Home LiteratureArticle Details
PMID: 16971531 Published · ppublish English Journal Article Research Support, Non-U.S. Gov't

The transcriptional activator hypoxia inducible factor 2 (HIF-2/EPAS-1) regulates the oxygen-dependent expression of erythropoietin in cortical astrocytes.

The Journal of neuroscience : the official journal of the Society for Neuroscience ·Vol. 26 ·No. 37 ·2006-09-13 ·Pages 9471-81

Chavez JC, Baranova O, Lin J, Pichiule P

Abstract

In the ischemic or hypoxic brain, astrocytes appear to be one of the main sources of erythropoietin (EPO). In this study, we investigated the differential contribution of hypoxia inducible factor (HIF) isoforms to the regulation of hypoxic EPO expression in cultured astrocytes. In addition, using an in vitro model of oxygen-glucose deprivation (OGD), we studied the role of HIF-1alpha and HIF-2alpha in the generation of paracrine protective signals by astrocytes that modulate the survival of neurons exposed to OGD. Expression of HIF-1alpha or HIF-2alpha was abrogated by infecting astrocytes with lentiviral particles encoding small interference RNA specific for HIF-1alpha or HIF-2alpha (siHIF-1alpha or siHIF-2alpha). Astrocytes infected with siHIF-1alpha showed abrogated hypoxic induction of vascular endothelial growth factor (VEGF) and lactate dehydrogenase (LDH) but normal EPO induction. In contrast, reduction of HIF-2alpha expression by siHIF-2alpha led to a drastic decrease of EPO hypoxic expression, but it did not affect LDH or VEGF upregulation. To further test whether HIF-2 is sufficient to drive EPO upregulation, we expressed oxygen-insensitive mutant forms of HIF-1alpha (mtHIF-1alpha) (P402A/P577A) and HIF-2alpha (mtHIF-2alpha) (P405A/P530A). Expression of mtHIF-2alpha but not mtHIF-1alpha in normoxic astrocytes resulted in a significant upregulation of EPO mRNA and protein. Accordingly, HIF-2alpha but not HIF-1alpha was found to be associated with the EPO hypoxia-response element by a chromatin immunoprecipitation assay. Interestingly, conditioned medium from astrocytes challenged by sublethal OGD improved neuronal survival to OGD; however, this effect was abolished during the downregulation of astrocytic HIF-2alpha using siHIF-2alpha. These results indicate that HIF-2alpha mediates the transcriptional activation of EPO expression in astrocytes, and this pathway may promote astrocytic paracrine-dependent neuronal survival during ischemia.

