51
|
Thorsen IS, Bleskestad IH, Åsberg A, Hartmann A, Skadberg Ø, Brede C, Ueland T, Pasch A, Reisæter AV, Gøransson LG. Vitamin D as a risk factor for patient survival after kidney transplantation: A prospective observational cohort study. Clin Transplant 2019; 33:e13517. [DOI: 10.1111/ctr.13517] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/08/2019] [Accepted: 02/27/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Inga S. Thorsen
- Department of Internal Medicine Stavanger University Hospital Stavanger Norway
- Department of Clinical Medicine University of Bergen Bergen Norway
| | - Inger H. Bleskestad
- Department of Internal Medicine Stavanger University Hospital Stavanger Norway
| | - Anders Åsberg
- Department of Transplantation Medicine Oslo University Hospital Oslo Norway
- Department of Pharmaceutical Biosciences, School of Pharmacy University of Oslo Oslo Norway
- Norwegian Renal Registry Oslo Norway
| | - Anders Hartmann
- Department of Transplantation Medicine Oslo University Hospital Oslo Norway
- Medical Faculty, Institute of Clinical Medicine University of Oslo Oslo Norway
| | - Øyvind Skadberg
- Department of Medical Biochemistry Stavanger University Hospital Stavanger Norway
| | - Cato Brede
- Department of Medical Biochemistry Stavanger University Hospital Stavanger Norway
| | - Thor Ueland
- Medical Faculty, Institute of Clinical Medicine University of Oslo Oslo Norway
- Research Institute of Internal Medicine University of Oslo Oslo Norway
| | | | - Anna V. Reisæter
- Department of Transplantation Medicine Oslo University Hospital Oslo Norway
- Norwegian Renal Registry Oslo Norway
| | - Lasse G. Gøransson
- Department of Internal Medicine Stavanger University Hospital Stavanger Norway
- Department of Clinical Medicine University of Bergen Bergen Norway
| |
Collapse
|
52
|
Beck-Nielsen SS, Mughal Z, Haffner D, Nilsson O, Levtchenko E, Ariceta G, de Lucas Collantes C, Schnabel D, Jandhyala R, Mäkitie O. FGF23 and its role in X-linked hypophosphatemia-related morbidity. Orphanet J Rare Dis 2019; 14:58. [PMID: 30808384 PMCID: PMC6390548 DOI: 10.1186/s13023-019-1014-8] [Citation(s) in RCA: 145] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 01/30/2019] [Indexed: 12/29/2022] Open
Abstract
Background X-linked hypophosphatemia (XLH) is an inherited disease of phosphate metabolism in which inactivating mutations of the Phosphate Regulating Endopeptidase Homolog, X-Linked (PHEX) gene lead to local and systemic effects including impaired growth, rickets, osteomalacia, bone abnormalities, bone pain, spontaneous dental abscesses, hearing difficulties, enthesopathy, osteoarthritis, and muscular dysfunction. Patients with XLH present with elevated levels of fibroblast growth factor 23 (FGF23), which is thought to mediate many of the aforementioned manifestations of the disease. Elevated FGF23 has also been observed in many other diseases of hypophosphatemia, and a range of animal models have been developed to study these diseases, yet the role of FGF23 in the pathophysiology of XLH is incompletely understood. Methods The role of FGF23 in the pathophysiology of XLH is here reviewed by describing what is known about phenotypes associated with various PHEX mutations, animal models of XLH, and non-nutritional diseases of hypophosphatemia, and by presenting molecular pathways that have been proposed to contribute to manifestations of XLH. Results The pathophysiology of XLH is complex, involving a range of molecular pathways that variously contribute to different manifestations of the disease. Hypophosphatemia due to elevated FGF23 is the most obvious contributor, however localised fluctuations in tissue non-specific alkaline phosphatase (TNAP), pyrophosphate, calcitriol and direct effects of FGF23 have been observed to be associated with certain manifestations. Conclusions By describing what is known about these pathways, this review highlights key areas for future research that would contribute to the understanding and clinical treatment of non-nutritional diseases of hypophosphatemia, particularly XLH.
Collapse
Affiliation(s)
| | - Zulf Mughal
- Royal Manchester Children's Hospital, Manchester, UK
| | | | - Ola Nilsson
- Karolinska Institutet, Stockholm, Sweden and Örebro University, Örebro, Sweden
| | | | - Gema Ariceta
- Hospital Universitario Materno-Infantil Vall d'Hebron, Universitat Autonoma de Barcelona, Barcelona, Spain
| | | | - Dirk Schnabel
- University Children's Hospital of Berlin, Berlin, Germany
| | | | - Outi Mäkitie
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| |
Collapse
|
53
|
Abstract
Purpose of review α-Klotho (Klotho) occurs in three isoforms, a membrane-bound form acting as a coreceptor for fibroblast growth factor-23 (FGF23) signalling, a shed soluble form consisting of Klotho's large ectodomain thought to act as an enzyme or a hormone, and a secreted truncated form generated by alternative splicing of the Klotho mRNA with unknown function. The purpose of this review is to highlight the recent advances in our understanding of Klotho's function in mineral homeostasis. Recent findings A number of seminal discoveries have recently been made in this area, shifting existing paradigms. The crystal structure of the ternary FGF receptor (FGFR)-1c/Klotho/FGF23 complex has been uncovered, revealing how the ligand FGF23 interacts with FGFR1c and the coreceptor Klotho at atomic resolution. Furthermore, it was shown that soluble Klotho lacks any glycosidase activity and serves as a bona fide coreceptor for FGF23 signalling. Experiments with a combination of Klotho and Fgf23-deficient mouse models demonstrated that all isoforms of Klotho lack any physiologically relevant, FGF23-independent functions in mineral homeostasis or ageing. Finally, it was demonstrated that the alternatively spliced Klotho mRNA is degraded and is not translated into a secreted Klotho protein isoform in humans. Summary Taken together, there is now overwhelming evidence that the main physiological function of transmembrane and soluble Klotho for mineral homeostasis is their role as coreceptors mediating FGF23 actions. In light of these findings, the main pathophysiological consequence of the downregulation of Klotho observed in acute and chronic renal failure may be the induction of renal FGF23 resistance.
Collapse
|
54
|
Su N, Yang J, Xie Y, Du X, Chen H, Zhou H, Chen L. Bone function, dysfunction and its role in diseases including critical illness. Int J Biol Sci 2019; 15:776-787. [PMID: 30906209 PMCID: PMC6429025 DOI: 10.7150/ijbs.27063] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 01/04/2019] [Indexed: 12/16/2022] Open
Abstract
The skeleton is one of the largest organs in the human body. In addition to its conventional functions such as support, movement and protection, the skeleton also contributes to whole body homeostasis and maintenance of multiple important non-bone organs/systems (extraskeletal functions). Both conventional and extraskeletal functions of the skeleton are defined as bone function. Bone-derived factors (BDFs) are key players regulating bone function. In some pathophysiological situations, including diseases affecting bone and/or other organs/systems, the disorders of bone itself and the subsequently impaired functions of extraskeletal organs/systems caused by abnormal bone (impaired extraskeletal functions of bone) are defined as bone dysfunction. In critical illness, which is a health status characterized by the dysfunction or severe damage of one or multiple important organs or systems, the skeleton shows rapid bone loss resulting from bone hyper-resorption and impaired osteoblast function. In addition, the dysfunctions of the skeleton itself are also closely related to the severity and prognosis of critical illness. Therefore, we propose that there is bone dysfunction in critical illness. Some methods to inhibit osteoclast activity or promote osteoblast function by the treatment of bisphosphonates or PTH1-34 benefit the outcome of critical illness, which indicates that enhancing bone function may be a potential novel strategy to improve prognosis of diseases including critical illness.
Collapse
Affiliation(s)
- Nan Su
- Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, China
| | - Jing Yang
- Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, China
| | - Yangli Xie
- Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, China
| | - Xiaolan Du
- Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, China
| | - Hangang Chen
- Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, China
| | - Hong Zhou
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Hospital Road, Sydney, NSW 2139, Australia
| | - Lin Chen
- Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, China
| |
Collapse
|
55
|
Meurer M, Höcherl K. Endotoxaemia differentially regulates the expression of renal Ca 2+ transport proteins in mice. Acta Physiol (Oxf) 2019; 225:e13175. [PMID: 30133162 DOI: 10.1111/apha.13175] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 08/17/2018] [Accepted: 08/18/2018] [Indexed: 12/16/2022]
Abstract
AIM Alterations in parathyroid hormone (PTH) and/or vitamin D signalling are frequently reported in patients with sepsis. The consequences on renal and intestinal Ca2+ and Pi regulatory mechanisms are still unclear. We hypothesized that endotoxaemia alters the expression of important renal and intestinal Ca2+ and Pi transport proteins. METHODS Male C57BL/6 mice were treated with lipopolysaccharide (LPS; 3 mg/kg; i.p.). The mRNA and protein levels of renal and intestinal Ca2+ and Pi transport proteins were measured by RT-qPCR, immunohistochemistry and western blot analysis. RESULTS Lipopolysaccharide-induced hypocalcaemia and hyperphosphataemia was paralleled by a decrease in glomerular filtration rate and urinary excretion of Ca2+ and Pi . Endotoxaemia augmented plasma levels of PTH and affected the fibroblast growth factor 23 (FGF23)-klotho-vitamin D axis by increasing plasma levels of FGF23 and downregulation of renal klotho expression. Renal expression of CYP27b1 and plasma levels of 1,25-dihydroxyvitamin D3 were increased in response to LPS. Endotoxaemia augmented the renal expression of TRPV5, TRPV6 and PiT1, whereas the renal expression of calbindin-D28K , NCX1, NaPi -2a and NaPi -2c were decreased. Incubation of primary distal tubule cells with LPS increased TRPV6 mRNA levels. Furthermore, LPS decreased the intestinal expression of TRPV6, calbindin-D9K and of NaPi -2b. CONCLUSION Our findings indicate that endotoxaemia is associated with hypocalcaemia and hyperphosphataemia and a disturbed FGF23-klotho-vitamin D signaling. Further, LPS-induced acute kidney injury was accompanied by an increased or decreased expression of specific renal and intestinal Ca2+ and Pi transporters respectively. It seems unlikely that LPS-induced hypocalcaemia is due to renal loss of Ca2+ .
Collapse
Affiliation(s)
- Manuel Meurer
- Institute of Experimental and Clinical Pharmacology and Toxicology; Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Erlangen Germany
| | - Klaus Höcherl
- Institute of Experimental and Clinical Pharmacology and Toxicology; Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Erlangen Germany
| |
Collapse
|
56
|
Mizobuchi M, Ogata H, Koiwa F. Secondary Hyperparathyroidism: Pathogenesis and Latest Treatment. Ther Apher Dial 2018; 23:309-318. [PMID: 30411503 DOI: 10.1111/1744-9987.12772] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/23/2018] [Accepted: 11/02/2018] [Indexed: 01/02/2023]
Abstract
The classic pathogenesis of secondary hyperparathyroidism (SHPT) began with the trade-off hypothesis based on parathyroid hormone hypersecretion brought about by renal failure resulting from a physiological response to correct metabolic disorder of calcium, phosphorus, and vitamin D. In dialysis patients with failed renal function, physiological mineral balance control by parathyroid hormone through the kidney fails and hyperparathyroidism progresses. In this process, many significant genetic findings have been established. Abnormalities of Ca-sensing receptor and vitamin D receptor are associated with the pathogenesis of SHPT, and fibroblast growth factor 23 has also been shown to be involved in the pathogenesis. Vitamin D receptor activators (VDRAs) are widely used for treatment of SHPT. However, VDRAs have calcemic and phosphatemic effects that limit their use to a subset of patients, and calcimimetics have been developed as alternative drugs for SHPT. Hyperphosphatemia also affects progression of SHPT, and control of hyperphosphatemia is, therefore, thought to be fundamental for control of SHPT. Currently, a combination of a VDRA and a calcimimetic is recognized as the optimal strategy for SHPT, and for other outcomes such as reduced cardiovascular disease and improved survival. The latest findings on the pathogenesis and treatment of SHPT are summarized in this review.
Collapse
Affiliation(s)
- Masahide Mizobuchi
- Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan
| | - Hiroaki Ogata
- Department of Medicine, Showa University Northern Yokohama Hospital, Yokohama, Japan
| | - Fumihiko Koiwa
- Division of Nephrology, Department of Medicine, Showa University Fujigaoka Hospital, Yokohama, Japan
| |
Collapse
|
57
|
Takashi Y, Fukumoto S. FGF23 beyond Phosphotropic Hormone. Trends Endocrinol Metab 2018; 29:755-767. [PMID: 30217676 DOI: 10.1016/j.tem.2018.08.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/13/2018] [Accepted: 08/14/2018] [Indexed: 12/14/2022]
Abstract
Fibroblast growth factor (FGF) 23 is a bone-derived phosphotropic hormone that regulates phosphate and vitamin D metabolism. FGF23 mainly affects kidney function via the FGF receptor (FGFR)/α-Klotho complex. The physiological roles of FGF23 and α-Klotho in the regulation of mineral homeostasis have been well established. In addition, recent studies have reported that FGF23 has various effects on many other tissues, sometimes in an α-Klotho-independent manner, especially under pathological conditions. However, how FGF23 works in these tissues without α-Klotho is not entirely clear. Here we review the recent reports concerning the actions of FGF23 on various tissues and discuss the remaining questions about FGF23.
