1
|
Dou X, Chen Z, Liu Y, Li Y, Ye J, Lu L. Zebrafish mutants in egln1 display a hypoxic response and develop polycythemia. Life Sci 2024; 344:122564. [PMID: 38492922 DOI: 10.1016/j.lfs.2024.122564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/10/2024] [Accepted: 03/13/2024] [Indexed: 03/18/2024]
Abstract
AIMS Prolyl hydroxylase domain 2 (PHD2), encoded by the Egln1 gene, serves as a pivotal regulator of the hypoxia-inducible factor (HIF) pathway and acts as a cellular oxygen sensor. Somatic inactivation of Phd2 in mice results in polycythemia and congestive heart failure. However, due to the embryonic lethality of Phd2 deficiency, its role in development remains elusive. Here, we investigated the function of two egln1 paralogous genes, egln1a and egln1b, in zebrafish. MAIN METHODS The egln1 null zebrafish were generated using the CRISPR/Cas9 system. Quantitative real-time PCR assays and Western blot analysis were employed to detect the effect of egln1 deficiency on the hypoxia signaling pathway. The hypoxia response of egln1 mutant zebrafish were assessed by analyzing heart rate, gill agitation frequency, and blood flow velocity. Subsequently, o-dianisidine staining and in situ hybridization were used to investigate the role of egln1 in zebrafish hematopoietic function. KEY FINDINGS Our data show that the loss of egln1a or egln1b individually has no visible effects on growth rate. However, the egln1a; egln1b double mutant displayed significant growth retardation and elevated mortality at around 2.5 months old. Both egln1a-null and egln1b-null zebrafish embryo exhibited enhanced tolerance to hypoxia, systemic hypoxic response that include hif pathway activation, increased cardiac activity, and polycythemia. SIGNIFICANCE Our research introduces zebrafish egln1 mutants as the first congenital embryonic viable systemic vertebrate animal model for PHD2, providing novel insights into hypoxic signaling and the progression of PHD2- associated disease.
Collapse
Affiliation(s)
- Xuehan Dou
- Laboratory for Marine Drugs and Bioproducts of Laoshan Laboratory, Qingdao, China; Key Laboratory of Marine Drugs, The Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Zhongyuan Chen
- Laboratory for Marine Drugs and Bioproducts of Laoshan Laboratory, Qingdao, China; Key Laboratory of Marine Drugs, The Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Yunzhang Liu
- Laboratory for Marine Drugs and Bioproducts of Laoshan Laboratory, Qingdao, China; Key Laboratory of Marine Drugs, The Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Yun Li
- Laboratory for Marine Drugs and Bioproducts of Laoshan Laboratory, Qingdao, China; Key Laboratory of Marine Drugs, The Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Junli Ye
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Ling Lu
- Laboratory for Marine Drugs and Bioproducts of Laoshan Laboratory, Qingdao, China; Key Laboratory of Marine Drugs, The Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China.
| |
Collapse
|
2
|
Fiorini G, Schofield CJ. Biochemistry of the hypoxia-inducible factor hydroxylases. Curr Opin Chem Biol 2024; 79:102428. [PMID: 38330792 DOI: 10.1016/j.cbpa.2024.102428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/11/2024] [Accepted: 01/11/2024] [Indexed: 02/10/2024]
Abstract
The hypoxia-inducible factors are α,β-heterodimeric transcription factors that mediate the chronic response to hypoxia in humans and other animals. Protein hydroxylases belonging to two different structural subfamilies of the Fe(II) and 2-oxoglutarate (2OG)-dependent oxygenase superfamily modify HIFα. HIFα prolyl-hydroxylation, as catalysed by the PHDs, regulates HIFα levels and, consequently, α,β-HIF levels. HIFα asparaginyl-hydroxylation, as catalysed by factor inhibiting HIF (FIH), regulates the transcriptional activity of α,β-HIF. The activities of the PHDs and FIH are regulated by O2 availability, enabling them to act as hypoxia sensors. We provide an overview of the biochemistry of the HIF hydroxylases, discussing evidence that their kinetic and structural properties may be tuned to their roles in the HIF system. Avenues for future research and therapeutic modulation are discussed.
Collapse
Affiliation(s)
- Giorgia Fiorini
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, 12 Mansfield Road, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom
| | - Christopher J Schofield
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, 12 Mansfield Road, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom.
| |
Collapse
|
3
|
Jucht AE, Scholz CC. PHD1-3 oxygen sensors in vivo-lessons learned from gene deletions. Pflugers Arch 2024:10.1007/s00424-024-02944-x. [PMID: 38509356 DOI: 10.1007/s00424-024-02944-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 03/02/2024] [Accepted: 03/07/2024] [Indexed: 03/22/2024]
Abstract
Oxygen sensors enable cells to adapt to limited oxygen availability (hypoxia), affecting various cellular and tissue responses. Prolyl-4-hydroxylase domain 1-3 (PHD1-3; also called Egln1-3, HIF-P4H 1-3, HIF-PH 1-3) proteins belong to the Fe2+- and 2-oxoglutarate-dependent dioxygenase superfamily and utilise molecular oxygen (O2) alongside 2-oxoglutarate as co-substrate to hydroxylate two proline residues of α subunits of the dimeric hypoxia inducible factor (HIF) transcription factor. PHD1-3-mediated hydroxylation of HIF-α leads to its degradation and inactivation. Recently, various PHD inhibitors (PHI) have entered the clinics for treatment of renal anaemia. Pre-clinical analyses indicate that PHI treatment may also be beneficial in numerous other hypoxia-associated diseases. Nonetheless, the underlying molecular mechanisms of the observed protective effects of PHIs are only partly understood, currently hindering their translation into the clinics. Moreover, the PHI-mediated increase of Epo levels is not beneficial in all hypoxia-associated diseases and PHD-selective inhibition may be advantageous. Here, we summarise the current knowledge about the relevance and function of each of the three PHD isoforms in vivo, based on the deletion or RNA interference-mediated knockdown of each single corresponding gene in rodents. This information is crucial for our understanding of the physiological relevance and function of the PHDs as well as for elucidating their individual impact on hypoxia-associated diseases. Furthermore, this knowledge highlights which diseases may best be targeted by PHD isoform-selective inhibitors in case such pharmacologic substances become available.
Collapse
Affiliation(s)
- Agnieszka E Jucht
- Institute of Physiology, University of Zurich, Zurich, 8057, Switzerland
| | - Carsten C Scholz
- Institute of Physiology, University Medicine Greifswald, Friedrich-Ludwig-Jahn-Str. 15a, 17475, Greifswald, Germany.
| |
Collapse
|
4
|
Delamare M, Le Roy A, Pacault M, Schmitt L, Garrec C, Maaziz N, Myllykoski M, Rimbert A, Karaghiannis V, Aral B, Catherwood M, Airaud F, Mansour-Hendili L, Hoogewijs D, Peroni E, Idriss S, Lesieur V, Caillaud A, Si-Tayeb K, Chariau C, Gaignerie A, Rab M, Haferlach T, Meggendorfer M, Bézieau S, Benetti A, Casadevall N, Hirsch P, Rose C, Wemeau M, Galacteros F, Cassinat B, Bellosillo B, Bento C, Van Wijk R, Petrides PE, Randi ML, McMullin MF, Koivunen P, Girodon F, Gardie B. Characterization of genetic variants in the EGLN1/PHD2 gene identified in a European collection of patients with erythrocytosis. Haematologica 2023; 108:3068-3085. [PMID: 37317877 PMCID: PMC10620589 DOI: 10.3324/haematol.2023.282913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 06/06/2023] [Indexed: 06/16/2023] Open
Abstract
Hereditary erythrocytosis is a rare hematologic disorder characterized by an excess of red blood cell production. Here we describe a European collaborative study involving a collection of 2,160 patients with erythrocytosis sequenced in ten different laboratories. We focused our study on the EGLN1 gene and identified 39 germline missense variants including one gene deletion in 47 probands. EGLN1 encodes the PHD2 prolyl 4-hydroxylase, a major inhibitor of hypoxia-inducible factor. We performed a comprehensive study to evaluate the causal role of the identified PHD2 variants: (i) in silico studies of localization, conservation, and deleterious effects; (ii) analysis of hematologic parameters of carriers identified in the UK Biobank; (iii) functional studies of the protein activity and stability; and (iv) a comprehensive study of PHD2 splicing. Altogether, these studies allowed the classification of 16 pathogenic or likely pathogenic mutants in a total of 48 patients and relatives. The in silico studies extended to the variants described in the literature showed that a minority of PHD2 variants can be classified as pathogenic (36/96), without any differences from the variants of unknown significance regarding the severity of the developed disease (hematologic parameters and complications). Here, we demonstrated the great value of federating laboratories working on such rare disorders in order to implement the criteria required for genetic classification, a strategy that should be extended to all hereditary hematologic diseases.
