1
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Chu X, Baek DS, Li W, Shyp T, Mooney B, Hines MG, Morin GB, Sorensen PH, Dimitrov DS. Human antibodies targeting ENPP1 as candidate therapeutics for cancers. Front Immunol 2023; 14:1070492. [PMID: 36761762 PMCID: PMC9905232 DOI: 10.3389/fimmu.2023.1070492] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 01/09/2023] [Indexed: 01/27/2023] Open
Abstract
Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) is a type II transmembrane glycoprotein expressed in many tissues. High expression levels of ENPP1 have been observed in many cancer types such as lung cancer, ovarian cancer, and breast cancer. Such overexpression has been associated with poor prognosis in these diseases. Hence, ENPP1 is a potential target for immunotherapy across multiple cancers. Here, we isolated and characterized two high-affinity and specific anti-ENPP1 Fab antibody candidates, 17 and 3G12, from large phage-displayed human Fab libraries. After conversion to IgG1, the binding of both antibodies increased significantly due to avidity effects. Based on these antibodies, we generated antibody-drug conjugates (ADCs), IgG-based bispecific T-cell engagers (IbTEs), and CAR T-cells which all exhibited potent killing of ENPP1-expressing cells. Thus, these various antibody-derived modalities are promising therapeutic candidates for cancers expressing human ENPP1.
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Affiliation(s)
- Xiaojie Chu
- Center for Antibody Therapeutics, Division of Infectious Diseases, Department of Medicine, University of Pittsburgh Medical School, Pittsburgh, PA, United States
| | - Du-San Baek
- Center for Antibody Therapeutics, Division of Infectious Diseases, Department of Medicine, University of Pittsburgh Medical School, Pittsburgh, PA, United States
| | - Wei Li
- Center for Antibody Therapeutics, Division of Infectious Diseases, Department of Medicine, University of Pittsburgh Medical School, Pittsburgh, PA, United States
| | - Taras Shyp
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.,Department of Molecular Oncology, BC Cancer Research Institute, Vancouver, BC, Canada
| | - Brian Mooney
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Margaret G Hines
- Center for Antibody Therapeutics, Division of Infectious Diseases, Department of Medicine, University of Pittsburgh Medical School, Pittsburgh, PA, United States
| | - Gregg B Morin
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Research Institute, University of British Columbia, Vancouver, BC, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Poul H Sorensen
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.,Department of Molecular Oncology, BC Cancer Research Institute, Vancouver, BC, Canada
| | - Dimiter S Dimitrov
- Center for Antibody Therapeutics, Division of Infectious Diseases, Department of Medicine, University of Pittsburgh Medical School, Pittsburgh, PA, United States.,Abound Bio, Pittsburgh, PA, United States
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2
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Berger JM, Karsenty G. Osteocalcin and the Physiology of Danger. FEBS Lett 2021; 596:665-680. [PMID: 34913486 PMCID: PMC9020278 DOI: 10.1002/1873-3468.14259] [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: 07/29/2021] [Revised: 11/29/2021] [Accepted: 12/07/2021] [Indexed: 12/02/2022]
Abstract
Bone biology has long been driven by the question as to what molecules affect cell differentiation or the functions of bone. Exploring this issue has been an extraordinarily powerful way to improve our knowledge of bone development and physiology. More recently, a second question has emerged: does bone have other functions besides making bone? Addressing this conundrum revealed that the bone-derived hormone osteocalcin affects a surprisingly large number of organs and physiological processes, including acute stress response. This review will focus on this emerging aspect of bone biology taking osteocalcin as a case study and will show how classical and endocrine functions of bone help to define a new functional identity for this tissue.
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Affiliation(s)
- Julian Meyer Berger
- Department of Genetics and Development, Vagelos College of Physicians and Surgeons, Columbia University, NY, 10032, USA
| | - Gerard Karsenty
- Department of Genetics and Development, Vagelos College of Physicians and Surgeons, Columbia University, NY, 10032, USA
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3
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Kozák E, Fülöp K, Tőkési N, Rao N, Li Q, Terry SF, Uitto J, Zhang X, Becker C, Váradi A, Pomozi V. Oral supplementation of inorganic pyrophosphate in pseudoxanthoma elasticum. Exp Dermatol 2021; 31:548-555. [PMID: 34758173 DOI: 10.1111/exd.14498] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/29/2021] [Accepted: 11/06/2021] [Indexed: 01/19/2023]
Abstract
Pseudoxanthoma elasticum (PXE; OMIM 264800) is a rare heritable multisystem disorder, characterized by ectopic mineralization affecting elastic fibres in the skin, eyes and the cardiovascular system. Skin findings often lead to early diagnosis of PXE, but currently, no specific treatment exists to counteract the progression of symptoms. PXE belongs to a group of Mendelian calcification disorders linked to pyrophosphate metabolism, which also includes generalized arterial calcification of infancy (GACI) and arterial calcification due to CD73 deficiency (ACDC). Inactivating mutations in ABCC6, ENPP1 and NT5E are the genetic cause of these diseases, respectively, and all of them result in reduced inorganic pyrophosphate (PPi ) concentration in the circulation. Although PPi is a strong inhibitor of ectopic calcification, oral supplementation therapy was initially not considered because of its low bioavailability. Our earlier work however demonstrated that orally administered pyrophosphate inhibits ectopic calcification in the animal models of PXE and GACI, and that orally given Na4 P2 O7 is absorbed in humans. Here, we report that gelatin-encapsulated Na2 H2 P2 O7 has similar absorption properties in healthy volunteers and people affected by PXE. The sodium-free K2 H2 P2 O7 form resulted in similar uptake in healthy volunteers and inhibited calcification in Abcc6-/- mice as effectively as its sodium counterpart. Novel pyrophosphate compounds showing higher bioavailability in mice were also identified. Our results provide an important step towards testing oral PPi in clinical trials in PXE, or potentially any condition accompanied by ectopic calcification including diabetes, chronic kidney disease or ageing.