Collapse
Affiliation(s)
- Yuichi Takashi
- Diabetes Therapeutics and Research Center, Institute of Advanced Medical Sciences, Tokushima University, 3-18-15 Kuramoto-cho, Tokushima, Tokushima 7708503, Japan; Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, 3-18-15 Kuramoto-cho, Tokushima, Tokushima 7708503, Japan
| | - Seiji Fukumoto
- Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, 3-18-15 Kuramoto-cho, Tokushima, Tokushima 7708503, Japan.
| |
Collapse
|
58
|
Abstract
Inorganic phosphate (Pi) is essential for signal transduction and cell metabolism, and is also an essential structural component of the extracellular matrix of the skeleton. Pi is sensed in bacteria and yeast at the plasma membrane, which activates intracellular signal transduction to control the expression of Pi transporters and other genes that control intracellular Pi levels. In multicellular organisms, Pi homeostasis must be maintained in the organism and at the cellular level, requiring an endocrine and metabolic Pi-sensing mechanism, about which little is currently known. This Review will discuss the metabolic effects of Pi, which are mediated by Pi transporters, inositol pyrophosphates and SYG1-Pho81-XPR1 (SPX)-domain proteins to maintain cellular phosphate homeostasis in the musculoskeletal system. In addition, we will discuss how Pi is sensed by the human body to regulate the production of fibroblast growth factor 23 (FGF23), parathyroid hormone and calcitriol to maintain serum levels of Pi in a narrow range. New findings on the crosstalk between iron and Pi homeostasis in the regulation of FGF23 expression will also be outlined. Mutations in components of these metabolic and endocrine phosphate sensors result in genetic disorders of phosphate homeostasis, cardiomyopathy and familial basal ganglial calcifications, highlighting the importance of this newly emerging area of research.
Collapse
Affiliation(s)
- Sampada Chande
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT, USA
| | - Clemens Bergwitz
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT, USA.
| |
Collapse
|
59
|
Ureña-Torres PA, Vervloet M, Mazzaferro S, Oury F, Brandenburg V, Bover J, Cavalier E, Cohen-Solal M, Covic A, Drüeke TB, Hindié E, Evenepoel P, Frazão J, Goldsmith D, Kazama JJ, Cozzolino M, Massy ZA. Novel insights into parathyroid hormone: report of The Parathyroid Day in Chronic Kidney Disease. Clin Kidney J 2018; 12:269-280. [PMID: 30976408 PMCID: PMC6452197 DOI: 10.1093/ckj/sfy061] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Indexed: 12/14/2022] Open
Abstract
Chronic kidney disease (CKD) is often associated with a mineral and bone disorder globally described as CKD-Mineral and Bone Disease (MBD), including renal osteodystrophy, the latter ranging from high bone turnover, as in case of secondary hyperparathyroidism (SHPT), to low bone turnover. The present article summarizes the important subjects that were covered during ‘The Parathyroid Day in Chronic Kidney Disease’ CME course organized in Paris in September 2017. It includes the latest insights on parathyroid gland growth, parathyroid hormone (PTH) synthesis, secretion and regulation by the calcium-sensing receptor, vitamin D receptor and fibroblast growth factor 23 (FGF23)–Klotho axis, as well as on parathyroid glands imaging. The skeletal action of PTH in early CKD stages to the steadily increasing activation of the often downregulated PTH receptor type 1 has been critically reviewed, emphasizing that therapeutic strategies to decrease PTH levels at these stages might not be recommended. The effects of PTH on the central nervous system, in particular cognitive functions, and on the cardiovascular system are revised, and the reliability and exchangeability of second- and third-generation PTH immunoassays discussed. The article also reviews the different circulating biomarkers used for the diagnosis and monitoring of CKD-MBD, including PTH and alkaline phosphatases isoforms. Moreover, it presents an update on the control of SHPT by vitamin D compounds, old and new calcimimetics, and parathyroidectomy. Finally, it covers the latest insights on the persistence and de novo occurrence of SHPT in renal transplant recipients.
Collapse
Affiliation(s)
- Pablo A Ureña-Torres
- Ramsay-Générale de Santé, Clinique du Landy, Department of Nephrology and Dialysis and Department of Renal Physiology, Necker Hospital, University of Paris Descartes, Paris, France
| | - Marc Vervloet
- Department of Nephrology and Amsterdam Cardiovascular Sciences (ACS), VU University Medical Center, Amsterdam, The Netherlands
| | - Sandro Mazzaferro
- Department of Cardiovascular Respiratory Nephrologic Anaesthetic and Geriatric Sciences, Sapienza University of Rome, Rome, Italy
| | - Franck Oury
- INEM, Centre de Mdecine Moléculaire Faculté de Médecine Paris Descartes, Sorbonne, Paris Cité Bâtiment Leriche, France
| | - Vincent Brandenburg
- Department of Cardiology, University Hospital RWTH Aachen, Pauwelsstraße, Aachen, Germany
| | - Jordi Bover
- Department of Nephrology, Fundació Puigvert, IIB Sant Pau, RedinRen, C. Cartagena, Catalonia, 340-350 Barcelona, Spain
| | - Etienne Cavalier
- Department of Clinical Chemistry, University of Liège, CHU Sart-Tilman, Liège, Belgium
| | - Martine Cohen-Solal
- INSERM U1132 & USPC Paris-Diderot, Department of Rheumatology, Hôpital Lariboisière, Paris, France
| | - Adrian Covic
- Department of Nephrology, University of Medicine and Pharmacy "Gr. T. Popa", Iasi, Romania
| | - Tilman B Drüeke
- Inserm Unit 1018, CESP, Team 5, Paul Brousse Hospital, Villejuif/Paris, France
| | - Elif Hindié
- Nuclear Medicine, University of Bordeaux, Haut-Lévêque Hospital, Pessac, France
| | - Pieter Evenepoel
- Department of Medicine, Division of Nephrology, University Hospital Leuven, Leuven, Belgium.,Dienst nefrologie, Universitair Ziekenhuis Gasthuisberg, Herestraat, Leuven, Belgium
| | - João Frazão
- Institute of Investigation and Innovation in Health, University of Porto, Porto, Portugal.,INEB-National Institute of Biomedical Engineer, University of Porto, Porto, Portugal.,Department of Nephrology, São João Hospital Center, Porto, Portugal.,School of Medicine of University of Porto, Porto, Portugal
| | | | - Junichiro James Kazama
- Department of Nephrology and Hypertension, Fukushima Medical University, 1 Hikarigaoka, Fukushima 960-1247, Japan
| | - Mario Cozzolino
- Renal Division, San Paolo Hospital, Department of Health Sciences, University of Milan, Milan, Italy
| | - Ziad A Massy
- Division of Nephrology, Ambroise Paré University Medical Center, APHP, University of Paris Ouest (UVSQ), Boulogne Billancourt/Paris, France
| | | |
Collapse
|
60
|
Krick S, Grabner A, Baumlin N, Yanucil C, Helton S, Grosche A, Sailland J, Geraghty P, Viera L, Russell DW, Wells JM, Xu X, Gaggar A, Barnes J, King GD, Campos M, Faul C, Salathe M. Fibroblast growth factor 23 and Klotho contribute to airway inflammation. Eur Respir J 2018; 52:1800236. [PMID: 29748308 PMCID: PMC6044452 DOI: 10.1183/13993003.00236-2018] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 04/27/2018] [Indexed: 01/20/2023]
Abstract
Circulating levels of fibroblast growth factor (FGF)23 are associated with systemic inflammation and increased mortality in chronic kidney disease. α-Klotho, a co-receptor for FGF23, is downregulated in chronic obstructive pulmonary disease (COPD). However, whether FGF23 and Klotho-mediated FGF receptor (FGFR) activation delineates a pathophysiological mechanism in COPD remains unclear. We hypothesised that FGF23 can potentiate airway inflammation via Klotho-independent FGFR4 activation.FGF23 and its effect were studied using plasma and transbronchial biopsies from COPD and control patients, and primary human bronchial epithelial cells isolated from COPD patients as well as a murine COPD model.Plasma FGF23 levels were significantly elevated in COPD patients. Exposure of airway epithelial cells to cigarette smoke and FGF23 led to a significant increase in interleukin-1β release via Klotho-independent FGFR4-mediated activation of phospholipase Cγ/nuclear factor of activated T-cells signalling. In addition, Klotho knockout mice developed COPD and showed airway inflammation and elevated FGFR4 expression in their lungs, whereas overexpression of Klotho led to an attenuation of airway inflammation.Cigarette smoke induces airway inflammation by downregulation of Klotho and activation of FGFR4 in the airway epithelium in COPD. Inhibition of FGF23 or FGFR4 might serve as a novel anti-inflammatory strategy in COPD.
Collapse
Affiliation(s)
- Stefanie Krick
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexander Grabner
- Division of Nephrology, Department of Medicine, Duke University Medical Center, Duke University, Durham, USA
| | - Nathalie Baumlin
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, FL 33136, USA
| | - Christopher Yanucil
- Division of Nephrology, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Scott Helton
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Astrid Grosche
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, FL 33136, USA
| | - Juliette Sailland
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, FL 33136, USA
| | - Patrick Geraghty
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Liliana Viera
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Derek W. Russell
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - J. Michael Wells
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
- UAB Lung Health Center, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Xin Xu
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Amit Gaggar
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jarrod Barnes
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Gwendalyn D. King
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Michael Campos
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, FL 33136, USA
| | - Christian Faul
- Division of Nephrology, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Matthias Salathe
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, FL 33136, USA
| |
Collapse
|
61
|
Kinoshita Y, Fukumoto S. X-Linked Hypophosphatemia and FGF23-Related Hypophosphatemic Diseases: Prospect for New Treatment. Endocr Rev 2018; 39:274-291. [PMID: 29381780 DOI: 10.1210/er.2017-00220] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 01/23/2018] [Indexed: 12/21/2022]
Abstract
Phosphate plays essential roles in many biological processes, and the serum phosphate level is tightly controlled. Chronic hypophosphatemia causes impaired mineralization of the bone matrix and results in rickets and osteomalacia. Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that regulates phosphate metabolism. FGF23 excess induces hypophosphatemia via impaired phosphate reabsorption in the renal proximal tubules and decreased phosphate absorption in the intestines. There are several types of genetic and acquired FGF23-related hypophosphatemic diseases. Among these diseases, X-linked hypophosphatemia (XLH), which is caused by inactivating mutations in the phosphate-regulating endopeptidase homolog, X-linked (PHEX) gene, is the most prevalent form of genetic FGF23-related hypophosphatemic rickets. Another clinically relevant form of FGF23-related hypophosphatemic disease is tumor-induced osteomalacia (TIO), a paraneoplastic syndrome associated with FGF23-producing tumors. A combination of active vitamin D and phosphate salts is the current medical therapy used to treat patients with XLH and inoperative TIO. However, this therapy has certain efficacy- and safety-associated limitations. Several measures to inhibit FGF23 activity have been considered as possible new treatments for FGF23-related hypophosphatemic diseases. In particular, a humanized monoclonal antibody for FGF23 (burosumab) is a promising treatment in patients with XLH and TIO. This review will focus on the phosphate metabolism and the pathogenesis and treatment of FGF23-related hypophosphatemic diseases.
Collapse
Affiliation(s)
- Yuka Kinoshita
- Division of Nephrology and Endocrinology, Department of Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Seiji Fukumoto
- Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| |
Collapse
|
62
|
Central role of the proximal tubular αKlotho/FGF receptor complex in FGF23-regulated phosphate and vitamin D metabolism. Sci Rep 2018; 8:6917. [PMID: 29720668 PMCID: PMC5932018 DOI: 10.1038/s41598-018-25087-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 04/16/2018] [Indexed: 02/06/2023] Open
Abstract
Fibroblast growth factor 23 (FGF23) plays critical roles in phosphate handling and vitamin D metabolism in the kidney. However, the effector cells of FGF23 in the kidney remain unclear. αKlotho, a putative enzyme possessing β-glucuronidase activity and also a permissive co-receptor for FGF23 to bind to FGF receptors (FGFRs), is expressed most abundantly in distal convoluted tubules, whereas it is expressed modestly in proximal tubules. Key molecular players of phosphate homeostasis and vitamin D-metabolizing enzymes are known to localize in proximal tubules. To clarify the direct function of FGF23 on proximal tubules, we ablated αKlotho or Fgfr1-4 genes specifically from these tubules using the Cre-loxP-mediated genetic recombination. Both conditional knockout mouse lines showed similar phenotypes that resembled those of systemic αKlotho or Fgf23 knockout mice. Compared with control mice, they showed significantly elevated levels of plasma phosphate, FGF23 and 1,25-dihydroxyvitamin D, ectopic calcification in the kidney and aging-related phenotypes like growth retardation, osteoporosis and shortened lifespan. These findings suggest that the primary function of FGF23 on mineral metabolism is mediated through αKlotho/FGFR co-receptors expressed in proximal tubular cells, and that the putative enzymatic function of αKlotho in the proximal tubule has a minor role in systemic mineral metabolism.
