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Wagner CA. The basics of phosphate metabolism. Nephrol Dial Transplant 2024; 39:190-201. [PMID: 37660247 PMCID: PMC10828206 DOI: 10.1093/ndt/gfad188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Indexed: 09/04/2023] Open
Abstract
Phosphorus is an essential mineral that is, in the form of inorganic phosphate (Pi), required for building cell membranes, DNA and RNA molecules, energy metabolism, signal transduction and pH buffering. In bone, Pi is essential for bone stability in the form of apatite. Intestinal absorption of dietary Pi depends on its bioavailability and has two distinct modes of active transcellular and passive paracellular absorption. Active transport is transporter mediated and partly regulated, while passive absorption depends mostly on bioavailability. Renal excretion controls systemic Pi levels, depends on transporters in the proximal tubule and is highly regulated. Deposition and release of Pi into and from soft tissues and bone has to be tightly controlled. The endocrine network coordinating intestinal absorption, renal excretion and bone turnover integrates dietary intake and metabolic requirements with renal excretion and is critical for bone stability and cardiovascular health during states of hypophosphataemia or hyperphosphataemia as evident from inborn or acquired diseases. This review provides an integrated overview of the biology of phosphate and Pi in mammals.
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Affiliation(s)
- Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland
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2
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Li L, Gan H. Intact Fibroblast Growth Factor 23 Regulates Chronic Kidney Disease–Induced Myocardial Fibrosis by Activating the Sonic Hedgehog Signaling Pathway. J Am Heart Assoc 2022; 11:e026365. [DOI: 10.1161/jaha.122.026365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background
Clinically, myocardial fibrosis is one of the most common complications caused by chronic kidney disease (CKD). However, the potential mechanisms of CKD‐induced myocardial fibrosis have not been clarified.
Methods and Results
In our in vivo study, a rat model of CKD with 5/6 nephrectomy was established. The CKD model was treated with the glioma 1 (Gli‐1) inhibitor GANT‐61, and myocardial fibrosis and serum intact fibroblast growth factor 23 levels were assessed 16 weeks after nephrectomy. Finally, we found that Gli‐1 and Smoothened in the Sonic Hedgehog (Shh) signaling pathway were activated and that collagen‐1 and collagen‐3, which constitute the fibrotic index, were expressed in CKD myocardial tissue. After administering the Gli‐1 inhibitor GANT‐61, the degree of myocardial fibrosis was reduced, and Gli‐1 expression was also inhibited. We also measured blood pressure, cardiac biomarkers, and other indicators in rats and performed hematoxylin‐eosin staining of myocardial tissue. Furthermore, in vitro studies showed that intact fibroblast growth factor 23 promoted cardiac fibroblast proliferation and transdifferentiation into myofibroblasts by activating the Shh signaling pathway, thereby promoting cardiac fibrosis, as manifested by increased expression of the Shh, Patch 1, and Gli‐1 mRNAs and Shh, Smoothened, and Gli‐1 proteins in the Shh signaling pathway. The protein and mRNA levels of other fibrosis indicators, such as α‐smooth muscle actin, which are also markers of transdifferentiation, collagen‐1, and collagen‐3, were increased.
Conclusions
On the basis of these results, intact fibroblast growth factor 23 promotes CKD‐induced myocardial fibrosis by activating the Shh signaling pathway.
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Affiliation(s)
- Lanlan Li
- Department of Nephrology The First Affiliated Hospital of Chongqing Medical University Chongqing China
| | - Hua Gan
- Department of Nephrology The First Affiliated Hospital of Chongqing Medical University Chongqing China
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Gayan‐Ramirez G, Janssens W. Vitamin D Actions: The Lung Is a Major Target for Vitamin D, FGF23, and Klotho. JBMR Plus 2021; 5:e10569. [PMID: 34950829 PMCID: PMC8674778 DOI: 10.1002/jbm4.10569] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 09/29/2021] [Accepted: 10/09/2021] [Indexed: 11/16/2022] Open
Abstract
Vitamin D is well known for its role as a calcium regulator and in maintenance of phosphate homeostasis in musculoskeletal health, and fibroblast growth factor 23 (FGF23) and its coreceptor α-klotho are known for their roles as regulators of serum phosphate levels. However, apart from these classical actions, recent data point out a relevant role of vitamin D and FGF23/klotho in lung health. The expression of the vitamin D receptor by different cell types in the lung and the fact that those cells respond to vitamin D or can locally produce vitamin D indicate that the lung represents a target for vitamin D actions. Similarly, the presence of the four FGF receptor isoforms in the lung and the ability of FGF23 to stimulate pulmonary cells support the concept that the lung is a target for FGF23 actions, whereas the contribution of klotho is still undetermined. This review will give an overview on how vitamin D or FGF23/klotho may act on the lung and interfere positively or negatively with lung health. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Ghislaine Gayan‐Ramirez
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), Department CHROMETAKU LeuvenLeuvenBelgium
| | - Wim Janssens
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), Department CHROMETAKU LeuvenLeuvenBelgium
- Clinical Department of Respiratory DiseasesUZ LeuvenLeuvenBelgium
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Braithwaite VS, Mwangi MN, Jones KS, Demir AY, Prentice A, Prentice AM, Andang'o PEA, Verhoef H. Antenatal iron supplementation, FGF23, and bone metabolism in Kenyan women and their offspring: secondary analysis of a randomized controlled trial. Am J Clin Nutr 2021; 113:1104-1114. [PMID: 33675347 PMCID: PMC8106766 DOI: 10.1093/ajcn/nqaa417] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 12/10/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Fibroblast growth factor-23 (FGF23) regulates body phosphate homeostasis primarily by increasing phosphaturia. It also acts as a vitamin D-regulating hormone. Maternal iron deficiency is associated with perturbed expression and/or regulation of FGF23 and hence might be implicated in the pathogenesis of hypophosphatemia-driven rickets in their offspring. OBJECTIVES We aimed to determine the effect of antenatal oral iron supplementation on FGF23 concentration and maternal and infant markers of bone-mineral regulation. METHODS We performed a secondary analysis of a trial in which 470 rural Kenyan women with singleton pregnancies and hemoglobin concentrations ≥ 90 g/L were randomly allocated to daily, supervised supplementation with 60 mg elemental iron as ferrous fumarate or placebo from 13-23 weeks of gestation until 1 mo postpartum. As previously reported, iron supplementation improved iron status in mothers and neonates. For the present study, we reanalyzed all available plasma samples collected in mothers and neonates at birth, with primary outcomes being concentrations of FGF23, measured by 2 assays: 1 that detects intact hormone and C-terminal cleavage products (total-FGF23) and another that detects the intact hormone only (intact-FGF23). RESULTS Analysis was performed on 433 women (n = 216, iron group; n = 217, placebo group) and 414 neonates (n = 207, iron group; n = 207, placebo group). Antenatal iron supplementation reduced geometric mean total-FGF23 concentrations in mothers and neonates by 62.6% (95% CI: 53.0%, 70.3%) and 15.2% (95% CI: -0.3%, 28.4%, P = 0.06), respectively. In addition, it increased geometric mean neonatal intact-FGF23 concentrations by 21.6% (95% CI: 1.2%, 46.1%), increased geometric mean maternal hepcidin concentrations by 136.4% (95% CI: 86.1%, 200.3%), and decreased mean maternal 25-hydroxyvitamin D concentrations by 6.1 nmol/L (95% CI: -11.0, -1.2 nmol/L). CONCLUSIONS Analysis of this randomized trial confirms that iron supplementation can reverse elevated FGF23 production caused by iron deficiency in iron-deficient mothers and their neonates. Further investigations are warranted to assess to what extent iron supplementation can prevent FGF23-mediated hypophosphatemic rickets or osteomalacia.
