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Martínez-Heredia L, Canelo-Moreno JM, García-Fontana B, Muñoz-Torres M. Non-Classical Effects of FGF23: Molecular and Clinical Features. Int J Mol Sci 2024; 25:4875. [PMID: 38732094 PMCID: PMC11084844 DOI: 10.3390/ijms25094875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 04/21/2024] [Accepted: 04/26/2024] [Indexed: 05/13/2024] Open
Abstract
This article reviews the role of fibroblast growth factor 23 (FGF23) protein in phosphate metabolism, highlighting its regulation of vitamin D, parathyroid hormone, and bone metabolism. Although it was traditionally thought that phosphate-calcium homeostasis was controlled exclusively by parathyroid hormone (PTH) and calcitriol, pathophysiological studies revealed the influence of FGF23. This protein, expressed mainly in bone, inhibits the renal reabsorption of phosphate and calcitriol formation, mediated by the α-klotho co-receptor. In addition to its role in phosphate metabolism, FGF23 exhibits pleiotropic effects in non-renal systems such as the cardiovascular, immune, and metabolic systems, including the regulation of gene expression and cardiac fibrosis. Although it has been proposed as a biomarker and therapeutic target, the inhibition of FGF23 poses challenges due to its potential side effects. However, the approval of drugs such as burosumab represents a milestone in the treatment of FGF23-related diseases.
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Affiliation(s)
- Luis Martínez-Heredia
- Instituto de Investigación Biosanitaria de Granada, 18014 Granada, Spain;
- Biomedical Research Network in Fragility and Healthy Aging (CIBERFES), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | | | - Beatriz García-Fontana
- Instituto de Investigación Biosanitaria de Granada, 18014 Granada, Spain;
- Biomedical Research Network in Fragility and Healthy Aging (CIBERFES), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Endocrinology and Nutrition Unit, University Hospital Clínico San Cecilio, 18016 Granada, Spain
- Department of Cell Biology, University of Granada, 18016 Granada, Spain
| | - Manuel Muñoz-Torres
- Instituto de Investigación Biosanitaria de Granada, 18014 Granada, Spain;
- Biomedical Research Network in Fragility and Healthy Aging (CIBERFES), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Endocrinology and Nutrition Unit, University Hospital Clínico San Cecilio, 18016 Granada, Spain
- Department of Medicine, University of Granada, 18016 Granada, Spain
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2
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Shen J, Liu YP, Wang Q, Chen H, Hu Y, Guo X, Liu X, Li Y. Integrated network pharmacology, transcriptomics and metabolomics analysis to reveal the mechanism of salt Eucommia cortex in the treatment of chronic kidney disease mineral bone disorders via the PPARG/AMPK signaling pathway. JOURNAL OF ETHNOPHARMACOLOGY 2023; 314:116590. [PMID: 37207881 DOI: 10.1016/j.jep.2023.116590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/05/2023] [Accepted: 05/02/2023] [Indexed: 05/21/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The skeletal complications associated with chronic kidney diseases from stages 3-5 in individuals are called Chronic Kidney Disease-Mineral Bone Disorder (CKD-MBD), which increases the incidence of cardiovascular diseases drastically and affects the quality of life of patients seriously. Eucommia cortex has the effect of tonifying kidneys and strengthening bones, and salt Eucommia cortex is one of the most commonly used traditional Chinese medicines in the clinical treatment of CKD-MBD instead of Eucommia cortex. However, its mechanism still remains unexplored. AIM OF THE STUDY The aim of this study was to investigate the effects and mechanisms of salt Eucommia cortex on CKD-MBD by integrating network pharmacology, transcriptomics, and metabolomics. MATERIALS AND METHODS The CKD-MBD mice induced by 5/6 nephrectomy and low calcium/high phosphorus diet were treated with salt Eucommia cortex. The renal functions and bone injuries were evaluated by serum biochemical detection, histopathological analyses, and femur Micro-CT examinations. Differentially expressed genes (DEGs) between the control group and model