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Centre de recherche de L'Hôtel-Dieu de Québec and the Department of Medicine, Université Laval, Québec, Canada (M.C.L., G.A.R., D.E.R.); and Center for Clinical Science Research, Department of Radiation Oncology, Stanford University, Stanford, California (D.A.C., A.J.G.)
Received for publication January 25, 2008.
Accepted for publication April 16, 2008.
| Abstract |
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-subunit and permitting the formation of a functional HIF complex. Here, we identify (2R)-[(4-biphenylylsulfonyl)amino]-N-hydroxy-3-phenylpropionamide (BiPS), a commercially available metalloprotease-2 and -9 inhibitor, as a rapid and potent inducer of HIFs. We show that in different cell lines, BiPS induces the HIF-
subunit by inhibiting its degradation through stabilization of its labile oxygen-dependent degradation domain. This is achieved through the inhibition of HIF-1
hydroxylation. The HIF-1 complex, formed after BiPS treatment, is capable of DNA binding and activation of HIF target genes, including the expression of vascular endothelial growth factor. Because novel HIF activators have generated considerable interest in the possible treatment of different ischemic diseases, we believe that BiPS and derivative molecules could have strong therapeutic potential.
, HIF-2
, or HIF-3
and a constitutive HIF-β subunit. HIF-1
is expressed ubiquitously and has been highly characterized. The regulation of HIF-2
, also named HLF, EPAS1, HRF, or MOP2, is similar to HIF-1
, but its expression is more restricted (Ema et al., 1997
has been less characterized and could act as a repressor of HIF-1 and HIF-2 activities (Gu et al., 1998
Under normal oxygen conditions, the
subunit is hydroxylated through the action of HIF prolyl hydroxylases (PHDs). This hydroxylation occurs on two specific proline residues (Pro402 and Pro564 on human HIF-1
) contained in its oxygen-dependent degradation domain (ODDD). Hydroxylation of HIF-
allows the binding of pVHL, the product of the von Hippel-Lindau tumor suppressor gene. As the recognition component of an E3 ubiquitin ligase complex, pVHL allows for HIF-
polyubiquitination and subsequent proteosomal degradation (Schofield and Ratcliffe, 2004
). Furthermore, HIF-
is hydroxylated on a specific asparagine residue (Asn803 on human HIF-1
) contained in its C-terminal transactivation domain by another dioxygenase, factor-inhibiting HIF. Asn803 hydroxylation inhibits HIF transcriptional activity by preventing binding of the coactivator p300/cAMP response element-binding protein-binding protein (Mahon et al., 2001
). Inactivated by hypoxia, HIF hydroxylases are dependent on oxygen and 2-oxoglutarate (2-OG) as substrates and ascorbate and iron as cofactors. Therefore, in most if not all cell types, the lack of oxygen permits the stabilization of HIF-
and the formation of a transcriptionally active HIF complex. Given the importance of HIF in response to ischemic conditions, the development of novel HIF inducers/activators has gained strong interest because of their therapeutic potential in the treatment of different ischemic disorders (Khan et al., 2003
; Simons and Ware, 2003
; Hewitson and Schofield, 2004
).
In this study, we present (2R)-[(4-biphenylylsulfonyl)-amino]-N-hydroxy-3-phenylpropionamide (BiPS) as a potent activator of both HIF-1 and HIF-2. This compound, derived from N-sulfonylamine acid, was originally designed as an inhibitor of matrix metalloproteases (MMP) -2 and -9 (Tamura et al., 1998
). A number of studies using this compound have demonstrated potent effects in different in vivo and in vitro situations. These include reducing lung colonization by Lewis lung carcinoma cells in mice (Tamura et al., 1998
), blocking lymphocyte migration across endothelial cells (Deem and Cook-Mills, 2004
), inhibiting transforming growth factor-β-induced cataract formation in rat lens (Dwivedi et al., 2006
), blocking the invasion of mouse brain microvessel endothelial cells in Matrigel (Fears et al., 2005
), and impeding the migration of smooth muscle cells (Lin et al., 2007
).
