细胞凋亡在大鼠酒精和高脂饮食诱导的脂肪性肝病中的作用

The apoptosis and expression of caspase-3 of hepatocytes in alcohol and/or high fat diet-induced fatty liver disease in rats

目的探讨在实验性脂肪性肝病动物模型中肝细胞凋亡的作用。方法雄性Wistar大鼠46只,分为对照组、酒精组、高脂组和高脂加酒精组。制模成功后取血测血清ALT、AST、CHO、TG、FFA;PCR法和免疫组化法测定肝组织caspase-3的基因与蛋白表达;TUNEL法测定肝细胞凋亡指数;电镜下观察肝细胞凋亡情况。结果酒精组、高脂组、酒精加高脂组细胞凋亡指数分别为2.16±0.43、2.33±0.60和3.93±0.80,显著高于正常对照组(1.070.27,P<0.05);实验组caspase-3无论是基因还是蛋白表达均较对照组升高(P<0.05),其中以酒精加高脂组增加最明显。析因分析显示,加用与不加用酒精或高脂饮食对caspase-3及其基因表达有显著性影响(P=0.00);高脂饮食与酒精交互效应显著(P<0.05)。结论酒精和高脂均能诱导肝细胞发生凋亡,同时酒精和高脂同时作用于肝脏加重肝细胞caspase-3的表达,两者具有协同损伤肝脏的作用。

Objective To study the apoptosis and expression of caspase-3 of hepatocytes in alcohol and/or high fat diet-induced fatty liver disease in rats. Methods Forty-six male Wistar rats were randomly divided into control, alcohol, fat-rich diet and alcohol/fat-rich diet group and fatty liver disease model was made by feeding alcohol and/or fat-rich diet. The serum AST, ALT, CHO,TG and FFA were detected. the expression of caspase-3 mRNA and caspase-3 protein in hepatic tissues was assayed by RT-PCR and by immunohistochemistry, respectively the apoptosis was detected by TdT- mediated x-dUTP nick end labeling and ultrastructural observation. Results The serum ALT and AST in experiment groups were increased （P〈0.05）. The apoptosis index in alcohol, fat-rich diet and alcohol/fat-rich diet group were 2.16 ± 0.43, 2.33±0.60, 3.93 ± 0.80, much higher than that in control group （ 1.07±0.27, P〈0.05 ）. The expression of caspase-3 protein and mRNA was significantly increased in the liver tissues of rats with fatty liver disease, and the highest expression was found in alcohol /fat-rich group （P〈0.01）. Factorial analysis indicated that alcohol and high fat diets had positive effect on expression of caspase-3 mRNA （P=0.00）. Conclusion Alcohol and fat-rich diets can induce the apoptosis of hepatocyte, which might aggravate the injury of liver.