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Kamenický P, Briot K, Munns CF, Linglart A. X-linked hypophosphataemia. Lancet 2024; 404:887-901. [PMID: 39181153 DOI: 10.1016/s0140-6736(24)01305-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 06/17/2024] [Accepted: 06/18/2024] [Indexed: 08/27/2024]
Abstract
X-linked hypophosphataemia is a genetic disease caused by defects in the phosphate regulating endopeptidase homolog X-linked (PHEX) gene and is characterised by X-linked dominant inheritance. The main consequence of PHEX deficiency is increased production of the phosphaturic hormone fibroblast growth factor 23 (FGF23) in osteoblasts and osteocytes. Chronic exposure to circulating FGF23 is responsible for renal phosphate wasting and decreased synthesis of calcitriol, which decreases intestinal phosphate absorption. These mechanisms result in lifelong hypophosphataemia, impaired growth plate and bone matrix mineralisation, and diverse manifestations in affected children and adults, including some debilitating morbidities and possibly increased mortality. Important progress has been made in disease knowledge and management over the past decade; in particular, targeting FGF23 is a therapeutic approach that has substantially improved outcomes. However, patients affected by this complex disease need lifelong care and innovative treatment strategies, such as gene repair of PHEX, are necessary to further limit the disease burden.
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Affiliation(s)
- Peter Kamenický
- Université Paris-Saclay, Inserm, Physiologie et Physiopathologie Endocriniennes, Le Kremlin-Bicêtre, France; Centre de Référence des Maladies du Métabolisme du Calcium et du Phosphate, Service d'Endocrinologie et des Maladies de la Reproduction, Hôpital Bicêtre, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France.
| | - Karine Briot
- Centre de Référence des Maladies du Métabolisme du Calcium et du Phosphate, Service de Rhumatologie, Hôpital Cochin, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Craig F Munns
- Department of Endocrinology and Diabetes, Queensland Children's Hospital and Child Health Research Centre and Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Agnès Linglart
- Université Paris-Saclay, Inserm, Physiologie et Physiopathologie Endocriniennes, Le Kremlin-Bicêtre, France; Service d'Endocrinologie et du Diabète de l'Enfant, Hôpital Bicêtre, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France
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2
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Brener A, Cleper R, Baruch G, Rothschild E, Yackobovitch-Gavan M, Beer G, Zeitlin L, Kapusta L. Cardiovascular health in pediatric patients with X-linked hypophosphatemia under two years of burosumab therapy. Front Endocrinol (Lausanne) 2024; 15:1400273. [PMID: 38818505 PMCID: PMC11137213 DOI: 10.3389/fendo.2024.1400273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 04/22/2024] [Indexed: 06/01/2024] Open
Abstract
Introduction X-linked hypophosphatemia (XLH) is caused by an inactivating mutation in the phosphate-regulating endopeptidase X-linked (PHEX) gene whose defective product fails to control phosphatonin fibroblast growth factor 23 (FGF23) serum levels. Although elevated FGF23 levels have been linked with detrimental cardiac effects, the cardiologic outcomes in XLH patients have been subject to debate. Our study aimed to evaluate the prevalence and severity of cardiovascular morbidity in pediatric XLH patients before, during, and after a 2-year treatment period with burosumab, a recombinant anti-FGF23 antibody. Methods This prospective observational study was conducted in a tertiary medical center, and included 13 individuals with XLH (age range 0.6-16.2 years) who received burosumab every 2 weeks. Clinical assessment at treatment initiation and after .5, 1, and 2 years of uninterrupted treatment included anthropometric measurements and cardiologic evaluations (blood pressure [BP], electrocardiogram, conventional echocardiography, and myocardial strain imaging). Results The linear growth of all patients improved significantly (mean height z-score: from -1.70 ± 0.80 to -0.96 ± 1.08, P=0.03). Other favorable effects were decline in overweight/obesity rates (from 46.2% to 23.1%) and decreased rates of elevated BP (systolic BP from 38.5% to 15.4%; diastolic BP from 38.5% to 23.1%). Electrocardiograms revealed no significant abnormality throughout the study period. Cardiac dimensions and myocardial strain parameters were within the normative range for age at baseline and remained unchanged during the study period. Conclusion Cardiologic evaluations provided reassurance that 2 years of burosumab therapy did not cause cardiac morbidity. The beneficial effect of this treatment was a reduction in cardiovascular risk factors, as evidenced by the lower prevalence of both overweight/obesity and elevated BP.
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Affiliation(s)
- Avivit Brener
- Institute of Pediatric Endocrinology and Diabetes, Dana-Dwek Children’s Hospital, Sourasky Medical Center, Tel Aviv, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Roxana Cleper
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Pediatric Nephrology Unit, Dana-Dwek Children’s Hospital, Sourasky Medical Center, Tel Aviv, Israel
| | - Guy Baruch
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Internal Medicine, Sourasky Medical Center, Tel Aviv, Israel
| | - Ehud Rothschild
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Internal Medicine, Sourasky Medical Center, Tel Aviv, Israel
| | - Michal Yackobovitch-Gavan
- Department of Epidemiology and Preventive Medicine, School of Public Health, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Gil Beer
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Pediatric Cardiology Unit, Dana-Dwek Children’s Hospital, Sourasky Medical Center, Tel Aviv, Israel
| | - Leonid Zeitlin
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Metabolic Bone Disease Unit, Pediatric Orthopedic Department, Dana-Dwek Children’s Hospital, Sourasky Medical Center, Tel Aviv, Israel
| | - Livia Kapusta
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Pediatric Cardiology Unit, Dana-Dwek Children’s Hospital, Sourasky Medical Center, Tel Aviv, Israel
- Department of Pediatrics, Amalia Children’s Hospital, Radboud University Medical Centre, Nijmegen, Netherlands
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3
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Nakanishi T, Yamazaki M, Tachikawa K, Ueta A, Kawai M, Ozono K, Michigami T. Complex intrinsic abnormalities in osteoblast lineage cells of X-linked hypophosphatemia: Analysis of human iPS cell models generated by CRISPR/Cas9-mediated gene ablation. Bone 2024; 181:117044. [PMID: 38331306 DOI: 10.1016/j.bone.2024.117044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/04/2024] [Accepted: 02/05/2024] [Indexed: 02/10/2024]
Abstract
X-linked hypophosphatemia (XLH) is caused by inactivating variants of the phosphate regulating endopeptidase homolog X-linked (PHEX) gene. Although the overproduction of fibroblast growth factor 23 (FGF23) is responsible for hypophosphatemia and impaired vitamin D metabolism, the pathogenesis of XLH remains unclear. We herein generated PHEX-knockout (KO) human induced pluripotent stem (iPS) cells by applying CRISPR/Cas9-mediated gene ablation to an iPS clone derived from a healthy male, and analyzed PHEX-KO iPS cells with deletions extending from exons 1 to 3 and frameshifts by inducing them to differentiate into the osteoblast lineage. We confirmed the increased production of FGF23 in osteoblast lineage cells differentiated from PHEX-KO iPS cells. In vitro mineralization was enhanced in osteoblast lineage cells from PHEX-KO iPS cells than in those from isogenic control iPS cells, which reminded us of high bone mineral density and enthesopathy in patients with XLH. The extracellular level of pyrophosphate (PPi), an inhibitor of mineralization, was elevated, and this increase appeared to be partly due to the reduced activity of tissue non-specific alkaline phosphatase (TNSALP). Osteoblast lineage cells derived from PHEX-KO iPS cells also showed the increased expression of multiple molecules such as dentine matrix protein 1, osteopontin, RUNX2, FGF receptor 1 and early growth response 1. This gene dysregulation was similar to that in the osteoblasts/osteocytes of Phex-deficient Hyp mice, suggesting that common pathogenic mechanisms are shared between human XLH and Hyp mice. Moreover, we found that the phosphorylation of CREB was markedly enhanced in osteoblast lineage cells derived from PHEX-KO iPS cells, which appeared to be associated with the up-regulation of the parathyroid hormone related protein gene. PHEX deficiency also affected the response of the ALPL gene encoding TNSALP to extracellular Pi. Collectively, these results indicate that complex intrinsic abnormalities in osteoblasts/osteocytes underlie the pathogenesis of human XLH.
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Affiliation(s)
- Tatsuro Nakanishi
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka 594-1101, Japan; Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Miwa Yamazaki
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka 594-1101, Japan
| | - Kanako Tachikawa
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka 594-1101, Japan
| | - Ayu Ueta
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka 594-1101, Japan; 1st Department of Oral and Maxillofacial Surgery, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Masanobu Kawai
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka 594-1101, Japan
| | | | - Toshimi Michigami
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka 594-1101, Japan.
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Zangerolamo L, Carvalho M, Velloso LA, Barbosa HCL. Endocrine FGFs and their signaling in the brain: Relevance for energy homeostasis. Eur J Pharmacol 2024; 963:176248. [PMID: 38056616 DOI: 10.1016/j.ejphar.2023.176248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/10/2023] [Accepted: 11/30/2023] [Indexed: 12/08/2023]
Abstract
Since their discovery in 2000, there has been a continuous expansion of studies investigating the physiology, biochemistry, and pharmacology of endocrine fibroblast growth factors (FGFs). FGF19, FGF21, and FGF23 comprise a subfamily with attributes that distinguish them from typical FGFs, as they can act as hormones and are, therefore, referred to as endocrine FGFs. As they participate in a broad cross-organ endocrine signaling axis, endocrine FGFs are crucial lipidic, glycemic, and energetic metabolism regulators during energy availability fluctuations. They function as powerful metabolic signals in physiological responses induced by metabolic diseases, like type 2 diabetes and obesity. Pharmacologically, FGF19 and FGF21 cause body weight loss and ameliorate glucose homeostasis and energy expenditure in rodents and humans. In contrast, FGF23 expression in mice and humans has been linked with insulin resistance and obesity. Here, we discuss emerging concepts in endocrine FGF signaling in the brain and critically assess their putative role as therapeutic targets for treating metabolic disorders.
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Affiliation(s)
- Lucas Zangerolamo
- Obesity and Comorbidities Research Center, University of Campinas, UNICAMP, Campinas, Sao Paulo, Brazil
| | - Marina Carvalho
- Obesity and Comorbidities Research Center, University of Campinas, UNICAMP, Campinas, Sao Paulo, Brazil
| | - Licio A Velloso
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, University of Campinas, UNICAMP, Campinas, Sao Paulo, Brazil
| | - Helena C L Barbosa
- Obesity and Comorbidities Research Center, University of Campinas, UNICAMP, Campinas, Sao Paulo, Brazil.
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Perumal NL, Padidela R. Phosphate Homeostasis and Disorders of Phosphate Metabolism. Curr Pediatr Rev 2024; 20:412-425. [PMID: 36545737 DOI: 10.2174/1573396319666221221121350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022]
Abstract
Phosphate is indispensable for human life and evolutionary changes over several millions of years have established tightly regulated mechanisms to ensure phosphate homeostasis. In this process, calcium and phosphate metabolism have come to be intricately linked together. Three hormones (PTH, FGF23 and Calcitriol) maintain the fine balance of calcium and phosphate metabolism through their actions at three sites (the gut, the kidneys and the skeleton). Disorders that disrupt this balance can have serious clinical consequences. Acute changes in serum phosphate levels can result in life threatening complications like respiratory failure and cardiac arrythmias. Chronic hypophosphataemia predominantly affects the musculoskeletal system and presents as impaired linear growth, rickets, osteomalacia and dental problems. Hyperphosphataemia is very common in the setting of chronic kidney disease and can be difficult to manage. A thorough understanding of calcium and phosphate homeostasis is essential to diagnose and treat conditions associated with hypo and hyperphosphataemia. In this review, we will discuss the calcium and phosphate metabolism, aetiologies and management of hypo and hyperphosphataemia.
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Affiliation(s)
| | - Raja Padidela
- Department of Endocrinology, Royal Manchester Children's Hospital, Manchester, United Kingdom
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6
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Raimann A, Misof BM, Fratzl P, Fratzl-Zelman N. Bone Material Properties in Bone Diseases Affecting Children. Curr Osteoporos Rep 2023; 21:787-805. [PMID: 37897675 DOI: 10.1007/s11914-023-00822-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/12/2023] [Indexed: 10/30/2023]
Abstract
PURPOSE OF REVIEW Metabolic and genetic bone disorders affect not only bone mass but often also the bone material, including degree of mineralization, matrix organization, and lacunar porosity. The quality of juvenile bone is moreover highly influenced by skeletal growth. This review aims to provide a compact summary of the present knowledge on the complex interplay between bone modeling and remodeling during skeletal growth and to alert the reader to the complexity of bone tissue characteristics in children with bone disorders. RECENT FINDINGS We describe cellular events together with the characteristics of the different tissues and organic matrix organization (cartilage, woven and lamellar bone) occurring during linear growth. Subsequently, we present typical alterations thereof in disorders leading to over-mineralized bone matrix compared to those associated with low or normal mineral content based on bone biopsy studies. Growth spurts or growth retardation might amplify or mask disease-related alterations in bone material, which makes the interpretation of bone tissue findings in children complex and challenging.
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Affiliation(s)
- Adalbert Raimann
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Pulmonology, Allergology and Endocrinology, Medical University of Vienna, Vienna, Austria
- Vienna Bone and Growth Center, Vienna, Austria
| | - Barbara M Misof
- Vienna Bone and Growth Center, Vienna, Austria
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Center Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Peter Fratzl
- Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Research Campus Golm, Potsdam, Germany
| | - Nadja Fratzl-Zelman
- Vienna Bone and Growth Center, Vienna, Austria.
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Center Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria.
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7
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Hacisahinogullari H, Tekin S, Tanrikulu S, Saribeyliler G, Yalin GY, Bilgic B, Isik EG, Salduz A, Tuncer S, Gul N, Uzum AK, Aral F, Tanakol R, Selcukbiricik OS. Diagnosis and management of tumor-induced osteomalacia: a single center experience. Endocrine 2023; 82:427-434. [PMID: 37480497 DOI: 10.1007/s12020-023-03450-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 07/06/2023] [Indexed: 07/24/2023]
Abstract
PURPOSE The aim of this study is to review the clinical and laboratory characteristics, diagnostic and treatment modalities of tumor-induced osteomalacia (TIO) cases managed in a single center. MATERIAL METHODS Demographic and clinical features, biochemical findings, diagnostic procedures, treatment modalities, and outcomes of nine patients who had the diagnosis of TIO were reviewed retrospectively. RESULTS Mean age of the study group (F/M: 4/5) was 45.8 ± 10.8 years, and mean time from the onset of symptoms to diagnosis was 4.7 ± 2.8 years. The clinical manifestations were muscle weakness and difficulty in walking (8/9), hip pain (3/9), multiple fractures (2/9), stress fracture (2/9). Mean plasma phosphorus concentration was 1.28 ± 0.4 mg/dl at presentation. We performed radionuclide imaging modalities (18F-FDG PET/CT, Ga68-DOTATATE PET/CT, octreotide scintigraphy) in seven of nine patients, and tumor was detected in all. Lower extremity (n = 6; %67), head region (n = 2; %22) and thorax (n = 1; %11) were the tumor locations of our cases. Eight patients underwent surgery and remission was achieved postoperatively in all of the operated patients and plasma phosphorus level normalized in 4 ± 2 days. Pathological examination revealed mesenchymal tumors with different subtypes. Recurrence occurred in three patients at 13 ± 10.5 months after the first surgery. Two patients were reoperated and radiotherapy was also performed in one of them. CONCLUSION Hypophosphatemia necessitates careful evaluation for the etiology. TIO is one of the important causes of adult-onset hypophosphatemic osteomalacia. Diagnosis of TIO is essential because the laboratory and clinical findings resolve after appropriate treatment.
