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Gadelkareem RA, Moeen AM, Reda A, Azoz NM, Elhadad AF, Taha TM, Mohammed N, Taha MI. Experience of a Tertiary-Level Urology Center in the Clinical Urological Events of Rare and Very Rare Incidence. III. Psychourological Events: 1. Psychic Anuria. Urol Int 2018; 101:80-84. [PMID: 29843132 DOI: 10.1159/000488881] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 03/28/2018] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Psychic anuria is an old term, referring to a very rare psycho-urological event that has scarcely been studied so far. MATERIALS AND METHODS A retrospective study of the patients with psychic anuria presented to Assiut Urology and Nephrology Hospital during the period July 1991-June 2016 was done. Psychic anuria was defined, and the demographic and clinical characteristics including the methods of diagnosis and management were studied. RESULTS Of more than 3,800 cases of anuria, 9 female patients (0.24%) experienced psychic anuria in the age range of 17-43 years. Cardinal clinical findings included anuria for 36-72 h with absence of organic causes and normal renal function tests. Psychosocial risk factors were reported in the 9 cases. Anuria was documented by reliable history (56%) or observable urine collection (44%). Diagnosis was done by exclusion, where the investigations revealed no organic causes. Seven cases responded to the placebo intervention and 2 cases were self-limiting and resolved spontaneously. CONCLUSIONS Psychic anuria is an extremely rare urological emergency that presents, mainly, in young adult females with unknown mechanisms. Renal vasoconstriction following psychosocial stressors is suggested. It is diagnosed by exclusion and resolves spontaneously or responds to placebo intervention as a mental distraction technique.
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Affiliation(s)
- Rabea A Gadelkareem
- Assiut Urology and Nephrology Hospital, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Ahmed M Moeen
- Assiut Urology and Nephrology Hospital, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Ahmed Reda
- Assiut Urology and Nephrology Hospital, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Nashwa M Azoz
- Department of Internal Medicine-Nephrology Unit, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Ali F Elhadad
- Department of Neuropsychiatry, Faculty of Medicine, Al-Azhar University-Assiut Branch, Assiut, Egypt
| | - Taha M Taha
- Assiut Urology and Nephrology Hospital, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Nasreldin Mohammed
- Assiut Urology and Nephrology Hospital, Faculty of Medicine, Assiut University, Assiut, Egypt
- Department of Urology, Martin-Luther University, Halle, Germany
| | - Mohammed I Taha
- Assiut Urology and Nephrology Hospital, Faculty of Medicine, Assiut University, Assiut, Egypt
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Ichii T, Morimoto R, Okumura T, Ishii H, Tatami Y, Yamamoto D, Aoki S, Hiraiwa H, Furusawa K, Kondo T, Watanabe N, Kano N, Fukaya K, Sawamura A, Suzuki S, Yasuda Y, Murohara T. Impact of Renal Functional/Morphological Dynamics on the Calcification of Coronary and Abdominal Arteries in Patients with Chronic Kidney Disease. J Atheroscler Thromb 2017; 24:1092-1104. [PMID: 28392544 PMCID: PMC5684475 DOI: 10.5551/jat.39271] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Aim: Fast-progressing vascular calcification (VC) is accompanied by renal atrophy and functional deterioration along with atherosclerosis in patients with chronic kidney disease (CKD). However, the relationship between VC progression and renal functional and/or morphological changes remains unclear. Methods: We included 70 asymptomatic patients with CKD without hemodialysis in our study. To identify temporal variations, the coronary artery calcification score (CACS), abdominal aortic calcification index (ACI), and renal parenchymal volume index (RPVI) were determined via spiral computed tomography scans taken during the study. We investigated significant factors related to annualized variations of CACS (ΔCACS/y) and ACI (ΔACI/y). Results: During the follow-up period (4.6 years), median values of CACS [in Agatston units (AU)] and ACI increased from 40.2 to 113.3 AU (p = 0.053) and from 13.2 to 21.7% (p = 0.036), respectively. Multivariate analysis revealed that CACS at baseline (p < 0.001) and diabetes mellitus (DM) status (p = 0.037) for ΔCACS/y and ACI at baseline (p = 0.017) and hypertension (HT) status (p = 0.046) for ΔACI/y were significant independent predictors. Furthermore, annualized RPVI variation was significantly related to both ΔCACS/y and ΔACI/y (R = −0.565, p < 0.001, and R = −0.289, p = 0.015, respectively). On the other hand, independent contributions of the estimated glomerular filtration rate (eGFR) and annualized eGFR variation to VC progression were not confirmed. Conclusion: The degree of VC at baseline, DM, HT, and changes in renal volume, but not eGFR, had a strong impact on VC progression in patients with CKD.
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Affiliation(s)
- Takeo Ichii
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Ryota Morimoto
- Department of Cardiology, Nagoya University Graduate School of Medicine.,Department of CKD Initiatives Internal Medicine, Nagoya University Graduate School of Medicine
| | - Takahiro Okumura
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Hideki Ishii
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Yosuke Tatami
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Dai Yamamoto
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Soichiro Aoki
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Hiroaki Hiraiwa
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Kenji Furusawa
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Toru Kondo
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Naoki Watanabe
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Naoaki Kano
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Kenji Fukaya
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Akinori Sawamura
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Susumu Suzuki
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Yoshinari Yasuda
- Department of CKD Initiatives Internal Medicine, Nagoya University Graduate School of Medicine
| | - Toyoaki Murohara
- Department of Cardiology, Nagoya University Graduate School of Medicine
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Parker VJ, Harjes LM, Dembek K, Young GS, Chew DJ, Toribio RE. Association of Vitamin D Metabolites with Parathyroid Hormone, Fibroblast Growth Factor-23, Calcium, and Phosphorus in Dogs with Various Stages of Chronic Kidney Disease. J Vet Intern Med 2017; 31:791-798. [PMID: 28186657 PMCID: PMC5435068 DOI: 10.1111/jvim.14653] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 10/28/2016] [Accepted: 12/06/2016] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Hypovitaminosis D is associated with progression of renal disease, development of renal secondary hyperparathyroidism (RHPT), chronic kidney disease-mineral bone disorder (CKD-MBD), and increased mortality in people with CKD. Despite what is known regarding vitamin D dysregulation in humans with CKD, little is known about vitamin D metabolism in dogs with CKD. OBJECTIVES The purpose of our study was to further elucidate vitamin D status in dogs with different stages of CKD and to relate it to factors that affect the development of CKD-MBD, including parathyroid hormone (PTH), fibroblast growth factor-23 (FGF-23), calcium, and phosphorus concentrations. METHODS Thirty-seven dogs with naturally occurring CKD were compared to 10 healthy dogs. Serum 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)2 D], and 24,25-dihydroxyvitamin D [24,25(OH)2 D], and PTH and FGF-23 concentrations were measured. Their association with serum calcium and phosphorus concentrations and IRIS stage was determined. RESULTS Compared to healthy dogs, all vitamin D metabolite concentrations were significantly lower in dogs with International Renal Interest Society (IRIS) stages 3 and 4 CKD (r [creatinine]: -0.49 to -0.60; P < .05) but not different in dogs with stages 1 and 2 CKD. All vitamin D metabolites were negatively correlated with PTH, FGF-23, and phosphorus concentrations (r: -0.39 to -0.64; P < .01). CONCLUSIONS AND CLINICAL IMPORTANCE CKD in dogs is associated with decreases in all vitamin D metabolites evaluated suggesting that multiple mechanisms, in addition to decreased renal mass, affect their metabolism. This information could have prognostic and therapeutic implications.
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Affiliation(s)
- V J Parker
- Veterinary Clinical Sciences, The Ohio State University, Columbus, OH
| | - L M Harjes
- Veterinary Clinical Sciences, The Ohio State University, Columbus, OH
| | - K Dembek
- Veterinary Clinical Sciences, The Ohio State University, Columbus, OH
| | - G S Young
- Center for Biostatistics, The Ohio State University, Columbus, OH
| | - D J Chew
- Veterinary Clinical Sciences, The Ohio State University, Columbus, OH
| | - R E Toribio
- Veterinary Clinical Sciences, The Ohio State University, Columbus, OH
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Kim CS, Bae EH, Ma SK, Han SH, Lee KB, Lee J, Oh KH, Chae DW, Kim SW. Chronic Kidney Disease-Mineral Bone Disorder in Korean Patients: a Report from the KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD). J Korean Med Sci 2017; 32:240-248. [PMID: 28049234 PMCID: PMC5219989 DOI: 10.3346/jkms.2017.32.2.240] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 11/14/2016] [Indexed: 12/12/2022] Open
Abstract
This study examined the characteristics of biochemical parameters, bone diseases, and vascular calcification in Korean patients with chronic kidney disease (CKD) not yet on dialysis. Serum levels of fibroblast growth factor 23 (FGF23), intact parathyroid hormone (iPTH), 25-hydroxyvitamin D3 (25D), and 1,25-dihydroxyvitamin D3 (1,25D); lumbar spine, total hip, and femur neck bone mineral densities; and brachial-to-ankle pulse wave velocity (baPWV) representing vascular calcification were measured at baseline for 2,238 CKD patients in the KoreaN Cohort Study for Outcomes in Patients With CKD (KNOW-CKD). Increases in serum FGF23 and iPTH preceded changes in serum calcium and phosphate, similar to Western populations. However, the 25D and 1,25D levels decreased earlier than serum FGF23 or iPTH increased, with a decreased estimated glomerular filtration rate (eGFR) in Korean CKD patients. Vitamin D deficiency occurred in 76.7% of patients with CKD stage 1. Bone mineral densities were lowest in CKD stage 5 (lumbar spine, -0.64 ± 1.67; total hip, -0.49 ± 1.21; femur neck, -1.02 ± 1.25). Osteoporosis was more prevalent in patients with higher CKD stages. The mean baPWV, abdominal aortic calcification (AAC), and coronary calcium score also increased, with declined eGFR. In conclusion, a decline in serum vitamin D levels was observed in early CKD stages before significant increases of FGF23 and iPTH in the Korean CKD population compared with that in Western populations. Increased bone disease and vascular calcification occurred in early-stage CKD.
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Affiliation(s)
- Chang Seong Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Eun Hui Bae
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Seong Kwon Ma
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Seung Hyeok Han
- Depatment of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Kyu Beck Lee
- Division of Nephrology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Joongyub Lee
- Medical Research Collaborating Center, Seoul National University Hospital and Seoul National University College of Medicine, Seoul, Korea
| | - Kook Hwan Oh
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea
| | - Dong Wan Chae
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul, Korea
| | - Soo Wan Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
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Sista SK, Arum SM. Management of adynamic bone disease in chronic kidney disease: A brief review. J Clin Transl Endocrinol 2016; 5:32-35. [PMID: 29067232 PMCID: PMC5644430 DOI: 10.1016/j.jcte.2016.07.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 07/07/2016] [Accepted: 07/12/2016] [Indexed: 12/17/2022] Open
Abstract
The Kidney Disease: Improving Global Outcomes (KDIGO) work group released recommendations in 2006 to define the bone-related pathology associated with chronic kidney disease as renal osteodystrophy. In 2009, KDIGO released revised clinical practice guidelines which redefined systemic disorders of bone and mineral metabolism due to chronic kidney disease as chronic kidney disease-mineral and bone disorders. Conditions under this overarching term include osteitis fibrosa cystica, osteomalacia, and adynamic bone disease. We aim to provide a brief review of the histopathology, pathophysiology, epidemiology, and diagnostic features of adynamic bone disease, focusing on current trends in the management of this complex bone disorder.
