Maher F, Clark S, Harrison L C
Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Parkville, Victoria, Australia.
Mol Endocrinol. 1989 Dec;3(12):2128-35. doi: 10.1210/mend-3-12-2128.
We have used differentiated L6 myocytes to investigate the regulation of glucose transporter gene expression by insulin and insulin-like growth factor-1 (IGF-1). Chronic exposure to insulin (1 microM) or IGF-1 (10 nm) resulted in a 2- to 5-fold stimulation of 3H-2-deoxy-D-glucose uptake and a corresponding increase in the expression of rat brain/HepG2-type glucose transporter mRNA (GTmRNA) and immunoreactive transporter protein. The dose responses to both insulin and IGF-1 for stimulation of glucose uptake were paralleled by the expression of GTmRNA. Glucose uptake and GTmRNA levels were half maximally stimulated by 350 and 100 nM insulin, respectively, or by 2 nM IGF-1. Comparison of receptor occupancy with stimulation of glucose uptake and GTmRNA expression suggests that insulin exerts its effects through the IGF-1 receptor. Fibroblast growth factor, epidermal growth factor, platelet-derived growth factor, and phorbol ester had little or no effect on GTmRNA expression. These results demonstrate that the IGF-1 receptor mediates chronic regulation of transporter mRNA expression and protein synthesis and activity in cultured rat muscle cells.
我们利用分化的L6肌细胞来研究胰岛素和胰岛素样生长因子-1（IGF-1）对葡萄糖转运蛋白基因表达的调控。长期暴露于胰岛素（1微摩尔）或IGF-1（10纳米）会导致3H-2-脱氧-D-葡萄糖摄取增加2至5倍，同时大鼠脑/HepG2型葡萄糖转运蛋白mRNA（GTmRNA）和免疫反应性转运蛋白的表达相应增加。对胰岛素和IGF-1刺激葡萄糖摄取的剂量反应与GTmRNA的表达平行。葡萄糖摄取和GTmRNA水平分别在350和100纳摩尔胰岛素或2纳摩尔IGF-1作用下达到最大刺激的一半。受体占有率与葡萄糖摄取刺激以及GTmRNA表达的比较表明，胰岛素通过IGF-1受体发挥其作用。成纤维细胞生长因子、表皮生长因子、血小板衍生生长因子和佛波酯对GTmRNA表达几乎没有影响。这些结果表明，IGF-1受体介导了培养的大鼠肌肉细胞中转运蛋白mRNA表达、蛋白质合成和活性的长期调控。