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Affiliation(s)
- Hulya Hacisahinogullari
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey.
| | - Sakin Tekin
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Zonguldak Bulent Ecevit University, Faculty of Medicine, Zonguldak, Turkey
| | - Seher Tanrikulu
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
| | - Goktug Saribeyliler
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
| | - Gulsah Yenidunya Yalin
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
| | - Bilge Bilgic
- Department of Pathology, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
| | - Emine Goknur Isik
- Department of Nuclear Medicine, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
| | - Ahmet Salduz
- Department of Orthopedics and Traumatology, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
| | - Samuray Tuncer
- Department of Ophthalmology, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
| | - Nurdan Gul
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
| | - Ayse Kubat Uzum
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
| | - Ferihan Aral
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
| | - Refik Tanakol
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
| | - Ozlem Soyluk Selcukbiricik
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey
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8
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Grimbly C, Graf D, Ward LM, Alexander RT. X-linked hypophosphatemia, fibroblast growth factor 23 signaling, and craniosynostosis. Exp Biol Med (Maywood) 2023; 248:2175-2182. [PMID: 38230523 PMCID: PMC10800125 DOI: 10.1177/15353702231222023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024] Open
Abstract
This review summarizes the current knowledge of fibroblast growth factor 23 signaling in bone and its role in the disease pathology of X-linked hypophosphatemia. Craniosynostosis is an under-recognized complication of X-linked hypophosphatemia. The clinical implications and potential cellular mechanisms invoked by increased fibroblast growth factor 23 signaling causing craniosynostosis are reviewed. Knowledge gaps are identified and provide direction for future clinical and basic science studies.
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Affiliation(s)
- Chelsey Grimbly
- Department of Pediatrics, Edmonton Clinic Health Academy, University of Alberta, Edmonton, AB T6G 2R7, Canada
- Women & Children’s Health Research Institute, University of Alberta, Edmonton, AB T6G 2R7, Canada
| | - Daniel Graf
- Women & Children’s Health Research Institute, University of Alberta, Edmonton, AB T6G 2R7, Canada
- Department of Dentistry and Dental Hygiene, University of Alberta, Edmonton, AB T6G 2R7, Canada
| | - Leanne M Ward
- Division of Endocrinology and Metabolism, Department of Pediatrics Faculty of Medicine, Children’s Hospital of Eastern Ontario, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - R Todd Alexander
- Department of Pediatrics, Edmonton Clinic Health Academy, University of Alberta, Edmonton, AB T6G 2R7, Canada
- Women & Children’s Health Research Institute, University of Alberta, Edmonton, AB T6G 2R7, Canada
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Zhang H, Xiang G, Li J, He S, Wang Y, Deng A, Wang Y, Guo C. Promotion effect of FGF23 on osteopenia in congenital scoliosis through FGFr3/TNAP/OPN pathway. Chin Med J (Engl) 2023; 136:1468-1477. [PMID: 37192015 PMCID: PMC10278695 DOI: 10.1097/cm9.0000000000002690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Indexed: 05/18/2023] Open
Abstract
BACKGROUND Congenital scoliosis (CS) is a complex spinal malformation of unknown etiology with abnormal bone metabolism. Fibroblast growth factor 23 (FGF23), secreted by osteoblasts and osteocytes, can inhibit bone formation and mineralization. This research aims to investigate the relationship between CS and FGF23. METHODS We collected peripheral blood from two pairs of identical twins for methylation sequencing of the target region. FGF23 mRNA levels in the peripheral blood of CS patients and age-matched controls were measured. Receiver operator characteristic (ROC) curve analyses were conducted to evaluate the specificity and sensitivity of FGF23. The expression levels of FGF23 and its downstream factors fibroblast growth factor receptor 3 (FGFr3)/tissue non-specific alkaline phosphatase (TNAP)/osteopontin (OPN) in primary osteoblasts from CS patients (CS-Ob) and controls (CT-Ob) were detected. In addition, the osteogenic abilities of FGF23-knockdown or FGF23-overexpressing Ob were examined. RESULTS DNA methylation of the FGF23 gene in CS patients was decreased compared to that of their identical twins, accompanied by increased mRNA levels. CS patients had increased peripheral blood FGF23 mRNA levels and decreased computed tomography (CT) values compared with controls. The FGF23 mRNA levels were negatively correlated with the CT value of the spine, and ROCs of FGF23 mRNA levels showed high sensitivity and specificity for CS. Additionally, significantly increased levels of FGF23, FGFr3, OPN, impaired osteogenic mineralization and lower TNAP levels were observed in CS-Ob. Moreover, FGF23 overexpression in CT-Ob increased FGFr3 and OPN levels and decreased TNAP levels, while FGF23 knockdown induced downregulation of FGFr3 and OPN but upregulation of TNAP in CS-Ob. Mineralization of CS-Ob was rescued after FGF23 knockdown. CONCLUSIONS Our results suggested increased peripheral blood FGF23 levels, decreased bone mineral density in CS patients, and a good predictive ability of CS by peripheral blood FGF23 levels. FGF23 may contribute to osteopenia in CS patients through FGFr3/TNAP / OPN pathway.
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Affiliation(s)
- Hongqi Zhang
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
- National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
| | - Gang Xiang
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
- National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
| | - Jiong Li
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
- National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
| | - Sihan He
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
- National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
| | - Yunjia Wang
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
- National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
| | - Ang Deng
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
- National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
| | - Yuxiang Wang
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
- National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
| | - Chaofeng Guo
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
- National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
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10
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Buss DJ, Rechav K, Reznikov N, McKee MD. Mineral tessellation in mouse enthesis fibrocartilage, Achilles tendon, and Hyp calcifying enthesopathy: A shared 3D mineralization pattern. Bone 2023:116818. [PMID: 37295663 DOI: 10.1016/j.bone.2023.116818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/17/2023] [Accepted: 06/01/2023] [Indexed: 06/12/2023]
Abstract
The hallmark of enthesis architecture is the 3D compositional and structural gradient encompassing four tissue zones - tendon/ligament, uncalcified fibrocartilage, calcified fibrocartilage and bone. This functional gradient accommodates the large stiffness differential between calcified bone and uncalcified tendon/ligament. Here we analyze in 3D the organization of the mouse Achilles enthesis and mineralizing Achilles tendon in comparison to lamellar bone. We use correlative, multiscale high-resolution volume imaging methods including μCT with submicrometer resolution and FIB-SEM tomography (both with deep learning-based image segmentation), and TEM and SEM imaging, to describe ultrastructural features of physiologic, age-related and aberrant mineral patterning. We applied these approaches to murine wildtype (WT) Achilles enthesis tissues to describe in normal calcifying fibrocartilage a crossfibrillar mineral tessellation pattern similar to that observed in lamellar bone, but with greater variance in mineral tesselle morphology and size. We also examined Achilles enthesis structure in Hyp mice, a murine model for the inherited osteomalacic disease X-linked hypophosphatemia (XLH) with calcifying enthesopathy. In Achilles enthesis fibrocartilage of Hyp mice, we show defective crossfibrillar mineral tessellation similar to that which occurs in Hyp lamellar bone. At the cellular level in fibrocartilage, unlike in bone where enlarged osteocyte mineral lacunae are found as peri-osteocytic lesions, mineral lacunar volumes for fibrochondrocytes did not differ between WT and Hyp mice. While both WT and Hyp aged mice demonstrate Achilles tendon midsubstance ectopic mineralization, a consistently defective mineralization pattern was observed in Hyp mice. Strong immunostaining for osteopontin was observed at all mineralization sites examined in both WT and Hyp mice. Taken together, this new 3D ultrastructural information describes details of common mineralization trajectories for enthesis, tendon and bone, which in Hyp/XLH are defective.
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Affiliation(s)
- Daniel J Buss
- Department of Anatomy and Cell Biology, School of Biomedical Sciences, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada
| | - Katya Rechav
- Electron Microscopy Unit, Weizmann Institute of Science, Rehovot, Israel
| | - Natalie Reznikov
- Department of Anatomy and Cell Biology, School of Biomedical Sciences, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada; Department of Bioengineering, Faculty of Engineering, McGill University, Montreal, Quebec, Canada; Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, Quebec, Canada
| | - Marc D McKee
- Department of Anatomy and Cell Biology, School of Biomedical Sciences, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada; Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, Quebec, Canada.
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11
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Patricia da Silva E, da Silva Feltran G, Alexandre Alcântara Dos Santos S, Cardoso de Oliveira R, Assis RIF, Antônio Justulin Junior L, Carleto Andia D, Zambuzzi WF, Latini A, Foganholi da Silva RA. Hyperglycemic microenvironment compromises the homeostasis of communication between the bone-brain axis by the epigenetic repression of the osteocalcin receptor, Gpr158 in the hippocampus. Brain Res 2023; 1803:148234. [PMID: 36634900 DOI: 10.1016/j.brainres.2023.148234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/05/2023] [Accepted: 01/07/2023] [Indexed: 01/11/2023]
Abstract
Diabetes mellitus (DM) is a chronic metabolic disease, mainly characterized by increased blood glucose and insulin dysfunction. In response to the persistent systemic hyperglycemic state, numerous metabolic and physiological complications have already been well characterized. However, its relationship to bone fragility, cognitive deficits and increased risk of dementia still needs to be better understood. The impact of chronic hyperglycemia on bone physiology and architecture was assessed in a model of chronic hyperglycemia induced by a single intraperitoneal administration of streptozotocin (STZ; 55 mg/kg) in Wistar rats. In addition, the bone-to-brain communication was investigated by analyzing the gene expression and methylation status of genes that encode the main osteokines released by the bone [Fgf23 (fibroblast growth factor 23), Bglap (bone gamma-carboxyglutamate protein) and Lcn2 (lipocalin 2) and their receptors in both, the bone and the brain [Fgfr1 (fibroblast growth factor receptor 1), Gpr6A (G-protein coupled receptor family C group 6 member A), Gpr158 (G protein-coupled receptor 158) and Slc22a17 (Solute carrier family 22 member 17)]. It was observed that chronic hyperglycemia negatively impacted on bone biology and compromised the balance of the bone-brain endocrine axis. Ultrastructural disorganization was accompanied by global DNA hypomethylation and changes in gene expression of DNA-modifying enzymes that were accompanied by changes in the methylation status of the osteokine promoter region Bglap and Lcn2 (lipocalin 2) in the femur. Additionally, the chronic hyperglycemic state was accompanied by modulation of gene expression of the osteokines Fgf23 (fibroblast growth factor 23), Bglap (bone gamma-carboxyglutamate protein) and Lcn2 (lipocalin 2) in the different brain regions. However, transcriptional regulation mediated by DNA methylation was observed only for the osteokine receptors, Fgfr1(fibroblast growth factor receptor 1) in the striatum and Gpr158 (G protein-coupled receptor 158) in the hippocampus. This is a pioneer study demonstrating that the chronic hyperglycemic state compromises the crosstalk between bone tissue and the brain, mainly affecting the hippocampus, through transcriptional silencing of the Bglap receptor by hypermethylation of Gpr158 gene.
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Affiliation(s)
- Ericka Patricia da Silva
- CEEpiRG, Program in Environmental and Experimental Pathology, Paulista University - UNIP, São Paulo, São Paulo, Brazil
| | - Geórgia da Silva Feltran
- Laboratory of Bioassays and Cellular Dynamics, Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | | | - Rodrigo Cardoso de Oliveira
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo -FOB, Bauru, São Paulo, Brazil
| | - Rahyza I F Assis
- Department of Clinical Dentistry, Federal University of Espírito Santo, Vitória, ES, Brazil
| | - Luis Antônio Justulin Junior
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Denise Carleto Andia
- School of Dentistry, Health Science Institute, Paulista University - UNIP, São Paulo, São Paulo, Brazil
| | - Willian F Zambuzzi
- Laboratory of Bioassays and Cellular Dynamics, Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Alexandra Latini
- LABOX, Department of Biochemistry, Center for Biological Sciences, Federal University of Santa Catarina - UFSC, Florianopolis, Brazil.
| | - Rodrigo A Foganholi da Silva
- CEEpiRG, Program in Environmental and Experimental Pathology, Paulista University - UNIP, São Paulo, São Paulo, Brazil; Department of Dentistry, University of Taubaté - UNITAU, Taubaté, São Paulo, Brazil.
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12
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Insights into the Molecular and Hormonal Regulation of Complications of X-Linked Hypophosphatemia. ENDOCRINES 2023. [DOI: 10.3390/endocrines4010014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
Abstract
X-linked hypophosphatemia (XLH) is characterized by mutations in the PHEX gene, leading to elevated serum levels of FGF23, decreased production of 1,25 dihydroxyvitamin D3 (1,25D), and hypophosphatemia. Those affected with XLH manifest impaired growth and skeletal and dentoalveolar mineralization as well as increased mineralization of the tendon–bone attachment site (enthesopathy), all of which lead to decreased quality of life. Many molecular and murine studies have detailed the role of mineral ions and hormones in regulating complications of XLH, including how they modulate growth and growth plate maturation, bone mineralization and structure, osteocyte-mediated mineral matrix resorption and canalicular organization, and enthesopathy development. While these studies have provided insight into the molecular underpinnings of these skeletal processes, current therapies available for XLH do not fully prevent or treat these complications. Therefore, further investigations are needed to determine the molecular pathophysiology underlying the complications of XLH.
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13
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Kritmetapak K, Kumar R. Phosphatonins: From Discovery to Therapeutics. Endocr Pract 2023; 29:69-79. [PMID: 36210014 DOI: 10.1016/j.eprac.2022.09.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Phosphate is crucial for cell signaling, energy metabolism, nucleotide synthesis, and bone mineralization. The gut-bone-parathyroid-kidney axis is influenced by parathyroid hormone, 1,25-dihydroxyvitamin D, and phosphatonins, especially fibroblast growth factor 23 (FGF23). These hormones facilitate maintenance of phosphate homeostasis. This review summarizes current knowledge regarding the phosphate homeostasis, phosphatonin pathophysiology, and clinical implications of FGF23-related hypophosphatemic disorders, with specific focus on burosumab treatment. METHOD A focused literature search of PubMed was conducted. RESULTS Phosphatonins including FGF23, secreted frizzled-related protein 4, matrix extracellular phosphoglycoprotein, and fibroblast growth factor 7 play a pathogenic role in several hypophosphatemic disorders. Excess FGF23 inhibits sodium-dependent phosphate cotransporters (NaPi-2a and NaPi-2c), resulting in hyperphosphaturia and hypophosphatemia. Additionally, FGF23 suppresses 1,25-dihydroxyvitamin D synthesis in the proximal renal tubule, and thus, it indirectly inhibits intestinal phosphate absorption. Disorders of FGF23-related hypophosphatemia include X-linked hypophosphatemia (XLH), autosomal dominant hypophosphatemic rickets, autosomal recessive hypophosphatemic rickets, fibrous dysplasia/McCune-Albright syndrome, and tumor-induced osteomalacia (TIO). Complications of conventional therapy with oral phosphate and vitamin D analogs comprise gastrointestinal distress, hypercalcemia, nephrocalcinosis, and secondary/tertiary hyperparathyroidism. In both children and adults with XLH and TIO, the anti-FGF23 antibody burosumab exhibits a favorable safety profile and is associated with healing of rickets in affected children and improvement of osteomalacia in both children and adults. CONCLUSION The treatment paradigm for XLH and TIO is changing based on data from recent clinical trials. Research suggest that burosumab is effective and safe for pediatric and adult patients with XLH or TIO.
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Affiliation(s)
| | - Rajiv Kumar
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota.