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Affiliation(s)
| | - Seth M. Arum
- Division of Endocrinology, Diabetes, and Metabolism, University of Massachusetts, 55 Lake Avenue North, Worcester, MA 01655, USA
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Ide N, Olauson H, Sato T, Densmore MJ, Wang H, Hanai JI, Larsson TE, Lanske B. In vivo evidence for a limited role of proximal tubular Klotho in renal phosphate handling. Kidney Int 2016; 90:348-362. [DOI: 10.1016/j.kint.2016.04.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 03/29/2016] [Accepted: 04/14/2016] [Indexed: 01/11/2023]
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Keles N, Caliskan M, Dogan B, Keles NN, Kalcik M, Aksu F, Kostek O, Aung SM, Isbilen B, Oguz A. Low Serum Level of Klotho Is an Early Predictor of Atherosclerosis. TOHOKU J EXP MED 2016; 237:17-23. [PMID: 26289053 DOI: 10.1620/tjem.237.17] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Klotho gene, identified as an 'aging suppressor' gene, encodes a single-pass transmembrane protein. The extracellular domain of Klotho is cleaved and released in the blood stream, where it may function as a vasculoprotective hormone. Carotid artery intima-media thickness (CIMT), flow-mediated dilation (FMD) of the brachial artery and epicardial fat thickness (EFT) have been reported as early predictors of atherosclerosis. We aimed to investigate the relationship between serum Klotho levels and early atherosclerotic predictors, including EFT, FMD and CIMT in healthy adults. Fifty healthy volunteers were enrolled in this study, consisting of 21 males and 29 females with median age of 32 years. They were free of known risk factors for cardiovascular diseases. Serum Klotho levels were determined by the ELISA method. The study population was divided into two groups (n = 25 for each) according to the median serum Klotho level (459.4 pg/mL): higher Klotho (HK) group (613.6 pg/mL; ranges of 501.2-772.6 pg/mL) and lower Klotho (LK) group (338.7 pg/mL; ranges of 278.8-430.3 pg/mL). EFT was measured by transthoracic echocardiography, and CIMT and FMD were measured with standard procedures. The LK group showed lower values of FMD (p = 0.012) and larger values of EFT (p = 0.01) and CIMT (p < 0.001), compared to the HK group. Thus, the low serum Klotho levels were associated with increased EFT and CIMT and with the decreased FMD in the study population. We propose that the lower serum Klotho level is a newly identified predictor of atherosclerosis.
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Affiliation(s)
- Nursen Keles
- Department of Cardiology, Goztepe Training and Research Hospital, Istanbul Medeniyet University
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Phosphate and FGF23 in the renoprotective benefit of RAAS inhibition. Pharmacol Res 2016; 106:87-91. [DOI: 10.1016/j.phrs.2016.02.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 02/07/2016] [Accepted: 02/15/2016] [Indexed: 01/15/2023]
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Quirós-González I, Román-García P, Alonso-Montes C, Barrio-Vázquez S, Carrillo-López N, Naves-Díaz M, Mora MI, Corrales FJ, López-Hernández FJ, Ruiz-Torres MP, Cannata-Andía JB, Fernández-Martín JL. Lamin A is involved in the development of vascular calcification induced by chronic kidney failure and phosphorus load. Bone 2016; 84:160-168. [PMID: 26769003 DOI: 10.1016/j.bone.2016.01.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 11/16/2015] [Accepted: 01/04/2016] [Indexed: 12/18/2022]
Abstract
Vascular calcification remains one of the main factors associated to morbidity and mortality in both ageing and chronic kidney disease. Both hyperphosphataemia, a well-known promoter of vascular calcification, and abnormal processing defects of lamin A/C have been associated to ageing. The main aim of this study was to analyse the effect of phosphorus load in the differential expression pattern of genes and proteins, particularly of lamin A/C, which are involved in phenotypic change of the vascular smooth muscle cells to osteoblast-like cells. The in vivo study of the calcified abdominal aortas from nephrectomized rats receiving a high phosphorus diet showed among others, a repression of muscle related proteins and overexpression of lamin A/C. Similar results were observed in vitro, where primary vascular smooth muscle cells cultured in calcifying medium showed increased expression of prelamin A and lamin A and abnormalities in the nuclear morphology. Co-immunoprecipitation assays showed novel and important physical interactions between lamin A and RUNX2 during the process of calcification. In fact, the knockdown of prelamin A and lamin A inhibited the increase of Runx2, osteocalcin and osteopontin gene expression, calcium deposition, nuclear abnormalities and the RUNX2 protein translocation into the nucleus of the cell. These in vivo and in vitro results highlight the important role played by lamin A in the process of vascular calcification.
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Affiliation(s)
- Isabel Quirós-González
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Pablo Román-García
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Cristina Alonso-Montes
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Sara Barrio-Vázquez
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Natalia Carrillo-López
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Manuel Naves-Díaz
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - María Isabel Mora
- Division of Hepatology and Gene Therapy, Proteomics, Genomics and Bioinformatics Unit, Centre for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain
| | - Fernando José Corrales
- Division of Hepatology and Gene Therapy, Proteomics, Genomics and Bioinformatics Unit, Centre for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain
| | - Francisco J López-Hernández
- Department of Renal Physiology, REDinREN del ISCIII, Faculty of Biology, University of Salamanca, 37007 Salamanca, Spain
| | - María Piedad Ruiz-Torres
- Department of Systems Biology, REDinREN del ISCIII, Faculty of Medicine, University of Alcalá, Alcalá de Henares, 28801, Madrid, Spain
| | - Jorge Benito Cannata-Andía
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, University of Oviedo, 33006 Oviedo, Asturias, Spain.
| | - José Luis Fernández-Martín
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, University of Oviedo, 33006 Oviedo, Asturias, Spain
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Abdallah E, Mosbah O, Khalifa G, Metwaly A, El-Bendary O. Assessment of the relationship between serum soluble Klotho and carotid intima-media thickness and left ventricular dysfunction in hemodialysis patients. Kidney Res Clin Pract 2016; 35:42-9. [PMID: 27069857 PMCID: PMC4811978 DOI: 10.1016/j.krcp.2015.12.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/27/2015] [Accepted: 12/16/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The aim of our study was to assess the relationship between soluble Klotho (s-Klotho) and carotid intima-media thickness (CIMT) and left ventricular (LV) dysfunction in hemodialysis (HD) patients. METHODS This is a cross-sectional study conducted on 88 patients with end-stage renal disease on regular HD. Serum levels of calcium, phosphorus, parathyroid hormone, and C-reactive protein were measured. The serum levels of s-Klotho and fibroblast growth factor-23 (FGF-23) were measured using an Enzyme linked immunosorbent assay (ELISA) kit. Echocardiography and measurement of CIMT were also conducted. The studied patients were divided according to the median s-Klotho level into 2 groups: patients with low s-Klotho (Group I) and patients with high s-Klotho (Group II). RESULTS Mean value of s-Klotho was significantly low in HD patients compared to controls (P = 0.001), and mean value of FGF-23 was significantly high in HD patients compared to controls (P = 0.001). The mean values of parathyroid hormone, FGF-23, and phosphorus were significantly high in Group I compared to Group II, whereas the mean value of serum calcium was significantly low in Group I compared to Group II. The mean values of CIMT, LV mass (LVM), LVM index, and LV ejection fraction (LVEF) were high in Group I compared to Group II. Patients with low s-Klotho had significantly more coronary artery disease (CAD). In a regression analysis of s-Klotho with different markers of cardiovascular diseases, s-Klotho showed significant association with CIMT, LVEF, and CAD, but not with LVM and LVM index. CONCLUSION The present study showed that patients with a low s-Klotho were more often associated with increased CIMT, LV dysfunction, and CAD, and it seems that there was independent association between s-Klotho and CIMT, LVEF, and CAD.
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Affiliation(s)
- Emad Abdallah
- Department of Nephrology, Theodor Bilharz Research Institute, Giza, Egypt
| | - Osama Mosbah
- Department of Nephrology, Theodor Bilharz Research Institute, Giza, Egypt
| | - Ghada Khalifa
- Department of Nephrology, Theodor Bilharz Research Institute, Giza, Egypt
| | - Amna Metwaly
- Department of Intensive Care Unit, Theodor Bilharz Research Institute, Giza, Egypt
| | - Omnia El-Bendary
- Department of Clinical Chemistry, Theodor Bilharz Research Institute, Giza, Egypt
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Keles N, Caliskan M, Dogan B, Aksu F, Bulur S, Keles NN, Kostek O, Aung SM, Isbilen B, Demircioglu K, Kalcik M, Oguz A. Is Low Serum Klotho Level Associated with Alterations in Coronary Flow Reserve? Echocardiography 2016; 33:881-8. [PMID: 26791446 DOI: 10.1111/echo.13176] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The Klotho gene, described as an "aging suppressor" gene, encodes a single-pass transmembrane protein. The extracellular part of Klotho is cleaved and released into the circulation where it may function as a vasculoprotective hormone. Coronary flow reserve (CFR) is accepted as a marker of coronary microvascular dysfunction when epicardial coronary stenosis is absent. There are no data regarding the relationship between serum Klotho levels and disorders in coronary microcirculation in healthy adults. We aimed to investigate the association between serum Klotho levels and alterations in coronary microcirculation in healthy adults using echocardiographic measurements of CFR. METHODS Thirty-four healthy volunteers (median age: 34 [27-39], 14 males) were enrolled in this study. The study population was divided into two subgroups according to the median value of serum Klotho levels: a high Klotho (HK) group (n = 17, median age: 34 [30-38]; 6 males) and a low Klotho (LK) group (n = 17, median age: 32 [26-39]; 8 males). The analysis of coronary flow velocities was performed by transthoracic Doppler echocardiography. RESULTS Hyperemic diastolic peak flow velocities and CFR were significantly higher in the HK group than in the LK group (70 [66-92] versus 61 [47-66], P = 0.003 and 3.0 [2.6-3.8] versus 2.2 [1.7-2.8], respectively, P = 0.001). Serum Klotho levels were positively correlated with CFR (P < 0.001). CONCLUSION Serum Klotho levels correlate with CFR in a healthy population. Low serum Klotho levels may potentially identify patients with impaired CFR.