Collapse
Affiliation(s)
- Marine Delamare
- Ecole Pratique des Hautes Etudes, EPHE, Université PSL, France; Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes
| | - Amandine Le Roy
- Ecole Pratique des Hautes Etudes, EPHE, Université PSL, France; Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes
| | - Mathilde Pacault
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France; Service de Génétique Médicale, CHU de Nantes, Nantes
| | - Loïc Schmitt
- Ecole Pratique des Hautes Etudes, EPHE, Université PSL, France; Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes
| | - Céline Garrec
- Service de Génétique Médicale, CHU de Nantes, Nantes
| | - Nada Maaziz
- Service d'Hématologie Biologique, Pôle Biologie, CHU de Dijon, Dijon
| | - Matti Myllykoski
- Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, Oulu Center for Cell-Matrix Research, University of Oulu, 90014 Oulu, Finland. 90014 Oulu
| | - Antoine Rimbert
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes
| | - Valéna Karaghiannis
- Ecole Pratique des Hautes Etudes, EPHE, Université PSL, France; Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes
| | - Bernard Aral
- Service d'Hématologie Biologique, Pôle Biologie, CHU de Dijon, Dijon
| | | | | | - Lamisse Mansour-Hendili
- Département de Biochimie-Biologie Moléculaire, Pharmacologie, Génétique Médicale AP-HP, Hôpitaux Universitaires Henri Mondor, Créteil, France; Université Paris-Est Créteil, IMRB Equipe Pirenne, Laboratoire d'excellence LABEX GRex, Créteil
| | - David Hoogewijs
- Section of Medicine, Department of Endocrinology, Metabolism and Cardiovascular System, University of Fribourg, CH-1700 Fribourg, Switzerland; National Center of Competence in Research "Kidney.CH"
| | - Edoardo Peroni
- Immunology and Molecular Oncology Unit, Veneto Institute of Oncology, IOV-IRCCS, 35128 Padova, Italy; Medical Genetics Unit, Mater Domini University Hospital, 88100 Catanzaro
| | - Salam Idriss
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes
| | - Valentine Lesieur
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes
| | - Amandine Caillaud
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes
| | - Karim Si-Tayeb
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes
| | - Caroline Chariau
- Nantes Université, CHU Nantes, CNRS, Inserm, BioCore, FR-44000, Nantes
| | - Anne Gaignerie
- Nantes Université, CHU Nantes, CNRS, Inserm, BioCore, FR-44000, Nantes
| | - Minke Rab
- Central Diagnostic Laboratory - Research, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands; Department of Hematology, University Medical Center Utrecht, Utrecht University, Utrecht
| | | | | | - Stéphane Bézieau
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France; Service de Génétique Médicale, CHU de Nantes, Nantes
| | - Andrea Benetti
- Department of Medicine-DIMED, University of Padua, Via Giustiniani 2, 35128, Padua
| | - Nicole Casadevall
- Sorbonne Université, INSERM, Centre de Recherche Saint-Antoine, CRSA, AP-HP, SIRIC CURAMUS, Hôpital Saint-Antoine, Service d'Hématologie Biologique, 75012, Paris
| | - Pierre Hirsch
- Sorbonne Université, INSERM, Centre de Recherche Saint-Antoine, CRSA, AP-HP, SIRIC CURAMUS, Hôpital Saint-Antoine, Service d'Hématologie Biologique, 75012, Paris
| | - Christian Rose
- Service d'onco-hématologie, Saint-Vincent de Paul Hospital, Boulevard de Belfort, Université Catholique de Lille, Univ. Nord de France, F-59000 Lille
| | - Mathieu Wemeau
- Hematology Department, Claude Huriez Hospital, Lille Hospital, 59000 Lille
| | - Frédéric Galacteros
- Département de Biochimie-Biologie Moléculaire, Pharmacologie, Génétique Médicale AP-HP, Hôpitaux Universitaires Henri Mondor, Créteil, France; Red Cell Disease Referral Center-UMGGR, AP-HP, Hôpitaux Universitaires Henri Mondor, Créteil
| | - Bruno Cassinat
- Université Paris Cité, APHP, Hôpital Saint-Louis, Laboratoire de Biologie Cellulaire, Paris
| | | | - Celeste Bento
- Hematology Department, Centro Hospitalar e Universitário de Coimbra; CIAS, University of Coimbra
| | - Richard Van Wijk
- Central Diagnostic Laboratory - Research, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands; Department of Hematology, University Medical Center Utrecht, Utrecht University, Utrecht
| | - Petro E Petrides
- Hematology Oncology Center and Ludwig-Maximilians-University Munich Medical School, Munich
| | - Maria Luigia Randi
- Department of Medicine-DIMED, University of Padua, Via Giustiniani 2, 35128, Padua
| | - Mary Frances McMullin
- Belfast Health and Social Care Trust, Belfast N.Ireland; Queen's University, Belfast, N. Ireland
| | - Peppi Koivunen
- Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, Oulu Center for Cell-Matrix Research, University of Oulu, 90014 Oulu, Finland. 90014 Oulu
| | - François Girodon
- Service d'Hématologie Biologique, Pôle Biologie, CHU de Dijon, Dijon, France; Inserm U1231, Université de Bourgogne, Dijon, France; Laboratoire d'Excellence GR-Ex
| | - Betty Gardie
- Ecole Pratique des Hautes Etudes, EPHE, Université PSL, France; Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France; Laboratoire d'Excellence GR-Ex
| |
Collapse
|
5
|
Rosenblum JS, Wang H, Nazari MA, Zhuang Z, Pacak K. Pacak-Zhuang syndrome: a model providing new insights into tumor syndromes. Endocr Relat Cancer 2023; 30:e230050. [PMID: 37450881 PMCID: PMC10512798 DOI: 10.1530/erc-23-0050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 07/14/2023] [Indexed: 07/18/2023]
Abstract
This article is a summary of the plenary lecture presented by Jared Rosenblum that was awarded the Manger Prize at the Sixth International Symposium on Pheochromocytoma/Paraganglioma held on 19-22 October 2022 in Prague, Czech Republic. Herein, we review our initial identification of a new syndrome of multiple paragangliomas, somatostatinomas, and polycythemia caused by early postzygotic mosaic mutations in EPAS1, encoding hypoxia-inducible factor 2 alpha (HIF-2α), and our continued exploration of new disease phenotypes in this syndrome, including vascular malformations and neural tube defects. Continued recruitment and close monitoring of patients with this syndrome as well as the generation and study of a corresponding disease mouse model as afforded by the pheochromocytoma/paraganglioma translational program at the National Institutes of Health has provided new insights into the natural history of these developmental anomalies and the pathophysiologic role of HIF-2α. Further, these studies have highlighted the importance of the timing of genetic defects in the development of related disease phenotypes. The recent discovery and continued study of this syndrome has not only rapidly evolved our understanding of pheochromocytoma and paraganglioma but also deepened our understanding of other developmental tumor syndromes, heritable syndromes, and sporadic diseases.
Collapse
Affiliation(s)
- Jared S Rosenblum
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Herui Wang
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Matthew A Nazari
- Eunice Kennedy Shriver National Institute of Child Health and Development, Bethesda, MD, 20892
| | - Zhengping Zhuang
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Karel Pacak
- Eunice Kennedy Shriver National Institute of Child Health and Development, Bethesda, MD, 20892
| |
Collapse
|
6
|
Jorgensen K, Song D, Weinstein J, Garcia OA, Pearson LN, Inclán M, Rivera-Chira M, León-Velarde F, Kiyamu M, Brutsaert TD, Bigham AW, Lee FS. High-Altitude Andean H194R HIF2A Allele Is a Hypomorphic Allele. Mol Biol Evol 2023; 40:msad162. [PMID: 37463421 PMCID: PMC10370452 DOI: 10.1093/molbev/msad162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/15/2023] [Accepted: 07/03/2023] [Indexed: 07/20/2023] Open
Abstract
For over 10,000 years, Andeans have resided at high altitude where the partial pressure of oxygen challenges human survival. Recent studies have provided evidence for positive selection acting in Andeans on the HIF2A (also known as EPAS1) locus, which encodes for a central transcription factor of the hypoxia-inducible factor pathway. However, the precise mechanism by which this allele might lead to altitude-adaptive phenotypes, if any, is unknown. By analyzing whole genome sequencing data from 46 high-coverage Peruvian Andean genomes, we confirm evidence for positive selection acting on HIF2A and a unique pattern of variation surrounding the Andean-specific single nucleotide variant (SNV), rs570553380, which encodes for an H194R amino acid substitution in HIF-2α. Genotyping the Andean-associated SNV rs570553380 in a group of 299 Peruvian Andeans from Cerro de Pasco, Peru (4,338 m), reveals a positive association with increased fraction of exhaled nitric oxide, a marker of nitric oxide biosynthesis. In vitro assays show that the H194R mutation impairs binding of HIF-2α to its heterodimeric partner, aryl hydrocarbon receptor nuclear translocator. A knockin mouse model bearing the H194R mutation in the Hif2a gene displays decreased levels of hypoxia-induced pulmonary Endothelin-1 transcripts and protection against hypoxia-induced pulmonary hypertension. We conclude the Andean H194R HIF2A allele is a hypomorphic (partial loss of function) allele.
Collapse
Affiliation(s)
- Kelsey Jorgensen
- Department of Anthropology, University of California, Los Angeles, CA, USA
| | - Daisheng Song
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Julien Weinstein
- Department of Anthropology, The University of Michigan, Ann Arbor, MI, USA
| | - Obed A Garcia
- Department of Biomedical Data Science, Stanford University, Stanford, CA, USA
| | - Laurel N Pearson
- Department of Anthropology, The Pennsylvania State University, State College, PA, USA
| | - María Inclán
- División de. Estudios Políticos, Centro de Investigación y Docencia Económicas, Mexico City, CDMX, Mexico
| | - Maria Rivera-Chira
- Departamento de Ciencias Biológicas y Fisiológicas, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Lima, Peru
| | - Fabiola León-Velarde
- Departamento de Ciencias Biológicas y Fisiológicas, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Lima, Peru
| | - Melisa Kiyamu
- Departamento de Ciencias Biológicas y Fisiológicas, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Lima, Peru
| | - Tom D Brutsaert
- Department of Exercise Science, Syracuse University, Syracuse, NY, USA
| | - Abigail W Bigham
- Department of Anthropology, University of California, Los Angeles, CA, USA
| | - Frank S Lee
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| |
Collapse
|
7
|
Song D, Peng K, Palmer BE, Lee FS. The ribosomal chaperone NACA recruits PHD2 to cotranslationally modify HIF-α. EMBO J 2022; 41:e112059. [PMID: 36219563 PMCID: PMC9670199 DOI: 10.15252/embj.2022112059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/23/2022] [Accepted: 09/23/2022] [Indexed: 01/13/2023] Open
Abstract
Prolyl hydroxylase domain protein 2 (PHD2)-catalyzed modification of hypoxia-inducible factor (HIF)-α is a key event in oxygen sensing. We previously showed that the zinc finger of PHD2 binds to a Pro-Xaa-Leu-Glu (PXLE) motif. Here, we show that the zinc finger binds to this motif in the ribosomal chaperone nascent polypeptide complex-α (NACA). This recruits PHD2 to the translation machinery to cotranslationally modify HIF-α. Importantly, this cotranslational modification is enhanced by a translational pause sequence in HIF-α. Mice with a knock-in Naca gene mutation that abolishes the PXLE motif display erythrocytosis, a reflection of HIF pathway dysregulation. In addition, human erythrocytosis-associated mutations in the zinc finger of PHD2 ablate interaction with NACA. Tibetans, who have adapted to the hypoxia of high altitude, harbor a PHD2 variant that we previously showed displays a defect in zinc finger binding to p23, a PXLE-containing HSP90 cochaperone. We show here that Tibetan PHD2 maintains interaction with NACA, thereby showing differential interactions with PXLE-containing proteins and providing an explanation for why Tibetans are not predisposed to erythrocytosis.