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14
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Kamiya Y, Matsushita M, Mishima K, Ohkawara B, Michigami T, Imagama S, Ohno K, Kitoh H. Meclozine ameliorates bone mineralization and growth plate structure in a mouse model of X‑linked hypophosphatemia. Exp Ther Med 2022; 25:39. [PMID: 36569439 PMCID: PMC9764053 DOI: 10.3892/etm.2022.11738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 10/13/2022] [Indexed: 12/02/2022] Open
Abstract
X-linked hypophosphatemic rickets (XLH) is characterized by hypo-mineralization of the bone due to hypophosphatemia. XLH is caused by abnormally high levels of fibroblast growth factor 23, which trigger renal phosphate wasting. Activated fibroblast growth factor receptor 3 (FGFR3) signaling is considered to be involved in XLH pathology. Our previous study revealed that meclozine attenuated FGFR3 signaling and promoted longitudinal bone growth in an achondroplasia mouse model. The present study aimed to examine whether meclozine affected the bone phenotype in a mouse model of XLH [X-linked hypophosphatemic (Hyp) mice]. Meclozine was administered orally to 7-day-old Hyp mice for 10 days, after which the mice were subjected to blood sampling and histological analyses of the first coccygeal vertebra, femur and tibia. Villanueva Goldner staining was used to assess bone mineralization, hematoxylin and eosin staining was used to determine the growth plate structure and tartrate-resistant acid phosphatase staining was used to measure osteoclast activity. The osteoid volume/bone volume of cortical bone was lower in meclozine-treated Hyp mice compared with untreated Hyp mice. Meclozine treatment improved the abnormally thick hypertrophic zone of the growth plate and ameliorated the downregulation of osteoclast surface/bone surface in Hyp mice. However, meclozine had only a marginal effect on mineralization in the trabecular bone and on calcium and phosphate plasma levels. A 10-day-tratment with meclozine partially ameliorated bone mineralization in Hyp mice; hence, meclozine could alleviate XLH symptoms.
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Affiliation(s)
- Yasunari Kamiya
- Department of Orthopaedic Surgery, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan,Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Masaki Matsushita
- Department of Orthopaedic Surgery, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan,Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan,Correspondence to: Dr Masaki Matsushita, Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Kenichi Mishima
- Department of Orthopaedic Surgery, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan,Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Bisei Ohkawara
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Toshimi Michigami
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka, 594-1101, Japan
| | - Shiro Imagama
- Department of Orthopaedic Surgery, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Kinji Ohno
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Hiroshi Kitoh
- Department of Orthopaedic Surgery, Aichi Children's Health and Medical Center, Obu, Aichi 474-8710, Japan,Department of Comprehensive Pediatric Medicine, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
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15
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Buck A, Prade VM, Kunzke T, Erben RG, Walch A. Spatial metabolomics reveals upregulation of several pyrophosphate-producing pathways in cortical bone of Hyp mice. JCI Insight 2022; 7:e162138. [PMID: 36278488 PMCID: PMC9714788 DOI: 10.1172/jci.insight.162138] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/31/2022] [Indexed: 06/28/2024] Open
Abstract
Patients with the renal phosphate-wasting disease X-linked hypophosphatemia (XLH) and Hyp mice, the murine homolog of XLH, are characterized by loss-of-function mutations in phosphate-regulating endopeptidase homolog X-linked (PHEX), leading to excessive secretion of the bone-derived phosphotropic hormone FGF23. The mineralization defect in patients with XLH and Hyp mice is caused by a combination of hypophosphatemia and local accumulation of mineralization-inhibiting molecules in bone. However, the mechanism by which PHEX deficiency regulates bone cell metabolism remains elusive. Here, we used spatial metabolomics by employing matrix-assisted laser desorption/ionization (MALDI) Fourier-transform ion cyclotron resonance mass spectrometry imaging (MSI) of undecalcified bone cryosections to characterize in situ metabolic changes in bones of Hyp mice in a holistic, unbiased manner. We found complex changes in Hyp bone metabolism, including perturbations in pentose phosphate, purine, pyrimidine, and phospholipid metabolism. Importantly, our study identified an upregulation of several biochemical pathways involved in intra- and extracellular production of the mineralization inhibitor pyrophosphate in the bone matrix of Hyp mice. Our data emphasize the utility of MSI-based spatial metabolomics in bone research and provide holistic in situ insights as to how Phex deficiency-induced changes in biochemical pathways in bone cells are linked to impaired bone mineralization.
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Affiliation(s)
- Achim Buck
- Research Unit Analytical Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Verena M. Prade
- Research Unit Analytical Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Thomas Kunzke
- Research Unit Analytical Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Reinhold G. Erben
- Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Axel Walch
- Research Unit Analytical Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
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16
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Wen X, Hu G, Xiao X, Zhang X, Zhang Q, Guo H, Li X, Liu Q, Li H. FGF2 positively regulates osteoclastogenesis via activating the ERK-CREB pathway. Arch Biochem Biophys 2022; 727:109348. [PMID: 35835230 DOI: 10.1016/j.abb.2022.109348] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 06/17/2022] [Accepted: 07/03/2022] [Indexed: 11/02/2022]
Abstract
Fibroblast growth factor 2 (FGF2) plays crucial roles in the growth and development of several tissues. However, its function in bone homeostasis remains controversial. Here, we found that exogenous FGF2 supplementation inhibited the mineralization of bone marrow stromal cells (BMSCs), at least partially, via up-regulating the gene expression of osteoclastogenesis. The FGF receptor (FGFR) allosteric antagonist SSR128129E modestly, whereas the FGFR tyrosine kinase inhibitor AZD4547 significantly antagonized the effects of FGF2. Mechanistically, FGF2 stimulated ERK phosphorylation, and the ERK signaling inhibitor PD325901 strongly blocked FGF2 enhancement of osteoclastogenesis. Moreover, the phosphorylation of CREB was also activated in response to FGF2, thereby potentiating the interaction of p-CREB with the promoter region of Rankl gene. Notably, FGF2-deficient BMSCs exhibited higher mineralization capability and lower osteoclastogenic gene expression. Correspondingly, FGF2-knockout mice showed increased bone mass and attenuated expression of osteoclast-related markers, which were associated with moderate inhibition of the ERK signaling. In conclusion, FGF2 positively regulates osteoclastogenesis via stimulating the ERK-CREB pathway. These findings establish the importance of FGF2 in bone homeostasis, hinting the potential use of FGF2/ERK/CREB specific inhibitors to fight against bone-related disorders, such as osteoporosis.
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Affiliation(s)
- Xin Wen
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Geng Hu
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, 271018, China
| | - Xue Xiao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Xinzhi Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Qiang Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Hengjun Guo
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Xianyao Li
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, 271018, China
| | - Qingxin Liu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China.
| | - Haifang Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China.
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17
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Fratzl-Zelman N, Hartmann MA, Gamsjaeger S, Rokidi S, Paschalis EP, Blouin S, Zwerina J. Bone Matrix Mineralization and Response to Burosumab in Adult Patients With X-Linked Hypophosphatemia: Results From the Phase 3, Single-Arm International Trial. J Bone Miner Res 2022; 37:1665-1678. [PMID: 35775373 DOI: 10.1002/jbmr.4641] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/20/2022] [Accepted: 06/25/2022] [Indexed: 11/06/2022]
Abstract
X-linked hypophosphatemia (XLH) is characterized by excess fibroblast growth factor 23 (FGF23) secretion, renal phosphate wasting, and low 1,25(OH)2 D3 . Adult patients present with osteomalacia, hypomineralized periosteocytic lesions, bone fragility, and pain. Burosumab is a fully human monoclonal FGF23 antibody approved for XLH treatment. UX023-CL304 was an open-label, phase 3 study investigating the effects of burosumab on osteomalacia in adults with XLH, who remained untreated at least 2 years prior enrollment. Here, we present the effect of burosumab on bone material properties. We analyzed transiliac bone biopsy samples from 11 individuals before and after 48 weeks of subcutaneous burosumab treatment (1.0 mg/kg administered every 4 weeks). We used quantitative backscattered electron imaging (qBEI) and Fourier transform infrared imaging (FTIRI) to assess bone mineralization density distribution (BMDD), mineralized bone volume, properties of the organic matrix, and size of periosteocytic lesions. The outcomes were compared with reference values from healthy adults and with four XLH patients either untreated or treated by conventional therapy. Prior to burosumab, the average mineralization in cancellous bone was lower than in healthy reference. CaLow, the fraction of lowly mineralized matrix, and CaHigh, the fraction of highly mineralized matrix, were both elevated resulting in a broad heterogeneity in mineralization (CaWidth). Burosumab resulted in a decrease of CaHigh toward normal range, whereas CaLow and CaWidth remained elevated. The mineralized bone volume was notably increased (+35.9%). The size of the periosteocytic lesions was variable but lower than in untreated XLH patients. FTIRI indicated decreased enzymatic collagen crosslink ratio heterogeneity. In summary, matrix mineralization in XLH is very heterogeneous. Highly mineralized regions represent old bone packets, probably protected from osteoclastic resorption by osteoid seams. The concomitant decrease of highly mineralized matrix, persistence of lowly mineralized matrix, and increase in mineralized bone volume after burosumab suggest a boost in mineralization of preexisting unmineralized or very lowly mineralized matrix, providing a potential explanation for previously observed improved osteomalacia. © 2022 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Nadja Fratzl-Zelman
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Med Department Hanusch Hospital, Vienna, Austria.,Vienna Bone and Growth Center, Vienna, Austria
| | - Markus A Hartmann
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Med Department Hanusch Hospital, Vienna, Austria.,Vienna Bone and Growth Center, Vienna, Austria
| | - Sonja Gamsjaeger
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Med Department Hanusch Hospital, Vienna, Austria
| | - Stamatia Rokidi
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Med Department Hanusch Hospital, Vienna, Austria
| | - Eleftherios P Paschalis
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Med Department Hanusch Hospital, Vienna, Austria.,Vienna Bone and Growth Center, Vienna, Austria
| | - Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Med Department Hanusch Hospital, Vienna, Austria.,Vienna Bone and Growth Center, Vienna, Austria
| | - Jochen Zwerina
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Med Department Hanusch Hospital, Vienna, Austria.,Vienna Bone and Growth Center, Vienna, Austria
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18
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Jurca CM, Iuhas O, Kozma K, Petchesi CD, Zaha DC, Bembea M, Jurca S, Paul C, Jurca AD. Effects of Burosumab Treatment on Two Siblings with X-Linked Hypophosphatemia. Case Report and Literature Review. Genes (Basel) 2022; 13:genes13081392. [PMID: 36011303 PMCID: PMC9407333 DOI: 10.3390/genes13081392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/01/2022] [Accepted: 08/03/2022] [Indexed: 11/16/2022] Open
Abstract
X-linked hypophosphatemia (XLH) or vitamin D-resistant rickets (MIM#307800), is a monogenic disorder with X-linked inheritance. It is caused by mutations present in the Phosphate Regulating Endopeptidase Homolog X-Linked (PHEX) gene responsible for the degradation of the bone-derived hormone fibroblast growth factor 23 (FGF23) into inactive fragments, but the entire mechanism is currently unclear. The inactivation of the gene prevents the degradation of FGF23, causing increased levels of FGF23, which leads to decreased tubular reabsorbtion of phosphorus. Clinical aspects are growth delay, limb deformities, bone pain, osteomalacia, dental anomalies, and enthesopathy. Laboratory evaluation shows hypophosphatemia, elevated alkaline phosphatase (ALP), and normal serum calcium levels, whereas parathormone (PTH) may be normal or increased and FGF23 greatly increased. Conventional treatment consists of administration of oral phosphate and calcitriol. Treatment with Burosumab, a monoclonal antibody that binds to FGF23, reducing its activity, was approved in 2018. Methods. We describe a case of two siblings, a girl and a boy, diagnosed with XLH, monitored by the Genetic Department of the County Emergency Clinical Hospital since 2019. The clinical picture is suggestive for XLH, both siblings exhibiting short stature, lower limb curvature, bone pain, marked walking weakness, and fatigue. Radiological aspects showed marked deformity of the lower limbs: genu varum in the girl, genu varum and valgum in the boy. Laboratory investigations showed hypophosphathemia, hyperphosphaturia, elevated ALP, normal PTH, and highly increased FGF23 in both. DNA analysis performed on the two siblings revealed a nonsense mutation in exone 5 of the PHEX gene: NM_000444.6(PHEX):c.565C > T (p.Gln189Ter). Results. At the age of 13½ on 7 June 2021, the two children started treatment with Burosumab in therapeutic doses and were monitored clinically and biochemically at regular intervals according to the protocol established by the Endocrinology Commission of the Romanian Health Ministry. Conclusions. The first results of the Burosumab treatment in the two siblings are extremely encouraging and suggest a favorable long-term evolution under this treatment.
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Affiliation(s)
- Claudia Maria Jurca
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
- Regional Center of Medical Genetics Bihor, County Emergency Clinical Hospital Oradea, Romania, (Part of ERN THACA), 410469 Oradea, Romania
| | - Oana Iuhas
- Regional Center of Medical Genetics Bihor, County Emergency Clinical Hospital Oradea, Romania, (Part of ERN THACA), 410469 Oradea, Romania
| | - Kinga Kozma
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
- Regional Center of Medical Genetics Bihor, County Emergency Clinical Hospital Oradea, Romania, (Part of ERN THACA), 410469 Oradea, Romania
| | - Codruta Diana Petchesi
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
- Correspondence:
| | - Dana Carmen Zaha
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
| | - Marius Bembea
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
| | - Sanziana Jurca
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
| | - Corina Paul
- Department of Pediatrics, Victor Babes University of Medicine and Pharmacy, 300041 Timisoara, Romania
| | - Alexandru Daniel Jurca
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
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19
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El Hakam C, Parenté A, Baraige F, Magnol L, Forestier L, Di Meo F, Blanquet V. PHEX L222P Mutation Increases Phex Expression in a New ENU Mouse Model for XLH Disease. Genes (Basel) 2022; 13:1356. [PMID: 36011266 PMCID: PMC9407253 DOI: 10.3390/genes13081356] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/26/2022] [Accepted: 07/26/2022] [Indexed: 02/02/2023] Open
Abstract
PhexL222P mouse is a new ENU mouse model for XLH disease due to Leu to Pro amino acid modification at position 222. PhexL222P mouse is characterized by growth retardation, hypophosphatemia, hypocalcemia, reduced body bone length, and increased epiphyseal growth plate thickness and femur diameter despite the increase in PHEXL222P expression. Actually, PhexL222P mice show an increase in Fgf23, Dmp1, and Mepe and Slc34a1 (Na-Pi IIa cotransporter) mRNA expression similar to those observed in Hyp mice. Femoral osteocalcin and sclerostin and Slc34a1 do not show any significant variation in PhexL222P mice. Molecular dynamics simulations support the experimental data. P222 might locally break the E217-Q224 β-sheet, which in turn might disrupt inter-β-sheet interactions. We can thus expect local protein misfolding, which might be responsible for the experimentally observed PHEXL222P loss of function. This model could be a valuable addition to the existing XLH model for further comprehension of the disease occurrence and testing of new therapies.
