Clioquinol, a Cu(II)/Zn(II) chelator, inhibits both ubiquitination and asparagine hydroxylation of hypoxia-inducible factor-1alpha, leading to expression of vascular endothelial growth factor and erythropoietin in normoxic cells.
We found that the Cu(II) and Zn(II)-specific chelator Clioquinol (10-50 microM) increased functional hypoxia-inducible factor 1alpha (HIF-1alpha) protein, leading to increased expression of its target genes, vascular endothelial growth factors and erythropoietin, in SH-SY5Y cells and HepG2 cells. Clioquinol inhibited ubiquitination of HIF-1alpha in a Cu(II)- and Zn(II)-dependent manner. It prevents FIH-1 from hydroxylating the asparagine residue (803) of HIF-1alpha in a Cu(II)- and Zn(II)-independent fashion. Therefore, it leads to the accumulation of HIF-1alpha that is prolyl but not asparaginyl hydroxylated. Consistent with this, co-immunoprecipitation assays showed that Clioquinol-induced HIF-1alpha interacted with cAMP-responsive element-binding protein in normoxic cells, implying that Clioquinol stabilizes the trans-active form of HIF-1alpha. Our results indicate that Clioquinol could be useful as an inducer of HIF-1alpha and its target genes in ischemic diseases.
Choi
Su Mi
SM
Department of Life Science, University of Seoul, Seoul 130-743, Korea.
Choi
Kyung-Ok
KO
Park
Young-Kwon
YK
Cho
Hyunju
H
Yang
Eun Gyeong
EG
Park
Hyunsung
H
D001216:Asparagine / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology; D015687:Cell Hypoxia; D002614:Chelating Agents / Q000494:pharmacology*; D007464:Clioquinol / Q000494:pharmacology*; D003300:Copper / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004921:Erythropoietin / Q000378:metabolism*; D006801:Humans; D006900:Hydroxylation / Q000187:drug effects; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases; D047468:Immunoprecipitation; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology; D009447:Neuroblastoma / Q000378:metabolism / Q000473:pathology; D010100:Oxygen / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D011393:Procollagen-Proline Dioxygenase / Q000378:metabolism; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D014407:Tumor Cells, Cultured; D025801:Ubiquitin / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D051794:Von Hippel-Lindau Tumor Suppressor Protein / Q000378:metabolism; D015032:Zinc / Q000378:metabolism
D002614:Chelating Agents; D017362:Cyclic AMP Response Element-Binding Protein; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D010446:Peptide Fragments; D025801:Ubiquitin; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D004921:Erythropoietin; D001216:Asparagine; D003300:Copper; D007464:Clioquinol; C490190:EGLN1 protein, human; D011393:Procollagen-Proline Dioxygenase; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases; D051794:Von Hippel-Lindau Tumor Suppressor Protein; C497446:VHL protein, human; D015032:Zinc; D010100:Oxygen