group, model group and high-dose Eucommia cortex group, model group and high-dose salt Eucommia cortex group were analyzed by transcriptomic analysis. The differentially expressed metabolites (DEMs) between the control group and model group, model group and high-dose Eucommia cortex group, model group and high-dose salt Eucommia cortex group were analyzed by metabolomics analysis.The common targets and pathways were obtained by integrating transcriptomics, metabolomics and network pharmacology, which were identified and verified by in vivo experiments. RESULTS The negative impacts on the renal functions and bone injuries were alleviated with salt Eucommia cortex treatment effectively. Compared with CKD-MBD model mice, the levels of serum BUN, Ca and urine Upr were significantly decreased in the salt Eucommia cortex group. And the Integrated network pharmacology, transcriptomics and metabolomics analysis revealed that Peroxisome Proliferative Activated Receptor, Gamma (PPARG) was the only common target, mainly involved by AMPK signaling pathways. The activation of PPARG in the kidney tissue was significantly decreased in CKD-MBD mice but increased in the salt Eucommia cortex treatment. The AMPK signaling pathway were verified that AMPK expression levels were decreased in CKD-MBD mice but increased in the salt Eucommia cortex treatment. CONCLUSIONS Our study presented that salt Eucommia cortex alleviated the negative impact of CKD-MBD on the renal injury and bone injury of mice induced by 5/6 nephrectomy with the low calcium/high phosphorus diet effectively, which is highly likely achieved through the PPARG/AMPK signaling pathway.
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Affiliation(s)
- Jie Shen
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chendu University of Traditional Chinese Medicine, Chengdu, 611137, PR China; Chongqing Hospital of Traditional Chinese Medicine, Chongqing, 400021, PR China
| | - You-Ping Liu
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chendu University of Traditional Chinese Medicine, Chengdu, 611137, PR China.
| | - Qin Wang
- Chongqing Hospital of Traditional Chinese Medicine, Chongqing, 400021, PR China
| | - Hongping Chen
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chendu University of Traditional Chinese Medicine, Chengdu, 611137, PR China
| | - Yuan Hu
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chendu University of Traditional Chinese Medicine, Chengdu, 611137, PR China
| | - Xiaohong Guo
- Chongqing Hospital of Traditional Chinese Medicine, Chongqing, 400021, PR China
| | - Xia Liu
- Chongqing Hospital of Traditional Chinese Medicine, Chongqing, 400021, PR China
| | - Yanhui Li
- Chongqing Hospital of Traditional Chinese Medicine, Chongqing, 400021, PR China
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Mouse Models of Mineral Bone Disorders Associated with Chronic Kidney Disease. Int J Mol Sci 2023; 24:ijms24065325. [PMID: 36982400 PMCID: PMC10048881 DOI: 10.3390/ijms24065325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 02/27/2023] [Accepted: 03/03/2023] [Indexed: 03/14/2023] Open
Abstract
Patients with chronic kidney disease (CKD) inevitably develop mineral and bone disorders (CKD–MBD), which negatively impact their survival and quality of life. For a better understanding of underlying pathophysiology and identification of novel therapeutic approaches, mouse models are essential. CKD can be induced by surgical reduction of a functional kidney mass, by nephrotoxic compounds and by genetic engineering specifically interfering with kidney development. These models develop a large range of bone diseases, recapitulating different types of human CKD–MBD and associated sequelae, including vascular calcifications. Bones are usually studied by quantitative histomorphometry, immunohistochemistry and micro-CT, but alternative strategies have emerged, such as longitudinal in vivo osteoblast activity quantification by tracer scintigraphy. The results gained from the CKD–MBD mouse models are consistent with clinical observations and have provided significant knowledge on specific pathomechanisms, bone properties and potential novel therapeutic strategies. This review discusses available mouse models to study bone disease in CKD.
