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Rauner M, Franke K, Murray M, Singh RP, Hiram-Bab S, Platzbecker U, Gassmann M, Socolovsky M, Neumann D, Gabet Y, Chavakis T, Hofbauer LC, Wielockx B. Increased EPO Levels Are Associated With Bone Loss in Mice Lacking PHD2 in EPO-Producing Cells. J Bone Miner Res 2016; 31:1877-1887. [PMID: 27082941 DOI: 10.1002/jbmr.2857] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 03/28/2016] [Accepted: 04/12/2016] [Indexed: 12/25/2022]
Abstract
The main oxygen sensor hypoxia inducible factor (HIF) prolyl hydroxylase 2 (PHD2) is a critical regulator of tissue homeostasis during erythropoiesis, hematopoietic stem cell maintenance, and wound healing. Recent studies point toward a role for the PHD2-erythropoietin (EPO) axis in the modulation of bone remodeling, even though the studies produced conflicting results. Here, we used a number of mouse strains deficient of PHD2 in different cell types to address the role of PHD2 and its downstream targets HIF-1α and HIF-2α in bone remodeling. Mice deficient for PHD2 in several cell lineages, including EPO-producing cells, osteoblasts, and hematopoietic cells (CD68:cre-PHD2f/f ) displayed a severe reduction of bone density at the distal femur as well as the vertebral body due to impaired bone formation but not bone resorption. Importantly, using osteoblast-specific (Osx:cre-PHD2f/f ) and osteoclast-specific PHD2 knock-out mice (Vav:cre- PHD2f/f ), we show that this effect is independent of the loss of PHD2 in osteoblast and osteoclasts. Using different in vivo and in vitro approaches, we show here that this bone phenotype, including the suppression of bone formation, is directly linked to the stabilization of the α-subunit of HIF-2, and possibly to the subsequent moderate induction of serum EPO, which directly influenced the differentiation and mineralization of osteoblast progenitors resulting in lower bone density. Taken together, our data identify the PHD2:HIF-2α:EPO axis as a so far unknown regulator of osteohematology by controlling bone homeostasis. Further, these data suggest that patients treated with PHD inhibitors or EPO should be monitored with respect to their bone status. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Martina Rauner
- Department of Medicine III, Technische Universität Dresden, Dresden, Germany
| | - Kristin Franke
- Department of Clinical Pathobiochemistry, Technische Universität Dresden, Dresden, Germany.,Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany
| | - Marta Murray
- Department of Clinical Pathobiochemistry, Technische Universität Dresden, Dresden, Germany.,Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany
| | - Rashim Pal Singh
- Department of Clinical Pathobiochemistry, Technische Universität Dresden, Dresden, Germany.,Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany
| | - Sahar Hiram-Bab
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Uwe Platzbecker
- Department of Medicine I, Technische Universität Dresden, Dresden, Germany
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland.,Zurich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland.,Universidad Peruana Cayetano Heredia (UPCH), Lima, Peru
| | - Merav Socolovsky
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA.,Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA
| | - Drorit Neumann
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Yankel Gabet
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Triantafyllos Chavakis
- Department of Clinical Pathobiochemistry, Technische Universität Dresden, Dresden, Germany.,Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany.,Center for Regenerative Therapies Dresden, Dresden, Germany
| | - Lorenz C Hofbauer
- Department of Medicine III, Technische Universität Dresden, Dresden, Germany.,Center for Regenerative Therapies Dresden, Dresden, Germany
| | - Ben Wielockx
- Department of Clinical Pathobiochemistry, Technische Universität Dresden, Dresden, Germany. .,Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany. .,Center for Regenerative Therapies Dresden, Dresden, Germany.
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Prolyl-4-hydroxylase 2 and 3 coregulate murine erythropoietin in brain pericytes. Blood 2016; 128:2550-2560. [PMID: 27683416 DOI: 10.1182/blood-2016-05-713545] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 09/22/2016] [Indexed: 12/20/2022] Open
Abstract
A classic response to systemic hypoxia is the increased production of red blood cells due to hypoxia-inducible factor (HIF)-mediated induction of erythropoietin (EPO). EPO is a glycoprotein hormone that is essential for normal erythropoiesis and is predominantly synthesized by peritubular renal interstitial fibroblast-like cells, which express cellular markers characteristic of neuronal cells and pericytes. To investigate whether the ability to synthesize EPO is a general functional feature of pericytes, we used conditional gene targeting to examine the von Hippel-Lindau/prolyl-4-hydroxylase domain (PHD)/HIF axis in cell-expressing neural glial antigen 2, a known molecular marker of pericytes in multiple organs. We found that pericytes in the brain synthesized EPO in mice with genetic HIF activation and were capable of responding to systemic hypoxia with the induction of Epo. Using high-resolution multiplex in situ hybridization, we determined that brain pericytes represent an important cellular source of Epo in the hypoxic brain (up to 70% of all Epo-expressing cells). We furthermore determined that Epo transcription in brain pericytes was HIF-2 dependent and cocontrolled by PHD2 and PHD3, oxygen- and 2-oxoglutarate-dependent prolyl-4-hydroxylases that regulate HIF activity. In summary, our studies provide experimental evidence that pericytes in the brain have the ability to function as oxygen sensors and respond to hypoxia with EPO synthesis. Our findings furthermore suggest that the ability to synthesize EPO may represent a functional feature of pericytes in the brain and kidney.
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53
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Frey H, Moreth K, Hsieh LTH, Zeng-Brouwers J, Rathkolb B, Fuchs H, Gailus-Durner V, Iozzo RV, de Angelis MH, Schaefer L. A novel biological function of soluble biglycan: Induction of erythropoietin production and polycythemia. Glycoconj J 2016; 34:393-404. [DOI: 10.1007/s10719-016-9722-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 07/21/2016] [Accepted: 08/05/2016] [Indexed: 11/29/2022]
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Gassmann NN, van Elteren HA, Goos TG, Morales CR, Rivera-Ch M, Martin DS, Cabala Peralta P, Passano Del Carpio A, Aranibar Machaca S, Huicho L, Reiss IKM, Gassmann M, de Jonge RCJ. Pregnancy at high altitude in the Andes leads to increased total vessel density in healthy newborns. J Appl Physiol (1985) 2016; 121:709-15. [PMID: 27445300 PMCID: PMC5142254 DOI: 10.1152/japplphysiol.00561.2016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 07/19/2016] [Indexed: 01/17/2023] Open
Abstract
The developing human fetus is able to cope with the physiological reduction in oxygen supply occurring in utero. However, it is not known if microvascularization of the fetus is augmented when pregnancy occurs at high altitude. Fifty-three healthy term newborns in Puno, Peru (3,840 m) were compared with sea-level controls. Pre- and postductal arterial oxygen saturation (SpO2) was determined. Cerebral and calf muscle regional tissue oxygenation was measured using near infrared spectroscopy (NIRS). Skin microcirculation was noninvasively measured using incident dark field imaging. Pre- and postductal SpO2 in Peruvian babies was 88.1 and 88.4%, respectively, which was 10.4 and 9.7% lower than in newborns at sea level (P < 0.001). Cerebral and regional oxygen saturation was significantly lower in the Peruvian newborns (cerebral: 71.0 vs. 74.9%; regional: 68.5 vs. 76.0%, P < 0.001). Transcutaneously measured total vessel density in the Peruvian newborns was 14% higher than that in the newborns born at sea level (29.7 vs. 26.0 mm/mm(2); P ≤ 0.001). This study demonstrates that microvascular vessel density in neonates born to mothers living at high altitude is higher than that in neonates born at sea level.
