摘要
目的观察脂多糖(LPS)刺激大鼠胰岛细胞的氧化应激和凋亡情况,探讨α-硫辛酸(α-LA)对LPS诱导大鼠胰岛B细胞氧化应激和凋亡的作用。方法对照组予磷酸盐缓冲液(PBS),LPS不同质量浓度处理组(LPS 0.01组、LPS 0.1组、LPS 1组、LPS 5组、LPS 10组)分别予LPS 0.01、0.1、1、5、10μg/mL,α-LA+LPS组予α-LA 4μg/mL预处理1h后加入LPS 10μg/mL,分别刺激刚分离的大鼠胰岛。采用四甲基偶氮唑盐(MTT)法检测胰岛B细胞活力,以2’,7’-二氢二氯荧光素二乙酸酯(DCFH-DA)为荧光探针检测胰岛氧化应激的状态,应用流式细胞仪检测细胞凋亡率。结果不同质量浓度的LPS处理大鼠胰岛24h后,仅LPS10组的光密度值显著低于对照组(P<0.05);不同LPS质量浓度处理组大鼠胰岛B细胞产生的活性氧自由(ROS)呈剂量依赖性增多(r=0.95,P<0.01),胰岛B细胞凋亡率亦呈剂量依赖性升高(r=0.87,P<0.01)。LPS 1组、LPS 5组、LPS 10组的平均荧光强度(MFI),以及LPS 5组、LPS 10组的胰岛B细胞凋亡率均显著高于对照组(P值均<0.01);而α-LA+LPS组的MFI、胰岛B细胞凋亡率均显著低于LPS 10组(P值分别<0.05、0.01)。结论一定质量浓度范围内的LPS刺激抑制胰岛B细胞活力,可诱导大鼠胰岛发生氧化应激和细胞凋亡,α-LA可以降低LPS诱导的ROS产生并抑制胰岛B细胞的凋亡。
Objective To observe the oxidative stress and apoptosis induced by lipopolysaccharide （LPS） in islet cells of rats, and to explore the protective effects of α-lipoic acid （α-LA）. Methods Phosphate buffer saline （PBS, control group）, different concentrations of LPS （0.01, 0.1, 1, 5, and 10μg/mL）, and α-LA -I-LPS （4 μg/mL -LA pretreatment 1 h before LPS intervened） were applied in pancreatic islet of rats, respectively. The viability of pancreatic B-cells was detected by 3-（4, 5）-dimethylthiahiazo （-z-y1）-3, 5- diphenytetrazoliumromide （MTT） method. Oxidative stress was measured by 2 ’, 7’-dichlorofluorescin diacetate （DCFH-DA） as a fluorescent probe. Flow cytometry was used to detect apoptosis. Results The optical density value of 10μg/mL LPS group was significantly lower than that in PBS control group 24 h after treatment （P〈 0.05）. The reactive oxygen species （ROS） production and apoptosis rate increased in a dose-dependent manner after treatment with various concentrations in pancreatic cells （correlation coefficient respectively was 0.95 and 0.87, both P〈0.01）. Compared with PBS control group, the mean fluorescent intensity （MFI） in 1, 5 and 10 μg/mL LPS groups and the apoptosis rate of pancreatic cells in 5 and 10 μg/mL LPS groups were significantly increased （all P〈0.01）. However, the MFI （P〈0. 05） and apoptosis rate （P〈0.01） of α-LA＋ LPS group were significantly lower than those of 10 μg/mL LPS group. Conclusion Certain concentrations of LPS can induce oxidative stress and apoptosis, and inhibit cell viability, α-LA may protect pancreatic β-cells from LPS induced oxidative stress and inhibit cell apoptosis.
出处
《上海医学》
CAS
CSCD
北大核心
2014年第9期751-754,I0001,共5页
Shanghai Medical Journal
基金
国家自然科学基金(81000354)
上海市自然科学基金(14ZR1427000)资助项目
关键词
氧化应激
脂多糖
胰岛B细胞
凋亡
Α-硫辛酸
Oxidative stress
Lipopolysaccharide
Pancreatic β-cells
Apoptosis； α-lipoic acid