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Affiliation(s)
- Nursen Keles
- Department of Cardiology, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey
| | - Mustafa Caliskan
- Department of Cardiology, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey
| | - Burcu Dogan
- Department of Family Physicians, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey
| | - Feyza Aksu
- Department of Cardiology, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey
| | - Serkan Bulur
- Department of Cardiology, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey
| | - Necibe Nur Keles
- Department of Neurology, Uskudar Government Hospital, İstanbul, Turkey
| | - Osman Kostek
- Department of Internal Medicine, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey
| | - Soe Moe Aung
- Department of Cardiology, Fatih University, Istanbul, Turkey
| | - Banu Isbilen
- Department of Biochemistry, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey
| | - Kenan Demircioglu
- Department of Cardiology, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey
| | - Macit Kalcik
- Department of Cardiology, Iskilip Atıf Hoca State Hospital, Corum, Turkey
| | - Aytekin Oguz
- Department of Internal Medicine, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey
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Liu Z, Su G, Guo X, Wu Y, Liu X, Zou C, Zhang L, Yang Q, Xu Y, Ma W. Dietary interventions for mineral and bone disorder in people with chronic kidney disease. Cochrane Database Syst Rev 2015; 2015:CD010350. [PMID: 26376110 PMCID: PMC9198407 DOI: 10.1002/14651858.cd010350.pub2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Chronic kidney disease-mineral and bone disorder (CKD-MBD) is a systemic dysfunction of mineral and bone metabolism in people with CKD. Recent research shows that phosphate retention plays a significant role in the development of CKD-MBD. Compared with drug therapies, dietary interventions may be simple, inexpensive and feasible for phosphate retention. However, there is little evidence to support these interventions. OBJECTIVES Our objective was to assess the benefits and harms of any dietary intervention for preventing and treating CKD-MBD. SEARCH METHODS We searched Cochrane Kidney and Transplant's Specialised Register to 27 August 2015 through contact with the Trials' Search Co-ordinator using search terms relevant to this review. We also searched the Chinese Biomedicine Database (CBM) (1976 to August 2015), China Knowledge Resource Integrated Database (CNKI) (1979 to August 2015), and VIP (1989 to August 2015). SELECTION CRITERIA Randomised controlled trials (RCTs) and quasi-RCTs looking at dietary interventions for prevention or treatment of CKD-MBD were eligible for inclusion. DATA COLLECTION AND ANALYSIS Two authors independently assessed the eligibility, methodological quality, and extracted data. Continuous outcomes (serum calcium level, serum phosphorus level, calcium × phosphate product, parathyroid hormone (PTH), fibroblast growth factor 23 (FGF-23) and alkaline phosphatase) were expressed as mean difference (MD) with 95% confidence interval (CI). Dichotomous outcomes (mortality) were expressed as risk ratio (RR) with 95% CI. We used a random-effects model to meta-analyse studies. MAIN RESULTS Nine studies were included in this review which analysed 634 participants. Study duration ranged from 4 to 24 weeks. The interventions included calcium-enriched bread, low phosphorus intake, low protein intake, very low protein intake, post haemodialysis supplements and hypolipaemic diet. Only one study reported death; none of the included studies reported cardiovascular events or fractures. There was insufficient reporting of design and methodological aspects among the included studies to enable robust assessment of risk of bias.There was limited and low-quality evidence to indicate that calcium-enriched bread increased serum calcium (1 study, 53 participants: MD -0.16 mmol/L, 95% CI -0.51 to -0.31), decreased serum phosphorus (53 participants: MD -0.41 mmol/L, 95% CI -0.51 to -0.31) and decreased the calcium × phosphate product (53 participants: MD -0.62 mmol²/L², 95% CI -0.77 to -0.47).Very low protein intake was not superior to conventional low protein intake in terms of effect on serum phosphorus (2 studies, 41 participants: MD -0.12 mmol/L, 95% CI -0.50 to 0.25), serum calcium (MD 0.00 mmol/L, 95% CI -0.17 to 0.17), or alkaline phosphatase (MD -22.00 U/L, 95% CI -78.25 to 34.25). PTH was significantly lower in the very low protein intake group (2 studies, 41 participants: MD -69.64 pmol/L, 95% CI -139.83 to 0.54).One study reported no significant difference in the number of deaths between low phosphorus intake and normal diet (279 participants: RR 0.18, 95% CI 0.01 to 3.82). Low phosphorus intake decreased serum phosphorus (2 studies, 359 participants: MD -0.18 mmol/L, 95% CI -0.29 to -0.07; I(2) = 0%).One study reported post-haemodialysis supplements did not increase serum phosphorus compared to normal diet (40 participants: MD 0.12 mmol/L, 95% CI -0.24 to 0.49).One study reported low phosphorus intake plus lanthanum carbonate significantly decreased FGF-23 (19 participants: MD -333.80 RU/mL, 95% CI -526.60 to -141.00), but did not decrease serum phosphorus (19 participants: MD -0.10 mg/dL, 95% CI -0.38 to 0.58) or PTH (19 participants: MD 31.60 pg/mL, 95% CI -29.82 to 93.02). AUTHORS' CONCLUSIONS There was limited low quality evidence to indicate that dietary interventions (calcium-enriched bread or low phosphorus/protein intake) may positively affect CKD-MBD by increasing serum calcium, decreasing serum phosphorus, the calcium × phosphate product and FGF-23. Large and well-designed RCTs are needed to evaluate the effects of various interventions for people with CKD-MBD.
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Affiliation(s)
- Zhuangzhu Liu
- Guangdong Provincial Hospital of Chinese MedicineDepartment of NephrologyGuangzhouChina
- Guangdong Provincial Hospital of Chinese MedicineEmergency DepartmentNo 111 Dade RoadGuangzhouGuangdongChina510120
| | - Guobin Su
- Guangdong Provincial Hospital of Chinese MedicineDepartment of NephrologyGuangzhouChina
- Karolinska InstitutetGlobal Health ‐ Health Systems and Policy: Medicines, focusing antibiotics, Department of Public Health SciencesTomtebodavägen 18a, Widerströmska HusetStockholmStockholmSweden171 77
| | - Xinfeng Guo
- Guangdong Provincial Hospital of Chinese MedicineEvidence‐Based Medicine and Clinical Research Service Group111 Dade RoadGuangzhouGuangDongChina510120
| | - Yifan Wu
- Guangdong Provincial Hospital of Chinese MedicineNephropathy LaboratoryDade RoadGuangzhouGuang DongChina510120
| | - Xusheng Liu
- Guangdong Provincial Hospital of Chinese MedicineDepartment of NephrologyGuangzhouChina
| | - Chuan Zou
- The Second Clinical College of Guangzhou University of Chinese MedicineNephropathy LaboratoryDade RoadGuangzhouGuang DongChina510120
| | - Lei Zhang
- Guangdong Provincial Hospital of Chinese MedicineDepartment of NephrologyGuangzhouChina
| | - Qianchun Yang
- Ewha Woman's UniversityGraduate School of Pharmaceutical Sciences, College of Pharmacy52 Ewhayeodae‐gil, Seodaemun‐guSeoulKorea, South120‐750
| | - Yuan Xu
- Guangdong Provincial Hospital of Chinese MedicineDepartment of NephrologyGuangzhouChina
| | - Weizhong Ma
- Guangdong Provincial Hospital of Chinese MedicineDepartment of NephrologyGuangzhouChina
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Kaku Y, Ookawara S, Miyazawa H, Ito K, Ueda Y, Hirai K, Hoshino T, Mori H, Yoshida I, Morishita Y, Tabei K. Approximation of Corrected Calcium Concentrations in Advanced Chronic Kidney Disease Patients with or without Dialysis Therapy. NEPHRON EXTRA 2015; 5:39-49. [PMID: 26557841 PMCID: PMC4592511 DOI: 10.1159/000437215] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Background The following calcium (Ca) correction formula (Payne) is conventionally used for serum Ca estimation: corrected total Ca (TCa) (mg/dl) = TCa (mg/dl) + [4 – albumin (g/dl)]; however, it is inapplicable to advanced chronic kidney disease (CKD) patients. Methods 1,922 samples in CKD G4 + G5 patients and 341 samples in CKD G5D patients were collected. Levels of TCa (mg/day), ionized Ca2+ (iCa2+) (mmol/l) and other clinical parameters were measured. We assumed the corrected TCa to be equal to eight times the iCa2+ value (measured corrected TCa). We subsequently performed stepwise multiple linear regression analysis using the clinical parameters. Results The following formula was devised from multiple linear regression analysis. For CKD G4 + G5 patients: approximated corrected TCa (mg/dl) = TCa + 0.25 × (4 – albumin) + 4 × (7.4 – pH) + 0.1 × (6 – P) + 0.22. For CKD G5D patients: approximated corrected TCa (mg/dl) = TCa + 0.25 × (4 – albumin) + 0.1 × (6 – P) + 0.05 × (24 – HCO3-) + 0.35. Receiver operating characteristic analysis showed the high values of the area under the curve of approximated corrected TCa for the detection of measured corrected TCa ≥8.4 mg/dl and ≤10.4 mg/dl for each CKD sample. Both intraclass correlation coefficients for each CKD sample demonstrated superior agreement using the new formula compared to the previously reported formulas. Conclusion Compared to other formulas, the approximated corrected TCa values calculated from the new formula for patients with CKD G4 + G5 and CKD G5D demonstrates superior agreement with the measured corrected TCa.
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Affiliation(s)
- Yoshio Kaku
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Susumu Ookawara
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Haruhisa Miyazawa
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Kiyonori Ito
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Yuichiro Ueda
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Keiji Hirai
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Taro Hoshino
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Honami Mori
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Izumi Yoshida
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Yoshiyuki Morishita
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Kaoru Tabei
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan
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Parker VJ, Gilor C, Chew DJ. Feline hyperparathyroidism: pathophysiology, diagnosis and treatment of primary and secondary disease. J Feline Med Surg 2015; 17:427-39. [PMID: 25896242 PMCID: PMC10816244 DOI: 10.1177/1098612x15581134] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
PRACTICAL RELEVANCE Hyperparathyroidism exists in primary and secondary forms. Primary hyperparathyroidism has typically been considered a disease that uncommonly affects cats, but this condition is more prevalent than previous diagnoses would suggest. Secondary hyperparathyroidism may be caused by either nutritional influences (ie, nutritional secondary hyperparathyroidism) or chronic kidney disease (ie, renal secondary hyperparathyroidism). Tertiary hyperparathyroidism has yet to be documented in veterinary medicine, but it is possible that this condition occurs in some cats following longstanding renal secondary hyperparathyroidism. CLINICAL CHALLENGES Diagnosis of this group of calcium metabolic disorders presents a number of challenges for the clinician. For example, clinical signs can be non-specific and, especially in the case of primary hyperparathyroidism, there is often a low index of suspicion for the disease; careful sample handling is required for testing of parathyroid hormone (PTH) and ionized calcium levels; and there is currently no feline-specific assay for PTH, which has implications for test sensitivity and interpretation of results. AIMS This article briefly outlines PTH and calcium physiology by way of introduction to a review of PTH measurement and interpretation. Various forms of feline hyperparathyroidism are then described, encompassing diagnosis and treatment options.
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Affiliation(s)
- Valerie J Parker
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, 601 Vernon L Tharp Street, Columbus, OH 43210, USA
| | - Chen Gilor
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, 601 Vernon L Tharp Street, Columbus, OH 43210, USA
| | - Dennis J Chew
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, 601 Vernon L Tharp Street, Columbus, OH 43210, USA
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de Cavanagh EMV, Inserra F, Ferder L. Angiotensin II blockade: how its molecular targets may signal to mitochondria and slow aging. Coincidences with calorie restriction and mTOR inhibition. Am J Physiol Heart Circ Physiol 2015; 309:H15-44. [PMID: 25934099 DOI: 10.1152/ajpheart.00459.2014] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 04/30/2015] [Indexed: 02/07/2023]
Abstract
Caloric restriction (CR), renin angiotensin system blockade (RAS-bl), and rapamycin-mediated mechanistic target of rapamycin (mTOR) inhibition increase survival and retard aging across species. Previously, we have summarized CR and RAS-bl's converging effects, and the mitochondrial function changes associated with their physiological benefits. mTOR inhibition and enhanced sirtuin and KLOTHO signaling contribute to the benefits of CR in aging. mTORC1/mTORC2 complexes contribute to cell growth and metabolic regulation. Prolonged mTORC1 activation may lead to age-related disease progression; thus, rapamycin-mediated mTOR inhibition and CR may extend lifespan and retard aging through mTORC1 interference. Sirtuins by deacetylating histone and transcription-related proteins modulate signaling and survival pathways and mitochondrial functioning. CR regulates several mammalian sirtuins favoring their role in aging regulation. KLOTHO/fibroblast growth factor 23 (FGF23) contribute to control Ca(2+), phosphate, and vitamin D metabolism, and their dysregulation may participate in age-related disease. Here we review how mTOR inhibition extends lifespan, how KLOTHO functions as an aging suppressor, how sirtuins mediate longevity, how vitamin D loss may contribute to age-related disease, and how they relate to mitochondrial function. Also, we discuss how RAS-bl downregulates mTOR and upregulates KLOTHO, sirtuin, and vitamin D receptor expression, suggesting that at least some of RAS-bl benefits in aging are mediated through the modulation of mTOR, KLOTHO, and sirtuin expression and vitamin D signaling, paralleling CR actions in age retardation. Concluding, the available evidence endorses the idea that RAS-bl is among the interventions that may turn out to provide relief to the spreading issue of age-associated chronic disease.
