Implications of glucose transporter protein type 1 (GLUT1)-hapiodeficiency in embryonic stem cells for their survival in response to hypoxic stress
Implications of glucose transporter protein type 1 (GLUT1)-hapiodeficiency in embryonic stem cells for their survival in response to hypoxic stress
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DOI：
10.1016/s0002-9440(10)63546-8
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发表时间：
2003-11-01
影响因子：
6
通讯作者：
Conner, D
中科院分区：
文献类型：
--
作者：
Heilig, C;Brosius, F;Conner, D
葡萄糖转运蛋白1（GLUT 1）是受精卵和植入前胚胎的主要葡萄糖转运蛋白。GLUT 1单倍不足导致人类GLUT 1缺乏综合征，但胚胎似乎不受影响。因此，在这里，我们产生了杂合GLUT 1敲除小鼠胚胎干细胞（GT 1 +/-），以研究GLUT 1缺陷在其生长，葡萄糖代谢和缺氧应激反应中的存活中的作用。确定GT 1（-/-）细胞无活力。GLUT 1和GLUT 3高亲和力、易化葡萄糖转运蛋白在GT 1（+/+）和GT 1（+/-）胚胎干细胞中表达。GT 1（+/-）显示GLUT 1 mRNA减少49 +/- 4%。这诱导了转录后GLUT 1补偿反应，导致GLUT 1蛋白减少24 +/- 4%。GLUT 3没有变化。GLUT 8和GLUT 12也在GT 1（+/-）中表达且未发生变化。在GT 1（+/-）中，通过叠氮化物抑制氧化磷酸化刺激糖酵解受损44%，GLUT 1蛋白上调受损。缺氧4小时后，GT 1（+/-）细胞凋亡率比GT 1（+/+）对照组高201%。在2小时时，GT 1（+/-）中的半胱天冬酶-3活性比GT 1（+/+）高76%。杂合敲除GLUT 1导致部分GLUT 1代偿反应，保护非应激细胞。然而，氧化磷酸化和缺氧的抑制都暴露了他们对这些压力的敏感性增加。
Glucose transporter protein type 1 (GLUT1) is a major glucose transporter of the fertilized egg and preimplantation embryo. Haploinsufficiency for GLUT1 causes the GLUT1 deficiency syndrome in humans, however the embryo appears unaffected. Therefore, here we produced heterozygous GLUT1 knockout murine embryonic stem cells (GT1+/-) to study the role of GLUT1 deficiency in their growth, glucose metabolism, and survival in response to hypoxic stress. GT1(-/-) cells were determined to be nonviable. Both the GLUT1 and GLUT3 high-affinity, facilitative glucose transporters were expressed in GT1(+/+) and GT1(+/-) embryonic stem cells. GT1(+/-) demonstrated 49 +/- 4% reduction of GLUT1 mRNA. This induced a posttranscriptional, GLUT1 compensatory response resulting in 24 +/- 4% reduction of GLUT1 protein. GLUT3 was unchanged. GLUT8 and GLUT12 were also expressed and unchanged in GT1(+/-). Stimulation of glycolysis by azide inhibition of oxidative phosphorylation was impaired by 44% in GT1(+/-), with impaired up-regulation of GLUT1 protein. Hypoxia for up to 4 hours led to 201% more apoptosis in GT1(+/-) than in GT1(+/+) controls. Caspase-3 activity was 76% higher in GT1(+/-) versus GT1(+/+) at 2 hours. Heterozygous knockout of GLUT1 led to a partial GLUT1 compensatory response protecting nonstressed cells. However, inhibition of oxidative phosphorylation and hypoxia both exposed their increased susceptibility to these stresses.