Desferrioxamine induces erythropoietin gene expression and hypoxia-inducible factor 1 DNA-binding activity: implications for models of hypoxia signal transduction.
Erythropoietin (EPO) gene transcription is activated in kidney cells in vivo and in Hep3B cells exposed to hypoxia or cobalt chloride. Hypoxia-inducible factor 1 (HIF-1) is a nuclear factor that binds to the hypoxia-inducible enhancer of the EPO gene at a site that is required for transcriptional activation. HIF-1 DNA-binding activity is induced by hypoxia or cobalt chloride treatment of Hep3B cells. We report that treatment of Hep3B cells with desferrioxamine (DFX) induced HIF-1 activity and EPO RNA expression with kinetics similar to the induction of HIF-1 by hypoxia or cobalt chloride. Induction by each of these stimuli was inhibited by cycloheximide, indicating a requirement for de novo protein synthesis. DFX appears to induce HIF-1 by chelating iron as induction was inhibited by coadministration of ferrous ammonium sulfate. DFX administration to mice transiently increased EPO RNA levels in the kidney. As previously shown for hypoxia and cobalt treatment, DFX also induced HIF-1 activity in non-EPO-producing cells, suggesting the existence of a common hypoxia signal-transduction pathway leading to HIF-1 induction in different cell types.
Wang
G L
GL
Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD.
Semenza
G L
GL
D001483:Base Sequence; D015687:Cell Hypoxia; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003035:Cobalt / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D003676:Deferoxamine / Q000494:pharmacology*; D004921:Erythropoietin / Q000096:biosynthesis*; D015870:Gene Expression / Q000187:drug effects*; D018197:Hepatoblastoma; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008113:Liver Neoplasms; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism*; D015345:Oligonucleotide Probes; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000302:isolation & purification; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D014157:Transcription Factors; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; C497442:HIF1A protein, human; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009687:Nuclear Proteins; D015345:Oligonucleotide Probes; D012334:RNA, Neoplasm; D014157:Transcription Factors; D004921:Erythropoietin; D003035:Cobalt; C018021:cobaltous chloride; D003676:Deferoxamine