In addition to its well-characterized effects on MMP activity, here we show that BiPS can also induce HIFs. In the present study, we demonstrate that BiPS stabilizes HIF-
protein by blocking HIF-
hydroxylation. This increase in HIF-
protein levels leads to the formation of active HIF complexes and the expression of HIF-target genes. Therefore, our study characterizes BiPS as a novel and potent activator of HIF complexes, which could be of particular interest in the chemical pharmacology of the HIF signaling cascade.
| Materials and Methods |
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344-582, pVHL-HA, and CMV-Luc-ODD constructs were kindly provided by Drs Jacques Pouysségur (Institute of Signaling, Developmental Biology and Cancer Research, Université de Nice, Nice, France), Peter Ratcliffe (University of Oxford, Oxford, England), and Richard K. Bruick (University of Texas, Austin, TX), respectively.
Cell Culture. VSMCs were isolated from thoracic aorta of 6-week-old male Wistar rats (Owens et al., 1986
) and cultured in Dulbecco's modified Eagle's medium (DMEM) containing 10% fetal bovine serum (FBS) and antibiotics (50 U/ml penicillin, 50 U/ml streptomycin). Bovine aortic endothelial cells (BAECs) were isolated from calf aortas and cultured in DMEM containing 10% FBS and antibiotics. HeLa cells were cultured in DMEM containing 10% heat-inactivated FBS and antibiotics. All cells were cultured in a humid atmosphere (5% CO2, 95% air) and serially passaged upon reaching confluence. Hypoxic conditions were obtained by placing cells in a sealed hypoxic workstation (Ruskinn, Bridgend, UK). The oxygen level in this workstation was maintained at 1% with the residual gas mixture containing 94% nitrogen and 5% carbon dioxide. All media for cell culture were from Invitrogen (Carlsbad, CA) unless otherwise indicated.
Western Blot Analysis. Cells were lysed in 2x Laemmli sample buffer. Protein concentration was determined by Lowry assay. Cell extracts (25 µg) were loaded on SDS-polyacrylamide gels and transferred onto polyvinylidene difluoride (Immobilon-P; Millipore Corporation, Billerica, MA) or nitrocellulose membranes (Hybond C Extra; GE Healthcare Life Sciences, Piscataway, NJ). Anti-HIF-1
and anti-HIF-2
antisera were raised in rabbits immunized against the last 20 amino acids of the C termini of each human protein (Richard et al., 1999
). Anti-hydroxylated HIF-1
raised against hydroxylated Pro402 and hydroxylated Pro564 of the human HIF-1
sequence were obtained as described previously (Chan et al., 2005
). Monoclonal anti-HIF-1
and anti-GST antibodies and polyclonal anti-HIF-1β antibody were from Novus Biologicals (Littleton, CO). Monoclonal HA.11 antibody was from Convance (Emeryville, CA). Total polyclonal p42/p44 MAPK antibody was from Millipore Biotechnology (Lake Placid, NY) and used as a loading control. Horseradish peroxidase-coupled anti-mouse and anti-rabbit antibodies were from Promega (Madison, WI). Proteins were visualized with an enhanced chemiluminescence system (GE Healthcare Life Sciences) or with the Odyssey Infrared Imaging System (LI-COR, Lincoln, NE). Western blots were quantified using Odyssey quantification software or ImageJ (available at http://rsb.info.nih.gov/ij).
RNA Interference. To down-regulate HIF-
protein expression in HeLa cells, small interfering RNA (siRNA) duplexes targeting human HIF-1
(accession number NM_001530
[GenBank]
; sense, 5'- AGGACAAGUCACAACAGGAUU-3') and human HIF-2
(accession number NM_001430
[GenBank]
; sense, 5'-GGGUCAGGUAGUAAGUGGCUU-3') were obtained from Ambion (Austin, TX). As a control, Silencer Negative Control #1 siRNA was used (Ambion). HeLa cells were transfected with siRNA duplexes (20 nM) by calcium phosphate precipitation.