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Affiliation(s)
- Elena M V de Cavanagh
- Center of Hypertension, Cardiology Department, Austral University Hospital, Derqui, Argentina; School of Biomedical Sciences, Austral University, Buenos Aires, Argentina; and
| | - Felipe Inserra
- Center of Hypertension, Cardiology Department, Austral University Hospital, Derqui, Argentina; School of Biomedical Sciences, Austral University, Buenos Aires, Argentina; and
| | - León Ferder
- Department of Physiology and Pharmacology, Ponce School of Medicine, Ponce, Puerto Rico
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D'Marco L, Bellasi A, Raggi P. Cardiovascular biomarkers in chronic kidney disease: state of current research and clinical applicability. DISEASE MARKERS 2015; 2015:586569. [PMID: 25944976 PMCID: PMC4402164 DOI: 10.1155/2015/586569] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 03/15/2015] [Accepted: 03/18/2015] [Indexed: 02/07/2023]
Abstract
The high incidence of cardiovascular events in chronic kidney disease (CKD) warrants an accurate evaluation of risk aimed at reducing the burden of disease and its consequences. The use of biomarkers to identify patients at high risk has been in use in the general population for several decades and has received mixed reactions in the medical community. Some practitioners have become staunch supporters and users while others doubt the utility of biomarkers and rarely measure them. In CKD patients numerous markers similar to those used in the general population and others more specific to the uremic population have emerged; however their utility for routine clinical application remains to be fully elucidated. The reproducibility and standardization of the serum assays are serious limitations to the broad implementation of these tests. The lack of focused research and validation in randomized trials rather than ad hoc measurement of multiple serum markers in observational studies is also cause for concern related to the clinical applicability of these markers. We review the current literature on biomarkers that may have a relevant role in field of nephrology.
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Affiliation(s)
- Luis D'Marco
- Unidad Avanzada de Investigación y Diagnostico Ecográfico y Renal, Clínica Puerto Ordaz, Puerto Ordaz, Venezuela
| | - Antonio Bellasi
- U.O.C. di Nefrologia e Dialisi, Ospedale Sant'Anna, Azienda Ospedaliera Sant'Anna, Como, Italy
- Department of Health Sciences, University of Milan, Milan, Italy
| | - Paolo Raggi
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
- Department of Radiology, Emory University, Atlanta, GA, USA
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Sawires HK, Essam RM, Morgan MF, Mahmoud RA. Serum klotho: relation to fibroblast growth factor-23 and other regulators of phosphate metabolism in children with chronic kidney disease. Nephron Clin Pract 2015; 129:293-9. [PMID: 25766835 DOI: 10.1159/000377633] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 01/31/2015] [Indexed: 11/19/2022] Open
Abstract
FGF23 and Klotho synergize to regulate phosphate homeostasis by promoting renal phosphate excretion. Chronic kidney disease (CKD) may be viewed as a state of FGF23 resistance caused by Klotho deficiency. This viewpoint explains several observations on phosphate metabolism in CKD that lack mechanistic insights. Our objectives were to correlate serum klotho and FGF-23 with other variables that regulate phosphate metabolism. We studied 40 patients with CKD on conservative treatment (group A), 44 patients with end-stage renal disease (ESRD) on regular hemodialysis (group B), 40 kidney transplant recipients (KTR) (group C) and 40 healthy controls for measuring serum klotho and FGF-23. Blood samples were withdrawn for measuring the levels of serum Calcium (Ca), Phosphorus (P), alkaline phosphatase (ALP), 1,25 (OH)2 D3, intact parathyroid hormone (PTH), FGF-23 and α klotho. The mean levels of FGF-23 and α klotho in control group were 225.78 ± 111.05 pg/ml (range: 102.4, 418.5) and 6.78 ± 1.90 ng/ml (range: 4, 11), respectively. The mean levels of FGF-23 in the 3 studied groups were 1,034.2 ± 84.6, 1,288.7 ± 131.4 and 1,008.7 ± 117.6 pg/ml, respectively. The median levels of s-klotho in the 3 studied groups were 3.15, 2.3 and 2.95, respectively. It was found that FGF-23 was significantly increased and α klotho was significantly decreased in all patients when compared with those in the control group (p < 0.001, <0.001, respectively). We found that there was a significant inverse correlation between serum Ca and α klotho in the studied groups. There was no significant correlation between FGF-23 and α klotho in the studied groups (p > 0.05). We have shown that circulating s-klotho was not related to FGF-23 in CKD, dialysis and KTR patients. In addition, we demonstrated a novel association between serum Ca and s-klotho that needs to be further studied.
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Rotondi S, Pasquali M, Tartaglione L, Muci ML, Mandanici G, Leonangeli C, Sales S, Farcomeni A, Mazzaferro S. Soluble α -Klotho Serum Levels in Chronic Kidney Disease. Int J Endocrinol 2015; 2015:872193. [PMID: 25873958 PMCID: PMC4383388 DOI: 10.1155/2015/872193] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 11/17/2014] [Indexed: 02/08/2023] Open
Abstract
Transmembrane α-Klotho (TM-Klotho), expressed in renal tubules, is a cofactor for FGF23-receptor. Circulating soluble-α-Klotho (s-Klotho) results from TM-Klotho shedding and acts on Phosphate (P) and Calcium (Ca) tubular transport. Decreased TM-Klotho, described in experimental chronic kidney disease (CKD), prevents actions of FGF23 and lessens circulating s-Klotho. Thus, levels of s-Klotho could represent a marker of CKD-MBD. To evaluate the clinical significance of s-Klotho in CKD we assayed serum s-Klotho and serum FGF23 in 68 patients (age 58 ± 15; eGFR 45 ± 21 mL/min). s-Klotho was lower than normal (519 ± 183 versus 845 ± 330 pg/mL, P < .0001) in renal patients and its reduction was detectable since CKD stage 2 (P < .01). s-Klotho correlated positively with eGFR and serum calcium (Cas) and negatively with serum phosphate (Ps), PTH and FGF23. FGF23 was higher than normal (73 ± 51 versus 36 ± 11, P < .0002) with significantly increased levels since CKD stage 2 (P < .001). Our data indicate a negative effect of renal disease on circulating s-Klotho starting very early in CKD. Assuming that s-Klotho mirrors TM-Klotho synthesis, low circulating s-Klotho seems to reflect the ensuing of tubular resistance to FGF23, which, accordingly, is increased. We endorse s-Klotho as an early marker of CKD-MBD.
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Affiliation(s)
- Silverio Rotondi
- Department of Cardiovascular, Respiratory, Nephrology, Geriatric, and Anesthetic Sciences, “Sapienza” University, 5 Piazzale Aldo Moro, 00185 Rome, Italy
| | - Marzia Pasquali
- Department of Cardiovascular, Respiratory, Nephrology, Geriatric, and Anesthetic Sciences, “Sapienza” University, 5 Piazzale Aldo Moro, 00185 Rome, Italy
| | - Lida Tartaglione
- Department of Cardiovascular, Respiratory, Nephrology, Geriatric, and Anesthetic Sciences, “Sapienza” University, 5 Piazzale Aldo Moro, 00185 Rome, Italy
| | - Maria Luisa Muci
- Department of Cardiovascular, Respiratory, Nephrology, Geriatric, and Anesthetic Sciences, “Sapienza” University, 5 Piazzale Aldo Moro, 00185 Rome, Italy
| | - Giusy Mandanici
- Department of Cardiovascular, Respiratory, Nephrology, Geriatric, and Anesthetic Sciences, “Sapienza” University, 5 Piazzale Aldo Moro, 00185 Rome, Italy
| | - Cristiana Leonangeli
- Department of Cardiovascular, Respiratory, Nephrology, Geriatric, and Anesthetic Sciences, “Sapienza” University, 5 Piazzale Aldo Moro, 00185 Rome, Italy
| | - Silvia Sales
- Department of Cardiovascular, Respiratory, Nephrology, Geriatric, and Anesthetic Sciences, “Sapienza” University, 5 Piazzale Aldo Moro, 00185 Rome, Italy
| | - Alessio Farcomeni
- Department of Public Health and Infectious Diseases, Section of Statistics, “Sapienza” University, 5 Piazzale Aldo Moro, 00185 Rome, Italy
| | - Sandro Mazzaferro
- Department of Cardiovascular, Respiratory, Nephrology, Geriatric, and Anesthetic Sciences, “Sapienza” University, 5 Piazzale Aldo Moro, 00185 Rome, Italy
- *Sandro Mazzaferro:
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Lang F, Ritz E, Alesutan I, Voelkl J. Impact of aldosterone on osteoinductive signaling and vascular calcification. Nephron Clin Pract 2014; 128:40-5. [PMID: 25377380 DOI: 10.1159/000368268] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Vascular calcification is frequently found already in early stages of chronic kidney disease (CKD) patients and is associated with high cardiovascular risk. The process of vascular calcification is not considered a passive phenomenon but involves, at least in part, phenotypical transformation of vascular smooth muscle cells (VSMCs). Following exposure to excessive extracellular phosphate concentrations, VSMCs undergo a reprogramming into osteo-/chondroblast-like cells. Such 'vascular osteoinduction' is characterized by expression of osteogenic transcription factors and triggered by increased phosphate concentrations. A key role in this process is assigned to cellular phosphate transporters, most notably the type III sodium-dependent phosphate transporter Pit1. Pit1 expression is stimulated by mineralocorticoid receptor activation. Therefore, aldosterone participates in the phenotypical transformation of VSMCs. In preclinical models, aldosterone antagonism reduces vascular osteoinduction. Patients with CKD suffer from hyperphosphatemia predisposing to vascular osteogenic transformation, potentially further fostered by concomitant hyperaldosteronism. Clearly, additional research is required to define the role of aldosterone in the regulation of osteogenic signaling and the consecutive vascular calcification in CKD, but more generally also other diseases associated with excessive vascular calcification and even in individuals without overt disease.
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Affiliation(s)
- Florian Lang
- Department of Physiology, University of Tübingen, Tübingen, Germany
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Scholze A, Liu Y, Pedersen L, Xia S, Roth HJ, Hocher B, Rasmussen LM, Tepel M. Soluble α-klotho and its relation to kidney function and fibroblast growth factor-23. J Clin Endocrinol Metab 2014; 99:E855-61. [PMID: 24606097 DOI: 10.1210/jc.2013-4171] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Relations between fibroblast growth factor-23 (FGF-23), soluble α-klotho (s-α-klotho), and kidney function in chronic kidney disease (CKD) are still unclear. Especially the role of s-α-klotho requires further study. OBJECTIVES Our objectives were to analyze the relation of s-α-klotho to estimated glomerular filtration rate (eGFR), FGF-23, and other parameters of calcium-phosphate metabolism and to investigate the response of s-α-klotho to cholecalciferol. PATIENTS, DESIGN, AND SETTING Twenty-four CKD (stage 1-5) patients participated in this 8-week randomized controlled trial (vitamin D and chronic renal insufficiency). INTERVENTIONS Interventions included 40 000 IU cholecalciferol or placebo weekly. MAIN OUTCOME MEASURE S-α-klotho was determined by ELISA with antihuman klotho antibodies 67G3 and 91F1. RESULTS For all patients, s-α-klotho concentrations did not differ between CKD stages. When patients were subdivided based on FGF-23 concentrations, a positive association of s-α-klotho with eGFR became apparent in patients with lower than median FGF-23 concentrations but not in those above median value. Patients with s-α-klotho below 204 pg/mL showed higher age, lower phosphate clearance, and lower bone-specific alkaline phosphatase compared with patients with higher s-α-klotho. Treatment with cholecalciferol significantly increased 1,25-dihydroxyvitamin D. The increase of FGF-23 had only borderline significance. There was no significant effect of high-dose cholecalciferol administration for 8 weeks on plasma s-α-klotho. CONCLUSIONS CKD patients with s-α-klotho below 204 pg/mL had higher age, lower phosphate clearance, and lower bone-specific alkaline phosphatase. An association of s-α-klotho with eGFR was observed only in the presence of close to normal, but not high, FGF-23 concentrations. Cholecalciferol treatment did not change s-α-klotho concentrations.