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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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Sirikul W, Siri-Angkul N, Chattipakorn N, Chattipakorn SC. Fibroblast Growth Factor 23 and Osteoporosis: Evidence from Bench to Bedside. Int J Mol Sci 2022; 23:ijms23052500. [PMID: 35269640 PMCID: PMC8909928 DOI: 10.3390/ijms23052500] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 02/05/2023] Open
Abstract
Osteoporosis is a chronic debilitating disease caused by imbalanced bone remodeling processes that impair the structural integrity of bone. Over the last ten years, the association between fibroblast growth factor 23 (FGF23) and osteoporosis has been studied in both pre-clinical and clinical investigations. FGF23 is a bone-derived endocrine factor that regulates mineral homeostasis via the fibroblast growth factor receptors (FGFRs)/αKlotho complex. These receptors are expressed in kidney and the parathyroid gland. Preclinical studies have supported the link between the local actions of FGF23 on the bone remodeling processes. In addition, clinical evidence regarding the effects of FGF23 on bone mass and fragility fractures suggest potential diagnostic and prognostic applications of FGF23 in clinical contexts, particularly in elderly and patients with chronic kidney disease. However, inconsistent findings exist and there are areas of uncertainty requiring exploration. This review comprehensively summarizes and discusses preclinical and clinical reports on the roles of FGF23 on osteoporosis, with an emphasis on the local action, as opposed to the systemic action, of FGF23 on the bone. Current gaps in knowledge and future research directions are also suggested to encourage further rigorous research in this important field.
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Affiliation(s)
- Wachiranun Sirikul
- Department of Community Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Natthaphat Siri-Angkul
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; (N.S.-A.); (N.C.)
- Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Nipon Chattipakorn
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; (N.S.-A.); (N.C.)
- Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Siriporn C. Chattipakorn
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; (N.S.-A.); (N.C.)
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai 50200, Thailand
- Department of Oral Biology and Diagnostic Sciences, Faculty of Dentistry, Chiang Mai University, Chiang Mai 50200, Thailand
- Correspondence: ; Tel.: +66-53-944-451; Fax: +66-53-222-844
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Kawao N, Kawaguchi M, Ohira T, Ehara H, Mizukami Y, Takafuji Y, Kaji H. Renal failure suppresses muscle irisin expression, and irisin blunts cortical bone loss in mice. J Cachexia Sarcopenia Muscle 2022; 13:758-771. [PMID: 34997830 PMCID: PMC8818650 DOI: 10.1002/jcsm.12892] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 10/25/2021] [Accepted: 11/22/2021] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Chronic renal failure induces bone mineral disorders and sarcopenia. Skeletal muscle affects other tissues, including bone, by releasing myokines. However, the effects of chronic renal failure on the interactions between muscle and bone remain unclear. METHODS We investigated the effects of renal failure on bone, muscle, and myokines linking muscle to bone using a mouse 5/6 nephrectomy (Nx) model. Muscle mass and bone mineral density (BMD) were analysed by quantitative computed tomography 8 weeks after Nx. RESULTS Nephrectomy significantly reduced muscle mass in the whole body (12.1% reduction, P < 0.05), grip strength (10.1% reduction, P < 0.05), and cortical BMD at the femurs of mice (9.5% reduction, P < 0.01) 8 weeks after surgery, but did not affect trabecular BMD at the femurs. Among the myokines linking muscle to bone, Nx reduced the expression of irisin, a proteolytic product of fibronectin type III domain-containing 5 (Fndc5), in the gastrocnemius muscles of mice (38% reduction, P < 0.01). Nx increased myostatin mRNA levels in the gastrocnemius muscles of mice (54% increase, P < 0.01). In simple regression analyses, cortical BMD, but not trabecular BMD, at the femurs was positively related to Fndc5 mRNA levels in the gastrocnemius muscles of mice (r = 0.651, P < 0.05). The weekly administration of recombinant irisin to mice ameliorated the decrease in cortical BMD, but not muscle mass or grip strength, induced by Nx (6.2% reduction in mice with Nx vs. 3.3% reduction in mice with Nx and irisin treatment, P < 0.05). CONCLUSIONS The present results demonstrated that renal failure decreases the expression of irisin in the gastrocnemius muscles of mice. Irisin may contribute to cortical bone loss induced by renal failure in mice as a myokine linking muscle to bone.