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Affiliation(s)
| | - Martin N Mwangi
- Wageningen University, Division of Human Nutrition and Health, P.O. Box 17, 6700 AA Wageningen, The Netherlands,University of Malawi, College of Medicine, Training and Research Unit of Excellence, Private Bag 360, BT 3, Chichiri, Blantyre, Malawi
| | - Kerry S Jones
- National Institute for Health Research (NIHR) Biomedical Research Centre Nutritional Biomarker Laboratory, MRC Epidemiology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0AH, United Kingdom
| | - Ayşe Y Demir
- Meander Medical Centre, Laboratory for Clinical Chemistry and Hematology, P.O. Box 1502, 3800 BM Amersfoort, The Netherlands
| | - Ann Prentice
- Medical Research Council (MRC) Nutrition and Bone Health Research Group, Clifford Allbutt Building, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0AH, United Kingdom (formerly the MRC Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, United Kingdom),Medical Research Council (MRC) Unit The Gambia at London School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, Banjul, The Gambia
| | - Andrew M Prentice
- Medical Research Council (MRC) Unit The Gambia at London School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, Banjul, The Gambia
| | - Pauline E A Andang'o
- Maseno University, School of Public Health and Community Development, Maseno, Kenya
| | - Hans Verhoef
- Wageningen University, Division of Human Nutrition and Health, P.O. Box 17, 6700 AA Wageningen, The Netherlands,Wageningen University, Cell Biology and Immunology Group, P.O. Box 338, 6708 WD Wageningen, The Netherlands
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5
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6
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Simultaneous management of disordered phosphate and iron homeostasis to correct fibroblast growth factor 23 and associated outcomes in chronic kidney disease. Curr Opin Nephrol Hypertens 2021; 29:359-366. [PMID: 32452919 DOI: 10.1097/mnh.0000000000000614] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW Hyperphosphatemia, iron deficiency, and anemia are powerful stimuli of fibroblast growth factor 23 (FGF23) production and are highly prevalent complications of chronic kidney disease (CKD). In this manuscript, we put in perspective the newest insights on FGF23 regulation by iron and phosphate and their effects on CKD progression and associated outcomes. We especially focus on new studies aiming to reduce FGF23 levels, and we present new data that suggest major benefits of combined corrections of iron, phosphate, and FGF23 in CKD. RECENT FINDINGS New studies show that simultaneously correcting iron deficiency and hyperphosphatemia in CKD reduces the magnitude of FGF23 increase. Promising therapies using iron-based phosphate binders in CKD might mitigate cardiac and renal injury and improve survival. SUMMARY New strategies to lower FGF23 have emerged, and we discuss their benefits and risks in the context of CKD. Novel clinical and preclinical studies highlight the effects of phosphate restriction and iron repletion on FGF23 regulation.
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Pool LR, Kershaw KN, Gordon-Larsen P, Gutiérrez OM, Reis JP, Isakova T, Wolf M, Carnethon MR. Racial Differences in the Associations Between Food Insecurity and Fibroblast Growth Factor 23 in the Coronary Artery Risk Development in Young Adults Study. J Ren Nutr 2020; 30:509-517. [PMID: 32147284 DOI: 10.1053/j.jrn.2020.01.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/20/2019] [Accepted: 01/12/2020] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE Food insecurity is associated with consumption of phosphate additive-laden processed food and beverage products, which could result in higher levels of fibroblast growth factor 23 (FGF23) to compensate for the increased dietary phosphate load. We sought to determine whether food insecurity is associated with higher levels of FGF23. We stratified analyses by race since differences may occur between food insecurity and diet quality across races. DESIGN AND METHODS The longitudinal community-based Coronary Artery Risk Development in Young Adults Study recruited from 4 US centers: Birmingham, AL; Chicago, IL; Minneapolis, MN; and Oakland, CA, during the cohort inception in 1985/1986. This analysis included 3,421 black and white participants from Coronary Artery Risk Development in Young Adults follow-up years 20, 25, and 30 who were enrolled in the study between the ages of 18 and 30 years. Econometric fixed effects models stratified by race that adjust by design for all time-invariant covariates were used to model the longitudinal association of food insecurity, defined as the self-reported ability to afford desired quantity and quality of food. The main outcome of interest was changing to the highest quartile of plasma FGF-23 concentrations. RESULTS During follow-up, 29% of blacks and 14% of whites experienced change in food security. Developing food insecurity was associated with a 1.48 greater odds of increasing to the highest quartile of FGF23 (95% confidence interval 1.02-2.15) among blacks; however, there was no significant longitudinal association among whites (odds ratio = 1.14, 95% confidence interval 0.67-1.95). CONCLUSIONS Among blacks, food insecurity was associated with an increase in levels of FGF23. Although phosphate consumption was presumed to mediate the association between food insecurity and FGF23 levels, we were unable to directly test this pathway.
