Induction of hypoxia-inducible-factor 1 by nitric oxide is mediated via the PI 3K pathway

KB Sandau, HG Faus, B Brüne - Biochemical and biophysical research …, 2000 - Elsevier
KB Sandau, HG Faus, B Brüne
Biochemical and biophysical research communications, 2000Elsevier
Adaptation to hypoxic stress provokes activation of the hypoxia-inducible-factor-1 (HIF-1)
which mediates gene expression of, eg, erythropoietin or vascular endothelial growth factor.
Detailed information on signaling pathways that stabilize HIF-1 is missing, but reactive
oxygen species degrade the HIF-1α subunit, whereas phosphorylation causes its
stabilization. It was believed that hypoxia resembles the only HIF-1 inducer but recent
evidence characterized other activators of HIF-1 such as nitric oxide (NO). Herein, we …
Adaptation to hypoxic stress provokes activation of the hypoxia-inducible-factor-1 (HIF-1) which mediates gene expression of, e.g., erythropoietin or vascular endothelial growth factor. Detailed information on signaling pathways that stabilize HIF-1 is missing, but reactive oxygen species degrade the HIF-1α subunit, whereas phosphorylation causes its stabilization. It was believed that hypoxia resembles the only HIF-1 inducer but recent evidence characterized other activators of HIF-1 such as nitric oxide (NO). Herein, we concentrated on NO-evoked HIF-1 induction as a heretofore unappreciated inflammatory response in association with massive NO formation. We demonstrated that S-nitrosoglutathione induces HIF-1α accumulation and concomitant DNA binding. The response was attenuated by the kinase inhibitor genistein and blockers of phosphatidylinositol 3-kinase such as Ly 294002 or wortmannin. Whereas mitogen-activated protein kinases were not involved, we noticed phosphorylation/activation of Akt in correlation with HIF-1α stabilization. NO appears to regulate HIF-1α via the PI 3K/Akt pathway under normoxic conditions.
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