Collapse
Affiliation(s)
- Daisheng Song
- Department of Pathology and Laboratory Medicine, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Kai Peng
- Department of Pathology and Laboratory Medicine, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
- Present address:
Chime BiologicsWuhanChina
| | - Bradleigh E Palmer
- Department of Pathology and Laboratory Medicine, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
- Present address:
Department of BiologyJohns Hopkins UniversityBaltimoreMDUSA
| | - Frank S Lee
- Department of Pathology and Laboratory Medicine, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| |
Collapse
|
8
|
Ohh M, Taber CC, Ferens FG, Tarade D. Hypoxia-inducible factor underlies von Hippel-Lindau disease stigmata. eLife 2022; 11:80774. [PMID: 36040300 PMCID: PMC9427099 DOI: 10.7554/elife.80774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 08/12/2022] [Indexed: 11/13/2022] Open
Abstract
von Hippel-Lindau (VHL) disease is a rare hereditary cancer syndrome that causes a predisposition to renal clear-cell carcinoma, hemangioblastoma, pheochromocytoma, and autosomal-recessive familial polycythemia. pVHL is the substrate conferring subunit of an E3 ubiquitin ligase complex that binds to the three hypoxia-inducible factor alpha subunits (HIF1-3α) for polyubiquitylation under conditions of normoxia, targeting them for immediate degradation by the proteasome. Certain mutations in pVHL have been determined to be causative of VHL disease through the disruption of HIFα degradation. However, it remains a focus of investigation and debate whether the disruption of HIFα degradation alone is sufficient to explain the complex genotype-phenotype relationship of VHL disease or whether the other lesser or yet characterized substrates and functions of pVHL impact the development of the VHL disease stigmata; the elucidation of which would have a significant ramification to the direction of research efforts and future management and care of VHL patients and for those manifesting sporadic counterparts of VHL disease. Here, we examine the current literature including the other emergent pseudohypoxic diseases and propose that the VHL disease-phenotypic spectrum could be explained solely by the varied disruption of HIFα signaling upon the loss or mutation in pVHL.
Collapse
Affiliation(s)
- Michael Ohh
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Canada.,Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Cassandra C Taber
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Fraser G Ferens
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Canada.,Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Daniel Tarade
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Canada
| |
Collapse
|
9
|
McMullin MF. Genetic Background of Congenital Erythrocytosis. Genes (Basel) 2021; 12:genes12081151. [PMID: 34440325 PMCID: PMC8392557 DOI: 10.3390/genes12081151] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 01/14/2023] Open
Abstract
True erythrocytosis is present when the red cell mass is greater than 125% of predicted sex and body mass, which is reflected by elevated hemoglobin and hematocrit. Erythrocytosis can be primary or secondary and congenital or acquired. Congenital defects are often found in those diagnosed at a young age and with a family history of erythrocytosis. Primary congenital defects mainly include mutations in the Erythropoietin receptor gene but SH2B3 has also been implicated. Secondary congenital erythrocytosis can arise through a variety of genetic mechanisms, including mutations in the genes in the oxygen sensing pathway, with high oxygen affinity hemoglobin variants and mutations in other genes such as BPMG, where ultimately the production of erythropoietin is increased, resulting in erythrocytosis. Recently, mutations in PIEZ01 have been associated with erythrocytosis. In many cases, a genetic variant cannot be identified, leaving a group of patients with the label idiopathic erythrocytosis who should be the subject of future investigations. The clinical course in congenital erythrocytosis is hard to evaluate as these are rare cases. However, some of these patients may well present at a young age and with sometimes catastrophic thromboembolic events. There is little evidence to guide the management of congenital erythrocytosis but the use of venesection and low dose aspirin should be considered.
Collapse
|
10
|
Storz JF. High-Altitude Adaptation: Mechanistic Insights from Integrated Genomics and Physiology. Mol Biol Evol 2021; 38:2677-2691. [PMID: 33751123 PMCID: PMC8233491 DOI: 10.1093/molbev/msab064] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Population genomic analyses of high-altitude humans and other vertebrates have identified numerous candidate genes for hypoxia adaptation, and the physiological pathways implicated by such analyses suggest testable hypotheses about underlying mechanisms. Studies of highland natives that integrate genomic data with experimental measures of physiological performance capacities and subordinate traits are revealing associations between genotypes (e.g., hypoxia-inducible factor gene variants) and hypoxia-responsive phenotypes. The subsequent search for causal mechanisms is complicated by the fact that observed genotypic associations with hypoxia-induced phenotypes may reflect second-order consequences of selection-mediated changes in other (unmeasured) traits that are coupled with the focal trait via feedback regulation. Manipulative experiments to decipher circuits of feedback control and patterns of phenotypic integration can help identify causal relationships that underlie observed genotype–phenotype associations. Such experiments are critical for correct inferences about phenotypic targets of selection and mechanisms of adaptation.
Collapse
Affiliation(s)
- Jay F Storz
- School of Biological Sciences, University of Nebraska, Lincoln, NE, USA
| |
Collapse
|
11
|
High-altitude deer mouse hypoxia-inducible factor-2α shows defective interaction with CREB-binding protein. J Biol Chem 2021; 296:100461. [PMID: 33639161 PMCID: PMC8024697 DOI: 10.1016/j.jbc.2021.100461] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 02/16/2021] [Accepted: 02/23/2021] [Indexed: 12/26/2022] Open
Abstract
Numerous mammalian species have adapted to the chronic hypoxia of high altitude. Recent genomic studies have identified evidence for natural selection of genes and associated genetic changes in these species. A major gap in our knowledge is an understanding of the functional significance, if any, of these changes. Deer mice (Peromyscus maniculatus) live at both low and high altitudes in North America, providing an opportunity to identify functionally important genetic changes. High-altitude deer mice show evidence of natural selection on the Epas1 gene, which encodes for hypoxia-inducible factor-2α (Hif-2α), a central transcription factor of the hypoxia-inducible factor pathway. An SNP encoding for a T755M change in the Hif-2α protein is highly enriched in high-altitude deer mice, but its functional significance is unknown. Here, using coimmunoprecipitation and transcriptional activity assays, we show that the T755M mutation produces a defect in the interaction of Hif-2α with the transcriptional coactivator CREB-binding protein. This results in a loss of function because of decreased transcriptional activity. Intriguingly, the effect of this mutation depends on the amino acid context. Interchanges between methionine and threonine at the corresponding position in house mouse (Mus musculus) Hif-2α are without effects on CREB-binding protein binding. Furthermore, transfer of a set of deer mouse–specific Hif-2α amino acids to house mouse Hif-2α is sufficient to confer sensitivity of house mouse Hif-2α to the T755M substitution. These findings provide insight into high-altitude adaptation in deer mice and evolution at the Epas1 locus.
Collapse
|
12
|
Mei H, Wu N, Huang X, Cui Z, Xu J, Yang X, Zeng F, Wang K. Possible mechanisms by which silkworm faeces extract ameliorates adenine-induced renal anaemia in rats. JOURNAL OF ETHNOPHARMACOLOGY 2021; 266:113448. [PMID: 33022342 DOI: 10.1016/j.jep.2020.113448] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 06/15/2020] [Accepted: 09/30/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Silkworm faeces are the dry faeces of the insect Bombyx mori (Linnaeus) and have historically been used in traditional Chinese medicine to treat blood deficiency and rheumatic pain. Silkworm faeces extract (SFE) is derived from silkworm faeces. AIM OF THE STUDY Clinical observations of patients in the Department of Nephrology have shown that SFE effectively improves renal anaemia. However, the molecular mechanism remains unclear. This article mainly explores the regulatory effects of SFE on erythropoietin (EPO) and hepcidin to identify the molecular mechanism of SFE. MATERIALS AND METHODS A rat model of renal anaemia was established by feeding rats food containing 0.75% adenine. SFE was orally administered to the rats, while recombinant human erythropoietin (rhEPO) was used as a positive control drug. Haematological parameters and inflammation levels were compared between rats from each group, and pathological kidney sections from each rat were observed. The serum EPO and hepcidin levels were detected using enzyme-linked immunosorbent assay (ELISA) kits, while Western blot analyses were performed to detect the levels of proteins involved in the EPO-related hypoxia-inducible factor 2α (HIF-2α)/prolyl hydroxylase 2 (PHD2) signalling pathway and hepcidin-related BMP6/SMAD4 and interleukin-6 (IL-6)/STAT3 signalling pathways. RESULTS SFE significantly ameliorated haematological parameters, renal function, and inflammation levels in the rats. A mechanistic study showed that SFE promoted EPO expression by upregulating HIF-2α expression and inhibiting the expression of NF-κB and GATA2 both in vivo and in vitro. In particular, SFE inhibited PHD2 expression, resulting in a decrease in the enzymatic reaction of HIF-2α to increase EPO expression. Furthermore, SFE inhibited hepcidin expression by blocking the BMP6/SMAD4 and IL-6/STAT3 pathways. CONCLUSIONS SFE regulated iron metabolism by inhibiting hepcidin and simultaneously promoted EPO synthesis to improve renal anaemia in rats.
Collapse
Affiliation(s)
- Hao Mei
- Hubei Key Laboratory of Nature Medicinal Chemistry and Resource Evaluation, Tongji Medical College of Huazhong University of Science and Technology, No. 13, Hongkong Road, 430030, Wuhan, China
| | - Niuniu Wu
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Xiao Huang
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Zheng Cui
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jingya Xu
- Hubei Key Laboratory of Nature Medicinal Chemistry and Resource Evaluation, Tongji Medical College of Huazhong University of Science and Technology, No. 13, Hongkong Road, 430030, Wuhan, China
| | - Xiawen Yang
- Hubei Key Laboratory of Nature Medicinal Chemistry and Resource Evaluation, Tongji Medical College of Huazhong University of Science and Technology, No. 13, Hongkong Road, 430030, Wuhan, China
| | - Fang Zeng
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Kaiping Wang
- Hubei Key Laboratory of Nature Medicinal Chemistry and Resource Evaluation, Tongji Medical College of Huazhong University of Science and Technology, No. 13, Hongkong Road, 430030, Wuhan, China.
| |
Collapse
|
13
|
Hypoxia Pathway Proteins are Master Regulators of Erythropoiesis. Int J Mol Sci 2020; 21:ijms21218131. [PMID: 33143240 PMCID: PMC7662373 DOI: 10.3390/ijms21218131] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 10/21/2020] [Accepted: 10/28/2020] [Indexed: 02/06/2023] Open
Abstract
Erythropoiesis is a complex process driving the production of red blood cells. During homeostasis, adult erythropoiesis takes place in the bone marrow and is tightly controlled by erythropoietin (EPO), a central hormone mainly produced in renal EPO-producing cells. The expression of EPO is strictly regulated by local changes in oxygen partial pressure (pO2) as under-deprived oxygen (hypoxia); the transcription factor hypoxia-inducible factor-2 induces EPO. However, erythropoiesis regulation extends beyond the well-established hypoxia-inducible factor (HIF)-EPO axis and involves processes modulated by other hypoxia pathway proteins (HPPs), including proteins involved in iron metabolism. The importance of a number of these factors is evident as their altered expression has been associated with various anemia-related disorders, including chronic kidney disease. Eventually, our emerging understanding of HPPs and their regulatory feedback will be instrumental in developing specific therapies for anemic patients and beyond.