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Affiliation(s)
- Lindsay R Pool
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
| | - Kiarri N Kershaw
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Penny Gordon-Larsen
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Orlando M Gutiérrez
- Department of Medicine and Epidemiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jared P Reis
- Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, Bethesda, Maryland
| | - Tamara Isakova
- Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Myles Wolf
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina
| | - Mercedes R Carnethon
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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8
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Ren Z, Yan J, Hu Q, Liu X, Pan C, Liu Y, Zhang X, Yang X, Yang X. Phosphorus Restriction Changes the Expression of Fibroblast Growth Factor 23 and Its Receptors in Laying Hens. Front Physiol 2020; 11:85. [PMID: 32116791 PMCID: PMC7034339 DOI: 10.3389/fphys.2020.00085] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/27/2020] [Indexed: 12/31/2022] Open
Abstract
Dietary phosphorus oversupply wastes non-renewable natural resources and raises environmental concerns in animal agriculture. We hypothesized that laying hens do not need large safety margins for dietary phosphorus because of the existence of fibroblast growth factor 23 (FGF23). In experiment 1, a total of 504 Hy-Line Brown laying hens (40-week-old) were randomly assigned to seven diets (for each diet, six replicates of 12 hens), containing 0.12, 0.17, 0.22, 0.27, 0.32, 0.37, and 0.42% non-phytate phosphorus, respectively, for 15 weeks. In experiment 2, a total of 14 Hy-Line Brown laying hens (40-week-old) were randomly assigned to two diets: (1) phosphorus restricted (n = 7) diet containing 0.14% non-phytate phosphorus, and (2) regular phosphorus (n = 7) diet containing 0.32% non-phytate phosphorus, for 21 days. Laying performance and egg quality were investigated in experiments 1 and 2. Phosphorus excretion and physiological changes were determined in experiment 2. It was found that dietary non-phytate phosphorus levels had no effects (P > 0.05) on laying performance and egg quality in either experiment. In experiment 2, laying hens fed 0.14% non-phytate phosphorus had decreased phosphorus excretion (by 52.6%, P < 0.001) when compared to those fed 0.32% non-phytate phosphorus. In response to the 0.14% non-phytate phosphorus diet, laying hens in experiment 2 exhibited: (1) suppressed calvaria mRNA expressions of FGF23 (by 57.8%, P < 0.001) and fibroblast growth factor receptor 1 (FGFR1, by 52.8%, P = 0.012), (2) decreased serum levels of FGF23 (by 41.7%, P = 0.011) and phosphorus (by 40.3%, P < 0.001), (3) decreased kidney mRNA expressions of FGFR1 (by 66.0%, P = 0.040) and FGFR4 (by 63.3%, P = 0.012) and decreased kidney protein expression of type 2a sodium-phosphorus co-transporter (NPt2a, by 51%, P = 0.025), (4) increased duodenum protein expression of NPt2b (by 45%, P = 0.032), and (5) increased excretion of calcium (by 22.9%, P ≤ 0.024). Collectively, decreasing dietary non-phytate phosphorus by up to 0.12% had no negative effects on egg-production performance but significantly decreased phosphorus excretion in laying hens. The laying hens adjusted to low-phosphorus diets by increasing intestinal NPt2b protein production, which was associated with decreased serum FGF23 concentration. Decreasing dietary non-phytate phosphorus is suggested to laying-hen nutritionists.
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Affiliation(s)
- Zhouzheng Ren
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Jiakun Yan
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Qianli Hu
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Xinshuai Liu
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Chong Pan
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Yanli Liu
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Xiaozhen Zhang
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Xin Yang
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Xiaojun Yang
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
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Delucchi Á, Toro L, Alzamora R, Barrientos V, González M, Andaur R, León P, Villanueva F, Galindo M, Las Heras F, Montecino M, Moena D, Lazcano A, Pinto V, Salas P, Reyes ML, Mericq V, Michea L. Glucocorticoids Decrease Longitudinal Bone Growth in Pediatric Kidney Transplant Recipients by Stimulating the FGF23/FGFR3 Signaling Pathway. J Bone Miner Res 2019; 34:1851-1861. [PMID: 31099911 DOI: 10.1002/jbmr.3761] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 05/05/2019] [Accepted: 05/11/2019] [Indexed: 12/11/2022]
Abstract
Renal transplantation (RTx) is an effective therapy to improve clinical outcomes in pediatric patients with terminal chronic kidney disease. However, chronic immunosuppression with glucocorticoids (GCs) reduces bone growth and BMD. The mechanisms causing GC-induced growth impairment have not been fully clarified. Fibroblast growth factor 23 (FGF23) is a peptide hormone that regulates phosphate homeostasis and bone growth. In pathological conditions, FGF23 excess or abnormal FGF receptors (FGFR) activity leads to bone growth impairment. Experimental data indicate that FGF23 expression is induced by chronic GC exposure. Therefore, we hypothesize that GCs impair bone growth by increasing FGF23 expression, which has direct effects on bone growth plate. In a post hoc analysis of a multicentric randomized clinical trial of prepubertal RTx children treated with early GC withdrawal or chronic GC treatment, we observed that GC withdrawal was associated with improvement in longitudinal growth and BMD, and lower plasma FGF23 levels as compared with a chronic GC group. In prepubertal rats, GC-induced bone growth retardation correlated with increased plasma FGF23 and bone FGF23 expression. Additionally, GC treatment decreased FGFR1 expression whereas it increased FGFR3 expression in mouse tibia explants. The GC-induced bone growth impairment in tibiae explants was prevented by blockade of FGF23 receptors using either a pan-FGFR antagonist (PD173074), a C-terminal FGF23 peptide (FGF23180-205) which blocks the binding of FGF23 to the FGFR-Klotho complex or a specific FGFR3 antagonist (P3). Finally, local administration of PD173074 into the tibia growth plate ameliorated cartilage growth impairment in GC-treated rats. These results show that GC treatment partially reduces longitudinal bone growth via upregulation of FGF23 and FGFR3 expression, thus suggesting that the FGF23/Klotho/FGFR3 axis at the growth plate could be a potential therapeutic target for the management of GC-induced growth impairment in children.