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Affiliation(s)
- Eszter Kozák
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Krisztina Fülöp
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Natália Tőkési
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Nidhi Rao
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Qiaoli Li
- Department of Dermatology and Cutaneous Biology, PXE International Center of Excellence in Research and Clinical Care, Sidney Kimmel Medicine College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Sharon F Terry
- PXE International, Washington, District of Columbia, USA
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, PXE International Center of Excellence in Research and Clinical Care, Sidney Kimmel Medicine College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Xiaoming Zhang
- Theratrophix, Sunnyvale, California, USA.,Pyrogenyx, Sunnyvale, California, USA
| | - Cyrus Becker
- Theratrophix, Sunnyvale, California, USA.,Pyrogenyx, Sunnyvale, California, USA
| | - András Váradi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Viola Pomozi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
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4
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Roberts FL, Rashdan NA, Phadwal K, Markby GR, Dillon S, Zoll J, Berger J, Milne E, Orriss IR, Karsenty G, Le Saux O, Morton NM, Farquharson C, MacRae VE. Osteoblast-specific deficiency of ectonucleotide pyrophosphatase or phosphodiesterase-1 engenders insulin resistance in high-fat diet fed mice. J Cell Physiol 2021; 236:4614-4624. [PMID: 33305372 PMCID: PMC9665351 DOI: 10.1002/jcp.30194] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 11/14/2020] [Accepted: 11/17/2020] [Indexed: 12/11/2022]
Abstract
Supraphysiological levels of the osteoblast-enriched mineralization regulator ectonucleotide pyrophosphatase or phosphodiesterase-1 (NPP1) is associated with type 2 diabetes mellitus. We determined the impact of osteoblast-specific Enpp1 ablation on skeletal structure and metabolic phenotype in mice. Female, but not male, 6-week-old mice lacking osteoblast NPP1 expression (osteoblast-specific knockout [KO]) exhibited increased femoral bone volume or total volume (17.50% vs. 11.67%; p < .01), and reduced trabecular spacing (0.187 vs. 0.157 mm; p < .01) compared with floxed (control) mice. Furthermore, an enhanced ability of isolated osteoblasts from the osteoblast-specific KO to calcify their matrix in vitro compared to fl/fl osteoblasts was observed (p < .05). Male osteoblast-specific KO and fl/fl mice showed comparable glucose and insulin tolerance despite increased levels of insulin-sensitizing under-carboxylated osteocalcin (195% increase; p < .05). However, following high-fat-diet challenge, osteoblast-specific KO mice showed impaired glucose and insulin tolerance compared with fl/fl mice. These data highlight a crucial local role for osteoblast NPP1 in skeletal development and a secondary metabolic impact that predominantly maintains insulin sensitivity.
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Affiliation(s)
- Fiona L. Roberts
- Functional Genetics and Development, The Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Midlothian, UK
| | - Nabil A. Rashdan
- Functional Genetics and Development, The Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Midlothian, UK
| | - Kanchan Phadwal
- Functional Genetics and Development, The Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Midlothian, UK
| | - Greg R. Markby
- Functional Genetics and Development, The Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Midlothian, UK
| | - Scott Dillon
- Functional Genetics and Development, The Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Midlothian, UK
| | - Janna Zoll
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, USA
| | - Julian Berger
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, USA
| | - Elspeth Milne
- Functional Genetics and Development, The Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Midlothian, UK
| | - Isabel R. Orriss
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, London, UK
| | - Gerard Karsenty
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, USA
| | - Olivier Le Saux
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, USA
| | - Nicholas M. Morton
- Centre for Cardiovascular Science, The Queen’s Medical Research Institute, The College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, UK
| | - Colin Farquharson
- Functional Genetics and Development, The Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Midlothian, UK
| | - Vicky E. MacRae
- Functional Genetics and Development, The Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Midlothian, UK
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5
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Woodward HJ, Zhu D, Hadoke PWF, MacRae VE. Regulatory Role of Sex Hormones in Cardiovascular Calcification. Int J Mol Sci 2021; 22:4620. [PMID: 33924852 PMCID: PMC8125640 DOI: 10.3390/ijms22094620] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/20/2021] [Accepted: 04/26/2021] [Indexed: 02/06/2023] Open
Abstract
Sex differences in cardiovascular disease (CVD), including aortic stenosis, atherosclerosis and cardiovascular calcification, are well documented. High levels of testosterone, the primary male sex hormone, are associated with increased risk of cardiovascular calcification, whilst estrogen, the primary female sex hormone, is considered cardioprotective. Current understanding of sexual dimorphism in cardiovascular calcification is still very limited. This review assesses the evidence that the actions of sex hormones influence the development of cardiovascular calcification. We address the current question of whether sex hormones could play a role in the sexual dimorphism seen in cardiovascular calcification, by discussing potential mechanisms of actions of sex hormones and evidence in pre-clinical research. More advanced investigations and understanding of sex hormones in calcification could provide a better translational outcome for those suffering with cardiovascular calcification.