Luciferase Assay. HeLa cells, seeded in six-well plates, were transiently transfected by calcium phosphate precipitation with pGL3 (R2.2) 3HRE-tk-LUC luciferase reporter vector (1 µg/well) or CMV-Luc-ODD (0.5 µg/well). Renilla reniformis luciferase expression vector (250 ng/well) was also used as a control for transfection efficiency. At 30 h after transfection, cells were stimulated, and luciferase assays were performed using the Dual Luciferase Reporter Assay System (Promega). Results were quantified with a Luminoskan Ascent microplate reader with integrated injectors (Thermo Electron, Milford, CA). Results are expressed as a ratio of firefly luciferase activity over R. reniformis luciferase activity. Experiments are an average ± S.E.M. of triplicate data and representative of three independent experiments performed on different cell cultures.
Transcription Factor Enzyme-Linked Immunoassay. Experiments were performed as described previously (Blouin et al., 2004
). In brief, high-bind NeutrAvidin-coated 96-well strip plates (Pierce Biotechnology, Rockford, IL) were incubated with a 5'-biotinylated 26 base pair double-stranded DNA oligonucleotide for 1 h at room temperature. This sequence contains the wild-type or mutant (underlined) HIF-1 binding motif described previously (Semenza and Wang, 1992
). Sequences used here were 5'-GATCGCCCTACGTGCTGTCTCAGATC-3' for W26 wild-type sequence and 5'-GATCGCCCTAAAAGCTGTCTCAGATC-3' for M26 mutant sequence. Nuclear extracts from HeLa cells were incubated with oligonucleotides, and HIF-1 complexes bound to DNA were detected using anti-HIF-1
or anti-HIF-β antibodies (Novus Biologicals), horseradish peroxidase-conjugated secondary antibodies, and TMB-ONE (Promega). Experiments are an average ± S.E.M. of triplicate data representative of three independent experiments performed on different cell cultures.
pVHL Capture Assay. HeLa cell were grown to confluence and stimulated as indicated. Cells were washed once in phosphate-buffered saline and twice in buffer containing 20 mM Tris, pH7.5, 5 mM KCl, 1.5 mM MgCl2, and 1 mM dithiothreitol. Cells were then suspended and lysed using a Dounce homogenizer. Cytoplasmic extracts were cleared by centrifugation (20,000g). Extracts (250 µg) were incubated with Sepharose-bound GST-HIF-1
344-582 (30 µg) for 1 h at room temperature, washed with NETN buffer (150 mM NaCl, 0.5 mM EDTA, 20 mM Tris, pH 8.0, 0.5% Igepal, and 100 µM deferoxamine), and incubated overnight with in vitro translated pVHL-HA in NETN at 4°C. Samples were washed with NETN, denatured in 2x Laemmli sample buffer, resolved in SDS-polyacrylamide gels (12%), and revealed by Western blotting with anti-HA and anti-GST antibodies.
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| Results |
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and HIF-2
protein induction was evaluated in different cell lines including the established human HeLa cell line and primary cultures of BAECs and rat aortic VSMCs. As seen in Fig. 1, BiPS induced HIF-
protein levels in all cell lines tested. In HeLa cells, a treatment with 10 µM BiPS for 2 h caused a detectable increase of both HIF-1
and HIF-2
proteins, whereas maximal induction was observed between 75 and 100 µM BiPS (Fig. 1, top). BiPS was more potent in BAEC because 5 µM led to a detectable increase of both HIF-
proteins, whereas maximal induction was observed at 25 µM (Fig. 1, middle). In VSMCs, 10 µM BiPS led to a detectable increase of HIF-1
protein, whereas maximal induction was observed at 50 µM BiPS (Fig. 1, bottom). However, we did not detect HIF-2
protein levels in VSMCs treated with BiPS or under hypoxic conditions. HIF-1
and HIF-2
protein induction by BiPS was also observed in the macrophage-like cell line NR8383, human embryonic kidney 293 cells, the murine endothelial cell line 1G11
[PDB]
and mouse embryonic fibroblasts (results not shown). It is interesting to note that the maximal induction of HIF-
after BiPS treatment was comparable with treatments under hypoxic conditions or in the presence of CoCl2, two main inducers of HIF-
. Finally, other MMP-2/9 inhibitors, such as GM6001 (galardin) and MMP-2/9 inhibitor I, did not induce HIF-
subunits (results not shown). These results indicate that the effect of BiPS on HIF-
induction was independent of MMP-2/9 inhibition and identify BiPS as a novel inducer of HIF-
subunits in normoxic cells.