MeSH Terms
Animals Astrocytes/metabolism Cell Survival/physiology Cells, Cultured Cerebral Cortex/metabolism,physiopathology Down-Regulation/physiology Erythropoietin/genetics,metabolism Genetic Vectors/genetics Hypoxia-Inducible Factor 1, alpha Subunit/genetics,metabolism Hypoxia-Ischemia, Brain/metabolism,physiopathology L-Lactate Dehydrogenase/metabolism Mice Mice, Inbred C57BL Mice, Knockout Mutation/genetics Oxygen/metabolism Paracrine Communication/physiology Response Elements/genetics Transcription Factors/genetics,metabolism Transcriptional Activation/physiology Transfection Up-Regulation/physiology Vascular Endothelial Growth Factor A/metabolism
Chemicals
HIF-2 protein, mouse Hif1a protein, mouse Hypoxia-Inducible Factor 1, alpha Subunit Transcription Factors Vascular Endothelial Growth Factor A Erythropoietin L-Lactate Dehydrogenase Oxygen
Authors & Affiliations
4 authors, click to expand affiliations / ORCID
Chavez Juan C
Burke Medical Research Institute, White Plains, New York 10605, USA. [email protected]
Baranova Oxana
Lin Janice
Pichiule Paola
References (55)
55 references, click to expand
  1. Regulation of the erythropoietin gene.
    Blood. 1999 Sep 15;94(6):1864-77 PMID: 10477715
  2. Induction of hypoxia-inducible factor-1 (HIF-1) and its target genes following focal ischaemia in rat brain.
    Eur J Neurosci. 1999 Dec;11(12):4159-70 PMID: 10594641
  3. Neurons and astrocytes express EPO mRNA: oxygen-sensing mechanisms that involve the redox-state of the brain.
    Glia. 2000 May;30(3):271-8 PMID: 10756076
  4. Hypoxia-inducible factor-1alpha is a positive factor in solid tumor growth.
    Cancer Res. 2000 Aug 1;60(15):4010-5 PMID: 10945599
  5. Enhanced proliferation, survival, and dopaminergic differentiation of CNS precursors in lowered oxygen.
    J Neurosci. 2000 Oct 1;20(19):7377-83 PMID: 11007896
  6. Expression of hypoxia-inducible factor-1alpha in the brain of rats during chronic hypoxia.
    J Appl Physiol (1985). 2000 Nov;89(5):1937-42 PMID: 11053346
  7. Tissue-specific regulation of erythropoietin production in the murine kidney, brain, and uterus.
    Am J Physiol Endocrinol Metab. 2000 Dec;279(6):E1242-8 PMID: 11093910
  8. Erythropoietin-mediated neuroprotection involves cross-talk between Jak2 and NF-kappaB signalling cascades.
    Nature. 2001 Aug 9;412(6847):641-7 PMID: 11493922
  9. Oxygen-regulated transcription factors and their role in pulmonary disease.
    Respir Res. 2000;1(3):159-62 PMID: 11667980
  10. HIF-1 is expressed in normoxic tissue and displays an organ-specific regulation under systemic hypoxia.
    FASEB J. 2001 Nov;15(13):2445-53 PMID: 11689469
  11. Erythropoietin regulates the in vitro and in vivo production of neuronal progenitors by mammalian forebrain neural stem cells.
    J Neurosci. 2001 Dec 15;21(24):9733-43 PMID: 11739582
  12. Desferrioxamine induces delayed tolerance against cerebral ischemia in vivo and in vitro.
    J Cereb Blood Flow Metab. 2002 May;22(5):520-5 PMID: 11973424
  13. Hypoxia-inducible erythropoietin gene expression in human neuroblastoma cells.
    Blood. 2002 Oct 1;100(7):2623-8 PMID: 12239177
  14. Activation of hypoxia-inducible factor-1 in the rat cerebral cortex after transient global ischemia: potential role of insulin-like growth factor-1.
    J Neurosci. 2002 Oct 15;22(20):8922-31 PMID: 12388599
  15. Erythropoietin is a paracrine mediator of ischemic tolerance in the brain: evidence from an in vitro model.
    J Neurosci. 2002 Dec 1;22(23):10291-301 PMID: 12451129
  16. Hypoxia rapidly activates HIF-3alpha mRNA expression.