Collapse
|
63
|
Courbebaisse M, Lanske B. Biology of Fibroblast Growth Factor 23: From Physiology to Pathology. Cold Spring Harb Perspect Med 2018; 8:a031260. [PMID: 28778965 PMCID: PMC5932574 DOI: 10.1101/cshperspect.a031260] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Fibroblast growth factor (FGF)23 is a phosphaturic hormone produced by osteocytes and osteoblasts that binds to FGF receptors in the presence of the transmembrane protein αKlotho. FGF23 mainly targets the renal proximal tubule to inhibit calcitriol production and the expression of the sodium/phosphate cotransporters NaPi2a and NaPi2c, thus inhibiting renal phosphate reabsorption. FGF23 also acts on the parathyroid glands to inhibit parathyroid hormone synthesis and secretion. FGF23 regulation involves many systemic and local factors, among them calcitriol, phosphate, and parathyroid hormone. Increased FGF23 is primarily observed in rare acquired or genetic disorders, but chronic kidney disease is associated with a reactional increase in FGF23 to combat hyperphosphatemia. However, high FGF23 levels induce left ventricular hypertrophy (LVH) and are associated with an increased risk of mortality. In this review, we describe FGF23 physiology and the pathological consequences of high or low FGF23 levels.
Collapse
Affiliation(s)
- Marie Courbebaisse
- Division of Bone and Mineral Research OMII, Harvard School of Dental Medicine, Boston, Massachusetts 02115
- Paris Descartes University, Paris 75006, France
| | - Beate Lanske
- Division of Bone and Mineral Research OMII, Harvard School of Dental Medicine, Boston, Massachusetts 02115
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| |
Collapse
|
64
|
Zheng S, Chen Y, Zheng Y, Zhou Z, Li Z. Correlation of serum levels of fibroblast growth factor 23 and Klotho protein levels with bone mineral density in maintenance hemodialysis patients. Eur J Med Res 2018; 23:18. [PMID: 29665846 PMCID: PMC5905149 DOI: 10.1186/s40001-018-0315-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 03/22/2018] [Indexed: 12/12/2022] Open
Abstract
Objective The correlation of serum fibroblast growth factor 23 (FGF-23) and Klotho protein levels with bone mineral density (BMD) in maintenance hemodialysis (MHD) patients was analyzed. Methods Between January 2015 and November 2015, 125 MHD patients in our hospital were enrolled. Dual-energy X-ray absorptiometry was used to examine the BMD in the femoral neck and lumbar spine of MHD patients. The patients were divided into three groups: a normal bone mass group, an osteopenia group, and an osteoporosis group. An ELISA was performed to measure serum FGF-23, Klotho protein, and 1,25(OH)2VitD3 levels. Other parameters, including calcium (Ca), phosphorus (P), and parathyroid hormone, were also measured. Results Of the 125 MHD patients, 82.40% of patients had femoral neck osteopenia, and 56.00% of patients had lumbar spinal osteopenia. The serum FGF-23 level was highest in the osteoporosis group. However, there was no significant difference in serum FGF-23 levels among the three groups, depending on femoral neck and lumbar spinal BMD (P > 0.05). Spearman’s correlation analysis also pointed to a lack of correlation between serum FGF-23 levels and BMD. Among the three groups, there were significant differences in serum Klotho protein levels and femoral neck BMD (P < 0.05). Serum Klotho protein levels in the osteoporosis group were clearly lower than those in the normal bone mass group and osteopenia group (P < 0.05). Similarly, serum Klotho protein levels were significantly lower in those with lumbar spinal osteopenia as compared with those in the normal group. There was a positive correlation between serum Klotho protein levels and BMD and T values for the femoral neck and lumbar spine. The results of a multiple linear regression analysis revealed that the serum Klotho protein level was one of the main factors affecting BMD in MHD patients. Conclusions The serum level of FGF-23 was not correlated with a change in BMD of MHD patients, whereas the serum Klotho protein level was associated with the degree of BMD. A high Klotho protein level may decrease the severity of chronic kidney disease and mineral bone disorder (CKD-MBD) in MHD patients with low BMD.
Collapse
Affiliation(s)
- Shubei Zheng
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuanxi Rd., Wenzhou, 325027, People's Republic of China
| | - Yan Chen
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuanxi Rd., Wenzhou, 325027, People's Republic of China
| | - Yu Zheng
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuanxi Rd., Wenzhou, 325027, People's Republic of China
| | - Zhihong Zhou
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuanxi Rd., Wenzhou, 325027, People's Republic of China
| | - Zhanyuan Li
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuanxi Rd., Wenzhou, 325027, People's Republic of China.
| |
Collapse
|
65
|
Chen X, Chen X, Wu W, Zhou Q, Gong X, Shi B. Effects of FGF‐23‐mediated ERK/MAPK signaling pathway on parathyroid hormone secretion of parathyroid cells in rats with secondary hyperparathyroidism. J Cell Physiol 2018; 233:7092-7102. [PMID: 29633272 DOI: 10.1002/jcp.26525] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 01/30/2018] [Indexed: 12/28/2022]
Affiliation(s)
- Xiao‐Jun Chen
- Department of EndocrinologyThe First Affiliated Hospital of Soochow UniversitySuzhouP.R. China
- Department of EndocrinologyThe First Affiliated Hospital of Wenzhou Medical UniversityWenzhouP.R. China
| | - Xiong Chen
- Department of EndocrinologyThe First Affiliated Hospital of Wenzhou Medical UniversityWenzhouP.R. China
| | - Wen‐Jun Wu
- Department of EndocrinologyThe First Affiliated Hospital of Wenzhou Medical UniversityWenzhouP.R. China
| | - Qi Zhou
- Department of EndocrinologyThe First Affiliated Hospital of Wenzhou Medical UniversityWenzhouP.R. China
| | - Xiao‐Hua Gong
- Department of EndocrinologyThe First Affiliated Hospital of Wenzhou Medical UniversityWenzhouP.R. China
| | - Bi‐Min Shi
- Department of EndocrinologyThe First Affiliated Hospital of Soochow UniversitySuzhouP.R. China
| |
Collapse
|
66
|
Interrelated role of Klotho and calcium-sensing receptor in parathyroid hormone synthesis and parathyroid hyperplasia. Proc Natl Acad Sci U S A 2018; 115:E3749-E3758. [PMID: 29618612 DOI: 10.1073/pnas.1717754115] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The pathogenesis of parathyroid gland hyperplasia is poorly understood, and a better understanding is essential if there is to be improvement over the current strategies for prevention and treatment of secondary hyperparathyroidism. Here we investigate the specific role of Klotho expressed in the parathyroid glands (PTGs) in mediating parathyroid hormone (PTH) and serum calcium homeostasis, as well as the potential interaction between calcium-sensing receptor (CaSR) and Klotho. We generated mouse strains with PTG-specific deletion of Klotho and CaSR and dual deletion of both genes. We show that ablating CaSR in the PTGs increases PTH synthesis, that Klotho has a pivotal role in suppressing PTH in the absence of CaSR, and that CaSR together with Klotho regulates PTH biosynthesis and PTG growth. We utilized the tdTomato gene in our mice to visualize and collect PTGs to reveal an inhibitory function of Klotho on PTG cell proliferation. Chronic hypocalcemia and ex vivo PTG culture demonstrated an independent role for Klotho in mediating PTH secretion. Moreover, we identify an interaction between PTG-expressed CaSR and Klotho. These findings reveal essential and interrelated functions for CaSR and Klotho during parathyroid hyperplasia.
Collapse
|
67
|
Covic A, Vervloet M, Massy ZA, Torres PU, Goldsmith D, Brandenburg V, Mazzaferro S, Evenepoel P, Bover J, Apetrii M, Cozzolino M. Bone and mineral disorders in chronic kidney disease: implications for cardiovascular health and ageing in the general population. Lancet Diabetes Endocrinol 2018; 6:319-331. [PMID: 29050900 DOI: 10.1016/s2213-8587(17)30310-8] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 07/17/2017] [Accepted: 08/10/2017] [Indexed: 12/11/2022]
Abstract
The patient with chronic kidney disease (CKD) represents an extreme model for arteriosclerosis, vascular calcification, and bone disorders, all of which are also associated with ageing in the general population. These pathological features are also relevant to other common chronic health disorders such as diabetes, and chronic inflammatory and cardiovascular diseases. Although management and interventions for these major risk factors are now incorporated into most public health guidelines (eg, smoking cessation and control of bodyweight and blood pressure, as well as glucose and cholesterol concentrations), some residual cardiovascular risk is not reduced by implementation of these interventions. CKD should be regarded as an atypical disease in which both traditional and novel cardiovascular risk factors have effects on outcomes. But CKD can also be viewed conceptually as an accelerator of traditional cardiovascular risk factors. Findings from research into mineral bone disorder associated with CKD (CKD-MBD) could help the medical community to better understand the vascular actions of certain molecules, such as phosphates, fibroblast growth factor 23, parathyroid hormone, sclerostin, or vitamin D and their relevance to the management of different pathologies in the general population. Importantly, these components, which are recognised in nephrology, could help to explain residual risk of cardiovascular events in the general population. Thus, achieving a better understanding of CKD-MBDs could provide substantial insight into future treatments for arteriosclerosis and osteoporosis, which are strongly associated with ageing and morbidity in the general population.
Collapse
Affiliation(s)
- Adrian Covic
- Department of Nephrology, Grigore T Popa University of Medicine and Pharmacy, Iasi, Romania.
| | - Marc Vervloet
- Department of Nephrology and Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, Netherlands
| | - Ziad A Massy
- Division of Nephrology, Ambroise Paré Hospital, Paris Ile de France Ouest Université, Paris, France; Inserm U1018, Université Paris-Saclay, Versailles Saint-Quentin-en-Yvelines University, Villejuif, France
| | - Pablo Ureña Torres
- Department of Nephrology and Dialysis, Ramsay-Générale de Santé, Necker Hospital, University of Paris Descartes, Paris, France
| | | | - Vincent Brandenburg
- Department of Cardiology and Intensive Care Medicine, RWTH University Hospital, Aachen, Germany
| | - Sandro Mazzaferro
- Department of Cardiovascular, Respiratory, Nephrologic and Geriatric Sciences, Sapienza University of Rome, Rome, Italy
| | - Pieter Evenepoel
- Department of Medicine, Division of Nephrology, Dialysis and Renal Transplantation, University Hospital Leuven, Leuven, Belgium
| | - Jordi Bover
- Fundació Puigvert, IIB Sant Pau, REDinREN, Barcelona, Spain
| | - Mugurel Apetrii
- Department of Nephrology, Grigore T Popa University of Medicine and Pharmacy, Iasi, Romania
| | - Mario Cozzolino
- Department of Health Sciences, Renal Division, San Paolo Hospital, University of Milan, Milan, Italy
| |
Collapse
|
68
|
The role of fibroblast growth factor 23 and Klotho in uremic cardiomyopathy. Curr Opin Nephrol Hypertens 2018; 25:314-24. [PMID: 27219043 DOI: 10.1097/mnh.0000000000000231] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW In chronic kidney disease (CKD), multiple factors contribute to the development of cardiac hypertrophy by directly targeting the heart or indirectly by inducing systemic changes such as hypertension, anemia, and inflammation. Furthermore, disturbances in phosphate metabolism have been identified as nonclassical risk factors for cardiovascular mortality in these patients. With declining kidney function, the physiologic regulators of phosphate homeostasis undergo changes in their activity as well as their circulating levels, thus potentially contributing to cardiac hypertrophy once they are out of balance. Recently, two of these phosphate regulators, fibroblast growth factor 23 (FGF23) and Klotho, have been shown to affect cardiac remodeling, thereby unveiling a novel pathomechanism of cardiac hypertrophy in CKD. Here we discuss the potential direct versus indirect effects of FGF23 and the soluble form of Klotho on the heart, and their crosstalk in the regulation of cardiac hypertrophy. RECENT FINDINGS In models of CKD, FGF23 can directly target cardiac myocytes via FGF receptor 4 and induce cardiac hypertrophy in a blood pressure-independent manner. Soluble Klotho may directly target the heart via an unknown receptor thereby protecting the myocardium from pathologic stress stimuli that are associated with CKD, such as uremic toxins or FGF23. SUMMARY Elevated serum levels of FGF23 and reduced serum levels of soluble Klotho contribute to uremic cardiomyopathy in a synergistic manner.