Collapse
|
14
|
Li L, Nakano D, Zhang A, Kittikulsuth W, Morisawa N, Ohsaki H, Suzuki N, Yamamoto M, Nishiyama A. Effects of post-renal anemia treatment with the HIF-PHD inhibitor molidustat on adenine-induced renal anemia and kidney disease in mice. J Pharmacol Sci 2020; 144:229-236. [PMID: 33070842 DOI: 10.1016/j.jphs.2020.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/27/2020] [Accepted: 09/14/2020] [Indexed: 02/06/2023] Open
Abstract
The kidneys are the major organs for erythropoietin (EPO) production in adults, and thus, kidney damage results in reduced EPO levels and anemia. Inhibitors of Hypoxia-inducible factor-prolyl hydroxylase domain-containing protein (HIF-PHD) are awaited as new therapeutic options for renal anemia. It can be predicted that most patients who receive HIF-PHD inhibitors have renal dysfunction as a cause of anemia. Therefore, in the present study, we investigated the effects of the HIF-PHD inhibitor molidustat on anemia and renal dysfunction when initiated after the onset of renal anemia. Male C57BL/6J mice received adenine orally to induce nephropathy. After the onset of nephropathy, the mice were treated with either vehicle or molidustat. After 4 weeks of administration, vehicle-treated mice displayed significant anemia, and molidustat ameliorated this anemia. Vehicle-treated mice exhibited reduced creatinine clearance and body weight, increased blood urea nitrogen levels, histopathological changes, immune cell infiltration, and dehydration. Molidustat reversed immune cell infiltration, dehydration, and renal fibrosis without improving renal functional parameters. In conclusion, molidustat treatment initiated after the onset of nephropathy and renal anemia reversed anemia in mice. Molidustat improved some parameters of renal abnormality, but it did not restore renal function.
Collapse
Affiliation(s)
- Lei Li
- Department of Pharmacology, Kagawa University Medical School, Kagawa, Japan
| | - Daisuke Nakano
- Department of Pharmacology, Kagawa University Medical School, Kagawa, Japan.
| | - Anqi Zhang
- Department of Pharmacology, Kagawa University Medical School, Kagawa, Japan
| | | | - Norihiko Morisawa
- Department of Pharmacology, Kagawa University Medical School, Kagawa, Japan
| | - Hiroyuki Ohsaki
- Laboratory of Pathology, Department of Medical Biophysics, Kobe University Graduate School of Health Sciences, Kobe, Japan
| | - Norio Suzuki
- Division of Oxygen Biology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Masayuki Yamamoto
- Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
| | - Akira Nishiyama
- Department of Pharmacology, Kagawa University Medical School, Kagawa, Japan
| |
Collapse
|
15
|
Minervini G, Pennuto M, Tosatto SCE. The pVHL neglected functions, a tale of hypoxia-dependent and -independent regulations in cancer. Open Biol 2020; 10:200109. [PMID: 32603638 PMCID: PMC7574549 DOI: 10.1098/rsob.200109] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The von Hippel–Lindau protein (pVHL) is a tumour suppressor mainly known for its role as master regulator of hypoxia-inducible factor (HIF) activity. Functional inactivation of pVHL is causative of the von Hippel–Lindau disease, an inherited predisposition to develop different cancers. Due to its impact on human health, pVHL has been widely studied in the last few decades. However, investigations mostly focus on its role in degrading HIFs, whereas alternative pVHL protein–protein interactions and functions are insistently surfacing in the literature. In this review, we analyse these almost neglected functions by dissecting specific conditions in which pVHL is proposed to have differential roles in promoting cancer. We reviewed its role in regulating phosphorylation as a number of works suggest pVHL to act as an inhibitor by either degrading or promoting downregulation of specific kinases. Further, we summarize hypoxia-dependent and -independent pVHL interactions with multiple protein partners and discuss their implications in tumorigenesis.
Collapse
Affiliation(s)
- Giovanni Minervini
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy
| | - Maria Pennuto
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy.,Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy
| | - Silvio C E Tosatto
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy
| |
Collapse
|
16
|
Bellanné-Chantelot C, Rabadan Moraes G, Schmaltz-Panneau B, Marty C, Vainchenker W, Plo I. Germline genetic factors in the pathogenesis of myeloproliferative neoplasms. Blood Rev 2020; 42:100710. [PMID: 32532454 DOI: 10.1016/j.blre.2020.100710] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 04/08/2020] [Accepted: 05/05/2020] [Indexed: 02/06/2023]
Abstract
Myeloproliferative neoplasms (MPN) are clonal hematological malignancies that lead to overproduction of mature myeloid cells. They are due to acquired mutations in genes encoding for AK2, MPL and CALR that result in the activation of the cytokine receptor/JAK2 signaling pathway. In addition, it exists germline variants that can favor the initiation of the disease or may affect its phenotype. First, they can be common risk alleles, which correspond to frequent single nucleotide variants present in control population and that contribute to the development of either sporadic or familial MPN. Second, some variants predispose to the onset of MPN with a higher penetrance and lead to familial clustering of MPN. Finally, some extremely rare genetic variants can induce MPN-like hereditary disease. We will review these different subtypes of germline genetic variants and discuss how they impact the initiation and/or development of the MPN disease.
Collapse
Affiliation(s)
- Christine Bellanné-Chantelot
- Department of Genetics, Assistance Publique-Hôpitaux de Paris (APHP), Hôpitaux Universitaires Pitié Salpêtrière-Charles Foix, Sorbonne Université, Paris, France; INSERM, UMR1287, Laboratory of Excellence GR-Ex, Villejuif, France
| | - Graciela Rabadan Moraes
- INSERM, UMR1287, Laboratory of Excellence GR-Ex, Villejuif, France; Université Paris Diderot (Paris 7), UMR1287, Gustave Roussy, Villejuif, France; Gustave Roussy, Villejuif, France
| | - Barbara Schmaltz-Panneau
- INSERM, UMR1287, Laboratory of Excellence GR-Ex, Villejuif, France; Gustave Roussy, Villejuif, France; Université Paris XI, UMR1287, Gustave Roussy, Villejuif, France
| | - Caroline Marty
- INSERM, UMR1287, Laboratory of Excellence GR-Ex, Villejuif, France; Gustave Roussy, Villejuif, France; Université Paris XI, UMR1287, Gustave Roussy, Villejuif, France
| | - William Vainchenker
- INSERM, UMR1287, Laboratory of Excellence GR-Ex, Villejuif, France; Gustave Roussy, Villejuif, France; Université Paris XI, UMR1287, Gustave Roussy, Villejuif, France
| | - Isabelle Plo
- INSERM, UMR1287, Laboratory of Excellence GR-Ex, Villejuif, France; Gustave Roussy, Villejuif, France; Université Paris XI, UMR1287, Gustave Roussy, Villejuif, France.
| |
Collapse
|
17
|
Abstract
Tibetans have adapted to the chronic hypoxia of high altitude and display a distinctive suite of physiologic adaptations, including augmented hypoxic ventilatory response and resistance to pulmonary hypertension. Genome-wide studies have consistently identified compelling genetic signatures of natural selection in two genes of the Hypoxia Inducible Factor pathway, PHD2 and HIF2A The product of the former induces the degradation of the product of the latter. Key issues regarding Tibetan PHD2 are whether it is a gain-of-function or loss-of-function allele, and how it might contribute to high-altitude adaptation. Tibetan PHD2 possesses two amino acid changes, D4E and C127S. We previously showed that in vitro, Tibetan PHD2 is defective in its interaction with p23, a cochaperone of the HSP90 pathway, and we proposed that Tibetan PHD2 is a loss-of-function allele. Here, we report that additional PHD2 mutations at or near Asp-4 or Cys-127 impair interaction with p23 in vitro. We find that mice with the Tibetan Phd2 allele display augmented hypoxic ventilatory response, supporting this loss-of-function proposal. This is phenocopied by mice with a mutation in p23 that abrogates the PHD2:p23 interaction. Hif2a haploinsufficiency, but not the Tibetan Phd2 allele, ameliorates hypoxia-induced increases in right ventricular systolic pressure. The Tibetan Phd2 allele is not associated with hemoglobin levels in mice. We propose that Tibetans possess genetic alterations that both activate and inhibit selective outputs of the HIF pathway to facilitate successful adaptation to the chronic hypoxia of high altitude.
Collapse
|
18
|
McMullin MF. Diagnostic workflow for hereditary erythrocytosis and thrombocytosis. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2019; 2019:391-396. [PMID: 31808840 PMCID: PMC6913500 DOI: 10.1182/hematology.2019000047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In the patient presenting with an elevated blood count who does not have an acquired clonal disorder causing a myeloproliferative neoplasm, hereditary erythrocytosis or hereditary thrombocytosis needs to be considered as a possible explanation. A young patient and/or those with a family history of myeloproliferative neoplasm should specifically raise this possibility. Among the causes of hereditary erythrocytosis are mutations in the genes in the oxygen sensing pathway and high-affinity hemoglobins. Hereditary thrombocytosis has been shown to be accounted for by mutations in THPO, MPL, and JAK2 genes. In those who have a possible hereditary erythrocytosis or thrombocytosis, the investigative pathway includes specific investigation to rule out the more common acquired clonal disorders, and, if indicated, other secondary causes, measurement of specific cytokines as indicated, and search for specific identified molecular lesions that have been shown to cause these hereditary disorders. There remain individuals who appear to have a hereditary disorder in whom a genetic lesion cannot currently be identified.