    FASEB J. 2003 Aug;17(11):1541-3 PMID: 12824304
  17. Hypoxia-induced stroke tolerance in the mouse is mediated by erythropoietin.
    Stroke. 2003 Aug;34(8):1981-6 PMID: 12829864
  18. Oxygen or glucose deprivation-induced neuronal injury in cortical cell cultures is reduced by tetanus toxin.
    Neuron. 1992 May;8(5):967-73 PMID: 1350203
  19. New roles for astrocytes (stars at last).
    Trends Neurosci. 2003 Oct;26(10):520-2 PMID: 14522143
  20. Oxygen sensing in the hypoxic response pathway: regulation of the hypoxia-inducible transcription factor.
    Genes Dev. 2003 Nov 1;17(21):2614-23 PMID: 14597660
  21. Differential roles of hypoxia-inducible factor 1alpha (HIF-1alpha) and HIF-2alpha in hypoxic gene regulation.
    Mol Cell Biol. 2003 Dec;23(24):9361-74 PMID: 14645546
  22. Oxygen-dependent and tissue-specific regulation of erythropoietin gene expression.
    Am J Physiol Regul Integr Comp Physiol. 2004 Jun;286(6):R977-88 PMID: 15142852
  23. Erythropoietin up-regulates SOCS2 in neuronal progenitor cells derived from SVZ of adult rat.
    Neuroreport. 2004 Jun 7;15(8):1225-9 PMID: 15167538
  24. Treatment of stroke with erythropoietin enhances neurogenesis and angiogenesis and improves neurological function in rats.
    Stroke. 2004 Jul;35(7):1732-7 PMID: 15178821
  25. Acute neuroprotective synergy of erythropoietin and insulin-like growth factor I.
    Proc Natl Acad Sci U S A. 2004 Jun 29;101(26):9855-60 PMID: 15210945
  26. Differentiating the functional role of hypoxia-inducible factor (HIF)-1alpha and HIF-2alpha (EPAS-1) by the use of RNA interference: erythropoietin is a HIF-2alpha target gene in Hep3B and Kelly cells.
    FASEB J. 2004 Sep;18(12):1462-4 PMID: 15240563
  27. Prosurvival and prodeath effects of hypoxia-inducible factor-1alpha stabilization in a murine hippocampal cell line.
    J Biol Chem. 2005 Feb 4;280(5):3996-4003 PMID: 15557337
  28. Lactate transport and transporters: general principles and functional roles in brain cells.
    J Neurosci Res. 2005 Jan 1-15;79(1-2):11-8 PMID: 15586354
  29. Thrombospondins are astrocyte-secreted proteins that promote CNS synaptogenesis.
    Cell. 2005 Feb 11;120(3):421-33 PMID: 15707899
  30. Astroglial cytoprotection by erythropoietin pre-conditioning: implications for ischemic and degenerative CNS disorders.
    J Neurochem. 2005 Apr;93(2):392-402 PMID: 15816862
  31. Role of glial cells in cerebral ischemia.
    Glia. 2005 Jun;50(4):281-6 PMID: 15846807
  32. Astrocytic contributions to bioenergetics of cerebral ischemia.
    Glia. 2005 Jun;50(4):362-88 PMID: 15846808
  33. Neuroprotection by hypoxic preconditioning involves oxidative stress-mediated expression of hypoxia-inducible factor and erythropoietin.
    Stroke. 2005 Jun;36(6):1264-9 PMID: 15890996
  34. Neuroprotection in the PNS: erythropoietin and immunophilin ligands.
    Ann N Y Acad Sci. 2005 Aug;1053:491-501 PMID: 16179557
  35. Astrocyte-neurone communication following oxygen-glucose deprivation.
    J Neurochem. 2005 Nov;95(4):1015-22 PMID: 16190880
  36. Hypoxia-inducible factor prolyl 4-hydroxylase inhibition. A target for neuroprotection in the central nervous system.
    J Biol Chem. 2005 Dec 16;280(50):41732-43 PMID: 16227210
  37. Regulation of erythropoietin production.
    Eur J Clin Invest. 2005 Dec;35 Suppl 3:13-9 PMID: 16281953
  38. Virally mediated increased neurotensin 1 receptor in the nucleus accumbens decreases behavioral effects of mesolimbic system activation.
    J Neurosci. 2005 Dec 14;25(50):11748-56 PMID: 16354933