Collapse
|
69
|
Mace ML, Gravesen E, Nordholm A, Olgaard K, Lewin E. Fibroblast Growth Factor (FGF) 23 Regulates the Plasma Levels of Parathyroid Hormone In Vivo Through the FGF Receptor in Normocalcemia, But Not in Hypocalcemia. Calcif Tissue Int 2018; 102:85-92. [PMID: 29063159 PMCID: PMC5760590 DOI: 10.1007/s00223-017-0333-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 09/22/2017] [Indexed: 01/09/2023]
Abstract
The calcium and phosphate homeostasis is regulated by a complex interplay between parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), and calcitriol. Experimental studies have demonstrated an inhibitory effect of FG23 on PTH production and secretion; the physiological role of this regulation is however not well understood. Surprisingly, in uremia, concomitantly elevated FGF23 and PTH levels are observed. The parathyroid gland rapidly loses its responsiveness to extracellular calcium in vitro and a functional parathyroid cell line has currently not been established. Therefore, the aim of the present investigation was to study the impact of FGF23 on the Ca2+/PTH relationship in vivo under conditions of normocalcemia and hypocalcemia. Wistar rats were allocated to treatment with intravenous recombinant FGF23 and inhibition of the FGF receptor in the setting of normocalcemia and acute hypocalcemia. We demonstrated that FGF23 rapidly inhibited PTH secretion and that this effect was completely blocked by inhibition of the FGF receptor. Furthermore, inhibition of the FGF receptor by itself significantly increased PTH levels, indicating that FGF23 has a suppressive tonus on the parathyroid gland's PTH secretion. In acute hypocalcemia, there was no effect of either recombinant FGF23 or FGF receptor inhibition on the physiological response to the low ionized calcium levels. In conclusion, FGF23 has an inhibitory tonus on PTH secretion in normocalcemia and signals through the FGF receptor. In acute hypocalcemia, when increased PTH secretion is needed to restore the calcium homeostasis, this inhibitory effect of FGF23 is abolished.
Collapse
Affiliation(s)
- Maria L Mace
- Department of Nephrology, Herlev Hospital, University of Copenhagen, 2730, Copenhagen, Denmark
- Department of Nephrology, Rigshospitalet Copenhagen, University of Copenhagen, Copenhagen, Denmark
| | - Eva Gravesen
- Department of Nephrology, Rigshospitalet Copenhagen, University of Copenhagen, Copenhagen, Denmark
| | - Anders Nordholm
- Department of Nephrology, Herlev Hospital, University of Copenhagen, 2730, Copenhagen, Denmark
- Department of Nephrology, Rigshospitalet Copenhagen, University of Copenhagen, Copenhagen, Denmark
| | - Klaus Olgaard
- Department of Nephrology, Rigshospitalet Copenhagen, University of Copenhagen, Copenhagen, Denmark
| | - Ewa Lewin
- Department of Nephrology, Herlev Hospital, University of Copenhagen, 2730, Copenhagen, Denmark.
- Department of Nephrology, Rigshospitalet Copenhagen, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
70
|
Abstract
Fibroblast growth factor-23 (FGF23) is a bone-derived hormone suppressing phosphate reabsorption and vitamin D hormone synthesis in the kidney. At physiological concentrations of the hormone, the endocrine actions of FGF23 in the kidney are αKlotho-dependent, because high-affinity binding of FGF23 to FGF receptors requires the presence of the co-receptor αKlotho on target cells. It is well established that excessive concentrations of intact FGF23 in the blood lead to phosphate wasting in patients with normal kidney function. Based on the importance of diseases associated with gain of FGF23 function such as phosphate-wasting diseases and chronic kidney disease, a large body of literature has focused on the pathophysiological consequences of FGF23 excess. Less emphasis has been put on the role of FGF23 in normal physiology. Nevertheless, during recent years, lessons we have learned from loss-of-function models have shown that besides the paramount physiological roles of FGF23 in the control of 1α-hydroxylase expression and of apical membrane expression of sodium-phosphate co-transporters in proximal renal tubules, FGF23 also is an important stimulator of calcium and sodium reabsorption in distal renal tubules. In addition, there is an emerging role of FGF23 as an auto-/paracrine regulator of alkaline phosphatase expression and mineralization in bone. In contrast to the renal actions of FGF23, the FGF23-mediated suppression of alkaline phosphatase in bone is αKlotho-independent. Moreover, FGF23 may be a physiological suppressor of differentiation of hematopoietic stem cells into the erythroid lineage in the bone microenvironment. At present, there is little evidence for a physiological role of FGF23 in organs other than kidney and bone. The purpose of this mini-review is to highlight the current knowledge about the complex physiological functions of FGF23.
Collapse
|
71
|
Richter B, Faul C. FGF23 Actions on Target Tissues-With and Without Klotho. Front Endocrinol (Lausanne) 2018; 9:189. [PMID: 29770125 PMCID: PMC5940753 DOI: 10.3389/fendo.2018.00189] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 04/06/2018] [Indexed: 12/11/2022] Open
Abstract
Fibroblast growth factor (FGF) 23 is a phosphaturic hormone whose physiologic actions on target tissues are mediated by FGF receptors (FGFR) and klotho, which functions as a co-receptor that increases the binding affinity of FGF23 for FGFRs. By stimulating FGFR/klotho complexes in the kidney and parathyroid gland, FGF23 reduces renal phosphate uptake and secretion of parathyroid hormone, respectively, thereby acting as a key regulator of phosphate metabolism. Recently, it has been shown that FGF23 can also target cell types that lack klotho. This unconventional signaling event occurs in an FGFR-dependent manner, but involves other downstream signaling pathways than in "classic" klotho-expressing target organs. It appears that klotho-independent signaling mechanisms are only activated in the presence of high FGF23 concentrations and result in pathologic cellular changes. Therefore, it has been postulated that massive elevations in circulating levels of FGF23, as found in patients with chronic kidney disease, contribute to associated pathologies by targeting cells and tissues that lack klotho. This includes the induction of cardiac hypertrophy and fibrosis, the elevation of inflammatory cytokine expression in the liver, and the inhibition of neutrophil recruitment. Here, we describe the signaling and cellular events that are caused by FGF23 in tissues lacking klotho, and we discuss FGF23's potential role as a hormone with widespread pathologic actions. Since the soluble form of klotho can function as a circulating co-receptor for FGF23, we also discuss the potential inhibitory effects of soluble klotho on FGF23-mediated signaling which might-at least partially-underlie the pleiotropic tissue-protective functions of klotho.
Collapse
|
72
|
Kaludjerovic J, Komaba H, Lanske B. Effects of klotho deletion from bone during chronic kidney disease. Bone 2017; 100:50-55. [PMID: 28232146 PMCID: PMC5474158 DOI: 10.1016/j.bone.2017.02.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 02/17/2017] [Accepted: 02/18/2017] [Indexed: 12/24/2022]
Abstract
Klotho is a type I transmembrane protein that acts as a permissive co-receptor for FGF23 and helps to maintain proper mineral metabolism. Mice carrying a loss-of-function mutation in either the Klotho or Fgf23 gene develop many similar phenotypes including osteoporosis. Based on these observations it was hypothesized that the bone phenotypes in Klotho- and Fgf23-null mice may be mediated through a common signaling pathway. Recent improvements in antibody specificity have shown that osteoblasts and osteocytes, which produce FGF23, also express low amount of membrane Klotho. But, the role of Klotho in bone is still largely unclear. In this review we summarize the literature and show that Klotho has an FGF23 dependent and independent effect in bone.
Collapse
Affiliation(s)
- Jovana Kaludjerovic
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Hirotaka Komaba
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Beate Lanske
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA; Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
73
|
Olauson H, Mencke R, Hillebrands JL, Larsson TE. Tissue expression and source of circulating αKlotho. Bone 2017; 100:19-35. [PMID: 28323144 DOI: 10.1016/j.bone.2017.03.043] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 03/15/2017] [Accepted: 03/16/2017] [Indexed: 12/16/2022]
Abstract
αKlotho (Klotho), a type I transmembrane protein and a coreceptor for Fibroblast Growth Factor-23, was initially thought to be expressed only in a limited number of tissues, most importantly the kidney, parathyroid gland and choroid plexus. Emerging data may suggest a more ubiquitous Klotho expression pattern which has prompted reevaluation of the restricted Klotho paradigm. Herein we systematically review the evidence for Klotho expression in various tissues and cell types in humans and other mammals, and discuss potential reasons behind existing conflicting data. Based on current literature and tissue expression atlases, we propose a classification of tissues into high, intermediate and low/absent Klotho expression. The functional relevance of Klotho in organs with low expression levels remain uncertain and there is currently limited data on a role for membrane-bound Klotho outside the kidney. Finally, we review the evidence for the tissue source of soluble Klotho, and conclude that the kidney is likely to be the principal source of circulating Klotho in physiology.
Collapse
Affiliation(s)
- Hannes Olauson
- Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.
| | - Rik Mencke
- Division of Pathology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan-Luuk Hillebrands
- Division of Pathology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Tobias E Larsson
- Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
74
|
Angelousi A, Dimitriadis GK, Zografos G, Nölting S, Kaltsas G, Grossman A. Molecular targeted therapies in adrenal, pituitary and parathyroid malignancies. Endocr Relat Cancer 2017; 24:R239-R259. [PMID: 28400402 DOI: 10.1530/erc-16-0542] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 04/10/2017] [Indexed: 12/15/2022]
Abstract
Tumourigenesis is a relatively common event in endocrine tissues. Currently, specific guidelines have been developed for common malignant endocrine tumours, which also incorporate advances in molecular targeted therapies (MTT), as in thyroid cancer and in gastrointestinal neuroendocrine malignancies. However, there is little information regarding the role and efficacy of MTT in the relatively rare malignant endocrine tumours mainly involving the adrenal medulla, adrenal cortex, pituitary, and parathyroid glands. Due to the rarity of these tumours and the lack of prospective studies, current guidelines are mostly based on retrospective data derived from surgical, locoregional and ablative therapies, and studies with systemic chemotherapy. In addition, in many of these malignancies the prognosis remains poor with individual patients responding differently to currently available treatments, necessitating the development of new personalised therapeutic strategies. Recently, major advances in the molecular understanding of endocrine tumours based on genomic, epigenomic, and transcriptome analysis have emerged, resulting in new insights into their pathogenesis and molecular pathology. This in turn has led to the use of novel MTTs in increasing numbers of patients. In this review, we aim to present currently existing and evolving data using MTT in the treatment of adrenal, pituitary and malignant parathyroid tumours, and explore the current utility and effectiveness of such therapies and their future evolution.
Collapse
Affiliation(s)
- Anna Angelousi
- Department of PathophysiologySector of Endocrinology, National & Kapodistrian University of Athens, Athens, Greece
| | - Georgios K Dimitriadis
- Division of Translational and Experimental MedicineUniversity of Warwick Medical School, Clinical Sciences Research Laboratories, Coventry, UK
| | - Georgios Zografos
- Third Department of SurgeryAthens General Hospital "Georgios Gennimatas", Athens, Greece
| | - Svenja Nölting
- Department of Internal Medicine IICampus Grosshadern, University-Hospital, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Gregory Kaltsas
- Department of PathophysiologySector of Endocrinology, National & Kapodistrian University of Athens, Athens, Greece
- Division of Translational and Experimental MedicineUniversity of Warwick Medical School, Clinical Sciences Research Laboratories, Coventry, UK
- Department of EndocrinologyOxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, UK
| | - Ashley Grossman
- Department of EndocrinologyOxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, UK
| |
Collapse
|
75
|
Grabner A, Mazzaferro S, Cianciolo G, Krick S, Capelli I, Rotondi S, Ronco C, La Manna G, Faul C. Fibroblast Growth Factor 23: Mineral Metabolism and Beyond. CONTRIBUTIONS TO NEPHROLOGY 2017; 190:83-95. [PMID: 28535521 DOI: 10.1159/000468952] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Patients affected by chronic kidney disease (CKD) exhibit a high risk of cardiovascular mortality that is poorly explained by traditional risk factors. There is a growing awareness about the role of derangement of mineral metabolism that is currently accepted as a trigger and sustainer of cardiovascular disease (CVD) in CKD patients. The synthetic definition of CKD mineral and bone disorder (CKD-MBD) split the concept that the indexes of mineral metabolism extend their effects beyond the bone until the vascular wall and metabolic milieu of CKD patients through complex pathways. A better understanding of the biomarkers and mechanisms of left ventricular hypertrophy, CVD, inflammation, and chronic renal damage may help with the diagnosis and treatment of the systemic impairment that occurs secondary to CKD-MBD, thus slowing the progression of renal and CVD and improving patient survival. Recent insights into fibroblast growth factor (FGF) 23 have led to marked advancement in interpreting data on CVD and CKD progression ascribing to FGF23 a pivotal role in these pathologies independent of its co-receptor klotho and well beyond mineral metabolism. This review article will discuss the current experimental and clinical evidence regarding the role of FGF23 in physiology and pathophysiology of CKD and its associated complications with an emphasis on CVD.
Collapse
|
76
|
Bleskestad IH, Thorsen IS, Jonsson G, Skadberg Ø, Gøransson LG. The impact of calcineurin inhibitors on neutrophil gelatinase-associated lipocalin and fibroblast growth factor 23 in long-term kidney transplant patients. Clin Transplant 2017; 31. [PMID: 28523792 DOI: 10.1111/ctr.13015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/15/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Neutrophil gelatinase-associated lipocalin (NGAL), a protein with bacteriostatic functions rapidly excreted from stimulated or damaged epithelial cells, is elevated in acute and chronic kidney disease. A calcineurin dependent signaling pathway for fibroblast growth factor 23 (FGF23) has been revealed, but the effect of calcineurin inhibitors (CNIs) on the levels of NGAL and markers of mineral metabolism in long-term kidney transplant patients has not been explored. METHODS In a cross-sectional study, 39 patients who received a first kidney transplant more than 10 years ago were split into two groups based on whether (n=28) or not (n=11) they used CNIs. Only patients with well-functioning grafts defined as an estimated glomerular filtration rate ≥45 mL/min per 1.73 m2 were included. RESULTS The median levels of NGAL, intact parathyroid hormone (iPTH), and iFGF23 were significantly higher in CNI users vs CNI nonusers, 167.0 (134.0-235.0) ng/mL vs 105.0 (91.3-117.0) ng/mL, P<.001, 13.8 (10.0-17.3) pmol/L vs 8.4 (6.4-9.9) pmol/L, P=.003, and 81.6 (56.4-116.5) pg/mL vs 61.8 (43.3-72.1) pg/mL, P=.04 respectively. CONCLUSIONS The median levels of iFGF23 were higher in CNI users compared to CNI nonusers giving support to the notion of a CNI induced FGF23 resistance in the parathyroid. The net result of CNIs side effects needs to be further explored.
