TY - JOUR
T1 - Implications of Glucose Transporter Protein Type 1 (GLUT1)-Haplodeficiency in Embryonic Stem Cells for Their Survival in Response to Hypoxic Stress
AU - Heilig, Charles
AU - Brosius, Frank
AU - Siu, Brian
AU - Concepcion, Luis
AU - Mortensen, Richard
AU - Heilig, Kathleen
AU - Zhu, Min
AU - Weldon, Richard
AU - Wu, Guimei
AU - Conner, David
N1 - Funding Information:
Supported by the National Institutes of Health ( RO1 DK54507 to C. H.); the American Diabetes Association (research award 2002-2005 to C. H.); the American Heart Association (research award 2002-2004 to C. H.); the National Kidney Foundation of Upstate New York (research award to C. H.); a University of Rochester Buswell award (to C. H.); the Fund of Henry Ford Hospital Award (to C. H.); the Howard Hughes Research Center, Department of Genetics, Harvard Medical School (C.H., D.C.); the Baxter Healthcare Corporation (research award to F. B.), and the National Kidney Foundation of Michigan (research award to F. B.).
PY - 2003/11
Y1 - 2003/11
N2 - 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.
AB - 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.
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U2 - 10.1016/S0002-9440(10)63546-8
DO - 10.1016/S0002-9440(10)63546-8
M3 - Article
C2 - 14578187
AN - SCOPUS:0142244201
VL - 163
SP - 1873
EP - 1885
JO - American Journal of Pathology
JF - American Journal of Pathology
SN - 0002-9440
IS - 5
ER -