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Affiliation(s)
- Holly J. Woodward
- The Roslin Institute & R(D)SVS, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK;
| | - Dongxing Zhu
- Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou 510260, China
| | - Patrick W. F. Hadoke
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK;
| | - Victoria E. MacRae
- The Roslin Institute & R(D)SVS, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK;
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6
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Shimada BK, Pomozi V, Zoll J, Kuo S, Martin L, Le Saux O. ABCC6, Pyrophosphate and Ectopic Calcification: Therapeutic Solutions. Int J Mol Sci 2021; 22:ijms22094555. [PMID: 33925341 PMCID: PMC8123679 DOI: 10.3390/ijms22094555] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 12/11/2022] Open
Abstract
Pathological (ectopic) mineralization of soft tissues occurs during aging, in several common conditions such as diabetes, hypercholesterolemia, and renal failure and in certain genetic disorders. Pseudoxanthoma elasticum (PXE), a multi-organ disease affecting dermal, ocular, and cardiovascular tissues, is a model for ectopic mineralization disorders. ABCC6 dysfunction is the primary cause of PXE, but also some cases of generalized arterial calcification of infancy (GACI). ABCC6 deficiency in mice underlies an inducible dystrophic cardiac calcification phenotype (DCC). These calcification diseases are part of a spectrum of mineralization disorders that also includes Calcification of Joints and Arteries (CALJA). Since the identification of ABCC6 as the “PXE gene” and the development of several animal models (mice, rat, and zebrafish), there has been significant progress in our understanding of the molecular genetics, the clinical phenotypes, and pathogenesis of these diseases, which share similarities with more common conditions with abnormal calcification. ABCC6 facilitates the cellular efflux of ATP, which is rapidly converted into inorganic pyrophosphate (PPi) and adenosine by the ectonucleotidases NPP1 and CD73 (NT5E). PPi is a potent endogenous inhibitor of calcification, whereas adenosine indirectly contributes to calcification inhibition by suppressing the synthesis of tissue non-specific alkaline phosphatase (TNAP). At present, therapies only exist to alleviate symptoms for both PXE and GACI; however, extensive studies have resulted in several novel approaches to treating PXE and GACI. This review seeks to summarize the role of ABCC6 in ectopic calcification in PXE and other calcification disorders, and discuss therapeutic strategies targeting various proteins in the pathway (ABCC6, NPP1, and TNAP) and direct inhibition of calcification via supplementation by various compounds.
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Affiliation(s)
- Briana K Shimada
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96817, USA
| | - Viola Pomozi
- Institute of Enzymology, RCNS, Hungarian Academy of Sciences, 1117 Budapest, Hungary
| | - Janna Zoll
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96817, USA
| | - Sheree Kuo
- Department of Pediatrics, Kapi'olani Medical Center for Women and Children, University of Hawaii, Honolulu, HI 96826, USA
| | - Ludovic Martin
- PXE Consultation Center, MAGEC Reference Center for Rare Skin Diseases, Angers University Hospital, 49100 Angers, France
- BNMI, CNRS 6214/INSERM 1083, University Bretagne-Loire, 49100 Angers, France
| | - Olivier Le Saux
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96817, USA
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7
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Suchacki KJ, Morton NM, Vary C, Huesa C, Yadav MC, Thomas BJ, Turban S, Bunger L, Ball D, Barrios-Llerena ME, Guntur AR, Khavandgar Z, Cawthorn WP, Ferron M, Karsenty G, Murshed M, Rosen CJ, MacRae VE, Millán JL, Farquharson C. PHOSPHO1 is a skeletal regulator of insulin resistance and obesity. BMC Biol 2020; 18:149. [PMID: 33092598 PMCID: PMC7584094 DOI: 10.1186/s12915-020-00880-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 09/25/2020] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The classical functions of the skeleton encompass locomotion, protection and mineral homeostasis. However, cell-specific gene deletions in the mouse and human genetic studies have identified the skeleton as a key endocrine regulator of metabolism. The bone-specific phosphatase, Phosphatase, Orphan 1 (PHOSPHO1), which is indispensable for bone mineralisation, has been recently implicated in the regulation of energy metabolism in humans, but its role in systemic metabolism remains unclear. Here, we probe the mechanism underlying metabolic regulation by analysing Phospho1 mutant mice. RESULTS Phospho1-/- mice exhibited improved basal glucose homeostasis and resisted high-fat-diet-induced weight gain and diabetes. The metabolic protection in Phospho1-/- mice was manifested in the absence of altered levels of osteocalcin. Osteoblasts isolated from Phospho1-/- mice were enriched for genes associated with energy metabolism and diabetes; Phospho1 both directly and indirectly interacted with genes associated with glucose transport and insulin receptor signalling. Canonical thermogenesis via brown adipose tissue did not underlie the metabolic protection observed in adult Phospho1-/- mice. However, the decreased serum choline levels in Phospho1-/- mice were normalised by feeding a 2% choline rich diet resulting in a normalisation in insulin sensitivity and fat mass. CONCLUSION We show that mice lacking the bone mineralisation enzyme PHOSPHO1 exhibit improved basal glucose homeostasis and resist high-fat-diet-induced weight gain and diabetes. This study identifies PHOSPHO1 as a potential bone-derived therapeutic target for the treatment of obesity and diabetes.
