探讨不同多不饱和脂肪酸饮食对载脂蛋白E(apoE)缺失小鼠含apoB100脂蛋白代谢的影响.2月龄雄性载脂蛋白E缺失小鼠添加2%紫苏籽油或红花油饮食干预6周,检测其血脂和血清apoB100水平;测定肝脏组织中HMG-Co A还原酶活性;使用实时定量PCR分析肝组织中含apoB100脂蛋白代谢相关基因表达;蛋白质印迹(Western blot)检测PPARα蛋白表达;油红O染色检测肝细胞中脂质积累.结果显示,紫苏籽油饮食干预可降低血清LDL-C和apoB100水平,降低肝组织中HMG-Co A还原酶活性以及apoB100、FAS、HMG-Co AR、ACAT2、LRP、LDLR和SREBP-1c基因mRNA的表达,显著升高转录因子PPARα的mRNA和蛋白质水平,明显降低肝脏中脂质沉积.而红花油饮食干预后升高了小鼠血清甘油三酯和高密度脂蛋白胆固醇以及肝脏apoB100的mRNA表达水平,降低PPARα的mRNA和蛋白质水平,明显促进肝脏中脂质积累.结果提示在饮食中添加紫苏籽油可有效降低含apoB100脂蛋白的代谢,对动脉粥样硬化以及脂肪肝等疾病有更好的保护作用,对于正常人群以及家族性Ⅲ型高脂蛋白血症患者的日常膳食提供理论依据.
To explore the polyunsaturated fatty acids (PUFAs) on the metabolism of apoB100-containing lipoproteins in apolipoprotein E deficient (apoE-/-) mice, which exists similar symptoms with human type Ⅲ familial hyperlipoproteinemia, two months old male apoE/ mice were fed the perilla seed oil or safflower oil diet and the control diet, respectively, for 6 weeks. Serum lipids, apoB 100 and hepatic HMG-CoA reductase were determined after 6 weeks intervention. The hepatic genes mRNA abundance involved in apoB100 containing lipoprotein metabolism were detected with real time RT-PCR. The hepatic PPARet protein expression was determined by Western blot. The hepatic lipid accumulation was detected by Oil Red O staining after frozen section. The results showed that the mice fed with the perilla seed oil diet decreased the serum LDL-C and apoB100 and HMG-CoA reductase activity. The hepatic genes such as FAS, apoB100, HMG-CoAR, ACAT2, LRP, LDLR and SREBP-1 c were decreased significantly compared with the control group. The mRNA and protein expression of PPARa increased significantly in mice fed the perilla seed oil diet, while decreased significantly in mice fed the safflower oil diet compared with the control group. The mice fed the safflower oil diet increased the serum triglyceride and HDL-C and the hepatic apoB100 mRNA level compared with the control group. The hepatic lipid accumulation was decreased in the mice fed the perilla seed oil diet, and was increased in the safflower oil diet compared with the control group. The results indicated that dietary perilla seed oil decreased obviously the metabolism of apoB 100-containing lipoprotein, which was benefit for the atherosclerosis and the fatty liver diseases, providing theoretical basis for the dietary of population and the human type Ⅲ familial hyperlipoproteinemia.