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Affiliation(s)
- Norina N Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, and Zurich Center for Integrative Human Physiology (ZIHP), Medical Faculty, University of Zurich, Zurich, Switzerland; Department of Pediatrics, Division of Neonatology, Erasmus MC-Sophia Children's Hospital, University Medical Center, Rotterdam, The Netherlands
| | - Hugo A van Elteren
- Department of Pediatrics, Division of Neonatology, Erasmus MC-Sophia Children's Hospital, University Medical Center, Rotterdam, The Netherlands
| | - Tom G Goos
- Department of Pediatrics, Division of Neonatology, Erasmus MC-Sophia Children's Hospital, University Medical Center, Rotterdam, The Netherlands; Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
| | - Claudia R Morales
- Laboratory of Adaptation to High Altitude, Universidad Peruana Cayetano Heredia (UPCH), Lima, Peru
| | - Maria Rivera-Ch
- Laboratory of Adaptation to High Altitude, Universidad Peruana Cayetano Heredia (UPCH), Lima, Peru; Center of Research for Integral and Sustainable Development (CIDIS), UPCH, Lima, Peru
| | - Daniel S Martin
- University College London Centre for Altitude Space and Extreme Environment Medicine, Univesity College London Hospital (UCLH) National Institute for Health Research (NIHR) Biomedical Research Centre, Institute of Sport and Exercise Health, London, United Kingdom
| | | | | | | | - Luis Huicho
- Center of Research for Integral and Sustainable Development (CIDIS), UPCH, Lima, Peru; School of Medicine, UPCH, Lima, Peru
| | - Irwin K M Reiss
- Department of Pediatrics, Division of Neonatology, Erasmus MC-Sophia Children's Hospital, University Medical Center, Rotterdam, The Netherlands
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, and Zurich Center for Integrative Human Physiology (ZIHP), Medical Faculty, University of Zurich, Zurich, Switzerland; School of Medicine, UPCH, Lima, Peru
| | - Rogier C J de Jonge
- Department of Pediatrics, Division of Neonatology, Erasmus MC-Sophia Children's Hospital, University Medical Center, Rotterdam, The Netherlands
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55
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Padayatty SJ, Levine M. Vitamin C: the known and the unknown and Goldilocks. Oral Dis 2016; 22:463-93. [PMID: 26808119 DOI: 10.1111/odi.12446] [Citation(s) in RCA: 376] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 01/08/2016] [Indexed: 12/11/2022]
Abstract
Vitamin C (Ascorbic Acid), the antiscorbutic vitamin, cannot be synthesized by humans and other primates, and has to be obtained from diet. Ascorbic acid is an electron donor and acts as a cofactor for fifteen mammalian enzymes. Two sodium-dependent transporters are specific for ascorbic acid, and its oxidation product dehydroascorbic acid is transported by glucose transporters. Ascorbic acid is differentially accumulated by most tissues and body fluids. Plasma and tissue vitamin C concentrations are dependent on amount consumed, bioavailability, renal excretion, and utilization. To be biologically meaningful or to be clinically relevant, in vitro and in vivo studies of vitamin C actions have to take into account physiologic concentrations of the vitamin. In this paper, we review vitamin C physiology; the many phenomena involving vitamin C where new knowledge has accrued or where understanding remains limited; raise questions about the vitamin that remain to be answered; and explore lines of investigations that are likely to be fruitful.
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Affiliation(s)
- S J Padayatty
- Molecular and Clinical Nutrition Section, Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - M Levine
- Molecular and Clinical Nutrition Section, Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
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Abstract
Oxygen represents one of the major molecules required for the development and maintenance of life. An adequate response to hypoxia is therefore required for the functioning of the majority of living organisms and relies on the activation of the hypoxia-inducible factor (HIF) pathway. HIF prolyl hydroxylase domain-2 (PHD2) has long been recognized as the major regulator of this response, controlling a myriad of outcomes that range from cell death to proliferation. However, this enzyme has been associated with more pathways, making the role of this protein remarkably complex under distinct pathologies. While a protective role seems to exist in physiological conditions such as erythropoiesis; the picture is more complex during pathologies such as cancer. Since the regulation of this enzyme and its closest family members is currently considered as a possible therapy for various diseases, understanding the different particular roles of this protein is essential.
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Affiliation(s)
- Ana M Meneses
- Heisenberg Research Group, Department of Clinical Pathobiochemistry, Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany
| | - Ben Wielockx
- Heisenberg Research Group, Department of Clinical Pathobiochemistry, Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany
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57
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Pichon A, Jeton F, El Hasnaoui-Saadani R, Hagström L, Launay T, Beaudry M, Marchant D, Quidu P, Macarlupu JL, Favret F, Richalet JP, Voituron N. Erythropoietin and the use of a transgenic model of erythropoietin-deficient mice. HYPOXIA 2016; 4:29-39. [PMID: 27800506 PMCID: PMC5085313 DOI: 10.2147/hp.s83540] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Despite its well-known role in red blood cell production, it is now accepted that erythropoietin (Epo) has other physiological functions. Epo and its receptors are expressed in many tissues, such as the brain and heart. The presence of Epo/Epo receptors in these organs suggests other roles than those usually assigned to this protein. Thus, the aim of this review is to describe the effects of Epo deficiency on adaptation to normoxic and hypoxic environments and to suggest a key role of Epo on main physiological adaptive functions. Our original model of Epo-deficient (Epo-TAgh) mice allowed us to improve our knowledge of the possible role of Epo in O2 homeostasis. The use of anemic transgenic mice revealed Epo as a crucial component of adaptation to hypoxia. Epo-TAgh mice survive well in hypoxic conditions despite low hematocrit. Furthermore, Epo plays a key role in neural control of ventilatory acclimatization and response to hypoxia, in deformability of red blood cells, in cerebral and cardiac angiogenesis, and in neuro- and cardioprotection.