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Affiliation(s)
- Karla J Suchacki
- Roslin Institute, R(D)SVS, University of Edinburgh, Edinburgh, Scotland, UK. .,Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK.
| | - Nicholas M Morton
- Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK
| | - Calvin Vary
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA
| | - Carmen Huesa
- Roslin Institute, R(D)SVS, University of Edinburgh, Edinburgh, Scotland, UK.,MRC Centre for Reproductive Health, University of Edinburgh, Edinburgh, Scotland, UK
| | - Manisha C Yadav
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, USA
| | - Benjamin J Thomas
- Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK
| | - Sophie Turban
- Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK
| | - Lutz Bunger
- Scottish Rural College, Edinburgh, Scotland, UK
| | - Derek Ball
- Medical Sciences and Nutrition, School of Medicine, University of Aberdeen, Aberdeen, Scotland, UK
| | | | - Anyonya R Guntur
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA
| | - Zohreh Khavandgar
- Department of Medicine and Faculty of Dentistry, McGill University, Montreal, Canada
| | - William P Cawthorn
- Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK
| | - Mathieu Ferron
- Molecular Physiology Research Unit, Institut de recherches cliniques de Montréal, Montreal, Canada
| | - Gérard Karsenty
- Department of Genetics and Development, Columbia University Medical Center, New York, USA
| | - Monzur Murshed
- Department of Medicine and Faculty of Dentistry, McGill University, Montreal, Canada
| | - Clifford J Rosen
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA
| | - Vicky E MacRae
- Roslin Institute, R(D)SVS, University of Edinburgh, Edinburgh, Scotland, UK
| | - Jose Luis Millán
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, USA
| | - Colin Farquharson
- Roslin Institute, R(D)SVS, University of Edinburgh, Edinburgh, Scotland, UK
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8
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Karsenty G. The facts of the matter: What is a hormone? PLoS Genet 2020; 16:e1008938. [PMID: 32589668 PMCID: PMC7319275 DOI: 10.1371/journal.pgen.1008938] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 06/17/2020] [Indexed: 12/17/2022] Open
Affiliation(s)
- Gerard Karsenty
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, New York, United States of America
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9
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Rashdan NA, Sim AM, Cui L, Phadwal K, Roberts FL, Carter R, Ozdemir DD, Hohenstein P, Hung J, Kaczynski J, Newby DE, Baker AH, Karsenty G, Morton NM, MacRae VE. Osteocalcin Regulates Arterial Calcification Via Altered Wnt Signaling and Glucose Metabolism. J Bone Miner Res 2020; 35:357-367. [PMID: 31596966 DOI: 10.1002/jbmr.3888] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 09/23/2019] [Accepted: 09/28/2019] [Indexed: 12/12/2022]
Abstract
Arterial calcification is an important hallmark of cardiovascular disease and shares many similarities with skeletal mineralization. The bone-specific protein osteocalcin (OCN) is an established marker of vascular smooth muscle cell (VSMC) osteochondrogenic transdifferentiation and a known regulator of glucose metabolism. However, the role of OCN in controlling arterial calcification is unclear. We hypothesized that OCN regulates calcification in VSMCs and sought to identify the underpinning signaling pathways. Immunohistochemistry revealed OCN co-localization with VSMC calcification in human calcified carotid artery plaques. Additionally, 3 mM phosphate treatment stimulated OCN mRNA expression in cultured VSMCs (1.72-fold, p < 0.001). Phosphate-induced calcification was blunted in VSMCs derived from OCN null mice (Ocn -/- ) compared with cells derived from wild-type (WT) mice (0.37-fold, p < 0.001). Ocn -/- VSMCs showed reduced mRNA expression of the osteogenic marker Runx2 (0.51-fold, p < 0.01) and the sodium-dependent phosphate transporter, PiT1 (0.70-fold, p < 0.001), with an increase in the calcification inhibitor Mgp (1.42-fold, p < 0.05) compared with WT. Ocn -/- VSMCs also showed reduced mRNA expression of Axin2 (0.13-fold, p < 0.001) and