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Affiliation(s)
- Naoyuki Kawao
- Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Miku Kawaguchi
- Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Takashi Ohira
- Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Hiroki Ehara
- Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Yuya Mizukami
- Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Yoshimasa Takafuji
- Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Hiroshi Kaji
- Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
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New Insights to the Crosstalk between Vascular and Bone Tissue in Chronic Kidney Disease-Mineral and Bone Disorder. Metabolites 2021; 11:metabo11120849. [PMID: 34940607 PMCID: PMC8708186 DOI: 10.3390/metabo11120849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/30/2021] [Accepted: 12/02/2021] [Indexed: 12/18/2022] Open
Abstract
Vasculature plays a key role in bone development and the maintenance of bone tissue throughout life. The two organ systems are not only linked in normal physiology, but also in pathophysiological conditions. The chronic kidney disease–mineral and bone disorder (CKD-MBD) is still the most serious complication to CKD, resulting in increased morbidity and mortality. Current treatment therapies aimed at the phosphate retention and parathyroid hormone disturbances fail to reduce the high cardiovascular mortality in CKD patients, underlining the importance of other factors in the complex syndrome. This review will focus on vascular disease and its interplay with bone disorders in CKD. It will present the very late data showing a direct effect of vascular calcification on bone metabolism, indicating a vascular-bone tissue crosstalk in CKD. The calcified vasculature not only suffers from the systemic effects of CKD but seems to be an active player in the CKD-MBD syndrome impairing bone metabolism and might be a novel target for treatment and prevention.
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8
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Leifheit-Nestler M, Haffner D. How FGF23 shapes multiple organs in chronic kidney disease. Mol Cell Pediatr 2021; 8:12. [PMID: 34536161 PMCID: PMC8449753 DOI: 10.1186/s40348-021-00123-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/07/2021] [Indexed: 12/13/2022] Open
Abstract
Chronic kidney disease (CKD) is associated with distinct alterations in mineral metabolism in children and adults resulting in multiple organ dysfunctions. Children with advanced CKD often suffer from impaired bone mineralization, bone deformities and fractures, growth failure, muscle weakness, and vascular and soft tissue calcification, a complex which was recently termed CKD-mineral and bone disorder (CKD-MBD). The latter is a major contributor to the enhanced cardiovascular disease comorbidity and mortality in these patients. Elevated circulating levels of the endocrine-acting phosphaturic hormone fibroblast growth factor (FGF) 23 are the first detectable alteration of mineral metabolism and thus CKD-MBD. FGF23 is expressed and secreted from osteocytes and osteoblasts and rises, most likely due to increased phosphate load, progressively as kidney function declines in order to maintain phosphate homeostasis. Although not measured in clinical routine yet, CKD-mediated increased circulating levels of FGF23 in children are associated with pathological cardiac remodeling, vascular alterations, and increased cognitive risk. Clinical and experimental studies addressing other FGF23-mediated complications of kidney failure, such as hypertension and impaired bone mineralization, show partly conflicting results, and the causal relationships are not always entirely clear. This short review summarizes regulators of FGF23 synthesis altered in CKD and the main CKD-mediated organ dysfunctions related to high FGF23 levels.