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Affiliation(s)
- Carole El Hakam
- INSERM U1094, INRAE USC1501, IRD U270, EpiMaCT-Epidemiology of Chronic Diseases in Tropical Zone, Univ. Limoges, 2 Rue Pr Descottes, F-87000 Limoges, France; (C.E.H.); (A.P.); (F.B.); (L.M.); (L.F.)
| | - Alexis Parenté
- INSERM U1094, INRAE USC1501, IRD U270, EpiMaCT-Epidemiology of Chronic Diseases in Tropical Zone, Univ. Limoges, 2 Rue Pr Descottes, F-87000 Limoges, France; (C.E.H.); (A.P.); (F.B.); (L.M.); (L.F.)
| | - Fabienne Baraige
- INSERM U1094, INRAE USC1501, IRD U270, EpiMaCT-Epidemiology of Chronic Diseases in Tropical Zone, Univ. Limoges, 2 Rue Pr Descottes, F-87000 Limoges, France; (C.E.H.); (A.P.); (F.B.); (L.M.); (L.F.)
| | - Laetitia Magnol
- INSERM U1094, INRAE USC1501, IRD U270, EpiMaCT-Epidemiology of Chronic Diseases in Tropical Zone, Univ. Limoges, 2 Rue Pr Descottes, F-87000 Limoges, France; (C.E.H.); (A.P.); (F.B.); (L.M.); (L.F.)
| | - Lionel Forestier
- INSERM U1094, INRAE USC1501, IRD U270, EpiMaCT-Epidemiology of Chronic Diseases in Tropical Zone, Univ. Limoges, 2 Rue Pr Descottes, F-87000 Limoges, France; (C.E.H.); (A.P.); (F.B.); (L.M.); (L.F.)
| | - Florent Di Meo
- INSERM U1248 Pharmacology & Transplantation, Univ. Limoges, 2 Rue Pr Descottes, F-87000 Limoges, France;
| | - Véronique Blanquet
- INSERM U1094, INRAE USC1501, IRD U270, EpiMaCT-Epidemiology of Chronic Diseases in Tropical Zone, Univ. Limoges, 2 Rue Pr Descottes, F-87000 Limoges, France; (C.E.H.); (A.P.); (F.B.); (L.M.); (L.F.)
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Gadion M, Hervé A, Herrou J, Rothenbuhler A, Smail‐Faugeron V, Courson F, Linglart A, Chaussain C, Biosse Duplan M. Burosumab and dental abscesses in children with X‐Linked Hypophosphatemia. JBMR Plus 2022; 6:e10672. [DOI: 10.1002/jbm4.10672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 07/08/2022] [Accepted: 07/27/2022] [Indexed: 11/09/2022] Open
Affiliation(s)
- Margaux Gadion
- Université Paris Cité, Faculté de Santé (UFR Odontologie et UFR de médecine) Paris France
- AP‐HP, Reference center for rare diseases of the calcium and phosphate metabolism, OSCAR network, FHU DDS‐net, ERN BOND, Department of dental medicine, Bretonneau hospital Paris France
| | - Agathe Hervé
- Université Paris Cité, Faculté de Santé (UFR Odontologie et UFR de médecine) Paris France
- AP‐HP, Reference center for rare diseases of the calcium and phosphate metabolism, OSCAR network, FHU DDS‐net, ERN BOND, Department of dental medicine, Bretonneau hospital Paris France
| | - Julia Herrou
- Université Paris Cité, Faculté de Santé (UFR Odontologie et UFR de médecine) Paris France
- AP‐HP, Reference center for rare diseases of the calcium and phosphate metabolism, OSCAR network, ERN BOND, Department of rheumatology, Cochin hospital Paris France
| | - Anya Rothenbuhler
- AP‐HP, Reference center for rare diseases of the calcium and phosphate metabolism, OSCAR network, Endo‐ERN and ERN BOND, Department of endocrinology and diabetology for children, Bicêtre Paris Saclay hospital Le Kremlin Bicêtre France
| | - Violaine Smail‐Faugeron
- Université Paris Cité, Faculté de Santé (UFR Odontologie et UFR de médecine) Paris France
- AP‐HP, Reference center for rare diseases of the calcium and phosphate metabolism, OSCAR network, FHU DDS‐net, ERN BOND, Department of dental medicine, Bretonneau hospital Paris France
| | - Frédéric Courson
- Université Paris Cité, Faculté de Santé (UFR Odontologie et UFR de médecine) Paris France
- AP‐HP, Reference center for rare diseases of the calcium and phosphate metabolism, OSCAR network, FHU DDS‐net, ERN BOND, Department of dental medicine, Bretonneau hospital Paris France
| | - Agnès Linglart
- AP‐HP, Reference center for rare diseases of the calcium and phosphate metabolism, OSCAR network, Endo‐ERN and ERN BOND, Department of endocrinology and diabetology for children, Bicêtre Paris Saclay hospital Le Kremlin Bicêtre France
- Université Paris Saclay, INSERM UMR 1185 Physiologie et physiopathologie endocrinienne Le Kremlin Bicêtre France
| | - Catherine Chaussain
- Université Paris Cité, Faculté de Santé (UFR Odontologie et UFR de médecine) Paris France
- AP‐HP, Reference center for rare diseases of the calcium and phosphate metabolism, OSCAR network, FHU DDS‐net, ERN BOND, Department of dental medicine, Bretonneau hospital Paris France
- Université Paris Cité, Laboratory URP2496 Orofacial Pathologies, Imaging and Biotherapies Paris France
| | - Martin Biosse Duplan
- Université Paris Cité, Faculté de Santé (UFR Odontologie et UFR de médecine) Paris France
- AP‐HP, Reference center for rare diseases of the calcium and phosphate metabolism, OSCAR network, FHU DDS‐net, ERN BOND, Department of dental medicine, Bretonneau hospital Paris France
- Institut Imagine, INSERM 1163 Paris France
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21
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Dörr K, Hödlmoser S, Kammer M, Reindl-Schwaighofer R, Lorenz M, Reiskopf B, Jagoditsch R, Marculescu R, Oberbauer R. Bone Specific Alkaline Phosphatase and Serum Calcification Propensity Are Not Influenced by Etelcalcetide vs. Alfacalcidol Treatment, and Only Bone Specific Alkaline Phosphatase Is Correlated With Fibroblast Growth Factor 23: Sub-Analysis Results of the ETACAR-HD Study. Front Med (Lausanne) 2022; 9:948177. [PMID: 35872799 PMCID: PMC9299083 DOI: 10.3389/fmed.2022.948177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 06/20/2022] [Indexed: 11/13/2022] Open
Abstract
Secondary hyperparathyroidism in chronic kidney disease poses a major risk factor for vascular calcification and high bone turnover, leading to mineralization defects. The aim was to analyze the effect of active vitamin D and calcimimetic treatment on fibroblast growth factor 23 (FGF23), serum calcification propensity (T50), a surrogate marker of calcification stress and bone specific alkaline phosphatase (BAP) in hemodialysis. This is a subanalysis of a randomized trial comparing etelcalcetide vs. alfacalcidol in 62 hemodialysis patients for 1 year. We compared the change of BAP and serum calcification propensity between the two medications and assessed the influence of FGF23 change over time. We found no significant differences in the change of BAP or serum calcification propensity (T50) levels from baseline to study end between treatment arms (difference in change of marker between treatment with etelcalcetide vs. alfacalcidol: BAP : 2.0 ng/ml [95% CI-1.5,5.4], p = 0.3; T50: –15 min [95% CI –49,19], p = 0.4). Using FGF23 change over time, we could show that BAP levels at study end were associated with FGF23 change (–0.14 [95% CI –0.21, –0.08], p < 0.001). We did not observe the same association between FGF23 change and T50 (effect of FGF23 change on T50: 3.7 [95% CI –5.1, 12], p = 0.4; R2 = 0.07 vs. R2 = 0.06). No significant difference was found in serum calcification propensity (T50) values between treatment arms. FGF23 was not associated with serum calcification propensity (T50), but was negatively correlated with BAP underlying its role in the bone metabolism.Clinical Trial Registration[www.ClinicalTrials.gov], identifier [NCT03182699].
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Affiliation(s)
- Katharina Dörr
- Department of Nephrology, Medical University of Vienna, Vienna, Austria
| | | | - Michael Kammer
- Department of Nephrology, Medical University of Vienna, Vienna, Austria
- Section for Clinical Biometrics, Center for Medical Statistics, Informatics and Intelligent Systems (CeMSIIS), Medical University of Vienna, Vienna, Austria
| | | | | | - Bianca Reiskopf
- Department of Nephrology, Medical University of Vienna, Vienna, Austria
| | - Rahel Jagoditsch
- Department of Nephrology, Medical University of Vienna, Vienna, Austria
| | - Rodrig Marculescu
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Rainer Oberbauer
- Department of Nephrology, Medical University of Vienna, Vienna, Austria
- *Correspondence: Rainer Oberbauer,
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Function of PHEX mutations p.Glu145* and p.Trp749Arg in families with X-linked hypophosphatemic rickets by the negative regulation mechanism on FGF23 promoter transcription. Cell Death Dis 2022; 13:518. [PMID: 35654784 PMCID: PMC9163062 DOI: 10.1038/s41419-022-04969-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 01/21/2023]
Abstract
X-linked hypophosphatemic rickets (XLH) is characterized by increased circulating fibroblast growth factor 23 (FGF23) concentration caused by PHEX (NM_000444.5) mutations. Renal tubular resorption of phosphate is impaired, resulting in rickets and impaired bone mineralization. By phenotypic-genetic linkage analysis, two PHEX pathogenic mutations were found in two XLH families: c.433 G > T, p.Glu145* in exon 4 and c.2245 T > C, p.Trp749Arg in exon 22. Immunofluorescence showed that the localization of p.Glu145* and p.Trp749Arg mutant and secretory PHEX (secPHEX) changed, with decreased expression. In a HEK293T cell model co-transfected with PHEX, secPHEX, and FGF23, wild-type PHEX, secPHEX, and FGF23 proteins were distributed in the cell membrane or endoplasmic reticulum, while the mutant was located in the nuclear membrane and cytoplasm. qPCR of p.Glu145* revealed decreased PHEX and secPHEX mRNA expression in cells, with no difference in mRNA expression of p.Trp749Arg. Both mutations decreased intracellular PHEX endopeptidase activity. Western blot analysis showed decrease in mutant and secPHEX protein expression and no FGF23 protein expression in single-transfected PHEX and secPHEX cells. In cells co-transfected with FGF23, PHEX and secPHEX mutation promoted FGF23 expression. Dual-luciferase reporter gene was used to detect the effect of PHEX on FGF23 promoter. The dual-luciferase reporter gene showed that after PHEX overexpression, the activity of mutant firefly luciferase was significantly higher than that of wild type. The regulatory mechanism between PHEX and FGF23 is still unclear, but we found that PHEX is a direct transcriptional inhibitor of FGF23 and affects the expression of FGF23. This study verified the pathogenicity of the two variants and revealed the possible regulatory mechanism between PHEX and FGF23.
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23
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Gupta M, Orozco G, Rao M, Gedaly R, Malluche HH, Neyra JA. The Role of Alterations in Alpha-Klotho and FGF-23 in Kidney Transplantation and Kidney Donation. Front Med (Lausanne) 2022; 9:803016. [PMID: 35602513 PMCID: PMC9121872 DOI: 10.3389/fmed.2022.803016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 02/03/2022] [Indexed: 12/12/2022] Open
Abstract
Cardiovascular disease and mineral bone disorders are major contributors to morbidity and mortality among patients with chronic kidney disease and often persist after renal transplantation. Ongoing hormonal imbalances after kidney transplant (KT) are associated with loss of graft function and poor outcomes. Fibroblast growth factor 23 (FGF-23) and its co-receptor, α-Klotho, are key factors in the underlying mechanisms that integrate accelerated atherosclerosis, vascular calcification, mineral disorders, and osteodystrophy. On the other hand, kidney donation is also associated with endocrine and metabolic adaptations that include transient increases in circulating FGF-23 and decreases in α-Klotho levels. However, the long-term impact of these alterations and their clinical relevance have not yet been determined. This manuscript aims to review and summarize current data on the role of FGF-23 and α-Klotho in the endocrine response to KT and living kidney donation, and importantly, underscore specific areas of research that may enhance diagnostics and therapeutics in the growing population of KT recipients and kidney donors.
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Affiliation(s)
- Meera Gupta
- Department of Surgery - Transplant Division, University of Kentucky, College of Medicine, Lexington, KY, United States
- Department of Surgery, University of Kentucky, Lexington, KY, United States
- *Correspondence: Meera Gupta
| | - Gabriel Orozco
- Department of Surgery - Transplant Division, University of Kentucky, College of Medicine, Lexington, KY, United States
- Department of Surgery, University of Kentucky, Lexington, KY, United States
| | - Madhumati Rao
- Department of Internal Medicine - Nephrology, Bone and Mineral Metabolism Division, University of Kentucky, College of Medicine, Lexington, KY, United States
| | - Roberto Gedaly
- Department of Surgery - Transplant Division, University of Kentucky, College of Medicine, Lexington, KY, United States
- Department of Surgery, University of Kentucky, Lexington, KY, United States
| | - Hartmut H. Malluche
- Department of Internal Medicine - Nephrology, Bone and Mineral Metabolism Division, University of Kentucky, College of Medicine, Lexington, KY, United States
| | - Javier A. Neyra
- Department of Internal Medicine - Nephrology, Bone and Mineral Metabolism Division, University of Kentucky, College of Medicine, Lexington, KY, United States
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Javier A. Neyra
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24
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Nam HK, Emmanouil E, Hatch NE. Deletion of the Pyrophosphate Generating Enzyme ENPP1 Rescues Craniofacial Abnormalities in the TNAP−/− Mouse Model of Hypophosphatasia and Reveals FGF23 as a Marker of Phenotype Severity. FRONTIERS IN DENTAL MEDICINE 2022; 3. [PMID: 35909501 PMCID: PMC9336114 DOI: 10.3389/fdmed.2022.846962] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Hypophosphatasia is a rare heritable metabolic disorder caused by deficient Tissue Non-specific Alkaline Phosphatase (TNAP) enzyme activity. A principal function of TNAP is to hydrolyze the tissue mineralization inhibitor pyrophosphate. ENPP1 (Ectonucleotide Pyrophosphatase/Phosphodiesterase 1) is a primary enzymatic generator of pyrophosphate and prior results showed that elimination of ENPP1 rescued bone hypomineralization of skull, vertebral and long bones to different extents in TNAP null mice. Current TNAP enzyme replacement therapy alleviates skeletal, motor and cognitive defects but does not eliminate craniosynostosis in pediatric hypophosphatasia patients. To further understand mechanisms underlying craniosynostosis development in hypophosphatasia, here we sought to determine if craniofacial abnormalities including craniosynostosis and skull shape defects would be alleviated in TNAP null mice by genetic ablation of ENPP1. Results show that homozygous deletion of ENPP1 significantly diminishes the incidence of craniosynostosis and that skull shape abnormalities are rescued by hemi- or homozygous deletion of ENPP1 in TNAP null mice. Skull and long bone hypomineralization were also alleviated in TNAP−/−/ENPP1−/− compared to TNAP−/−/ENPP1+/+ mice, though loss of ENPP1 in combination with TNAP had different effects than loss of only TNAP on long bone trabeculae. Investigation of a relatively large cohort of mice revealed that the skeletal phenotypes of TNAP null mice were markedly variable. Because FGF23 circulating levels are known to be increased in ENPP1 null mice and because FGF23 influences bone, we measured serum intact FGF23 levels in the TNAP null mice and found that a subset of TNAP−/−/ENPP1+/+ mice exhibited markedly high serum FGF23. Serum FGF23 levels also correlated to mouse body measurements, the incidence of craniosynostosis, skull shape abnormalities and skull bone density and volume fraction. Together, our results demonstrate that balanced expression of TNAP and ENPP1 enzymes are essential for microstructure and mineralization of both skull and long bones, and for preventing craniosynostosis. The results also show that FGF23 rises in the TNAP−/− model of murine lethal hypophosphatasia. Future studies are required to determine if the rise in FGF23 is a cause, consequence, or marker of disease phenotype severity.