Cyclin D (0.71 fold, p < 0.01), markers of Wnt signaling. CHIR99021 (GSK3β inhibitor) treatment increased calcium deposition in WT and Ocn -/- VSMCs (1 μM, p < 0.001). Ocn -/- VSMCs, however, calcified less than WT cells (1 μM; 0.27-fold, p < 0.001). Ocn -/- VSMCs showed reduced mRNA expression of Glut1 (0.78-fold, p < 0.001), Hex1 (0.77-fold, p < 0.01), and Pdk4 (0.47-fold, p < 0.001). This was accompanied by reduced glucose uptake (0.38-fold, p < 0.05). Subsequent mitochondrial function assessment revealed increased ATP-linked respiration (1.29-fold, p < 0.05), spare respiratory capacity (1.59-fold, p < 0.01), and maximal respiration (1.52-fold, p < 0.001) in Ocn -/- versus WT VSMCs. Together these data suggest that OCN plays a crucial role in arterial calcification mediated by Wnt/β-catenin signaling through reduced maximal respiration. Mitochondrial dynamics may therefore represent a novel therapeutic target for clinical intervention. © 2019 American Society for Bone and Mineral Research.
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Affiliation(s)
- Nabil A Rashdan
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Alisia M Sim
- School of Chemistry, University of Edinburgh, Edinburgh, UK
| | - Lin Cui
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Kanchan Phadwal
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Fiona L Roberts
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Roderick Carter
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Derya D Ozdemir
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Peter Hohenstein
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - John Hung
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Jakub Kaczynski
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - David E Newby
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Andrew H Baker
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Gerard Karsenty
- Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Nicholas M Morton
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Vicky E MacRae
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
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10
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Sharma A, Goring A, Staines KA, Emery RJ, Pitsillides AA, Oreffo RO, Mahajan S, Clarkin CE. Raman spectroscopy links differentiating osteoblast matrix signatures to pro-angiogenic potential. Matrix Biol Plus 2020; 5:100018. [PMID: 33543015 PMCID: PMC7852201 DOI: 10.1016/j.mbplus.2019.100018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 08/21/2019] [Accepted: 10/09/2019] [Indexed: 01/25/2023] Open
Abstract
Mineralization of bone is achieved by the sequential maturation of the immature amorphous calcium phase to mature hydroxyapatite (HA) and is central in the process of bone development and repair. To study normal and dysregulated mineralization in vitro, substrates are often coated with poly-l-lysine (PLL) which facilitates cell attachment. This study has used Raman spectroscopy to investigate the effect of PLL coating on osteoblast (OB) matrix composition during differentiation, with a focus on collagen specific proline and hydroxyproline and precursors of HA. Deconvolution analysis of murine derived long bone OB Raman spectra revealed collagen species were 4.01-fold higher in OBs grown on PLL. Further, an increase of 1.91-fold in immature mineral species (amorphous calcium phosphate) was coupled with a 9.32-fold reduction in mature mineral species (carbonated apatite) on PLL versus controls. These unique low mineral signatures identified in OBs were linked with reduced alkaline phosphatase enzymatic activity, reduced Alizarin Red staining and altered osteogenic gene expression. The promotion of immature mineral species and restriction of mature mineral species of OB grown on PLL were linked to increased cell viability and pro-angiogenic vascular endothelial growth factor (VEGF) production. These results demonstrate the utility of Raman spectroscopy to link distinct matrix signatures with OB maturation and VEGF release. Importantly, Raman spectroscopy could provide a label-free approach to clinically assess the angiogenic potential of bone during fracture repair or degenerative bone loss.
