适量酒精对棕榈酸引起的胰岛β细胞功能损伤的保护作用

Protective effects of moderate ethanol consumption on β-cell dysfunction induced by palmitate

目的观察酒精、棕榈酸对胰岛β细胞(INS-1细胞)功能的影响。方法 INS-1细胞分为对照组、20 mmol/L酒精(模拟适量饮酒)组、100 mmol/L酒精(模拟大量饮酒)组、0.2 mmol/L棕榈酸(PA)组、PA+20 mmol/L酒精组以及PA+100 mmol/L酒精组。作用48 h后,采用放射免疫法检测糖刺激胰岛素的释放量,Westernblotting检测胰腺十二指肠同源异型盒因子1(PDX-1)、葡萄糖转运蛋白2(GLUT2)和磷酸化腺苷酸活化蛋白激酶(AMPK,包括T-AMPK和P-AMPK)蛋白水平。结果①与对照组相比,20 mmol/L酒精对INS-1细胞无显著影响(P>0.05);100 mmol/L酒精组和PA组均下调了INS-1细胞PDX-1、GLUT2蛋白水平和胰岛素释放量(P均<0.05)。相对于单独PA组,20 mmol/L酒精和PA合用时显著增加细胞PDX-1、GLUT2蛋白水平和胰岛素释放量(P均<0.05)。100 mmol/L酒精和PA合用时则未出现这种现象(P>0.05);②与对照组相比,20 mmol/L酒精对细胞AMPK表达和活化无明显影响(P>0.05);100 mmol/L酒精仅仅下调AMPK表达(P<0.05);PA同时下调AMPK表达和活化(P<0.05)。当20 mmol/L酒精和PA合用时,可以改善由PA引起的AMPK表达和活化的下调(P<0.05);而100 mmol/L酒精与PA合用组则无明显变化(P>0.05)。结论大量酒精和PA均能损害INS-1细胞功能;适量酒精(20 mmol/L酒精)能够改善由棕榈酸引起的胰岛β细胞功能损伤。

Objective To observe the effects of ethanol,palmitate or combined on pancreatic β-cells,INS-1 cells.Methods INS-1 cells were divided into six groups： the control group,the 20 mmol/L ethanol treatment group（to mimic moderate drinking）,the 100 mmol/L ethanol treatment group（to mimic heavy drinking）,the palmitate（PA） treatment group,PA ＋20 mmol/L ethanol treatment group,and the PA ＋100 mmol/L ethanol treatment group.Incubated for 48 hours,all cells were tested by radioimmunoassy（RIA） for insulin secretion,Western blotting for protein expression of Pancreas Duodenum Homeobox-1（PDX-1）,Glucose Transporter 2（Glut2） and AMP-activated Protein Kinase（AMPK）（including T-AMPK and P-AMPK） were used.Results ① Compared with the control,the 20 mmol/L ethanol treatment showed no obvious effect on INS-1 cells（P〉0.05）,while 100 mmol/L ethanol and PA treatment decreased PDX-1 and GLUT2 expression as well as insulin secreting content（all P〈0.05）.In contrast to the PA treatment,combined PA and 20 mmol/L ethanol treatment significantly increased PDX-1 and GLUT2 expressions as well as insulin secreting content（all P〈0.05）,while combined PA and 100 mmol/L ethanol treatment did not exhibit such effects（P〉0.05）.② Compared with the control,20 mmol/L ethanol demonstrated no effect on AMPK,total protein expression or activation（P〉0.05）.The 100 mmol/L ethanol treatment only decreased the T-AMPK level（P〈0.05） and PA treatment reduced both expression and activation of AMPK（P〈0.05）.Compared with the PA treatment,PA＋20 mmol/L ethanol treatment remarkably increased the level of T-AMPK and the ratio of p-AMPK to T-AMPK（P〈0.05）,while PA＋100 mmol/L ethanol treatment displayed no obvious discrepancy（P〉0.05）.Conclusions Large amounts of ethanol and palmitate can damage INS-1 cell function.Moderate ethanol（20 mmol/L） can ameliorate impairments of pancreatic β cell function caused by palmitate.