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Affiliation(s)
- Ángela Delucchi
- Division of Nephrology, Hospital Luis Calvo Mackenna, Santiago, Chile.,Division of Nephrology, Clínica Alemana de Santiago, Santiago, Chile
| | - Luis Toro
- Division of Nephrology, Department of Medicine, Hospital Clínico Universidad de Chile, Santiago, Chile.,Centro de Investigación Clínica Avanzada, Hospital Clínico Universidad de Chile, Santiago, Chile.,Clinica Las Condes, Santiago, Chile
| | - Rodrigo Alzamora
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Victor Barrientos
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Magdalena González
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Rodrigo Andaur
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Pablo León
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Francisco Villanueva
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Mario Galindo
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Millennium Institute on Immunology and Immunotherapy (MIII), Santiago, Chile
| | - Facundo Las Heras
- Clinica Las Condes, Santiago, Chile.,Department of Anatomic Pathology, Hospital Clínico Universidad de Chile, Santiago, Chile
| | - Martín Montecino
- Institute of Biomedical Sciences, Faculty of Medicine and Faculty of Life Sciences, Universidad Andrés Bello, Santiago, Chile.,FONDAP Center for Genome Regulation, Universidad Andres Bello, Santiago, Chile
| | - Daniel Moena
- Institute of Biomedical Sciences, Faculty of Medicine and Faculty of Life Sciences, Universidad Andrés Bello, Santiago, Chile.,FONDAP Center for Genome Regulation, Universidad Andres Bello, Santiago, Chile
| | - Andrea Lazcano
- Division of Nephrology, Clínica Alemana de Santiago, Santiago, Chile.,Division of Nephrology, Hospital de Niños Roberto del Río, Santiago, Chile
| | - Viola Pinto
- Clinica Las Condes, Santiago, Chile.,Pediatric Nephrology Unit, Hospital Doctor Exequiel González Cortés, Santiago, Chile
| | - Paulina Salas
- Pediatric Nephrology Unit, Hospital Doctor Exequiel González Cortés, Santiago, Chile
| | - María Loreto Reyes
- Pediatric Endocrinology Unit, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Verónica Mericq
- Clinica Las Condes, Santiago, Chile.,Institute of Maternal and Child Research, Universidad de Chile, Santiago, Chile
| | - Luis Michea
- Division of Nephrology, Department of Medicine, Hospital Clínico Universidad de Chile, Santiago, Chile.,Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Millennium Institute on Immunology and Immunotherapy (MIII), Santiago, Chile
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FGF23-Mediated Activation of Local RAAS Promotes Cardiac Hypertrophy and Fibrosis. Int J Mol Sci 2019; 20:ijms20184634. [PMID: 31540546 PMCID: PMC6770314 DOI: 10.3390/ijms20184634] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/09/2019] [Accepted: 09/16/2019] [Indexed: 12/25/2022] Open
Abstract
Patients with chronic kidney disease (CKD) are prone to developing cardiac hypertrophy and fibrosis, which is associated with increased fibroblast growth factor 23 (FGF23) serum levels. Elevated circulating FGF23 was shown to induce left ventricular hypertrophy (LVH) via the calcineurin/NFAT pathway and contributed to cardiac fibrosis by stimulation of profibrotic factors. We hypothesized that FGF23 may also stimulate the local renin–angiotensin–aldosterone system (RAAS) in the heart, thereby further promoting the progression of FGF23-mediated cardiac pathologies. We evaluated LVH and fibrosis in association with cardiac FGF23 and activation of RAAS in heart tissue of 5/6 nephrectomized (5/6Nx) rats compared to sham-operated animals followed by in vitro studies with isolated neonatal rat ventricular myocytes and fibroblast (NRVM, NRCF), respectively. Uremic rats showed enhanced cardiomyocyte size and cardiac fibrosis compared with sham. The cardiac expression of Fgf23 and RAAS genes were increased in 5/6Nx rats and correlated with the degree of cardiac fibrosis. In NRVM and NRCF, FGF23 stimulated the expression of RAAS genes and induced Ngal indicating mineralocorticoid receptor activation. The FGF23-mediated hypertrophic growth of NRVM and induction of NFAT target genes were attenuated by cyclosporine A, losartan and spironolactone. In NRCF, FGF23 induced Tgfb and Ctgf, which were suppressed by losartan and spironolactone, only. Our data suggest that FGF23-mediated activation of local RAAS in the heart promotes cardiac hypertrophy and fibrosis.
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Francis C, Courbon G, Gerber C, Neuburg S, Wang X, Dussold C, Capella M, Qi L, Isakova T, Mehta R, Martin A, Wolf M, David V. Ferric citrate reduces fibroblast growth factor 23 levels and improves renal and cardiac function in a mouse model of chronic kidney disease. Kidney Int 2019; 96:1346-1358. [PMID: 31668632 DOI: 10.1016/j.kint.2019.07.026] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 07/02/2019] [Accepted: 07/18/2019] [Indexed: 12/25/2022]
Abstract
Iron deficiency, anemia, hyperphosphatemia, and increased fibroblast growth factor 23 (FGF23) are common and interrelated complications of chronic kidney disease (CKD) that are linked to CKD progression, cardiovascular disease and death. Ferric citrate is an oral phosphate binder that decreases dietary phosphate absorption and serum FGF23 concentrations while increasing iron stores and hemoglobin in patients with CKD. Here we compared the effects of ferric citrate administration versus a mineral sufficient control diet using the Col4a3 knockout mouse model of progressive CKD and age-matched wild-type mice. Ferric citrate was given to knockout mice for four weeks beginning at six weeks of age when they had overt CKD, or for six weeks beginning at four weeks of age when they had early CKD. Ten-week-old knockout mice on the control diet showed overt iron deficiency, anemia, hyperphosphatemia, increased serum FGF23, hypertension, decreased kidney function, and left ventricular systolic dysfunction. Ferric citrate rescued iron deficiency and anemia in knockout mice regardless of the timing of treatment initiation. Circulating levels and bone expression of FGF23 were reduced in knockout mice given ferric citrate with more pronounced reductions observed when ferric citrate was initiated in early CKD. Ferric citrate decreased serum phosphate only when it was initiated in early CKD. While ferric citrate mitigated systolic dysfunction in knockout mice regardless of timing of treatment initiation, early initiation of ferric citrate also reduced renal fibrosis and proteinuria, improved kidney function, and prolonged life span. Thus, initiation of ferric citrate treatment early in the course of murine CKD lowered FGF23, slowed CKD progression, improved cardiac function and significantly improved survival.
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Affiliation(s)
- Connor Francis
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Guillaume Courbon
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Claire Gerber
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Samantha Neuburg
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Xueyan Wang
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Corey Dussold
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Maralee Capella
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Lixin Qi
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Tamara Isakova
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Rupal Mehta
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Aline Martin
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Myles Wolf
- Division of Nephrology, Department of Medicine, and Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
| | - Valentin David
- Division of Nephrology and Hypertension, Department of Medicine, and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
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12
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Abstract
PURPOSE OF REVIEW The purpose of this study is to review the current literature related to the role of inorganic phosphate in the pathogenesis of hypertension. RECENT FINDINGS An increasing number of publications have revealed a detrimental role of inorganic phosphate, which is commonly used as a flavor enhancer or preservative in the processed food, in promoting hypertension in otherwise healthy individuals. Animal experimental data indicate that dietary phosphate excess engages multiple mechanisms that promote hypertension, including overactivation of the sympathetic nervous system, increased vascular stiffness, impaired endothelium-dependent vasodilation, as well as increased renal sodium absorption or renal injury. These effects may be explained by direct effects of high extracellular phosphate levels or increase in phosphaturic hormones such as fibroblast growth factor 23, or downregulation of klotho, a transmembrane protein expressed in multiple organs which possess antiaging property. SUMMARY Dietary phosphate, particularly inorganic phosphate, is an emerging risk factor for hypertension which is ubiquitous in the western diet. Large randomized clinical trials are needed to determine if lowering dietary phosphate content constitutes an effective nonpharmacologic intervention for prevention and treatment of hypertension.