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Affiliation(s)
- Maren Leifheit-Nestler
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School Children's Hospital, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School Children's Hospital, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
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Radloff J, Latic N, Pfeiffenberger U, Schüler C, Tangermann S, Kenner L, Erben RG. A phosphate and calcium-enriched diet promotes progression of 5/6-nephrectomy-induced chronic kidney disease in C57BL/6 mice. Sci Rep 2021; 11:14868. [PMID: 34290280 PMCID: PMC8295299 DOI: 10.1038/s41598-021-94264-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/06/2021] [Indexed: 02/06/2023] Open
Abstract
C57BL/6 mice are known to be rather resistant to the induction of experimental chronic kidney disease (CKD) by 5/6-nephrectomy (5/6-Nx). Here, we sought to characterize the development of CKD and its cardiac and skeletal sequelae during the first three months after 5/6-Nx in C57BL/6 mice fed a calcium- and phosphate enriched diet (CPD) with a balanced calcium/phosphate ratio. 5/6-NX mice on CPD showed increased renal fibrosis and a more pronounced decrease in glomerular filtration rate when compared to 5/6-Nx mice on normal diet (ND). Interestingly, despite comparable levels of serum calcium, phosphate, and parathyroid hormone (PTH), circulating intact fibroblast growth factor-23 (FGF23) was 5 times higher in 5/6-Nx mice on CPD, relative to 5/6-Nx mice on ND. A time course experiment revealed that 5/6-Nx mice on CPD developed progressive renal functional decline, renal fibrosis, cortical bone loss, impaired bone mineralization as well as hypertension, but not left ventricular hypertrophy. Collectively, our data show that the resistance of C57BL/6 mice to 5/6-Nx can be partially overcome by feeding the CPD, and that the CPD induces a profound, PTH-independent increase in FGF23 in 5/6-Nx mice, making it an interesting tool to assess the pathophysiological significance of FGF23 in CKD.
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Affiliation(s)
- J Radloff
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria
| | - N Latic
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria
| | - U Pfeiffenberger
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria
| | - C Schüler
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria
| | - S Tangermann
- Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - L Kenner
- Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - R G Erben
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria.
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10
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Radloff J, Pagitz M, Andrukhova O, Oberbauer R, Burgener IA, Erben RG. Aldosterone Is Positively Associated With Circulating FGF23 Levels in Chronic Kidney Disease Across Four Species, and May Drive FGF23 Secretion Directly. Front Physiol 2021; 12:649921. [PMID: 33995120 PMCID: PMC8117232 DOI: 10.3389/fphys.2021.649921] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/06/2021] [Indexed: 11/13/2022] Open
Abstract
Background Chronic kidney disease (CKD) is accompanied by increases in circulating fibroblast growth factor 23 (FGF23) and aldosterone levels. Here, we tested the hypothesis that aldosterone may be one of the driving forces behind increased FGF23 secretion in CKD. Methods Using data from a prospective study in humans, a retrospective study in dogs and cats, and an experimental study in 5/6-nephrectomized mice, we analyzed the relationship between circulating FGF23 and serum aldosterone levels in CKD across four species. To assess the effects of acute inhibition of aldosterone signaling on circulating FGF23, we acutely treated mice with established CKD with the mineralocorticoid receptor blocker canrenone (50 mg/kg iv/sc), and measured intact FGF23 before and 24 h as well as 72 h after start of administration of the drug. Results We found a tight positive association between circulating intact FGF23 and serum aldosterone in human, canine, and feline CKD patients, as well as in experimental murine CKD (humans: r S = 0.57, p = 0.0368; dogs: r S = 0.66, p = 0.0019; cats: r S = 0.75, p = 0.0003; mice: r S = 0.49, p = 0.0004). Injection of canrenone in mice with established CKD did not lead to changes in FGF23 levels within 24 h, but reduced FGF23 in all mice at 72 h. Conclusion Aldosterone may drive enhanced FGF23 secretion in CKD, possibly explaining the tight positive association between circulating intact FGF23 and aldosterone in human, canine, and feline CKD patients as well as in experimental CKD models.
