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，导致高死亡率和发病率，而慢性酒精滥用是慢性胰腺炎的第二大原因，仅次于胆道疾病。然而，酒精性胰腺炎的发病机制尚不清楚。酒精脱氢酶(ADH)催化的乙醇氧化代谢在胰腺中可以忽略不计，而FAEE合成酶催化的乙醇非氧化代谢为脂肪酸乙酯(FAEE)似乎是慢性酒精滥用时胰腺中乙醇处置的主要机制。令人惊讶的是，关于内源性FAEs在酒精性胰腺炎中的作用，人们知之甚少。根据我们的初步研究显示，肝脏ADH缺陷(ADH-)鹿小鼠胰腺中FAEE水平是ADH正常鹿小鼠的-14倍，以及乙醇暴露后ADH缺陷的人肝细胞癌(HepG2)细胞中FAEE和FAEE诱导的细胞凋亡的剂量和时间依赖的形成，我们假设FAEE的形成增加是酒精性胰腺炎的触发事件，FAEE和FAEE合成酶可以作为胰腺损伤的早期标志。我们的初步研究还表明，在培养的大鼠胰腺肿瘤(AR42J)细胞中可以形成FAEEs。因此，为了研究内源性FAEs的毒性潜力，并阐明它们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。在目标1中，我们将以剂量和时间依赖的方式检测乙醇暴露后ADH-鹿小鼠血浆和胰腺中FAEs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ADH-鹿小鼠胰腺和酒精暴露后AR42J细胞中的细胞凋亡(目标2)。FAEE合成酶的抑制剂或诱导剂将分别用于减弱或增加在AR42J细胞中FAEE的形成，以进一步研究内源性形成的FAEE在乙醇诱导的细胞凋亡和毒性中的作用(目标3)。实现我们的具体目标1-3将确立FAEEs在乙醇诱导的胰腺损伤中的作用，为未来的人类研究开发这些参数作为乙醇诱导的胰腺损伤的早期标志物奠定基础，并最终有利于我们开发新的预防/治疗策略，以便在胰腺发生不可逆转的损伤之前进行早期干预。

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.