Glucose uptake and lactate production in cells exposed to CoCl2 and in cells overexpressing the Glut-1 glucose transporter
Glucose uptake and lactate production in cells exposed to CoCl2 and in cells overexpressing the Glut-1 glucose transporter
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DOI：
10.1006/abbi.2002.2758
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发表时间：
2002-03-15
影响因子：
3.9
通讯作者：
Ismail-Beigi, F
中科院分区：
文献类型：
--
作者：
Hwang, DY;Ismail-Beigi, F
Glut-1介导的葡萄糖转运响应于各种条件和刺激而增强。在这项研究中，我们研究了葡萄糖在细胞中的代谢命运，其中葡萄糖转运被暴露于氯化钴刺激，一种刺激一组缺氧反应基因，包括几个糖酵解酶和Glut-1葡萄糖转运蛋白的表达的试剂。类似地，我们确定了葡萄糖在稳定转染过表达Glut-1的细胞中的代谢命运。将克隆9肝细胞系、3 T3-L1成纤维细胞和C2 C12成肌细胞暴露于CoCl 2导致葡萄糖摄取增加以及葡萄糖磷酸化（“己糖激酶”）和乳酸脱氢酶的活性增加。在用氯化钴处理的细胞中，葡萄糖摄取的净增加是由于其几乎完全转化为乳酸。稳定转染过表达Glut-1的细胞也表现出葡萄糖净摄取增强，增加的葡萄糖几乎完全转化为乳酸;然而，在这些细胞中观察到的效果是在两种糖酵解酶活性没有任何变化的情况下观察到的。这些发现表明，在葡萄糖转运是葡萄糖代谢限速的细胞中，葡萄糖进入步骤本身的增强导致额外的葡萄糖几乎完全转化为乳酸。(C)2002 Elsevier Science（美国）。
Glut-1-mediated glucose transport is augmented in response to a variety of conditions and stimuli. In this study we examined the metabolic fate of glucose in cells in which glucose transport is stimulated by exposure to CoCl2 an agent that stimulates the expression of a set of hypoxia-responsive genes including several glycolytic enzymes and the Glut-1 glucose transporter. Similarly, we determined the metabolic fate of glucose in stably transfected cells overexpressing Glut-1. Exposure of Clone 9 liver cell line, 3T3-L1 fibroblasts, and C2C12 myoblasts to CoCl2 resulted in an increase glucose uptake and in the activity of glucose phosphorylation ("hexokinase") and lactate dehydrogenase. In cells treated with CoCl2 the net increase in glucose taken up was accounted for by its near-complete conversion to lactate. Cells stably transfected to overexpress Glut-1 also exhibited enhanced net uptake of glucose with the near-complete conversion of the increased glucose taken up to lactate; however, the effect in these cells was observed in the absence of any change in the activity of two glycolytic enzymes examined. These findings suggest that in cells in which glucose transport is rate-limiting for glucose metabolism, enhancement of the glucose entry step per se results in a near-complete conversion of the extra glucose to lactate. (C) 2002 Elsevier Science (USA).