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Affiliation(s)
- Judith Radloff
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Maximilian Pagitz
- Division of Small Animal Internal Medicine, Department for Companion Animals and Horses, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Olena Andrukhova
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Rainer Oberbauer
- Department of Nephrology, Medical University of Vienna, Vienna, Austria
| | - Iwan A Burgener
- Division of Small Animal Internal Medicine, Department for Companion Animals and Horses, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Reinhold G Erben
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
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Hypoxia Pathway Proteins are Master Regulators of Erythropoiesis. Int J Mol Sci 2020; 21:ijms21218131. [PMID: 33143240 PMCID: PMC7662373 DOI: 10.3390/ijms21218131] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 10/21/2020] [Accepted: 10/28/2020] [Indexed: 02/06/2023] Open
Abstract
Erythropoiesis is a complex process driving the production of red blood cells. During homeostasis, adult erythropoiesis takes place in the bone marrow and is tightly controlled by erythropoietin (EPO), a central hormone mainly produced in renal EPO-producing cells. The expression of EPO is strictly regulated by local changes in oxygen partial pressure (pO2) as under-deprived oxygen (hypoxia); the transcription factor hypoxia-inducible factor-2 induces EPO. However, erythropoiesis regulation extends beyond the well-established hypoxia-inducible factor (HIF)-EPO axis and involves processes modulated by other hypoxia pathway proteins (HPPs), including proteins involved in iron metabolism. The importance of a number of these factors is evident as their altered expression has been associated with various anemia-related disorders, including chronic kidney disease. Eventually, our emerging understanding of HPPs and their regulatory feedback will be instrumental in developing specific therapies for anemic patients and beyond.
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12
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Weidner H, Baschant U, Lademann F, Ledesma Colunga MG, Balaian E, Hofbauer C, Misof BM, Roschger P, Blouin S, Richards WG, Platzbecker U, Hofbauer LC, Rauner M. Increased FGF-23 levels are linked to ineffective erythropoiesis and impaired bone mineralization in myelodysplastic syndromes. JCI Insight 2020; 5:137062. [PMID: 32759495 DOI: 10.1172/jci.insight.137062] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 06/25/2020] [Indexed: 12/26/2022] Open
Abstract
Myelodysplastic syndromes (MDS) are clonal malignant hematopoietic disorders in the elderly characterized by ineffective hematopoiesis. This is accompanied by an altered bone microenvironment, which contributes to MDS progression and higher bone fragility. The underlying mechanisms remain largely unexplored. Here, we show that myelodysplastic NUP98‑HOXD13 (NHD13) transgenic mice display an abnormally high number of osteoblasts, yet a higher fraction of nonmineralized bone, indicating delayed bone mineralization. This was accompanied by high fibroblast growth factor-23 (FGF-23) serum levels, a phosphaturic hormone that inhibits bone mineralization and erythropoiesis. While Fgf23 mRNA expression was low in bone, brain, and kidney of NHD13 mice, its expression was increased in erythroid precursors. Coculturing these precursors with WT osteoblasts induced osteoblast marker gene expression, which was inhibited by blocking FGF-23. Finally, antibody-based neutralization of FGF-23 in myelodysplastic NHD13 mice improved bone mineralization and bone microarchitecture, and it ameliorated anemia. Importantly, higher serum levels of FGF‑23 and an elevated amount of nonmineralized bone in patients with MDS validated the findings. C‑terminal FGF‑23 correlated negatively with hemoglobin levels and positively with the amount of nonmineralized bone. Thus, our study identifies FGF-23 as a link between altered bone structure and ineffective erythropoiesis in MDS with the prospects of a targeted therapeutic intervention.