  39. A critical role of erythropoietin receptor in neurogenesis and post-stroke recovery.
    J Neurosci. 2006 Jan 25;26(4):1269-74 PMID: 16436614
  40. Functional analysis of an oxygen-regulated transcriptional enhancer lying 3' to the mouse erythropoietin gene.
    Proc Natl Acad Sci U S A. 1991 Dec 1;88(23):10553-7 PMID: 1961720
  41. Hypoxia-inducible factor 1 is a basic-helix-loop-helix-PAS heterodimer regulated by cellular O2 tension.
    Proc Natl Acad Sci U S A. 1995 Jun 6;92(12):5510-4 PMID: 7539918
  42. Localization of specific erythropoietin binding sites in defined areas of the mouse brain.
    Proc Natl Acad Sci U S A. 1995 Apr 25;92(9):3717-20 PMID: 7731971
  43. A novel site of erythropoietin production. Oxygen-dependent production in cultured rat astrocytes.
    J Biol Chem. 1994 Jul 29;269(30):19488-93 PMID: 8034718
  44. Inducible operation of the erythropoietin 3' enhancer in multiple cell lines: evidence for a widespread oxygen-sensing mechanism.
    Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2423-7 PMID: 8460154
  45. Dimerization, DNA binding, and transactivation properties of hypoxia-inducible factor 1.
    J Biol Chem. 1996 Jul 26;271(30):17771-8 PMID: 8663540
  46. Erythropoietin receptor is expressed in rat hippocampal and cerebral cortical neurons, and erythropoietin prevents in vitro glutamate-induced neuronal death.
    Neuroscience. 1997 Jan;76(1):105-16 PMID: 8971763
  47. Analysis of chromatin structure by in vivo formaldehyde cross-linking.
    Methods. 1997 Feb;11(2):205-14 PMID: 8993033
  48. Detection of erythropoietin in human liquor: intrinsic erythropoietin production in the brain.
    Kidney Int. 1997 Feb;51(2):416-8 PMID: 9027715
  49. Structural and functional analysis of hypoxia-inducible factor 1.
    Kidney Int. 1997 Feb;51(2):553-5 PMID: 9027737
  50. Erythropoietin gene expression in human, monkey and murine brain.
    Eur J Neurosci. 1996 Apr;8(4):666-76 PMID: 9081618
  51. Activation of hypoxia-inducible factor-1; definition of regulatory domains within the alpha subunit.
    J Biol Chem. 1997 Apr 25;272(17):11205-14 PMID: 9111021
  52. Cellular and developmental control of O2 homeostasis by hypoxia-inducible factor 1 alpha.
    Genes Dev. 1998 Jan 15;12(2):149-62 PMID: 9436976
  53. Erythropoietin: a model system for studying oxygen-dependent gene regulation.
    J Exp Biol. 1998 Apr;201(Pt 8):1197-201 PMID: 9510530
  54. The human hypoxia-inducible factor 1alpha gene: HIF1A structure and evolutionary conservation.
    Genomics. 1998 Sep 1;52(2):159-65 PMID: 9782081
  55. Hypoxia-inducible factor 1: master regulator of O2 homeostasis.
    Curr Opin Genet Dev. 1998 Oct;8(5):588-94 PMID: 9794818
Article Info
Journal
The Journal of neuroscience : the official journal of the Society for Neuroscience
Abbr.
J Neurosci
ISSN
1529-2401
DOI
10.1523/JNEUROSCI.2838-06.2006
Email
[email protected]
Published
2006-09-13
Pages
9471-81
Language
English
Region
United States
NLM ID
8102140
PMCID
PMC6674587
Subset
IM
External Links
PubMed source DOI: 10.1523/JNEUROSCI.2838-06.2006 PMC Full Text View journal details
Analysis Services
Analysis Services

Contact

No. 2 Wenbo Road, Zhangqiu District, Jinan, Shandong

Qilu Normal University · Genelibs Bioinformatics Lab

750 Shunhua Rd, Jinan

2F, Bldg F, University Science Park

Tel: 0531-88819269

WeChat Official Account

Follow our WeChat subscription account for real-time updates and the latest in medical and biological research.


Business Email

E-mail: [email protected]

Copyright © 2026.Genelibs Jinan Honghui Biotechnology Co., Ltd. 鲁ICP备20007159号-2