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Affiliation(s)
- Han-Kyul Kim
- Hypertension Section, University of Texas Southwestern Medical Center, Dallas, TX
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Masaki Mizuno
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
- Department of Health Care Sciences, University of Texas Southwestern Medical Center, Dallas, TX
| | - Wanpen Vongpatanasin
- Hypertension Section, University of Texas Southwestern Medical Center, Dallas, TX
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
- Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX
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13
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Billington EO, Murphy R, Gamble GD, Callon K, Davies N, Plank LD, Booth M, Reid IR. Fibroblast growth factor 23 levels decline following sleeve gastrectomy. Clin Endocrinol (Oxf) 2019; 91:87-93. [PMID: 30943313 DOI: 10.1111/cen.13981] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/29/2019] [Accepted: 03/31/2019] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Levels of fibroblast growth factor 23 (FGF23) have been positively associated with measures of adiposity, cardiovascular disease and mortality. It is unclear whether the relationship of FGF23 with cardiovascular disease and mortality is confounded by obesity. We aimed to determine whether FGF23 concentrations decline following a reduction in adiposity after sleeve gastrectomy (SG). DESIGN The effect of SG on FGF23 was evaluated in 22 obese adults (59% male) with type 2 diabetes. Fat mass, weight, BMI, plasma intact FGF23, parathyroid hormone (PTH) and leptin were determined at baseline and at 12 months following SG. RESULTS At baseline, median (IQR) age was 51 (43-54) years, fat mass 47.8 (41.0-59.4) kg, BMI 40.9 (36.9-46.9) kg/m2 and FGF23 66.2 (55.3-82.9) pg/mL. Significant changes in median BMI (-10.8 kg/m2 , 95% CI: -12.9 to -7.2, P < 0.0001), fat mass (-20.0 kg, 95% CI: -26.7 to -12.4, P < 0.0001) and weight (-34.7 kg, 95% CI -40.0 to -23.1, P < 0.0001) were observed after SG. FGF23 (-12.4 pg/mL, 95% CI: -19.5 to 2.0, P = 0.005), PTH (-1.1 pmol/L, 95% CI: -1.7 to 0.2, P = 0.009) and leptin (-1687 pg/mL, 95% CI -4524 to -563, P = 0.01) declined following SG. Change in FGF23 was not significantly associated with change in measures of adiposity, PTH or leptin. CONCLUSIONS FGF23 concentrations decline in the setting of significant weight loss following SG, implying that increased FGF23 concentrations are a downstream consequence of obesity, which may confound its association with cardiometabolic dysfunction. Mediators of the relationship between adiposity and FGF23 require further elucidation.
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Affiliation(s)
- Emma O Billington
- Faculty of Medical and Health Sciences, Department of Medicine, University of Auckland, Auckland, New Zealand
- Cumming School of Medicine, Division of Endocrinology & Metabolism, University of Calgary, Calgary, Alberta, Canada
| | - Rinki Murphy
- Faculty of Medical and Health Sciences, Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Greg D Gamble
- Faculty of Medical and Health Sciences, Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Karen Callon
- Faculty of Medical and Health Sciences, Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Naomi Davies
- Faculty of Medical and Health Sciences, Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Lindsay D Plank
- Faculty of Medical and Health Sciences, Department of Surgery, University of Auckland, Auckland, New Zealand
| | - Michael Booth
- Department of Surgery, North Shore Hospital, Waitemata District Health Board, Auckland, New Zealand
| | - Ian R Reid
- Faculty of Medical and Health Sciences, Department of Medicine, University of Auckland, Auckland, New Zealand
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14
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Palmieri S, Bedeschi MF, Cairoli E, Morelli V, Lunati ME, Scillitani A, Carnevale V, Lalatta F, Barbieri AM, Orsi E, Spada A, Chiodini I, Eller-Vainicher C. Bone involvement and mineral metabolism in Williams' syndrome. J Endocrinol Invest 2019; 42:337-344. [PMID: 30030744 DOI: 10.1007/s40618-018-0924-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 07/10/2018] [Indexed: 12/13/2022]
Abstract
CONTEXT The previous studies suggested a possible increased risk of hypercalcaemia and reduced bone mineral density (BMD) in Williams' syndrome (WS). However, an extensive study regarding bone metabolism has never been performed. OBJECTIVE To investigate bone health in young adults with WS. DESIGN Cross-sectional study. SETTINGS Endocrinology and Metabolic Diseases and Medical Genetic Units. PATIENTS 29 WS young adults and 29 age- and sex-matched controls. MAIN OUTCOME MEASURES In all subjects, calcium, phosphorus, bone alkaline phosphatase (bALP), parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHVitD), osteocalcin (OC), carboxyterminal cross-linking telopeptide of type I collagen (CTX), 24-h urinary calcium and phosphorus, femoral-neck (FN) and lumbar-spine (LS) BMD and vertebral fractures (VFx) were assessed. In 19 patients, serum fibroblast growth factor-23 (FGF23) levels were measured. RESULTS WS patients showed lower phosphorus (3.1 ± 0.7 vs 3.8 ± 0.5 mg/dL, p = 0.0001) and TmP/GFR (0.81 ± 0.32 vs 1.06 ± 0.25 mmol/L, p = 0.001), and an increased prevalence (p = 0.005) of hypophosphoremia (34.5 vs 3.4%) and reduced TmP/GFR (37.9 vs 3.4%). Moreover, bALP (26.3 ± 8.5 vs 35.0 ± 8.0 U/L), PTH (24.5 ± 12.6 vs 33.7 ± 10.8 pg/mL), OC (19.4 ± 5.3 vs 24.5 ± 8.7 ng/mL), and FN-BMD (- 0.51 ± 0.32 vs 0.36 ± 0.32) were significantly lower (p < 0.05), while CTX significantly higher (401.2 ± 169.3 vs 322.3 ± 122.4 pg/mL, p < 0.05). Serum and urinary calcium and 25OHVitD levels, LS-BMD and VFx prevalence were comparable. No cases of hypercalcemia and suppressed FGF23 were documented. Patients with low vs normal phosphorus and low vs normal TmP/GFR showed comparable FGF23 levels. FGF23 did not correlate with phosphorus and TmP/GFR values. CONCLUSIONS Adult WS patients have reduced TmP/GFR, inappropriately normal FGF23 levels and an uncoupled bone turnover with low femoral BMD.
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Affiliation(s)
- S Palmieri
- Department of Medical Sciences and Community Health, University of Milan, Milan, Italy.
