Criddle David N
Department of Cellular & Molecular Physiology & NIHR Liverpool Pancreas Biomedical Research Unit, RLBUHT, Institute of Translational Medicine, University of Liverpool, UK.
Pancreatology. 2015 Jul;15(4 Suppl):S6-S12. doi: 10.1016/j.pan.2015.02.009. Epub 2015 Mar 28.
Excessive alcohol consumption is a major trigger for severe acute pancreatitis which may lead to multi-organ dysfunction and premature death of the individual. Hyperlipidaemia is a risk factor for both acute and chronic pancreatitis and the role of fatty acids in mediating damage has received increasing attention in recent years. In the pancreas ethanol is metabolised by both oxidative and non-oxidative pathways. The latter, predominant route generates fatty acid ethyl esters (FAEEs) from fatty acid substrates via the action of diverse enzymes called FAEE synthases, including carboxylester lipase an enzyme synthesized and secreted by the acinar cells. Inhibition of the oxidative pathway promotes formation of FAEEs which induce sustained elevations of cytosolic calcium leading to inhibition of mitochondrial function, loss of ATP and necrosis of isolated pancreatic acinar cells. Furthermore, FAEEs undergo hydrolysis in the mitochondria releasing free fatty acids that exert toxic effects. Our recent work has shown that pharmacological inhibition of carboxylester lipase ameliorated detrimental effects of non-oxidative ethanol metabolism in isolated pancreatic acinar cells in vitro and in a new in vivo experimental model of alcoholic acute pancreatitis, revealing a specific enzyme target for ethanol-induced injury. Strategies that prevent FAEE synthesis, protect mitochondria, reduce calcium overload or sustain calcium homeostasis by ATP provision may provide promising therapeutic avenues for the treatment of alcoholic acute pancreatitis.
过量饮酒是严重急性胰腺炎的主要诱因,可能导致多器官功能障碍和个体过早死亡。高脂血症是急性和慢性胰腺炎的危险因素,近年来脂肪酸在介导损伤中的作用受到越来越多的关注。在胰腺中,乙醇通过氧化和非氧化途径代谢。后者是主要途径,通过多种称为脂肪酸乙酯合成酶的酶的作用,从脂肪酸底物生成脂肪酸乙酯(FAEEs),包括由腺泡细胞合成和分泌的一种酶——羧酸酯酶。氧化途径的抑制促进了FAEEs的形成,FAEEs会导致胞质钙持续升高,从而抑制线粒体功能、ATP丢失以及分离的胰腺腺泡细胞坏死。此外,FAEEs在线粒体中发生水解,释放出具有毒性作用的游离脂肪酸。我们最近的研究表明,在体外分离的胰腺腺泡细胞以及酒精性急性胰腺炎的新体内实验模型中,对羧酸酯酶的药理学抑制改善了非氧化乙醇代谢的有害影响,揭示了乙醇诱导损伤的一个特定酶靶点。通过提供ATP来防止FAEEs合成、保护线粒体、减少钙超载或维持钙稳态的策略,可能为酒精性急性胰腺炎的治疗提供有前景的治疗途径。