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Affiliation(s)
- Aurélien Pichon
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex; Laboratory of Excellence GR-Ex, Paris; Laboratory MOVE EA 6314, FSS, Poitiers University, Poitiers, France
| | - Florine Jeton
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex; Laboratory of Excellence GR-Ex, Paris
| | | | - Luciana Hagström
- Laboratório Interdisciplinar de Biociências, Universidade de Brasília, Brasília, Brazil
| | - Thierry Launay
- Unité de Biologie Intégrative des Adaptations à l'Exercice, University Paris Saclay and Genopole , University Sorbonne-Paris-Cité, Paris, France
| | - Michèle Beaudry
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex
| | - Dominique Marchant
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex
| | - Patricia Quidu
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex
| | - Jose-Luis Macarlupu
- High Altitude Unit, Laboratories for Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Fabrice Favret
- Laboratory "Mitochondrie, Stress Oxydant et Protection Musculaire" EA 3072, University of Strasbourg, Strasbourg, France
| | - Jean-Paul Richalet
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex; Laboratory of Excellence GR-Ex, Paris
| | - Nicolas Voituron
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex; Laboratory of Excellence GR-Ex, Paris
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59
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Leigh J, Saha MN, Mok A, Champsi O, Wang R, Lobb I, Sener A. Hydrogen Sulfide Induced Erythropoietin Synthesis is Regulated by HIF Proteins. J Urol 2016; 196:251-60. [PMID: 26880412 DOI: 10.1016/j.juro.2016.01.113] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2016] [Indexed: 12/27/2022]
Abstract
PURPOSE Anemia of end stage renal disease affects 90% of patients on hemodialysis and it is a tremendous concern of patients and health care providers. Renal disease creates a state of renal hypoxia, which may contribute to a lack of erythropoietin production from the kidney when low oxygen levels are sensed. This necessitates the use of exogenous erythropoietin preparations. MATERIALS AND METHODS Recent evidence suggests that endogenously derived hydrogen sulfide may mediate oxygen sensing in tissues. Given the known involvement of other small molecules such as nitric oxide in erythropoietin production and the observation of decreased urinary H2S levels in patients with renal failure, we postulated that H2S may be the primary mediator of erythropoietin production during hypoxia. PK1, 786-O and Hep3B cells were incubated in hypoxia (1% O2) for 24 hours. Hypoxic cells were treated with the H2S donor GYY 4137 and the H2S inhibitor hydroxylamine. Following hypoxia erythropoietin, HIF-1α, HIF-2α and CBS expression was measured by quantitative real-time polymerase chain reaction and Western blot. RESULTS Hydroxylamine administration led to a significant decrease in erythropoietin, HIF-1α, HIF-2α and CBS protein levels during hypoxia. This was rescued by administration of GYY 4137 for erythropoietin, CBS and HIF-2α. Additionally, CSE -/- mice placed in hypoxia for 72 hours showed decreased renal erythropoietin production compared to wild-type mice. CONCLUSIONS These data suggest previously undocumented interplay of the production and action of H2S during hypoxia with subsequent erythropoietin production. The use of novel hydrogen sulfide donors could represent an alternative to standard therapies of anemia of renal failure.
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Affiliation(s)
- Jennifer Leigh
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada; Matthew Mailing Centre for Translational Transplant Studies, London Health Sciences Centre, London, Ontario, Canada
| | - Manujendra N Saha
- Matthew Mailing Centre for Translational Transplant Studies, London Health Sciences Centre, London, Ontario, Canada
| | - Amy Mok
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada; Matthew Mailing Centre for Translational Transplant Studies, London Health Sciences Centre, London, Ontario, Canada
| | - Omar Champsi
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada; Matthew Mailing Centre for Translational Transplant Studies, London Health Sciences Centre, London, Ontario, Canada
| | - Rui Wang
- Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Ontario, Canada
| | - Ian Lobb
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada; Matthew Mailing Centre for Translational Transplant Studies, London Health Sciences Centre, London, Ontario, Canada
| | - Alp Sener
- Department of Surgery, Western University, London, Ontario, Canada; Multi-Organ Transplant Program, London Health Sciences Centre, London, Ontario, Canada.
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Limiting hepatic Bmp-Smad signaling by matriptase-2 is required for erythropoietin-mediated hepcidin suppression in mice. Blood 2016; 127:2327-36. [PMID: 26755707 DOI: 10.1182/blood-2015-11-681494] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 12/29/2015] [Indexed: 12/29/2022] Open
Abstract
Hepcidin, the main regulator of iron homeostasis, is repressed when erythropoiesis is acutely stimulated by erythropoietin (EPO) to favor iron supply to maturing erythroblasts. Erythroferrone (ERFE) has been identified as the erythroid regulator that inhibits hepcidin in stress erythropoiesis. A powerful hepcidin inhibitor is the serine protease matriptase-2, encoded by TMPRSS6, whose mutations cause iron refractory iron deficiency anemia. Because this condition has inappropriately elevated hepcidin in the presence of high EPO levels, a role is suggested for matriptase-2 in EPO-mediated hepcidin repression. To investigate the relationship between EPO/ERFE and matriptase-2, we show that EPO injection induces Erfe messenger RNA expression but does not suppress hepcidin in Tmprss6 knockout (KO) mice. Similarly, wild-type (WT) animals, in which the bone morphogenetic protein-mothers against decapentaplegic homolog (Bmp-Smad) pathway is upregulated by iron treatment, fail to suppress hepcidin in response to EPO. To further investigate whether the high level of Bmp-Smad signaling of Tmprss6 KO mice counteracts hepcidin suppression by EPO, we generated double KO Bmp6-Tmprss6 KO mice. Despite having Bmp-Smad signaling and hepcidin levels that are similar to WT mice under basal conditions, double KO mice do not suppress hepcidin in response to EPO. However, pharmacologic downstream inhibition of the Bmp-Smad pathway by dorsomorphin, which targets the BMP receptors, improves the hepcidin responsiveness to EPO in Tmprss6 KO mice. We concluded that the function of matriptase-2 is dominant over that of ERFE and is essential in facilitating hepcidin suppression by attenuating the BMP-SMAD signaling.
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Mori Y, Takahashi N, Ogawa N, Gudermann T. Oxygen physiology: sensors and ion channels. Pflugers Arch 2015; 468:1-2. [PMID: 26590926 PMCID: PMC4700094 DOI: 10.1007/s00424-015-1762-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 11/16/2015] [Indexed: 01/05/2023]
Affiliation(s)
- Yasuo Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, 615-8510, Japan. .,Laboratory of Environmental Systems Biology, Department of Technology and Ecology, Hall of Global Environmental Studies, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan.