Collapse
|
19
|
Association of EGLN1 gene with high aerobic capacity of Peruvian Quechua at high altitude. Proc Natl Acad Sci U S A 2019; 116:24006-24011. [PMID: 31712437 DOI: 10.1073/pnas.1906171116] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Highland native Andeans have resided at altitude for millennia. They display high aerobic capacity (VO2max) at altitude, which may be a reflection of genetic adaptation to hypoxia. Previous genomewide (GW) scans for natural selection have nominated Egl-9 homolog 1 gene (EGLN1) as a candidate gene. The encoded protein, EGLN1/PHD2, is an O2 sensor that controls levels of the Hypoxia Inducible Factor-α (HIF-α), which regulates the cellular response to hypoxia. From GW association and analysis of covariance performed on a total sample of 429 Peruvian Quechua and 94 US lowland referents, we identified 5 EGLN1 SNPs associated with higher VO2max (L⋅min-1 and mL⋅min-1⋅kg-1) in hypoxia (rs1769793, rs2064766, rs2437150, rs2491403, rs479200). For 4 of these SNPs, Quechua had the highest frequency of the advantageous (high VO2max) allele compared with 25 diverse lowland comparison populations from the 1000 Genomes Project. Genotype effects were substantial, with high versus low VO2max genotype categories differing by ∼11% (e.g., for rs1769793 SNP genotype TT = 34.2 mL⋅min-1⋅kg-1 vs. CC = 30.5 mL⋅min-1⋅kg-1). To guard against spurious association, we controlled for population stratification. Findings were replicated for EGLN1 SNP rs1769793 in an independent Andean sample collected in 2002. These findings contextualize previous reports of natural selection at EGLN1 in Andeans, and support the hypothesis that natural selection has increased the frequency of an EGLN1 causal variant that enhances O2 delivery or use during exercise at altitude in Peruvian Quechua.
Collapse
|
20
|
Lappin TR, Lee FS. Update on mutations in the HIF: EPO pathway and their role in erythrocytosis. Blood Rev 2019; 37:100590. [PMID: 31350093 DOI: 10.1016/j.blre.2019.100590] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 07/02/2019] [Accepted: 07/15/2019] [Indexed: 12/20/2022]
Abstract
Identification of the underlying defects in congenital erythrocytosis has provided mechanistic insights into the regulation of erythropoiesis and oxygen homeostasis. The Hypoxia Inducible Factor (HIF) pathway plays a key role in this regard. In this pathway, an enzyme, Prolyl Hydroxylase Domain protein 2 (PHD2), constitutively prolyl hydroxylates HIF-2α, thereby targeting HIF-2α for degradation by the von Hippel Lindau (VHL) tumor suppressor protein. Under hypoxia, this modification is attenuated, resulting in the stabilization of HIF-2α and transcriptional activation of the erythropoietin (EPO) gene. Circulating EPO then binds to the EPO receptor (EPOR) on red cell progenitors in the bone marrow, leading to expansion of red cell mass. Loss of function mutations in PHD2 and VHL, as well as gain of function mutations in HIF-2α and EPOR, are well established causes of erythrocytosis. Here, we highlight recent developments that show that the study of this condition is still evolving. Specifically, novel mutations have been identified that either change amino acids in the zinc finger domain of PHD2 or alter splicing of the VHL gene. In addition, continued study of HIF-2α mutations has revealed a distinctive genotype-phenotype correlation. Finally, novel mutations have recently been identified in the EPO gene itself. Thus, the cascade of genes that at a molecular level leads to EPO action, namely PHD2 - > HIF2A - > VHL - > EPO - > EPOR, are all mutational targets in congenital erythrocytosis.
Collapse
Affiliation(s)
- Terence R Lappin
- Centre for Cancer Research and Cell Biology, Queen's University, Belfast, UK.
| | - Frank S Lee
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
21
|
Gurnari C, Lombardi AM, Cosi E, Biagetti G, Buccisano F, Franceschini L, Di Veroli A, Falconi G, Fabiani E, Cantonetti M, Nasso D, Lo-Coco F, Randi ML, Voso MT. Genetic analysis of erythrocytosis reveals possible causative and modifier gene mutations. Br J Haematol 2019; 186:e100-e103. [PMID: 31016714 DOI: 10.1111/bjh.15931] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Carmelo Gurnari
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Anna M Lombardi
- Department of Medicine, University of Padua Medical School, Padua, Italy
| | - Elisabetta Cosi
- Department of Medicine, University of Padua Medical School, Padua, Italy
| | - Giacomo Biagetti
- Department of Medicine, University of Padua Medical School, Padua, Italy
| | - Francesco Buccisano
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Luca Franceschini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Ambra Di Veroli
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Giulia Falconi
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Emiliano Fabiani
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Maria Cantonetti
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Daniela Nasso
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Francesco Lo-Coco
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Maria L Randi
- Department of Medicine, University of Padua Medical School, Padua, Italy
| | - Maria T Voso
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| |
Collapse
|
22
|
Loss of Phd2 cooperates with BRAF V600E to drive melanomagenesis. Nat Commun 2018; 9:5426. [PMID: 30575721 PMCID: PMC6303344 DOI: 10.1038/s41467-018-07126-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 10/15/2018] [Indexed: 12/30/2022] Open
Abstract
Prolyl hydroxylase domain protein 2 (PHD2) is a well-known master oxygen sensor. However, the role of PHD2 in tumor initiation remains controversial. We find that during the transition of human nevi to melanoma, the expression of PHD2 protein is significantly decreased and lower expression PHD2 in melanoma is associated with worse clinical outcome. Knockdown of PHD2 leads to elevated Akt phosphorylation in human melanocytes. Mice with conditional melanocyte-specific expression of Phd2lox/lox (Tyr::CreER;Phd2lox/lox) fail to develop pigmented lesions. However, deletion of Phd2 in combination with expression of BRafV600E in melanocytes (Tyr::CreER;Phd2lox/lox;BRafCA) leads to the development of melanoma with 100% penetrance and frequent lymph node metastasis. Analysis of tumor tissues using reverse phase protein arrays demonstrates that Phd2 deletion activates the AKT-mTOR-S6 signaling axis in the recovered tumors. These data indicate that PHD2 is capable of suppressing tumor initiation largely mediated through inhibiting of the Akt-mTOR signaling pathway in the melanocyte lineage. Prolyl hydroxylase domain protein 2 (PHD2) regulates cellular response to hypoxia. Here the authors show that PHD2 is downregulated in melanoma and that PHD2 depletion, in a mouse model, promotes the progression of benign melanocytic lesions into melanoma, via activation of the Akt/mTOR signaling cascade.
Collapse
|
23
|
Fielding JW, Hodson EJ, Cheng X, Ferguson DJP, Eckardt L, Adam J, Lip P, Maton‐Howarth M, Ratnayaka I, Pugh CW, Buckler KJ, Ratcliffe PJ, Bishop T. PHD2 inactivation in Type I cells drives HIF-2α-dependent multilineage hyperplasia and the formation of paraganglioma-like carotid bodies. J Physiol 2018; 596:4393-4412. [PMID: 29917232 PMCID: PMC6138294 DOI: 10.1113/jp275996] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 05/17/2018] [Indexed: 02/06/2023] Open
Abstract
KEY POINTS The carotid body is a peripheral arterial chemoreceptor that regulates ventilation in response to both acute and sustained hypoxia. Type I cells in this organ respond to low oxygen both acutely by depolarization and dense core vesicle secretion and, over the longer term, via cellular proliferation and enhanced ventilatory responses. Using lineage analysis, the present study shows that the Type I cell lineage itself proliferates and expands in response to sustained hypoxia. Inactivation of HIF-2α in Type I cells impairs the ventilatory, proliferative and cell intrinsic (dense core vesicle) responses to hypoxia. Inactivation of PHD2 in Type I cells induces multilineage hyperplasia and ultrastructural changes in dense core vesicles to form paraganglioma-like carotid bodies. These changes, similar to those observed in hypoxia, are dependent on HIF-2α. Taken together, these findings demonstrate a key role for the PHD2-HIF-2α couple in Type I cells with respect to the oxygen sensing functions of the carotid body. ABSTRACT The carotid body is a peripheral chemoreceptor that plays a central role in mammalian oxygen homeostasis. In response to sustained hypoxia, it manifests a rapid cellular proliferation and an associated increase in responsiveness to hypoxia. Understanding the cellular and molecular mechanisms underlying these processes is of interest both to specialized chemoreceptive functions of that organ and, potentially, to the general physiology and pathophysiology of cellular hypoxia. We have combined cell lineage tracing technology and conditionally inactivated alleles in recombinant mice to examine the role of components of the HIF hydroxylase pathway in specific cell types within the carotid body. We show that exposure to sustained hypoxia (10% oxygen) drives rapid expansion of the Type I, tyrosine hydroxylase expressing cell lineage, with little transdifferentiation to (or from) that lineage. Inactivation of a specific HIF isoform, HIF-2α, in the Type I cells was associated with a greatly reduced proliferation of Type I cells and hypoxic ventilatory responses, with ultrastructural evidence of an abnormality in the action of hypoxia on dense core secretory vesicles. We also show that inactivation of the principal HIF prolyl hydroxylase PHD2 within the Type I cell lineage is sufficient to cause multilineage expansion of the carotid body, with characteristics resembling paragangliomas. These morphological changes were dependent on the integrity of HIF-2α. These findings implicate specific components of the HIF hydroxylase pathway (PHD2 and HIF-2α) within Type I cells of the carotid body with respect to the oxygen sensing and adaptive functions of that organ.
Collapse
Affiliation(s)
- James W. Fielding
- Target Discovery InstituteUniversity of Oxford, Oxford, UK
- Ludwig Institute for Cancer ResearchUniversity of Oxford, Oxford, UK
| | - Emma J. Hodson
- Target Discovery InstituteUniversity of Oxford, Oxford, UK
| | - Xiaotong Cheng
- Target Discovery InstituteUniversity of Oxford, Oxford, UK
- Ludwig Institute for Cancer ResearchUniversity of Oxford, Oxford, UK
| | | | - Luise Eckardt
- Target Discovery InstituteUniversity of Oxford, Oxford, UK
| | - Julie Adam
- Target Discovery InstituteUniversity of Oxford, Oxford, UK
- Ludwig Institute for Cancer ResearchUniversity of Oxford, Oxford, UK
| | - Philomena Lip
- Target Discovery InstituteUniversity of Oxford, Oxford, UK
| | | | - Indrika Ratnayaka
- Ludwig Institute for Cancer ResearchUniversity of Oxford, Oxford, UK
| | | | - Keith J. Buckler
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUK
| | - Peter J. Ratcliffe
- Target Discovery InstituteUniversity of Oxford, Oxford, UK
- Ludwig Institute for Cancer ResearchUniversity of Oxford, Oxford, UK
- The Francis Crick InstituteLondonUK
| | - Tammie Bishop
- Target Discovery InstituteUniversity of Oxford, Oxford, UK
| |
Collapse
|
24
|
Zhang J, Zhang Q. VHL and Hypoxia Signaling: Beyond HIF in Cancer. Biomedicines 2018; 6:biomedicines6010035. [PMID: 29562667 PMCID: PMC5874692 DOI: 10.3390/biomedicines6010035] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 03/12/2018] [Accepted: 03/16/2018] [Indexed: 12/12/2022] Open
Abstract
Von Hippel-Lindau (VHL) is an important tumor suppressor that is lost in the majority of clear cell carcinoma of renal cancer (ccRCC). Its regulatory pathway involves the activity of E3 ligase, which targets hypoxia inducible factor α (including HIF1α and HIF2α) for proteasome degradation. In recent years, emerging literature suggests that VHL also possesses other HIF-independent functions. This review will focus on VHL-mediated signaling pathways involving the latest identified substrates/binding partners, including N-Myc downstream-regulated gene 3 (NDRG3), AKT, and G9a, etc., and their physiological roles in hypoxia signaling and cancer. We will also discuss the crosstalk between VHL and NF-κB signaling. Lastly, we will review the latest findings on targeting VHL signaling in cancer.