- Unit of Endocrinology and Metabolic Diseases, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy.
| | - M F Bedeschi
- Medical Genetic Unit, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - E Cairoli
- Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
| | - V Morelli
- Unit of Endocrinology and Metabolic Diseases, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - M E Lunati
- Unit of Endocrinology and Metabolic Diseases, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - A Scillitani
- Unit of Endocrinology, "Casa Sollievo della Sofferenza", Hospital, IRCCS, San Giovanni Rotondo, Foggia, Italy
| | - V Carnevale
- Unit of Internal Medicine, "Casa Sollievo della Sofferenza", Hospital, IRCCS, San Giovanni Rotondo, Foggia, Italy
| | - F Lalatta
- Medical Genetic Unit, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - A M Barbieri
- Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
- Unit of Endocrinology and Metabolic Diseases, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - E Orsi
- Unit of Endocrinology and Metabolic Diseases, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - A Spada
- Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
| | - I Chiodini
- Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
- Unit for Bone Metabolism Diseases and Diabetes and Lab of Endocrine and Metabolic Research, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - C Eller-Vainicher
- Unit of Endocrinology and Metabolic Diseases, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
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15
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Akhabue E, Vu THT, Vaidya A, Michos ED, de Boer IH, Kestenbaum B, Allison M, Szklo M, Ouyang P, Yancy CW, Wolf M, Isakova T, Carnethon MR. Fibroblast Growth Factor-23, Heart Failure Risk, and Renin-Angiotensin-Aldosterone-System Blockade in Hypertension: The MESA Study. Am J Hypertens 2019; 32:18-25. [PMID: 30256890 PMCID: PMC7179751 DOI: 10.1093/ajh/hpy142] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/26/2018] [Accepted: 09/24/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Higher fibroblast growth factor-23 (FGF23) concentrations have been found to be associated with incident heart failure (HF). Experimental data suggest FGF23 directly stimulates myocardial hypertrophy. FGF23 may also enhance renin-angiotensin-aldosterone system activity. Whether FGF23 is associated with increased HF risk in populations with hypertension and whether this association is weaker in the presence of angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker (ARB) therapy is unknown. METHODS We studied 2,858 adults with hypertension free of cardiovascular disease at baseline (65.6 ± 9.5 years, 46.2% male) participating in the Multi-Ethnic Study of Atherosclerosis (MESA). We investigated the association of baseline serum intact FGF23 with incident HF over a 14-year median follow-up and whether ACEI/ARB therapy modified this risk. We also investigated the relationship of FGF23 with aldosterone and plasma renin activity in a random subgroup of the entire MESA cohort with available assays (N = 1,642). RESULTS In adjusted Cox regression models, higher FGF23 was associated with a 63% greater hazard of incident HF (hazard ratio: 1.63, 95% confidence interval: [1.13-2.36] per 1-unit increase in log-transformed FGF23), which persisted after exclusion of participants with chronic kidney disease (hazard ratio: 1.94 [1.10-3.43]). There was no heterogeneity by ACEI/ARB use (Pinteraction = 0.438). FGF23 improved model fit over covariables (likelihood ratio χ2 = 6.67, P = 0.010). In multivariable linear regression models, there was no association between FGF23 and aldosterone or plasma renin activity. CONCLUSIONS Higher FGF23 concentrations are associated with a significantly increased risk of HF in hypertension but this risk did not differ by ACEI/ARB treatment status. FGF23 may be a useful biomarker for HF risk in hypertensive populations.
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Affiliation(s)
- Ehimare Akhabue
- Division of Cardiovascular Diseases and Hypertension, Department of Medicine, Rutgers University Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
| | - Thanh-Huyen T Vu
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Anand Vaidya
- Division of Endocrinology, Diabetes and Hypertension, Harvard Medical School, Boston, Massachusetts, USA
| | - Erin D Michos
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Ian H de Boer
- Division of Nephrology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Bryan Kestenbaum
- Division of Nephrology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Matthew Allison
- Division of Preventive Medicine, University of California-San Diego School of Medicine, La Jolla, California, USA
| | - Moyses Szklo
- Division of Cardiovascular and Clinical Epidemiology, John Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Pamela Ouyang
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Clyde W Yancy
- Division of Cardiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Myles Wolf
- Division of Nephrology, Duke University School of Medicine, Durham, North Carolin, USA
| | - Tamara Isakova
- Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Mercedes R Carnethon
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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16
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Complementary Biomarker Assessment of Components Absorbed from Diet and Creatinine Excretion Rate Reflecting Muscle Mass in Dialysis Patients. Nutrients 2018; 10:nu10121827. [PMID: 30486226 PMCID: PMC6316271 DOI: 10.3390/nu10121827] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 11/12/2018] [Accepted: 11/20/2018] [Indexed: 12/21/2022] Open
Abstract
To prevent protein energy malnutrition (PEM) and accumulation of waste products, dialysis patients require diet adjustments. Dietary intake assessed by self-reported intakes often provides biased information and standard 24-h urinary excretion is inapplicable in dialysis patients. We aimed to assess dietary intake via a complementary, less biased biomarker method, and to compare this to dietary diaries. Additionally, we investigated the prospective association of creatinine excretion rate (CER) reflecting muscle mass with mortality. Complete intradialytic dialysate and interdialytic urinary collections were used to calculate 24-h excretion of protein, sodium, potassium, phosphate and creatinine in 42 chronic dialysis patients and compared with protein, sodium, potassium, and phosphate intake assessed by 5-day dietary diaries. Cox regression analyses were employed to investigate associations of CER with mortality. Mean age was 64 ± 13 years and 52% were male. Complementary biomarker assessed (CBA) and dietary assessed (DA) protein intake were significantly correlated (r = 0.610; p < 0.001), but there was a constant bias, as dietary diaries overestimated protein intake in most patients. Correlations were found between CBA and DA sodium intake (r = 0.297; p = 0.056), potassium intake (r = 0.312; p = 0.047) and phosphate uptake/intake (r = 0.409; p = 0.008). However, Bland-Altman analysis showed significant proportional bias. During a median follow-up of 26.6 (25.3–31.5) months, nine dialysis patients (23%) died. CER was independently and inversely associated with survival (HR: 0.59 (0.42–0.84); p = 0.003). Excretion measurements may be a more reliable assessment of dietary intake in dialysis patients, as this method is relatively free from biases known to exist for self-reported intakes. CER seems to be a promising tool for monitoring PEM.
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17
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Stremke ER, McCabe LD, McCabe GP, Martin BR, Moe SM, Weaver CM, Peacock M, Hill Gallant KM. Twenty-Four-Hour Urine Phosphorus as a Biomarker of Dietary Phosphorus Intake and Absorption in CKD: A Secondary Analysis from a Controlled Diet Balance Study. Clin J Am Soc Nephrol 2018; 13:1002-1012. [PMID: 29921736 PMCID: PMC6032595 DOI: 10.2215/cjn.00390118] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 04/17/2018] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND OBJECTIVES Twenty-four-hour urine phosphorus is commonly used as a surrogate measure for phosphorus intake and absorption in research studies, but its reliability and accuracy are unproven in health or CKD. This secondary analysis sought to determine the reliability and accuracy of 24-hour urine phosphorus as a biomarker of phosphorus intake and absorption in moderate CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Eight patients with stage 3-4 CKD participated in 2-week balance studies with tightly controlled phosphorus and calcium intakes. Thirteen 24-hour urine collections per patient were analyzed for variability and reliability of 24-hour urine phosphorus and phosphorus-to-creatinine ratio. The accuracy of 24-hour urine phosphorus to predict phosphorus intake was determined using a published equation. The relationships of 24-hour urine phosphorus with phosphorus intake, net absorption, and retention were determined. RESULTS There was wide day-to-day variation in 24-hour urine phosphorus within and among subjects (coefficient of variation of 30% and 37%, respectively). Two 24-hour urine measures were needed to achieve ≥75% reliability. Estimating dietary phosphorus intake from a single 24-hour urine resulted in underestimation up to 98% in some patients and overestimation up to 79% in others. Twenty-four-hour urine phosphorus negatively correlated with whole-body retention but was not related to net absorption. CONCLUSIONS From a sample of eight patients with moderate CKD on a tightly controlled dietary intake, 24-hour urine phosphorus was highly variable and did not relate to dietary phosphorus intake or absorption, rather it inversely related to phosphorus retention.