Collapse
Affiliation(s)
| | - Inga Strand Thorsen
- Department of Internal Medicine, Stavanger University Hospital, Stavanger, Norway
| | - Grete Jonsson
- Department of Medical Biochemistry, Stavanger University Hospital, Stavanger, Norway
| | - Øyvind Skadberg
- Department of Medical Biochemistry, Stavanger University Hospital, Stavanger, Norway
| | - Lasse Gunnar Gøransson
- Department of Internal Medicine, Stavanger University Hospital, Stavanger, Norway.,Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway
| |
Collapse
|
77
|
Bienaimé F, Dechartres A, Anglicheau D, Sabbah L, Montgermont P, Friedlander G, Ravaud P, Legendre C, Prié D. The Association Between Fibroblast Growth Factor 23 and Renal Transplantation Outcome Is Modified by Follow-up Duration and Glomerular Filtration Rate Assessment Method. Kidney Int Rep 2017; 2:881-892. [PMID: 29270495 PMCID: PMC5733761 DOI: 10.1016/j.ekir.2017.05.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 05/03/2017] [Accepted: 05/11/2017] [Indexed: 12/21/2022] Open
Abstract
Introduction Fibroblast growth factor 23 (FGF23) could contribute to cardiovascular morbidity in chronic kidney disease. In studies of kidney transplant recipients, a high circulating level of FGF23 has been associated with death and graft loss independently of estimated glomerular filtration rate (GFR). Whether FGF23 is associated with adverse outcomes in the early posttransplantation period is unknown. Methods We analyzed a cohort of 845 kidney transplant recipients in stable condition who had GFR measured in the first years after transplantation with a median follow-up of 71 months. Results A high FGF23 concentration was associated with death or graft loss in univariate analysis, but this association was lost after adjustment for measured GFR. In contrast, FGF23 remained significantly associated with the composite outcome when estimated GFR was substituted for measured GFR. We also observed that follow-up duration modified the association between FGF23 and outcome. Although FGF23 was not associated with any endpoint in the full duration of the study, we found an independent association between FGF23 and the incidence of graft loss within the 4 years after FGF23 measurement. We did not find an association between FGF23 levels and left ventricular mass in a subgroup of 227 patients who had echocardiography performed within 3 months of FGF23 measurement. Discussion This study demonstrates that FGF23 measured during the first year after transplantation is not an independent predictor of death and graft loss and is not associated with left ventricular hypertrophy in the posttransplantation period. It further unveils important factors modifying the association between FGF23 and outcome in this population.
Collapse
Affiliation(s)
- Frank Bienaimé
- Université Paris Descartes, Faculté de Médecine, Institut Necker-Enfants Malades INSERM U1151, Paris, France.,Service de Physiologie-Explorations Fonctionnelles, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Agnès Dechartres
- Université Paris Descartes, Faculté de Médecine, INSERM U1153, Centre de Recherche Epidémiologie et Statistiques, Hôtel-Dieu (APHP), Paris, France
| | - Dany Anglicheau
- Université Paris Descartes, Faculté de Médecine, Institut Necker-Enfants Malades INSERM U1151, Paris, France.,Service de Néphrologie Adulte, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris, France and Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Laurent Sabbah
- Service de Cardiologie Adulte, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Patrick Montgermont
- Service de Cardiologie Adulte, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Gérard Friedlander
- Université Paris Descartes, Faculté de Médecine, Institut Necker-Enfants Malades INSERM U1151, Paris, France.,Service de Physiologie-Explorations Fonctionnelles, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Philippe Ravaud
- Université Paris Descartes, Faculté de Médecine, INSERM U1153, Centre de Recherche Epidémiologie et Statistiques, Hôtel-Dieu (APHP), Paris, France
| | - Christophe Legendre
- Université Paris Descartes, Faculté de Médecine, Institut Necker-Enfants Malades INSERM U1151, Paris, France.,Service de Néphrologie Adulte, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris, France and Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Dominique Prié
- Université Paris Descartes, Faculté de Médecine, Institut Necker-Enfants Malades INSERM U1151, Paris, France.,Service de Physiologie-Explorations Fonctionnelles, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris, France
| |
Collapse
|
78
|
Uchida K, Tanaka Y, Ichikawa H, Watanabe M, Mitani S, Morita K, Fujii H, Ishikawa M, Yoshino G, Okinaga H, Nagae G, Aburatani H, Ikeda Y, Susa T, Tamamori-Adachi M, Fukusato T, Uozaki H, Okazaki T, Iizuka M. An Excess of CYP24A1, Lack of CaSR, and a Novel lncRNA Near the PTH Gene Characterize an Ectopic PTH-Producing Tumor. J Endocr Soc 2017; 1:691-711. [PMID: 29264523 PMCID: PMC5686629 DOI: 10.1210/js.2017-00063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/25/2017] [Indexed: 12/11/2022] Open
Abstract
Thus far, only 23 cases of the ectopic production of parathyroid hormone (PTH) have been reported. We have characterized the genome-wide transcription profile of an ectopic PTH-producing tumor originating from a retroperitoneal histiocytoma. We found that the calcium-sensing receptor (CaSR) was barely expressed in the tumor. Lack of CaSR, a crucial braking apparatus in the presence of both intraparathyroid and, probably, serendipitous PTH expression, might contribute strongly to the establishment and maintenance of the ectopic transcriptional activation of the PTH gene in nonparathyroid cells. Along with candidate drivers with a crucial frameshift mutation or copy number variation at specific chromosomal areas obtained from whole exome sequencing, we identified robust tumor-specific cytochrome P450 family 24 subfamily A member 1 (CYP24A1) overproduction, which was not observed in other non–PTH-expressing retroperitoneal histiocytoma and parathyroid adenoma samples. We then found a 2.5-kb noncoding RNA in the PTH 3′-downstream region that was exclusively present in the parathyroid adenoma and our tumor. Such a co-occurrence might act as another driver of ectopic PTH-producing tumorigenesis; both might release the control of PTH gene expression by shutting down the other branches of the safety system (e.g., CaSR and the vitamin D3–vitamin D receptor axis).
Collapse
Affiliation(s)
- Kosuke Uchida
- Department of Biochemistry, Teikyo University School of Medicine, Tokyo 173-0003, Japan.,Department of General Practice, National Defense Medical College, Saitama 359-0042, Japan
| | - Yuji Tanaka
- Department of General Practice, National Defense Medical College, Saitama 359-0042, Japan
| | - Hitoshi Ichikawa
- Genetics Division, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Masato Watanabe
- Department of Pathology, Teikyo University School of Medicine, Tokyo 173-0003, Japan
| | - Sachiyo Mitani
- Genetics Division, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Koji Morita
- Department of Internal Medicine, Teikyo University School of Medicine, Tokyo 173-0003, Japan
| | - Hiroko Fujii
- Department of Biochemistry, Teikyo University School of Medicine, Tokyo 173-0003, Japan.,Department of Internal Medicine, Self-Defense Forces Central Hospital, Tokyo 154-8532, Japan
| | - Mayumi Ishikawa
- Diabetes and Arteriosclerosis, Nippon Medical School, Musashikosugi Hospital, Kanagawa 211-8533, Japan
| | - Gen Yoshino
- Center for Diabetes, Shinsuma General Hospital, Hyogo 654-0047, Japan
| | - Hiroko Okinaga
- Department of Internal Medicine, Teikyo University School of Medicine, Tokyo 173-0003, Japan
| | - Genta Nagae
- Genome Science Laboratory Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan
| | - Hiroyuki Aburatani
- Genome Science Laboratory Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan
| | - Yoshifumi Ikeda
- Department of Surgery, Teikyo University School of Medicine, Tokyo 173-0003, Japan
| | - Takao Susa
- Department of Biochemistry, Teikyo University School of Medicine, Tokyo 173-0003, Japan
| | - Mimi Tamamori-Adachi
- Department of Biochemistry, Teikyo University School of Medicine, Tokyo 173-0003, Japan
| | - Toshio Fukusato
- Department of Pathology, Teikyo University School of Medicine, Tokyo 173-0003, Japan
| | - Hiroshi Uozaki
- Department of Pathology, Teikyo University School of Medicine, Tokyo 173-0003, Japan
| | - Tomoki Okazaki
- Department of Biochemistry, Teikyo University School of Medicine, Tokyo 173-0003, Japan
| | - Masayoshi Iizuka
- Department of Biochemistry, Teikyo University School of Medicine, Tokyo 173-0003, Japan
| |
Collapse
|
79
|
Mencke R, Hillebrands JL. The role of the anti-ageing protein Klotho in vascular physiology and pathophysiology. Ageing Res Rev 2017; 35:124-146. [PMID: 27693241 DOI: 10.1016/j.arr.2016.09.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 09/23/2016] [Indexed: 02/08/2023]
Abstract
Klotho is an anti-ageing protein that functions in many pathways that govern ageing, like regulation of phosphate homeostasis, insulin signaling, and Wnt signaling. Klotho expression levels and levels in blood decline during ageing. The vascular phenotype of Klotho deficiency features medial calcification, intima hyperplasia, endothelial dysfunction, arterial stiffening, hypertension, and impaired angiogenesis and vasculogenesis, with characteristics similar to aged human arteries. Klotho-deficient phenotypes can be prevented and rescued by Klotho gene expression or protein supplementation. High phosphate levels are likely to be directly pathogenic and are a prerequisite for medial calcification, but more important determinants are pathways that regulate cellular senescence, suggesting that deficiency of Klotho renders cells susceptible to phosphate toxicity. Overexpression of Klotho is shown to ameliorate medial calcification, endothelial dysfunction, and hypertension. Endogenous vascular Klotho expression is a controversial subject and, currently, no compelling evidence exists that supports the existence of vascular membrane-bound Klotho expression, as expressed in kidney. In vitro, Klotho has been shown to decrease oxidative stress and apoptosis in both SMCs and ECs, to reduce SMC calcification, to maintain the contractile SMC phenotype, and to prevent μ-calpain overactivation in ECs. Klotho has many protective effects with regard to the vasculature and constitutes a very promising therapeutic target. The purpose of this review is to explore the etiology of the vascular phenotype of Klotho deficiency and the therapeutic potential of Klotho in vascular disease.
Collapse
|
80
|
Hum JM, O'Bryan LM, Tatiparthi AK, Cass TA, Clinkenbeard EL, Cramer MS, Bhaskaran M, Johnson RL, Wilson JM, Smith RC, White KE. Chronic Hyperphosphatemia and Vascular Calcification Are Reduced by Stable Delivery of Soluble Klotho. J Am Soc Nephrol 2017; 28:1162-1174. [PMID: 27837149 PMCID: PMC5373441 DOI: 10.1681/asn.2015111266] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 10/01/2016] [Indexed: 12/22/2022] Open
Abstract
αKlotho (αKL) regulates mineral metabolism, and diseases associated with αKL deficiency are characterized by hyperphosphatemia and vascular calcification (VC). αKL is expressed as a membrane-bound protein (mKL) and recognized as the coreceptor for fibroblast growth factor-23 (FGF23) and a circulating soluble form (cKL) created by endoproteolytic cleavage of mKL. The functions of cKL with regard to phosphate metabolism are unclear. We tested the ability of cKL to regulate pathways and phenotypes associated with hyperphosphatemia in a mouse model of CKD-mineral bone disorder and αKL-null mice. Stable delivery of adeno-associated virus (AAV) expressing cKL to diabetic endothelial nitric oxide synthase-deficient mice or αKL-null mice reduced serum phosphate levels. Acute injection of recombinant cKL downregulated the renal sodium-phosphate cotransporter Npt2a in αKL-null mice supporting direct actions of cKL in the absence of mKL. αKL-null mice with sustained AAV-cKL expression had a 74%-78% reduction in aorta mineral content and a 72%-77% reduction in mineral volume compared with control-treated counterparts (P<0.01). Treatment of UMR-106 osteoblastic cells with cKL + FGF23 increased the phosphorylation of extracellular signal-regulated kinase 1/2 and induced Fgf23 expression. CRISPR/Cas9-mediated deletion of fibroblast growth factor receptor 1 (FGFR1) or pretreatment with inhibitors of mitogen-activated kinase kinase 1 or FGFR ablated these responses. In summary, sustained cKL treatment reduced hyperphosphatemia in a mouse model of CKD-mineral bone disorder, and it reduced hyperphosphatemia and prevented VC in mice without endogenous αKL. Furthermore, cKL stimulated Fgf23 in an FGFR1-dependent manner in bone cells. Collectively, these findings indicate that cKL has mKL-independent activity and suggest the potential for enhancing cKL activity in diseases of hyperphosphatemia with associated VC.