Collapse
Affiliation(s)
- Jing Zhang
- Department of Pathology and Laboratory Medicine, Lineberger Comprehensive Cancer Center, UNC-Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Qing Zhang
- Department of Pathology and Laboratory Medicine, Lineberger Comprehensive Cancer Center, UNC-Chapel Hill, Chapel Hill, NC 27599, USA.
- Department of Pharmacology, UNC-Chapel Hill, Chapel Hill, NC 27599, USA.
| |
Collapse
|
25
|
Kaplan JM, Sharma N, Dikdan S. Hypoxia-Inducible Factor and Its Role in the Management of Anemia in Chronic Kidney Disease. Int J Mol Sci 2018; 19:ijms19020389. [PMID: 29382128 PMCID: PMC5855611 DOI: 10.3390/ijms19020389] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 01/04/2018] [Accepted: 01/08/2018] [Indexed: 12/25/2022] Open
Abstract
Hypoxia-inducible factor (HIF) plays a crucial role in the response to hypoxia at the cellular, tissue, and organism level. New agents under development to pharmacologically manipulate HIF may provide new and exciting possibilities in the treatment of anemia of chronic kidney disease (CKD) as well as in multiple other disease states involving ischemia-reperfusion injury. This article provides an overview of recent studies describing current standards of care for patients with anemia in CKD and associated clinical issues, and those supporting the clinical potential for targeting HIF stabilization with HIF prolyl-hydroxylase inhibitors (HIF-PHI) in these patients. Additionally, articles reporting the clinical potential for HIF-PHIs in 'other' putative therapeutic areas, the tissue and intracellular distribution of HIF- and prolyl-hydroxylase domain (PHD) isoforms, and HIF isoforms targeted by the different PHDs, were identified. There is increasing uncertainty regarding the optimal treatment for anemia of CKD with poorer outcomes associated with treatment to higher hemoglobin targets, and the increasing use of iron and consequent risk of iron imbalance. Attainment and maintenance of more physiologic erythropoietin levels associated with HIF stabilization may improve the management of patients resistant to treatment with erythropoiesis-stimulating agents and improve outcomes at higher hemoglobin targets.
Collapse
Affiliation(s)
- Joshua M Kaplan
- Division of Nephrology and Hypertension, Rutgers-New Jersey Medical School, University Hospital, 185 South Orange Avenue, I512, Newark, NJ 07103, USA.
| | - Neeraj Sharma
- Division of Nephrology and Hypertension, Rutgers-New Jersey Medical School, University Hospital, 185 South Orange Avenue, I512, Newark, NJ 07103, USA.
| | - Sean Dikdan
- Division of Nephrology and Hypertension, Rutgers-New Jersey Medical School, University Hospital, 185 South Orange Avenue, I512, Newark, NJ 07103, USA.
| |
Collapse
|
26
|
Notch Downregulation and Extramedullary Erythrocytosis in Hypoxia-Inducible Factor Prolyl 4-Hydroxylase 2-Deficient Mice. Mol Cell Biol 2017; 37:MCB.00529-16. [PMID: 27821476 DOI: 10.1128/mcb.00529-16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 10/27/2016] [Indexed: 12/23/2022] Open
Abstract
Erythrocytosis is driven mainly by erythropoietin, which is regulated by hypoxia-inducible factor (HIF). Mutations in HIF prolyl 4-hydroxylase 2 (HIF-P4H-2) (PHD2/EGLN1), the major downregulator of HIFα subunits, are found in familiar erythrocytosis, and large-spectrum conditional inactivation of HIF-P4H-2 in mice leads to severe erythrocytosis. Although bone marrow is the primary site for erythropoiesis, spleen remains capable of extramedullary erythropoiesis. We studied HIF-P4H-2-deficient (Hif-p4h-2gt/gt) mice, which show slightly induced erythropoiesis upon aging despite nonincreased erythropoietin levels, and identified spleen as the site of extramedullary erythropoiesis. Splenic hematopoietic stem cells (HSCs) of these mice exhibited increased erythroid burst-forming unit (BFU-E) growth, and the mice were protected against anemia. HIF-1α and HIF-2α were stabilized in the spleens, while the Notch ligand genes Jag1, Jag2, and Dll1 and target Hes1 became downregulated upon aging HIF-2α dependently. Inhibition of Notch signaling in wild-type spleen HSCs phenocopied the increased BFU-E growth. HIFα stabilization can thus mediate non-erythropoietin-driven splenic erythropoiesis via altered Notch signaling.
Collapse
|
27
|
Arsenault PR, Song D, Bergkamp M, Ravaschiere AM, Navalsky BE, Lieberman PM, Lee FS. Identification of Small-Molecule PHD2 Zinc Finger Inhibitors that Activate Hypoxia Inducible Factor. Chembiochem 2016; 17:2316-2323. [PMID: 27770548 DOI: 10.1002/cbic.201600493] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Indexed: 02/06/2023]
Abstract
The prolyl hydroxylase domain (PHD) protein:hypoxia inducible factor (HIF) pathway is the main pathway by which changes in oxygen concentration are transduced to changes in gene expression. In mammals, there are three PHD paralogues, and PHD2 has emerged as a particularly critical one for regulating HIF target genes such as erythropoietin (EPO), which controls red cell mass and hematocrit. PHD2 is distinctive among the three PHDs in that it contains an N-terminal MYND-type zinc finger. We have proposed that this zinc finger binds a Pro-Xaa-Leu-Glu (PXLE) motif found in proteins of the HSP90 pathway to facilitate HIF-α hydroxylation. Targeting this motif could provide a means of specifically inhibiting this PHD isoform. Here, we screened a library of chemical compounds for their capacity to inhibit the zinc finger of PHD2. We identified compounds that, in vitro, can inhibit PHD2 binding to a PXLE-containing peptide and induce activation of HIF. Injection of one of these compounds into mice induces an increase in hematocrit. This study offers proof of principle that inhibition of the zinc finger of PHD2 can provide a means of selectively targeting PHD2 to activate the HIF pathway.
Collapse
Affiliation(s)
- Patrick R Arsenault
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Daisheng Song
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Marian Bergkamp
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Andrew M Ravaschiere
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Bradleigh E Navalsky
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Paul M Lieberman
- The Wistar Institute, 3601 Spruce St., Philadelphia, PA, 19104, USA
| | - Frank S Lee
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA
| |
Collapse
|
28
|
Chowdhury R, Leung IKH, Tian YM, Abboud MI, Ge W, Domene C, Cantrelle FX, Landrieu I, Hardy AP, Pugh CW, Ratcliffe PJ, Claridge TDW, Schofield CJ. Structural basis for oxygen degradation domain selectivity of the HIF prolyl hydroxylases. Nat Commun 2016; 7:12673. [PMID: 27561929 PMCID: PMC5007464 DOI: 10.1038/ncomms12673] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 07/21/2016] [Indexed: 02/06/2023] Open
Abstract
The response to hypoxia in animals involves the expression of multiple genes regulated by the αβ-hypoxia-inducible transcription factors (HIFs). The hypoxia-sensing mechanism involves oxygen limited hydroxylation of prolyl residues in the N- and C-terminal oxygen-dependent degradation domains (NODD and CODD) of HIFα isoforms, as catalysed by prolyl hydroxylases (PHD 1-3). Prolyl hydroxylation promotes binding of HIFα to the von Hippel-Lindau protein (VHL)-elongin B/C complex, thus signalling for proteosomal degradation of HIFα. We reveal that certain PHD2 variants linked to familial erythrocytosis and cancer are highly selective for CODD or NODD. Crystalline and solution state studies coupled to kinetic and cellular analyses reveal how wild-type and variant PHDs achieve ODD selectivity via different dynamic interactions involving loop and C-terminal regions. The results inform on how HIF target gene selectivity is achieved and will be of use in developing selective PHD inhibitors.
Collapse
Affiliation(s)
- Rasheduzzaman Chowdhury
- Chemistry Research Laboratory, Department of Chemistry, Oxford Centre for Integrative Systems Biology, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | - Ivanhoe K. H. Leung
- Chemistry Research Laboratory, Department of Chemistry, Oxford Centre for Integrative Systems Biology, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | - Ya-Min Tian
- Nuffield Department of Clinical Medicine, University of Oxford, Henry Wellcome Building for Molecular Physiology, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Martine I. Abboud
- Chemistry Research Laboratory, Department of Chemistry, Oxford Centre for Integrative Systems Biology, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | - Wei Ge
- Chemistry Research Laboratory, Department of Chemistry, Oxford Centre for Integrative Systems Biology, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | - Carmen Domene
- Chemistry Research Laboratory, Department of Chemistry, Oxford Centre for Integrative Systems Biology, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | | | | | - Adam P. Hardy
- Chemistry Research Laboratory, Department of Chemistry, Oxford Centre for Integrative Systems Biology, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | - Christopher W. Pugh
- Nuffield Department of Clinical Medicine, University of Oxford, Henry Wellcome Building for Molecular Physiology, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Peter J. Ratcliffe
- Nuffield Department of Clinical Medicine, University of Oxford, Henry Wellcome Building for Molecular Physiology, Roosevelt Drive, Oxford OX3 7BN, UK
- Ludwig Institute for Cancer Research, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Timothy D. W. Claridge
- Chemistry Research Laboratory, Department of Chemistry, Oxford Centre for Integrative Systems Biology, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | - Christopher J. Schofield
- Chemistry Research Laboratory, Department of Chemistry, Oxford Centre for Integrative Systems Biology, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| |
Collapse
|
29
|
The Zinc Finger of Prolyl Hydroxylase Domain Protein 2 Is Essential for Efficient Hydroxylation of Hypoxia-Inducible Factor α. Mol Cell Biol 2016; 36:2328-43. [PMID: 27325674 DOI: 10.1128/mcb.00090-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 06/12/2016] [Indexed: 12/21/2022] Open
Abstract
Prolyl hydroxylase domain protein 2 (PHD2) (also known as EGLN1) is a key oxygen sensor in mammals that posttranslationally modifies hypoxia-inducible factor α (HIF-α) and targets it for degradation. In addition to its catalytic domain, PHD2 contains an evolutionarily conserved zinc finger domain, which we have previously proposed recruits PHD2 to the HSP90 pathway to promote HIF-α hydroxylation. Here, we provide evidence that this recruitment is critical both in vitro and in vivo We show that in vitro, the zinc finger can function as an autonomous recruitment domain to facilitate interaction with HIF-α. In vivo, ablation of zinc finger function by a C36S/C42S Egln1 knock-in mutation results in upregulation of the erythropoietin gene, erythrocytosis, and augmented hypoxic ventilatory response, all hallmarks of Egln1 loss of function and HIF stabilization. Hence, the zinc finger ordinarily performs a critical positive regulatory function. Intriguingly, the function of this zinc finger is impaired in high-altitude-adapted Tibetans, suggesting that their adaptation to high altitude may, in part, be due to a loss-of-function EGLN1 allele. Thus, these findings have important implications for understanding both the molecular mechanism of the hypoxic response and human adaptation to high altitude.
