蓝莓对小鼠急性酒精性脂肪肝TNF-α-R1和SREBP-1c影响的初步研究

Effects of blueberry on the expression of TNF-α-R1 and SREBP-1c in acute alcoholic fatty liver

摘要:

目的：观察蓝莓对急性酒精性脂肪肝（alcoholic fatty liver，AFL）小鼠肝组织中肿瘤坏死因子-α-受体1（tumor necrosis factor-α-recepter1，TNF-α-R1）、胆固醇调节元件结合蛋白（sterol regulatory element-binding protein，SREBP）-1c mRNA及蛋白表达的影响。方法：50只C57BL/6雄性小鼠随机分为空白组、模型组、蓝莓汁高剂量组（20.0 g/kg）、蓝莓汁低剂量组（10.0 g/kg）、硫普罗宁组（30 mg/kg），每组10只。除空白组外，其余各组小鼠分别予Lieber-DeCarli酒精饲料喂饲，蓝莓汁高、低剂量组及硫普罗宁组同时分别予相应剂量蓝莓汁或硫普罗宁灌胃1次/d，连续15 d，第16天给予1次乙醇灌胃，建立急性AFL动物模型。全自动生化分析仪测定血清丙氨酸氨基转移酶（alanine transaminase，ALT）、天冬氨酸氨基转移酶（aspartate transaminase，AST）、甘油三酯（triglycerides，TG）及胆固醇（cholesterol，TC），酶联免疫吸附法检测血清TNF-α，光镜下观察小鼠肝脏病理学变化，RT-PCR、Western blot检测小鼠肝组织中TNF-α-R1、SREBP-1c mRNA及蛋白质表达。结果：蓝莓汁高、低剂量组和硫普罗宁组小鼠血清ALT分别为（67.70±5.86）、（81.66±4.93）、（63.49±3.27） U/L，AST分别为（184.46±14.57）、（214.45±22.03）、（169.16± 18.52） U/L，TG分别为（0.88±0.06）、（1.22±0.08）、（0.81±0.09） mmol/L，TC分别为（2.30±0.13）、（2.74±0.10）、（2.21±0.16） mmol/L，TNF分别为（49.14±6.14）、（66.55±5.67）、（44.68±5.39） ng/L，均显著低于模型组（P=0.000或P=0.025），肝细胞病理学改变明显轻于模型组（P=0.000）；蓝莓汁高、低剂量组和硫普罗宁组小鼠肝组织TNF-α-R1 mRNA表达分别为100.44±9.51、132.70±8.07、94.02±6.05，蛋白表达分别为0.52±0.04、0.72±0.04、0.49±0.04，SREBP-1c mRNA表达分别为133.52±5.91、174.51±10.62、129.83±9.83，蛋白表达分别为0.26±0.05、0.41±0.03、0.23±0.05，均明显低于模型组（均P=0.000）。结论：蓝莓能改善小鼠急性AFL，可能与下调其肝组织TNF-α-R1与SREBP-1c的表达有关。

Abstract:

Objective：To observe the effect of blueberry on the mRNA and protein expression of tumor necrosis factor（TNF）-α-R1 and sterol regulatory element-binding protein（SREBP）-1c in acute alcoholic fatty liver（AFL）. Methods：A total of 50 male C57BL/6 mice were randomly divided into normal control group（A），model group（B），high dose blueberry group（20.0 g/kg）（C），low dose blueberry group（10.0 g/kg）（D），and tiopronin group（30 mg/kg）（E），10 in each group. All mice except those in group A were fed with the Lieber-DeCarli diet for 15 d and were gastrogavaged with alcohol on the 16th day to induce AFL model. Mice in groups C－E were respec－tively administered with corresponding drugs by gastrogavage，once per day for 15 d. Detection of alanine transaminase（ALT），aspar－tate transaminase（AST），triglycerides（TG） and cholesterol（TC） in serum were performed by an automatic biochemical analyser. The level of TNF-α in serum was determined by an enzyme-linked immunosorbent assay. The morphological changes of the liver tissue were observed by HE staining. The mRNA and protein expressions of TNF-α-R1 and SREBP-1c in the liver tissue were determined by RT-PCR and Western blot，respectively. Results：Compared with those in group B，the levels of ALT，AST，TG，TC and TNF-α in serum were significantly lower（P=0.000 or P=0.025），the degree of hepatic steatosis and degen－erative necrosis were significantly improved in groups C－E（P=0.000），and the mRNA and protein expression of TNF-α-R1 and SREBP-1c were significantly lower in groups C－E（all P=0.000）. Conclusion：Blue berry has a good protective effect on acute AFL in mice，the mechanism is probably related to the inhibition of the expression of TNF-α-R1 and SREBP-1c.