Collapse
Affiliation(s)
- Julia M Hum
- Department of Medical and Molecular Genetics, Division of Molecular Genetics and Gene Therapy, Indiana University School of Medicine, Indianapolis, Indiana
| | - Linda M O'Bryan
- Biotechnology Discovery Research, Lilly Research Laboratories
| | - Arun K Tatiparthi
- Lead Optimization Toxicology and Pharmacology, Covance Inc., Greenfield, Indiana
| | - Taryn A Cass
- Department of Medical and Molecular Genetics, Division of Molecular Genetics and Gene Therapy, Indiana University School of Medicine, Indianapolis, Indiana
| | - Erica L Clinkenbeard
- Department of Medical and Molecular Genetics, Division of Molecular Genetics and Gene Therapy, Indiana University School of Medicine, Indianapolis, Indiana
| | - Martin S Cramer
- Biotechnology Discovery Research, Lilly Research Laboratories
| | | | | | - Jonathan M Wilson
- Tailored Therapeutics, Eli Lilly and Company, Indianapolis, Indiana; and
| | | | - Kenneth E White
- Department of Medical and Molecular Genetics, Division of Molecular Genetics and Gene Therapy, Indiana University School of Medicine, Indianapolis, Indiana;
| |
Collapse
|
81
|
Abstract
Fibroblast growth factor 23 (FGF23) is an important regulator of phosphate and vitamin D metabolism and its excessive or insufficient production leads to a wide variety of skeletal disorders. This article reviews the FGF23-α-Klotho signaling pathway, highlighting the latest developments in FGF23 regulation and action, and describes the disorders associated with FGF23 excess or deficiency.
Collapse
Affiliation(s)
- Anda R Gonciulea
- Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Suzanne M Jan De Beur
- Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| |
Collapse
|
82
|
Kaludjerovic J, Komaba H, Sato T, Erben RG, Baron R, Olauson H, Larsson TE, Lanske B. Klotho expression in long bones regulates FGF23 production during renal failure. FASEB J 2017; 31:2050-2064. [PMID: 28183805 DOI: 10.1096/fj.201601036r] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 01/17/2017] [Indexed: 12/24/2022]
Abstract
Circulating levels of bone-derived fibroblast growth factor 23 (FGF23) increase early during acute and chronic kidney disease and are associated with adverse outcomes. Membrane-bound Klotho acts as a permissive coreceptor for FGF23, and its expression was recently found in osteoblasts/osteocytes. We hypothesized that Klotho in bone cells is part of an autocrine feedback loop that regulates FGF23 expression during renal failure. Thus, we induced renal failure in mice with targeted deletion of Klotho in long bones. Uremic wild-type (KLfl/fl ) and knockout (Prx1-Cre;KLfl/fl ) mice both responded with reduced body weight, kidney atrophy, hyperphosphatemia, and increased bone turnover. Importantly, long bones of Prx1-Cre;KLfl/fl mice but not their axial skeleton failed to increase FGF23 expression as observed in uremic KLfl/fl mice. Consequently, Prx1-Cre;KLfl/fl mice had significantly lower serum FGF23 and parathyroid hormone levels, and higher renal 1-α-hydroxylase expression, serum 1,25-dihydroxyvitamin D, and calcium levels than KLfl/fl mice. These results were confirmed in two independent models of renal failure, adenine diet induced and 5/6 nephrectomy. Moreover, FGF23-treated bone cells required Klotho to increase FGF23 mRNA and ERK phosphorylation. In summary, our novel findings show that Klotho in bone is crucial for inducing FGF23 production upon renal failure. We propose the presence of an autocrine feedback loop in which Klotho senses the need for FGF23.-Kaludjerovic, J., Komaba, H., Sato, T., Erben, R. G., Baron, R., Olauson, H., Larsson, T. E., Lanske, B. Klotho expression in long bones regulates FGF23 production during renal failure.
Collapse
Affiliation(s)
- Jovana Kaludjerovic
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA
| | - Hirotaka Komaba
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA
| | - Tadatoshi Sato
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA
| | - Reinhold G Erben
- Unit of Physiology, Pathophysiology, and Experimental Endocrinology, University of Veterinary Medicine, Vienna, Austria
| | - Roland Baron
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA.,Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Hannes Olauson
- Division of Renal Medicine, Department of Clinical Sciences, Intervention, and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Tobias E Larsson
- Division of Renal Medicine, Department of Clinical Sciences, Intervention, and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Beate Lanske
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA; .,Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
83
|
Persistent fibroblast growth factor 23 signalling in the parathyroid glands for secondary hyperparathyroidism in mice with chronic kidney disease. Sci Rep 2017; 7:40534. [PMID: 28094278 PMCID: PMC5240111 DOI: 10.1038/srep40534] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 12/07/2016] [Indexed: 02/07/2023] Open
Abstract
Secondary hyperparathyroidism, in which parathyroid hormone (PTH) is excessively secreted in response to factors such as hyperphosphataemia, hypocalcaemia, and low 1,25-dihydroxyvitamin D (1,25(OH)2D) levels, is commonly observed in patients with chronic kidney disease (CKD), and is accompanied by high levels of fibroblast growth factor 23 (FGF23). However, the effect of FGF23 on the parathyroid glands (PG) remains controversial. To bind to FGF receptors, FGF23 requires αKlotho, which is highly expressed in the PG. Here, we examined the effects of Fgfr1–3, αKlotho, or Fgfr1–4 ablation specifically in the PG (conditional knockout, cKO). When mice with early to mid-stage CKD with and without cKO were compared, plasma concentrations of calcium, phosphate, FGF23, and 1,25(OH)2D did not change significantly. In contrast, plasma PTH levels, which were elevated in CKD mice, were significantly
decreased in cKO mice. PG from CKD mice showed augmentation of cell proliferation, which was significantly suppressed by cKO. Parathyroid tissue cultured for 4 days showed upregulation of PTH secretion and cell proliferation in response to FGF23. Both these effects were inhibited by cKO. These findings suggest that FGF23 is a long-term inducer of parathyroid cell proliferation and PTH secretion, and is one cause of secondary hyperparathyroidism in CKD.
Collapse
|
84
|
David V, Francis C, Babitt JL. Ironing out the cross talk between FGF23 and inflammation. Am J Physiol Renal Physiol 2017; 312:F1-F8. [PMID: 27582104 PMCID: PMC5283889 DOI: 10.1152/ajprenal.00359.2016] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/20/2016] [Indexed: 01/10/2023] Open
Abstract
The bone-secreted hormone fibroblast growth factor 23 (FGF23) has an essential role in phosphate homeostasis by regulating expression of the kidney proximal tubule sodium-phosphate cotransporters as well as parathyroid hormone levels. Induction of FGF23 early in chronic kidney disease (CKD) helps to maintain normal phosphorous levels. However, high FGF23 levels become pathological as kidney disease progresses and are associated with an increased risk of CKD progression, cardiovascular events, and death. The factors responsible for increasing FGF23 levels early in CKD are unknown, but recent work has proposed a role for inflammation and disordered iron homeostasis. Notably, FGF23 has recently been shown to elicit an inflammatory response and to display immunomodulatory properties. Here, we will review emerging evidence on the cross talk between inflammation, iron, FGF23, and bone and mineral metabolism and discuss the relevance for CKD patients.
Collapse
Affiliation(s)
- Valentin David
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois; and
| | - Connor Francis
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois; and
| | - Jodie L Babitt
- Nephrology Division, Program in Membrane Biology, and Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
85
|
Kuczera P, Adamczak M, Wiecek A. Fibroblast Growth Factor-23-A Potential Uremic Toxin. Toxins (Basel) 2016; 8:toxins8120369. [PMID: 27941640 PMCID: PMC5198563 DOI: 10.3390/toxins8120369] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/30/2016] [Accepted: 12/01/2016] [Indexed: 12/25/2022] Open
Abstract
Fibroblast growth factor-23 (FGF23) is a circulating member of the FGF family produced mainly by the osteocytes and osteoblasts that can act as a hormone. The main action of FGF23 is to lower phosphatemia via the reduction of urinary phosphate reabsorption and the decrease of 1,25(OH)2-D generation in the kidney. In the course of chronic kidney disease (CKD), plasma FGF23 concentration rises early, most probably to compensate the inability of the deteriorating kidneys to excrete an adequate amount of phosphate. However, this comes at the cost of FGF23-related target organ toxicity. Results of clinical studies suggest that elevated plasma FGF23 concentration is independently associated with the increased risk of CKD progression, occurrence of cardio-vascular complications, and mortality in different stages of CKD. FGF23 also contributes to cardiomyocyte hypertrophy, vascular calcification, and endothelial dysfunction. The impact of FGF23 on heart muscle is not dependent on Klotho, but rather on the PLCγ–calcineurin–NFAT (nuclear factor of activated T-cells) pathway. Among the factors increasing plasma FGF23 concentration, active vitamin D analogues play a significant role. Additionally, inflammation and iron deficiency can contribute to the increase of plasma FGF23. Among the factors decreasing plasma FGF23, dietary phosphate restriction, some intestinal phosphate binders, cinacalcet (and other calcimimetics), and nicotinamide can be enumerated. Anti-FGF23 antibodies have also recently been developed to inhibit the action of FGF23 in target organs. Still, the best way to normalize plasma FGF23 in maintenance hemodialysis patients is restoring kidney function by successful kidney transplantation.
Collapse
Affiliation(s)
- Piotr Kuczera
- Department of Nephrology, Transplantation and Internal Medicine, Medical University of Silesia, Katowice 40-027, Poland.
| | - Marcin Adamczak
- Department of Nephrology, Transplantation and Internal Medicine, Medical University of Silesia, Katowice 40-027, Poland.
| | - Andrzej Wiecek
- Department of Nephrology, Transplantation and Internal Medicine, Medical University of Silesia, Katowice 40-027, Poland.
| |
Collapse
|
86
|
Andrukhova O, Streicher C, Zeitz U, Erben RG. Fgf23 and parathyroid hormone signaling interact in kidney and bone. Mol Cell Endocrinol 2016; 436:224-39. [PMID: 27498418 DOI: 10.1016/j.mce.2016.07.035] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 07/26/2016] [Accepted: 07/26/2016] [Indexed: 12/19/2022]
Abstract
Fibroblast growth factor-23 (FGF23) is a bone-derived hormone, suppressing renal phosphate reabsorption and vitamin D hormone synthesis in proximal tubules, and stimulating calcium reabsorption in distal tubules of the kidney. Here, we analyzed the long term sequelae of deficient Fgf23 signaling on bone and mineral metabolism in 9-month-old mice lacking both Fgf23 or Klotho and a functioning vitamin D receptor (VDR). To prevent hypocalcemia in VDR deficient mice, all mice were kept on a rescue diet enriched with calcium, phosphate, and lactose. VDR mutants were normocalcemic and normophosphatemic, and had normal tibial bone mineral density. Relative to VDR mutants, Fgf23/VDR and Klotho/VDR compound mutants were characterized by hypocalcemia, hyperphosphatemia, and very high serum parathyroid hormone (PTH). Despite ∼10-fold higher serum PTH levels in compound mutants, urinary excretion of phosphate and calcium as well as osteoclast numbers in bone remained unchanged relative to VDR mutants. The increase in plasma cAMP after hPTH(1-34) injection was similar in all genotypes. However, a 5-day infusion of hPTH(1-34) via osmotic minipumps resulted in reduced phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) in bone and kidney of Fgf23/VDR and Klotho/VDR compound mutants, relative to VDR and WT controls. Similarly, the PTH-mediated ERK1/2 phosphorylation was reduced in primary osteoblasts isolated from Fgf23 and Klotho deficient mice, but was restored by concomitant treatment with recombinant FGF23. Collectively, our data indicate that the phosphaturic, calcium-conserving, and bone resorption-stimulating actions of PTH are blunted by Fgf23 or Klotho deficiency. Hence, FGF23 may be an important modulator of PTH signaling in bone and kidney.