The kinetics of HIF-
protein induction under BiPS treatment were rapid and comparable with hypoxic HIF-
induction. In HeLa cells, a detectable increase of HIF-1
was observed by 30 min, and maximal induction was attained after 2 h of treatment with 75 µM BiPS (Fig. 2). It is interesting that although HIF-1
levels were maintained in hypoxia for more than 6 h, treatment of cells with BiPS maintained HIF-1
levels for up to 4 h and then subsequently decreased to basal levels. HIF-2
protein induction by BiPS followed a similar kinetic pattern to HIF-1
. These results suggest that like hypoxia, BiPS stabilizes HIF-
instead of exploiting transcriptional or translational mechanisms for protein induction as seen for other normoxic inducers.
To directly evaluate the effect of BiPS on HIF-
subunit stabilization, HeLa cells were transfected with a construct encoding a luciferase protein chimera destabilized by the HIF-1
ODDD (Salnikow et al., 2004
). In these conditions, changes in luciferase activity by treatment with BiPS would indicate the specific stabilization of HIF-1
's ODDD. As expected, the treatment of cells with CoCl2 (Fig. 3A) or the proteasome inhibitor MG132 (results not shown) strongly increased luciferase activity. It is noteworthy that treatment with BiPS also increased luciferase activity to levels similar to those observed during MG132 and CoCl2 treatments. This result indicates that BiPS stabilizes the HIF-1
ODDD.
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stabilization, we examined pVHL binding to HIF-1
after BiPS treatment. HeLa cells were treated with BiPS or CoCl2 followed by the preparation of cytosolic extracts and in vitro hydroxylation of GST-HIF-1
(344-582). After incubation with in vitro translated pVHL and GST pull-down, we observed that the treatment of cells with BiPS strongly prevented pVHL binding to HIF-1
(Fig. 3B). It is interesting that the inhibition of pVHL binding with BiPS was more potent than with CoCl2 treatment. This result suggests that BiPS inhibits PHD-mediated HIF-
hydroxylation. To confirm this, we evaluated the level of HIF-1
hydroxylation using two specific antibodies against hydroxylated proline residues, Pro402 and Pro564 (Chan et al., 2005
protein hydroxylation of both proline residues (Fig. 3C). The treatment of cells with BiPS also strongly decreased both HIF-1
Pro402 and Pro564 hydroxylation. Taken together, these results indicate that BiPS is a potent inhibitor of PHD activity.
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subunits, we wanted to evaluate possibility that BiPS could inhibit PHD activity by acting as an iron chelating agent. In an iron chelation assay, deferoxamine, a well known iron chelator and HIF-
stabilizing agent, was able to chelate more than 80% of the iron present in our experimental conditions (Fig. 4A). However, BiPS did not act as an iron chelating agent because total free iron was completely accessible for reaction with FerroZine. This result suggests that BiPS does not inhibit PHD activity through iron chelation. PHDs belong to a large group of enzymes that use 2-oxoglutarate as a cosubstrate (Schofield and Ratcliffe, 2004
(Fig. 4B). It is interesting that the treatment of cellular extracts with BiPS blocked 2-OG-induced pVHL binding to HIF-1
. These results indicate that BiPS decreases PHD activity by interfering with 2-OG binding.