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Affiliation(s)
- Alexandra Scholze
- Clinical Research Unit (A.S., M.T.), Department of Nephrology, and Centre for Individualized Medicine in Arterial Diseases (L.P., L.M.R.), Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, 5000 Odense C, Denmark; Institute of Clinical Research (A.S., M.T.) and Institute of Molecular Medicine (Y.L., S.X., M.T.), Cardiovascular and Renal Research, University of Southern Denmark, 5000 Odense C, Denmark; Labor Dr Limbach und Kollegen (H.J.R.), Medizinisches Versorgungszentrum, 69126 Heidelberg, Germany; and Institute of Nutritional Science (B.H.), University of Potsdam, 14558 Nuthetal/Potsdam, Germany
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Stompór T. Coronary artery calcification in chronic kidney disease: An update. World J Cardiol 2014; 6:115-129. [PMID: 24772252 PMCID: PMC3999332 DOI: 10.4330/wjc.v6.i4.115] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 02/10/2014] [Accepted: 03/17/2014] [Indexed: 02/06/2023] Open
Abstract
Arterial calcification is a well-recognized complication of advanced atherosclerosis. Chronic kidney disease (CKD) is characterized by significantly more pronounced, disseminated and fast-progressing calcification of the vascular system, including the coronary arteries. New computed tomography-based imaging techniques allow for the noninvasive assessment and monitoring of calcification in different vascular sites. Coronary artery calcification (CAC) develops early in the course of CKD and is tightly associated with mineral and bone disorders, which include but are not limited to secondary hyperparathyroidism. In this review, recent data on the pathogenesis of CAC development and progression are discussed, with a special emphasis on fibroblast growth factor 23 and its co-receptor, klotho. The prevalence, progression and prognostic significance of CAC are reviewed separately for patients with end-stage renal disease treated with dialysis, kidney transplant recipients and patients with earlier stages of CKD. In the last section, therapeutic considerations are discussed, with special attention paid to the importance of treatment that addresses mineral and bone disorders of CKD.
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Leone F, Lofaro D, Gigliotti P, Perri A, Vizza D, Toteda G, Lupinacci S, Armentano F, Papalia T, Bonofiglio R. Soluble Klotho levels in adult renal transplant recipients are modulated by recombinant human erythropoietin. J Nephrol 2014; 27:577-85. [PMID: 24760622 DOI: 10.1007/s40620-014-0089-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 03/31/2014] [Indexed: 12/25/2022]
Abstract
BACKGROUND Data on serum soluble Klotho levels in chronic kidney disease are contradictory and even less is known after renal transplantation. Experimental studies demonstrated that recombinant human erythropoietin (rhEPO) treatment mitigates Klotho reduction caused by renal damage. Therefore, this study aimed to determine serum Klotho levels in a cohort of kidney transplant recipients (KTR) and to evaluate whether rhEPO treatment can modulate, in vivo and in vitro, soluble Klotho. METHODS 117 KTR and 22 healthy subjects (HS) were enrolled. In 17 KTR, rhEPO was discontinued for 5 weeks and Klotho levels were compared to 34 propensity score-matched controls. Moreover, we evaluated Klotho mRNA expression and protein secretion in HK-2 tubular cells treated with cyclosporin A (CyA) and rhEPO, alone or in combination. RESULTS Serum Klotho levels in KTR were significantly higher than in HS (0.68 vs. 0.37, p = 0.002) and significantly associated with estimated glomerular filtration rate (r = -0.378, p = 0.003) and fibroblast growth factor 23 (r = -0.307, p < 0.0001). After 5 weeks of rhEPO discontinuation, treated KTR showed a sharper reduction of Klotho levels than controls (-0.56 vs. -0.11 ng/ml, p < 0.0001). In HK-2 cells CyA treatment induced a Klotho down-regulation that was mitigated by rhEPO pre-treatment. In the same experimental conditions, our results revealed that cells treated with CyA + rhEPO secreted higher soluble Klotho levels than those exposed to CyA or rhEPO alone. CONCLUSIONS Our results demonstrate that KTR have higher serum Klotho levels than HS and that rhEPO treatment modulates these concentrations, suggesting a link between rhEPO and soluble Klotho in KTR.
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Affiliation(s)
- Francesca Leone
- Kidney and Transplantation Research Center, "Annunziata" Hospital, via F. Migliori, 87100, Cosenza, Italy
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Kuczera P, Adamczak M, Wiecek A. Cinacalcet treatment decreases plasma fibroblast growth factor 23 concentration in haemodialysed patients with chronic kidney disease and secondary hyperparathyroidism. Clin Endocrinol (Oxf) 2014; 80:607-12. [PMID: 24111496 DOI: 10.1111/cen.12326] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Revised: 05/07/2013] [Accepted: 09/11/2013] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Recent clinical studies suggest that fibroblast growth factor 23 (FGF23) is important in the pathogenesis of calcium-phosphate abnormalities in patients with chronic kidney disease and that increased plasma FGF23 concentration is a cardiovascular risk factor in these patients. The aim of this prospective, single-arm, open-label clinical study was to assess the influence of 6-month cinacalcet treatment on plasma FGF23 concentration in haemodialysed patients with secondary hyperparathyroidism (sHPT). DESIGN, PATIENTS AND MEASUREMENTS In 58 haemodialysed patients with sHPT (parathormone PTH > 300 ng/l), serum PTH, FGF23, calcium and phosphate concentrations were assessed before the first dose of cinacalcet and after 3 and 6 months of treatment. RESULTS Serum PTH concentration decreased significantly after 3 and 6 months of treatment, and the mean serum calcium and phosphate concentrations remained stable during the treatment period. Plasma FGF23 concentration (geometric mean with 95% confidence index) decreased after 3 and 6 months of treatment from 354 (261-481) ng/l to 295 (204-428) ng/l; P = 0·099 and to 183 (117-285) ng/l; P = 0·015, respectively. FGF23 concentration decreased in 52% of patients. In multivariate regression analysis, plasma FGF23 concentration changes were explained by the changes in serum phosphate, but not by serum PTH or calcium changes or by the dose of cinacalcet. CONCLUSIONS 1. Cinacalcet treatment decreases plasma FGF23 concentration in haemodialysed patients with secondary hyperparathyroidism. 2. The decrease in plasma FGF23 concentration seems to be related to the decrease in serum phosphate concentration.
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Affiliation(s)
- Piotr Kuczera
- Department of Nephrology, Endocrinology and Metabolic Diseases, Medical University of Silesia, Katowice, Poland
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Browne OT, Allgar V, Bhandari S. Analysis of factors predicting mortality of new patients commencing renal replacement therapy 10 years of follow-up. BMC Nephrol 2014; 15:20. [PMID: 24444187 PMCID: PMC3902419 DOI: 10.1186/1471-2369-15-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 01/16/2014] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND The natural history of patients commencing dialysis in East Yorkshire is not well characterised and there is little convincing evidence which has studied the impact of potential factors prior to commencement of renal replacement therapy (RRT) at predicting mortality during dialysis. The aim of this study was to examine the previously published 5-year data on end stage renal disease and co-morbid risk factors for mortality at 10 years. METHODS An observational cohort study of subjects commencing dialysis in 2001/02 in East Yorkshire with a mean follow up from dialysis initiation of 8.8 years. Predictors of mortality were determined by univariate, multivariate analysis and survival via Kaplan-Meier analysis. Assessment of the utility of the Tangri risk calculator was carried out in addition to slope change in eGFR prior to dialysis commencement. RESULTS Baseline characteristics and the preferred mode of dialysis remained concordant with the original trial. The mortality rate at the end of the study period was 60% (56/94) with 30% (29) of patients having been transplanted. Highlighted in the 5 year data a significant proportion of mortality was made up of vascular disease and sepsis (71%) but this proportion had decreased (57%) by 10 years. Cardiac disease was the commonest cause of death but notably in 18% of patients, death was related to dialysis or withdrawal of treatment. Vascular disease and diabetes remained independent risk factors and predicative of mortality. Calcium-phosphate product which was associated in the early years with mortality was not in later years. Use of the risk calculator was predictive of commencement of RRT but not mortality but slope change in eGFR was predictive of mortality. CONCLUSIONS Although diabetes and vascular disease remained predictive of mortality, interestingly calcium-phosphate levels are no longer significant and may be a more specific predictor of early cardiac mortality. Slope eGFR changes prior to RRT are a predictor of mortality. We speculate that aggressive management of cardiac risk factors in addition to early transplantation may be key to influencing the impact of survival in this cohort in addition to possible measures to delay renal progression.
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Affiliation(s)
| | - Victoria Allgar
- Department of Statistics, Hull York Medical School and University of Hull Hull, UK
| | - Sunil Bhandari
- Hull York Medical School, Hull, East Yorkshire, UK
- Department of Renal Medicine, Hull and East Yorkshire Hospitals NHS Trust, Kingston upon Hull HU32JZ, UK
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Vadakke Madathil S, Coe LM, Casu C, Sitara D. Klotho deficiency disrupts hematopoietic stem cell development and erythropoiesis. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:827-41. [PMID: 24412515 DOI: 10.1016/j.ajpath.2013.11.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 10/30/2013] [Accepted: 11/04/2013] [Indexed: 12/15/2022]
Abstract
Klotho deficiency is a characteristic feature of chronic kidney disease in which anemia and cardiovascular complications are prevalent. Disruption of the Klotho gene in mice results in hypervitaminosis D and a syndrome resembling accelerated aging that includes osteopenia and vascular calcifications. Given that the bone microenvironment and its cellular components considerably influence hematopoiesis, in the present study, we addressed the in vivo role of klotho in blood cell formation and differentiation. Herein, we report that genetic ablation of Klotho in mice results in a significant increase in erythropoiesis and a decrease in the hematopoietic stem cell pool size in the bone marrow, leading to impaired hematopoietic stem cell homing in vivo. Our data also suggest that high vitamin D levels are only partially responsible for these hematopoietic changes in Klotho(-/-) mice. Importantly, we found similar hematopoietic abnormalities in Klotho(-/-) fetal liver cells, suggesting that the effects of klotho in hematopoietic stem cell development are independent of the bone microenvironment. Finally, injection of klotho protein results in hematopoietic changes opposite to the ones observed in Klotho(-/-) mice. These observations unveil a novel role for the antiaging hormone klotho in the regulation of prenatal and postnatal hematopoiesis and provide new insights for the development of therapeutic strategies targeting klotho to treat hematopoietic disorders associated with aging.
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Affiliation(s)
- Sangeetha Vadakke Madathil
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York
| | - Lindsay M Coe
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York
| | - Carla Casu
- Department of Pediatric Hematology, Weill Cornell Medical College, New York
| | - Despina Sitara
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York; Department of Medicine, New York University School of Medicine, New York, New York.