Collapse
Affiliation(s)
- Olena Andrukhova
- Department of Biomedical Sciences, University of Veterinary Medicine, 1210, Vienna, Austria
| | - Carmen Streicher
- Department of Biomedical Sciences, University of Veterinary Medicine, 1210, Vienna, Austria
| | - Ute Zeitz
- Department of Biomedical Sciences, University of Veterinary Medicine, 1210, Vienna, Austria
| | - Reinhold G Erben
- Department of Biomedical Sciences, University of Veterinary Medicine, 1210, Vienna, Austria.
| |
Collapse
|
87
|
Bianchi A, Guibert M, Cailotto F, Gasser A, Presle N, Mainard D, Netter P, Kempf H, Jouzeau JY, Reboul P. Fibroblast Growth Factor 23 drives MMP13 expression in human osteoarthritic chondrocytes in a Klotho-independent manner. Osteoarthritis Cartilage 2016; 24:1961-1969. [PMID: 27307356 DOI: 10.1016/j.joca.2016.06.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 06/02/2016] [Accepted: 06/07/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Fibroblast Growth Factor 23 (FGF23) may represent an attractive candidate that could participate to the osteoarthritic (OA)-induced phenotype switch of chondrocytes. To address this hypothesis, we investigated the expression of FGF23, its receptors (FGFRs) and co-receptor (Klotho) in human cartilage and studied the effects of rhFGF23 on OA chondrocytes. METHOD Gene expression or protein levels were analysed by RT-PCR and immunohistochemistry. Collagenase 3 (MMP13) activity was measured by a fluorescent assay. MAPK signalling pathways were investigated by phosphoprotein array, immunoblotting and the use of selective inhibitors. RNA silencing was performed to confirm the respective contribution of FGFR1 and Klotho. RESULTS We showed that the expression of FGF23, FGFR1 and Klotho was up-regulated at both mRNA and protein levels in OA chondrocytes when compared to healthy ones. These overexpressions were markedly elevated in the damaged regions of OA cartilage. When stimulated with rhFGF23, OA chondrocytes displayed an extended expression of FGF23 and of markers of hypertrophy such as MMP13, COL10A1, and VEGF. We demonstrated that FGF23 auto-stimulation was both FGFR1-and Klotho-dependent, whereas the expression of markers of hypertrophy was mainly dependent on FGFR1 alone. Finally, we showed that FGF23-induced MMP13 expression was strongly regulated by the MEK/ERK cascade and to a lesser extent, by the PI-3K/AKT pathway. CONCLUSION These results demonstrate that FGF23 sustains differentiation of OA chondrocytes in a Klotho-independent manner.
Collapse
Affiliation(s)
- A Bianchi
- UMR 7365 CNRS-Université de Lorraine « Ingénierie Moléculaire et Physiopathologie Articulaire » (IMoPA), Biopôle de l'Université de Lorraine, Campus Biologie-Santé, Vandœuvre-lès-Nancy, France.
| | - M Guibert
- UMR 7365 CNRS-Université de Lorraine « Ingénierie Moléculaire et Physiopathologie Articulaire » (IMoPA), Biopôle de l'Université de Lorraine, Campus Biologie-Santé, Vandœuvre-lès-Nancy, France.
| | - F Cailotto
- UMR 7365 CNRS-Université de Lorraine « Ingénierie Moléculaire et Physiopathologie Articulaire » (IMoPA), Biopôle de l'Université de Lorraine, Campus Biologie-Santé, Vandœuvre-lès-Nancy, France.
| | - A Gasser
- UMR 7365 CNRS-Université de Lorraine « Ingénierie Moléculaire et Physiopathologie Articulaire » (IMoPA), Biopôle de l'Université de Lorraine, Campus Biologie-Santé, Vandœuvre-lès-Nancy, France.
| | - N Presle
- UMR 7365 CNRS-Université de Lorraine « Ingénierie Moléculaire et Physiopathologie Articulaire » (IMoPA), Biopôle de l'Université de Lorraine, Campus Biologie-Santé, Vandœuvre-lès-Nancy, France.
| | - D Mainard
- UMR 7365 CNRS-Université de Lorraine « Ingénierie Moléculaire et Physiopathologie Articulaire » (IMoPA), Biopôle de l'Université de Lorraine, Campus Biologie-Santé, Vandœuvre-lès-Nancy, France; Département de Chirurgie Orthopédique et Traumatologique, Centre Hospitalier Universitaire, Nancy, France.
| | - P Netter
- UMR 7365 CNRS-Université de Lorraine « Ingénierie Moléculaire et Physiopathologie Articulaire » (IMoPA), Biopôle de l'Université de Lorraine, Campus Biologie-Santé, Vandœuvre-lès-Nancy, France; Département de Pharmacologie Clinique et Toxicologie, Centre Hospitalier Universitaire, Nancy, France.
| | - H Kempf
- UMR 7365 CNRS-Université de Lorraine « Ingénierie Moléculaire et Physiopathologie Articulaire » (IMoPA), Biopôle de l'Université de Lorraine, Campus Biologie-Santé, Vandœuvre-lès-Nancy, France.
| | - J-Y Jouzeau
- UMR 7365 CNRS-Université de Lorraine « Ingénierie Moléculaire et Physiopathologie Articulaire » (IMoPA), Biopôle de l'Université de Lorraine, Campus Biologie-Santé, Vandœuvre-lès-Nancy, France; Département de Pharmacologie Clinique et Toxicologie, Centre Hospitalier Universitaire, Nancy, France.
| | - P Reboul
- UMR 7365 CNRS-Université de Lorraine « Ingénierie Moléculaire et Physiopathologie Articulaire » (IMoPA), Biopôle de l'Université de Lorraine, Campus Biologie-Santé, Vandœuvre-lès-Nancy, France.
| |
Collapse
|
88
|
Abstract
Calcium is an important ion in cell signaling, hormone regulation, and bone health. Its regulation is complex and intimately connected to that of phosphate homeostasis. Both ions are maintained at appropriate levels to maintain the extracellular to intracellular gradients, allow for mineralization of bone, and to prevent extra skeletal and urinary calcification. The homeostasis involves the target organs intestine, parathyroid glands, kidney, and bone. Multiple hormones converge to regulate the extracellular calcium level: parathyroid hormone, vitamin D (principally 25(OH)D or 1,25(OH)2D), fibroblast growth factor 23, and α-klotho. Fine regulation of calcium homeostasis occurs in the thick ascending limb and collecting tubule segments via actions of the calcium sensing receptor and several channels/transporters. The kidney participates in homeostatic loops with bone, intestine, and parathyroid glands. Initially in the course of progressive kidney disease, the homeostatic response maintains serum levels of calcium and phosphorus in the desired range, and maintains neutral balance. However, once the kidneys are no longer able to appropriately respond to hormones and excrete calcium and phosphate, positive balance ensues leading to adverse cardiac and skeletal abnormalities. © 2016 American Physiological Society. Compr Physiol 6:1781-1800, 2016.
Collapse
Affiliation(s)
- Sharon M Moe
- Division of Nephrology, Indiana University School of Medicine, Roudebush Veterans Administration Medical Center, Indianapolis, Indiana.,Section of Nephrology, Roudebush Veterans Administration Medical Center, Indianapolis, Indiana
| |
Collapse
|
89
|
Cianciolo G, Cozzolino M. FGF23 in kidney transplant: the strange case of Doctor Jekyll and Mister Hyde. Clin Kidney J 2016; 9:665-8. [PMID: 27679712 PMCID: PMC5036904 DOI: 10.1093/ckj/sfw072] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 07/06/2016] [Indexed: 02/07/2023] Open
Abstract
During the last decade, a new view into the molecular mechanisms of chronic kidney disease-mineral bone disorder (CKD-MBD) has been proposed, with fibroblast growth factor 23 (FGF23) as a novel player in the field. Enhanced serum FGF23 levels cause a reduction in serum phosphate, together with calcitriol suppression and consequent hyperparathyroidism (HPT). In contrast, reduced serum FGF23 levels are associated with hyperphosphatemia, higher calcitriol levels and parathyroid hormone (PTH) suppression. In addition, serum FGF23 levels are greatly increased and positively correlated with serum phosphate levels in CKD patients. In this population, high serum FGF23 concentration seems to predict the occurrence of refractory secondary HPT and to be associated with higher mortality risk in incident haemodialysis patients. In living-donor kidney transplant recipients, a faster normalization of FGF23 and phosphate levels with a lower prevalence of HPT, may be considered a major pathway to investigate.
Collapse
Affiliation(s)
- Giuseppe Cianciolo
- Nephrology Dialysis and Renal Transplant Unit, S. Orsola Hospital, Department of Experimental Diagnostic and Specialty Medicine (DIMES) , University of Bologna , Bologna , Italy
| | - Mario Cozzolino
- Renal Unit, San Paolo Hospital Milan, Department of Health and Science , University of Milan , Milan , Italy
| |
Collapse
|
90
|
Abstract
Fibroblast growth factor-23 (FGF23) is a bone-derived hormone known to suppress phosphate reabsorption and vitamin D hormone production in the kidney. Klotho was originally discovered as an anti-aging factor, but the functional role of Klotho is still a controversial issue. Three major functions have been proposed, a hormonal function of soluble Klotho, an enzymatic function as glycosidase, and the function as an obligatory co-receptor for FGF23 signaling. The purpose of this review is to highlight the recent advances in the area of FGF23 and Klotho signaling in the kidney, in the parathyroid gland, in the cardiovascular system, in bone, and in the central nervous system. During recent years, major new functions of FGF23 and Klotho have been discovered in these organ systems. Based on these novel findings, FGF23 has emerged as a pleiotropic endocrine and auto-/paracrine factor influencing not only mineral metabolism but also cardiovascular function.
Collapse
|
91
|
González-Parra E, Aceña Á, Lorenzo Ó, Tarín N, González-Casaus ML, Cristóbal C, Huelmos A, Mahíllo-Fernández I, Pello AM, Carda R, Hernández-González I, Alonso J, Rodríguez-Artalejo F, López-Bescós L, Ortiz A, Egido J, Tuñón J. Important abnormalities of bone mineral metabolism are present in patients with coronary artery disease with a mild decrease of the estimated glomerular filtration rate. J Bone Miner Metab 2016; 34:587-98. [PMID: 26298279 DOI: 10.1007/s00774-015-0706-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 07/16/2015] [Indexed: 11/29/2022]
Abstract
Chronic kidney disease (CKD)-mineral and bone disorder (MBD) is characterized by increased circulating levels of parathormone (PTH) and fibroblast growth factor 23 (FGF23), bone disease, and vascular calcification, and is associated with adverse outcomes. We studied the prevalence of mineral metabolism disorders, and the potential relationship between decreased estimated glomerular filtration rate (eGFR) and CKD-MBD in coronary artery disease patients in a cross-sectional study of 704 outpatients 7.5 ± 3.0 months after an acute coronary syndrome. The mean eGFR (CKD Epidemiology Collaboration formula) was 75.8 ± 19.1 ml/min/1.73 m(2). Our patients showed lower calcidiol plasma levels than a healthy cohort from the same geographical area. In the case of men, this finding was present despite similar creatinine levels in both groups and older age of the healthy subjects. Most patients (75.6 %) had an eGFR below 90 ml/min/1.73 m(2) (eGFR categories G2-G5), with 55.3 % of patients exhibiting values of 60-89 ml/min/1.73 m(2) (G2). PTH (r = -0.3329, p < 0.0001) and FGF23 (r = -0.3641, p < 0.0001) levels inversely correlated with eGFR, whereas calcidiol levels and serum phosphate levels did not. Overall, PTH levels were above normal in 34.9 % of patients. This proportion increased from 19.4 % in G1 category patients, to 33.7 % in G2 category patients and 56.6 % in G3-G5 category patients (p < 0.001). In multivariate analysis, eGFR and calcidiol levels were the main independent determinants of serum PTH. The mean FGF23 levels were 69.9 (54.6-96.2) relative units (RU)/ml, and 33.2 % of patients had FGF23 levels above 85.5 RU/ml (18.4 % in G1 category patients, 30.0 % in G2 category patients, and 59.2 % in G3-G5 category patients; p < 0.001). In multivariate analysis, eGFR was the main predictor of FGF23 levels. Increased phosphate levels were present in 0.7 % of the whole sample: 0 % in G1 category patients, 0.3 % in G2 category patients, and 2.8 % in G3-G5 category patients (p = 0.011). Almost 90 % of patients had calcidiol insufficiency without significant differences among the different degrees of eGFR. In conclusion, in patients with coronary artery disease there is a large prevalence of increased FGF23 and PTH levels. These findings have an independent relationship with decreased eGFR, and are evident at an eGFR of 60-89 ml/min/1.73 m(2). Then, mild decreases in eGFR must be taken in consideration by the clinician because they are associated with progressive abnormalities of mineral metabolism.
