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Potent and Selective Triazole-Based Inhibitors of the Hypoxia-Inducible Factor Prolyl-Hydroxylases with Activity in the Murine Brain.

Chan MC, Atasoylu O, Hodson E, Tumber A, Leung IK, Chowdhury R, Gómez-Pérez V, Demetriades M, Rydzik AM, Holt-Martyn J, Tian YM, Bishop T, Claridge TD, Kawamura A, Pugh CW, Ratcliffe PJ, Schofield CJ - PLoS ONE (2015)

Bottom Line: Therapeutic activation of the natural human hypoxic response can be achieved by the inhibition of the hypoxia sensors for the HIF system, i.e. the HIF prolyl-hydroxylases (PHDs).Here, we report studies on tricyclic triazole-containing compounds as potent and selective PHD inhibitors which compete with the 2-oxoglutarate co-substrate.One compound (IOX4) induces HIFα in cells and in wildtype mice with marked induction in the brain tissue, revealing that it is useful for studies aimed at validating the upregulation of HIF for treatment of cerebral diseases including stroke.

View Article: PubMed Central - PubMed

Affiliation: Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom; Centre for Cellular and Molecular Physiology, University of Oxford, Oxford, United Kingdom.

ABSTRACT
As part of the cellular adaptation to limiting oxygen availability in animals, the expression of a large set of genes is activated by the upregulation of the hypoxia-inducible transcription factors (HIFs). Therapeutic activation of the natural human hypoxic response can be achieved by the inhibition of the hypoxia sensors for the HIF system, i.e. the HIF prolyl-hydroxylases (PHDs). Here, we report studies on tricyclic triazole-containing compounds as potent and selective PHD inhibitors which compete with the 2-oxoglutarate co-substrate. One compound (IOX4) induces HIFα in cells and in wildtype mice with marked induction in the brain tissue, revealing that it is useful for studies aimed at validating the upregulation of HIF for treatment of cerebral diseases including stroke.

No MeSH data available.


Related in: MedlinePlus

IOX4 induces HIFα in mice.(a) Immunoblots showing HIF1α and HIF2α induction in various mouse tissues (liver, brain, kidney, heart) after 1 h treatment at equimolar concentrations of IOX2 (37.7 mg/kg), IOX4 (35 mg/kg) or dimethyl N-oxalylglycine DMOG (75 mg/kg). (b-c) Immunoblot showing dose-dependent induction of HIF1α and HIF2α in the mouse liver (b) and in the mouse brain (c) after 1 h treatment by various doses of IOX4 (17.5 to 70 mg/kg) in comparison to vehicle control and DMOG (160 mg/kg). n.s.: non-specific; l.e.: long exposure.
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pone.0132004.g004: IOX4 induces HIFα in mice.(a) Immunoblots showing HIF1α and HIF2α induction in various mouse tissues (liver, brain, kidney, heart) after 1 h treatment at equimolar concentrations of IOX2 (37.7 mg/kg), IOX4 (35 mg/kg) or dimethyl N-oxalylglycine DMOG (75 mg/kg). (b-c) Immunoblot showing dose-dependent induction of HIF1α and HIF2α in the mouse liver (b) and in the mouse brain (c) after 1 h treatment by various doses of IOX4 (17.5 to 70 mg/kg) in comparison to vehicle control and DMOG (160 mg/kg). n.s.: non-specific; l.e.: long exposure.

Mentions: To explore their utility in a mammalian animal model, IOX2 and IOX4 were tested for their ability to induce HIFα in mice. The inhibitors or vehicle controls were injected intraperitonially into wild type C57BL/6 mice and sacrificed after the indicated treatment time before harvesting their tissues to be analysed for HIFα levels by immunoblotting. The results reveal HIF1α is induced in mouse liver after 1 h of treatment of IOX2, which persisted even after 2.5 h of treatment albeit at a lower level than the shorter treatment (S5 Fig). In contrast, treatment with another PHD inhibitor FG2216/IOX3 (see S1B Fig, previously used in mice studies) [26,44] at an equivalent molar dose to that of IOX2 led to a lower and shorter induction of HIF1α (S5 Fig). To compare the potencies of IOX2, IOX4 and DMOG, mice were treated with equimolar concentrations of each inhibitor for 1 h. Immunoblot analyses across multiple tissues reveal induction of HIF1α and HIF2α by all three inhibitors, with IOX2 displaying the strongest induction followed by IOX4 and DMOG in the liver, kidney and heart (Fig 4A). Importantly, both HIF1α and HIF2α were induced in the brain by IOX4 but not IOX2 or DMOG, suggesting that IOX4 may better penetrate the blood-brain barrier than the latter two inhibitors. Dose-dependent induction of both HIF1α and HIF2α in the liver and brain was observed after IOX4 treatment (Fig 4B and 4C). These observations reveal both IOX2 and IOX4 as active PHD inhibitors in mice; however, induction of HIF1α and HIF2α protein levels in the brain were only observed with IOX4.