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Abstract
Extracellular phosphate is toxic to the cell at high concentrations. When the phosphate level is increased in the blood by impaired urinary phosphate excretion, premature aging ensues. When the phosphate level is increased in the urine by dietary phosphate overload, this may lead to kidney damage (tubular injury and interstitial fibrosis). Extracellular phosphate exerts its cytotoxicity when it forms insoluble nanoparticles with calcium and fetuin-A, referred to as calciprotein particles (CPPs). CPPs are highly bioactive ligands that can induce various cellular responses, including osteogenic transformation of vascular smooth muscle cells and cell death in vascular endothelium and renal tubular epithelium. CPPs are detected in the blood of animal models and patients with chronic kidney disease (CKD) and associated with adaptation of the endocrine axes mediated by fibroblast growth factor-23 (FGF23) and Klotho that regulate mineral metabolism and aging. These observations have raised the possibility that CPPs may contribute to the pathophysiology of CKD. This notion, if validated, is expected to provide new diagnostic and therapeutic targets for CKD.
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de Brito Galvao JF, Nagode LA, Schenck PA, Chew DJ. Calcitriol, calcidiol, parathyroid hormone, and fibroblast growth factor-23 interactions in chronic kidney disease. J Vet Emerg Crit Care (San Antonio) 2013; 23:134-62. [PMID: 23566108 PMCID: PMC3677418 DOI: 10.1111/vec.12036] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2012] [Accepted: 02/05/2013] [Indexed: 12/13/2022]
Abstract
Objective To review the inter-relationships between calcium, phosphorus, parathyroid hormone (PTH), parent and activated vitamin D metabolites (vitamin D, 25(OH)-vitamin D, 1,25(OH)2-vitamin D, 24,25(OH)2-vitamin D), and fibroblast growth factor-23 (FGF-23) during chronic kidney disease (CKD) in dogs and cats. Data Sources Human and veterinary literature. Human Data Synthesis Beneficial effects of calcitriol treatment during CKD have traditionally been attributed to regulation of PTH but new perspectives emphasize direct renoprotective actions independent of PTH and calcium. It is now apparent that calcitriol exerts an important effect on renal tubular reclamation of filtered 25(OH)-vitamin D, which may be important in maintaining adequate circulating 25(OH)-vitamin D. This in turn may be vital for important pleiotropic actions in peripheral tissues through autocrine/paracrine mechanisms that impact the health of those local tissues. Veterinary Data Synthesis Limited information is available reporting the benefit of calcitriol treatment in dogs and cats with CKD. Conclusions A survival benefit has been shown for dogs with CKD treated with calcitriol compared to placebo. The concentrations of circulating 25(OH)-vitamin D have recently been shown to be low in people and dogs with CKD and are related to survival in people with CKD. Combination therapy for people with CKD using both parental and activated vitamin D compounds is common in human nephrology and there is a developing emphasis using combination treatment with activated vitamin D and renin-angiotensin-aldosterone-system (RAAS) inhibitors.
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Dërmaku-Sopjani M, Kolgeci S, Abazi S, Sopjani M. Significance of the anti-aging protein Klotho. Mol Membr Biol 2013; 30:369-85. [PMID: 24124751 DOI: 10.3109/09687688.2013.837518] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The Klotho gene was identified as an 'aging suppressor' in mice. Overexpression of the Klotho gene extends lifespan and defective Klotho results in rapid aging and early death. Both the membrane and secreted forms of Klotho have biological activity that include regulatory effects on general metabolism and a more specific effect on mineral metabolism that correlates with its effect on aging. Klotho serves as a co-receptor for fibroblast growth factor (FGF), but it also functions as a humoral factor that regulates cell survival and proliferation, vitamin D metabolism, and calcium and phosphate homeostasis and may serve as a potential tumor suppressor. Moreover, Klotho protects against several pathogenic processes in a FGF23-independent manner. These processes include cancer metastasis, vascular calcification, and renal fibrosis. This review covers the recent advances in Klotho research and discusses novel Klotho-dependent mechanisms that are clinically relevant in aging and age-related diseases.
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Block GA, Ix JH, Ketteler M, Martin KJ, Thadhani RI, Tonelli M, Wolf M, Jüppner H, Hruska K, Wheeler DC. Phosphate Homeostasis in CKD: Report of a Scientific Symposium Sponsored by the National Kidney Foundation. Am J Kidney Dis 2013; 62:457-73. [DOI: 10.1053/j.ajkd.2013.03.042] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 03/19/2013] [Indexed: 02/08/2023]
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Kuro-o M. Klotho, phosphate and FGF-23 in ageing and disturbed mineral metabolism. Nat Rev Nephrol 2013; 9:650-60. [DOI: 10.1038/nrneph.2013.111] [Citation(s) in RCA: 188] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Liu Z, Su G, Guo XF, Wu Y, Liu X, Zou C, Zhang L, Yang Q, Xu Y, Ma W. Dietary interventions for mineral and bone disorder in people with chronic kidney disease. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2013. [DOI: 10.1002/14651858.cd010350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Kitagawa M, Sugiyama H, Morinaga H, Inoue T, Takiue K, Ogawa A, Yamanari T, Kikumoto Y, Uchida HA, Kitamura S, Maeshima Y, Nakamura K, Ito H, Makino H. A decreased level of serum soluble Klotho is an independent biomarker associated with arterial stiffness in patients with chronic kidney disease. PLoS One 2013; 8:e56695. [PMID: 23431388 PMCID: PMC3576368 DOI: 10.1371/journal.pone.0056695] [Citation(s) in RCA: 153] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 01/14/2013] [Indexed: 12/26/2022] Open
Abstract
Background Klotho was originally identified in a mutant mouse strain unable to express the gene that consequently showed shortened life spans. In humans, low serum Klotho levels are related to the prevalence of cardiovascular diseases in community-dwelling adults. However, it is unclear whether the serum Klotho levels are associated with signs of vascular dysfunction such as arterial stiffness, a major determinant of prognosis, in human subjects with chronic kidney disease (CKD). Methods We determined the levels of serum soluble Klotho in 114 patients with CKD using ELISA and investigated the relationship between the level of Klotho and markers of CKD-mineral and bone disorder (CKD-MBD) and various types of vascular dysfunction, including flow-mediated dilatation, a marker of endothelial dysfunction, ankle-brachial pulse wave velocity (baPWV), a marker of arterial stiffness, intima-media thickness (IMT), a marker of atherosclerosis, and the aortic calcification index (ACI), a marker of vascular calcification. Results The serum Klotho level significantly correlated with the 1,25-dihydroxyvitamin D level and inversely correlated with the parathyroid hormone level and the fractional excretion of phosphate. There were significant decreases in serum Klotho in patients with arterial stiffness defined as baPWV≥1400 cm/sec, atherosclerosis defined as maximum IMT≥1.1 mm and vascular calcification scores of ACI>0%. The serum Klotho level was a significant determinant of arterial stiffness, but not endothelial dysfunction, atherosclerosis or vascular calcification, in the multivariate analysis in either metabolic model, the CKD model or the CKD-MBD model. The adjusted odds ratio of serum Klotho for the baPWV was 0.60 (p = 0.0075). Conclusions Decreases in the serum soluble Klotho levels are independently associated with signs of vascular dysfunction such as arterial stiffness in patients with CKD. Further research exploring whether therapeutic approaches to maintain or elevate the Klotho level could improve arterial stiffness in CKD patients is warranted.
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Affiliation(s)
- Masashi Kitagawa
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Hitoshi Sugiyama
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
- Department of Chronic Kidney Disease and Peritoneal Dialysis, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
- * E-mail:
| | - Hiroshi Morinaga
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
- Department of Chronic Kidney Disease and Peritoneal Dialysis, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Tatsuyuki Inoue
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Keiichi Takiue
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Ayu Ogawa
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Toshio Yamanari
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Yoko Kikumoto
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Haruhito Adam Uchida
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Shinji Kitamura
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Yohei Maeshima
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kazufumi Nakamura
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Hiroshi Ito
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Hirofumi Makino
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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Voelkl J, Alesutan I, Leibrock CB, Quintanilla-Martinez L, Kuhn V, Feger M, Mia S, Ahmed MSE, Rosenblatt KP, Kuro-O M, Lang F. Spironolactone ameliorates PIT1-dependent vascular osteoinduction in klotho-hypomorphic mice. J Clin Invest 2013; 123:812-22. [PMID: 23298834 DOI: 10.1172/jci64093] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 11/01/2012] [Indexed: 12/21/2022] Open
Abstract
Klotho is a potent regulator of 1,25-hydroxyvitamin D3 [1,25(OH)2D3] formation and calcium-phosphate metabolism. Klotho-hypomorphic mice (kl/kl mice) suffer from severe growth deficits, rapid aging, hyperphosphatemia, hyperaldosteronism, and extensive vascular and soft tissue calcification. Sequelae of klotho deficiency are similar to those of end-stage renal disease. We show here that the mineralocorticoid receptor antagonist spironolactone reduced vascular and soft tissue calcification and increased the life span of kl/kl mice, without significant effects on 1,25(OH)2D3, FGF23, calcium, and phosphate plasma concentrations. Spironolactone also reduced the expression of osteoinductive Pit1 and Tnfa mRNA, osteogenic transcription factors, and alkaline phosphatase (Alpl) in calcified tissues of kl/kl mice. In human aortic smooth muscle cells (HAoSMCs), aldosterone dose-dependently increased PIT1 mRNA expression, an effect paralleled by increased expression of osteogenic transcription factors and enhanced ALP activity. The effects of aldosterone were reversed by both spironolactone treatment and PIT1 silencing and were mitigated by FGF23 cotreatment in HAoSMCs. In conclusion, aldosterone contributes to vascular and soft tissue calcification, an effect due, at least in part, to stimulation of spironolactone-sensitive, PIT1-dependent osteoinductive signaling.
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Affiliation(s)
- Jakob Voelkl
- Department of Physiology, University of Tübingen, Tübingen, Germany
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Gravesen E, Hofman-Bang J, Lewin E, Olgaard K. Ergocalciferol treatment and aspects of mineral homeostasis in patients with chronic kidney disease stage 4-5. Scand J Clin Lab Invest 2013; 73:107-16. [PMID: 23281842 DOI: 10.3109/00365513.2012.744464] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Focus on non-classical effects and possible less side effects of treatment with nutritional vitamin D, raises the expectation of possible benefits from treating chronic kidney disease (CKD) patients with ergocalciferol (vitamin D2). Treatment with 1,25(OH)2 vitamin D (calcitriol) induces elevated fibroblast growth factor 23 (FGF23), while epidemiological studies have found positive effects of nutritional and 25(OH)vitamin D on mortality in CKD. Disturbed mineral homeostasis in CKD is correlated to adverse outcome and cardiovascular mortality. The objective was to examine the possible effects of treatment with high doses of ergocalciferol on parameters of mineral homeostasis in predialysis CKD patients. METHODS A total of 43 adult patients with CKD stage 4-5, not receiving vitamin D supplementation, were studied, and allocated by simple randomization to either an intervention (n = 26) or a control group (n = 17). The intervention group received ergocalciferol, 50.000 IU/week for 6 weeks. Plasma FGF23, creatinine, parathyroid hormone (PTH), phosphate and ionized calcium were obtained at baseline and after the 6 weeks. RESULTS The intervention group had a significant increase in 25(OH)D2 concentration from < 10 to 90 ± 4 nmol/L, while 1,25(OH)2D (62 ± 6 at baseline and 67 ± 6 pmol/L at 6 weeks) remained stable. No changes were seen in the circulating vitamin D concentrations in the control group. After the 6 weeks of treatment no significant changes were seen in concentration of creatinine, phosphate, ionized calcium, PTH and FGF23 remained stable. CONCLUSION No harmful effects of short-term treatment with high-dose ergocalciferol were observed on markers of mineral homeostasis and FGF23 in CKD patients stage 4-5.