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Affiliation(s)
- Heike Weidner
- Bone Lab Dresden, Department of Medicine III & Center for Healthy Aging, and
| | - Ulrike Baschant
- Bone Lab Dresden, Department of Medicine III & Center for Healthy Aging, and
| | - Franziska Lademann
- Bone Lab Dresden, Department of Medicine III & Center for Healthy Aging, and
| | | | - Ekaterina Balaian
- Department of Medicine I, Technische Universität Dresden, Dresden, Germany.,German Cancer Consortium (DKTK), partner site Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Christine Hofbauer
- Bone Lab Dresden, Department of Medicine III & Center for Healthy Aging, and.,Department of Orthopedics and Trauma Surgery, Technische Universität Dresden, Dresden, Germany
| | - Barbara M Misof
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEKG and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Paul Roschger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEKG and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEKG and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | | | - Uwe Platzbecker
- Department of Medicine I, Technische Universität Dresden, Dresden, Germany.,German Cancer Consortium (DKTK), partner site Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Lorenz C Hofbauer
- Bone Lab Dresden, Department of Medicine III & Center for Healthy Aging, and.,German Cancer Consortium (DKTK), partner site Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Martina Rauner
- Bone Lab Dresden, Department of Medicine III & Center for Healthy Aging, and
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13
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Vimalraj S. Alkaline phosphatase: Structure, expression and its function in bone mineralization. Gene 2020; 754:144855. [PMID: 32522695 DOI: 10.1016/j.gene.2020.144855] [Citation(s) in RCA: 309] [Impact Index Per Article: 77.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 06/03/2020] [Accepted: 06/03/2020] [Indexed: 12/16/2022]
Abstract
Alkaline phosphatase (ALP) is highly expressed in the cells of mineralized tissue and plays a critical function in the formation of hard tissue. The existing status of this critical enzyme should be reviewed periodically. ALP increases inorganic phosphate local rates and facilitates mineralization as well as reduces the extracellular pyrophosphate concentration, an inhibitor of mineral formation. Mineralization is the production, inside matrix vesicles, of hydroxyapatite crystals that bud from the outermembrane of hypertrophic osteoblasts and chondrocytes. The expansion of hydroxyapatite formsinto the extracellular matrix and its accumulation between collagen fibrils is observed. Among various isoforms, the tissue-nonspecific isozyme of ALP (TNAP) is strongly expressed in bone, liver and kidney and plays a key function in the calcification of bones. TNAP hydrolyzes pyrophosphate and supplies inorganic phosphate to enhance mineralization. The biochemical substrates of TNAP are believed to be inorganic pyrophosphate and pyridoxal phosphate. These substrates concentrate in TNAP deficient condition which results in hypophosphatasia. The increased level of ALP expression and development in this environment would undoubtedly provide new and essential information about the fundamental molecular mechanisms of bone formation, offer therapeutic possibilities for the management of bone-related diseases.
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Affiliation(s)
- Selvaraj Vimalraj
- Centre for Biotechnology, Anna University, Chennai 600 025, Tamil Nadu, India.
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14
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Abstract
PURPOSE OF REVIEW The molecular mechanisms of the bone disease associated with chronic kidney disease (CKD), called renal osteodystrophy (ROD), are poorly understood. New transcriptomics technologies may provide clinically relevant insights into the pathogenesis of ROD. This review summarizes current progress and limitations in the study and treatment of ROD, and in transcriptomics analyses of skeletal tissues. RECENT FINDINGS ROD is characterized by poor bone quality and strength leading to increased risk of fracture. Recent studies indicate permanent alterations in bone cell populations during ROD. Single-cell transcriptomics analyses, successful at identifying specialized cell subpopulations in bone, have not yet been performed in ROD. ROD is a widespread poorly understood bone disease with limited treatment options. Transcriptomics analyses of bone are needed to identify the bone cell subtypes and their role in the pathogenesis of ROD, and to develop adequate diagnosis and treatment strategies.
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Affiliation(s)
- Aline Martin
- Division of Nephrology and Hypertension, Center for Translational Metabolism and Health and Feinberg Cardiovascular and Renal Research Institute, Northwestern University, 320 East Superior Street, Chicago, IL, 60611, USA.
| | - Valentin David
- Division of Nephrology and Hypertension, Center for Translational Metabolism and Health and Feinberg Cardiovascular and Renal Research Institute, Northwestern University, 320 East Superior Street, Chicago, IL, 60611, USA.
