重组腺病毒对小鼠肝脏能量代谢的影响

Hepatic energy metabolism of mouse infected by recombinant adenovirus

目的 :探讨重组腺病毒感染小鼠肝脏后,对肝脏的能量代谢和氧化应激水平的影响。方法 :将Balb/c小鼠随机分为正常组及重组腺病毒感染组,通过小鼠尾静脉注射含编码绿色荧光蛋白(GFP)外源基因的重组腺病毒,利用荧光显微镜观察GFP在肝脏的表达水平;检测血浆中丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、葡萄糖、胆固醇、甘油三酯、β-羟丁酸(β-HB)、成纤维细胞生长因子(FGF-21)、丙二醛(MDA)等水平;测定肝脏糖原含量;检测肝脏组织中参与糖异生、脂质合成、脂肪酸氧化等基因的表达水平。结果:重组腺病毒主要在小鼠肝脏表达,并于注射后第5天表达最高。与对照组小鼠比较,重组腺病毒感染小鼠的血浆中ALT、AST明显升高,β-HB和FGF-21呈升高趋势。Real-time PCR检测发现,重组腺病毒感染小鼠的肝脏组织中,参与糖异生及脂质合成的基因m RNA水平明显降低,而脂肪酸氧化相关基因的m RNA水平明显升高。此外,重组腺病毒感染后,小鼠血浆MDA及肝脏中氧自由基产生基因的表达水平明显增高。结论:小鼠肝脏在感染重组腺病毒后,糖异生及脂质合成能力下降,而脂肪酸氧化增强。这种能量代谢的改变可能与重组腺病毒感染引起的氧化应激有关。

Objective：To study the alterations of energy metabolism and oxidative stress in mouse liver after infection of recombinant adenovirus. Methods：Seven-week-old male Balb/c mice were randomly assigned to control and adenovirus infection groups. Recombinant adenovirus encoding green fluorescent protein （GFP） or phosphate-buffered saline（PBS） was delivered by tail vein injection. Tissue distribution of GFP was determined by fluorescence microscopy. The levels of alanine transaminase （ALT）, aspartate amino transferase （AST）,glueose,cholesterol,triglyeeride,~3-hydroxybutyrate （13-HB）,fibroblast growth factor-21（FGF-21） and malondialdehyde（MDA） in plasma as well as hepatic glucogen contents were detected 5 days after injection. Hepatic expressions of genes involved in gluconeogenesis,lipogenesis and fatty acid oxidation were examined by quantitative real-time PCR. To determine the oxidative stress levels in mice, MDA in blood and hepatic mRNA expression levels of reactive oxygen species （ROS）-generating or antioxidant genes were also examined. Results：The expression of GFP delivered by tail vein injection was mainly in the liver of mice,with the highest levels at 5 days after injection. Compared with the control mice, adenovirus infection led to an obvious increase of ALT and AST in plasma of mice in the adenovirus infection group. The levels of f3-HB and FGF-21 were also elevated. Analysis of the liver transcripts indicated that genes implicated in fatty acid oxidation were increased while those involved in lipogenesis and gluconeogenesis pathways were suppressed by adenovirus infection. Besides ,hepatic levels of ROS were also increased. Conclusion： Our findings indicate that adenovirus infection improved fatty acid oxidation and inhibited glueoneogenesis and lipogenesis. The alterations of energy metabolism may be mediated by the increased oxidative stress in liver after adenovirus infection.