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Affiliation(s)
| | | | | | | | - Sharon M. Moe
- Divisions of Nephrology and
- Roudebush Veterans Administration Medical Center, Indianapolis, Indiana
| | | | - Munro Peacock
- Endocrinology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana; and
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18
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Akhabue E, Montag S, Reis JP, Pool LR, Mehta R, Yancy CW, Zhao L, Wolf M, Gutierrez OM, Carnethon MR, Isakova T. FGF23 (Fibroblast Growth Factor-23) and Incident Hypertension in Young and Middle-Aged Adults: The CARDIA Study. Hypertension 2018; 72:70-76. [PMID: 29712737 PMCID: PMC6002950 DOI: 10.1161/hypertensionaha.118.11060] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 02/28/2018] [Accepted: 03/30/2018] [Indexed: 12/21/2022]
Abstract
Blacks have the highest prevalence of hypertension in the United States. Higher levels of FGF23 (fibroblast growth factor-23) have been associated with worse cardiovascular outcomes. Whether FGF23 is associated with rising blood pressure (BP) and racial differences in incident hypertension is unclear. We studied 1758 adults (45.0±3.7 years; 57.8% female; 36.9% black) without hypertension or cardiovascular disease who participated in the year 20 (2005-2006) follow-up examination of the CARDIA study (Coronary Artery Risk Development in Young Adults). We investigated the associations of baseline (year 20) cFGF23 (C-terminal FGF23) levels with longitudinal BP patterns and incident hypertension (defined as being on antihypertensive medication, systolic BP ≥130 or diastolic BP ≥80 mm Hg) during 2 follow-up visits (years 25 and 30). During follow-up, 35.2% of participants developed hypertension. In multivariable linear mixed models, there were greater increases in systolic BP from year 20 to 25 and year 25 to 30 in the highest FGF23 quartile relative to the lowest quartile (+2.1 mm Hg, P=0.0057 and +2.2 mm Hg, P=0.0108, respectively for each time period), whereas there were greater increases in diastolic BP from year 20 to 25 in the highest quartile relative to the lowest (+1.6 mm Hg; P=0.0024). In multivariable modified Poisson regression analyses, the highest FGF23 quartile was associated with a 45% greater risk of developing hypertension during follow-up compared with the lowest quartile (relative risk, 1.45 [1.18-1.77]). Results did not vary by race (Pinteraction=0.1523). Higher FGF23 levels are independently associated with rising BP over time and an increased risk of incident hypertension but not racial differences in hypertension.
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Affiliation(s)
- Ehimare Akhabue
- From the Northwestern University Feinberg School of Medicine, Chicago, IL (E.A., S.M., L.R.P., R.M., C.W.Y., L.Z., M.R.C., T.I.)
| | - Samantha Montag
- From the Northwestern University Feinberg School of Medicine, Chicago, IL (E.A., S.M., L.R.P., R.M., C.W.Y., L.Z., M.R.C., T.I.)
| | - Jared P Reis
- National Heart, Lung, and Blood Institute, Bethesda, MD (J.P.R.)
| | - Lindsay R Pool
- From the Northwestern University Feinberg School of Medicine, Chicago, IL (E.A., S.M., L.R.P., R.M., C.W.Y., L.Z., M.R.C., T.I.)
| | - Rupal Mehta
- From the Northwestern University Feinberg School of Medicine, Chicago, IL (E.A., S.M., L.R.P., R.M., C.W.Y., L.Z., M.R.C., T.I.)
| | - Clyde W Yancy
- From the Northwestern University Feinberg School of Medicine, Chicago, IL (E.A., S.M., L.R.P., R.M., C.W.Y., L.Z., M.R.C., T.I.)
| | - Lihui Zhao
- From the Northwestern University Feinberg School of Medicine, Chicago, IL (E.A., S.M., L.R.P., R.M., C.W.Y., L.Z., M.R.C., T.I.)
| | - Myles Wolf
- Duke University School of Medicine, Durham, NC (M.W.)
| | | | - Mercedes R Carnethon
- From the Northwestern University Feinberg School of Medicine, Chicago, IL (E.A., S.M., L.R.P., R.M., C.W.Y., L.Z., M.R.C., T.I.)
| | - Tamara Isakova
- From the Northwestern University Feinberg School of Medicine, Chicago, IL (E.A., S.M., L.R.P., R.M., C.W.Y., L.Z., M.R.C., T.I.)
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19
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Shan Z, Alvarez-Sola G, Uriarte I, Arechederra M, Fernández-Barrena MG, Berasain C, Ju C, Avila MA. Fibroblast growth factors 19 and 21 in acute liver damage. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:257. [PMID: 30069459 DOI: 10.21037/atm.2018.05.26] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Currently there are very few pharmacological options available to treat acute liver injury. Because its natural exposure to noxious stimuli the liver has developed a strong endogenous hepatoprotective capacity. Indeed, experimental evidence exposed a variety of endogenous hepatic and systemic responses naturally activated to protect the hepatic parenchyma and to foster liver regeneration, therefore preserving individual's survival. The fibroblast growth factor (FGF) family encompasses a range of polypeptides with important effects on cellular differentiation, growth survival and metabolic regulation in adult organisms. Among these FGFs, FGF19 and FGF21 are endocrine hormones that profoundly influence systemic metabolism but also exert important hepatoprotective activities. In this review, we revisit the biology of these factors and highlight their potential application for the clinical management of acute liver injury.