Collapse
|
30
|
Affiliation(s)
- M. F. McMullin
- Department of Haematology; Belfast City Hospital; Queen's University Belfast; Belfast UK
| |
Collapse
|
31
|
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.
Collapse
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
| |
Collapse
|
32
|
Hodson EJ, Nicholls LG, Turner PJ, Llyr R, Fielding JW, Douglas G, Ratnayaka I, Robbins PA, Pugh CW, Buckler KJ, Ratcliffe PJ, Bishop T. Regulation of ventilatory sensitivity and carotid body proliferation in hypoxia by the PHD2/HIF-2 pathway. J Physiol 2016; 594:1179-95. [PMID: 26337139 PMCID: PMC4771794 DOI: 10.1113/jp271050] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/26/2015] [Indexed: 12/24/2022] Open
Abstract
Ventilatory sensitivity to hypoxia increases in response to continued hypoxic exposure as part of acute acclimatisation. Although this process is incompletely understood, insights have been gained through studies of the hypoxia-inducible factor (HIF) hydroxylase system. Genetic studies implicate these pathways widely in the integrated physiology of hypoxia, through effects on developmental or adaptive processes. In keeping with this, mice that are heterozygous for the principal HIF prolyl hydroxylase, PHD2, show enhanced ventilatory sensitivity to hypoxia and carotid body hyperplasia. Here we have sought to understand this process better through comparative analysis of inducible and constitutive inactivation of PHD2 and its principal targets HIF-1α and HIF-2α. We demonstrate that general inducible inactivation of PHD2 in tamoxifen-treated Phd2(f/f);Rosa26(+/CreERT2) mice, like constitutive, heterozygous PHD2 deficiency, enhances hypoxic ventilatory responses (HVRs: 7.2 ± 0.6 vs. 4.4 ± 0.4 ml min(-1) g(-1) in controls, P < 0.01). The ventilatory phenotypes associated with both inducible and constitutive inactivation of PHD2 were strongly compensated for by concomitant inactivation of HIF-2α, but not HIF-1α. Furthermore, inducible inactivation of HIF-2α strikingly impaired ventilatory acclimatisation to chronic hypoxia (HVRs: 4.1 ± 0.5 vs. 8.6 ± 0.5 ml min(-1) g(-1) in controls, P < 0.0001), as well as carotid body cell proliferation (400 ± 81 vs. 2630 ± 390 bromodeoxyuridine-positive cells mm(-2) in controls, P < 0.0001). The findings demonstrate the importance of the PHD2/HIF-2α enzyme-substrate couple in modulating ventilatory sensitivity to hypoxia.
Collapse
Affiliation(s)
- Emma J Hodson
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford, OX3 7BN, UK
| | - Lynn G Nicholls
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford, OX3 7BN, UK
| | - Philip J Turner
- Department of Physiology, Anatomy and Genetics, Sherrington Building, South Parks Road, University of Oxford, Oxford, OX1 3PT, UK
| | - Ronan Llyr
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford, OX3 7BN, UK
| | - James W Fielding
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford, OX3 7BN, UK
- Ludwig Institute for Cancer Research, Roosevelt Drive, University of Oxford, Oxford, OX3 7DQ, UK
| | - Gillian Douglas
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford, OX3 7BN, UK
| | - Indrika Ratnayaka
- Ludwig Institute for Cancer Research, Roosevelt Drive, University of Oxford, Oxford, OX3 7DQ, UK
| | - Peter A Robbins
- Department of Physiology, Anatomy and Genetics, Sherrington Building, South Parks Road, University of Oxford, Oxford, OX1 3PT, UK
| | - Christopher W Pugh
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford, OX3 7BN, UK
| | - Keith J Buckler
- Department of Physiology, Anatomy and Genetics, Sherrington Building, South Parks Road, University of Oxford, Oxford, OX1 3PT, UK
| | - Peter J Ratcliffe
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford, OX3 7BN, UK
- Ludwig Institute for Cancer Research, Roosevelt Drive, University of Oxford, Oxford, OX3 7DQ, UK
| | - Tammie Bishop
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford, OX3 7BN, UK
| |
Collapse
|
33
|
Heir P, Srikumar T, Bikopoulos G, Bunda S, Poon BP, Lee JE, Raught B, Ohh M. Oxygen-dependent Regulation of Erythropoietin Receptor Turnover and Signaling. J Biol Chem 2016; 291:7357-72. [PMID: 26846855 DOI: 10.1074/jbc.m115.694562] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Indexed: 01/29/2023] Open
Abstract
von Hippel-Lindau (VHL) disease is a rare familial cancer predisposition syndrome caused by a loss or mutation in a single gene,VHL, but it exhibits a wide phenotypic variability that can be categorized into distinct subtypes. The phenotypic variability has been largely argued to be attributable to the extent of deregulation of the α subunit of hypoxia-inducible factor α, a well established target of VHL E3 ubiquitin ligase, ECV (Elongins/Cul2/VHL). Here, we show that erythropoietin receptor (EPOR) is hydroxylated on proline 419 and 426 via prolyl hydroxylase 3. EPOR hydroxylation is required for binding to the β domain of VHL and polyubiquitylation via ECV, leading to increased EPOR turnover. In addition, several type-specific VHL disease-causing mutants, including those that have retained proper binding and regulation of hypoxia-inducible factor α, showed a severe defect in binding prolyl hydroxylated EPOR peptides. These results identify EPOR as the secondbona fidehydroxylation-dependent substrate of VHL that potentially influences oxygen homeostasis and contributes to the complex genotype-phenotype correlation in VHL disease.
Collapse
Affiliation(s)
- Pardeep Heir
- From the Departments of Laboratory Medicine and Pathobiology and
| | - Tharan Srikumar
- the Princess Margaret Cancer Centre, Toronto, Ontario M5G 1L7, Canada
| | | | - Severa Bunda
- From the Departments of Laboratory Medicine and Pathobiology and
| | - Betty P Poon
- From the Departments of Laboratory Medicine and Pathobiology and Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8 and
| | - Jeffrey E Lee
- From the Departments of Laboratory Medicine and Pathobiology and
| | - Brian Raught
- the Princess Margaret Cancer Centre, Toronto, Ontario M5G 1L7, Canada
| | - Michael Ohh
- From the Departments of Laboratory Medicine and Pathobiology and Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8 and
| |
Collapse
|
34
|
Pharmacological targeting of the HIF hydroxylases--A new field in medicine development. Mol Aspects Med 2016; 47-48:54-75. [PMID: 26791432 DOI: 10.1016/j.mam.2016.01.001] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 12/11/2015] [Accepted: 01/04/2016] [Indexed: 12/13/2022]
Abstract
In human cells oxygen levels are 'sensed' by a set of ferrous iron and 2-oxoglutarate dependent dioxygenases. These enzymes regulate a broad range of cellular and systemic responses to hypoxia by catalysing the post-translational hydroxylation of specific residues in the alpha subunits of hypoxia inducible factor (HIF) transcriptional complexes. The HIF hydroxylases are now the subject of pharmaceutical targeting by small molecule inhibitors that aim to activate or augment the endogenous HIF transcriptional response for the treatment of anaemia and other hypoxic human diseases. Here we consider the rationale for this therapeutic strategy from the biochemical, biological and medical perspectives. We outline structural and mechanistic considerations that are relevant to the design of HIF hydroxylase inhibitors, including likely determinants of specificity, and review published reports on their activity in pre-clinical models and clinical trials.
Collapse
|
35
|
Abstract
Humans have adapted to the chronic hypoxia of high altitude in several locations, and recent genome-wide studies have indicated a genetic basis. In some populations, genetic signatures have been identified in the hypoxia-inducible factor (HIF) pathway, which orchestrates the transcriptional response to hypoxia. In Tibetans, they have been found in the HIF2A (EPAS1) gene, which encodes for HIF-2α, and the prolyl hydroxylase domain protein 2 (PHD2, also known as EGLN1) gene, which encodes for one of its key regulators, PHD2. High-altitude adaptation may be due to multiple genes that act in concert with one another. Unraveling their mechanism of action can offer new therapeutic approaches toward treating common human diseases characterized by chronic hypoxia.
Collapse
Affiliation(s)
- Abigail W Bigham
- Department of Anthropology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Frank S Lee
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| |
Collapse
|
36
|
Mimicking hypoxia to treat anemia: HIF-stabilizer BAY 85-3934 (Molidustat) stimulates erythropoietin production without hypertensive effects. PLoS One 2014; 9:e111838. [PMID: 25392999 PMCID: PMC4230943 DOI: 10.1371/journal.pone.0111838] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 10/01/2014] [Indexed: 11/30/2022] Open
Abstract
Oxygen sensing by hypoxia-inducible factor prolyl hydroxylases (HIF-PHs) is the dominant regulatory mechanism of erythropoietin (EPO) expression. In chronic kidney disease (CKD), impaired EPO expression causes anemia, which can be treated by supplementation with recombinant human EPO (rhEPO). However, treatment can result in rhEPO levels greatly exceeding the normal physiological range for endogenous EPO, and there is evidence that this contributes to hypertension in patients with CKD. Mimicking hypoxia by inhibiting HIF-PHs, thereby stabilizing HIF, is a novel treatment concept for restoring endogenous EPO production. HIF stabilization by oral administration of the HIF-PH inhibitor BAY 85-3934 (molidustat) resulted in dose-dependent production of EPO in healthy Wistar rats and cynomolgus monkeys. In repeat oral dosing of BAY 85-3934, hemoglobin levels were increased compared with animals that received vehicle, while endogenous EPO remained within the normal physiological range. BAY 85-3934 therapy was also effective in the treatment of renal anemia in rats with impaired kidney function and, unlike treatment with rhEPO, resulted in normalization of hypertensive blood pressure in a rat model of CKD. Notably, unlike treatment with the antihypertensive enalapril, the blood pressure normalization was achieved without a compensatory activation of the renin–angiotensin system. Thus, BAY 85-3934 may provide an approach to the treatment of anemia in patients with CKD, without the increased risk of adverse cardiovascular effects seen for patients treated with rhEPO. Clinical studies are ongoing to investigate the effects of BAY 85-3934 therapy in patients with renal anemia.