To determine the effect of BiPS treatment on HIF activity, we first evaluated its effect on the formation of an active HIF-1 transcription complex. To perform these studies, we used a HIF-1 transcription factor enzyme-linked immunoassay (Blouin et al., 2004
). Nuclear extracts from HeLa cells maintained in hypoxic conditions or in the presence of BiPS both demonstrated increased DNA-binding activity for HIF-1
and HIF-1β (Fig. 5, W26). To control for specificity, we substituted the W26 double-stranded DNA oligonucleotide sequence with a sequence mutated on two essential residues of the HIF-1-binding sequence (Fig. 5, M26). In this case, very little HIF-1 binding could be observed. This result indicates that BiPS stabilizes HIF-1
and permits the formation of the HIF-1 complex and binding to target hypoxia response element (HRE) sequences.
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and HIF-2
. The silencing of HIF-1
protein strongly reduced the expression of VEGF, whereas the silencing of HIF-2
caused a modest inhibition of the expression of this gene. Finally, the silencing of both HIF-
isoforms led to an additive inhibitory effect on VEGF mRNA expression. Effective silencing of HIF-1
and HIF-2
protein levels in HeLa cells is shown in the bottom of Fig. 7. Taken together, our results identify BiPS as a potent activator of HIF complexes. | Discussion |
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protein by blocking HIF
hydroxylation. This increase in HIF-
protein levels leads to the formation of active HIF complexes and the expression of HIF target genes. Therefore, BiPS or derivative molecules could have interesting therapeutic options for HIF-regulated responses.
To our knowledge, the only compounds currently used to stabilize and activate HIFs are inhibitors of PHD activity. The hydroxylase activity of theses enzymes is modulated by their cofactors, namely O2, 2-OG, and Fe(II). The identification of PHD cofactors has led to the identification/design of compounds able to increase HIFs, including compounds that chelate Fe(II) (deferoxamine) or compete with 2-OG binding to PHD (Hewitson and Schofield, 2004
). Because BiPS can efficiently inhibit HIF-1
hydroxylation and pVHL binding without chelating iron, we believe that BiPS functions by interfering with the binding of 2-OG to PHD. This is supported by the demonstration that BiPS blocks the potentiation of pVHL binding by 2-OG. In addition, using a docking simulation software (AutoDock, available at http://autodock.scripps.edu/), we performed a binding simulation of 2-OG and BiPS to PHD2, which corresponds to the current understanding of the 2-OG/PHD2 binding model (McDonough et al., 2006
). In this simulation, the most probable position for BiPS binding to PHD2 was the 2-OG binding site in the cavity containing the Fe(II) atom. The biphenyl group of BiPS was positioned inside the cavity, whereas the two oxygen atoms of the sulfur group interacted with the Fe(II) atom. Furthermore, this model predicted that the PHD2 binding energy of BiPS is 1.65 times higher than 2-OG (mean of -7.009 ± 0.3 kcal/mol for BiPS and -4.245 ± 0.04 kcal/mol for 2-OG). Taken together, experimental and in silico evidence strongly suggests that BiPS induces and activates HIF by interfering with the binding of the PHD cofactor, 2-OG, leading to PHD inhibition.
We have successfully used BiPS for HIF induction in a variety of cell types. These characteristics reveal BiPS as an interesting compound for researchers interested in studying the HIF system. As a potent inhibitor of MMP-2/9, BiPS was used by many different groups that were unaware of its effect on HIF activity. BiPS was used to study migration and invasion properties of cells (Deem and Cook-Mills, 2004
; Fears et al., 2005
; Lin et al., 2007
), to study the colonization of cancer cells in mice (Tamura et al., 1998
), and to evaluate the remodeling and inflammation of airways during asthma (Lee et al., 2004
). Depending on tissues targeted by BiPS the concentrations used, HIF activation could play an important role in the responses obtained using BiPS as an MMP-2/9 inhibitor. We believe that researchers considering the use of BiPS in their studies should strongly consider this possibility.
