title: Tuning the Transcriptional Response to Hypoxia by Inhibiting Hypoxia-inducible Factor (HIF) Prolyl and Asparaginyl Hydroxylases.
abstract: The hypoxia-inducible factor (HIF) system orchestrates cellular responses to hypoxia in animals. HIF is an α/β-heterodimeric transcription factor that regulates the expression of hundreds of genes in a tissue context-dependent manner. The major hypoxia-sensing component of the HIF system involves oxygen-dependent catalysis by the HIF hydroxylases; in humans there are three HIF prolyl hydroxylases (PHD1-3) and an asparaginyl hydroxylase (factor-inhibiting HIF (FIH)). PHD catalysis regulates HIFα levels, and FIH catalysis regulates HIF activity. How differences in HIFα hydroxylation status relate to variations in the induction of specific HIF target gene transcription is unknown. We report studies using small molecule HIF hydroxylase inhibitors that investigate the extent to which HIF target gene expression is induced by PHD or FIH inhibition. The results reveal substantial differences in the role of prolyl and asparaginyl hydroxylation in regulating hypoxia-responsive genes in cells. PHD inhibitors with different structural scaffolds behave similarly. Under the tested conditions, a broad-spectrum 2-oxoglutarate dioxygenase inhibitor is a better mimic of the overall transcriptional response to hypoxia than the selective PHD inhibitors, consistent with an important role for FIH in the hypoxic transcriptional response. Indeed, combined application of selective PHD and FIH inhibitors resulted in the transcriptional induction of a subset of genes not fully responsive to PHD inhibition alone. Thus, for the therapeutic regulation of HIF target genes, it is important to consider both PHD and FIH activity, and in the case of some sets of target genes, simultaneous inhibition of the PHDs and FIH catalysis may be preferable.
authors: From the Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, the Centre for Cellular and Molecular Physiology, University of Oxford, Oxford OX3 7BN.
authors: Mun Chiang
authors: MC
authors: Chan
authors: the Computational Genomics Analysis and Training Programme, MRC Functional Genomics Unit Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, and.
authors: Nicholas E
authors: NE
authors: Ilott
authors: the Centre for Cellular and Molecular Physiology, University of Oxford, Oxford OX3 7BN.
authors: Johannes
authors: J
authors: Schödel
authors: the Computational Genomics Analysis and Training Programme, MRC Functional Genomics Unit Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, and.
authors: David
authors: D
authors: Sims
authors: the Target Discovery Institute, University of Oxford, Oxford OX3 7FZ, United Kingdom.
authors: Anthony
authors: A
authors: Tumber
authors: From the Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA.
authors: Kerstin
authors: K
authors: Lippl
authors: the Centre for Cellular and Molecular Physiology, University of Oxford, Oxford OX3 7BN.
authors: David R
authors: DR
authors: Mole
authors: the Centre for Cellular and Molecular Physiology, University of Oxford, Oxford OX3 7BN.
authors: Christopher W
authors: CW
authors: Pugh
authors: the Centre for Cellular and Molecular Physiology, University of Oxford, Oxford OX3 7BN.
authors: Peter J
authors: PJ
authors: Ratcliffe
authors: the Computational Genomics Analysis and Training Programme, MRC Functional Genomics Unit Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, and.
authors: Chris P
authors: CP
authors: Ponting
authors: From the Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, christopher.schofield@chem.ox.ac.uk.
authors: Christopher J
authors: CJ
authors: Schofield
mesh_terms: D015687:Cell Hypoxia / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases / Q000096:biosynthesis* / Q000235:genetics; D061986:MCF-7 Cells; D014158:Transcription, Genetic / Q000502:physiology*
chemical_list: C490190:EGLN1 protein, human; C447780:EGLN2 protein, human; C488894:EGLN3 protein, human; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases
keywords: 2-oxoglutarate and ferrous iron dioxygenase; anaemia; erythropoiesis; hydroxylase; hypoxia; hypoxia-inducible factor (HIF); inhibitor; metallo-enzyme inhibitor; oxygen sensing; transcriptional regulation