Bafiomycin A1对小鼠急性胰腺炎的作用及其机制

Effect and mechanism of Bafiomycin A1 on acute pancreatitis in mice

目的探讨Bafiomycin A1对小鼠急性胰腺炎的疗效及其作用机制。方法BALB/c小鼠60只随机分为对照组、模型组、低剂量组和高剂量组（n＝15）。模型组、低剂量组和高剂量组小鼠经腹腔注射雨蛙素50 μg/kg，每小时1次，共7次，建立急性胰腺炎模型。低剂量组和高剂量组小鼠经腹腔注射25和75 μg/kg Bafiomycin A1，对照组和模型组经腹腔注射等体积生理盐水。4组小鼠分别在治疗后24 h处死，采用酶联免疫吸附试验（ELISA）法测定小鼠血清淀粉酶（AMY）、炎性因子肿瘤坏死因子-α（TNF-α）和白细胞介素（IL）-6，采用苏木素-伊红（HE）染色观察小鼠胰腺病变并评分（Schmidt评分）；采用Western blot分析自噬底物p62和微管相关蛋白1轻链3（LC3）的变化；采用免疫荧光分析胰腺组织p62的变化。结果与模型组[（4 910.98±349.43） U/L、（109.43±10.43） pg/L、（329.16±20.91） pg/L、（9.43±3.98）分]比较，低剂量组[（3 109.13±301.44） U/L、（80.18±9.34） pg/L、（215.32±18.43） pg/L、（6.48±3.18）分]和高剂量组[（1 432.33±187.43） U/L、（45.19±8.14） pg/L、（153.22±12.63） pg/L、（3.14±1.02）分]小鼠在治疗后24 h后AMY、TNF-α、IL-6以及Schmidt评分均显著下降，差异有统计学意义（P＝0.000）。与低剂量组比较，高剂量组小鼠在治疗后24 h后AMY、TNF-α、IL-6以及Schmidt评分下降更显著，差异有统计学意义（P＝0.000）。与模型组（0.15±0.06、0.56±0.06）比较，低剂量组（0.39±0.09、0.75±0.09）和高剂量组（0.61±0.07、0.99±0.08）小鼠胰腺组织中p62和LC3明显堆积，差异有统计学意义（P＝0.000）。与低剂量组比较，高剂量组小鼠胰腺组织中p62和LC3堆积更加明显，差异有统计学意义（P＝0.000）。结论Bafiomycin A1可以显著抑制急性胰腺炎小鼠胰腺组织的自噬水平，对胰腺组织起到一定的保护作用。

Objective To investigate the effect and mechanism of Bafiomycin A1 on acute pancreatitis in mice.Methods 60 BALB/c mice were randomly divided into control group, model group, low dose group and high dose group （15 mice in each group）. Model group, low dose group and high dose group of mice by intraperitoneal injection of caerulein 50 g/kg, 1/h, a total of 7 times to establish the model of acute pancreatitis. Mice in low dose group and high dose group were intraperitoneally injected with 25 and 75 μg/kg Bafiomycin A1. Mice in the control group and model group were injected with equal volume of normal saline intraperitoneally. Mice in four groups were sacrificed in 24 h after treatment. Serum amylase in mice （AMY）, inflammatory factor tumor necrosis factor-α （TNF-α） and interleukin （IL）-6 were analyzed by enzyme linked immunosorbent assay （ELISA）. The mouse pancreatic lesions and score （Schmidt score） were analyzed by hematoxylin and eosin （HE） staining. autophagy substrate p62 and microtubule-associated protein 1 light chain 3 （LC3） were detected by Western blotting. The pancreatic tissue p62 were analyzed by immunofluorescence.Results Compared with the model group [（4 910.98±349.43） U/L, （109.43±10.43） pg/L, （329.16±20.91） pg/L, 9.43±3.98], the AMY, TNF-α, IL-6 and Schmidt scores of the low dose group [（3 109.13±301.44） U/L, （80.18±9.34） pg/L, （215.32±18.43） pg/L, 6.48±3.18] and the high dose group [（1 432.33±187.43） U/L, （45.19±8.14） pg/L, （153.22±12.63） pg/L, 3.14±1.02] significantly decreased （P=0.000）. Compared with the low dose group, the AMY, TNF-α, IL-6 and Schmidt scores of the high dose group more significantly decreased. Compared with model group （0.15±0.06, 0.56±0.06）, p62 and LC3 in pancreatic tissue of mice in low dose group （0.39±0.09, 0.75±0.09） and high dose group （0.61±0.07, 0.99±0.08） obviously enhanced （P=0.000）. Compared with the low dose group, the accumulation of p62 and LC3 in the pancreatic tissue of the high dose group more obviously accumulated （P=0.000）.Conclusion Bafiomycin A1 can significantly inhibit the level of autophagy in pancreatic tissue of mice with acute pancreatitis and play a protective role in pancreatic tissue.