation for future human studies to develop these parameters as early markers for ethanol-induced pancreatic damage, and ultimately benefit us in developing new preventive/therapeutic strategies for early intervention before irreversible damage to pancreas occurs.