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Sasaki S, Shiozaki Y, Hanazaki A, Koike M, Tanifuji K, Uga M, Kawahara K, Kaneko I, Kawamoto Y, Wiriyasermkul P, Hasegawa T, Amizuka N, Miyamoto KI, Nagamori S, Kanai Y, Segawa H. Tmem174, a regulator of phosphate transporter prevents hyperphosphatemia. Sci Rep 2022; 12:6353. [PMID: 35428804 PMCID: PMC9012787 DOI: 10.1038/s41598-022-10409-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 04/05/2022] [Indexed: 11/23/2022] Open
Abstract
Renal type II sodium-dependent inorganic phosphate (Pi) transporters NaPi2a and NaPi2c cooperate with other organs to strictly regulate the plasma Pi concentration. A high Pi load induces expression and secretion of the phosphaturic hormones parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) that enhance urinary Pi excretion and prevent the onset of hyperphosphatemia. How FGF23 secretion from bone is increased by a high Pi load and the setpoint of the plasma Pi concentration, however, are unclear. Here, we investigated the role of Transmembrane protein 174 (Tmem174) and observed evidence for gene co-expression networks in NaPi2a and NaPi2c function. Tmem174 is localized in the renal proximal tubules and interacts with NaPi2a, but not NaPi2c. In Tmem174-knockout (KO) mice, the serum FGF23 concentration was markedly increased but increased Pi excretion and hypophosphatemia were not observed. In addition, Tmem174-KO mice exhibit reduced NaPi2a responsiveness to FGF23 and PTH administration. Furthermore, a dietary Pi load causes marked hyperphosphatemia and abnormal NaPi2a regulation in Tmem174-KO mice. Thus, Tmem174 is thought to be associated with FGF23 induction in bones and the regulation of NaPi2a to prevent an increase in the plasma Pi concentration due to a high Pi load and kidney injury.
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Affiliation(s)
- Sumire Sasaki
- Department of Applied Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Yuji Shiozaki
- Department of Applied Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Ai Hanazaki
- Department of Applied Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Megumi Koike
- Department of Applied Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Kazuya Tanifuji
- Department of Applied Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Minori Uga
- Department of Applied Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Kota Kawahara
- Department of Applied Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Ichiro Kaneko
- Department of Applied Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Yasuharu Kawamoto
- Department of Bio-System Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Pattama Wiriyasermkul
- Department of Laboratory Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Tomoka Hasegawa
- Developmental Biology of Hard Tissue, Faculty of Dental Medicine, Hokkaido University, Sapporo, Japan
| | - Norio Amizuka
- Developmental Biology of Hard Tissue, Faculty of Dental Medicine, Hokkaido University, Sapporo, Japan
| | - Ken-Ichi Miyamoto
- Department of Applied Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.,Graduate School of Agriculture, Ryukoku University, Ohtsu, Japan
| | - Shushi Nagamori
- Department of Laboratory Medicine, The Jikei University School of Medicine, Tokyo, Japan.
| | - Yoshikatsu Kanai
- Department of Bio-System Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan.
| | - Hiroko Segawa
- Department of Applied Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
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Choi JUA, Kijas AW, Lauko J, Rowan AE. The Mechanosensory Role of Osteocytes and Implications for Bone Health and Disease States. Front Cell Dev Biol 2022; 9:770143. [PMID: 35265628 PMCID: PMC8900535 DOI: 10.3389/fcell.2021.770143] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/13/2021] [Indexed: 12/14/2022] Open
Abstract
Bone homeostasis is a dynamic equilibrium between bone-forming osteoblasts and bone-resorbing osteoclasts. This process is primarily controlled by the most abundant and mechanosensitive bone cells, osteocytes, that reside individually, within chambers of porous hydroxyapatite bone matrix. Recent studies have unveiled additional functional roles for osteocytes in directly contributing to local matrix regulation as well as systemic roles through endocrine functions by communicating with distant organs such as the kidney. Osteocyte function is governed largely by both biochemical signaling and the mechanical stimuli exerted on bone. Mechanical stimulation is required to maintain bone health whilst aging and reduced level of loading are known to result in bone loss. To date, both in vivo and in vitro approaches have been established to answer important questions such as the effect of mechanical stimuli, the mechanosensors involved, and the mechanosensitive signaling pathways in osteocytes. However, our understanding of osteocyte mechanotransduction has been limited due to the technical challenges of working with these cells since they are individually embedded within the hard hydroxyapatite bone matrix. This review highlights the current knowledge of the osteocyte functional role in maintaining bone health and the key regulatory pathways of these mechanosensitive cells. Finally, we elaborate on the current therapeutic opportunities offered by existing treatments and the potential for targeting osteocyte-directed signaling.
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Affiliation(s)
- Jung Un Ally Choi
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Amanda W Kijas
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Jan Lauko
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Alan E Rowan
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
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27
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Yang Y, Wang Y, Shen Y, Liu M, Dai S, Wang X, Liu H. Identification of a Novel Missense Mutation of the PHEX Gene in a Large Chinese Family with X-Linked Hypophosphataemia. Front Genet 2022; 13:792183. [PMID: 35251124 PMCID: PMC8891598 DOI: 10.3389/fgene.2022.792183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 01/18/2022] [Indexed: 11/13/2022] Open
Abstract
X-linked hypophosphataemia (XLH) is an X-linked dominant rare disease that refers to the most common hereditary hypophosphatemia (HH) caused by mutations in the phosphate-regulating endopeptidase homolog X-linked gene (PHEX; OMIM: * 300550). However, mutations that have already been reported cannot account for all cases of XLH. Extensive genetic analysis can thus be helpful for arriving at the diagnosis of XLH. Herein, we identified a novel heterozygous mutation of PHEX (NM_000444.5: c.1768G > A) in a large Chinese family with XLH by whole-exome sequencing (WES). In addition, the negative effect of this mutation in PHEX was confirmed by both bioinformatics analysis and in vitro experimentation. The three-dimensional protein-model analysis predicted that this mutation might impair normal zinc binding. Immunofluorescence staining, qPCR, and western blotting analysis confirmed that the mutation we detected attenuated PHEX protein expression. The heterozygous mutation of PHEX (NM_000444.5: c.1768G > A) identified in this study by genetic and functional experiments constitutes a novel genetic cause of XLH, but further study will be required to expand its use in clinical and molecular diagnoses of XLH.
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Affiliation(s)
- Yanting Yang
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Medical Genetics Department/Prenatal Diagnostic Center, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, China
| | - Yuanda Wang
- State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Ying Shen
- Department of Obstetrics/Gynecology, Joint Laboratory of Reproductive Medicine (SCU-CUHK), Key Laboratory of Obstetric, Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Mohan Liu
- State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Siyu Dai
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Medical Genetics Department/Prenatal Diagnostic Center, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, China
| | - Xiaodong Wang
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, China
- *Correspondence: Xiaodong Wang, ; Hongqian Liu,
| | - Hongqian Liu
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Medical Genetics Department/Prenatal Diagnostic Center, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, China
- *Correspondence: Xiaodong Wang, ; Hongqian Liu,
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28
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Fuente R, García-Bengoa M, Fernández-Iglesias Á, Gil-Peña H, Santos F, López JM. Cellular and Molecular Alterations Underlying Abnormal Bone Growth in X-Linked Hypophosphatemia. Int J Mol Sci 2022; 23:ijms23020934. [PMID: 35055123 PMCID: PMC8778463 DOI: 10.3390/ijms23020934] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 12/21/2022] Open
Abstract
X-linked hypophosphatemia (XLH), the most common form of hereditary hypophosphatemic rickets, is caused by inactivating mutations of the phosphate-regulating endopeptidase gene (PHEX). XLH is mainly characterized by short stature, bone deformities and rickets, while in hypophosphatemia, normal or low vitamin D levels and low renal phosphate reabsorption are the principal biochemical aspects. The cause of growth impairment in patients with XLH is not completely understood yet, thus making the study of the growth plate (GP) alterations necessary. New treatment strategies targeting FGF23 have shown promising results in normalizing the growth velocity and improving the skeletal effects of XLH patients. However, further studies are necessary to evaluate how this treatment affects the GP as well as its long-term effects and the impact on adult height.
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Affiliation(s)
- Rocío Fuente
- Division of Pediatrics, Department of Medicine, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain; (R.F.); (M.G.-B.); (Á.F.-I.); (H.G.-P.); (F.S.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Institute of Physiology, Center for Integrative Human Physiology (ZIHP), University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - María García-Bengoa
- Division of Pediatrics, Department of Medicine, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain; (R.F.); (M.G.-B.); (Á.F.-I.); (H.G.-P.); (F.S.)
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, 30559 Hanover, Germany
| | - Ángela Fernández-Iglesias
- Division of Pediatrics, Department of Medicine, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain; (R.F.); (M.G.-B.); (Á.F.-I.); (H.G.-P.); (F.S.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
| | - Helena Gil-Peña
- Division of Pediatrics, Department of Medicine, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain; (R.F.); (M.G.-B.); (Á.F.-I.); (H.G.-P.); (F.S.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Department of Pediatrics, Hospital Universitario Central de Asturias (HUCA), 33011 Oviedo, Spain
| | - Fernando Santos
- Division of Pediatrics, Department of Medicine, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain; (R.F.); (M.G.-B.); (Á.F.-I.); (H.G.-P.); (F.S.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Department of Pediatrics, Hospital Universitario Central de Asturias (HUCA), 33011 Oviedo, Spain
| | - José Manuel López
- Department of Morphology and Cellular Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
- Correspondence:
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Sharma S, Porwal K, Kulkarni C, Pal S, Kumar S, Sihota P, Tiwari MC, Katekar R, Kumar A, Rajput S, Singh P, Guha R, Kumar N, Gayen JR, Chattopadhyay N. Diosmin, a citrus fruit-derived phlebotonic bioflavonoid protects rats from chronic kidney disease-induced loss of bone mass and strength without deteriorating renal function. Food Funct 2022; 13:2184-2199. [DOI: 10.1039/d1fo03867b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Kidney Disease: Improving Global Outcomes (KDIGO) 2017 Clinical Practice Guideline recommended treatment decisions for patients with chronic kidney disease (CKD) with osteoporosis and/or high risk of fracture. Bisphosphonates, the first-line...
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Tripathi A, John AA, Kumar D, Kaushal SK, Singh DP, Husain N, Sarkar J, Singh D. MiR-539-3p impairs osteogenesis by suppressing Wnt interaction with LRP-6 co-receptor and subsequent inhibition of Akap-3 signaling pathway. Front Endocrinol (Lausanne) 2022; 13:977347. [PMID: 36267566 PMCID: PMC9577939 DOI: 10.3389/fendo.2022.977347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 09/07/2022] [Indexed: 11/21/2022] Open
Abstract
X-linked hypophosphatemia (XLH), an inheritable form of rickets is caused due to mutation in Phex gene. Several factors are linked to the disease's aetiology, including non-coding RNA molecules (miRNAs), which are key post-transcriptional regulators of gene expression and play a significant role in osteoblast functions. MicroRNAs sequence analysis showed differentially regulated miRNAs in phex silenced osteoblast cells. In this article, we report miR-539-3p, an unidentified novel miRNA, in the functional regulation of osteoblast. MiR-539-3p overexpression impaired osteoblast differentiation. Target prediction algorithm and experimental confirmation by luciferase 3' UTR reporter assay identified LRP-6 as a direct target of miR-539-3p. Over expression of miR-539-3p in osteoblasts down regulated Wnt/beta catenin signaling components and deteriorated trabecular microarchitecture leading to decreased bone formation in ovariectomized (Ovx) mice. Additionally, biochemical bone resorption markers like CTx and Trap-5b were elevated in serum samples of mimic treated group, while, reverse effect was observed in anti-miR treated animals along with increased bone formation marker P1NP. Moreover, transcriptome analysis with miR-539-3p identified a novel uncharacterized Akap-3 gene in osteoblast cells, knock down of which resulted in downregulation of osteoblast differentiation markers at both transcriptional and translational level. Overall, our study for the first time reported the role of miR-539-3p in osteoblast functions and its downstream Akap-3 signalling in regulation of osteoblastogenesis.
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Affiliation(s)
- Alok Tripathi
- Division of Endocrinology, Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow, India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad, Uttar Pradesh, India
| | - Aijaz A. John
- Division of Endocrinology, Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow, India
| | - Deepak Kumar
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad, Uttar Pradesh, India
- Division of Cancer Biology, Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow, India
| | - Saurabh Kumar Kaushal
- Division of Endocrinology, Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow, India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad, Uttar Pradesh, India
| | - Devendra Pratap Singh
- Division of Endocrinology, Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow, India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad, Uttar Pradesh, India
| | - Nazim Husain
- Division of Endocrinology, Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow, India
| | - Jayanta Sarkar
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad, Uttar Pradesh, India
- Division of Cancer Biology, Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow, India
| | - Divya Singh
- Division of Endocrinology, Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow, India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad, Uttar Pradesh, India
- *Correspondence: Divya Singh,
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Delsmann MM, Peichl J, Yorgan TA, Beil FT, Amling M, Demay MB, Rolvien T. Prevention of Hypomineralization In Auditory Ossicles of Vitamin D Receptor (Vdr) Deficient Mice. Front Endocrinol (Lausanne) 2022; 13:901265. [PMID: 35733772 PMCID: PMC9207527 DOI: 10.3389/fendo.2022.901265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 04/21/2022] [Indexed: 11/20/2022] Open
Abstract
Intact mineralization of the auditory ossicles - the smallest bones in the body - is essential for sound transmission in the middle ear, while ossicular hypomineralization is associated with conductive hearing loss. Here, we performed a high-resolution analysis of the ossicles in vitamin D receptor deficient mice (Vdr-/- ), which are characterized by hypocalcemia and skeletal mineralization defects, and investigated whether local hypomineralization can be prevented by feeding a calcium-rich rescue diet (Vdr-/- res ). In Vdr-/- mice fed a regular diet (Vdr-/- reg ), quantitative backscattered electron imaging (qBEI) revealed an increased void volume (porosity, p<0.0001) along with lower mean calcium content (CaMean, p=0.0008) and higher heterogeneity of mineralization (CaWidth, p=0.003) compared to WT mice. Furthermore, a higher osteoid volume per bone volume (OV/BV; p=0.0002) and a higher osteocyte lacunar area (Lc.Ar; p=0.01) were found in histomorphometric analysis in Vdr-/- reg mice. In Vdr-/- res mice, full rescue of OV/BV and Lc.Ar (both p>0.05 vs. WT) and partial rescue of porosity and CaWidth (p=0.02 and p=0.04 vs. WT) were observed. Compared with Hyp mice, a model of X-linked hypophosphatemic rickets, Vdr-/- reg mice showed a lower osteoid volume in the ossicles (p=0.0002), but similar values in the lumbar spine. These results are consistent with later postnatal impairment of mineral homeostasis in Vdr-/- mice than in Hyp mice, underscoring the importance of intact mineral homeostasis for ossicle mineralization during development. In conclusion, we revealed a distinct phenotype of hypomineralization in the auditory ossicles of Vdr-/- mice that can be partially prevented by a rescue diet. Since a positive effect of a calcium-rich diet on ossicular mineralization was demonstrated, our results open new treatment strategies for conductive hearing loss. Future studies should investigate the impact of improved ossicular mineralization on hearing function.