In this study, we present evidence that BiPS is a novel and potent PHD inhibitor in addition to its known role as an MMP-2/9 inhibitor. A PHD inhibitor, BiPS prevents pVHL binding to HIF-
and its subsequent degradation. In addition, BiPS permits the transcriptional activity of HIFs and the expression of target genes. Because PHD inhibitors are now recognized as potential therapeutic drugs in the treatment of anemia and ischemic diseases, we strongly believe that BiPS and derivative molecules could have strong therapeutic potential.
| Acknowledgements |
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| Footnotes |
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ABBREVIATIONS: HIF, hypoxia-inducible factor; PHD, hypoxia-inducible factor prolyl hydroxylase; ODDD, oxygen-dependent degradation domain; pVHL, von Hippel Lindau protein; MMP, matrix metalloprotease; BAEC, bovine aortic endothelial cell; VSMC, vascular smooth muscle cell; 2-OG, 2-oxoglutarate; BiPS, (2R)-[(4-biphenylylsulfonyl)amino]-N-hydroxy-3-phenylpropionamide; MG132, N-benzoyloxycarbonyl (Z)-Leu-Leuleucinal; DMEM, Dulbecco's modified Eagle's medium; FBS, fetal bovine serum; siRNA, small interfering RNA; NETN buffer, NaCl, EDTA, Tris, Igepal, and deferoxamine; HA, hemagglutinin; HRE, hypoxia response element; PAGE, polyacrylamide gel electrophoresis; MAPK, mitogen-activated protein kinase; DMSO, dimethyl sulfoxide; GM6001, galardin.
Address correspondence to: Dr. Darren E. Richard, Centre de recherche de L'Hôtel-Dieu de Québec, 10 Rue McMahon, Québec QC G1R 2J6, Canada. E-mail: darren.richard{at}crhdq.ulaval.ca
| References |
|---|
|
|
|---|
Chan DA, Sutphin PD, Yen SE, and Giaccia AJ (2005) Coordinate regulation of the oxygen-dependent degradation domains of hypoxia-inducible factor 1 alpha. Mol Cell Biol 25: 6415-6426.
Deem TL and Cook-Mills JM (2004) Vascular cell adhesion molecule 1 (VCAM-1) activation of endothelial cell matrix metalloproteinases: role of reactive oxygen species. Blood 104: 2385-2393.
Dwivedi DJ, Pino G, Banh A, Nathu Z, Howchin D, Margetts P, Sivak JG, and West-Mays JA (2006) Matrix metalloproteinase inhibitors suppress transforming growth factor-beta-induced subcapsular cataract formation. Am J Pathol 168: 69-79.
Ebert BL, Firth JD, and Ratcliffe PJ (1995) Hypoxia and mitochondrial inhibitors regulate expression of glucose transporter-1 via distinct Cis-acting sequences. J Biol Chem 270: 29083-29089.
Elson DA, Thurston G, Huang LE, Ginzinger DG, McDonald DM, Johnson RS, and Arbeit JM. (2001) Induction of hypervascularity without leakage or inflammation in transgenic mice overexpressing hypoxia-inducible factor-1alpha. Genes Dev 15: 2520-2532.
Ema M, Taya S, Yokotani N, Sogawa K, Matsuda Y, and Fujii-Kuriyama Y (1997) A novel bHLH-PAS factor with close sequence similarity to hypoxia-inducible factor 1
regulates the VEGF expression and is potentially involved in lung and vascular development. Proc Natl Acad Sci U S A 94: 4273-4278.
Fears CY, Grammer JR, Stewart JE Jr, Annis DS, Mosher DF, Bornstein P, and Gladson CL (2005) Low-density lipoprotein receptor-related protein contributes to the antiangiogenic activity of thrombospondin-2 in a murine glioma model. Cancer Res 65: 9338-9346.
Ferrara N (2004) Vascular endothelial growth factor: basic science and clinical progress. Endocr Rev 25: 581-611.
