Peer-Reviewed Journal Details
Mandatory Fields
Zhdanov, AV,Dmitriev, RI,Golubeva, AV,Gavrilova, SA,Papkovsky, DB
2013
June
Biochimica Et Biophysica Acta-General Subjects
Chronic hypoxia leads to a glycolytic phenotype and suppressed HIF-2 signaling in PC12 cells
Validated
()
Optional Fields
Chronic hypoxia Cell energy budget HIF-2 Mitochondria Oxygen and glucose deprivation PC12 cells ACTIVATED PROTEIN-KINASE INDUCIBLE FACTOR-I CYTOCHROME-C EXPRESSION NERVE GROWTH-FACTOR PROLYL HYDROXYLASE INTRACELLULAR OXYGEN FACTOR (HIF)-1-ALPHA FUMARATE-HYDRATASE OXIDATIVE STRESS IRON-DEFICIENCY
1830
3553
3569
Background: Along with other regulators of cell metabolism, hypoxia-inducible factors HIF-1 and HIF-2 differentially regulate cell adaptation to hypoxia. Switches in HIF-1/HIF-2 signaling in chronic hypoxia have not been fully investigated.Methods: Proliferation, viability, apoptosis, neuronal and bioenergetic markers, mitochondrial function, respiration, glycolysis, HIF signalling, responses to O-2 and glucose deprivation (OGD) were examined using tumor PC12 and SH-SY5Y cells continuously grown at 3% O-2.Results: Hypoxic PC12 cells (H-cells) exhibit reduced proliferation and histone H4 acetylation, NGF-independent differentiation, activation of AMPK, inhibition of Akt, altered mitochondria and response to NGF. Cellular cytochrome c is increased with no effect on apoptosis. Reduction in respiration has minor effect on cellular ATP which is maintained through activated uptake (GLUT1) and utilization (HK2, PFK2) of glucose. H-cells exhibit resistance to OGD linked to increased glycogen stores. HIF-2alpha protein is decreased without changes in mRNA. Unlike HIF-1alpha, HIF-2alpha is not stabilized pharmacologically or by O-2 deprivation. Capacity for HIF-2alpha stabilization is partly restored when H-cells are cultured at normoxia. In low-respiring SH-SY5Y cells cultured under the same conditions HIF-2alpha stabilization and energy budget are not affected.Conclusions: In chronically hypoxic PC12 cells glycolytic energy budget, increased energy preservation and low susceptibility to OGD are observed. HIF-2alpha no longer orchestrates adaptive responses to anoxia.General significance: Demonstrated switch in HIF-1/HIF-2 signaling upon chronic hypoxia can facilitate cell survival in energy crisis, by regulating balance between energy saving and decrease in proliferation, on one hand and active cell growth and tumor expansion, on the other. (C) 2013 Elsevier B.V. All rights reserved.
10.1016/j.bbagen.2013.02.016
Grant Details