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Key Words
- ACP, amorphous calcium phosphate
- ALP, tissue non-specific alkaline phosphatase
- CAP, carbonated apatite
- CCEC, collagenase-collagenase-EDTA-collagenase
- ECM, extracellular matrix
- HA, hydroxyapatite
- HBSS, Hank's balanced salt solution
- MV, matrix vesicles
- OB, osteoblast
- OCP, octacalcium phosphate
- Osteoblast mineralization
- PCA, principle component analysis
- PLL, poly-l-lysine
- Poly-l-lysine
- RT-qPCR, reverse transcription-quantiative PCR
- Raman spectroscopy
- VEGF
- VEGF, vascular endothelial growth factor
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Affiliation(s)
- Aikta Sharma
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, SO17 1BJ, United Kingdom of Great Britain and Northern Ireland
| | - Alice Goring
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, SO17 1BJ, United Kingdom of Great Britain and Northern Ireland
| | - Katherine A. Staines
- School of Applied Sciences, Sighthill Campus, Edinburgh Napier University, Edinburgh, EH11 4BN, United Kingdom of Great Britain and Northern Ireland
| | - Roger J.H. Emery
- Department of Surgery and Cancer, Faculty of Medicine, St Mary's Campus, Imperial College London, London, W2 1PG, United Kingdom of Great Britain and Northern Ireland
| | - Andrew A. Pitsillides
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, NW1 0TU, United Kingdom of Great Britain and Northern Ireland
| | - Richard O.C. Oreffo
- Centre for Human Development, Stem Cell and Regeneration, Institute of Developmental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, United Kingdom of Great Britain and Northern Ireland
| | - Sumeet Mahajan
- School of Chemistry and Institute for Life Sciences, Highfield Campus, University of Southampton, Southampton, SO17 1BJ, United Kingdom of Great Britain and Northern Ireland
| | - Claire E. Clarkin
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, SO17 1BJ, United Kingdom of Great Britain and Northern Ireland
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11
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Onyedibe KI, Wang M, Sintim HO. ENPP1, an Old Enzyme with New Functions, and Small Molecule Inhibitors-A STING in the Tale of ENPP1. Molecules 2019; 24:molecules24224192. [PMID: 31752288 PMCID: PMC6891441 DOI: 10.3390/molecules24224192] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/07/2019] [Accepted: 11/13/2019] [Indexed: 11/16/2022] Open
Abstract
Ectonucleotide pyrophosphatase/phosphodiesterase I (ENPP1) was identified several decades ago as a type II transmembrane glycoprotein with nucleotide pyrophosphatase and phosphodiesterase enzymatic activities, critical for purinergic signaling. Recently, ENPP1 has emerged as a critical phosphodiesterase that degrades the stimulator of interferon genes (STING) ligand, cyclic GMP-AMP (cGAMP). cGAMP or analogs thereof have emerged as potent immunostimulatory agents, which have potential applications in immunotherapy. This emerging role of ENPP1 has placed this "old" enzyme at the frontier of immunotherapy. This review highlights the roles played by ENPP1, the mechanism of cGAMP hydrolysis by ENPP1, and small molecule inhibitors of ENPP1 with potential applications in diverse disease states, including cancer.
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Affiliation(s)
- Kenneth I. Onyedibe
- Chemistry Department, Institute for Drug Discovery, Purdue University, West Lafayette, IN 47907, USA; (K.I.O.); (M.W.)
- Purdue Institute for Inflammation, Immunology, and Infectious Diseases, West Lafayette, IN 47907, USA
| | - Modi Wang
- Chemistry Department, Institute for Drug Discovery, Purdue University, West Lafayette, IN 47907, USA; (K.I.O.); (M.W.)
| | - Herman O. Sintim
- Chemistry Department, Institute for Drug Discovery, Purdue University, West Lafayette, IN 47907, USA; (K.I.O.); (M.W.)
- Purdue Institute for Inflammation, Immunology, and Infectious Diseases, West Lafayette, IN 47907, USA
- Purdue University Center for Cancer Research, West Lafayette, IN 47907, USA
- Correspondence: ; Tel.: +1-(765)-496-6078; Fax: +1-(765)-494-0239
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12
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ENPP1 in the Regulation of Mineralization and Beyond. Trends Biochem Sci 2019; 44:616-628. [PMID: 30799235 DOI: 10.1016/j.tibs.2019.01.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/26/2019] [Accepted: 01/29/2019] [Indexed: 12/24/2022]
Abstract
ENPP1 is well known for its role in regulating skeletal and soft tissue mineralization. It primarily exerts its function through the generation of pyrophosphate, a key inhibitor of hydroxyapatite formation. Several previous studies have suggested that ENPP1 also contributes to a range of human diseases including diabetes, cancer, cardiovascular disease, and osteoarthritis. In this review, we summarize the pathological roles of ENPP1 in mineralization and these soft tissue disorders. We also discuss the underlying mechanisms through which ENPP1 exerts its pathological effects. A fuller understanding of the pathways through which ENPP1 acts may help to develop novel therapeutic strategies for these commonly diagnosed morbidities.
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13
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Tam V, Turcotte M, Meyre D. Established and emerging strategies to crack the genetic code of obesity. Obes Rev 2019; 20:212-240. [PMID: 30353704 DOI: 10.1111/obr.12770] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 12/11/2022]
Abstract
Tremendous progress has been made in the genetic elucidation of obesity over the past two decades, driven largely by technological, methodological and organizational innovations. Current strategies for identifying obesity-predisposing loci/genes, including cytogenetics, linkage analysis, homozygosity mapping, admixture mapping, candidate gene studies, genome-wide association studies, custom genotyping arrays, whole-exome sequencing and targeted exome sequencing, have achieved differing levels of success, and the identified loci in aggregate explain only a modest fraction of the estimated heritability of obesity. This review outlines the successes and limitations of these approaches and proposes novel strategies, including the use of exceptionally large sample sizes, the study of diverse ethnic groups and deep phenotypes and the application of innovative methods and study designs, to identify the remaining obesity-predisposing genes. The use of both established and emerging strategies has the potential to crack the genetic code of obesity in the not-too-distant future. The resulting knowledge is likely to yield improvements in obesity prediction, prevention and care.
