【摘要】 采用同位素示踪技术研究RNAi介导线粒体融合素基因-2(Mfn2)沉默小鼠体内物质代谢变化。构建了含Mfn2短发卡RNA(short hair RNA,shRNA)干扰质粒和阴性对照质粒。24只BALB/c小鼠分为转染组和阴性对照组,每组各12只,转染组经尾静脉注射Mfn2干扰质粒,对照组注入阴性对照质粒。质粒注入5 d后,将氚水(3H2O)或氚标记葡萄糖(3-3H-Glucose)经腹腔或尾静脉注射到小鼠体内,留取血标本和组织标本,用液体闪烁计数仪测定标本放射性浓度,计算小鼠组织脂肪酸合成率和肝脏葡萄糖生成率,两组间均数比较采用t检验。结果显示,Mfn2基因转染组小鼠肝脏葡萄糖生成率为49.43±16.31,明显高于阴性对照组的24.91±4.07(P<0.05),肝脏、肌肉、心脏、脂肪组织的脂肪酸合成率分别为0.10±0.00、9.12±1.90、1.18±0.28、11.11±1.31,显著低于阴性对照组0.79±0.07,70.52±13.95,53.88±9.90,45.43±5.91。以上结果表明,Mfn2基因在体内葡萄糖和脂肪酸代谢中起重要作用。更多还原

【Abstract】 In order to investigate the function of Mfn2,isotopic tracer technique was used to measure the changes of fatty acid synthesis and hepatic glucose production in Mfn2 gene silencing mice mediated by RNA interference.Mfn2 shRNA and negative control plasmid were constructed by using shRNA target finder program.Twenty-four mice were randomly divided into transfection and control group.In transfection group,mice were injected with Mfn2 shRNA plasmid by vena caudalis;and in control group,mice were injected with negative control plasmid by vena caudalis.5 days after injection,all mice were administered 3H-labeled glucose or 3H2O by vena caudalis or intraperitoneal injection.Then blood and tissue samples were taken at specific times.Radioactivity was measured in all samples with liquid scintillation counter.The rates of hepatic glucose production and fatty acid synthesis in vivo were calculated.The rate of hepatic glucose production was significantly elevated in Mfn2 gene silencing mice(49.43±16.31),compared with negative control mice(24.91±4.07),P<0.05.The rates of fatty acid synthesis in liver,muscle,heart,and adipose tissue(0.10±0.00,9.12±1.90,1.18±0.28 and 11.11±1.31,respectively) in transfection group,were significantly lower than that in control group(0.79±0.07,70.52±13.95,53.88±9.90 and 45.43±5.91).3H tracer study confirms that Mfn2 gene plays an important role in maintaining glucose and lipid homeostasis in vivo.更多还原