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Affiliation(s)
- Maximilian M. Delsmann
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Jonathan Peichl
- Department of Otorhinolaryngology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Timur A. Yorgan
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Frank Timo Beil
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Marie B. Demay
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Tim Rolvien
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- *Correspondence: Tim Rolvien,
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Brener R, Zeitlin L, Lebenthal Y, Brener A. Dental health of pediatric patients with X-linked hypophosphatemia (XLH) after three years of burosumab therapy. Front Endocrinol (Lausanne) 2022; 13:947814. [PMID: 36051396 PMCID: PMC9425915 DOI: 10.3389/fendo.2022.947814] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
An inactivating PHEX gene mutation with the resultant accumulation of several mineralization-inhibiting proteins (e.g., FGF23) causes skeletal and dental morbidity in X-linked hypophosphatemia (XLH). This prospective case-control study explored the effect of burosumab, an anti-FGF23 antibody, on dental health of children with XLH. Ten children (age 4.3-15 years) with XLH underwent burosumab treatment per protocol. Assessment of their dental status at treatment initiation and after 1 and 3 years of treatment included clinical, laboratory and radiographic evaluation of rickets and dentition. Orthopantomographic examinations of ten healthy sex- and age-matched controls were selected for comparison. Coronal and pulp dimensions of a selected permanent mandibular molar were measured with Planmeca Romexis® software. One year of treatment led to improvement of height z-score (p=0.019) and healing of the rickets (p<0.001) in the XLH patients, and those achievements were maintained after three years of treatment. Dental morphology of XLH patients, distinguished by increased pulp-coronal ratios compared to controls (p=0.002), remained larger after the first year of treatment (p<0.001) and did not attain the decrease expected with age after three years of treatment. Five patients had a history of recurrent dental abscesses, with three having undergone at least one episode during the year before burosumab initiation. One patient sustained recurrent abscesses throughout three years of treatment. The persistence of the unique dental morphology of XLH patients undergoing burosumab therapy, as evidenced by excessively larger pulp dimensions, supports the role of other PHEX gene-related local mineralization inhibitors, such as osteopontin, in the pathogenesis of dental morbidity.
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Affiliation(s)
- Rafi Brener
- The Endodontic Unit, Galilee College of Dental Sciences, Galilee Medical Center, Nahariya, Israel
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Leonid Zeitlin
- The Metabolic Bone Disease Unit, Dana-Dwek Children’s Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yael Lebenthal
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Pediatric Endocrinology and Diabetes Unit, Dana-Dwek Children’s Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Avivit Brener
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Pediatric Endocrinology and Diabetes Unit, Dana-Dwek Children’s Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- *Correspondence: Avivit Brener,
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Lafage-Proust MH. What are the benefits of the anti-FGF23 antibody burosumab on the manifestations of X-linked hypophosphatemia in adults in comparison with conventional therapy? A review. THERAPEUTIC ADVANCES IN RARE DISEASE 2022; 3:26330040221074702. [PMID: 37180412 PMCID: PMC10032432 DOI: 10.1177/26330040221074702] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 01/03/2022] [Indexed: 05/16/2023]
Abstract
X-linked hypophosphatemia (XLH) is a genetic disease mostly related to PHEX gene mutations which increases FGF23 serum levels, leading to hypophosphatemia and osteomalacia in adults, while affected children, in addition, develop rickets. Most of adults with XLH suffer from reduced quality of life and physical disability due to chronic bone and joint pain related to limb deformities, early osteoarthritis, delayed-healing of insufficiency fractures, and enthesopathies. Dental infections, muscle dysfunction, and deafness are also frequent. The current treatment consists of 2-5 times daily oral administration of phosphate combined to active vitamin D, often badly tolerated with immediate digestive side effects, responsible for poor compliance. In the long term, it may induce nephrocalcinosis and hyperparathyroidism. Burosumab, an anti-FGF23 blocking antibody, was approved for treating children with XLH in many countries. A randomized 24-week-long placebo-controlled trial, followed by an open-label period of equal duration was conducted in 134 XLH adults treated with 1 mg/kg burosumab/4 weeks. During burosumab treatment, 94% of the patients normalized serum phosphate values versus 7% in the placebo group. Fracture healing was increased 16.7 times compared with placebo-treated patients. All pain and disability tests improved significantly in a time-dependent manner. Burosumab for 48 weeks improved histological lesions of osteomalacia in a single-arm longitudinal study analyzing paired bone biopsies. Another single-arm, open-label study investigated the long-term safety and efficacy of burosumab in 20 adult patients followed for 3.2 years. Burosumab was beneficial on pain and disability scores and on bone remodeling markers. No major side effects especially no hyperphosphatemic episodes were reported. Overall, the benefit/risk ratio of burosumab is positive in adult patients with clinical and/or biological complications of XLH. Burosumab corrects hypophosphatemia, promotes fracture healing, and induces a modest but significant effect on XLH-induced subjective pain and disability symptoms. Plain language title and summary Effects of conventional treatment and burosumab in adults with X-linked hypophosphatemia.X-linked hypophosphatemia (XLH) is a disease of genetic origin that affects mineralized tissues (skeleton and teeth) and impairs muscle function. It induces a decrease in blood phosphate levels. This leads to under mineralization of bones and insufficiency fractures that heal slowly, associated with poor dental health characterized by spontaneous dental abscesses. Adults with XLH suffer from chronic pain and limb deformities that alter their quality of life. They are currently treated with daily administration of vitamin D and several daily doses of phosphate. This treatment may induce parathyroid gland dysfunction and mineral deposits in the kidney. If not tightly monitored, these side effects may lead to tertiary hyperparathyroidism and the need for parathyroid gland surgery, or to nephrocalcinosis which may proceed to chronic kidney disease. Burosumab is an antibody that blocks the action of FGF23 the factor that circulates in excess in blood and is responsible for phosphate renal leak in XLH. Three studies demonstrated that burosumab, injected every 4 weeks, is efficient and safe for treating adults with XLH.
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Delsmann MM, Seist R, Stürznickel J, Schmidt FN, Mansour A, Kobelski MM, Broocks G, Peichl J, Oheim R, Praetorius M, Schinke T, Amling M, Demay MB, Stankovic KM, Rolvien T. Conductive Hearing Loss in the Hyp Mouse Model of X-Linked Hypophosphatemia Is Accompanied by Hypomineralization of the Auditory Ossicles. J Bone Miner Res 2021; 36:2317-2328. [PMID: 34523743 PMCID: PMC8688200 DOI: 10.1002/jbmr.4443] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/27/2021] [Accepted: 09/13/2021] [Indexed: 01/10/2023]
Abstract
X-linked hypophosphatemia (XLH) is a hereditary musculoskeletal disorder caused by loss-of-function mutations in the PHEX gene. In XLH, increased circulating fibroblast growth factor 23 (FGF23) levels cause renal phosphate wasting and low concentrations of 1,25-dihydroxyvitamin D, leading to an early clinical manifestation of rickets. Importantly, hearing loss is commonly observed in XLH patients. We present here data from two XLH patients with marked conductive hearing loss. To decipher the underlying pathophysiology of hearing loss in XLH, we utilized the Hyp mouse model of XLH and measured auditory brain stem responses (ABRs) and distortion product otoacoustic emissions (DPOAEs) to functionally assess hearing. As evidenced by the increased ABR/DPOAE threshold shifts in the mid-frequency range, these measurements indicated a predominantly conductive hearing loss in Hyp mice compared to wild-type (WT) mice. Therefore, we carried out an in-depth histomorphometric and scanning electron microscopic analysis of the auditory ossicles. Quantitative backscattered electron imaging (qBEI) indicated a severe hypomineralization of the ossicles in Hyp mice, evidenced by lower calcium content (CaMean) and higher void volume (ie, porosity) compared to WT mice. Histologically, voids correlated with unmineralized bone (ie, osteoid), and the osteoid volume per bone volume (OV/BV) was markedly higher in Hyp mice than WT mice. The density of osteocyte lacunae was lower in Hyp mice than in WT mice, whereas osteocyte lacunae were enlarged. Taken together, our findings highlight the importance of ossicular mineralization for hearing conduction and point toward the potential benefit of improving mineralization to prevent hearing loss in XLH. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Maximilian M Delsmann
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany.,Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Richard Seist
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA.,Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Julian Stürznickel
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany.,Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Felix N Schmidt
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Amer Mansour
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA
| | - Margaret M Kobelski
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Gabriel Broocks
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jonathan Peichl
- Department of Otorhinolaryngology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ralf Oheim
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Mark Praetorius
- Department of Otorhinolaryngology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Marie B Demay
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Konstantina M Stankovic
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA.,Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Tim Rolvien
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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35
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Tang PK, Geddes RF, Jepson RE, Elliott J. A feline-focused review of chronic kidney disease-mineral and bone disorders - Part 1: Physiology of calcium handling. Vet J 2021; 275:105719. [PMID: 34311095 DOI: 10.1016/j.tvjl.2021.105719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 06/03/2021] [Accepted: 07/21/2021] [Indexed: 01/01/2023]
Abstract
Mineral derangements are a common consequence of chronic kidney disease (CKD). Despite the well-established role of phosphorus in the pathophysiology of CKD, the implications of calcium disturbances associated with CKD remain equivocal. Calcium plays an essential role in numerous physiological functions in the body and is a fundamental structural component of bone. An understanding of calcium metabolism is required to understand the potential adverse clinical implications and outcomes secondary to the (mal)adaptation of calcium-regulating hormones in CKD. The first part of this two-part review covers the physiology of calcium homeostasis (kidneys, intestines and bones) and details the intimate relationships between calcium-regulating hormones (parathyroid hormone, calcitriol, fibroblast growth factor 23, α-Klotho and calcitonin) and the role of the calcium-sensing receptor.
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Affiliation(s)
- Pak-Kan Tang
- Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, London, UK.
| | - Rebecca F Geddes
- Department of Clinical Science and Services, Royal Veterinary College, University of London, London, UK
| | - Rosanne E Jepson
- Department of Clinical Science and Services, Royal Veterinary College, University of London, London, UK
| | - Jonathan Elliott
- Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, London, UK
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Xiao Z, Liu J, Liu SH, Petridis L, Cai C, Cao L, Wang G, Chin AL, Cleveland JW, Ikedionwu MO, Carrick JD, Smith JC, Quarles LD. Novel Small Molecule Fibroblast Growth Factor 23 Inhibitors Increase Serum Phosphate and Improve Skeletal Abnormalities in Hyp Mice. Mol Pharmacol 2021; 101:408-421. [PMID: 35339985 PMCID: PMC11033927 DOI: 10.1124/molpharm.121.000471] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 03/20/2022] [Indexed: 11/22/2022] Open
Abstract
Excess fibroblast growth factor (FGF) 23 causes hereditary hypophosphatemic rickets, such as X-linked hypophosphatemia (XLH) and tumor-induced osteomalacia (TIO). A small molecule that specifically binds to FGF23 to prevent activation of the fibroblast growth factor receptor/α-Klotho complex has potential advantages over the currently approved systemically administered FGF23 blocking antibody. Using structure-based drug design, we previously identified ZINC13407541 (N-[[2-(2-phenylethenyl)cyclopenten-1-yl]methylidene]hydroxylamine) as a small molecule antagonist for FGF23. Additional structure-activity studies developed a series of ZINC13407541 analogs with enhanced drug-like properties. In this study, we tested in a preclinical Hyp mouse homolog of XLH a direct connect analog [(E)-2-(4-(tert-butyl)phenyl)cyclopent-1-ene-1-carbaldehyde oxime] (8n), which exhibited the greatest stability in microsomal assays, and [(E)-2-((E)-4-methylstyryl)benzaldehyde oxime] (13a), which exhibited increased in vitro potency. Using cryo-electron microscopy structure and computational docking, we identified a key binding residue (Q156) of the FGF23 antagonists, ZINC13407541, and its analogs (8n and 13a) in the N-terminal domain of FGF23 protein. Site-directed mutagenesis and bimolecular fluorescence complementation-fluorescence resonance energy transfer assay confirmed the binding site of these three antagonists. We found that pharmacological inhibition of FGF23 with either of these compounds blocked FGF23 signaling and increased serum phosphate and 1,25-dihydroxyvitamin D [1,25(OH)2D] concentrations in Hyp mice. Long-term parenteral treatment with 8n or 13a also enhanced linear bone growth, increased mineralization of bone, and narrowed the growth plate in Hyp mice. The more potent 13a compound had greater therapeutic effects in Hyp mice. Further optimization of these FGF23 inhibitors may lead to versatile drugs to treat excess FGF23-mediated disorders. SIGNIFICANCE STATEMENT: This study used structure-based drug design and medicinal chemistry approaches to identify and optimize small molecules with different stability and potency, which antagonize excessive actions of fibroblast growth factor 23 (FGF23) in hereditary hypophosphatemic rickets. The findings confirmed that these antagonists bind to the N-terminus of FGF23 to inhibit its binding to and activation of the fibroblast growth factor receptors/α-Klotho signaling complex. Administration of these lead compounds improved phosphate homeostasis and abnormal skeletal phenotypes in a preclinical Hyp mouse model.
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Affiliation(s)
- Zhousheng Xiao
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
| | - Jiawang Liu
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
| | - Shih-Hsien Liu
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
| | - Loukas Petridis
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
| | - Chun Cai
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
| | - Li Cao
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
| | - Guangwei Wang
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
| | - Ai Lin Chin
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
| | - Jacob W Cleveland
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
| | - Munachi O Ikedionwu
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
| | - Jesse D Carrick
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
| | - Jeremy C Smith
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
| | - Leigh Darryl Quarles
- Department of Medicine, College of Medicine (Z.X., C.C., L.C., G.W.W., L.D.Q.) and Department of Pharmaceutical Sciences, College of Pharmacy (J.L.), University of Tennessee Health Science Center, Memphis, Tennessee; University of Tennessee (UT)/Oak Ridge National Laboratory (ORNL) Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee (S.H.L., L.P., J.C.S.); Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee (L.P., J.C.S.); and Department of Chemistry, Tennessee Technological University, Cookeville, Tennessee (A.L.C., J.W.C., M.O.I., J.D.C.)
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González-Casaus ML, Gonzalez-Parra E, Fernandez-Calle P, Buño-Soto A. FGF23: From academic nephrology to personalized patients' care. Nefrologia 2021; 41:276-283. [PMID: 36166244 DOI: 10.1016/j.nefroe.2021.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 09/20/2020] [Indexed: 06/16/2023] Open
Abstract
Twenty years have passed since the identification of klotho and the fibroblast growth factor 23 (FGF23), the regulatory binomial of phosphate homeostasis. Being kidney the main source of klotho as well as a target organ in the phosphate regulation, most studies involving klotho and FGF23 had a "nephrocentric" focus. Considering that circulating FGF23 can reach exaggerated levels at the end stage of chronic kidney disease (CKD), the bias of this approach allowed to recognize the harmful "off target" klotho-independent effect of FGF23. All of these findings have caused a revolution on our previous knowledge about mineral homeostasis and currently, we are facing a new scenario in the clinical management of CKD, where FGF23 emerges simultaneously as an early biomarker of phosphate retention but also as a therapeutic target. In this review, we describe the disturbances of FGF23 in the CKD and we focus on how the maintenance of circulating FGF23 into a supraphysiological adaptive range from the initial stages of CKD and the control of "unlimited hyperphosphatonism" generated by the resistance to FGF23 action at end stages should emerge as new treatment paradigms in CKD-MBD. The recent development of an automated FGF23 assay, already validated for clinical use, should be the starting point to individualize all our knowledge from epidemiological studies and will allow us to use it properly for the patient's personalized care. Then, now we are in the momentum to assess the discriminating thresholds to distinguish the physiological adaptive FGF23 elevation related to each CKD stage from the exaggerated increase that would be interpreted as a poor regulatory compensation that will requires the adoption of therapeutic intervention.