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Affiliation(s)
- Eva Gravesen
- University of Copenhagen, Nephrological Department P, Rigshospitalet, Copenhagen, Denmark
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Wang M, You L, Li H, Lin Y, Zhang Z, Hao C, Chen J. Association of circulating fibroblast growth factor-23 with renal phosphate excretion among hemodialysis patients with residual renal function. Clin J Am Soc Nephrol 2013; 8:116-25. [PMID: 23085728 PMCID: PMC3531650 DOI: 10.2215/cjn.00230112] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2012] [Accepted: 09/20/2012] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES High serum levels of fibroblast growth factor-23 (FGF-23) are associated with mortality in patients with ESRD, but whether it still acts as a phosphaturic factor is unknown. This study aimed to explore the role of circulating FGF-23 on urinary phosphate excretion and phosphate balance in maintenance hemodialysis (MHD) patients with residual renal function (RRF). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS There were 134 MHD patients enrolled in this cross-sectional study from June to July 2010. Demographics, laboratory data, and excretion capacity of phosphate were recorded. Multivariable linear regression was used to analyze the relationship of serum phosphate and the tubular reabsorption rate of phosphate with other factors. RESULTS The median age of the patients was 61.0 years and 47.8% were male. Thirty percent of the patients had high urinary output (>200 ml/d) accompanied by lower serum levels of phosphate, calcium, intact parathyroid hormone, and FGF-23 compared with those with low urine output (≤200 ml/d). The independent predictors of serum phosphate were normalized protein nitrogen appearance, intact parathyroid hormone, and FGF-23 in the low urine output group and female sex and GFR in the high urine output group. The tubular reabsorption rate of phosphate decreased to 50% of the normal level in patients with RRF. Elevated circulating FGF-23 was significantly associated with lower tubular phosphate reabsorption after adjusting for GFR. CONCLUSIONS RRF is associated with significant capacity to excrete phosphate in MHD patients and high levels of serum FGF-23 may promote phosphate excretion by remnant nephrons.
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Affiliation(s)
| | - Li You
- Divisions of Nephrology and
| | | | - Yong Lin
- Clinical Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhijie Zhang
- Department of Epidemiology and Biostatistics, School of Public Health, Fudan University, Shanghai, China; and
- Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
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Abstract
PURPOSE OF REVIEW Description of the recent advances on the regulation of phosphate metabolism, gene mutations, and new approaches to treatment in patients with hypophosphatemic rickets. RECENT FINDINGS Fibroblast growth factor 23 (FGF23) overproduction may be a primary cause of hypophosphatemic rickets. Inactivating mutations of phosphate-regulating gene with homologies to endopeptidases on the X chromosome, dentin matrix acidic phosphoprotein 1, and ectonucleotide pyrophosphatase/phosphodiesterase 1 are associated with X-linked hypophosphatemic rickets, autosomal recessive hypophosphatemic rickets 1, and autosomal recessive hypophosphatemic rickets 2, respectively. Activating mutations of FGF23 gene is the cause of autosomal dominant hypophosphatemic rickets. Iron deficiency may affect autosomal dominant hypophosphatemic rickets phenotype by regulating FGF23 production.Current treatment with activated vitamin D metabolites and oral inorganic phosphate salts may partially correct skeletal lesions and linear growth in patients with hypophosphatemic rickets. However, some patients have poor improvement by the current treatment. SUMMARY Identification of the causative mutation in patients with hypophosphatemic rickets may be useful to confirm the diagnosis and probably for prognosis. Inhibition of FGF23 overproduction by anti-FGF23 neutralizing antibodies could be a future approach for treatment of patients with FGF23-dependent hypophosphatemic rickets.
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Affiliation(s)
- Giampiero I Baroncelli
- Pediatric Unit I, Department of Obstetrics, Gynecology and Pediatrics, University-Hospital, Pisa, Italy.
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Brandenburg VM, Vervloet MG, Marx N. The role of vitamin D in cardiovascular disease: From present evidence to future perspectives. Atherosclerosis 2012; 225:253-63. [DOI: 10.1016/j.atherosclerosis.2012.08.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 08/02/2012] [Accepted: 08/08/2012] [Indexed: 12/17/2022]
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Thang OHD, Serné EH, Grooteman MPC, Smulders YM, Ter Wee PM, Tangelder GJ, Nubé MJ. Premature aging of the microcirculation in patients with advanced chronic kidney disease. NEPHRON EXTRA 2012; 2:283-92. [PMID: 23243413 PMCID: PMC3521446 DOI: 10.1159/000343295] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Background Increasing age and advanced chronic kidney disease (CKD) are both associated with an attenuated vasodilator response of the skin microcirculation. In the present study, we investigated the effect of aging on microvascular reactivity in patients with advanced CKD. Methods Acetylcholine (ACh)-mediated endothelium-dependent vasodilation and sodium nitroprusside (SNP)-mediated endothelium-independent vasodilation were assessed by iontophoresis combined with laser Doppler flowmetry. Microvascular function was compared between 52 patients with advanced CKD (stage 4–5: n = 16; end-stage renal disease: n = 36) and 33 healthy control subjects. As aging has an important effect on microvascular function, both control subjects and CKD patients were divided in subgroups younger and older than 45 years. Linear regression analysis was applied to assess potential associations between microvascular function and various demographic and clinical parameters. Results There were three main findings. (1) In young patients with advanced CKD, both ACh- and SNP-mediated vasodilations were impaired if compared to young healthy controls (p = 0.04 and p = 0.056, respectively). (2) In young patients with advanced CKD, microvascular function was similar to old healthy controls and elderly patients with advanced CKD. (3) Whereas age was inversely associated with microvascular function in healthy controls (log ACh-mediated vasodilation R = −0.41; p = 0.02 and log SNP-mediated vasodilation R = −0.38; p = 0.03), no such relation was found in patients with advanced CKD. Conclusions Our results are consistent with premature aging of the microvascular vasodilatory capacity in patients with advanced CKD.
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Affiliation(s)
- Oanh H D Thang
- Department of Nephrology, Institute for Cardiovascular Research VU Medical Center, Amsterdam, The Netherlands
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89
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Shroff R, Long DA, Shanahan C. Mechanistic insights into vascular calcification in CKD. J Am Soc Nephrol 2012; 24:179-89. [PMID: 23138485 DOI: 10.1681/asn.2011121191] [Citation(s) in RCA: 255] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cardiovascular disease begins early in the course of renal decline and is a life-limiting problem in patients with CKD. The increased burden of cardiovascular disease is due, at least in part, to calcification of the vessel wall. The uremic milieu provides a perfect storm of risk factors for accelerated calcification, but elevated calcium and phosphate levels remain key to the initiation and progression of vascular smooth muscle cell calcification in CKD. Vascular calcification is a highly regulated process that involves a complex interplay between promoters and inhibitors of calcification and has many similarities to bone ossification. Here, we discuss current understanding of the process of vascular calcification, focusing specifically on the discrete and synergistic effects of calcium and phosphate in mediating vascular smooth muscle cell apoptosis, osteochondrocytic differentiation, vesicle release, calcification inhibitor expression, senescence, and death. Using our model of intact human vessels, factors initiating vascular calcification in vivo and the role of calcium and phosphate in driving accelerated calcification ex vivo are described. This work allows us to link clinical and basic research into a working theoretical model to explain the pathway of development of vascular calcification in CKD.
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Affiliation(s)
- Rukshana Shroff
- Nephro-Urology Unit, Great Ormond Street Hospital for Children and University College London Institute of Child Health, London, UK.
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90
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Pavik I, Jaeger P, Ebner L, Wagner CA, Petzold K, Spichtig D, Poster D, Wüthrich RP, Russmann S, Serra AL. Secreted Klotho and FGF23 in chronic kidney disease Stage 1 to 5: a sequence suggested from a cross-sectional study. Nephrol Dial Transplant 2012; 28:352-9. [PMID: 23129826 DOI: 10.1093/ndt/gfs460] [Citation(s) in RCA: 164] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Klotho and fibroblast growth factor 23 (FGF23) are key regulators of mineral metabolism in renal insufficiency. FGF23 levels have been shown to increase early in chronic kidney disease (CKD); however, the corresponding soluble Klotho levels at the different CKD stages are not known. METHODS Soluble Klotho, FGF23, parathyroid hormone (PTH), 1,25-dihydroxy vitamin D(3) (1,25D) and other parameters of mineral metabolism were measured in an observational cross-sectional study in 87 patients. Locally weighted scatter plot smoothing function of these parameters were plotted versus estimated glomerular filtration rate (eGFR) to illustrate the pattern of the relationship. Linear and non-linear regression analyses were performed to estimate changes in mineral metabolism parameters per 1mL/min/1.73 m(2) decline. RESULTS In CKD 1-5, Klotho and 1,25D linearly decreased, whereas both FGF23 and PTH showed a baseline at early CKD stages and then a curvilinear increase. Crude mean Klotho level declined by 4.8 pg/mL (95% CI 3.5-6.2 pg/mL, P < 0.0001) and 1,25D levels by 0.30 ng/L (95% CI 0.18-0.41 ng/L, P < 0.0001) as GFR declined by 1 mL/min/1.73 m(2). After adjustment for age, gender, serum 25-hydroxyvitamin D levels and concomitant medications (calcium, supplemental vitamin D and calcitriol), we estimated that the mean Klotho change was 3.2 pg/mL (95% CI 1.2-5.2 pg/mL, P = 0.0019) for each 1 mL/min/1.73 m(2) GFR change. FGF23 departed from the baseline at an eGFR of 47 mL/min/1.73 m(2) (95% CI 39-56 mL/min/1.73 m(2)), whereas PTH departed at an eGFR of 34 mL/min/1.73 m(2) (95% CI 19-50 mL/min/1.73 m(2)). CONCLUSIONS Soluble Klotho and 1,25D levels decrease and FGF23 levels increase at early CKD stages, whereas PTH levels increase at more advanced CKD stages.
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Affiliation(s)
- Ivana Pavik
- Institute of Physiology and Zurich Center for Integrative Human Physiology, Zurich, Switzerland
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91
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Abstract
Nephrogenic systemic fibrosis (NSF) is a rare and a debilitating disease noted uncommonly in patients with impaired renal function when exposed to low-stability gadolinium-based contrast agents (Gd-CAs). According to experimental studies, cytokines released by the stimulation of effector cells such as skin macrophages and peripheral blood monocytes activate circulating fibroblasts which play a major role in the development of NSF lesions. The presence of permissive factors, presumably, provides an environment conducive to facilitate the process of fibrosis. Multiple treatment modalities have been tried with variable success rates. More research is necessary to elucidate the underlying pathophysiological mechanisms which could potentially target the initial steps of fibrosis in these patients. This paper attempts to collate the inferences from the in vivo and in vitro experiments to the clinical observations to understand the pathogenesis of NSF. Schematic representations of receptor-mediated molecular pathways of activation of macrophages and fibroblasts by gadolinium and the final pathway to fibrosis are incorporated in the discussion.