| | - Nobuaki Takahashi
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, 615-8510, Japan.,Department of Cell Biology, Harvard Medical School, Boston, MA, 02115, USA
| | - Nozomi Ogawa
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, 615-8510, Japan
| | - Thomas Gudermann
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians University, Munich, Germany.,Comprehensive Pneumology Center Munich (CPC-M), German Center for Lung Research, Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Munich Heart Alliance, Munich, Germany
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62
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Grasso G, Tomasello G, Noto M, Alafaci C, Cappello F. Erythropoietin for the Treatment of Subarachnoid Hemorrhage: A Feasible Ingredient for a Successful Medical Recipe. Mol Med 2015; 21:979-987. [PMID: 26581085 DOI: 10.2119/molmed.2015.00177] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/16/2015] [Indexed: 11/06/2022] Open
Abstract
Subarachnoid hemorrhage (SAH) following aneurysm bleeding accounts for 6% to 8% of all cerebrovascular accidents. Although an aneurysm can be effectively managed by surgery or endovascular therapy, delayed cerebral ischemia is diagnosed in a high percentage of patients resulting in significant morbidity and mortality. Cerebral vasospasm occurs in more than half of all patients after aneurysm rupture and is recognized as the leading cause of delayed cerebral ischemia after SAH. Hemodynamic strategies and endovascular procedures may be considered for the treatment of cerebral vasospasm. In recent years, the mechanisms contributing to the development of vasospasm, abnormal reactivity of cerebral arteries and cerebral ischemia following SAH, have been investigated intensively. A number of pathological processes have been identified in the pathogenesis of vasospasm, including endothelial injury, smooth muscle cell contraction from spasmogenic substances produced by the subarachnoid blood clots, changes in vascular responsiveness and inflammatory response of the vascular endothelium. To date, the current therapeutic interventions remain ineffective as they are limited to the manipulation of systemic blood pressure, variation of blood volume and viscosity and control of arterial carbon dioxide tension. In this scenario, the hormone erythropoietin (EPO) has been found to exert neuroprotective action during experimental SAH when its recombinant form (rHuEPO) is administered systemically. However, recent translation of experimental data into clinical trials has suggested an unclear role of recombinant human EPO in the setting of SAH. In this context, the aim of the current review is to present current evidence on the potential role of EPO in cerebrovascular dysfunction following aneurysmal subarachnoid hemorrhage.
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Affiliation(s)
- Giovanni Grasso
- Neurosurgical Clinic, Department of Experimental Biomedicine and Clinical Neurosciences, Euro-Mediterranean Institute of Science and Technology (IEMEST), Palermo, Italy
| | - Giovanni Tomasello
- Section of Anatomy, Department of Experimental Biomedicine and Clinical Neurosciences, and Euro-Mediterranean Institute of Science and Technology (IEMEST), Palermo, Italy
| | | | - Concetta Alafaci
- Department of Neurosurgery, University of Messina, Messina, Italy
| | - Francesco Cappello
- Section of Anatomy, Department of Experimental Biomedicine and Clinical Neurosciences, and Euro-Mediterranean Institute of Science and Technology (IEMEST), Palermo, Italy
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63
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Rainville N, Jachimowicz E, Wojchowski DM. Targeting EPO and EPO receptor pathways in anemia and dysregulated erythropoiesis. Expert Opin Ther Targets 2015; 20:287-301. [PMID: 26419263 DOI: 10.1517/14728222.2016.1090975] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Recombinant human erythropoietin (rhEPO) is a first-line therapeutic for the anemia of chronic kidney disease, cancer chemotherapy, AIDS (Zidovudine therapy), and lower-risk myelodysplastic syndrome. However, rhEPO frequently elevates hypertension, is costly, and may affect cancer progression. Potentially high merit therefore exists for defining new targets for anti-anemia agents within erythropoietin (EPO) and EPO receptor (EPOR) regulatory circuits. AREAS COVERED EPO production by renal interstitial fibroblasts is subject to modulation by several regulators of hypoxia-inducible factor 2a (HIF2a) including Iron Response Protein-1, prolyl hydroxylases, and HIF2a acetylases, each of which holds potential as anti-anemia drug targets. The cell surface receptor for EPO (EPOR) preassembles as a homodimer, together with Janus Kinase 2 (JAK2), and therefore it remains attractive to develop novel agents that trigger EPOR complex activation (activating antibodies, mimetics, small-molecule agonists). Additionally, certain downstream transducers of EPOR/JAK2 signaling may be druggable, including Erythroferrone (a hepcidin regulator), a cytoprotective Spi2a serpin, and select EPOR-associated protein tyrosine phosphatases. EXPERT OPINION While rhEPO (and biosimilars) are presently important mainstay erythropoiesis-stimulating agents (ESAs), impetus exists for studies of novel ESAs that fortify HIF2a's effects, act as EPOR agonists, and/or bolster select downstream EPOR pathways to erythroid cell formation. Such agents could lessen rhEPO dosing, side effects, and/or costs.
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Affiliation(s)
- Nicole Rainville
- a 1 Maine Medical Center Research Institute, Molecular Medicine Division , Scarborough, ME, USA
| | - Edward Jachimowicz
- a 1 Maine Medical Center Research Institute, Molecular Medicine Division , Scarborough, ME, USA
| | - Don M Wojchowski
- a 1 Maine Medical Center Research Institute, Molecular Medicine Division , Scarborough, ME, USA.,b 2 Tufts University School of Medicine , Boston, MA, USA.,c 3 Maine Medical Center Research Institute, Center of Excellence in Stem & Progenitor Cell Biology and Regenerative Medicine , Scarborough, ME 04074, USA ; .,d 4 Tufts University School of Medicine , Boston, MA, USA
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Albiñana V, Villar Gómez de Las Heras K, Serrano-Heras G, Segura T, Perona-Moratalla AB, Mota-Pérez M, de Campos JM, Botella LM. Propranolol reduces viability and induces apoptosis in hemangioblastoma cells from von Hippel-Lindau patients. Orphanet J Rare Dis 2015; 10:118. [PMID: 26394686 PMCID: PMC4579575 DOI: 10.1186/s13023-015-0343-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 09/16/2015] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Von Hippel-Lindau (VHL) disease is a rare oncological disease with an incidence of 1:36,000, and is characterized by the growth of different types of tumors: hemangioblastomas in the central nervous system (CNS) and retina, renal carcinoma, pheochromocytomas, pancreatic serous cystadenoma, and endolymphatic sac tumors. These tumors do not express VHL protein (pVHL). pVHL ubiquitinates hypoxia inducible factor (HIF) protein for degradation by the proteasome; in the absence of VHL, HIF translocates to the nucleus to activate the expression of its target genes. Targeting VHL-derived tumors with drugs that have reduced side effects is urgent to avoid repeat CNS surgeries. Recent reports have shown that propranolol, a β-blocker used for the treatment of hypertension and other cardiac and neurological diseases, is the best option for infantile hemangioma (IH). Propranolol could be an efficient treatment to control hemangioblastoma growth in VHL disease because of its antiangiogenic effects demonstrated in IH and the hypothetical impact on HIF levels. METHODS HeLa 9X (HRE) hypoxia responsive element cell line and primary hemangioblastoma-derived cells were subjected to propranolol treatment and cell viability and apoptosis were evaluated. HIF1-α and Hif-2α expression after propranolol treatment was analyzed by western blotting. Quantitative PCR was performed to study the mRNA expression of HIF target genes. Vascular endothelial growth factor (VEGF) was measured in culture supernatants by immunoassay. RESULTS Propranolol downregulated HIF-dependent transcription in HeLa 9XHRE cells. Under hypoxic conditions, propranolol decreased the expression of HIF target genes in hemangioblastoma cells, which stopped proliferating and died following long-term treatment. These results suggests that propranolol treatment promoted reduced HIF protein expression and corresponding downregulation of HIF target genes, and inhibited cell proliferation in parallel with induction of cell death by apoptosis. CONCLUSIONS Our results suggest that propranolol could reduce the growth of HIF-dependent tumors and may thus be a promising treatment to delay surgery in VHL patients.
