自噬相关基因在小鼠急性胰腺炎中的表达及其意义

Expression and significance of autophagy-related genes in acute pancreatitis

目的检测小鼠急性胰腺炎（AP）胰腺组织中自噬相关基因微管相关蛋白1轻链3（LC3）、p62和溶酶体相关膜蛋白2（LAMP-2）的表达，并探讨其意义。 方法20只小鼠随机分为AP组和对照组。采用腹腔内注射20%L-精氨酸溶液（4 g/kg体重）2次、间隔1 h的方法制备AP模型；对照组腹腔注射等容积生理盐水。24 h后观察两组小鼠胰腺组织的病理改变，采用蛋白质印迹法检测小鼠胰腺组织LC3、p62和LAMP-2蛋白的表达。 结果对照组小鼠胰腺组织未见明显病理改变；AP组小鼠胰腺腺泡水肿，腺泡结构破坏、消失，叶间隔、小叶间隔及腺泡间隔显著增宽，腺泡细胞呈不同程度变性坏死。AP组胰腺组织水肿、出血、坏死和炎症评分分别为（3.13±0.50）、（2.83±0.32）、（3.25±0.46）、（3.16±0.47）分，对照组的4项评分均为0分，差异均有统计学意义（P值均〈0.01）。AP组胰腺组织LC3-Ⅱ/LC3-Ⅰ比值及p62、LAMP-2蛋白表达量分别为1.16±0.08、0.94±0.04、0.35±0.04；对照组分别为0.24±0.02、0.34±0.03、0.95±0.03。AP组胰腺组织LC3-Ⅱ/LC3-Ⅰ比值、p62蛋白表达显著高于对照组，LAMP-2蛋白表达显著低于对照组，差异均有统计学意义（P值均〈0.01）。

ObjectiveTo examine the expression and analyze the significance of autophagy-related gene microtubule-associated protein 1 light chain 3 （MAP1-LC3, LC3）, p62 and lysosome-associated membrane protein 2 （LAMP-2） in pancreatic tissues of mice with acute pancreatitis （AP）. MethodsTwenty mice were randomized into AP group and control group, and the number of mice was equal between two groups. AP group was intra-peritoneally injected by 20% L-arginine solution （two injections of 4 g/kg body weight, every 1 h） in the dosage of 4 g/1 kg twice every 1 hour to establish AP model, while control group was administered with equal volume of normal saline by intra-peritoneal injection. All the mice were euthanized at 24 hour after the last injection. Pancreatic histopathological changes were measured. In addition, the protein expressions of LC3, p62 and LAMP-2 were detected by Western blot. ResultsNo obvious pathological changes were observed in control group. Pancreatic acinar edema, structure destruction, missing, the obvious widening of interlobular septum, small interlobular septum and acinar septum, and the necrosis of acinar cells at different degrees were observed in AP group. The pathological score for tissue edema, hemorrhage, necrosis and inflammation in AP group was 3.13±0.50, 2.83±0.32, 3.25±0.46 and 3.16±0.47, respectively, which was all 0 in control group. The differences were statistically significant between AP group and control group （P〈0.01）. In AP group, the ratio of LC3-Ⅱ/LC3-Ⅰ, p62 and LAMP-2 protein in pancreatic tissue were 1.16±0.08, 0.94±0.04 and 0.35±0.04, respectively, which were 0.24±0.02, 0.34±0.03 and 0.95±0.03 in control group. The ratio of LC3-Ⅱ/LC3-Ⅰ and p62 protein in pancreatic tissue in AP group were much higher than those in control group, while LAMP-2 in AP group was lower than that in control group, and there was statistically significant difference between two groups （all P〈0.01）. ConclusionsIntra-peritoneal injection of L-arginine could induce acute pancreatitis, and autophagy is impaired, which was associated with decreased LAMP-2 protein expression.