Fish WW (1988) Rapid colorimetric micromethod for the quantitation of complexed iron in biological samples. Methods Enzymol 158: 357-364.[Medline]
Flamme I, Frohlich T, von Reutern M, Kappel A, Damert A, and Risau W (1997) HRF, a putative basic helix-loop-helix-PAS-domain transcription factor is closely related to hypoxia-inducible factor-1 alpha and developmentally expressed in blood vessels. Mech Dev 63: 51-60.[CrossRef][Medline]
Forsythe JA, Jiang BH, Iyer NV, Agani F, Leung SW, Koos RD, and Semenza GL (1996) Activation of vascular endothelial growth factor gene transcription by hypoxia-inducible factor 1. Mol Cell Biol 16: 4604-4613.[Abstract]
Gu YZ, Moran SM, Hogenesch JB, Wartman L, and Bradfield CA (1998) Molecular characterization and chromosomal localization of a third alpha-class hypoxia inducible factor subunit, HIF3alpha. Gene Expr 7: 205-213.[Medline]
Hewitson KS and Schofield CJ (2004) The HIF pathway as a therapeutic target. Drug Discov Today 9: 704-711.[CrossRef][Medline]
Hogenesch JB, Chan WK, Jackiw VH, Brown RC, Gu YZ, Pray-Grant M, Perdew GH, and Bradfield CA. (1997) Characterization of a subset of the basic-helix-loop-helix-PAS superfamily that interacts with components of the dioxin signaling pathway. J Biol Chem 272: 8581-8593.
Hsieh MM, Linde NS, Wynter A, Metzger M, Wong C, Langsetmo I, Lin A, Smith R, Rodgers GP, Donahue RE, et al. (2007) HIF prolyl hydroxylase inhibition results in endogenous erythropoietin induction, erythrocytosis, and modest fetal hemoglobin expression in rhesus macaques. Blood 110: 2140-2147.
Kasiganesan H, Sridharan V, and Wright G (2007) Prolyl hydroxylase inhibitor treatment confers whole-animal hypoxia tolerance. Acta Physiol (Oxf) 190: 163-169.[CrossRef][Medline]
Khan TA, Sellke FW, and Laham RJ (2003) Gene therapy progress and prospects: therapeutic angiogenesis for limb and myocardial ischemia. Gene Ther 10: 285-291.[CrossRef][Medline]
Lauzier MC, Page EL, Michaud MD, and Richard DE (2007) Differential regulation of hypoxia-inducible factor-1 through receptor tyrosine kinase transactivation in vascular smooth muscle cells. Endocrinology 148: 4023-4031.
Lee KS, Jin SM, Kim SS, and Lee YC (2004) Doxycycline reduces airway inflammation and hyperresponsiveness in a murine model of toluene diisocyanate-induced asthma. J Allergy Clin Immunol 113: 902-909.[CrossRef][Medline]
Li J, Post M, Volk R, Gao Y, Li M, Metais C, Sato K, Tsai J, Aird W, Rosenberg RD, et al. (2000) PR39, a peptide regulator of angiogenesis. Nat Med 6: 49-55.[CrossRef][Medline]
Lin SJ, Lee IT, Chen YH, Lin FY, Sheu LM, Ku HH, Shiao MS, Chen JW, and Chen YL (2007) Salvianolic acid B attenuates MMP-2 and MMP-9 expression in vivo in apolipoprotein-E-deficient mouse aorta and in vitro in LPS-treated human aortic smooth muscle cells. J Cell Biochem 100: 372-384.[CrossRef][Medline]
Liu Y, Cox SR, Morita T, and Kourembanas S (1995) Hypoxia regulates vascular endothelial growth factor gene expression in endothelial cells. Identification of a 5' enhancer. Circ Res 77: 638-643.
Mahon PC, Hirota K, and Semenza GL (2001) FIH-1: a novel protein that interacts with HIF-1alpha and VHL to mediate repression of HIF-1 transcriptional activity. Genes Dev 15: 2675-2686.
Makino Y, Cao R, Svensson K, Bertilsson G, Asman M, Tanaka H, Cao Y, Berkenstam A, and Poellinger L (2001) Inhibitory PAS domain protein is a negative regulator of hypoxia-inducible gene expression. Nature 414: 550-554.[CrossRef][Medline]
Makino Y, Kanopka A, Wilson WJ, Tanaka H, and Poellinger L (2002) Inhibitory PAS domain protein (IPAS) is a hypoxia-inducible splicing variant of the hypoxia-inducible factor-3
locus. J Biol Chem 277: 32405-32408.
