Impaired adaptive resynthesis and prolonged depletion of hepatic mitochondrial DNA after repeated alcohol binges in mice
Impaired adaptive resynthesis and prolonged depletion of hepatic mitochondrial DNA after repeated alcohol binges in mice
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DOI：
10.1053/gast.2002.35952
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发表时间：
2002-10-01
期刊：
影响因子：
29.4
通讯作者：
Fromenty, B
中科院分区：
文献类型：
--
作者：
Demeilliers, C;Maisonneuve, C;Fromenty, B
背景和目标：单剂量的酒精会导致小鼠短暂的肝线粒体DNA（mtDNA）耗竭，随后是mtDNA合成增加和mtDNA水平过冲。我们确定了反复酗酒对小鼠肝脏mtDNA的影响。研究方法：乙醇（5 g/kg），每天通过胃插管给药4天，并通过狭缝印迹杂交，在细胞器[H-3]脱氧胸苷三磷酸掺入，和长聚合酶链反应分析，分别评估mtDNA水平，合成和完整性。结果如下：在最后一次注射后48小时内mtDNA水平下降，之后没有过冲现象。在第四次注射后2小时和24小时，长聚合酶链反应实验显示DNA损伤阻断了聚合酶的进展，并且在细胞器中mtDNA合成减少，尽管DNA聚合酶γ活性在合成模板中没有变化。线粒体表现出超微结构异常，呼吸受损后2和24小时第四狂欢。细胞色素P450 2 E1，线粒体产生的过氧化物，硫代巴比妥酸反应物，和乙烷呼气增加。结论：在重复剂量的乙醇后，未修复的mtDNA损伤（可能涉及脂质过氧化诱导的加合物）的积累阻断了mtDNA上的聚合酶γ的进展，并阻止了适应性mtDNA再合成，导致肝mtDNA长期耗竭。
Background & Aims: A single dose of alcohol causes transient hepatic mitochondrial DNA (mtDNA) depletion in mice followed by increased mtDNA synthesis and an overshoot of mtDNA levels. We determined the effect of repeated alcohol binges on hepatic mtDNA in mice. Methods: Ethanol (5 g/kg) was administered by gastric intubation daily for 4 days, and mtDNA levels, synthesis, and integrity were assessed by slot blot hybridization, in organello [H-3]deoxythymidine triphosphate incorporation, and long polymerase chain reaction analysis, respectively. Results: mtDNA levels were decreased for 48 hours after the last dose, with no overshoot phenomenon later on. Two and 24 hours after the fourth dose, long polymerase chain reaction experiments showed DNA lesions that blocked the progress of the polymerases and in organello mtDNA synthesis was decreased, although DNA polymerase gamma activity was unchanged with synthetic templates. Mitochondria exhibited ultrastructural abnormalities, and respiration was impaired 2 and 24 hours after the fourth binge. Cytochrome P450 2E1, mitochondrial generation of peroxides, thiobarbituric acid reactants, and ethane exhalation were increased. Conclusions: After repeated doses of ethanol, the accumulation of unrepaired mtDNA lesions (possibly involving lipid peroxidation-induced adducts) blocks the progress of polymerase gamma on mtDNA and prevents adaptive mtDNA resynthesis, causing prolonged hepatic mtDNA depletion.