Collapse
|
37
|
García-Heredia JM, Felipe-Abrio B, Cano DA, Carnero A. Genetic modification of hypoxia signaling in animal models and its effect on cancer. Clin Transl Oncol 2014; 17:90-102. [PMID: 25351170 DOI: 10.1007/s12094-014-1236-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 09/24/2014] [Indexed: 12/19/2022]
Abstract
Conditions that cause hypoxemia or generalized tissue hypoxia, which can last for days, months, or even years, are very common in the human population and are among the leading causes of morbidity, disability, and mortality. Therefore, the molecular pathophysiology of hypoxia and its potential deleterious effects on human health are important issues at the forefront of biomedical research. Generalized hypoxia is a consequence of highly prevalent medical disorders that can severely reduce the capacity for O2 exchange between the air and pulmonary capillaries. In recent years, some of the key O2-dependent signaling pathways have been characterized at the molecular level. In particular, the prolyl hydroxylase (PHD)-hypoxia-inducible factor (HIF) cascade has emerged as the master regulator of a general gene expression program involved in cell/tissue/organ adaptation to hypoxia. Hypoxia has emerged as a critical factor in cancer because it can promote tumor initiation, progression, and resistance to therapy. Beyond its role in neovascularization as a mechanism of tumor adaptation to nutrient and O2 deprivation, hypoxia has been linked to prolonged cellular lifespan and immortalization, the generation of "oncometabolites", deregulation of stem cell proliferation, and inflammation, among other tumor hallmarks. Hypoxia may contribute to cancer through several independent pathways, the inter-connections of which have yet to be elucidated. Furthermore, the relevance of chronic hypoxemia in the initiation and progression of cancer has not been studied in depth in the whole organism. Therefore, we explore here the contributions of hypoxia to the whole organism by reviewing studies on genetically modified mice with alterations in the key molecular factors regulating hypoxia.
Collapse
Affiliation(s)
- J M García-Heredia
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, 41013, Seville, Spain
| | | | | | | |
Collapse
|
38
|
Cheng S, Xing W, Pourteymoor S, Mohan S. Conditional disruption of the prolyl hydroxylase domain-containing protein 2 (Phd2) gene defines its key role in skeletal development. J Bone Miner Res 2014; 29:2276-86. [PMID: 24753072 DOI: 10.1002/jbmr.2258] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 03/04/2014] [Accepted: 03/13/2014] [Indexed: 01/04/2023]
Abstract
We have previously shown that the increase in osterix (Osx) expression during osteoblast maturation is dependent on the activity of the prolyl hydroxylase domain-containing protein 2 (Phd2), a key regulator of protein levels of the hypoxia-inducible factor family proteins in many tissues. In this study, we generated conditional Phd2 knockout mice (cKO) in osteoblast lineage cells by crossing floxed Phd2 mice with a Col1α2-iCre line to investigate the function of Phd2 in vivo. The cKO mice developed short stature and premature death at 12 to 14 weeks of age. Bone mineral content, bone area, and bone mineral density were decreased in femurs and tibias, but not vertebrae of the cKO mice compared to WT mice. The total volume (TV), bone volume (BV), and bone volume fraction (BV/TV) in the femoral trabecular bones of cKO mice were significantly decreased. Cross-sectional area of the femoral mid-diaphysis was also reduced in the cKO mice. The reduced bone size and trabecular bone volume in the cKO mice were a result of impaired bone formation but not bone resorption as revealed by dynamic histomorphometric analyses. Bone marrow stromal cells derived from cKO mice formed fewer and smaller nodules when cultured with mineralization medium. Quantitative RT-PCR and immunohistochemistry detected reduced expression of Osx, osteocalcin, and bone sialoprotein in cKO bone cells. These data indicate that Phd2 plays an important role in regulating bone formation in part by modulating expression of Osx and bone formation marker genes.
Collapse
Affiliation(s)
- Shaohong Cheng
- Musculoskeletal Disease Center, Jerry L Pettis VA Medical Center, Loma Linda, CA, USA
| | | | | | | |
Collapse
|
39
|
Germ-line PHD1 and PHD2 mutations detected in patients with pheochromocytoma/paraganglioma-polycythemia. J Mol Med (Berl) 2014; 93:93-104. [PMID: 25263965 DOI: 10.1007/s00109-014-1205-7] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 08/27/2014] [Accepted: 09/02/2014] [Indexed: 10/24/2022]
Abstract
UNLABELLED We have investigated genetic/pathogenetic factors associated with a new clinical entity in patients presenting with pheochromocytoma/paraganglioma (PHEO/PGL) and polycythemia. Two patients without hypoxia-inducible factor 2α (HIF2A) mutations, who presented with similar clinical manifestations, were analyzed for other gene mutations, including prolyl hydroxylase (PHD) mutations. We have found for the first time a germ-line mutation in PHD1 in one patient and a novel germ-line PHD2 mutation in a second patient. Both mutants exhibited reduced protein stability with substantial quantitative protein loss and thus compromised catalytic activities. Due to the unique association of patients' polycythemia with borderline or mildly elevated erythropoietin (EPO) levels, we also performed an in vitro sensitivity assay of erythroid progenitors to EPO and for EPO receptor (EPOR) expression. The results show inappropriate hypersensitivity of erythroid progenitors to EPO in these patients, indicating increased EPOR expression/activity. In addition, the present study indicates that HIF dysregulation due to PHD mutations plays an important role in the pathogenesis of these tumors and associated polycythemia. The PHD1 mutation appears to be a new member contributing to the genetic landscape of this novel clinical entity. Our results support the existence of a specific PHD1- and PHD2-associated PHEO/PGL-polycythemia disorder. KEY MESSAGE • A novel germ-l i n e PHD1 mutation causing heochromocytoma/paraganglioma and polycythemia. • Increased EPOR activity and inappropriate hypersensitivity of erythroid progenitors to EPO.
Collapse
|
40
|
Yang M, Su H, Soga T, Kranc KR, Pollard PJ. Prolyl hydroxylase domain enzymes: important regulators of cancer metabolism. HYPOXIA 2014; 2:127-142. [PMID: 27774472 PMCID: PMC5045062 DOI: 10.2147/hp.s47968] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The hypoxia-inducible factor (HIF) prolyl hydroxylase domain enzymes (PHDs) regulate the stability of HIF protein by post-translational hydroxylation of two conserved prolyl residues in its α subunit in an oxygen-dependent manner. Trans-4-prolyl hydroxylation of HIFα under normal oxygen (O2) availability enables its association with the von Hippel-Lindau (VHL) tumor suppressor pVHL E3 ligase complex, leading to the degradation of HIFα via the ubiquitin-proteasome pathway. Due to the obligatory requirement of molecular O2 as a co-substrate, the activity of PHDs is inhibited under hypoxic conditions, resulting in stabilized HIFα, which dimerizes with HIFβ and, together with transcriptional co-activators CBP/p300, activates the transcription of its target genes. As a key molecular regulator of adaptive response to hypoxia, HIF plays important roles in multiple cellular processes and its overexpression has been detected in various cancers. The HIF1α isoform in particular has a strong impact on cellular metabolism, most notably by promoting anaerobic, whilst inhibiting O2-dependent, metabolism of glucose. The PHD enzymes also seem to have HIF-independent functions and are subject to regulation by factors other than O2, such as by metabolic status, oxidative stress, and abnormal levels of endogenous metabolites (oncometabolites) that have been observed in some types of cancers. In this review, we aim to summarize current understandings of the function and regulation of PHDs in cancer with an emphasis on their roles in metabolism.
Collapse
Affiliation(s)
- Ming Yang
- Cancer Biology and Metabolism Group, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Huizhong Su
- Cancer Biology and Metabolism Group, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Mizukami, Tsuruoka, Yamagata, Japan
| | - Kamil R Kranc
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK
| | - Patrick J Pollard
- Cancer Biology and Metabolism Group, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
41
|
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.
Collapse
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
| |
Collapse
|
42
|
Song D, Li LS, Arsenault PR, Tan Q, Bigham AW, Heaton-Johnson KJ, Master SR, Lee FS. Defective Tibetan PHD2 binding to p23 links high altitude adaption to altered oxygen sensing. J Biol Chem 2014; 289:14656-65. [PMID: 24711448 PMCID: PMC4031521 DOI: 10.1074/jbc.m113.541227] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 03/14/2014] [Indexed: 12/11/2022] Open
Abstract
The Tibetan population has adapted to the chronic hypoxia of high altitude. Tibetans bear a genetic signature in the prolyl hydroxylase domain protein 2 (PHD2/EGLN1) gene, which encodes for the central oxygen sensor of the hypoxia-inducible factor (HIF) pathway. Recent studies have focused attention on two nonsynonymous coding region substitutions, D4E and C127S, both of which are markedly enriched in the Tibetan population. These amino acids reside in a region of PHD2 that harbors a zinc finger, which we have previously discovered binds to a Pro-Xaa-Leu-Glu (PXLE) motif in the HSP90 cochaperone p23, thereby recruiting PHD2 to the HSP90 pathway to facilitate HIF-α hydroxylation. We herein report that the Tibetan PHD2 haplotype (D4E/C127S) strikingly diminishes the interaction of PHD2 with p23, resulting in impaired PHD2 down-regulation of the HIF pathway. The defective binding to p23 depends on both the D4E and C127S substitutions. We also identify a PXLE motif in HSP90 itself that can mediate binding to PHD2 but find that this interaction is maintained with the D4E/C127S PHD2 haplotype. We propose that the Tibetan PHD2 variant is a loss of function (hypomorphic) allele, leading to augmented HIF activation to facilitate adaptation to high altitude.
Collapse
Affiliation(s)
- Daisheng Song
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Lin-sheng Li
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Patrick R Arsenault
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Qiulin Tan
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Abigail W Bigham
- the Department of Anthropology, University of Michigan, Ann Arbor, Michigan 48109
| | - Katherine J Heaton-Johnson
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Stephen R Master
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Frank S Lee
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| |
Collapse
|