Mazure NM, Chen EY, Yeh P, Laderoute KR, and Giaccia AJ (1996) Oncogenic transformation and hypoxia synergistically act to modulate vascular endothelial growth factor expression. Cancer Res 56: 3436-3440.
McDonough MA, Li V, Flashman E, Chowdhury R, Mohr C, Lienard BM, Zondlo J, Oldham NJ, Clifton IJ, Lewis J, et al. (2006) Cellular oxygen sensing: crystal structure of hypoxia-inducible factor prolyl hydroxylase (PHD2). Proc Natl Acad Sci U S A 103: 9814-9819.
Owens GK, Loeb A, Gordon D, and Thompson MM (1986) Expression of smooth muscle-specific alpha-isoactin in cultured vascular smooth muscle cells: relationship between growth and cytodifferentiation. J Cell Biol 102: 343-352.
Richard DE, Berra E, Gothie E, Roux D, and Pouyssegur J (1999) p42/p44 mitogen-activated protein kinases phosphorylate hypoxia-inducible factor 1alpha (HIF-1
) and enhance the transcriptional activity of HIF-1. J Biol Chem 274: 32631-32637.
Salnikow K, Donald SP, Bruick RK, Zhitkovich A, Phang JM, and Kasprzak KS (2004) Depletion of intracellular ascorbate by the carcinogenic metals nickel and cobalt results in the induction of hypoxic stress. J Biol Chem 279: 40337-40344.
Schofield CJ and Ratcliffe PJ (2004) Oxygen sensing by HIF hydroxylases. Nat Rev Mol Cell Biol 5: 343-354.[CrossRef][Medline]
Semenza GL (2003) Targeting HIF-1 for cancer therapy. Nat Rev Cancer 3: 721-732.[CrossRef][Medline]
Semenza GL and Wang GL (1992) A nuclear factor induced by hypoxia via de novo protein synthesis binds to the human erythropoietin gene enhancer at a site required for transcriptional activation. Mol Cell Biol 12: 5447-5454.
Shyu KG, Wang MT, Wang BW, Chang CC, Leu JG, Kuan P, and Chang H (2002) Intramyocardial injection of naked DNA encoding HIF-1alpha/VP16 hybrid to enhance angiogenesis in an acute myocardial infection model in the rat. Cardiovasc Res 54: 576-583.
Simons M and Ware JA (2003) Therapeutic angiogenesis in cardiovascular disease. Nat Rev Drug Discov 2: 863-871.[CrossRef][Medline]
Stookey L (1970) Ferrozine-A new spectrophotometric reagent for iron. Anal Chem 42: 779-781.
Tamura Y, Watanabe F, Nakatani T, Yasui K, Fuji M, Komurasaki T, Tsuzuki H, Maekawa R, Yoshioka T, Kawada K, et al. (1998) Highly selective and orally active inhibitors of type IV collagenase (MMP-9 and MMP-2): N-sulfonylamino acid derivatives. J Med Chem 41: 640-649.[CrossRef][Medline]
Tian H, McKnight SL, and Russell DW (1997) Endothelial PAS domain protein 1 (EPAS1), a transcription factor selectively expressed in endothelial cells. Genes Dev 11: 72-82.
Vincent KA, Shyu KG, Luo Y, Magner M, Tio RA, Jiang C, Goldberg MA, Akita GY, Gregory RJ, and Isner JM (2000) Angiogenesis is induced in a rabbit model of hindlimb ischemia by naked DNA encoding an HIF-1alpha/VP16 hybrid transcription factor. Circulation 102: 2255-2261.
Willam C, Masson N, Tian YM, Mahmood SA, Wilson MI, Bicknell R, Eckardt KU, Maxwell PH, Ratcliffe PJ, and Pugh CW (2002) Peptide blockade of HIF
degradation modulates cellular metabolism and angiogenesis. Proc Natl Acad Sci U S A 99: 10423-10428.
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