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Affiliation(s)
| | | | - Gemma Serrano-Heras
- Unidad de Investigación, Complejo Universitario Hospital Albacete, Albacete, Spain.
| | - Tomás Segura
- Unidad de Investigación, Complejo Universitario Hospital Albacete, Albacete, Spain.
| | | | | | | | - Luisa María Botella
- Centro de Investigaciones Biológicas, CSIC, Madrid, Spain. .,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain.
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65
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Abstract
Hypoxia inducible factors (HIFs) are α/β heterodimeric transcription factors that direct multiple cellular and systemic responses in response to changes in oxygen availability. The oxygen sensitive signal is generated by a series of iron and 2-oxoglutarate-dependent dioxygenases that catalyze post-translational hydroxylation of specific prolyl and asparaginyl residues in HIFα subunits and thereby promote their destruction and inactivation in the presence of oxygen. In hypoxia, these processes are suppressed allowing HIF to activate a massive transcriptional cascade. Elucidation of these pathways has opened several new fields of cardiovascular research. Here, we review the role of HIF hydroxylase pathways in cardiac development and in cardiovascular control. We also consider the current status, opportunities, and challenges of therapeutic modulation of HIF hydroxylases in the therapy of cardiovascular disease.
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Affiliation(s)
- Tammie Bishop
- From the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Peter J Ratcliffe
- From the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.
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66
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Gassmann M, Muckenthaler MU. Adaptation of iron requirement to hypoxic conditions at high altitude. J Appl Physiol (1985) 2015; 119:1432-40. [PMID: 26183475 DOI: 10.1152/japplphysiol.00248.2015] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 07/10/2015] [Indexed: 12/12/2022] Open
Abstract
Adequate acclimatization time to enable adjustment to hypoxic conditions is one of the most important aspects for mountaineers ascending to high altitude. Accordingly, most reviews emphasize mechanisms that cope with reduced oxygen supply. However, during sojourns to high altitude adjustment to elevated iron demand is equally critical. Thus in this review we focus on the interaction between oxygen and iron homeostasis. We review the role of iron 1) in the oxygen sensing process and erythropoietin (Epo) synthesis, 2) in gene expression control mediated by the hypoxia-inducible factor-2 (HIF-2), and 3) as an oxygen carrier in hemoglobin, myoglobin, and cytochromes. The blood hormone Epo that is abundantly expressed by the kidney under hypoxic conditions stimulates erythropoiesis in the bone marrow, a process requiring high iron levels. To ensure that sufficient iron is provided, Epo-controlled erythroferrone that is expressed in erythroid precursor cells acts in the liver to reduce expression of the iron hormone hepcidin. Consequently, suppression of hepcidin allows for elevated iron release from storage organs and enhanced absorption of dietary iron by enterocytes. As recently observed in sojourners at high altitude, however, iron uptake may be hampered by reduced appetite and gastrointestinal bleeding. Reduced iron availability, as observed in a hypoxic mountaineer, enhances hypoxia-induced pulmonary hypertension and may contribute to other hypoxia-related diseases. Overall, adequate systemic iron availability is an important prerequisite to adjust to high-altitude hypoxia and may have additional implications for disease-related hypoxic conditions.
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Affiliation(s)
- Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, and Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland, and Universidad Peruana Cayetano Heredia, Lima, Peru; and
| | - Martina U Muckenthaler
- Pediatric Oncology, Hematology and Immunology, University Hospital Heidelberg, Molecular Medicine Partnership Unit, University of Heidelberg, Translational Lung Research Center Heidelberg, and German Center for Lung Research, Heidelberg, Germany
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67
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Suzuki N. Erythropoietin gene expression: developmental-stage specificity, cell-type specificity, and hypoxia inducibility. TOHOKU J EXP MED 2015; 235:233-40. [PMID: 25786542 DOI: 10.1620/tjem.235.233] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Erythrocytes play an essential role in the delivery of oxygen from the lung to every organ; a decrease in erythrocytes (anemia) causes hypoxic stress and tissue damage. To maintain oxygen homeostasis in adult mammals, when the kidney senses hypoxia, it secretes an erythroid growth factor, erythropoietin (Epo), which stimulates erythropoiesis in the bone marrow. Recently, studies using genetically modified mice have shown that the in vivo expression profile of the Epo gene changes dramatically during development. The first Epo-producing cells emerge in the neural crest and neuroepithelium of mid-stage embryos and support primitive erythropoiesis in the yolk sac. Subsequently, Epo from the hepatocytes stimulates erythropoiesis in the fetal liver of later stage embryos in a paracrine manner. In fact, erythroid lineage cells comprise the largest cell population in the fetal liver, and hepatocytes are distributed among the erythroid cell clusters. Adult erythropoiesis in the bone marrow requires Epo that is secreted by renal Epo-producing cells (REP cells). REP cells are widely distributed in the renal cortex and outer medulla. Hypoxia-inducible Epo production both in hepatocytes and REP cells is controlled at the gene transcription level that is mainly mediated by the hypoxia-inducible transcription factor (HIF) pathway. These mouse studies further provide insights into the molecular mechanisms of the cell-type specific, hypoxia-inducible expression of the Epo gene, which involves multiple sets of cis- and trans-regulatory elements.
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Affiliation(s)
- Norio Suzuki
- Division of Interdisciplinary Medical Science, Center for Oxygen Medicine, United Centers for Advanced Research and Translational Medicine, Tohoku University Graduate School of Medicine
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68
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Hypoxia Signaling Cascade for Erythropoietin Production in Hepatocytes. Mol Cell Biol 2015; 35:2658-72. [PMID: 26012551 DOI: 10.1128/mcb.00161-15] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/22/2015] [Indexed: 01/01/2023] Open
Abstract
Erythropoietin (Epo) is produced in the kidney and liver in a hypoxia-inducible manner via the activation of hypoxia-inducible transcription factors (HIFs) to maintain oxygen homeostasis. Accelerating Epo production in hepatocytes is one plausible therapeutic strategy for treating anemia caused by kidney diseases. To elucidate the regulatory mechanisms of hepatic Epo production, we analyzed mouse lines harboring liver-specific deletions of genes encoding HIF-prolyl-hydroxylase isoforms (PHD1, PHD2, and PHD3) that mediate the inactivation of HIF1α and HIF2α under normal oxygen conditions. The loss of all PHD isoforms results in both polycythemia, which is caused by Epo overproduction, and fatty livers. We found that deleting any combination of two PHD isoforms induces polycythemia without steatosis complications, whereas the deletion of a single isoform induces no apparent phenotype. Polycythemia is prevented by the loss of either HIF2α or the hepatocyte-specific Epo gene enhancer (EpoHE). Chromatin analyses show that the histones around EpoHE dissociate from the nucleosome structure after HIF2α activation. HIF2α also induces the expression of HIF3α, which is involved in the attenuation of Epo production. These results demonstrate that the total amount of PHD activity is more important than the specific function of each isoform for hepatic Epo expression regulated by a PHD-HIF2α-EpoHE cascade in vivo.