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Affiliation(s)
- Zhao Shan
- Department of Anesthesiology, McGovern Medical School, University of Texas Health Science Center at Houston, TX, USA
| | - Gloria Alvarez-Sola
- Hepatology Program, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.,CIBERehd, Carlos III Institute of Health, Pamplona, Spain
| | - Iker Uriarte
- Hepatology Program, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.,CIBERehd, Carlos III Institute of Health, Pamplona, Spain
| | - María Arechederra
- Hepatology Program, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.,CIBERehd, Carlos III Institute of Health, Pamplona, Spain
| | - Maite G Fernández-Barrena
- Hepatology Program, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.,CIBERehd, Carlos III Institute of Health, Pamplona, Spain
| | - Carmen Berasain
- Hepatology Program, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.,CIBERehd, Carlos III Institute of Health, Pamplona, Spain.,Instituto de Investigaciones Sanitarias de Navarra (IDISNA), Pamplona, Spain
| | - Cynthia Ju
- Department of Anesthesiology, McGovern Medical School, University of Texas Health Science Center at Houston, TX, USA
| | - Matías A Avila
- Hepatology Program, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.,CIBERehd, Carlos III Institute of Health, Pamplona, Spain.,Instituto de Investigaciones Sanitarias de Navarra (IDISNA), Pamplona, Spain
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20
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Zhang X, Guo K, Xia F, Zhao X, Huang Z, Niu J. FGF23 C-tail improves diabetic nephropathy by attenuating renal fibrosis and inflammation. BMC Biotechnol 2018; 18:33. [PMID: 29843712 PMCID: PMC5975516 DOI: 10.1186/s12896-018-0449-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 05/18/2018] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND High level of serum fibroblast growth factor 23 (FGF23) is implicated in the development and progression of diabetic nephropathy (DN), making it a crucial factor in the pathogenesis of DN. FGF23 is also tightly correlated with inflammation in the progression of DN. The aim of this study was to explore whether the C-terminal of FGF23 (FGF23C-tail), an antagonist that can block the FGF23 signaling pathway by competing with intact FGF23, could exhibit a therapeutic effect on DN. RESULTS Biochemical data and histological examination showed that FGF23 C-tail administration ameliorated the functional and morphological abnormalities of db/db mice with DN without changing the levels of circulating FGF23 and phosphate. Evaluation of morphology and fibrosis by Masson's trichrome staining and IHC staining of fibronectin, PCR, and western blot analysis showed that FGF23C-tail prevents diabetes-induced fibrosis in db/db mice. Importantly, FGF23C-tail decreased the levels of inflammatory cytokines in serum and renal tissues. CONCLUSION FGF23C-tail may improve diabetic nephropathy by decreasing inflammation and fibrosis in db/db mice, suggesting that blocking of FGF23 action remains an important therapeutic target for the prevention or attenuation of the progression of DN.
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Affiliation(s)
- Xiaomin Zhang
- Department of Biopharmacy, School of Pharmacy, Wenzhou Medical University, Chashan Town, Wenzhou, 325035, China
| | - Kaiwen Guo
- Department of Biopharmacy, School of Pharmacy, Wenzhou Medical University, Chashan Town, Wenzhou, 325035, China
| | - Feng Xia
- Department of Biopharmacy, School of Pharmacy, Wenzhou Medical University, Chashan Town, Wenzhou, 325035, China
| | - Xinyu Zhao
- Department of Biopharmacy, School of Pharmacy, Wenzhou Medical University, Chashan Town, Wenzhou, 325035, China
| | - Zhifeng Huang
- Department of Biopharmacy, School of Pharmacy, Wenzhou Medical University, Chashan Town, Wenzhou, 325035, China.
| | - Jianlou Niu
- Department of Biopharmacy, School of Pharmacy, Wenzhou Medical University, Chashan Town, Wenzhou, 325035, China.
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Visceral Congestion in Heart Failure: Right Ventricular Dysfunction, Splanchnic Hemodynamics, and the Intestinal Microenvironment. Curr Heart Fail Rep 2018; 14:519-528. [PMID: 29075956 DOI: 10.1007/s11897-017-0370-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE OF REVIEW Visceral venous congestion of the gut may play a key role in the pathogenesis of right-sided heart failure (HF) and cardiorenal syndromes. Here, we review the role of right ventricular (RV) dysfunction, visceral congestion, splanchnic hemodynamics, and the intestinal microenvironment in the setting of right-sided HF. We review recent literature on this topic, outline possible mechanisms of disease pathogenesis, and discuss potential therapeutics. RECENT FINDINGS There are several mechanisms linking RV-gut interactions via visceral venous congestion which could result in (1) hypoxia and acidosis in enterocytes, which may lead to enhanced sodium-hydrogen exchanger 3 (NHE3) expression with increased sodium and fluid retention; (2) decreased luminal pH in the intestines, which could lead to alteration of the gut microbiome which could increase gut permeability and inflammation; (3) alteration of renal hemodynamics with triggering of the cardiorenal syndrome; and (4) altered phosphate metabolism resulting in increased pulmonary artery stiffening, thereby increasing RV afterload. A wide variety of therapeutic interventions that act on the RV, pulmonary vasculature, intestinal microenvironment, and the kidney could alter these pathways and should be tested in patients with right-sided HF. The RV-gut axis is an important aspect of HF pathogenesis that deserves more attention. Modulation of the pathways interconnecting the right heart, visceral congestion, and the intestinal microenvironment could be a novel avenue of intervention for right-sided HF.
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Richter B, Faul C. FGF23 Actions on Target Tissues-With and Without Klotho. Front Endocrinol (Lausanne) 2018; 9:189. [PMID: 29770125 PMCID: PMC5940753 DOI: 10.3389/fendo.2018.00189] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 04/06/2018] [Indexed: 12/11/2022] Open
Abstract
Fibroblast growth factor (FGF) 23 is a phosphaturic hormone whose physiologic actions on target tissues are mediated by FGF receptors (FGFR) and klotho, which functions as a co-receptor that increases the binding affinity of FGF23 for FGFRs. By stimulating FGFR/klotho complexes in the kidney and parathyroid gland, FGF23 reduces renal phosphate uptake and secretion of parathyroid hormone, respectively, thereby acting as a key regulator of phosphate metabolism. Recently, it has been shown that FGF23 can also target cell types that lack klotho. This unconventional signaling event occurs in an FGFR-dependent manner, but involves other downstream signaling pathways than in "classic" klotho-expressing target organs. It appears that klotho-independent signaling mechanisms are only activated in the presence of high FGF23 concentrations and result in pathologic cellular changes. Therefore, it has been postulated that massive elevations in circulating levels of FGF23, as found in patients with chronic kidney disease, contribute to associated pathologies by targeting cells and tissues that lack klotho. This includes the induction of cardiac hypertrophy and fibrosis, the elevation of inflammatory cytokine expression in the liver, and the inhibition of neutrophil recruitment. Here, we describe the signaling and cellular events that are caused by FGF23 in tissues lacking klotho, and we discuss FGF23's potential role as a hormone with widespread pathologic actions. Since the soluble form of klotho can function as a circulating co-receptor for FGF23, we also discuss the potential inhibitory effects of soluble klotho on FGF23-mediated signaling which might-at least partially-underlie the pleiotropic tissue-protective functions of klotho.
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