Decrease of intracellular ATP content downregulated UCP2 expression in mouse hepatocytes
Decrease of intracellular ATP content downregulated UCP2 expression in mouse hepatocytes
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DOI：
10.1016/s0006-291x(03)01409-8
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发表时间：
2003-08-29
影响因子：
3.1
通讯作者：
Chavin, KD
中科院分区：
文献类型：
--
作者：
Cheng, G;Polito, CC;Chavin, KD
线粒体解偶联蛋白2（UCP2）在调节能量代谢中发挥着重要作用。我们之前报道过，脂肪变性肝脏中 UCP2 表达增加，导致肝脏 ATP 储存减少，并使脂肪变性肝细胞容易受到缺血性损伤。在本研究中，使用抑制 ATP 产生的试剂来模拟肝脏缺血状态，以研究细胞内 ATP 水平降低对鼠肝细胞系 (HEP6-16) 中 UCP2 表达的影响。羰基氰化物对三氟甲氧基苯腙 (FCCP) 是一种氧化磷酸化解偶联剂，被发现能以剂量和时间依赖性方式降低细胞内 ATP 水平。需要相对较高浓度的 FCCP（8 至 80 μM）来降低细胞内 ATP 浓度。 2-脱氧-D-葡萄糖显着增强了 FCCP 对细胞内 ATP 的抑制作用，2-脱氧-D-葡萄糖是一种糖酵解抑制剂，单独给药时对小鼠肝细胞中的细胞 ATP 水平没有负面影响。细胞内 ATP 水平降低伴随着 UCP2 mRNA 表达降低。去除 FCCP 和/或 2-脱氧-D-葡萄糖并用正常培养基重新培养后，ATP 和 UCP2 mRNA 水平在几小时内恢复正常。 HEP6-16细胞中的线粒体膜电位被80μM FCCP驱散，但8μM FCCP则没有，这表明FCCP对UCP2表达的下调与线粒体电位变化无关。因此，ATP 储存的体外操作与缺血/再灌注损伤相关的体内观察结果是一致的。 (C) 2003 Elsevier Inc. 保留所有权利。
Mitochondrial uncoupling protein 2 (UCP2) plays an important role in regulating energy metabolism. We previously reported that UCP2 expression in steatotic livers is increased which leads to diminished hepatic ATP stores and renders steatotic hepatocytes vulnerable to ischemic damage. In this study, reagents that inhibit the production of ATP were used to mimic an ischemic state in the liver in order to investigate the effects of decreased intracellular ATP levels on UCP2 expression in a murine hepatocyte cell line (HEP6-16). Carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP), an oxidative phosphorylation uncoupler, was found to decrease intracellular ATP levels in a dose- and time-dependent manner. Relatively high concentrations of FCCP from 8 to 80 muM were required to reduce the intracellular concentration of ATP. The inhibitory effect of FCCP on intracellular ATP was significantly potentiated by 2-deoxy-D-glucose, an inhibitor of glycolysis that when administered alone had no negative effect on cellular ATP levels in mouse hepatocytes. Decreased intracellular ATP levels were accompanied by lower UCP2 mRNA expression. Upon removal of FCCP and/or 2-deoxy-D-glucose and reculture with normal medium, ATP and UCP2 mRNA levels returned to normal within a few hours. Mitochondrial membrane potential in HEP6-16 cells was dissipated by 80 muM FCCP but not 8 muM FCCP, suggesting that the downregulation of UCP2 expression by FCCP was not related to mitochondrial potential changes. Consequently, the in vitro manipulation of ATP stores is consistent with the in vivo observations associated with ischemia/reperfusion injury. (C) 2003 Elsevier Inc. All rights reserved.