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69
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Jochmans-Lemoine A, Villalpando G, Gonzales M, Valverde I, Soria R, Joseph V. Divergent physiological responses in laboratory rats and mice raised at high altitude. J Exp Biol 2015; 218:1035-1043. [DOI: 10.1242/jeb.112862] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
ABSTRACTEcological studies show that mice can be found at high altitude (HA – up to 4000 m) while rats are absent at these altitudes, and there are no data to explain this discrepancy. We used adult laboratory rats and mice that have been raised for more than 30 generations in La Paz, Bolivia (3600 m), and compared their hematocrit levels, right ventricular hypertrophy (index of pulmonary hypertension) and alveolar surface area in the lungs. We also used whole-body plethysmography, indirect calorimetry and pulse oxymetry to measure ventilation, metabolic rate (O2 consumption and CO2 production), heart rate and pulse oxymetry oxygen saturation (pO2,sat) under ambient conditions, and in response to exposure to sea level PO2 (32% O2=160 mmHg for 10 min) and hypoxia (18% and 15% O2=90 and 75 mmHg for 10 min each). The variables used for comparisons between species were corrected for body mass using standard allometric equations, and are termed mass-corrected variables. Under baseline, compared with rats, adult mice had similar levels of pO2,sat, but lower hematocrit and hemoglobin levels, reduced right ventricular hypertrophy and higher mass-corrected alveolar surface area, tidal volume and metabolic rate. In response to sea level PO2 and hypoxia, mice and rats had similar changes of ventilation, but metabolic rate decreased much more in hypoxia in mice, while pO2,sat remained higher in mice. We conclude that laboratory mice and rats that have been raised at HA for >30 generations have different physiological responses to altitude. These differences might explain the different altitude distribution observed in wild rats and mice.
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Affiliation(s)
| | - Gabriella Villalpando
- Instituto Boliviano de Biologia de Altura, and Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Marcelino Gonzales
- Instituto Boliviano de Biologia de Altura, and Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Ibana Valverde
- Instituto Boliviano de Biologia de Altura, and Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Rudy Soria
- Instituto Boliviano de Biologia de Altura, and Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Vincent Joseph
- Centre de Recherche du CHU de Québec, and Université Laval, Quebec, Quebec, Canada G1L3L5
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Abstract
Long overlooked as the virtual compartment and then strictly characterized through descriptive morphologic analysis, the renal interstitium has finally been associated with function. With identification of interstitial renin- and erythropoietin-producing cells, the most prominent endocrine functions of the kidney have now been attributed to the renal interstitium. This article reviews the functional role of renal interstitium.
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Affiliation(s)
- Michael Zeisberg
- Department of Nephrology and Rheumatology, Göttingen University Medical Center, Georg August University, Göttingen, Germany; and
| | - Raghu Kalluri
- Department of Cancer Biology and the Metastasis Research Center, University of Texas MD Anderson Cancer Center, Houston, Texas
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71
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Roy-Chaudhury P. Emerging Therapies for Chronic Kidney Disease. CHRONIC RENAL DISEASE 2015:771-780. [DOI: 10.1016/b978-0-12-411602-3.00064-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
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Bowers DT, Tanes ML, Das A, Lin Y, Keane NA, Neal RA, Ogle ME, Brayman KL, Fraser CL, Botchwey EA. Spatiotemporal oxygen sensing using dual emissive boron dye-polylactide nanofibers. ACS NANO 2014; 8:12080-91. [PMID: 25426706 PMCID: PMC4278692 DOI: 10.1021/nn504332j] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Oxygenation in tissue scaffolds continues to be a limiting factor in regenerative medicine despite efforts to induce neovascularization or to use oxygen-generating materials. Unfortunately, many established methods to measure oxygen concentration, such as using electrodes, require mechanical disturbance of the tissue structure. To address the need for scaffold-based oxygen concentration monitoring, a single-component, self-referenced oxygen sensor was made into nanofibers. Electrospinning process parameters were tuned to produce a biomaterial scaffold with specific morphological features. The ratio of an oxygen sensitive phosphorescence signal to an oxygen insensitive fluorescence signal was calculated at each image pixel to determine an oxygenation value. A single component boron dye-polymer conjugate was chosen for additional investigation due to improved resistance to degradation in aqueous media compared to a boron dye polymer blend. Standardization curves show that in fully supplemented media, the fibers are responsive to dissolved oxygen concentrations less than 15 ppm. Spatial (millimeters) and temporal (minutes) ratiometric gradients were observed in vitro radiating outward from the center of a dense adherent cell grouping on scaffolds. Sensor activation in ischemia and cell transplant models in vivo show oxygenation decreases on the scale of minutes. The nanofiber construct offers a robust approach to biomaterial scaffold oxygen sensing.
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Affiliation(s)
- Daniel T. Bowers
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Michael L. Tanes
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Anusuya Das
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
- Orthopaedic Surgery, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Yong Lin
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Nicole A. Keane
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Rebekah A. Neal
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Molly E. Ogle
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Kenneth L. Brayman
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
- Department of Surgery, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Cassandra L. Fraser
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Edward A. Botchwey
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
- Address correspondence to
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73
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Bishop T, Ratcliffe PJ. Signaling hypoxia by hypoxia-inducible factor protein hydroxylases: a historical overview and future perspectives. HYPOXIA 2014; 2:197-213. [PMID: 27774477 PMCID: PMC5045067 DOI: 10.2147/hp.s47598] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
By the early 1900s, the close matching of oxygen supply with demand was recognized to be a fundamental requirement for physiological function, and multiple adaptive responses to environment hypoxia had been described. Nevertheless, the widespread operation of mechanisms that directly sense and respond to levels of oxygen in animal cells was not appreciated for most of the twentieth century with investigators generally stressing the regulatory importance of metabolic products. Work over the last 25 years has overturned that paradigm. It has revealed the existence of a set of “oxygen-sensing” 2-oxoglutarate dependent dioxygenases that catalyze the hydroxylation of specific amino acid residues and thereby control the stability and activity of hypoxia-inducible factor. The hypoxia-inducible factor hydroxylase pathway regulates a massive transcriptional cascade that is operative in essentially all animal cells. It transduces a wide range of responses to hypoxia, extending well beyond the classical boundaries of hypoxia physiology. Here we review the discovery and elucidation of these pathways, and consider the opportunities and challenges that have been brought into focus by the findings, including new implications for the integrated physiology of hypoxia and therapeutic approaches to ischemic/hypoxic disease.
