title: Competitive HIF Prolyl Hydroxylase Inhibitors Show Protection against Oxidative Stress by a Mechanism Partially Dependent on Glycolysis.
abstract: The hypoxia inducible factor 1 (HIF-1) is a central transcription factor involved in the cellular and molecular adaptation to hypoxia and low glucose supply. The level of HIF-1 is to a large degree regulated by the HIF prolyl hydroxylase enzymes (HPHs) belonging to the Fe(II) and 2-oxoglutarate-dependent dioxygenase superfamily. In the present study, we compared competitive and noncompetitive HPH-inhibitor compounds in two different cell types (SH-SY5Y and PC12). Although the competitive HPH-inhibitor compounds were found to be pharmacologically more potent than the non-competitive compounds at inhibiting HPH2 and HPH1, this was not translated into the cellular effects of the compounds, where the non-competitive inhibitors were actually more potent than the competitive in stabilizing and translocatingHIF1 α to the nucleus (quantified with Cellomics ArrayScan technology). This could be explained by the high cellular concentrations of the cofactor 2-oxoglutarate (2-OG) as the competitive inhibitors act by binding to the 2-OG site of the HPH enzymes. Both competitive and non-competitive HPH inhibitors protected the cells against 6-OHDA induced oxidative stress. In addition, the protective effect of a specific HPH inhibitor was partially preserved when the cells were serum starved and exposed to 2-deoxyglucose, an inhibitor of glycolysis, indicating that other processes than restoring energy supply could be important for the HIF-mediated cytoprotection.
authors.affiliation: Department of Neurodegeneration, Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark.
authors.forename: Ann-Louise
authors.initials: AL
authors.lastname: Bergström
authors.affiliation: Department of Neurodegeneration, Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark.
authors.forename: Karina
authors.initials: K
authors.lastname: Fog
authors.affiliation: Department of Neurodegeneration, Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark.
authors.forename: Thomas Nikolaj
authors.initials: TN
authors.lastname: Sager
authors.affiliation: Department of Computational and Analytical Chemistry, Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark.
authors.forename: Anne Techau
authors.initials: AT
authors.lastname: Bruun
authors.affiliation: Department of Neurodegeneration, Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Thirstrup