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Affiliation(s)
- V Tam
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - M Turcotte
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - D Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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14
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Danino O, Svetitsky S, Kenigsberg S, Levin A, Journo S, Gold A, Drexler M, Snir N, Elkayam O, Fischer B, Arad U. Inhibition of nucleotide pyrophosphatase/phosphodiesterase 1: implications for developing a calcium pyrophosphate deposition disease modifying drug. Rheumatology (Oxford) 2018; 57:1472-1480. [PMID: 29688536 DOI: 10.1093/rheumatology/key092] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Indexed: 12/16/2022] Open
Abstract
Objectives Calcium pyrophosphate deposition (CPPD) is associated with osteoarthritis and is the cause of a common inflammatory articular disease. Ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (eNPP1) is the major ecto-pyrophosphatase in chondrocytes and cartilage-derived matrix vesicles (MVs). Thus, eNPP1 is a principle contributor to extracellular pyrophosphate levels and a potential target for interventions aimed at preventing CPPD. Recently, we synthesized and described a novel eNPP1-specific inhibitor, SK4A, and we set out to evaluate whether this inhibitor attenuates nucleotide pyrophosphatase activity in human OA cartilage. Methods Cartilage tissue, chondrocytes and cartilage-derived MVs were obtained from donors with OA undergoing arthroplasty. The effect of SK4A on cell viability was assayed by the XTT method. eNPP1 expression was evaluated by western blot. Nucleotide pyrophosphatase activity was measured by a colorimetric assay and by HPLC analysis of adenosine triphosphate (ATP) levels. ATP-induced calcium deposition in cultured chondrocytes was visualized and quantified with Alizarin red S staining. Results OA chondrocytes expressed eNPP1 in early passages, but this expression was subsequently lost upon further passaging. Similarly, significant nucleotide pyrophosphatase activity was only detected in early-passage chondrocytes. The eNPP1 inhibitor, SK4A, was not toxic to chondrocytes and stable in culture medium and human plasma. SK4A effectively inhibited nucleotide pyrophosphatase activity in whole cartilage tissue, in chondrocytes and in cartilage-derived MVs and reduced ATP-induced CPPD. Conclusion Nucleotide analogues such as SK4A may be developed as potent and specific inhibitors of eNPP1 for the purpose of lowering extracellular pyrophosphate levels in human cartilage with the aim of preventing and treating CPPD disease.
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Affiliation(s)
- Ortal Danino
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel
| | - Shuli Svetitsky
- Department of Rheumatology, Tel Aviv University, Tel Aviv, Israel
| | | | - Asaf Levin
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel
| | - Shani Journo
- Department of Rheumatology, Tel Aviv University, Tel Aviv, Israel
| | - Aviram Gold
- Division of Orthopedics, Tel Aviv Medical Center and the Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Michael Drexler
- Division of Orthopedics, Tel Aviv Medical Center and the Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Nimrod Snir
- Division of Orthopedics, Tel Aviv Medical Center and the Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ori Elkayam
- Department of Rheumatology, Tel Aviv University, Tel Aviv, Israel
| | - Bilha Fischer
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel
| | - Uri Arad
- Department of Rheumatology, Tel Aviv University, Tel Aviv, Israel
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15
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ATP-degrading ENPP1 is required for survival (or persistence) of long-lived plasma cells. Sci Rep 2017; 7:17867. [PMID: 29259245 PMCID: PMC5736562 DOI: 10.1038/s41598-017-18028-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/05/2017] [Indexed: 02/05/2023] Open
Abstract
Survival of antibody-secreting plasma cells (PCs) is vital for sustained antibody production. However, it remains poorly understood how long-lived PCs (LLPCs) are generated and maintained. Here we report that ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) is preferentially upregulated in bone marrow LLPCs compared with their splenic short-lived counterparts (SLPCs). We studied ENPP1-deficient mice (Enpp1−/−) to determine how the enzyme affects PC biology. Although Enpp1−/− mice generated normal levels of germinal center B cells and plasmablasts in periphery, they produced significantly reduced numbers of LLPCs following immunization with T-dependent antigens or infection with plasmodium C. chabaudi. Bone marrow chimeric mice showed B cell intrinsic effect of ENPP1 selectively on generation of bone marrow as well as splenic LLPCs. Moreover, Enpp1−/− PCs took up less glucose and had lower levels of glycolysis than those of wild-type controls. Thus, ENPP1 deficiency confers an energetic disadvantage to PCs for long-term survival and antibody production.