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15
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Milovanovic P, Busse B. Phenomenon of osteocyte lacunar mineralization: indicator of former osteocyte death and a novel marker of impaired bone quality? Endocr Connect 2020; 9:R70-R80. [PMID: 32168472 PMCID: PMC7159263 DOI: 10.1530/ec-19-0531] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 03/13/2020] [Indexed: 11/09/2022]
Abstract
An increasing number of patients worldwide suffer from bone fractures that occur after low intensity trauma. Such fragility fractures are usually associated with advanced age and osteoporosis but also with long-term immobilization, corticosteroid therapy, diabetes mellitus, and other endocrine disorders. It is important to understand the skeletal origins of increased bone fragility in these conditions for preventive and therapeutic strategies to combat one of the most common health problems of the aged population. This review summarizes current knowledge pertaining to the phenomenon of micropetrosis (osteocyte lacunar mineralization). As an indicator of former osteocyte death, micropetrosis is more common in aged bone and osteoporotic bone. Considering that the number of mineralized osteocyte lacunae per bone area can distinguish healthy, untreated osteoporotic and bisphosphonate-treated osteoporotic patients, it could be regarded as a novel structural marker of impaired bone quality. Further research is needed to clarify the mechanism of lacunar mineralization and to explore whether it could be an additional target for preventing or treating bone fragility related to aging and various endocrine diseases.
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Affiliation(s)
- Petar Milovanovic
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Laboratory for Anthropology and Skeletal Biology, Institute of Anatomy, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Correspondence should be addressed to B Busse:
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16
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van Vuren AJ, Gaillard CAJM, Eisenga MF, van Wijk R, van Beers EJ. The EPO-FGF23 Signaling Pathway in Erythroid Progenitor Cells: Opening a New Area of Research. Front Physiol 2019; 10:304. [PMID: 30971944 PMCID: PMC6443968 DOI: 10.3389/fphys.2019.00304] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 03/07/2019] [Indexed: 12/14/2022] Open
Abstract
We provide an overview of the evidence for an erythropoietin-fibroblast growth factor 23 (FGF23) signaling pathway directly influencing erythroid cells in the bone marrow. We outline its importance for red blood cell production, which might add, among others, to the understanding of bone marrow responses to endogenous erythropoietin in rare hereditary anemias. FGF23 is a hormone that is mainly known as the core regulator of phosphate and vitamin D metabolism and it has been recognized as an important regulator of bone mineralization. Osseous tissue has been regarded as the major source of FGF23. Interestingly, erythroid progenitor cells highly express FGF23 protein and carry the FGF receptor. This implies that erythroid progenitor cells could be a prime target in FGF23 biology. FGF23 is formed as an intact, biologically active protein (iFGF23) and proteolytic cleavage results in the formation of the presumed inactive C-terminal tail of FGF23 (cFGF23). FGF23-knockout or injection of an iFGF23 blocking peptide in mice results in increased erythropoiesis, reduced erythroid cell apoptosis and elevated renal and bone marrow erythropoietin mRNA expression with increased levels of circulating erythropoietin. By competitive inhibition, a relative increase in cFGF23 compared to iFGF23 results in reduced FGF23 receptor signaling and mimics the positive effects of FGF23-knockout or iFGF23 blocking peptide. Injection of recombinant erythropoietin increases FGF23 mRNA expression in the bone marrow with a concomitant increase in circulating FGF23 protein. However, erythropoietin also augments iFGF23 cleavage, thereby decreasing the iFGF23 to cFGF23 ratio. Therefore, the net result of erythropoietin is a reduction of iFGF23 to cFGF23 ratio, which inhibits the effects of iFGF23 on erythropoiesis and erythropoietin production. Elucidation of the EPO-FGF23 signaling pathway and its downstream signaling in hereditary anemias with chronic hemolysis or ineffective erythropoiesis adds to the understanding of the pathophysiology of these diseases and its complications; in addition, it provides promising new targets for treatment downstream of erythropoietin in the signaling cascade.
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Affiliation(s)
- Annelies J van Vuren
- Van Creveldkliniek, Department of Internal Medicine and Dermatology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Carlo A J M Gaillard
- Department of Internal Medicine and Dermatology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Michele F Eisenga
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Richard van Wijk
- Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Eduard J van Beers
- Van Creveldkliniek, Department of Internal Medicine and Dermatology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
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