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Biosse Duplan M, Dambroise E, Estibals V, Veziers J, Guicheux J, Legeai-Mallet L. An Fgfr3-activating mutation in immature murine osteoblasts affects the appendicular and craniofacial skeleton. Dis Model Mech 2021; 14:dmm048272. [PMID: 33737326 PMCID: PMC8084574 DOI: 10.1242/dmm.048272] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/03/2021] [Indexed: 12/17/2022] Open
Abstract
Achondroplasia (ACH), the most common form of dwarfism, is caused by a missense mutation in the gene coding for fibroblast growth factor receptor 3 (FGFR3). The resulting increase in FGFR3 signaling perturbs the proliferation and differentiation of chondrocytes (CCs), alters the process of endochondral ossification and thus reduces bone elongation. Increased FGFR3 signaling in osteoblasts (OBs) might also contribute to bone anomalies in ACH. In the present study of a mouse model of ACH, we sought to determine whether FGFR3 overactivation in OBs leads to bone modifications. The model carries an Fgfr3-activating mutation (Fgfr3Y367C/+) that accurately mimics ACH; we targeted the mutation to either immature OBs and hypertrophic CCs or to mature OBs by using the Osx-cre and collagen 1α1 (2.3 kb Col1a1)-cre mouse strains, respectively. We observed that Fgfr3 activation in immature OBs and hypertrophic CCs (Osx-Fgfr3) not only perturbed the hypertrophic cells of the growth plate (thus affecting long bone growth) but also led to osteopenia and low cortical thickness in long bones in adult (3-month-old) mice but not growing (3-week-old) mice. Importantly, craniofacial membranous bone defects were present in the adult mice. In contrast, activation of Fgfr3 in mature OBs (Col1-Fgfr3) had very limited effects on skeletal shape, size and micro-architecture. In vitro, we observed that Fgfr3 activation in immature OBs was associated with low mineralization activity. In conclusion, immature OBs appear to be affected by Fgfr3 overactivation, which might contribute to the bone modifications observed in ACH independently of CCs.
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Affiliation(s)
- Martin Biosse Duplan
- Laboratory of Molecular and Physiopathological Bases of Osteochondrodysplasia, INSERM UMR 1163, Imagine Institute, Paris 75015, France
- Université de Paris, Paris 75006, France
- Service de Médecine Bucco-Dentaire, Hôpital Bretonneau, AP-HP, Paris 75018, France
| | - Emilie Dambroise
- Laboratory of Molecular and Physiopathological Bases of Osteochondrodysplasia, INSERM UMR 1163, Imagine Institute, Paris 75015, France
- Université de Paris, Paris 75006, France
| | - Valentin Estibals
- Laboratory of Molecular and Physiopathological Bases of Osteochondrodysplasia, INSERM UMR 1163, Imagine Institute, Paris 75015, France
- Université de Paris, Paris 75006, France
| | - Joelle Veziers
- Inserm, UMR 1229, RMeS – Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France
- SC3M, SFR Santé F. Bonamy, FED 4203, UMS Inserm 016, CNRS 3556, Nantes F-44042, France
- CHU Nantes, PHU4 OTONN, Nantes, F-44093, France
| | - Jérome Guicheux
- Inserm, UMR 1229, RMeS – Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France
- SC3M, SFR Santé F. Bonamy, FED 4203, UMS Inserm 016, CNRS 3556, Nantes F-44042, France
- CHU Nantes, PHU4 OTONN, Nantes, F-44093, France
| | - Laurence Legeai-Mallet
- Laboratory of Molecular and Physiopathological Bases of Osteochondrodysplasia, INSERM UMR 1163, Imagine Institute, Paris 75015, France
- Université de Paris, Paris 75006, France
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Bover J, Ureña-Torres P, Cozzolino M, Rodríguez-García M, Gómez-Alonso C. The Non-invasive Diagnosis of Bone Disorders in CKD. Calcif Tissue Int 2021; 108:512-527. [PMID: 33398414 DOI: 10.1007/s00223-020-00781-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 11/17/2020] [Indexed: 12/14/2022]
Abstract
Abnormal bone metabolism is an integral part of the chronic kidney disease-mineral bone disorder (CKD-MBD). For several reasons, the difficult bone compartment was neglected for some time, but there has been renewed interest as a result of the conception of bone as a new endocrine organ, the increasing recognition of the cross-talk between bone and vessels, and, especially, the very high risk of osteoporotic fractures (and associated mortality) demonstrated in patients with CKD. Therefore, it has been acknowledged in different guidelines that action is needed in respect of fracture risk assessment and the diagnosis and treatment of osteoporosis in the context of CKD and CKD-MBD, even beyond renal osteodystrophy. These updated guidelines clearly underline the need to improve a non-invasive approach to these bone disorders in order to guide treatment decisions aimed at not only controlling CKD-MBD but also decreasing the risk of fracture. In this report, we review the current role of the most often clinically used or promising biochemical circulating biomarkers such as parathyroid hormone, alkaline phosphatases, and other biochemical markers of bone activity as alternatives to some aspects of bone histomorphometry. We also mention the potential role of classic and new imaging techniques for CKD patients. Information on many aspects is still scarce and heterogeneous, but many of us consider that it is indeed time for action, recognizing our definitely limited ability to base certain treatment decisions only on our current non-comprehensive knowledge.
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Affiliation(s)
- Jordi Bover
- Department of Nephrology, Fundació Puigvert and Universitat Autònoma, IIB Sant Pau, REDinREN, C. Cartagena 340-350, 08025, Barcelona, Catalonia, Spain.
| | - Pablo Ureña-Torres
- Department of Dialysis, AURA Nord Saint Ouen and Department of Renal Physiology, Necker Hospital, University of Paris Descartes, Paris, France
| | - Mario Cozzolino
- Renal Division, ASST Santi Paolo e Carlo, Department of Health Sciences, University of Milan, Milan, Italy
| | - Minerva Rodríguez-García
- Unidad de Gestión Clínica de Nefrología, Hospital Universitario Central de Asturias, REDinREN, Universidad de Oviedo, Oviedo, Spain
| | - Carlos Gómez-Alonso
- Unidad de Gestión Clínica de Metabolismo Óseo y Mineral, Instituto de Investigación Sanitaria del Principado de Asturias, Hospital Universitario Central de Asturias, Oviedo, Spain
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Baroncelli GI, Zampollo E, Manca M, Toschi B, Bertelloni S, Michelucci A, Isola A, Bulleri A, Peroni D, Giuca MR. Pulp chamber features, prevalence of abscesses, disease severity, and PHEX mutation in X-linked hypophosphatemic rickets. J Bone Miner Metab 2021; 39:212-223. [PMID: 32772199 DOI: 10.1007/s00774-020-01136-8] [Citation(s) in RCA: 16] [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: 03/23/2020] [Accepted: 07/27/2020] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Rickets, growth failure, and recurrent periapical abscesses with fistulae are main signs in patients with X-linked hypophosphatemic rickets (XLH). Prevalence of abscesses, pulp chamber features, biochemical findings, disease severity, and PHEX gene mutation were examined. MATERIALS AND METHODS Pulp chambers size, shape, and morphology were assessed by orthopantomography in XLH patients (n = 24, age 5.8 ± 1.6 years) and in sex and age-matched healthy controls (n = 23, age 6.2 ± 1.4 years). XLH patients received conventional treatment (3.5 ± 1.9 years). Pulp chamber features were assessed in teeth of primary dentition and in the permanent left mandibular first molar and compared with those of controls. Rickets severity score was assessed at wrist, knee, and ankle. RESULTS The mean pulp chamber area/tooth area ratio, mean pulp chamber height/pulp chamber width ratio, and prominence of pulp horns into the tooth crown in primary and secondary molars were significantly higher in patients than in controls and in patients suffered abscesses than in patients without abscesses. Sixteen patients (67%) had a history of abscesses; incisors were affected more than canines and molars. Severity of rickets and mean serum parathyroid hormone (PTH) levels were significantly higher, and mean serum 1,25-dihydroxyvitamin D [1,25(OH)2D] levels significantly lower in patients suffered abscesses than in patients without abscesses. PHEX gene mutations were not correlated with dental phenotype and disease severity. CONCLUSION Enlarged pulp chambers with altered shape and morphology affected the majority of XLH patients predisposing to recurrent periapical abscesses with fistulae. Dental phenotype was associated with severity of rickets, high serum PTH, and low serum 1,25(OH)2D levels.
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Affiliation(s)
- Giampiero I Baroncelli
- Division of Pediatrics, Endocrine Unit, Department of Obstetrics, Gynecology and Pediatrics, University-Hospital, Via Roma 67, 56126, Pisa, Italy.
| | - Elisa Zampollo
- Division of Dentistry and Oral Surgery, Department of Surgical Specialties, University-Hospital, Pisa, Italy
| | - Mario Manca
- Unit of Orthopedics, Usl Northwest-Tuscany, Versilia Hospital, Camaiore, Italy
| | - Benedetta Toschi
- Division of Medical Genetics, Department of Medical and Oncological Area, University-Hospital, Pisa, Italy
| | - Silvano Bertelloni
- Division of Pediatrics, Endocrine Unit, Department of Obstetrics, Gynecology and Pediatrics, University-Hospital, Via Roma 67, 56126, Pisa, Italy
| | - Angela Michelucci
- Unit of Molecular Genetics, Department of Laboratory Medicine, University-Hospital, Pisa, Italy
| | - Alessandro Isola
- Unit of Orthopedics, Usl Northwest-Tuscany, Versilia Hospital, Camaiore, Italy
| | - Alessandra Bulleri
- Unit of Radiodiagnostic, Department of Diagnostic Imaging, University-Hospital, Pisa, Italy
| | - Diego Peroni
- Division of Pediatrics, Endocrine Unit, Department of Obstetrics, Gynecology and Pediatrics, University-Hospital, Via Roma 67, 56126, Pisa, Italy
| | - Maria Rita Giuca
- Division of Dentistry and Oral Surgery, Department of Surgical Specialties, University-Hospital, Pisa, Italy
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Abstract
Fibroblast growth factor 23 (FGF23) is a phosphotropic hormone that belongs to a subfamily of endocrine FGFs with evolutionarily conserved functions in worms and fruit flies. FAM20C phosphorylates FGF23 post-translationally, targeting it to proteolysis through subtilisin-like proprotein convertase FURIN, resulting in secretion of FGF23 fragments. O-glycosylation of FGF23 through GALNT3 appears to prevent proteolysis, resulting in secretion of biologically active intact FGF23. In the circulation, FGF23 may undergo further processing by plasminogen activators. Crystal structures show that the ectodomain of the cognate FGF23 receptor FGFR1c binds with the ectodomain of the co-receptor alpha-KLOTHO. The KLOTHO-FGFR1c double heterodimer creates a high-affinity binding site for the FGF23 C-terminus. The topology of FGF23 deviates from that of paracrine FGFs, resulting in poor affinity for heparan sulphate, which may explain why FGF23 diffuses freely in the bone matrix to enter the bloodstream following its secretion by cells of osteoblastic lineage. Intact FGF23 signalling by this canonical pathway activates FRS2/RAS/RAF/MEK/ERK1/2. It reduces serum phosphate by inhibiting 1,25-dihydroxyvitamin D synthesis, suppressing intestinal phosphate absorption, and by downregulating the transporters NPT2a and NPT2c, suppressing phosphate reabsorption in the proximal tubules. The physiological role of FGF23 fragments, which may be inhibitory, remains unclear. Pharmacological and genetic activation of canonical FGF23 signalling causes hypophosphatemic disorders, while its inhibition results in hyperphosphatemic disorders. Non-canonical FGF23 signalling through binding and activation of FGFR3/FGFR4/calcineurin/NFAT in an alpha-KLOTHO-independent fashion mainly occurs at extremely elevated circulating FGF23 levels and may contribute to mortality due to cardiovascular disease and left ventricular hypertrophy in chronic kidney disease.
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Affiliation(s)
- Bryan B Ho
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Clemens Bergwitz
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, Connecticut, USA
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[FGF23: from academic nephrology to personalized patient́s care]. Nefrologia 2021; 41:276-283. [PMID: 33422302 DOI: 10.1016/j.nefro.2020.09.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 09/14/2020] [Accepted: 09/20/2020] [Indexed: 11/21/2022] Open
Abstract
Twenty years have passed since the identification of klotho and the fibroblast growth factor 23 (FGF23), the regulatory binomial of phosphate homeostasis. Being kidney the main source of klotho as well as a target organ in the phosphate regulation, most studies involving klotho and FGF23 had a «nephrocentric» focus. Considering that circulating FGF23 can reach exaggerated levels at the end stage of chronic kidney disease (CKD), the bias of this approach allowed to recognize the harmful «off target» klotho-independent effect of FGF23. All of these findings have caused a revolution on our previous knowledge about mineral homeostasis and currently, we are facing a new scenario in the clinical management of CKD, where FGF23 emerges simultaneously as an early biomarker of phosphate retention but also as a therapeutic target. In this review, we describe the disturbances of FGF23 in the CKD and we focus on how the maintenance of circulating FGF23 into a supraphysiological adaptive range from the initial stages of CKD and the control of «unlimited hyperphosphatonism» generated by the resistance to FGF23 action at end stages should emerge as new treatment paradigms in chronic kidney disease - mineral and bone disorders (CKD-MBD). The recent development of an automated FGF23 assay, already validated for clinical use, should be the starting point to individualize all our knowledge from epidemiological studies and will allow us to use it properly for the patient's personalized care. Then, now we are in the momentum to assess the discriminating thresholds to distinguish the physiological adaptive FGF23 elevation related to each CKD stage from the exaggerated increase that would be interpreted as a poor regulatory compensation that will requires the adoption of therapeutic intervention.
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Marcucci G, Brandi ML. Congenital Conditions of Hypophosphatemia Expressed in Adults. Calcif Tissue Int 2021; 108:91-103. [PMID: 32409880 DOI: 10.1007/s00223-020-00695-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/15/2020] [Indexed: 01/05/2023]
Abstract
The main congenital conditions of hypophosphatemia expressed in adulthood include several forms of hereditary hypophosphatemic rickets and a congenital disorder of vitamin D metabolism characterized by osteomalacia and hypophosphatemia in adult patients. Hypophosphatemia in adults is defined as serum phosphate concentration < 0.80 mmol/L. The principal regulators of phosphate homeostasis, as is well known, are parathyroid hormone (PTH), activated vitamin D, and Fibroblast Growth Factor 23 (FGF23). Differential diagnosis of hypophosphatemia is based on the evaluation of mechanisms leading to this alteration, such as high PTH activity, inadequate phosphate absorption from the gut, or renal phosphate wasting, either due to primary tubular defects or high FGF23 levels. The most common inherited form associated to hypophosphatemia is X-linked hypophosphatemic rickets (XLH), caused by PHEX gene mutations with enhanced secretion of the FGF23. Until now, the management of hypophosphatemia in adulthood has been poorly investigated. It is widely debated whether adult patients benefit from the conventional treatments normally used for pediatric patients. The new treatment for XLH with burosumab, a recombinant human IgG1 monoclonal antibody that binds to FGF23, blocking its activity, may change the pharmacological management of adult subjects with hypophosphatemia associated to FGF23-dependent mechanisms.
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Affiliation(s)
- Gemma Marcucci
- Bone Metabolic Diseases Unit, Department of Biomedical, Experimental and Clinical Sciences, University of Florence, AOU Careggi, Florence, Italy
| | - Maria Luisa Brandi
- Bone Metabolic Diseases Unit, Department of Biomedical, Experimental and Clinical Sciences, University of Florence, AOU Careggi, Florence, Italy.
- Head Bone Metabolic Diseases Unit, Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Largo Palagi 1, 50139, Florence, Italy.
