Fortunato Franco, Bürgers Heinrich, Bergmann Frank, Rieger Peter, Büchler Markus W, Kroemer Guido, Werner Jens
Department of General, Visceral, and Transplantation Surgery, University Hospital Heidelberg, Germany.
Gastroenterology. 2009 Jul;137(1):350-60, 360.e1-5. doi: 10.1053/j.gastro.2009.04.003. Epub 2009 Apr 9.
BACKGROUND & AIMS: Acute pancreatitis constitutes a life-threatening condition in which pancreatic acinar cells undergo massive cell death. We investigated the incidence of apoptosis, autophagy, and necrosis affecting acinar cells in the early onset of acute pancreatitis induced by chronic alcohol feeding and acute endotoxemia.
Rats were fed either an ethanol-containing or a control diet over 14 weeks and killed 3 or 24 hours after a single lipopolysaccharide injection. Apoptosis, necrosis, and autophagy of pancreatic acinar cells were assessed by histology, electron microscopy, immunofluorescence, and biochemical methods.
The combination of alcohol exposure and endotoxemia resulted in the depletion of several lysosomal proteins including lysosomal-associated membrane protein-2 (Lamp-2), a protein that is required for the proper fusion of autophagosomes with lysosomes. Accordingly, Lamp-2 depletion correlated with the accumulation of autophagosomes and a relative paucity of autolysosomes, reduced adenosine-5'-triphosphate levels, and a switch from apoptotic to necrotic cell death. This switch to necrosis was accompanied by reduced caspase activation and the nuclear release of the proinflammatory factor high mobility group box 1. Importantly, human patients with alcoholic pancreatitis also exhibited local Lamp-2 depletion, which points to a crucial role for Lamp-2 and autophagy in pancreatic acinar cell death.
Our data suggest that acinar cell vacuolization in pancreatitis is mediated by an endotoxemia-induced inhibition of the late stage of autophagy. The combination of alcohol and endotoxemia attenuated apoptosis response yet enhanced acinar cell necrosis. The depletion of lysosomal proteins plays a critical role in the early onset of acute pancreatitis.
急性胰腺炎是一种危及生命的疾病，其中胰腺腺泡细胞会发生大量细胞死亡。我们研究了慢性酒精喂养和急性内毒素血症诱导的急性胰腺炎早期，影响腺泡细胞的凋亡、自噬和坏死的发生率。
大鼠在14周内喂食含乙醇或对照饮食，并在单次注射脂多糖后3或24小时处死。通过组织学、电子显微镜、免疫荧光和生化方法评估胰腺腺泡细胞的凋亡、坏死和自噬。
酒精暴露和内毒素血症的联合作用导致几种溶酶体蛋白的消耗，包括溶酶体相关膜蛋白-2（Lamp-2），该蛋白是自噬体与溶酶体正确融合所必需的。因此，Lamp-2的消耗与自噬体的积累和自溶酶体的相对缺乏、三磷酸腺苷水平降低以及细胞死亡从凋亡向坏死的转变相关。这种向坏死的转变伴随着半胱天冬酶激活的减少和促炎因子高迁移率族蛋白B1的核释放。重要的是，酒精性胰腺炎患者也表现出局部Lamp-2的消耗，这表明Lamp-2和自噬在胰腺腺泡细胞死亡中起关键作用。
我们的数据表明，胰腺炎中腺泡细胞空泡化是由内毒素血症诱导的自噬后期抑制介导的。酒精和内毒素血症的联合作用减弱了凋亡反应，但增强了腺泡细胞坏死。溶酶体蛋白的消耗在急性胰腺炎的早期发病中起关键作用。