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92
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Glade MJ. Vitamin D: health panacea or false prophet? Nutrition 2012; 29:37-41. [PMID: 23085014 DOI: 10.1016/j.nut.2012.05.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 05/09/2012] [Accepted: 05/11/2012] [Indexed: 12/23/2022]
Abstract
Vitamin D deficiency, diagnosed when the serum 25-hydroxyvitamin D (25-OHD(3)) concentration is less than 20 ng/mL, has joined vitamin A deficiency as two of the most common nutrition-responsive medical conditions worldwide. There have been more scientific articles published about vitamin D in the 21st century than about any other vitamin, reflecting the massive expansion of the field of vitamin D research. Adequate vitamin D status has been linked to decreased risks of developing specific cancers, including cancers of the esophagus, stomach, colon, rectum, gallbladder, pancreas, lung, breast, uterus, ovary, prostate, urinary bladder, kidney, skin, thyroid, and hematopoietic system (e.g., Hodgkin's lymphoma, non-Hodgkin's lymphoma, multiple myeloma); bacterial infections; rheumatoid arthritis; Crohn's disease; periodontal disease; multiple sclerosis; asthma; type 2 diabetes; cardiovascular disease; stroke; peripheral artery disease; hypertension; chronic kidney disease; muscle weakness; cognitive impairment; Alzheimer's disease; clinical depression; and premature death. On the other hand, inadequate vitamin D status during human pregnancy may be associated with increased risk for the development of type 1 diabetes in the offspring. However, this point of view may be excessively optimistic. There also is evidence that despite the current heavy reliance on serum 25-OHD(3) concentration for the diagnosis of an individual's vitamin D status, local tissue vitamin D intoxication may be present in individuals with much lower serum 25-OHD(3) concentrations than are currently appreciated. Only rarely are the symptoms of local tissue vitamin D intoxication associated with vitamin D status or intake. An individual's serum 25-OHD(3) concentration may appear to be "low" for reasons totally independent of sunlight exposure or vitamin D intake. Serum 25-OHD(3) concentration is only poorly responsive to increases in vitamin D intake, and the prolonged routine consumption of thousands of international units of vitamin D may interfere with the regulation of phosphate homeostasis by fibroblast growth factor-23 (FGF23) and the Klotho gene product, with consequences that are detrimental to human health. In light of these counterbalancing observations, curbing excessive enthusiasm for universally increasing vitamin D intake recommendations may be in order.
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93
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Chen TH, Kuro-O M, Chen CH, Sue YM, Chen YC, Wu HH, Cheng CY. The secreted Klotho protein restores phosphate retention and suppresses accelerated aging in Klotho mutant mice. Eur J Pharmacol 2012; 698:67-73. [PMID: 23041151 DOI: 10.1016/j.ejphar.2012.09.032] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 09/14/2012] [Accepted: 09/22/2012] [Indexed: 01/03/2023]
Abstract
Klotho was identified as the responsible gene in a mutant mouse line whose disruption results in a variety of premature aging-related phenotypes. Nonetheless, the related mechanisms were still unknown. Many studies report that dietary phosphate restriction and genetic ablation of vitamin D pathways indirectly reverse premature aging processes in these mice. Furthermore, transgenic overexpression of klotho in mice extends their life span through inhibition of insulin and IGF1 signaling. We found that intraperitoneal injection of recombinant soluble Klotho protein at dose of 0.02 mg/kg every other day effectively extends the life span of kl/kl mice by 17.4%. Soluble Klotho administration also ameliorated premature aging-related phenotype, such as growth retardation, premature thymus involution and vascular calcification, and effectively enhanced urinary phosphate excretion in kl/kl mice. Klotho treatment attenuated renal fibrosis through down-regulation of transforming growth factor-β signaling as well as reduced cellular senescence through down-regulation of p21-cip1 mRNA levels. In addition, soluble Klotho treatment significantly reduced both renal and aorta calcium deposits. In conclusion, our study shows the therapeutic potential of soluble Klotho protein to treat age-related disorders in mice.
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Affiliation(s)
- Tso-Hsiao Chen
- Division of Nephrology, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, No 111, Section 3 Hsin-Long Road, Wen-Shang District, Taipei, Taiwan
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94
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Abstract
PURPOSE OF REVIEW The klotho gene was originally identified as a putative aging-suppressor gene in mice that extended life span when overexpressed and induced a premature aging syndrome when disrupted. Subsequently, it became clear that the Klotho family of membrane proteins function as obligate co-receptors for endocrine fibroblast growth factors (FGFs) that regulate various metabolic processes. This review focuses on the Klotho-FGF23 endocrine system that maintains phosphate (Pi) homeostasis, and discusses the mechanism of action and the potential contribution of Klotho deficiency to acute kidney injury (AKI), chronic kidney disease (CKD) and cancer. RECENT FINDINGS Klotho functions as a receptor for the phosphaturic hormone FGF23. Klotho deficiency induces resistance to FGF23 and predisposition to Pi retention, which represents a critical feature of pathophysiology of CKD. The extracellular domain of Klotho protein is subject to ectodomain shedding and released into the blood and urine. Secreted Klotho functions as a humoral factor that inhibits AKI, vascular calcification, renal fibrosis, and cancer metastasis in an FGF23-independent manner. SUMMARY Various factors that affect Klotho expression have been identified. Prevention of Klotho decline and supplementation of Klotho can be a novel therapeutic strategy for many age-related diseases.
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95
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A comparative transcriptome analysis identifying FGF23 regulated genes in the kidney of a mouse CKD model. PLoS One 2012; 7:e44161. [PMID: 22970174 PMCID: PMC3435395 DOI: 10.1371/journal.pone.0044161] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Accepted: 07/30/2012] [Indexed: 01/03/2023] Open
Abstract
Elevations of circulating Fibroblast growth factor 23 (FGF23) are associated with adverse cardiovascular outcomes and progression of renal failure in chronic kidney disease (CKD). Efforts to identify gene products whose transcription is directly regulated by FGF23 stimulation of fibroblast growth factor receptors (FGFR)/α-Klotho complexes in the kidney is confounded by both systemic alterations in calcium, phosphorus and vitamin D metabolism and intrinsic alterations caused by the underlying renal pathology in CKD. To identify FGF23 responsive genes in the kidney that might explain the association between FGF23 and adverse outcomes in CKD, we performed comparative genome wide analysis of gene expression profiles in the kidney of the Collagen 4 alpha 3 null mice (Col4a3−/−) model of progressive kidney disease with kidney expression profiles of Hypophosphatemic (Hyp) and FGF23 transgenic mouse models of elevated FGF23. The different complement of potentially confounding factors in these models allowed us to identify genes that are directly targeted by FGF23. This analysis found that α-Klotho, an anti-aging hormone and FGF23 co-receptor, was decreased by FGF23. We also identified additional FGF23-responsive transcripts and activation of networks associated with renal damage and chronic inflammation, including lipocalin 2 (Lcn2), transforming growth factor beta (TGF-β) and tumor necrosis factor-alpha (TNF-α) signaling pathways. Finally, we found that FGF23 suppresses angiotensin-converting enzyme 2 (ACE2) expression in the kidney, thereby providing a pathway for FGF23 regulation of the renin-angiotensin system. These gene products provide a possible mechanistic links between elevated FGF23 and pathways responsible for renal failure progression and cardiovascular diseases.
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96
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Kiattisunthorn K, Moe SM. Chronic Kidney Disease-Mineral Bone Disorder: Definitions and Rationale for a Systemic Disorder. Clin Rev Bone Miner Metab 2012. [DOI: 10.1007/s12018-011-9119-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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97
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Mangos S, Amaral AP, Faul C, Jüppner H, Reiser J, Wolf M. Expression of fgf23 and αklotho in developing embryonic tissues and adult kidney of the zebrafish, Danio rerio. Nephrol Dial Transplant 2012; 27:4314-22. [PMID: 22885518 DOI: 10.1093/ndt/gfs335] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Fibroblast growth factor 23 (FGF23) is an endocrine hormone that is secreted by bone and acts on the kidney and parathyroid glands to regulate phosphate homeostasis. The effects of FGF23 on phosphate homeostasis are mediated by binding to FGF receptors and their coreceptor, αklotho, which are abundantly expressed in the kidney and parathyroid glands. However, the mechanisms of how FGF23 regulates phosphate handling in the proximal tubule are unclear because αklotho is primarily expressed in the distal nephron in humans and rodents. The purpose of this study was to gain additional insight into the FGF23-αklotho system by investigating the spatial and temporal aspects of the expression of fgf23 and αklotho in the zebrafish, Danio rerio. Here, we report that zebrafish fgf23 begins to be expressed after organogenesis and is continually expressed into adulthood in the corpuscles of Stannius, which are endocrine glands that lie in close proximity to the nephron and are thought to contribute to calcium and phosphate homeostasis in fish. Zebrafish αklotho expression can be detected by 24-h postfertilization in the brain, pancreas and the distal pronephros, and by 56-h postfertilization in liver. Expression in the distal pronephros persists throughout development, and by Day 5, there is also strong expression in the proximal pronephros. αklotho continues to be expressed in the tubules of the metanephros of the adult kidney. These data indicate conservation of the FGF23-αklotho system across species and suggest a likely role for αklotho in the proximal and distal tubules.
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Affiliation(s)
- Steve Mangos
- Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
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98
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Azuma M, Koyama D, Kikuchi J, Yoshizawa H, Thasinas D, Shiizaki K, Kuro-o M, Furukawa Y, Kusano E. Promoter methylation confers kidney-specific expression of the Klotho gene. FASEB J 2012; 26:4264-74. [PMID: 22782974 DOI: 10.1096/fj.12-211631] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The aging suppressor geneKlotho is predominantly expressed in the kidney irrespective of species. Because Klotho protein is an essential component of an endocrine axis that regulates renal phosphate handling, the kidney-specific expression is biologically relevant; however, little is known about its underlying mechanisms. Here we provide in vitro and in vivo evidence indicating that promoter methylation restricts the expression of the Klotho gene in the kidney. Based on evolutionary conservation and histone methylation patterns, the region up to -1200 bp was defined as a major promoter element of the human Klotho gene. This region displayed promoter activity equally in Klotho-expressing and -nonexpressing cells in transient reporter assays, but the activity was reduced to ∼20% when the constructs were integrated into the chromatin in the latter. Both endogenous and transfected Klotho promoters were 30-40% methylated in Klotho-nonexpressing cells, but unmethylated in Klotho-expressing renal tubular cells. DNA demethylating agents increased Klotho expression 1.5- to 3.0-fold in nonexpressing cells and restored the activity of silenced reporter constructs. Finally, we demonstrated that a severe hypomorphic allele of Klotho had aberrant CpG methylation in kl/kl mice. These findings might be useful in therapeutic intervention for accelerated aging and several complications caused by Klotho down-regulation.
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Affiliation(s)
- Masahiro Azuma
- Department of Internal Medicine, Center for Molecular Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
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99
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Abstract
Chronic kidney disease (CKD) is a public health epidemic that affects millions of people worldwide. Presence of CKD predisposes individuals to high risks of end-stage renal disease, cardiovascular disease and premature death. Disordered phosphate homeostasis with elevated circulating levels of fibroblast growth factor 23 (FGF23) is an early and pervasive complication of CKD. CKD is likely the most common cause of chronically elevated FGF23 levels, and the clinical condition in which levels are most markedly elevated. Although increases in FGF23 levels help maintain serum phosphate in the normal range in CKD, prospective studies in populations of pre-dialysis CKD, incident and prevalent end-stage renal disease, and kidney transplant recipients demonstrate that elevated FGF23 levels are independently associated with progression of CKD and development of cardiovascular events and mortality. It was originally thought that these observations were driven by elevated FGF23 acting as a highly sensitive biomarker of toxicity due to phosphate. However, FGF23 itself has now been shown to mediate “off-target,” direct, end-organ toxicity in the heart, which suggests that elevated FGF23 may be a novel mechanism of adverse outcomes in CKD. This report reviews recent advances in FGF23 biology relevant to CKD, the classical effects of FGF23 on mineral homeostasis, and the studies that established FGF23 excess as a biomarker and novel mechanism of cardiovascular disease. The report concludes with a critical review of the effects of different therapeutic strategies targeting FGF23 reduction and how these might be leveraged in a future randomized trial aimed at improving outcomes in CKD.
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100
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Tangri N, Levey AS. Fibroblast Growth Factor 23 and CKD Prognosis. Am J Kidney Dis 2012; 59:607-10. [DOI: 10.1053/j.ajkd.2011.11.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 11/17/2011] [Indexed: 11/11/2022]
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