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Ratsma DMA, Zillikens MC, van der Eerden BCJ. Upstream Regulators of Fibroblast Growth Factor 23. Front Endocrinol (Lausanne) 2021; 12:588096. [PMID: 33716961 PMCID: PMC7952762 DOI: 10.3389/fendo.2021.588096] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 01/11/2021] [Indexed: 12/11/2022] Open
Abstract
Fibroblast growth factor 23 (FGF23) has been described as an important regulator of mineral homeostasis, but has lately also been linked to iron deficiency, inflammation, and erythropoiesis. FGF23 is essential for the maintenance of phosphate homeostasis in the body and activating mutations in the gene itself or inactivating mutations in its upstream regulators can result in severe chronic hypophosphatemia, where an unbalanced mineral homeostasis often leads to rickets in children and osteomalacia in adults. FGF23 can be regulated by changes in transcriptional activity or by changes at the post-translational level. The balance between O-glycosylation and phosphorylation is an important determinant of how much active intact or inactive cleaved FGF23 will be released in the circulation. In the past years, it has become evident that iron deficiency and inflammation regulate FGF23 in a way that is not associated with its classical role in mineral metabolism. These conditions will not only result in an upregulation of FGF23 transcription, but also in increased cleavage, leaving the levels of active intact FGF23 unchanged. The exact mechanisms behind and function of this process are still unclear. However, a deeper understanding of FGF23 regulation in both the classical and non-classical way is important to develop better treatment options for diseases associated with disturbed FGF23 biology. In this review, we describe how the currently known upstream regulators of FGF23 change FGF23 transcription and affect its post-translational modifications at the molecular level.
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Brener A, Lebenthal Y, Cleper R, Kapusta L, Zeitlin L. Body composition and cardiometabolic health of pediatric patients with X-linked hypophosphatemia (XLH) under burosumab therapy. Ther Adv Endocrinol Metab 2021; 12:20420188211001150. [PMID: 33796255 PMCID: PMC7970173 DOI: 10.1177/20420188211001150] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 02/12/2021] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Burosumab, a recombinant anti-FGF23 monoclonal antibody, was recently introduced as a treatment for X-linked hypophosphatemia (XLH). Burosumab normalizes blood phosphate levels, thereby healing rickets, decreasing leg bowing, and reducing pain. We aimed to explore the body composition and cardiometabolic health of pediatric patients with XLH treated with burosumab. METHODS This observational real-life study was conducted on growing children and adolescents. The outcome measures included changes in sex- and age-adjusted anthropometric and body composition parameters [fat mass (FM), fat-free mass (FFM), appendicular skeletal muscle mass (ASMM), muscle-to-fat ratio (MFR)], blood pressure, laboratory evaluation, and radiographic rickets severity [Thacher Rickets Severity Score (TRSS)]. Body composition was assessed by bioelectrical impedance analysis (BIA). Percentiles for FFM% and ASMM% were calculated according to BIA pediatric reference curves. The delta variable was calculated as the variable at 12 months minus the variable at baseline. RESULTS A total of 15 pediatric patients with XLH are treated in our clinic; included in the analyses were 7 children and adolescents (3 males, mean age 8.7 ± 3.2 years) with XLH without comorbidities. Baseline BIA revealed an unfavorable physique, with increased body fat percentage in five patients and decreased muscle mass in six. Indices of lean body mass significantly increased after 6 and 12 months of treatment: FFM(kg) (p = 0.001, p = 0.046, respectively) and ASMM(kg) (p = 0.012, p = 0.034, respectively), without any significant change in FM(kg). The percentile of ASMM% increased significantly after 6 months of treatment (p = 0.006) and stabilized thereafter. TRSS improved significantly after 12 months of therapy (p = 0.005). Age was positively correlated with delta TRSS (r = 0.814, p = 0.026), and delta TRSS was negatively correlated with delta MFR (r = -0.826, p = 0.022). CONCLUSIONS There was a heretofore unrecognized improvement in body composition of growing children and adolescents with XLH who were treated with burosumab. These findings highlight the need to initiate burosumab treatment at a younger age when rickets is less severe.
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Affiliation(s)
| | - Yael Lebenthal
- Pediatric Endocrinology and Diabetes Unit,
Dana-Dwek Children’s Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv,
Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv,
Israel
| | - Roxana Cleper
- Pediatric Nephrology Unit, Dana-Dwek Children’s
Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv
University, Tel Aviv, Israel
| | - Livia Kapusta
- Pediatric Cardiology Unit, Dana-Dwek Children’s
Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv
University, Tel Aviv, Israel
- Department of Paediatric Cardiology, Amalia
Children’s Hospital, Radboud University Medical Centre, Nijmegen, The
Netherlands
| | - Leonid Zeitlin
- Pediatric Orthopedic Department, Dana-Dwek
Children’s Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv,
Israel
- Sackler Faculty of Medicine, Tel Aviv
University, Tel Aviv, Israel
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Lin Y, Xu J, Li X, Sheng H, Su L, Wu M, Cheng J, Huang Y, Mao X, Zhou Z, Zhang W, Li C, Cai Y, Wu D, Lu Z, Yin X, Zeng C, Liu L. Novel variants and uncommon cases among southern Chinese children with X-linked hypophosphatemia. J Endocrinol Invest 2020; 43:1577-1590. [PMID: 32253725 DOI: 10.1007/s40618-020-01240-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 03/24/2020] [Indexed: 12/17/2022]
Abstract
PURPOSE X-linked hypophosphatemia (XLH) is the most common inherited renal phosphate wasting disorder and is often misdiagnosed as vitamin D deficiency. This study aims to provide clinical and mutational characteristics of 65 XLH pediatric patients in southern China. METHODS In this work, a combination of DNA sequencing and qPCR analysis was used to study the PHEX gene in 80 pediatric patients diagnosed with hypophosphatemia. The clinical and laboratory data of confirmed 65 XLH patients were assessed and analyzed retrospectively. RESULTS In 65 XLH patients from 61 families, 51 different variants in the PHEX gene were identified, including 23 previously reported variants and 28 novel variants. In this cohort of XLH patients, the c.1601C>T(p.Pro534Leu) variant appears more frequently. Fourteen uncommon XLH cases were described, including four boys with de novo mosaic variants, eight patients with large deletions and a pair of monozygotic twins. The clinical manifestations in this cohort are very similar to those previously reported. CONCLUSION This study extends the mutational spectrum of the PHEX gene, which will contribute to accurate diagnosis. This study also suggests a supplementary qPCR or MLPA assay may be performed along with classical sequencing to confirm the gross insertion/deletion.
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Affiliation(s)
- Y Lin
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - J Xu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - X Li
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - H Sheng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - L Su
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - M Wu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - J Cheng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - Y Huang
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - X Mao
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - Z Zhou
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - W Zhang
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - C Li
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - Y Cai
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - D Wu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - Z Lu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - X Yin
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - C Zeng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China.
| | - L Liu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China.
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Robinson ME, AlQuorain H, Murshed M, Rauch F. Mineralized tissues in hypophosphatemic rickets. Pediatr Nephrol 2020; 35:1843-1854. [PMID: 31392510 DOI: 10.1007/s00467-019-04290-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 06/03/2019] [Accepted: 06/06/2019] [Indexed: 12/19/2022]
Abstract
Hypophosphatemic rickets is caused by renal phosphate wasting that is most commonly due to X-linked dominant mutations in PHEX. PHEX mutations cause hypophosphatemia indirectly, through the increased expression of fibroblast growth factor 23 (FGF23) by osteocytes. FGF23 decreases renal phosphate reabsorption and thereby increases phosphate excretion. The lack of phosphate leads to a mineralization defect at the level of growth plates (rickets), bone tissue (osteomalacia), and teeth, where the defect facilitates the formation of abscesses. The bone tissue immediately adjacent to osteocytes often remains unmineralized ("periosteocytic lesions"), highlighting the osteocyte defect in this disorder. Common clinical features of XLH include deformities of the lower extremities, short stature, enthesopathies, dental abscesses, as well as skull abnormalities such as craniosynostosis and Chiari I malformation. For the past four decades, XLH has been treated by oral phosphate supplementation and calcitriol, which improves rickets and osteomalacia and the dental manifestations, but often does not resolve all aspects of the mineralization defects. A newer treatment approach using inactivating FGF23 antibodies leads to more stable control of serum inorganic phosphorus levels and seems to heal rickets more reliably. However, the long-term benefits of FGF23 antibody treatment remain to be elucidated.
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Affiliation(s)
- Marie-Eve Robinson
- Shriners Hospital for Children and McGill University, 1003 Boulevard Decarie, Montreal, Québec, H4A 0A9, Canada
| | - Haitham AlQuorain
- Shriners Hospital for Children and McGill University, 1003 Boulevard Decarie, Montreal, Québec, H4A 0A9, Canada
| | - Monzur Murshed
- Shriners Hospital for Children and McGill University, 1003 Boulevard Decarie, Montreal, Québec, H4A 0A9, Canada
| | - Frank Rauch
- Shriners Hospital for Children and McGill University, 1003 Boulevard Decarie, Montreal, Québec, H4A 0A9, Canada.
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Hoac B, Østergaard M, Wittig NK, Boukpessi T, Buss DJ, Chaussain C, Birkedal H, Murshed M, McKee MD. Genetic Ablation of Osteopontin in Osteomalacic Hyp Mice Partially Rescues the Deficient Mineralization Without Correcting Hypophosphatemia. J Bone Miner Res 2020; 35:2032-2048. [PMID: 32501585 DOI: 10.1002/jbmr.4101] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/24/2020] [Accepted: 06/01/2020] [Indexed: 11/09/2022]
Abstract
PHEX is predominantly expressed by bone and tooth-forming cells, and its inactivating mutations in X-linked hypophosphatemia (XLH) lead to renal phosphate wasting and severe hypomineralization of bones and teeth. Also present in XLH are hallmark hypomineralized periosteocytic lesions (POLs, halos) that persist despite stable correction of serum phosphate (Pi ) that improves bulk bone mineralization. In XLH, mineralization-inhibiting osteopontin (OPN, a substrate for PHEX) accumulates in the extracellular matrix of bone. To investigate how OPN functions in Hyp mice (a model for XLH), double-null (Hyp;Opn-/- ) mice were generated. Undecalcified histomorphometry performed on lumbar vertebrae revealed that Hyp;Opn-/- mice had significantly reduced osteoid area/bone area (OV/BV) and osteoid thickness of trabecular bone as compared to Hyp mice, despite being as hypophosphatemic as Hyp littermate controls. However, tibias examined by synchrotron radiation micro-CT showed that mineral lacunar volumes remained abnormally enlarged in these double-null mice. When Hyp;Opn-/- mice were fed a high-Pi diet, serum Pi concentration increased, and OV/BV and osteoid thickness normalized, yet mineral lacunar area remained abnormally enlarged. Enpp1 and Ankh gene expression were increased in double-null mice fed a high-Pi diet, potentially indicating a role for elevated inhibitory pyrophosphate (PPi ) in the absence of OPN. To further investigate the persistence of POLs in Hyp mice despite stable correction of serum Pi , immunohistochemistry for OPN on Hyp mice fed a high-Pi diet showed elevated OPN in the osteocyte pericellular lacunar matrix as compared to Hyp mice fed a control diet. This suggests that POLs persisting in Hyp mice despite correction of serum Pi may be attributable to the well-known upregulation of mineralization-inhibiting OPN by Pi , and its accumulation in the osteocyte pericellular matrix. This study shows that OPN contributes to osteomalacia in Hyp mice, and that genetic ablation of OPN in Hyp mice improves the mineralization phenotype independent of systemic Pi -regulating factors. © 2020 American Society for Bone and Mineral Research.
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Affiliation(s)
- Betty Hoac
- Faculty of Dentistry, McGill University, Montreal, QC, Canada
| | - Maja Østergaard
- Department of Chemistry and the Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark
| | - Nina K Wittig
- Department of Chemistry and the Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark
| | - Tchilalo Boukpessi
- Faculty of Dentistry, McGill University, Montreal, QC, Canada.,EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, School of Dentistry Université de Paris, Paris, France.,Assistance Publique-Hôpitaux de Paris (AP-HP) Department of Odontology, Charles Foix and Bretonneau Hospitals and Reference Center for Rare Diseases of Calcium and Phosphorus Metabolism, Paris, France
| | - Daniel J Buss
- Department of Anatomy and Cell Biology, Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Catherine Chaussain
- EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, School of Dentistry Université de Paris, Paris, France.,Assistance Publique-Hôpitaux de Paris (AP-HP) Department of Odontology, Charles Foix and Bretonneau Hospitals and Reference Center for Rare Diseases of Calcium and Phosphorus Metabolism, Paris, France
| | - Henrik Birkedal
- Department of Chemistry and the Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark
| | - Monzur Murshed
- Faculty of Dentistry, McGill University, Montreal, QC, Canada.,Department of Medicine, Faculty of Medicine, McGill University, Montreal, QC, Canada.,Shriners Hospital for Children, Montreal, QC, Canada
| | - Marc D McKee
- Faculty of Dentistry, McGill University, Montreal, QC, Canada.,Department of Anatomy and Cell Biology, Faculty of Medicine, McGill University, Montreal, QC, Canada
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Expression of the type 1 lysophosphatidic acid receptor in osteoblastic cell lineage controls both bone mineralization and osteocyte specification. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158715. [DOI: 10.1016/j.bbalip.2020.158715] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/03/2020] [Accepted: 04/10/2020] [Indexed: 11/23/2022]
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50
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Padidela R, Nilsson O, Makitie O, Beck-Nielsen S, Ariceta G, Schnabel D, Brandi ML, Boot A, Levtchenko E, Smyth M, Jandhyala R, Mughal Z. The international X-linked hypophosphataemia (XLH) registry (NCT03193476): rationale for and description of an international, observational study. Orphanet J Rare Dis 2020; 15:172. [PMID: 32605590 PMCID: PMC7329472 DOI: 10.1186/s13023-020-01434-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 06/04/2020] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND X-linked hypophosphataemia (XLH) is a rare, hereditary, progressive and lifelong phosphate wasting disorder characterised by pathological elevations in fibroblast growth factor (FGF) 23 concentration and activity; XLH has an incidence of approximately 1 in 20-25,000 individuals. Excess FGF23 activity leads to increased phosphate excretion in the kidneys - mediated by downregulation of renal tubular phosphate transporters - and reduced phosphate absorption in the intestines - due to impaired vitamin D activation. This results in impaired bone growth and mineralisation, short and disproportionate stature, leg bowing, musculoskeletal pain, spontaneous dental abscesses, rickets, and osteomalacia. The spectrum of manifestations differs between paediatric and adult patients. Those involved in the treatment of this condition face many challenges, including a lack of robust natural history and demographic data. This multicentre, international, rare-disease patient registry (XLH Registry) was established to address the paucity of data in XLH and to help inform future clinical practice. RESULTS The XLH Registry collects standard diagnostic and monitoring practice data, including (where applicable) diagnosis and disease progression history, treatment regimens and family history; the protocol does not mandate any interventions or clinical assessments. The XLH Registry aims to recruit 1200 paediatric and adult patients with XLH over 10 years, and several data analyses and peer-reviewed publications are expected to be generated throughout this period. A post-authorisation safety study for Bburosumab, for which the registry Sponsor is the marketing authorisation holder, will be nested as a sub-study within the XLH Registry via a subsequent protocol amendment. CONCLUSION The data collected within this rare-disease patient registry will be utilised to synthesise real-world evidence to inform the management of XLH, to improve the quality of life and standard of care of patients living with this rare debilitating disease.
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Affiliation(s)
- Raja Padidela
- Royal Manchester Children's Hospital and Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Ola Nilsson
- Karolinska Institutet, Stockholm, Sweden
- Örebro University, Örebro, Sweden
| | - Outi Makitie
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | | | - Gema Ariceta
- Hospital Vall d'Hebron, Universitat Autonoma Barcelona, Barcelona, Spain
| | - Dirk Schnabel
- Center for Chronic Sick Children, Pediatric Endocrinology, Charité, University Medicine Berlin, Berlin, Germany
| | | | | | | | | | | | - Zulf Mughal
- Royal Manchester Children's Hospital and Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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