Collapse
Affiliation(s)
- Emilio González-Parra
- Division of Nephrology and Hypertension, IIS-Fundación Jiménez Díaz and Autónoma University, Madrid, Spain
| | - Álvaro Aceña
- Department of Cardiology, IIS-Fundación Jiménez Díaz, Madrid, Spain
| | - Óscar Lorenzo
- Renal and Vascular Research Laboratory, IIS-Fundación Jiménez Díaz and Autónoma University, Madrid, Spain
| | - Nieves Tarín
- Department of Cardiology, Hospital Universitario de Móstoles, Madrid, Spain
| | | | - Carmen Cristóbal
- Department of Cardiology, Hospital de Fuenlabrada and Rey Juan Carlos University, Fuenlabrada, Spain
| | - Ana Huelmos
- Department of Cardiology, Hospital Universitario Fundación Alcorcón, Madrid, Spain
| | | | - Ana María Pello
- Department of Cardiology, IIS-Fundación Jiménez Díaz, Madrid, Spain
| | - Rocío Carda
- Department of Cardiology, IIS-Fundación Jiménez Díaz, Madrid, Spain
| | | | - Joaquín Alonso
- Department of Cardiology, Hospital de Fuenlabrada and Rey Juan Carlos University, Fuenlabrada, Spain
| | - Fernando Rodríguez-Artalejo
- Department of Preventive Medicine and Public Health, School of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
| | | | - Alberto Ortiz
- Division of Nephrology and Hypertension, IIS-Fundación Jiménez Díaz and Autónoma University, Madrid, Spain
| | - Jesús Egido
- Division of Nephrology and Hypertension, IIS-Fundación Jiménez Díaz and Autónoma University, Madrid, Spain
- Renal, Vascular and Diabetes Research Laboratory, IIS-Fundación Jiménez Díaz, Autónoma University, and CIBERDEM, Madrid, Spain
| | - José Tuñón
- Department of Cardiology and Laboratory of Vascular Pathology, IIS-Fundación Jiménez Díaz and Autónoma University, 28040, Madrid, Spain.
| |
Collapse
|
92
|
|
93
|
Fukumoto S. FGF23-FGF Receptor/Klotho Pathway as a New Drug Target for Disorders of Bone and Mineral Metabolism. Calcif Tissue Int 2016; 98:334-40. [PMID: 26126937 DOI: 10.1007/s00223-015-0029-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 06/19/2015] [Indexed: 10/23/2022]
Abstract
Fibroblast growth factor 23 (FGF23) is a phosphaturic hormone produced by bone and works by binding to Klotho-FGF receptor complex. Excessive and deficient actions of FGF23 result in hypophosphatemic and hyperphosphatemic diseases, respectively. Therefore, it is reasonable to think that modulating FGF23 activities may be a novel therapeutic measure for these diseases. Several preclinical reports indicate that the inhibition of FGF23 activities ameliorates hypophosphatemic rickets/osteomalacia caused by excessive actions of FGF23. In addition, phase I-II clinical trials of anti-FGF23 antibody in adult patients with X-linked hypophosphatemia rickets, the most prevalent cause of genetic FGF23-related hypophosphatemic rickets, indicated that the antibody enhances renal tubular phosphate reabsorption and increases serum phosphate. However, it is not known whether the inhibition of FGF23 activities actually brings clinical improvement of rickets and osteomalacia. Available data indicate that FGF23-FGF receptor/Klotho pathway can be a new drug target for disorders of phosphate and bone metabolism.
Collapse
Affiliation(s)
- Seiji Fukumoto
- Department of Nuclear Receptor Ligands and Vitamins Research, Fujii Memorial Institute of Medical Sciences, Tokushima University, 3-18-15 Kuramoto-cho, Tokushima-shi, Tokushima, 770-8503, Japan.
| |
Collapse
|
94
|
Carrillo-López N, Panizo S, Alonso-Montes C, Román-García P, Rodríguez I, Martínez-Salgado C, Dusso AS, Naves M, Cannata-Andía JB. Direct inhibition of osteoblastic Wnt pathway by fibroblast growth factor 23 contributes to bone loss in chronic kidney disease. Kidney Int 2016; 90:77-89. [PMID: 27165819 DOI: 10.1016/j.kint.2016.01.024] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 12/23/2015] [Accepted: 01/14/2016] [Indexed: 12/20/2022]
Abstract
Bone loss and increased fractures are common complications in chronic kidney disease. Because Wnt pathway activation is essential for normal bone mineralization, we assessed whether Wnt inhibition contributes to high-phosphorus-induced mineralization defects in uremic rats. By week 20 after 7/8 nephrectomy, rats fed a high-phosphorus diet had the expected high serum creatinine, phosphorus, parathyroid hormone, and fibroblast growth factor 23 (FGF23) levels and low serum calcium. There was a 15% reduction in tibial mineral density and a doubling of bone cortical porosity compared to uremic rats fed a normal-phosphorus diet. The decreases in tibial mineral density were preceded by time-dependent increments in gene expression of bone formation (Osteocalcin and Runx2) and resorption (Cathepsin K) markers, which paralleled elevations in gene expression of the Wnt inhibitors Sfrp1 and Dkk1 in bone. Similar elevations of Wnt inhibitors plus an increased phospho-β-catenin/β-catenin ratio occurred upon exposure of the osteoblast cell line UMR106-01 either to uremic serum or to the combination of parathyroid hormone, FGF23, and soluble Klotho, at levels present in uremic serum. Strikingly, while osteoblast exposure to parathyroid hormone suppressed the expression of Wnt inhibitors, FGF23 directly inhibited the osteoblastic Wnt pathway through a soluble Klotho/MAPK-mediated process that required Dkk1 induction. Thus, the induction of Dkk1 by FGF23/soluble Klotho in osteoblasts inactivates Wnt/β-catenin signaling. This provides a novel autocrine/paracrine mechanism for the adverse impact of high FGF23 levels on bone in chronic kidney disease.
Collapse
Affiliation(s)
- Natalia Carrillo-López
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación Nefrológica, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain
| | - Sara Panizo
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación Nefrológica, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain
| | - Cristina Alonso-Montes
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación Nefrológica, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain
| | - Pablo Román-García
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación Nefrológica, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain
| | - Isabel Rodríguez
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación Nefrológica, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain
| | - Carlos Martínez-Salgado
- Instituto de Estudios de Ciencias de la Salud de Castilla y León (IECSCYL)-Instituto Biosanitario de Salamanca (IBSAL), Hospital Universitario de Salamanca, Salamanca, Spain
| | - Adriana S Dusso
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación Nefrológica, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain
| | - Manuel Naves
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación Nefrológica, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain
| | - Jorge B Cannata-Andía
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación Nefrológica, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain; Departmento de Medicina, Universidad de Oviedo, Oviedo, Asturias, Spain.
| |
Collapse
|
95
|
Wei K, Yin Z, Xie Y. Roles of the kidney in the formation, remodeling and repair of bone. J Nephrol 2016; 29:349-357. [PMID: 26943181 PMCID: PMC4879154 DOI: 10.1007/s40620-016-0284-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 02/05/2016] [Indexed: 12/14/2022]
Abstract
The relationship between the kidney and bone is highly complex, and the kidney plays an important role in the regulation of bone development and metabolism. The kidney is the major organ involved in the regulation of calcium and phosphate homeostasis, which is essential for bone mineralization and development. Many substances synthesized by the kidney, such as 1,25(OH)2D3, Klotho, bone morphogenetic protein-7, and erythropoietin, are involved in different stages of bone formation, remodeling and repair. In addition, some cytokines which can be affected by the kidney, such as osteoprotegerin, sclerostin, fibroblast growth factor -23 and parathyroid hormone, also play important roles in bone metabolism. In this paper, we summarize the possible effects of these kidney-related cytokines on bone and their possible mechanisms. Most of these cytokines can interact with one another, constituting an intricate network between the kidney and bone. Therefore, kidney diseases should be considered among patients presenting with osteodystrophy and disturbances in bone and mineral metabolism, and treatment for renal dysfunction may accelerate their recovery.
Collapse
Affiliation(s)
- Kai Wei
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, 28 Fuxing Road, Beijing, 100853, People's Republic of China.,Medical College, NanKai University, Tianjin, 300071, People's Republic of China
| | - Zhiwei Yin
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, 28 Fuxing Road, Beijing, 100853, People's Republic of China
| | - Yuansheng Xie
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, 28 Fuxing Road, Beijing, 100853, People's Republic of China.
| |
Collapse
|
96
|
Kinoshita S, Kawai M. The FGF23/KLOTHO Regulatory Network and Its Roles in Human Disorders. VITAMINS AND HORMONES 2016; 101:151-74. [PMID: 27125741 DOI: 10.1016/bs.vh.2016.02.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The functions of Klotho (KL) are multifaceted and include the regulation of aging and mineral metabolism. It was originally identified as the gene responsible for premature aging-like symptoms in mice and was subsequently shown to function as a coreceptor in the fibroblast growth factor (FGF) 23 signaling pathway. The discovery of KL as a partner for FGF23 led to significant advances in understanding of the molecular mechanisms underlying phosphate and vitamin D metabolism, and simultaneously clarified the pathogenic roles of the FGF23 signaling pathway in human diseases. These novel insights led to the development of new strategies to combat disorders associated with the dysregulated metabolism of phosphate and vitamin D, and clinical trials on the blockade of FGF23 signaling in X-linked hypophosphatemic rickets are ongoing. Molecular and functional insights on KL and FGF23 have been discussed in this review and were extended to how dysregulation of the FGF23/KL axis causes human disorders associated with abnormal mineral metabolism.
Collapse
Affiliation(s)
- S Kinoshita
- Osaka Medical Center and Research Institute for Maternal and Child Health, Izumi, Japan
| | - M Kawai
- Osaka Medical Center and Research Institute for Maternal and Child Health, Izumi, Japan.
| |
Collapse
|
97
|
Kronenberg HM. Bone and Mineral Metabolism: Where Are We, Where Are We Going, and How Will We Get There? J Clin Endocrinol Metab 2016; 101:795-8. [PMID: 26908104 PMCID: PMC4803156 DOI: 10.1210/jc.2015-3607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Advances in diagnosing and treating metabolic bone diseases will require ways to assess cellular signaling within human bones, ideally noninvasively. Only then will we be able to fully harness the increased molecular understanding of bone that derives from human genetics and model organisms, primarily rodents. New hormones regulating mineral ion homeostasis surely remain to be discovered, probably through advances in the study of human genetic disease.
Collapse
Affiliation(s)
- Henry M Kronenberg
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| |
Collapse
|
98
|
Abstract
The regulation of phosphate metabolism as an influence on bone homeostasis is profound. Recent advances in understanding the systemic control of Fibroblast growth factor-23 (FGF23) has uncovered novel effectors of endocrine feedback loops for calcium, phosphate, and vitamin D balance that interact with 'traditional' feedback loops for mineral metabolism. Not only are these findings re-shaping research studying phosphate handling and skeletal interactions, they have provided new therapeutic interventions. Emerging data support that the control of FGF23 production in bone and its circulating concentrations is a multi-layered process, with some influences affecting FGF23 transcription and some post-translational modification of the secreted, bioactive protein. Additionally, the actions of FGF23 on its target tissues via its co-receptor αKlotho, are subject to regulatory events just coming to light. The recent findings of systemic influences on circulating FGF23 and the downstream manifestations on bone homeostasis will be reviewed herein.
Collapse
Affiliation(s)
- Erica L Clinkenbeard
- Department of Medical and Molecular Genetics, Division of Molecular Genetics and Gene Therapy, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Kenneth E White
- Department of Medical and Molecular Genetics, Division of Molecular Genetics and Gene Therapy, Indiana University School of Medicine, Indianapolis, IN 46202
| |
Collapse
|
99
|
Hassan A, Durlacher K, Silver J, Naveh-Many T, Levi R. The fibroblast growth factor receptor mediates the increased FGF23 expression in acute and chronic uremia. Am J Physiol Renal Physiol 2016; 310:F217-21. [DOI: 10.1152/ajprenal.00332.2015] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 08/20/2015] [Indexed: 11/22/2022] Open
Abstract
Serum FGF23 is markedly elevated in chronic kidney disease and has been associated with poor long-term outcomes. FGF23 expression is increased by activation of the FGF receptor 1 (FGFR1) in rats with normal renal function and in vitro in bone-derived osteoblast-like cells. We studied the regulation of FGF23 by FGFR1 in vivo in acute and chronic uremia in mice and rats. Folic acid-induced acute kidney injury increased calvaria FGF23 mRNA and serum FGF23 and parathyroid hormone (PTH) levels at 6 h. The FGFR1 receptor inhibitor PD173074 prevented the folic acid-induced increase in both FGF23 mRNA and serum levels but had no effect on serum PTH levels. A more prolonged uremia due to an adenine high-phosphorus diet for 14 days resulted in high levels of FGF23 mRNA and serum FGF23 and PTH. PD173074 decreased serum FGF23 and mRNA levels with no effect on PTH in the adenine high phosphorus-induced uremic rats. Therefore, a derangement in FGF23 regulation starts early in the course of acute kidney injury, is in part independent of the increase in serum PTH, and involves activation of FGFR1. It is possible that FGFR1 in the osteocyte is activated by locally produced canonical FGFs, which are increased in uremia. This is the first demonstration that activation of FGFR1 is essential for the high levels of FGF23 in acute and chronic experimental uremia.
Collapse
Affiliation(s)
- Alia Hassan
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Karina Durlacher
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Justin Silver
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Tally Naveh-Many
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Ronen Levi
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| |
Collapse
|
100
|
Kawai M. The FGF23/Klotho axis in the regulation of mineral and metabolic homeostasis. Horm Mol Biol Clin Investig 2016; 28:55-67. [DOI: 10.1515/hmbci-2015-0068] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 01/07/2016] [Indexed: 11/15/2022]
Abstract
AbstractThe function of fibroblast growth factor (FGF) 23 has been suggested to be multifaceted beyond its canonical function as a regulator of mineral metabolism. FGF23 was originally shown to play a central role in phosphate (Pi) and vitamin D metabolism, and a number of diseases associated with dysregulated Pi metabolism have been attributed to abnormal FGF23 signaling activities. The discovery of Klotho as a co-receptor for FGF23 signaling has also accelerated understanding on the molecular mechanisms underlying Pi and vitamin D metabolism. In addition to these canonical functions, FGF23 has recently been implicated in a number of metabolic diseases including chronic kidney disease-associated complications, cardiovascular diseases, and obesity-related disorders; however, the physiological significance and molecular mechanisms of these emerging roles of FGF23 remain largely unknown. Molecular and functional insights into the FGF23 pathway will be discussed in the present review, with an emphasis on its role in human disorders related to dysregulated Pi metabolism as well as metabolic disorders.
Collapse
|