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16
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Suchacki KJ, Roberts F, Lovdel A, Farquharson C, Morton NM, MacRae VE, Cawthorn WP. Skeletal energy homeostasis: a paradigm of endocrine discovery. J Endocrinol 2017; 234:R67-R79. [PMID: 28455432 DOI: 10.1530/joe-17-0147] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 04/28/2017] [Indexed: 12/15/2022]
Abstract
Throughout the last decade, significant developments in cellular, molecular and mouse models have revealed major endocrine functions of the skeleton. More recent studies have evolved the interplay between bone-specific hormones, the skeleton, marrow adipose tissue, muscle and the brain. This review focuses on literature from the last decade, addressing the endocrine regulation of global energy metabolism via the skeleton. In addition, we will highlight several recent studies that further our knowledge of new endocrine functions of some organs; explore remaining unanswered questions; and, finally, we will discuss future directions for this more complex era of bone biology research.
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Affiliation(s)
- Karla J Suchacki
- The Queen's Medical Research InstituteThe University of Edinburgh, Edinburgh, UK
| | - Fiona Roberts
- The Roslin InstituteThe University of Edinburgh, Easter Bush, Midltohian, UK
| | - Andrea Lovdel
- The Queen's Medical Research InstituteThe University of Edinburgh, Edinburgh, UK
| | - Colin Farquharson
- The Roslin InstituteThe University of Edinburgh, Easter Bush, Midltohian, UK
| | - Nik M Morton
- The Queen's Medical Research InstituteThe University of Edinburgh, Edinburgh, UK
| | - Vicky E MacRae
- The Roslin InstituteThe University of Edinburgh, Easter Bush, Midltohian, UK
| | - William P Cawthorn
- The Queen's Medical Research InstituteThe University of Edinburgh, Edinburgh, UK
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17
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New perspectives on rare connective tissue calcifying diseases. Curr Opin Pharmacol 2016; 28:14-23. [DOI: 10.1016/j.coph.2016.02.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 01/27/2016] [Accepted: 02/08/2016] [Indexed: 12/27/2022]
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18
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Huesa C, Staines KA, Millán JL, MacRae VE. Effects of etidronate on the Enpp1⁻/⁻ mouse model of generalized arterial calcification of infancy. Int J Mol Med 2015; 36:159-65. [PMID: 25975272 PMCID: PMC4494596 DOI: 10.3892/ijmm.2015.2212] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/22/2015] [Indexed: 12/23/2022] Open
Abstract
Generalized arterial calcification of infancy (GACI) is an autosomal recessive disorder of spontaneous infantile arterial and periarticular calcification which is attributed to mutations in the ectonucleotide pyrophosphatase/phosphodiesterase 1 (Enpp1) gene. Whilst the bisphosphonate, etidronate, is currently used off-label for the treatment for GACI, recent studies have highlighted its detrimental effects on bone mineralisation. In the present study, we used the Enpp1-/- mouse model of GACI to examine the effects of etidronate treatment (100 µg/kg), on vascular and skeletal calcification. Micro-computed tomography (µCT) analysis revealed a significant decrease in trabecular bone mass, as reflected by the decrease in trabecular bone volume/tissue volume (BV/TV; %), trabecular thickness, trabecular separation, trabecular number and pattern factor (P<0.05) in the Enpp1-/- mice in comparison to the wild-type (WT) mice. Mechanical testing revealed that in the WT mice, treatment with etidronate significantly improved work to fracture and increased work post-failure (P<0.05, in comparison to the vehicle-treated WT mice). This significant increase, however, was not observed in the Enpp1-/- mice. Treatment with etidronate had no effect on bone parameters in the WT mice; however, the Enpp1-/- mice displayed an increased structural model index (SMI; P<0.05). We used a recently developed 3D µCT protocol to reconstruct and quantify the extensive aortic calcification in Enpp1-/- mice in comparison to the WT mice. However, treatment with etidronate did not prevent de novo calcification, and did not arrest the progression of established calcification of the aorta.
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Affiliation(s)
- Carmen Huesa
- Roslin Institute and R(D)SVS, The University of Edinburgh, Edinburgh, UK
| | | | - Jose Luis Millán
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - Vicky E MacRae
- Roslin Institute and R(D)SVS, The University of Edinburgh, Edinburgh, UK
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19
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Abstract
Recent developments in endocrinology, made possible by the combination of mouse genetics, integrative physiology and clinical observations have resulted in rapid and unanticipated advances in the field of skeletal biology. Indeed, the skeleton, classically viewed as a structural scaffold necessary for mobility, and regulator of calcium-phosphorus homoeostasis and maintenance of the haematopoietic niche has now been identified as an important regulator of male fertility and whole-body glucose metabolism, in addition to the classical insulin target tissues. These seminal findings confirm bone to be a true endocrine organ. This review is intended to detail the key events commencing from the elucidation of osteocalcin (OC) in bone metabolism to identification of new and emerging candidates that may regulate energy metabolism independently of OC.
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Affiliation(s)
- K J Oldknow
- Developmental BiologyThe Roslin Institute, Edinburgh, UK
| | - V E MacRae
- Developmental BiologyThe Roslin Institute, Edinburgh, UK
| | - C Farquharson
- Developmental BiologyThe Roslin Institute, Edinburgh, UK
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