Potent and Selective Triazole-Based Inhibitors of the Hypoxia-Inducible Factor Prolyl-Hydroxylases with Activity in the Murine Brain.

Chan MC, Atasoylu O, Hodson E, Tumber A, Leung IK, Chowdhury R, Gómez-Pérez V, Demetriades M, Rydzik AM, Holt-Martyn J, Tian YM, Bishop T, Claridge TD, Kawamura A, Pugh CW, Ratcliffe PJ, Schofield CJ - PLoS ONE (2015)

IOX4 induces HIFα in mice.(a) Immunoblots showing HIF1α and HIF2α induction in various mouse tissues (liver, brain, kidney, heart) after 1 h treatment at equimolar concentrations of IOX2 (37.7 mg/kg), IOX4 (35 mg/kg) or dimethyl N-oxalylglycine DMOG (75 mg/kg). (b-c) Immunoblot showing dose-dependent induction of HIF1α and HIF2α in the mouse liver (b) and in the mouse brain (c) after 1 h treatment by various doses of IOX4 (17.5 to 70 mg/kg) in comparison to vehicle control and DMOG (160 mg/kg). n.s.: non-specific; l.e.: long exposure.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4492579&req=5

pone.0132004.g004: IOX4 induces HIFα in mice.(a) Immunoblots showing HIF1α and HIF2α induction in various mouse tissues (liver, brain, kidney, heart) after 1 h treatment at equimolar concentrations of IOX2 (37.7 mg/kg), IOX4 (35 mg/kg) or dimethyl N-oxalylglycine DMOG (75 mg/kg). (b-c) Immunoblot showing dose-dependent induction of HIF1α and HIF2α in the mouse liver (b) and in the mouse brain (c) after 1 h treatment by various doses of IOX4 (17.5 to 70 mg/kg) in comparison to vehicle control and DMOG (160 mg/kg). n.s.: non-specific; l.e.: long exposure.
Mentions: To explore their utility in a mammalian animal model, IOX2 and IOX4 were tested for their ability to induce HIFα in mice. The inhibitors or vehicle controls were injected intraperitonially into wild type C57BL/6 mice and sacrificed after the indicated treatment time before harvesting their tissues to be analysed for HIFα levels by immunoblotting. The results reveal HIF1α is induced in mouse liver after 1 h of treatment of IOX2, which persisted even after 2.5 h of treatment albeit at a lower level than the shorter treatment (S5 Fig). In contrast, treatment with another PHD inhibitor FG2216/IOX3 (see S1B Fig, previously used in mice studies) [26,44] at an equivalent molar dose to that of IOX2 led to a lower and shorter induction of HIF1α (S5 Fig). To compare the potencies of IOX2, IOX4 and DMOG, mice were treated with equimolar concentrations of each inhibitor for 1 h. Immunoblot analyses across multiple tissues reveal induction of HIF1α and HIF2α by all three inhibitors, with IOX2 displaying the strongest induction followed by IOX4 and DMOG in the liver, kidney and heart (Fig 4A). Importantly, both HIF1α and HIF2α were induced in the brain by IOX4 but not IOX2 or DMOG, suggesting that IOX4 may better penetrate the blood-brain barrier than the latter two inhibitors. Dose-dependent induction of both HIF1α and HIF2α in the liver and brain was observed after IOX4 treatment (Fig 4B and 4C). These observations reveal both IOX2 and IOX4 as active PHD inhibitors in mice; however, induction of HIF1α and HIF2α protein levels in the brain were only observed with IOX4.

Bottom Line: Therapeutic activation of the natural human hypoxic response can be achieved by the inhibition of the hypoxia sensors for the HIF system, i.e. the HIF prolyl-hydroxylases (PHDs).Here, we report studies on tricyclic triazole-containing compounds as potent and selective PHD inhibitors which compete with the 2-oxoglutarate co-substrate.One compound (IOX4) induces HIFα in cells and in wildtype mice with marked induction in the brain tissue, revealing that it is useful for studies aimed at validating the upregulation of HIF for treatment of cerebral diseases including stroke.

View Article: PubMed Central - PubMed

Affiliation: Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom; Centre for Cellular and Molecular Physiology, University of Oxford, Oxford, United Kingdom.

ABSTRACT
As part of the cellular adaptation to limiting oxygen availability in animals, the expression of a large set of genes is activated by the upregulation of the hypoxia-inducible transcription factors (HIFs). Therapeutic activation of the natural human hypoxic response can be achieved by the inhibition of the hypoxia sensors for the HIF system, i.e. the HIF prolyl-hydroxylases (PHDs). Here, we report studies on tricyclic triazole-containing compounds as potent and selective PHD inhibitors which compete with the 2-oxoglutarate co-substrate. One compound (IOX4) induces HIFα in cells and in wildtype mice with marked induction in the brain tissue, revealing that it is useful for studies aimed at validating the upregulation of HIF for treatment of cerebral diseases including stroke.

No MeSH data available.


Related in: MedlinePlus