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Affiliation(s)
- Tammie Bishop
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
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74
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Wojtal KA, Cee A, Lang S, Götze O, Frühauf H, Geier A, Pastor-Anglada M, Torres-Torronteras J, Martí R, Fried M, Lutz TA, Maggiorini M, Gassmann M, Rogler G, Vavricka SR. Downregulation of duodenal SLC transporters and activation of proinflammatory signaling constitute the early response to high altitude in humans. Am J Physiol Gastrointest Liver Physiol 2014; 307:G673-88. [PMID: 24970780 DOI: 10.1152/ajpgi.00353.2013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Solute carrier (SLC) transporters mediate the uptake of biologically active compounds in the intestine. Reduced oxygenation (hypoxia) is an important factor influencing intestinal homeostasis. The aim of this study was to investigate the pathophysiological consequences of hypoxia on the expression and function of SLCs in human intestine. Hypoxia was induced in human intestinal epithelial cells (IECs) in vitro (0.2; 1% O2 or CoCl2). For human in vivo studies, duodenal biopsies and serum samples were obtained from individuals (n = 16) acutely exposed to 4,554 meters above sea levels. Expression of relevant targets was analyzed by quantitative PCR, Western blotting, or immunofluorescence. Serum levels of inflammatory mediators and nucleosides were determined by ELISA and LC/MS-MS, respectively. In the duodenum of volunteers exposed to high altitude we observed decreased mRNA levels of apical sodium-dependent bile acid transporter (ASBT), concentrative nucleoside transporters 1/2 (CNT1/2), organic anion transporting polypeptide 2B1 (OATP2B1), organic cation transporter 2 (OCTN2), peptide transporter 1 (PEPT1), serotonin transporter (SERT), and higher levels of IFN-γ, IL-6, and IL-17A. Serum levels of IL-10, IFN-γ, matrix metalloproteinase-2 (MMP-2), and serotonin were elevated, whereas the levels of uridine decreased upon exposure to hypoxia. Hypoxic IECs showed reduced levels of equilibrative nucleoside transporter 2 (ENT2), OCTN2, and SERT mRNAs in vitro, which was confirmed on the protein level and was accompanied by activation of ERK1/2, increase of hypoxia-inducible factor (HIF) proteins, and production of IL-8 mRNA. Costimulation with IFN-γ and IL-6 during hypoxia further decreased the expression of SERT, ENT2, and CNT2 in vitro. Reduced oxygen supply affects the expression pattern of duodenal SLCs that is accompanied by changes in serum levels of proinflammatory cytokines and biologically active compounds demonstrating that intestinal transport is affected during systemic exposure to hypoxia in humans.
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Affiliation(s)
- Kacper A Wojtal
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland;
| | - Alexandra Cee
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Silvia Lang
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Oliver Götze
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland; Department of Gastroenterology and Hepatology, University Clinic Würzburg, Würzburg, Germany
| | - Heiko Frühauf
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland; Division of Gastroenterology and Hepatology, Hospital Triemli, Zurich, Switzerland
| | - Andreas Geier
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland; Department of Gastroenterology and Hepatology, University Clinic Würzburg, Würzburg, Germany
| | - Marçal Pastor-Anglada
- Pharmacology and Experimental Therapeutics, Department of Biochemistry and Molecular Biology, Institute of Biomedicine and Oncology Programme, National Biomedical Research Institute of Liver and Gastrointestinal Disease (CIBER EHD), University of Barcelona, Barcelona, Spain
| | - Javier Torres-Torronteras
- Neuromuscular and Mitochondrial Disorders Unit, and Biomedical Network Research Centre on Rare Diseases (CIBERER), Vall d'Hebron Institut de Recerca, Autonomous University of Barcelona, Barcelona, Spain
| | - Ramon Martí
- Neuromuscular and Mitochondrial Disorders Unit, and Biomedical Network Research Centre on Rare Diseases (CIBERER), Vall d'Hebron Institut de Recerca, Autonomous University of Barcelona, Barcelona, Spain
| | - Michael Fried
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Thomas A Lutz
- Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland; Institute of Laboratory Animal Science, University of Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland
| | - Marco Maggiorini
- Intensive Care Unit, Department of Internal Medicine, University of Zurich, Zurich, Switzerland
| | - Max Gassmann
- Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland; Cayetano Heredia University (UPCH), Lima, Peru; and Zurich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland
| | - Gerhard Rogler
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland
| | - Stephan R Vavricka
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland; Division of Gastroenterology and Hepatology, Hospital Triemli, Zurich, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland
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Gardie B, Percy MJ, Hoogewijs D, Chowdhury R, Bento C, Arsenault PR, Richard S, Almeida H, Ewing J, Lambert F, McMullin MF, Schofield CJ, Lee FS. The role of PHD2 mutations in the pathogenesis of erythrocytosis. HYPOXIA 2014; 2:71-90. [PMID: 27774468 PMCID: PMC5045058 DOI: 10.2147/hp.s54455] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The transcription of the erythropoietin (EPO) gene is tightly regulated by the hypoxia response pathway to maintain oxygen homeostasis. Elevations in serum EPO level may be reflected in an augmentation in the red cell mass, thereby causing erythrocytosis. Studies on erythrocytosis have provided insights into the function of the oxygen-sensing pathway and the critical proteins involved in the regulation of EPO transcription. The α subunits of the hypoxia-inducible transcription factor are hydroxylated by three prolyl hydroxylase domain (PHD) enzymes, which belong to the iron and 2-oxoglutarate-dependent oxygenase superfamily. Sequence analysis of the genes encoding the PHDs in patients with erythrocytosis has revealed heterozygous germline mutations only occurring in Egl nine homolog 1 (EGLN1, also known as PHD2), the gene that encodes PHD2. To date, 24 different EGLN1 mutations comprising missense, frameshift, and nonsense mutations have been described. The phenotypes associated with the patients carrying these mutations are fairly homogeneous and typically limited to erythrocytosis with normal to elevated EPO. However, exceptions exist; for example, there is one case with development of concurrent paraganglioma (PHD2-H374R). Analysis of the erythrocytosis-associated PHD2 missense mutations has shown heterogeneous results. Structural studies reveal that mutations can affect different domains of PHD2. Some are close to the hypoxia-inducible transcription factor α/2-oxoglutarate or the iron binding sites for PHD2. In silico studies demonstrate that the mutations do not always affect fully conserved residues. In vitro and in cellulo studies showed varying effects of the mutations, ranging from mild effects to severe loss of function. The exact mechanism of a potential tumor-suppressor role for PHD2 still needs to be elucidated. A knockin mouse model expressing the first reported PHD2-P317R mutation recapitulates the phenotype observed in humans (erythrocytosis with inappropriately normal serum EPO levels) and demonstrates that haploinsufficiency and partial deregulation of PHD2 is sufficient to cause erythrocytosis.
