二氢杨梅素抑制高脂喂养小鼠肝脏脂肪蓄积与线粒体融裂基因变化的关系

目的 探讨肝脏线粒体融裂相关基因表达变化在二氢杨梅素抑制高脂喂养小鼠肝脏脂肪蓄积中的可能作用.方法 45只6周龄C57BL/6J雄性小鼠,按随机数表法分为普通饲料组(CON),高脂饲料组(HFD)和高脂加二氢杨梅素组(HFD+ DHM),每组15只,干预12周.检测小鼠体质量、肝脏指数、血清生化指标;分别采用HE染色和油红O染色观察肝细胞脂肪变性和脂滴数量与形态.使用增强型ATP试剂盒检测肝脏ATP含量;采用荧光定量PCR和Western blot分别检测肝脏线粒体融合与分裂相关基因动力相关蛋白1(dynamin-related protein 1,Drp1)、分裂蛋白1(fission 1,Fis1)、融合蛋白2(mitofusion 2,Mfn2)、视神经萎缩蛋白1(optic atrophy1,Opa1)]的mRNA及蛋白表达.结果 与CON组相比,HFD组小鼠体质量、肝脏指数、空腹血糖、空腹胰岛素水平、甘油三酯、总胆固醇、低密度胆固醇明显增高(P＜0.05),肝脏ATP含量显著降低(P＜0.05),HE染色见明显的肝内脂肪空泡和肝细胞气球样变,油红O染色见大量的脂滴蓄积,肝脏组织Fis1、Drp1 mRNA和蛋白表达显著增高(P＜0.05),而Mfn2、Opa1明显降低(P＜0.05).二氢杨梅素干预显著抑制高脂喂养诱导的肝脏指数、空腹血糖、空腹胰岛素和血甘油三酯的升高,肝脏脂肪蓄积以及肝脏ATP含量的降低,并且明显拮抗高脂诱导的线粒体分裂与融合基因mRNA和蛋白的表达水平变化.结论 二氢杨梅素可明显改善高脂喂养小鼠肝脏的脂肪蓄积,该效应可能与其调节肝脏线粒体的融合与分裂有关.

Relationship of mitochondrial fusion/fission genes with dihydromyricetin inhibiting liver fat accumulation in high-fat fed mice

Objective To investigate the role of the hepatic mitochondrial fusior/fission-related genes in the dihydromyricetin (DHM)-induced inhibition of liver fat accumulation in mice after high-fat diet(HFD).Methods Forty-five male C57BL/6J mice (6 weeks old) were randomly divided into control group (CON),HFD group (HFD) and HFD with DHM treatment (HFD + DHM),with 15 mice per group.After 12 weeks,the body weight,hepatic index and serum biochemical indexes were detected.HE and oil red Ostaining were applied to observe the changes of hepatic steatosis and lipid droplets accumulation.The ATP production was measured by an enhanced ATP detecting kit.The mRNA and protein levels of mitochondrial fusion/fission genes,fission 1 (Fis1),dynamin-related protein 1 (Drp1),mitofusion 2 (Mfn2) and optic atrophy1 (Opa1) were determined by PCR and Western blotting.Results HFD significantly increased body weight,hepatic index,fasting glucose,fasting insulin,triglyceride,total cholesterol and low density lipoprotein (P ＜ 0.05),while decreased the ATP production (P ＜ 0.05).HE staining displayed notable intrahepatic fat vacuoles and hepatocyte balloon-like changes in the liver of HFD mice.And oil red O staining showed more fat droplets in HFD mice.The mRNA and protein levels of hepatic Fis1 and Drp1 were significantly increased (P ＜ 0.05),while those of Mfn2 and Opa1 were dominantly decreased in HFD group (P ＜0.05).However,DHM treatment could significantly reverse all above changes induced by HFD (P ＜0.05).Conclusion DHM attenuates lipid accumulation in the HFD mice,which may be related to its regulation on mitochondrial fusion/fission functions.