Role of 5′-AMP-activated protein kinase in stimulation of glucose transport in response to inhibition of oxidative phosphorylation
Role of 5′-AMP-activated protein kinase in stimulation of glucose transport in response to inhibition of oxidative phosphorylation
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DOI：
10.1152/ajpcell.00321.2005
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发表时间：
2006-02-01
影响因子：
5.5
通讯作者：
Ismail-Beigi, F
中科院分区：
文献类型：
--
作者：
Jing, M;Ismail-Beigi, F
葡萄糖转运在多种细胞和组织中响应于氧化磷酸化的抑制而被刺激。然而，基本的机制和调解步骤仍然在很大程度上是未知的。在本研究中，我们首先测试了细胞本身的氧化还原状态的降低以及由此产生的活性氧（ROS）的增加是否会刺激葡萄糖转运。将克隆9细胞（表达促进性葡萄糖转运蛋白的Glut 1同种型）暴露于叠氮化物、乳酸盐和乙醇1 h。尽管所有三种药物都刺激葡萄糖转运，增加细胞NADH与NAD（+）的比率和磷酸化ERK 1/2，表明ROS产生增加，但对刺激的反应不被N-乙酰基-L-半胱氨酸（一种对抗ROS的药物）阻断;此外，对叠氮化物的反应不被二酰胺（一种细胞内巯基氧化剂）阻断。然后，我们发现细胞AMP与ATP和ADP与ATP的比率增加，并且5 '-AMP活化的蛋白激酶（AMPK）被所有三种试剂刺激，如AMPK和乙酰辅酶A羧化酶的磷酸化增加所证明的。我们的结论是，虽然叠氮化物，乳酸，乙醇增加NADH-NAD（+）的比例和ROS的生产，他们对葡萄糖转运的刺激作用是不介导的ROS的产生增加。然而，这三种药物都增加了细胞AMP与ATP的比率，并刺激了AMPK，这使得后一种途径可能在葡萄糖转运反应中起重要作用。
Glucose transport is stimulated in a variety of cells and tissues in response to inhibition of oxidative phosphorylation. However, the underlying mechanisms and mediating steps remain largely unknown. In the present study we first tested whether a decrease in the redox state of the cell per se and the resultant increase in generation of reactive oxygen species (ROS) lead to stimulation of glucose transport. Clone 9 cells ( expressing the Glut1 isoform of facilitative glucose transporters) were exposed to azide, lactate, and ethanol for 1 h. Although all three agents stimulated glucose transport and increased cell NADH-to-NAD(+) ratio and phospho-ERK1/2, signifying increased ROS generation, the response to the stimuli was not blocked by N-acetyl-L-cysteine ( an agent that counteracts ROS); moreover, the response to azide was not blocked by diamide ( an intracellular sulfhydryl oxidizing agent). We then found that cell AMP-to-ATP and ADP-to-ATP ratios were increased and 5'-AMP-activated protein kinase ( AMPK) was stimulated by all three agents, as evidenced by increased phosphorylation of AMPK and acetyl-CoA carboxylase. We conclude that although azide, lactate, and ethanol increase NADH- to-NAD(+) ratios and ROS production, their stimulatory effect on glucose transport is not mediated by increased ROS generation. However, all three agents increased cell AMP-to-ATP ratio and stimulated AMPK, making it likely that the latter pathway plays an important role in the glucose transport response.