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Affiliation(s)
- Betty Gardie
- Laboratoire de Génétique Oncologique de l'Ecole Pratique des Hautes Etudes, Villejuif; Unité Mixte de Recherche, Institut national de la santé et de la recherche médicale U892, Centre national de la recherche scientifique 6299, Centre de Recherche en Cancérologie Nantes/Angers, Université de Nantes, Nantes, France
| | - Melanie J Percy
- Department of Haematology, Belfast City Hospital, Belfast, UK
| | - David Hoogewijs
- Institute of Physiology and Zürich Center for Integrative Human Physiology, University of Zürich, Zürich, Switzerland
| | - Rasheduzzaman Chowdhury
- Department of Chemistry and Oxford Centre for Integrative Systems Biology, Chemistry Research Laboratory, University of Oxford, Oxford, UK
| | - Celeste Bento
- Department of Hematology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Patrick R Arsenault
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Stéphane Richard
- Laboratoire de Génétique Oncologique de l'Ecole Pratique des Hautes Etudes, Villejuif; Institut national de la santé et de la recherche médicale U753, Institut de cancérologie Gustave Roussy (IGR), Villejuif, France; Faculté de Médecine Paris-Sud, Le Kremlin-Bicêtre, France
| | - Helena Almeida
- Department of Hematology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | | | - Frédéric Lambert
- Center for Human Genetics, Pathology Institute, UniLab-Lg, Molecular Haemato-Oncology Unit, CHU of Liege, Liege, Belgium
| | | | - Christopher J Schofield
- Department of Chemistry and Oxford Centre for Integrative Systems Biology, Chemistry Research Laboratory, University of Oxford, Oxford, UK
| | - Frank S Lee
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Vicha A, Taieb D, Pacak K. Current views on cell metabolism in SDHx-related pheochromocytoma and paraganglioma. Endocr Relat Cancer 2014; 21:R261-77. [PMID: 24500761 PMCID: PMC4016161 DOI: 10.1530/erc-13-0398] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Warburg's metabolic hypothesis is based on the assumption that a cancer cell's respiration must be under attack, leading to its damage, in order to obtain increased glycolysis. Although this may not apply to all cancers, there is some evidence proving that primarily abnormally functioning mitochondrial complexes are indeed related to cancer development. Thus, mutations in complex II (succinate dehydrogenase (SDH)) lead to the formation of pheochromocytoma (PHEO)/paraganglioma (PGL). Mutations in one of the SDH genes (SDHx mutations) lead to succinate accumulation associated with very low fumarate levels, increased glutaminolysis, the generation of reactive oxygen species, and pseudohypoxia. This results in significant changes in signaling pathways (many of them dependent on the stabilization of hypoxia-inducible factor), including oxidative phosphorylation, glycolysis, specific expression profiles, as well as genomic instability and increased mutability resulting in tumor development. Although there is currently no very effective therapy for SDHx-related metastatic PHEOs/PGLs, targeting their fundamental metabolic abnormalities may provide a unique opportunity for the development of novel and more effective forms of therapy for these tumors.
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Affiliation(s)
- Ales Vicha
- Department of Pediatric Hematology and Oncology, 2 Medical School, Charles University and University Hospital Motol, Prague, Czech Republic
| | - David Taieb
- Service Central de Biophysique et de Médecine Nucléaire, CERIMED Centre hospitalo-universitaire Timone, Marseille, France
- Département d’Oncologie Moléculaire, Centre de Recherche en Cancérologie de Marseille, Marseille, France
| | - Karel Pacak
- Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), National Institutes of Health, Bethesda, Maryland, 20892 USA
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Takahashi N, Mori Y. The O(2)-sensing TRPA1 channel illustrates the significance of vagal nerves in cardio-respiratory adaptation to hypoxia. Acta Physiol (Oxf) 2014; 210:705-7. [PMID: 24761462 DOI: 10.1111/apha.12251] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- N. Takahashi
- Laboratory of Molecular Biology; Department of Synthetic Chemistry and Biological Chemistry; Graduate School of Engineering; Kyoto University; Kyoto Japan
- Advanced Biomedical Engineering Research Unit; Kyoto University; Kyoto Japan
| | - Y. Mori
- Laboratory of Molecular Biology; Department of Synthetic Chemistry and Biological Chemistry; Graduate School of Engineering; Kyoto University; Kyoto Japan
- Laboratory of Environmental Systems Biology; Department of Technology and Ecology; Hall of Global Environmental Studies; Kyoto University; Kyoto Japan
- CREST; JST; Chiyoda-ku; Tokyo Japan
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Kaneko N, Kako E, Sawamoto K. Enhancement of ventricular-subventricular zone-derived neurogenesis and oligodendrogenesis by erythropoietin and its derivatives. Front Cell Neurosci 2013; 7:235. [PMID: 24348331 PMCID: PMC3842008 DOI: 10.3389/fncel.2013.00235] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 11/08/2013] [Indexed: 12/17/2022] Open
Abstract
In the postnatal mammalian brain, stem cells in the ventricular-subventricular zone (V-SVZ) continuously generate neuronal and glial cells throughout life. Genetic labeling of cells of specific lineages have demonstrated that the V-SVZ is an important source of the neuroblasts and/or oligodendrocyte progenitor cells (OPCs) that migrate toward injured brain areas in response to several types of insult, including ischemia and demyelinating diseases. However, this spontaneous regeneration is insufficient for complete structural and functional restoration of the injured brain, so interventions to enhance these processes are sought for clinical applications. Erythropoietin (EPO), a clinically applied erythropoietic factor, is reported to have cytoprotective effects in various kinds of insult in the central nervous system. Moreover, recent studies suggest that EPO promotes the V-SVZ-derived neurogenesis and oligodendrogenesis. EPO increases the proliferation of progenitors in the V-SVZ and/or the migration and differentiation of their progenies in and around injured areas, depending on the dosage, timing, and duration of treatment, as well as the type of animal model used. On the other hand, EPO has undesirable side effects, including thrombotic complications. We recently demonstrated that a 2-week treatment with the EPO derivative asialo-EPO promotes the differentiation of V-SVZ-derived OPCs into myelin-forming mature oligodendrocytes in the injured white matter of neonatal mice without causing erythropoiesis. Here we present an overview of the multifaceted effects of EPO and its derivatives in the V-SVZ and discuss the possible applications of these molecules in regenerative medicine.
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Affiliation(s)
- Naoko Kaneko
- Department of Developmental and Regenerative Biology, Nagoya City University Graduate School of Medical Sciences Nagoya, Japan
| | - Eisuke Kako
- Department of Developmental and Regenerative Biology, Nagoya City University Graduate School of Medical Sciences Nagoya, Japan ; Department of Anesthesiology and Medical Crisis Management, Nagoya City University Graduate School of Medical Sciences Nagoya, Japan
| | - Kazunobu Sawamoto
- Department of Developmental and Regenerative Biology, Nagoya City University Graduate School of Medical Sciences Nagoya, Japan
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